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1910.02423
Harikrishnan Nellippallil Balakrishnan
Harikrishnan Nellippallil Balakrishnan, Aditi Kathpalia, Snehanshu Saha, Nithin Nagaraj
ChaosNet: A Chaos based Artificial Neural Network Architecture for Classification
27 pages, 23 figures
null
null
null
cs.LG nlin.CD stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by chaotic firing of neurons in the brain, we propose ChaosNet -- a novel chaos based artificial neural network architecture for classification tasks. ChaosNet is built using layers of neurons, each of which is a 1D chaotic map known as the Generalized Luroth Series (GLS) which has been shown in earlier works to possess very useful properties for compression, cryptography and for computing XOR and other logical operations. In this work, we design a novel learning algorithm on ChaosNet that exploits the topological transitivity property of the chaotic GLS neurons. The proposed learning algorithm gives consistently good performance accuracy in a number of classification tasks on well known publicly available datasets with very limited training samples. Even with as low as 7 (or fewer) training samples/class (which accounts for less than 0.05% of the total available data), ChaosNet yields performance accuracies in the range 73.89 % - 98.33 %. We demonstrate the robustness of ChaosNet to additive parameter noise and also provide an example implementation of a 2-layer ChaosNet for enhancing classification accuracy. We envisage the development of several other novel learning algorithms on ChaosNet in the near future.
[ { "created": "Sun, 6 Oct 2019 11:40:40 GMT", "version": "v1" } ]
2019-10-08
[ [ "Balakrishnan", "Harikrishnan Nellippallil", "" ], [ "Kathpalia", "Aditi", "" ], [ "Saha", "Snehanshu", "" ], [ "Nagaraj", "Nithin", "" ] ]
Inspired by chaotic firing of neurons in the brain, we propose ChaosNet -- a novel chaos based artificial neural network architecture for classification tasks. ChaosNet is built using layers of neurons, each of which is a 1D chaotic map known as the Generalized Luroth Series (GLS) which has been shown in earlier works to possess very useful properties for compression, cryptography and for computing XOR and other logical operations. In this work, we design a novel learning algorithm on ChaosNet that exploits the topological transitivity property of the chaotic GLS neurons. The proposed learning algorithm gives consistently good performance accuracy in a number of classification tasks on well known publicly available datasets with very limited training samples. Even with as low as 7 (or fewer) training samples/class (which accounts for less than 0.05% of the total available data), ChaosNet yields performance accuracies in the range 73.89 % - 98.33 %. We demonstrate the robustness of ChaosNet to additive parameter noise and also provide an example implementation of a 2-layer ChaosNet for enhancing classification accuracy. We envisage the development of several other novel learning algorithms on ChaosNet in the near future.
0801.4230
Simon Perdrix
Simon Perdrix
Quantum entanglement analysis based on abstract interpretation
13 pages
Proc. of 15th International Static Analysis Symposium (SAS 2008). LNCS 5079, pp 270-282
10.1007/978-3-540-69166-2_18
null
cs.LO cs.PL quant-ph
null
Entanglement is a non local property of quantum states which has no classical counterpart and plays a decisive role in quantum information theory. Several protocols, like the teleportation, are based on quantum entangled states. Moreover, any quantum algorithm which does not create entanglement can be efficiently simulated on a classical computer. The exact role of the entanglement is nevertheless not well understood. Since an exact analysis of entanglement evolution induces an exponential slowdown, we consider approximative analysis based on the framework of abstract interpretation. In this paper, a concrete quantum semantics based on superoperators is associated with a simple quantum programming language. The representation of entanglement, i.e. the design of the abstract domain is a key issue. A representation of entanglement as a partition of the memory is chosen. An abstract semantics is introduced, and the soundness of the approximation is proven.
[ { "created": "Mon, 28 Jan 2008 10:45:47 GMT", "version": "v1" } ]
2008-12-08
[ [ "Perdrix", "Simon", "" ] ]
Entanglement is a non local property of quantum states which has no classical counterpart and plays a decisive role in quantum information theory. Several protocols, like the teleportation, are based on quantum entangled states. Moreover, any quantum algorithm which does not create entanglement can be efficiently simulated on a classical computer. The exact role of the entanglement is nevertheless not well understood. Since an exact analysis of entanglement evolution induces an exponential slowdown, we consider approximative analysis based on the framework of abstract interpretation. In this paper, a concrete quantum semantics based on superoperators is associated with a simple quantum programming language. The representation of entanglement, i.e. the design of the abstract domain is a key issue. A representation of entanglement as a partition of the memory is chosen. An abstract semantics is introduced, and the soundness of the approximation is proven.
1401.0561
Janne Lindqvist
Michael Sherman, Gradeigh Clark, Yulong Yang, Shridatt Sugrim, Arttu Modig, Janne Lindqvist, Antti Oulasvirta, Teemu Roos
User-Generated Free-Form Gestures for Authentication: Security and Memorability
null
null
null
null
cs.CR cs.HC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper studies the security and memorability of free-form multitouch gestures for mobile authentication. Towards this end, we collected a dataset with a generate-test-retest paradigm where participants (N=63) generated free-form gestures, repeated them, and were later retested for memory. Half of the participants decided to generate one-finger gestures, and the other half generated multi-finger gestures. Although there has been recent work on template-based gestures, there are yet no metrics to analyze security of either template or free-form gestures. For example, entropy-based metrics used for text-based passwords are not suitable for capturing the security and memorability of free-form gestures. Hence, we modify a recently proposed metric for analyzing information capacity of continuous full-body movements for this purpose. Our metric computed estimated mutual information in repeated sets of gestures. Surprisingly, one-finger gestures had higher average mutual information. Gestures with many hard angles and turns had the highest mutual information. The best-remembered gestures included signatures and simple angular shapes. We also implemented a multitouch recognizer to evaluate the practicality of free-form gestures in a real authentication system and how they perform against shoulder surfing attacks. We conclude the paper with strategies for generating secure and memorable free-form gestures, which present a robust method for mobile authentication.
[ { "created": "Thu, 2 Jan 2014 23:15:27 GMT", "version": "v1" } ]
2014-01-06
[ [ "Sherman", "Michael", "" ], [ "Clark", "Gradeigh", "" ], [ "Yang", "Yulong", "" ], [ "Sugrim", "Shridatt", "" ], [ "Modig", "Arttu", "" ], [ "Lindqvist", "Janne", "" ], [ "Oulasvirta", "Antti", "" ], [ "Roos", "Teemu", "" ] ]
This paper studies the security and memorability of free-form multitouch gestures for mobile authentication. Towards this end, we collected a dataset with a generate-test-retest paradigm where participants (N=63) generated free-form gestures, repeated them, and were later retested for memory. Half of the participants decided to generate one-finger gestures, and the other half generated multi-finger gestures. Although there has been recent work on template-based gestures, there are yet no metrics to analyze security of either template or free-form gestures. For example, entropy-based metrics used for text-based passwords are not suitable for capturing the security and memorability of free-form gestures. Hence, we modify a recently proposed metric for analyzing information capacity of continuous full-body movements for this purpose. Our metric computed estimated mutual information in repeated sets of gestures. Surprisingly, one-finger gestures had higher average mutual information. Gestures with many hard angles and turns had the highest mutual information. The best-remembered gestures included signatures and simple angular shapes. We also implemented a multitouch recognizer to evaluate the practicality of free-form gestures in a real authentication system and how they perform against shoulder surfing attacks. We conclude the paper with strategies for generating secure and memorable free-form gestures, which present a robust method for mobile authentication.
2005.13956
Mao Ye
Xinpeng Li
Improving Generalized Zero-Shot Learning by Semantic Discriminator
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is a recognized fact that the classification accuracy of unseen classes in the setting of Generalized Zero-Shot Learning (GZSL) is much lower than that of traditional Zero-Shot Leaning (ZSL). One of the reasons is that an instance is always misclassified to the wrong domain. Here we refer to the seen and unseen classes as two domains respectively. We propose a new approach to distinguish whether the instances come from the seen or unseen classes. First the visual feature of instance is projected into the semantic space. Then the absolute norm difference between the projected semantic vector and the class semantic embedding vector, and the minimum distance between the projected semantic vectors and the semantic embedding vectors of the seen classes are used as discrimination basis. This approach is termed as SD (Semantic Discriminator) because domain judgement of instance is performed in the semantic space. Our approach can be combined with any existing ZSL method and fully supervision classification model to form a new GZSL method. Furthermore, our approach is very simple and does not need any fixed parameters.
[ { "created": "Thu, 28 May 2020 12:48:38 GMT", "version": "v1" }, { "created": "Thu, 11 Jun 2020 14:43:10 GMT", "version": "v2" } ]
2020-06-12
[ [ "Li", "Xinpeng", "" ] ]
It is a recognized fact that the classification accuracy of unseen classes in the setting of Generalized Zero-Shot Learning (GZSL) is much lower than that of traditional Zero-Shot Leaning (ZSL). One of the reasons is that an instance is always misclassified to the wrong domain. Here we refer to the seen and unseen classes as two domains respectively. We propose a new approach to distinguish whether the instances come from the seen or unseen classes. First the visual feature of instance is projected into the semantic space. Then the absolute norm difference between the projected semantic vector and the class semantic embedding vector, and the minimum distance between the projected semantic vectors and the semantic embedding vectors of the seen classes are used as discrimination basis. This approach is termed as SD (Semantic Discriminator) because domain judgement of instance is performed in the semantic space. Our approach can be combined with any existing ZSL method and fully supervision classification model to form a new GZSL method. Furthermore, our approach is very simple and does not need any fixed parameters.
2211.14086
Jingwang Ling
Jingwang Ling, Zhibo Wang, Feng Xu
ShadowNeuS: Neural SDF Reconstruction by Shadow Ray Supervision
CVPR 2023. Project page: https://gerwang.github.io/shadowneus/
null
null
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
By supervising camera rays between a scene and multi-view image planes, NeRF reconstructs a neural scene representation for the task of novel view synthesis. On the other hand, shadow rays between the light source and the scene have yet to be considered. Therefore, we propose a novel shadow ray supervision scheme that optimizes both the samples along the ray and the ray location. By supervising shadow rays, we successfully reconstruct a neural SDF of the scene from single-view images under multiple lighting conditions. Given single-view binary shadows, we train a neural network to reconstruct a complete scene not limited by the camera's line of sight. By further modeling the correlation between the image colors and the shadow rays, our technique can also be effectively extended to RGB inputs. We compare our method with previous works on challenging tasks of shape reconstruction from single-view binary shadow or RGB images and observe significant improvements. The code and data are available at https://github.com/gerwang/ShadowNeuS.
[ { "created": "Fri, 25 Nov 2022 13:14:56 GMT", "version": "v1" }, { "created": "Thu, 23 Mar 2023 14:21:24 GMT", "version": "v2" } ]
2023-03-24
[ [ "Ling", "Jingwang", "" ], [ "Wang", "Zhibo", "" ], [ "Xu", "Feng", "" ] ]
By supervising camera rays between a scene and multi-view image planes, NeRF reconstructs a neural scene representation for the task of novel view synthesis. On the other hand, shadow rays between the light source and the scene have yet to be considered. Therefore, we propose a novel shadow ray supervision scheme that optimizes both the samples along the ray and the ray location. By supervising shadow rays, we successfully reconstruct a neural SDF of the scene from single-view images under multiple lighting conditions. Given single-view binary shadows, we train a neural network to reconstruct a complete scene not limited by the camera's line of sight. By further modeling the correlation between the image colors and the shadow rays, our technique can also be effectively extended to RGB inputs. We compare our method with previous works on challenging tasks of shape reconstruction from single-view binary shadow or RGB images and observe significant improvements. The code and data are available at https://github.com/gerwang/ShadowNeuS.
1907.07366
Yen Hao Huang
Yen-Hao Huang, Yi-Hsin Chen, Fernando Henrique Calderon Alvarado, Ssu-Rui Lee, Shu-I Wu, Yuwen Lai and Yi-Shin Chen
Leveraging Linguistic Characteristics for Bipolar Disorder Recognition with Gender Differences
Accepted by DSHealth '19: 2019 KDD Workshop on Applied Data Science for Healthcare
null
null
null
cs.IR cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most previous studies on automatic recognition model for bipolar disorder (BD) were based on both social media and linguistic features. The present study investigates the possibility of adopting only language-based features, namely the syntax and morpheme collocation. We also examine the effect of gender on the results considering gender has long been recognized as an important modulating factor for mental disorders, yet it received little attention in previous linguistic models. The present study collects Twitter posts 3 months prior to the self-disclosure by 349 BD users (231 female, 118 male). We construct a set of syntactic patterns in terms of the word usage based on graph pattern construction and pattern attention mechanism. The factors examined are gender differences, syntactic patterns, and bipolar recognition performance. The performance indicates our F1 scores reach over 91% and outperform several baselines, including those using TF-IDF, LIWC and pre-trained language models (ELMO and BERT). The contributions of the present study are: (1) The features are contextualized, domain-agnostic, and purely linguistic. (2) The performance of BD recognition is improved by gender-enriched linguistic pattern features, which are constructed with gender differences in language usage.
[ { "created": "Wed, 17 Jul 2019 07:37:13 GMT", "version": "v1" } ]
2019-07-18
[ [ "Huang", "Yen-Hao", "" ], [ "Chen", "Yi-Hsin", "" ], [ "Alvarado", "Fernando Henrique Calderon", "" ], [ "Lee", "Ssu-Rui", "" ], [ "Wu", "Shu-I", "" ], [ "Lai", "Yuwen", "" ], [ "Chen", "Yi-Shin", "" ] ]
Most previous studies on automatic recognition model for bipolar disorder (BD) were based on both social media and linguistic features. The present study investigates the possibility of adopting only language-based features, namely the syntax and morpheme collocation. We also examine the effect of gender on the results considering gender has long been recognized as an important modulating factor for mental disorders, yet it received little attention in previous linguistic models. The present study collects Twitter posts 3 months prior to the self-disclosure by 349 BD users (231 female, 118 male). We construct a set of syntactic patterns in terms of the word usage based on graph pattern construction and pattern attention mechanism. The factors examined are gender differences, syntactic patterns, and bipolar recognition performance. The performance indicates our F1 scores reach over 91% and outperform several baselines, including those using TF-IDF, LIWC and pre-trained language models (ELMO and BERT). The contributions of the present study are: (1) The features are contextualized, domain-agnostic, and purely linguistic. (2) The performance of BD recognition is improved by gender-enriched linguistic pattern features, which are constructed with gender differences in language usage.
2310.09238
Saumajit Saha
Saumajit Saha and Albert Nanda
BanglaNLP at BLP-2023 Task 2: Benchmarking different Transformer Models for Sentiment Analysis of Bangla Social Media Posts
7 pages, 2 figures, workshop
null
null
null
cs.CL
http://creativecommons.org/licenses/by/4.0/
Bangla is the 7th most widely spoken language globally, with a staggering 234 million native speakers primarily hailing from India and Bangladesh. This morphologically rich language boasts a rich literary tradition, encompassing diverse dialects and language-specific challenges. Despite its linguistic richness and history, Bangla remains categorized as a low-resource language within the natural language processing (NLP) and speech community. This paper presents our submission to Task 2 (Sentiment Analysis of Bangla Social Media Posts) of the BLP Workshop. We experiment with various Transformer-based architectures to solve this task. Our quantitative results show that transfer learning really helps in better learning of the models in this low-resource language scenario. This becomes evident when we further finetune a model which has already been finetuned on twitter data for sentiment analysis task and that finetuned model performs the best among all other models. We also perform a detailed error analysis where we find some instances where ground truth labels need to be relooked at. We obtain a micro-F1 of 67.02\% on the test set and our performance in this shared task is ranked at 21 in the leaderboard.
[ { "created": "Fri, 13 Oct 2023 16:46:38 GMT", "version": "v1" }, { "created": "Wed, 18 Oct 2023 03:51:38 GMT", "version": "v2" } ]
2023-10-19
[ [ "Saha", "Saumajit", "" ], [ "Nanda", "Albert", "" ] ]
Bangla is the 7th most widely spoken language globally, with a staggering 234 million native speakers primarily hailing from India and Bangladesh. This morphologically rich language boasts a rich literary tradition, encompassing diverse dialects and language-specific challenges. Despite its linguistic richness and history, Bangla remains categorized as a low-resource language within the natural language processing (NLP) and speech community. This paper presents our submission to Task 2 (Sentiment Analysis of Bangla Social Media Posts) of the BLP Workshop. We experiment with various Transformer-based architectures to solve this task. Our quantitative results show that transfer learning really helps in better learning of the models in this low-resource language scenario. This becomes evident when we further finetune a model which has already been finetuned on twitter data for sentiment analysis task and that finetuned model performs the best among all other models. We also perform a detailed error analysis where we find some instances where ground truth labels need to be relooked at. We obtain a micro-F1 of 67.02\% on the test set and our performance in this shared task is ranked at 21 in the leaderboard.
1403.7720
Quan Yu
Quan Yu, Chi Wan Sung, Terence H. Chan
Irregular Fractional Repetition Code Optimization for Heterogeneous Cloud Storage
12 pages, 10 figures. to appear in IEEE Journal on Selected Areas in Communications 2014
null
10.1109/JSAC.2014.140523
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents a flexible irregular model for heterogeneous cloud storage systems and investigates how the cost of repairing failed nodes can be minimized. The fractional repetition code, originally designed for minimizing repair bandwidth for homogeneous storage systems, is generalized to the irregular fractional repetition code, which is adaptable to heterogeneous environments. The code structure and the associated storage allocation can be obtained by solving an integer linear programming problem. For moderate sized networks, a heuristic algorithm is proposed and shown to be near-optimal by computer simulations.
[ { "created": "Sun, 30 Mar 2014 09:00:51 GMT", "version": "v1" } ]
2016-11-18
[ [ "Yu", "Quan", "" ], [ "Sung", "Chi Wan", "" ], [ "Chan", "Terence H.", "" ] ]
This paper presents a flexible irregular model for heterogeneous cloud storage systems and investigates how the cost of repairing failed nodes can be minimized. The fractional repetition code, originally designed for minimizing repair bandwidth for homogeneous storage systems, is generalized to the irregular fractional repetition code, which is adaptable to heterogeneous environments. The code structure and the associated storage allocation can be obtained by solving an integer linear programming problem. For moderate sized networks, a heuristic algorithm is proposed and shown to be near-optimal by computer simulations.
2112.08765
Enguerrand Prebet
Enguerrand Prebet (ENS Lyon, FOCUS)
On Up-to Context Techniques in the $\pi$-calculus
null
null
null
null
cs.LO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a variant of the theory of compatible functions on relations, due to Sangiorgi and Pous. We show that the up-to context proof technique for bisimulation is compatible in this setting for two subsets of the pi-calculus: the asynchronous pi-calculus and a pi-calculus with immediately available names.
[ { "created": "Thu, 16 Dec 2021 10:24:09 GMT", "version": "v1" }, { "created": "Fri, 3 Jun 2022 08:32:10 GMT", "version": "v2" } ]
2022-06-06
[ [ "Prebet", "Enguerrand", "", "ENS Lyon, FOCUS" ] ]
We present a variant of the theory of compatible functions on relations, due to Sangiorgi and Pous. We show that the up-to context proof technique for bisimulation is compatible in this setting for two subsets of the pi-calculus: the asynchronous pi-calculus and a pi-calculus with immediately available names.
2107.00584
Lucas da Silva Reis
Claudio Qureshi and Lucas Reis
On the functional graph of the power map over finite groups
null
null
null
null
cs.DM math.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we study the description of the functional graphs associated with the power maps over finite groups. We present a structural result which describes the isomorphism class of these graphs for abelian groups and also for flower groups, which is a special class of non abelian groups introduced in this paper. Unlike the abelian case where all the trees associated with periodic points are isomorphic, in the case of flower groups we prove that several different classes of trees can occur. The class of central trees (i.e. associated with periodic points that are in the center of the group) are in general non-elementary and a recursive description is given in this work. Flower groups include many non abelian groups such as dihedral and generalized quaternion groups, and the projective general linear group of order two over a finite field. In particular, we provide improvements on past works regarding the description of the dynamics of the power map over these groups.
[ { "created": "Thu, 1 Jul 2021 16:17:00 GMT", "version": "v1" }, { "created": "Tue, 6 Sep 2022 19:56:23 GMT", "version": "v2" } ]
2022-09-08
[ [ "Qureshi", "Claudio", "" ], [ "Reis", "Lucas", "" ] ]
In this paper we study the description of the functional graphs associated with the power maps over finite groups. We present a structural result which describes the isomorphism class of these graphs for abelian groups and also for flower groups, which is a special class of non abelian groups introduced in this paper. Unlike the abelian case where all the trees associated with periodic points are isomorphic, in the case of flower groups we prove that several different classes of trees can occur. The class of central trees (i.e. associated with periodic points that are in the center of the group) are in general non-elementary and a recursive description is given in this work. Flower groups include many non abelian groups such as dihedral and generalized quaternion groups, and the projective general linear group of order two over a finite field. In particular, we provide improvements on past works regarding the description of the dynamics of the power map over these groups.
2401.09621
Jes\'us Camacho-Rodr\'iguez
Ashvin Agrawal, Tim Brown, Anoop Johnson, Jes\'us Camacho-Rodr\'iguez, Kyle Weller, Carlo Curino, Raghu Ramakrishnan
XTable in Action: Seamless Interoperability in Data Lakes
null
null
null
null
cs.DB
http://creativecommons.org/licenses/by-nc-nd/4.0/
Contemporary approaches to data management are increasingly relying on unified analytics and AI platforms to foster collaboration, interoperability, seamless access to reliable data, and high performance. Data Lakes featuring open standard table formats such as Delta Lake, Apache Hudi, and Apache Iceberg are central components of these data architectures. Choosing the right format for managing a table is crucial for achieving the objectives mentioned above. The challenge lies in selecting the best format, a task that is onerous and can yield temporary results, as the ideal choice may shift over time with data growth, evolving workloads, and the competitive development of table formats and processing engines. Moreover, restricting data access to a single format can hinder data sharing resulting in diminished business value over the long term. The ability to seamlessly interoperate between formats and with negligible overhead can effectively address these challenges. Our solution in this direction is an innovative omni-directional translator, XTable, that facilitates writing data in one format and reading it in any format, thus achieving the desired format interoperability. In this work, we demonstrate the effectiveness of XTable through application scenarios inspired by real-world use cases.
[ { "created": "Wed, 17 Jan 2024 22:18:00 GMT", "version": "v1" } ]
2024-01-19
[ [ "Agrawal", "Ashvin", "" ], [ "Brown", "Tim", "" ], [ "Johnson", "Anoop", "" ], [ "Camacho-Rodríguez", "Jesús", "" ], [ "Weller", "Kyle", "" ], [ "Curino", "Carlo", "" ], [ "Ramakrishnan", "Raghu", "" ] ]
Contemporary approaches to data management are increasingly relying on unified analytics and AI platforms to foster collaboration, interoperability, seamless access to reliable data, and high performance. Data Lakes featuring open standard table formats such as Delta Lake, Apache Hudi, and Apache Iceberg are central components of these data architectures. Choosing the right format for managing a table is crucial for achieving the objectives mentioned above. The challenge lies in selecting the best format, a task that is onerous and can yield temporary results, as the ideal choice may shift over time with data growth, evolving workloads, and the competitive development of table formats and processing engines. Moreover, restricting data access to a single format can hinder data sharing resulting in diminished business value over the long term. The ability to seamlessly interoperate between formats and with negligible overhead can effectively address these challenges. Our solution in this direction is an innovative omni-directional translator, XTable, that facilitates writing data in one format and reading it in any format, thus achieving the desired format interoperability. In this work, we demonstrate the effectiveness of XTable through application scenarios inspired by real-world use cases.
2203.08321
Emadeldeen Eldele
Mohamed Ragab, Emadeldeen Eldele, Wee Ling Tan, Chuan-Sheng Foo, Zhenghua Chen, Min Wu, Chee-Keong Kwoh, Xiaoli Li
ADATIME: A Benchmarking Suite for Domain Adaptation on Time Series Data
Accepted in the ACM Transactions on Knowledge Discovery from Data (TKDD)
null
10.1145/3587937
null
cs.LG
http://creativecommons.org/licenses/by/4.0/
Unsupervised domain adaptation methods aim to generalize well on unlabeled test data that may have a different (shifted) distribution from the training data. Such methods are typically developed on image data, and their application to time series data is less explored. Existing works on time series domain adaptation suffer from inconsistencies in evaluation schemes, datasets, and backbone neural network architectures. Moreover, labeled target data are often used for model selection, which violates the fundamental assumption of unsupervised domain adaptation. To address these issues, we develop a benchmarking evaluation suite (AdaTime) to systematically and fairly evaluate different domain adaptation methods on time series data. Specifically, we standardize the backbone neural network architectures and benchmarking datasets, while also exploring more realistic model selection approaches that can work with no labeled data or just a few labeled samples. Our evaluation includes adapting state-of-the-art visual domain adaptation methods to time series data as well as the recent methods specifically developed for time series data. We conduct extensive experiments to evaluate 11 state-of-the-art methods on five representative datasets spanning 50 cross-domain scenarios. Our results suggest that with careful selection of hyper-parameters, visual domain adaptation methods are competitive with methods proposed for time series domain adaptation. In addition, we find that hyper-parameters could be selected based on realistic model selection approaches. Our work unveils practical insights for applying domain adaptation methods on time series data and builds a solid foundation for future works in the field. The code is available at \href{https://github.com/emadeldeen24/AdaTime}{github.com/emadeldeen24/AdaTime}.
[ { "created": "Tue, 15 Mar 2022 23:55:05 GMT", "version": "v1" }, { "created": "Fri, 5 May 2023 14:06:57 GMT", "version": "v2" } ]
2023-05-08
[ [ "Ragab", "Mohamed", "" ], [ "Eldele", "Emadeldeen", "" ], [ "Tan", "Wee Ling", "" ], [ "Foo", "Chuan-Sheng", "" ], [ "Chen", "Zhenghua", "" ], [ "Wu", "Min", "" ], [ "Kwoh", "Chee-Keong", "" ], [ "Li", "Xiaoli", "" ] ]
Unsupervised domain adaptation methods aim to generalize well on unlabeled test data that may have a different (shifted) distribution from the training data. Such methods are typically developed on image data, and their application to time series data is less explored. Existing works on time series domain adaptation suffer from inconsistencies in evaluation schemes, datasets, and backbone neural network architectures. Moreover, labeled target data are often used for model selection, which violates the fundamental assumption of unsupervised domain adaptation. To address these issues, we develop a benchmarking evaluation suite (AdaTime) to systematically and fairly evaluate different domain adaptation methods on time series data. Specifically, we standardize the backbone neural network architectures and benchmarking datasets, while also exploring more realistic model selection approaches that can work with no labeled data or just a few labeled samples. Our evaluation includes adapting state-of-the-art visual domain adaptation methods to time series data as well as the recent methods specifically developed for time series data. We conduct extensive experiments to evaluate 11 state-of-the-art methods on five representative datasets spanning 50 cross-domain scenarios. Our results suggest that with careful selection of hyper-parameters, visual domain adaptation methods are competitive with methods proposed for time series domain adaptation. In addition, we find that hyper-parameters could be selected based on realistic model selection approaches. Our work unveils practical insights for applying domain adaptation methods on time series data and builds a solid foundation for future works in the field. The code is available at \href{https://github.com/emadeldeen24/AdaTime}{github.com/emadeldeen24/AdaTime}.
