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2007.02325
Shuiqiao Yang
Jianlong Zhou, Hamad Zogan, Shuiqiao Yang, Shoaib Jameel, Guandong Xu, Fang Chen
Detecting Community Depression Dynamics Due to COVID-19 Pandemic in Australia
null
null
null
null
cs.SI cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent COVID-19 pandemic has caused unprecedented impact across the globe. We have also witnessed millions of people with increased mental health issues, such as depression, stress, worry, fear, disgust, sadness, and anxiety, which have become one of the major public health concerns during this severe health crisis. For instance, depression is one of the most common mental health issues according to the findings made by the World Health Organisation (WHO). Depression can cause serious emotional, behavioural and physical health problems with significant consequences, both personal and social costs included. This paper studies community depression dynamics due to COVID-19 pandemic through user-generated content on Twitter. A new approach based on multi-modal features from tweets and Term Frequency-Inverse Document Frequency (TF-IDF) is proposed to build depression classification models. Multi-modal features capture depression cues from emotion, topic and domain-specific perspectives. We study the problem using recently scraped tweets from Twitter users emanating from the state of New South Wales in Australia. Our novel classification model is capable of extracting depression polarities which may be affected by COVID-19 and related events during the COVID-19 period. The results found that people became more depressed after the outbreak of COVID-19. The measures implemented by the government such as the state lockdown also increased depression levels. Further analysis in the Local Government Area (LGA) level found that the community depression level was different across different LGAs. Such granular level analysis of depression dynamics not only can help authorities such as governmental departments to take corresponding actions more objectively in specific regions if necessary but also allows users to perceive the dynamics of depression over the time.
[ { "created": "Sun, 5 Jul 2020 12:55:34 GMT", "version": "v1" } ]
2020-07-07
[ [ "Zhou", "Jianlong", "" ], [ "Zogan", "Hamad", "" ], [ "Yang", "Shuiqiao", "" ], [ "Jameel", "Shoaib", "" ], [ "Xu", "Guandong", "" ], [ "Chen", "Fang", "" ] ]
The recent COVID-19 pandemic has caused unprecedented impact across the globe. We have also witnessed millions of people with increased mental health issues, such as depression, stress, worry, fear, disgust, sadness, and anxiety, which have become one of the major public health concerns during this severe health crisis. For instance, depression is one of the most common mental health issues according to the findings made by the World Health Organisation (WHO). Depression can cause serious emotional, behavioural and physical health problems with significant consequences, both personal and social costs included. This paper studies community depression dynamics due to COVID-19 pandemic through user-generated content on Twitter. A new approach based on multi-modal features from tweets and Term Frequency-Inverse Document Frequency (TF-IDF) is proposed to build depression classification models. Multi-modal features capture depression cues from emotion, topic and domain-specific perspectives. We study the problem using recently scraped tweets from Twitter users emanating from the state of New South Wales in Australia. Our novel classification model is capable of extracting depression polarities which may be affected by COVID-19 and related events during the COVID-19 period. The results found that people became more depressed after the outbreak of COVID-19. The measures implemented by the government such as the state lockdown also increased depression levels. Further analysis in the Local Government Area (LGA) level found that the community depression level was different across different LGAs. Such granular level analysis of depression dynamics not only can help authorities such as governmental departments to take corresponding actions more objectively in specific regions if necessary but also allows users to perceive the dynamics of depression over the time.
2407.03511
Oleksandr Kuznetsov
Oleksandr Kuznetsov, Anton Yezhov, Vladyslav Yusiuk, and Kateryna Kuznetsova
Scalable Zero-Knowledge Proofs for Verifying Cryptographic Hashing in Blockchain Applications
null
null
null
null
cs.CR
http://creativecommons.org/licenses/by/4.0/
Zero-knowledge proofs (ZKPs) have emerged as a promising solution to address the scalability challenges in modern blockchain systems. This study proposes a methodology for generating and verifying ZKPs to ensure the computational integrity of cryptographic hashing, specifically focusing on the SHA-256 algorithm. By leveraging the Plonky2 framework, which implements the PLONK protocol with FRI commitment scheme, we demonstrate the efficiency and scalability of our approach for both random data and real data blocks from the NEAR blockchain. The experimental results show consistent performance across different data sizes and types, with the time required for proof generation and verification remaining within acceptable limits. The generated circuits and proofs maintain manageable sizes, even for real-world data blocks with a large number of transactions. The proposed methodology contributes to the development of secure and trustworthy blockchain systems, where the integrity of computations can be verified without revealing the underlying data. Further research is needed to assess the applicability of the approach to other cryptographic primitives and to evaluate its performance in more complex real-world scenarios.
[ { "created": "Wed, 3 Jul 2024 21:19:01 GMT", "version": "v1" } ]
2024-07-08
[ [ "Kuznetsov", "Oleksandr", "" ], [ "Yezhov", "Anton", "" ], [ "Yusiuk", "Vladyslav", "" ], [ "Kuznetsova", "Kateryna", "" ] ]
Zero-knowledge proofs (ZKPs) have emerged as a promising solution to address the scalability challenges in modern blockchain systems. This study proposes a methodology for generating and verifying ZKPs to ensure the computational integrity of cryptographic hashing, specifically focusing on the SHA-256 algorithm. By leveraging the Plonky2 framework, which implements the PLONK protocol with FRI commitment scheme, we demonstrate the efficiency and scalability of our approach for both random data and real data blocks from the NEAR blockchain. The experimental results show consistent performance across different data sizes and types, with the time required for proof generation and verification remaining within acceptable limits. The generated circuits and proofs maintain manageable sizes, even for real-world data blocks with a large number of transactions. The proposed methodology contributes to the development of secure and trustworthy blockchain systems, where the integrity of computations can be verified without revealing the underlying data. Further research is needed to assess the applicability of the approach to other cryptographic primitives and to evaluate its performance in more complex real-world scenarios.
2305.04050
Bar Karov
Bar Karov and Moni Naor
New Algorithms and Applications for Risk-Limiting Audits
A shorter version of this paper appears in the Proceeding of the 4th Annual Symposium on Foundations of Responsible Computing, FORC 2023
null
null
null
cs.CY cs.CR
http://creativecommons.org/licenses/by/4.0/
Risk-limiting audits (RLAs) are a significant tool in increasing confidence in the accuracy of elections. They consist of randomized algorithms which check that an election's vote tally, as reported by a vote tabulation system, corresponds to the correct candidates winning. If an initial vote count leads to the wrong election winner, an RLA guarantees to identify the error with high probability over its own randomness. These audits operate by sequentially sampling and examining ballots until they can either confirm the reported winner or identify the true winner. The first part of this work suggests a new generic method, called ``Batchcomp", for converting classical (ballot-level) RLAs into ones that operate on batches. As a concrete application of the suggested method, we develop the first ballot-level RLA for the Israeli Knesset elections, and convert it to one which operates on batches. We ran the suggested ``Batchcomp" procedure on the results of 22nd, 23rd and 24th Knesset elections, both with and without errors. The second part of this work suggests a new use-case for RLAs: verifying that a population census leads to the correct allocation of political power to a nation's districts or federal-states. We present an adaptation of ALPHA, an existing RLA method, to a method which applies to censuses. Our census-RLA is applicable in nations where parliament seats are allocated to geographical regions in proportion to their population according to a certain class of functions (highest averages). It relies on data from both the census and from an additional procedure which is already conducted in many countries today, called a post-enumeration survey.
[ { "created": "Sat, 6 May 2023 13:34:39 GMT", "version": "v1" } ]
2023-05-09
[ [ "Karov", "Bar", "" ], [ "Naor", "Moni", "" ] ]
Risk-limiting audits (RLAs) are a significant tool in increasing confidence in the accuracy of elections. They consist of randomized algorithms which check that an election's vote tally, as reported by a vote tabulation system, corresponds to the correct candidates winning. If an initial vote count leads to the wrong election winner, an RLA guarantees to identify the error with high probability over its own randomness. These audits operate by sequentially sampling and examining ballots until they can either confirm the reported winner or identify the true winner. The first part of this work suggests a new generic method, called ``Batchcomp", for converting classical (ballot-level) RLAs into ones that operate on batches. As a concrete application of the suggested method, we develop the first ballot-level RLA for the Israeli Knesset elections, and convert it to one which operates on batches. We ran the suggested ``Batchcomp" procedure on the results of 22nd, 23rd and 24th Knesset elections, both with and without errors. The second part of this work suggests a new use-case for RLAs: verifying that a population census leads to the correct allocation of political power to a nation's districts or federal-states. We present an adaptation of ALPHA, an existing RLA method, to a method which applies to censuses. Our census-RLA is applicable in nations where parliament seats are allocated to geographical regions in proportion to their population according to a certain class of functions (highest averages). It relies on data from both the census and from an additional procedure which is already conducted in many countries today, called a post-enumeration survey.
2308.00538
Lala Shakti Swarup Ray
Lala Shakti Swarup Ray, Vitor Fortes Rey, Bo Zhou, Sungho Suh, Paul Lukowicz
PressureTransferNet: Human Attribute Guided Dynamic Ground Pressure Profile Transfer using 3D simulated Pressure Maps
Activity and Behavior Computing 2023
null
null
null
cs.CV cs.AI cs.GR eess.IV
http://creativecommons.org/licenses/by/4.0/
We propose PressureTransferNet, a novel method for Human Activity Recognition (HAR) using ground pressure information. Our approach generates body-specific dynamic ground pressure profiles for specific activities by leveraging existing pressure data from different individuals. PressureTransferNet is an encoder-decoder model taking a source pressure map and a target human attribute vector as inputs, producing a new pressure map reflecting the target attribute. To train the model, we use a sensor simulation to create a diverse dataset with various human attributes and pressure profiles. Evaluation on a real-world dataset shows its effectiveness in accurately transferring human attributes to ground pressure profiles across different scenarios. We visually confirm the fidelity of the synthesized pressure shapes using a physics-based deep learning model and achieve a binary R-square value of 0.79 on areas with ground contact. Validation through classification with F1 score (0.911$\pm$0.015) on physical pressure mat data demonstrates the correctness of the synthesized pressure maps, making our method valuable for data augmentation, denoising, sensor simulation, and anomaly detection. Applications span sports science, rehabilitation, and bio-mechanics, contributing to the development of HAR systems.
[ { "created": "Tue, 1 Aug 2023 13:31:25 GMT", "version": "v1" } ]
2023-08-02
[ [ "Ray", "Lala Shakti Swarup", "" ], [ "Rey", "Vitor Fortes", "" ], [ "Zhou", "Bo", "" ], [ "Suh", "Sungho", "" ], [ "Lukowicz", "Paul", "" ] ]
We propose PressureTransferNet, a novel method for Human Activity Recognition (HAR) using ground pressure information. Our approach generates body-specific dynamic ground pressure profiles for specific activities by leveraging existing pressure data from different individuals. PressureTransferNet is an encoder-decoder model taking a source pressure map and a target human attribute vector as inputs, producing a new pressure map reflecting the target attribute. To train the model, we use a sensor simulation to create a diverse dataset with various human attributes and pressure profiles. Evaluation on a real-world dataset shows its effectiveness in accurately transferring human attributes to ground pressure profiles across different scenarios. We visually confirm the fidelity of the synthesized pressure shapes using a physics-based deep learning model and achieve a binary R-square value of 0.79 on areas with ground contact. Validation through classification with F1 score (0.911$\pm$0.015) on physical pressure mat data demonstrates the correctness of the synthesized pressure maps, making our method valuable for data augmentation, denoising, sensor simulation, and anomaly detection. Applications span sports science, rehabilitation, and bio-mechanics, contributing to the development of HAR systems.
2401.03428
Yuheng Cheng
Yuheng Cheng, Ceyao Zhang, Zhengwen Zhang, Xiangrui Meng, Sirui Hong, Wenhao Li, Zihao Wang, Zekai Wang, Feng Yin, Junhua Zhao, Xiuqiang He
Exploring Large Language Model based Intelligent Agents: Definitions, Methods, and Prospects
null
null
null
null
cs.AI cs.MA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Intelligent agents stand out as a potential path toward artificial general intelligence (AGI). Thus, researchers have dedicated significant effort to diverse implementations for them. Benefiting from recent progress in large language models (LLMs), LLM-based agents that use universal natural language as an interface exhibit robust generalization capabilities across various applications -- from serving as autonomous general-purpose task assistants to applications in coding, social, and economic domains, LLM-based agents offer extensive exploration opportunities. This paper surveys current research to provide an in-depth overview of LLM-based intelligent agents within single-agent and multi-agent systems. It covers their definitions, research frameworks, and foundational components such as their composition, cognitive and planning methods, tool utilization, and responses to environmental feedback. We also delve into the mechanisms of deploying LLM-based agents in multi-agent systems, including multi-role collaboration, message passing, and strategies to alleviate communication issues between agents. The discussions also shed light on popular datasets and application scenarios. We conclude by envisioning prospects for LLM-based agents, considering the evolving landscape of AI and natural language processing.
[ { "created": "Sun, 7 Jan 2024 09:08:24 GMT", "version": "v1" } ]
2024-01-09
[ [ "Cheng", "Yuheng", "" ], [ "Zhang", "Ceyao", "" ], [ "Zhang", "Zhengwen", "" ], [ "Meng", "Xiangrui", "" ], [ "Hong", "Sirui", "" ], [ "Li", "Wenhao", "" ], [ "Wang", "Zihao", "" ], [ "Wang", "Zekai", "" ], [ "Yin", "Feng", "" ], [ "Zhao", "Junhua", "" ], [ "He", "Xiuqiang", "" ] ]
Intelligent agents stand out as a potential path toward artificial general intelligence (AGI). Thus, researchers have dedicated significant effort to diverse implementations for them. Benefiting from recent progress in large language models (LLMs), LLM-based agents that use universal natural language as an interface exhibit robust generalization capabilities across various applications -- from serving as autonomous general-purpose task assistants to applications in coding, social, and economic domains, LLM-based agents offer extensive exploration opportunities. This paper surveys current research to provide an in-depth overview of LLM-based intelligent agents within single-agent and multi-agent systems. It covers their definitions, research frameworks, and foundational components such as their composition, cognitive and planning methods, tool utilization, and responses to environmental feedback. We also delve into the mechanisms of deploying LLM-based agents in multi-agent systems, including multi-role collaboration, message passing, and strategies to alleviate communication issues between agents. The discussions also shed light on popular datasets and application scenarios. We conclude by envisioning prospects for LLM-based agents, considering the evolving landscape of AI and natural language processing.
2401.04692
Nils Rodrigues
Nils Rodrigues, Frederik L. Dennig, Vincent Brandt, Daniel A. Keim, Daniel Weiskopf
Comparative Evaluation of Animated Scatter Plot Transitions
null
null
null
null
cs.HC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Scatter plots are popular for displaying 2D data, but in practice, many data sets have more than two dimensions. For the analysis of such multivariate data, it is often necessary to switch between scatter plots of different dimension pairs, e.g., in a scatter plot matrix (SPLOM). Alternative approaches include a "grand tour" for an overview of the entire data set or creating artificial axes from dimensionality reduction (DR). A cross-cutting concern in all techniques is the ability of viewers to find correspondence between data points in different views. Previous work proposed animations to preserve the mental map between view changes and to trace points as well as clusters between scatter plots of the same underlying data set. In this paper, we evaluate a variety of spline- and rotation-based view transitions in a crowdsourced user study focusing on ecological validity. Using the study results, we assess each animation's suitability for tracing points and clusters across view changes. We evaluate whether the order of horizontal and vertical rotation is relevant for task accuracy. The results show that rotations with an orthographic camera or staged expansion of a depth axis significantly outperform all other animation techniques for the traceability of individual points. Further, we provide a ranking of the animated transition techniques for traceability of individual points. However, we could not find any significant differences for the traceability of clusters. Furthermore, we identified differences by animation direction that could guide further studies to determine potential confounds for these differences. We publish the study data for reuse and provide the animation framework as a D3.js plug-in.
[ { "created": "Tue, 9 Jan 2024 17:39:45 GMT", "version": "v1" } ]
2024-01-10
[ [ "Rodrigues", "Nils", "" ], [ "Dennig", "Frederik L.", "" ], [ "Brandt", "Vincent", "" ], [ "Keim", "Daniel A.", "" ], [ "Weiskopf", "Daniel", "" ] ]
Scatter plots are popular for displaying 2D data, but in practice, many data sets have more than two dimensions. For the analysis of such multivariate data, it is often necessary to switch between scatter plots of different dimension pairs, e.g., in a scatter plot matrix (SPLOM). Alternative approaches include a "grand tour" for an overview of the entire data set or creating artificial axes from dimensionality reduction (DR). A cross-cutting concern in all techniques is the ability of viewers to find correspondence between data points in different views. Previous work proposed animations to preserve the mental map between view changes and to trace points as well as clusters between scatter plots of the same underlying data set. In this paper, we evaluate a variety of spline- and rotation-based view transitions in a crowdsourced user study focusing on ecological validity. Using the study results, we assess each animation's suitability for tracing points and clusters across view changes. We evaluate whether the order of horizontal and vertical rotation is relevant for task accuracy. The results show that rotations with an orthographic camera or staged expansion of a depth axis significantly outperform all other animation techniques for the traceability of individual points. Further, we provide a ranking of the animated transition techniques for traceability of individual points. However, we could not find any significant differences for the traceability of clusters. Furthermore, we identified differences by animation direction that could guide further studies to determine potential confounds for these differences. We publish the study data for reuse and provide the animation framework as a D3.js plug-in.
cs/0309038
Valmir Barbosa
V. C. Barbosa, L. C. D. Campos
A novel evolutionary formulation of the maximum independent set problem
null
Journal of Combinatorial Optimization 8 (2004), 419-437
10.1007/s10878-004-4835-9
ES-615/03
cs.NE
null
We introduce a novel evolutionary formulation of the problem of finding a maximum independent set of a graph. The new formulation is based on the relationship that exists between a graph's independence number and its acyclic orientations. It views such orientations as individuals and evolves them with the aid of evolutionary operators that are very heavily based on the structure of the graph and its acyclic orientations. The resulting heuristic has been tested on some of the Second DIMACS Implementation Challenge benchmark graphs, and has been found to be competitive when compared to several of the other heuristics that have also been tested on those graphs.
[ { "created": "Mon, 22 Sep 2003 13:05:51 GMT", "version": "v1" } ]
2007-05-23
[ [ "Barbosa", "V. C.", "" ], [ "Campos", "L. C. D.", "" ] ]
We introduce a novel evolutionary formulation of the problem of finding a maximum independent set of a graph. The new formulation is based on the relationship that exists between a graph's independence number and its acyclic orientations. It views such orientations as individuals and evolves them with the aid of evolutionary operators that are very heavily based on the structure of the graph and its acyclic orientations. The resulting heuristic has been tested on some of the Second DIMACS Implementation Challenge benchmark graphs, and has been found to be competitive when compared to several of the other heuristics that have also been tested on those graphs.
2309.11202
Uduak Uboh
Uduak Uboh
Using Artificial Intelligence for the Automation of Knitting Patterns
null
null
null
null
cs.AI
http://creativecommons.org/licenses/by-nc-nd/4.0/
Knitting patterns are a crucial component in the creation and design of knitted materials. Traditionally, these patterns were taught informally, but thanks to advancements in technology, anyone interested in knitting can use the patterns as a guide to start knitting. Perhaps because knitting is mostly a hobby, with the exception of industrial manufacturing utilising specialised knitting machines, the use of Al in knitting is less widespread than its application in other fields. However, it is important to determine whether knitted pattern classification using an automated system is viable. In order to recognise and classify knitting patterns. Using data augmentation and a transfer learning technique, this study proposes a deep learning model. The Inception ResNet-V2 is the main feature extraction and classification algorithm used in the model. Metrics like accuracy, logarithmic loss, F1-score, precision, and recall score were used to evaluate the model. The model evaluation's findings demonstrate high model accuracy, precision, recall, and F1 score. In addition, the AUC score for majority of the classes was in the range (0.7-0.9). A comparative analysis was done using other pretrained models and a ResNet-50 model with transfer learning and the proposed model evaluation results surpassed all others. The major limitation for this project is time, as with more time, there might have been better accuracy over a larger number of epochs.
[ { "created": "Wed, 20 Sep 2023 10:38:08 GMT", "version": "v1" } ]
2023-09-21
[ [ "Uboh", "Uduak", "" ] ]
Knitting patterns are a crucial component in the creation and design of knitted materials. Traditionally, these patterns were taught informally, but thanks to advancements in technology, anyone interested in knitting can use the patterns as a guide to start knitting. Perhaps because knitting is mostly a hobby, with the exception of industrial manufacturing utilising specialised knitting machines, the use of Al in knitting is less widespread than its application in other fields. However, it is important to determine whether knitted pattern classification using an automated system is viable. In order to recognise and classify knitting patterns. Using data augmentation and a transfer learning technique, this study proposes a deep learning model. The Inception ResNet-V2 is the main feature extraction and classification algorithm used in the model. Metrics like accuracy, logarithmic loss, F1-score, precision, and recall score were used to evaluate the model. The model evaluation's findings demonstrate high model accuracy, precision, recall, and F1 score. In addition, the AUC score for majority of the classes was in the range (0.7-0.9). A comparative analysis was done using other pretrained models and a ResNet-50 model with transfer learning and the proposed model evaluation results surpassed all others. The major limitation for this project is time, as with more time, there might have been better accuracy over a larger number of epochs.
2303.01070
Xiaoyang Yu
Xiaoyang Yu, Youfang Lin, Xiangsen Wang, Sheng Han, Kai Lv
GHQ: Grouped Hybrid Q Learning for Heterogeneous Cooperative Multi-agent Reinforcement Learning
null
null
10.1007/s40747-024-01415-1
null
cs.MA cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Previous deep multi-agent reinforcement learning (MARL) algorithms have achieved impressive results, typically in homogeneous scenarios. However, heterogeneous scenarios are also very common and usually harder to solve. In this paper, we mainly discuss cooperative heterogeneous MARL problems in Starcraft Multi-Agent Challenges (SMAC) environment. We firstly define and describe the heterogeneous problems in SMAC. In order to comprehensively reveal and study the problem, we make new maps added to the original SMAC maps. We find that baseline algorithms fail to perform well in those heterogeneous maps. To address this issue, we propose the Grouped Individual-Global-Max Consistency (GIGM) and a novel MARL algorithm, Grouped Hybrid Q Learning (GHQ). GHQ separates agents into several groups and keeps individual parameters for each group, along with a novel hybrid structure for factorization. To enhance coordination between groups, we maximize the Inter-group Mutual Information (IGMI) between groups' trajectories. Experiments on original and new heterogeneous maps show the fabulous performance of GHQ compared to other state-of-the-art algorithms.
[ { "created": "Thu, 2 Mar 2023 08:45:49 GMT", "version": "v1" }, { "created": "Wed, 14 Aug 2024 09:05:09 GMT", "version": "v2" } ]
2024-08-15
[ [ "Yu", "Xiaoyang", "" ], [ "Lin", "Youfang", "" ], [ "Wang", "Xiangsen", "" ], [ "Han", "Sheng", "" ], [ "Lv", "Kai", "" ] ]
Previous deep multi-agent reinforcement learning (MARL) algorithms have achieved impressive results, typically in homogeneous scenarios. However, heterogeneous scenarios are also very common and usually harder to solve. In this paper, we mainly discuss cooperative heterogeneous MARL problems in Starcraft Multi-Agent Challenges (SMAC) environment. We firstly define and describe the heterogeneous problems in SMAC. In order to comprehensively reveal and study the problem, we make new maps added to the original SMAC maps. We find that baseline algorithms fail to perform well in those heterogeneous maps. To address this issue, we propose the Grouped Individual-Global-Max Consistency (GIGM) and a novel MARL algorithm, Grouped Hybrid Q Learning (GHQ). GHQ separates agents into several groups and keeps individual parameters for each group, along with a novel hybrid structure for factorization. To enhance coordination between groups, we maximize the Inter-group Mutual Information (IGMI) between groups' trajectories. Experiments on original and new heterogeneous maps show the fabulous performance of GHQ compared to other state-of-the-art algorithms.
1903.01888
Luana Ruiz
Luana Ruiz, Fernando Gama and Alejandro Ribeiro
Gated Graph Convolutional Recurrent Neural Networks
Accepted at EUSIPCO 2019
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Graph processes model a number of important problems such as identifying the epicenter of an earthquake or predicting weather. In this paper, we propose a Graph Convolutional Recurrent Neural Network (GCRNN) architecture specifically tailored to deal with these problems. GCRNNs use convolutional filter banks to keep the number of trainable parameters independent of the size of the graph and of the time sequences considered. We also put forward Gated GCRNNs, a time-gated variation of GCRNNs akin to LSTMs. When compared with GNNs and another graph recurrent architecture in experiments using both synthetic and real-word data, GCRNNs significantly improve performance while using considerably less parameters.
[ { "created": "Tue, 5 Mar 2019 15:13:02 GMT", "version": "v1" }, { "created": "Tue, 18 Jun 2019 14:15:19 GMT", "version": "v2" }, { "created": "Thu, 27 Jun 2019 14:55:04 GMT", "version": "v3" } ]
2019-06-28
[ [ "Ruiz", "Luana", "" ], [ "Gama", "Fernando", "" ], [ "Ribeiro", "Alejandro", "" ] ]
Graph processes model a number of important problems such as identifying the epicenter of an earthquake or predicting weather. In this paper, we propose a Graph Convolutional Recurrent Neural Network (GCRNN) architecture specifically tailored to deal with these problems. GCRNNs use convolutional filter banks to keep the number of trainable parameters independent of the size of the graph and of the time sequences considered. We also put forward Gated GCRNNs, a time-gated variation of GCRNNs akin to LSTMs. When compared with GNNs and another graph recurrent architecture in experiments using both synthetic and real-word data, GCRNNs significantly improve performance while using considerably less parameters.
2211.05590
Pierre-Alain Mo\"ellic
Raphael Joud, Pierre-Alain Moellic, Simon Pontie, Jean-Baptiste Rigaud
A Practical Introduction to Side-Channel Extraction of Deep Neural Network Parameters
Accepted at Smart Card Research and Advanced Application Conference (CARDIS 2022)
null
null
null
cs.CR cs.LG
http://creativecommons.org/licenses/by-nc-nd/4.0/
Model extraction is a major threat for embedded deep neural network models that leverages an extended attack surface. Indeed, by physically accessing a device, an adversary may exploit side-channel leakages to extract critical information of a model (i.e., its architecture or internal parameters). Different adversarial objectives are possible including a fidelity-based scenario where the architecture and parameters are precisely extracted (model cloning). We focus this work on software implementation of deep neural networks embedded in a high-end 32-bit microcontroller (Cortex-M7) and expose several challenges related to fidelity-based parameters extraction through side-channel analysis, from the basic multiplication operation to the feed-forward connection through the layers. To precisely extract the value of parameters represented in the single-precision floating point IEEE-754 standard, we propose an iterative process that is evaluated with both simulations and traces from a Cortex-M7 target. To our knowledge, this work is the first to target such an high-end 32-bit platform. Importantly, we raise and discuss the remaining challenges for the complete extraction of a deep neural network model, more particularly the critical case of biases.
[ { "created": "Thu, 10 Nov 2022 14:02:39 GMT", "version": "v1" } ]
2022-11-11
[ [ "Joud", "Raphael", "" ], [ "Moellic", "Pierre-Alain", "" ], [ "Pontie", "Simon", "" ], [ "Rigaud", "Jean-Baptiste", "" ] ]
Model extraction is a major threat for embedded deep neural network models that leverages an extended attack surface. Indeed, by physically accessing a device, an adversary may exploit side-channel leakages to extract critical information of a model (i.e., its architecture or internal parameters). Different adversarial objectives are possible including a fidelity-based scenario where the architecture and parameters are precisely extracted (model cloning). We focus this work on software implementation of deep neural networks embedded in a high-end 32-bit microcontroller (Cortex-M7) and expose several challenges related to fidelity-based parameters extraction through side-channel analysis, from the basic multiplication operation to the feed-forward connection through the layers. To precisely extract the value of parameters represented in the single-precision floating point IEEE-754 standard, we propose an iterative process that is evaluated with both simulations and traces from a Cortex-M7 target. To our knowledge, this work is the first to target such an high-end 32-bit platform. Importantly, we raise and discuss the remaining challenges for the complete extraction of a deep neural network model, more particularly the critical case of biases.
1110.6384
Serge Gaspers
Serge Gaspers and Stefan Szeider
Backdoors to Acyclic SAT
null
null
null
null
cs.DS cs.AI cs.CC math.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Backdoor sets, a notion introduced by Williams et al. in 2003, are certain sets of key variables of a CNF formula F that make it easy to solve the formula; by assigning truth values to the variables in a backdoor set, the formula gets reduced to one or several polynomial-time solvable formulas. More specifically, a weak backdoor set of F is a set X of variables such that there exits a truth assignment t to X that reduces F to a satisfiable formula F[t] that belongs to a polynomial-time decidable base class C. A strong backdoor set is a set X of variables such that for all assignments t to X, the reduced formula F[t] belongs to C. We study the problem of finding backdoor sets of size at most k with respect to the base class of CNF formulas with acyclic incidence graphs, taking k as the parameter. We show that 1. the detection of weak backdoor sets is W[2]-hard in general but fixed-parameter tractable for r-CNF formulas, for any fixed r>=3, and 2. the detection of strong backdoor sets is fixed-parameter approximable. Result 1 is the the first positive one for a base class that does not have a characterization with obstructions of bounded size. Result 2 is the first positive one for a base class for which strong backdoor sets are more powerful than deletion backdoor sets. Not only SAT, but also #SAT can be solved in polynomial time for CNF formulas with acyclic incidence graphs. Hence Result 2 establishes a new structural parameter that makes #SAT fixed-parameter tractable and that is incomparable with known parameters such as treewidth and clique-width. We obtain the algorithms by a combination of an algorithmic version of the Erd\"os-P\'osa Theorem, Courcelle's model checking for monadic second order logic, and new combinatorial results on how disjoint cycles can interact with the backdoor set.
