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2202.00155
Hattie Zhou
Hattie Zhou, Ankit Vani, Hugo Larochelle, Aaron Courville
Fortuitous Forgetting in Connectionist Networks
ICLR Camera Ready
ICLR 2022
null
null
cs.LG cs.AI cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Forgetting is often seen as an unwanted characteristic in both human and machine learning. However, we propose that forgetting can in fact be favorable to learning. We introduce "forget-and-relearn" as a powerful paradigm for shaping the learning trajectories of artificial neural networks. In this process, the forgetting step selectively removes undesirable information from the model, and the relearning step reinforces features that are consistently useful under different conditions. The forget-and-relearn framework unifies many existing iterative training algorithms in the image classification and language emergence literature, and allows us to understand the success of these algorithms in terms of the disproportionate forgetting of undesirable information. We leverage this understanding to improve upon existing algorithms by designing more targeted forgetting operations. Insights from our analysis provide a coherent view on the dynamics of iterative training in neural networks and offer a clear path towards performance improvements.
[ { "created": "Tue, 1 Feb 2022 00:15:58 GMT", "version": "v1" } ]
2022-02-02
[ [ "Zhou", "Hattie", "" ], [ "Vani", "Ankit", "" ], [ "Larochelle", "Hugo", "" ], [ "Courville", "Aaron", "" ] ]
Forgetting is often seen as an unwanted characteristic in both human and machine learning. However, we propose that forgetting can in fact be favorable to learning. We introduce "forget-and-relearn" as a powerful paradigm for shaping the learning trajectories of artificial neural networks. In this process, the forgetting step selectively removes undesirable information from the model, and the relearning step reinforces features that are consistently useful under different conditions. The forget-and-relearn framework unifies many existing iterative training algorithms in the image classification and language emergence literature, and allows us to understand the success of these algorithms in terms of the disproportionate forgetting of undesirable information. We leverage this understanding to improve upon existing algorithms by designing more targeted forgetting operations. Insights from our analysis provide a coherent view on the dynamics of iterative training in neural networks and offer a clear path towards performance improvements.
1901.07366
James Hahn
James Hahn, Adriana Kovashka
Measuring Effectiveness of Video Advertisements
9 pages, 7 figures, 2 tables
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Advertisements are unavoidable in modern society. Times Square is notorious for its incessant display of advertisements. Its popularity is worldwide and smaller cities possess miniature versions of the display, such as Pittsburgh and its digital works in Oakland on Forbes Avenue. Tokyo's Ginza district recently rose to popularity due to its upscale shops and constant onslaught of advertisements to pedestrians. Advertisements arise in other mediums as well. For example, they help popular streaming services, such as Spotify, Hulu, and Youtube TV gather significant streams of revenue to reduce the cost of monthly subscriptions for consumers. Ads provide an additional source of money for companies and entire industries to allocate resources toward alternative business motives. They are attractive to companies and nearly unavoidable for consumers. One challenge for advertisers is examining a advertisement's effectiveness or usefulness in conveying a message to their targeted demographics. Rather than constructing a single, static image of content, a video advertisement possesses hundreds of frames of data with varying scenes, actors, objects, and complexity. Therefore, measuring effectiveness of video advertisements is important to impacting a billion-dollar industry. This paper explores the combination of human-annotated features and common video processing techniques to predict effectiveness ratings of advertisements collected from Youtube. This task is seen as a binary (effective vs. non-effective), four-way, and five-way machine learning classification task. The first findings in terms of accuracy and inference on this dataset, as well as some of the first ad research, on a small dataset are presented. Accuracies of 84\%, 65\%, and 55\% are reached on the binary, four-way, and five-way tasks respectively.
[ { "created": "Tue, 15 Jan 2019 03:41:37 GMT", "version": "v1" }, { "created": "Mon, 28 Jan 2019 20:15:03 GMT", "version": "v2" } ]
2019-01-30
[ [ "Hahn", "James", "" ], [ "Kovashka", "Adriana", "" ] ]
Advertisements are unavoidable in modern society. Times Square is notorious for its incessant display of advertisements. Its popularity is worldwide and smaller cities possess miniature versions of the display, such as Pittsburgh and its digital works in Oakland on Forbes Avenue. Tokyo's Ginza district recently rose to popularity due to its upscale shops and constant onslaught of advertisements to pedestrians. Advertisements arise in other mediums as well. For example, they help popular streaming services, such as Spotify, Hulu, and Youtube TV gather significant streams of revenue to reduce the cost of monthly subscriptions for consumers. Ads provide an additional source of money for companies and entire industries to allocate resources toward alternative business motives. They are attractive to companies and nearly unavoidable for consumers. One challenge for advertisers is examining a advertisement's effectiveness or usefulness in conveying a message to their targeted demographics. Rather than constructing a single, static image of content, a video advertisement possesses hundreds of frames of data with varying scenes, actors, objects, and complexity. Therefore, measuring effectiveness of video advertisements is important to impacting a billion-dollar industry. This paper explores the combination of human-annotated features and common video processing techniques to predict effectiveness ratings of advertisements collected from Youtube. This task is seen as a binary (effective vs. non-effective), four-way, and five-way machine learning classification task. The first findings in terms of accuracy and inference on this dataset, as well as some of the first ad research, on a small dataset are presented. Accuracies of 84\%, 65\%, and 55\% are reached on the binary, four-way, and five-way tasks respectively.
2209.02156
Farhad Aghili
Farhad Aghili
Adaptive Visual Servo Control for Autonomous Robots
null
null
10.1109/TMECH.2021.3087729
null
cs.RO cs.SY eess.SY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper focuses on an adaptive and fault-tolerant vision-guided robotic system that enables to choose the most appropriate control action if partial or complete failure of the vision system in the short term occurs. Moreover, the autonomous robotic system takes physical and operational constraints into account to perform the demands of a specific visual servoing task in a way to minimize a cost function. A hierarchical control architecture is developed based on interwoven integration of a variant of the iterative closest point (ICP) image registration, a constrained noise-adaptive Kalman filter, a fault detection logic and recovery, together with a constrained optimal path planner. The dynamic estimator estimates unknown states and uncertain parameters required for motion prediction while imposing a set of inequality constraints for consistency of the estimation process and adjusting adaptively the Kalman filter parameters in the face of unexpected vision errors. It is followed by the implementation of a fault recovery strategy based on a fault detection logic that monitors the health of the visual feedback using the metric fit error of the image registration. Subsequently, the estimated/predicted pose and parameters are passed to an optimal path planner in order to bring the robot end-effector to the grasping point of a moving target as quickly as possible subject to multiple constraints such as acceleration limit, smooth capture, and line-of-sight angle of the target.
[ { "created": "Mon, 5 Sep 2022 22:22:29 GMT", "version": "v1" } ]
2022-09-07
[ [ "Aghili", "Farhad", "" ] ]
This paper focuses on an adaptive and fault-tolerant vision-guided robotic system that enables to choose the most appropriate control action if partial or complete failure of the vision system in the short term occurs. Moreover, the autonomous robotic system takes physical and operational constraints into account to perform the demands of a specific visual servoing task in a way to minimize a cost function. A hierarchical control architecture is developed based on interwoven integration of a variant of the iterative closest point (ICP) image registration, a constrained noise-adaptive Kalman filter, a fault detection logic and recovery, together with a constrained optimal path planner. The dynamic estimator estimates unknown states and uncertain parameters required for motion prediction while imposing a set of inequality constraints for consistency of the estimation process and adjusting adaptively the Kalman filter parameters in the face of unexpected vision errors. It is followed by the implementation of a fault recovery strategy based on a fault detection logic that monitors the health of the visual feedback using the metric fit error of the image registration. Subsequently, the estimated/predicted pose and parameters are passed to an optimal path planner in order to bring the robot end-effector to the grasping point of a moving target as quickly as possible subject to multiple constraints such as acceleration limit, smooth capture, and line-of-sight angle of the target.
2307.08671
Jaehyun Choi
Gyojin Han, Dong-Jae Lee, Jiwan Hur, Jaehyun Choi, Junmo Kim
Deep Cross-Modal Steganography Using Neural Representations
ICIP 2023 Oral
null
null
null
cs.CR cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Steganography is the process of embedding secret data into another message or data, in such a way that it is not easily noticeable. With the advancement of deep learning, Deep Neural Networks (DNNs) have recently been utilized in steganography. However, existing deep steganography techniques are limited in scope, as they focus on specific data types and are not effective for cross-modal steganography. Therefore, We propose a deep cross-modal steganography framework using Implicit Neural Representations (INRs) to hide secret data of various formats in cover images. The proposed framework employs INRs to represent the secret data, which can handle data of various modalities and resolutions. Experiments on various secret datasets of diverse types demonstrate that the proposed approach is expandable and capable of accommodating different modalities.
[ { "created": "Sun, 2 Jul 2023 08:08:02 GMT", "version": "v1" }, { "created": "Tue, 18 Jul 2023 08:12:14 GMT", "version": "v2" }, { "created": "Sat, 7 Oct 2023 05:45:58 GMT", "version": "v3" } ]
2023-10-10
[ [ "Han", "Gyojin", "" ], [ "Lee", "Dong-Jae", "" ], [ "Hur", "Jiwan", "" ], [ "Choi", "Jaehyun", "" ], [ "Kim", "Junmo", "" ] ]
Steganography is the process of embedding secret data into another message or data, in such a way that it is not easily noticeable. With the advancement of deep learning, Deep Neural Networks (DNNs) have recently been utilized in steganography. However, existing deep steganography techniques are limited in scope, as they focus on specific data types and are not effective for cross-modal steganography. Therefore, We propose a deep cross-modal steganography framework using Implicit Neural Representations (INRs) to hide secret data of various formats in cover images. The proposed framework employs INRs to represent the secret data, which can handle data of various modalities and resolutions. Experiments on various secret datasets of diverse types demonstrate that the proposed approach is expandable and capable of accommodating different modalities.
1810.04599
Hui Miao
Hui Miao and Amol Deshpande
Understanding Data Science Lifecycle Provenance via Graph Segmentation and Summarization
null
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Increasingly modern data science platforms today have non-intrusive and extensible provenance ingestion mechanisms to collect rich provenance and context information, handle modifications to the same file using distinguishable versions, and use graph data models (e.g., property graphs) and query languages (e.g., Cypher) to represent and manipulate the stored provenance/context information. Due to the schema-later nature of the metadata, multiple versions of the same files, and unfamiliar artifacts introduced by team members, the "provenance graph" is verbose and evolving, and hard to understand; using standard graph query model, it is difficult to compose queries and utilize this valuable information. In this paper, we propose two high-level graph query operators to address the verboseness and evolving nature of such provenance graphs. First, we introduce a graph segmentation operator, which queries the retrospective provenance between a set of source vertices and a set of destination vertices via flexible boundary criteria to help users get insight about the derivation relationships among those vertices. We show the semantics of such a query in terms of a context-free grammar, and develop efficient algorithms that run orders of magnitude faster than state-of-the-art. Second, we propose a graph summarization operator that combines similar segments together to query prospective provenance of the underlying project. The operator allows tuning the summary by ignoring vertex details and characterizing local structures, and ensures the provenance meaning using path constraints. We show the optimal summary problem is PSPACE-complete and develop effective approximation algorithms. The operators are implemented on top of a property graph backend. We evaluate our query methods extensively and show the effectiveness and efficiency of the proposed methods.
[ { "created": "Wed, 10 Oct 2018 15:40:27 GMT", "version": "v1" }, { "created": "Tue, 16 Oct 2018 05:05:07 GMT", "version": "v2" } ]
2018-10-17
[ [ "Miao", "Hui", "" ], [ "Deshpande", "Amol", "" ] ]
Increasingly modern data science platforms today have non-intrusive and extensible provenance ingestion mechanisms to collect rich provenance and context information, handle modifications to the same file using distinguishable versions, and use graph data models (e.g., property graphs) and query languages (e.g., Cypher) to represent and manipulate the stored provenance/context information. Due to the schema-later nature of the metadata, multiple versions of the same files, and unfamiliar artifacts introduced by team members, the "provenance graph" is verbose and evolving, and hard to understand; using standard graph query model, it is difficult to compose queries and utilize this valuable information. In this paper, we propose two high-level graph query operators to address the verboseness and evolving nature of such provenance graphs. First, we introduce a graph segmentation operator, which queries the retrospective provenance between a set of source vertices and a set of destination vertices via flexible boundary criteria to help users get insight about the derivation relationships among those vertices. We show the semantics of such a query in terms of a context-free grammar, and develop efficient algorithms that run orders of magnitude faster than state-of-the-art. Second, we propose a graph summarization operator that combines similar segments together to query prospective provenance of the underlying project. The operator allows tuning the summary by ignoring vertex details and characterizing local structures, and ensures the provenance meaning using path constraints. We show the optimal summary problem is PSPACE-complete and develop effective approximation algorithms. The operators are implemented on top of a property graph backend. We evaluate our query methods extensively and show the effectiveness and efficiency of the proposed methods.
2403.01412
Lingfeng Liu
Lingfeng Liu, Dong Ni, Hangjie Yuan
LUM-ViT: Learnable Under-sampling Mask Vision Transformer for Bandwidth Limited Optical Signal Acquisition
Accepted to ICLR 2024
null
null
null
cs.CV eess.IV eess.SP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Bandwidth constraints during signal acquisition frequently impede real-time detection applications. Hyperspectral data is a notable example, whose vast volume compromises real-time hyperspectral detection. To tackle this hurdle, we introduce a novel approach leveraging pre-acquisition modulation to reduce the acquisition volume. This modulation process is governed by a deep learning model, utilizing prior information. Central to our approach is LUM-ViT, a Vision Transformer variant. Uniquely, LUM-ViT incorporates a learnable under-sampling mask tailored for pre-acquisition modulation. To further optimize for optical calculations, we propose a kernel-level weight binarization technique and a three-stage fine-tuning strategy. Our evaluations reveal that, by sampling a mere 10% of the original image pixels, LUM-ViT maintains the accuracy loss within 1.8% on the ImageNet classification task. The method sustains near-original accuracy when implemented on real-world optical hardware, demonstrating its practicality. Code will be available at https://github.com/MaxLLF/LUM-ViT.
[ { "created": "Sun, 3 Mar 2024 06:49:01 GMT", "version": "v1" } ]
2024-03-05
[ [ "Liu", "Lingfeng", "" ], [ "Ni", "Dong", "" ], [ "Yuan", "Hangjie", "" ] ]
Bandwidth constraints during signal acquisition frequently impede real-time detection applications. Hyperspectral data is a notable example, whose vast volume compromises real-time hyperspectral detection. To tackle this hurdle, we introduce a novel approach leveraging pre-acquisition modulation to reduce the acquisition volume. This modulation process is governed by a deep learning model, utilizing prior information. Central to our approach is LUM-ViT, a Vision Transformer variant. Uniquely, LUM-ViT incorporates a learnable under-sampling mask tailored for pre-acquisition modulation. To further optimize for optical calculations, we propose a kernel-level weight binarization technique and a three-stage fine-tuning strategy. Our evaluations reveal that, by sampling a mere 10% of the original image pixels, LUM-ViT maintains the accuracy loss within 1.8% on the ImageNet classification task. The method sustains near-original accuracy when implemented on real-world optical hardware, demonstrating its practicality. Code will be available at https://github.com/MaxLLF/LUM-ViT.
1611.08699
Colin Brown J
Colin J Brown, Ghassan Hamarneh
Machine Learning on Human Connectome Data from MRI
51 pages, 6 figures. To be submitted to a journal
null
null
null
cs.LG q-bio.NC stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Functional MRI (fMRI) and diffusion MRI (dMRI) are non-invasive imaging modalities that allow in-vivo analysis of a patient's brain network (known as a connectome). Use of these technologies has enabled faster and better diagnoses and treatments of neurological disorders and a deeper understanding of the human brain. Recently, researchers have been exploring the application of machine learning models to connectome data in order to predict clinical outcomes and analyze the importance of subnetworks in the brain. Connectome data has unique properties, which present both special challenges and opportunities when used for machine learning. The purpose of this work is to review the literature on the topic of applying machine learning models to MRI-based connectome data. This field is growing rapidly and now encompasses a large body of research. To summarize the research done to date, we provide a comparative, structured summary of 77 relevant works, tabulated according to different criteria, that represent the majority of the literature on this topic. (We also published a living version of this table online at http://connectomelearning.cs.sfu.ca that the community can continue to contribute to.) After giving an overview of how connectomes are constructed from dMRI and fMRI data, we discuss the variety of machine learning tasks that have been explored with connectome data. We then compare the advantages and drawbacks of different machine learning approaches that have been employed, discussing different feature selection and feature extraction schemes, as well as the learning models and regularization penalties themselves. Throughout this discussion, we focus particularly on how the methods are adapted to the unique nature of graphical connectome data. Finally, we conclude by summarizing the current state of the art and by outlining what we believe are strategic directions for future research.
[ { "created": "Sat, 26 Nov 2016 11:14:22 GMT", "version": "v1" } ]
2016-12-06
[ [ "Brown", "Colin J", "" ], [ "Hamarneh", "Ghassan", "" ] ]
Functional MRI (fMRI) and diffusion MRI (dMRI) are non-invasive imaging modalities that allow in-vivo analysis of a patient's brain network (known as a connectome). Use of these technologies has enabled faster and better diagnoses and treatments of neurological disorders and a deeper understanding of the human brain. Recently, researchers have been exploring the application of machine learning models to connectome data in order to predict clinical outcomes and analyze the importance of subnetworks in the brain. Connectome data has unique properties, which present both special challenges and opportunities when used for machine learning. The purpose of this work is to review the literature on the topic of applying machine learning models to MRI-based connectome data. This field is growing rapidly and now encompasses a large body of research. To summarize the research done to date, we provide a comparative, structured summary of 77 relevant works, tabulated according to different criteria, that represent the majority of the literature on this topic. (We also published a living version of this table online at http://connectomelearning.cs.sfu.ca that the community can continue to contribute to.) After giving an overview of how connectomes are constructed from dMRI and fMRI data, we discuss the variety of machine learning tasks that have been explored with connectome data. We then compare the advantages and drawbacks of different machine learning approaches that have been employed, discussing different feature selection and feature extraction schemes, as well as the learning models and regularization penalties themselves. Throughout this discussion, we focus particularly on how the methods are adapted to the unique nature of graphical connectome data. Finally, we conclude by summarizing the current state of the art and by outlining what we believe are strategic directions for future research.
2003.01433
Dong Liu
Dong Liu and Baptiste Cavarec and Lars K. Rasmussen and Jing Yue
On Dominant Interference in Random Networks and Communication Reliability
null
ICC 2019
null
null
cs.IT eess.SP math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we study the characteristics of dominant interference power with directional reception in a random network modelled by a Poisson Point Process. Additionally, the Laplace functional of cumulative interference excluding the $n$ dominant interferers is also derived, which turns out to be a generalization of omni-directional reception and complete accumulative interference. As an application of these results, we study the impact of directional receivers in random networks in terms of outage probability and error probability with queue length constraint.
[ { "created": "Tue, 3 Mar 2020 10:36:44 GMT", "version": "v1" } ]
2020-03-04
[ [ "Liu", "Dong", "" ], [ "Cavarec", "Baptiste", "" ], [ "Rasmussen", "Lars K.", "" ], [ "Yue", "Jing", "" ] ]
In this paper, we study the characteristics of dominant interference power with directional reception in a random network modelled by a Poisson Point Process. Additionally, the Laplace functional of cumulative interference excluding the $n$ dominant interferers is also derived, which turns out to be a generalization of omni-directional reception and complete accumulative interference. As an application of these results, we study the impact of directional receivers in random networks in terms of outage probability and error probability with queue length constraint.
1610.09726
Kirthevasan Kandasamy
Kirthevasan Kandasamy and Gautam Dasarathy and Jeff Schneider and Barnab\'as P\'oczos
The Multi-fidelity Multi-armed Bandit
To appear at NIPS 2016
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a variant of the classical stochastic $K$-armed bandit where observing the outcome of each arm is expensive, but cheap approximations to this outcome are available. For example, in online advertising the performance of an ad can be approximated by displaying it for shorter time periods or to narrower audiences. We formalise this task as a multi-fidelity bandit, where, at each time step, the forecaster may choose to play an arm at any one of $M$ fidelities. The highest fidelity (desired outcome) expends cost $\lambda^{(m)}$. The $m^{\text{th}}$ fidelity (an approximation) expends $\lambda^{(m)} < \lambda^{(M)}$ and returns a biased estimate of the highest fidelity. We develop MF-UCB, a novel upper confidence bound procedure for this setting and prove that it naturally adapts to the sequence of available approximations and costs thus attaining better regret than naive strategies which ignore the approximations. For instance, in the above online advertising example, MF-UCB would use the lower fidelities to quickly eliminate suboptimal ads and reserve the larger expensive experiments on a small set of promising candidates. We complement this result with a lower bound and show that MF-UCB is nearly optimal under certain conditions.
[ { "created": "Sun, 30 Oct 2016 23:07:49 GMT", "version": "v1" } ]
2016-11-01
[ [ "Kandasamy", "Kirthevasan", "" ], [ "Dasarathy", "Gautam", "" ], [ "Schneider", "Jeff", "" ], [ "Póczos", "Barnabás", "" ] ]
We study a variant of the classical stochastic $K$-armed bandit where observing the outcome of each arm is expensive, but cheap approximations to this outcome are available. For example, in online advertising the performance of an ad can be approximated by displaying it for shorter time periods or to narrower audiences. We formalise this task as a multi-fidelity bandit, where, at each time step, the forecaster may choose to play an arm at any one of $M$ fidelities. The highest fidelity (desired outcome) expends cost $\lambda^{(m)}$. The $m^{\text{th}}$ fidelity (an approximation) expends $\lambda^{(m)} < \lambda^{(M)}$ and returns a biased estimate of the highest fidelity. We develop MF-UCB, a novel upper confidence bound procedure for this setting and prove that it naturally adapts to the sequence of available approximations and costs thus attaining better regret than naive strategies which ignore the approximations. For instance, in the above online advertising example, MF-UCB would use the lower fidelities to quickly eliminate suboptimal ads and reserve the larger expensive experiments on a small set of promising candidates. We complement this result with a lower bound and show that MF-UCB is nearly optimal under certain conditions.
2108.06696
Peter Hillmann
Peter Hillmann, Erik Heiland, Andreas Karcher
Automated Enterprise Architecture Model Mining
null
NISecurity 2021
null
null
cs.IR cs.CR cs.NI cs.SY eess.SY
http://creativecommons.org/licenses/by-nc-sa/4.0/
Metadata are like the steam engine of the 21st century, driving businesses and offer multiple enhancements. Nevertheless, many companies are unaware that these data can be used efficiently to improve their own operation. This is where the Enterprise Architecture Framework comes in. It empowers an organisation to get a clear view of their business, application, technical and physical layer. This modelling approach is an established method for organizations to take a deeper look into their structure and processes. The development of such models requires a great deal of effort, is carried out manually by interviewing stakeholders and requires continuous maintenance. Our new approach enables the automated mining of Enterprise Architecture models. The system uses common technologies to collect the metadata based on network traffic, log files and other information in an organisation. Based on this, the new approach generates EA models with the desired views points. Furthermore, a rule and knowledge-based reasoning is used to obtain a holistic overview. This offers a strategic decision support from business structure over process design up to planning the appropriate support technology. Therefore, it forms the base for organisations to act in an agile way. The modelling can be performed in different modelling languages, including ArchiMate and the Nato Architecture Framework (NAF). The designed approach is already evaluated on a small company with multiple services and an infrastructure with several nodes.
[ { "created": "Sun, 15 Aug 2021 09:01:57 GMT", "version": "v1" } ]
2021-08-17
[ [ "Hillmann", "Peter", "" ], [ "Heiland", "Erik", "" ], [ "Karcher", "Andreas", "" ] ]
Metadata are like the steam engine of the 21st century, driving businesses and offer multiple enhancements. Nevertheless, many companies are unaware that these data can be used efficiently to improve their own operation. This is where the Enterprise Architecture Framework comes in. It empowers an organisation to get a clear view of their business, application, technical and physical layer. This modelling approach is an established method for organizations to take a deeper look into their structure and processes. The development of such models requires a great deal of effort, is carried out manually by interviewing stakeholders and requires continuous maintenance. Our new approach enables the automated mining of Enterprise Architecture models. The system uses common technologies to collect the metadata based on network traffic, log files and other information in an organisation. Based on this, the new approach generates EA models with the desired views points. Furthermore, a rule and knowledge-based reasoning is used to obtain a holistic overview. This offers a strategic decision support from business structure over process design up to planning the appropriate support technology. Therefore, it forms the base for organisations to act in an agile way. The modelling can be performed in different modelling languages, including ArchiMate and the Nato Architecture Framework (NAF). The designed approach is already evaluated on a small company with multiple services and an infrastructure with several nodes.
2306.08013
Pum Jun Kim
Pum Jun Kim, Yoojin Jang, Jisu Kim, Jaejun Yoo
TopP&R: Robust Support Estimation Approach for Evaluating Fidelity and Diversity in Generative Models
Accepted to NeurIPS 2023
null
null
null
cs.LG cs.AI cs.CV
http://creativecommons.org/licenses/by/4.0/
We propose a robust and reliable evaluation metric for generative models by introducing topological and statistical treatments for rigorous support estimation. Existing metrics, such as Inception Score (IS), Frechet Inception Distance (FID), and the variants of Precision and Recall (P&R), heavily rely on supports that are estimated from sample features. However, the reliability of their estimation has not been seriously discussed (and overlooked) even though the quality of the evaluation entirely depends on it. In this paper, we propose Topological Precision and Recall (TopP&R, pronounced 'topper'), which provides a systematic approach to estimating supports, retaining only topologically and statistically important features with a certain level of confidence. This not only makes TopP&R strong for noisy features, but also provides statistical consistency. Our theoretical and experimental results show that TopP&R is robust to outliers and non-independent and identically distributed (Non-IID) perturbations, while accurately capturing the true trend of change in samples. To the best of our knowledge, this is the first evaluation metric focused on the robust estimation of the support and provides its statistical consistency under noise.
[ { "created": "Tue, 13 Jun 2023 11:46:00 GMT", "version": "v1" }, { "created": "Wed, 21 Jun 2023 07:51:07 GMT", "version": "v2" }, { "created": "Fri, 22 Sep 2023 08:41:31 GMT", "version": "v3" }, { "created": "Wed, 8 Nov 2023 06:51:05 GMT", "version": "v4" }, { "created": "Thu, 9 Nov 2023 05:51:52 GMT", "version": "v5" }, { "created": "Wed, 24 Jan 2024 07:48:34 GMT", "version": "v6" } ]
2024-01-25
[ [ "Kim", "Pum Jun", "" ], [ "Jang", "Yoojin", "" ], [ "Kim", "Jisu", "" ], [ "Yoo", "Jaejun", "" ] ]
We propose a robust and reliable evaluation metric for generative models by introducing topological and statistical treatments for rigorous support estimation. Existing metrics, such as Inception Score (IS), Frechet Inception Distance (FID), and the variants of Precision and Recall (P&R), heavily rely on supports that are estimated from sample features. However, the reliability of their estimation has not been seriously discussed (and overlooked) even though the quality of the evaluation entirely depends on it. In this paper, we propose Topological Precision and Recall (TopP&R, pronounced 'topper'), which provides a systematic approach to estimating supports, retaining only topologically and statistically important features with a certain level of confidence. This not only makes TopP&R strong for noisy features, but also provides statistical consistency. Our theoretical and experimental results show that TopP&R is robust to outliers and non-independent and identically distributed (Non-IID) perturbations, while accurately capturing the true trend of change in samples. To the best of our knowledge, this is the first evaluation metric focused on the robust estimation of the support and provides its statistical consistency under noise.
2407.10704
Tianxiang Hao
Tianxiang Hao, Xiaohan Ding, Juexiao Feng, Yuhong Yang, Hui Chen and Guiguang Ding
Quantized Prompt for Efficient Generalization of Vision-Language Models
ECCV 2024
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the past few years, large-scale pre-trained vision-language models like CLIP have achieved tremendous success in various fields. Naturally, how to transfer the rich knowledge in such huge pre-trained models to downstream tasks and datasets becomes a hot topic. During downstream adaptation, the most challenging problems are overfitting and catastrophic forgetting, which can cause the model to overly focus on the current data and lose more crucial domain-general knowledge. Existing works use classic regularization techniques to solve the problems. As solutions become increasingly complex, the ever-growing storage and inference costs are also a significant problem that urgently needs to be addressed. While in this paper, we start from an observation that proper random noise can suppress overfitting and catastrophic forgetting. Then we regard quantization error as a kind of noise, and explore quantization for regularizing vision-language model, which is quite efficiency and effective. Furthermore, to improve the model's generalization capability while maintaining its specialization capacity at minimal cost, we deeply analyze the characteristics of the weight distribution in prompts, conclude several principles for quantization module design and follow such principles to create several competitive baselines. The proposed method is significantly efficient due to its inherent lightweight nature, making it possible to adapt on extremely resource-limited devices. Our method can be fruitfully integrated into many existing approaches like MaPLe, enhancing accuracy while reducing storage overhead, making it more powerful yet versatile. Extensive experiments on 11 datasets shows great superiority of our method sufficiently. Code is available at https://github.com/beyondhtx/QPrompt.
[ { "created": "Mon, 15 Jul 2024 13:19:56 GMT", "version": "v1" }, { "created": "Fri, 19 Jul 2024 22:52:27 GMT", "version": "v2" } ]
2024-07-23
[ [ "Hao", "Tianxiang", "" ], [ "Ding", "Xiaohan", "" ], [ "Feng", "Juexiao", "" ], [ "Yang", "Yuhong", "" ], [ "Chen", "Hui", "" ], [ "Ding", "Guiguang", "" ] ]
In the past few years, large-scale pre-trained vision-language models like CLIP have achieved tremendous success in various fields. Naturally, how to transfer the rich knowledge in such huge pre-trained models to downstream tasks and datasets becomes a hot topic. During downstream adaptation, the most challenging problems are overfitting and catastrophic forgetting, which can cause the model to overly focus on the current data and lose more crucial domain-general knowledge. Existing works use classic regularization techniques to solve the problems. As solutions become increasingly complex, the ever-growing storage and inference costs are also a significant problem that urgently needs to be addressed. While in this paper, we start from an observation that proper random noise can suppress overfitting and catastrophic forgetting. Then we regard quantization error as a kind of noise, and explore quantization for regularizing vision-language model, which is quite efficiency and effective. Furthermore, to improve the model's generalization capability while maintaining its specialization capacity at minimal cost, we deeply analyze the characteristics of the weight distribution in prompts, conclude several principles for quantization module design and follow such principles to create several competitive baselines. The proposed method is significantly efficient due to its inherent lightweight nature, making it possible to adapt on extremely resource-limited devices. Our method can be fruitfully integrated into many existing approaches like MaPLe, enhancing accuracy while reducing storage overhead, making it more powerful yet versatile. Extensive experiments on 11 datasets shows great superiority of our method sufficiently. Code is available at https://github.com/beyondhtx/QPrompt.