2006.01713
ShiLiang Zhang
Zhifu Gao, Shiliang Zhang, Ming Lei, Ian McLoughlin
SAN-M: Memory Equipped Self-Attention for End-to-End Speech Recognition
submitted to INTERSPEECH2020
null
null
null
cs.SD eess.AS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
End-to-end speech recognition has become popular in recent years, since it can integrate the acoustic, pronunciation and language models into a single neural network. Among end-to-end approaches, attention-based methods have emerged as being superior. For example, Transformer, which adopts an encoder-decoder architecture. The key improvement introduced by Transformer is the utilization of self-attention instead of recurrent mechanisms, enabling both encoder and decoder to capture long-range dependencies with lower computational complexity.In this work, we propose boosting the self-attention ability with a DFSMN memory block, forming the proposed memory equipped self-attention (SAN-M) mechanism. Theoretical and empirical comparisons have been made to demonstrate the relevancy and complementarity between self-attention and the DFSMN memory block. Furthermore, the proposed SAN-M provides an efficient mechanism to integrate these two modules. We have evaluated our approach on the public AISHELL-1 benchmark and an industrial-level 20,000-hour Mandarin speech recognition task. On both tasks, SAN-M systems achieved much better performance than the self-attention based Transformer baseline system. Specially, it can achieve a CER of 6.46% on the AISHELL-1 task even without using any external LM, comfortably outperforming other state-of-the-art systems.
[ { "created": "Thu, 21 May 2020 03:33:09 GMT", "version": "v1" } ]
2020-06-03
[ [ "Gao", "Zhifu", "" ], [ "Zhang", "Shiliang", "" ], [ "Lei", "Ming", "" ], [ "McLoughlin", "Ian", "" ] ]
End-to-end speech recognition has become popular in recent years, since it can integrate the acoustic, pronunciation and language models into a single neural network. Among end-to-end approaches, attention-based methods have emerged as being superior. For example, Transformer, which adopts an encoder-decoder architecture. The key improvement introduced by Transformer is the utilization of self-attention instead of recurrent mechanisms, enabling both encoder and decoder to capture long-range dependencies with lower computational complexity.In this work, we propose boosting the self-attention ability with a DFSMN memory block, forming the proposed memory equipped self-attention (SAN-M) mechanism. Theoretical and empirical comparisons have been made to demonstrate the relevancy and complementarity between self-attention and the DFSMN memory block. Furthermore, the proposed SAN-M provides an efficient mechanism to integrate these two modules. We have evaluated our approach on the public AISHELL-1 benchmark and an industrial-level 20,000-hour Mandarin speech recognition task. On both tasks, SAN-M systems achieved much better performance than the self-attention based Transformer baseline system. Specially, it can achieve a CER of 6.46% on the AISHELL-1 task even without using any external LM, comfortably outperforming other state-of-the-art systems.
1701.08407
Lu Lu
Lu Lu, Haiquan Zhao
Subband adaptive filter trained by differential evolution for channel estimation
7 pages, 4 figures
null
null
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The normalized subband adaptive filter (NSAF) is widely accepted as a preeminent adaptive filtering algorithm because of its efficiency under the colored excitation. However, the convergence rate of NSAF is slow. To address this drawback, in this paper, a variant of the NSAF, called the differential evolution (DE)-NSAF (DE-NSAF), is proposed for channel estimation based on DE strategy. It is worth noticing that there are several papers concerning designing DE strategies for adaptive filter. But their signal models are still the single adaptive filter model rather than the fullband adaptive filter model considered in this paper. Thus, the problem considered in our work is quite different from those. The proposed DE-NSAF algorithm is based on real-valued manipulations and has fast convergence rate for searching the global solution of optimized weight vector. Moreover, a design step of new algorithm is given in detail. Simulation results demonstrate the improved performance of the proposed DE-NSAF algorithm in terms of the convergence rate.
[ { "created": "Sun, 29 Jan 2017 17:30:53 GMT", "version": "v1" }, { "created": "Sun, 5 Mar 2017 18:33:38 GMT", "version": "v2" }, { "created": "Fri, 17 Mar 2017 02:04:06 GMT", "version": "v3" } ]
2017-03-20
[ [ "Lu", "Lu", "" ], [ "Zhao", "Haiquan", "" ] ]
The normalized subband adaptive filter (NSAF) is widely accepted as a preeminent adaptive filtering algorithm because of its efficiency under the colored excitation. However, the convergence rate of NSAF is slow. To address this drawback, in this paper, a variant of the NSAF, called the differential evolution (DE)-NSAF (DE-NSAF), is proposed for channel estimation based on DE strategy. It is worth noticing that there are several papers concerning designing DE strategies for adaptive filter. But their signal models are still the single adaptive filter model rather than the fullband adaptive filter model considered in this paper. Thus, the problem considered in our work is quite different from those. The proposed DE-NSAF algorithm is based on real-valued manipulations and has fast convergence rate for searching the global solution of optimized weight vector. Moreover, a design step of new algorithm is given in detail. Simulation results demonstrate the improved performance of the proposed DE-NSAF algorithm in terms of the convergence rate.
2302.07116
Lechao Cheng
Tian Qiu, Linyun Zhou, Wenxiang Xu, Lechao Cheng, Zunlei Feng, Mingli Song
Team DETR: Guide Queries as a Professional Team in Detection Transformers
null
null
null
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
Recent proposed DETR variants have made tremendous progress in various scenarios due to their streamlined processes and remarkable performance. However, the learned queries usually explore the global context to generate the final set prediction, resulting in redundant burdens and unfaithful results. More specifically, a query is commonly responsible for objects of different scales and positions, which is a challenge for the query itself, and will cause spatial resource competition among queries. To alleviate this issue, we propose Team DETR, which leverages query collaboration and position constraints to embrace objects of interest more precisely. We also dynamically cater to each query member's prediction preference, offering the query better scale and spatial priors. In addition, the proposed Team DETR is flexible enough to be adapted to other existing DETR variants without increasing parameters and calculations. Extensive experiments on the COCO dataset show that Team DETR achieves remarkable gains, especially for small and large objects. Code is available at \url{https://github.com/horrible-dong/TeamDETR}.
[ { "created": "Tue, 14 Feb 2023 15:21:53 GMT", "version": "v1" }, { "created": "Wed, 15 Feb 2023 07:25:10 GMT", "version": "v2" }, { "created": "Tue, 28 Feb 2023 04:28:12 GMT", "version": "v3" } ]
2023-03-01
[ [ "Qiu", "Tian", "" ], [ "Zhou", "Linyun", "" ], [ "Xu", "Wenxiang", "" ], [ "Cheng", "Lechao", "" ], [ "Feng", "Zunlei", "" ], [ "Song", "Mingli", "" ] ]
Recent proposed DETR variants have made tremendous progress in various scenarios due to their streamlined processes and remarkable performance. However, the learned queries usually explore the global context to generate the final set prediction, resulting in redundant burdens and unfaithful results. More specifically, a query is commonly responsible for objects of different scales and positions, which is a challenge for the query itself, and will cause spatial resource competition among queries. To alleviate this issue, we propose Team DETR, which leverages query collaboration and position constraints to embrace objects of interest more precisely. We also dynamically cater to each query member's prediction preference, offering the query better scale and spatial priors. In addition, the proposed Team DETR is flexible enough to be adapted to other existing DETR variants without increasing parameters and calculations. Extensive experiments on the COCO dataset show that Team DETR achieves remarkable gains, especially for small and large objects. Code is available at \url{https://github.com/horrible-dong/TeamDETR}.
1912.00369
Roger Moore
Roger K. Moore
Talking with Robots: Opportunities and Challenges
Submitted for presentation at the UNESCO International Conference Language Technologies for All (LT4All), Paris, 4-6 December 2019 (https://en.unesco.org/LT4All)
null
null
null
cs.HC cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Notwithstanding the tremendous progress that is taking place in spoken language technology, effective speech-based human-robot interaction still raises a number of important challenges. Not only do the fields of robotics and spoken language technology present their own special problems, but their combination raises an additional set of issues. In particular, there is a large gap between the formulaic speech that typifies contemporary spoken dialogue systems and the flexible nature of human-human conversation. It is pointed out that grounded and situated speech-based human-robot interaction may lead to deeper insights into the pragmatics of language usage, thereby overcoming the current `habitability gap'.
[ { "created": "Sun, 1 Dec 2019 09:42:50 GMT", "version": "v1" } ]
2019-12-03
[ [ "Moore", "Roger K.", "" ] ]
Notwithstanding the tremendous progress that is taking place in spoken language technology, effective speech-based human-robot interaction still raises a number of important challenges. Not only do the fields of robotics and spoken language technology present their own special problems, but their combination raises an additional set of issues. In particular, there is a large gap between the formulaic speech that typifies contemporary spoken dialogue systems and the flexible nature of human-human conversation. It is pointed out that grounded and situated speech-based human-robot interaction may lead to deeper insights into the pragmatics of language usage, thereby overcoming the current `habitability gap'.
2107.13304
Bang Xiang Yong
Bang Xiang Yong, Tim Pearce, Alexandra Brintrup
Bayesian Autoencoders: Analysing and Fixing the Bernoulli likelihood for Out-of-Distribution Detection
Presented at the ICML 2020 Workshop on Uncertainty and Ro-bustness in Deep Learning
null
null
null
cs.LG stat.ML
http://creativecommons.org/licenses/by/4.0/
After an autoencoder (AE) has learnt to reconstruct one dataset, it might be expected that the likelihood on an out-of-distribution (OOD) input would be low. This has been studied as an approach to detect OOD inputs. Recent work showed this intuitive approach can fail for the dataset pairs FashionMNIST vs MNIST. This paper suggests this is due to the use of Bernoulli likelihood and analyses why this is the case, proposing two fixes: 1) Compute the uncertainty of likelihood estimate by using a Bayesian version of the AE. 2) Use alternative distributions to model the likelihood.
[ { "created": "Wed, 28 Jul 2021 11:51:35 GMT", "version": "v1" } ]
2021-07-29
[ [ "Yong", "Bang Xiang", "" ], [ "Pearce", "Tim", "" ], [ "Brintrup", "Alexandra", "" ] ]
After an autoencoder (AE) has learnt to reconstruct one dataset, it might be expected that the likelihood on an out-of-distribution (OOD) input would be low. This has been studied as an approach to detect OOD inputs. Recent work showed this intuitive approach can fail for the dataset pairs FashionMNIST vs MNIST. This paper suggests this is due to the use of Bernoulli likelihood and analyses why this is the case, proposing two fixes: 1) Compute the uncertainty of likelihood estimate by using a Bayesian version of the AE. 2) Use alternative distributions to model the likelihood.
2009.12626
Klim Zaporojets
Klim Zaporojets, Johannes Deleu, Chris Develder, Thomas Demeester
DWIE: an entity-centric dataset for multi-task document-level information extraction
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents DWIE, the 'Deutsche Welle corpus for Information Extraction', a newly created multi-task dataset that combines four main Information Extraction (IE) annotation subtasks: (i) Named Entity Recognition (NER), (ii) Coreference Resolution, (iii) Relation Extraction (RE), and (iv) Entity Linking. DWIE is conceived as an entity-centric dataset that describes interactions and properties of conceptual entities on the level of the complete document. This contrasts with currently dominant mention-driven approaches that start from the detection and classification of named entity mentions in individual sentences. Further, DWIE presented two main challenges when building and evaluating IE models for it. First, the use of traditional mention-level evaluation metrics for NER and RE tasks on entity-centric DWIE dataset can result in measurements dominated by predictions on more frequently mentioned entities. We tackle this issue by proposing a new entity-driven metric that takes into account the number of mentions that compose each of the predicted and ground truth entities. Second, the document-level multi-task annotations require the models to transfer information between entity mentions located in different parts of the document, as well as between different tasks, in a joint learning setting. To realize this, we propose to use graph-based neural message passing techniques between document-level mention spans. Our experiments show an improvement of up to 5.5 F1 percentage points when incorporating neural graph propagation into our joint model. This demonstrates DWIE's potential to stimulate further research in graph neural networks for representation learning in multi-task IE. We make DWIE publicly available at https://github.com/klimzaporojets/DWIE.
[ { "created": "Sat, 26 Sep 2020 15:53:22 GMT", "version": "v1" }, { "created": "Tue, 9 Mar 2021 13:46:09 GMT", "version": "v2" } ]
2021-03-10
[ [ "Zaporojets", "Klim", "" ], [ "Deleu", "Johannes", "" ], [ "Develder", "Chris", "" ], [ "Demeester", "Thomas", "" ] ]
This paper presents DWIE, the 'Deutsche Welle corpus for Information Extraction', a newly created multi-task dataset that combines four main Information Extraction (IE) annotation subtasks: (i) Named Entity Recognition (NER), (ii) Coreference Resolution, (iii) Relation Extraction (RE), and (iv) Entity Linking. DWIE is conceived as an entity-centric dataset that describes interactions and properties of conceptual entities on the level of the complete document. This contrasts with currently dominant mention-driven approaches that start from the detection and classification of named entity mentions in individual sentences. Further, DWIE presented two main challenges when building and evaluating IE models for it. First, the use of traditional mention-level evaluation metrics for NER and RE tasks on entity-centric DWIE dataset can result in measurements dominated by predictions on more frequently mentioned entities. We tackle this issue by proposing a new entity-driven metric that takes into account the number of mentions that compose each of the predicted and ground truth entities. Second, the document-level multi-task annotations require the models to transfer information between entity mentions located in different parts of the document, as well as between different tasks, in a joint learning setting. To realize this, we propose to use graph-based neural message passing techniques between document-level mention spans. Our experiments show an improvement of up to 5.5 F1 percentage points when incorporating neural graph propagation into our joint model. This demonstrates DWIE's potential to stimulate further research in graph neural networks for representation learning in multi-task IE. We make DWIE publicly available at https://github.com/klimzaporojets/DWIE.
2107.01726
Vladimir Vovk
Vladimir Vovk, Ivan Petej, and Alex Gammerman
Protected probabilistic classification
23 pages, 14 figures, and 4 tables
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper proposes a way of protecting probabilistic prediction models against changes in the data distribution, concentrating on the case of classification and paying particular attention to binary classification. This is important in applications of machine learning, where the quality of a trained prediction algorithm may drop significantly in the process of its exploitation. Our techniques are based on recent work on conformal test martingales and older work on prediction with expert advice, namely tracking the best expert.
[ { "created": "Sun, 4 Jul 2021 20:32:52 GMT", "version": "v1" }, { "created": "Fri, 22 Oct 2021 19:04:51 GMT", "version": "v2" } ]
2021-10-26
[ [ "Vovk", "Vladimir", "" ], [ "Petej", "Ivan", "" ], [ "Gammerman", "Alex", "" ] ]
This paper proposes a way of protecting probabilistic prediction models against changes in the data distribution, concentrating on the case of classification and paying particular attention to binary classification. This is important in applications of machine learning, where the quality of a trained prediction algorithm may drop significantly in the process of its exploitation. Our techniques are based on recent work on conformal test martingales and older work on prediction with expert advice, namely tracking the best expert.
2302.05889
Yifei Wang
Yifei Wang, Yupan Wang, Zeyu Zhang, Song Yang, Kaiqi Zhao, Jiamou Liu
USER: Unsupervised Structural Entropy-based Robust Graph Neural Network
null
null
10.1609/aaai.v37i8.26219
null
cs.LG cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Unsupervised/self-supervised graph neural networks (GNN) are vulnerable to inherent randomness in the input graph data which greatly affects the performance of the model in downstream tasks. In this paper, we alleviate the interference of graph randomness and learn appropriate representations of nodes without label information. To this end, we propose USER, an unsupervised robust version of graph neural networks that is based on structural entropy. We analyze the property of intrinsic connectivity and define intrinsic connectivity graph. We also identify the rank of the adjacency matrix as a crucial factor in revealing a graph that provides the same embeddings as the intrinsic connectivity graph. We then introduce structural entropy in the objective function to capture such a graph. Extensive experiments conducted on clustering and link prediction tasks under random-noises and meta-attack over three datasets show USER outperforms benchmarks and is robust to heavier randomness.
[ { "created": "Sun, 12 Feb 2023 10:32:12 GMT", "version": "v1" } ]
2023-08-14
[ [ "Wang", "Yifei", "" ], [ "Wang", "Yupan", "" ], [ "Zhang", "Zeyu", "" ], [ "Yang", "Song", "" ], [ "Zhao", "Kaiqi", "" ], [ "Liu", "Jiamou", "" ] ]
Unsupervised/self-supervised graph neural networks (GNN) are vulnerable to inherent randomness in the input graph data which greatly affects the performance of the model in downstream tasks. In this paper, we alleviate the interference of graph randomness and learn appropriate representations of nodes without label information. To this end, we propose USER, an unsupervised robust version of graph neural networks that is based on structural entropy. We analyze the property of intrinsic connectivity and define intrinsic connectivity graph. We also identify the rank of the adjacency matrix as a crucial factor in revealing a graph that provides the same embeddings as the intrinsic connectivity graph. We then introduce structural entropy in the objective function to capture such a graph. Extensive experiments conducted on clustering and link prediction tasks under random-noises and meta-attack over three datasets show USER outperforms benchmarks and is robust to heavier randomness.
2405.09550
Jeongjin Shin
Jeongjin Shin
Mask-based Invisible Backdoor Attacks on Object Detection
7 pages, 3 figures
null
null
null
cs.CV cs.AI cs.CR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep learning models have achieved unprecedented performance in the domain of object detection, resulting in breakthroughs in areas such as autonomous driving and security. However, deep learning models are vulnerable to backdoor attacks. These attacks prompt models to behave similarly to standard models without a trigger; however, they act maliciously upon detecting a predefined trigger. Despite extensive research on backdoor attacks in image classification, their application to object detection remains relatively underexplored. Given the widespread application of object detection in critical real-world scenarios, the sensitivity and potential impact of these vulnerabilities cannot be overstated. In this study, we propose an effective invisible backdoor attack on object detection utilizing a mask-based approach. Three distinct attack scenarios were explored for object detection: object disappearance, object misclassification, and object generation attack. Through extensive experiments, we comprehensively examined the effectiveness of these attacks and tested certain defense methods to determine effective countermeasures. Code will be available at https://github.com/jeongjin0/invisible-backdoor-object-detection
[ { "created": "Wed, 20 Mar 2024 12:27:30 GMT", "version": "v1" }, { "created": "Fri, 24 May 2024 13:17:39 GMT", "version": "v2" }, { "created": "Tue, 4 Jun 2024 11:28:42 GMT", "version": "v3" } ]
2024-06-05
[ [ "Shin", "Jeongjin", "" ] ]
Deep learning models have achieved unprecedented performance in the domain of object detection, resulting in breakthroughs in areas such as autonomous driving and security. However, deep learning models are vulnerable to backdoor attacks. These attacks prompt models to behave similarly to standard models without a trigger; however, they act maliciously upon detecting a predefined trigger. Despite extensive research on backdoor attacks in image classification, their application to object detection remains relatively underexplored. Given the widespread application of object detection in critical real-world scenarios, the sensitivity and potential impact of these vulnerabilities cannot be overstated. In this study, we propose an effective invisible backdoor attack on object detection utilizing a mask-based approach. Three distinct attack scenarios were explored for object detection: object disappearance, object misclassification, and object generation attack. Through extensive experiments, we comprehensively examined the effectiveness of these attacks and tested certain defense methods to determine effective countermeasures. Code will be available at https://github.com/jeongjin0/invisible-backdoor-object-detection
2405.11267
Yo\`av Montacute
Yo\`av Montacute and Glynn Winskel
Concurrent Games over Relational Structures: The Origin of Game Comonads
Extended version of the paper in Logic in Computer Science (LICS) 2024 Proceedings
null
null
null
cs.LO cs.PL math.CT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Spoiler-Duplicator games are used in finite model theory to examine the expressive power of logics. Their strategies have recently been reformulated as coKleisli maps of game comonads over relational structures, providing new results in finite model theory via categorical techniques. We present a novel framework for studying Spoiler-Duplicator games by viewing them as event structures. We introduce a first systematic method for constructing comonads for all one-sided Spoiler-Duplicator games: game comonads are now realised by adjunctions to a category of games, generically constructed from a comonad in a bicategory of game schema (called signature games). Maps of the constructed categories of games are strategies and generalise coKleisli maps of game comonads; in the case of one-sided games they are shown to coincide with suitably generalised homomorphisms. Finally, we provide characterisations of strategies on two-sided Spoiler-Duplicator games; in a common special case they coincide with spans of event structures.
[ { "created": "Sat, 18 May 2024 11:34:05 GMT", "version": "v1" } ]
2024-05-21
[ [ "Montacute", "Yoàv", "" ], [ "Winskel", "Glynn", "" ] ]
Spoiler-Duplicator games are used in finite model theory to examine the expressive power of logics. Their strategies have recently been reformulated as coKleisli maps of game comonads over relational structures, providing new results in finite model theory via categorical techniques. We present a novel framework for studying Spoiler-Duplicator games by viewing them as event structures. We introduce a first systematic method for constructing comonads for all one-sided Spoiler-Duplicator games: game comonads are now realised by adjunctions to a category of games, generically constructed from a comonad in a bicategory of game schema (called signature games). Maps of the constructed categories of games are strategies and generalise coKleisli maps of game comonads; in the case of one-sided games they are shown to coincide with suitably generalised homomorphisms. Finally, we provide characterisations of strategies on two-sided Spoiler-Duplicator games; in a common special case they coincide with spans of event structures.
2205.00872
Chen Xu
Chen Xu, Piji Li, Wei Wang, Haoran Yang, Siyun Wang, and Chuangbai Xiao
COSPLAY: Concept Set Guided Personalized Dialogue Generation Across Both Party Personas
Accepted by SIGIR 2022, 11 pages, 9 figures
null
10.1145/3477495.3531957
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Maintaining a consistent persona is essential for building a human-like conversational model. However, the lack of attention to the partner makes the model more egocentric: they tend to show their persona by all means such as twisting the topic stiffly, pulling the conversation to their own interests regardless, and rambling their persona with little curiosity to the partner. In this work, we propose COSPLAY(COncept Set guided PersonaLized dialogue generation Across both partY personas) that considers both parties as a "team": expressing self-persona while keeping curiosity toward the partner, leading responses around mutual personas, and finding the common ground. Specifically, we first represent self-persona, partner persona and mutual dialogue all in the concept sets. Then, we propose the Concept Set framework with a suite of knowledge-enhanced operations to process them such as set algebras, set expansion, and set distance. Based on these operations as medium, we train the model by utilizing 1) concepts of both party personas, 2) concept relationship between them, and 3) their relationship to the future dialogue. Extensive experiments on a large public dataset, Persona-Chat, demonstrate that our model outperforms state-of-the-art baselines for generating less egocentric, more human-like, and higher quality responses in both automatic and human evaluations.
[ { "created": "Mon, 2 May 2022 12:55:40 GMT", "version": "v1" }, { "created": "Wed, 4 May 2022 16:26:23 GMT", "version": "v2" }, { "created": "Sun, 15 May 2022 06:42:43 GMT", "version": "v3" } ]
2022-05-17
[ [ "Xu", "Chen", "" ], [ "Li", "Piji", "" ], [ "Wang", "Wei", "" ], [ "Yang", "Haoran", "" ], [ "Wang", "Siyun", "" ], [ "Xiao", "Chuangbai", "" ] ]
Maintaining a consistent persona is essential for building a human-like conversational model. However, the lack of attention to the partner makes the model more egocentric: they tend to show their persona by all means such as twisting the topic stiffly, pulling the conversation to their own interests regardless, and rambling their persona with little curiosity to the partner. In this work, we propose COSPLAY(COncept Set guided PersonaLized dialogue generation Across both partY personas) that considers both parties as a "team": expressing self-persona while keeping curiosity toward the partner, leading responses around mutual personas, and finding the common ground. Specifically, we first represent self-persona, partner persona and mutual dialogue all in the concept sets. Then, we propose the Concept Set framework with a suite of knowledge-enhanced operations to process them such as set algebras, set expansion, and set distance. Based on these operations as medium, we train the model by utilizing 1) concepts of both party personas, 2) concept relationship between them, and 3) their relationship to the future dialogue. Extensive experiments on a large public dataset, Persona-Chat, demonstrate that our model outperforms state-of-the-art baselines for generating less egocentric, more human-like, and higher quality responses in both automatic and human evaluations.
1803.02096
Maarten Bieshaar
G\"unther Reitberger and Stefan Zernetsch and Maarten Bieshaar and Bernhard Sick and Konrad Doll and Erich Fuchs
Cooperative Tracking of Cyclists Based on Smart Devices and Infrastructure
7 pages, 6 figures. submitted (accepted for publication) IEEE Conference on Intelligent Transportation Systems(ITSC) 2018, Maui, HI
null
null
null
cs.CY cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In future traffic scenarios, vehicles and other traffic participants will be interconnected and equipped with various types of sensors, allowing for cooperation based on data or information exchange. This article presents an approach to cooperative tracking of cyclists using smart devices and infrastructure-based sensors. A smart device is carried by the cyclists and an intersection is equipped with a wide angle stereo camera system. Two tracking models are presented and compared. The first model is based on the stereo camera system detections only, whereas the second model cooperatively combines the camera based detections with velocity and yaw rate data provided by the smart device. Our aim is to overcome limitations of tracking approaches based on single data sources. We show in numerical evaluations on scenes where cyclists are starting or turning right that the cooperation leads to an improvement in both the ability to keep track of a cyclist and the accuracy of the track particularly when it comes to occlusions in the visual system. We, therefore, contribute to the safety of vulnerable road users in future traffic.
[ { "created": "Tue, 6 Mar 2018 10:33:35 GMT", "version": "v1" }, { "created": "Tue, 3 Jul 2018 08:13:51 GMT", "version": "v2" } ]
2018-07-04
[ [ "Reitberger", "Günther", "" ], [ "Zernetsch", "Stefan", "" ], [ "Bieshaar", "Maarten", "" ], [ "Sick", "Bernhard", "" ], [ "Doll", "Konrad", "" ], [ "Fuchs", "Erich", "" ] ]
In future traffic scenarios, vehicles and other traffic participants will be interconnected and equipped with various types of sensors, allowing for cooperation based on data or information exchange. This article presents an approach to cooperative tracking of cyclists using smart devices and infrastructure-based sensors. A smart device is carried by the cyclists and an intersection is equipped with a wide angle stereo camera system. Two tracking models are presented and compared. The first model is based on the stereo camera system detections only, whereas the second model cooperatively combines the camera based detections with velocity and yaw rate data provided by the smart device. Our aim is to overcome limitations of tracking approaches based on single data sources. We show in numerical evaluations on scenes where cyclists are starting or turning right that the cooperation leads to an improvement in both the ability to keep track of a cyclist and the accuracy of the track particularly when it comes to occlusions in the visual system. We, therefore, contribute to the safety of vulnerable road users in future traffic.
2405.01646
Alessio Xompero
Alessio Xompero, Myriam Bontonou, Jean-Michel Arbona, Emmanouil Benetos, Andrea Cavallaro
Explaining models relating objects and privacy
7 pages, 3 figures, 1 table, supplementary material included as Appendix. Paper accepted at the 3rd XAI4CV Workshop at CVPR 2024. Code: https://github.com/graphnex/ig-privacy
null
null
null
cs.CV
http://creativecommons.org/licenses/by-nc-sa/4.0/
Accurately predicting whether an image is private before sharing it online is difficult due to the vast variety of content and the subjective nature of privacy itself. In this paper, we evaluate privacy models that use objects extracted from an image to determine why the image is predicted as private. To explain the decision of these models, we use feature-attribution to identify and quantify which objects (and which of their features) are more relevant to privacy classification with respect to a reference input (i.e., no objects localised in an image) predicted as public. We show that the presence of the person category and its cardinality is the main factor for the privacy decision. Therefore, these models mostly fail to identify private images depicting documents with sensitive data, vehicle ownership, and internet activity, or public images with people (e.g., an outdoor concert or people walking in a public space next to a famous landmark). As baselines for future benchmarks, we also devise two strategies that are based on the person presence and cardinality and achieve comparable classification performance of the privacy models.