[ { "created": "Fri, 28 Oct 2011 16:10:32 GMT", "version": "v1" }, { "created": "Mon, 31 Oct 2011 15:09:42 GMT", "version": "v2" }, { "created": "Tue, 21 Feb 2012 17:15:41 GMT", "version": "v3" } ]
2012-02-22
[ [ "Gaspers", "Serge", "" ], [ "Szeider", "Stefan", "" ] ]
Backdoor sets, a notion introduced by Williams et al. in 2003, are certain sets of key variables of a CNF formula F that make it easy to solve the formula; by assigning truth values to the variables in a backdoor set, the formula gets reduced to one or several polynomial-time solvable formulas. More specifically, a weak backdoor set of F is a set X of variables such that there exits a truth assignment t to X that reduces F to a satisfiable formula F[t] that belongs to a polynomial-time decidable base class C. A strong backdoor set is a set X of variables such that for all assignments t to X, the reduced formula F[t] belongs to C. We study the problem of finding backdoor sets of size at most k with respect to the base class of CNF formulas with acyclic incidence graphs, taking k as the parameter. We show that 1. the detection of weak backdoor sets is W[2]-hard in general but fixed-parameter tractable for r-CNF formulas, for any fixed r>=3, and 2. the detection of strong backdoor sets is fixed-parameter approximable. Result 1 is the the first positive one for a base class that does not have a characterization with obstructions of bounded size. Result 2 is the first positive one for a base class for which strong backdoor sets are more powerful than deletion backdoor sets. Not only SAT, but also #SAT can be solved in polynomial time for CNF formulas with acyclic incidence graphs. Hence Result 2 establishes a new structural parameter that makes #SAT fixed-parameter tractable and that is incomparable with known parameters such as treewidth and clique-width. We obtain the algorithms by a combination of an algorithmic version of the Erd\"os-P\'osa Theorem, Courcelle's model checking for monadic second order logic, and new combinatorial results on how disjoint cycles can interact with the backdoor set.
2406.09815
Zhenrui Yue
Zhenrui Yue, Huimin Zeng, Lanyu Shang, Yifan Liu, Yang Zhang, Dong Wang
Retrieval Augmented Fact Verification by Synthesizing Contrastive Arguments
Accepted to ACL 2024
null
null
null
cs.CL cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The rapid propagation of misinformation poses substantial risks to public interest. To combat misinformation, large language models (LLMs) are adapted to automatically verify claim credibility. Nevertheless, existing methods heavily rely on the embedded knowledge within LLMs and / or black-box APIs for evidence collection, leading to subpar performance with smaller LLMs or upon unreliable context. In this paper, we propose retrieval augmented fact verification through the synthesis of contrasting arguments (RAFTS). Upon input claims, RAFTS starts with evidence retrieval, where we design a retrieval pipeline to collect and re-rank relevant documents from verifiable sources. Then, RAFTS forms contrastive arguments (i.e., supporting or refuting) conditioned on the retrieved evidence. In addition, RAFTS leverages an embedding model to identify informative demonstrations, followed by in-context prompting to generate the prediction and explanation. Our method effectively retrieves relevant documents as evidence and evaluates arguments from varying perspectives, incorporating nuanced information for fine-grained decision-making. Combined with informative in-context examples as prior, RAFTS achieves significant improvements to supervised and LLM baselines without complex prompts. We demonstrate the effectiveness of our method through extensive experiments, where RAFTS can outperform GPT-based methods with a significantly smaller 7B LLM.
[ { "created": "Fri, 14 Jun 2024 08:13:34 GMT", "version": "v1" } ]
2024-06-17
[ [ "Yue", "Zhenrui", "" ], [ "Zeng", "Huimin", "" ], [ "Shang", "Lanyu", "" ], [ "Liu", "Yifan", "" ], [ "Zhang", "Yang", "" ], [ "Wang", "Dong", "" ] ]
The rapid propagation of misinformation poses substantial risks to public interest. To combat misinformation, large language models (LLMs) are adapted to automatically verify claim credibility. Nevertheless, existing methods heavily rely on the embedded knowledge within LLMs and / or black-box APIs for evidence collection, leading to subpar performance with smaller LLMs or upon unreliable context. In this paper, we propose retrieval augmented fact verification through the synthesis of contrasting arguments (RAFTS). Upon input claims, RAFTS starts with evidence retrieval, where we design a retrieval pipeline to collect and re-rank relevant documents from verifiable sources. Then, RAFTS forms contrastive arguments (i.e., supporting or refuting) conditioned on the retrieved evidence. In addition, RAFTS leverages an embedding model to identify informative demonstrations, followed by in-context prompting to generate the prediction and explanation. Our method effectively retrieves relevant documents as evidence and evaluates arguments from varying perspectives, incorporating nuanced information for fine-grained decision-making. Combined with informative in-context examples as prior, RAFTS achieves significant improvements to supervised and LLM baselines without complex prompts. We demonstrate the effectiveness of our method through extensive experiments, where RAFTS can outperform GPT-based methods with a significantly smaller 7B LLM.
1911.11494
Christopher Thraves Caro
Rosa Becerra and Christopher Thraves Caro
The Sitting Closer to Friends than Enemies Problem in Trees
10 pages, 5 figures
null
null
null
cs.DM cs.CG math.CO
http://creativecommons.org/licenses/by-nc-nd/4.0/
A metric space $\mathcal{T}$ is a \emph{real tree} if for any pair of points $x, y \in \mathcal{T}$ all topological embeddings $\sigma$ of the segment $[0,1]$ into $\mathcal{T}$, such that $\sigma (0)=x$ and $\sigma (1)=y$, have the same image (which is then a geodesic segment from $x$ to $y$). A \emph{signed graph} is a graph where each edge has a positive or negative sign. The \emph{Sitting Closer to Friends than Enemies} problem in trees has a signed graph $S$ as an input. The purpose is to determine if there exists an injective mapping (called \emph{valid distance drawing}) from $V(S)$ to the points of a real tree such that, for every $u \in V(S)$, for every positive neighbor $v$ of $u$, and negative neighbor $w$ of $u$, the distance between $v$ and $u$ is smaller than the distance between $w$ and $u$. In this work, we show that a complete signed graph has a valid distance drawing in a real tree if and only if its subgraph composed of all (and only) its positive edges has an intersection representation by unit balls in a real tree. Besides, as an instrumental result, we show that a graph has an intersection representation by unit balls in a real tree if and only if it has an intersection representation by proper balls, and if and only if it has an intersection representation by arbitrary balls in a real tree.
[ { "created": "Tue, 26 Nov 2019 12:31:50 GMT", "version": "v1" }, { "created": "Tue, 16 Feb 2021 14:38:17 GMT", "version": "v2" }, { "created": "Mon, 5 Jul 2021 15:01:24 GMT", "version": "v3" } ]
2021-07-06
[ [ "Becerra", "Rosa", "" ], [ "Caro", "Christopher Thraves", "" ] ]
A metric space $\mathcal{T}$ is a \emph{real tree} if for any pair of points $x, y \in \mathcal{T}$ all topological embeddings $\sigma$ of the segment $[0,1]$ into $\mathcal{T}$, such that $\sigma (0)=x$ and $\sigma (1)=y$, have the same image (which is then a geodesic segment from $x$ to $y$). A \emph{signed graph} is a graph where each edge has a positive or negative sign. The \emph{Sitting Closer to Friends than Enemies} problem in trees has a signed graph $S$ as an input. The purpose is to determine if there exists an injective mapping (called \emph{valid distance drawing}) from $V(S)$ to the points of a real tree such that, for every $u \in V(S)$, for every positive neighbor $v$ of $u$, and negative neighbor $w$ of $u$, the distance between $v$ and $u$ is smaller than the distance between $w$ and $u$. In this work, we show that a complete signed graph has a valid distance drawing in a real tree if and only if its subgraph composed of all (and only) its positive edges has an intersection representation by unit balls in a real tree. Besides, as an instrumental result, we show that a graph has an intersection representation by unit balls in a real tree if and only if it has an intersection representation by proper balls, and if and only if it has an intersection representation by arbitrary balls in a real tree.
1404.7335
Florent Jacquemard
Florent Jacquemard (Inria Paris-Rocquencourt, STMS), Cl\'ement Poncelet Sanchez (Inria Paris-Rocquencourt, STMS)
Antescofo Intermediate Representation
RR-8520 (2014)
null
null
null
cs.MM cs.PL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe an intermediate language designed as a medium-level internal representation of programs of the interactive music system Antescofo. This representation is independent both of the Antescofo source language and of the architecture of the execution platform. It is used in tasks such as verification of timings, model-based conformance testing, static control-flow analysis or simulation. This language is essentially a flat representation of Antescofo's code, as a finite state machine extended with local and global variables, with delays and with concurrent threads creation. It features a small number of simple instructions which are either blocking (wait for external event, signal or duration) or not (variable assignment, message emission and control).
[ { "created": "Tue, 29 Apr 2014 12:30:36 GMT", "version": "v1" } ]
2014-04-30
[ [ "Jacquemard", "Florent", "", "Inria Paris-Rocquencourt, STMS" ], [ "Sanchez", "Clément Poncelet", "", "Inria Paris-Rocquencourt, STMS" ] ]
We describe an intermediate language designed as a medium-level internal representation of programs of the interactive music system Antescofo. This representation is independent both of the Antescofo source language and of the architecture of the execution platform. It is used in tasks such as verification of timings, model-based conformance testing, static control-flow analysis or simulation. This language is essentially a flat representation of Antescofo's code, as a finite state machine extended with local and global variables, with delays and with concurrent threads creation. It features a small number of simple instructions which are either blocking (wait for external event, signal or duration) or not (variable assignment, message emission and control).
2010.13903
Denghui Zhang
Denghui Zhang, Yanchi Liu, Wei Cheng, Bo Zong, Jingchao Ni, Zhengzhang Chen, Haifeng Chen, Hui Xiong
T$^2$-Net: A Semi-supervised Deep Model for Turbulence Forecasting
Accepted by ICDM 2020
null
null
null
cs.LG
http://creativecommons.org/licenses/by-nc-sa/4.0/
Accurate air turbulence forecasting can help airlines avoid hazardous turbulence, guide the routes that keep passengers safe, maximize efficiency, and reduce costs. Traditional turbulence forecasting approaches heavily rely on painstakingly customized turbulence indexes, which are less effective in dynamic and complex weather conditions. The recent availability of high-resolution weather data and turbulence records allows more accurate forecasting of the turbulence in a data-driven way. However, it is a non-trivial task for developing a machine learning based turbulence forecasting system due to two challenges: (1) Complex spatio-temporal correlations, turbulence is caused by air movement with complex spatio-temporal patterns, (2) Label scarcity, very limited turbulence labels can be obtained. To this end, in this paper, we develop a unified semi-supervised framework, T$^2$-Net, to address the above challenges. Specifically, we first build an encoder-decoder paradigm based on the convolutional LSTM to model the spatio-temporal correlations. Then, to tackle the label scarcity problem, we propose a novel Dual Label Guessing method to take advantage of massive unlabeled turbulence data. It integrates complementary signals from the main Turbulence Forecasting task and the auxiliary Turbulence Detection task to generate pseudo-labels, which are dynamically utilized as additional training data. Finally, extensive experimental results on a real-world turbulence dataset validate the superiority of our method on turbulence forecasting.
[ { "created": "Mon, 26 Oct 2020 21:14:15 GMT", "version": "v1" } ]
2020-10-28
[ [ "Zhang", "Denghui", "" ], [ "Liu", "Yanchi", "" ], [ "Cheng", "Wei", "" ], [ "Zong", "Bo", "" ], [ "Ni", "Jingchao", "" ], [ "Chen", "Zhengzhang", "" ], [ "Chen", "Haifeng", "" ], [ "Xiong", "Hui", "" ] ]
Accurate air turbulence forecasting can help airlines avoid hazardous turbulence, guide the routes that keep passengers safe, maximize efficiency, and reduce costs. Traditional turbulence forecasting approaches heavily rely on painstakingly customized turbulence indexes, which are less effective in dynamic and complex weather conditions. The recent availability of high-resolution weather data and turbulence records allows more accurate forecasting of the turbulence in a data-driven way. However, it is a non-trivial task for developing a machine learning based turbulence forecasting system due to two challenges: (1) Complex spatio-temporal correlations, turbulence is caused by air movement with complex spatio-temporal patterns, (2) Label scarcity, very limited turbulence labels can be obtained. To this end, in this paper, we develop a unified semi-supervised framework, T$^2$-Net, to address the above challenges. Specifically, we first build an encoder-decoder paradigm based on the convolutional LSTM to model the spatio-temporal correlations. Then, to tackle the label scarcity problem, we propose a novel Dual Label Guessing method to take advantage of massive unlabeled turbulence data. It integrates complementary signals from the main Turbulence Forecasting task and the auxiliary Turbulence Detection task to generate pseudo-labels, which are dynamically utilized as additional training data. Finally, extensive experimental results on a real-world turbulence dataset validate the superiority of our method on turbulence forecasting.
1810.07273
R.Stuart Geiger
R. Stuart Geiger, Aaron Halfaker
Operationalizing Conflict and Cooperation between Automated Software Agents in Wikipedia: A Replication and Expansion of 'Even Good Bots Fight'
33 pages. In ACM CSCW 2018
Proc ACM on Human Computer Interaction. 1(2), Article 49. CSCW 2018
10.1145/3134684
null
cs.CY cs.HC cs.SI
http://creativecommons.org/licenses/by/4.0/
This paper replicates, extends, and refutes conclusions made in a study published in PLoS ONE ("Even Good Bots Fight"), which claimed to identify substantial levels of conflict between automated software agents (or bots) in Wikipedia using purely quantitative methods. By applying an integrative mixed-methods approach drawing on trace ethnography, we place these alleged cases of bot-bot conflict into context and arrive at a better understanding of these interactions. We found that overwhelmingly, the interactions previously characterized as problematic instances of conflict are typically better characterized as routine, productive, even collaborative work. These results challenge past work and show the importance of qualitative/quantitative collaboration. In our paper, we present quantitative metrics and qualitative heuristics for operationalizing bot-bot conflict. We give thick descriptions of kinds of events that present as bot-bot reverts, helping distinguish conflict from non-conflict. We computationally classify these kinds of events through patterns in edit summaries. By interpreting found/trace data in the socio-technical contexts in which people give that data meaning, we gain more from quantitative measurements, drawing deeper understandings about the governance of algorithmic systems in Wikipedia. We have also released our data collection, processing, and analysis pipeline, to facilitate computational reproducibility of our findings and to help other researchers interested in conducting similar mixed-method scholarship in other platforms and contexts.
[ { "created": "Tue, 16 Oct 2018 20:59:19 GMT", "version": "v1" } ]
2018-10-18
[ [ "Geiger", "R. Stuart", "" ], [ "Halfaker", "Aaron", "" ] ]
This paper replicates, extends, and refutes conclusions made in a study published in PLoS ONE ("Even Good Bots Fight"), which claimed to identify substantial levels of conflict between automated software agents (or bots) in Wikipedia using purely quantitative methods. By applying an integrative mixed-methods approach drawing on trace ethnography, we place these alleged cases of bot-bot conflict into context and arrive at a better understanding of these interactions. We found that overwhelmingly, the interactions previously characterized as problematic instances of conflict are typically better characterized as routine, productive, even collaborative work. These results challenge past work and show the importance of qualitative/quantitative collaboration. In our paper, we present quantitative metrics and qualitative heuristics for operationalizing bot-bot conflict. We give thick descriptions of kinds of events that present as bot-bot reverts, helping distinguish conflict from non-conflict. We computationally classify these kinds of events through patterns in edit summaries. By interpreting found/trace data in the socio-technical contexts in which people give that data meaning, we gain more from quantitative measurements, drawing deeper understandings about the governance of algorithmic systems in Wikipedia. We have also released our data collection, processing, and analysis pipeline, to facilitate computational reproducibility of our findings and to help other researchers interested in conducting similar mixed-method scholarship in other platforms and contexts.
2203.10470
Yuanming Ren
Yuanming Ren, Shihao Shen, Yanli Ju, Xiaofei Wang, Wenyu Wang, Victor C.M. Leung
EdgeMatrix: A Resources Redefined Edge-Cloud System for Prioritized Services
null
null
null
null
cs.NI cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The edge-cloud system has the potential to combine the advantages of heterogeneous devices and truly realize ubiquitous computing. However, for service providers to guarantee the Service-Level-Agreement (SLA) priorities, the complex networked environment brings inherent challenges such as multi-resource heterogeneity, resource competition, and networked system dynamics. In this paper, we design a framework for the edge-cloud system, namely EdgeMatrix, to maximize the throughput while guaranteeing various SLA priorities. First, EdgeMatrix introduces Networked Multi-agent Actor-Critic (NMAC) algorithm to redefine physical resources as logically isolated resource combinations, i.e., resource cells. Then, we use a clustering algorithm to group the cells with similar characteristics into various sets, i.e., resource channels, for different channels can offer different SLA guarantees. Besides, we design a multi-task mechanism to solve the problem of joint service orchestration and request dispatch (JSORD) among edge-cloud clusters, significantly reducing the runtime than traditional methods. To ensure stability, EdgeMatrix adopts a two-time-scale framework, i.e., coordinating resources and services at the large time scale and dispatching requests at the small time scale. The real trace-based experimental results verify that EdgeMatrix can improve system throughput in complex networked environments, reduce SLA violations, and significantly reduce the runtime than traditional methods.
[ { "created": "Sun, 20 Mar 2022 06:47:34 GMT", "version": "v1" } ]
2022-03-22
[ [ "Ren", "Yuanming", "" ], [ "Shen", "Shihao", "" ], [ "Ju", "Yanli", "" ], [ "Wang", "Xiaofei", "" ], [ "Wang", "Wenyu", "" ], [ "Leung", "Victor C. M.", "" ] ]
The edge-cloud system has the potential to combine the advantages of heterogeneous devices and truly realize ubiquitous computing. However, for service providers to guarantee the Service-Level-Agreement (SLA) priorities, the complex networked environment brings inherent challenges such as multi-resource heterogeneity, resource competition, and networked system dynamics. In this paper, we design a framework for the edge-cloud system, namely EdgeMatrix, to maximize the throughput while guaranteeing various SLA priorities. First, EdgeMatrix introduces Networked Multi-agent Actor-Critic (NMAC) algorithm to redefine physical resources as logically isolated resource combinations, i.e., resource cells. Then, we use a clustering algorithm to group the cells with similar characteristics into various sets, i.e., resource channels, for different channels can offer different SLA guarantees. Besides, we design a multi-task mechanism to solve the problem of joint service orchestration and request dispatch (JSORD) among edge-cloud clusters, significantly reducing the runtime than traditional methods. To ensure stability, EdgeMatrix adopts a two-time-scale framework, i.e., coordinating resources and services at the large time scale and dispatching requests at the small time scale. The real trace-based experimental results verify that EdgeMatrix can improve system throughput in complex networked environments, reduce SLA violations, and significantly reduce the runtime than traditional methods.
2210.02576
Yongbin Liu
Liu Yongbin, Liu Qingjie, Chen Jiaxin, Wang Yunhong
Reading Chinese in Natural Scenes with a Bag-of-Radicals Prior
Accepted by BMVC 2022
null
null
null
cs.CV cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Scene text recognition (STR) on Latin datasets has been extensively studied in recent years, and state-of-the-art (SOTA) models often reach high accuracy. However, the performance on non-Latin transcripts, such as Chinese, is not satisfactory. In this paper, we collect six open-source Chinese STR datasets and evaluate a series of classic methods performing well on Latin datasets, finding a significant performance drop. To improve the performance on Chinese datasets, we propose a novel radical-embedding (RE) representation to utilize the ideographic descriptions of Chinese characters. The ideographic descriptions of Chinese characters are firstly converted to bags of radicals and then fused with learnable character embeddings by a character-vector-fusion-module (CVFM). In addition, we utilize a bag of radicals as supervision signals for multi-task training to improve the ideographic structure perception of our model. Experiments show performance of the model with RE + CVFM + multi-task training is superior compared with the baseline on six Chinese STR datasets. In addition, we utilize a bag of radicals as supervision signals for multi-task training to improve the ideographic structure perception of our model. Experiments show performance of the model with RE + CVFM + multi-task training is superior compared with the baseline on six Chinese STR datasets.
[ { "created": "Wed, 5 Oct 2022 21:56:09 GMT", "version": "v1" } ]
2022-10-07
[ [ "Yongbin", "Liu", "" ], [ "Qingjie", "Liu", "" ], [ "Jiaxin", "Chen", "" ], [ "Yunhong", "Wang", "" ] ]
Scene text recognition (STR) on Latin datasets has been extensively studied in recent years, and state-of-the-art (SOTA) models often reach high accuracy. However, the performance on non-Latin transcripts, such as Chinese, is not satisfactory. In this paper, we collect six open-source Chinese STR datasets and evaluate a series of classic methods performing well on Latin datasets, finding a significant performance drop. To improve the performance on Chinese datasets, we propose a novel radical-embedding (RE) representation to utilize the ideographic descriptions of Chinese characters. The ideographic descriptions of Chinese characters are firstly converted to bags of radicals and then fused with learnable character embeddings by a character-vector-fusion-module (CVFM). In addition, we utilize a bag of radicals as supervision signals for multi-task training to improve the ideographic structure perception of our model. Experiments show performance of the model with RE + CVFM + multi-task training is superior compared with the baseline on six Chinese STR datasets. In addition, we utilize a bag of radicals as supervision signals for multi-task training to improve the ideographic structure perception of our model. Experiments show performance of the model with RE + CVFM + multi-task training is superior compared with the baseline on six Chinese STR datasets.
2302.02048
Junyuan Gao
Junyuan Gao, Yongpeng Wu, Tianya Li, and Wenjun Zhang
Energy Efficiency of MIMO Massive Unsourced Random Access with Finite Blocklength
Accepted by IEEE Wireless Communications Letters
null
null
null
cs.IT math.IT
http://creativecommons.org/licenses/by/4.0/
This paper investigates the energy efficiency of massive unsourced random access~(URA) in multiple-input multiple-output quasi-static Rayleigh fading channels. Specifically, we derive achievability and converse bounds on the minimum required energy-per-bit under the per-user probability of error constraint, where the converse bounds contain two parts: one is general and the other is a weaker ensemble bound. Numerical evaluation shows that the gap between our achievability and converse bounds is less than $5$~dB in the considered regime. Some practical schemes are energy-inefficient compared with our bounds especially when there are many users. Moreover, we observe that in contrast to the sourced random access paradigm, the URA paradigm achieves higher spectral efficiency.
[ { "created": "Sat, 4 Feb 2023 01:11:18 GMT", "version": "v1" } ]
2023-02-07
[ [ "Gao", "Junyuan", "" ], [ "Wu", "Yongpeng", "" ], [ "Li", "Tianya", "" ], [ "Zhang", "Wenjun", "" ] ]
This paper investigates the energy efficiency of massive unsourced random access~(URA) in multiple-input multiple-output quasi-static Rayleigh fading channels. Specifically, we derive achievability and converse bounds on the minimum required energy-per-bit under the per-user probability of error constraint, where the converse bounds contain two parts: one is general and the other is a weaker ensemble bound. Numerical evaluation shows that the gap between our achievability and converse bounds is less than $5$~dB in the considered regime. Some practical schemes are energy-inefficient compared with our bounds especially when there are many users. Moreover, we observe that in contrast to the sourced random access paradigm, the URA paradigm achieves higher spectral efficiency.
2007.07155
Mohammad Shojaeshafiei
Mohammad Shojaeshafiei, Letha Etzkorn, and Michael Anderson
multiple layers of fuzzy logic to quantify vulnerabilies in iot
null
null
null
null
cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quantifying vulnerabilities of network systems has been a highly controversial issue in the fields of network security and IoT. Much research has been conducted on this purpose; however, these have many ambiguities and uncertainties. In this paper, we investigate the quantification of vulnerability in the Department of Transportation (DOT) as our proof of concept. We initiate the analysis of security requirements, using Security Quality Requirements Engineering (SQUARE) for security requirements elicitation. Then we apply published security standards such as NIST SP-800 and ISO 27001 to map our security factors and sub-factors. Finally, we propose our Multi-layered Fuzzy Logic (MFL) approach based on Goal question Metrics (GQM) to quantify network security and IoT (Mobile Devices) vulnerability in DOT.
[ { "created": "Tue, 14 Jul 2020 16:14:51 GMT", "version": "v1" } ]
2020-07-15
[ [ "Shojaeshafiei", "Mohammad", "" ], [ "Etzkorn", "Letha", "" ], [ "Anderson", "Michael", "" ] ]
Quantifying vulnerabilities of network systems has been a highly controversial issue in the fields of network security and IoT. Much research has been conducted on this purpose; however, these have many ambiguities and uncertainties. In this paper, we investigate the quantification of vulnerability in the Department of Transportation (DOT) as our proof of concept. We initiate the analysis of security requirements, using Security Quality Requirements Engineering (SQUARE) for security requirements elicitation. Then we apply published security standards such as NIST SP-800 and ISO 27001 to map our security factors and sub-factors. Finally, we propose our Multi-layered Fuzzy Logic (MFL) approach based on Goal question Metrics (GQM) to quantify network security and IoT (Mobile Devices) vulnerability in DOT.
2307.13661
Henry DeYoung
Henry DeYoung and Andreia Mordido and Frank Pfenning and Ankush Das
Parametric Subtyping for Structural Parametric Polymorphism
36 pages
null
null
null
cs.PL cs.LO
http://creativecommons.org/licenses/by/4.0/
We study the interaction of structural subtyping with parametric polymorphism and recursively defined type constructors. Although structural subtyping is undecidable in this setting, we describe a notion of parametricity for type constructors and then exploit it to define parametric subtyping, a conceptually simple, decidable, and expressive fragment of structural subtyping that strictly generalizes rigid subtyping. We present and prove correct an effective saturation-based decision procedure for parametric subtyping, demonstrating its applicability using a variety of examples. We also provide an implementation of this decision procedure online.
[ { "created": "Tue, 25 Jul 2023 17:14:49 GMT", "version": "v1" }, { "created": "Fri, 27 Oct 2023 15:55:47 GMT", "version": "v2" } ]
2023-10-30
[ [ "DeYoung", "Henry", "" ], [ "Mordido", "Andreia", "" ], [ "Pfenning", "Frank", "" ], [ "Das", "Ankush", "" ] ]
We study the interaction of structural subtyping with parametric polymorphism and recursively defined type constructors. Although structural subtyping is undecidable in this setting, we describe a notion of parametricity for type constructors and then exploit it to define parametric subtyping, a conceptually simple, decidable, and expressive fragment of structural subtyping that strictly generalizes rigid subtyping. We present and prove correct an effective saturation-based decision procedure for parametric subtyping, demonstrating its applicability using a variety of examples. We also provide an implementation of this decision procedure online.
1310.1362
J. M. Landsberg
Fulvio Gesmundo, Jonathan Hauenstein, Christian Ikenmeyer, and JM Landsberg
Complexity of linear circuits and geometry
29 pages, final version to appear in FOCM
null
null
null
cs.CC math.AG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use algebraic geometry to study matrix rigidity, and more generally, the complexity of computing a matrix-vector product, continuing a study initiated by Kumar, et. al. We (i) exhibit many non-obvious equations testing for (border) rigidity, (ii) compute degrees of varieties associated to rigidity, (iii) describe algebraic varieties associated to families of matrices that are expected to have super-linear rigidity, and (iv) prove results about the ideals and degrees of cones that are of interest in their own right.
[ { "created": "Fri, 4 Oct 2013 18:34:45 GMT", "version": "v1" }, { "created": "Tue, 10 Mar 2015 19:36:21 GMT", "version": "v2" } ]
2015-03-11
[ [ "Gesmundo", "Fulvio", "" ], [ "Hauenstein", "Jonathan", "" ], [ "Ikenmeyer", "Christian", "" ], [ "Landsberg", "JM", "" ] ]
We use algebraic geometry to study matrix rigidity, and more generally, the complexity of computing a matrix-vector product, continuing a study initiated by Kumar, et. al. We (i) exhibit many non-obvious equations testing for (border) rigidity, (ii) compute degrees of varieties associated to rigidity, (iii) describe algebraic varieties associated to families of matrices that are expected to have super-linear rigidity, and (iv) prove results about the ideals and degrees of cones that are of interest in their own right.