1001.3213
Jean-Philippe Chancelier
Jean-Philippe Chancelier (CERMICS), J\'er\^ome Lelong (LJK), Bernard Lapeyre (CERMICS)
Using Premia and Nsp for Constructing a Risk Management Benchmark for Testing Parallel Architecture
null
null
null
null
cs.CE cs.DC cs.MS cs.NA q-fin.CP q-fin.PR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Financial institutions have massive computations to carry out overnight which are very demanding in terms of the consumed CPU. The challenge is to price many different products on a cluster-like architecture. We have used the Premia software to valuate the financial derivatives. In this work, we explain how Premia can be embedded into Nsp, a scientific software like Matlab, to provide a powerful tool to valuate a whole portfolio. Finally, we have integrated an MPI toolbox into Nsp to enable to use Premia to solve a bunch of pricing problems on a cluster. This unified framework can then be used to test different parallel architectures.
[ { "created": "Tue, 19 Jan 2010 07:54:16 GMT", "version": "v1" }, { "created": "Mon, 21 May 2012 19:13:53 GMT", "version": "v2" } ]
2012-05-23
[ [ "Chancelier", "Jean-Philippe", "", "CERMICS" ], [ "Lelong", "Jérôme", "", "LJK" ], [ "Lapeyre", "Bernard", "", "CERMICS" ] ]
Financial institutions have massive computations to carry out overnight which are very demanding in terms of the consumed CPU. The challenge is to price many different products on a cluster-like architecture. We have used the Premia software to valuate the financial derivatives. In this work, we explain how Premia can be embedded into Nsp, a scientific software like Matlab, to provide a powerful tool to valuate a whole portfolio. Finally, we have integrated an MPI toolbox into Nsp to enable to use Premia to solve a bunch of pricing problems on a cluster. This unified framework can then be used to test different parallel architectures.
2309.09756
Ege Onat \"Ozs\"uer
Ege Onat \"Ozs\"uer, Bar{\i}\c{s} Akg\"un, Fatma G\"uney
Privileged to Predicted: Towards Sensorimotor Reinforcement Learning for Urban Driving
7 pages
null
null
null
cs.RO cs.CV
http://creativecommons.org/licenses/by/4.0/
Reinforcement Learning (RL) has the potential to surpass human performance in driving without needing any expert supervision. Despite its promise, the state-of-the-art in sensorimotor self-driving is dominated by imitation learning methods due to the inherent shortcomings of RL algorithms. Nonetheless, RL agents are able to discover highly successful policies when provided with privileged ground truth representations of the environment. In this work, we investigate what separates privileged RL agents from sensorimotor agents for urban driving in order to bridge the gap between the two. We propose vision-based deep learning models to approximate the privileged representations from sensor data. In particular, we identify aspects of state representation that are crucial for the success of the RL agent such as desired route generation and stop zone prediction, and propose solutions to gradually develop less privileged RL agents. We also observe that bird's-eye-view models trained on offline datasets do not generalize to online RL training due to distribution mismatch. Through rigorous evaluation on the CARLA simulation environment, we shed light on the significance of the state representations in RL for autonomous driving and point to unresolved challenges for future research.
[ { "created": "Mon, 18 Sep 2023 13:34:41 GMT", "version": "v1" } ]
2023-09-19
[ [ "Özsüer", "Ege Onat", "" ], [ "Akgün", "Barış", "" ], [ "Güney", "Fatma", "" ] ]
Reinforcement Learning (RL) has the potential to surpass human performance in driving without needing any expert supervision. Despite its promise, the state-of-the-art in sensorimotor self-driving is dominated by imitation learning methods due to the inherent shortcomings of RL algorithms. Nonetheless, RL agents are able to discover highly successful policies when provided with privileged ground truth representations of the environment. In this work, we investigate what separates privileged RL agents from sensorimotor agents for urban driving in order to bridge the gap between the two. We propose vision-based deep learning models to approximate the privileged representations from sensor data. In particular, we identify aspects of state representation that are crucial for the success of the RL agent such as desired route generation and stop zone prediction, and propose solutions to gradually develop less privileged RL agents. We also observe that bird's-eye-view models trained on offline datasets do not generalize to online RL training due to distribution mismatch. Through rigorous evaluation on the CARLA simulation environment, we shed light on the significance of the state representations in RL for autonomous driving and point to unresolved challenges for future research.
2012.11753
Qian Wang
Qian Wang, Toby P. Breckon
Contraband Materials Detection Within Volumetric 3D Computed Tomography Baggage Security Screening Imagery
8 pages
null
null
null
cs.CV cs.LG eess.IV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Automatic prohibited object detection within 2D/3D X-ray Computed Tomography (CT) has been studied in literature to enhance the aviation security screening at checkpoints. Deep Convolutional Neural Networks (CNN) have demonstrated superior performance in 2D X-ray imagery. However, there exists very limited proof of how deep neural networks perform in materials detection within volumetric 3D CT baggage screening imagery. We attempt to close this gap by applying Deep Neural Networks in 3D contraband substance detection based on their material signatures. Specifically, we formulate it as a 3D semantic segmentation problem to identify material types for all voxels based on which contraband materials can be detected. To this end, we firstly investigate 3D CNN based semantic segmentation algorithms such as 3D U-Net and its variants. In contrast to the original dense representation form of volumetric 3D CT data, we propose to convert the CT volumes into sparse point clouds which allows the use of point cloud processing approaches such as PointNet++ towards more efficient processing. Experimental results on a publicly available dataset (NEU ATR) demonstrate the effectiveness of both 3D U-Net and PointNet++ in materials detection in 3D CT imagery for baggage security screening.
[ { "created": "Mon, 21 Dec 2020 23:48:06 GMT", "version": "v1" } ]
2020-12-23
[ [ "Wang", "Qian", "" ], [ "Breckon", "Toby P.", "" ] ]
Automatic prohibited object detection within 2D/3D X-ray Computed Tomography (CT) has been studied in literature to enhance the aviation security screening at checkpoints. Deep Convolutional Neural Networks (CNN) have demonstrated superior performance in 2D X-ray imagery. However, there exists very limited proof of how deep neural networks perform in materials detection within volumetric 3D CT baggage screening imagery. We attempt to close this gap by applying Deep Neural Networks in 3D contraband substance detection based on their material signatures. Specifically, we formulate it as a 3D semantic segmentation problem to identify material types for all voxels based on which contraband materials can be detected. To this end, we firstly investigate 3D CNN based semantic segmentation algorithms such as 3D U-Net and its variants. In contrast to the original dense representation form of volumetric 3D CT data, we propose to convert the CT volumes into sparse point clouds which allows the use of point cloud processing approaches such as PointNet++ towards more efficient processing. Experimental results on a publicly available dataset (NEU ATR) demonstrate the effectiveness of both 3D U-Net and PointNet++ in materials detection in 3D CT imagery for baggage security screening.
2304.04480
Yannis Stamatiou
V. Liagkou and P.E. Nastou and P. Spirakis and Y.C. Stamatiou
On the existence of highly organized communities in networks of locally interacting agents
null
null
null
null
cs.CR cs.DM
http://creativecommons.org/licenses/by/4.0/
In this paper we investigate phenomena of spontaneous emergence or purposeful formation of highly organized structures in networks of related agents. We show that the formation of large organized structures requires exponentially large, in the size of the structures, networks. Our approach is based on Kolmogorov, or descriptional, complexity of networks viewed as finite size strings. We apply this approach to the study of the emergence or formation of simple organized, hierarchical, structures based on Sierpinski Graphs and we prove a Ramsey type theorem that bounds the number of vertices in Kolmogorov random graphs that contain Sierpinski Graphs as subgraphs. Moreover, we show that Sierpinski Graphs encompass close-knit relationships among their vertices that facilitate fast spread and learning of information when agents in their vertices are engaged in pairwise interactions modelled as two person games. Finally, we generalize our findings for any organized structure with succinct representations. Our work can be deployed, in particular, to study problems related to the security of networks by identifying conditions which enable or forbid the formation of sufficiently large insider subnetworks with malicious common goal to overtake the network or cause disruption of its operation.
[ { "created": "Mon, 10 Apr 2023 09:39:41 GMT", "version": "v1" } ]
2023-04-11
[ [ "Liagkou", "V.", "" ], [ "Nastou", "P. E.", "" ], [ "Spirakis", "P.", "" ], [ "Stamatiou", "Y. C.", "" ] ]
In this paper we investigate phenomena of spontaneous emergence or purposeful formation of highly organized structures in networks of related agents. We show that the formation of large organized structures requires exponentially large, in the size of the structures, networks. Our approach is based on Kolmogorov, or descriptional, complexity of networks viewed as finite size strings. We apply this approach to the study of the emergence or formation of simple organized, hierarchical, structures based on Sierpinski Graphs and we prove a Ramsey type theorem that bounds the number of vertices in Kolmogorov random graphs that contain Sierpinski Graphs as subgraphs. Moreover, we show that Sierpinski Graphs encompass close-knit relationships among their vertices that facilitate fast spread and learning of information when agents in their vertices are engaged in pairwise interactions modelled as two person games. Finally, we generalize our findings for any organized structure with succinct representations. Our work can be deployed, in particular, to study problems related to the security of networks by identifying conditions which enable or forbid the formation of sufficiently large insider subnetworks with malicious common goal to overtake the network or cause disruption of its operation.
1709.02082
Romain Lopez
Romain Lopez, Jeffrey Regier, Michael Cole, Michael Jordan and Nir Yosef
A deep generative model for gene expression profiles from single-cell RNA sequencing
BayLearn2017, NIPS workshop MLCB 2017
null
null
null
cs.LG q-bio.GN stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a probabilistic model for interpreting gene expression levels that are observed through single-cell RNA sequencing. In the model, each cell has a low-dimensional latent representation. Additional latent variables account for technical effects that may erroneously set some observations of gene expression levels to zero. Conditional distributions are specified by neural networks, giving the proposed model enough flexibility to fit the data well. We use variational inference and stochastic optimization to approximate the posterior distribution. The inference procedure scales to over one million cells, whereas competing algorithms do not. Even for smaller datasets, for several tasks, the proposed procedure outperforms state-of-the-art methods like ZIFA and ZINB-WaVE. We also extend our framework to account for batch effects and other confounding factors, and propose a Bayesian hypothesis test for differential expression that outperforms DESeq2.
[ { "created": "Thu, 7 Sep 2017 05:59:49 GMT", "version": "v1" }, { "created": "Tue, 17 Oct 2017 01:41:27 GMT", "version": "v2" }, { "created": "Wed, 18 Oct 2017 00:37:51 GMT", "version": "v3" }, { "created": "Tue, 16 Jan 2018 22:44:59 GMT", "version": "v4" } ]
2018-01-18
[ [ "Lopez", "Romain", "" ], [ "Regier", "Jeffrey", "" ], [ "Cole", "Michael", "" ], [ "Jordan", "Michael", "" ], [ "Yosef", "Nir", "" ] ]
We propose a probabilistic model for interpreting gene expression levels that are observed through single-cell RNA sequencing. In the model, each cell has a low-dimensional latent representation. Additional latent variables account for technical effects that may erroneously set some observations of gene expression levels to zero. Conditional distributions are specified by neural networks, giving the proposed model enough flexibility to fit the data well. We use variational inference and stochastic optimization to approximate the posterior distribution. The inference procedure scales to over one million cells, whereas competing algorithms do not. Even for smaller datasets, for several tasks, the proposed procedure outperforms state-of-the-art methods like ZIFA and ZINB-WaVE. We also extend our framework to account for batch effects and other confounding factors, and propose a Bayesian hypothesis test for differential expression that outperforms DESeq2.
1610.07336
Steffen Urban
Steffen Urban and Stefan Hinz
MultiCol-SLAM - A Modular Real-Time Multi-Camera SLAM System
15 pages, 8 figures, 2 tables
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The basis for most vision based applications like robotics, self-driving cars and potentially augmented and virtual reality is a robust, continuous estimation of the position and orientation of a camera system w.r.t the observed environment (scene). In recent years many vision based systems that perform simultaneous localization and mapping (SLAM) have been presented and released as open source. In this paper, we extend and improve upon a state-of-the-art SLAM to make it applicable to arbitrary, rigidly coupled multi-camera systems (MCS) using the MultiCol model. In addition, we include a performance evaluation on accurate ground truth and compare the robustness of the proposed method to a single camera version of the SLAM system. An open source implementation of the proposed multi-fisheye camera SLAM system can be found on-line https://github.com/urbste/MultiCol-SLAM.
[ { "created": "Mon, 24 Oct 2016 09:27:47 GMT", "version": "v1" } ]
2016-10-25
[ [ "Urban", "Steffen", "" ], [ "Hinz", "Stefan", "" ] ]
The basis for most vision based applications like robotics, self-driving cars and potentially augmented and virtual reality is a robust, continuous estimation of the position and orientation of a camera system w.r.t the observed environment (scene). In recent years many vision based systems that perform simultaneous localization and mapping (SLAM) have been presented and released as open source. In this paper, we extend and improve upon a state-of-the-art SLAM to make it applicable to arbitrary, rigidly coupled multi-camera systems (MCS) using the MultiCol model. In addition, we include a performance evaluation on accurate ground truth and compare the robustness of the proposed method to a single camera version of the SLAM system. An open source implementation of the proposed multi-fisheye camera SLAM system can be found on-line https://github.com/urbste/MultiCol-SLAM.
2108.03206
Bo Yu
Shengzhao Wang, Meitang Li, Bo Yu, Shan Bao, Yuren Chen
Investigating The Impacting Factors on The Public's Attitudes Towards Autonomous Vehicles Using Sentiment Analysis from Social Media Data
22 pages, 5 figures
null
null
null
cs.SI
http://creativecommons.org/licenses/by/4.0/
The public's attitudes play a critical role in the acceptance, purchase, use, and research and development of autonomous vehicles (AVs). To date, the public's attitudes towards AVs were mostly estimated through traditional survey data with high labor costs and a low quantity of samples, which also might be one of the reasons why the influencing factors on the public's attitudes of AVs have not been studied from multiple aspects in a comprehensive way yet. To address the issue, this study aims to propose a method by using large-scale social media data to investigate key factors that affect the public's attitudes and acceptance of AVs. A total of 954,151 Twitter data related to AVs and 53 candidate independent variables from seven categories were extracted using the web scraping method. Then, sentiment analysis was used to measure the public attitudes towards AVs by calculating sentiment scores. Random forests algorithm was employed to preliminarily select candidate independent variables according to their importance, while a linear mixed model was performed to explore the impacting factors considering the unobserved heterogeneities caused by the subjectivity level of tweets. The results showed that the overall attitude of the public on AVs was slightly optimistic. Factors like "drunk", "blind spot", and "mobility" had the largest impacts on public attitudes. In addition, people were more likely to express positive feelings when talking about words such as "lidar" and "Tesla" that relate to high technologies. Conversely, factors such as "COVID-19", "pedestrian", "sleepy", and "highway" were found to have significantly negative effects on the public's attitudes. The findings of this study are beneficial for the development of AV technologies, the guidelines for AV-related policy formulation, and the public's understanding and acceptance of AVs.
[ { "created": "Fri, 6 Aug 2021 17:07:29 GMT", "version": "v1" } ]
2021-08-09
[ [ "Wang", "Shengzhao", "" ], [ "Li", "Meitang", "" ], [ "Yu", "Bo", "" ], [ "Bao", "Shan", "" ], [ "Chen", "Yuren", "" ] ]
The public's attitudes play a critical role in the acceptance, purchase, use, and research and development of autonomous vehicles (AVs). To date, the public's attitudes towards AVs were mostly estimated through traditional survey data with high labor costs and a low quantity of samples, which also might be one of the reasons why the influencing factors on the public's attitudes of AVs have not been studied from multiple aspects in a comprehensive way yet. To address the issue, this study aims to propose a method by using large-scale social media data to investigate key factors that affect the public's attitudes and acceptance of AVs. A total of 954,151 Twitter data related to AVs and 53 candidate independent variables from seven categories were extracted using the web scraping method. Then, sentiment analysis was used to measure the public attitudes towards AVs by calculating sentiment scores. Random forests algorithm was employed to preliminarily select candidate independent variables according to their importance, while a linear mixed model was performed to explore the impacting factors considering the unobserved heterogeneities caused by the subjectivity level of tweets. The results showed that the overall attitude of the public on AVs was slightly optimistic. Factors like "drunk", "blind spot", and "mobility" had the largest impacts on public attitudes. In addition, people were more likely to express positive feelings when talking about words such as "lidar" and "Tesla" that relate to high technologies. Conversely, factors such as "COVID-19", "pedestrian", "sleepy", and "highway" were found to have significantly negative effects on the public's attitudes. The findings of this study are beneficial for the development of AV technologies, the guidelines for AV-related policy formulation, and the public's understanding and acceptance of AVs.
2108.11845
Bin Liu
Bin Liu
Consistent Relative Confidence and Label-Free Model Selection for Convolutional Neural Networks
This paper has been accepted by 2022 International Conference on Pattern Recognition and Machine Learning (PRML 2022)
null
null
null
cs.CV cs.LG
http://creativecommons.org/licenses/by-nc-nd/4.0/
In this paper, we are concerned with image classification with deep convolutional neural networks (CNNs). We focus on the following question: given a set of candidate CNN models, how to select the right one with the best generalization property for the current task? Current model selection methods all require access to a batch of labeled data for computing a pre-specified performance metric, such as the cross-entropy loss, the classification error rate and the negative log-likelihood. In many practical cases, labels are not available in time as labeling itself is a time-consuming and expensive task. To this end, we propose an approach to CNN model selection using only unlabeled data. We develop this method based on a principle termed consistent relative confidence. Experimental results on benchmark datasets demonstrate the effectiveness and efficiency of our method.
[ { "created": "Thu, 26 Aug 2021 15:14:38 GMT", "version": "v1" }, { "created": "Mon, 24 Jan 2022 10:35:57 GMT", "version": "v2" }, { "created": "Wed, 26 Jan 2022 13:17:47 GMT", "version": "v3" }, { "created": "Thu, 27 Jan 2022 02:45:29 GMT", "version": "v4" }, { "created": "Fri, 28 Jan 2022 06:10:27 GMT", "version": "v5" }, { "created": "Mon, 31 Jan 2022 11:46:08 GMT", "version": "v6" }, { "created": "Thu, 28 Apr 2022 07:36:07 GMT", "version": "v7" }, { "created": "Sat, 28 May 2022 08:27:53 GMT", "version": "v8" }, { "created": "Tue, 31 May 2022 03:16:02 GMT", "version": "v9" } ]
2022-06-01
[ [ "Liu", "Bin", "" ] ]
In this paper, we are concerned with image classification with deep convolutional neural networks (CNNs). We focus on the following question: given a set of candidate CNN models, how to select the right one with the best generalization property for the current task? Current model selection methods all require access to a batch of labeled data for computing a pre-specified performance metric, such as the cross-entropy loss, the classification error rate and the negative log-likelihood. In many practical cases, labels are not available in time as labeling itself is a time-consuming and expensive task. To this end, we propose an approach to CNN model selection using only unlabeled data. We develop this method based on a principle termed consistent relative confidence. Experimental results on benchmark datasets demonstrate the effectiveness and efficiency of our method.
2402.03202
Rashid Iqbal
Rashid Iqbal, Mauro Biagi, Ahmed Zoha, Muhammad Ali Imran, Hanaa Abumarshoud
Leveraging IRS Induced Time Delay for Enhanced Physical Layer Security in VLC Systems
null
null
null
null
cs.IT cs.CR math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Indoor visible light communication (VLC) is considered secure against attackers outside the confined area where the light propagates, but it is still susceptible to interception from inside the coverage area. A new technology, intelligent reflecting surfaces (IRS), has been recently introduced, offering a way to enhance physical layer security (PLS). Most research on IRS-assisted VLC assumes the same time of arrival from all reflecting elements and overlooks the effect of time delay and the associated intersymbol interference. This paper tackles, for the first time, the effect of time delay on the secrecy rate in VLC systems. Our results show that, at a fixed light-emitting diode (LED) power of 3W, the secrecy rate can be enhanced by up to 253\% at random positions for the legitimate user when the eavesdropper is located within a 1-meter radius of the LED. Our results also show that careful allocation of the IRS elements can lead to enhanced PLS even when the eavesdropper has a more favourable position and, thus, a better channel gain than the legitimate user.
[ { "created": "Mon, 5 Feb 2024 17:13:12 GMT", "version": "v1" }, { "created": "Fri, 10 May 2024 15:03:43 GMT", "version": "v2" } ]
2024-05-13
[ [ "Iqbal", "Rashid", "" ], [ "Biagi", "Mauro", "" ], [ "Zoha", "Ahmed", "" ], [ "Imran", "Muhammad Ali", "" ], [ "Abumarshoud", "Hanaa", "" ] ]
Indoor visible light communication (VLC) is considered secure against attackers outside the confined area where the light propagates, but it is still susceptible to interception from inside the coverage area. A new technology, intelligent reflecting surfaces (IRS), has been recently introduced, offering a way to enhance physical layer security (PLS). Most research on IRS-assisted VLC assumes the same time of arrival from all reflecting elements and overlooks the effect of time delay and the associated intersymbol interference. This paper tackles, for the first time, the effect of time delay on the secrecy rate in VLC systems. Our results show that, at a fixed light-emitting diode (LED) power of 3W, the secrecy rate can be enhanced by up to 253\% at random positions for the legitimate user when the eavesdropper is located within a 1-meter radius of the LED. Our results also show that careful allocation of the IRS elements can lead to enhanced PLS even when the eavesdropper has a more favourable position and, thus, a better channel gain than the legitimate user.
2109.04385
Maximilian Mozes
Maximilian Mozes, Max Bartolo, Pontus Stenetorp, Bennett Kleinberg, Lewis D. Griffin
Contrasting Human- and Machine-Generated Word-Level Adversarial Examples for Text Classification
EMNLP 2021
null
null
null
cs.CL
http://creativecommons.org/licenses/by/4.0/
Research shows that natural language processing models are generally considered to be vulnerable to adversarial attacks; but recent work has drawn attention to the issue of validating these adversarial inputs against certain criteria (e.g., the preservation of semantics and grammaticality). Enforcing constraints to uphold such criteria may render attacks unsuccessful, raising the question of whether valid attacks are actually feasible. In this work, we investigate this through the lens of human language ability. We report on crowdsourcing studies in which we task humans with iteratively modifying words in an input text, while receiving immediate model feedback, with the aim of causing a sentiment classification model to misclassify the example. Our findings suggest that humans are capable of generating a substantial amount of adversarial examples using semantics-preserving word substitutions. We analyze how human-generated adversarial examples compare to the recently proposed TextFooler, Genetic, BAE and SememePSO attack algorithms on the dimensions naturalness, preservation of sentiment, grammaticality and substitution rate. Our findings suggest that human-generated adversarial examples are not more able than the best algorithms to generate natural-reading, sentiment-preserving examples, though they do so by being much more computationally efficient.
[ { "created": "Thu, 9 Sep 2021 16:16:04 GMT", "version": "v1" } ]
2021-09-10
[ [ "Mozes", "Maximilian", "" ], [ "Bartolo", "Max", "" ], [ "Stenetorp", "Pontus", "" ], [ "Kleinberg", "Bennett", "" ], [ "Griffin", "Lewis D.", "" ] ]
Research shows that natural language processing models are generally considered to be vulnerable to adversarial attacks; but recent work has drawn attention to the issue of validating these adversarial inputs against certain criteria (e.g., the preservation of semantics and grammaticality). Enforcing constraints to uphold such criteria may render attacks unsuccessful, raising the question of whether valid attacks are actually feasible. In this work, we investigate this through the lens of human language ability. We report on crowdsourcing studies in which we task humans with iteratively modifying words in an input text, while receiving immediate model feedback, with the aim of causing a sentiment classification model to misclassify the example. Our findings suggest that humans are capable of generating a substantial amount of adversarial examples using semantics-preserving word substitutions. We analyze how human-generated adversarial examples compare to the recently proposed TextFooler, Genetic, BAE and SememePSO attack algorithms on the dimensions naturalness, preservation of sentiment, grammaticality and substitution rate. Our findings suggest that human-generated adversarial examples are not more able than the best algorithms to generate natural-reading, sentiment-preserving examples, though they do so by being much more computationally efficient.
1409.3651
Dushyant Vaghela Mr.
Dushyant Vaghela
An Advanced Approach On Load Balancing in Grid Computing
We have applied our Research work on various servers, NGIX performs better, VPS Hosting Godadday servers Representative for http://explorequotes.com/ working fine, finally we have concluded that all the experiments were satisfactory
null
null
null
cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the rapid development in wide area networks and low cost, powerful computational resources, grid computing has gained its popularity. With the advent of grid computing, space limitations of conventional distributed systems can be overcome and underutilized computing resources at different locations around the world can be put to distributed jobs. Workload and resource management is the main key grid services at the service level of grid infrastructures, out of which load balancing in the main concern for grid developers. It has been found that load is the major problem which server faces, especially when the number of users increases. A lot of research is being done in the area of load management. This paper presents the various mechanisms of load balancing in grid computing so that the readers will get an idea of which algorithm would be suitable in different situations. Keywords: wide area network, distributed computing, load balancing.
[ { "created": "Fri, 12 Sep 2014 05:40:34 GMT", "version": "v1" } ]
2014-09-15
[ [ "Vaghela", "Dushyant", "" ] ]
With the rapid development in wide area networks and low cost, powerful computational resources, grid computing has gained its popularity. With the advent of grid computing, space limitations of conventional distributed systems can be overcome and underutilized computing resources at different locations around the world can be put to distributed jobs. Workload and resource management is the main key grid services at the service level of grid infrastructures, out of which load balancing in the main concern for grid developers. It has been found that load is the major problem which server faces, especially when the number of users increases. A lot of research is being done in the area of load management. This paper presents the various mechanisms of load balancing in grid computing so that the readers will get an idea of which algorithm would be suitable in different situations. Keywords: wide area network, distributed computing, load balancing.
1711.10839
Sevil Dr\"axler
Sevil Dr\"axler, Holger Karl, Zolt\'an \'Ad\'am Mann
JASPER: Joint Optimization of Scaling, Placement, and Routing of Virtual Network Services
null
null
10.1109/TNSM.2018.2846572
null
cs.NI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
To adapt to continuously changing workloads in networks, components of the running network services may need to be replicated (scaling the network service) and allocated to physical resources (placement) dynamically, also necessitating dynamic re-routing of flows between service components. In this paper, we propose JASPER, a fully automated approach to jointly optimizing scaling, placement, and routing for complex network services, consisting of multiple (virtualized) components. JASPER handles multiple network services that share the same substrate network; services can be dynamically added or removed and dynamic workload changes are handled. Our approach lets service designers specify their services on a high level of abstraction using service templates. From the service templates and a description of the substrate network, JASPER automatically makes scaling, placement and routing decisions, enabling quick reaction to changes. We formalize the problem, analyze its complexity, and develop two algorithms to solve it. Extensive empirical results show the applicability and effectiveness of the proposed approach.
[ { "created": "Wed, 29 Nov 2017 13:22:07 GMT", "version": "v1" } ]
2018-06-15
[ [ "Dräxler", "Sevil", "" ], [ "Karl", "Holger", "" ], [ "Mann", "Zoltán Ádám", "" ] ]
To adapt to continuously changing workloads in networks, components of the running network services may need to be replicated (scaling the network service) and allocated to physical resources (placement) dynamically, also necessitating dynamic re-routing of flows between service components. In this paper, we propose JASPER, a fully automated approach to jointly optimizing scaling, placement, and routing for complex network services, consisting of multiple (virtualized) components. JASPER handles multiple network services that share the same substrate network; services can be dynamically added or removed and dynamic workload changes are handled. Our approach lets service designers specify their services on a high level of abstraction using service templates. From the service templates and a description of the substrate network, JASPER automatically makes scaling, placement and routing decisions, enabling quick reaction to changes. We formalize the problem, analyze its complexity, and develop two algorithms to solve it. Extensive empirical results show the applicability and effectiveness of the proposed approach.
2202.02864
Jerry Van Aken
Jerry R. Van Aken
Alpha Blending with No Division Operations
10 pages, 1 figure
null
null
null
cs.GR
http://creativecommons.org/licenses/by/4.0/
Highly accurate alpha blending can be performed entirely with integer operations, and no divisions. To reduce the number of integer multiplications, multiple color components can be blended in parallel in the same 32-bit or 64-bit register. This tutorial explains how to avoid division operations when alpha blending with 32-bit RGBA pixels. An RGBA pixel contains four 8-bit components (red, green, blue, and alpha) whose values range from 0 to 255. Alpha blending requires multiplication of the color components by an alpha value, after which (for greatest accuracy) each of these products is divided by 255 and then rounded to the nearest integer. This tutorial presents an approximate alpha-blending formula that replaces the division operation with an integer shift and add -- and also enables the number of multiplications to be reduced. When the same blending calculation is carried out to high precision using double-precision floating-point division operations, the results are found to exactly match those produced by this approximation. C++ code examples are included.
[ { "created": "Sun, 6 Feb 2022 21:48:04 GMT", "version": "v1" }, { "created": "Thu, 17 Feb 2022 23:20:12 GMT", "version": "v2" } ]
2022-02-21
[ [ "Van Aken", "Jerry R.", "" ] ]
Highly accurate alpha blending can be performed entirely with integer operations, and no divisions. To reduce the number of integer multiplications, multiple color components can be blended in parallel in the same 32-bit or 64-bit register. This tutorial explains how to avoid division operations when alpha blending with 32-bit RGBA pixels. An RGBA pixel contains four 8-bit components (red, green, blue, and alpha) whose values range from 0 to 255. Alpha blending requires multiplication of the color components by an alpha value, after which (for greatest accuracy) each of these products is divided by 255 and then rounded to the nearest integer. This tutorial presents an approximate alpha-blending formula that replaces the division operation with an integer shift and add -- and also enables the number of multiplications to be reduced. When the same blending calculation is carried out to high precision using double-precision floating-point division operations, the results are found to exactly match those produced by this approximation. C++ code examples are included.
2012.15754
Stefanos Tsimenidis
Stefanos Tsimenidis
Limitations of Deep Neural Networks: a discussion of G. Marcus' critical appraisal of deep learning
16 pages
null
null
null
cs.AI cs.CY cs.LG
http://creativecommons.org/licenses/by/4.0/
Deep neural networks have triggered a revolution in artificial intelligence, having been applied with great results in medical imaging, semi-autonomous vehicles, ecommerce, genetics research, speech recognition, particle physics, experimental art, economic forecasting, environmental science, industrial manufacturing, and a wide variety of applications in nearly every field. This sudden success, though, may have intoxicated the research community and blinded them to the potential pitfalls of assigning deep learning a higher status than warranted. Also, research directed at alleviating the weaknesses of deep learning may seem less attractive to scientists and engineers, who focus on the low-hanging fruit of finding more and more applications for deep learning models, thus letting short-term benefits hamper long-term scientific progress. Gary Marcus wrote a paper entitled Deep Learning: A Critical Appraisal, and here we discuss Marcus' core ideas, as well as attempt a general assessment of the subject. This study examines some of the limitations of deep neural networks, with the intention of pointing towards potential paths for future research, and of clearing up some metaphysical misconceptions, held by numerous researchers, that may misdirect them.