[ { "created": "Thu, 2 May 2024 18:06:48 GMT", "version": "v1" } ]
2024-05-06
[ [ "Xompero", "Alessio", "" ], [ "Bontonou", "Myriam", "" ], [ "Arbona", "Jean-Michel", "" ], [ "Benetos", "Emmanouil", "" ], [ "Cavallaro", "Andrea", "" ] ]
Accurately predicting whether an image is private before sharing it online is difficult due to the vast variety of content and the subjective nature of privacy itself. In this paper, we evaluate privacy models that use objects extracted from an image to determine why the image is predicted as private. To explain the decision of these models, we use feature-attribution to identify and quantify which objects (and which of their features) are more relevant to privacy classification with respect to a reference input (i.e., no objects localised in an image) predicted as public. We show that the presence of the person category and its cardinality is the main factor for the privacy decision. Therefore, these models mostly fail to identify private images depicting documents with sensitive data, vehicle ownership, and internet activity, or public images with people (e.g., an outdoor concert or people walking in a public space next to a famous landmark). As baselines for future benchmarks, we also devise two strategies that are based on the person presence and cardinality and achieve comparable classification performance of the privacy models.
2106.11033
Stephan Stahlschmidt
Axel Oberschelp, Stephan Stahlschmidt
Gr\"o{\ss}e als Erfolgsgarant? Zur Bedeutung der Organisationstruktur f\"ur die Einwerbung von Drittmitteln der Deutschen Forschungsgemeinschaft
in German
null
null
null
cs.CY physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Research funding through third-party financing is of considerable importance for the German science system. The funds of the German Research Foundation (DFG) serve as the central focus due to the high reputation of the foundation. However, it has not been clarified yet to what extent the chances of successfully acquiring these funds depend on the structure of the university as an institution. The present study analyses DFG funding in the context of university research and examines the role of organisational conditions in the acquisition of funding. Several factors, such as size of the institution, equipment, and teaching activities, are analysed. The empirical study focuses on four subjects and investigates the correlation between funding success and conditional factors using a Bayesian approach. Results reveal the considerable relevance of the factors size as well as provision of academic and non-academic personnel. This implies that the organisational conditions are to be taken into account while evaluating third-party financing success.
[ { "created": "Thu, 3 Jun 2021 08:47:34 GMT", "version": "v1" } ]
2021-06-22
[ [ "Oberschelp", "Axel", "" ], [ "Stahlschmidt", "Stephan", "" ] ]
Research funding through third-party financing is of considerable importance for the German science system. The funds of the German Research Foundation (DFG) serve as the central focus due to the high reputation of the foundation. However, it has not been clarified yet to what extent the chances of successfully acquiring these funds depend on the structure of the university as an institution. The present study analyses DFG funding in the context of university research and examines the role of organisational conditions in the acquisition of funding. Several factors, such as size of the institution, equipment, and teaching activities, are analysed. The empirical study focuses on four subjects and investigates the correlation between funding success and conditional factors using a Bayesian approach. Results reveal the considerable relevance of the factors size as well as provision of academic and non-academic personnel. This implies that the organisational conditions are to be taken into account while evaluating third-party financing success.
2107.02112
Meng-Jiun Chiou
Meng-Jiun Chiou, Henghui Ding, Hanshu Yan, Changhu Wang, Roger Zimmermann, Jiashi Feng
Recovering the Unbiased Scene Graphs from the Biased Ones
Accepted by ACMMM 2021. Source code will be available at https://github.com/coldmanck/recovering-unbiased-scene-graphs
null
null
null
cs.CV cs.MM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Given input images, scene graph generation (SGG) aims to produce comprehensive, graphical representations describing visual relationships among salient objects. Recently, more efforts have been paid to the long tail problem in SGG; however, the imbalance in the fraction of missing labels of different classes, or reporting bias, exacerbating the long tail is rarely considered and cannot be solved by the existing debiasing methods. In this paper we show that, due to the missing labels, SGG can be viewed as a "Learning from Positive and Unlabeled data" (PU learning) problem, where the reporting bias can be removed by recovering the unbiased probabilities from the biased ones by utilizing label frequencies, i.e., the per-class fraction of labeled, positive examples in all the positive examples. To obtain accurate label frequency estimates, we propose Dynamic Label Frequency Estimation (DLFE) to take advantage of training-time data augmentation and average over multiple training iterations to introduce more valid examples. Extensive experiments show that DLFE is more effective in estimating label frequencies than a naive variant of the traditional estimate, and DLFE significantly alleviates the long tail and achieves state-of-the-art debiasing performance on the VG dataset. We also show qualitatively that SGG models with DLFE produce prominently more balanced and unbiased scene graphs.
[ { "created": "Mon, 5 Jul 2021 16:10:41 GMT", "version": "v1" } ]
2021-07-06
[ [ "Chiou", "Meng-Jiun", "" ], [ "Ding", "Henghui", "" ], [ "Yan", "Hanshu", "" ], [ "Wang", "Changhu", "" ], [ "Zimmermann", "Roger", "" ], [ "Feng", "Jiashi", "" ] ]
Given input images, scene graph generation (SGG) aims to produce comprehensive, graphical representations describing visual relationships among salient objects. Recently, more efforts have been paid to the long tail problem in SGG; however, the imbalance in the fraction of missing labels of different classes, or reporting bias, exacerbating the long tail is rarely considered and cannot be solved by the existing debiasing methods. In this paper we show that, due to the missing labels, SGG can be viewed as a "Learning from Positive and Unlabeled data" (PU learning) problem, where the reporting bias can be removed by recovering the unbiased probabilities from the biased ones by utilizing label frequencies, i.e., the per-class fraction of labeled, positive examples in all the positive examples. To obtain accurate label frequency estimates, we propose Dynamic Label Frequency Estimation (DLFE) to take advantage of training-time data augmentation and average over multiple training iterations to introduce more valid examples. Extensive experiments show that DLFE is more effective in estimating label frequencies than a naive variant of the traditional estimate, and DLFE significantly alleviates the long tail and achieves state-of-the-art debiasing performance on the VG dataset. We also show qualitatively that SGG models with DLFE produce prominently more balanced and unbiased scene graphs.
2401.10226
Xiangtai Li Dr
Jianzong Wu, Xiangtai Li, Chenyang Si, Shangchen Zhou, Jingkang Yang, Jiangning Zhang, Yining Li, Kai Chen, Yunhai Tong, Ziwei Liu, Chen Change Loy
Towards Language-Driven Video Inpainting via Multimodal Large Language Models
Project Page: https://jianzongwu.github.io/projects/rovi
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a new task -- language-driven video inpainting, which uses natural language instructions to guide the inpainting process. This approach overcomes the limitations of traditional video inpainting methods that depend on manually labeled binary masks, a process often tedious and labor-intensive. We present the Remove Objects from Videos by Instructions (ROVI) dataset, containing 5,650 videos and 9,091 inpainting results, to support training and evaluation for this task. We also propose a novel diffusion-based language-driven video inpainting framework, the first end-to-end baseline for this task, integrating Multimodal Large Language Models to understand and execute complex language-based inpainting requests effectively. Our comprehensive results showcase the dataset's versatility and the model's effectiveness in various language-instructed inpainting scenarios. We will make datasets, code, and models publicly available.
[ { "created": "Thu, 18 Jan 2024 18:59:13 GMT", "version": "v1" } ]
2024-01-19
[ [ "Wu", "Jianzong", "" ], [ "Li", "Xiangtai", "" ], [ "Si", "Chenyang", "" ], [ "Zhou", "Shangchen", "" ], [ "Yang", "Jingkang", "" ], [ "Zhang", "Jiangning", "" ], [ "Li", "Yining", "" ], [ "Chen", "Kai", "" ], [ "Tong", "Yunhai", "" ], [ "Liu", "Ziwei", "" ], [ "Loy", "Chen Change", "" ] ]
We introduce a new task -- language-driven video inpainting, which uses natural language instructions to guide the inpainting process. This approach overcomes the limitations of traditional video inpainting methods that depend on manually labeled binary masks, a process often tedious and labor-intensive. We present the Remove Objects from Videos by Instructions (ROVI) dataset, containing 5,650 videos and 9,091 inpainting results, to support training and evaluation for this task. We also propose a novel diffusion-based language-driven video inpainting framework, the first end-to-end baseline for this task, integrating Multimodal Large Language Models to understand and execute complex language-based inpainting requests effectively. Our comprehensive results showcase the dataset's versatility and the model's effectiveness in various language-instructed inpainting scenarios. We will make datasets, code, and models publicly available.
2011.06253
Avraham. Trahtman N
A.N.Trahtman
Precise estimation on the order of local testability of deterministic finite automaton
15 pages
null
null
null
cs.FL
http://creativecommons.org/licenses/by/4.0/
A locally testable language L is a language with the property that for some non negative integer k, called the order or the level of local testable, whether or not a word u in the language L depends on (1) the prefix and the suffix of the word u of length k-1 and (2) the set of intermediate partial strings of length k of the word u. For given k the language is called k-testable. We give necessary and sufficient conditions for the language of an automaton to be k-testable in the terms of the length of paths of a related graph. Some estimations of the upper and of the lower bound of testable order follow from these results. We improve the upper bound on the testable order of locally testable deterministic finite automaton with n states to n(n-2)+1 This bound is the best possible. We give an answer on the following conjecture of Kim, McNaughton and Mac-CLoskey for deterministic finite locally testable automaton with n states: \Is the local testable order of no greater than n in power 1.5 when the alphabet size is two?" Our answer is negative. In the case of size two the situation is the same as in general case.
[ { "created": "Thu, 12 Nov 2020 08:18:02 GMT", "version": "v1" } ]
2020-11-13
[ [ "Trahtman", "A. N.", "" ] ]
A locally testable language L is a language with the property that for some non negative integer k, called the order or the level of local testable, whether or not a word u in the language L depends on (1) the prefix and the suffix of the word u of length k-1 and (2) the set of intermediate partial strings of length k of the word u. For given k the language is called k-testable. We give necessary and sufficient conditions for the language of an automaton to be k-testable in the terms of the length of paths of a related graph. Some estimations of the upper and of the lower bound of testable order follow from these results. We improve the upper bound on the testable order of locally testable deterministic finite automaton with n states to n(n-2)+1 This bound is the best possible. We give an answer on the following conjecture of Kim, McNaughton and Mac-CLoskey for deterministic finite locally testable automaton with n states: \Is the local testable order of no greater than n in power 1.5 when the alphabet size is two?" Our answer is negative. In the case of size two the situation is the same as in general case.
2007.09186
Kristjan Arumae
Parminder Bhatia, Lan Liu, Kristjan Arumae, Nima Pourdamghani, Suyog Deshpande, Ben Snively, Mona Mona, Colby Wise, George Price, Shyam Ramaswamy, Xiaofei Ma, Ramesh Nallapati, Zhiheng Huang, Bing Xiang, Taha Kass-Hout
AWS CORD-19 Search: A Neural Search Engine for COVID-19 Literature
null
null
null
null
cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Coronavirus disease (COVID-19) has been declared as a pandemic by WHO with thousands of cases being reported each day. Numerous scientific articles are being published on the disease raising the need for a service which can organize, and query them in a reliable fashion. To support this cause we present AWS CORD-19 Search (ACS), a public, COVID-19 specific, neural search engine that is powered by several machine learning systems to support natural language based searches. ACS with capabilities such as document ranking, passage ranking, question answering and topic classification provides a scalable solution to COVID-19 researchers and policy makers in their search and discovery for answers to high priority scientific questions. We present a quantitative evaluation and qualitative analysis of the system against other leading COVID-19 search platforms. ACS is top performing across these systems yielding quality results which we detail with relevant examples in this work.
[ { "created": "Fri, 17 Jul 2020 18:41:29 GMT", "version": "v1" }, { "created": "Sat, 25 Jul 2020 01:38:58 GMT", "version": "v2" }, { "created": "Wed, 7 Oct 2020 05:59:53 GMT", "version": "v3" } ]
2020-10-08
[ [ "Bhatia", "Parminder", "" ], [ "Liu", "Lan", "" ], [ "Arumae", "Kristjan", "" ], [ "Pourdamghani", "Nima", "" ], [ "Deshpande", "Suyog", "" ], [ "Snively", "Ben", "" ], [ "Mona", "Mona", "" ], [ "Wise", "Colby", "" ], [ "Price", "George", "" ], [ "Ramaswamy", "Shyam", "" ], [ "Ma", "Xiaofei", "" ], [ "Nallapati", "Ramesh", "" ], [ "Huang", "Zhiheng", "" ], [ "Xiang", "Bing", "" ], [ "Kass-Hout", "Taha", "" ] ]
Coronavirus disease (COVID-19) has been declared as a pandemic by WHO with thousands of cases being reported each day. Numerous scientific articles are being published on the disease raising the need for a service which can organize, and query them in a reliable fashion. To support this cause we present AWS CORD-19 Search (ACS), a public, COVID-19 specific, neural search engine that is powered by several machine learning systems to support natural language based searches. ACS with capabilities such as document ranking, passage ranking, question answering and topic classification provides a scalable solution to COVID-19 researchers and policy makers in their search and discovery for answers to high priority scientific questions. We present a quantitative evaluation and qualitative analysis of the system against other leading COVID-19 search platforms. ACS is top performing across these systems yielding quality results which we detail with relevant examples in this work.
2303.06844
Kijung Lee
Kijung Lee
Why do Tweeters regret sharing? Impacts of Twitter users' perception of sharing risk, perceived problems on Twitter, and the motivation of use on their behavior of regret sharing
null
null
null
null
cs.SI cs.HC
http://creativecommons.org/licenses/by-nc-sa/4.0/
This study presents a secondary data analysis of the survey data collected as part of the American Trends Panel series by the Pew Research Center. A logistic regression was performed to ascertain the effects of the perceived risk of sharing, perceived problems on Twitter, and motivation of using Twitter on the likelihood that participants regret sharing on Twitter. The logistic regression model was statistically significant, \c{hi}2(15) = 102.5, p < .001. The model correctly classified 78.5 percent of cases. Whether or not Twitter users regret sharing on Twitter depends on different motivations for using Twitter. We observe that "A way to express my opinion" is statistically significant in the mod-el, indicating that the odds of Twitter users regretting sharing for this motivation is 2.1 times higher than that of entertainment. Perceived risks of potential hostility and visibility were negatively associated with an increased likelihood of regret sharing. In contrast, perceived problems on Twitter concerning misinformation were negatively associated with the likelihood of regret sharing.
[ { "created": "Mon, 13 Mar 2023 04:20:37 GMT", "version": "v1" } ]
2023-03-14
[ [ "Lee", "Kijung", "" ] ]
This study presents a secondary data analysis of the survey data collected as part of the American Trends Panel series by the Pew Research Center. A logistic regression was performed to ascertain the effects of the perceived risk of sharing, perceived problems on Twitter, and motivation of using Twitter on the likelihood that participants regret sharing on Twitter. The logistic regression model was statistically significant, \c{hi}2(15) = 102.5, p < .001. The model correctly classified 78.5 percent of cases. Whether or not Twitter users regret sharing on Twitter depends on different motivations for using Twitter. We observe that "A way to express my opinion" is statistically significant in the mod-el, indicating that the odds of Twitter users regretting sharing for this motivation is 2.1 times higher than that of entertainment. Perceived risks of potential hostility and visibility were negatively associated with an increased likelihood of regret sharing. In contrast, perceived problems on Twitter concerning misinformation were negatively associated with the likelihood of regret sharing.
1703.02002
Md Mizanur Rahman
Mahmudur Rahman, Mizanur Rahman, Bogdan Carbunar, Duen Horng Chau
FairPlay: Fraud and Malware Detection in Google Play
Proceedings of the 2016 SIAM International Conference on Data Mining. Society for Industrial and Applied Mathematics, 2016
null
null
null
cs.SI cs.CR cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fraudulent behaviors in Google Android app market fuel search rank abuse and malware proliferation. We present FairPlay, a novel system that uncovers both malware and search rank fraud apps, by picking out trails that fraudsters leave behind. To identify suspicious apps, FairPlay PCF algorithm correlates review activities and uniquely combines detected review relations with linguistic and behavioral signals gleaned from longitudinal Google Play app data. We contribute a new longitudinal app dataset to the community, which consists of over 87K apps, 2.9M reviews, and 2.4M reviewers, collected over half a year. FairPlay achieves over 95% accuracy in classifying gold standard datasets of malware, fraudulent and legitimate apps. We show that 75% of the identified malware apps engage in search rank fraud. FairPlay discovers hundreds of fraudulent apps that currently evade Google Bouncer detection technology, and reveals a new type of attack campaign, where users are harassed into writing positive reviews, and install and review other apps.
[ { "created": "Mon, 6 Mar 2017 17:51:16 GMT", "version": "v1" } ]
2017-03-07
[ [ "Rahman", "Mahmudur", "" ], [ "Rahman", "Mizanur", "" ], [ "Carbunar", "Bogdan", "" ], [ "Chau", "Duen Horng", "" ] ]
Fraudulent behaviors in Google Android app market fuel search rank abuse and malware proliferation. We present FairPlay, a novel system that uncovers both malware and search rank fraud apps, by picking out trails that fraudsters leave behind. To identify suspicious apps, FairPlay PCF algorithm correlates review activities and uniquely combines detected review relations with linguistic and behavioral signals gleaned from longitudinal Google Play app data. We contribute a new longitudinal app dataset to the community, which consists of over 87K apps, 2.9M reviews, and 2.4M reviewers, collected over half a year. FairPlay achieves over 95% accuracy in classifying gold standard datasets of malware, fraudulent and legitimate apps. We show that 75% of the identified malware apps engage in search rank fraud. FairPlay discovers hundreds of fraudulent apps that currently evade Google Bouncer detection technology, and reveals a new type of attack campaign, where users are harassed into writing positive reviews, and install and review other apps.
1904.10158
Sasinee Pruekprasert
Sasinee Pruekprasert, Xiaoyi Zhang, J\'er\'emy Dubut, Chao Huang, Masako Kishida
Decision Making for Autonomous Vehicles at Unsignalized Intersection in Presence of Malicious Vehicles
IEEE Conference on Intelligent Transportation Systems (ITSC), 2019
null
null
null
cs.SY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we investigate the decision making of autonomous vehicles in an unsignalized intersection in presence of malicious vehicles, which are vehicles that do not respect the law by not using the proper rules of the right of way. Each vehicle computes its control input as a Nash equilibrium of a game determined by the priority order based on its own belief: each of non-malicious vehicle bases its order on the law, while a malicious one considers itself as having priority. To illustrate our method, we provide numerical simulations, with different scenarios given by different cases of malicious vehicles.
[ { "created": "Tue, 23 Apr 2019 05:38:25 GMT", "version": "v1" }, { "created": "Thu, 3 Oct 2019 22:35:00 GMT", "version": "v2" } ]
2019-10-07
[ [ "Pruekprasert", "Sasinee", "" ], [ "Zhang", "Xiaoyi", "" ], [ "Dubut", "Jérémy", "" ], [ "Huang", "Chao", "" ], [ "Kishida", "Masako", "" ] ]
In this paper, we investigate the decision making of autonomous vehicles in an unsignalized intersection in presence of malicious vehicles, which are vehicles that do not respect the law by not using the proper rules of the right of way. Each vehicle computes its control input as a Nash equilibrium of a game determined by the priority order based on its own belief: each of non-malicious vehicle bases its order on the law, while a malicious one considers itself as having priority. To illustrate our method, we provide numerical simulations, with different scenarios given by different cases of malicious vehicles.
1807.01864
Wei Ao
Wei Ao, Yanwei Fu and Feng Xu
Detecting Tiny Moving Vehicles in Satellite Videos
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years, the satellite videos have been captured by a moving satellite platform. In contrast to consumer, movie, and common surveillance videos, satellite video can record the snapshot of the city-scale scene. In a broad field-of-view of satellite videos, each moving target would be very tiny and usually composed of several pixels in frames. Even worse, the noise signals also existed in the video frames, since the background of the video frame has the subpixel-level and uneven moving thanks to the motion of satellites. We argue that this is a new type of computer vision task since previous technologies are unable to detect such tiny vehicles efficiently. This paper proposes a novel framework that can identify the small moving vehicles in satellite videos. In particular, we offer a novel detecting algorithm based on the local noise modeling. We differentiate the potential vehicle targets from noise patterns by an exponential probability distribution. Subsequently, a multi-morphological-cue based discrimination strategy is designed to distinguish correct vehicle targets from a few existing noises further. Another significant contribution is to introduce a series of evaluation protocols to measure the performance of tiny moving vehicle detection systematically. We annotate a satellite video manually and use it to test our algorithms under different evaluation criterion. The proposed algorithm is also compared with the state-of-the-art baselines, and demonstrates the advantages of our framework over the benchmarks.
[ { "created": "Thu, 5 Jul 2018 06:46:31 GMT", "version": "v1" } ]
2018-07-06
[ [ "Ao", "Wei", "" ], [ "Fu", "Yanwei", "" ], [ "Xu", "Feng", "" ] ]
In recent years, the satellite videos have been captured by a moving satellite platform. In contrast to consumer, movie, and common surveillance videos, satellite video can record the snapshot of the city-scale scene. In a broad field-of-view of satellite videos, each moving target would be very tiny and usually composed of several pixels in frames. Even worse, the noise signals also existed in the video frames, since the background of the video frame has the subpixel-level and uneven moving thanks to the motion of satellites. We argue that this is a new type of computer vision task since previous technologies are unable to detect such tiny vehicles efficiently. This paper proposes a novel framework that can identify the small moving vehicles in satellite videos. In particular, we offer a novel detecting algorithm based on the local noise modeling. We differentiate the potential vehicle targets from noise patterns by an exponential probability distribution. Subsequently, a multi-morphological-cue based discrimination strategy is designed to distinguish correct vehicle targets from a few existing noises further. Another significant contribution is to introduce a series of evaluation protocols to measure the performance of tiny moving vehicle detection systematically. We annotate a satellite video manually and use it to test our algorithms under different evaluation criterion. The proposed algorithm is also compared with the state-of-the-art baselines, and demonstrates the advantages of our framework over the benchmarks.
2107.02547
Cheng Chu
Dawen Xu, Cheng Chu, Cheng Liu, Ying Wang, Huawei Li, Xiaowei Li, Kwang-Ting Cheng
Energy-Efficient Accelerator Design for Deformable Convolution Networks
null
null
null
null
cs.AR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deformable convolution networks (DCNs) proposed to address the image recognition with geometric or photometric variations typically involve deformable convolution that convolves on arbitrary locations of input features. The locations change with different inputs and induce considerable dynamic and irregular memory accesses which cannot be handled by classic neural network accelerators (NNAs). Moreover, bilinear interpolation (BLI) operation that is required to obtain deformed features in DCNs also cannot be deployed on existing NNAs directly. Although a general purposed processor (GPP) seated along with classic NNAs can process the deformable convolution, the processing on GPP can be extremely slow due to the lack of parallel computing capability. To address the problem, we develop a DCN accelerator on existing NNAs to support both the standard convolution and deformable convolution. Specifically, for the dynamic and irregular accesses in DCNs, we have both the input and output features divided into tiles and build a tile dependency table (TDT) to track the irregular tile dependency at runtime. With the TDT, we further develop an on-chip tile scheduler to handle the dynamic and irregular accesses efficiently. In addition, we propose a novel mapping strategy to enable parallel BLI processing on NNAs and apply layer fusion techniques for more energy-efficient DCN processing. According to our experiments, the proposed accelerator achieves orders of magnitude higher performance and energy efficiency compared to the typical computing architectures including ARM, ARM+TPU, and GPU with 6.6\% chip area penalty to a classic NNA.
[ { "created": "Tue, 6 Jul 2021 11:26:33 GMT", "version": "v1" } ]
2021-07-07
[ [ "Xu", "Dawen", "" ], [ "Chu", "Cheng", "" ], [ "Liu", "Cheng", "" ], [ "Wang", "Ying", "" ], [ "Li", "Huawei", "" ], [ "Li", "Xiaowei", "" ], [ "Cheng", "Kwang-Ting", "" ] ]
Deformable convolution networks (DCNs) proposed to address the image recognition with geometric or photometric variations typically involve deformable convolution that convolves on arbitrary locations of input features. The locations change with different inputs and induce considerable dynamic and irregular memory accesses which cannot be handled by classic neural network accelerators (NNAs). Moreover, bilinear interpolation (BLI) operation that is required to obtain deformed features in DCNs also cannot be deployed on existing NNAs directly. Although a general purposed processor (GPP) seated along with classic NNAs can process the deformable convolution, the processing on GPP can be extremely slow due to the lack of parallel computing capability. To address the problem, we develop a DCN accelerator on existing NNAs to support both the standard convolution and deformable convolution. Specifically, for the dynamic and irregular accesses in DCNs, we have both the input and output features divided into tiles and build a tile dependency table (TDT) to track the irregular tile dependency at runtime. With the TDT, we further develop an on-chip tile scheduler to handle the dynamic and irregular accesses efficiently. In addition, we propose a novel mapping strategy to enable parallel BLI processing on NNAs and apply layer fusion techniques for more energy-efficient DCN processing. According to our experiments, the proposed accelerator achieves orders of magnitude higher performance and energy efficiency compared to the typical computing architectures including ARM, ARM+TPU, and GPU with 6.6\% chip area penalty to a classic NNA.
2401.13716
Vibeke Binz Vallevik Mrs
Vibeke Binz Vallevik, Aleksandar Babic, Serena Elizabeth Marshall, Severin Elvatun, Helga Br{\o}gger, Sharmini Alagaratnam, Bj{\o}rn Edwin, Narasimha Raghavan Veeraragavan, Anne Kjersti Befring, Jan Franz Nyg{\aa}rd
Can I trust my fake data -- A comprehensive quality assessment framework for synthetic tabular data in healthcare
null
Int. J. Med. Inform.185 (2024)
10.1016/j.ijmedinf.2024.105413
null
cs.LG cs.AI
http://creativecommons.org/licenses/by/4.0/
Ensuring safe adoption of AI tools in healthcare hinges on access to sufficient data for training, testing and validation. In response to privacy concerns and regulatory requirements, using synthetic data has been suggested. Synthetic data is created by training a generator on real data to produce a dataset with similar statistical properties. Competing metrics with differing taxonomies for quality evaluation have been suggested, resulting in a complex landscape. Optimising quality entails balancing considerations that make the data fit for use, yet relevant dimensions are left out of existing frameworks. We performed a comprehensive literature review on the use of quality evaluation metrics on SD within the scope of tabular healthcare data and SD made using deep generative methods. Based on this and the collective team experiences, we developed a conceptual framework for quality assurance. The applicability was benchmarked against a practical case from the Dutch National Cancer Registry. We present a conceptual framework for quality assurance of SD for AI applications in healthcare that aligns diverging taxonomies, expands on common quality dimensions to include the dimensions of Fairness and Carbon footprint, and proposes stages necessary to support real-life applications. Building trust in synthetic data by increasing transparency and reducing the safety risk will accelerate the development and uptake of trustworthy AI tools for the benefit of patients. Despite the growing emphasis on algorithmic fairness and carbon footprint, these metrics were scarce in the literature review. The overwhelming focus was on statistical similarity using distance metrics while sequential logic detection was scarce. A consensus-backed framework that includes all relevant quality dimensions can provide assurance for safe and responsible real-life applications of SD.