2305.17179
Tomasz Limisiewicz
Tomasz Limisiewicz and Ji\v{r}\'i Balhar and David Mare\v{c}ek
Tokenization Impacts Multilingual Language Modeling: Assessing Vocabulary Allocation and Overlap Across Languages
in ACL Findings 2023
null
null
null
cs.CL
http://creativecommons.org/licenses/by/4.0/
Multilingual language models have recently gained attention as a promising solution for representing multiple languages in a single model. In this paper, we propose new criteria to evaluate the quality of lexical representation and vocabulary overlap observed in sub-word tokenizers. Our findings show that the overlap of vocabulary across languages can be actually detrimental to certain downstream tasks (POS, dependency tree labeling). In contrast, NER and sentence-level tasks (cross-lingual retrieval, NLI) benefit from sharing vocabulary. We also observe that the coverage of the language-specific tokens in the multilingual vocabulary significantly impacts the word-level tasks. Our study offers a deeper understanding of the role of tokenizers in multilingual language models and guidelines for future model developers to choose the most suitable tokenizer for their specific application before undertaking costly model pre-training
[ { "created": "Fri, 26 May 2023 18:06:49 GMT", "version": "v1" } ]
2023-05-30
[ [ "Limisiewicz", "Tomasz", "" ], [ "Balhar", "Jiří", "" ], [ "Mareček", "David", "" ] ]
Multilingual language models have recently gained attention as a promising solution for representing multiple languages in a single model. In this paper, we propose new criteria to evaluate the quality of lexical representation and vocabulary overlap observed in sub-word tokenizers. Our findings show that the overlap of vocabulary across languages can be actually detrimental to certain downstream tasks (POS, dependency tree labeling). In contrast, NER and sentence-level tasks (cross-lingual retrieval, NLI) benefit from sharing vocabulary. We also observe that the coverage of the language-specific tokens in the multilingual vocabulary significantly impacts the word-level tasks. Our study offers a deeper understanding of the role of tokenizers in multilingual language models and guidelines for future model developers to choose the most suitable tokenizer for their specific application before undertaking costly model pre-training
2108.00382
Matthew Andres Moreno
Matthew Andres Moreno, Santiago Rodriguez Papa, Alexander Lalejini, Charles Ofria
SignalGP-Lite: Event Driven Genetic Programming Library for Large-Scale Artificial Life Applications
null
null
null
null
cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Event-driven genetic programming representations have been shown to outperform traditional imperative representations on interaction-intensive problems. The event-driven approach organizes genome content into modules that are triggered in response to environmental signals, simplifying simulation design and implementation. Existing work developing event-driven genetic programming methodology has largely used the SignalGP library, which caters to traditional program synthesis applications. The SignalGP-Lite library enables larger-scale artificial life experiments with streamlined agents by reducing control flow overhead and trading run-time flexibility for better performance due to compile-time configuration. Here, we report benchmarking experiments that show an 8x to 30x speedup. We also report solution quality equivalent to SignalGP on two benchmark problems originally developed to test the ability of evolved programs to respond to a large number of signals and to modulate signal response based on context.
[ { "created": "Sun, 1 Aug 2021 07:20:49 GMT", "version": "v1" } ]
2021-08-03
[ [ "Moreno", "Matthew Andres", "" ], [ "Papa", "Santiago Rodriguez", "" ], [ "Lalejini", "Alexander", "" ], [ "Ofria", "Charles", "" ] ]
Event-driven genetic programming representations have been shown to outperform traditional imperative representations on interaction-intensive problems. The event-driven approach organizes genome content into modules that are triggered in response to environmental signals, simplifying simulation design and implementation. Existing work developing event-driven genetic programming methodology has largely used the SignalGP library, which caters to traditional program synthesis applications. The SignalGP-Lite library enables larger-scale artificial life experiments with streamlined agents by reducing control flow overhead and trading run-time flexibility for better performance due to compile-time configuration. Here, we report benchmarking experiments that show an 8x to 30x speedup. We also report solution quality equivalent to SignalGP on two benchmark problems originally developed to test the ability of evolved programs to respond to a large number of signals and to modulate signal response based on context.
1706.09667
Maxinder S. Kanwal
Maxinder S. Kanwal, Joshua A. Grochow, Nihat Ay
Comparing Information-Theoretic Measures of Complexity in Boltzmann Machines
16 pages, 7 figures; Appears in Entropy, Special Issue "Information Geometry II"
Entropy (2017), 19(7), 310
10.3390/e19070310
null
cs.IT cs.NE math.IT q-bio.NC
http://creativecommons.org/licenses/by/4.0/
In the past three decades, many theoretical measures of complexity have been proposed to help understand complex systems. In this work, for the first time, we place these measures on a level playing field, to explore the qualitative similarities and differences between them, and their shortcomings. Specifically, using the Boltzmann machine architecture (a fully connected recurrent neural network) with uniformly distributed weights as our model of study, we numerically measure how complexity changes as a function of network dynamics and network parameters. We apply an extension of one such information-theoretic measure of complexity to understand incremental Hebbian learning in Hopfield networks, a fully recurrent architecture model of autoassociative memory. In the course of Hebbian learning, the total information flow reflects a natural upward trend in complexity as the network attempts to learn more and more patterns.
[ { "created": "Thu, 29 Jun 2017 10:39:15 GMT", "version": "v1" }, { "created": "Sun, 30 Jul 2017 01:01:49 GMT", "version": "v2" } ]
2017-08-01
[ [ "Kanwal", "Maxinder S.", "" ], [ "Grochow", "Joshua A.", "" ], [ "Ay", "Nihat", "" ] ]
In the past three decades, many theoretical measures of complexity have been proposed to help understand complex systems. In this work, for the first time, we place these measures on a level playing field, to explore the qualitative similarities and differences between them, and their shortcomings. Specifically, using the Boltzmann machine architecture (a fully connected recurrent neural network) with uniformly distributed weights as our model of study, we numerically measure how complexity changes as a function of network dynamics and network parameters. We apply an extension of one such information-theoretic measure of complexity to understand incremental Hebbian learning in Hopfield networks, a fully recurrent architecture model of autoassociative memory. In the course of Hebbian learning, the total information flow reflects a natural upward trend in complexity as the network attempts to learn more and more patterns.
1508.04228
Hyeji Kim
Hyeji Kim and Benjamin Nachman and Abbas El Gamal
Superposition Coding is Almost Always Optimal for the Poisson Broadcast Channel
17 pages, 11 figures, submitted to IEEE Transactions on Information Theory
null
null
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper shows that the capacity region of the continuous-time Poisson broadcast channel is achieved via superposition coding for most channel parameter values. Interestingly, the channel in some subset of these parameter values does not belong to any of the existing classes of broadcast channels for which superposition coding is optimal (e.g., degraded, less noisy, more capable). In particular, we introduce the notion of effectively less noisy broadcast channel and show that it implies less noisy but is not in general implied by more capable. For the rest of the channel parameter values, we show that there is a gap between Marton's inner bound and the UV outer bound.
[ { "created": "Tue, 18 Aug 2015 06:49:33 GMT", "version": "v1" }, { "created": "Wed, 26 Aug 2015 23:11:04 GMT", "version": "v2" } ]
2015-08-28
[ [ "Kim", "Hyeji", "" ], [ "Nachman", "Benjamin", "" ], [ "Gamal", "Abbas El", "" ] ]
This paper shows that the capacity region of the continuous-time Poisson broadcast channel is achieved via superposition coding for most channel parameter values. Interestingly, the channel in some subset of these parameter values does not belong to any of the existing classes of broadcast channels for which superposition coding is optimal (e.g., degraded, less noisy, more capable). In particular, we introduce the notion of effectively less noisy broadcast channel and show that it implies less noisy but is not in general implied by more capable. For the rest of the channel parameter values, we show that there is a gap between Marton's inner bound and the UV outer bound.
1807.11241
Mahendran Subramanian
Billy Woods, Mahendran Subramanian, Ali Shafti and A. Aldo Faisal
Mechanomyography based closed-loop Functional Electrical Stimulation cycling system
Functional Electrical Stimulation Closed loop system, The 7th IEEE RAS/EMBS International Conference on Biomedical Robotics and Biomechatronics 2018
null
null
null
cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Functional Electrical Stimulation (FES) systems are successful in restoring motor function and supporting paralyzed users. Commercially available FES products are open loop, meaning that the system is unable to adapt to changing conditions with the user and their muscles which results in muscle fatigue and poor stimulation protocols. This is because it is difficult to close the loop between stimulation and monitoring of muscle contraction using adaptive stimulation. FES causes electrical artefacts which make it challenging to monitor muscle contractions with traditional methods such as electromyography (EMG). We look to overcome this limitation by combining FES with novel mechanomyographic (MMG) sensors to be able to monitor muscle activity during stimulation in real time. To provide a meaningful task we built an FES cycling rig with a software interface that enabled us to perform adaptive recording and stimulation, and then combine this with sensors to record forces applied to the pedals using force sensitive resistors (FSRs), crank angle position using a magnetic incremental encoder and inputs from the user using switches and a potentiometer. We illustrated this with a closed-loop stimulation algorithm that used the inputs from the sensors to control the output of a programmable RehaStim 1 FES stimulator (Hasomed) in real-time. This recumbent bicycle rig was used as a testing platform for FES cycling. The algorithm was designed to respond to a change in requested speed (RPM) from the user and change the stimulation power (% of maximum current mA) until this speed was achieved and then maintain it.
[ { "created": "Mon, 30 Jul 2018 08:59:14 GMT", "version": "v1" } ]
2018-07-31
[ [ "Woods", "Billy", "" ], [ "Subramanian", "Mahendran", "" ], [ "Shafti", "Ali", "" ], [ "Faisal", "A. Aldo", "" ] ]
Functional Electrical Stimulation (FES) systems are successful in restoring motor function and supporting paralyzed users. Commercially available FES products are open loop, meaning that the system is unable to adapt to changing conditions with the user and their muscles which results in muscle fatigue and poor stimulation protocols. This is because it is difficult to close the loop between stimulation and monitoring of muscle contraction using adaptive stimulation. FES causes electrical artefacts which make it challenging to monitor muscle contractions with traditional methods such as electromyography (EMG). We look to overcome this limitation by combining FES with novel mechanomyographic (MMG) sensors to be able to monitor muscle activity during stimulation in real time. To provide a meaningful task we built an FES cycling rig with a software interface that enabled us to perform adaptive recording and stimulation, and then combine this with sensors to record forces applied to the pedals using force sensitive resistors (FSRs), crank angle position using a magnetic incremental encoder and inputs from the user using switches and a potentiometer. We illustrated this with a closed-loop stimulation algorithm that used the inputs from the sensors to control the output of a programmable RehaStim 1 FES stimulator (Hasomed) in real-time. This recumbent bicycle rig was used as a testing platform for FES cycling. The algorithm was designed to respond to a change in requested speed (RPM) from the user and change the stimulation power (% of maximum current mA) until this speed was achieved and then maintain it.
1711.05611
David Bau iii
Bolei Zhou, David Bau, Aude Oliva, and Antonio Torralba
Interpreting Deep Visual Representations via Network Dissection
*B. Zhou and D. Bau contributed equally to this work. 15 pages, 27 figures
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The success of recent deep convolutional neural networks (CNNs) depends on learning hidden representations that can summarize the important factors of variation behind the data. However, CNNs often criticized as being black boxes that lack interpretability, since they have millions of unexplained model parameters. In this work, we describe Network Dissection, a method that interprets networks by providing labels for the units of their deep visual representations. The proposed method quantifies the interpretability of CNN representations by evaluating the alignment between individual hidden units and a set of visual semantic concepts. By identifying the best alignments, units are given human interpretable labels across a range of objects, parts, scenes, textures, materials, and colors. The method reveals that deep representations are more transparent and interpretable than expected: we find that representations are significantly more interpretable than they would be under a random equivalently powerful basis. We apply the method to interpret and compare the latent representations of various network architectures trained to solve different supervised and self-supervised training tasks. We then examine factors affecting the network interpretability such as the number of the training iterations, regularizations, different initializations, and the network depth and width. Finally we show that the interpreted units can be used to provide explicit explanations of a prediction given by a CNN for an image. Our results highlight that interpretability is an important property of deep neural networks that provides new insights into their hierarchical structure.
[ { "created": "Wed, 15 Nov 2017 15:05:25 GMT", "version": "v1" }, { "created": "Tue, 26 Jun 2018 15:38:31 GMT", "version": "v2" } ]
2018-06-27
[ [ "Zhou", "Bolei", "" ], [ "Bau", "David", "" ], [ "Oliva", "Aude", "" ], [ "Torralba", "Antonio", "" ] ]
The success of recent deep convolutional neural networks (CNNs) depends on learning hidden representations that can summarize the important factors of variation behind the data. However, CNNs often criticized as being black boxes that lack interpretability, since they have millions of unexplained model parameters. In this work, we describe Network Dissection, a method that interprets networks by providing labels for the units of their deep visual representations. The proposed method quantifies the interpretability of CNN representations by evaluating the alignment between individual hidden units and a set of visual semantic concepts. By identifying the best alignments, units are given human interpretable labels across a range of objects, parts, scenes, textures, materials, and colors. The method reveals that deep representations are more transparent and interpretable than expected: we find that representations are significantly more interpretable than they would be under a random equivalently powerful basis. We apply the method to interpret and compare the latent representations of various network architectures trained to solve different supervised and self-supervised training tasks. We then examine factors affecting the network interpretability such as the number of the training iterations, regularizations, different initializations, and the network depth and width. Finally we show that the interpreted units can be used to provide explicit explanations of a prediction given by a CNN for an image. Our results highlight that interpretability is an important property of deep neural networks that provides new insights into their hierarchical structure.
1812.01167
Erik Demaine
Erik D. Demaine and Martin L. Demaine and David A. Huffman and Duks Koschitz and Tomohiro Tachi
Conic Crease Patterns with Reflecting Rule Lines
17 pages, 12 figures. In Origami^7: Proceedings of the 7th International Meeting on Origami in Science, Mathematics and Education
null
null
null
cs.CG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We characterize when two conic curved creases are compatible with each other, when the rule lines must converge to conic foci and reflect at the crease. Namely, two conics are compatible (can be connected by rule segments in a foldable curved crease pattern) if and only if they have equal or reciprocal eccentricity. Thus, circles (eccentricity 0) and parabolas (eccentricity 1) are compatible with only themselves (when scaled from a focus), and ellipses (eccentricity strictly between 0 and 1) and hyperbolas (eccentricity above 1) are compatible with themselves and each other (but only in specific pairings). The foundation of this result is a general condition relating any two curved creases connected by rule segments. We also use our characterization to analyze several curved crease designs.
[ { "created": "Tue, 4 Dec 2018 02:18:12 GMT", "version": "v1" } ]
2018-12-05
[ [ "Demaine", "Erik D.", "" ], [ "Demaine", "Martin L.", "" ], [ "Huffman", "David A.", "" ], [ "Koschitz", "Duks", "" ], [ "Tachi", "Tomohiro", "" ] ]
We characterize when two conic curved creases are compatible with each other, when the rule lines must converge to conic foci and reflect at the crease. Namely, two conics are compatible (can be connected by rule segments in a foldable curved crease pattern) if and only if they have equal or reciprocal eccentricity. Thus, circles (eccentricity 0) and parabolas (eccentricity 1) are compatible with only themselves (when scaled from a focus), and ellipses (eccentricity strictly between 0 and 1) and hyperbolas (eccentricity above 1) are compatible with themselves and each other (but only in specific pairings). The foundation of this result is a general condition relating any two curved creases connected by rule segments. We also use our characterization to analyze several curved crease designs.
1507.08569
Mohsen Yaghoubi Suraki
Mohsen Yaghoubi Suraki, Morteza Yaghoubi Suraki, Leila SourakiAzad
HMIoT: A New Healthcare Model Based on Internet of Things
8 pages, 9 figures, Journal
IJCSI International Journal of Computer Science Issues, Volume 12, Issue 1, No 1, January 2015 ISSN (Print): 1694-0814 | ISSN (Online): 1694-0784 www.IJCSI.org
null
null
cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent century, with developing of equipment, using of the internet and things connected to the internet is growing. Therefore, the need for informing in the process of expanding the scope of its application is very necessary and important. These days, using intelligent and autonomous devices in our daily lives has become commonplace and the Internet is the most important part of the relationship between these tools and even at close distances also. Things connected to the Internet that are currently in use and can be inclusive of all the sciences as a step to develop and coordinate of them. In this paper we investigate application and using of Internet of things from the perspective of various sciences. We show that how this phenomenon can influence on future health of people.
[ { "created": "Tue, 28 Jul 2015 20:18:18 GMT", "version": "v1" } ]
2015-07-31
[ [ "Suraki", "Mohsen Yaghoubi", "" ], [ "Suraki", "Morteza Yaghoubi", "" ], [ "SourakiAzad", "Leila", "" ] ]
In recent century, with developing of equipment, using of the internet and things connected to the internet is growing. Therefore, the need for informing in the process of expanding the scope of its application is very necessary and important. These days, using intelligent and autonomous devices in our daily lives has become commonplace and the Internet is the most important part of the relationship between these tools and even at close distances also. Things connected to the Internet that are currently in use and can be inclusive of all the sciences as a step to develop and coordinate of them. In this paper we investigate application and using of Internet of things from the perspective of various sciences. We show that how this phenomenon can influence on future health of people.
2304.12931
Victor Jung
Victor J.B. Jung, Arne Symons, Linyan Mei, Marian Verhelst, Luca Benini
SALSA: Simulated Annealing based Loop-Ordering Scheduler for DNN Accelerators
5 pages, 6 figures, open-source at https://github.com/ZigZag-Project/zigzag
null
null
null
cs.AR cs.AI
http://creativecommons.org/licenses/by-nc-sa/4.0/
To meet the growing need for computational power for DNNs, multiple specialized hardware architectures have been proposed. Each DNN layer should be mapped onto the hardware with the most efficient schedule, however, SotA schedulers struggle to consistently provide optimum schedules in a reasonable time across all DNN-HW combinations. This paper proposes SALSA, a fast dual-engine scheduler to generate optimal execution schedules for both even and uneven mapping. We introduce a new strategy, combining exhaustive search with simulated annealing to address the dynamic nature of the loop ordering design space size across layers. SALSA is extensively benchmarked against two SotA schedulers, LOMA and Timeloop on 5 different DNNs, on average SALSA finds schedules with 11.9% and 7.6% lower energy while speeding up the search by 1.7x and 24x compared to LOMA and Timeloop, respectively.
[ { "created": "Thu, 20 Apr 2023 12:00:08 GMT", "version": "v1" }, { "created": "Fri, 14 Jun 2024 07:49:38 GMT", "version": "v2" } ]
2024-06-17
[ [ "Jung", "Victor J. B.", "" ], [ "Symons", "Arne", "" ], [ "Mei", "Linyan", "" ], [ "Verhelst", "Marian", "" ], [ "Benini", "Luca", "" ] ]
To meet the growing need for computational power for DNNs, multiple specialized hardware architectures have been proposed. Each DNN layer should be mapped onto the hardware with the most efficient schedule, however, SotA schedulers struggle to consistently provide optimum schedules in a reasonable time across all DNN-HW combinations. This paper proposes SALSA, a fast dual-engine scheduler to generate optimal execution schedules for both even and uneven mapping. We introduce a new strategy, combining exhaustive search with simulated annealing to address the dynamic nature of the loop ordering design space size across layers. SALSA is extensively benchmarked against two SotA schedulers, LOMA and Timeloop on 5 different DNNs, on average SALSA finds schedules with 11.9% and 7.6% lower energy while speeding up the search by 1.7x and 24x compared to LOMA and Timeloop, respectively.
1405.0641
Xiaojun Wan
Xiaojun Wan
x-index: a fantastic new indicator for quantifying a scientist's scientific impact
null
null
null
null
cs.DL physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
h-index has become the most popular indicator for quantifying a scientist's scientific impact in various scientific fields. h-index is defined as the largest number of papers with citation number larger than or equal to h and it treats each citation equally. However, different citations usually come from different papers with different influence and quality, and a citation from a highly influential paper is a greater recognition of the target paper than a citation from an ordinary paper. Based on this assumption, we proposed a new indicator named x-index to quantify a scientist's scientific impact by considering only the citations coming from influential papers. x-index is defined as the largest number of papers with influential citation number larger than or equal to x, where each influential citation comes from a paper for which the average ACNPP (Average Citation Number Per Paper) of its authors larger than or equal to x . Through analysis on the APS dataset, we find that the proposed x-index has much better ability to discriminate between Physics Prize Winners and ordinary physicists.
[ { "created": "Sun, 4 May 2014 02:26:52 GMT", "version": "v1" } ]
2014-05-06
[ [ "Wan", "Xiaojun", "" ] ]
h-index has become the most popular indicator for quantifying a scientist's scientific impact in various scientific fields. h-index is defined as the largest number of papers with citation number larger than or equal to h and it treats each citation equally. However, different citations usually come from different papers with different influence and quality, and a citation from a highly influential paper is a greater recognition of the target paper than a citation from an ordinary paper. Based on this assumption, we proposed a new indicator named x-index to quantify a scientist's scientific impact by considering only the citations coming from influential papers. x-index is defined as the largest number of papers with influential citation number larger than or equal to x, where each influential citation comes from a paper for which the average ACNPP (Average Citation Number Per Paper) of its authors larger than or equal to x . Through analysis on the APS dataset, we find that the proposed x-index has much better ability to discriminate between Physics Prize Winners and ordinary physicists.
2105.12990
Tianyi Zhang
Tianyi Zhang, Jie Lin, Peng Hu, Bin Zhao, Mohamed M. Sabry Aly
PSRR-MaxpoolNMS: Pyramid Shifted MaxpoolNMS with Relationship Recovery
Accepted by CVPR2021
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Non-maximum Suppression (NMS) is an essential postprocessing step in modern convolutional neural networks for object detection. Unlike convolutions which are inherently parallel, the de-facto standard for NMS, namely GreedyNMS, cannot be easily parallelized and thus could be the performance bottleneck in convolutional object detection pipelines. MaxpoolNMS is introduced as a parallelizable alternative to GreedyNMS, which in turn enables faster speed than GreedyNMS at comparable accuracy. However, MaxpoolNMS is only capable of replacing the GreedyNMS at the first stage of two-stage detectors like Faster-RCNN. There is a significant drop in accuracy when applying MaxpoolNMS at the final detection stage, due to the fact that MaxpoolNMS fails to approximate GreedyNMS precisely in terms of bounding box selection. In this paper, we propose a general, parallelizable and configurable approach PSRR-MaxpoolNMS, to completely replace GreedyNMS at all stages in all detectors. By introducing a simple Relationship Recovery module and a Pyramid Shifted MaxpoolNMS module, our PSRR-MaxpoolNMS is able to approximate GreedyNMS more precisely than MaxpoolNMS. Comprehensive experiments show that our approach outperforms MaxpoolNMS by a large margin, and it is proven faster than GreedyNMS with comparable accuracy. For the first time, PSRR-MaxpoolNMS provides a fully parallelizable solution for customized hardware design, which can be reused for accelerating NMS everywhere.
[ { "created": "Thu, 27 May 2021 08:24:21 GMT", "version": "v1" } ]
2021-05-28
[ [ "Zhang", "Tianyi", "" ], [ "Lin", "Jie", "" ], [ "Hu", "Peng", "" ], [ "Zhao", "Bin", "" ], [ "Aly", "Mohamed M. Sabry", "" ] ]
Non-maximum Suppression (NMS) is an essential postprocessing step in modern convolutional neural networks for object detection. Unlike convolutions which are inherently parallel, the de-facto standard for NMS, namely GreedyNMS, cannot be easily parallelized and thus could be the performance bottleneck in convolutional object detection pipelines. MaxpoolNMS is introduced as a parallelizable alternative to GreedyNMS, which in turn enables faster speed than GreedyNMS at comparable accuracy. However, MaxpoolNMS is only capable of replacing the GreedyNMS at the first stage of two-stage detectors like Faster-RCNN. There is a significant drop in accuracy when applying MaxpoolNMS at the final detection stage, due to the fact that MaxpoolNMS fails to approximate GreedyNMS precisely in terms of bounding box selection. In this paper, we propose a general, parallelizable and configurable approach PSRR-MaxpoolNMS, to completely replace GreedyNMS at all stages in all detectors. By introducing a simple Relationship Recovery module and a Pyramid Shifted MaxpoolNMS module, our PSRR-MaxpoolNMS is able to approximate GreedyNMS more precisely than MaxpoolNMS. Comprehensive experiments show that our approach outperforms MaxpoolNMS by a large margin, and it is proven faster than GreedyNMS with comparable accuracy. For the first time, PSRR-MaxpoolNMS provides a fully parallelizable solution for customized hardware design, which can be reused for accelerating NMS everywhere.
1003.1940
Vamsi Kundeti
Vamsi Kundeti, Sanguthevar Rajasekaran, Hieu Dinh
Efficient Parallel and Out of Core Algorithms for Constructing Large Bi-directed de Bruijn Graphs
null
null
null
null
cs.DS cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Assembling genomic sequences from a set of overlapping reads is one of the most fundamental problems in computational biology. Algorithms addressing the assembly problem fall into two broad categories -- based on the data structures which they employ. The first class uses an overlap/string graph and the second type uses a de Bruijn graph. However with the recent advances in short read sequencing technology, de Bruijn graph based algorithms seem to play a vital role in practice. Efficient algorithms for building these massive de Bruijn graphs are very essential in large sequencing projects based on short reads. In Jackson et. al. ICPP-2008, an $O(n/p)$ time parallel algorithm has been given for this problem. Here $n$ is the size of the input and $p$ is the number of processors. This algorithm enumerates all possible bi-directed edges which can overlap with a node and ends up generating $\Theta(n\Sigma)$ messages. In this paper we present a $\Theta(n/p)$ time parallel algorithm with a communication complexity equal to that of parallel sorting and is not sensitive to $\Sigma$. The generality of our algorithm makes it very easy to extend it even to the out-of-core model and in this case it has an optimal I/O complexity of $\Theta(\frac{n\log(n/B)}{B\log(M/B)})$. We demonstrate the scalability of our parallel algorithm on a SGI/Altix computer. A comparison of our algorithm with that of Jackson et. al. ICPP-2008 reveals that our algorithm is faster. We also provide efficient algorithms for the bi-directed chain compaction problem.
[ { "created": "Tue, 9 Mar 2010 17:54:01 GMT", "version": "v1" } ]
2010-03-10
[ [ "Kundeti", "Vamsi", "" ], [ "Rajasekaran", "Sanguthevar", "" ], [ "Dinh", "Hieu", "" ] ]
Assembling genomic sequences from a set of overlapping reads is one of the most fundamental problems in computational biology. Algorithms addressing the assembly problem fall into two broad categories -- based on the data structures which they employ. The first class uses an overlap/string graph and the second type uses a de Bruijn graph. However with the recent advances in short read sequencing technology, de Bruijn graph based algorithms seem to play a vital role in practice. Efficient algorithms for building these massive de Bruijn graphs are very essential in large sequencing projects based on short reads. In Jackson et. al. ICPP-2008, an $O(n/p)$ time parallel algorithm has been given for this problem. Here $n$ is the size of the input and $p$ is the number of processors. This algorithm enumerates all possible bi-directed edges which can overlap with a node and ends up generating $\Theta(n\Sigma)$ messages. In this paper we present a $\Theta(n/p)$ time parallel algorithm with a communication complexity equal to that of parallel sorting and is not sensitive to $\Sigma$. The generality of our algorithm makes it very easy to extend it even to the out-of-core model and in this case it has an optimal I/O complexity of $\Theta(\frac{n\log(n/B)}{B\log(M/B)})$. We demonstrate the scalability of our parallel algorithm on a SGI/Altix computer. A comparison of our algorithm with that of Jackson et. al. ICPP-2008 reveals that our algorithm is faster. We also provide efficient algorithms for the bi-directed chain compaction problem.
2401.00031
Xiaoqian Liu
Xiaoqian Liu, Jianbin Jiao, Junge Zhang
Self-supervised Pretraining for Decision Foundation Model: Formulation, Pipeline and Challenges
null
null
null
null
cs.LG cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Decision-making is a dynamic process requiring perception, memory, and reasoning to make choices and find optimal policies. Traditional approaches to decision-making suffer from sample efficiency and generalization, while large-scale self-supervised pretraining has enabled fast adaptation with fine-tuning or few-shot learning in language and vision. We thus argue to integrate knowledge acquired from generic large-scale self-supervised pretraining into downstream decision-making problems. We propose Pretrain-Then-Adapt pipeline and survey recent work on data collection, pretraining objectives and adaptation strategies for decision-making pretraining and downstream inference. Finally, we identify critical challenges and future directions for developing decision foundation model with the help of generic and flexible self-supervised pretraining.
[ { "created": "Fri, 29 Dec 2023 08:18:52 GMT", "version": "v1" }, { "created": "Fri, 5 Jan 2024 07:21:06 GMT", "version": "v2" } ]
2024-01-08
[ [ "Liu", "Xiaoqian", "" ], [ "Jiao", "Jianbin", "" ], [ "Zhang", "Junge", "" ] ]
Decision-making is a dynamic process requiring perception, memory, and reasoning to make choices and find optimal policies. Traditional approaches to decision-making suffer from sample efficiency and generalization, while large-scale self-supervised pretraining has enabled fast adaptation with fine-tuning or few-shot learning in language and vision. We thus argue to integrate knowledge acquired from generic large-scale self-supervised pretraining into downstream decision-making problems. We propose Pretrain-Then-Adapt pipeline and survey recent work on data collection, pretraining objectives and adaptation strategies for decision-making pretraining and downstream inference. Finally, we identify critical challenges and future directions for developing decision foundation model with the help of generic and flexible self-supervised pretraining.