[ { "created": "Tue, 22 Dec 2020 12:11:19 GMT", "version": "v1" } ]
2021-01-01
[ [ "Tsimenidis", "Stefanos", "" ] ]
Deep neural networks have triggered a revolution in artificial intelligence, having been applied with great results in medical imaging, semi-autonomous vehicles, ecommerce, genetics research, speech recognition, particle physics, experimental art, economic forecasting, environmental science, industrial manufacturing, and a wide variety of applications in nearly every field. This sudden success, though, may have intoxicated the research community and blinded them to the potential pitfalls of assigning deep learning a higher status than warranted. Also, research directed at alleviating the weaknesses of deep learning may seem less attractive to scientists and engineers, who focus on the low-hanging fruit of finding more and more applications for deep learning models, thus letting short-term benefits hamper long-term scientific progress. Gary Marcus wrote a paper entitled Deep Learning: A Critical Appraisal, and here we discuss Marcus' core ideas, as well as attempt a general assessment of the subject. This study examines some of the limitations of deep neural networks, with the intention of pointing towards potential paths for future research, and of clearing up some metaphysical misconceptions, held by numerous researchers, that may misdirect them.
2009.11508
Yang Bai
Yang Bai and Yuyuan Zeng and Yong Jiang and Yisen Wang and Shu-Tao Xia and Weiwei Guo
Improving Query Efficiency of Black-box Adversarial Attack
Accepted to ECCV2020
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep neural networks (DNNs) have demonstrated excellent performance on various tasks, however they are under the risk of adversarial examples that can be easily generated when the target model is accessible to an attacker (white-box setting). As plenty of machine learning models have been deployed via online services that only provide query outputs from inaccessible models (e.g. Google Cloud Vision API2), black-box adversarial attacks (inaccessible target model) are of critical security concerns in practice rather than white-box ones. However, existing query-based black-box adversarial attacks often require excessive model queries to maintain a high attack success rate. Therefore, in order to improve query efficiency, we explore the distribution of adversarial examples around benign inputs with the help of image structure information characterized by a Neural Process, and propose a Neural Process based black-box adversarial attack (NP-Attack) in this paper. Extensive experiments show that NP-Attack could greatly decrease the query counts under the black-box setting.
[ { "created": "Thu, 24 Sep 2020 06:22:56 GMT", "version": "v1" }, { "created": "Fri, 25 Sep 2020 07:09:25 GMT", "version": "v2" } ]
2020-09-28
[ [ "Bai", "Yang", "" ], [ "Zeng", "Yuyuan", "" ], [ "Jiang", "Yong", "" ], [ "Wang", "Yisen", "" ], [ "Xia", "Shu-Tao", "" ], [ "Guo", "Weiwei", "" ] ]
Deep neural networks (DNNs) have demonstrated excellent performance on various tasks, however they are under the risk of adversarial examples that can be easily generated when the target model is accessible to an attacker (white-box setting). As plenty of machine learning models have been deployed via online services that only provide query outputs from inaccessible models (e.g. Google Cloud Vision API2), black-box adversarial attacks (inaccessible target model) are of critical security concerns in practice rather than white-box ones. However, existing query-based black-box adversarial attacks often require excessive model queries to maintain a high attack success rate. Therefore, in order to improve query efficiency, we explore the distribution of adversarial examples around benign inputs with the help of image structure information characterized by a Neural Process, and propose a Neural Process based black-box adversarial attack (NP-Attack) in this paper. Extensive experiments show that NP-Attack could greatly decrease the query counts under the black-box setting.
2205.11343
M. Park
Minjae Park
Heterogeneous Graph Neural Network for Personalized Session-Based Recommendation with User-Session Constraints
There is a fatal error in the derived experiment results
null
null
null
cs.IR cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recommendation system provides users with an appropriate limit of recent online large amounts of information. Session-based recommendation, a sub-area of recommender systems, attempts to recommend items by interpreting sessions that consist of sequences of items. Recently, research to include user information in these sessions is progress. However, it is difficult to generate high-quality user representation that includes session representations generated by user. In this paper, we consider various relationships in graph created by sessions through Heterogeneous attention network. Constraints also force user representations to consider the user's preferences presented in the session. It seeks to increase performance through additional optimization in the training process. The proposed model outperformed other methods on various real-world datasets.
[ { "created": "Mon, 23 May 2022 14:35:26 GMT", "version": "v1" }, { "created": "Tue, 24 May 2022 08:46:21 GMT", "version": "v2" }, { "created": "Sun, 26 Jun 2022 14:35:10 GMT", "version": "v3" } ]
2022-06-28
[ [ "Park", "Minjae", "" ] ]
The recommendation system provides users with an appropriate limit of recent online large amounts of information. Session-based recommendation, a sub-area of recommender systems, attempts to recommend items by interpreting sessions that consist of sequences of items. Recently, research to include user information in these sessions is progress. However, it is difficult to generate high-quality user representation that includes session representations generated by user. In this paper, we consider various relationships in graph created by sessions through Heterogeneous attention network. Constraints also force user representations to consider the user's preferences presented in the session. It seeks to increase performance through additional optimization in the training process. The proposed model outperformed other methods on various real-world datasets.
2309.02145
Patrick Eickhoff
Patrick Eickhoff, Matthias M\"oller, Theresa Pekarek Rosin, Johannes Twiefel, Stefan Wermter
Bring the Noise: Introducing Noise Robustness to Pretrained Automatic Speech Recognition
Submitted and accepted for ICANN 2023 (32nd International Conference on Artificial Neural Networks)
null
null
null
cs.CL cs.SD eess.AS
http://creativecommons.org/licenses/by/4.0/
In recent research, in the domain of speech processing, large End-to-End (E2E) systems for Automatic Speech Recognition (ASR) have reported state-of-the-art performance on various benchmarks. These systems intrinsically learn how to handle and remove noise conditions from speech. Previous research has shown, that it is possible to extract the denoising capabilities of these models into a preprocessor network, which can be used as a frontend for downstream ASR models. However, the proposed methods were limited to specific fully convolutional architectures. In this work, we propose a novel method to extract the denoising capabilities, that can be applied to any encoder-decoder architecture. We propose the Cleancoder preprocessor architecture that extracts hidden activations from the Conformer ASR model and feeds them to a decoder to predict denoised spectrograms. We train our pre-processor on the Noisy Speech Database (NSD) to reconstruct denoised spectrograms from noisy inputs. Then, we evaluate our model as a frontend to a pretrained Conformer ASR model as well as a frontend to train smaller Conformer ASR models from scratch. We show that the Cleancoder is able to filter noise from speech and that it improves the total Word Error Rate (WER) of the downstream model in noisy conditions for both applications.
[ { "created": "Tue, 5 Sep 2023 11:34:21 GMT", "version": "v1" } ]
2023-09-06
[ [ "Eickhoff", "Patrick", "" ], [ "Möller", "Matthias", "" ], [ "Rosin", "Theresa Pekarek", "" ], [ "Twiefel", "Johannes", "" ], [ "Wermter", "Stefan", "" ] ]
In recent research, in the domain of speech processing, large End-to-End (E2E) systems for Automatic Speech Recognition (ASR) have reported state-of-the-art performance on various benchmarks. These systems intrinsically learn how to handle and remove noise conditions from speech. Previous research has shown, that it is possible to extract the denoising capabilities of these models into a preprocessor network, which can be used as a frontend for downstream ASR models. However, the proposed methods were limited to specific fully convolutional architectures. In this work, we propose a novel method to extract the denoising capabilities, that can be applied to any encoder-decoder architecture. We propose the Cleancoder preprocessor architecture that extracts hidden activations from the Conformer ASR model and feeds them to a decoder to predict denoised spectrograms. We train our pre-processor on the Noisy Speech Database (NSD) to reconstruct denoised spectrograms from noisy inputs. Then, we evaluate our model as a frontend to a pretrained Conformer ASR model as well as a frontend to train smaller Conformer ASR models from scratch. We show that the Cleancoder is able to filter noise from speech and that it improves the total Word Error Rate (WER) of the downstream model in noisy conditions for both applications.
1508.04467
Zhao Kang
Zhao Kang, Chong Peng, Qiang Cheng
Robust Subspace Clustering via Smoothed Rank Approximation
Journal, code is available
IEEE Signal Processing Letters, 22(2015)2088-2092
10.1109/LSP.2015.2460737
null
cs.CV cs.IT cs.LG cs.NA math.IT stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Matrix rank minimizing subject to affine constraints arises in many application areas, ranging from signal processing to machine learning. Nuclear norm is a convex relaxation for this problem which can recover the rank exactly under some restricted and theoretically interesting conditions. However, for many real-world applications, nuclear norm approximation to the rank function can only produce a result far from the optimum. To seek a solution of higher accuracy than the nuclear norm, in this paper, we propose a rank approximation based on Logarithm-Determinant. We consider using this rank approximation for subspace clustering application. Our framework can model different kinds of errors and noise. Effective optimization strategy is developed with theoretical guarantee to converge to a stationary point. The proposed method gives promising results on face clustering and motion segmentation tasks compared to the state-of-the-art subspace clustering algorithms.
[ { "created": "Tue, 18 Aug 2015 21:54:03 GMT", "version": "v1" } ]
2015-08-20
[ [ "Kang", "Zhao", "" ], [ "Peng", "Chong", "" ], [ "Cheng", "Qiang", "" ] ]
Matrix rank minimizing subject to affine constraints arises in many application areas, ranging from signal processing to machine learning. Nuclear norm is a convex relaxation for this problem which can recover the rank exactly under some restricted and theoretically interesting conditions. However, for many real-world applications, nuclear norm approximation to the rank function can only produce a result far from the optimum. To seek a solution of higher accuracy than the nuclear norm, in this paper, we propose a rank approximation based on Logarithm-Determinant. We consider using this rank approximation for subspace clustering application. Our framework can model different kinds of errors and noise. Effective optimization strategy is developed with theoretical guarantee to converge to a stationary point. The proposed method gives promising results on face clustering and motion segmentation tasks compared to the state-of-the-art subspace clustering algorithms.
2212.14181
Guangwei Gao
Wenjie Li, Juncheng Li, Guangwei Gao, Weihong Deng, Jian Yang, Guo-Jun Qi and Chia-Wen Lin
Efficient Image Super-Resolution with Feature Interaction Weighted Hybrid Network
15 pages, 14 figures, extention of our AAAI2022
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, great progress has been made in single-image super-resolution (SISR) based on deep learning technology. However, the existing methods usually require a large computational cost. Meanwhile, the activation function will cause some features of the intermediate layer to be lost. Therefore, it is a challenge to make the model lightweight while reducing the impact of intermediate feature loss on the reconstruction quality. In this paper, we propose a Feature Interaction Weighted Hybrid Network (FIWHN) to alleviate the above problem. Specifically, FIWHN consists of a series of novel Wide-residual Distillation Interaction Blocks (WDIB) as the backbone, where every third WDIBs form a Feature shuffle Weighted Group (FSWG) by mutual information mixing and fusion. In addition, to mitigate the adverse effects of intermediate feature loss on the reconstruction results, we introduced a well-designed Wide Convolutional Residual Weighting (WCRW) and Wide Identical Residual Weighting (WIRW) units in WDIB, and effectively cross-fused features of different finenesses through a Wide-residual Distillation Connection (WRDC) framework and a Self-Calibrating Fusion (SCF) unit. Finally, to complement the global features lacking in the CNN model, we introduced the Transformer into our model and explored a new way of combining the CNN and Transformer. Extensive quantitative and qualitative experiments on low-level and high-level tasks show that our proposed FIWHN can achieve a good balance between performance and efficiency, and is more conducive to downstream tasks to solve problems in low-pixel scenarios.
[ { "created": "Thu, 29 Dec 2022 05:57:29 GMT", "version": "v1" } ]
2023-01-02
[ [ "Li", "Wenjie", "" ], [ "Li", "Juncheng", "" ], [ "Gao", "Guangwei", "" ], [ "Deng", "Weihong", "" ], [ "Yang", "Jian", "" ], [ "Qi", "Guo-Jun", "" ], [ "Lin", "Chia-Wen", "" ] ]
Recently, great progress has been made in single-image super-resolution (SISR) based on deep learning technology. However, the existing methods usually require a large computational cost. Meanwhile, the activation function will cause some features of the intermediate layer to be lost. Therefore, it is a challenge to make the model lightweight while reducing the impact of intermediate feature loss on the reconstruction quality. In this paper, we propose a Feature Interaction Weighted Hybrid Network (FIWHN) to alleviate the above problem. Specifically, FIWHN consists of a series of novel Wide-residual Distillation Interaction Blocks (WDIB) as the backbone, where every third WDIBs form a Feature shuffle Weighted Group (FSWG) by mutual information mixing and fusion. In addition, to mitigate the adverse effects of intermediate feature loss on the reconstruction results, we introduced a well-designed Wide Convolutional Residual Weighting (WCRW) and Wide Identical Residual Weighting (WIRW) units in WDIB, and effectively cross-fused features of different finenesses through a Wide-residual Distillation Connection (WRDC) framework and a Self-Calibrating Fusion (SCF) unit. Finally, to complement the global features lacking in the CNN model, we introduced the Transformer into our model and explored a new way of combining the CNN and Transformer. Extensive quantitative and qualitative experiments on low-level and high-level tasks show that our proposed FIWHN can achieve a good balance between performance and efficiency, and is more conducive to downstream tasks to solve problems in low-pixel scenarios.
1610.03437
Jo\~ao Oliveira
Jo\~ao P. Oliveira and Ana Bragan\c{c}a and Jos\'e Bioucas-Dias and M\'ario Figueiredo and Lu\'is Alc\'acer and Jorge Morgado and Quirina Ferreira
Restoring STM images via Sparse Coding: noise and artifact removal
14 pages, 6 figures
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we present a denoising algorithm to improve the interpretation and quality of scanning tunneling microscopy (STM) images. Given the high level of self-similarity of STM images, we propose a denoising algorithm by reformulating the true estimation problem as a sparse regression, often termed sparse coding. We introduce modifications to the algorithm to cope with the existence of artifacts, mainly dropouts, which appear in a structured way as consecutive line segments on the scanning direction. The resulting algorithm treats the artifacts as missing data, and the estimated values outperform those algorithms that substitute the outliers by a local filtering. We provide code implementations for both Matlab and Gwyddion.
[ { "created": "Tue, 11 Oct 2016 17:37:47 GMT", "version": "v1" } ]
2016-10-12
[ [ "Oliveira", "João P.", "" ], [ "Bragança", "Ana", "" ], [ "Bioucas-Dias", "José", "" ], [ "Figueiredo", "Mário", "" ], [ "Alcácer", "Luís", "" ], [ "Morgado", "Jorge", "" ], [ "Ferreira", "Quirina", "" ] ]
In this article, we present a denoising algorithm to improve the interpretation and quality of scanning tunneling microscopy (STM) images. Given the high level of self-similarity of STM images, we propose a denoising algorithm by reformulating the true estimation problem as a sparse regression, often termed sparse coding. We introduce modifications to the algorithm to cope with the existence of artifacts, mainly dropouts, which appear in a structured way as consecutive line segments on the scanning direction. The resulting algorithm treats the artifacts as missing data, and the estimated values outperform those algorithms that substitute the outliers by a local filtering. We provide code implementations for both Matlab and Gwyddion.
2207.04103
Dominik Lewy
Dominik Lewy, Jacek Ma\'ndziuk, Maria Ganzha, Marcin Paprzycki
StatMix: Data augmentation method that relies on image statistics in federated learning
null
null
null
null
cs.LG cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Availability of large amount of annotated data is one of the pillars of deep learning success. Although numerous big datasets have been made available for research, this is often not the case in real life applications (e.g. companies are not able to share data due to GDPR or concerns related to intellectual property rights protection). Federated learning (FL) is a potential solution to this problem, as it enables training a global model on data scattered across multiple nodes, without sharing local data itself. However, even FL methods pose a threat to data privacy, if not handled properly. Therefore, we propose StatMix, an augmentation approach that uses image statistics, to improve results of FL scenario(s). StatMix is empirically tested on CIFAR-10 and CIFAR-100, using two neural network architectures. In all FL experiments, application of StatMix improves the average accuracy, compared to the baseline training (with no use of StatMix). Some improvement can also be observed in non-FL setups.
[ { "created": "Fri, 8 Jul 2022 19:02:41 GMT", "version": "v1" } ]
2022-07-12
[ [ "Lewy", "Dominik", "" ], [ "Mańdziuk", "Jacek", "" ], [ "Ganzha", "Maria", "" ], [ "Paprzycki", "Marcin", "" ] ]
Availability of large amount of annotated data is one of the pillars of deep learning success. Although numerous big datasets have been made available for research, this is often not the case in real life applications (e.g. companies are not able to share data due to GDPR or concerns related to intellectual property rights protection). Federated learning (FL) is a potential solution to this problem, as it enables training a global model on data scattered across multiple nodes, without sharing local data itself. However, even FL methods pose a threat to data privacy, if not handled properly. Therefore, we propose StatMix, an augmentation approach that uses image statistics, to improve results of FL scenario(s). StatMix is empirically tested on CIFAR-10 and CIFAR-100, using two neural network architectures. In all FL experiments, application of StatMix improves the average accuracy, compared to the baseline training (with no use of StatMix). Some improvement can also be observed in non-FL setups.
1804.11162
Joaqu\'in Arias M.Sc.
Joaqu\'in Arias, Manuel Carro, Elmer Salazar, Kyle Marple and Gopal Gupta
Constraint Answer Set Programming without Grounding
Paper presented at the 34nd International Conference on Logic Programming (ICLP 2018), Oxford, UK, July 14 to July 17, 2018 18 pages, LaTeX
null
null
null
cs.PL cs.LO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Extending ASP with constraints (CASP) enhances its expressiveness and performance. This extension is not straightforward as the grounding phase, present in most ASP systems, removes variables and the links among them, and also causes a combinatorial explosion in the size of the program. Several methods to overcome this issue have been devised: restricting the constraint domains (e.g., discrete instead of dense), or the type (or number) of models that can be returned. In this paper we propose to incorporate constraints into s(ASP), a goal-directed, top-down execution model which implements ASP while retaining logical variables both during execution and in the answer sets. The resulting model, s(CASP), can constrain variables that, as in CLP, are kept during the execution and in the answer sets. s(CASP) inherits and generalizes the execution model of s(ASP) and is parametric w.r.t. the constraint solver. We describe this novel execution model and show through several examples the enhanced expressiveness of s(CASP) w.r.t. ASP, CLP, and other CASP systems. We also report improved performance w.r.t. other very mature, highly optimized ASP systems in some benchmarks. This paper is under consideration for publication in Theory and Practice of Logic Programming (TPLP).
[ { "created": "Mon, 30 Apr 2018 12:50:28 GMT", "version": "v1" }, { "created": "Thu, 31 May 2018 15:33:53 GMT", "version": "v2" } ]
2018-06-01
[ [ "Arias", "Joaquín", "" ], [ "Carro", "Manuel", "" ], [ "Salazar", "Elmer", "" ], [ "Marple", "Kyle", "" ], [ "Gupta", "Gopal", "" ] ]
Extending ASP with constraints (CASP) enhances its expressiveness and performance. This extension is not straightforward as the grounding phase, present in most ASP systems, removes variables and the links among them, and also causes a combinatorial explosion in the size of the program. Several methods to overcome this issue have been devised: restricting the constraint domains (e.g., discrete instead of dense), or the type (or number) of models that can be returned. In this paper we propose to incorporate constraints into s(ASP), a goal-directed, top-down execution model which implements ASP while retaining logical variables both during execution and in the answer sets. The resulting model, s(CASP), can constrain variables that, as in CLP, are kept during the execution and in the answer sets. s(CASP) inherits and generalizes the execution model of s(ASP) and is parametric w.r.t. the constraint solver. We describe this novel execution model and show through several examples the enhanced expressiveness of s(CASP) w.r.t. ASP, CLP, and other CASP systems. We also report improved performance w.r.t. other very mature, highly optimized ASP systems in some benchmarks. This paper is under consideration for publication in Theory and Practice of Logic Programming (TPLP).
2403.14356
Xudong Sun
Xudong Sun, Carla Feistner, Alexej Gossmann, George Schwarz, Rao Muhammad Umer, Lisa Beer, Patrick Rockenschaub, Rahul Babu Shrestha, Armin Gruber, Nutan Chen, Sayedali Shetab Boushehri, Florian Buettner, Carsten Marr
DomainLab: A modular Python package for domain generalization in deep learning
null
null
null
null
cs.LG cs.SE
http://creativecommons.org/licenses/by/4.0/
Poor generalization performance caused by distribution shifts in unseen domains often hinders the trustworthy deployment of deep neural networks. Many domain generalization techniques address this problem by adding a domain invariant regularization loss terms during training. However, there is a lack of modular software that allows users to combine the advantages of different methods with minimal effort for reproducibility. DomainLab is a modular Python package for training user specified neural networks with composable regularization loss terms. Its decoupled design allows the separation of neural networks from regularization loss construction. Hierarchical combinations of neural networks, different domain generalization methods, and associated hyperparameters, can all be specified together with other experimental setup in a single configuration file. Hierarchical combinations of neural networks, different domain generalization methods, and associated hyperparameters, can all be specified together with other experimental setup in a single configuration file. In addition, DomainLab offers powerful benchmarking functionality to evaluate the generalization performance of neural networks in out-of-distribution data. The package supports running the specified benchmark on an HPC cluster or on a standalone machine. The package is well tested with over 95 percent coverage and well documented. From the user perspective, it is closed to modification but open to extension. The package is under the MIT license, and its source code, tutorial and documentation can be found at https://github.com/marrlab/DomainLab.
[ { "created": "Thu, 21 Mar 2024 12:35:46 GMT", "version": "v1" } ]
2024-03-22
[ [ "Sun", "Xudong", "" ], [ "Feistner", "Carla", "" ], [ "Gossmann", "Alexej", "" ], [ "Schwarz", "George", "" ], [ "Umer", "Rao Muhammad", "" ], [ "Beer", "Lisa", "" ], [ "Rockenschaub", "Patrick", "" ], [ "Shrestha", "Rahul Babu", "" ], [ "Gruber", "Armin", "" ], [ "Chen", "Nutan", "" ], [ "Boushehri", "Sayedali Shetab", "" ], [ "Buettner", "Florian", "" ], [ "Marr", "Carsten", "" ] ]
Poor generalization performance caused by distribution shifts in unseen domains often hinders the trustworthy deployment of deep neural networks. Many domain generalization techniques address this problem by adding a domain invariant regularization loss terms during training. However, there is a lack of modular software that allows users to combine the advantages of different methods with minimal effort for reproducibility. DomainLab is a modular Python package for training user specified neural networks with composable regularization loss terms. Its decoupled design allows the separation of neural networks from regularization loss construction. Hierarchical combinations of neural networks, different domain generalization methods, and associated hyperparameters, can all be specified together with other experimental setup in a single configuration file. Hierarchical combinations of neural networks, different domain generalization methods, and associated hyperparameters, can all be specified together with other experimental setup in a single configuration file. In addition, DomainLab offers powerful benchmarking functionality to evaluate the generalization performance of neural networks in out-of-distribution data. The package supports running the specified benchmark on an HPC cluster or on a standalone machine. The package is well tested with over 95 percent coverage and well documented. From the user perspective, it is closed to modification but open to extension. The package is under the MIT license, and its source code, tutorial and documentation can be found at https://github.com/marrlab/DomainLab.
2404.09408
Xinyu Liang
Xinyu Liang, Ruiying Du, Jing Chen, Yu Zhang, Meng Jia, Shuangxi Cao, Yufeng Wei, Shixiong Yao
A Distributed Scalable Cross-chain State Channel Scheme Based on Recursive State Synchronization
null
null
null
null
cs.NI
http://creativecommons.org/licenses/by-sa/4.0/
As cross-chain technology continues to advance, the scale of cross-chain transactions is experiencing significant expansion. To improve scalability, researchers have turned to the study of cross-chain state channels. However, most of the existing schemes rely on trusted parties to support channel operations. To address this issue, we present Interpipe: a distributed cross-chain state channel scheme. Specifically, we propose a real-time cross-chain synchronization scheme to ensure consistent operations between two blockchains to a cross-chain state channel. Moreover, we propose a batch transaction proof scheme based on recursive SNARK to meet the cross-chain verification needs of large-scale users. Based on the above designs, Interpipe offers protocols for opening, updating, closing, and disputing operations to cross-chain state channels. Security analysis shows that Interpipe has consistency and resistance, and experimental results demonstrate that a cross-chain state channel can be nearly as efficient as an existing intra-chain state channel.
[ { "created": "Mon, 15 Apr 2024 01:50:28 GMT", "version": "v1" } ]
2024-04-16
[ [ "Liang", "Xinyu", "" ], [ "Du", "Ruiying", "" ], [ "Chen", "Jing", "" ], [ "Zhang", "Yu", "" ], [ "Jia", "Meng", "" ], [ "Cao", "Shuangxi", "" ], [ "Wei", "Yufeng", "" ], [ "Yao", "Shixiong", "" ] ]
As cross-chain technology continues to advance, the scale of cross-chain transactions is experiencing significant expansion. To improve scalability, researchers have turned to the study of cross-chain state channels. However, most of the existing schemes rely on trusted parties to support channel operations. To address this issue, we present Interpipe: a distributed cross-chain state channel scheme. Specifically, we propose a real-time cross-chain synchronization scheme to ensure consistent operations between two blockchains to a cross-chain state channel. Moreover, we propose a batch transaction proof scheme based on recursive SNARK to meet the cross-chain verification needs of large-scale users. Based on the above designs, Interpipe offers protocols for opening, updating, closing, and disputing operations to cross-chain state channels. Security analysis shows that Interpipe has consistency and resistance, and experimental results demonstrate that a cross-chain state channel can be nearly as efficient as an existing intra-chain state channel.
2301.05776
Iurii Medvedev
Iurii Medvedev and Farhad Shadmand and Nuno Gon\c{c}alves
Young Labeled Faces in the Wild (YLFW): A Dataset for Children Faces Recognition
11 pages, 3 figures
null
null
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
Face recognition has achieved outstanding performance in the last decade with the development of deep learning techniques. Nowadays, the challenges in face recognition are related to specific scenarios, for instance, the performance under diverse image quality, the robustness for aging and edge cases of person age (children and elders), distinguishing of related identities. In this set of problems, recognizing children's faces is one of the most sensitive and important. One of the reasons for this problem is the existing bias towards adults in existing face datasets. In this work, we present a benchmark dataset for children's face recognition, which is compiled similarly to the famous face recognition benchmarks LFW, CALFW, CPLFW, XQLFW and AgeDB. We also present a development dataset (separated into train and test parts) for adapting face recognition models for face images of children. The proposed data is balanced for African, Asian, Caucasian, and Indian races. To the best of our knowledge, this is the first standartized data tool set for benchmarking and the largest collection for development for children's face recognition. Several face recognition experiments are presented to demonstrate the performance of the proposed data tool set.
[ { "created": "Fri, 13 Jan 2023 22:19:44 GMT", "version": "v1" } ]
2023-01-18
[ [ "Medvedev", "Iurii", "" ], [ "Shadmand", "Farhad", "" ], [ "Gonçalves", "Nuno", "" ] ]
Face recognition has achieved outstanding performance in the last decade with the development of deep learning techniques. Nowadays, the challenges in face recognition are related to specific scenarios, for instance, the performance under diverse image quality, the robustness for aging and edge cases of person age (children and elders), distinguishing of related identities. In this set of problems, recognizing children's faces is one of the most sensitive and important. One of the reasons for this problem is the existing bias towards adults in existing face datasets. In this work, we present a benchmark dataset for children's face recognition, which is compiled similarly to the famous face recognition benchmarks LFW, CALFW, CPLFW, XQLFW and AgeDB. We also present a development dataset (separated into train and test parts) for adapting face recognition models for face images of children. The proposed data is balanced for African, Asian, Caucasian, and Indian races. To the best of our knowledge, this is the first standartized data tool set for benchmarking and the largest collection for development for children's face recognition. Several face recognition experiments are presented to demonstrate the performance of the proposed data tool set.
2202.13536
Geon-Hyeong Kim
Geon-Hyeong Kim, Jongmin Lee, Youngsoo Jang, Hongseok Yang, Kee-Eung Kim
LobsDICE: Offline Learning from Observation via Stationary Distribution Correction Estimation
33 pages, Accepted at NeurIPS 2022
null
null
null
cs.LG cs.AI
http://creativecommons.org/licenses/by-nc-sa/4.0/
We consider the problem of learning from observation (LfO), in which the agent aims to mimic the expert's behavior from the state-only demonstrations by experts. We additionally assume that the agent cannot interact with the environment but has access to the action-labeled transition data collected by some agents with unknown qualities. This offline setting for LfO is appealing in many real-world scenarios where the ground-truth expert actions are inaccessible and the arbitrary environment interactions are costly or risky. In this paper, we present LobsDICE, an offline LfO algorithm that learns to imitate the expert policy via optimization in the space of stationary distributions. Our algorithm solves a single convex minimization problem, which minimizes the divergence between the two state-transition distributions induced by the expert and the agent policy. Through an extensive set of offline LfO tasks, we show that LobsDICE outperforms strong baseline methods.
[ { "created": "Mon, 28 Feb 2022 04:24:30 GMT", "version": "v1" }, { "created": "Tue, 18 Oct 2022 02:31:21 GMT", "version": "v2" } ]
2022-10-19
[ [ "Kim", "Geon-Hyeong", "" ], [ "Lee", "Jongmin", "" ], [ "Jang", "Youngsoo", "" ], [ "Yang", "Hongseok", "" ], [ "Kim", "Kee-Eung", "" ] ]
We consider the problem of learning from observation (LfO), in which the agent aims to mimic the expert's behavior from the state-only demonstrations by experts. We additionally assume that the agent cannot interact with the environment but has access to the action-labeled transition data collected by some agents with unknown qualities. This offline setting for LfO is appealing in many real-world scenarios where the ground-truth expert actions are inaccessible and the arbitrary environment interactions are costly or risky. In this paper, we present LobsDICE, an offline LfO algorithm that learns to imitate the expert policy via optimization in the space of stationary distributions. Our algorithm solves a single convex minimization problem, which minimizes the divergence between the two state-transition distributions induced by the expert and the agent policy. Through an extensive set of offline LfO tasks, we show that LobsDICE outperforms strong baseline methods.
2104.08942
Neel Kanwal
Neel Kanwal, Giuseppe Rizzo
Attention-based Clinical Note Summarization
Accepted at ACM SAC 2022, in Special Track "KNLP"
ACM SAC 2022
10.1145/3477314.3507256
978-1-4503-8713-2/22/04
cs.CL cs.AI cs.IR cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years, the trend of deploying digital systems in numerous industries has hiked. The health sector has observed an extensive adoption of digital systems and services that generate significant medical records. Electronic health records contain valuable information for prospective and retrospective analysis that is often not entirely exploited because of the complicated dense information storage. The crude purpose of condensing health records is to select the information that holds most characteristics of the original documents based on a reported disease. These summaries may boost diagnosis and save a doctor's time during a saturated workload situation like the COVID-19 pandemic. In this paper, we are applying a multi-head attention-based mechanism to perform extractive summarization of meaningful phrases on clinical notes. Our method finds major sentences for a summary by correlating tokens, segments, and positional embeddings of sentences in a clinical note. The model outputs attention scores that are statistically transformed to extract critical phrases for visualization on the heat-mapping tool and for human use.