[ { "created": "Wed, 24 Jan 2024 08:14:20 GMT", "version": "v1" } ]
2024-04-19
[ [ "Vallevik", "Vibeke Binz", "" ], [ "Babic", "Aleksandar", "" ], [ "Marshall", "Serena Elizabeth", "" ], [ "Elvatun", "Severin", "" ], [ "Brøgger", "Helga", "" ], [ "Alagaratnam", "Sharmini", "" ], [ "Edwin", "Bjørn", "" ], [ "Veeraragavan", "Narasimha Raghavan", "" ], [ "Befring", "Anne Kjersti", "" ], [ "Nygård", "Jan Franz", "" ] ]
Ensuring safe adoption of AI tools in healthcare hinges on access to sufficient data for training, testing and validation. In response to privacy concerns and regulatory requirements, using synthetic data has been suggested. Synthetic data is created by training a generator on real data to produce a dataset with similar statistical properties. Competing metrics with differing taxonomies for quality evaluation have been suggested, resulting in a complex landscape. Optimising quality entails balancing considerations that make the data fit for use, yet relevant dimensions are left out of existing frameworks. We performed a comprehensive literature review on the use of quality evaluation metrics on SD within the scope of tabular healthcare data and SD made using deep generative methods. Based on this and the collective team experiences, we developed a conceptual framework for quality assurance. The applicability was benchmarked against a practical case from the Dutch National Cancer Registry. We present a conceptual framework for quality assurance of SD for AI applications in healthcare that aligns diverging taxonomies, expands on common quality dimensions to include the dimensions of Fairness and Carbon footprint, and proposes stages necessary to support real-life applications. Building trust in synthetic data by increasing transparency and reducing the safety risk will accelerate the development and uptake of trustworthy AI tools for the benefit of patients. Despite the growing emphasis on algorithmic fairness and carbon footprint, these metrics were scarce in the literature review. The overwhelming focus was on statistical similarity using distance metrics while sequential logic detection was scarce. A consensus-backed framework that includes all relevant quality dimensions can provide assurance for safe and responsible real-life applications of SD.
1606.03248
ShenChen Ruan
Shenchen Ruan, Haixia Wang and Dongsheng Wang
MAC: a novel systematically multilevel cache replacement policy for PCM memory
null
null
null
null
cs.AR cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The rapid development of multi-core system and increase of data-intensive application in recent years call for larger main memory. Traditional DRAM memory can increase its capacity by reducing the feature size of storage cell. Now further scaling of DRAM faces great challenge, and the frequent refresh operations of DRAM can bring a lot of energy consumption. As an emerging technology, Phase Change Memory (PCM) is promising to be used as main memory. It draws wide attention due to the advantages of low power consumption, high density and nonvolatility, while it incurs finite endurance and relatively long write latency. To handle the problem of write, optimizing the cache replacement policy to protect dirty cache block is an efficient way. In this paper, we construct a systematically multilevel structure, and based on it propose a novel cache replacement policy called MAC. MAC can effectively reduce write traffic to PCM memory with low hardware overhead. We conduct simulation experiments on GEM5 to evaluate the performances of MAC and other related works. The results show that MAC performs best in reducing the amount of writes (averagely 25.12%) without increasing the program execution time.
[ { "created": "Fri, 10 Jun 2016 09:47:14 GMT", "version": "v1" } ]
2016-06-13
[ [ "Ruan", "Shenchen", "" ], [ "Wang", "Haixia", "" ], [ "Wang", "Dongsheng", "" ] ]
The rapid development of multi-core system and increase of data-intensive application in recent years call for larger main memory. Traditional DRAM memory can increase its capacity by reducing the feature size of storage cell. Now further scaling of DRAM faces great challenge, and the frequent refresh operations of DRAM can bring a lot of energy consumption. As an emerging technology, Phase Change Memory (PCM) is promising to be used as main memory. It draws wide attention due to the advantages of low power consumption, high density and nonvolatility, while it incurs finite endurance and relatively long write latency. To handle the problem of write, optimizing the cache replacement policy to protect dirty cache block is an efficient way. In this paper, we construct a systematically multilevel structure, and based on it propose a novel cache replacement policy called MAC. MAC can effectively reduce write traffic to PCM memory with low hardware overhead. We conduct simulation experiments on GEM5 to evaluate the performances of MAC and other related works. The results show that MAC performs best in reducing the amount of writes (averagely 25.12%) without increasing the program execution time.
1702.05977
Jos\'e Mairton Barros da Silva J\'unior
Jose Mairton B. da Silva Jr., Gabor Fodor, Carlo Fischione
On the Spectral Efficiency and Fairness in Full-Duplex Cellular Networks
6 pages, 4 figures, accepted in IEEE ICC 2017. arXiv admin note: text overlap with arXiv:1603.00671
null
null
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
To increase the spectral efficiency of wireless networks without requiring full-duplex capability of user devices, a potential solution is the recently proposed three-node full-duplex mode. To realize this potential, networks employing three-node full-duplex transmissions must deal with self-interference and user-to-user interference, which can be managed by frequency channel and power allocation techniques. Whereas previous works investigated either spectral efficient or fair mechanisms, a scheme that balances these two metrics among users is investigated in this paper. This balancing scheme is based on a new solution method of the multi-objective optimization problem to maximize the weighted sum of the per-user spectral efficiency and the minimum spectral efficiency among users. The mixed integer non-linear nature of this problem is dealt by Lagrangian duality. Based on the proposed solution approach, a low-complexity centralized algorithm is developed, which relies on large scale fading measurements that can be advantageously implemented at the base station. Numerical results indicate that the proposed algorithm increases the spectral efficiency and fairness among users without the need of weighting the spectral efficiency. An important conclusion is that managing user-to-user interference by resource assignment and power control is crucial for ensuring spectral efficient and fair operation of full-duplex networks.
[ { "created": "Mon, 20 Feb 2017 14:10:19 GMT", "version": "v1" } ]
2017-02-25
[ [ "Silva", "Jose Mairton B. da", "Jr." ], [ "Fodor", "Gabor", "" ], [ "Fischione", "Carlo", "" ] ]
To increase the spectral efficiency of wireless networks without requiring full-duplex capability of user devices, a potential solution is the recently proposed three-node full-duplex mode. To realize this potential, networks employing three-node full-duplex transmissions must deal with self-interference and user-to-user interference, which can be managed by frequency channel and power allocation techniques. Whereas previous works investigated either spectral efficient or fair mechanisms, a scheme that balances these two metrics among users is investigated in this paper. This balancing scheme is based on a new solution method of the multi-objective optimization problem to maximize the weighted sum of the per-user spectral efficiency and the minimum spectral efficiency among users. The mixed integer non-linear nature of this problem is dealt by Lagrangian duality. Based on the proposed solution approach, a low-complexity centralized algorithm is developed, which relies on large scale fading measurements that can be advantageously implemented at the base station. Numerical results indicate that the proposed algorithm increases the spectral efficiency and fairness among users without the need of weighting the spectral efficiency. An important conclusion is that managing user-to-user interference by resource assignment and power control is crucial for ensuring spectral efficient and fair operation of full-duplex networks.
1304.6146
Marc Killpack
Advait Jain, Marc D. Killpack, Aaron Edsinger, Charles C. Kemp
Manipulation in Clutter with Whole-Arm Tactile Sensing
This is the first version of a paper that we submitted to the International Journal of Robotics Research on December 31, 2011 and uploaded to our website on January 16, 2012
The International Journal of Robotics Research April 2013 vol. 32 no. 4 pg. 458-482
10.1177/0278364912471865
null
cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We begin this paper by presenting our approach to robot manipulation, which emphasizes the benefits of making contact with the world across the entire manipulator. We assume that low contact forces are benign, and focus on the development of robots that can control their contact forces during goal-directed motion. Inspired by biology, we assume that the robot has low-stiffness actuation at its joints, and tactile sensing across the entire surface of its manipulator. We then describe a novel controller that exploits these assumptions. The controller only requires haptic sensing and does not need an explicit model of the environment prior to contact. It also handles multiple contacts across the surface of the manipulator. The controller uses model predictive control (MPC) with a time horizon of length one, and a linear quasi-static mechanical model that it constructs at each time step. We show that this controller enables both real and simulated robots to reach goal locations in high clutter with low contact forces. Our experiments include tests using a real robot with a novel tactile sensor array on its forearm reaching into simulated foliage and a cinder block. In our experiments, robots made contact across their entire arms while pushing aside movable objects, deforming compliant objects, and perceiving the world.
[ { "created": "Tue, 23 Apr 2013 01:40:46 GMT", "version": "v1" } ]
2013-04-24
[ [ "Jain", "Advait", "" ], [ "Killpack", "Marc D.", "" ], [ "Edsinger", "Aaron", "" ], [ "Kemp", "Charles C.", "" ] ]
We begin this paper by presenting our approach to robot manipulation, which emphasizes the benefits of making contact with the world across the entire manipulator. We assume that low contact forces are benign, and focus on the development of robots that can control their contact forces during goal-directed motion. Inspired by biology, we assume that the robot has low-stiffness actuation at its joints, and tactile sensing across the entire surface of its manipulator. We then describe a novel controller that exploits these assumptions. The controller only requires haptic sensing and does not need an explicit model of the environment prior to contact. It also handles multiple contacts across the surface of the manipulator. The controller uses model predictive control (MPC) with a time horizon of length one, and a linear quasi-static mechanical model that it constructs at each time step. We show that this controller enables both real and simulated robots to reach goal locations in high clutter with low contact forces. Our experiments include tests using a real robot with a novel tactile sensor array on its forearm reaching into simulated foliage and a cinder block. In our experiments, robots made contact across their entire arms while pushing aside movable objects, deforming compliant objects, and perceiving the world.
1805.08498
Michael Figurnov
Michael Figurnov, Shakir Mohamed, Andriy Mnih
Implicit Reparameterization Gradients
NeurIPS 2018
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By providing a simple and efficient way of computing low-variance gradients of continuous random variables, the reparameterization trick has become the technique of choice for training a variety of latent variable models. However, it is not applicable to a number of important continuous distributions. We introduce an alternative approach to computing reparameterization gradients based on implicit differentiation and demonstrate its broader applicability by applying it to Gamma, Beta, Dirichlet, and von Mises distributions, which cannot be used with the classic reparameterization trick. Our experiments show that the proposed approach is faster and more accurate than the existing gradient estimators for these distributions.
[ { "created": "Tue, 22 May 2018 11:00:19 GMT", "version": "v1" }, { "created": "Fri, 1 Jun 2018 12:38:04 GMT", "version": "v2" }, { "created": "Thu, 1 Nov 2018 17:49:12 GMT", "version": "v3" }, { "created": "Wed, 30 Jan 2019 15:24:42 GMT", "version": "v4" } ]
2019-01-31
[ [ "Figurnov", "Michael", "" ], [ "Mohamed", "Shakir", "" ], [ "Mnih", "Andriy", "" ] ]
By providing a simple and efficient way of computing low-variance gradients of continuous random variables, the reparameterization trick has become the technique of choice for training a variety of latent variable models. However, it is not applicable to a number of important continuous distributions. We introduce an alternative approach to computing reparameterization gradients based on implicit differentiation and demonstrate its broader applicability by applying it to Gamma, Beta, Dirichlet, and von Mises distributions, which cannot be used with the classic reparameterization trick. Our experiments show that the proposed approach is faster and more accurate than the existing gradient estimators for these distributions.
2006.05158
Liangzu Peng
Liangzu Peng and Manolis C. Tsakiris
Homomorphic Sensing of Subspace Arrangements
18 pages
Applied and Computational Harmonic Analysis, 55, 466-485 (2021)
10.1016/j.acha.2021.06.008
null
cs.LG math.AG stat.ML
http://creativecommons.org/licenses/by/4.0/
Homomorphic sensing is a recent algebraic-geometric framework that studies the unique recovery of points in a linear subspace from their images under a given collection of linear maps. It has been successful in interpreting such a recovery in the case of permutations composed by coordinate projections, an important instance in applications known as unlabeled sensing, which models data that are out of order and have missing values. In this paper, we provide tighter and simpler conditions that guarantee the unique recovery for the single-subspace case, extend the result to the case of a subspace arrangement, and show that the unique recovery in a single subspace is locally stable under noise. We specialize our results to several examples of homomorphic sensing such as real phase retrieval and unlabeled sensing. In so doing, in a unified way, we obtain conditions that guarantee the unique recovery for those examples, typically known via diverse techniques in the literature, as well as novel conditions for sparse and unsigned versions of unlabeled sensing. Similarly, our noise result also implies that the unique recovery in unlabeled sensing is locally stable.
[ { "created": "Tue, 9 Jun 2020 09:52:15 GMT", "version": "v1" }, { "created": "Wed, 30 Dec 2020 03:27:36 GMT", "version": "v2" }, { "created": "Tue, 1 Jun 2021 06:36:14 GMT", "version": "v3" }, { "created": "Mon, 19 Sep 2022 14:13:47 GMT", "version": "v4" } ]
2022-09-20
[ [ "Peng", "Liangzu", "" ], [ "Tsakiris", "Manolis C.", "" ] ]
Homomorphic sensing is a recent algebraic-geometric framework that studies the unique recovery of points in a linear subspace from their images under a given collection of linear maps. It has been successful in interpreting such a recovery in the case of permutations composed by coordinate projections, an important instance in applications known as unlabeled sensing, which models data that are out of order and have missing values. In this paper, we provide tighter and simpler conditions that guarantee the unique recovery for the single-subspace case, extend the result to the case of a subspace arrangement, and show that the unique recovery in a single subspace is locally stable under noise. We specialize our results to several examples of homomorphic sensing such as real phase retrieval and unlabeled sensing. In so doing, in a unified way, we obtain conditions that guarantee the unique recovery for those examples, typically known via diverse techniques in the literature, as well as novel conditions for sparse and unsigned versions of unlabeled sensing. Similarly, our noise result also implies that the unique recovery in unlabeled sensing is locally stable.
2211.05229
Rajdeep Adak
Rajdeep Adak, Abhishek Kumbhar, Rajas Pathare, Sagar Gowda
Automatic Number Plate Recognition (ANPR) with YOLOv3-CNN
29 pages, 4 figures, 2 tables
null
null
null
cs.CV eess.IV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a YOLOv3-CNN pipeline for detecting vehicles, segregation of number plates, and local storage of final recognized characters. Vehicle identification is performed under various image correction schemes to determine the effect of environmental factors (angle of perception, luminosity, motion-blurring, and multi-line custom font etc.). A YOLOv3 object detection model was trained to identify vehicles from a dataset of traffic images. A second YOLOv3 layer was trained to identify number plates from vehicle images. Based upon correction schemes, individual characters were segregated and verified against real-time data to calculate accuracy of this approach. While characters under direct view were recognized accurately, some numberplates affected by environmental factors had reduced levels of accuracy. We summarize the results under various environmental factors against real-time data and produce an overall accuracy of the pipeline model.
[ { "created": "Mon, 7 Nov 2022 12:59:01 GMT", "version": "v1" } ]
2022-11-11
[ [ "Adak", "Rajdeep", "" ], [ "Kumbhar", "Abhishek", "" ], [ "Pathare", "Rajas", "" ], [ "Gowda", "Sagar", "" ] ]
We present a YOLOv3-CNN pipeline for detecting vehicles, segregation of number plates, and local storage of final recognized characters. Vehicle identification is performed under various image correction schemes to determine the effect of environmental factors (angle of perception, luminosity, motion-blurring, and multi-line custom font etc.). A YOLOv3 object detection model was trained to identify vehicles from a dataset of traffic images. A second YOLOv3 layer was trained to identify number plates from vehicle images. Based upon correction schemes, individual characters were segregated and verified against real-time data to calculate accuracy of this approach. While characters under direct view were recognized accurately, some numberplates affected by environmental factors had reduced levels of accuracy. We summarize the results under various environmental factors against real-time data and produce an overall accuracy of the pipeline model.
1412.0879
Sean Gallagher
Sean Gallagher, Wlodek Zadrozny, Walid Shalaby, Adarsh Avadhani
Watsonsim: Overview of a Question Answering Engine
null
null
null
null
cs.CL cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The objective of the project is to design and run a system similar to Watson, designed to answer Jeopardy questions. In the course of a semester, we developed an open source question answering system using the Indri, Lucene, Bing and Google search engines, Apache UIMA, Open- and CoreNLP, and Weka among additional modules. By the end of the semester, we achieved 18% accuracy on Jeopardy questions, and work has not stopped since then.
[ { "created": "Tue, 2 Dec 2014 12:15:18 GMT", "version": "v1" } ]
2014-12-03
[ [ "Gallagher", "Sean", "" ], [ "Zadrozny", "Wlodek", "" ], [ "Shalaby", "Walid", "" ], [ "Avadhani", "Adarsh", "" ] ]
The objective of the project is to design and run a system similar to Watson, designed to answer Jeopardy questions. In the course of a semester, we developed an open source question answering system using the Indri, Lucene, Bing and Google search engines, Apache UIMA, Open- and CoreNLP, and Weka among additional modules. By the end of the semester, we achieved 18% accuracy on Jeopardy questions, and work has not stopped since then.
2211.15382
Tim Whittaker
Tim Whittaker, Romuald A. Janik, Yaron Oz
Neural Network Complexity of Chaos and Turbulence
null
Eur. Phys. J. E 46, 57 (2023)
10.1140/epje/s10189-023-00321-7
null
cs.LG hep-th nlin.CD physics.flu-dyn
http://creativecommons.org/licenses/by/4.0/
Chaos and turbulence are complex physical phenomena, yet a precise definition of the complexity measure that quantifies them is still lacking. In this work we consider the relative complexity of chaos and turbulence from the perspective of deep neural networks. We analyze a set of classification problems, where the network has to distinguish images of fluid profiles in the turbulent regime from other classes of images such as fluid profiles in the chaotic regime, various constructions of noise and real world images. We analyze incompressible as well as weakly compressible fluid flows. We quantify the complexity of the computation performed by the network via the intrinsic dimensionality of the internal feature representations, and calculate the effective number of independent features which the network uses in order to distinguish between classes. In addition to providing a numerical estimate of the complexity of the computation, the measure also characterizes the neural network processing at intermediate and final stages. We construct adversarial examples and use them to identify the two point correlation spectra for the chaotic and turbulent vorticity as the feature used by the network for classification.
[ { "created": "Thu, 24 Nov 2022 13:21:36 GMT", "version": "v1" }, { "created": "Thu, 20 Jul 2023 12:18:49 GMT", "version": "v2" } ]
2023-07-21
[ [ "Whittaker", "Tim", "" ], [ "Janik", "Romuald A.", "" ], [ "Oz", "Yaron", "" ] ]
Chaos and turbulence are complex physical phenomena, yet a precise definition of the complexity measure that quantifies them is still lacking. In this work we consider the relative complexity of chaos and turbulence from the perspective of deep neural networks. We analyze a set of classification problems, where the network has to distinguish images of fluid profiles in the turbulent regime from other classes of images such as fluid profiles in the chaotic regime, various constructions of noise and real world images. We analyze incompressible as well as weakly compressible fluid flows. We quantify the complexity of the computation performed by the network via the intrinsic dimensionality of the internal feature representations, and calculate the effective number of independent features which the network uses in order to distinguish between classes. In addition to providing a numerical estimate of the complexity of the computation, the measure also characterizes the neural network processing at intermediate and final stages. We construct adversarial examples and use them to identify the two point correlation spectra for the chaotic and turbulent vorticity as the feature used by the network for classification.
2111.11720
Xingkai Zheng
Xingkai Zheng, Xirui Li, Ke Xu, Xinghao Jiang, Tanfeng Sun
Gait Identification under Surveillance Environment based on Human Skeleton
null
null
null
null
cs.CV cs.AI
http://creativecommons.org/licenses/by/4.0/
As an emerging biological identification technology, vision-based gait identification is an important research content in biometrics. Most existing gait identification methods extract features from gait videos and identify a probe sample by a query in the gallery. However, video data contains redundant information and can be easily influenced by bagging (BG) and clothing (CL). Since human body skeletons convey essential information about human gaits, a skeleton-based gait identification network is proposed in our project. First, extract skeleton sequences from the video and map them into a gait graph. Then a feature extraction network based on Spatio-Temporal Graph Convolutional Network (ST-GCN) is constructed to learn gait representations. Finally, the probe sample is identified by matching with the most similar piece in the gallery. We tested our method on the CASIA-B dataset. The result shows that our approach is highly adaptive and gets the advanced result in BG, CL conditions, and average.
[ { "created": "Tue, 23 Nov 2021 08:30:26 GMT", "version": "v1" }, { "created": "Wed, 24 Nov 2021 14:43:51 GMT", "version": "v2" } ]
2021-11-25
[ [ "Zheng", "Xingkai", "" ], [ "Li", "Xirui", "" ], [ "Xu", "Ke", "" ], [ "Jiang", "Xinghao", "" ], [ "Sun", "Tanfeng", "" ] ]
As an emerging biological identification technology, vision-based gait identification is an important research content in biometrics. Most existing gait identification methods extract features from gait videos and identify a probe sample by a query in the gallery. However, video data contains redundant information and can be easily influenced by bagging (BG) and clothing (CL). Since human body skeletons convey essential information about human gaits, a skeleton-based gait identification network is proposed in our project. First, extract skeleton sequences from the video and map them into a gait graph. Then a feature extraction network based on Spatio-Temporal Graph Convolutional Network (ST-GCN) is constructed to learn gait representations. Finally, the probe sample is identified by matching with the most similar piece in the gallery. We tested our method on the CASIA-B dataset. The result shows that our approach is highly adaptive and gets the advanced result in BG, CL conditions, and average.
2202.12093
Qinghua Zhao
Qinghua Zhao, Shuai Ma, Shuo Ren
KESA: A Knowledge Enhanced Approach For Sentiment Analysis
null
null
null
null
cs.CL cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Though some recent works focus on injecting sentiment knowledge into pre-trained language models, they usually design mask and reconstruction tasks in the post-training phase. In this paper, we aim to benefit from sentiment knowledge in a lighter way. To achieve this goal, we study sentence-level sentiment analysis and, correspondingly, propose two sentiment-aware auxiliary tasks named sentiment word cloze and conditional sentiment prediction. The first task learns to select the correct sentiment words within the input, given the overall sentiment polarity as prior knowledge. On the contrary, the second task predicts the overall sentiment polarity given the sentiment polarity of the word as prior knowledge. In addition, two kinds of label combination methods are investigated to unify multiple types of labels in each task. We argue that more information can promote the models to learn more profound semantic representation. We implement it in a straightforward way to verify this hypothesis. The experimental results demonstrate that our approach consistently outperforms pre-trained models and is additive to existing knowledge-enhanced post-trained models. The code and data are released at https://github.com/lshowway/KESA.
[ { "created": "Thu, 24 Feb 2022 13:21:27 GMT", "version": "v1" } ]
2022-02-25
[ [ "Zhao", "Qinghua", "" ], [ "Ma", "Shuai", "" ], [ "Ren", "Shuo", "" ] ]
Though some recent works focus on injecting sentiment knowledge into pre-trained language models, they usually design mask and reconstruction tasks in the post-training phase. In this paper, we aim to benefit from sentiment knowledge in a lighter way. To achieve this goal, we study sentence-level sentiment analysis and, correspondingly, propose two sentiment-aware auxiliary tasks named sentiment word cloze and conditional sentiment prediction. The first task learns to select the correct sentiment words within the input, given the overall sentiment polarity as prior knowledge. On the contrary, the second task predicts the overall sentiment polarity given the sentiment polarity of the word as prior knowledge. In addition, two kinds of label combination methods are investigated to unify multiple types of labels in each task. We argue that more information can promote the models to learn more profound semantic representation. We implement it in a straightforward way to verify this hypothesis. The experimental results demonstrate that our approach consistently outperforms pre-trained models and is additive to existing knowledge-enhanced post-trained models. The code and data are released at https://github.com/lshowway/KESA.
2206.01812
Andrew Li
Andrew C. Li, Pashootan Vaezipoor, Rodrigo Toro Icarte, Sheila A. McIlraith
Challenges to Solving Combinatorially Hard Long-Horizon Deep RL Tasks
null
null
null
null
cs.LG cs.AI cs.RO
http://creativecommons.org/licenses/by/4.0/
Deep reinforcement learning has shown promise in discrete domains requiring complex reasoning, including games such as Chess, Go, and Hanabi. However, this type of reasoning is less often observed in long-horizon, continuous domains with high-dimensional observations, where instead RL research has predominantly focused on problems with simple high-level structure (e.g. opening a drawer or moving a robot as fast as possible). Inspired by combinatorially hard optimization problems, we propose a set of robotics tasks which admit many distinct solutions at the high-level, but require reasoning about states and rewards thousands of steps into the future for the best performance. Critically, while RL has traditionally suffered on complex, long-horizon tasks due to sparse rewards, our tasks are carefully designed to be solvable without specialized exploration. Nevertheless, our investigation finds that standard RL methods often neglect long-term effects due to discounting, while general-purpose hierarchical RL approaches struggle unless additional abstract domain knowledge can be exploited.
[ { "created": "Fri, 3 Jun 2022 20:38:27 GMT", "version": "v1" } ]
2022-06-07
[ [ "Li", "Andrew C.", "" ], [ "Vaezipoor", "Pashootan", "" ], [ "Icarte", "Rodrigo Toro", "" ], [ "McIlraith", "Sheila A.", "" ] ]
Deep reinforcement learning has shown promise in discrete domains requiring complex reasoning, including games such as Chess, Go, and Hanabi. However, this type of reasoning is less often observed in long-horizon, continuous domains with high-dimensional observations, where instead RL research has predominantly focused on problems with simple high-level structure (e.g. opening a drawer or moving a robot as fast as possible). Inspired by combinatorially hard optimization problems, we propose a set of robotics tasks which admit many distinct solutions at the high-level, but require reasoning about states and rewards thousands of steps into the future for the best performance. Critically, while RL has traditionally suffered on complex, long-horizon tasks due to sparse rewards, our tasks are carefully designed to be solvable without specialized exploration. Nevertheless, our investigation finds that standard RL methods often neglect long-term effects due to discounting, while general-purpose hierarchical RL approaches struggle unless additional abstract domain knowledge can be exploited.
1604.00794
Pramod Bhatotia
Pramod Bhatotia
Asymptotic Analysis of Self-Adjusting Contraction Trees
null
null
null
null
cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we present asymptotic analysis of self-adjusting contraction trees for incremental sliding window analytics.
[ { "created": "Mon, 4 Apr 2016 09:55:06 GMT", "version": "v1" } ]
2016-04-05
[ [ "Bhatotia", "Pramod", "" ] ]
In this paper, we present asymptotic analysis of self-adjusting contraction trees for incremental sliding window analytics.
2306.12686
Yu Zhang
Yu Zhang, Hao Zeng, Bowen Ma, Wei Zhang, Zhimeng Zhang, Yu Ding, Tangjie Lv, Changjie Fan
FlowFace++: Explicit Semantic Flow-supervised End-to-End Face Swapping
arXiv admin note: text overlap with arXiv:2212.02797
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This work proposes a novel face-swapping framework FlowFace++, utilizing explicit semantic flow supervision and end-to-end architecture to facilitate shape-aware face-swapping. Specifically, our work pretrains a facial shape discriminator to supervise the face swapping network. The discriminator is shape-aware and relies on a semantic flow-guided operation to explicitly calculate the shape discrepancies between the target and source faces, thus optimizing the face swapping network to generate highly realistic results. The face swapping network is a stack of a pre-trained face-masked autoencoder (MAE), a cross-attention fusion module, and a convolutional decoder. The MAE provides a fine-grained facial image representation space, which is unified for the target and source faces and thus facilitates final realistic results. The cross-attention fusion module carries out the source-to-target face swapping in a fine-grained latent space while preserving other attributes of the target image (e.g. expression, head pose, hair, background, illumination, etc). Lastly, the convolutional decoder further synthesizes the swapping results according to the face-swapping latent embedding from the cross-attention fusion module. Extensive quantitative and qualitative experiments on in-the-wild faces demonstrate that our FlowFace++ outperforms the state-of-the-art significantly, particularly while the source face is obstructed by uneven lighting or angle offset.