1406.5153
Ioannis Giotis
Josep D\'iaz, Ioannis Giotis, Lefteris Kirousis, Yiannis Mourtos, Maria J. Serna
Optimizing the Social Cost of Congestion Games by Imposing Variable Delays
null
null
null
null
cs.GT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe a new coordination mechanism for non-atomic congestion games that leads to a (selfish) social cost which is arbitrarily close to the non-selfish optimal. This mechanism does not incur any additional extra cost, like tolls, which are usually differentiated from the social cost as expressed in terms of delays only.
[ { "created": "Thu, 19 Jun 2014 19:05:40 GMT", "version": "v1" } ]
2014-06-20
[ [ "Díaz", "Josep", "" ], [ "Giotis", "Ioannis", "" ], [ "Kirousis", "Lefteris", "" ], [ "Mourtos", "Yiannis", "" ], [ "Serna", "Maria J.", "" ] ]
We describe a new coordination mechanism for non-atomic congestion games that leads to a (selfish) social cost which is arbitrarily close to the non-selfish optimal. This mechanism does not incur any additional extra cost, like tolls, which are usually differentiated from the social cost as expressed in terms of delays only.
0901.0753
Sung-eok Jeon
Sung-eok Jeon and Chuanyi Ji
Distributed Preemption Decisions: Probabilistic Graphical Model, Algorithm and Near-Optimality
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cooperative decision making is a vision of future network management and control. Distributed connection preemption is an important example where nodes can make intelligent decisions on allocating resources and controlling traffic flows for multi-class service networks. A challenge is that nodal decisions are spatially dependent as traffic flows trespass multiple nodes in a network. Hence the performance-complexity trade-off becomes important, i.e., how accurate decisions are versus how much information is exchanged among nodes. Connection preemption is known to be NP-complete. Centralized preemption is optimal but computationally intractable. Decentralized preemption is computationally efficient but may result in a poor performance. This work investigates distributed preemption where nodes decide whether and which flows to preempt using only local information exchange with neighbors. We develop, based on the probabilistic graphical models, a near-optimal distributed algorithm. The algorithm is used by each node to make collectively near-optimal preemption decisions. We study trade-offs between near-optimal performance and complexity that corresponds to the amount of information-exchange of the distributed algorithm. The algorithm is validated by both analysis and simulation.
[ { "created": "Wed, 7 Jan 2009 04:36:58 GMT", "version": "v1" } ]
2009-01-08
[ [ "Jeon", "Sung-eok", "" ], [ "Ji", "Chuanyi", "" ] ]
Cooperative decision making is a vision of future network management and control. Distributed connection preemption is an important example where nodes can make intelligent decisions on allocating resources and controlling traffic flows for multi-class service networks. A challenge is that nodal decisions are spatially dependent as traffic flows trespass multiple nodes in a network. Hence the performance-complexity trade-off becomes important, i.e., how accurate decisions are versus how much information is exchanged among nodes. Connection preemption is known to be NP-complete. Centralized preemption is optimal but computationally intractable. Decentralized preemption is computationally efficient but may result in a poor performance. This work investigates distributed preemption where nodes decide whether and which flows to preempt using only local information exchange with neighbors. We develop, based on the probabilistic graphical models, a near-optimal distributed algorithm. The algorithm is used by each node to make collectively near-optimal preemption decisions. We study trade-offs between near-optimal performance and complexity that corresponds to the amount of information-exchange of the distributed algorithm. The algorithm is validated by both analysis and simulation.
2305.13067
Joe Stacey
Joe Stacey and Marek Rei
Distilling Robustness into Natural Language Inference Models with Domain-Targeted Augmentation
Accepted at ACL Findings 2024
null
null
null
cs.CL cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Knowledge distillation optimises a smaller student model to behave similarly to a larger teacher model, retaining some of the performance benefits. While this method can improve results on in-distribution examples, it does not necessarily generalise to out-of-distribution (OOD) settings. We investigate two complementary methods for improving the robustness of the resulting student models on OOD domains. The first approach augments the distillation with generated unlabelled examples that match the target distribution. The second method upsamples data points among the training set that are similar to the target distribution. When applied on the task of natural language inference (NLI), our experiments on MNLI show that distillation with these modifications outperforms previous robustness solutions. We also find that these methods improve performance on OOD domains even beyond the target domain.
[ { "created": "Mon, 22 May 2023 14:37:05 GMT", "version": "v1" }, { "created": "Thu, 30 May 2024 10:00:14 GMT", "version": "v2" }, { "created": "Wed, 24 Jul 2024 18:54:53 GMT", "version": "v3" } ]
2024-07-26
[ [ "Stacey", "Joe", "" ], [ "Rei", "Marek", "" ] ]
Knowledge distillation optimises a smaller student model to behave similarly to a larger teacher model, retaining some of the performance benefits. While this method can improve results on in-distribution examples, it does not necessarily generalise to out-of-distribution (OOD) settings. We investigate two complementary methods for improving the robustness of the resulting student models on OOD domains. The first approach augments the distillation with generated unlabelled examples that match the target distribution. The second method upsamples data points among the training set that are similar to the target distribution. When applied on the task of natural language inference (NLI), our experiments on MNLI show that distillation with these modifications outperforms previous robustness solutions. We also find that these methods improve performance on OOD domains even beyond the target domain.
1403.2237
Li Li
Li Li, Jun Pang, Yang Liu, Jun Sun, Jin Song Dong
Stateful Security Protocol Verification
null
null
null
null
cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A long-standing research problem in security protocol design is how to efficiently verify security protocols with tamper-resistant global states. In this paper, we address this problem by first proposing a protocol specification framework, which explicitly represents protocol execution states and state transformations. Secondly, we develop an algorithm for verifying security properties by utilizing the key ingredients of the first-order reasoning for reachability analysis, while tracking state transformation and checking the validity of newly generated states. Our verification algorithm is proven to be (partially) correct, if it terminates. We have implemented the proposed framework and verification algorithms in a tool named SSPA, and evaluate it using a number of stateful security protocols. The experimental results show that our approach is not only feasible but also practically efficient. In particular, we have found a security flaw on the digital envelope protocol, which could not be detected by existing security protocol verifiers.
[ { "created": "Mon, 10 Mar 2014 13:40:00 GMT", "version": "v1" } ]
2014-03-11
[ [ "Li", "Li", "" ], [ "Pang", "Jun", "" ], [ "Liu", "Yang", "" ], [ "Sun", "Jun", "" ], [ "Dong", "Jin Song", "" ] ]
A long-standing research problem in security protocol design is how to efficiently verify security protocols with tamper-resistant global states. In this paper, we address this problem by first proposing a protocol specification framework, which explicitly represents protocol execution states and state transformations. Secondly, we develop an algorithm for verifying security properties by utilizing the key ingredients of the first-order reasoning for reachability analysis, while tracking state transformation and checking the validity of newly generated states. Our verification algorithm is proven to be (partially) correct, if it terminates. We have implemented the proposed framework and verification algorithms in a tool named SSPA, and evaluate it using a number of stateful security protocols. The experimental results show that our approach is not only feasible but also practically efficient. In particular, we have found a security flaw on the digital envelope protocol, which could not be detected by existing security protocol verifiers.
2312.01487
Lung-Pan Cheng
Eden Cong-He Xu, Lung-Pan Cheng
BetterMinton Service: Analyzing the Badminton Service using Open Kinetic Chain
14 pages, The 9th Annual Conference of Taiwanese Association of Computer-Human Interaction
null
null
null
cs.HC
http://creativecommons.org/licenses/by/4.0/
We present a badminton training system that focuses on the backhand short service. Unlike the prior motor skill training systems which focus on the trainee's posture, our system analyzes the process of moving joints with the open kinetic chain (OKC), which helps align movement and minimize muscle use for better joint control. We process the users' mocap data to visually show their last service process comparing to 4 ideal OKC characteristics that we collected from a 6-sub-elite formative study as well as recommended contact posture. We validate our system through a 12-user study that measures serving accuracy, qualitative feedback, and skeletal data with users at various skill levels and open source our skeletal analysis model for future use. While the participants' overall service accuracy was not significantly improved, our results show that our system helps participants in the short term to fine-tune their service motion closer to our ideal 4 OKC characteristics.
[ { "created": "Sun, 3 Dec 2023 19:02:52 GMT", "version": "v1" } ]
2023-12-05
[ [ "Xu", "Eden Cong-He", "" ], [ "Cheng", "Lung-Pan", "" ] ]
We present a badminton training system that focuses on the backhand short service. Unlike the prior motor skill training systems which focus on the trainee's posture, our system analyzes the process of moving joints with the open kinetic chain (OKC), which helps align movement and minimize muscle use for better joint control. We process the users' mocap data to visually show their last service process comparing to 4 ideal OKC characteristics that we collected from a 6-sub-elite formative study as well as recommended contact posture. We validate our system through a 12-user study that measures serving accuracy, qualitative feedback, and skeletal data with users at various skill levels and open source our skeletal analysis model for future use. While the participants' overall service accuracy was not significantly improved, our results show that our system helps participants in the short term to fine-tune their service motion closer to our ideal 4 OKC characteristics.
2103.08306
Bushra Sabir
Bushra Sabir, M. Ali Babar, Raj Gaire
ReinforceBug: A Framework to Generate Adversarial Textual Examples
Accepted in NAACL-HLT 2021
null
null
null
cs.LG cs.AI
http://creativecommons.org/licenses/by/4.0/
Adversarial Examples (AEs) generated by perturbing original training examples are useful in improving the robustness of Deep Learning (DL) based models. Most prior works, generate AEs that are either unconscionable due to lexical errors or semantically or functionally deviant from original examples. In this paper, we present ReinforceBug, a reinforcement learning framework, that learns a policy that is transferable on unseen datasets and generates utility-preserving and transferable (on other models) AEs. Our results show that our method is on average 10% more successful as compared to the state-of-the-art attack TextFooler. Moreover, the target models have on average 73.64% confidence in the wrong prediction, the generated AEs preserve the functional equivalence and semantic similarity (83.38% ) to their original counterparts, and are transferable on other models with an average success rate of 46%.
[ { "created": "Thu, 11 Mar 2021 05:35:51 GMT", "version": "v1" } ]
2021-03-16
[ [ "Sabir", "Bushra", "" ], [ "Babar", "M. Ali", "" ], [ "Gaire", "Raj", "" ] ]
Adversarial Examples (AEs) generated by perturbing original training examples are useful in improving the robustness of Deep Learning (DL) based models. Most prior works, generate AEs that are either unconscionable due to lexical errors or semantically or functionally deviant from original examples. In this paper, we present ReinforceBug, a reinforcement learning framework, that learns a policy that is transferable on unseen datasets and generates utility-preserving and transferable (on other models) AEs. Our results show that our method is on average 10% more successful as compared to the state-of-the-art attack TextFooler. Moreover, the target models have on average 73.64% confidence in the wrong prediction, the generated AEs preserve the functional equivalence and semantic similarity (83.38% ) to their original counterparts, and are transferable on other models with an average success rate of 46%.
1703.05060
Dave Zachariah
Dave Zachariah and Petre Stoica and Thomas B. Sch\"on
Online Learning for Distribution-Free Prediction
null
null
null
null
cs.LG stat.CO stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop an online learning method for prediction, which is important in problems with large and/or streaming data sets. We formulate the learning approach using a covariance-fitting methodology, and show that the resulting predictor has desirable computational and distribution-free properties: It is implemented online with a runtime that scales linearly in the number of samples; has a constant memory requirement; avoids local minima problems; and prunes away redundant feature dimensions without relying on restrictive assumptions on the data distribution. In conjunction with the split conformal approach, it also produces distribution-free prediction confidence intervals in a computationally efficient manner. The method is demonstrated on both real and synthetic datasets.
[ { "created": "Wed, 15 Mar 2017 10:20:32 GMT", "version": "v1" } ]
2017-03-16
[ [ "Zachariah", "Dave", "" ], [ "Stoica", "Petre", "" ], [ "Schön", "Thomas B.", "" ] ]
We develop an online learning method for prediction, which is important in problems with large and/or streaming data sets. We formulate the learning approach using a covariance-fitting methodology, and show that the resulting predictor has desirable computational and distribution-free properties: It is implemented online with a runtime that scales linearly in the number of samples; has a constant memory requirement; avoids local minima problems; and prunes away redundant feature dimensions without relying on restrictive assumptions on the data distribution. In conjunction with the split conformal approach, it also produces distribution-free prediction confidence intervals in a computationally efficient manner. The method is demonstrated on both real and synthetic datasets.
1903.01003
Mohamed Akrout
Ismail Akrout, Amal Feriani, Mohamed Akrout
Hacking Google reCAPTCHA v3 using Reinforcement Learning
Accepted for the Conference on Reinforcement Learning and Decision Making (RLDM) 2019
null
null
null
cs.LG cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a Reinforcement Learning (RL) methodology to bypass Google reCAPTCHA v3. We formulate the problem as a grid world where the agent learns how to move the mouse and click on the reCAPTCHA button to receive a high score. We study the performance of the agent when we vary the cell size of the grid world and show that the performance drops when the agent takes big steps toward the goal. Finally, we used a divide and conquer strategy to defeat the reCAPTCHA system for any grid resolution. Our proposed method achieves a success rate of 97.4% on a 100x100 grid and 96.7% on a 1000x1000 screen resolution.
[ { "created": "Sun, 3 Mar 2019 22:10:47 GMT", "version": "v1" }, { "created": "Tue, 12 Mar 2019 05:22:08 GMT", "version": "v2" }, { "created": "Thu, 18 Apr 2019 16:22:33 GMT", "version": "v3" } ]
2019-04-19
[ [ "Akrout", "Ismail", "" ], [ "Feriani", "Amal", "" ], [ "Akrout", "Mohamed", "" ] ]
We present a Reinforcement Learning (RL) methodology to bypass Google reCAPTCHA v3. We formulate the problem as a grid world where the agent learns how to move the mouse and click on the reCAPTCHA button to receive a high score. We study the performance of the agent when we vary the cell size of the grid world and show that the performance drops when the agent takes big steps toward the goal. Finally, we used a divide and conquer strategy to defeat the reCAPTCHA system for any grid resolution. Our proposed method achieves a success rate of 97.4% on a 100x100 grid and 96.7% on a 1000x1000 screen resolution.
1711.01262
He Sun
He Sun and Luca Zanetti
Distributed Graph Clustering and Sparsification
null
null
null
null
cs.DS cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Graph clustering is a fundamental computational problem with a number of applications in algorithm design, machine learning, data mining, and analysis of social networks. Over the past decades, researchers have proposed a number of algorithmic design methods for graph clustering. Most of these methods, however, are based on complicated spectral techniques or convex optimisation, and cannot be directly applied for clustering many networks that occur in practice, whose information is often collected on different sites. Designing a simple and distributed clustering algorithm is of great interest, and has wide applications for processing big datasets. In this paper we present a simple and distributed algorithm for graph clustering: for a wide class of graphs that are characterised by a strong cluster-structure, our algorithm finishes in a poly-logarithmic number of rounds, and recovers a partition of the graph close to optimal. One of the main components behind our algorithm is a sampling scheme that, given a dense graph as input, produces a sparse subgraph that provably preserves the cluster-structure of the input. Compared with previous sparsification algorithms that require Laplacian solvers or involve combinatorial constructions, this component is easy to implement in a distributed way and runs fast in practice.
[ { "created": "Fri, 3 Nov 2017 17:52:28 GMT", "version": "v1" } ]
2017-11-06
[ [ "Sun", "He", "" ], [ "Zanetti", "Luca", "" ] ]
Graph clustering is a fundamental computational problem with a number of applications in algorithm design, machine learning, data mining, and analysis of social networks. Over the past decades, researchers have proposed a number of algorithmic design methods for graph clustering. Most of these methods, however, are based on complicated spectral techniques or convex optimisation, and cannot be directly applied for clustering many networks that occur in practice, whose information is often collected on different sites. Designing a simple and distributed clustering algorithm is of great interest, and has wide applications for processing big datasets. In this paper we present a simple and distributed algorithm for graph clustering: for a wide class of graphs that are characterised by a strong cluster-structure, our algorithm finishes in a poly-logarithmic number of rounds, and recovers a partition of the graph close to optimal. One of the main components behind our algorithm is a sampling scheme that, given a dense graph as input, produces a sparse subgraph that provably preserves the cluster-structure of the input. Compared with previous sparsification algorithms that require Laplacian solvers or involve combinatorial constructions, this component is easy to implement in a distributed way and runs fast in practice.
2004.00140
Ligong Han
Ligong Han, Robert F. Murphy, and Deva Ramanan
Learning Generative Models of Tissue Organization with Supervised GANs
Accepted at WACV-18
null
null
null
cs.CV
http://creativecommons.org/publicdomain/zero/1.0/
A key step in understanding the spatial organization of cells and tissues is the ability to construct generative models that accurately reflect that organization. In this paper, we focus on building generative models of electron microscope (EM) images in which the positions of cell membranes and mitochondria have been densely annotated, and propose a two-stage procedure that produces realistic images using Generative Adversarial Networks (or GANs) in a supervised way. In the first stage, we synthesize a label "image" given a noise "image" as input, which then provides supervision for EM image synthesis in the second stage. The full model naturally generates label-image pairs. We show that accurate synthetic EM images are produced using assessment via (1) shape features and global statistics, (2) segmentation accuracies, and (3) user studies. We also demonstrate further improvements by enforcing a reconstruction loss on intermediate synthetic labels and thus unifying the two stages into one single end-to-end framework.
[ { "created": "Tue, 31 Mar 2020 22:22:58 GMT", "version": "v1" } ]
2020-04-02
[ [ "Han", "Ligong", "" ], [ "Murphy", "Robert F.", "" ], [ "Ramanan", "Deva", "" ] ]
A key step in understanding the spatial organization of cells and tissues is the ability to construct generative models that accurately reflect that organization. In this paper, we focus on building generative models of electron microscope (EM) images in which the positions of cell membranes and mitochondria have been densely annotated, and propose a two-stage procedure that produces realistic images using Generative Adversarial Networks (or GANs) in a supervised way. In the first stage, we synthesize a label "image" given a noise "image" as input, which then provides supervision for EM image synthesis in the second stage. The full model naturally generates label-image pairs. We show that accurate synthetic EM images are produced using assessment via (1) shape features and global statistics, (2) segmentation accuracies, and (3) user studies. We also demonstrate further improvements by enforcing a reconstruction loss on intermediate synthetic labels and thus unifying the two stages into one single end-to-end framework.
1510.03891
Juan-Pablo Ortega
Lyudmila Grigoryeva, Julie Henriques, Laurent Larger, and Juan-Pablo Ortega
Nonlinear memory capacity of parallel time-delay reservoir computers in the processing of multidimensional signals
24 pages, 6 figures
null
null
null
cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper addresses the reservoir design problem in the context of delay-based reservoir computers for multidimensional input signals, parallel architectures, and real-time multitasking. First, an approximating reservoir model is presented in those frameworks that provides an explicit functional link between the reservoir parameters and architecture and its performance in the execution of a specific task. Second, the inference properties of the ridge regression estimator in the multivariate context is used to assess the impact of finite sample training on the decrease of the reservoir capacity. Finally, an empirical study is conducted that shows the adequacy of the theoretical results with the empirical performances exhibited by various reservoir architectures in the execution of several nonlinear tasks with multidimensional inputs. Our results confirm the robustness properties of the parallel reservoir architecture with respect to task misspecification and parameter choice that had already been documented in the literature.
[ { "created": "Tue, 13 Oct 2015 20:56:49 GMT", "version": "v1" } ]
2015-10-15
[ [ "Grigoryeva", "Lyudmila", "" ], [ "Henriques", "Julie", "" ], [ "Larger", "Laurent", "" ], [ "Ortega", "Juan-Pablo", "" ] ]
This paper addresses the reservoir design problem in the context of delay-based reservoir computers for multidimensional input signals, parallel architectures, and real-time multitasking. First, an approximating reservoir model is presented in those frameworks that provides an explicit functional link between the reservoir parameters and architecture and its performance in the execution of a specific task. Second, the inference properties of the ridge regression estimator in the multivariate context is used to assess the impact of finite sample training on the decrease of the reservoir capacity. Finally, an empirical study is conducted that shows the adequacy of the theoretical results with the empirical performances exhibited by various reservoir architectures in the execution of several nonlinear tasks with multidimensional inputs. Our results confirm the robustness properties of the parallel reservoir architecture with respect to task misspecification and parameter choice that had already been documented in the literature.
2205.13430
Ian Hunter
Ian Frederick Vigogne Goodbody Hunter
GNOLL: Efficient Software for Real-World Dice Notation and Extensions
11 pages, 12 figures, Under Review for JCDCG^3 '22
null
null
null
cs.PL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
GNOLL ("GNOLL's Not *OLL") is a software library for dice notation. Unlike previous papers, GNOLL's dice notation syntax is focused on parsing a language that tabletop role-players and board gamers are already used to for specifying dice rolls in many popular software applications. Existing implementations of such a syntax are either incomplete, fragile, or proprietary, meaning that anyone hoping to use such syntax in their application likely needs to write their own solution. GNOLL is an open-source project using the compilation tool 'YACC' and lexical tool 'LEX' which can be integrated into many applications with relative ease. This paper explores GNOLL's extended dice notation syntax and its competitive performance.
[ { "created": "Thu, 26 May 2022 15:35:38 GMT", "version": "v1" }, { "created": "Mon, 4 Jul 2022 13:55:55 GMT", "version": "v2" } ]
2022-07-05
[ [ "Hunter", "Ian Frederick Vigogne Goodbody", "" ] ]
GNOLL ("GNOLL's Not *OLL") is a software library for dice notation. Unlike previous papers, GNOLL's dice notation syntax is focused on parsing a language that tabletop role-players and board gamers are already used to for specifying dice rolls in many popular software applications. Existing implementations of such a syntax are either incomplete, fragile, or proprietary, meaning that anyone hoping to use such syntax in their application likely needs to write their own solution. GNOLL is an open-source project using the compilation tool 'YACC' and lexical tool 'LEX' which can be integrated into many applications with relative ease. This paper explores GNOLL's extended dice notation syntax and its competitive performance.
1611.05660
Henrik Barthels
Henrik Barthels, Paolo Bientinesi
The Matrix Chain Algorithm to Compile Linear Algebra Expressions
DSLDI 2016
null
null
null
cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The matrix chain problem consists in finding the parenthesization of a matrix product $M := A_1 A_2 \cdots A_n$ that minimizes the number of scalar operations. In practical applications, however, one frequently encounters more complicated scenarios, where expressions involve transposition, inversion, matrices with given properties, and sequences. The computation of such expressions makes use of a set of computational kernels that offer functionality well beyond the simple matrix product. The challenge then shifts from finding an optimal parenthesization to finding an optimal mapping of the input expression to the available kernels. Furthermore, it is often the case that a solution based on the minimization of scalar operations does not result in the optimal solution in terms of execution time, and/or might be numerically unstable. In this paper, we introduce a number of generalizations of the matrix chain problem--including kernels, properties, sequences, and cost functions--and present corresponding algorithmic solutions. The motivation for this work comes from the fact that--despite great advances in the development of compilers--the task of mapping linear algebra problems to optimized kernels is still to be done manually. In order to relieve the user from this complex task, new techniques for the compilation of linear algebra expressions have to be developed.
[ { "created": "Thu, 17 Nov 2016 12:44:15 GMT", "version": "v1" } ]
2016-11-18
[ [ "Barthels", "Henrik", "" ], [ "Bientinesi", "Paolo", "" ] ]
The matrix chain problem consists in finding the parenthesization of a matrix product $M := A_1 A_2 \cdots A_n$ that minimizes the number of scalar operations. In practical applications, however, one frequently encounters more complicated scenarios, where expressions involve transposition, inversion, matrices with given properties, and sequences. The computation of such expressions makes use of a set of computational kernels that offer functionality well beyond the simple matrix product. The challenge then shifts from finding an optimal parenthesization to finding an optimal mapping of the input expression to the available kernels. Furthermore, it is often the case that a solution based on the minimization of scalar operations does not result in the optimal solution in terms of execution time, and/or might be numerically unstable. In this paper, we introduce a number of generalizations of the matrix chain problem--including kernels, properties, sequences, and cost functions--and present corresponding algorithmic solutions. The motivation for this work comes from the fact that--despite great advances in the development of compilers--the task of mapping linear algebra problems to optimized kernels is still to be done manually. In order to relieve the user from this complex task, new techniques for the compilation of linear algebra expressions have to be developed.
2311.10793
Chuang Yang
Chuang Yang, Kai Zhuang, Mulin Chen, Haozhao Ma, Xu Han, Tao Han, Changxing Guo, Han Han, Bingxuan Zhao, and Qi Wang
Traffic Sign Interpretation in Real Road Scene
null
null
null
null
cs.CV cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most existing traffic sign-related works are dedicated to detecting and recognizing part of traffic signs individually, which fails to analyze the global semantic logic among signs and may convey inaccurate traffic instruction. Following the above issues, we propose a traffic sign interpretation (TSI) task, which aims to interpret global semantic interrelated traffic signs (e.g.,~driving instruction-related texts, symbols, and guide panels) into a natural language for providing accurate instruction support to autonomous or assistant driving. Meanwhile, we design a multi-task learning architecture for TSI, which is responsible for detecting and recognizing various traffic signs and interpreting them into a natural language like a human. Furthermore, the absence of a public TSI available dataset prompts us to build a traffic sign interpretation dataset, namely TSI-CN. The dataset consists of real road scene images, which are captured from the highway and the urban way in China from a driver's perspective. It contains rich location labels of texts, symbols, and guide panels, and the corresponding natural language description labels. Experiments on TSI-CN demonstrate that the TSI task is achievable and the TSI architecture can interpret traffic signs from scenes successfully even if there is a complex semantic logic among signs. The TSI-CN dataset and the source code of the TSI architecture will be publicly available after the revision process.
[ { "created": "Fri, 17 Nov 2023 02:30:36 GMT", "version": "v1" }, { "created": "Tue, 28 Nov 2023 10:23:46 GMT", "version": "v2" } ]
2023-11-30
[ [ "Yang", "Chuang", "" ], [ "Zhuang", "Kai", "" ], [ "Chen", "Mulin", "" ], [ "Ma", "Haozhao", "" ], [ "Han", "Xu", "" ], [ "Han", "Tao", "" ], [ "Guo", "Changxing", "" ], [ "Han", "Han", "" ], [ "Zhao", "Bingxuan", "" ], [ "Wang", "Qi", "" ] ]
Most existing traffic sign-related works are dedicated to detecting and recognizing part of traffic signs individually, which fails to analyze the global semantic logic among signs and may convey inaccurate traffic instruction. Following the above issues, we propose a traffic sign interpretation (TSI) task, which aims to interpret global semantic interrelated traffic signs (e.g.,~driving instruction-related texts, symbols, and guide panels) into a natural language for providing accurate instruction support to autonomous or assistant driving. Meanwhile, we design a multi-task learning architecture for TSI, which is responsible for detecting and recognizing various traffic signs and interpreting them into a natural language like a human. Furthermore, the absence of a public TSI available dataset prompts us to build a traffic sign interpretation dataset, namely TSI-CN. The dataset consists of real road scene images, which are captured from the highway and the urban way in China from a driver's perspective. It contains rich location labels of texts, symbols, and guide panels, and the corresponding natural language description labels. Experiments on TSI-CN demonstrate that the TSI task is achievable and the TSI architecture can interpret traffic signs from scenes successfully even if there is a complex semantic logic among signs. The TSI-CN dataset and the source code of the TSI architecture will be publicly available after the revision process.
2311.18046
Srravya Chandhiramowuli
Srravya Chandhiramowuli, Alex Taylor, Sara Heitlinger, Ding Wang
Making Data Work Count
Accepted for publication at CSCW 2024. Forthcoming in the Proceedings of the ACM on Human-Computer Interaction
null
null
null
cs.HC cs.AI cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we examine the work of data annotation. Specifically, we focus on the role of counting or quantification in organising annotation work. Based on an ethnographic study of data annotation in two outsourcing centres in India, we observe that counting practices and its associated logics are an integral part of day-to-day annotation activities. In particular, we call attention to the presumption of total countability observed in annotation - the notion that everything, from tasks, datasets and deliverables, to workers, work time, quality and performance, can be managed by applying the logics of counting. To examine this, we draw on sociological and socio-technical scholarship on quantification and develop the lens of a 'regime of counting' that makes explicit the specific counts, practices, actors and structures that underpin the pervasive counting in annotation. We find that within the AI supply chain and data work, counting regimes aid the assertion of authority by the AI clients (also called requesters) over annotation processes, constituting them as reductive, standardised, and homogenous. We illustrate how this has implications for i) how annotation work and workers get valued, ii) the role human discretion plays in annotation, and iii) broader efforts to introduce accountable and more just practices in AI. Through these implications, we illustrate the limits of operating within the logic of total countability. Instead, we argue for a view of counting as partial - located in distinct geographies, shaped by specific interests and accountable in only limited ways. This, we propose, sets the stage for a fundamentally different orientation to counting and what counts in data annotation.