[ { "created": "Sun, 18 Apr 2021 19:40:26 GMT", "version": "v1" }, { "created": "Fri, 1 Oct 2021 10:51:26 GMT", "version": "v2" }, { "created": "Mon, 28 Feb 2022 11:15:16 GMT", "version": "v3" } ]
2022-03-01
[ [ "Kanwal", "Neel", "" ], [ "Rizzo", "Giuseppe", "" ] ]
In recent years, the trend of deploying digital systems in numerous industries has hiked. The health sector has observed an extensive adoption of digital systems and services that generate significant medical records. Electronic health records contain valuable information for prospective and retrospective analysis that is often not entirely exploited because of the complicated dense information storage. The crude purpose of condensing health records is to select the information that holds most characteristics of the original documents based on a reported disease. These summaries may boost diagnosis and save a doctor's time during a saturated workload situation like the COVID-19 pandemic. In this paper, we are applying a multi-head attention-based mechanism to perform extractive summarization of meaningful phrases on clinical notes. Our method finds major sentences for a summary by correlating tokens, segments, and positional embeddings of sentences in a clinical note. The model outputs attention scores that are statistically transformed to extract critical phrases for visualization on the heat-mapping tool and for human use.
2008.07397
Daniel Engelsman
Daniel Engelsman
A Study of a Genetic Algorithm for Polydisperse Spray Flames
Advisor : Prof. Barry J. Greenberg, 66 Pages, 65 figures
null
null
null
cs.NE
http://creativecommons.org/publicdomain/zero/1.0/
Modern technological advancements constantly push forward the human-machine interaction. Evolutionary Algorithms (EA) are an machine learning (ML) subclass inspired by the process of natural selection - Survival of the Fittest, as stated by the Darwinian Theory of Evolution. The most notable algorithm in that class is the Genetic Algorithm (GA) - a powerful heuristic tool which enables the generation of a high-quality solutions to optimization problems. In recent decades the algorithm underwent remarkable improvement, which adapted it into a wide range of engineering problems, by heuristically searching for the optimal solution. Despite being well-defined, many engineering problems may suffer from heavy analytical entanglement when approaching the derivation process, as required in classic optimization methods. Therefore, the main motivation here, is to work around that obstacle. In this piece of work, I would like to harness the GA capabilities to examine optimality with respect to a unique combustion problem, in a way that was never performed before. To be more precise, I would like to utilize it to answer the question : What form of an initial droplet size distribution (iDSD) will guarantee an optimal flame ? To answer this question, I will first provide a general introduction to the GA method, then develop the combustion model, and eventually merge both into an optimization problem.
[ { "created": "Tue, 11 Aug 2020 10:17:42 GMT", "version": "v1" } ]
2020-08-18
[ [ "Engelsman", "Daniel", "" ] ]
Modern technological advancements constantly push forward the human-machine interaction. Evolutionary Algorithms (EA) are an machine learning (ML) subclass inspired by the process of natural selection - Survival of the Fittest, as stated by the Darwinian Theory of Evolution. The most notable algorithm in that class is the Genetic Algorithm (GA) - a powerful heuristic tool which enables the generation of a high-quality solutions to optimization problems. In recent decades the algorithm underwent remarkable improvement, which adapted it into a wide range of engineering problems, by heuristically searching for the optimal solution. Despite being well-defined, many engineering problems may suffer from heavy analytical entanglement when approaching the derivation process, as required in classic optimization methods. Therefore, the main motivation here, is to work around that obstacle. In this piece of work, I would like to harness the GA capabilities to examine optimality with respect to a unique combustion problem, in a way that was never performed before. To be more precise, I would like to utilize it to answer the question : What form of an initial droplet size distribution (iDSD) will guarantee an optimal flame ? To answer this question, I will first provide a general introduction to the GA method, then develop the combustion model, and eventually merge both into an optimization problem.
2102.11262
Lei Ding
Lei Ding, Hao Tang, Yahui Liu, Yilei Shi, Xiao Xiang Zhu and Lorenzo Bruzzone
Adversarial Shape Learning for Building Extraction in VHR Remote Sensing Images
null
null
10.1109/TIP.2021.3134455
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Building extraction in VHR RSIs remains a challenging task due to occlusion and boundary ambiguity problems. Although conventional convolutional neural networks (CNNs) based methods are capable of exploiting local texture and context information, they fail to capture the shape patterns of buildings, which is a necessary constraint in the human recognition. To address this issue, we propose an adversarial shape learning network (ASLNet) to model the building shape patterns that improve the accuracy of building segmentation. In the proposed ASLNet, we introduce the adversarial learning strategy to explicitly model the shape constraints, as well as a CNN shape regularizer to strengthen the embedding of shape features. To assess the geometric accuracy of building segmentation results, we introduced several object-based quality assessment metrics. Experiments on two open benchmark datasets show that the proposed ASLNet improves both the pixel-based accuracy and the object-based quality measurements by a large margin. The code is available at: https://github.com/ggsDing/ASLNet
[ { "created": "Mon, 22 Feb 2021 18:49:43 GMT", "version": "v1" }, { "created": "Thu, 25 Feb 2021 13:58:51 GMT", "version": "v2" }, { "created": "Tue, 9 Mar 2021 20:59:18 GMT", "version": "v3" }, { "created": "Wed, 17 Mar 2021 10:16:18 GMT", "version": "v4" }, { "created": "Tue, 30 Mar 2021 22:12:26 GMT", "version": "v5" }, { "created": "Sat, 18 Dec 2021 01:20:28 GMT", "version": "v6" } ]
2021-12-21
[ [ "Ding", "Lei", "" ], [ "Tang", "Hao", "" ], [ "Liu", "Yahui", "" ], [ "Shi", "Yilei", "" ], [ "Zhu", "Xiao Xiang", "" ], [ "Bruzzone", "Lorenzo", "" ] ]
Building extraction in VHR RSIs remains a challenging task due to occlusion and boundary ambiguity problems. Although conventional convolutional neural networks (CNNs) based methods are capable of exploiting local texture and context information, they fail to capture the shape patterns of buildings, which is a necessary constraint in the human recognition. To address this issue, we propose an adversarial shape learning network (ASLNet) to model the building shape patterns that improve the accuracy of building segmentation. In the proposed ASLNet, we introduce the adversarial learning strategy to explicitly model the shape constraints, as well as a CNN shape regularizer to strengthen the embedding of shape features. To assess the geometric accuracy of building segmentation results, we introduced several object-based quality assessment metrics. Experiments on two open benchmark datasets show that the proposed ASLNet improves both the pixel-based accuracy and the object-based quality measurements by a large margin. The code is available at: https://github.com/ggsDing/ASLNet
1907.10937
Mohsen Ghaffari
V\'aclav Rozho\v{n} and Mohsen Ghaffari
Polylogarithmic-Time Deterministic Network Decomposition and Distributed Derandomization
Extended version of an article that appears at the Symposium on Theory of Computing (STOC) 2020
null
null
null
cs.DS cs.DC cs.DM math.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a simple polylogarithmic-time deterministic distributed algorithm for network decomposition. This improves on a celebrated $2^{O(\sqrt{\log n})}$-time algorithm of Panconesi and Srinivasan [STOC'92] and settles a central and long-standing question in distributed graph algorithms. It also leads to the first polylogarithmic-time deterministic distributed algorithms for numerous other problems, hence resolving several well-known and decades-old open problems, including Linial's question about the deterministic complexity of maximal independent set [FOCS'87; SICOMP'92]---which had been called the most outstanding problem in the area. The main implication is a more general distributed derandomization theorem: Put together with the results of Ghaffari, Kuhn, and Maus [STOC'17] and Ghaffari, Harris, and Kuhn [FOCS'18], our network decomposition implies that $$\mathsf{P}\textit{-}\mathsf{RLOCAL} = \mathsf{P}\textit{-}\mathsf{LOCAL}.$$ That is, for any problem whose solution can be checked deterministically in polylogarithmic-time, any polylogarithmic-time randomized algorithm can be derandomized to a polylogarithmic-time deterministic algorithm. Informally, for the standard first-order interpretation of efficiency as polylogarithmic-time, distributed algorithms do not need randomness for efficiency. By known connections, our result leads also to substantially faster randomized distributed algorithms for a number of well-studied problems including $(\Delta+1)$-coloring, maximal independent set, and Lov\'{a}sz Local Lemma, as well as massively parallel algorithms for $(\Delta+1)$-coloring.
[ { "created": "Thu, 25 Jul 2019 10:01:49 GMT", "version": "v1" }, { "created": "Sun, 10 May 2020 18:24:18 GMT", "version": "v2" } ]
2020-05-12
[ [ "Rozhoň", "Václav", "" ], [ "Ghaffari", "Mohsen", "" ] ]
We present a simple polylogarithmic-time deterministic distributed algorithm for network decomposition. This improves on a celebrated $2^{O(\sqrt{\log n})}$-time algorithm of Panconesi and Srinivasan [STOC'92] and settles a central and long-standing question in distributed graph algorithms. It also leads to the first polylogarithmic-time deterministic distributed algorithms for numerous other problems, hence resolving several well-known and decades-old open problems, including Linial's question about the deterministic complexity of maximal independent set [FOCS'87; SICOMP'92]---which had been called the most outstanding problem in the area. The main implication is a more general distributed derandomization theorem: Put together with the results of Ghaffari, Kuhn, and Maus [STOC'17] and Ghaffari, Harris, and Kuhn [FOCS'18], our network decomposition implies that $$\mathsf{P}\textit{-}\mathsf{RLOCAL} = \mathsf{P}\textit{-}\mathsf{LOCAL}.$$ That is, for any problem whose solution can be checked deterministically in polylogarithmic-time, any polylogarithmic-time randomized algorithm can be derandomized to a polylogarithmic-time deterministic algorithm. Informally, for the standard first-order interpretation of efficiency as polylogarithmic-time, distributed algorithms do not need randomness for efficiency. By known connections, our result leads also to substantially faster randomized distributed algorithms for a number of well-studied problems including $(\Delta+1)$-coloring, maximal independent set, and Lov\'{a}sz Local Lemma, as well as massively parallel algorithms for $(\Delta+1)$-coloring.
2401.10122
Zhechen Li
Zhechen Li, Zimai Guo, Lirong Xia, Yongzhi Cao, Hanpin Wang
Differentially Private Approval-Based Committee Voting
null
null
null
null
cs.GT
http://creativecommons.org/licenses/by/4.0/
In this paper, we investigate tradeoffs between differential privacy (DP) and several voting axioms for approval-based committee voting, including proportionality, Pareto efficiency, Condorcet criterion, and strategyproofness. For all the axioms except strategyproofness, we show their incompatibility with DP, and provide both upper and lower bounds for their tradeoffs with DP. Furthermore, we show that any $\epsilon$-DP mechanism satisfies $e^{-\epsilon}$-cardinality strategyproofness, and the satisfaction can be further improved if the mechanism satisfies monotonicity.
[ { "created": "Thu, 18 Jan 2024 16:51:51 GMT", "version": "v1" } ]
2024-01-19
[ [ "Li", "Zhechen", "" ], [ "Guo", "Zimai", "" ], [ "Xia", "Lirong", "" ], [ "Cao", "Yongzhi", "" ], [ "Wang", "Hanpin", "" ] ]
In this paper, we investigate tradeoffs between differential privacy (DP) and several voting axioms for approval-based committee voting, including proportionality, Pareto efficiency, Condorcet criterion, and strategyproofness. For all the axioms except strategyproofness, we show their incompatibility with DP, and provide both upper and lower bounds for their tradeoffs with DP. Furthermore, we show that any $\epsilon$-DP mechanism satisfies $e^{-\epsilon}$-cardinality strategyproofness, and the satisfaction can be further improved if the mechanism satisfies monotonicity.
2303.10280
Ketul Shah
Arun V. Reddy, Ketul Shah, William Paul, Rohita Mocharla, Judy Hoffman, Kapil D. Katyal, Dinesh Manocha, Celso M. de Melo, Rama Chellappa
Synthetic-to-Real Domain Adaptation for Action Recognition: A Dataset and Baseline Performances
ICRA 2023. The first two authors contributed equally. Dataset available at: https://github.com/reddyav1/RoCoG-v2
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Human action recognition is a challenging problem, particularly when there is high variability in factors such as subject appearance, backgrounds and viewpoint. While deep neural networks (DNNs) have been shown to perform well on action recognition tasks, they typically require large amounts of high-quality labeled data to achieve robust performance across a variety of conditions. Synthetic data has shown promise as a way to avoid the substantial costs and potential ethical concerns associated with collecting and labeling enormous amounts of data in the real-world. However, synthetic data may differ from real data in important ways. This phenomenon, known as \textit{domain shift}, can limit the utility of synthetic data in robotics applications. To mitigate the effects of domain shift, substantial effort is being dedicated to the development of domain adaptation (DA) techniques. Yet, much remains to be understood about how best to develop these techniques. In this paper, we introduce a new dataset called Robot Control Gestures (RoCoG-v2). The dataset is composed of both real and synthetic videos from seven gesture classes, and is intended to support the study of synthetic-to-real domain shift for video-based action recognition. Our work expands upon existing datasets by focusing the action classes on gestures for human-robot teaming, as well as by enabling investigation of domain shift in both ground and aerial views. We present baseline results using state-of-the-art action recognition and domain adaptation algorithms and offer initial insight on tackling the synthetic-to-real and ground-to-air domain shifts.
[ { "created": "Fri, 17 Mar 2023 23:23:55 GMT", "version": "v1" }, { "created": "Thu, 1 Aug 2024 18:49:11 GMT", "version": "v2" } ]
2024-08-05
[ [ "Reddy", "Arun V.", "" ], [ "Shah", "Ketul", "" ], [ "Paul", "William", "" ], [ "Mocharla", "Rohita", "" ], [ "Hoffman", "Judy", "" ], [ "Katyal", "Kapil D.", "" ], [ "Manocha", "Dinesh", "" ], [ "de Melo", "Celso M.", "" ], [ "Chellappa", "Rama", "" ] ]
Human action recognition is a challenging problem, particularly when there is high variability in factors such as subject appearance, backgrounds and viewpoint. While deep neural networks (DNNs) have been shown to perform well on action recognition tasks, they typically require large amounts of high-quality labeled data to achieve robust performance across a variety of conditions. Synthetic data has shown promise as a way to avoid the substantial costs and potential ethical concerns associated with collecting and labeling enormous amounts of data in the real-world. However, synthetic data may differ from real data in important ways. This phenomenon, known as \textit{domain shift}, can limit the utility of synthetic data in robotics applications. To mitigate the effects of domain shift, substantial effort is being dedicated to the development of domain adaptation (DA) techniques. Yet, much remains to be understood about how best to develop these techniques. In this paper, we introduce a new dataset called Robot Control Gestures (RoCoG-v2). The dataset is composed of both real and synthetic videos from seven gesture classes, and is intended to support the study of synthetic-to-real domain shift for video-based action recognition. Our work expands upon existing datasets by focusing the action classes on gestures for human-robot teaming, as well as by enabling investigation of domain shift in both ground and aerial views. We present baseline results using state-of-the-art action recognition and domain adaptation algorithms and offer initial insight on tackling the synthetic-to-real and ground-to-air domain shifts.
2311.11396
Dmitry Kangin
Plamen Angelov, Dmitry Kangin, Ziyang Zhang
Towards interpretable-by-design deep learning algorithms
null
null
null
null
cs.LG
http://creativecommons.org/licenses/by-nc-sa/4.0/
The proposed framework named IDEAL (Interpretable-by-design DEep learning ALgorithms) recasts the standard supervised classification problem into a function of similarity to a set of prototypes derived from the training data, while taking advantage of existing latent spaces of large neural networks forming so-called Foundation Models (FM). This addresses the issue of explainability (stage B) while retaining the benefits from the tremendous achievements offered by DL models (e.g., visual transformers, ViT) pre-trained on huge data sets such as IG-3.6B + ImageNet-1K or LVD-142M (stage A). We show that one can turn such DL models into conceptually simpler, explainable-through-prototypes ones. The key findings can be summarized as follows: (1) the proposed models are interpretable through prototypes, mitigating the issue of confounded interpretations, (2) the proposed IDEAL framework circumvents the issue of catastrophic forgetting allowing efficient class-incremental learning, and (3) the proposed IDEAL approach demonstrates that ViT architectures narrow the gap between finetuned and non-finetuned models allowing for transfer learning in a fraction of time \textbf{without} finetuning of the feature space on a target dataset with iterative supervised methods.
[ { "created": "Sun, 19 Nov 2023 18:40:49 GMT", "version": "v1" } ]
2023-11-21
[ [ "Angelov", "Plamen", "" ], [ "Kangin", "Dmitry", "" ], [ "Zhang", "Ziyang", "" ] ]
The proposed framework named IDEAL (Interpretable-by-design DEep learning ALgorithms) recasts the standard supervised classification problem into a function of similarity to a set of prototypes derived from the training data, while taking advantage of existing latent spaces of large neural networks forming so-called Foundation Models (FM). This addresses the issue of explainability (stage B) while retaining the benefits from the tremendous achievements offered by DL models (e.g., visual transformers, ViT) pre-trained on huge data sets such as IG-3.6B + ImageNet-1K or LVD-142M (stage A). We show that one can turn such DL models into conceptually simpler, explainable-through-prototypes ones. The key findings can be summarized as follows: (1) the proposed models are interpretable through prototypes, mitigating the issue of confounded interpretations, (2) the proposed IDEAL framework circumvents the issue of catastrophic forgetting allowing efficient class-incremental learning, and (3) the proposed IDEAL approach demonstrates that ViT architectures narrow the gap between finetuned and non-finetuned models allowing for transfer learning in a fraction of time \textbf{without} finetuning of the feature space on a target dataset with iterative supervised methods.
2003.10895
Amir Livne
Amir Livne, Alex Bronstein, Ron Kimmel, Ziv Aviv, Shahaf Grofit
Do We Need Depth in State-Of-The-Art Face Authentication?
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Some face recognition methods are designed to utilize geometric information extracted from depth sensors to overcome the weaknesses of single-image based recognition technologies. However, the accurate acquisition of the depth profile is an expensive and challenging process. Here, we introduce a novel method that learns to recognize faces from stereo camera systems without the need to explicitly compute the facial surface or depth map. The raw face stereo images along with the location in the image from which the face is extracted allow the proposed CNN to improve the recognition task while avoiding the need to explicitly handle the geometric structure of the face. This way, we keep the simplicity and cost efficiency of identity authentication from a single image, while enjoying the benefits of geometric data without explicitly reconstructing it. We demonstrate that the suggested method outperforms both existing single-image and explicit depth based methods on large-scale benchmarks, and even capable of recognize spoofing attacks. We also provide an ablation study that shows that the suggested method uses the face locations in the left and right images to encode informative features that improve the overall performance.
[ { "created": "Tue, 24 Mar 2020 14:51:25 GMT", "version": "v1" }, { "created": "Tue, 10 Nov 2020 11:52:04 GMT", "version": "v2" } ]
2020-11-11
[ [ "Livne", "Amir", "" ], [ "Bronstein", "Alex", "" ], [ "Kimmel", "Ron", "" ], [ "Aviv", "Ziv", "" ], [ "Grofit", "Shahaf", "" ] ]
Some face recognition methods are designed to utilize geometric information extracted from depth sensors to overcome the weaknesses of single-image based recognition technologies. However, the accurate acquisition of the depth profile is an expensive and challenging process. Here, we introduce a novel method that learns to recognize faces from stereo camera systems without the need to explicitly compute the facial surface or depth map. The raw face stereo images along with the location in the image from which the face is extracted allow the proposed CNN to improve the recognition task while avoiding the need to explicitly handle the geometric structure of the face. This way, we keep the simplicity and cost efficiency of identity authentication from a single image, while enjoying the benefits of geometric data without explicitly reconstructing it. We demonstrate that the suggested method outperforms both existing single-image and explicit depth based methods on large-scale benchmarks, and even capable of recognize spoofing attacks. We also provide an ablation study that shows that the suggested method uses the face locations in the left and right images to encode informative features that improve the overall performance.
1707.05982
Sergey Triputen
Sergey Triputen, Kristiaan Schreve, Viktor Tkachev and Matthias Ratsch
Closed-form Solution for IMU based LSD-SLAM Point Cloud Conversion into the Scaled 3D World Environment
6 pages, 8 figures
null
null
null
cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
SLAM is a very popular research stream in computer vision and robotics nowadays. For more effective SLAM implementation it is necessary to have reliable informa- tion about the environment, also the data should be aligned and scaled according to the real world coordinate system. Monocular SLAM research is an attractive sub-stream, because of the low equipment cost, size and weight. In this paper we present a way to build a conversion from LSD-SLAM coordinate space to the real world coordinates using a true metric scale with IMU sensor data implementation. The causes of differences between the real and calculated spaces are explained and the possibility of conversions between the spaces is proved. Additionally, a closed-form solution for inter space trans- formation calculation is presented. The synthetic method of generating high level accurate and well controlled input data for the LSD-SLAM algorithm is presented. Finally, the reconstructed 3D environment representation is delivered as an output of the implemented conversion.
[ { "created": "Wed, 19 Jul 2017 08:56:04 GMT", "version": "v1" } ]
2017-07-20
[ [ "Triputen", "Sergey", "" ], [ "Schreve", "Kristiaan", "" ], [ "Tkachev", "Viktor", "" ], [ "Ratsch", "Matthias", "" ] ]
SLAM is a very popular research stream in computer vision and robotics nowadays. For more effective SLAM implementation it is necessary to have reliable informa- tion about the environment, also the data should be aligned and scaled according to the real world coordinate system. Monocular SLAM research is an attractive sub-stream, because of the low equipment cost, size and weight. In this paper we present a way to build a conversion from LSD-SLAM coordinate space to the real world coordinates using a true metric scale with IMU sensor data implementation. The causes of differences between the real and calculated spaces are explained and the possibility of conversions between the spaces is proved. Additionally, a closed-form solution for inter space trans- formation calculation is presented. The synthetic method of generating high level accurate and well controlled input data for the LSD-SLAM algorithm is presented. Finally, the reconstructed 3D environment representation is delivered as an output of the implemented conversion.
2403.12945
Karl Pertsch
Alexander Khazatsky, Karl Pertsch, Suraj Nair, Ashwin Balakrishna, Sudeep Dasari, Siddharth Karamcheti, Soroush Nasiriany, Mohan Kumar Srirama, Lawrence Yunliang Chen, Kirsty Ellis, Peter David Fagan, Joey Hejna, Masha Itkina, Marion Lepert, Yecheng Jason Ma, Patrick Tree Miller, Jimmy Wu, Suneel Belkhale, Shivin Dass, Huy Ha, Arhan Jain, Abraham Lee, Youngwoon Lee, Marius Memmel, Sungjae Park, Ilija Radosavovic, Kaiyuan Wang, Albert Zhan, Kevin Black, Cheng Chi, Kyle Beltran Hatch, Shan Lin, Jingpei Lu, Jean Mercat, Abdul Rehman, Pannag R Sanketi, Archit Sharma, Cody Simpson, Quan Vuong, Homer Rich Walke, Blake Wulfe, Ted Xiao, Jonathan Heewon Yang, Arefeh Yavary, Tony Z. Zhao, Christopher Agia, Rohan Baijal, Mateo Guaman Castro, Daphne Chen, Qiuyu Chen, Trinity Chung, Jaimyn Drake, Ethan Paul Foster, Jensen Gao, David Antonio Herrera, Minho Heo, Kyle Hsu, Jiaheng Hu, Donovon Jackson, Charlotte Le, Yunshuang Li, Kevin Lin, Roy Lin, Zehan Ma, Abhiram Maddukuri, Suvir Mirchandani, Daniel Morton, Tony Nguyen, Abigail O'Neill, Rosario Scalise, Derick Seale, Victor Son, Stephen Tian, Emi Tran, Andrew E. Wang, Yilin Wu, Annie Xie, Jingyun Yang, Patrick Yin, Yunchu Zhang, Osbert Bastani, Glen Berseth, Jeannette Bohg, Ken Goldberg, Abhinav Gupta, Abhishek Gupta, Dinesh Jayaraman, Joseph J Lim, Jitendra Malik, Roberto Mart\'in-Mart\'in, Subramanian Ramamoorthy, Dorsa Sadigh, Shuran Song, Jiajun Wu, Michael C. Yip, Yuke Zhu, Thomas Kollar, Sergey Levine, Chelsea Finn
DROID: A Large-Scale In-The-Wild Robot Manipulation Dataset
Project website: https://droid-dataset.github.io/
null
null
null
cs.RO
http://creativecommons.org/licenses/by/4.0/
The creation of large, diverse, high-quality robot manipulation datasets is an important stepping stone on the path toward more capable and robust robotic manipulation policies. However, creating such datasets is challenging: collecting robot manipulation data in diverse environments poses logistical and safety challenges and requires substantial investments in hardware and human labour. As a result, even the most general robot manipulation policies today are mostly trained on data collected in a small number of environments with limited scene and task diversity. In this work, we introduce DROID (Distributed Robot Interaction Dataset), a diverse robot manipulation dataset with 76k demonstration trajectories or 350 hours of interaction data, collected across 564 scenes and 84 tasks by 50 data collectors in North America, Asia, and Europe over the course of 12 months. We demonstrate that training with DROID leads to policies with higher performance and improved generalization ability. We open source the full dataset, policy learning code, and a detailed guide for reproducing our robot hardware setup.
[ { "created": "Tue, 19 Mar 2024 17:48:38 GMT", "version": "v1" } ]
2024-03-20
[ [ "Khazatsky", "Alexander", "" ], [ "Pertsch", "Karl", "" ], [ "Nair", "Suraj", "" ], [ "Balakrishna", "Ashwin", "" ], [ "Dasari", "Sudeep", "" ], [ "Karamcheti", "Siddharth", "" ], [ "Nasiriany", "Soroush", "" ], [ "Srirama", "Mohan Kumar", "" ], [ "Chen", "Lawrence Yunliang", "" ], [ "Ellis", "Kirsty", "" ], [ "Fagan", "Peter David", "" ], [ "Hejna", "Joey", "" ], [ "Itkina", "Masha", "" ], [ "Lepert", "Marion", "" ], [ "Ma", "Yecheng Jason", "" ], [ "Miller", "Patrick Tree", "" ], [ "Wu", "Jimmy", "" ], [ "Belkhale", "Suneel", "" ], [ "Dass", "Shivin", "" ], [ "Ha", "Huy", "" ], [ "Jain", "Arhan", "" ], [ "Lee", "Abraham", "" ], [ "Lee", "Youngwoon", "" ], [ "Memmel", "Marius", "" ], [ "Park", "Sungjae", "" ], [ "Radosavovic", "Ilija", "" ], [ "Wang", "Kaiyuan", "" ], [ "Zhan", "Albert", "" ], [ "Black", "Kevin", "" ], [ "Chi", "Cheng", "" ], [ "Hatch", "Kyle Beltran", "" ], [ "Lin", "Shan", "" ], [ "Lu", "Jingpei", "" ], [ "Mercat", "Jean", "" ], [ "Rehman", "Abdul", "" ], [ "Sanketi", "Pannag R", "" ], [ "Sharma", "Archit", "" ], [ "Simpson", "Cody", "" ], [ "Vuong", "Quan", "" ], [ "Walke", "Homer Rich", "" ], [ "Wulfe", "Blake", "" ], [ "Xiao", "Ted", "" ], [ "Yang", "Jonathan Heewon", "" ], [ "Yavary", "Arefeh", "" ], [ "Zhao", "Tony Z.", "" ], [ "Agia", "Christopher", "" ], [ "Baijal", "Rohan", "" ], [ "Castro", "Mateo Guaman", "" ], [ "Chen", "Daphne", "" ], [ "Chen", "Qiuyu", "" ], [ "Chung", "Trinity", "" ], [ "Drake", "Jaimyn", "" ], [ "Foster", "Ethan Paul", "" ], [ "Gao", "Jensen", "" ], [ "Herrera", "David Antonio", "" ], [ "Heo", "Minho", "" ], [ "Hsu", "Kyle", "" ], [ "Hu", "Jiaheng", "" ], [ "Jackson", "Donovon", "" ], [ "Le", "Charlotte", "" ], [ "Li", "Yunshuang", "" ], [ "Lin", "Kevin", "" ], [ "Lin", "Roy", "" ], [ "Ma", "Zehan", "" ], [ "Maddukuri", "Abhiram", "" ], [ "Mirchandani", "Suvir", "" ], [ "Morton", "Daniel", "" ], [ "Nguyen", "Tony", "" ], [ "O'Neill", "Abigail", "" ], [ "Scalise", "Rosario", "" ], [ "Seale", "Derick", "" ], [ "Son", "Victor", "" ], [ "Tian", "Stephen", "" ], [ "Tran", "Emi", "" ], [ "Wang", "Andrew E.", "" ], [ "Wu", "Yilin", "" ], [ "Xie", "Annie", "" ], [ "Yang", "Jingyun", "" ], [ "Yin", "Patrick", "" ], [ "Zhang", "Yunchu", "" ], [ "Bastani", "Osbert", "" ], [ "Berseth", "Glen", "" ], [ "Bohg", "Jeannette", "" ], [ "Goldberg", "Ken", "" ], [ "Gupta", "Abhinav", "" ], [ "Gupta", "Abhishek", "" ], [ "Jayaraman", "Dinesh", "" ], [ "Lim", "Joseph J", "" ], [ "Malik", "Jitendra", "" ], [ "Martín-Martín", "Roberto", "" ], [ "Ramamoorthy", "Subramanian", "" ], [ "Sadigh", "Dorsa", "" ], [ "Song", "Shuran", "" ], [ "Wu", "Jiajun", "" ], [ "Yip", "Michael C.", "" ], [ "Zhu", "Yuke", "" ], [ "Kollar", "Thomas", "" ], [ "Levine", "Sergey", "" ], [ "Finn", "Chelsea", "" ] ]
The creation of large, diverse, high-quality robot manipulation datasets is an important stepping stone on the path toward more capable and robust robotic manipulation policies. However, creating such datasets is challenging: collecting robot manipulation data in diverse environments poses logistical and safety challenges and requires substantial investments in hardware and human labour. As a result, even the most general robot manipulation policies today are mostly trained on data collected in a small number of environments with limited scene and task diversity. In this work, we introduce DROID (Distributed Robot Interaction Dataset), a diverse robot manipulation dataset with 76k demonstration trajectories or 350 hours of interaction data, collected across 564 scenes and 84 tasks by 50 data collectors in North America, Asia, and Europe over the course of 12 months. We demonstrate that training with DROID leads to policies with higher performance and improved generalization ability. We open source the full dataset, policy learning code, and a detailed guide for reproducing our robot hardware setup.
0906.0798
Subhash Kak
Subhash Kak
Single Neuron Memories and the Network's Proximity Matrix
10 pages
null
null
null
cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper extends the treatment of single-neuron memories obtained by the B-matrix approach. The spreading of the activity within the network is determined by the network's proximity matrix which represents the separations amongst the neurons through the neural pathways.
[ { "created": "Wed, 3 Jun 2009 23:10:25 GMT", "version": "v1" } ]
2009-06-05
[ [ "Kak", "Subhash", "" ] ]
This paper extends the treatment of single-neuron memories obtained by the B-matrix approach. The spreading of the activity within the network is determined by the network's proximity matrix which represents the separations amongst the neurons through the neural pathways.