[ { "created": "Thu, 22 Jun 2023 06:18:29 GMT", "version": "v1" }, { "created": "Mon, 26 Jun 2023 05:11:17 GMT", "version": "v2" } ]
2023-06-27
[ [ "Zhang", "Yu", "" ], [ "Zeng", "Hao", "" ], [ "Ma", "Bowen", "" ], [ "Zhang", "Wei", "" ], [ "Zhang", "Zhimeng", "" ], [ "Ding", "Yu", "" ], [ "Lv", "Tangjie", "" ], [ "Fan", "Changjie", "" ] ]
This work proposes a novel face-swapping framework FlowFace++, utilizing explicit semantic flow supervision and end-to-end architecture to facilitate shape-aware face-swapping. Specifically, our work pretrains a facial shape discriminator to supervise the face swapping network. The discriminator is shape-aware and relies on a semantic flow-guided operation to explicitly calculate the shape discrepancies between the target and source faces, thus optimizing the face swapping network to generate highly realistic results. The face swapping network is a stack of a pre-trained face-masked autoencoder (MAE), a cross-attention fusion module, and a convolutional decoder. The MAE provides a fine-grained facial image representation space, which is unified for the target and source faces and thus facilitates final realistic results. The cross-attention fusion module carries out the source-to-target face swapping in a fine-grained latent space while preserving other attributes of the target image (e.g. expression, head pose, hair, background, illumination, etc). Lastly, the convolutional decoder further synthesizes the swapping results according to the face-swapping latent embedding from the cross-attention fusion module. Extensive quantitative and qualitative experiments on in-the-wild faces demonstrate that our FlowFace++ outperforms the state-of-the-art significantly, particularly while the source face is obstructed by uneven lighting or angle offset.
2310.16656
Dani Valevski
Eyal Segalis, Dani Valevski, Danny Lumen, Yossi Matias, Yaniv Leviathan
A Picture is Worth a Thousand Words: Principled Recaptioning Improves Image Generation
null
null
null
null
cs.CV cs.AI cs.LG
http://creativecommons.org/licenses/by/4.0/
Text-to-image diffusion models achieved a remarkable leap in capabilities over the last few years, enabling high-quality and diverse synthesis of images from a textual prompt. However, even the most advanced models often struggle to precisely follow all of the directions in their prompts. The vast majority of these models are trained on datasets consisting of (image, caption) pairs where the images often come from the web, and the captions are their HTML alternate text. A notable example is the LAION dataset, used by Stable Diffusion and other models. In this work we observe that these captions are often of low quality, and argue that this significantly affects the model's capability to understand nuanced semantics in the textual prompts. We show that by relabeling the corpus with a specialized automatic captioning model and training a text-to-image model on the recaptioned dataset, the model benefits substantially across the board. First, in overall image quality: e.g. FID 14.84 vs. the baseline of 17.87, and 64.3% improvement in faithful image generation according to human evaluation. Second, in semantic alignment, e.g. semantic object accuracy 84.34 vs. 78.90, counting alignment errors 1.32 vs. 1.44 and positional alignment 62.42 vs. 57.60. We analyze various ways to relabel the corpus and provide evidence that this technique, which we call RECAP, both reduces the train-inference discrepancy and provides the model with more information per example, increasing sample efficiency and allowing the model to better understand the relations between captions and images.
[ { "created": "Wed, 25 Oct 2023 14:10:08 GMT", "version": "v1" } ]
2023-10-26
[ [ "Segalis", "Eyal", "" ], [ "Valevski", "Dani", "" ], [ "Lumen", "Danny", "" ], [ "Matias", "Yossi", "" ], [ "Leviathan", "Yaniv", "" ] ]
Text-to-image diffusion models achieved a remarkable leap in capabilities over the last few years, enabling high-quality and diverse synthesis of images from a textual prompt. However, even the most advanced models often struggle to precisely follow all of the directions in their prompts. The vast majority of these models are trained on datasets consisting of (image, caption) pairs where the images often come from the web, and the captions are their HTML alternate text. A notable example is the LAION dataset, used by Stable Diffusion and other models. In this work we observe that these captions are often of low quality, and argue that this significantly affects the model's capability to understand nuanced semantics in the textual prompts. We show that by relabeling the corpus with a specialized automatic captioning model and training a text-to-image model on the recaptioned dataset, the model benefits substantially across the board. First, in overall image quality: e.g. FID 14.84 vs. the baseline of 17.87, and 64.3% improvement in faithful image generation according to human evaluation. Second, in semantic alignment, e.g. semantic object accuracy 84.34 vs. 78.90, counting alignment errors 1.32 vs. 1.44 and positional alignment 62.42 vs. 57.60. We analyze various ways to relabel the corpus and provide evidence that this technique, which we call RECAP, both reduces the train-inference discrepancy and provides the model with more information per example, increasing sample efficiency and allowing the model to better understand the relations between captions and images.
1111.4898
Vijesh M
Vijesh M., Sudarshan Iyengar, Vijay Mahantesh, Amitash Ramesh, Veni Madhavan
A Navigation Algorithm Inspired by Human Navigation
Human Navigation, Path Concatenation, Hotspots, Center Strategic Paths, Approximation Algorithm
null
null
null
cs.SI physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Human navigation has been a topic of interest in spatial cognition from the past few decades. It has been experimentally observed that humans accomplish the task of way-finding a destination in an unknown environment by recognizing landmarks. Investigations using network analytic techniques reveal that humans, when asked to way-find their destination, learn the top ranked nodes of a network. In this paper we report a study simulating the strategy used by humans to recognize the centers of a network. We show that the paths obtained from our simulation has the same properties as the paths obtained in human based experiment. The simulation thus performed leads to a novel way of path-finding in a network. We discuss the performance of our method and compare it with the existing techniques to find a path between a pair of nodes in a network.
[ { "created": "Mon, 21 Nov 2011 15:37:15 GMT", "version": "v1" } ]
2011-11-22
[ [ "M.", "Vijesh", "" ], [ "Iyengar", "Sudarshan", "" ], [ "Mahantesh", "Vijay", "" ], [ "Ramesh", "Amitash", "" ], [ "Madhavan", "Veni", "" ] ]
Human navigation has been a topic of interest in spatial cognition from the past few decades. It has been experimentally observed that humans accomplish the task of way-finding a destination in an unknown environment by recognizing landmarks. Investigations using network analytic techniques reveal that humans, when asked to way-find their destination, learn the top ranked nodes of a network. In this paper we report a study simulating the strategy used by humans to recognize the centers of a network. We show that the paths obtained from our simulation has the same properties as the paths obtained in human based experiment. The simulation thus performed leads to a novel way of path-finding in a network. We discuss the performance of our method and compare it with the existing techniques to find a path between a pair of nodes in a network.
2205.08685
Jinwei Xing
Jinwei Xing, Takashi Nagata, Xinyun Zou, Emre Neftci, Jeffrey L. Krichmar
Policy Distillation with Selective Input Gradient Regularization for Efficient Interpretability
null
null
null
null
cs.LG cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Although deep Reinforcement Learning (RL) has proven successful in a wide range of tasks, one challenge it faces is interpretability when applied to real-world problems. Saliency maps are frequently used to provide interpretability for deep neural networks. However, in the RL domain, existing saliency map approaches are either computationally expensive and thus cannot satisfy the real-time requirement of real-world scenarios or cannot produce interpretable saliency maps for RL policies. In this work, we propose an approach of Distillation with selective Input Gradient Regularization (DIGR) which uses policy distillation and input gradient regularization to produce new policies that achieve both high interpretability and computation efficiency in generating saliency maps. Our approach is also found to improve the robustness of RL policies to multiple adversarial attacks. We conduct experiments on three tasks, MiniGrid (Fetch Object), Atari (Breakout) and CARLA Autonomous Driving, to demonstrate the importance and effectiveness of our approach.
[ { "created": "Wed, 18 May 2022 01:47:16 GMT", "version": "v1" } ]
2022-05-19
[ [ "Xing", "Jinwei", "" ], [ "Nagata", "Takashi", "" ], [ "Zou", "Xinyun", "" ], [ "Neftci", "Emre", "" ], [ "Krichmar", "Jeffrey L.", "" ] ]
Although deep Reinforcement Learning (RL) has proven successful in a wide range of tasks, one challenge it faces is interpretability when applied to real-world problems. Saliency maps are frequently used to provide interpretability for deep neural networks. However, in the RL domain, existing saliency map approaches are either computationally expensive and thus cannot satisfy the real-time requirement of real-world scenarios or cannot produce interpretable saliency maps for RL policies. In this work, we propose an approach of Distillation with selective Input Gradient Regularization (DIGR) which uses policy distillation and input gradient regularization to produce new policies that achieve both high interpretability and computation efficiency in generating saliency maps. Our approach is also found to improve the robustness of RL policies to multiple adversarial attacks. We conduct experiments on three tasks, MiniGrid (Fetch Object), Atari (Breakout) and CARLA Autonomous Driving, to demonstrate the importance and effectiveness of our approach.
1908.00418
Yang Xin
Hui Li, Jiangxing Wu, Xin Yang, Han Wang, Julong Lan, Ke Xu, Yunyong Zhang, Jinwu Wei, Shisheng Chen, Wei Liang, Fusheng Zhu, Yiqin Lu, Wai Ho Mow, Yeung Wai-Ho, Zefeng Zheng, Peng Yi, Xinsheng Ji, Qinrang Liu, Wei Li, Kaiyan Tian, Jiang Zhu, Jiaxing Song, Yijun Liu, Junfeng Ma, Jiawei Hu, Rui Xu, Jiansen Huang, Guohua Wei, Jiuhua Qi, Ting Huang, Kaixuan Xing
MIN: Co-Governing Multi-Identifier Network Architecture and its Prototype on Operator's Network
13 pages
null
null
null
cs.NI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
IP protocol is the core of TCP/IP network layer. However, since IP address and its Domain Name are allocated and managed by a single agency, there are risks of centralization. The semantic overload of IP address also reduces its scalability and mobility, which further hinders the security. This paper proposes a co-governing Multi-Identifier Network (MIN) architecture that constructs a network layer with parallel coexistence of multiple identifiers, including identity, content, geographic information, and IP address. On the management plane, we develop an efficient management system using consortium blockchain with voting consensus, so the network can simultaneously manage and support by hundreds or thousands of nodes with high throughput. On the data plane, we propose an algorithm merging hash table and prefix tree (HTP) for FIB, which avoids the false-negative error and can inter-translate different identifiers with tens of billions of entries. Further, we propose a scheme to transport IP packets using CCN as a tunnel for supporting progressive deployment. We deployed the prototype of MIN to the largest operators' network in Mainland China, Hongkong and Macao, and demonstrated that the network can register identifier under co-governing consensus algorithm, support VoD service very well.
[ { "created": "Thu, 1 Aug 2019 14:12:27 GMT", "version": "v1" } ]
2019-08-02
[ [ "Li", "Hui", "" ], [ "Wu", "Jiangxing", "" ], [ "Yang", "Xin", "" ], [ "Wang", "Han", "" ], [ "Lan", "Julong", "" ], [ "Xu", "Ke", "" ], [ "Zhang", "Yunyong", "" ], [ "Wei", "Jinwu", "" ], [ "Chen", "Shisheng", "" ], [ "Liang", "Wei", "" ], [ "Zhu", "Fusheng", "" ], [ "Lu", "Yiqin", "" ], [ "Mow", "Wai Ho", "" ], [ "Wai-Ho", "Yeung", "" ], [ "Zheng", "Zefeng", "" ], [ "Yi", "Peng", "" ], [ "Ji", "Xinsheng", "" ], [ "Liu", "Qinrang", "" ], [ "Li", "Wei", "" ], [ "Tian", "Kaiyan", "" ], [ "Zhu", "Jiang", "" ], [ "Song", "Jiaxing", "" ], [ "Liu", "Yijun", "" ], [ "Ma", "Junfeng", "" ], [ "Hu", "Jiawei", "" ], [ "Xu", "Rui", "" ], [ "Huang", "Jiansen", "" ], [ "Wei", "Guohua", "" ], [ "Qi", "Jiuhua", "" ], [ "Huang", "Ting", "" ], [ "Xing", "Kaixuan", "" ] ]
IP protocol is the core of TCP/IP network layer. However, since IP address and its Domain Name are allocated and managed by a single agency, there are risks of centralization. The semantic overload of IP address also reduces its scalability and mobility, which further hinders the security. This paper proposes a co-governing Multi-Identifier Network (MIN) architecture that constructs a network layer with parallel coexistence of multiple identifiers, including identity, content, geographic information, and IP address. On the management plane, we develop an efficient management system using consortium blockchain with voting consensus, so the network can simultaneously manage and support by hundreds or thousands of nodes with high throughput. On the data plane, we propose an algorithm merging hash table and prefix tree (HTP) for FIB, which avoids the false-negative error and can inter-translate different identifiers with tens of billions of entries. Further, we propose a scheme to transport IP packets using CCN as a tunnel for supporting progressive deployment. We deployed the prototype of MIN to the largest operators' network in Mainland China, Hongkong and Macao, and demonstrated that the network can register identifier under co-governing consensus algorithm, support VoD service very well.
2003.00946
Piotr Kicki
Piotr Kicki, Tomasz Gawron, Piotr Skrzypczy\'nski
A Self-Supervised Learning Approach to Rapid Path Planning for Car-Like Vehicles Maneuvering in Urban Environment
null
null
null
null
cs.RO cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An efficient path planner for autonomous car-like vehicles should handle the strong kinematic constraints, particularly in confined spaces commonly encountered while maneuvering in city traffic, and should enable rapid planning, as the city traffic scenarios are highly dynamic. State-of-the-art planning algorithms handle such difficult cases at high computational cost, often yielding non-deterministic results. However, feasible local paths can be quickly generated leveraging the past planning experience gained in the same or similar environment. While learning through supervised training is problematic for real traffic scenarios, we introduce in this paper a novel neural network-based method for path planning, which employs a gradient-based self-supervised learning algorithm to predict feasible paths. This approach strongly exploits the experience gained in the past and rapidly yields feasible maneuver plans for car-like vehicles with limited steering-angle. The effectiveness of such an approach has been confirmed by computational experiments.
[ { "created": "Mon, 2 Mar 2020 14:48:29 GMT", "version": "v1" } ]
2020-03-03
[ [ "Kicki", "Piotr", "" ], [ "Gawron", "Tomasz", "" ], [ "Skrzypczyński", "Piotr", "" ] ]
An efficient path planner for autonomous car-like vehicles should handle the strong kinematic constraints, particularly in confined spaces commonly encountered while maneuvering in city traffic, and should enable rapid planning, as the city traffic scenarios are highly dynamic. State-of-the-art planning algorithms handle such difficult cases at high computational cost, often yielding non-deterministic results. However, feasible local paths can be quickly generated leveraging the past planning experience gained in the same or similar environment. While learning through supervised training is problematic for real traffic scenarios, we introduce in this paper a novel neural network-based method for path planning, which employs a gradient-based self-supervised learning algorithm to predict feasible paths. This approach strongly exploits the experience gained in the past and rapidly yields feasible maneuver plans for car-like vehicles with limited steering-angle. The effectiveness of such an approach has been confirmed by computational experiments.
1912.07447
Nian Xue
Zhen Li, Hanyang Shao, Nian Xue, Liang Niu and LiangLiang Cao
Progressive Learning Algorithm for Efficient Person Re-Identification
ICPR2020
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper studies the problem of Person Re-Identification (ReID)for large-scale applications. Recent research efforts have been devoted to building complicated part models, which introduce considerably high computational cost and memory consumption, inhibiting its practicability in large-scale applications. This paper aims to develop a novel learning strategy to find efficient feature embeddings while maintaining the balance of accuracy and model complexity. More specifically, we find by enhancing the classical triplet loss together with cross-entropy loss, our method can explore the hard examples and build a discriminant feature embedding yet compact enough for large-scale applications. Our method is carried out progressively using Bayesian optimization, and we call it the Progressive Learning Algorithm (PLA). Extensive experiments on three large-scale datasets show that our PLA is comparable or better than the-state-of-the-arts. Especially, on the challenging Market-1501 dataset, we achieve Rank-1=94.7\%/mAP=89.4\% while saving at least 30\% parameters than strong part models.
[ { "created": "Mon, 16 Dec 2019 15:32:01 GMT", "version": "v1" }, { "created": "Mon, 23 Nov 2020 22:08:16 GMT", "version": "v2" } ]
2020-11-25
[ [ "Li", "Zhen", "" ], [ "Shao", "Hanyang", "" ], [ "Xue", "Nian", "" ], [ "Niu", "Liang", "" ], [ "Cao", "LiangLiang", "" ] ]
This paper studies the problem of Person Re-Identification (ReID)for large-scale applications. Recent research efforts have been devoted to building complicated part models, which introduce considerably high computational cost and memory consumption, inhibiting its practicability in large-scale applications. This paper aims to develop a novel learning strategy to find efficient feature embeddings while maintaining the balance of accuracy and model complexity. More specifically, we find by enhancing the classical triplet loss together with cross-entropy loss, our method can explore the hard examples and build a discriminant feature embedding yet compact enough for large-scale applications. Our method is carried out progressively using Bayesian optimization, and we call it the Progressive Learning Algorithm (PLA). Extensive experiments on three large-scale datasets show that our PLA is comparable or better than the-state-of-the-arts. Especially, on the challenging Market-1501 dataset, we achieve Rank-1=94.7\%/mAP=89.4\% while saving at least 30\% parameters than strong part models.
1609.03205
Ella Rabinovich
Ella Rabinovich and Shuly Wintner
Unsupervised Identification of Translationese
TACL2015, 14 pages
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Translated texts are distinctively different from original ones, to the extent that supervised text classification methods can distinguish between them with high accuracy. These differences were proven useful for statistical machine translation. However, it has been suggested that the accuracy of translation detection deteriorates when the classifier is evaluated outside the domain it was trained on. We show that this is indeed the case, in a variety of evaluation scenarios. We then show that unsupervised classification is highly accurate on this task. We suggest a method for determining the correct labels of the clustering outcomes, and then use the labels for voting, improving the accuracy even further. Moreover, we suggest a simple method for clustering in the challenging case of mixed-domain datasets, in spite of the dominance of domain-related features over translation-related ones. The result is an effective, fully-unsupervised method for distinguishing between original and translated texts that can be applied to new domains with reasonable accuracy.
[ { "created": "Sun, 11 Sep 2016 19:52:28 GMT", "version": "v1" } ]
2016-09-13
[ [ "Rabinovich", "Ella", "" ], [ "Wintner", "Shuly", "" ] ]
Translated texts are distinctively different from original ones, to the extent that supervised text classification methods can distinguish between them with high accuracy. These differences were proven useful for statistical machine translation. However, it has been suggested that the accuracy of translation detection deteriorates when the classifier is evaluated outside the domain it was trained on. We show that this is indeed the case, in a variety of evaluation scenarios. We then show that unsupervised classification is highly accurate on this task. We suggest a method for determining the correct labels of the clustering outcomes, and then use the labels for voting, improving the accuracy even further. Moreover, we suggest a simple method for clustering in the challenging case of mixed-domain datasets, in spite of the dominance of domain-related features over translation-related ones. The result is an effective, fully-unsupervised method for distinguishing between original and translated texts that can be applied to new domains with reasonable accuracy.
1811.03531
Zachary Charles
Zachary Charles, Harrison Rosenberg, Dimitris Papailiopoulos
A Geometric Perspective on the Transferability of Adversarial Directions
null
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
State-of-the-art machine learning models frequently misclassify inputs that have been perturbed in an adversarial manner. Adversarial perturbations generated for a given input and a specific classifier often seem to be effective on other inputs and even different classifiers. In other words, adversarial perturbations seem to transfer between different inputs, models, and even different neural network architectures. In this work, we show that in the context of linear classifiers and two-layer ReLU networks, there provably exist directions that give rise to adversarial perturbations for many classifiers and data points simultaneously. We show that these "transferable adversarial directions" are guaranteed to exist for linear separators of a given set, and will exist with high probability for linear classifiers trained on independent sets drawn from the same distribution. We extend our results to large classes of two-layer ReLU networks. We further show that adversarial directions for ReLU networks transfer to linear classifiers while the reverse need not hold, suggesting that adversarial perturbations for more complex models are more likely to transfer to other classifiers. We validate our findings empirically, even for deeper ReLU networks.
[ { "created": "Thu, 8 Nov 2018 16:23:50 GMT", "version": "v1" } ]
2018-11-09
[ [ "Charles", "Zachary", "" ], [ "Rosenberg", "Harrison", "" ], [ "Papailiopoulos", "Dimitris", "" ] ]
State-of-the-art machine learning models frequently misclassify inputs that have been perturbed in an adversarial manner. Adversarial perturbations generated for a given input and a specific classifier often seem to be effective on other inputs and even different classifiers. In other words, adversarial perturbations seem to transfer between different inputs, models, and even different neural network architectures. In this work, we show that in the context of linear classifiers and two-layer ReLU networks, there provably exist directions that give rise to adversarial perturbations for many classifiers and data points simultaneously. We show that these "transferable adversarial directions" are guaranteed to exist for linear separators of a given set, and will exist with high probability for linear classifiers trained on independent sets drawn from the same distribution. We extend our results to large classes of two-layer ReLU networks. We further show that adversarial directions for ReLU networks transfer to linear classifiers while the reverse need not hold, suggesting that adversarial perturbations for more complex models are more likely to transfer to other classifiers. We validate our findings empirically, even for deeper ReLU networks.
2010.01113
S. Mohammad Razavizadeh
Anahid Rafieifar, and S. Mohammad Razavizadeh
Secrecy Rate Maximization in Multi-IRS Millimeter Wave Networks
20 pages, 6 figures
Physical Communication (Elsevier) - vol.48 - Oct. 2021
10.1016/j.phycom.2021.101436
null
cs.IT eess.SP math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper investigates the problem of increasing the security at the physical layer of a Millimeter Wave (mmWave) network equipped with several Intelligent Reflecting Surfaces (IRSs). In this network, multiple IRSs help the Base Station (BS) to reach the signal to the desired user and at the same time maintain the security of the network i.e. securing the signal from receiving by the unallowable eavesdropper. The target of the proposed scheme is to maximize the secrecy rate by jointly optimizing the active beamforming at the BS and passive beamforming at the IRSs. This leads to a non-convex optimization problem which we solve by decomposing into two sub-problems. The sub-problems alternatively solve the active and passive beamforming design problems using the Semi-Definite Relaxation (SDR) technique. Finally, simulations are done to assess the performance of the proposed algorithm. These results show the superiority of using multiple IRSs in the enhancement of the secrecy rate in the wireless networks that operate in the mmWave frequency bands.
[ { "created": "Fri, 2 Oct 2020 17:17:13 GMT", "version": "v1" }, { "created": "Fri, 21 May 2021 13:24:49 GMT", "version": "v2" } ]
2021-10-07
[ [ "Rafieifar", "Anahid", "" ], [ "Razavizadeh", "S. Mohammad", "" ] ]
This paper investigates the problem of increasing the security at the physical layer of a Millimeter Wave (mmWave) network equipped with several Intelligent Reflecting Surfaces (IRSs). In this network, multiple IRSs help the Base Station (BS) to reach the signal to the desired user and at the same time maintain the security of the network i.e. securing the signal from receiving by the unallowable eavesdropper. The target of the proposed scheme is to maximize the secrecy rate by jointly optimizing the active beamforming at the BS and passive beamforming at the IRSs. This leads to a non-convex optimization problem which we solve by decomposing into two sub-problems. The sub-problems alternatively solve the active and passive beamforming design problems using the Semi-Definite Relaxation (SDR) technique. Finally, simulations are done to assess the performance of the proposed algorithm. These results show the superiority of using multiple IRSs in the enhancement of the secrecy rate in the wireless networks that operate in the mmWave frequency bands.
1711.11499
Leonardo Ermann
Leonardo Ermann, Klaus M. Frahm and Dima L. Shepelyansky
Google matrix of Bitcoin network
12 pages, 15 figures
Eur. Phys. J. B 91, 127 (2018)
10.1140/epjb/e2018-80674-y
null
cs.SI physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct and study the Google matrix of Bitcoin transactions during the time period from the very beginning in 2009 till April 2013. The Bitcoin network has up to a few millions of bitcoin users and we present its main characteristics including the PageRank and CheiRank probability distributions, the spectrum of eigenvalues of Google matrix and related eigenvectors. We find that the spectrum has an unusual circle-type structure which we attribute to existing hidden communities of nodes linked between their members. We show that the Gini coefficient of the transactions for the whole period is close to unity showing that the main part of wealth of the network is captured by a small fraction of users.
[ { "created": "Thu, 30 Nov 2017 16:35:43 GMT", "version": "v1" } ]
2018-06-29
[ [ "Ermann", "Leonardo", "" ], [ "Frahm", "Klaus M.", "" ], [ "Shepelyansky", "Dima L.", "" ] ]
We construct and study the Google matrix of Bitcoin transactions during the time period from the very beginning in 2009 till April 2013. The Bitcoin network has up to a few millions of bitcoin users and we present its main characteristics including the PageRank and CheiRank probability distributions, the spectrum of eigenvalues of Google matrix and related eigenvectors. We find that the spectrum has an unusual circle-type structure which we attribute to existing hidden communities of nodes linked between their members. We show that the Gini coefficient of the transactions for the whole period is close to unity showing that the main part of wealth of the network is captured by a small fraction of users.
2102.06984
Hanbaek Lyu
Hanbaek Lyu, Yacoub H. Kureh, Joshua Vendrow, Mason A. Porter
Learning low-rank latent mesoscale structures in networks
82 pages, 25 figures, 2 tables
null
null
null
cs.SI cs.LG math.OC physics.soc-ph stat.ML
http://creativecommons.org/licenses/by/4.0/
It is common to use networks to encode the architecture of interactions between entities in complex systems in the physical, biological, social, and information sciences. To study the large-scale behavior of complex systems, it is useful to examine mesoscale structures in networks as building blocks that influence such behavior. We present a new approach for describing low-rank mesoscale structures in networks, and we illustrate our approach using several synthetic network models and empirical friendship, collaboration, and protein--protein interaction (PPI) networks. We find that these networks possess a relatively small number of `latent motifs' that together can successfully approximate most subgraphs of a network at a fixed mesoscale. We use an algorithm for `network dictionary learning' (NDL), which combines a network-sampling method and nonnegative matrix factorization, to learn the latent motifs of a given network. The ability to encode a network using a set of latent motifs has a wide variety of applications to network-analysis tasks, such as comparison, denoising, and edge inference. Additionally, using a new network denoising and reconstruction (NDR) algorithm, we demonstrate how to denoise a corrupted network by using only the latent motifs that one learns directly from the corrupted network.
[ { "created": "Sat, 13 Feb 2021 18:54:49 GMT", "version": "v1" }, { "created": "Sun, 25 Jul 2021 16:45:12 GMT", "version": "v2" }, { "created": "Tue, 16 Aug 2022 23:13:44 GMT", "version": "v3" }, { "created": "Sat, 4 Mar 2023 05:52:30 GMT", "version": "v4" }, { "created": "Thu, 13 Jul 2023 05:42:06 GMT", "version": "v5" } ]
2023-07-14
[ [ "Lyu", "Hanbaek", "" ], [ "Kureh", "Yacoub H.", "" ], [ "Vendrow", "Joshua", "" ], [ "Porter", "Mason A.", "" ] ]
It is common to use networks to encode the architecture of interactions between entities in complex systems in the physical, biological, social, and information sciences. To study the large-scale behavior of complex systems, it is useful to examine mesoscale structures in networks as building blocks that influence such behavior. We present a new approach for describing low-rank mesoscale structures in networks, and we illustrate our approach using several synthetic network models and empirical friendship, collaboration, and protein--protein interaction (PPI) networks. We find that these networks possess a relatively small number of `latent motifs' that together can successfully approximate most subgraphs of a network at a fixed mesoscale. We use an algorithm for `network dictionary learning' (NDL), which combines a network-sampling method and nonnegative matrix factorization, to learn the latent motifs of a given network. The ability to encode a network using a set of latent motifs has a wide variety of applications to network-analysis tasks, such as comparison, denoising, and edge inference. Additionally, using a new network denoising and reconstruction (NDR) algorithm, we demonstrate how to denoise a corrupted network by using only the latent motifs that one learns directly from the corrupted network.