[ { "created": "Wed, 29 Nov 2023 19:45:14 GMT", "version": "v1" } ]
2023-12-01
[ [ "Chandhiramowuli", "Srravya", "" ], [ "Taylor", "Alex", "" ], [ "Heitlinger", "Sara", "" ], [ "Wang", "Ding", "" ] ]
In this paper, we examine the work of data annotation. Specifically, we focus on the role of counting or quantification in organising annotation work. Based on an ethnographic study of data annotation in two outsourcing centres in India, we observe that counting practices and its associated logics are an integral part of day-to-day annotation activities. In particular, we call attention to the presumption of total countability observed in annotation - the notion that everything, from tasks, datasets and deliverables, to workers, work time, quality and performance, can be managed by applying the logics of counting. To examine this, we draw on sociological and socio-technical scholarship on quantification and develop the lens of a 'regime of counting' that makes explicit the specific counts, practices, actors and structures that underpin the pervasive counting in annotation. We find that within the AI supply chain and data work, counting regimes aid the assertion of authority by the AI clients (also called requesters) over annotation processes, constituting them as reductive, standardised, and homogenous. We illustrate how this has implications for i) how annotation work and workers get valued, ii) the role human discretion plays in annotation, and iii) broader efforts to introduce accountable and more just practices in AI. Through these implications, we illustrate the limits of operating within the logic of total countability. Instead, we argue for a view of counting as partial - located in distinct geographies, shaped by specific interests and accountable in only limited ways. This, we propose, sets the stage for a fundamentally different orientation to counting and what counts in data annotation.
2208.13446
Sabine Cornelsen
Sabine Cornelsen and Gregor Diatzko
Planar Confluent Orthogonal Drawings of 4-Modal Digraphs
Appears in the Proceedings of the 30th International Symposium on Graph Drawing and Network Visualization (GD 2022)
null
null
null
cs.CG cs.DS
http://creativecommons.org/licenses/by-nc-sa/4.0/
In a planar confluent orthogonal drawing (PCOD) of a directed graph (digraph) vertices are drawn as points in the plane and edges as orthogonal polylines starting with a vertical segment and ending with a horizontal segment. Edges may overlap in their first or last segment, but must not intersect otherwise. PCODs can be seen as a directed variant of Kandinsky drawings or as planar L-drawings of subdivisions of digraphs. The maximum number of subdivision vertices in an edge is then the split complexity. A PCOD is upward if each edge is drawn with monotonically increasing y-coordinates and quasi-upward if no edge starts with decreasing y-coordinates. We study the split complexity of PCODs and (quasi-)upward PCODs for various classes of graphs.
[ { "created": "Mon, 29 Aug 2022 09:28:49 GMT", "version": "v1" }, { "created": "Wed, 31 Aug 2022 09:26:55 GMT", "version": "v2" } ]
2022-09-01
[ [ "Cornelsen", "Sabine", "" ], [ "Diatzko", "Gregor", "" ] ]
In a planar confluent orthogonal drawing (PCOD) of a directed graph (digraph) vertices are drawn as points in the plane and edges as orthogonal polylines starting with a vertical segment and ending with a horizontal segment. Edges may overlap in their first or last segment, but must not intersect otherwise. PCODs can be seen as a directed variant of Kandinsky drawings or as planar L-drawings of subdivisions of digraphs. The maximum number of subdivision vertices in an edge is then the split complexity. A PCOD is upward if each edge is drawn with monotonically increasing y-coordinates and quasi-upward if no edge starts with decreasing y-coordinates. We study the split complexity of PCODs and (quasi-)upward PCODs for various classes of graphs.
2302.13408
Lingjie Kong
Lingjie Kong, Pankaj Rajak, and Siamak Shakeri
Generative Models for 3D Point Clouds
null
null
null
null
cs.CV cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Point clouds are rich geometric data structures, where their three dimensional structure offers an excellent domain for understanding the representation learning and generative modeling in 3D space. In this work, we aim to improve the performance of point cloud latent-space generative models by experimenting with transformer encoders, latent-space flow models, and autoregressive decoders. We analyze and compare both generation and reconstruction performance of these models on various object types.
[ { "created": "Sun, 26 Feb 2023 21:34:19 GMT", "version": "v1" } ]
2023-02-28
[ [ "Kong", "Lingjie", "" ], [ "Rajak", "Pankaj", "" ], [ "Shakeri", "Siamak", "" ] ]
Point clouds are rich geometric data structures, where their three dimensional structure offers an excellent domain for understanding the representation learning and generative modeling in 3D space. In this work, we aim to improve the performance of point cloud latent-space generative models by experimenting with transformer encoders, latent-space flow models, and autoregressive decoders. We analyze and compare both generation and reconstruction performance of these models on various object types.
2203.12707
Yanwu Xu
Yanwu Xu, Shaoan Xie, Wenhao Wu, Kun Zhang, Mingming Gong and Kayhan Batmanghelich
Maximum Spatial Perturbation Consistency for Unpaired Image-to-Image Translation
CVPR 2022 accepted paper
null
null
null
cs.CV eess.IV
http://creativecommons.org/licenses/by/4.0/
Unpaired image-to-image translation (I2I) is an ill-posed problem, as an infinite number of translation functions can map the source domain distribution to the target distribution. Therefore, much effort has been put into designing suitable constraints, e.g., cycle consistency (CycleGAN), geometry consistency (GCGAN), and contrastive learning-based constraints (CUTGAN), that help better pose the problem. However, these well-known constraints have limitations: (1) they are either too restrictive or too weak for specific I2I tasks; (2) these methods result in content distortion when there is a significant spatial variation between the source and target domains. This paper proposes a universal regularization technique called maximum spatial perturbation consistency (MSPC), which enforces a spatial perturbation function (T ) and the translation operator (G) to be commutative (i.e., TG = GT ). In addition, we introduce two adversarial training components for learning the spatial perturbation function. The first one lets T compete with G to achieve maximum perturbation. The second one lets G and T compete with discriminators to align the spatial variations caused by the change of object size, object distortion, background interruptions, etc. Our method outperforms the state-of-the-art methods on most I2I benchmarks. We also introduce a new benchmark, namely the front face to profile face dataset, to emphasize the underlying challenges of I2I for real-world applications. We finally perform ablation experiments to study the sensitivity of our method to the severity of spatial perturbation and its effectiveness for distribution alignment.
[ { "created": "Wed, 23 Mar 2022 19:59:04 GMT", "version": "v1" }, { "created": "Tue, 29 Mar 2022 15:16:29 GMT", "version": "v2" } ]
2022-03-30
[ [ "Xu", "Yanwu", "" ], [ "Xie", "Shaoan", "" ], [ "Wu", "Wenhao", "" ], [ "Zhang", "Kun", "" ], [ "Gong", "Mingming", "" ], [ "Batmanghelich", "Kayhan", "" ] ]
Unpaired image-to-image translation (I2I) is an ill-posed problem, as an infinite number of translation functions can map the source domain distribution to the target distribution. Therefore, much effort has been put into designing suitable constraints, e.g., cycle consistency (CycleGAN), geometry consistency (GCGAN), and contrastive learning-based constraints (CUTGAN), that help better pose the problem. However, these well-known constraints have limitations: (1) they are either too restrictive or too weak for specific I2I tasks; (2) these methods result in content distortion when there is a significant spatial variation between the source and target domains. This paper proposes a universal regularization technique called maximum spatial perturbation consistency (MSPC), which enforces a spatial perturbation function (T ) and the translation operator (G) to be commutative (i.e., TG = GT ). In addition, we introduce two adversarial training components for learning the spatial perturbation function. The first one lets T compete with G to achieve maximum perturbation. The second one lets G and T compete with discriminators to align the spatial variations caused by the change of object size, object distortion, background interruptions, etc. Our method outperforms the state-of-the-art methods on most I2I benchmarks. We also introduce a new benchmark, namely the front face to profile face dataset, to emphasize the underlying challenges of I2I for real-world applications. We finally perform ablation experiments to study the sensitivity of our method to the severity of spatial perturbation and its effectiveness for distribution alignment.
2303.15429
Okko Makkonen
Okko Makkonen, Elif Sa\c{c}{\i}kara, Camilla Hollanti
Algebraic Geometry Codes for Secure Distributed Matrix Multiplication
16 pages, 1 figure
null
null
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose a novel construction for secure distributed matrix multiplication (SDMM) based on algebraic geometry (AG) codes, which we call the PoleGap SDMM scheme. The proposed construction is inspired by the GASP code, where so-called gaps in a certain polynomial are utilized to achieve higher communication rates. Our construction considers the gaps in a Weierstrass semigroup of a rational place in an algebraic function field to achieve a similar increase in the rate. This construction shows that there is potential in utilizing AG codes and their subcodes in SDMM since we demonstrate a better performance compared to state-of-the-art schemes in some parameter regimes.
[ { "created": "Mon, 27 Mar 2023 17:53:25 GMT", "version": "v1" }, { "created": "Fri, 9 Jun 2023 10:05:44 GMT", "version": "v2" } ]
2023-06-12
[ [ "Makkonen", "Okko", "" ], [ "Saçıkara", "Elif", "" ], [ "Hollanti", "Camilla", "" ] ]
In this paper, we propose a novel construction for secure distributed matrix multiplication (SDMM) based on algebraic geometry (AG) codes, which we call the PoleGap SDMM scheme. The proposed construction is inspired by the GASP code, where so-called gaps in a certain polynomial are utilized to achieve higher communication rates. Our construction considers the gaps in a Weierstrass semigroup of a rational place in an algebraic function field to achieve a similar increase in the rate. This construction shows that there is potential in utilizing AG codes and their subcodes in SDMM since we demonstrate a better performance compared to state-of-the-art schemes in some parameter regimes.
1812.02969
Delcho Donev
Delcho Donev and Georg B\"ocherer
Polar-Coded Pulse Position Modulation for the Poisson Channel
7 pages, 9 figures
2018 9th Advanced Satellite Multimedia Systems Conference and the 15th Signal Processing for Space Communications Workshop (ASMS/SPSC)
10.1109/ASMS-SPSC.2018.8510721
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A polar-coded modulation scheme for deep-space optical communication is proposed. The photon counting Poisson channel with pulse position modulation (PPM) is considered. We use the fact that PPM is particularly well suited to be used with multilevel codes to design a polar-coded modulation scheme for the system in consideration. The construction of polar codes for the Poisson channel based on Gaussian approximation is demonstrated to be accurate. The proposed scheme uses a cyclic redundancy check outer code and a successive cancellation decoder with list decoding and it is shown that it outperforms the competing schemes.
[ { "created": "Fri, 7 Dec 2018 10:34:56 GMT", "version": "v1" } ]
2018-12-10
[ [ "Donev", "Delcho", "" ], [ "Böcherer", "Georg", "" ] ]
A polar-coded modulation scheme for deep-space optical communication is proposed. The photon counting Poisson channel with pulse position modulation (PPM) is considered. We use the fact that PPM is particularly well suited to be used with multilevel codes to design a polar-coded modulation scheme for the system in consideration. The construction of polar codes for the Poisson channel based on Gaussian approximation is demonstrated to be accurate. The proposed scheme uses a cyclic redundancy check outer code and a successive cancellation decoder with list decoding and it is shown that it outperforms the competing schemes.
1904.06962
Manohar Kuse
Manohar Kuse, Shaojie Shen
Learning Whole-Image Descriptors for Real-time Loop Detection andKidnap Recovery under Large Viewpoint Difference
null
null
null
null
cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a real-time stereo visual-inertial-SLAM system which is able to recover from complicatedkidnap scenarios and failures online in realtime. We propose to learn the whole-image-descriptorin a weakly supervised manner based on NetVLAD and decoupled convolutions. We analyse thetraining difficulties in using standard loss formulations and propose an allpairloss and show itseffect through extensive experiments. Compared to standard NetVLAD, our network takes an orderof magnitude fewer computations and model parameters, as a result runs about three times faster.We evaluate the representation power of our descriptor on standard datasets with precision-recall.Unlike previous loop detection methods which have been evaluated only on fronto-parallel revisits,we evaluate the performace of our method with competing methods on scenarios involving largeviewpoint difference. Finally, we present the fully functional system with relative computation andhandling of multiple world co-ordinate system which is able to reduce odometry drift, recover fromcomplicated kidnap scenarios and random odometry failures. We open source our fully functional system as an add-on for the popular VINS-Fusion.
[ { "created": "Mon, 15 Apr 2019 11:01:04 GMT", "version": "v1" } ]
2019-04-16
[ [ "Kuse", "Manohar", "" ], [ "Shen", "Shaojie", "" ] ]
We present a real-time stereo visual-inertial-SLAM system which is able to recover from complicatedkidnap scenarios and failures online in realtime. We propose to learn the whole-image-descriptorin a weakly supervised manner based on NetVLAD and decoupled convolutions. We analyse thetraining difficulties in using standard loss formulations and propose an allpairloss and show itseffect through extensive experiments. Compared to standard NetVLAD, our network takes an orderof magnitude fewer computations and model parameters, as a result runs about three times faster.We evaluate the representation power of our descriptor on standard datasets with precision-recall.Unlike previous loop detection methods which have been evaluated only on fronto-parallel revisits,we evaluate the performace of our method with competing methods on scenarios involving largeviewpoint difference. Finally, we present the fully functional system with relative computation andhandling of multiple world co-ordinate system which is able to reduce odometry drift, recover fromcomplicated kidnap scenarios and random odometry failures. We open source our fully functional system as an add-on for the popular VINS-Fusion.
2101.00008
Farah Shamout
Munachiso Nwadike, Takumi Miyawaki, Esha Sarkar, Michail Maniatakos, Farah Shamout
Explainability Matters: Backdoor Attacks on Medical Imaging
null
null
null
null
cs.CR cs.CV cs.LG eess.IV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep neural networks have been shown to be vulnerable to backdoor attacks, which could be easily introduced to the training set prior to model training. Recent work has focused on investigating backdoor attacks on natural images or toy datasets. Consequently, the exact impact of backdoors is not yet fully understood in complex real-world applications, such as in medical imaging where misdiagnosis can be very costly. In this paper, we explore the impact of backdoor attacks on a multi-label disease classification task using chest radiography, with the assumption that the attacker can manipulate the training dataset to execute the attack. Extensive evaluation of a state-of-the-art architecture demonstrates that by introducing images with few-pixel perturbations into the training set, an attacker can execute the backdoor successfully without having to be involved with the training procedure. A simple 3$\times$3 pixel trigger can achieve up to 1.00 Area Under the Receiver Operating Characteristic (AUROC) curve on the set of infected images. In the set of clean images, the backdoored neural network could still achieve up to 0.85 AUROC, highlighting the stealthiness of the attack. As the use of deep learning based diagnostic systems proliferates in clinical practice, we also show how explainability is indispensable in this context, as it can identify spatially localized backdoors in inference time.
[ { "created": "Wed, 30 Dec 2020 09:41:19 GMT", "version": "v1" } ]
2021-01-05
[ [ "Nwadike", "Munachiso", "" ], [ "Miyawaki", "Takumi", "" ], [ "Sarkar", "Esha", "" ], [ "Maniatakos", "Michail", "" ], [ "Shamout", "Farah", "" ] ]
Deep neural networks have been shown to be vulnerable to backdoor attacks, which could be easily introduced to the training set prior to model training. Recent work has focused on investigating backdoor attacks on natural images or toy datasets. Consequently, the exact impact of backdoors is not yet fully understood in complex real-world applications, such as in medical imaging where misdiagnosis can be very costly. In this paper, we explore the impact of backdoor attacks on a multi-label disease classification task using chest radiography, with the assumption that the attacker can manipulate the training dataset to execute the attack. Extensive evaluation of a state-of-the-art architecture demonstrates that by introducing images with few-pixel perturbations into the training set, an attacker can execute the backdoor successfully without having to be involved with the training procedure. A simple 3$\times$3 pixel trigger can achieve up to 1.00 Area Under the Receiver Operating Characteristic (AUROC) curve on the set of infected images. In the set of clean images, the backdoored neural network could still achieve up to 0.85 AUROC, highlighting the stealthiness of the attack. As the use of deep learning based diagnostic systems proliferates in clinical practice, we also show how explainability is indispensable in this context, as it can identify spatially localized backdoors in inference time.
2308.12539
Vipul Gupta
Vipul Gupta, Pranav Narayanan Venkit, Hugo Lauren\c{c}on, Shomir Wilson, Rebecca J. Passonneau
CALM : A Multi-task Benchmark for Comprehensive Assessment of Language Model Bias
null
null
null
null
cs.CL cs.AI cs.LG
http://creativecommons.org/licenses/by/4.0/
As language models (LMs) become increasingly powerful and widely used, it is important to quantify them for sociodemographic bias with potential for harm. Prior measures of bias are sensitive to perturbations in the templates designed to compare performance across social groups, due to factors such as low diversity or limited number of templates. Also, most previous work considers only one NLP task. We introduce Comprehensive Assessment of Language Models (CALM) for robust measurement of two types of universally relevant sociodemographic bias, gender and race. CALM integrates sixteen datasets for question-answering, sentiment analysis and natural language inference. Examples from each dataset are filtered to produce 224 templates with high diversity (e.g., length, vocabulary). We assemble 50 highly frequent person names for each of seven distinct demographic groups to generate 78,400 prompts covering the three NLP tasks. Our empirical evaluation shows that CALM bias scores are more robust and far less sensitive than previous bias measurements to perturbations in the templates, such as synonym substitution, or to random subset selection of templates. We apply CALM to 20 large language models, and find that for 2 language model series, larger parameter models tend to be more biased than smaller ones. The T0 series is the least biased model families, of the 20 LLMs investigated here. The code is available at https://github.com/vipulgupta1011/CALM.
[ { "created": "Thu, 24 Aug 2023 03:53:55 GMT", "version": "v1" }, { "created": "Wed, 24 Jan 2024 01:09:01 GMT", "version": "v2" }, { "created": "Thu, 8 Aug 2024 03:20:17 GMT", "version": "v3" } ]
2024-08-09
[ [ "Gupta", "Vipul", "" ], [ "Venkit", "Pranav Narayanan", "" ], [ "Laurençon", "Hugo", "" ], [ "Wilson", "Shomir", "" ], [ "Passonneau", "Rebecca J.", "" ] ]
As language models (LMs) become increasingly powerful and widely used, it is important to quantify them for sociodemographic bias with potential for harm. Prior measures of bias are sensitive to perturbations in the templates designed to compare performance across social groups, due to factors such as low diversity or limited number of templates. Also, most previous work considers only one NLP task. We introduce Comprehensive Assessment of Language Models (CALM) for robust measurement of two types of universally relevant sociodemographic bias, gender and race. CALM integrates sixteen datasets for question-answering, sentiment analysis and natural language inference. Examples from each dataset are filtered to produce 224 templates with high diversity (e.g., length, vocabulary). We assemble 50 highly frequent person names for each of seven distinct demographic groups to generate 78,400 prompts covering the three NLP tasks. Our empirical evaluation shows that CALM bias scores are more robust and far less sensitive than previous bias measurements to perturbations in the templates, such as synonym substitution, or to random subset selection of templates. We apply CALM to 20 large language models, and find that for 2 language model series, larger parameter models tend to be more biased than smaller ones. The T0 series is the least biased model families, of the 20 LLMs investigated here. The code is available at https://github.com/vipulgupta1011/CALM.
2205.08441
Max Argus
Sergio Izquierdo, Max Argus, Thomas Brox
Conditional Visual Servoing for Multi-Step Tasks
null
null
null
null
cs.RO cs.CV cs.LG
http://creativecommons.org/licenses/by-nc-nd/4.0/
Visual Servoing has been effectively used to move a robot into specific target locations or to track a recorded demonstration. It does not require manual programming, but it is typically limited to settings where one demonstration maps to one environment state. We propose a modular approach to extend visual servoing to scenarios with multiple demonstration sequences. We call this conditional servoing, as we choose the next demonstration conditioned on the observation of the robot. This method presents an appealing strategy to tackle multi-step problems, as individual demonstrations can be combined flexibly into a control policy. We propose different selection functions and compare them on a shape-sorting task in simulation. With the reprojection error yielding the best overall results, we implement this selection function on a real robot and show the efficacy of the proposed conditional servoing. For videos of our experiments, please check out our project page: https://lmb.informatik.uni-freiburg.de/projects/conditional_servoing/
[ { "created": "Tue, 17 May 2022 15:34:54 GMT", "version": "v1" } ]
2022-05-18
[ [ "Izquierdo", "Sergio", "" ], [ "Argus", "Max", "" ], [ "Brox", "Thomas", "" ] ]
Visual Servoing has been effectively used to move a robot into specific target locations or to track a recorded demonstration. It does not require manual programming, but it is typically limited to settings where one demonstration maps to one environment state. We propose a modular approach to extend visual servoing to scenarios with multiple demonstration sequences. We call this conditional servoing, as we choose the next demonstration conditioned on the observation of the robot. This method presents an appealing strategy to tackle multi-step problems, as individual demonstrations can be combined flexibly into a control policy. We propose different selection functions and compare them on a shape-sorting task in simulation. With the reprojection error yielding the best overall results, we implement this selection function on a real robot and show the efficacy of the proposed conditional servoing. For videos of our experiments, please check out our project page: https://lmb.informatik.uni-freiburg.de/projects/conditional_servoing/
1602.07029
Siddharth Reddy
Siddharth Reddy, Igor Labutov, Thorsten Joachims
Latent Skill Embedding for Personalized Lesson Sequence Recommendation
Under review by the ACM SIGKDD Conference on Knowledge Discovery and Data Mining
null
null
null
cs.LG cs.AI cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Students in online courses generate large amounts of data that can be used to personalize the learning process and improve quality of education. In this paper, we present the Latent Skill Embedding (LSE), a probabilistic model of students and educational content that can be used to recommend personalized sequences of lessons with the goal of helping students prepare for specific assessments. Akin to collaborative filtering for recommender systems, the algorithm does not require students or content to be described by features, but it learns a representation using access traces. We formulate this problem as a regularized maximum-likelihood embedding of students, lessons, and assessments from historical student-content interactions. An empirical evaluation on large-scale data from Knewton, an adaptive learning technology company, shows that this approach predicts assessment results competitively with benchmark models and is able to discriminate between lesson sequences that lead to mastery and failure.
[ { "created": "Tue, 23 Feb 2016 04:20:40 GMT", "version": "v1" } ]
2016-02-24
[ [ "Reddy", "Siddharth", "" ], [ "Labutov", "Igor", "" ], [ "Joachims", "Thorsten", "" ] ]
Students in online courses generate large amounts of data that can be used to personalize the learning process and improve quality of education. In this paper, we present the Latent Skill Embedding (LSE), a probabilistic model of students and educational content that can be used to recommend personalized sequences of lessons with the goal of helping students prepare for specific assessments. Akin to collaborative filtering for recommender systems, the algorithm does not require students or content to be described by features, but it learns a representation using access traces. We formulate this problem as a regularized maximum-likelihood embedding of students, lessons, and assessments from historical student-content interactions. An empirical evaluation on large-scale data from Knewton, an adaptive learning technology company, shows that this approach predicts assessment results competitively with benchmark models and is able to discriminate between lesson sequences that lead to mastery and failure.
2402.17615
Artur Gaspar Da Silva
M\'ario S. Alvim, Artur Gaspar da Silva, Sophia Knight, and Frank Valencia
A Multi-Agent Model for Opinion Evolution under Cognitive Biases
null
null
null
null
cs.MA cs.SI
http://creativecommons.org/licenses/by/4.0/
We generalize the DeGroot model for opinion dynamics to better capture realistic social scenarios. We introduce a model where each agent has their own individual cognitive biases. Society is represented as a directed graph whose edges indicate how much agents influence one another. Biases are represented as the functions in the square region $[-1,1]^2$ and categorized into four sub-regions based on the potential reactions they may elicit in an agent during instances of opinion disagreement. Under the assumption that each bias of every agent is a continuous function within the region of receptive but resistant reactions ($\mathbf{R}$), we show that the society converges to a consensus if the graph is strongly connected. Under the same assumption, we also establish that the entire society converges to a unanimous opinion if and only if the source components of the graph-namely, strongly connected components with no external influence-converge to that opinion. We illustrate that convergence is not guaranteed for strongly connected graphs when biases are either discontinuous functions in $\mathbf{R}$ or not included in $\mathbf{R}$. We showcase our model through a series of examples and simulations, offering insights into how opinions form in social networks under cognitive biases.
[ { "created": "Tue, 27 Feb 2024 15:44:12 GMT", "version": "v1" } ]
2024-02-28
[ [ "Alvim", "Mário S.", "" ], [ "da Silva", "Artur Gaspar", "" ], [ "Knight", "Sophia", "" ], [ "Valencia", "Frank", "" ] ]
We generalize the DeGroot model for opinion dynamics to better capture realistic social scenarios. We introduce a model where each agent has their own individual cognitive biases. Society is represented as a directed graph whose edges indicate how much agents influence one another. Biases are represented as the functions in the square region $[-1,1]^2$ and categorized into four sub-regions based on the potential reactions they may elicit in an agent during instances of opinion disagreement. Under the assumption that each bias of every agent is a continuous function within the region of receptive but resistant reactions ($\mathbf{R}$), we show that the society converges to a consensus if the graph is strongly connected. Under the same assumption, we also establish that the entire society converges to a unanimous opinion if and only if the source components of the graph-namely, strongly connected components with no external influence-converge to that opinion. We illustrate that convergence is not guaranteed for strongly connected graphs when biases are either discontinuous functions in $\mathbf{R}$ or not included in $\mathbf{R}$. We showcase our model through a series of examples and simulations, offering insights into how opinions form in social networks under cognitive biases.
2010.09254
Jingang Wang
Yang Yang, Junmei Hao, Canjia Li, Zili Wang, Jingang Wang, Fuzheng Zhang, Rao Fu, Peixu Hou, Gong Zhang, Zhongyuan Wang
Query-aware Tip Generation for Vertical Search
Accepted By CIKM 2020 Applied Research Track
null
null
null
cs.CL cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As a concise form of user reviews, tips have unique advantages to explain the search results, assist users' decision making, and further improve user experience in vertical search scenarios. Existing work on tip generation does not take query into consideration, which limits the impact of tips in search scenarios. To address this issue, this paper proposes a query-aware tip generation framework, integrating query information into encoding and subsequent decoding processes. Two specific adaptations of Transformer and Recurrent Neural Network (RNN) are proposed. For Transformer, the query impact is incorporated into the self-attention computation of both the encoder and the decoder. As for RNN, the query-aware encoder adopts a selective network to distill query-relevant information from the review, while the query-aware decoder integrates the query information into the attention computation during decoding. The framework consistently outperforms the competing methods on both public and real-world industrial datasets. Last but not least, online deployment experiments on Dianping demonstrate the advantage of the proposed framework for tip generation as well as its online business values.
[ { "created": "Mon, 19 Oct 2020 06:48:40 GMT", "version": "v1" } ]
2020-10-20
[ [ "Yang", "Yang", "" ], [ "Hao", "Junmei", "" ], [ "Li", "Canjia", "" ], [ "Wang", "Zili", "" ], [ "Wang", "Jingang", "" ], [ "Zhang", "Fuzheng", "" ], [ "Fu", "Rao", "" ], [ "Hou", "Peixu", "" ], [ "Zhang", "Gong", "" ], [ "Wang", "Zhongyuan", "" ] ]
As a concise form of user reviews, tips have unique advantages to explain the search results, assist users' decision making, and further improve user experience in vertical search scenarios. Existing work on tip generation does not take query into consideration, which limits the impact of tips in search scenarios. To address this issue, this paper proposes a query-aware tip generation framework, integrating query information into encoding and subsequent decoding processes. Two specific adaptations of Transformer and Recurrent Neural Network (RNN) are proposed. For Transformer, the query impact is incorporated into the self-attention computation of both the encoder and the decoder. As for RNN, the query-aware encoder adopts a selective network to distill query-relevant information from the review, while the query-aware decoder integrates the query information into the attention computation during decoding. The framework consistently outperforms the competing methods on both public and real-world industrial datasets. Last but not least, online deployment experiments on Dianping demonstrate the advantage of the proposed framework for tip generation as well as its online business values.
0812.2990
Frederic Mazoit
Fr\'ed\'eric Mazoit (LaBRI)
Tree-width of hypergraphs and surface duality
null
null
null
null
cs.DM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In Graph Minor III, Robertson and Seymour conjecture that the tree-width of a planar graph and that of its dual differ by at most one. We prove that given a hypergraph H on a surface of Euler genus k, the tree-width of H^* is at most the maximum of tw(H) + 1 + k and the maximum size of a hyperedge of H^*.
[ { "created": "Tue, 16 Dec 2008 07:47:50 GMT", "version": "v1" } ]
2008-12-17
[ [ "Mazoit", "Frédéric", "", "LaBRI" ] ]
In Graph Minor III, Robertson and Seymour conjecture that the tree-width of a planar graph and that of its dual differ by at most one. We prove that given a hypergraph H on a surface of Euler genus k, the tree-width of H^* is at most the maximum of tw(H) + 1 + k and the maximum size of a hyperedge of H^*.
2306.17000
Ce Zhang Dr.
Ce Zhang, Chengjie Zhang, Yiluan Guo, Lingji Chen, Michael Happold
MotionTrack: End-to-End Transformer-based Multi-Object Tracing with LiDAR-Camera Fusion
This paper is accepted by CVPR WAD 2023
null
null
null
cs.CV
http://creativecommons.org/licenses/by-nc-nd/4.0/
Multiple Object Tracking (MOT) is crucial to autonomous vehicle perception. End-to-end transformer-based algorithms, which detect and track objects simultaneously, show great potential for the MOT task. However, most existing methods focus on image-based tracking with a single object category. In this paper, we propose an end-to-end transformer-based MOT algorithm (MotionTrack) with multi-modality sensor inputs to track objects with multiple classes. Our objective is to establish a transformer baseline for the MOT in an autonomous driving environment. The proposed algorithm consists of a transformer-based data association (DA) module and a transformer-based query enhancement module to achieve MOT and Multiple Object Detection (MOD) simultaneously. The MotionTrack and its variations achieve better results (AMOTA score at 0.55) on the nuScenes dataset compared with other classical baseline models, such as the AB3DMOT, the CenterTrack, and the probabilistic 3D Kalman filter. In addition, we prove that a modified attention mechanism can be utilized for DA to accomplish the MOT, and aggregate history features to enhance the MOD performance.