2305.07598
Hakjin Lee
Hakjin Lee, Minki Song, Jamyoung Koo, Junghoon Seo
Hausdorff Distance Matching with Adaptive Query Denoising for Rotated Detection Transformer
Under review, 16 pages, 12 tables, 8 figures
null
null
null
cs.CV cs.LG
http://creativecommons.org/licenses/by/4.0/
The Detection Transformer (DETR) has emerged as a pivotal role in object detection tasks, setting new performance benchmarks due to its end-to-end design and scalability. Despite its advancements, the application of DETR in detecting rotated objects has demonstrated suboptimal performance relative to established oriented object detectors. Our analysis identifies a key limitation: the L1 cost used in Hungarian Matching leads to duplicate predictions due to the square-like problem in oriented object detection, thereby obstructing the training process of the detector. We introduce a Hausdorff distance-based cost for Hungarian matching, which more accurately quantifies the discrepancy between predictions and ground truths. Moreover, we note that a static denoising approach hampers the training of rotated DETR, particularly when the detector's predictions surpass the quality of noised ground truths. We propose an adaptive query denoising technique, employing Hungarian matching to selectively filter out superfluous noised queries that no longer contribute to model improvement. Our proposed modifications to DETR have resulted in superior performance, surpassing previous rotated DETR models and other alternatives. This is evidenced by our model's state-of-the-art achievements in benchmarks such as DOTA-v1.0/v1.5/v2.0, and DIOR-R.
[ { "created": "Fri, 12 May 2023 16:42:54 GMT", "version": "v1" }, { "created": "Mon, 15 May 2023 07:01:45 GMT", "version": "v2" }, { "created": "Tue, 6 Jun 2023 09:06:28 GMT", "version": "v3" }, { "created": "Wed, 29 Nov 2023 08:56:29 GMT", "version": "v4" } ]
2023-11-30
[ [ "Lee", "Hakjin", "" ], [ "Song", "Minki", "" ], [ "Koo", "Jamyoung", "" ], [ "Seo", "Junghoon", "" ] ]
The Detection Transformer (DETR) has emerged as a pivotal role in object detection tasks, setting new performance benchmarks due to its end-to-end design and scalability. Despite its advancements, the application of DETR in detecting rotated objects has demonstrated suboptimal performance relative to established oriented object detectors. Our analysis identifies a key limitation: the L1 cost used in Hungarian Matching leads to duplicate predictions due to the square-like problem in oriented object detection, thereby obstructing the training process of the detector. We introduce a Hausdorff distance-based cost for Hungarian matching, which more accurately quantifies the discrepancy between predictions and ground truths. Moreover, we note that a static denoising approach hampers the training of rotated DETR, particularly when the detector's predictions surpass the quality of noised ground truths. We propose an adaptive query denoising technique, employing Hungarian matching to selectively filter out superfluous noised queries that no longer contribute to model improvement. Our proposed modifications to DETR have resulted in superior performance, surpassing previous rotated DETR models and other alternatives. This is evidenced by our model's state-of-the-art achievements in benchmarks such as DOTA-v1.0/v1.5/v2.0, and DIOR-R.
1510.04221
Venet Osmani
Enrique Garcia-Ceja, Venet Osmani, Oscar Mayora
Automatic Stress Detection in Working Environments from Smartphones' Accelerometer Data: A First Step
in IEEE Journal of Biomedical and Health Informatics, 2015
null
10.1109/JBHI.2015.2446195
null
cs.HC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Increase in workload across many organisations and consequent increase in occupational stress is negatively affecting the health of the workforce. Measuring stress and other human psychological dynamics is difficult due to subjective nature of self- reporting and variability between and within individuals. With the advent of smartphones it is now possible to monitor diverse aspects of human behaviour, including objectively measured behaviour related to psychological state and consequently stress. We have used data from the smartphone's built-in accelerometer to detect behaviour that correlates with subjects stress levels. Accelerometer sensor was chosen because it raises fewer privacy concerns (in comparison to location, video or audio recording, for example) and because its low power consumption makes it suitable to be embedded in smaller wearable devices, such as fitness trackers. 30 subjects from two different organizations were provided with smartphones. The study lasted for 8 weeks and was conducted in real working environments, with no constraints whatsoever placed upon smartphone usage. The subjects reported their perceived stress levels three times during their working hours. Using combination of statistical models to classify self reported stress levels, we achieved a maximum overall accuracy of 71% for user-specific models and an accuracy of 60% for the use of similar-users models, relying solely on data from a single accelerometer.
[ { "created": "Wed, 14 Oct 2015 18:10:28 GMT", "version": "v1" } ]
2015-10-15
[ [ "Garcia-Ceja", "Enrique", "" ], [ "Osmani", "Venet", "" ], [ "Mayora", "Oscar", "" ] ]
Increase in workload across many organisations and consequent increase in occupational stress is negatively affecting the health of the workforce. Measuring stress and other human psychological dynamics is difficult due to subjective nature of self- reporting and variability between and within individuals. With the advent of smartphones it is now possible to monitor diverse aspects of human behaviour, including objectively measured behaviour related to psychological state and consequently stress. We have used data from the smartphone's built-in accelerometer to detect behaviour that correlates with subjects stress levels. Accelerometer sensor was chosen because it raises fewer privacy concerns (in comparison to location, video or audio recording, for example) and because its low power consumption makes it suitable to be embedded in smaller wearable devices, such as fitness trackers. 30 subjects from two different organizations were provided with smartphones. The study lasted for 8 weeks and was conducted in real working environments, with no constraints whatsoever placed upon smartphone usage. The subjects reported their perceived stress levels three times during their working hours. Using combination of statistical models to classify self reported stress levels, we achieved a maximum overall accuracy of 71% for user-specific models and an accuracy of 60% for the use of similar-users models, relying solely on data from a single accelerometer.
1906.04777
Pieter Peers
Victoria L. Cooper, James C. Bieron, Pieter Peers
Estimating Homogeneous Data-driven BRDF Parameters from a Reflectance Map under Known Natural Lighting
null
null
null
null
cs.GR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we demonstrate robust estimation of the model parameters of a fully-linear data-driven BRDF model from a reflectance map under known natural lighting. To regularize the estimation of the model parameters, we leverage the reflectance similarities within a material class. We approximate the space of homogeneous BRDFs using a Gaussian mixture model, and assign a material class to each Gaussian in the mixture model. We formulate the estimation of the model parameters as a non-linear maximum a-posteriori optimization, and introduce a linear approximation that estimates a solution per material class from which the best solution is selected. We demonstrate the efficacy and robustness of our method using the MERL BRDF database under a variety of natural lighting conditions, and we provide a proof-of-concept real-world experiment.
[ { "created": "Tue, 11 Jun 2019 19:28:09 GMT", "version": "v1" } ]
2019-06-13
[ [ "Cooper", "Victoria L.", "" ], [ "Bieron", "James C.", "" ], [ "Peers", "Pieter", "" ] ]
In this paper we demonstrate robust estimation of the model parameters of a fully-linear data-driven BRDF model from a reflectance map under known natural lighting. To regularize the estimation of the model parameters, we leverage the reflectance similarities within a material class. We approximate the space of homogeneous BRDFs using a Gaussian mixture model, and assign a material class to each Gaussian in the mixture model. We formulate the estimation of the model parameters as a non-linear maximum a-posteriori optimization, and introduce a linear approximation that estimates a solution per material class from which the best solution is selected. We demonstrate the efficacy and robustness of our method using the MERL BRDF database under a variety of natural lighting conditions, and we provide a proof-of-concept real-world experiment.
1904.11563
Suayb Arslan
Suayb S. Arslan
Array BP-XOR Codes for Hierarchically Distributed Matrix Multiplication
22 pages, 5 figures, 4 tables. Accepted to IEEE Transactions on Information Theory, 2021. arXiv admin note: text overlap with arXiv:1709.07949
null
10.1109/TIT.2021.3132043
null
cs.IT cs.DC math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A novel fault-tolerant computation technique based on array Belief Propagation (BP)-decodable XOR (BP-XOR) codes is proposed for distributed matrix-matrix multiplication. The proposed scheme is shown to be configurable and suited for modern hierarchical compute architectures such as Graphical Processing Units (GPUs) equipped with multiple nodes, whereby each has many small independent processing units with increased core-to-core communications. The proposed scheme is shown to outperform a few of the well--known earlier strategies in terms of total end-to-end execution time while in presence of slow nodes, called $stragglers$. This performance advantage is due to the careful design of array codes which distributes the encoding operation over the cluster (slave) nodes at the expense of increased master-slave communication. An interesting trade-off between end-to-end latency and total communication cost is precisely described. In addition, to be able to address an identified problem of scaling stragglers, an asymptotic version of array BP-XOR codes based on projection geometry is proposed at the expense of some computation overhead. A thorough latency analysis is conducted for all schemes to demonstrate that the proposed scheme achieves order-optimal computation in both the sublinear as well as the linear regimes in the size of the computed product from an end-to-end delay perspective.
[ { "created": "Thu, 25 Apr 2019 19:59:47 GMT", "version": "v1" }, { "created": "Mon, 13 May 2019 16:28:32 GMT", "version": "v2" }, { "created": "Fri, 10 Dec 2021 12:33:11 GMT", "version": "v3" } ]
2021-12-13
[ [ "Arslan", "Suayb S.", "" ] ]
A novel fault-tolerant computation technique based on array Belief Propagation (BP)-decodable XOR (BP-XOR) codes is proposed for distributed matrix-matrix multiplication. The proposed scheme is shown to be configurable and suited for modern hierarchical compute architectures such as Graphical Processing Units (GPUs) equipped with multiple nodes, whereby each has many small independent processing units with increased core-to-core communications. The proposed scheme is shown to outperform a few of the well--known earlier strategies in terms of total end-to-end execution time while in presence of slow nodes, called $stragglers$. This performance advantage is due to the careful design of array codes which distributes the encoding operation over the cluster (slave) nodes at the expense of increased master-slave communication. An interesting trade-off between end-to-end latency and total communication cost is precisely described. In addition, to be able to address an identified problem of scaling stragglers, an asymptotic version of array BP-XOR codes based on projection geometry is proposed at the expense of some computation overhead. A thorough latency analysis is conducted for all schemes to demonstrate that the proposed scheme achieves order-optimal computation in both the sublinear as well as the linear regimes in the size of the computed product from an end-to-end delay perspective.
1902.03534
Ali Vakilian
Piotr Indyk, Sepideh Mahabadi, Ronitt Rubinfeld, Ali Vakilian, Anak Yodpinyanee
Set Cover in Sub-linear Time
null
null
null
null
cs.DS cs.DM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the classic set cover problem from the perspective of sub-linear algorithms. Given access to a collection of $m$ sets over $n$ elements in the query model, we show that sub-linear algorithms derived from existing techniques have almost tight query complexities. On one hand, first we show an adaptation of the streaming algorithm presented in Har-Peled et al. [2016] to the sub-linear query model, that returns an $\alpha$-approximate cover using $\tilde{O}(m(n/k)^{1/(\alpha-1)} + nk)$ queries to the input, where $k$ denotes the value of a minimum set cover. We then complement this upper bound by proving that for lower values of $k$, the required number of queries is $\tilde{\Omega}(m(n/k)^{1/(2\alpha)})$, even for estimating the optimal cover size. Moreover, we prove that even checking whether a given collection of sets covers all the elements would require $\Omega(nk)$ queries. These two lower bounds provide strong evidence that the upper bound is almost tight for certain values of the parameter $k$. On the other hand, we show that this bound is not optimal for larger values of the parameter $k$, as there exists a $(1+\varepsilon)$-approximation algorithm with $\tilde{O}(mn/k\varepsilon^2)$ queries. We show that this bound is essentially tight for sufficiently small constant $\varepsilon$, by establishing a lower bound of $\tilde{\Omega}(mn/k)$ query complexity.
[ { "created": "Sun, 10 Feb 2019 04:10:34 GMT", "version": "v1" } ]
2019-02-12
[ [ "Indyk", "Piotr", "" ], [ "Mahabadi", "Sepideh", "" ], [ "Rubinfeld", "Ronitt", "" ], [ "Vakilian", "Ali", "" ], [ "Yodpinyanee", "Anak", "" ] ]
We study the classic set cover problem from the perspective of sub-linear algorithms. Given access to a collection of $m$ sets over $n$ elements in the query model, we show that sub-linear algorithms derived from existing techniques have almost tight query complexities. On one hand, first we show an adaptation of the streaming algorithm presented in Har-Peled et al. [2016] to the sub-linear query model, that returns an $\alpha$-approximate cover using $\tilde{O}(m(n/k)^{1/(\alpha-1)} + nk)$ queries to the input, where $k$ denotes the value of a minimum set cover. We then complement this upper bound by proving that for lower values of $k$, the required number of queries is $\tilde{\Omega}(m(n/k)^{1/(2\alpha)})$, even for estimating the optimal cover size. Moreover, we prove that even checking whether a given collection of sets covers all the elements would require $\Omega(nk)$ queries. These two lower bounds provide strong evidence that the upper bound is almost tight for certain values of the parameter $k$. On the other hand, we show that this bound is not optimal for larger values of the parameter $k$, as there exists a $(1+\varepsilon)$-approximation algorithm with $\tilde{O}(mn/k\varepsilon^2)$ queries. We show that this bound is essentially tight for sufficiently small constant $\varepsilon$, by establishing a lower bound of $\tilde{\Omega}(mn/k)$ query complexity.
1709.10063
Sebastian Kuhnert
V. Arvind, Johannes K\"obler, Sebastian Kuhnert and Jacobo Toran
Finding Small Weight Isomorphisms with Additional Constraints is Fixed-Parameter Tractable
An extended abstract of this article appears in the proceedings of IPEC 2017
null
null
null
cs.CC math.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lubiw showed that several variants of Graph Isomorphism are NP-complete, where the solutions are required to satisfy certain additional constraints [SICOMP 10, 1981]. One of these, called Isomorphism With Restrictions, is to decide for two given graphs $X_1=(V,E_1)$ and $X_2=(V,E_2)$ and a subset $R\subseteq V\times V$ of forbidden pairs whether there is an isomorphism $\pi$ from $X_1$ to $X_2$ such that $\pi(i)\neq j$ for all $(i,j)\in R$. We prove that this problem and several of its generalizations are in fact in FPT: - The problem of deciding whether there is an isomorphism between two graphs that moves k vertices and satisfies Lubiw-style constraints is in FPT, with k and the size of $R$ as parameters. The problem remains in FPT if a CNF of such constraints is allowed. It follows that the problem to decide whether there is an isomorphism that moves exactly k vertices is in FPT. This solves a question left open in our article on exact weight automorphisms [STACS 2017]. - When the weight and complexity are unrestricted, finding isomorphisms that satisfy a CNF of Lubiw-style constraints can be solved in FPT with access to a GI oracle. - Checking if there is an isomorphism $\pi$ between two graphs with complexity t is also in FPT with t as parameter, where the complexity of a permutation is the Cayley measure defined as the minimum number t such that $\pi$ can be expressed as a product of t transpositions. - We consider a more general problem in which the vertex set of a graph X is partitioned into Red and Blue, and we are interested in an automorphism that stabilizes Red and Blue and moves exactly k vertices in Blue, where k is the parameter. This problem was introduced by [Downey and Fellows 1999], and we showed [STACS 2017] that it is W[1]-hard even with color classes of size 4 inside Red. Now, for color classes of size at most 3 inside Red, we show the problem is in FPT.
[ { "created": "Thu, 28 Sep 2017 17:08:11 GMT", "version": "v1" } ]
2017-09-29
[ [ "Arvind", "V.", "" ], [ "Köbler", "Johannes", "" ], [ "Kuhnert", "Sebastian", "" ], [ "Toran", "Jacobo", "" ] ]
Lubiw showed that several variants of Graph Isomorphism are NP-complete, where the solutions are required to satisfy certain additional constraints [SICOMP 10, 1981]. One of these, called Isomorphism With Restrictions, is to decide for two given graphs $X_1=(V,E_1)$ and $X_2=(V,E_2)$ and a subset $R\subseteq V\times V$ of forbidden pairs whether there is an isomorphism $\pi$ from $X_1$ to $X_2$ such that $\pi(i)\neq j$ for all $(i,j)\in R$. We prove that this problem and several of its generalizations are in fact in FPT: - The problem of deciding whether there is an isomorphism between two graphs that moves k vertices and satisfies Lubiw-style constraints is in FPT, with k and the size of $R$ as parameters. The problem remains in FPT if a CNF of such constraints is allowed. It follows that the problem to decide whether there is an isomorphism that moves exactly k vertices is in FPT. This solves a question left open in our article on exact weight automorphisms [STACS 2017]. - When the weight and complexity are unrestricted, finding isomorphisms that satisfy a CNF of Lubiw-style constraints can be solved in FPT with access to a GI oracle. - Checking if there is an isomorphism $\pi$ between two graphs with complexity t is also in FPT with t as parameter, where the complexity of a permutation is the Cayley measure defined as the minimum number t such that $\pi$ can be expressed as a product of t transpositions. - We consider a more general problem in which the vertex set of a graph X is partitioned into Red and Blue, and we are interested in an automorphism that stabilizes Red and Blue and moves exactly k vertices in Blue, where k is the parameter. This problem was introduced by [Downey and Fellows 1999], and we showed [STACS 2017] that it is W[1]-hard even with color classes of size 4 inside Red. Now, for color classes of size at most 3 inside Red, we show the problem is in FPT.
2407.19484
Hao Shi
Zhengyi Jiang, Hao Shi, Zhongyi Huang, Linqi Song, Bo Bai, Gong Zhang, Hanxu Hou
Error Correction Decoding Algorithms of RS Codes Based on An Earlier Termination Algorithm to Find The Error Locator Polynomial
null
null
null
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Reed-Solomon (RS) codes are widely used to correct errors in storage systems. Finding the error locator polynomial is one of the key steps in the error correction procedure of RS codes. Modular Approach (MA) is an effective algorithm for solving the Welch-Berlekamp (WB) key-equation problem to find the error locator polynomial that needs $2t$ steps, where $t$ is the error correction capability. In this paper, we first present a new MA algorithm that only requires $2e$ steps and then propose two fast decoding algorithms for RS codes based on our MA algorithm, where $e$ is the number of errors and $e\leq t$. We propose Improved-Frequency Domain Modular Approach (I-FDMA) algorithm that needs $2e$ steps to solve the error locator polynomial and present our first decoding algorithm based on the I-FDMA algorithm. We show that, compared with the existing methods based on MA algorithms, our I-FDMA algorithm can effectively reduce the decoding complexity of RS codes when $e<t$. Furthermore, we propose the $t_0$-Shortened I-FDMA ($t_0$-SI-FDMA) algorithm ($t_0$ is a predetermined even number less than $2t-1$) based on the new termination mechanism to solve the error number $e$ quickly. We propose our second decoding algorithm based on the SI-FDMA algorithm for RS codes and show that the multiplication complexity of our second decoding algorithm is lower than our first decoding algorithm (the I-FDMA decoding algorithm) when $2e<t_0+1$.
[ { "created": "Sun, 28 Jul 2024 12:32:07 GMT", "version": "v1" } ]
2024-07-30
[ [ "Jiang", "Zhengyi", "" ], [ "Shi", "Hao", "" ], [ "Huang", "Zhongyi", "" ], [ "Song", "Linqi", "" ], [ "Bai", "Bo", "" ], [ "Zhang", "Gong", "" ], [ "Hou", "Hanxu", "" ] ]
Reed-Solomon (RS) codes are widely used to correct errors in storage systems. Finding the error locator polynomial is one of the key steps in the error correction procedure of RS codes. Modular Approach (MA) is an effective algorithm for solving the Welch-Berlekamp (WB) key-equation problem to find the error locator polynomial that needs $2t$ steps, where $t$ is the error correction capability. In this paper, we first present a new MA algorithm that only requires $2e$ steps and then propose two fast decoding algorithms for RS codes based on our MA algorithm, where $e$ is the number of errors and $e\leq t$. We propose Improved-Frequency Domain Modular Approach (I-FDMA) algorithm that needs $2e$ steps to solve the error locator polynomial and present our first decoding algorithm based on the I-FDMA algorithm. We show that, compared with the existing methods based on MA algorithms, our I-FDMA algorithm can effectively reduce the decoding complexity of RS codes when $e<t$. Furthermore, we propose the $t_0$-Shortened I-FDMA ($t_0$-SI-FDMA) algorithm ($t_0$ is a predetermined even number less than $2t-1$) based on the new termination mechanism to solve the error number $e$ quickly. We propose our second decoding algorithm based on the SI-FDMA algorithm for RS codes and show that the multiplication complexity of our second decoding algorithm is lower than our first decoding algorithm (the I-FDMA decoding algorithm) when $2e<t_0+1$.
1904.06118
Elgin Akp{\i}nar
Elgin Akp{\i}nar, Yeliz Ye\c{s}ilada, Selim Temizer
Ability and Context Based Adaptive System: A Proposal for Machine Learning Approach
Presented at the CHI'19 Workshop: Addressing the Challenges of Situationally-Induced Impairments and Disabilities in Mobile Interaction, 2019 (arXiv:1904.05382)
null
null
SIID/2019/no02
cs.HC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
When we interact with small screen devices, sometimes we make errors, due to our abilities/disabilities, contextual factors that distract our attention or problems related to the interface. Recovering from these errors may be time consuming or cause frustration. Predicting and learning these errors based on the previous user interaction and contextual factors, and adapting user interface to prevent from these errors can improve user performance and satisfaction. In this paper, we propose a system that aims to monitor user performance and contextual changes and do adaptations based on the user performance by using machine learning techniques. Here, we briefly present our systematic literature review findings and discuss our research questions towards developing such an adaptive system.
[ { "created": "Fri, 12 Apr 2019 09:24:34 GMT", "version": "v1" } ]
2019-04-15
[ [ "Akpınar", "Elgin", "" ], [ "Yeşilada", "Yeliz", "" ], [ "Temizer", "Selim", "" ] ]
When we interact with small screen devices, sometimes we make errors, due to our abilities/disabilities, contextual factors that distract our attention or problems related to the interface. Recovering from these errors may be time consuming or cause frustration. Predicting and learning these errors based on the previous user interaction and contextual factors, and adapting user interface to prevent from these errors can improve user performance and satisfaction. In this paper, we propose a system that aims to monitor user performance and contextual changes and do adaptations based on the user performance by using machine learning techniques. Here, we briefly present our systematic literature review findings and discuss our research questions towards developing such an adaptive system.
2312.11559
Harris Papadopoulos
Harris Papadopoulos and Nestoras Georgiou and Charalambos Eliades and Andreas Konstantinidis
Android Malware Detection with Unbiased Confidence Guarantees
null
Neurocomputing, Volume 280, Pages 3-12, 2018
10.1016/j.neucom.2017.08.072
null
cs.CR cs.LG
http://creativecommons.org/licenses/by-nc-nd/4.0/
The impressive growth of smartphone devices in combination with the rising ubiquity of using mobile platforms for sensitive applications such as Internet banking, have triggered a rapid increase in mobile malware. In recent literature, many studies examine Machine Learning techniques, as the most promising approach for mobile malware detection, without however quantifying the uncertainty involved in their detections. In this paper, we address this problem by proposing a machine learning dynamic analysis approach that provides provably valid confidence guarantees in each malware detection. Moreover the particular guarantees hold for both the malicious and benign classes independently and are unaffected by any bias in the data. The proposed approach is based on a novel machine learning framework, called Conformal Prediction, combined with a random forests classifier. We examine its performance on a large-scale dataset collected by installing 1866 malicious and 4816 benign applications on a real android device. We make this collection of dynamic analysis data available to the research community. The obtained experimental results demonstrate the empirical validity, usefulness and unbiased nature of the outputs produced by the proposed approach.
[ { "created": "Sun, 17 Dec 2023 11:07:31 GMT", "version": "v1" } ]
2023-12-20
[ [ "Papadopoulos", "Harris", "" ], [ "Georgiou", "Nestoras", "" ], [ "Eliades", "Charalambos", "" ], [ "Konstantinidis", "Andreas", "" ] ]
The impressive growth of smartphone devices in combination with the rising ubiquity of using mobile platforms for sensitive applications such as Internet banking, have triggered a rapid increase in mobile malware. In recent literature, many studies examine Machine Learning techniques, as the most promising approach for mobile malware detection, without however quantifying the uncertainty involved in their detections. In this paper, we address this problem by proposing a machine learning dynamic analysis approach that provides provably valid confidence guarantees in each malware detection. Moreover the particular guarantees hold for both the malicious and benign classes independently and are unaffected by any bias in the data. The proposed approach is based on a novel machine learning framework, called Conformal Prediction, combined with a random forests classifier. We examine its performance on a large-scale dataset collected by installing 1866 malicious and 4816 benign applications on a real android device. We make this collection of dynamic analysis data available to the research community. The obtained experimental results demonstrate the empirical validity, usefulness and unbiased nature of the outputs produced by the proposed approach.
2203.03038
Ashkan Jasour
Weiqiao Han and Ashkan Jasour and Brian Williams
Non-Gaussian Risk Bounded Trajectory Optimization for Stochastic Nonlinear Systems in Uncertain Environments
Accepted at the 39th IEEE Conference on Robotics and Automation (ICRA), 2022
null
null
null
cs.RO cs.SY eess.SY math.OC
http://creativecommons.org/licenses/by-nc-nd/4.0/
We address the risk bounded trajectory optimization problem of stochastic nonlinear robotic systems. More precisely, we consider the motion planning problem in which the robot has stochastic nonlinear dynamics and uncertain initial locations, and the environment contains multiple dynamic uncertain obstacles with arbitrary probabilistic distributions. The goal is to plan a sequence of control inputs for the robot to navigate to the target while bounding the probability of colliding with obstacles. Existing approaches to address risk bounded trajectory optimization problems are limited to particular classes of models and uncertainties such as Gaussian linear problems. In this paper, we deal with stochastic nonlinear models, nonlinear safety constraints, and arbitrary probabilistic uncertainties, the most general setting ever considered. To address the risk bounded trajectory optimization problem, we first formulate the problem as an optimization problem with stochastic dynamics equations and chance constraints. We then convert probabilistic constraints and stochastic dynamics constraints on random variables into a set of deterministic constraints on the moments of state probability distributions. Finally, we solve the resulting deterministic optimization problem using nonlinear optimization solvers and get a sequence of control inputs. To our best knowledge, it is the first time that the motion planning problem to such a general extent is considered and solved. To illustrate the performance of the proposed method, we provide several robotics examples.
[ { "created": "Sun, 6 Mar 2022 19:48:08 GMT", "version": "v1" } ]
2022-03-08
[ [ "Han", "Weiqiao", "" ], [ "Jasour", "Ashkan", "" ], [ "Williams", "Brian", "" ] ]
We address the risk bounded trajectory optimization problem of stochastic nonlinear robotic systems. More precisely, we consider the motion planning problem in which the robot has stochastic nonlinear dynamics and uncertain initial locations, and the environment contains multiple dynamic uncertain obstacles with arbitrary probabilistic distributions. The goal is to plan a sequence of control inputs for the robot to navigate to the target while bounding the probability of colliding with obstacles. Existing approaches to address risk bounded trajectory optimization problems are limited to particular classes of models and uncertainties such as Gaussian linear problems. In this paper, we deal with stochastic nonlinear models, nonlinear safety constraints, and arbitrary probabilistic uncertainties, the most general setting ever considered. To address the risk bounded trajectory optimization problem, we first formulate the problem as an optimization problem with stochastic dynamics equations and chance constraints. We then convert probabilistic constraints and stochastic dynamics constraints on random variables into a set of deterministic constraints on the moments of state probability distributions. Finally, we solve the resulting deterministic optimization problem using nonlinear optimization solvers and get a sequence of control inputs. To our best knowledge, it is the first time that the motion planning problem to such a general extent is considered and solved. To illustrate the performance of the proposed method, we provide several robotics examples.
2304.11042
Ali Momeni
Ali Momeni, Babak Rahmani, Matthieu Mallejac, Philipp Del Hougne, and Romain Fleury
Backpropagation-free Training of Deep Physical Neural Networks
44 pages, 12 figures
null
null
null
cs.LG cs.NE physics.app-ph physics.optics
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent years have witnessed the outstanding success of deep learning in various fields such as vision and natural language processing. This success is largely indebted to the massive size of deep learning models that is expected to increase unceasingly. This growth of the deep learning models is accompanied by issues related to their considerable energy consumption, both during the training and inference phases, as well as their scalability. Although a number of work based on unconventional physical systems have been proposed which addresses the issue of energy efficiency in the inference phase, efficient training of deep learning models has remained unaddressed. So far, training of digital deep learning models mainly relies on backpropagation, which is not suitable for physical implementation as it requires perfect knowledge of the computation performed in the so-called forward pass of the neural network. Here, we tackle this issue by proposing a simple deep neural network architecture augmented by a biologically plausible learning algorithm, referred to as "model-free forward-forward training". The proposed architecture enables training deep physical neural networks consisting of layers of physical nonlinear systems, without requiring detailed knowledge of the nonlinear physical layers' properties. We show that our method outperforms state-of-the-art hardware-aware training methods by improving training speed, decreasing digital computations, and reducing power consumption in physical systems. We demonstrate the adaptability of the proposed method, even in systems exposed to dynamic or unpredictable external perturbations. To showcase the universality of our approach, we train diverse wave-based physical neural networks that vary in the underlying wave phenomenon and the type of non-linearity they use, to perform vowel and image classification tasks experimentally.
[ { "created": "Thu, 20 Apr 2023 14:02:49 GMT", "version": "v1" }, { "created": "Tue, 9 May 2023 12:16:53 GMT", "version": "v2" }, { "created": "Mon, 12 Jun 2023 18:24:02 GMT", "version": "v3" } ]
2023-06-14
[ [ "Momeni", "Ali", "" ], [ "Rahmani", "Babak", "" ], [ "Mallejac", "Matthieu", "" ], [ "Del Hougne", "Philipp", "" ], [ "Fleury", "Romain", "" ] ]
Recent years have witnessed the outstanding success of deep learning in various fields such as vision and natural language processing. This success is largely indebted to the massive size of deep learning models that is expected to increase unceasingly. This growth of the deep learning models is accompanied by issues related to their considerable energy consumption, both during the training and inference phases, as well as their scalability. Although a number of work based on unconventional physical systems have been proposed which addresses the issue of energy efficiency in the inference phase, efficient training of deep learning models has remained unaddressed. So far, training of digital deep learning models mainly relies on backpropagation, which is not suitable for physical implementation as it requires perfect knowledge of the computation performed in the so-called forward pass of the neural network. Here, we tackle this issue by proposing a simple deep neural network architecture augmented by a biologically plausible learning algorithm, referred to as "model-free forward-forward training". The proposed architecture enables training deep physical neural networks consisting of layers of physical nonlinear systems, without requiring detailed knowledge of the nonlinear physical layers' properties. We show that our method outperforms state-of-the-art hardware-aware training methods by improving training speed, decreasing digital computations, and reducing power consumption in physical systems. We demonstrate the adaptability of the proposed method, even in systems exposed to dynamic or unpredictable external perturbations. To showcase the universality of our approach, we train diverse wave-based physical neural networks that vary in the underlying wave phenomenon and the type of non-linearity they use, to perform vowel and image classification tasks experimentally.
1201.1972
Abdelhakim Khlifi
Abdelhakim Khlifi and Ridha Bouallegue
Hybrid LS-LMMSE Channel Estimation Technique for LTE Downlink Systems
13 pages, 11 figures
International Journal of Next Generation Networks (IJNGN) Vol.3, No.4, December 2011, 1-13
10.5121/ijngn.2011.3401
null
cs.NI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose to improve the performance of the channel estimation for LTE Downlink systems under the effect of the channel length. As LTE Downlink system is a MIMO-OFDMA based system, a cyclic prefix (CP) is inserted at the beginning of each transmitted OFDM symbol in order to mitigate both inter-carrier interference (ICI) and inter-symbol interference (ISI). The inserted CP is usually equal to or longer than the channel length. However, the cyclic prefix can be shorter because of some unforeseen channel behaviour. Previous works have shown that in the case where the cyclic prefix is equal to or longer than the channel length, LMMSE performs better than LSE but at the cost of computational complexity .In the other case, LMMSE performs also better than LS only for low SNR values. However, LS shows better performance for LTE Downlink systems for high SNR values. Therefore, we propose a hybrid LS-LMMSE channel estimation technique robust to the channel length effect. MATLAB Monte-Carlo simulations are used to evaluate the performance of the proposed estimator in terms of Mean Square Error (MSE) and Bit Error Rate (BER) for 2x2 LTE Downlink systems.