1807.01185
Iman Valiulahi
Iman Valiulahi, Farzan Haddadi, and Arash Amini
Robustness of Two-Dimensional Line Spectral Estimation Against Spiky Noise
null
null
10.1109/TSP.2019.2951220
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The aim of two-dimensional line spectral estimation is to super-resolve the spectral point sources of the signal from time samples. In many associated applications such as radar and sonar, due to cut-off and saturation regions in electronic devices, some of the numbers of samples are corrupted by spiky noise. To overcome this problem, we present a new convex program to simultaneously estimate spectral point sources and spiky noise in two dimensions. To prove uniqueness of the solution, it is sufficient to show that a dual certificate exists. Construction of the dual certificate imposes a mild condition on the separation of the spectral point sources. Also, the number of spikes and detectable sparse sources are shown to be a logarithmic function of the number of time samples. Simulation results confirm the conclusions of our general theory.
[ { "created": "Tue, 3 Jul 2018 13:45:56 GMT", "version": "v1" } ]
2020-01-08
[ [ "Valiulahi", "Iman", "" ], [ "Haddadi", "Farzan", "" ], [ "Amini", "Arash", "" ] ]
The aim of two-dimensional line spectral estimation is to super-resolve the spectral point sources of the signal from time samples. In many associated applications such as radar and sonar, due to cut-off and saturation regions in electronic devices, some of the numbers of samples are corrupted by spiky noise. To overcome this problem, we present a new convex program to simultaneously estimate spectral point sources and spiky noise in two dimensions. To prove uniqueness of the solution, it is sufficient to show that a dual certificate exists. Construction of the dual certificate imposes a mild condition on the separation of the spectral point sources. Also, the number of spikes and detectable sparse sources are shown to be a logarithmic function of the number of time samples. Simulation results confirm the conclusions of our general theory.
2009.02406
Xinli Yu T
Xinli Yu, Mohsen Malmir, Cynthia He, Yue Liu, Rex Wu
Video Moment Retrieval via Natural Language Queries
needs internal approval
null
null
null
cs.CV cs.AI cs.CL cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose a novel method for video moment retrieval (VMR) that achieves state of the arts (SOTA) performance on R@1 metrics and surpassing the SOTA on the high IoU metric (R@1, IoU=0.7). First, we propose to use a multi-head self-attention mechanism, and further a cross-attention scheme to capture video/query interaction and long-range query dependencies from video context. The attention-based methods can develop frame-to-query interaction and query-to-frame interaction at arbitrary positions and the multi-head setting ensures the sufficient understanding of complicated dependencies. Our model has a simple architecture, which enables faster training and inference while maintaining . Second, We also propose to use multiple task training objective consists of moment segmentation task, start/end distribution prediction and start/end location regression task. We have verified that start/end prediction are noisy due to annotator disagreement and joint training with moment segmentation task can provide richer information since frames inside the target clip are also utilized as positive training examples. Third, we propose to use an early fusion approach, which achieves better performance at the cost of inference time. However, the inference time will not be a problem for our model since our model has a simple architecture which enables efficient training and inference.
[ { "created": "Fri, 4 Sep 2020 22:06:34 GMT", "version": "v1" }, { "created": "Thu, 10 Sep 2020 14:49:04 GMT", "version": "v2" } ]
2020-09-11
[ [ "Yu", "Xinli", "" ], [ "Malmir", "Mohsen", "" ], [ "He", "Cynthia", "" ], [ "Liu", "Yue", "" ], [ "Wu", "Rex", "" ] ]
In this paper, we propose a novel method for video moment retrieval (VMR) that achieves state of the arts (SOTA) performance on R@1 metrics and surpassing the SOTA on the high IoU metric (R@1, IoU=0.7). First, we propose to use a multi-head self-attention mechanism, and further a cross-attention scheme to capture video/query interaction and long-range query dependencies from video context. The attention-based methods can develop frame-to-query interaction and query-to-frame interaction at arbitrary positions and the multi-head setting ensures the sufficient understanding of complicated dependencies. Our model has a simple architecture, which enables faster training and inference while maintaining . Second, We also propose to use multiple task training objective consists of moment segmentation task, start/end distribution prediction and start/end location regression task. We have verified that start/end prediction are noisy due to annotator disagreement and joint training with moment segmentation task can provide richer information since frames inside the target clip are also utilized as positive training examples. Third, we propose to use an early fusion approach, which achieves better performance at the cost of inference time. However, the inference time will not be a problem for our model since our model has a simple architecture which enables efficient training and inference.
0704.3433
Tshilidzi Marwala
Tshilidzi Marwala and Bodie Crossingham
Bayesian approach to rough set
20 pages, 3 figures
null
null
null
cs.AI
null
This paper proposes an approach to training rough set models using Bayesian framework trained using Markov Chain Monte Carlo (MCMC) method. The prior probabilities are constructed from the prior knowledge that good rough set models have fewer rules. Markov Chain Monte Carlo sampling is conducted through sampling in the rough set granule space and Metropolis algorithm is used as an acceptance criteria. The proposed method is tested to estimate the risk of HIV given demographic data. The results obtained shows that the proposed approach is able to achieve an average accuracy of 58% with the accuracy varying up to 66%. In addition the Bayesian rough set give the probabilities of the estimated HIV status as well as the linguistic rules describing how the demographic parameters drive the risk of HIV.
[ { "created": "Wed, 25 Apr 2007 19:50:59 GMT", "version": "v1" } ]
2007-05-23
[ [ "Marwala", "Tshilidzi", "" ], [ "Crossingham", "Bodie", "" ] ]
This paper proposes an approach to training rough set models using Bayesian framework trained using Markov Chain Monte Carlo (MCMC) method. The prior probabilities are constructed from the prior knowledge that good rough set models have fewer rules. Markov Chain Monte Carlo sampling is conducted through sampling in the rough set granule space and Metropolis algorithm is used as an acceptance criteria. The proposed method is tested to estimate the risk of HIV given demographic data. The results obtained shows that the proposed approach is able to achieve an average accuracy of 58% with the accuracy varying up to 66%. In addition the Bayesian rough set give the probabilities of the estimated HIV status as well as the linguistic rules describing how the demographic parameters drive the risk of HIV.
2207.04403
Litao Yu
Litao Yu, Zhibin Li, Jian Zhang, Qiang Wu
Self-attention on Multi-Shifted Windows for Scene Segmentation
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Scene segmentation in images is a fundamental yet challenging problem in visual content understanding, which is to learn a model to assign every image pixel to a categorical label. One of the challenges for this learning task is to consider the spatial and semantic relationships to obtain descriptive feature representations, so learning the feature maps from multiple scales is a common practice in scene segmentation. In this paper, we explore the effective use of self-attention within multi-scale image windows to learn descriptive visual features, then propose three different strategies to aggregate these feature maps to decode the feature representation for dense prediction. Our design is based on the recently proposed Swin Transformer models, which totally discards convolution operations. With the simple yet effective multi-scale feature learning and aggregation, our models achieve very promising performance on four public scene segmentation datasets, PASCAL VOC2012, COCO-Stuff 10K, ADE20K and Cityscapes.
[ { "created": "Sun, 10 Jul 2022 07:36:36 GMT", "version": "v1" } ]
2022-07-12
[ [ "Yu", "Litao", "" ], [ "Li", "Zhibin", "" ], [ "Zhang", "Jian", "" ], [ "Wu", "Qiang", "" ] ]
Scene segmentation in images is a fundamental yet challenging problem in visual content understanding, which is to learn a model to assign every image pixel to a categorical label. One of the challenges for this learning task is to consider the spatial and semantic relationships to obtain descriptive feature representations, so learning the feature maps from multiple scales is a common practice in scene segmentation. In this paper, we explore the effective use of self-attention within multi-scale image windows to learn descriptive visual features, then propose three different strategies to aggregate these feature maps to decode the feature representation for dense prediction. Our design is based on the recently proposed Swin Transformer models, which totally discards convolution operations. With the simple yet effective multi-scale feature learning and aggregation, our models achieve very promising performance on four public scene segmentation datasets, PASCAL VOC2012, COCO-Stuff 10K, ADE20K and Cityscapes.
1703.09200
Yuanhan Mo
Yuanhan Mo, Fangde Liu, Douglas McIlwraith, Guang Yang, Jingqing Zhang, Taigang He, Yike Guo
The Deep Poincar\'e Map: A Novel Approach for Left Ventricle Segmentation
MICCAI 2018 Spotlight
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Precise segmentation of the left ventricle (LV) within cardiac MRI images is a prerequisite for the quantitative measurement of heart function. However, this task is challenging due to the limited availability of labeled data and motion artifacts from cardiac imaging. In this work, we present an iterative segmentation algorithm for LV delineation. By coupling deep learning with a novel dynamic-based labeling scheme, we present a new methodology where a policy model is learned to guide an agent to travel over the the image, tracing out a boundary of the ROI -- using the magnitude difference of the Poincar\'e map as a stopping criterion. Our method is evaluated on two datasets, namely the Sunnybrook Cardiac Dataset (SCD) and data from the STACOM 2011 LV segmentation challenge. Our method outperforms the previous research over many metrics. In order to demonstrate the transferability of our method we present encouraging results over the STACOM 2011 data, when using a model trained on the SCD dataset.
[ { "created": "Mon, 27 Mar 2017 17:37:33 GMT", "version": "v1" }, { "created": "Tue, 30 Oct 2018 11:10:09 GMT", "version": "v2" } ]
2018-10-31
[ [ "Mo", "Yuanhan", "" ], [ "Liu", "Fangde", "" ], [ "McIlwraith", "Douglas", "" ], [ "Yang", "Guang", "" ], [ "Zhang", "Jingqing", "" ], [ "He", "Taigang", "" ], [ "Guo", "Yike", "" ] ]
Precise segmentation of the left ventricle (LV) within cardiac MRI images is a prerequisite for the quantitative measurement of heart function. However, this task is challenging due to the limited availability of labeled data and motion artifacts from cardiac imaging. In this work, we present an iterative segmentation algorithm for LV delineation. By coupling deep learning with a novel dynamic-based labeling scheme, we present a new methodology where a policy model is learned to guide an agent to travel over the the image, tracing out a boundary of the ROI -- using the magnitude difference of the Poincar\'e map as a stopping criterion. Our method is evaluated on two datasets, namely the Sunnybrook Cardiac Dataset (SCD) and data from the STACOM 2011 LV segmentation challenge. Our method outperforms the previous research over many metrics. In order to demonstrate the transferability of our method we present encouraging results over the STACOM 2011 data, when using a model trained on the SCD dataset.
2407.11344
Xu Zheng
Xu Zheng, Yuanhuiyi Lyu, Jiazhou Zhou, Lin Wang
Centering the Value of Every Modality: Towards Efficient and Resilient Modality-agnostic Semantic Segmentation
Accepted to ECCV 2024
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fusing an arbitrary number of modalities is vital for achieving robust multi-modal fusion of semantic segmentation yet remains less explored to date. Recent endeavors regard RGB modality as the center and the others as the auxiliary, yielding an asymmetric architecture with two branches. However, the RGB modality may struggle in certain circumstances, e.g., nighttime, while others, e.g., event data, own their merits; thus, it is imperative for the fusion model to discern robust and fragile modalities, and incorporate the most robust and fragile ones to learn a resilient multi-modal framework. To this end, we propose a novel method, named MAGIC, that can be flexibly paired with various backbones, ranging from compact to high-performance models. Our method comprises two key plug-and-play modules. Firstly, we introduce a multi-modal aggregation module to efficiently process features from multi-modal batches and extract complementary scene information. On top, a unified arbitrary-modal selection module is proposed to utilize the aggregated features as the benchmark to rank the multi-modal features based on the similarity scores. This way, our method can eliminate the dependence on RGB modality and better overcome sensor failures while ensuring the segmentation performance. Under the commonly considered multi-modal setting, our method achieves state-of-the-art performance while reducing the model parameters by 60%. Moreover, our method is superior in the novel modality-agnostic setting, where it outperforms prior arts by a large margin of +19.41% mIoU
[ { "created": "Tue, 16 Jul 2024 03:19:59 GMT", "version": "v1" } ]
2024-07-17
[ [ "Zheng", "Xu", "" ], [ "Lyu", "Yuanhuiyi", "" ], [ "Zhou", "Jiazhou", "" ], [ "Wang", "Lin", "" ] ]
Fusing an arbitrary number of modalities is vital for achieving robust multi-modal fusion of semantic segmentation yet remains less explored to date. Recent endeavors regard RGB modality as the center and the others as the auxiliary, yielding an asymmetric architecture with two branches. However, the RGB modality may struggle in certain circumstances, e.g., nighttime, while others, e.g., event data, own their merits; thus, it is imperative for the fusion model to discern robust and fragile modalities, and incorporate the most robust and fragile ones to learn a resilient multi-modal framework. To this end, we propose a novel method, named MAGIC, that can be flexibly paired with various backbones, ranging from compact to high-performance models. Our method comprises two key plug-and-play modules. Firstly, we introduce a multi-modal aggregation module to efficiently process features from multi-modal batches and extract complementary scene information. On top, a unified arbitrary-modal selection module is proposed to utilize the aggregated features as the benchmark to rank the multi-modal features based on the similarity scores. This way, our method can eliminate the dependence on RGB modality and better overcome sensor failures while ensuring the segmentation performance. Under the commonly considered multi-modal setting, our method achieves state-of-the-art performance while reducing the model parameters by 60%. Moreover, our method is superior in the novel modality-agnostic setting, where it outperforms prior arts by a large margin of +19.41% mIoU
2307.03017
Yijie Deng
Yijie Deng, Lei Han, Tianpeng Lin, Lin Li, Jinzhi Zhang, and Lu Fang
RealLiFe: Real-Time Light Field Reconstruction via Hierarchical Sparse Gradient Descent
Submitted to IEEE TPAMI
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the rise of Extended Reality (XR) technology, there is a growing need for real-time light field generation from sparse view inputs. Existing methods can be classified into offline techniques, which can generate high-quality novel views but at the cost of long inference/training time, and online methods, which either lack generalizability or produce unsatisfactory results. However, we have observed that the intrinsic sparse manifold of Multi-plane Images (MPI) enables a significant acceleration of light field generation while maintaining rendering quality. Based on this insight, we introduce EffLiFe, a novel light field optimization method, which leverages the proposed Hierarchical Sparse Gradient Descent (HSGD) to produce high-quality light fields from sparse view images in real time. Technically, the coarse MPI of a scene is first generated using a 3D CNN, and it is further sparsely optimized by focusing only on important MPI gradients in a few iterations. Nevertheless, relying solely on optimization can lead to artifacts at occlusion boundaries. Therefore, we propose an occlusion-aware iterative refinement module that removes visual artifacts in occluded regions by iteratively filtering the input. Extensive experiments demonstrate that our method achieves comparable visual quality while being 100x faster on average than state-of-the-art offline methods and delivering better performance (about 2 dB higher in PSNR) compared to other online approaches.
[ { "created": "Thu, 6 Jul 2023 14:31:01 GMT", "version": "v1" }, { "created": "Mon, 10 Jul 2023 12:47:34 GMT", "version": "v2" }, { "created": "Mon, 27 Nov 2023 11:38:39 GMT", "version": "v3" } ]
2023-11-28
[ [ "Deng", "Yijie", "" ], [ "Han", "Lei", "" ], [ "Lin", "Tianpeng", "" ], [ "Li", "Lin", "" ], [ "Zhang", "Jinzhi", "" ], [ "Fang", "Lu", "" ] ]
With the rise of Extended Reality (XR) technology, there is a growing need for real-time light field generation from sparse view inputs. Existing methods can be classified into offline techniques, which can generate high-quality novel views but at the cost of long inference/training time, and online methods, which either lack generalizability or produce unsatisfactory results. However, we have observed that the intrinsic sparse manifold of Multi-plane Images (MPI) enables a significant acceleration of light field generation while maintaining rendering quality. Based on this insight, we introduce EffLiFe, a novel light field optimization method, which leverages the proposed Hierarchical Sparse Gradient Descent (HSGD) to produce high-quality light fields from sparse view images in real time. Technically, the coarse MPI of a scene is first generated using a 3D CNN, and it is further sparsely optimized by focusing only on important MPI gradients in a few iterations. Nevertheless, relying solely on optimization can lead to artifacts at occlusion boundaries. Therefore, we propose an occlusion-aware iterative refinement module that removes visual artifacts in occluded regions by iteratively filtering the input. Extensive experiments demonstrate that our method achieves comparable visual quality while being 100x faster on average than state-of-the-art offline methods and delivering better performance (about 2 dB higher in PSNR) compared to other online approaches.
2406.16300
Sidak Pal Singh
Sidak Pal Singh, Linara Adilova, Michael Kamp, Asja Fischer, Bernhard Sch\"olkopf, Thomas Hofmann
Landscaping Linear Mode Connectivity
ICML 2024 HiLD workshop paper
null
null
null
cs.LG
http://creativecommons.org/licenses/by/4.0/
The presence of linear paths in parameter space between two different network solutions in certain cases, i.e., linear mode connectivity (LMC), has garnered interest from both theoretical and practical fronts. There has been significant research that either practically designs algorithms catered for connecting networks by adjusting for the permutation symmetries as well as some others that more theoretically construct paths through which networks can be connected. Yet, the core reasons for the occurrence of LMC, when in fact it does occur, in the highly non-convex loss landscapes of neural networks are far from clear. In this work, we take a step towards understanding it by providing a model of how the loss landscape needs to behave topographically for LMC (or the lack thereof) to manifest. Concretely, we present a `mountainside and ridge' perspective that helps to neatly tie together different geometric features that can be spotted in the loss landscape along the training runs. We also complement this perspective by providing a theoretical analysis of the barrier height, for which we provide empirical support, and which additionally extends as a faithful predictor of layer-wise LMC. We close with a toy example that provides further intuition on how barriers arise in the first place, all in all, showcasing the larger aim of the work -- to provide a working model of the landscape and its topography for the occurrence of LMC.
[ { "created": "Mon, 24 Jun 2024 03:53:30 GMT", "version": "v1" } ]
2024-06-25
[ [ "Singh", "Sidak Pal", "" ], [ "Adilova", "Linara", "" ], [ "Kamp", "Michael", "" ], [ "Fischer", "Asja", "" ], [ "Schölkopf", "Bernhard", "" ], [ "Hofmann", "Thomas", "" ] ]
The presence of linear paths in parameter space between two different network solutions in certain cases, i.e., linear mode connectivity (LMC), has garnered interest from both theoretical and practical fronts. There has been significant research that either practically designs algorithms catered for connecting networks by adjusting for the permutation symmetries as well as some others that more theoretically construct paths through which networks can be connected. Yet, the core reasons for the occurrence of LMC, when in fact it does occur, in the highly non-convex loss landscapes of neural networks are far from clear. In this work, we take a step towards understanding it by providing a model of how the loss landscape needs to behave topographically for LMC (or the lack thereof) to manifest. Concretely, we present a `mountainside and ridge' perspective that helps to neatly tie together different geometric features that can be spotted in the loss landscape along the training runs. We also complement this perspective by providing a theoretical analysis of the barrier height, for which we provide empirical support, and which additionally extends as a faithful predictor of layer-wise LMC. We close with a toy example that provides further intuition on how barriers arise in the first place, all in all, showcasing the larger aim of the work -- to provide a working model of the landscape and its topography for the occurrence of LMC.
2305.17400
Xiao Hu
Xiao Hu, Jianxiong Li, Xianyuan Zhan, Qing-Shan Jia, Ya-Qin Zhang
Query-Policy Misalignment in Preference-Based Reinforcement Learning
Accepted by ICLR 2024
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Preference-based reinforcement learning (PbRL) provides a natural way to align RL agents' behavior with human desired outcomes, but is often restrained by costly human feedback. To improve feedback efficiency, most existing PbRL methods focus on selecting queries to maximally improve the overall quality of the reward model, but counter-intuitively, we find that this may not necessarily lead to improved performance. To unravel this mystery, we identify a long-neglected issue in the query selection schemes of existing PbRL studies: Query-Policy Misalignment. We show that the seemingly informative queries selected to improve the overall quality of reward model actually may not align with RL agents' interests, thus offering little help on policy learning and eventually resulting in poor feedback efficiency. We show that this issue can be effectively addressed via near on-policy query and a specially designed hybrid experience replay, which together enforce the bidirectional query-policy alignment. Simple yet elegant, our method can be easily incorporated into existing approaches by changing only a few lines of code. We showcase in comprehensive experiments that our method achieves substantial gains in both human feedback and RL sample efficiency, demonstrating the importance of addressing query-policy misalignment in PbRL tasks.
[ { "created": "Sat, 27 May 2023 07:55:17 GMT", "version": "v1" }, { "created": "Thu, 23 Nov 2023 16:27:42 GMT", "version": "v2" }, { "created": "Fri, 5 Jul 2024 14:26:21 GMT", "version": "v3" } ]
2024-07-08
[ [ "Hu", "Xiao", "" ], [ "Li", "Jianxiong", "" ], [ "Zhan", "Xianyuan", "" ], [ "Jia", "Qing-Shan", "" ], [ "Zhang", "Ya-Qin", "" ] ]
Preference-based reinforcement learning (PbRL) provides a natural way to align RL agents' behavior with human desired outcomes, but is often restrained by costly human feedback. To improve feedback efficiency, most existing PbRL methods focus on selecting queries to maximally improve the overall quality of the reward model, but counter-intuitively, we find that this may not necessarily lead to improved performance. To unravel this mystery, we identify a long-neglected issue in the query selection schemes of existing PbRL studies: Query-Policy Misalignment. We show that the seemingly informative queries selected to improve the overall quality of reward model actually may not align with RL agents' interests, thus offering little help on policy learning and eventually resulting in poor feedback efficiency. We show that this issue can be effectively addressed via near on-policy query and a specially designed hybrid experience replay, which together enforce the bidirectional query-policy alignment. Simple yet elegant, our method can be easily incorporated into existing approaches by changing only a few lines of code. We showcase in comprehensive experiments that our method achieves substantial gains in both human feedback and RL sample efficiency, demonstrating the importance of addressing query-policy misalignment in PbRL tasks.
1707.06391
William Moses Jr.
Ankush Agarwalla, John Augustine, William K. Moses Jr., Madhav Sankar K., Arvind Krishna Sridhar
Deterministic Dispersion of Mobile Robots in Dynamic Rings
21 pages, 10 figures, concise version of paper to appear in ICDCN 2018
null
null
null
cs.DC cs.DS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we study the problem of dispersion of mobile robots on dynamic rings. The problem of dispersion of $n$ robots on an $n$ node graph, introduced by Augustine and Moses Jr. [1], requires robots to coordinate with each other and reach a configuration where exactly one robot is present on each node. This problem has real world applications and applies whenever we want to minimize the total cost of $n$ agents sharing $n$ resources, located at various places, subject to the constraint that the cost of an agent moving to a different resource is comparatively much smaller than the cost of multiple agents sharing a resource (e.g. smart electric cars sharing recharge stations). The study of this problem also provides indirect benefits to the study of scattering on graphs, the study of exploration by mobile robots, and the study of load balancing on graphs. We solve the problem of dispersion in the presence of two types of dynamism in the underlying graph: (i) vertex permutation and (ii) 1-interval connectivity. We introduce the notion of vertex permutation dynamism and have it mean that for a given set of nodes, in every round, the adversary ensures a ring structure is maintained, but the connections between the nodes may change. We use the idea of 1-interval connectivity from Di Luna et al. [10], where for a given ring, in each round, the adversary chooses at most one edge to remove. We assume robots have full visibility and present asymptotically time optimal algorithms to achieve dispersion in the presence of both types of dynamism when robots have chirality. When robots do not have chirality, we present asymptotically time optimal algorithms to achieve dispersion subject to certain constraints. Finally, we provide impossibility results for dispersion when robots have no visibility.
[ { "created": "Thu, 20 Jul 2017 06:46:15 GMT", "version": "v1" }, { "created": "Wed, 4 Oct 2017 03:29:44 GMT", "version": "v2" }, { "created": "Mon, 16 Oct 2017 13:50:46 GMT", "version": "v3" } ]
2017-10-17
[ [ "Agarwalla", "Ankush", "" ], [ "Augustine", "John", "" ], [ "Moses", "William K.", "Jr." ], [ "K.", "Madhav Sankar", "" ], [ "Sridhar", "Arvind Krishna", "" ] ]
In this work, we study the problem of dispersion of mobile robots on dynamic rings. The problem of dispersion of $n$ robots on an $n$ node graph, introduced by Augustine and Moses Jr. [1], requires robots to coordinate with each other and reach a configuration where exactly one robot is present on each node. This problem has real world applications and applies whenever we want to minimize the total cost of $n$ agents sharing $n$ resources, located at various places, subject to the constraint that the cost of an agent moving to a different resource is comparatively much smaller than the cost of multiple agents sharing a resource (e.g. smart electric cars sharing recharge stations). The study of this problem also provides indirect benefits to the study of scattering on graphs, the study of exploration by mobile robots, and the study of load balancing on graphs. We solve the problem of dispersion in the presence of two types of dynamism in the underlying graph: (i) vertex permutation and (ii) 1-interval connectivity. We introduce the notion of vertex permutation dynamism and have it mean that for a given set of nodes, in every round, the adversary ensures a ring structure is maintained, but the connections between the nodes may change. We use the idea of 1-interval connectivity from Di Luna et al. [10], where for a given ring, in each round, the adversary chooses at most one edge to remove. We assume robots have full visibility and present asymptotically time optimal algorithms to achieve dispersion in the presence of both types of dynamism when robots have chirality. When robots do not have chirality, we present asymptotically time optimal algorithms to achieve dispersion subject to certain constraints. Finally, we provide impossibility results for dispersion when robots have no visibility.
2208.12184
Mahdi Hejrati
Mahdi Hejrati, Jouni Mattila
Decentralized Nonlinear Control of Redundant Upper Limb Exoskeleton with Natural Adaptation Law
Manuscript is published in 2022 IEEE-RAS 21st International Conference on Humanoid Robots (Humanoids)
null
10.1109/Humanoids53995.2022.10000105
null
cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The aim of this work is to utilize an adaptive decentralized control method called virtual decomposition control (VDC) to control the orientation and position of the end-effector of a 7 degrees of freedom (DoF) right-hand upper-limb exoskeleton. The prevailing adaptive VDC approach requires tuning of 13n adaptation gains along with 26n upper and lower parameter bounds, where n is the number of rigid bodies. Therefore, utilizing the VDC scheme to control high DoF robots like the 7-DoF upper-limb exoskeleton can be an arduous task. In this paper, a new adaptation function, so-called natural adaptation law (NAL), is employed to eliminate these burdens from VDC, which results in reducing all 13n gains to one and removing dependency on upper and lower bounds. In doing so, VDC-based dynamic equations are restructured, and inertial parameter vectors are made compatible with NAL. Then, the NAL adaptation function is exploited to design a new adaptive VDC scheme. This novel adaptive VDC approach ensures physical consistency conditions for estimated parameters with no need for upper and lower bounds. Finally, the asymptotic stability of the algorithm is proved with the virtual stability concept and the accompanying function. The experimental results are utilized to demonstrate the excellent performance of the proposed new adaptive VDC scheme.