[ { "created": "Thu, 29 Jun 2023 15:00:12 GMT", "version": "v1" } ]
2023-06-30
[ [ "Zhang", "Ce", "" ], [ "Zhang", "Chengjie", "" ], [ "Guo", "Yiluan", "" ], [ "Chen", "Lingji", "" ], [ "Happold", "Michael", "" ] ]
Multiple Object Tracking (MOT) is crucial to autonomous vehicle perception. End-to-end transformer-based algorithms, which detect and track objects simultaneously, show great potential for the MOT task. However, most existing methods focus on image-based tracking with a single object category. In this paper, we propose an end-to-end transformer-based MOT algorithm (MotionTrack) with multi-modality sensor inputs to track objects with multiple classes. Our objective is to establish a transformer baseline for the MOT in an autonomous driving environment. The proposed algorithm consists of a transformer-based data association (DA) module and a transformer-based query enhancement module to achieve MOT and Multiple Object Detection (MOD) simultaneously. The MotionTrack and its variations achieve better results (AMOTA score at 0.55) on the nuScenes dataset compared with other classical baseline models, such as the AB3DMOT, the CenterTrack, and the probabilistic 3D Kalman filter. In addition, we prove that a modified attention mechanism can be utilized for DA to accomplish the MOT, and aggregate history features to enhance the MOD performance.
2402.05657
Antoine Renard
Antoine Renard, Michel Rigo, Markus A. Whiteland
q-Parikh Matrices and q-deformed binomial coefficients of words
26 pages, submitted
null
null
null
cs.FL cs.DM math.CO
http://creativecommons.org/licenses/by/4.0/
We have introduced a q-deformation, i.e., a polynomial in q with natural coefficients, of the binomial coefficient of two finite words u and v counting the number of occurrences of v as a subword of u. In this paper, we examine the q-deformation of Parikh matrices as introduced by E\u{g}ecio\u{g}lu in 2004. Many classical results concerning Parikh matrices generalize to this new framework: Our first important observation is that the elements of such a matrix are in fact q-deformations of binomial coefficients of words. We also study their inverses and as an application, we obtain new identities about q-binomials. For a finite word z and for the sequence $(p_n)_{n\ge 0}$ of prefixes of an infinite word, we show that the polynomial sequence $\binom{p_n}{z}_q$ converges to a formal series. We present links with additive number theory and k-regular sequences. In the case of a periodic word $u^\omega$, we generalize a result of Salomaa: the sequence $\binom{u^n}{z}_q$ satisfies a linear recurrence relation with polynomial coefficients. Related to the theory of integer partition, we describe the growth and the zero set of the coefficients of the series associated with $u^\omega$. Finally, we show that the minors of a q-Parikh matrix are polynomials with natural coefficients and consider a generalization of Cauchy's inequality. We also compare q-Parikh matrices associated with an arbitrary word with those associated with a canonical word $12\cdots k$ made of pairwise distinct symbols.
[ { "created": "Thu, 8 Feb 2024 13:21:26 GMT", "version": "v1" } ]
2024-02-09
[ [ "Renard", "Antoine", "" ], [ "Rigo", "Michel", "" ], [ "Whiteland", "Markus A.", "" ] ]
We have introduced a q-deformation, i.e., a polynomial in q with natural coefficients, of the binomial coefficient of two finite words u and v counting the number of occurrences of v as a subword of u. In this paper, we examine the q-deformation of Parikh matrices as introduced by E\u{g}ecio\u{g}lu in 2004. Many classical results concerning Parikh matrices generalize to this new framework: Our first important observation is that the elements of such a matrix are in fact q-deformations of binomial coefficients of words. We also study their inverses and as an application, we obtain new identities about q-binomials. For a finite word z and for the sequence $(p_n)_{n\ge 0}$ of prefixes of an infinite word, we show that the polynomial sequence $\binom{p_n}{z}_q$ converges to a formal series. We present links with additive number theory and k-regular sequences. In the case of a periodic word $u^\omega$, we generalize a result of Salomaa: the sequence $\binom{u^n}{z}_q$ satisfies a linear recurrence relation with polynomial coefficients. Related to the theory of integer partition, we describe the growth and the zero set of the coefficients of the series associated with $u^\omega$. Finally, we show that the minors of a q-Parikh matrix are polynomials with natural coefficients and consider a generalization of Cauchy's inequality. We also compare q-Parikh matrices associated with an arbitrary word with those associated with a canonical word $12\cdots k$ made of pairwise distinct symbols.
2003.00888
Guus Engels
Guus Engels, Nerea Aranjuelo, Ignacio Arganda-Carreras, Marcos Nieto and Oihana Otaegui
3D Object Detection From LiDAR Data Using Distance Dependent Feature Extraction
10 pages, 8 figures, 6th International Conference on Vehicle Technology and Intelligent Transport Systems (VEHITS 2020)
null
10.5220/0009330402890300
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents a new approach to 3D object detection that leverages the properties of the data obtained by a LiDAR sensor. State-of-the-art detectors use neural network architectures based on assumptions valid for camera images. However, point clouds obtained from LiDAR are fundamentally different. Most detectors use shared filter kernels to extract features which do not take into account the range dependent nature of the point cloud features. To show this, different detectors are trained on two splits of the KITTI dataset: close range (objects up to 25 meters from LiDAR) and long-range. Top view images are generated from point clouds as input for the networks. Combined results outperform the baseline network trained on the full dataset with a single backbone. Additional research compares the effect of using different input features when converting the point cloud to image. The results indicate that the network focuses on the shape and structure of the objects, rather than exact values of the input. This work proposes an improvement for 3D object detectors by taking into account the properties of LiDAR point clouds over distance. Results show that training separate networks for close-range and long-range objects boosts performance for all KITTI benchmark difficulties.
[ { "created": "Mon, 2 Mar 2020 13:16:35 GMT", "version": "v1" }, { "created": "Tue, 3 Mar 2020 07:47:20 GMT", "version": "v2" } ]
2021-04-09
[ [ "Engels", "Guus", "" ], [ "Aranjuelo", "Nerea", "" ], [ "Arganda-Carreras", "Ignacio", "" ], [ "Nieto", "Marcos", "" ], [ "Otaegui", "Oihana", "" ] ]
This paper presents a new approach to 3D object detection that leverages the properties of the data obtained by a LiDAR sensor. State-of-the-art detectors use neural network architectures based on assumptions valid for camera images. However, point clouds obtained from LiDAR are fundamentally different. Most detectors use shared filter kernels to extract features which do not take into account the range dependent nature of the point cloud features. To show this, different detectors are trained on two splits of the KITTI dataset: close range (objects up to 25 meters from LiDAR) and long-range. Top view images are generated from point clouds as input for the networks. Combined results outperform the baseline network trained on the full dataset with a single backbone. Additional research compares the effect of using different input features when converting the point cloud to image. The results indicate that the network focuses on the shape and structure of the objects, rather than exact values of the input. This work proposes an improvement for 3D object detectors by taking into account the properties of LiDAR point clouds over distance. Results show that training separate networks for close-range and long-range objects boosts performance for all KITTI benchmark difficulties.
2407.19951
Muhammad Rashid
Muhammad Rashid, Elvio Amparore, Enrico Ferrari, Damiano Verda
Can I trust my anomaly detection system? A case study based on explainable AI
World Conference on eXplainable Artificial Intelligence
null
10.1007/978-3-031-63803-9_13
null
cs.LG cs.AI
http://creativecommons.org/licenses/by/4.0/
Generative models based on variational autoencoders are a popular technique for detecting anomalies in images in a semi-supervised context. A common approach employs the anomaly score to detect the presence of anomalies, and it is known to reach high level of accuracy on benchmark datasets. However, since anomaly scores are computed from reconstruction disparities, they often obscure the detection of various spurious features, raising concerns regarding their actual efficacy. This case study explores the robustness of an anomaly detection system based on variational autoencoder generative models through the use of eXplainable AI methods. The goal is to get a different perspective on the real performances of anomaly detectors that use reconstruction differences. In our case study we discovered that, in many cases, samples are detected as anomalous for the wrong or misleading factors.
[ { "created": "Mon, 29 Jul 2024 12:39:07 GMT", "version": "v1" } ]
2024-07-30
[ [ "Rashid", "Muhammad", "" ], [ "Amparore", "Elvio", "" ], [ "Ferrari", "Enrico", "" ], [ "Verda", "Damiano", "" ] ]
Generative models based on variational autoencoders are a popular technique for detecting anomalies in images in a semi-supervised context. A common approach employs the anomaly score to detect the presence of anomalies, and it is known to reach high level of accuracy on benchmark datasets. However, since anomaly scores are computed from reconstruction disparities, they often obscure the detection of various spurious features, raising concerns regarding their actual efficacy. This case study explores the robustness of an anomaly detection system based on variational autoencoder generative models through the use of eXplainable AI methods. The goal is to get a different perspective on the real performances of anomaly detectors that use reconstruction differences. In our case study we discovered that, in many cases, samples are detected as anomalous for the wrong or misleading factors.
2202.09039
Manojkumar Parmar
Kanak Tekwani, Manojkumar Parmar
Critical Checkpoints for Evaluating Defence Models Against Adversarial Attack and Robustness
16 pages, 8 figures
null
null
null
cs.CR cs.AI cs.CV cs.LG
http://creativecommons.org/licenses/by/4.0/
From past couple of years there is a cycle of researchers proposing a defence model for adversaries in machine learning which is arguably defensible to most of the existing attacks in restricted condition (they evaluate on some bounded inputs or datasets). And then shortly another set of researcher finding the vulnerabilities in that defence model and breaking it by proposing a stronger attack model. Some common flaws are been noticed in the past defence models that were broken in very short time. Defence models being broken so easily is a point of concern as decision of many crucial activities are taken with the help of machine learning models. So there is an utter need of some defence checkpoints that any researcher should keep in mind while evaluating the soundness of technique and declaring it to be decent defence technique. In this paper, we have suggested few checkpoints that should be taken into consideration while building and evaluating the soundness of defence models. All these points are recommended after observing why some past defence models failed and how some model remained adamant and proved their soundness against some of the very strong attacks.
[ { "created": "Fri, 18 Feb 2022 06:15:49 GMT", "version": "v1" } ]
2022-02-21
[ [ "Tekwani", "Kanak", "" ], [ "Parmar", "Manojkumar", "" ] ]
From past couple of years there is a cycle of researchers proposing a defence model for adversaries in machine learning which is arguably defensible to most of the existing attacks in restricted condition (they evaluate on some bounded inputs or datasets). And then shortly another set of researcher finding the vulnerabilities in that defence model and breaking it by proposing a stronger attack model. Some common flaws are been noticed in the past defence models that were broken in very short time. Defence models being broken so easily is a point of concern as decision of many crucial activities are taken with the help of machine learning models. So there is an utter need of some defence checkpoints that any researcher should keep in mind while evaluating the soundness of technique and declaring it to be decent defence technique. In this paper, we have suggested few checkpoints that should be taken into consideration while building and evaluating the soundness of defence models. All these points are recommended after observing why some past defence models failed and how some model remained adamant and proved their soundness against some of the very strong attacks.
1802.09119
Ruggiero Lovreglio
Ruggiero Lovreglio, Vicente Gonzalez, Zhenan Feng, Robert Amor, Michael Spearpoint, Jared Thomas, Margaret Trotter, Rafael Sacks
Prototyping Virtual Reality Serious Games for Building Earthquake Preparedness: The Auckland City Hospital Case Study
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Enhancing evacuee safety is a key factor in reducing the number of injuries and deaths that result from earthquakes. One way this can be achieved is by training occupants. Virtual Reality (VR) and Serious Games (SGs), represent novel techniques that may overcome the limitations of traditional training approaches. VR and SGs have been examined in the fire emergency context, however, their application to earthquake preparedness has not yet been extensively examined. We provide a theoretical discussion of the advantages and limitations of using VR SGs to investigate how building occupants behave during earthquake evacuations and to train building occupants to cope with such emergencies. We explore key design components for developing a VR SG framework: (a) what features constitute an earthquake event, (b) which building types can be selected and represented within the VR environment, (c) how damage to the building can be determined and represented, (d) how non-player characters (NPC) can be designed, and (e) what level of interaction there can be between NPC and the human participants. We illustrate the above by presenting the Auckland City Hospital, New Zealand as a case study, and propose a possible VR SG training tool to enhance earthquake preparedness in public buildings.
[ { "created": "Mon, 26 Feb 2018 01:08:51 GMT", "version": "v1" } ]
2018-02-27
[ [ "Lovreglio", "Ruggiero", "" ], [ "Gonzalez", "Vicente", "" ], [ "Feng", "Zhenan", "" ], [ "Amor", "Robert", "" ], [ "Spearpoint", "Michael", "" ], [ "Thomas", "Jared", "" ], [ "Trotter", "Margaret", "" ], [ "Sacks", "Rafael", "" ] ]
Enhancing evacuee safety is a key factor in reducing the number of injuries and deaths that result from earthquakes. One way this can be achieved is by training occupants. Virtual Reality (VR) and Serious Games (SGs), represent novel techniques that may overcome the limitations of traditional training approaches. VR and SGs have been examined in the fire emergency context, however, their application to earthquake preparedness has not yet been extensively examined. We provide a theoretical discussion of the advantages and limitations of using VR SGs to investigate how building occupants behave during earthquake evacuations and to train building occupants to cope with such emergencies. We explore key design components for developing a VR SG framework: (a) what features constitute an earthquake event, (b) which building types can be selected and represented within the VR environment, (c) how damage to the building can be determined and represented, (d) how non-player characters (NPC) can be designed, and (e) what level of interaction there can be between NPC and the human participants. We illustrate the above by presenting the Auckland City Hospital, New Zealand as a case study, and propose a possible VR SG training tool to enhance earthquake preparedness in public buildings.
1911.07988
Ashwin Kallingal Joshy
Ashwin Kallingal Joshy, Wei Le
Invariant Diffs
null
null
null
null
cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Software development is inherently incremental. Nowadays, many software companies adopt an agile process and a shorter release cycle, where software needs to be delivered faster with quality assurances. On the other hand, the majority of existing program analysis tools still target single versions of programs and are slow and inflexible to handle changes. In the popular version control systems such as git, the program changes are still presented using source code diffs. It is hard to understand what program conditions are changed and which source code lines cause them. In this paper, we propose to compute "invariant diffs" to specify changes. Similar to source diffs that report common code and code churns, we define version invariants to represent program conditions that are common across versions, and invariant churns to show the changes of program conditions between versions. We designed a static demand-driven, path-sensitive analysis to compute and compare invariants for multiple versions of programs using multiversion control flow graphs. We report invariant diffs at the matched program points where comparing invariants are meaningful. Importantly, our analysis correlates source diffs with invariant diffs to explain what source code changes lead to the property changes. We implemented our algorithms in a tool called $H_2$ and performed experiments on 104 versions of programs. Our results show that we are able to compute invariant diffs correctly within reasonable amount of time. The version invariants can capture the common properties of program versions even constructed by different persons, and the invariant churns can specify the semantics of changes such as how a patch changed a buggy condition to a correct condition.
[ { "created": "Mon, 18 Nov 2019 22:39:38 GMT", "version": "v1" }, { "created": "Tue, 30 Jun 2020 02:16:21 GMT", "version": "v2" } ]
2020-07-01
[ [ "Joshy", "Ashwin Kallingal", "" ], [ "Le", "Wei", "" ] ]
Software development is inherently incremental. Nowadays, many software companies adopt an agile process and a shorter release cycle, where software needs to be delivered faster with quality assurances. On the other hand, the majority of existing program analysis tools still target single versions of programs and are slow and inflexible to handle changes. In the popular version control systems such as git, the program changes are still presented using source code diffs. It is hard to understand what program conditions are changed and which source code lines cause them. In this paper, we propose to compute "invariant diffs" to specify changes. Similar to source diffs that report common code and code churns, we define version invariants to represent program conditions that are common across versions, and invariant churns to show the changes of program conditions between versions. We designed a static demand-driven, path-sensitive analysis to compute and compare invariants for multiple versions of programs using multiversion control flow graphs. We report invariant diffs at the matched program points where comparing invariants are meaningful. Importantly, our analysis correlates source diffs with invariant diffs to explain what source code changes lead to the property changes. We implemented our algorithms in a tool called $H_2$ and performed experiments on 104 versions of programs. Our results show that we are able to compute invariant diffs correctly within reasonable amount of time. The version invariants can capture the common properties of program versions even constructed by different persons, and the invariant churns can specify the semantics of changes such as how a patch changed a buggy condition to a correct condition.
1202.2820
Christina Boucher
Christina Boucher, Gad M. Landau, Avivit Levy, David Pritchard and Oren Weimann
On Approximating String Selection Problems with Outliers
null
null
null
null
cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many problems in bioinformatics are about finding strings that approximately represent a collection of given strings. We look at more general problems where some input strings can be classified as outliers. The Close to Most Strings problem is, given a set S of same-length strings, and a parameter d, find a string x that maximizes the number of "non-outliers" within Hamming distance d of x. We prove this problem has no PTAS unless ZPP=NP, correcting a decade-old mistake. The Most Strings with Few Bad Columns problem is to find a maximum-size subset of input strings so that the number of non-identical positions is at most k; we show it has no PTAS unless P=NP. We also observe Closest to k Strings has no EPTAS unless W[1]=FPT. In sum, outliers help model problems associated with using biological data, but we show the problem of finding an approximate solution is computationally difficult.
[ { "created": "Mon, 13 Feb 2012 19:09:26 GMT", "version": "v1" } ]
2012-02-14
[ [ "Boucher", "Christina", "" ], [ "Landau", "Gad M.", "" ], [ "Levy", "Avivit", "" ], [ "Pritchard", "David", "" ], [ "Weimann", "Oren", "" ] ]
Many problems in bioinformatics are about finding strings that approximately represent a collection of given strings. We look at more general problems where some input strings can be classified as outliers. The Close to Most Strings problem is, given a set S of same-length strings, and a parameter d, find a string x that maximizes the number of "non-outliers" within Hamming distance d of x. We prove this problem has no PTAS unless ZPP=NP, correcting a decade-old mistake. The Most Strings with Few Bad Columns problem is to find a maximum-size subset of input strings so that the number of non-identical positions is at most k; we show it has no PTAS unless P=NP. We also observe Closest to k Strings has no EPTAS unless W[1]=FPT. In sum, outliers help model problems associated with using biological data, but we show the problem of finding an approximate solution is computationally difficult.
2206.08800
Rasmus Haugaard
Rasmus Laurvig Haugaard, Anders Glent Buch, Thorbj{\o}rn Mosekj{\ae}r Iversen
Self-supervised deep visual servoing for high precision peg-in-hole insertion
Accepted at IEEE CASE 2022
null
null
null
cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many industrial assembly tasks involve peg-in-hole like insertions with sub-millimeter tolerances which are challenging, even in highly calibrated robot cells. Visual servoing can be employed to increase the robustness towards uncertainties in the system, however, state of the art methods either rely on accurate 3D models for synthetic renderings or manual involvement in acquisition of training data. We present a novel self-supervised visual servoing method for high precision peg-in-hole insertion, which is fully automated and does not rely on synthetic data. We demonstrate its applicability for insertion of electronic components into a printed circuit board with tight tolerances. We show that peg-in-hole insertion can be drastically sped up by preceding a robust but slow force-based insertion strategy with our proposed visual servoing method, the configuration of which is fully autonomous.
[ { "created": "Fri, 17 Jun 2022 14:29:21 GMT", "version": "v1" } ]
2022-06-20
[ [ "Haugaard", "Rasmus Laurvig", "" ], [ "Buch", "Anders Glent", "" ], [ "Iversen", "Thorbjørn Mosekjær", "" ] ]
Many industrial assembly tasks involve peg-in-hole like insertions with sub-millimeter tolerances which are challenging, even in highly calibrated robot cells. Visual servoing can be employed to increase the robustness towards uncertainties in the system, however, state of the art methods either rely on accurate 3D models for synthetic renderings or manual involvement in acquisition of training data. We present a novel self-supervised visual servoing method for high precision peg-in-hole insertion, which is fully automated and does not rely on synthetic data. We demonstrate its applicability for insertion of electronic components into a printed circuit board with tight tolerances. We show that peg-in-hole insertion can be drastically sped up by preceding a robust but slow force-based insertion strategy with our proposed visual servoing method, the configuration of which is fully autonomous.
2305.06898
Yujie Zeng
Yujie Zeng, Yiming Huang, Xiao-Long Ren, Linyuan L\"u
Identifying vital nodes through augmented random walks on higher-order networks
null
null
null
null
cs.SI physics.soc-ph stat.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Empirical networks possess considerable heterogeneity of node connections, resulting in a small portion of nodes playing crucial roles in network structure and function. Yet, how to characterize nodes' influence and identify vital nodes is by far still unclear in the study of networks with higher-order interactions. In this paper, we introduce a multi-order graph obtained by incorporating the higher-order bipartite graph and the classical pairwise graph, and propose a Higher-order Augmented Random Walk (HoRW) model through random walking on it. This representation preserves as much information about the higher-interacting network as possible. The results indicate that the proposed method effectively addresses the localization problem of certain classical centralities. In contrast to random walks along pairwise interactions only, performing more walks along higher-order interactions assists in not only identifying the most important nodes but also distinguishing nodes that ranked in the middle and bottom. Our method outperforms classical centralities in identifying vital nodes and can scale to various tasks in networks, including information spread maximization and network dismantling problems. The proposed higher-order representation and the random walk model provide novel insights and potent tools for studying higher-order mechanisms and functionality.
[ { "created": "Thu, 11 May 2023 15:39:47 GMT", "version": "v1" }, { "created": "Sat, 25 Nov 2023 08:40:04 GMT", "version": "v2" }, { "created": "Sun, 3 Dec 2023 13:49:00 GMT", "version": "v3" } ]
2023-12-05
[ [ "Zeng", "Yujie", "" ], [ "Huang", "Yiming", "" ], [ "Ren", "Xiao-Long", "" ], [ "Lü", "Linyuan", "" ] ]
Empirical networks possess considerable heterogeneity of node connections, resulting in a small portion of nodes playing crucial roles in network structure and function. Yet, how to characterize nodes' influence and identify vital nodes is by far still unclear in the study of networks with higher-order interactions. In this paper, we introduce a multi-order graph obtained by incorporating the higher-order bipartite graph and the classical pairwise graph, and propose a Higher-order Augmented Random Walk (HoRW) model through random walking on it. This representation preserves as much information about the higher-interacting network as possible. The results indicate that the proposed method effectively addresses the localization problem of certain classical centralities. In contrast to random walks along pairwise interactions only, performing more walks along higher-order interactions assists in not only identifying the most important nodes but also distinguishing nodes that ranked in the middle and bottom. Our method outperforms classical centralities in identifying vital nodes and can scale to various tasks in networks, including information spread maximization and network dismantling problems. The proposed higher-order representation and the random walk model provide novel insights and potent tools for studying higher-order mechanisms and functionality.
2106.09242
Song Wang
Moshi Wei, Yuchao Huang, Jinqiu Yang, Junjie Wang, Song Wang
CoCoFuzzing: Testing Neural Code Models with Coverage-Guided Fuzzing
null
null
null
null
cs.SE
http://creativecommons.org/licenses/by-sa/4.0/
Deep learning-based code processing models have shown good performance for tasks such as predicting method names, summarizing programs, and comment generation. However, despite the tremendous progress, deep learning models are often prone to adversarial attacks, which can significantly threaten the robustness and generalizability of these models by leading them to misclassification with unexpected inputs. To address the above issue, many deep learning testing approaches have been proposed, however, these approaches mainly focus on testing deep learning applications in the domains of image, audio, and text analysis, etc., which cannot be directly applied to neural models for code due to the unique properties of programs. In this paper, we propose a coverage-based fuzzing framework, CoCoFuzzing, for testing deep learning-based code processing models. In particular, we first propose ten mutation operators to automatically generate valid and semantically preserving source code examples as tests; then we propose a neuron coverage-based approach to guide the generation of tests. We investigate the performance of CoCoFuzzing on three state-of-the-art neural code models, i.e., NeuralCodeSum, CODE2SEQ, and CODE2VEC. Our experiment results demonstrate that CoCoFuzzing can generate valid and semantically preserving source code examples for testing the robustness and generalizability of these models and improve the neuron coverage. Moreover, these tests can be used to improve the performance of the target neural code models through adversarial retraining.
[ { "created": "Thu, 17 Jun 2021 04:33:37 GMT", "version": "v1" } ]
2021-06-18
[ [ "Wei", "Moshi", "" ], [ "Huang", "Yuchao", "" ], [ "Yang", "Jinqiu", "" ], [ "Wang", "Junjie", "" ], [ "Wang", "Song", "" ] ]
Deep learning-based code processing models have shown good performance for tasks such as predicting method names, summarizing programs, and comment generation. However, despite the tremendous progress, deep learning models are often prone to adversarial attacks, which can significantly threaten the robustness and generalizability of these models by leading them to misclassification with unexpected inputs. To address the above issue, many deep learning testing approaches have been proposed, however, these approaches mainly focus on testing deep learning applications in the domains of image, audio, and text analysis, etc., which cannot be directly applied to neural models for code due to the unique properties of programs. In this paper, we propose a coverage-based fuzzing framework, CoCoFuzzing, for testing deep learning-based code processing models. In particular, we first propose ten mutation operators to automatically generate valid and semantically preserving source code examples as tests; then we propose a neuron coverage-based approach to guide the generation of tests. We investigate the performance of CoCoFuzzing on three state-of-the-art neural code models, i.e., NeuralCodeSum, CODE2SEQ, and CODE2VEC. Our experiment results demonstrate that CoCoFuzzing can generate valid and semantically preserving source code examples for testing the robustness and generalizability of these models and improve the neuron coverage. Moreover, these tests can be used to improve the performance of the target neural code models through adversarial retraining.
2406.14015
Qingpeng Cai
Qingpeng Cai, Kaiping Zheng, H.V. Jagadish, Beng Chin Ooi and James Yip
CohortNet: Empowering Cohort Discovery for Interpretable Healthcare Analytics
10 pages, 12 figures
null
null
null
cs.LG
http://creativecommons.org/licenses/by/4.0/
Cohort studies are of significant importance in the field of healthcare analysis. However, existing methods typically involve manual, labor-intensive, and expert-driven pattern definitions or rely on simplistic clustering techniques that lack medical relevance. Automating cohort studies with interpretable patterns has great potential to facilitate healthcare analysis but remains an unmet need in prior research efforts. In this paper, we propose a cohort auto-discovery model, CohortNet, for interpretable healthcare analysis, focusing on the effective identification, representation, and exploitation of cohorts characterized by medically meaningful patterns. CohortNet initially learns fine-grained patient representations by separately processing each feature, considering both individual feature trends and feature interactions at each time step. Subsequently, it classifies each feature into distinct states and employs a heuristic cohort exploration strategy to effectively discover substantial cohorts with concrete patterns. For each identified cohort, it learns comprehensive cohort representations with credible evidence through associated patient retrieval. Ultimately, given a new patient, CohortNet can leverage relevant cohorts with distinguished importance, which can provide a more holistic understanding of the patient's conditions. Extensive experiments on three real-world datasets demonstrate that it consistently outperforms state-of-the-art approaches and offers interpretable insights from diverse perspectives in a top-down fashion.
[ { "created": "Thu, 20 Jun 2024 06:12:23 GMT", "version": "v1" } ]
2024-06-21
[ [ "Cai", "Qingpeng", "" ], [ "Zheng", "Kaiping", "" ], [ "Jagadish", "H. V.", "" ], [ "Ooi", "Beng Chin", "" ], [ "Yip", "James", "" ] ]
Cohort studies are of significant importance in the field of healthcare analysis. However, existing methods typically involve manual, labor-intensive, and expert-driven pattern definitions or rely on simplistic clustering techniques that lack medical relevance. Automating cohort studies with interpretable patterns has great potential to facilitate healthcare analysis but remains an unmet need in prior research efforts. In this paper, we propose a cohort auto-discovery model, CohortNet, for interpretable healthcare analysis, focusing on the effective identification, representation, and exploitation of cohorts characterized by medically meaningful patterns. CohortNet initially learns fine-grained patient representations by separately processing each feature, considering both individual feature trends and feature interactions at each time step. Subsequently, it classifies each feature into distinct states and employs a heuristic cohort exploration strategy to effectively discover substantial cohorts with concrete patterns. For each identified cohort, it learns comprehensive cohort representations with credible evidence through associated patient retrieval. Ultimately, given a new patient, CohortNet can leverage relevant cohorts with distinguished importance, which can provide a more holistic understanding of the patient's conditions. Extensive experiments on three real-world datasets demonstrate that it consistently outperforms state-of-the-art approaches and offers interpretable insights from diverse perspectives in a top-down fashion.