[ { "created": "Tue, 10 Jan 2012 06:14:26 GMT", "version": "v1" } ]
2012-01-11
[ [ "Khlifi", "Abdelhakim", "" ], [ "Bouallegue", "Ridha", "" ] ]
In this paper, we propose to improve the performance of the channel estimation for LTE Downlink systems under the effect of the channel length. As LTE Downlink system is a MIMO-OFDMA based system, a cyclic prefix (CP) is inserted at the beginning of each transmitted OFDM symbol in order to mitigate both inter-carrier interference (ICI) and inter-symbol interference (ISI). The inserted CP is usually equal to or longer than the channel length. However, the cyclic prefix can be shorter because of some unforeseen channel behaviour. Previous works have shown that in the case where the cyclic prefix is equal to or longer than the channel length, LMMSE performs better than LSE but at the cost of computational complexity .In the other case, LMMSE performs also better than LS only for low SNR values. However, LS shows better performance for LTE Downlink systems for high SNR values. Therefore, we propose a hybrid LS-LMMSE channel estimation technique robust to the channel length effect. MATLAB Monte-Carlo simulations are used to evaluate the performance of the proposed estimator in terms of Mean Square Error (MSE) and Bit Error Rate (BER) for 2x2 LTE Downlink systems.
2203.15251
Yueming Jin
Yueming Jin, Yang Yu, Cheng Chen, Zixu Zhao, Pheng-Ann Heng, Danail Stoyanov
Exploring Intra- and Inter-Video Relation for Surgical Semantic Scene Segmentation
Accepted at IEEE TMI
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Automatic surgical scene segmentation is fundamental for facilitating cognitive intelligence in the modern operating theatre. Previous works rely on conventional aggregation modules (e.g., dilated convolution, convolutional LSTM), which only make use of the local context. In this paper, we propose a novel framework STswinCL that explores the complementary intra- and inter-video relations to boost segmentation performance, by progressively capturing the global context. We firstly develop a hierarchy Transformer to capture intra-video relation that includes richer spatial and temporal cues from neighbor pixels and previous frames. A joint space-time window shift scheme is proposed to efficiently aggregate these two cues into each pixel embedding. Then, we explore inter-video relation via pixel-to-pixel contrastive learning, which well structures the global embedding space. A multi-source contrast training objective is developed to group the pixel embeddings across videos with the ground-truth guidance, which is crucial for learning the global property of the whole data. We extensively validate our approach on two public surgical video benchmarks, including EndoVis18 Challenge and CaDIS dataset. Experimental results demonstrate the promising performance of our method, which consistently exceeds previous state-of-the-art approaches. Code is available at https://github.com/YuemingJin/STswinCL.
[ { "created": "Tue, 29 Mar 2022 05:52:23 GMT", "version": "v1" }, { "created": "Fri, 24 Jun 2022 16:48:23 GMT", "version": "v2" } ]
2022-06-27
[ [ "Jin", "Yueming", "" ], [ "Yu", "Yang", "" ], [ "Chen", "Cheng", "" ], [ "Zhao", "Zixu", "" ], [ "Heng", "Pheng-Ann", "" ], [ "Stoyanov", "Danail", "" ] ]
Automatic surgical scene segmentation is fundamental for facilitating cognitive intelligence in the modern operating theatre. Previous works rely on conventional aggregation modules (e.g., dilated convolution, convolutional LSTM), which only make use of the local context. In this paper, we propose a novel framework STswinCL that explores the complementary intra- and inter-video relations to boost segmentation performance, by progressively capturing the global context. We firstly develop a hierarchy Transformer to capture intra-video relation that includes richer spatial and temporal cues from neighbor pixels and previous frames. A joint space-time window shift scheme is proposed to efficiently aggregate these two cues into each pixel embedding. Then, we explore inter-video relation via pixel-to-pixel contrastive learning, which well structures the global embedding space. A multi-source contrast training objective is developed to group the pixel embeddings across videos with the ground-truth guidance, which is crucial for learning the global property of the whole data. We extensively validate our approach on two public surgical video benchmarks, including EndoVis18 Challenge and CaDIS dataset. Experimental results demonstrate the promising performance of our method, which consistently exceeds previous state-of-the-art approaches. Code is available at https://github.com/YuemingJin/STswinCL.
2407.15720
Zhenmei Shi
Zhuoyan Xu, Zhenmei Shi, Yingyu Liang
Do Large Language Models Have Compositional Ability? An Investigation into Limitations and Scalability
null
null
null
null
cs.CL cs.AI cs.LG
http://creativecommons.org/licenses/by/4.0/
Large language models (LLMs) have emerged as powerful tools for many AI problems and exhibit remarkable in-context learning (ICL) capabilities. Compositional ability, solving unseen complex tasks that combine two or more simple tasks, is an essential reasoning ability for Artificial General Intelligence. Despite the tremendous success of LLMs, how they approach composite tasks, especially those not encountered during the pretraining phase, remains an open and largely underexplored question. In this study, we delve into the ICL capabilities of LLMs on composite tasks, with only simple tasks as in-context examples. We develop a test suite of composite tasks including linguistic and logical challenges and perform empirical studies across different LLM families. We observe that models exhibit divergent behaviors: (1) For simpler composite tasks that apply distinct mapping mechanisms to different input segments, the models demonstrate decent compositional ability, while scaling up the model enhances this ability; (2) for more complex composite tasks involving reasoning multiple steps, where each step represents one task, models typically underperform, and scaling up generally provides no improvements. We offer theoretical analysis in a simplified setting, explaining that models exhibit compositional capability when the task handles different input parts separately. We believe our work sheds new light on the capabilities of LLMs in solving composite tasks regarding the nature of the tasks and model scale. Our dataset and code are available at {\url{https://github.com/OliverXUZY/LLM_Compose}}.
[ { "created": "Mon, 22 Jul 2024 15:22:34 GMT", "version": "v1" }, { "created": "Sun, 11 Aug 2024 04:39:16 GMT", "version": "v2" } ]
2024-08-13
[ [ "Xu", "Zhuoyan", "" ], [ "Shi", "Zhenmei", "" ], [ "Liang", "Yingyu", "" ] ]
Large language models (LLMs) have emerged as powerful tools for many AI problems and exhibit remarkable in-context learning (ICL) capabilities. Compositional ability, solving unseen complex tasks that combine two or more simple tasks, is an essential reasoning ability for Artificial General Intelligence. Despite the tremendous success of LLMs, how they approach composite tasks, especially those not encountered during the pretraining phase, remains an open and largely underexplored question. In this study, we delve into the ICL capabilities of LLMs on composite tasks, with only simple tasks as in-context examples. We develop a test suite of composite tasks including linguistic and logical challenges and perform empirical studies across different LLM families. We observe that models exhibit divergent behaviors: (1) For simpler composite tasks that apply distinct mapping mechanisms to different input segments, the models demonstrate decent compositional ability, while scaling up the model enhances this ability; (2) for more complex composite tasks involving reasoning multiple steps, where each step represents one task, models typically underperform, and scaling up generally provides no improvements. We offer theoretical analysis in a simplified setting, explaining that models exhibit compositional capability when the task handles different input parts separately. We believe our work sheds new light on the capabilities of LLMs in solving composite tasks regarding the nature of the tasks and model scale. Our dataset and code are available at {\url{https://github.com/OliverXUZY/LLM_Compose}}.
2211.17100
Tommy Nilsson
Anna Vock, Tommy Nilsson
Holistic Outpost Design for Lunar Lava Tubes
73rd International Astronautical Congress (IAC)
null
null
null
cs.HC
http://creativecommons.org/licenses/by-nc-nd/4.0/
As the space industry continues its rapid development, humanity is poised to expand beyond Low Earth Orbit (LEO), seeking to establish permanent presence on the Moon and beyond. While space travel has traditionally been the domain of a small number of highly specialized professionals, a new era of human exploration, involving non-space actors and stakeholders, is now becoming a reality. In spite of this development, most space habitats are still designed for a narrow target group. This paper seeks to address this deficit by rethinking the established design approaches, typically limited to tackling engineering and challenges of human space exploration (such as radiation or hypogravity), by instead adopting an interdisciplinary "big picture" perspective encompassing social, psychological and cultural aspects of future space habitats. By elaborating and reflecting on our concept, this paper seeks to demonstrate the importance of a trans-disciplinary approach to designing thriving sustainable colonies beyond LEO. We demonstrate the potentially key role of design as mediator in advancing macro-strategies promoting thriving existence and sustainable growth. With this approach we tackle big-picture questions about humanity's future and prospects amongst the stars.
[ { "created": "Wed, 19 Oct 2022 09:30:02 GMT", "version": "v1" } ]
2022-12-01
[ [ "Vock", "Anna", "" ], [ "Nilsson", "Tommy", "" ] ]
As the space industry continues its rapid development, humanity is poised to expand beyond Low Earth Orbit (LEO), seeking to establish permanent presence on the Moon and beyond. While space travel has traditionally been the domain of a small number of highly specialized professionals, a new era of human exploration, involving non-space actors and stakeholders, is now becoming a reality. In spite of this development, most space habitats are still designed for a narrow target group. This paper seeks to address this deficit by rethinking the established design approaches, typically limited to tackling engineering and challenges of human space exploration (such as radiation or hypogravity), by instead adopting an interdisciplinary "big picture" perspective encompassing social, psychological and cultural aspects of future space habitats. By elaborating and reflecting on our concept, this paper seeks to demonstrate the importance of a trans-disciplinary approach to designing thriving sustainable colonies beyond LEO. We demonstrate the potentially key role of design as mediator in advancing macro-strategies promoting thriving existence and sustainable growth. With this approach we tackle big-picture questions about humanity's future and prospects amongst the stars.
2305.00730
Sanath Kumar Vengaldas
Sanath Kumar Vengaldas and Adarsh Reddy Muthyala and Bharath Chaitanya Konkati and P. Venkata Subba Reddy
Integer Linear Programming Formulations for Triple and Quadruple Roman Domination Problems
null
null
null
null
cs.DM math.CO
http://creativecommons.org/licenses/by/4.0/
Roman domination is a well researched topic in graph theory. Recently two new variants of Roman domination, namely triple Roman domination and quadruple Roman domination problems have been introduced, to provide better defense strategies. However, triple Roman domination and quadruple Roman domination problems are NP-hard. In this paper, we have provided genetic algorithm for solving triple and quadruple Roman domination problems. Programming (ILP) formulations for triple Roman domination and quadruple Roman domination problems have been proposed. The proposed models are implemented using IBM CPLEX 22.1 optimization solvers and obtained results for random graphs generated using NetworkX Erdos-Renyi model.
[ { "created": "Mon, 1 May 2023 09:13:24 GMT", "version": "v1" } ]
2023-05-02
[ [ "Vengaldas", "Sanath Kumar", "" ], [ "Muthyala", "Adarsh Reddy", "" ], [ "Konkati", "Bharath Chaitanya", "" ], [ "Reddy", "P. Venkata Subba", "" ] ]
Roman domination is a well researched topic in graph theory. Recently two new variants of Roman domination, namely triple Roman domination and quadruple Roman domination problems have been introduced, to provide better defense strategies. However, triple Roman domination and quadruple Roman domination problems are NP-hard. In this paper, we have provided genetic algorithm for solving triple and quadruple Roman domination problems. Programming (ILP) formulations for triple Roman domination and quadruple Roman domination problems have been proposed. The proposed models are implemented using IBM CPLEX 22.1 optimization solvers and obtained results for random graphs generated using NetworkX Erdos-Renyi model.
1901.00716
Marmar Orooji
Marmar Orooji, Gerald M. Knapp
Improving Suppression to Reduce Disclosure Risk and Enhance Data Utility
6 pages, conference
Institute of Industrial and Systems Engineers (2018)
null
null
cs.DB cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In Privacy Preserving Data Publishing, various privacy models have been developed for employing anonymization operations on sensitive individual level datasets, in order to publish the data for public access while preserving the privacy of individuals in the dataset. However, there is always a trade-off between preserving privacy and data utility; the more changes we make on the confidential dataset to reduce disclosure risk, the more information the data loses and the less data utility it preserves. The optimum privacy technique is the one that results in a dataset with minimum disclosure risk and maximum data utility. In this paper, we propose an improved suppression method, which reduces the disclosure risk and enhances the data utility by targeting the highest risk records and keeping other records intact. We have shown the effectiveness of our approach through an experiment on a real-world confidential dataset.
[ { "created": "Wed, 2 Jan 2019 18:48:34 GMT", "version": "v1" }, { "created": "Tue, 8 Jan 2019 01:36:58 GMT", "version": "v2" } ]
2019-01-09
[ [ "Orooji", "Marmar", "" ], [ "Knapp", "Gerald M.", "" ] ]
In Privacy Preserving Data Publishing, various privacy models have been developed for employing anonymization operations on sensitive individual level datasets, in order to publish the data for public access while preserving the privacy of individuals in the dataset. However, there is always a trade-off between preserving privacy and data utility; the more changes we make on the confidential dataset to reduce disclosure risk, the more information the data loses and the less data utility it preserves. The optimum privacy technique is the one that results in a dataset with minimum disclosure risk and maximum data utility. In this paper, we propose an improved suppression method, which reduces the disclosure risk and enhances the data utility by targeting the highest risk records and keeping other records intact. We have shown the effectiveness of our approach through an experiment on a real-world confidential dataset.
1210.7138
Lse Lse
Nicolas Anquetil (INRIA Lille - Nord Europe), Jannik Laval (INRIA Lille - Nord Europe)
Legacy Software Restructuring: Analyzing a Concrete Case
null
Proceedings of the 15th European Conference on Software Maintenance and Reengineering (CSMR'11) (2011) 279--286
null
null
cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Software re-modularization is an old preoccupation of reverse engineering research. The advantages of a well structured or modularized system are well known. Yet after so much time and efforts, the field seems unable to come up with solutions that make a clear difference in practice. Recently, some researchers started to question whether some basic assumptions of the field were not overrated. The main one consists in evaluating the high-cohesion/low-coupling dogma with metrics of unknown relevance. In this paper, we study a real structuring case (on the Eclipse platform) to try to better understand if (some) existing metrics would have helped the software engineers in the task. Results show that the cohesion and coupling metrics used in the experiment did not behave as expected and would probably not have helped the maintainers reach there goal. We also measured another possible restructuring which is to decrease the number of cyclic dependencies between modules. Again, the results did not meet expectations.
[ { "created": "Fri, 26 Oct 2012 13:20:00 GMT", "version": "v1" } ]
2012-10-29
[ [ "Anquetil", "Nicolas", "", "INRIA Lille - Nord Europe" ], [ "Laval", "Jannik", "", "INRIA\n Lille - Nord Europe" ] ]
Software re-modularization is an old preoccupation of reverse engineering research. The advantages of a well structured or modularized system are well known. Yet after so much time and efforts, the field seems unable to come up with solutions that make a clear difference in practice. Recently, some researchers started to question whether some basic assumptions of the field were not overrated. The main one consists in evaluating the high-cohesion/low-coupling dogma with metrics of unknown relevance. In this paper, we study a real structuring case (on the Eclipse platform) to try to better understand if (some) existing metrics would have helped the software engineers in the task. Results show that the cohesion and coupling metrics used in the experiment did not behave as expected and would probably not have helped the maintainers reach there goal. We also measured another possible restructuring which is to decrease the number of cyclic dependencies between modules. Again, the results did not meet expectations.
2208.04246
Colorado J Reed
Malachy Moran and Kayla Woputz and Derrick Hee and Manuela Girotto and Paolo D'Odorico and Ritwik Gupta and Daniel Feldman and Puya Vahabi and Alberto Todeschini and Colorado J Reed
Snowpack Estimation in Key Mountainous Water Basins from Openly-Available, Multimodal Data Sources
Accepted Oral Presentation at CVPR 2022 MultiEarth
null
null
null
cs.CV cs.LG
http://creativecommons.org/licenses/by/4.0/
Accurately estimating the snowpack in key mountainous basins is critical for water resource managers to make decisions that impact local and global economies, wildlife, and public policy. Currently, this estimation requires multiple LiDAR-equipped plane flights or in situ measurements, both of which are expensive, sparse, and biased towards accessible regions. In this paper, we demonstrate that fusing spatial and temporal information from multiple, openly-available satellite and weather data sources enables estimation of snowpack in key mountainous regions. Our multisource model outperforms single-source estimation by 5.0 inches RMSE, as well as outperforms sparse in situ measurements by 1.2 inches RMSE.
[ { "created": "Mon, 8 Aug 2022 16:17:36 GMT", "version": "v1" } ]
2022-08-09
[ [ "Moran", "Malachy", "" ], [ "Woputz", "Kayla", "" ], [ "Hee", "Derrick", "" ], [ "Girotto", "Manuela", "" ], [ "D'Odorico", "Paolo", "" ], [ "Gupta", "Ritwik", "" ], [ "Feldman", "Daniel", "" ], [ "Vahabi", "Puya", "" ], [ "Todeschini", "Alberto", "" ], [ "Reed", "Colorado J", "" ] ]
Accurately estimating the snowpack in key mountainous basins is critical for water resource managers to make decisions that impact local and global economies, wildlife, and public policy. Currently, this estimation requires multiple LiDAR-equipped plane flights or in situ measurements, both of which are expensive, sparse, and biased towards accessible regions. In this paper, we demonstrate that fusing spatial and temporal information from multiple, openly-available satellite and weather data sources enables estimation of snowpack in key mountainous regions. Our multisource model outperforms single-source estimation by 5.0 inches RMSE, as well as outperforms sparse in situ measurements by 1.2 inches RMSE.
2307.08086
Murad Tukan
Murad Tukan, Alaa Maalouf, Margarita Osadchy
Dataset Distillation Meets Provable Subset Selection
null
null
null
null
cs.LG cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep learning has grown tremendously over recent years, yielding state-of-the-art results in various fields. However, training such models requires huge amounts of data, increasing the computational time and cost. To address this, dataset distillation was proposed to compress a large training dataset into a smaller synthetic one that retains its performance -- this is usually done by (1) uniformly initializing a synthetic set and (2) iteratively updating/learning this set according to a predefined loss by uniformly sampling instances from the full data. In this paper, we improve both phases of dataset distillation: (1) we present a provable, sampling-based approach for initializing the distilled set by identifying important and removing redundant points in the data, and (2) we further merge the idea of data subset selection with dataset distillation, by training the distilled set on ``important'' sampled points during the training procedure instead of randomly sampling the next batch. To do so, we define the notion of importance based on the relative contribution of instances with respect to two different loss functions, i.e., one for the initialization phase (a kernel fitting function for kernel ridge regression and $K$-means based loss function for any other distillation method), and the relative cross-entropy loss (or any other predefined loss) function for the training phase. Finally, we provide experimental results showing how our method can latch on to existing dataset distillation techniques and improve their performance.
[ { "created": "Sun, 16 Jul 2023 15:58:19 GMT", "version": "v1" } ]
2023-07-18
[ [ "Tukan", "Murad", "" ], [ "Maalouf", "Alaa", "" ], [ "Osadchy", "Margarita", "" ] ]
Deep learning has grown tremendously over recent years, yielding state-of-the-art results in various fields. However, training such models requires huge amounts of data, increasing the computational time and cost. To address this, dataset distillation was proposed to compress a large training dataset into a smaller synthetic one that retains its performance -- this is usually done by (1) uniformly initializing a synthetic set and (2) iteratively updating/learning this set according to a predefined loss by uniformly sampling instances from the full data. In this paper, we improve both phases of dataset distillation: (1) we present a provable, sampling-based approach for initializing the distilled set by identifying important and removing redundant points in the data, and (2) we further merge the idea of data subset selection with dataset distillation, by training the distilled set on ``important'' sampled points during the training procedure instead of randomly sampling the next batch. To do so, we define the notion of importance based on the relative contribution of instances with respect to two different loss functions, i.e., one for the initialization phase (a kernel fitting function for kernel ridge regression and $K$-means based loss function for any other distillation method), and the relative cross-entropy loss (or any other predefined loss) function for the training phase. Finally, we provide experimental results showing how our method can latch on to existing dataset distillation techniques and improve their performance.
1705.04300
Nan Yang
Nan Yang, Rui Wang, Xiang Gao, Daniel Cremers
Challenges in Monocular Visual Odometry: Photometric Calibration, Motion Bias and Rolling Shutter Effect
Accepted by IEEE Robotics and Automation Letters (RA-L), 2018. The first two authors contributed equally to this paper
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Monocular visual odometry (VO) and simultaneous localization and mapping (SLAM) have seen tremendous improvements in accuracy, robustness and efficiency, and have gained increasing popularity over recent years. Nevertheless, not so many discussions have been carried out to reveal the influences of three very influential yet easily overlooked aspects: photometric calibration, motion bias and rolling shutter effect. In this work, we evaluate these three aspects quantitatively on the state of the art of direct, feature-based and semi-direct methods, providing the community with useful practical knowledge both for better applying existing methods and developing new algorithms of VO and SLAM. Conclusions (some of which are counter-intuitive) are drawn with both technical and empirical analyses to all of our experiments. Possible improvements on existing methods are directed or proposed, such as a sub-pixel accuracy refinement of ORB-SLAM which boosts its performance.
[ { "created": "Thu, 11 May 2017 17:36:43 GMT", "version": "v1" }, { "created": "Fri, 21 Jul 2017 11:25:45 GMT", "version": "v2" }, { "created": "Mon, 18 Sep 2017 13:21:30 GMT", "version": "v3" }, { "created": "Thu, 7 Jun 2018 11:46:59 GMT", "version": "v4" } ]
2018-06-08
[ [ "Yang", "Nan", "" ], [ "Wang", "Rui", "" ], [ "Gao", "Xiang", "" ], [ "Cremers", "Daniel", "" ] ]
Monocular visual odometry (VO) and simultaneous localization and mapping (SLAM) have seen tremendous improvements in accuracy, robustness and efficiency, and have gained increasing popularity over recent years. Nevertheless, not so many discussions have been carried out to reveal the influences of three very influential yet easily overlooked aspects: photometric calibration, motion bias and rolling shutter effect. In this work, we evaluate these three aspects quantitatively on the state of the art of direct, feature-based and semi-direct methods, providing the community with useful practical knowledge both for better applying existing methods and developing new algorithms of VO and SLAM. Conclusions (some of which are counter-intuitive) are drawn with both technical and empirical analyses to all of our experiments. Possible improvements on existing methods are directed or proposed, such as a sub-pixel accuracy refinement of ORB-SLAM which boosts its performance.
1608.00684
Pauline Chou
David Savage, Xiuzhen Zhang, Xinghuo Yu, Pauline Chou, Qingmai Wang
Detection of opinion spam based on anomalous rating deviation
null
Expert Systems with Applications 42 (2015) 8650-8657
null
null
cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The publication of fake reviews by parties with vested interests has become a severe problem for consumers who use online product reviews in their decision making. To counter this problem a number of methods for detecting these fake reviews, termed opinion spam, have been proposed. However, to date, many of these methods focus on analysis of review text, making them unsuitable for many review systems where accom-panying text is optional, or not possible. Moreover, these approaches are often computationally expensive, requiring extensive resources to handle text analysis over the scale of data typically involved. In this paper, we consider opinion spammers manipulation of average ratings for products, focusing on dif-ferences between spammer ratings and the majority opinion of honest reviewers. We propose a lightweight, effective method for detecting opinion spammers based on these differences. This method uses binomial regression to identify reviewers having an anomalous proportion of ratings that deviate from the majority opinion. Experiments on real-world and synthetic data show that our approach is able to successfully iden-tify opinion spammers. Comparison with the current state-of-the-art approach, also based only on ratings, shows that our method is able to achieve similar detection accuracy while removing the need for assump-tions regarding probabilities of spam and non-spam reviews and reducing the heavy computation required for learning.
[ { "created": "Tue, 2 Aug 2016 02:52:18 GMT", "version": "v1" } ]
2016-08-03
[ [ "Savage", "David", "" ], [ "Zhang", "Xiuzhen", "" ], [ "Yu", "Xinghuo", "" ], [ "Chou", "Pauline", "" ], [ "Wang", "Qingmai", "" ] ]
The publication of fake reviews by parties with vested interests has become a severe problem for consumers who use online product reviews in their decision making. To counter this problem a number of methods for detecting these fake reviews, termed opinion spam, have been proposed. However, to date, many of these methods focus on analysis of review text, making them unsuitable for many review systems where accom-panying text is optional, or not possible. Moreover, these approaches are often computationally expensive, requiring extensive resources to handle text analysis over the scale of data typically involved. In this paper, we consider opinion spammers manipulation of average ratings for products, focusing on dif-ferences between spammer ratings and the majority opinion of honest reviewers. We propose a lightweight, effective method for detecting opinion spammers based on these differences. This method uses binomial regression to identify reviewers having an anomalous proportion of ratings that deviate from the majority opinion. Experiments on real-world and synthetic data show that our approach is able to successfully iden-tify opinion spammers. Comparison with the current state-of-the-art approach, also based only on ratings, shows that our method is able to achieve similar detection accuracy while removing the need for assump-tions regarding probabilities of spam and non-spam reviews and reducing the heavy computation required for learning.
1909.12535
Duc Bui
Duc Bui, Kshitiz Malik, Jack Goetz, Honglei Liu, Seungwhan Moon, Anuj Kumar, Kang G. Shin
Federated User Representation Learning
null
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Collaborative personalization, such as through learned user representations (embeddings), can improve the prediction accuracy of neural-network-based models significantly. We propose Federated User Representation Learning (FURL), a simple, scalable, privacy-preserving and resource-efficient way to utilize existing neural personalization techniques in the Federated Learning (FL) setting. FURL divides model parameters into federated and private parameters. Private parameters, such as private user embeddings, are trained locally, but unlike federated parameters, they are not transferred to or averaged on the server. We show theoretically that this parameter split does not affect training for most model personalization approaches. Storing user embeddings locally not only preserves user privacy, but also improves memory locality of personalization compared to on-server training. We evaluate FURL on two datasets, demonstrating a significant improvement in model quality with 8% and 51% performance increases, and approximately the same level of performance as centralized training with only 0% and 4% reductions. Furthermore, we show that user embeddings learned in FL and the centralized setting have a very similar structure, indicating that FURL can learn collaboratively through the shared parameters while preserving user privacy.
[ { "created": "Fri, 27 Sep 2019 07:40:08 GMT", "version": "v1" } ]
2019-09-30
[ [ "Bui", "Duc", "" ], [ "Malik", "Kshitiz", "" ], [ "Goetz", "Jack", "" ], [ "Liu", "Honglei", "" ], [ "Moon", "Seungwhan", "" ], [ "Kumar", "Anuj", "" ], [ "Shin", "Kang G.", "" ] ]
Collaborative personalization, such as through learned user representations (embeddings), can improve the prediction accuracy of neural-network-based models significantly. We propose Federated User Representation Learning (FURL), a simple, scalable, privacy-preserving and resource-efficient way to utilize existing neural personalization techniques in the Federated Learning (FL) setting. FURL divides model parameters into federated and private parameters. Private parameters, such as private user embeddings, are trained locally, but unlike federated parameters, they are not transferred to or averaged on the server. We show theoretically that this parameter split does not affect training for most model personalization approaches. Storing user embeddings locally not only preserves user privacy, but also improves memory locality of personalization compared to on-server training. We evaluate FURL on two datasets, demonstrating a significant improvement in model quality with 8% and 51% performance increases, and approximately the same level of performance as centralized training with only 0% and 4% reductions. Furthermore, we show that user embeddings learned in FL and the centralized setting have a very similar structure, indicating that FURL can learn collaboratively through the shared parameters while preserving user privacy.
2402.11061
Bin Han
Anthony Kiggundu, Bin Han, Dennis Krummacker, and Hans D. Schotten
Chronicles of jockeying in queuing systems
Submitted to ACM Computing Surveys
null
null
null
cs.NI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The relevance of studies in queuing theory in social systems has inspired its adoption in other mainstream technologies with its application in distributed and communication systems becoming an intense research domain. Considerable work has been done regarding the application of the impatient queuing phenomenon in distributed computing to achieve optimal resource sharing and allocation for performance improvement. Generally, there are two types of common impatient queuing behaviour that have been well studied, namely balking and reneging, respectively. In this survey, we are interested in the third type of impatience: jockeying, a phenomenon that draws origins from impatient customers switching from one queue to another. This survey chronicles classical and latest efforts that labor to model and exploit the jockeying behaviour in queuing systems, with a special focus on those related to information and communication systems, especially in the context of Multi-Access Edge Computing. We comparatively summarize the reviewed literature regarding their methodologies, invoked models, and use cases.
[ { "created": "Fri, 16 Feb 2024 20:24:02 GMT", "version": "v1" }, { "created": "Wed, 12 Jun 2024 19:07:13 GMT", "version": "v2" }, { "created": "Fri, 28 Jun 2024 11:53:32 GMT", "version": "v3" } ]
2024-07-01
[ [ "Kiggundu", "Anthony", "" ], [ "Han", "Bin", "" ], [ "Krummacker", "Dennis", "" ], [ "Schotten", "Hans D.", "" ] ]
The relevance of studies in queuing theory in social systems has inspired its adoption in other mainstream technologies with its application in distributed and communication systems becoming an intense research domain. Considerable work has been done regarding the application of the impatient queuing phenomenon in distributed computing to achieve optimal resource sharing and allocation for performance improvement. Generally, there are two types of common impatient queuing behaviour that have been well studied, namely balking and reneging, respectively. In this survey, we are interested in the third type of impatience: jockeying, a phenomenon that draws origins from impatient customers switching from one queue to another. This survey chronicles classical and latest efforts that labor to model and exploit the jockeying behaviour in queuing systems, with a special focus on those related to information and communication systems, especially in the context of Multi-Access Edge Computing. We comparatively summarize the reviewed literature regarding their methodologies, invoked models, and use cases.
2402.18465
Lukas Brand
Lukas Brand, Yan Wang, Maurizio Magarini, Robert Schober, and Sebastian Lotter
Semantic Information in MC: Chemotaxis Beyond Shannon
7 pages, 5 figures, This work has been submitted in part for possible publication to the IEEE Global Communications Conference (GLOBECOM) 2024
null
null
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recently emerged molecular communication (MC) paradigm intends to leverage communication engineering tools for the design of synthetic chemical communication systems. These systems are envisioned to operate at nanoscale and in biological environments, such as the human body, and catalyze the emergence of revolutionary applications in the context of early disease monitoring and drug targeting. Despite the abundance of theoretical (and recently also experimental) MC system designs proposed over the past years, some fundamental questions remain unresolved, hindering the breakthrough of MC in real-world applications. One of these questions is: What can be a useful measure of information in the context of MC applications? While most existing works on MC build upon the concept of syntactic information as introduced by Shannon, in this paper, we explore the framework of semantic information as introduced by Kolchinsky and Wolpert for the information-theoretic analysis of a natural MC system, namely bacterial chemotaxis. Exploiting computational agent-based modeling (ABM), we are able to quantify, for the first time, the amount of information that the considered chemotactic bacterium (CB) utilizes to adapt to and survive in a dynamic environment. In other words, we show how the flow of information between the environment and the CB is related to the effectiveness of communication. Effectiveness here refers to the adaptation of the CB to the dynamic environment in order to ensure survival. Our analysis reveals that it highly depends on the environmental conditions how much information the CB can effectively utilize for improving their survival chances. Encouraged by our results, we envision that the proposed semantic information framework can open new avenues for the development of theoretical and experimental MC system designs for future nanoscale applications.