[ { "created": "Thu, 25 Aug 2022 16:10:49 GMT", "version": "v1" }, { "created": "Thu, 29 Sep 2022 15:00:41 GMT", "version": "v2" }, { "created": "Fri, 20 Jan 2023 15:50:32 GMT", "version": "v3" } ]
2023-01-23
[ [ "Hejrati", "Mahdi", "" ], [ "Mattila", "Jouni", "" ] ]
The aim of this work is to utilize an adaptive decentralized control method called virtual decomposition control (VDC) to control the orientation and position of the end-effector of a 7 degrees of freedom (DoF) right-hand upper-limb exoskeleton. The prevailing adaptive VDC approach requires tuning of 13n adaptation gains along with 26n upper and lower parameter bounds, where n is the number of rigid bodies. Therefore, utilizing the VDC scheme to control high DoF robots like the 7-DoF upper-limb exoskeleton can be an arduous task. In this paper, a new adaptation function, so-called natural adaptation law (NAL), is employed to eliminate these burdens from VDC, which results in reducing all 13n gains to one and removing dependency on upper and lower bounds. In doing so, VDC-based dynamic equations are restructured, and inertial parameter vectors are made compatible with NAL. Then, the NAL adaptation function is exploited to design a new adaptive VDC scheme. This novel adaptive VDC approach ensures physical consistency conditions for estimated parameters with no need for upper and lower bounds. Finally, the asymptotic stability of the algorithm is proved with the virtual stability concept and the accompanying function. The experimental results are utilized to demonstrate the excellent performance of the proposed new adaptive VDC scheme.
1908.07195
Pei Ke
Pei Ke, Fei Huang, Minlie Huang, Xiaoyan Zhu
ARAML: A Stable Adversarial Training Framework for Text Generation
Accepted by EMNLP 2019
null
null
null
cs.CL cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most of the existing generative adversarial networks (GAN) for text generation suffer from the instability of reinforcement learning training algorithms such as policy gradient, leading to unstable performance. To tackle this problem, we propose a novel framework called Adversarial Reward Augmented Maximum Likelihood (ARAML). During adversarial training, the discriminator assigns rewards to samples which are acquired from a stationary distribution near the data rather than the generator's distribution. The generator is optimized with maximum likelihood estimation augmented by the discriminator's rewards instead of policy gradient. Experiments show that our model can outperform state-of-the-art text GANs with a more stable training process.
[ { "created": "Tue, 20 Aug 2019 07:25:14 GMT", "version": "v1" } ]
2019-08-21
[ [ "Ke", "Pei", "" ], [ "Huang", "Fei", "" ], [ "Huang", "Minlie", "" ], [ "Zhu", "Xiaoyan", "" ] ]
Most of the existing generative adversarial networks (GAN) for text generation suffer from the instability of reinforcement learning training algorithms such as policy gradient, leading to unstable performance. To tackle this problem, we propose a novel framework called Adversarial Reward Augmented Maximum Likelihood (ARAML). During adversarial training, the discriminator assigns rewards to samples which are acquired from a stationary distribution near the data rather than the generator's distribution. The generator is optimized with maximum likelihood estimation augmented by the discriminator's rewards instead of policy gradient. Experiments show that our model can outperform state-of-the-art text GANs with a more stable training process.
2105.10332
Kyle Niemeyer
Anthony S. Walker and Kyle E. Niemeyer
The Two-Dimensional Swept Rule Applied on Heterogeneous Architectures
18 pages, 11 figures
null
null
null
cs.DC cs.MS physics.comp-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The partial differential equations describing compressible fluid flows can be notoriously difficult to resolve on a pragmatic scale and often require the use of high performance computing systems and/or accelerators. However, these systems face scaling issues such as latency, the fixed cost of communicating information between devices in the system. The swept rule is a technique designed to minimize these costs by obtaining a solution to unsteady equations at as many possible spatial locations and times prior to communicating. In this study, we implemented and tested the swept rule for solving two-dimensional problems on heterogeneous computing systems across two distinct systems. Our solver showed a speedup range of 0.22-2.71 for the heat diffusion equation and 0.52-1.46 for the compressible Euler equations. We can conclude from this study that the swept rule offers both potential for speedups and slowdowns and that care should be taken when designing such a solver to maximize benefits. These results can help make decisions to maximize these benefits and inform designs.
[ { "created": "Thu, 1 Apr 2021 20:06:09 GMT", "version": "v1" } ]
2021-05-24
[ [ "Walker", "Anthony S.", "" ], [ "Niemeyer", "Kyle E.", "" ] ]
The partial differential equations describing compressible fluid flows can be notoriously difficult to resolve on a pragmatic scale and often require the use of high performance computing systems and/or accelerators. However, these systems face scaling issues such as latency, the fixed cost of communicating information between devices in the system. The swept rule is a technique designed to minimize these costs by obtaining a solution to unsteady equations at as many possible spatial locations and times prior to communicating. In this study, we implemented and tested the swept rule for solving two-dimensional problems on heterogeneous computing systems across two distinct systems. Our solver showed a speedup range of 0.22-2.71 for the heat diffusion equation and 0.52-1.46 for the compressible Euler equations. We can conclude from this study that the swept rule offers both potential for speedups and slowdowns and that care should be taken when designing such a solver to maximize benefits. These results can help make decisions to maximize these benefits and inform designs.
1512.05403
Jose Morales Escalante
Jose Morales-Escalante, Irene M. Gamba, Yingda Cheng, Armando Majorana, Chi-Wang Shu, and James Chelikowsky
Discontinuous Galerkin Deterministic Solvers for a Boltzmann-Poisson Model of Hot Electron Transport by Averaged Empirical Pseudopotential Band Structures
submission to CMAME (Computer Methods in Applied Mechanics and Engineering) Journal as a reply to the reviewers on February 2017
Computer Methods in Applied Mechanics and Engineering, Volume 321, 2017, Pages 209-234
10.1016/j.cma.2017.03.003
null
cs.CE cond-mat.mes-hall math.NA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The purpose of this work is to incorporate numerically, in a discontinuous Galerkin (DG) solver of a Boltzmann-Poisson model for hot electron transport, an electronic conduction band whose values are obtained by the spherical averaging of the full band structure given by a local empirical pseudopotential method (EPM) around a local minimum of the conduction band for silicon, as a midpoint between a radial band model and an anisotropic full band, in order to provide a more accurate physical description of the electron group velocity and conduction energy band structure in a semiconductor. This gives a better quantitative description of the transport and collision phenomena that fundamentally define the behaviour of the Boltzmann - Poisson model for electron transport used in this work. The numerical values of the derivatives of this conduction energy band, needed for the description of the electron group velocity, are obtained by means of a cubic spline interpolation. The EPM-Boltzmann-Poisson transport with this spherically averaged EPM calculated energy surface is numerically simulated and compared to the output of traditional analytic band models such as the parabolic and Kane bands, numerically implemented too, for the case of 1D $n^+-n-n^+$ silicon diodes with 400nm and 50nm channels. Quantitative differences are observed in the kinetic moments related to the conduction energy band used, such as mean velocity, average energy, and electric current (momentum).
[ { "created": "Wed, 16 Dec 2015 22:51:53 GMT", "version": "v1" }, { "created": "Wed, 17 Jan 2018 20:46:27 GMT", "version": "v2" } ]
2018-01-19
[ [ "Morales-Escalante", "Jose", "" ], [ "Gamba", "Irene M.", "" ], [ "Cheng", "Yingda", "" ], [ "Majorana", "Armando", "" ], [ "Shu", "Chi-Wang", "" ], [ "Chelikowsky", "James", "" ] ]
The purpose of this work is to incorporate numerically, in a discontinuous Galerkin (DG) solver of a Boltzmann-Poisson model for hot electron transport, an electronic conduction band whose values are obtained by the spherical averaging of the full band structure given by a local empirical pseudopotential method (EPM) around a local minimum of the conduction band for silicon, as a midpoint between a radial band model and an anisotropic full band, in order to provide a more accurate physical description of the electron group velocity and conduction energy band structure in a semiconductor. This gives a better quantitative description of the transport and collision phenomena that fundamentally define the behaviour of the Boltzmann - Poisson model for electron transport used in this work. The numerical values of the derivatives of this conduction energy band, needed for the description of the electron group velocity, are obtained by means of a cubic spline interpolation. The EPM-Boltzmann-Poisson transport with this spherically averaged EPM calculated energy surface is numerically simulated and compared to the output of traditional analytic band models such as the parabolic and Kane bands, numerically implemented too, for the case of 1D $n^+-n-n^+$ silicon diodes with 400nm and 50nm channels. Quantitative differences are observed in the kinetic moments related to the conduction energy band used, such as mean velocity, average energy, and electric current (momentum).
1904.07429
Mingxin Jin
Mingxin Jin, Yongsheng Dong, Lintao Zheng, Lingfei Liang, Tianyu Wang, Hongyan zhang
Shortest Paths in HSI Space for Color Texture Classification
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Color texture representation is an important step in the task of texture classification. Shortest paths was used to extract color texture features from RGB and HSV color spaces. In this paper, we propose to use shortest paths in the HSI space to build a texture representation for classification. In particular, two undirected graphs are used to model the H channel and the S and I channels respectively in order to represent a color texture image. Moreover, the shortest paths is constructed by using four pairs of pixels according to different scales and directions of the texture image. Experimental results on colored Brodatz and USPTex databases reveal that our proposed method is effective, and the highest classification accuracy rate is 96.93% in the Brodatz database.
[ { "created": "Tue, 16 Apr 2019 03:24:35 GMT", "version": "v1" } ]
2019-04-17
[ [ "Jin", "Mingxin", "" ], [ "Dong", "Yongsheng", "" ], [ "Zheng", "Lintao", "" ], [ "Liang", "Lingfei", "" ], [ "Wang", "Tianyu", "" ], [ "zhang", "Hongyan", "" ] ]
Color texture representation is an important step in the task of texture classification. Shortest paths was used to extract color texture features from RGB and HSV color spaces. In this paper, we propose to use shortest paths in the HSI space to build a texture representation for classification. In particular, two undirected graphs are used to model the H channel and the S and I channels respectively in order to represent a color texture image. Moreover, the shortest paths is constructed by using four pairs of pixels according to different scales and directions of the texture image. Experimental results on colored Brodatz and USPTex databases reveal that our proposed method is effective, and the highest classification accuracy rate is 96.93% in the Brodatz database.
1804.00344
Marcin Junczys-Dowmunt
Marcin Junczys-Dowmunt, Roman Grundkiewicz, Tomasz Dwojak, Hieu Hoang, Kenneth Heafield, Tom Neckermann, Frank Seide, Ulrich Germann, Alham Fikri Aji, Nikolay Bogoychev, Andr\'e F. T. Martins, Alexandra Birch
Marian: Fast Neural Machine Translation in C++
Demonstration paper
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present Marian, an efficient and self-contained Neural Machine Translation framework with an integrated automatic differentiation engine based on dynamic computation graphs. Marian is written entirely in C++. We describe the design of the encoder-decoder framework and demonstrate that a research-friendly toolkit can achieve high training and translation speed.
[ { "created": "Sun, 1 Apr 2018 20:50:57 GMT", "version": "v1" }, { "created": "Tue, 3 Apr 2018 04:11:44 GMT", "version": "v2" }, { "created": "Wed, 4 Apr 2018 15:34:17 GMT", "version": "v3" } ]
2018-04-05
[ [ "Junczys-Dowmunt", "Marcin", "" ], [ "Grundkiewicz", "Roman", "" ], [ "Dwojak", "Tomasz", "" ], [ "Hoang", "Hieu", "" ], [ "Heafield", "Kenneth", "" ], [ "Neckermann", "Tom", "" ], [ "Seide", "Frank", "" ], [ "Germann", "Ulrich", "" ], [ "Aji", "Alham Fikri", "" ], [ "Bogoychev", "Nikolay", "" ], [ "Martins", "André F. T.", "" ], [ "Birch", "Alexandra", "" ] ]
We present Marian, an efficient and self-contained Neural Machine Translation framework with an integrated automatic differentiation engine based on dynamic computation graphs. Marian is written entirely in C++. We describe the design of the encoder-decoder framework and demonstrate that a research-friendly toolkit can achieve high training and translation speed.
1902.10645
Kurniawan Irianto
Kurniawan D. Irianto, Juan A. Cabrera, Giang T. Nguyen, Hani Salah, and Frank H.P. Fitzek
S-PRAC: Fast Partial Packet Recovery with Network Coding in Very Noisy Wireless Channels
null
null
10.1109/WD.2019.8734223
null
cs.NI
http://creativecommons.org/licenses/by/4.0/
Well-known error detection and correction solutions in wireless communications are slow or incur high transmission overhead. Recently, notable solutions like PRAC and DAPRAC, implementing partial packet recovery with network coding, could address these problems. However, they perform slowly when there are many errors. We propose S-PRAC, a fast scheme for partial packet recovery, particularly designed for very noisy wireless channels. S-PRAC improves on DAPRAC. It divides each packet into segments consisting of a fixed number of small RLNC encoded symbols and then attaches a CRC code to each segment and one to each coded packet. Extensive simulations show that S-PRAC can detect and correct errors quickly. It also outperforms DAPRAC significantly when the number of errors is high.
[ { "created": "Wed, 27 Feb 2019 17:25:56 GMT", "version": "v1" } ]
2019-10-07
[ [ "Irianto", "Kurniawan D.", "" ], [ "Cabrera", "Juan A.", "" ], [ "Nguyen", "Giang T.", "" ], [ "Salah", "Hani", "" ], [ "Fitzek", "Frank H. P.", "" ] ]
Well-known error detection and correction solutions in wireless communications are slow or incur high transmission overhead. Recently, notable solutions like PRAC and DAPRAC, implementing partial packet recovery with network coding, could address these problems. However, they perform slowly when there are many errors. We propose S-PRAC, a fast scheme for partial packet recovery, particularly designed for very noisy wireless channels. S-PRAC improves on DAPRAC. It divides each packet into segments consisting of a fixed number of small RLNC encoded symbols and then attaches a CRC code to each segment and one to each coded packet. Extensive simulations show that S-PRAC can detect and correct errors quickly. It also outperforms DAPRAC significantly when the number of errors is high.
1701.08554
Maxime Ferreira Da Costa
Maxime Ferreira Da Costa and Wei Dai
Low Dimensional Atomic Norm Representations in Line Spectral Estimation
null
null
10.1109/ISIT.2017.8006523
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The line spectral estimation problem consists in recovering the frequencies of a complex valued time signal that is assumed to be sparse in the spectral domain from its discrete observations. Unlike the gridding required by the classical compressed sensing framework, line spectral estimation reconstructs signals whose spectral supports lie continuously in the Fourier domain. If recent advances have shown that atomic norm relaxation produces highly robust estimates in this context, the computational cost of this approach remains, however, the major flaw for its application to practical systems. In this work, we aim to bridge the complexity issue by studying the atomic norm minimization problem from low dimensional projection of the signal samples. We derive conditions on the sub-sampling matrix under which the partial atomic norm can be expressed by a low-dimensional semidefinite program. Moreover, we illustrate the tightness of this relaxation by showing that it is possible to recover the original signal in poly-logarithmic time for two specific sub-sampling patterns.
[ { "created": "Mon, 30 Jan 2017 11:35:04 GMT", "version": "v1" } ]
2021-10-18
[ [ "Da Costa", "Maxime Ferreira", "" ], [ "Dai", "Wei", "" ] ]
The line spectral estimation problem consists in recovering the frequencies of a complex valued time signal that is assumed to be sparse in the spectral domain from its discrete observations. Unlike the gridding required by the classical compressed sensing framework, line spectral estimation reconstructs signals whose spectral supports lie continuously in the Fourier domain. If recent advances have shown that atomic norm relaxation produces highly robust estimates in this context, the computational cost of this approach remains, however, the major flaw for its application to practical systems. In this work, we aim to bridge the complexity issue by studying the atomic norm minimization problem from low dimensional projection of the signal samples. We derive conditions on the sub-sampling matrix under which the partial atomic norm can be expressed by a low-dimensional semidefinite program. Moreover, we illustrate the tightness of this relaxation by showing that it is possible to recover the original signal in poly-logarithmic time for two specific sub-sampling patterns.
cs/0003005
Prasan Roy
Prasan Roy, Krithi Ramamritham, S. Seshadri, Pradeep Shenoy, S. Sudarshan
Don't Trash your Intermediate Results, Cache 'em
22 pages, 4 figures
null
null
null
cs.DB
null
In data warehouse and data mart systems, queries often take a long time to execute due to their complex nature. Query response times can be greatly improved by caching final/intermediate results of previous queries, and using them to answer later queries. In this paper we describe a caching system called Exchequer which incorporates several novel features including optimization aware cache maintenance and the use of a cache aware optimizer. In contrast, in existing work, the module that makes cost-benefit decisions is part of the cache manager and works independent of the optimizer which essentially reconsiders these decisions while finding the best plan for a query. In our work, the optimizer takes the decisions for the cache manager. Furthermore, existing approaches are either restricted to cube (slice/point) queries, or cache just the query results. On the other hand, our work is extens ible and in fact presents a data-model independent framework and algorithm. Our experimental results attest to the efficacy of our cache management techniques and show that over a wide range of parameters (a) Exchequer's query response times are lower by more than 30% compared to the best performing competitor, and (b) Exchequer can deliver the same response time as its competitor with just one tenth of the cache size.
[ { "created": "Thu, 2 Mar 2000 08:15:21 GMT", "version": "v1" } ]
2007-05-23
[ [ "Roy", "Prasan", "" ], [ "Ramamritham", "Krithi", "" ], [ "Seshadri", "S.", "" ], [ "Shenoy", "Pradeep", "" ], [ "Sudarshan", "S.", "" ] ]
In data warehouse and data mart systems, queries often take a long time to execute due to their complex nature. Query response times can be greatly improved by caching final/intermediate results of previous queries, and using them to answer later queries. In this paper we describe a caching system called Exchequer which incorporates several novel features including optimization aware cache maintenance and the use of a cache aware optimizer. In contrast, in existing work, the module that makes cost-benefit decisions is part of the cache manager and works independent of the optimizer which essentially reconsiders these decisions while finding the best plan for a query. In our work, the optimizer takes the decisions for the cache manager. Furthermore, existing approaches are either restricted to cube (slice/point) queries, or cache just the query results. On the other hand, our work is extens ible and in fact presents a data-model independent framework and algorithm. Our experimental results attest to the efficacy of our cache management techniques and show that over a wide range of parameters (a) Exchequer's query response times are lower by more than 30% compared to the best performing competitor, and (b) Exchequer can deliver the same response time as its competitor with just one tenth of the cache size.
2302.09420
Marwan Omar Dr
Marwan Omar
RobustNLP: A Technique to Defend NLP Models Against Backdoor Attacks
null
null
null
null
cs.CR
http://creativecommons.org/licenses/by/4.0/
As machine learning (ML) systems are being increasingly employed in the real world to handle sensitive tasks and make decisions in various fields, the security and privacy of those models have also become increasingly critical. In particular, Deep Neural Networks (DNN) have been shown to be vulnerable to backdoor attacks whereby adversaries have access to the training data and the opportunity to manipulate such data by inserting carefully developed samples into the training dataset. Although the NLP community has produced several studies on generating backdoor attacks proving the vulnerable state of language modes, to the best of our knowledge, there does not exist any work to combat such attacks. To bridge this gap, we present RobustEncoder: a novel clustering-based technique for detecting and removing backdoor attacks in the text domain. Extensive empirical results demonstrate the effectiveness of our technique in detecting and removing backdoor triggers. Our code is available at https://github.com/marwanomar1/Backdoor-Learning-for-NLP
[ { "created": "Sat, 18 Feb 2023 20:52:08 GMT", "version": "v1" } ]
2023-02-21
[ [ "Omar", "Marwan", "" ] ]
As machine learning (ML) systems are being increasingly employed in the real world to handle sensitive tasks and make decisions in various fields, the security and privacy of those models have also become increasingly critical. In particular, Deep Neural Networks (DNN) have been shown to be vulnerable to backdoor attacks whereby adversaries have access to the training data and the opportunity to manipulate such data by inserting carefully developed samples into the training dataset. Although the NLP community has produced several studies on generating backdoor attacks proving the vulnerable state of language modes, to the best of our knowledge, there does not exist any work to combat such attacks. To bridge this gap, we present RobustEncoder: a novel clustering-based technique for detecting and removing backdoor attacks in the text domain. Extensive empirical results demonstrate the effectiveness of our technique in detecting and removing backdoor triggers. Our code is available at https://github.com/marwanomar1/Backdoor-Learning-for-NLP
2006.16533
Shusen Liu
Shusen Liu, Bhavya Kailkhura, Jize Zhang, Anna M. Hiszpanski, Emily Robertson, Donald Loveland, T. Yong-Jin Han
Actionable Attribution Maps for Scientific Machine Learning
null
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The scientific community has been increasingly interested in harnessing the power of deep learning to solve various domain challenges. However, despite the effectiveness in building predictive models, fundamental challenges exist in extracting actionable knowledge from the deep neural network due to their opaque nature. In this work, we propose techniques for exploring the behavior of deep learning models by injecting domain-specific actionable concepts as tunable ``knobs'' in the analysis pipeline. By incorporating the domain knowledge with generative modeling, we are not only able to better understand the behavior of these black-box models, but also provide scientists with actionable insights that can potentially lead to fundamental discoveries.
[ { "created": "Tue, 30 Jun 2020 05:12:29 GMT", "version": "v1" } ]
2020-07-01
[ [ "Liu", "Shusen", "" ], [ "Kailkhura", "Bhavya", "" ], [ "Zhang", "Jize", "" ], [ "Hiszpanski", "Anna M.", "" ], [ "Robertson", "Emily", "" ], [ "Loveland", "Donald", "" ], [ "Han", "T. Yong-Jin", "" ] ]
The scientific community has been increasingly interested in harnessing the power of deep learning to solve various domain challenges. However, despite the effectiveness in building predictive models, fundamental challenges exist in extracting actionable knowledge from the deep neural network due to their opaque nature. In this work, we propose techniques for exploring the behavior of deep learning models by injecting domain-specific actionable concepts as tunable ``knobs'' in the analysis pipeline. By incorporating the domain knowledge with generative modeling, we are not only able to better understand the behavior of these black-box models, but also provide scientists with actionable insights that can potentially lead to fundamental discoveries.
1608.08142
Reza Rafie Borujeny
Reza Rafie Borujeny, Moslem Noori, Masoud Ardakani
Maximizing Data Rate for Multiway Relay Channels with Pairwise Transmission Strategy
Submitted to IEEE Transactions on Wireless Communications, under second round of revisions. 10 pages, 8 figures. arXiv admin note: text overlap with arXiv:1406.4610
null
null
null
cs.IT math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a multiway relay channel (MWRC), pairwise transmission strategy can be used to reduce the computational complexity at the relay and the users without sacrificing the data rate, significantly. The performance of such pairwise strategies, however, is affected by the way that the users are paired to transmit. In this paper, we study the effect of pairing on the common rate and sum rate of an MWRC with functional-decode-forward (FDF) relaying strategy where users experience asymmetric channel conditions. To this end, we first develop a graphical model for an MWRC with pairwise transmission strategy. Using this model, we then find the maximum achievable common rate and sum rate as well as the user pairings that achieve these rates. This marks the ultimate performance of FDF relaying in an MWRC setup. Further, we show that the rate enhancement achieved through the optimal user pairing becomes less pronounced at higher SNRs. Using computer simulations, the performance of the optimal pairing is compared with those of other proposed pairings in the literature.
[ { "created": "Mon, 29 Aug 2016 16:47:09 GMT", "version": "v1" } ]
2016-08-30
[ [ "Borujeny", "Reza Rafie", "" ], [ "Noori", "Moslem", "" ], [ "Ardakani", "Masoud", "" ] ]
In a multiway relay channel (MWRC), pairwise transmission strategy can be used to reduce the computational complexity at the relay and the users without sacrificing the data rate, significantly. The performance of such pairwise strategies, however, is affected by the way that the users are paired to transmit. In this paper, we study the effect of pairing on the common rate and sum rate of an MWRC with functional-decode-forward (FDF) relaying strategy where users experience asymmetric channel conditions. To this end, we first develop a graphical model for an MWRC with pairwise transmission strategy. Using this model, we then find the maximum achievable common rate and sum rate as well as the user pairings that achieve these rates. This marks the ultimate performance of FDF relaying in an MWRC setup. Further, we show that the rate enhancement achieved through the optimal user pairing becomes less pronounced at higher SNRs. Using computer simulations, the performance of the optimal pairing is compared with those of other proposed pairings in the literature.
2307.02443
Leon Moonen
Max Hort and Anastasiia Grishina and Leon Moonen
An Exploratory Literature Study on Sharing and Energy Use of Language Models for Source Code
Accepted for publication in the 17th ACM/IEEE International Symposium on Empirical Software Engineering and Measurement (ESEM 2023)
null
null
null
cs.SE cs.AI cs.CL cs.LG cs.NE
http://creativecommons.org/licenses/by/4.0/
Large language models trained on source code can support a variety of software development tasks, such as code recommendation and program repair. Large amounts of data for training such models benefit the models' performance. However, the size of the data and models results in long training times and high energy consumption. While publishing source code allows for replicability, users need to repeat the expensive training process if models are not shared. The main goal of the study is to investigate if publications that trained language models for software engineering (SE) tasks share source code and trained artifacts. The second goal is to analyze the transparency on training energy usage. We perform a snowballing-based literature search to find publications on language models for source code, and analyze their reusability from a sustainability standpoint. From 494 unique publications, we identified 293 relevant publications that use language models to address code-related tasks. Among them, 27% (79 out of 293) make artifacts available for reuse. This can be in the form of tools or IDE plugins designed for specific tasks or task-agnostic models that can be fine-tuned for a variety of downstream tasks. Moreover, we collect insights on the hardware used for model training, as well as training time, which together determine the energy consumption of the development process. We find that there are deficiencies in the sharing of information and artifacts for current studies on source code models for software engineering tasks, with 40% of the surveyed papers not sharing source code or trained artifacts. We recommend the sharing of source code as well as trained artifacts, to enable sustainable reproducibility. Moreover, comprehensive information on training times and hardware configurations should be shared for transparency on a model's carbon footprint.
[ { "created": "Wed, 5 Jul 2023 17:13:00 GMT", "version": "v1" } ]
2023-07-06
[ [ "Hort", "Max", "" ], [ "Grishina", "Anastasiia", "" ], [ "Moonen", "Leon", "" ] ]
Large language models trained on source code can support a variety of software development tasks, such as code recommendation and program repair. Large amounts of data for training such models benefit the models' performance. However, the size of the data and models results in long training times and high energy consumption. While publishing source code allows for replicability, users need to repeat the expensive training process if models are not shared. The main goal of the study is to investigate if publications that trained language models for software engineering (SE) tasks share source code and trained artifacts. The second goal is to analyze the transparency on training energy usage. We perform a snowballing-based literature search to find publications on language models for source code, and analyze their reusability from a sustainability standpoint. From 494 unique publications, we identified 293 relevant publications that use language models to address code-related tasks. Among them, 27% (79 out of 293) make artifacts available for reuse. This can be in the form of tools or IDE plugins designed for specific tasks or task-agnostic models that can be fine-tuned for a variety of downstream tasks. Moreover, we collect insights on the hardware used for model training, as well as training time, which together determine the energy consumption of the development process. We find that there are deficiencies in the sharing of information and artifacts for current studies on source code models for software engineering tasks, with 40% of the surveyed papers not sharing source code or trained artifacts. We recommend the sharing of source code as well as trained artifacts, to enable sustainable reproducibility. Moreover, comprehensive information on training times and hardware configurations should be shared for transparency on a model's carbon footprint.
2308.07789
Matteo Acclavio
Matteo Acclavio, Gianluca Curzi, Giulio Guerrieri
Infinitary cut-elimination via finite approximations (extended version)
Extended version of the paper "Infinitary cut-elimination via finite approximations" accepted at CSL2024
null
null
null
cs.LO
http://creativecommons.org/licenses/by/4.0/
We investigate non-wellfounded proof systems based on parsimonious logic, a weaker variant of linear logic where the exponential modality ! is interpreted as a constructor for streams over finite data. Logical consistency is maintained at a global level by adapting a standard progressing criterion. We present an infinitary version of cut-elimination based on finite approximations, and we prove that, in presence of the progressing criterion, it returns well-defined non-wellfounded proofs at its limit. Furthermore, we show that cut-elimination preserves the progressive criterion and various regularity conditions internalizing degrees of proof-theoretical uniformity. Finally, we provide a denotational semantics for our systems based on the relational model.