2406.02481
Jakub Ho\'sci{\l}owicz
Jakub Hoscilowicz, Pawel Popiolek, Jan Rudkowski, Jedrzej Bieniasz, Artur Janicki
Large Language Models as Carriers of Hidden Messages
Work in progress. Code is available at https://github.com/j-hoscilowic/zurek-stegano
null
null
null
cs.CL cs.CR
http://creativecommons.org/licenses/by/4.0/
With the help of simple fine-tuning, one can artificially embed hidden text into large language models (LLMs). This text is revealed only when triggered by a specific query to the LLM. Two primary applications are LLM fingerprinting and steganography. In the context of LLM fingerprinting, a unique text identifier (fingerprint) is embedded within the model to verify licensing compliance. In the context of steganography, the LLM serves as a carrier for hidden messages that can be disclosed through a chosen trigger question. Our work demonstrates that embedding hidden text in the LLM via fine-tuning, though seemingly secure due to the vast number of potential triggers (any sequence of characters or tokens could serve as a trigger), is susceptible to extraction through analysis of the LLM's output decoding process. We propose an extraction attack called Unconditional Token Forcing (UTF). It is premised on the hypothesis that iteratively feeding each token from the LLM's vocabulary into the model should reveal output sequences with abnormally high token probabilities, indicating potential hidden text candidates. We also present a defense method to hide text in such a way that it is resistant to both UTF and attacks based on sampling decoding methods, which we named Unconditional Token Forcing Confusion (UTFC). To the best of our knowledge, there is no attack method that can extract text hidden with UTFC. UTFC has both benign applications (improving LLM fingerprinting) and malign applications (using LLMs to create covert communication channels). Code is available at github.com/j-hoscilowic/zurek-stegano
[ { "created": "Tue, 4 Jun 2024 16:49:06 GMT", "version": "v1" }, { "created": "Mon, 29 Jul 2024 16:30:17 GMT", "version": "v2" } ]
2024-07-30
[ [ "Hoscilowicz", "Jakub", "" ], [ "Popiolek", "Pawel", "" ], [ "Rudkowski", "Jan", "" ], [ "Bieniasz", "Jedrzej", "" ], [ "Janicki", "Artur", "" ] ]
With the help of simple fine-tuning, one can artificially embed hidden text into large language models (LLMs). This text is revealed only when triggered by a specific query to the LLM. Two primary applications are LLM fingerprinting and steganography. In the context of LLM fingerprinting, a unique text identifier (fingerprint) is embedded within the model to verify licensing compliance. In the context of steganography, the LLM serves as a carrier for hidden messages that can be disclosed through a chosen trigger question. Our work demonstrates that embedding hidden text in the LLM via fine-tuning, though seemingly secure due to the vast number of potential triggers (any sequence of characters or tokens could serve as a trigger), is susceptible to extraction through analysis of the LLM's output decoding process. We propose an extraction attack called Unconditional Token Forcing (UTF). It is premised on the hypothesis that iteratively feeding each token from the LLM's vocabulary into the model should reveal output sequences with abnormally high token probabilities, indicating potential hidden text candidates. We also present a defense method to hide text in such a way that it is resistant to both UTF and attacks based on sampling decoding methods, which we named Unconditional Token Forcing Confusion (UTFC). To the best of our knowledge, there is no attack method that can extract text hidden with UTFC. UTFC has both benign applications (improving LLM fingerprinting) and malign applications (using LLMs to create covert communication channels). Code is available at github.com/j-hoscilowic/zurek-stegano
2402.17767
Arjun Gupta
Arjun Gupta, Michelle Zhang, Rishik Sathua, Saurabh Gupta
Opening Cabinets and Drawers in the Real World using a Commodity Mobile Manipulator
Project webpage: https://arjung128.github.io/opening-cabinets-and-drawers
null
null
null
cs.RO cs.AI cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Pulling open cabinets and drawers presents many difficult technical challenges in perception (inferring articulation parameters for objects from onboard sensors), planning (producing motion plans that conform to tight task constraints), and control (making and maintaining contact while applying forces on the environment). In this work, we build an end-to-end system that enables a commodity mobile manipulator (Stretch RE2) to pull open cabinets and drawers in diverse previously unseen real world environments. We conduct 4 days of real world testing of this system spanning 31 different objects from across 13 different real world environments. Our system achieves a success rate of 61% on opening novel cabinets and drawers in unseen environments zero-shot. An analysis of the failure modes suggests that errors in perception are the most significant challenge for our system. We will open source code and models for others to replicate and build upon our system.
[ { "created": "Tue, 27 Feb 2024 18:58:54 GMT", "version": "v1" } ]
2024-02-28
[ [ "Gupta", "Arjun", "" ], [ "Zhang", "Michelle", "" ], [ "Sathua", "Rishik", "" ], [ "Gupta", "Saurabh", "" ] ]
Pulling open cabinets and drawers presents many difficult technical challenges in perception (inferring articulation parameters for objects from onboard sensors), planning (producing motion plans that conform to tight task constraints), and control (making and maintaining contact while applying forces on the environment). In this work, we build an end-to-end system that enables a commodity mobile manipulator (Stretch RE2) to pull open cabinets and drawers in diverse previously unseen real world environments. We conduct 4 days of real world testing of this system spanning 31 different objects from across 13 different real world environments. Our system achieves a success rate of 61% on opening novel cabinets and drawers in unseen environments zero-shot. An analysis of the failure modes suggests that errors in perception are the most significant challenge for our system. We will open source code and models for others to replicate and build upon our system.
1707.06841
Youmna Farag
Youmna Farag, Marek Rei, Ted Briscoe
An Error-Oriented Approach to Word Embedding Pre-Training
10 pages, 2 figures, 4 tables, BEA 2017
The 12th Workshop on Innovative Use of NLP for Building Educational Applications (BEA 2017)
null
null
cs.CL cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel word embedding pre-training approach that exploits writing errors in learners' scripts. We compare our method to previous models that tune the embeddings based on script scores and the discrimination between correct and corrupt word contexts in addition to the generic commonly-used embeddings pre-trained on large corpora. The comparison is achieved by using the aforementioned models to bootstrap a neural network that learns to predict a holistic score for scripts. Furthermore, we investigate augmenting our model with error corrections and monitor the impact on performance. Our results show that our error-oriented approach outperforms other comparable ones which is further demonstrated when training on more data. Additionally, extending the model with corrections provides further performance gains when data sparsity is an issue.
[ { "created": "Fri, 21 Jul 2017 11:06:12 GMT", "version": "v1" } ]
2019-07-05
[ [ "Farag", "Youmna", "" ], [ "Rei", "Marek", "" ], [ "Briscoe", "Ted", "" ] ]
We propose a novel word embedding pre-training approach that exploits writing errors in learners' scripts. We compare our method to previous models that tune the embeddings based on script scores and the discrimination between correct and corrupt word contexts in addition to the generic commonly-used embeddings pre-trained on large corpora. The comparison is achieved by using the aforementioned models to bootstrap a neural network that learns to predict a holistic score for scripts. Furthermore, we investigate augmenting our model with error corrections and monitor the impact on performance. Our results show that our error-oriented approach outperforms other comparable ones which is further demonstrated when training on more data. Additionally, extending the model with corrections provides further performance gains when data sparsity is an issue.
2312.16812
Zhang Chen
Zhan Li, Zhang Chen, Zhong Li, Yi Xu
Spacetime Gaussian Feature Splatting for Real-Time Dynamic View Synthesis
Accepted to CVPR 2024. Project page: https://oppo-us-research.github.io/SpacetimeGaussians-website/
null
null
null
cs.CV cs.GR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Novel view synthesis of dynamic scenes has been an intriguing yet challenging problem. Despite recent advancements, simultaneously achieving high-resolution photorealistic results, real-time rendering, and compact storage remains a formidable task. To address these challenges, we propose Spacetime Gaussian Feature Splatting as a novel dynamic scene representation, composed of three pivotal components. First, we formulate expressive Spacetime Gaussians by enhancing 3D Gaussians with temporal opacity and parametric motion/rotation. This enables Spacetime Gaussians to capture static, dynamic, as well as transient content within a scene. Second, we introduce splatted feature rendering, which replaces spherical harmonics with neural features. These features facilitate the modeling of view- and time-dependent appearance while maintaining small size. Third, we leverage the guidance of training error and coarse depth to sample new Gaussians in areas that are challenging to converge with existing pipelines. Experiments on several established real-world datasets demonstrate that our method achieves state-of-the-art rendering quality and speed, while retaining compact storage. At 8K resolution, our lite-version model can render at 60 FPS on an Nvidia RTX 4090 GPU. Our code is available at https://github.com/oppo-us-research/SpacetimeGaussians.
[ { "created": "Thu, 28 Dec 2023 04:14:55 GMT", "version": "v1" }, { "created": "Thu, 4 Apr 2024 22:31:18 GMT", "version": "v2" } ]
2024-04-08
[ [ "Li", "Zhan", "" ], [ "Chen", "Zhang", "" ], [ "Li", "Zhong", "" ], [ "Xu", "Yi", "" ] ]
Novel view synthesis of dynamic scenes has been an intriguing yet challenging problem. Despite recent advancements, simultaneously achieving high-resolution photorealistic results, real-time rendering, and compact storage remains a formidable task. To address these challenges, we propose Spacetime Gaussian Feature Splatting as a novel dynamic scene representation, composed of three pivotal components. First, we formulate expressive Spacetime Gaussians by enhancing 3D Gaussians with temporal opacity and parametric motion/rotation. This enables Spacetime Gaussians to capture static, dynamic, as well as transient content within a scene. Second, we introduce splatted feature rendering, which replaces spherical harmonics with neural features. These features facilitate the modeling of view- and time-dependent appearance while maintaining small size. Third, we leverage the guidance of training error and coarse depth to sample new Gaussians in areas that are challenging to converge with existing pipelines. Experiments on several established real-world datasets demonstrate that our method achieves state-of-the-art rendering quality and speed, while retaining compact storage. At 8K resolution, our lite-version model can render at 60 FPS on an Nvidia RTX 4090 GPU. Our code is available at https://github.com/oppo-us-research/SpacetimeGaussians.
2407.09902
Ian Miller
Ian D. Miller, Fernando Cladera, Trey Smith, Camillo Jose Taylor, Vijay Kumar
Air-Ground Collaboration with SPOMP: Semantic Panoramic Online Mapping and Planning
Video: https://www.youtube.com/watch?v=ieNYH40buBo
IEEE Transactions on Field Robotics (2024)
10.1109/TFR.2024.3424748
null
cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mapping and navigation have gone hand-in-hand since long before robots existed. Maps are a key form of communication, allowing someone who has never been somewhere to nonetheless navigate that area successfully. In the context of multi-robot systems, the maps and information that flow between robots are necessary for effective collaboration, whether those robots are operating concurrently, sequentially, or completely asynchronously. In this paper, we argue that maps must go beyond encoding purely geometric or visual information to enable increasingly complex autonomy, particularly between robots. We propose a framework for multi-robot autonomy, focusing in particular on air and ground robots operating in outdoor 2.5D environments. We show that semantic maps can enable the specification, planning, and execution of complex collaborative missions, including localization in GPS-denied settings. A distinguishing characteristic of this work is that we strongly emphasize field experiments and testing, and by doing so demonstrate that these ideas can work at scale in the real world. We also perform extensive simulation experiments to validate our ideas at even larger scales. We believe these experiments and the experimental results constitute a significant step forward toward advancing the state-of-the-art of large-scale, collaborative multi-robot systems operating with real communication, navigation, and perception constraints.
[ { "created": "Sat, 13 Jul 2024 14:37:44 GMT", "version": "v1" } ]
2024-07-16
[ [ "Miller", "Ian D.", "" ], [ "Cladera", "Fernando", "" ], [ "Smith", "Trey", "" ], [ "Taylor", "Camillo Jose", "" ], [ "Kumar", "Vijay", "" ] ]
Mapping and navigation have gone hand-in-hand since long before robots existed. Maps are a key form of communication, allowing someone who has never been somewhere to nonetheless navigate that area successfully. In the context of multi-robot systems, the maps and information that flow between robots are necessary for effective collaboration, whether those robots are operating concurrently, sequentially, or completely asynchronously. In this paper, we argue that maps must go beyond encoding purely geometric or visual information to enable increasingly complex autonomy, particularly between robots. We propose a framework for multi-robot autonomy, focusing in particular on air and ground robots operating in outdoor 2.5D environments. We show that semantic maps can enable the specification, planning, and execution of complex collaborative missions, including localization in GPS-denied settings. A distinguishing characteristic of this work is that we strongly emphasize field experiments and testing, and by doing so demonstrate that these ideas can work at scale in the real world. We also perform extensive simulation experiments to validate our ideas at even larger scales. We believe these experiments and the experimental results constitute a significant step forward toward advancing the state-of-the-art of large-scale, collaborative multi-robot systems operating with real communication, navigation, and perception constraints.
1504.06746
Francisco Monteiro
Jo\~ao S. Lemos, Francisco Ros\'ario, Francisco A. Monteiro, Jo\~ao Xavier, Ant\'onio Rodrigues
Massive MIMO Full-Duplex Relaying with Optimal Power Allocation for Independent Multipairs
Accepted to the 16th IEEE International Workshop on Signal Processing Advances in Wireless Communications - SPAWC, Stockholm, Sweden 2015
null
10.1109/SPAWC.2015.7227049
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the help of an in-band full-duplex relay station, it is possible to simultaneously transmit and receive signals from multiple users. The performance of such system can be greatly increased when the relay station is equipped with a large number of antennas on both transmitter and receiver sides. In this paper, we exploit the use of massive arrays to effectively suppress the loopback interference (LI) of a decode-and-forward relay (DF) and evaluate the performance of the end-to-end (e2e) transmission. This paper assumes imperfect channel state information is available at the relay and designs a minimum mean-square error (MMSE) filter to mitigate the interference. Subsequently, we adopt zero-forcing (ZF) filters for both detection and beamforming. The performance of such system is evaluated in terms of bit error rate (BER) at both relay and destinations, and an optimal choice for the transmission power at the relay is shown. We then propose a complexity efficient optimal power allocation (OPA) algorithm that, using the channel statistics, computes the minimum power that satisfies the rate constraints of each pair. The results obtained via simulation show that when both MMSE filtering and OPA method are used, better values for the energy efficiency are attained.
[ { "created": "Sat, 25 Apr 2015 18:39:57 GMT", "version": "v1" }, { "created": "Tue, 12 May 2015 17:58:40 GMT", "version": "v2" } ]
2016-11-17
[ [ "Lemos", "João S.", "" ], [ "Rosário", "Francisco", "" ], [ "Monteiro", "Francisco A.", "" ], [ "Xavier", "João", "" ], [ "Rodrigues", "António", "" ] ]
With the help of an in-band full-duplex relay station, it is possible to simultaneously transmit and receive signals from multiple users. The performance of such system can be greatly increased when the relay station is equipped with a large number of antennas on both transmitter and receiver sides. In this paper, we exploit the use of massive arrays to effectively suppress the loopback interference (LI) of a decode-and-forward relay (DF) and evaluate the performance of the end-to-end (e2e) transmission. This paper assumes imperfect channel state information is available at the relay and designs a minimum mean-square error (MMSE) filter to mitigate the interference. Subsequently, we adopt zero-forcing (ZF) filters for both detection and beamforming. The performance of such system is evaluated in terms of bit error rate (BER) at both relay and destinations, and an optimal choice for the transmission power at the relay is shown. We then propose a complexity efficient optimal power allocation (OPA) algorithm that, using the channel statistics, computes the minimum power that satisfies the rate constraints of each pair. The results obtained via simulation show that when both MMSE filtering and OPA method are used, better values for the energy efficiency are attained.
2404.14519
Della Hendrickson
MIT Hardness Group, Della Hendrickson, Andy Tockman
Complexity of Planar Graph Orientation Consistency, Promise-Inference, and Uniqueness, with Applications to Minesweeper Variants
null
null
null
null
cs.CC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study three problems related to the computational complexity of the popular game Minesweeper. The first is consistency: given a set of clues, is there any arrangement of mines that satisfies it? This problem has been known to be NP-complete since 2000, but our framework proves it as a side effect. The second is inference: given a set of clues, is there any cell that the player can prove is safe? The coNP-completeness of this problem has been in the literature since 2011, but we discovered a flaw that we believe is present in all published results, and we provide a fixed proof. Finally, the third is solvability: given the full state of a Minesweeper game, can the player win the game by safely clicking all non-mine cells? This problem has not yet been studied, and we prove that it is coNP-complete.
[ { "created": "Mon, 22 Apr 2024 18:38:36 GMT", "version": "v1" } ]
2024-04-24
[ [ "MIT Hardness Group", "", "" ], [ "Hendrickson", "Della", "" ], [ "Tockman", "Andy", "" ] ]
We study three problems related to the computational complexity of the popular game Minesweeper. The first is consistency: given a set of clues, is there any arrangement of mines that satisfies it? This problem has been known to be NP-complete since 2000, but our framework proves it as a side effect. The second is inference: given a set of clues, is there any cell that the player can prove is safe? The coNP-completeness of this problem has been in the literature since 2011, but we discovered a flaw that we believe is present in all published results, and we provide a fixed proof. Finally, the third is solvability: given the full state of a Minesweeper game, can the player win the game by safely clicking all non-mine cells? This problem has not yet been studied, and we prove that it is coNP-complete.
1711.09594
Alan Lukezic
Alan Luke\v{z}i\v{c}, Luka \v{C}ehovin Zajc, Tom\'a\v{s} Voj\'i\v{r}, Ji\v{r}\'i Matas, Matej Kristan
FuCoLoT -- A Fully-Correlational Long-Term Tracker
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose FuCoLoT -- a Fully Correlational Long-term Tracker. It exploits the novel DCF constrained filter learning method to design a detector that is able to re-detect the target in the whole image efficiently. FuCoLoT maintains several correlation filters trained on different time scales that act as the detector components. A novel mechanism based on the correlation response is used for tracking failure estimation. FuCoLoT achieves state-of-the-art results on standard short-term benchmarks and it outperforms the current best-performing tracker on the long-term UAV20L benchmark by over 19%. It has an order of magnitude smaller memory footprint than its best-performing competitors and runs at 15fps in a single CPU thread.
[ { "created": "Mon, 27 Nov 2017 09:31:05 GMT", "version": "v1" }, { "created": "Mon, 14 Jan 2019 09:32:02 GMT", "version": "v2" } ]
2019-01-15
[ [ "Lukežič", "Alan", "" ], [ "Zajc", "Luka Čehovin", "" ], [ "Vojíř", "Tomáš", "" ], [ "Matas", "Jiří", "" ], [ "Kristan", "Matej", "" ] ]
We propose FuCoLoT -- a Fully Correlational Long-term Tracker. It exploits the novel DCF constrained filter learning method to design a detector that is able to re-detect the target in the whole image efficiently. FuCoLoT maintains several correlation filters trained on different time scales that act as the detector components. A novel mechanism based on the correlation response is used for tracking failure estimation. FuCoLoT achieves state-of-the-art results on standard short-term benchmarks and it outperforms the current best-performing tracker on the long-term UAV20L benchmark by over 19%. It has an order of magnitude smaller memory footprint than its best-performing competitors and runs at 15fps in a single CPU thread.
2309.13939
Irene Celino
Irene Celino and Heiko Paulheim
The Time Traveler's Guide to Semantic Web Research: Analyzing Fictitious Research Themes in the ESWC "Next 20 Years" Track
13 pages, 8 figures, 2 tables
null
null
null
cs.AI
http://creativecommons.org/licenses/by/4.0/
What will Semantic Web research focus on in 20 years from now? We asked this question to the community and collected their visions in the "Next 20 years" track of ESWC 2023. We challenged the participants to submit "future" research papers, as if they were submitting to the 2043 edition of the conference. The submissions - entirely fictitious - were expected to be full scientific papers, with research questions, state of the art references, experimental results and future work, with the goal to get an idea of the research agenda for the late 2040s and early 2050s. We received ten submissions, eight of which were accepted for presentation at the conference, that mixed serious ideas of potential future research themes and discussion topics with some fun and irony. In this paper, we intend to provide a survey of those "science fiction" papers, considering the emerging research themes and topics, analysing the research methods applied by the authors in these very special submissions, and investigating also the most fictitious parts (e.g., neologisms, fabricated references). Our goal is twofold: on the one hand, we investigate what this special track tells us about the Semantic Web community and, on the other hand, we aim at getting some insights on future research practices and directions.
[ { "created": "Mon, 25 Sep 2023 08:20:06 GMT", "version": "v1" } ]
2023-09-26
[ [ "Celino", "Irene", "" ], [ "Paulheim", "Heiko", "" ] ]
What will Semantic Web research focus on in 20 years from now? We asked this question to the community and collected their visions in the "Next 20 years" track of ESWC 2023. We challenged the participants to submit "future" research papers, as if they were submitting to the 2043 edition of the conference. The submissions - entirely fictitious - were expected to be full scientific papers, with research questions, state of the art references, experimental results and future work, with the goal to get an idea of the research agenda for the late 2040s and early 2050s. We received ten submissions, eight of which were accepted for presentation at the conference, that mixed serious ideas of potential future research themes and discussion topics with some fun and irony. In this paper, we intend to provide a survey of those "science fiction" papers, considering the emerging research themes and topics, analysing the research methods applied by the authors in these very special submissions, and investigating also the most fictitious parts (e.g., neologisms, fabricated references). Our goal is twofold: on the one hand, we investigate what this special track tells us about the Semantic Web community and, on the other hand, we aim at getting some insights on future research practices and directions.
2404.08888
Yue Zhou
Yue Zhou, Barbara Di Eugenio, Brian Ziebart, Lisa Sharp, Bing Liu, Ben Gerber, Nikolaos Agadakos and Shweta Yadav
Towards Enhancing Health Coaching Dialogue in Low-Resource Settings
Accepted to the main conference of COLING 2022
null
null
null
cs.CL cs.LG
http://creativecommons.org/licenses/by/4.0/
Health coaching helps patients identify and accomplish lifestyle-related goals, effectively improving the control of chronic diseases and mitigating mental health conditions. However, health coaching is cost-prohibitive due to its highly personalized and labor-intensive nature. In this paper, we propose to build a dialogue system that converses with the patients, helps them create and accomplish specific goals, and can address their emotions with empathy. However, building such a system is challenging since real-world health coaching datasets are limited and empathy is subtle. Thus, we propose a modularized health coaching dialogue system with simplified NLU and NLG frameworks combined with mechanism-conditioned empathetic response generation. Through automatic and human evaluation, we show that our system generates more empathetic, fluent, and coherent responses and outperforms the state-of-the-art in NLU tasks while requiring less annotation. We view our approach as a key step towards building automated and more accessible health coaching systems.
[ { "created": "Sat, 13 Apr 2024 03:23:15 GMT", "version": "v1" } ]
2024-04-16
[ [ "Zhou", "Yue", "" ], [ "Di Eugenio", "Barbara", "" ], [ "Ziebart", "Brian", "" ], [ "Sharp", "Lisa", "" ], [ "Liu", "Bing", "" ], [ "Gerber", "Ben", "" ], [ "Agadakos", "Nikolaos", "" ], [ "Yadav", "Shweta", "" ] ]
Health coaching helps patients identify and accomplish lifestyle-related goals, effectively improving the control of chronic diseases and mitigating mental health conditions. However, health coaching is cost-prohibitive due to its highly personalized and labor-intensive nature. In this paper, we propose to build a dialogue system that converses with the patients, helps them create and accomplish specific goals, and can address their emotions with empathy. However, building such a system is challenging since real-world health coaching datasets are limited and empathy is subtle. Thus, we propose a modularized health coaching dialogue system with simplified NLU and NLG frameworks combined with mechanism-conditioned empathetic response generation. Through automatic and human evaluation, we show that our system generates more empathetic, fluent, and coherent responses and outperforms the state-of-the-art in NLU tasks while requiring less annotation. We view our approach as a key step towards building automated and more accessible health coaching systems.
2206.01010
Weide Liu
Weide Liu, Zhonghua Wu, Yiming Wang, Henghui Ding, Fayao Liu, Jie Lin and Guosheng Lin
Long-tailed Recognition by Learning from Latent Categories
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we address the challenging task of long-tailed image recognition. Previous long-tailed recognition methods commonly focus on the data augmentation or re-balancing strategy of the tail classes to give more attention to tail classes during the model training. However, due to the limited training images for tail classes, the diversity of tail class images is still restricted, which results in poor feature representations. In this work, we hypothesize that common latent features among the head and tail classes can be used to give better feature representation. Motivated by this, we introduce a Latent Categories based long-tail Recognition (LCReg) method. Specifically, we propose to learn a set of class-agnostic latent features shared among the head and tail classes. Then, we implicitly enrich the training sample diversity via applying semantic data augmentation to the latent features. Extensive experiments on five long-tailed image recognition datasets demonstrate that our proposed LCReg is able to significantly outperform previous methods and achieve state-of-the-art results.
[ { "created": "Thu, 2 Jun 2022 12:19:51 GMT", "version": "v1" }, { "created": "Tue, 2 Aug 2022 07:27:42 GMT", "version": "v2" }, { "created": "Mon, 12 Sep 2022 07:05:51 GMT", "version": "v3" } ]
2022-09-13
[ [ "Liu", "Weide", "" ], [ "Wu", "Zhonghua", "" ], [ "Wang", "Yiming", "" ], [ "Ding", "Henghui", "" ], [ "Liu", "Fayao", "" ], [ "Lin", "Jie", "" ], [ "Lin", "Guosheng", "" ] ]
In this work, we address the challenging task of long-tailed image recognition. Previous long-tailed recognition methods commonly focus on the data augmentation or re-balancing strategy of the tail classes to give more attention to tail classes during the model training. However, due to the limited training images for tail classes, the diversity of tail class images is still restricted, which results in poor feature representations. In this work, we hypothesize that common latent features among the head and tail classes can be used to give better feature representation. Motivated by this, we introduce a Latent Categories based long-tail Recognition (LCReg) method. Specifically, we propose to learn a set of class-agnostic latent features shared among the head and tail classes. Then, we implicitly enrich the training sample diversity via applying semantic data augmentation to the latent features. Extensive experiments on five long-tailed image recognition datasets demonstrate that our proposed LCReg is able to significantly outperform previous methods and achieve state-of-the-art results.
2209.10307
Dong Zhang
Dong Zhang, Yi Lin, Hao Chen, Zhuotao Tian, Xin Yang, Jinhui Tang, Kwang Ting Cheng
Understanding the Tricks of Deep Learning in Medical Image Segmentation: Challenges and Future Directions
Under submission
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Over the past few years, the rapid development of deep learning technologies for computer vision has significantly improved the performance of medical image segmentation (MedISeg). However, the diverse implementation strategies of various models have led to an extremely complex MedISeg system, resulting in a potential problem of unfair result comparisons. In this paper, we collect a series of MedISeg tricks for different model implementation phases (i.e., pre-training model, data pre-processing, data augmentation, model implementation, model inference, and result post-processing), and experimentally explore the effectiveness of these tricks on consistent baselines. With the extensive experimental results on both the representative 2D and 3D medical image datasets, we explicitly clarify the effect of these tricks. Moreover, based on the surveyed tricks, we also open-sourced a strong MedISeg repository, where each component has the advantage of plug-and-play. We believe that this milestone work not only completes a comprehensive and complementary survey of the state-of-the-art MedISeg approaches, but also offers a practical guide for addressing the future medical image processing challenges including but not limited to small dataset, class imbalance learning, multi-modality learning, and domain adaptation. The code and training weights have been released at: https://github.com/hust-linyi/seg_trick.
[ { "created": "Wed, 21 Sep 2022 12:30:05 GMT", "version": "v1" }, { "created": "Mon, 8 May 2023 10:23:24 GMT", "version": "v2" } ]
2023-05-09
[ [ "Zhang", "Dong", "" ], [ "Lin", "Yi", "" ], [ "Chen", "Hao", "" ], [ "Tian", "Zhuotao", "" ], [ "Yang", "Xin", "" ], [ "Tang", "Jinhui", "" ], [ "Cheng", "Kwang Ting", "" ] ]
Over the past few years, the rapid development of deep learning technologies for computer vision has significantly improved the performance of medical image segmentation (MedISeg). However, the diverse implementation strategies of various models have led to an extremely complex MedISeg system, resulting in a potential problem of unfair result comparisons. In this paper, we collect a series of MedISeg tricks for different model implementation phases (i.e., pre-training model, data pre-processing, data augmentation, model implementation, model inference, and result post-processing), and experimentally explore the effectiveness of these tricks on consistent baselines. With the extensive experimental results on both the representative 2D and 3D medical image datasets, we explicitly clarify the effect of these tricks. Moreover, based on the surveyed tricks, we also open-sourced a strong MedISeg repository, where each component has the advantage of plug-and-play. We believe that this milestone work not only completes a comprehensive and complementary survey of the state-of-the-art MedISeg approaches, but also offers a practical guide for addressing the future medical image processing challenges including but not limited to small dataset, class imbalance learning, multi-modality learning, and domain adaptation. The code and training weights have been released at: https://github.com/hust-linyi/seg_trick.