[ { "created": "Wed, 28 Feb 2024 16:41:52 GMT", "version": "v1" }, { "created": "Thu, 4 Apr 2024 09:02:31 GMT", "version": "v2" } ]
2024-04-05
[ [ "Brand", "Lukas", "" ], [ "Wang", "Yan", "" ], [ "Magarini", "Maurizio", "" ], [ "Schober", "Robert", "" ], [ "Lotter", "Sebastian", "" ] ]
The recently emerged molecular communication (MC) paradigm intends to leverage communication engineering tools for the design of synthetic chemical communication systems. These systems are envisioned to operate at nanoscale and in biological environments, such as the human body, and catalyze the emergence of revolutionary applications in the context of early disease monitoring and drug targeting. Despite the abundance of theoretical (and recently also experimental) MC system designs proposed over the past years, some fundamental questions remain unresolved, hindering the breakthrough of MC in real-world applications. One of these questions is: What can be a useful measure of information in the context of MC applications? While most existing works on MC build upon the concept of syntactic information as introduced by Shannon, in this paper, we explore the framework of semantic information as introduced by Kolchinsky and Wolpert for the information-theoretic analysis of a natural MC system, namely bacterial chemotaxis. Exploiting computational agent-based modeling (ABM), we are able to quantify, for the first time, the amount of information that the considered chemotactic bacterium (CB) utilizes to adapt to and survive in a dynamic environment. In other words, we show how the flow of information between the environment and the CB is related to the effectiveness of communication. Effectiveness here refers to the adaptation of the CB to the dynamic environment in order to ensure survival. Our analysis reveals that it highly depends on the environmental conditions how much information the CB can effectively utilize for improving their survival chances. Encouraged by our results, we envision that the proposed semantic information framework can open new avenues for the development of theoretical and experimental MC system designs for future nanoscale applications.
1409.1467
Erik Leitinger
Erik Leitinger and Paul Meissner and Christoph R\"udisser and Gregor Dumphart and Klaus Witrisal
Evaluation of Position-related Information in Multipath Components for Indoor Positioning
14 pages, 10 figures, submitted to the IEEE Journal on Selected Areas in Communications: Localization-Awareness for Radios and Networks
null
null
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Location awareness is a key factor for a wealth of wireless indoor applications. Its provision requires the careful fusion of diverse information sources. For agents that use radio signals for localization, this information may either come from signal transmissions with respect to fixed anchors, from cooperative transmissions inbetween agents, or from radar-like monostatic transmissions. Using a-priori knowledge of a floor plan of the environment, specular multipath components can be exploited, based on a geometric-stochastic channel model. In this paper, a unified framework is presented for the quantification of this type of position-related information, using the concept of equivalent Fisher information. We derive analytical results for the Cram\'er-Rao lower bound of multipath-assisted positioning, considering bistatic transmissions between agents and fixed anchors, monostatic transmissions from agents, cooperative measurements inbetween agents, and combinations thereof, including the effect of clock offsets. Awareness of this information enables highly accurate and robust indoor positioning. Computational results show the applicability of the framework for the characterization of the localization capabilities of a given environment, quantifying the influence of different system setups, signal parameters, and the impact of path overlap.
[ { "created": "Thu, 4 Sep 2014 15:30:59 GMT", "version": "v1" }, { "created": "Mon, 10 Dec 2018 12:50:39 GMT", "version": "v2" } ]
2018-12-11
[ [ "Leitinger", "Erik", "" ], [ "Meissner", "Paul", "" ], [ "Rüdisser", "Christoph", "" ], [ "Dumphart", "Gregor", "" ], [ "Witrisal", "Klaus", "" ] ]
Location awareness is a key factor for a wealth of wireless indoor applications. Its provision requires the careful fusion of diverse information sources. For agents that use radio signals for localization, this information may either come from signal transmissions with respect to fixed anchors, from cooperative transmissions inbetween agents, or from radar-like monostatic transmissions. Using a-priori knowledge of a floor plan of the environment, specular multipath components can be exploited, based on a geometric-stochastic channel model. In this paper, a unified framework is presented for the quantification of this type of position-related information, using the concept of equivalent Fisher information. We derive analytical results for the Cram\'er-Rao lower bound of multipath-assisted positioning, considering bistatic transmissions between agents and fixed anchors, monostatic transmissions from agents, cooperative measurements inbetween agents, and combinations thereof, including the effect of clock offsets. Awareness of this information enables highly accurate and robust indoor positioning. Computational results show the applicability of the framework for the characterization of the localization capabilities of a given environment, quantifying the influence of different system setups, signal parameters, and the impact of path overlap.
2012.10860
Guangming Wang
Guangming Wang, Muyao Chen, Hanwen Liu, Yehui Yang, Zhe Liu, Hesheng Wang
Anchor-Based Spatio-Temporal Attention 3D Convolutional Networks for Dynamic 3D Point Cloud Sequences
10 pages, 6 figures, under review
IEEE Transactions on Instrumentation and Measurement, 2021
10.1109/TIM.2021.3106101
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the rapid development of measurement technology, LiDAR and depth cameras are widely used in the perception of the 3D environment. Recent learning based methods for robot perception most focus on the image or video, but deep learning methods for dynamic 3D point cloud sequences are underexplored. Therefore, developing efficient and accurate perception method compatible with these advanced instruments is pivotal to autonomous driving and service robots. An Anchor-based Spatio-Temporal Attention 3D Convolution operation (ASTA3DConv) is proposed in this paper to process dynamic 3D point cloud sequences. The proposed convolution operation builds a regular receptive field around each point by setting several virtual anchors around each point. The features of neighborhood points are firstly aggregated to each anchor based on the spatio-temporal attention mechanism. Then, anchor-based 3D convolution is adopted to aggregate these anchors' features to the core points. The proposed method makes better use of the structured information within the local region and learns spatio-temporal embedding features from dynamic 3D point cloud sequences. Anchor-based Spatio-Temporal Attention 3D Convolutional Neural Networks (ASTA3DCNNs) are built for classification and segmentation tasks based on the proposed ASTA3DConv and evaluated on action recognition and semantic segmentation tasks. The experiments and ablation studies on MSRAction3D and Synthia datasets demonstrate the superior performance and effectiveness of our method for dynamic 3D point cloud sequences. Our method achieves the state-of-the-art performance among the methods with dynamic 3D point cloud sequences as input on MSRAction3D and Synthia datasets.
[ { "created": "Sun, 20 Dec 2020 07:35:37 GMT", "version": "v1" }, { "created": "Thu, 29 Jul 2021 13:55:33 GMT", "version": "v2" } ]
2021-11-04
[ [ "Wang", "Guangming", "" ], [ "Chen", "Muyao", "" ], [ "Liu", "Hanwen", "" ], [ "Yang", "Yehui", "" ], [ "Liu", "Zhe", "" ], [ "Wang", "Hesheng", "" ] ]
With the rapid development of measurement technology, LiDAR and depth cameras are widely used in the perception of the 3D environment. Recent learning based methods for robot perception most focus on the image or video, but deep learning methods for dynamic 3D point cloud sequences are underexplored. Therefore, developing efficient and accurate perception method compatible with these advanced instruments is pivotal to autonomous driving and service robots. An Anchor-based Spatio-Temporal Attention 3D Convolution operation (ASTA3DConv) is proposed in this paper to process dynamic 3D point cloud sequences. The proposed convolution operation builds a regular receptive field around each point by setting several virtual anchors around each point. The features of neighborhood points are firstly aggregated to each anchor based on the spatio-temporal attention mechanism. Then, anchor-based 3D convolution is adopted to aggregate these anchors' features to the core points. The proposed method makes better use of the structured information within the local region and learns spatio-temporal embedding features from dynamic 3D point cloud sequences. Anchor-based Spatio-Temporal Attention 3D Convolutional Neural Networks (ASTA3DCNNs) are built for classification and segmentation tasks based on the proposed ASTA3DConv and evaluated on action recognition and semantic segmentation tasks. The experiments and ablation studies on MSRAction3D and Synthia datasets demonstrate the superior performance and effectiveness of our method for dynamic 3D point cloud sequences. Our method achieves the state-of-the-art performance among the methods with dynamic 3D point cloud sequences as input on MSRAction3D and Synthia datasets.
1102.5046
Tamara Kolda
C. Seshadhri, Ali Pinar, Tamara G. Kolda
An In-Depth Analysis of Stochastic Kronecker Graphs
null
Journal of the ACM 60(2):13 (32 pages), April 2013
10.1145/2450142.2450149
null
cs.SI cs.DM physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Graph analysis is playing an increasingly important role in science and industry. Due to numerous limitations in sharing real-world graphs, models for generating massive graphs are critical for developing better algorithms. In this paper, we analyze the stochastic Kronecker graph model (SKG), which is the foundation of the Graph500 supercomputer benchmark due to its favorable properties and easy parallelization. Our goal is to provide a deeper understanding of the parameters and properties of this model so that its functionality as a benchmark is increased. We develop a rigorous mathematical analysis that shows this model cannot generate a power-law distribution or even a lognormal distribution. However, we formalize an enhanced version of the SKG model that uses random noise for smoothing. We prove both in theory and in practice that this enhancement leads to a lognormal distribution. Additionally, we provide a precise analysis of isolated vertices, showing that the graphs that are produced by SKG might be quite different than intended. For example, between 50% and 75% of the vertices in the Graph500 benchmarks will be isolated. Finally, we show that this model tends to produce extremely small core numbers (compared to most social networks and other real graphs) for common parameter choices.
[ { "created": "Thu, 24 Feb 2011 17:36:57 GMT", "version": "v1" }, { "created": "Thu, 8 Sep 2011 18:34:32 GMT", "version": "v2" }, { "created": "Wed, 2 Jan 2013 23:59:15 GMT", "version": "v3" } ]
2013-09-16
[ [ "Seshadhri", "C.", "" ], [ "Pinar", "Ali", "" ], [ "Kolda", "Tamara G.", "" ] ]
Graph analysis is playing an increasingly important role in science and industry. Due to numerous limitations in sharing real-world graphs, models for generating massive graphs are critical for developing better algorithms. In this paper, we analyze the stochastic Kronecker graph model (SKG), which is the foundation of the Graph500 supercomputer benchmark due to its favorable properties and easy parallelization. Our goal is to provide a deeper understanding of the parameters and properties of this model so that its functionality as a benchmark is increased. We develop a rigorous mathematical analysis that shows this model cannot generate a power-law distribution or even a lognormal distribution. However, we formalize an enhanced version of the SKG model that uses random noise for smoothing. We prove both in theory and in practice that this enhancement leads to a lognormal distribution. Additionally, we provide a precise analysis of isolated vertices, showing that the graphs that are produced by SKG might be quite different than intended. For example, between 50% and 75% of the vertices in the Graph500 benchmarks will be isolated. Finally, we show that this model tends to produce extremely small core numbers (compared to most social networks and other real graphs) for common parameter choices.
2212.14296
Yan Jia
Rongkuan Ma, Qiang Wei, Jingyi Wang, Shunkai Zhu, Shouling Ji, Peng Cheng, Yan Jia, Qingxian Wang
Towards Comprehensively Understanding the Run-time Security of Programmable Logic Controllers: A 3-year Empirical Study
null
null
null
null
cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Programmable Logic Controllers (PLCs) are the core control devices in Industrial Control Systems (ICSs), which control and monitor the underlying physical plants such as power grids. PLCs were initially designed to work in a trusted industrial network, which however can be brittle once deployed in an Internet-facing (or penetrated) network. Yet, there is a lack of systematic empirical analysis of the run-time security of modern real-world PLCs. To close this gap, we present the first large-scale measurement on 23 off-the-shelf PLCs across 13 leading vendors. We find many common security issues and unexplored implications that should be more carefully addressed in the design and implementation. To sum up, the unsupervised logic applications can cause system resource/privilege abuse, which gives adversaries new means to hijack the control flow of a runtime system remotely (without exploiting memory vulnerabilities); 2) the improper access control mechanisms bring many unauthorized access implications; 3) the proprietary or semi-proprietary protocols are fragile regarding confidentiality and integrity protection of run-time data. We empirically evaluated the corresponding attack vectors on multiple PLCs, which demonstrates that the security implications are severe and broad. Our findings were reported to the related parties responsibly, and 20 bugs have been confirmed with 7 assigned CVEs.
[ { "created": "Thu, 29 Dec 2022 13:18:11 GMT", "version": "v1" } ]
2023-01-02
[ [ "Ma", "Rongkuan", "" ], [ "Wei", "Qiang", "" ], [ "Wang", "Jingyi", "" ], [ "Zhu", "Shunkai", "" ], [ "Ji", "Shouling", "" ], [ "Cheng", "Peng", "" ], [ "Jia", "Yan", "" ], [ "Wang", "Qingxian", "" ] ]
Programmable Logic Controllers (PLCs) are the core control devices in Industrial Control Systems (ICSs), which control and monitor the underlying physical plants such as power grids. PLCs were initially designed to work in a trusted industrial network, which however can be brittle once deployed in an Internet-facing (or penetrated) network. Yet, there is a lack of systematic empirical analysis of the run-time security of modern real-world PLCs. To close this gap, we present the first large-scale measurement on 23 off-the-shelf PLCs across 13 leading vendors. We find many common security issues and unexplored implications that should be more carefully addressed in the design and implementation. To sum up, the unsupervised logic applications can cause system resource/privilege abuse, which gives adversaries new means to hijack the control flow of a runtime system remotely (without exploiting memory vulnerabilities); 2) the improper access control mechanisms bring many unauthorized access implications; 3) the proprietary or semi-proprietary protocols are fragile regarding confidentiality and integrity protection of run-time data. We empirically evaluated the corresponding attack vectors on multiple PLCs, which demonstrates that the security implications are severe and broad. Our findings were reported to the related parties responsibly, and 20 bugs have been confirmed with 7 assigned CVEs.
1106.1820
R. Barzilay
R. Barzilay, N. Elhadad
Inferring Strategies for Sentence Ordering in Multidocument News Summarization
null
Journal Of Artificial Intelligence Research, Volume 17, pages 35-55, 2002
10.1613/jair.991
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The problem of organizing information for multidocument summarization so that the generated summary is coherent has received relatively little attention. While sentence ordering for single document summarization can be determined from the ordering of sentences in the input article, this is not the case for multidocument summarization where summary sentences may be drawn from different input articles. In this paper, we propose a methodology for studying the properties of ordering information in the news genre and describe experiments done on a corpus of multiple acceptable orderings we developed for the task. Based on these experiments, we implemented a strategy for ordering information that combines constraints from chronological order of events and topical relatedness. Evaluation of our augmented algorithm shows a significant improvement of the ordering over two baseline strategies.
[ { "created": "Thu, 9 Jun 2011 13:57:02 GMT", "version": "v1" } ]
2011-06-10
[ [ "Barzilay", "R.", "" ], [ "Elhadad", "N.", "" ] ]
The problem of organizing information for multidocument summarization so that the generated summary is coherent has received relatively little attention. While sentence ordering for single document summarization can be determined from the ordering of sentences in the input article, this is not the case for multidocument summarization where summary sentences may be drawn from different input articles. In this paper, we propose a methodology for studying the properties of ordering information in the news genre and describe experiments done on a corpus of multiple acceptable orderings we developed for the task. Based on these experiments, we implemented a strategy for ordering information that combines constraints from chronological order of events and topical relatedness. Evaluation of our augmented algorithm shows a significant improvement of the ordering over two baseline strategies.
2306.04252
Skander Karkar
Skander Karkar and Patrick Gallinari and Alain Rakotomamonjy
Adversarial Sample Detection Through Neural Network Transport Dynamics
ECML PKDD 2023
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a detector of adversarial samples that is based on the view of neural networks as discrete dynamic systems. The detector tells clean inputs from abnormal ones by comparing the discrete vector fields they follow through the layers. We also show that regularizing this vector field during training makes the network more regular on the data distribution's support, thus making the activations of clean inputs more distinguishable from those of abnormal ones. Experimentally, we compare our detector favorably to other detectors on seen and unseen attacks, and show that the regularization of the network's dynamics improves the performance of adversarial detectors that use the internal embeddings as inputs, while also improving test accuracy.
[ { "created": "Wed, 7 Jun 2023 08:47:41 GMT", "version": "v1" }, { "created": "Thu, 8 Jun 2023 08:43:40 GMT", "version": "v2" } ]
2023-06-09
[ [ "Karkar", "Skander", "" ], [ "Gallinari", "Patrick", "" ], [ "Rakotomamonjy", "Alain", "" ] ]
We propose a detector of adversarial samples that is based on the view of neural networks as discrete dynamic systems. The detector tells clean inputs from abnormal ones by comparing the discrete vector fields they follow through the layers. We also show that regularizing this vector field during training makes the network more regular on the data distribution's support, thus making the activations of clean inputs more distinguishable from those of abnormal ones. Experimentally, we compare our detector favorably to other detectors on seen and unseen attacks, and show that the regularization of the network's dynamics improves the performance of adversarial detectors that use the internal embeddings as inputs, while also improving test accuracy.
0807.1543
Xiaohu Shang
Xiaohu Shang, Biao Chen, Gerhard Kramer, H. Vincent Poor
On the Capacity of MIMO Interference Channels
8 pages, 2 figures, submitted to Allerton 2008
null
null
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The capacity region of a multiple-input-multiple-output interference channel (MIMO IC) where the channel matrices are square and invertible is studied. The capacity region for strong interference is established where the definition of strong interference parallels that of scalar channels. Moreover, the sum-rate capacity for Z interference, noisy interference, and mixed interference is established. These results generalize known results for the scalar Gaussian IC.
[ { "created": "Thu, 10 Jul 2008 00:39:06 GMT", "version": "v1" }, { "created": "Thu, 25 Sep 2008 19:40:13 GMT", "version": "v2" } ]
2008-09-25
[ [ "Shang", "Xiaohu", "" ], [ "Chen", "Biao", "" ], [ "Kramer", "Gerhard", "" ], [ "Poor", "H. Vincent", "" ] ]
The capacity region of a multiple-input-multiple-output interference channel (MIMO IC) where the channel matrices are square and invertible is studied. The capacity region for strong interference is established where the definition of strong interference parallels that of scalar channels. Moreover, the sum-rate capacity for Z interference, noisy interference, and mixed interference is established. These results generalize known results for the scalar Gaussian IC.
cs/0608025
Dinesh Kumar
Dinesh Kumar (INRIA Sophia Antipolis), Eitan Altman (INRIA Sophia Antipolis), Jean-Marc Kelif (INRIA Sophia Antipolis)
User-Network Association in a WLAN-UMTS Hybrid Cell: Global & Individual Optimality
null
null
null
null
cs.NI
null
We study optimal user-network association in an integrated 802.11 WLAN and 3G-UMTS hybrid cell. Assuming saturated resource allocation on the downlink of WLAN and UMTS networks and a single QoS class of mobiles arriving at an average location in the hybrid cell, we formulate the problem with two different approaches: Global and Individual optimality. The Globally optimal association is formulated as an SMDP (Semi Markov Decision Process) connection routing decision problem where rewards comprise a financial gain component and an aggregate network throughput component. The corresponding Dynamic Programming equations are solved using Value Iteration method and a stationary optimal policy with neither convex nor concave type switching curve structure is obtained. Threshold type and symmetric switching curves are observed for the analogous homogenous network cases. The Individual optimality is studied under a non-cooperative dynamic game framework with expected service time of a mobile as the decision cost criteria. It is shown that individual optimality in a WLAN-UMTS hybrid cell, results in a threshold policy curve of descending staircase form with increasing Poisson arrival rate of mobiles.
[ { "created": "Fri, 4 Aug 2006 11:44:31 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kumar", "Dinesh", "", "INRIA Sophia Antipolis" ], [ "Altman", "Eitan", "", "INRIA Sophia\n Antipolis" ], [ "Kelif", "Jean-Marc", "", "INRIA Sophia Antipolis" ] ]
We study optimal user-network association in an integrated 802.11 WLAN and 3G-UMTS hybrid cell. Assuming saturated resource allocation on the downlink of WLAN and UMTS networks and a single QoS class of mobiles arriving at an average location in the hybrid cell, we formulate the problem with two different approaches: Global and Individual optimality. The Globally optimal association is formulated as an SMDP (Semi Markov Decision Process) connection routing decision problem where rewards comprise a financial gain component and an aggregate network throughput component. The corresponding Dynamic Programming equations are solved using Value Iteration method and a stationary optimal policy with neither convex nor concave type switching curve structure is obtained. Threshold type and symmetric switching curves are observed for the analogous homogenous network cases. The Individual optimality is studied under a non-cooperative dynamic game framework with expected service time of a mobile as the decision cost criteria. It is shown that individual optimality in a WLAN-UMTS hybrid cell, results in a threshold policy curve of descending staircase form with increasing Poisson arrival rate of mobiles.
2303.11910
Jiaming Zhang
Zhifeng Teng, Jiaming Zhang, Kailun Yang, Kunyu Peng, Hao Shi, Simon Rei{\ss}, Ke Cao, Rainer Stiefelhagen
360BEV: Panoramic Semantic Mapping for Indoor Bird's-Eye View
Code and datasets are available at the project page: https://jamycheung.github.io/360BEV.html. Accepted to WACV 2024
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Seeing only a tiny part of the whole is not knowing the full circumstance. Bird's-eye-view (BEV) perception, a process of obtaining allocentric maps from egocentric views, is restricted when using a narrow Field of View (FoV) alone. In this work, mapping from 360{\deg} panoramas to BEV semantics, the 360BEV task, is established for the first time to achieve holistic representations of indoor scenes in a top-down view. Instead of relying on narrow-FoV image sequences, a panoramic image with depth information is sufficient to generate a holistic BEV semantic map. To benchmark 360BEV, we present two indoor datasets, 360BEV-Matterport and 360BEV-Stanford, both of which include egocentric panoramic images and semantic segmentation labels, as well as allocentric semantic maps. Besides delving deep into different mapping paradigms, we propose a dedicated solution for panoramic semantic mapping, namely 360Mapper. Through extensive experiments, our methods achieve 44.32% and 45.78% in mIoU on both datasets respectively, surpassing previous counterparts with gains of +7.60% and +9.70% in mIoU. Code and datasets are available at the project page: https://jamycheung.github.io/360BEV.html.
[ { "created": "Tue, 21 Mar 2023 15:01:02 GMT", "version": "v1" }, { "created": "Wed, 22 Mar 2023 08:23:28 GMT", "version": "v2" }, { "created": "Fri, 25 Aug 2023 15:59:04 GMT", "version": "v3" }, { "created": "Mon, 4 Sep 2023 18:17:27 GMT", "version": "v4" } ]
2023-09-06
[ [ "Teng", "Zhifeng", "" ], [ "Zhang", "Jiaming", "" ], [ "Yang", "Kailun", "" ], [ "Peng", "Kunyu", "" ], [ "Shi", "Hao", "" ], [ "Reiß", "Simon", "" ], [ "Cao", "Ke", "" ], [ "Stiefelhagen", "Rainer", "" ] ]
Seeing only a tiny part of the whole is not knowing the full circumstance. Bird's-eye-view (BEV) perception, a process of obtaining allocentric maps from egocentric views, is restricted when using a narrow Field of View (FoV) alone. In this work, mapping from 360{\deg} panoramas to BEV semantics, the 360BEV task, is established for the first time to achieve holistic representations of indoor scenes in a top-down view. Instead of relying on narrow-FoV image sequences, a panoramic image with depth information is sufficient to generate a holistic BEV semantic map. To benchmark 360BEV, we present two indoor datasets, 360BEV-Matterport and 360BEV-Stanford, both of which include egocentric panoramic images and semantic segmentation labels, as well as allocentric semantic maps. Besides delving deep into different mapping paradigms, we propose a dedicated solution for panoramic semantic mapping, namely 360Mapper. Through extensive experiments, our methods achieve 44.32% and 45.78% in mIoU on both datasets respectively, surpassing previous counterparts with gains of +7.60% and +9.70% in mIoU. Code and datasets are available at the project page: https://jamycheung.github.io/360BEV.html.
1701.05804
Daniele Tantari
Paolo Barucca, Fabrizio Lillo, Piero Mazzarisi, Daniele Tantari
Disentangling group and link persistence in Dynamic Stochastic Block models
13 pages, 8 figures; Final Section added; figures updated
null
null
null
cs.SI cs.LG physics.soc-ph stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the inference of a model of dynamic networks in which both communities and links keep memory of previous network states. By considering maximum likelihood inference from single snapshot observations of the network, we show that link persistence makes the inference of communities harder, decreasing the detectability threshold, while community persistence tends to make it easier. We analytically show that communities inferred from single network snapshot can share a maximum overlap with the underlying communities of a specific previous instant in time. This leads to time-lagged inference: the identification of past communities rather than present ones. Finally we compute the time lag and propose a corrected algorithm, the Lagged Snapshot Dynamic (LSD) algorithm, for community detection in dynamic networks. We analytically and numerically characterize the detectability transitions of such algorithm as a function of the memory parameters of the model and we make a comparison with a full dynamic inference.
[ { "created": "Fri, 20 Jan 2017 14:33:45 GMT", "version": "v1" }, { "created": "Wed, 5 Jul 2017 11:40:17 GMT", "version": "v2" }, { "created": "Fri, 10 Nov 2017 17:52:52 GMT", "version": "v3" }, { "created": "Wed, 19 Dec 2018 17:53:42 GMT", "version": "v4" } ]
2018-12-20
[ [ "Barucca", "Paolo", "" ], [ "Lillo", "Fabrizio", "" ], [ "Mazzarisi", "Piero", "" ], [ "Tantari", "Daniele", "" ] ]
We study the inference of a model of dynamic networks in which both communities and links keep memory of previous network states. By considering maximum likelihood inference from single snapshot observations of the network, we show that link persistence makes the inference of communities harder, decreasing the detectability threshold, while community persistence tends to make it easier. We analytically show that communities inferred from single network snapshot can share a maximum overlap with the underlying communities of a specific previous instant in time. This leads to time-lagged inference: the identification of past communities rather than present ones. Finally we compute the time lag and propose a corrected algorithm, the Lagged Snapshot Dynamic (LSD) algorithm, for community detection in dynamic networks. We analytically and numerically characterize the detectability transitions of such algorithm as a function of the memory parameters of the model and we make a comparison with a full dynamic inference.
1407.4640
Valerii Sopin
Valerii Sopin
A new algorithm for solving the rSUM problem
null
null
null
null
cs.DS cs.CC cs.CG math.NT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A determined algorithm is presented for solving the rSUM problem for any natural r with a sub-quadratic assessment of time complexity in some cases. In terms of an amount of memory used the obtained algorithm is the nlog^3(n) order. The idea of the obtained algorithm is based not considering integer numbers, but rather k (is a natural) successive bits of these numbers in the binary numeration system. It is shown that if a sum of integer numbers is equal to zero, then the sum of numbers presented by any k successive bits of these numbers must be sufficiently "close" to zero. This makes it possible to discard the numbers, which a fortiori, do not establish the solution.
[ { "created": "Thu, 17 Jul 2014 11:27:30 GMT", "version": "v1" }, { "created": "Tue, 5 Aug 2014 19:02:34 GMT", "version": "v2" }, { "created": "Fri, 15 Aug 2014 00:24:38 GMT", "version": "v3" }, { "created": "Mon, 18 Aug 2014 22:18:07 GMT", "version": "v4" }, { "created": "Mon, 9 Feb 2015 09:59:04 GMT", "version": "v5" } ]
2015-02-10
[ [ "Sopin", "Valerii", "" ] ]
A determined algorithm is presented for solving the rSUM problem for any natural r with a sub-quadratic assessment of time complexity in some cases. In terms of an amount of memory used the obtained algorithm is the nlog^3(n) order. The idea of the obtained algorithm is based not considering integer numbers, but rather k (is a natural) successive bits of these numbers in the binary numeration system. It is shown that if a sum of integer numbers is equal to zero, then the sum of numbers presented by any k successive bits of these numbers must be sufficiently "close" to zero. This makes it possible to discard the numbers, which a fortiori, do not establish the solution.
1301.4337
Hiren Joshi
Mahimn Pandya, Hiren Joshi, Ashish Jani
A Novel Digital Watermarking Algorithm using Random Matrix Image
4 pages, 8 figures
International Journal of Computer Applications, Volume 61, Number 2, pp. 18-12, 2013
10.5120/9900-4481
null
cs.MM cs.CR
http://creativecommons.org/licenses/by/3.0/
The availability of bandwidth for internet access is sufficient enough to communicate digital assets. These digital assets are subjected to various types of threats. [19] As a result of this, protection mechanism required for the protection of digital assets is of priority in research. The threat of current focus is unauthorized copying of digital assets which give boost to piracy. This under the copyright act is illegal and a robust mechanism is required to curb this kind of unauthorized copy. To safeguard the copyright digital assets, a robust digital watermarking technique is needed. The existing digital watermarking techniques protect digital assets by embedding a digital watermark into a host digital image. This embedding does induce slight distortion in the host image but the distortion is usually too small to be noticed. At the same time the embedded watermark must be robust enough to with stand deliberate attacks. There are various techniques of digital watermarking but researchers are making constant efforts to increase the robustness of the watermark image. The layered approach of watermarking based on Huffman coding [5] can soon increase the robustness of digital watermark.[11] Ultimately, increasing the security of copyright of protection. The proposed work is in similar direction where in RMI (Random Matrix Image) is used in place of Huffman coding. This innovative algorithm has considerably increased the robustness in digital watermark while also enhancing security of production
[ { "created": "Fri, 18 Jan 2013 10:16:21 GMT", "version": "v1" }, { "created": "Tue, 22 Jan 2013 13:24:23 GMT", "version": "v2" } ]
2013-01-23
[ [ "Pandya", "Mahimn", "" ], [ "Joshi", "Hiren", "" ], [ "Jani", "Ashish", "" ] ]
The availability of bandwidth for internet access is sufficient enough to communicate digital assets. These digital assets are subjected to various types of threats. [19] As a result of this, protection mechanism required for the protection of digital assets is of priority in research. The threat of current focus is unauthorized copying of digital assets which give boost to piracy. This under the copyright act is illegal and a robust mechanism is required to curb this kind of unauthorized copy. To safeguard the copyright digital assets, a robust digital watermarking technique is needed. The existing digital watermarking techniques protect digital assets by embedding a digital watermark into a host digital image. This embedding does induce slight distortion in the host image but the distortion is usually too small to be noticed. At the same time the embedded watermark must be robust enough to with stand deliberate attacks. There are various techniques of digital watermarking but researchers are making constant efforts to increase the robustness of the watermark image. The layered approach of watermarking based on Huffman coding [5] can soon increase the robustness of digital watermark.[11] Ultimately, increasing the security of copyright of protection. The proposed work is in similar direction where in RMI (Random Matrix Image) is used in place of Huffman coding. This innovative algorithm has considerably increased the robustness in digital watermark while also enhancing security of production
2405.02173
Adish Singla
Chao Wen, Ahana Ghosh, Jacqueline Staub, Adish Singla
Task Synthesis for Elementary Visual Programming in XLogoOnline Environment
Accepted as a paper at the AIED'24 conference in the late-breaking results track
null
null
null
cs.HC cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years, the XLogoOnline programming platform has gained popularity among novice learners. It integrates the Logo programming language with visual programming, providing a visual interface for learning computing concepts. However, XLogoOnline offers only a limited set of tasks, which are inadequate for learners to master the computing concepts that require sufficient practice. To address this, we introduce XLogoSyn, a novel technique for synthesizing high-quality tasks for varying difficulty levels. Given a reference task, XLogoSyn can generate practice tasks at varying difficulty levels that cater to the varied needs and abilities of different learners. XLogoSyn achieves this by combining symbolic execution and constraint satisfaction techniques. Our expert study demonstrates the effectiveness of XLogoSyn. We have also deployed synthesized practice tasks into XLogoOnline, highlighting the educational benefits of these synthesized practice tasks.