1609.02305
Klaus-Tycho Foerster
Klaus-Tycho Foerster, Stefan Schmid, Stefano Vissicchio
Survey of Consistent Software-Defined Network Updates
null
IEEE Communications Surveys & Tutorials 2019
10.1109/COMST.2018.2876749
null
cs.NI cs.DC cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Computer networks have become a critical infrastructure. In fact, networks should not only meet strict requirements in terms of correctness, availability, and performance, but they should also be very flexible and support fast updates, e.g., due to policy changes, increasing traffic, or failures. This paper presents a structured survey of mechanism and protocols to update computer networks in a fast and consistent manner. In particular, we identify and discuss the different desirable consistency properties that should be provided throughout a network update, the algorithmic techniques which are needed to meet these consistency properties, and the implications on the speed and costs at which updates can be performed. We also explain the relationship between consistent network update problems and classic algorithmic optimization ones. While our survey is mainly motivated by the advent of Software-Defined Networks (SDNs) and their primary need for correct and efficient update techniques, the fundamental underlying problems are not new, and we provide a historical perspective of the subject as well.
[ { "created": "Thu, 8 Sep 2016 07:34:39 GMT", "version": "v1" }, { "created": "Thu, 8 Feb 2018 15:42:18 GMT", "version": "v2" }, { "created": "Tue, 26 Mar 2019 13:33:38 GMT", "version": "v3" } ]
2019-03-27
[ [ "Foerster", "Klaus-Tycho", "" ], [ "Schmid", "Stefan", "" ], [ "Vissicchio", "Stefano", "" ] ]
Computer networks have become a critical infrastructure. In fact, networks should not only meet strict requirements in terms of correctness, availability, and performance, but they should also be very flexible and support fast updates, e.g., due to policy changes, increasing traffic, or failures. This paper presents a structured survey of mechanism and protocols to update computer networks in a fast and consistent manner. In particular, we identify and discuss the different desirable consistency properties that should be provided throughout a network update, the algorithmic techniques which are needed to meet these consistency properties, and the implications on the speed and costs at which updates can be performed. We also explain the relationship between consistent network update problems and classic algorithmic optimization ones. While our survey is mainly motivated by the advent of Software-Defined Networks (SDNs) and their primary need for correct and efficient update techniques, the fundamental underlying problems are not new, and we provide a historical perspective of the subject as well.
1912.05291
Michael Horowitz
Michael C. Horowitz, Paul Scharre, and Alexander Velez-Green
A Stable Nuclear Future? The Impact of Autonomous Systems and Artificial Intelligence
null
null
null
null
cs.CY cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The potential for advances in information-age technologies to undermine nuclear deterrence and influence the potential for nuclear escalation represents a critical question for international politics. One challenge is that uncertainty about the trajectory of technologies such as autonomous systems and artificial intelligence (AI) makes assessments difficult. This paper evaluates the relative impact of autonomous systems and artificial intelligence in three areas: nuclear command and control, nuclear delivery platforms and vehicles, and conventional applications of autonomous systems with consequences for nuclear stability. We argue that countries may be more likely to use risky forms of autonomy when they fear that their second-strike capabilities will be undermined. Additionally, the potential deployment of uninhabited, autonomous nuclear delivery platforms and vehicles could raise the prospect for accidents and miscalculation. Conventional military applications of autonomous systems could simultaneously influence nuclear force postures and first-strike stability in previously unanticipated ways. In particular, the need to fight at machine speed and the cognitive risk introduced by automation bias could increase the risk of unintended escalation. Finally, used properly, there should be many applications of more autonomous systems in nuclear operations that can increase reliability, reduce the risk of accidents, and buy more time for decision-makers in a crisis.
[ { "created": "Wed, 11 Dec 2019 13:35:36 GMT", "version": "v1" }, { "created": "Fri, 13 Dec 2019 18:37:36 GMT", "version": "v2" } ]
2019-12-28
[ [ "Horowitz", "Michael C.", "" ], [ "Scharre", "Paul", "" ], [ "Velez-Green", "Alexander", "" ] ]
The potential for advances in information-age technologies to undermine nuclear deterrence and influence the potential for nuclear escalation represents a critical question for international politics. One challenge is that uncertainty about the trajectory of technologies such as autonomous systems and artificial intelligence (AI) makes assessments difficult. This paper evaluates the relative impact of autonomous systems and artificial intelligence in three areas: nuclear command and control, nuclear delivery platforms and vehicles, and conventional applications of autonomous systems with consequences for nuclear stability. We argue that countries may be more likely to use risky forms of autonomy when they fear that their second-strike capabilities will be undermined. Additionally, the potential deployment of uninhabited, autonomous nuclear delivery platforms and vehicles could raise the prospect for accidents and miscalculation. Conventional military applications of autonomous systems could simultaneously influence nuclear force postures and first-strike stability in previously unanticipated ways. In particular, the need to fight at machine speed and the cognitive risk introduced by automation bias could increase the risk of unintended escalation. Finally, used properly, there should be many applications of more autonomous systems in nuclear operations that can increase reliability, reduce the risk of accidents, and buy more time for decision-makers in a crisis.
1904.00158
Peipei Li
Peipei Li, Huaibo Huang, Yibo Hu, Xiang Wu, Ran He and Zhenan Sun
UVA: A Universal Variational Framework for Continuous Age Analysis
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Conventional methods for facial age analysis tend to utilize accurate age labels in a supervised way. However, existing age datasets lies in a limited range of ages, leading to a long-tailed distribution. To alleviate the problem, this paper proposes a Universal Variational Aging (UVA) framework to formulate facial age priors in a disentangling manner. Benefiting from the variational evidence lower bound, the facial images are encoded and disentangled into an age-irrelevant distribution and an age-related distribution in the latent space. A conditional introspective adversarial learning mechanism is introduced to boost the image quality. In this way, when manipulating the age-related distribution, UVA can achieve age translation with arbitrary ages. Further, by sampling noise from the age-irrelevant distribution, we can generate photorealistic facial images with a specific age. Moreover, given an input face image, the mean value of age-related distribution can be treated as an age estimator. These indicate that UVA can efficiently and accurately estimate the age-related distribution by a disentangling manner, even if the training dataset performs a long-tailed age distribution. UVA is the first attempt to achieve facial age analysis tasks, including age translation, age generation and age estimation, in a universal framework. The qualitative and quantitative experiments demonstrate the superiority of UVA on five popular datasets, including CACD2000, Morph, UTKFace, MegaAge-Asian and FG-NET.
[ { "created": "Sat, 30 Mar 2019 07:07:06 GMT", "version": "v1" } ]
2019-04-02
[ [ "Li", "Peipei", "" ], [ "Huang", "Huaibo", "" ], [ "Hu", "Yibo", "" ], [ "Wu", "Xiang", "" ], [ "He", "Ran", "" ], [ "Sun", "Zhenan", "" ] ]
Conventional methods for facial age analysis tend to utilize accurate age labels in a supervised way. However, existing age datasets lies in a limited range of ages, leading to a long-tailed distribution. To alleviate the problem, this paper proposes a Universal Variational Aging (UVA) framework to formulate facial age priors in a disentangling manner. Benefiting from the variational evidence lower bound, the facial images are encoded and disentangled into an age-irrelevant distribution and an age-related distribution in the latent space. A conditional introspective adversarial learning mechanism is introduced to boost the image quality. In this way, when manipulating the age-related distribution, UVA can achieve age translation with arbitrary ages. Further, by sampling noise from the age-irrelevant distribution, we can generate photorealistic facial images with a specific age. Moreover, given an input face image, the mean value of age-related distribution can be treated as an age estimator. These indicate that UVA can efficiently and accurately estimate the age-related distribution by a disentangling manner, even if the training dataset performs a long-tailed age distribution. UVA is the first attempt to achieve facial age analysis tasks, including age translation, age generation and age estimation, in a universal framework. The qualitative and quantitative experiments demonstrate the superiority of UVA on five popular datasets, including CACD2000, Morph, UTKFace, MegaAge-Asian and FG-NET.
2309.08475
Japneet Singh
Anuran Makur, Japneet Singh
Doeblin Coefficients and Related Measures
26 pages, 1 figure
IEEE Transactions on Information Theory, vol. 70, no. 7, July 2024
10.1109/TIT.2024.3367856
null
cs.IT math.IT math.PR math.ST stat.TH
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Doeblin coefficients are a classical tool for analyzing the ergodicity and exponential convergence rates of Markov chains. Propelled by recent works on contraction coefficients of strong data processing inequalities, we investigate whether Doeblin coefficients also exhibit some of the notable properties of canonical contraction coefficients. In this paper, we present several new structural and geometric properties of Doeblin coefficients. Specifically, we show that Doeblin coefficients form a multi-way divergence, exhibit tensorization, and possess an extremal trace characterization. We then show that they also have extremal coupling and simultaneously maximal coupling characterizations. By leveraging these characterizations, we demonstrate that Doeblin coefficients act as a nice generalization of the well-known total variation (TV) distance to a multi-way divergence, enabling us to measure the "distance" between multiple distributions rather than just two. We then prove that Doeblin coefficients exhibit contraction properties over Bayesian networks similar to other canonical contraction coefficients. We additionally derive some other results and discuss an application of Doeblin coefficients to distribution fusion. Finally, in a complementary vein, we introduce and discuss three new quantities: max-Doeblin coefficient, max-DeGroot distance, and min-DeGroot distance. The max-Doeblin coefficient shares a connection with the concept of maximal leakage in information security; we explore its properties and provide a coupling characterization. On the other hand, the max-DeGroot and min-DeGroot measures extend the concept of DeGroot distance to multiple distributions.
[ { "created": "Fri, 15 Sep 2023 15:31:07 GMT", "version": "v1" }, { "created": "Tue, 2 Jul 2024 06:36:33 GMT", "version": "v2" } ]
2024-07-03
[ [ "Makur", "Anuran", "" ], [ "Singh", "Japneet", "" ] ]
Doeblin coefficients are a classical tool for analyzing the ergodicity and exponential convergence rates of Markov chains. Propelled by recent works on contraction coefficients of strong data processing inequalities, we investigate whether Doeblin coefficients also exhibit some of the notable properties of canonical contraction coefficients. In this paper, we present several new structural and geometric properties of Doeblin coefficients. Specifically, we show that Doeblin coefficients form a multi-way divergence, exhibit tensorization, and possess an extremal trace characterization. We then show that they also have extremal coupling and simultaneously maximal coupling characterizations. By leveraging these characterizations, we demonstrate that Doeblin coefficients act as a nice generalization of the well-known total variation (TV) distance to a multi-way divergence, enabling us to measure the "distance" between multiple distributions rather than just two. We then prove that Doeblin coefficients exhibit contraction properties over Bayesian networks similar to other canonical contraction coefficients. We additionally derive some other results and discuss an application of Doeblin coefficients to distribution fusion. Finally, in a complementary vein, we introduce and discuss three new quantities: max-Doeblin coefficient, max-DeGroot distance, and min-DeGroot distance. The max-Doeblin coefficient shares a connection with the concept of maximal leakage in information security; we explore its properties and provide a coupling characterization. On the other hand, the max-DeGroot and min-DeGroot measures extend the concept of DeGroot distance to multiple distributions.
1307.8029
EPTCS
Adel Bouhoula, Tetsuo Ida, Fairouz Kamareddine
Proceedings Fourth International Symposium on Symbolic Computation in Software Science
null
EPTCS 122, 2013
10.4204/EPTCS.122
null
cs.SC cs.LO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Symbolic computation is the science of computing with symbolic objects (terms, formulae, programs, algebraic objects, geometrical objects, etc). Powerful symbolic algorithms have been developed during the past decades and have played an influential role in theorem proving, automated reasoning, software verification, model checking, rewriting, formalisation of mathematics, network security, Groebner bases, characteristic sets, etc. The international Symposium on "Symbolic Computation in Software Science" is the fourth in the SCSS workshop series. SCSS 2008 and 2010 took place at the Research Institute for Symbolic Computation (RISC), Hagenberg, Austria, and, SCSS 2009 took place in Gammarth, Tunisia. These symposium grew out of internal workshops that bring together researchers from: a) SCORE (Symbolic Computation Research Group) at the University of Tsukuba, Japan, b) Theorema Group at the Research Institute for Symbolic Computation, Johannes Kepler University Linz, Austria, c) SSFG (Software Science Foundation Group) at Kyoto University, Japan, and d) Sup'Com (Higher School of Communication of Tunis) at the University of Carthage, Tunisia.
[ { "created": "Tue, 30 Jul 2013 16:01:33 GMT", "version": "v1" } ]
2013-07-31
[ [ "Bouhoula", "Adel", "" ], [ "Ida", "Tetsuo", "" ], [ "Kamareddine", "Fairouz", "" ] ]
Symbolic computation is the science of computing with symbolic objects (terms, formulae, programs, algebraic objects, geometrical objects, etc). Powerful symbolic algorithms have been developed during the past decades and have played an influential role in theorem proving, automated reasoning, software verification, model checking, rewriting, formalisation of mathematics, network security, Groebner bases, characteristic sets, etc. The international Symposium on "Symbolic Computation in Software Science" is the fourth in the SCSS workshop series. SCSS 2008 and 2010 took place at the Research Institute for Symbolic Computation (RISC), Hagenberg, Austria, and, SCSS 2009 took place in Gammarth, Tunisia. These symposium grew out of internal workshops that bring together researchers from: a) SCORE (Symbolic Computation Research Group) at the University of Tsukuba, Japan, b) Theorema Group at the Research Institute for Symbolic Computation, Johannes Kepler University Linz, Austria, c) SSFG (Software Science Foundation Group) at Kyoto University, Japan, and d) Sup'Com (Higher School of Communication of Tunis) at the University of Carthage, Tunisia.
1611.07610
Marianna Rapoport
Marianna Rapoport and Ond\v{r}ej Lhot\'ak
Mutable WadlerFest DOT
null
null
null
null
cs.PL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Dependent Object Types (DOT) calculus aims to model the essence of Scala, with a focus on abstract type members, path-dependent types, and subtyping. Other Scala features could be defined by translation to DOT. Mutation is a fundamental feature of Scala currently missing in DOT. Mutation in DOT is needed not only to model effectful computation and mutation in Scala programs, but even to precisely specify how Scala initializes immutable variables and fields (vals). We present an extension to DOT that adds typed mutable reference cells. We have proven the extension sound with a mechanized proof in Coq. We present the key features of our extended calculus and its soundness proof, and discuss the challenges that we encountered in our search for a sound design and the alternative solutions that we considered.
[ { "created": "Wed, 23 Nov 2016 02:37:51 GMT", "version": "v1" } ]
2016-11-24
[ [ "Rapoport", "Marianna", "" ], [ "Lhoták", "Ondřej", "" ] ]
The Dependent Object Types (DOT) calculus aims to model the essence of Scala, with a focus on abstract type members, path-dependent types, and subtyping. Other Scala features could be defined by translation to DOT. Mutation is a fundamental feature of Scala currently missing in DOT. Mutation in DOT is needed not only to model effectful computation and mutation in Scala programs, but even to precisely specify how Scala initializes immutable variables and fields (vals). We present an extension to DOT that adds typed mutable reference cells. We have proven the extension sound with a mechanized proof in Coq. We present the key features of our extended calculus and its soundness proof, and discuss the challenges that we encountered in our search for a sound design and the alternative solutions that we considered.
2108.07996
Shubhangi Agarwal
Shubhangi Agarwal, Sourav Dutta, Arnab Bhattacharya
VerSaChI: Finding Statistically Significant Subgraph Matches using Chebyshev's Inequality
null
null
10.1145/3459637.3482217
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Approximate subgraph matching, which is an important primitive for many applications like question answering, community detection, and motif discovery, often involves large labeled graphs such as knowledge graphs, social networks, and protein sequences. Effective methods for extracting matching subgraphs, in terms of label and structural similarities to a query, should depict accuracy, computational efficiency, and robustness to noise. In this paper, we propose VerSaChI for finding the top-k most similar subgraphs based on 2-hop label and structural overlap similarity with the query. The similarity is characterized using Chebyshev's inequality to compute the chi-square statistical significance for measuring the degree of matching of the subgraphs. Experiments on real-life graph datasets showcase significant improvements in terms of accuracy compared to state-of-the-art methods, as well as robustness to noise.
[ { "created": "Wed, 18 Aug 2021 06:53:39 GMT", "version": "v1" } ]
2021-08-19
[ [ "Agarwal", "Shubhangi", "" ], [ "Dutta", "Sourav", "" ], [ "Bhattacharya", "Arnab", "" ] ]
Approximate subgraph matching, which is an important primitive for many applications like question answering, community detection, and motif discovery, often involves large labeled graphs such as knowledge graphs, social networks, and protein sequences. Effective methods for extracting matching subgraphs, in terms of label and structural similarities to a query, should depict accuracy, computational efficiency, and robustness to noise. In this paper, we propose VerSaChI for finding the top-k most similar subgraphs based on 2-hop label and structural overlap similarity with the query. The similarity is characterized using Chebyshev's inequality to compute the chi-square statistical significance for measuring the degree of matching of the subgraphs. Experiments on real-life graph datasets showcase significant improvements in terms of accuracy compared to state-of-the-art methods, as well as robustness to noise.
1710.00208
Mohammad Etemad
Mohammad Etemad and Alptekin K\"up\c{c}\"u and Charalampos Papamanthou and David Evans
Efficient Dynamic Searchable Encryption with Forward Privacy
null
null
null
null
cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Searchable symmetric encryption (SSE) enables a client to perform searches over its outsourced encrypted files while preserving privacy of the files and queries. Dynamic schemes, where files can be added or removed, leak more information than static schemes. For dynamic schemes, forward privacy requires that a newly added file cannot be linked to previous searches. We present a new dynamic SSE scheme that achieves forward privacy by replacing the keys revealed to the server on each search. Our scheme is efficient and parallelizable and outperforms the best previous schemes providing forward privacy, and achieves competitive performance with dynamic schemes without forward privacy. We provide a full security proof in the random oracle model. In our experiments on the Wikipedia archive of about four million pages, the server takes one second to perform a search with 100,000 results.
[ { "created": "Sat, 30 Sep 2017 14:45:06 GMT", "version": "v1" } ]
2017-10-03
[ [ "Etemad", "Mohammad", "" ], [ "Küpçü", "Alptekin", "" ], [ "Papamanthou", "Charalampos", "" ], [ "Evans", "David", "" ] ]
Searchable symmetric encryption (SSE) enables a client to perform searches over its outsourced encrypted files while preserving privacy of the files and queries. Dynamic schemes, where files can be added or removed, leak more information than static schemes. For dynamic schemes, forward privacy requires that a newly added file cannot be linked to previous searches. We present a new dynamic SSE scheme that achieves forward privacy by replacing the keys revealed to the server on each search. Our scheme is efficient and parallelizable and outperforms the best previous schemes providing forward privacy, and achieves competitive performance with dynamic schemes without forward privacy. We provide a full security proof in the random oracle model. In our experiments on the Wikipedia archive of about four million pages, the server takes one second to perform a search with 100,000 results.
1403.2009
Olawale Hassan
Olawale Hassan (1), Iyad Kanj (1), Daniel Lokshtanov (2), and Ljubomir Perkovi\'c (1) ((1) School of Computing, DePaul University, (2) Department of Informatics, University of Bergen, Bergen, Norway)
On the Ordered List Subgraph Embedding Problems
null
null
null
null
cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the (parameterized) Ordered List Subgraph Embedding problem (p-OLSE) we are given two graphs $G$ and $H$, each with a linear order defined on its vertices, a function $L$ that associates with every vertex in $G$ a list of vertices in $H$, and a parameter $k$. The question is to decide if we can embed (one-to-one) a subgraph $S$ of $G$ of $k$ vertices into $H$ such that: (1) every vertex of $S$ is mapped to a vertex from its associated list, (2) the linear orders inherited by $S$ and its image under the embedding are respected, and (3) if there is an edge between two vertices in $S$ then there is an edge between their images. If we require the subgraph $S$ to be embedded as an induced subgraph, we obtain the Ordered List Induced Subgraph Embedding problem (p-OLISE). The p-OLSE and p-OLISE problems model various problems in Bioinformatics related to structural comparison/alignment of proteins. We investigate the complexity of p-OLSE and p-OLISE with respect to the following structural parameters: the width $\Delta_L$ of the function $L$ (size of the largest list), and the maximum degree $\Delta_H$ of $H$ and $\Delta_G$ of $G$. In terms of the structural parameters under consideration, we draw a complete complexity landscape of p-OLSE and p-OLISE (and their optimization versions) with respect to the computational frameworks of classical complexity, parameterized complexity, and approximation.
[ { "created": "Sat, 8 Mar 2014 22:10:25 GMT", "version": "v1" } ]
2014-03-11
[ [ "Hassan", "Olawale", "" ], [ "Kanj", "Iyad", "" ], [ "Lokshtanov", "Daniel", "" ], [ "Perković", "Ljubomir", "" ] ]
In the (parameterized) Ordered List Subgraph Embedding problem (p-OLSE) we are given two graphs $G$ and $H$, each with a linear order defined on its vertices, a function $L$ that associates with every vertex in $G$ a list of vertices in $H$, and a parameter $k$. The question is to decide if we can embed (one-to-one) a subgraph $S$ of $G$ of $k$ vertices into $H$ such that: (1) every vertex of $S$ is mapped to a vertex from its associated list, (2) the linear orders inherited by $S$ and its image under the embedding are respected, and (3) if there is an edge between two vertices in $S$ then there is an edge between their images. If we require the subgraph $S$ to be embedded as an induced subgraph, we obtain the Ordered List Induced Subgraph Embedding problem (p-OLISE). The p-OLSE and p-OLISE problems model various problems in Bioinformatics related to structural comparison/alignment of proteins. We investigate the complexity of p-OLSE and p-OLISE with respect to the following structural parameters: the width $\Delta_L$ of the function $L$ (size of the largest list), and the maximum degree $\Delta_H$ of $H$ and $\Delta_G$ of $G$. In terms of the structural parameters under consideration, we draw a complete complexity landscape of p-OLSE and p-OLISE (and their optimization versions) with respect to the computational frameworks of classical complexity, parameterized complexity, and approximation.
2011.07631
Debesh Jha
Debesh Jha, Sharib Ali, Nikhil Kumar Tomar, H{\aa}vard D. Johansen, Dag D. Johansen, Jens Rittscher, Michael A. Riegler, and P{\aa}l Halvorsen
Real-Time Polyp Detection, Localization and Segmentation in Colonoscopy Using Deep Learning
null
Published in: IEEE Access, Page(s): 40496 - 40510, Date of Publication: 04 March 2021, Electronic ISSN: 2169-3536, PubMed ID: 33747684 Publisher: IEEE
10.1109/ACCESS.2021.3063716
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
Computer-aided detection, localisation, and segmentation methods can help improve colonoscopy procedures. Even though many methods have been built to tackle automatic detection and segmentation of polyps, benchmarking of state-of-the-art methods still remains an open problem. This is due to the increasing number of researched computer vision methods that can be applied to polyp datasets. Benchmarking of novel methods can provide a direction to the development of automated polyp detection and segmentation tasks. Furthermore, it ensures that the produced results in the community are reproducible and provide a fair comparison of developed methods. In this paper, we benchmark several recent state-of-the-art methods using Kvasir-SEG, an open-access dataset of colonoscopy images for polyp detection, localisation, and segmentation evaluating both method accuracy and speed. Whilst, most methods in literature have competitive performance over accuracy, we show that the proposed ColonSegNet achieved a better trade-off between an average precision of 0.8000 and mean IoU of 0.8100, and the fastest speed of 180 frames per second for the detection and localisation task. Likewise, the proposed ColonSegNet achieved a competitive dice coefficient of 0.8206 and the best average speed of 182.38 frames per second for the segmentation task. Our comprehensive comparison with various state-of-the-art methods reveals the importance of benchmarking the deep learning methods for automated real-time polyp identification and delineations that can potentially transform current clinical practices and minimise miss-detection rates.
[ { "created": "Sun, 15 Nov 2020 21:14:50 GMT", "version": "v1" }, { "created": "Wed, 31 Mar 2021 20:21:06 GMT", "version": "v2" } ]
2021-04-02
[ [ "Jha", "Debesh", "" ], [ "Ali", "Sharib", "" ], [ "Tomar", "Nikhil Kumar", "" ], [ "Johansen", "Håvard D.", "" ], [ "Johansen", "Dag D.", "" ], [ "Rittscher", "Jens", "" ], [ "Riegler", "Michael A.", "" ], [ "Halvorsen", "Pål", "" ] ]
Computer-aided detection, localisation, and segmentation methods can help improve colonoscopy procedures. Even though many methods have been built to tackle automatic detection and segmentation of polyps, benchmarking of state-of-the-art methods still remains an open problem. This is due to the increasing number of researched computer vision methods that can be applied to polyp datasets. Benchmarking of novel methods can provide a direction to the development of automated polyp detection and segmentation tasks. Furthermore, it ensures that the produced results in the community are reproducible and provide a fair comparison of developed methods. In this paper, we benchmark several recent state-of-the-art methods using Kvasir-SEG, an open-access dataset of colonoscopy images for polyp detection, localisation, and segmentation evaluating both method accuracy and speed. Whilst, most methods in literature have competitive performance over accuracy, we show that the proposed ColonSegNet achieved a better trade-off between an average precision of 0.8000 and mean IoU of 0.8100, and the fastest speed of 180 frames per second for the detection and localisation task. Likewise, the proposed ColonSegNet achieved a competitive dice coefficient of 0.8206 and the best average speed of 182.38 frames per second for the segmentation task. Our comprehensive comparison with various state-of-the-art methods reveals the importance of benchmarking the deep learning methods for automated real-time polyp identification and delineations that can potentially transform current clinical practices and minimise miss-detection rates.
2408.00147
Colin Shea-Blymyer
Colin Shea-Blymyer, Houssam Abbas
Formal Ethical Obligations in Reinforcement Learning Agents: Verification and Policy Updates
null
null
null
null
cs.AI cs.LO
http://creativecommons.org/licenses/by-sa/4.0/
When designing agents for operation in uncertain environments, designers need tools to automatically reason about what agents ought to do, how that conflicts with what is actually happening, and how a policy might be modified to remove the conflict. These obligations include ethical and social obligations, permissions and prohibitions, which constrain how the agent achieves its mission and executes its policy. We propose a new deontic logic, Expected Act Utilitarian deontic logic, for enabling this reasoning at design time: for specifying and verifying the agent's strategic obligations, then modifying its policy from a reference policy to meet those obligations. Unlike approaches that work at the reward level, working at the logical level increases the transparency of the trade-offs. We introduce two algorithms: one for model-checking whether an RL agent has the right strategic obligations, and one for modifying a reference decision policy to make it meet obligations expressed in our logic. We illustrate our algorithms on DAC-MDPs which accurately abstract neural decision policies, and on toy gridworld environments.
[ { "created": "Wed, 31 Jul 2024 20:21:15 GMT", "version": "v1" } ]
2024-08-02
[ [ "Shea-Blymyer", "Colin", "" ], [ "Abbas", "Houssam", "" ] ]
When designing agents for operation in uncertain environments, designers need tools to automatically reason about what agents ought to do, how that conflicts with what is actually happening, and how a policy might be modified to remove the conflict. These obligations include ethical and social obligations, permissions and prohibitions, which constrain how the agent achieves its mission and executes its policy. We propose a new deontic logic, Expected Act Utilitarian deontic logic, for enabling this reasoning at design time: for specifying and verifying the agent's strategic obligations, then modifying its policy from a reference policy to meet those obligations. Unlike approaches that work at the reward level, working at the logical level increases the transparency of the trade-offs. We introduce two algorithms: one for model-checking whether an RL agent has the right strategic obligations, and one for modifying a reference decision policy to make it meet obligations expressed in our logic. We illustrate our algorithms on DAC-MDPs which accurately abstract neural decision policies, and on toy gridworld environments.
2008.06453
Davide Ancona
Davide Ancona and Angelo Ferrando and Viviana Mascardi
Can determinism and compositionality coexist in RML? (extended version)
null
null
null
null
cs.LO cs.PL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Runtime verification (RV) consists in dynamically verifying that the event traces generated by single runs of a system under scrutiny (SUS) are compliant with the formal specification of its expected properties. RML (Runtime Monitoring Language) is a simple but expressive Domain Specific Language for RV; its semantics is based on a trace calculus formalized by a deterministic rewriting system which drives the implementation of the interpreter of the monitors generated by the RML compiler from the specifications. While determinism of the trace calculus ensures better performances of the generated monitors, it makes the semantics of its operators less intuitive. In this paper we move a first step towards a compositional semantics of the RML trace calculus, by interpreting its basic operators as operations on sets of instantiated event traces and by proving that such an interpretation is equivalent to the operational semantics of the calculus.
[ { "created": "Fri, 14 Aug 2020 16:33:36 GMT", "version": "v1" }, { "created": "Mon, 17 Aug 2020 15:24:13 GMT", "version": "v2" } ]
2020-08-18
[ [ "Ancona", "Davide", "" ], [ "Ferrando", "Angelo", "" ], [ "Mascardi", "Viviana", "" ] ]
Runtime verification (RV) consists in dynamically verifying that the event traces generated by single runs of a system under scrutiny (SUS) are compliant with the formal specification of its expected properties. RML (Runtime Monitoring Language) is a simple but expressive Domain Specific Language for RV; its semantics is based on a trace calculus formalized by a deterministic rewriting system which drives the implementation of the interpreter of the monitors generated by the RML compiler from the specifications. While determinism of the trace calculus ensures better performances of the generated monitors, it makes the semantics of its operators less intuitive. In this paper we move a first step towards a compositional semantics of the RML trace calculus, by interpreting its basic operators as operations on sets of instantiated event traces and by proving that such an interpretation is equivalent to the operational semantics of the calculus.