[ { "created": "Fri, 3 May 2024 15:22:46 GMT", "version": "v1" } ]
2024-05-06
[ [ "Wen", "Chao", "" ], [ "Ghosh", "Ahana", "" ], [ "Staub", "Jacqueline", "" ], [ "Singla", "Adish", "" ] ]
In recent years, the XLogoOnline programming platform has gained popularity among novice learners. It integrates the Logo programming language with visual programming, providing a visual interface for learning computing concepts. However, XLogoOnline offers only a limited set of tasks, which are inadequate for learners to master the computing concepts that require sufficient practice. To address this, we introduce XLogoSyn, a novel technique for synthesizing high-quality tasks for varying difficulty levels. Given a reference task, XLogoSyn can generate practice tasks at varying difficulty levels that cater to the varied needs and abilities of different learners. XLogoSyn achieves this by combining symbolic execution and constraint satisfaction techniques. Our expert study demonstrates the effectiveness of XLogoSyn. We have also deployed synthesized practice tasks into XLogoOnline, highlighting the educational benefits of these synthesized practice tasks.
2311.07445
Junkai Zhou
Junkai Zhou, Liang Pang, Huawei Shen, Xueqi Cheng
Think Before You Speak: Cultivating Communication Skills of Large Language Models via Inner Monologue
Accepted by NAACL 2024 Findings
null
null
null
cs.CL cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The emergence of large language models (LLMs) further improves the capabilities of open-domain dialogue systems and can generate fluent, coherent, and diverse responses. However, LLMs still lack a crucial ability: communication skills. This limitation renders them more like information seeking tools rather than anthropomorphic chatbots. Communication skills, such as topic transition, proactively asking questions, concept guidance, empathy, and summarising often should be taken into consideration, to make LLMs more anthropomorphic and proactive during the conversation, thereby increasing the interest of users and attracting them to chat for longer. However, enabling these communication skills in black-box LLMs remains a key challenge because they do not have the same utterance formation mode as real people: think before speaking. Inspired by linguistics and cognitive science, we empower LLMs with communication skills through inner monologues. To evaluate various communication skills, we construct a benchmark named Cskills, which can also more comprehensively evaluate the dialogue generation ability of the model. Experimental results show that the proposed CSIM strategy improves the backbone models and outperforms the baselines.
[ { "created": "Mon, 13 Nov 2023 16:19:42 GMT", "version": "v1" }, { "created": "Fri, 15 Mar 2024 08:30:30 GMT", "version": "v2" } ]
2024-03-18
[ [ "Zhou", "Junkai", "" ], [ "Pang", "Liang", "" ], [ "Shen", "Huawei", "" ], [ "Cheng", "Xueqi", "" ] ]
The emergence of large language models (LLMs) further improves the capabilities of open-domain dialogue systems and can generate fluent, coherent, and diverse responses. However, LLMs still lack a crucial ability: communication skills. This limitation renders them more like information seeking tools rather than anthropomorphic chatbots. Communication skills, such as topic transition, proactively asking questions, concept guidance, empathy, and summarising often should be taken into consideration, to make LLMs more anthropomorphic and proactive during the conversation, thereby increasing the interest of users and attracting them to chat for longer. However, enabling these communication skills in black-box LLMs remains a key challenge because they do not have the same utterance formation mode as real people: think before speaking. Inspired by linguistics and cognitive science, we empower LLMs with communication skills through inner monologues. To evaluate various communication skills, we construct a benchmark named Cskills, which can also more comprehensively evaluate the dialogue generation ability of the model. Experimental results show that the proposed CSIM strategy improves the backbone models and outperforms the baselines.
cs/9901010
Tao Jiang
Tao Jiang (McMaster U.), Ming Li (U of Waterloo), Paul Vitanyi (CWI and U of Amsterdam)
Average-Case Complexity of Shellsort
11 pages. Submitted to ICALP'99
null
null
null
cs.DS cs.CC
null
We prove a general lower bound on the average-case complexity of Shellsort: the average number of data-movements (and comparisons) made by a $p$-pass Shellsort for any incremental sequence is $\Omega (pn^{1 + 1/p)$ for all $p \leq \log n$. Using similar arguments, we analyze the average-case complexity of several other sorting algorithms.
[ { "created": "Wed, 20 Jan 1999 16:32:01 GMT", "version": "v1" } ]
2007-05-23
[ [ "Jiang", "Tao", "", "McMaster U." ], [ "Li", "Ming", "", "U of Waterloo" ], [ "Vitanyi", "Paul", "", "CWI\n and U of Amsterdam" ] ]
We prove a general lower bound on the average-case complexity of Shellsort: the average number of data-movements (and comparisons) made by a $p$-pass Shellsort for any incremental sequence is $\Omega (pn^{1 + 1/p)$ for all $p \leq \log n$. Using similar arguments, we analyze the average-case complexity of several other sorting algorithms.
2301.11099
Runze Lei
Runze Lei, Pinghui Wang, Junzhou Zhao, Lin Lan, Jing Tao, Chao Deng, Junlan Feng, Xidian Wang, Xiaohong Guan
Federated Learning over Coupled Graphs
Accepted by IEEE Transactions on Parallel and Distributed Systems
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Graphs are widely used to represent the relations among entities. When one owns the complete data, an entire graph can be easily built, therefore performing analysis on the graph is straightforward. However, in many scenarios, it is impractical to centralize the data due to data privacy concerns. An organization or party only keeps a part of the whole graph data, i.e., graph data is isolated from different parties. Recently, Federated Learning (FL) has been proposed to solve the data isolation issue, mainly for Euclidean data. It is still a challenge to apply FL on graph data because graphs contain topological information which is notorious for its non-IID nature and is hard to partition. In this work, we propose a novel FL framework for graph data, FedCog, to efficiently handle coupled graphs that are a kind of distributed graph data, but widely exist in a variety of real-world applications such as mobile carriers' communication networks and banks' transaction networks. We theoretically prove the correctness and security of FedCog. Experimental results demonstrate that our method FedCog significantly outperforms traditional FL methods on graphs. Remarkably, our FedCog improves the accuracy of node classification tasks by up to 14.7%.
[ { "created": "Thu, 26 Jan 2023 13:43:26 GMT", "version": "v1" } ]
2023-01-27
[ [ "Lei", "Runze", "" ], [ "Wang", "Pinghui", "" ], [ "Zhao", "Junzhou", "" ], [ "Lan", "Lin", "" ], [ "Tao", "Jing", "" ], [ "Deng", "Chao", "" ], [ "Feng", "Junlan", "" ], [ "Wang", "Xidian", "" ], [ "Guan", "Xiaohong", "" ] ]
Graphs are widely used to represent the relations among entities. When one owns the complete data, an entire graph can be easily built, therefore performing analysis on the graph is straightforward. However, in many scenarios, it is impractical to centralize the data due to data privacy concerns. An organization or party only keeps a part of the whole graph data, i.e., graph data is isolated from different parties. Recently, Federated Learning (FL) has been proposed to solve the data isolation issue, mainly for Euclidean data. It is still a challenge to apply FL on graph data because graphs contain topological information which is notorious for its non-IID nature and is hard to partition. In this work, we propose a novel FL framework for graph data, FedCog, to efficiently handle coupled graphs that are a kind of distributed graph data, but widely exist in a variety of real-world applications such as mobile carriers' communication networks and banks' transaction networks. We theoretically prove the correctness and security of FedCog. Experimental results demonstrate that our method FedCog significantly outperforms traditional FL methods on graphs. Remarkably, our FedCog improves the accuracy of node classification tasks by up to 14.7%.
cs/0610174
Marko Samer
Marko Samer, Stefan Szeider
A Fixed-Parameter Algorithm for #SAT with Parameter Incidence Treewidth
9 pages, 1 figure
null
null
null
cs.DS cs.CC cs.LO
null
We present an efficient fixed-parameter algorithm for #SAT parameterized by the incidence treewidth, i.e., the treewidth of the bipartite graph whose vertices are the variables and clauses of the given CNF formula; a variable and a clause are joined by an edge if and only if the variable occurs in the clause. Our algorithm runs in time O(4^k k l N), where k denotes the incidence treewidth, l denotes the size of a largest clause, and N denotes the number of nodes of the tree-decomposition.
[ { "created": "Tue, 31 Oct 2006 12:58:36 GMT", "version": "v1" }, { "created": "Wed, 21 Feb 2007 20:56:15 GMT", "version": "v2" } ]
2007-05-23
[ [ "Samer", "Marko", "" ], [ "Szeider", "Stefan", "" ] ]
We present an efficient fixed-parameter algorithm for #SAT parameterized by the incidence treewidth, i.e., the treewidth of the bipartite graph whose vertices are the variables and clauses of the given CNF formula; a variable and a clause are joined by an edge if and only if the variable occurs in the clause. Our algorithm runs in time O(4^k k l N), where k denotes the incidence treewidth, l denotes the size of a largest clause, and N denotes the number of nodes of the tree-decomposition.
1701.07802
Gleb Pogudin
Manuel Kauers, Gleb Pogudin
Bounds for Substituting Algebraic Functions into D-finite Functions
null
null
null
null
cs.SC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is well known that the composition of a D-finite function with an algebraic function is again D-finite. We give the first estimates for the orders and the degrees of annihilating operators for the compositions. We find that the analysis of removable singularities leads to an order-degree curve which is much more accurate than the order-degree curve obtained from the usual linear algebra reasoning.
[ { "created": "Thu, 26 Jan 2017 18:12:52 GMT", "version": "v1" }, { "created": "Fri, 27 Jan 2017 09:04:38 GMT", "version": "v2" }, { "created": "Fri, 26 May 2017 09:53:44 GMT", "version": "v3" } ]
2017-05-29
[ [ "Kauers", "Manuel", "" ], [ "Pogudin", "Gleb", "" ] ]
It is well known that the composition of a D-finite function with an algebraic function is again D-finite. We give the first estimates for the orders and the degrees of annihilating operators for the compositions. We find that the analysis of removable singularities leads to an order-degree curve which is much more accurate than the order-degree curve obtained from the usual linear algebra reasoning.
1811.07555
Yuxin Zhang
Yuxin Zhang, Huan Wang, Yang Luo, Lu Yu, Haoji Hu, Hangguan Shan, Tony Q. S. Quek
Three Dimensional Convolutional Neural Network Pruning with Regularization-Based Method
ICIP 2019
ICIP 2019
null
null
cs.LG cs.CV stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Despite enjoying extensive applications in video analysis, three-dimensional convolutional neural networks (3D CNNs)are restricted by their massive computation and storage consumption. To solve this problem, we propose a threedimensional regularization-based neural network pruning method to assign different regularization parameters to different weight groups based on their importance to the network. Further we analyze the redundancy and computation cost for each layer to determine the different pruning ratios. Experiments show that pruning based on our method can lead to 2x theoretical speedup with only 0.41% accuracy loss for 3DResNet18 and 3.28% accuracy loss for C3D. The proposed method performs favorably against other popular methods for model compression and acceleration.
[ { "created": "Mon, 19 Nov 2018 08:40:00 GMT", "version": "v1" }, { "created": "Mon, 20 May 2019 03:48:09 GMT", "version": "v2" } ]
2019-05-21
[ [ "Zhang", "Yuxin", "" ], [ "Wang", "Huan", "" ], [ "Luo", "Yang", "" ], [ "Yu", "Lu", "" ], [ "Hu", "Haoji", "" ], [ "Shan", "Hangguan", "" ], [ "Quek", "Tony Q. S.", "" ] ]
Despite enjoying extensive applications in video analysis, three-dimensional convolutional neural networks (3D CNNs)are restricted by their massive computation and storage consumption. To solve this problem, we propose a threedimensional regularization-based neural network pruning method to assign different regularization parameters to different weight groups based on their importance to the network. Further we analyze the redundancy and computation cost for each layer to determine the different pruning ratios. Experiments show that pruning based on our method can lead to 2x theoretical speedup with only 0.41% accuracy loss for 3DResNet18 and 3.28% accuracy loss for C3D. The proposed method performs favorably against other popular methods for model compression and acceleration.
2009.10808
Anuj Tiwari Dr
Anuj Tiwari, Arya V. Dadhania, Vijay Avin Balaji Ragunathrao, Edson R. A. Oliveira
Using Machine Learning to Develop a Novel COVID-19 Vulnerability Index (C19VI)
null
null
null
null
cs.LG stat.AP
http://creativecommons.org/licenses/by/4.0/
COVID19 is now one of the most leading causes of death in the United States. Systemic health, social and economic disparities have put the minorities and economically poor communities at a higher risk than others. There is an immediate requirement to develop a reliable measure of county-level vulnerabilities that can capture the heterogeneity of both vulnerable communities and the COVID19 pandemic. This study reports a COVID19 Vulnerability Index (C19VI) for identification and mapping of vulnerable counties in the United States. We proposed a Random Forest machine learning based COVID19 vulnerability model using CDC sociodemographic and COVID19-specific themes. An innovative COVID19 Impact Assessment algorithm was also developed using homogeneity and trend assessment technique for evaluating severity of the pandemic in all counties and train RF model. Developed C19VI was statistically validated and compared with the CDC COVID19 Community Vulnerability Index (CCVI). Finally, using C19VI along with census data, we explored racial inequalities and economic disparities in COVID19 health outcomes amongst different regions in the United States. Our C19VI index indicates that 18.30% of the counties falls into very high vulnerability class, 24.34% in high, 23.32% in moderate, 22.34% in low, and 11.68% in very low. Furthermore, C19VI reveals that 75.57% of racial minorities and 82.84% of economically poor communities are very high or high COVID19 vulnerable regions. The proposed approach of vulnerability modeling takes advantage of both the well-established field of statistical analysis and the fast-evolving domain of machine learning. C19VI provides an accurate and more reliable way to measure county level vulnerability in the United States. This index aims at helping emergency planners to develop more effective mitigation strategies especially for the disproportionately impacted communities.
[ { "created": "Tue, 22 Sep 2020 20:48:19 GMT", "version": "v1" } ]
2020-09-24
[ [ "Tiwari", "Anuj", "" ], [ "Dadhania", "Arya V.", "" ], [ "Ragunathrao", "Vijay Avin Balaji", "" ], [ "Oliveira", "Edson R. A.", "" ] ]
COVID19 is now one of the most leading causes of death in the United States. Systemic health, social and economic disparities have put the minorities and economically poor communities at a higher risk than others. There is an immediate requirement to develop a reliable measure of county-level vulnerabilities that can capture the heterogeneity of both vulnerable communities and the COVID19 pandemic. This study reports a COVID19 Vulnerability Index (C19VI) for identification and mapping of vulnerable counties in the United States. We proposed a Random Forest machine learning based COVID19 vulnerability model using CDC sociodemographic and COVID19-specific themes. An innovative COVID19 Impact Assessment algorithm was also developed using homogeneity and trend assessment technique for evaluating severity of the pandemic in all counties and train RF model. Developed C19VI was statistically validated and compared with the CDC COVID19 Community Vulnerability Index (CCVI). Finally, using C19VI along with census data, we explored racial inequalities and economic disparities in COVID19 health outcomes amongst different regions in the United States. Our C19VI index indicates that 18.30% of the counties falls into very high vulnerability class, 24.34% in high, 23.32% in moderate, 22.34% in low, and 11.68% in very low. Furthermore, C19VI reveals that 75.57% of racial minorities and 82.84% of economically poor communities are very high or high COVID19 vulnerable regions. The proposed approach of vulnerability modeling takes advantage of both the well-established field of statistical analysis and the fast-evolving domain of machine learning. C19VI provides an accurate and more reliable way to measure county level vulnerability in the United States. This index aims at helping emergency planners to develop more effective mitigation strategies especially for the disproportionately impacted communities.
2009.00774
Yanchao Sun
Yanchao Sun, Da Huo and Furong Huang
Vulnerability-Aware Poisoning Mechanism for Online RL with Unknown Dynamics
null
The Ninth International Conference on Learning Representations (ICLR 2021)
null
null
cs.LG cs.CR stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Poisoning attacks on Reinforcement Learning (RL) systems could take advantage of RL algorithm's vulnerabilities and cause failure of the learning. However, prior works on poisoning RL usually either unrealistically assume the attacker knows the underlying Markov Decision Process (MDP), or directly apply the poisoning methods in supervised learning to RL. In this work, we build a generic poisoning framework for online RL via a comprehensive investigation of heterogeneous poisoning models in RL. Without any prior knowledge of the MDP, we propose a strategic poisoning algorithm called Vulnerability-Aware Adversarial Critic Poison (VA2C-P), which works for most policy-based deep RL agents, closing the gap that no poisoning method exists for policy-based RL agents. VA2C-P uses a novel metric, stability radius in RL, that measures the vulnerability of RL algorithms. Experiments on multiple deep RL agents and multiple environments show that our poisoning algorithm successfully prevents agents from learning a good policy or teaches the agents to converge to a target policy, with a limited attacking budget.
[ { "created": "Wed, 2 Sep 2020 01:43:30 GMT", "version": "v1" }, { "created": "Fri, 20 Nov 2020 22:24:47 GMT", "version": "v2" }, { "created": "Tue, 4 May 2021 16:09:16 GMT", "version": "v3" }, { "created": "Sat, 12 Feb 2022 16:46:31 GMT", "version": "v4" }, { "created": "Tue, 15 Feb 2022 22:18:13 GMT", "version": "v5" } ]
2022-02-17
[ [ "Sun", "Yanchao", "" ], [ "Huo", "Da", "" ], [ "Huang", "Furong", "" ] ]
Poisoning attacks on Reinforcement Learning (RL) systems could take advantage of RL algorithm's vulnerabilities and cause failure of the learning. However, prior works on poisoning RL usually either unrealistically assume the attacker knows the underlying Markov Decision Process (MDP), or directly apply the poisoning methods in supervised learning to RL. In this work, we build a generic poisoning framework for online RL via a comprehensive investigation of heterogeneous poisoning models in RL. Without any prior knowledge of the MDP, we propose a strategic poisoning algorithm called Vulnerability-Aware Adversarial Critic Poison (VA2C-P), which works for most policy-based deep RL agents, closing the gap that no poisoning method exists for policy-based RL agents. VA2C-P uses a novel metric, stability radius in RL, that measures the vulnerability of RL algorithms. Experiments on multiple deep RL agents and multiple environments show that our poisoning algorithm successfully prevents agents from learning a good policy or teaches the agents to converge to a target policy, with a limited attacking budget.
2403.06185
Zheyu Wu
Zheyu Wu, Ya-Feng Liu, Wei-Kun Chen, Christos Masouros
Quantized Constant-Envelope Waveform Design for Massive MIMO DFRC Systems
17 pages, 11 figures, submitted for possible publication
null
null
null
cs.IT eess.SP math.IT math.OC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Both dual-functional radar-communication (DFRC) and massive multiple-input multiple-output (MIMO) have been recognized as enabling technologies for 6G wireless networks. This paper considers the advanced waveform design for hardware-efficient massive MIMO DFRC systems. Specifically, the transmit waveform is imposed with the quantized constant-envelope (QCE) constraint, which facilitates the employment of low-resolution digital-to-analog converters (DACs) and power-efficient amplifiers. The waveform design problem is formulated as the minimization of the mean square error (MSE) between the designed and desired beampatterns subject to the constructive interference (CI)-based communication quality of service (QoS) constraints and the QCE constraint. To solve the formulated problem, we first utilize the penalty technique to transform the discrete problem into an equivalent continuous penalty model. Then, we propose an inexact augmented Lagrangian method (ALM) algorithm for solving the penalty model. In particular, the ALM subproblem at each iteration is solved by a custom-built block successive upper-bound minimization (BSUM) algorithm, which admits closed-form updates, making the proposed inexact ALM algorithm computationally efficient. Simulation results demonstrate the superiority of the proposed approach over existing state-of-the-art ones. In addition, extensive simulations are conducted to examine the impact of various system parameters on the trade-off between communication and radar performances.
[ { "created": "Sun, 10 Mar 2024 12:05:50 GMT", "version": "v1" } ]
2024-03-12
[ [ "Wu", "Zheyu", "" ], [ "Liu", "Ya-Feng", "" ], [ "Chen", "Wei-Kun", "" ], [ "Masouros", "Christos", "" ] ]
Both dual-functional radar-communication (DFRC) and massive multiple-input multiple-output (MIMO) have been recognized as enabling technologies for 6G wireless networks. This paper considers the advanced waveform design for hardware-efficient massive MIMO DFRC systems. Specifically, the transmit waveform is imposed with the quantized constant-envelope (QCE) constraint, which facilitates the employment of low-resolution digital-to-analog converters (DACs) and power-efficient amplifiers. The waveform design problem is formulated as the minimization of the mean square error (MSE) between the designed and desired beampatterns subject to the constructive interference (CI)-based communication quality of service (QoS) constraints and the QCE constraint. To solve the formulated problem, we first utilize the penalty technique to transform the discrete problem into an equivalent continuous penalty model. Then, we propose an inexact augmented Lagrangian method (ALM) algorithm for solving the penalty model. In particular, the ALM subproblem at each iteration is solved by a custom-built block successive upper-bound minimization (BSUM) algorithm, which admits closed-form updates, making the proposed inexact ALM algorithm computationally efficient. Simulation results demonstrate the superiority of the proposed approach over existing state-of-the-art ones. In addition, extensive simulations are conducted to examine the impact of various system parameters on the trade-off between communication and radar performances.
2403.17259
Trung-Kien Nguyen
Trung-Kien Nguyen, Yuan Fang
Diffusion-based Negative Sampling on Graphs for Link Prediction
Accepted in the TheWebConf 2024
null
null
null
cs.LG cs.SI
http://creativecommons.org/licenses/by/4.0/
Link prediction is a fundamental task for graph analysis with important applications on the Web, such as social network analysis and recommendation systems, etc. Modern graph link prediction methods often employ a contrastive approach to learn robust node representations, where negative sampling is pivotal. Typical negative sampling methods aim to retrieve hard examples based on either predefined heuristics or automatic adversarial approaches, which might be inflexible or difficult to control. Furthermore, in the context of link prediction, most previous methods sample negative nodes from existing substructures of the graph, missing out on potentially more optimal samples in the latent space. To address these issues, we investigate a novel strategy of multi-level negative sampling that enables negative node generation with flexible and controllable ``hardness'' levels from the latent space. Our method, called Conditional Diffusion-based Multi-level Negative Sampling (DMNS), leverages the Markov chain property of diffusion models to generate negative nodes in multiple levels of variable hardness and reconcile them for effective graph link prediction. We further demonstrate that DMNS follows the sub-linear positivity principle for robust negative sampling. Extensive experiments on several benchmark datasets demonstrate the effectiveness of DMNS.
[ { "created": "Mon, 25 Mar 2024 23:07:31 GMT", "version": "v1" } ]
2024-03-27
[ [ "Nguyen", "Trung-Kien", "" ], [ "Fang", "Yuan", "" ] ]
Link prediction is a fundamental task for graph analysis with important applications on the Web, such as social network analysis and recommendation systems, etc. Modern graph link prediction methods often employ a contrastive approach to learn robust node representations, where negative sampling is pivotal. Typical negative sampling methods aim to retrieve hard examples based on either predefined heuristics or automatic adversarial approaches, which might be inflexible or difficult to control. Furthermore, in the context of link prediction, most previous methods sample negative nodes from existing substructures of the graph, missing out on potentially more optimal samples in the latent space. To address these issues, we investigate a novel strategy of multi-level negative sampling that enables negative node generation with flexible and controllable ``hardness'' levels from the latent space. Our method, called Conditional Diffusion-based Multi-level Negative Sampling (DMNS), leverages the Markov chain property of diffusion models to generate negative nodes in multiple levels of variable hardness and reconcile them for effective graph link prediction. We further demonstrate that DMNS follows the sub-linear positivity principle for robust negative sampling. Extensive experiments on several benchmark datasets demonstrate the effectiveness of DMNS.
2103.07371
Huizi Mao
Huizi Mao, Sibo Zhu, Song Han, William J. Dally
PatchNet -- Short-range Template Matching for Efficient Video Processing
null
null
null
null
cs.CV cs.AI
http://creativecommons.org/publicdomain/zero/1.0/
Object recognition is a fundamental problem in many video processing tasks, accurately locating seen objects at low computation cost paves the way for on-device video recognition. We propose PatchNet, an efficient convolutional neural network to match objects in adjacent video frames. It learns the patchwise correlation features instead of pixel features. PatchNet is very compact, running at just 58MFLOPs, $5\times$ simpler than MobileNetV2. We demonstrate its application on two tasks, video object detection and visual object tracking. On ImageNet VID, PatchNet reduces the flops of R-FCN ResNet-101 by 5x and EfficientDet-D0 by 3.4x with less than 1% mAP loss. On OTB2015, PatchNet reduces SiamFC and SiamRPN by 2.5x with no accuracy loss. Experiments on Jetson Nano further demonstrate 2.8x to 4.3x speed-ups associated with flops reduction. Code is open sourced at https://github.com/RalphMao/PatchNet.
[ { "created": "Wed, 10 Mar 2021 20:56:07 GMT", "version": "v1" } ]
2021-03-15
[ [ "Mao", "Huizi", "" ], [ "Zhu", "Sibo", "" ], [ "Han", "Song", "" ], [ "Dally", "William J.", "" ] ]
Object recognition is a fundamental problem in many video processing tasks, accurately locating seen objects at low computation cost paves the way for on-device video recognition. We propose PatchNet, an efficient convolutional neural network to match objects in adjacent video frames. It learns the patchwise correlation features instead of pixel features. PatchNet is very compact, running at just 58MFLOPs, $5\times$ simpler than MobileNetV2. We demonstrate its application on two tasks, video object detection and visual object tracking. On ImageNet VID, PatchNet reduces the flops of R-FCN ResNet-101 by 5x and EfficientDet-D0 by 3.4x with less than 1% mAP loss. On OTB2015, PatchNet reduces SiamFC and SiamRPN by 2.5x with no accuracy loss. Experiments on Jetson Nano further demonstrate 2.8x to 4.3x speed-ups associated with flops reduction. Code is open sourced at https://github.com/RalphMao/PatchNet.
2110.06875
Ildik\'o Schlotter
Ildik\'o Schlotter, P\'eter Bir\'o, Tam\'as Fleiner
The core of housing markets from an agent's perspective: Is it worth sprucing up your home?
33 pages
null
null
null
cs.GT cs.DS
http://creativecommons.org/licenses/by/4.0/
We study housing markets as introduced by Shapley and Scarf (1974). We investigate the computational complexity of various questions regarding the situation of an agent $a$ in a housing market $H$: we show that it is $\mathsf{NP}$-hard to find an allocation in the core of $H$ where (i) $a$ receives a certain house, (ii) $a$ does not receive a certain house, or (iii) $a$ receives a house other than her own. We prove that the core of housing markets respects improvement in the following sense: given an allocation in the core of $H$ where agent $a$ receives a house $h$, if the value of the house owned by $a$ increases, then the resulting housing market admits an allocation in its core in which $a$ receives either $h$, or a house that $a$ prefers to $h$; moreover, such an allocation can be found efficiently. We further show an analogous result in the Stable Roommates setting by proving that stable matchings in a one-sided market also respect improvement.
[ { "created": "Wed, 13 Oct 2021 17:11:06 GMT", "version": "v1" }, { "created": "Tue, 4 Apr 2023 08:29:11 GMT", "version": "v2" }, { "created": "Wed, 10 Jan 2024 07:45:52 GMT", "version": "v3" } ]
2024-01-11
[ [ "Schlotter", "Ildikó", "" ], [ "Biró", "Péter", "" ], [ "Fleiner", "Tamás", "" ] ]
We study housing markets as introduced by Shapley and Scarf (1974). We investigate the computational complexity of various questions regarding the situation of an agent $a$ in a housing market $H$: we show that it is $\mathsf{NP}$-hard to find an allocation in the core of $H$ where (i) $a$ receives a certain house, (ii) $a$ does not receive a certain house, or (iii) $a$ receives a house other than her own. We prove that the core of housing markets respects improvement in the following sense: given an allocation in the core of $H$ where agent $a$ receives a house $h$, if the value of the house owned by $a$ increases, then the resulting housing market admits an allocation in its core in which $a$ receives either $h$, or a house that $a$ prefers to $h$; moreover, such an allocation can be found efficiently. We further show an analogous result in the Stable Roommates setting by proving that stable matchings in a one-sided market also respect improvement.
2005.04987
Daniele Silvestro
Daniele Silvestro and Tobias Andermann
Prior choice affects ability of Bayesian neural networks to identify unknowns
null
null
null
null
cs.LG cs.AI stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep Bayesian neural networks (BNNs) are a powerful tool, though computationally demanding, to perform parameter estimation while jointly estimating uncertainty around predictions. BNNs are typically implemented using arbitrary normal-distributed prior distributions on the model parameters. Here, we explore the effects of different prior distributions on classification tasks in BNNs and evaluate the evidence supporting the predictions based on posterior probabilities approximated by Markov Chain Monte Carlo sampling and by computing Bayes factors. We show that the choice of priors has a substantial impact on the ability of the model to confidently assign data to the correct class (true positive rates). Prior choice also affects significantly the ability of a BNN to identify out-of-distribution instances as unknown (false positive rates). When comparing our results against neural networks (NN) with Monte Carlo dropout we found that BNNs generally outperform NNs. Finally, in our tests we did not find a single best choice as prior distribution. Instead, each dataset yielded the best results under a different prior, indicating that testing alternative options can improve the performance of BNNs.
[ { "created": "Mon, 11 May 2020 10:32:47 GMT", "version": "v1" } ]
2020-05-12
[ [ "Silvestro", "Daniele", "" ], [ "Andermann", "Tobias", "" ] ]
Deep Bayesian neural networks (BNNs) are a powerful tool, though computationally demanding, to perform parameter estimation while jointly estimating uncertainty around predictions. BNNs are typically implemented using arbitrary normal-distributed prior distributions on the model parameters. Here, we explore the effects of different prior distributions on classification tasks in BNNs and evaluate the evidence supporting the predictions based on posterior probabilities approximated by Markov Chain Monte Carlo sampling and by computing Bayes factors. We show that the choice of priors has a substantial impact on the ability of the model to confidently assign data to the correct class (true positive rates). Prior choice also affects significantly the ability of a BNN to identify out-of-distribution instances as unknown (false positive rates). When comparing our results against neural networks (NN) with Monte Carlo dropout we found that BNNs generally outperform NNs. Finally, in our tests we did not find a single best choice as prior distribution. Instead, each dataset yielded the best results under a different prior, indicating that testing alternative options can improve the performance of BNNs.