[ { "created": "Tue, 15 Aug 2023 14:10:56 GMT", "version": "v1" }, { "created": "Mon, 27 May 2024 18:52:23 GMT", "version": "v2" } ]
2024-05-29
[ [ "Acclavio", "Matteo", "" ], [ "Curzi", "Gianluca", "" ], [ "Guerrieri", "Giulio", "" ] ]
We investigate non-wellfounded proof systems based on parsimonious logic, a weaker variant of linear logic where the exponential modality ! is interpreted as a constructor for streams over finite data. Logical consistency is maintained at a global level by adapting a standard progressing criterion. We present an infinitary version of cut-elimination based on finite approximations, and we prove that, in presence of the progressing criterion, it returns well-defined non-wellfounded proofs at its limit. Furthermore, we show that cut-elimination preserves the progressive criterion and various regularity conditions internalizing degrees of proof-theoretical uniformity. Finally, we provide a denotational semantics for our systems based on the relational model.
cs/0309040
Valmir Barbosa
L. D. Penso, V. C. Barbosa
A distributed algorithm to find k-dominating sets
To appear in Discrete Applied Mathematics
Discrete Applied Mathematics 141 (2004), 243-253
10.1016/S0166-218X(03)00368-8
ES-552/01
cs.DC
null
We consider a connected undirected graph $G(n,m)$ with $n$ nodes and $m$ edges. A $k$-dominating set $D$ in $G$ is a set of nodes having the property that every node in $G$ is at most $k$ edges away from at least one node in $D$. Finding a $k$-dominating set of minimum size is NP-hard. We give a new synchronous distributed algorithm to find a $k$-dominating set in $G$ of size no greater than $\lfloor n/(k+1)\rfloor$. Our algorithm requires $O(k\log^*n)$ time and $O(m\log k+n\log k\log^*n)$ messages to run. It has the same time complexity as the best currently known algorithm, but improves on that algorithm's message complexity and is, in addition, conceptually simpler.
[ { "created": "Tue, 23 Sep 2003 01:14:43 GMT", "version": "v1" } ]
2007-05-23
[ [ "Penso", "L. D.", "" ], [ "Barbosa", "V. C.", "" ] ]
We consider a connected undirected graph $G(n,m)$ with $n$ nodes and $m$ edges. A $k$-dominating set $D$ in $G$ is a set of nodes having the property that every node in $G$ is at most $k$ edges away from at least one node in $D$. Finding a $k$-dominating set of minimum size is NP-hard. We give a new synchronous distributed algorithm to find a $k$-dominating set in $G$ of size no greater than $\lfloor n/(k+1)\rfloor$. Our algorithm requires $O(k\log^*n)$ time and $O(m\log k+n\log k\log^*n)$ messages to run. It has the same time complexity as the best currently known algorithm, but improves on that algorithm's message complexity and is, in addition, conceptually simpler.
1804.07396
David Eppstein
David Eppstein
Making Change in 2048
13 pages, 1 figure. To appear in the Proceedings of the 9th International Conference on Fun with Algorithms (FUN 2018), Leibniz International Proceedings in Informatics
null
null
null
cs.DM
http://creativecommons.org/licenses/by/4.0/
The 2048 game involves tiles labeled with powers of two that can be merged to form bigger powers of two; variants of the same puzzle involve similar merges of other tile values. We analyze the maximum score achievable in these games by proving a min-max theorem equating this maximum score (in an abstract generalized variation of 2048 that allows all the moves of the original game) with the minimum value that causes a greedy change-making algorithm to use a given number of coins. A widely-followed strategy in 2048 maintains tiles that represent the move number in binary notation, and a similar strategy in the Fibonacci number variant of the game (987) maintains the Zeckendorf representation of the move number as a sum of the fewest possible Fibonacci numbers; our analysis shows that the ability to follow these strategies is intimately connected with the fact that greedy change-making is optimal for binary and Fibonacci coinage. For variants of 2048 using tile values for which greedy change-making is suboptimal, it is the greedy strategy, not the optimal representation as sums of tile values, that controls the length of the game. In particular, the game will always terminate whenever the sequence of allowable tile values has arbitrarily large gaps between consecutive values.
[ { "created": "Thu, 19 Apr 2018 22:58:51 GMT", "version": "v1" } ]
2018-04-23
[ [ "Eppstein", "David", "" ] ]
The 2048 game involves tiles labeled with powers of two that can be merged to form bigger powers of two; variants of the same puzzle involve similar merges of other tile values. We analyze the maximum score achievable in these games by proving a min-max theorem equating this maximum score (in an abstract generalized variation of 2048 that allows all the moves of the original game) with the minimum value that causes a greedy change-making algorithm to use a given number of coins. A widely-followed strategy in 2048 maintains tiles that represent the move number in binary notation, and a similar strategy in the Fibonacci number variant of the game (987) maintains the Zeckendorf representation of the move number as a sum of the fewest possible Fibonacci numbers; our analysis shows that the ability to follow these strategies is intimately connected with the fact that greedy change-making is optimal for binary and Fibonacci coinage. For variants of 2048 using tile values for which greedy change-making is suboptimal, it is the greedy strategy, not the optimal representation as sums of tile values, that controls the length of the game. In particular, the game will always terminate whenever the sequence of allowable tile values has arbitrarily large gaps between consecutive values.
2310.10486
Milad Shafiee
Milad Shafiee, Guillaume Bellegarda and Auke Ijspeert
ManyQuadrupeds: Learning a Single Locomotion Policy for Diverse Quadruped Robots
Accepted for IEEE International Conference on Robotics and Automation (ICRA) 2024, Webpage: https://miladshafiee.github.io/ManyQuadrupeds/
null
null
null
cs.RO cs.AI cs.LG cs.SY eess.SY
http://creativecommons.org/licenses/by-sa/4.0/
Learning a locomotion policy for quadruped robots has traditionally been constrained to a specific robot morphology, mass, and size. The learning process must usually be repeated for every new robot, where hyperparameters and reward function weights must be re-tuned to maximize performance for each new system. Alternatively, attempting to train a single policy to accommodate different robot sizes, while maintaining the same degrees of freedom (DoF) and morphology, requires either complex learning frameworks, or mass, inertia, and dimension randomization, which leads to prolonged training periods. In our study, we show that drawing inspiration from animal motor control allows us to effectively train a single locomotion policy capable of controlling a diverse range of quadruped robots. The robot differences encompass: a variable number of DoFs, (i.e. 12 or 16 joints), three distinct morphologies, a broad mass range spanning from 2 kg to 200 kg, and nominal standing heights ranging from 18 cm to 100 cm. Our policy modulates a representation of the Central Pattern Generator (CPG) in the spinal cord, effectively coordinating both frequencies and amplitudes of the CPG to produce rhythmic output (Rhythm Generation), which is then mapped to a Pattern Formation (PF) layer. Across different robots, the only varying component is the PF layer, which adjusts the scaling parameters for the stride height and length. Subsequently, we evaluate the sim-to-real transfer by testing the single policy on both the Unitree Go1 and A1 robots. Remarkably, we observe robust performance, even when adding a 15 kg load, equivalent to 125% of the A1 robot's nominal mass.
[ { "created": "Mon, 16 Oct 2023 15:06:16 GMT", "version": "v1" }, { "created": "Fri, 8 Mar 2024 14:10:02 GMT", "version": "v2" } ]
2024-03-11
[ [ "Shafiee", "Milad", "" ], [ "Bellegarda", "Guillaume", "" ], [ "Ijspeert", "Auke", "" ] ]
Learning a locomotion policy for quadruped robots has traditionally been constrained to a specific robot morphology, mass, and size. The learning process must usually be repeated for every new robot, where hyperparameters and reward function weights must be re-tuned to maximize performance for each new system. Alternatively, attempting to train a single policy to accommodate different robot sizes, while maintaining the same degrees of freedom (DoF) and morphology, requires either complex learning frameworks, or mass, inertia, and dimension randomization, which leads to prolonged training periods. In our study, we show that drawing inspiration from animal motor control allows us to effectively train a single locomotion policy capable of controlling a diverse range of quadruped robots. The robot differences encompass: a variable number of DoFs, (i.e. 12 or 16 joints), three distinct morphologies, a broad mass range spanning from 2 kg to 200 kg, and nominal standing heights ranging from 18 cm to 100 cm. Our policy modulates a representation of the Central Pattern Generator (CPG) in the spinal cord, effectively coordinating both frequencies and amplitudes of the CPG to produce rhythmic output (Rhythm Generation), which is then mapped to a Pattern Formation (PF) layer. Across different robots, the only varying component is the PF layer, which adjusts the scaling parameters for the stride height and length. Subsequently, we evaluate the sim-to-real transfer by testing the single policy on both the Unitree Go1 and A1 robots. Remarkably, we observe robust performance, even when adding a 15 kg load, equivalent to 125% of the A1 robot's nominal mass.
2109.08771
Jacky Liang
Jacky Liang, Mohit Sharma, Alex LaGrassa, Shivam Vats, Saumya Saxena, Oliver Kroemer
Search-Based Task Planning with Learned Skill Effect Models for Lifelong Robotic Manipulation
To appear in the International Conference on Robotics and Automation (ICRA) 2022
null
null
null
cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Robots deployed in many real-world settings need to be able to acquire new skills and solve new tasks over time. Prior works on planning with skills often make assumptions on the structure of skills and tasks, such as subgoal skills, shared skill implementations, or task-specific plan skeletons, which limit adaptation to new skills and tasks. By contrast, we propose doing task planning by jointly searching in the space of parameterized skills using high-level skill effect models learned in simulation. We use an iterative training procedure to efficiently generate relevant data to train such models. Our approach allows flexible skill parameterizations and task specifications to facilitate lifelong learning in general-purpose domains. Experiments demonstrate the ability of our planner to integrate new skills in a lifelong manner, finding new task strategies with lower costs in both train and test tasks. We additionally show that our method can transfer to the real world without further fine-tuning.
[ { "created": "Fri, 17 Sep 2021 22:06:58 GMT", "version": "v1" }, { "created": "Thu, 14 Apr 2022 01:07:35 GMT", "version": "v2" } ]
2022-04-15
[ [ "Liang", "Jacky", "" ], [ "Sharma", "Mohit", "" ], [ "LaGrassa", "Alex", "" ], [ "Vats", "Shivam", "" ], [ "Saxena", "Saumya", "" ], [ "Kroemer", "Oliver", "" ] ]
Robots deployed in many real-world settings need to be able to acquire new skills and solve new tasks over time. Prior works on planning with skills often make assumptions on the structure of skills and tasks, such as subgoal skills, shared skill implementations, or task-specific plan skeletons, which limit adaptation to new skills and tasks. By contrast, we propose doing task planning by jointly searching in the space of parameterized skills using high-level skill effect models learned in simulation. We use an iterative training procedure to efficiently generate relevant data to train such models. Our approach allows flexible skill parameterizations and task specifications to facilitate lifelong learning in general-purpose domains. Experiments demonstrate the ability of our planner to integrate new skills in a lifelong manner, finding new task strategies with lower costs in both train and test tasks. We additionally show that our method can transfer to the real world without further fine-tuning.
2303.14953
Ming Wang
Ming Wang, Xianda Guo, Beibei Lin, Tian Yang, Zheng Zhu, Lincheng Li, Shunli Zhang and Xin Yu
DyGait: Exploiting Dynamic Representations for High-performance Gait Recognition
null
null
null
null
cs.CV
http://creativecommons.org/licenses/by-nc-nd/4.0/
Gait recognition is a biometric technology that recognizes the identity of humans through their walking patterns. Compared with other biometric technologies, gait recognition is more difficult to disguise and can be applied to the condition of long-distance without the cooperation of subjects. Thus, it has unique potential and wide application for crime prevention and social security. At present, most gait recognition methods directly extract features from the video frames to establish representations. However, these architectures learn representations from different features equally but do not pay enough attention to dynamic features, which refers to a representation of dynamic parts of silhouettes over time (e.g. legs). Since dynamic parts of the human body are more informative than other parts (e.g. bags) during walking, in this paper, we propose a novel and high-performance framework named DyGait. This is the first framework on gait recognition that is designed to focus on the extraction of dynamic features. Specifically, to take full advantage of the dynamic information, we propose a Dynamic Augmentation Module (DAM), which can automatically establish spatial-temporal feature representations of the dynamic parts of the human body. The experimental results show that our DyGait network outperforms other state-of-the-art gait recognition methods. It achieves an average Rank-1 accuracy of 71.4% on the GREW dataset, 66.3% on the Gait3D dataset, 98.4% on the CASIA-B dataset and 98.3% on the OU-MVLP dataset.
[ { "created": "Mon, 27 Mar 2023 07:36:47 GMT", "version": "v1" } ]
2023-03-28
[ [ "Wang", "Ming", "" ], [ "Guo", "Xianda", "" ], [ "Lin", "Beibei", "" ], [ "Yang", "Tian", "" ], [ "Zhu", "Zheng", "" ], [ "Li", "Lincheng", "" ], [ "Zhang", "Shunli", "" ], [ "Yu", "Xin", "" ] ]
Gait recognition is a biometric technology that recognizes the identity of humans through their walking patterns. Compared with other biometric technologies, gait recognition is more difficult to disguise and can be applied to the condition of long-distance without the cooperation of subjects. Thus, it has unique potential and wide application for crime prevention and social security. At present, most gait recognition methods directly extract features from the video frames to establish representations. However, these architectures learn representations from different features equally but do not pay enough attention to dynamic features, which refers to a representation of dynamic parts of silhouettes over time (e.g. legs). Since dynamic parts of the human body are more informative than other parts (e.g. bags) during walking, in this paper, we propose a novel and high-performance framework named DyGait. This is the first framework on gait recognition that is designed to focus on the extraction of dynamic features. Specifically, to take full advantage of the dynamic information, we propose a Dynamic Augmentation Module (DAM), which can automatically establish spatial-temporal feature representations of the dynamic parts of the human body. The experimental results show that our DyGait network outperforms other state-of-the-art gait recognition methods. It achieves an average Rank-1 accuracy of 71.4% on the GREW dataset, 66.3% on the Gait3D dataset, 98.4% on the CASIA-B dataset and 98.3% on the OU-MVLP dataset.
2103.16434
Georgios Papadopoulos Th.
Georgios Th. Papadopoulos, Asterios Leonidis, Margherita Antona, Constantine Stephanidis
User profile-driven large-scale multi-agent learning from demonstration in federated human-robot collaborative environments
arXiv admin note: substantial text overlap with arXiv:2012.08174
null
null
null
cs.RO cs.AI cs.HC cs.LG
http://creativecommons.org/licenses/by/4.0/
Learning from Demonstration (LfD) has been established as the dominant paradigm for efficiently transferring skills from human teachers to robots. In this context, the Federated Learning (FL) conceptualization has very recently been introduced for developing large-scale human-robot collaborative environments, targeting to robustly address, among others, the critical challenges of multi-agent learning and long-term autonomy. In the current work, the latter scheme is further extended and enhanced, by designing and integrating a novel user profile formulation for providing a fine-grained representation of the exhibited human behavior, adopting a Deep Learning (DL)-based formalism. In particular, a hierarchically organized set of key information sources is considered, including: a) User attributes (e.g. demographic, anthropomorphic, educational, etc.), b) User state (e.g. fatigue detection, stress detection, emotion recognition, etc.) and c) Psychophysiological measurements (e.g. gaze, electrodermal activity, heart rate, etc.) related data. Then, a combination of Long Short-Term Memory (LSTM) and stacked autoencoders, with appropriately defined neural network architectures, is employed for the modelling step. The overall designed scheme enables both short- and long-term analysis/interpretation of the human behavior (as observed during the feedback capturing sessions), so as to adaptively adjust the importance of the collected feedback samples when aggregating information originating from the same and different human teachers, respectively.
[ { "created": "Tue, 30 Mar 2021 15:33:21 GMT", "version": "v1" } ]
2021-03-31
[ [ "Papadopoulos", "Georgios Th.", "" ], [ "Leonidis", "Asterios", "" ], [ "Antona", "Margherita", "" ], [ "Stephanidis", "Constantine", "" ] ]
Learning from Demonstration (LfD) has been established as the dominant paradigm for efficiently transferring skills from human teachers to robots. In this context, the Federated Learning (FL) conceptualization has very recently been introduced for developing large-scale human-robot collaborative environments, targeting to robustly address, among others, the critical challenges of multi-agent learning and long-term autonomy. In the current work, the latter scheme is further extended and enhanced, by designing and integrating a novel user profile formulation for providing a fine-grained representation of the exhibited human behavior, adopting a Deep Learning (DL)-based formalism. In particular, a hierarchically organized set of key information sources is considered, including: a) User attributes (e.g. demographic, anthropomorphic, educational, etc.), b) User state (e.g. fatigue detection, stress detection, emotion recognition, etc.) and c) Psychophysiological measurements (e.g. gaze, electrodermal activity, heart rate, etc.) related data. Then, a combination of Long Short-Term Memory (LSTM) and stacked autoencoders, with appropriately defined neural network architectures, is employed for the modelling step. The overall designed scheme enables both short- and long-term analysis/interpretation of the human behavior (as observed during the feedback capturing sessions), so as to adaptively adjust the importance of the collected feedback samples when aggregating information originating from the same and different human teachers, respectively.
1604.04675
Hamid Tizhoosh
Shujin Zhu, H.R.Tizhoosh
Radon Features and Barcodes for Medical Image Retrieval via SVM
To appear in proceedings of The 2016 IEEE International Joint Conference on Neural Networks (IJCNN 2016), July 24-29, 2016, Vancouver, Canada
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For more than two decades, research has been performed on content-based image retrieval (CBIR). By combining Radon projections and the support vector machines (SVM), a content-based medical image retrieval method is presented in this work. The proposed approach employs the normalized Radon projections with corresponding image category labels to build an SVM classifier, and the Radon barcode database which encodes every image in a binary format is also generated simultaneously to tag all images. To retrieve similar images when a query image is given, Radon projections and the barcode of the query image are generated. Subsequently, the k-nearest neighbor search method is applied to find the images with minimum Hamming distance of the Radon barcode within the same class predicted by the trained SVM classifier that uses Radon features. The performance of the proposed method is validated by using the IRMA 2009 dataset with 14,410 x-ray images in 57 categories. The results demonstrate that our method has the capacity to retrieve similar responses for the correctly identified query image and even for those mistakenly classified by SVM. The approach further is very fast and has low memory requirement.
[ { "created": "Sat, 16 Apr 2016 01:13:23 GMT", "version": "v1" } ]
2016-04-19
[ [ "Zhu", "Shujin", "" ], [ "Tizhoosh", "H. R.", "" ] ]
For more than two decades, research has been performed on content-based image retrieval (CBIR). By combining Radon projections and the support vector machines (SVM), a content-based medical image retrieval method is presented in this work. The proposed approach employs the normalized Radon projections with corresponding image category labels to build an SVM classifier, and the Radon barcode database which encodes every image in a binary format is also generated simultaneously to tag all images. To retrieve similar images when a query image is given, Radon projections and the barcode of the query image are generated. Subsequently, the k-nearest neighbor search method is applied to find the images with minimum Hamming distance of the Radon barcode within the same class predicted by the trained SVM classifier that uses Radon features. The performance of the proposed method is validated by using the IRMA 2009 dataset with 14,410 x-ray images in 57 categories. The results demonstrate that our method has the capacity to retrieve similar responses for the correctly identified query image and even for those mistakenly classified by SVM. The approach further is very fast and has low memory requirement.
2105.02742
Christopher K\"ummel
Christopher Kissel, Christopher K\"ummel, Dennis Ritter, Kristian Hildebrand
Pose-Guided Sign Language Video GAN with Dynamic Lambda
null
null
null
null
cs.CV
http://creativecommons.org/licenses/by-sa/4.0/
We propose a novel approach for the synthesis of sign language videos using GANs. We extend the previous work of Stoll et al. by using the human semantic parser of the Soft-Gated Warping-GAN from to produce photorealistic videos guided by region-level spatial layouts. Synthesizing target poses improves performance on independent and contrasting signers. Therefore, we have evaluated our system with the highly heterogeneous MS-ASL dataset with over 200 signers resulting in a SSIM of 0.893. Furthermore, we introduce a periodic weighting approach to the generator that reactivates the training and leads to quantitatively better results.
[ { "created": "Thu, 6 May 2021 15:12:09 GMT", "version": "v1" } ]
2021-05-07
[ [ "Kissel", "Christopher", "" ], [ "Kümmel", "Christopher", "" ], [ "Ritter", "Dennis", "" ], [ "Hildebrand", "Kristian", "" ] ]
We propose a novel approach for the synthesis of sign language videos using GANs. We extend the previous work of Stoll et al. by using the human semantic parser of the Soft-Gated Warping-GAN from to produce photorealistic videos guided by region-level spatial layouts. Synthesizing target poses improves performance on independent and contrasting signers. Therefore, we have evaluated our system with the highly heterogeneous MS-ASL dataset with over 200 signers resulting in a SSIM of 0.893. Furthermore, we introduce a periodic weighting approach to the generator that reactivates the training and leads to quantitatively better results.
2103.05902
Dongseok Shim
Dongseok Shim and H. Jin Kim
Learning a Domain-Agnostic Visual Representation for Autonomous Driving via Contrastive Loss
IEEE IROS 2021 Submission
null
null
null
cs.CV cs.LG cs.RO
http://creativecommons.org/licenses/by/4.0/
Deep neural networks have been widely studied in autonomous driving applications such as semantic segmentation or depth estimation. However, training a neural network in a supervised manner requires a large amount of annotated labels which are expensive and time-consuming to collect. Recent studies leverage synthetic data collected from a virtual environment which are much easier to acquire and more accurate compared to data from the real world, but they usually suffer from poor generalization due to the inherent domain shift problem. In this paper, we propose a Domain-Agnostic Contrastive Learning (DACL) which is a two-stage unsupervised domain adaptation framework with cyclic adversarial training and contrastive loss. DACL leads the neural network to learn domain-agnostic representation to overcome performance degradation when there exists a difference between training and test data distribution. Our proposed approach achieves better performance in the monocular depth estimation task compared to previous state-of-the-art methods and also shows effectiveness in the semantic segmentation task.
[ { "created": "Wed, 10 Mar 2021 07:06:03 GMT", "version": "v1" } ]
2021-03-11
[ [ "Shim", "Dongseok", "" ], [ "Kim", "H. Jin", "" ] ]
Deep neural networks have been widely studied in autonomous driving applications such as semantic segmentation or depth estimation. However, training a neural network in a supervised manner requires a large amount of annotated labels which are expensive and time-consuming to collect. Recent studies leverage synthetic data collected from a virtual environment which are much easier to acquire and more accurate compared to data from the real world, but they usually suffer from poor generalization due to the inherent domain shift problem. In this paper, we propose a Domain-Agnostic Contrastive Learning (DACL) which is a two-stage unsupervised domain adaptation framework with cyclic adversarial training and contrastive loss. DACL leads the neural network to learn domain-agnostic representation to overcome performance degradation when there exists a difference between training and test data distribution. Our proposed approach achieves better performance in the monocular depth estimation task compared to previous state-of-the-art methods and also shows effectiveness in the semantic segmentation task.
2303.12394
Qianxiong Xu
Qianxiong Xu, Cheng Long, Liang Yu, Chen Zhang
Road Extraction with Satellite Images and Partial Road Maps
This paper has been accepted by IEEE Transactions on Geoscience and Remote Sensing
null
10.1109/TGRS.2023.3261332
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Road extraction is a process of automatically generating road maps mainly from satellite images. Existing models all target to generate roads from the scratch despite that a large quantity of road maps, though incomplete, are publicly available (e.g. those from OpenStreetMap) and can help with road extraction. In this paper, we propose to conduct road extraction based on satellite images and partial road maps, which is new. We then propose a two-branch Partial to Complete Network (P2CNet) for the task, which has two prominent components: Gated Self-Attention Module (GSAM) and Missing Part (MP) loss. GSAM leverages a channel-wise self-attention module and a gate module to capture long-range semantics, filter out useless information, and better fuse the features from two branches. MP loss is derived from the partial road maps, trying to give more attention to the road pixels that do not exist in partial road maps. Extensive experiments are conducted to demonstrate the effectiveness of our model, e.g. P2CNet achieves state-of-the-art performance with the IoU scores of 70.71% and 75.52%, respectively, on the SpaceNet and OSM datasets.
[ { "created": "Wed, 22 Mar 2023 08:59:42 GMT", "version": "v1" } ]
2023-05-03
[ [ "Xu", "Qianxiong", "" ], [ "Long", "Cheng", "" ], [ "Yu", "Liang", "" ], [ "Zhang", "Chen", "" ] ]
Road extraction is a process of automatically generating road maps mainly from satellite images. Existing models all target to generate roads from the scratch despite that a large quantity of road maps, though incomplete, are publicly available (e.g. those from OpenStreetMap) and can help with road extraction. In this paper, we propose to conduct road extraction based on satellite images and partial road maps, which is new. We then propose a two-branch Partial to Complete Network (P2CNet) for the task, which has two prominent components: Gated Self-Attention Module (GSAM) and Missing Part (MP) loss. GSAM leverages a channel-wise self-attention module and a gate module to capture long-range semantics, filter out useless information, and better fuse the features from two branches. MP loss is derived from the partial road maps, trying to give more attention to the road pixels that do not exist in partial road maps. Extensive experiments are conducted to demonstrate the effectiveness of our model, e.g. P2CNet achieves state-of-the-art performance with the IoU scores of 70.71% and 75.52%, respectively, on the SpaceNet and OSM datasets.
2111.05688
Antoine Vacavant
Antoine Vacavant and Bertrand Kerautret and Fabien Feschet
Robust reconstructions by multi-scale/irregular tangential covering
null
null
null
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
In this paper, we propose an original manner to employ a tangential cover algorithm - minDSS - in order to geometrically reconstruct noisy digital contours. To do so, we exploit the representation of graphical objects by maximal primitives we have introduced in previous works. By calculating multi-scale and irregular isothetic representations of the contour, we obtained 1-D (one-dimensional) intervals, and achieved afterwards a decomposition into maximal line segments or circular arcs. By adapting minDSS to this sparse and irregular data of 1-D intervals supporting the maximal primitives, we are now able to reconstruct the input noisy objects into cyclic contours made of lines or arcs with a minimal number of primitives. In this work, we explain our novel complete pipeline, and present its experimental evaluation by considering both synthetic and real image data. We also show that this is a robust approach, with respect to selected references from state-of-the-art, and by considering a multi-scale noise evaluation process.
[ { "created": "Wed, 10 Nov 2021 14:02:05 GMT", "version": "v1" } ]
2021-11-11
[ [ "Vacavant", "Antoine", "" ], [ "Kerautret", "Bertrand", "" ], [ "Feschet", "Fabien", "" ] ]
In this paper, we propose an original manner to employ a tangential cover algorithm - minDSS - in order to geometrically reconstruct noisy digital contours. To do so, we exploit the representation of graphical objects by maximal primitives we have introduced in previous works. By calculating multi-scale and irregular isothetic representations of the contour, we obtained 1-D (one-dimensional) intervals, and achieved afterwards a decomposition into maximal line segments or circular arcs. By adapting minDSS to this sparse and irregular data of 1-D intervals supporting the maximal primitives, we are now able to reconstruct the input noisy objects into cyclic contours made of lines or arcs with a minimal number of primitives. In this work, we explain our novel complete pipeline, and present its experimental evaluation by considering both synthetic and real image data. We also show that this is a robust approach, with respect to selected references from state-of-the-art, and by considering a multi-scale noise evaluation process.
2302.03567
Daniel Rigobon
Daniel E. Rigobon
From Utilitarian to Rawlsian Designs for Algorithmic Fairness
null
null
null
null
cs.CY cs.LG
http://creativecommons.org/licenses/by/4.0/
There is a lack of consensus within the literature as to how `fairness' of algorithmic systems can be measured, and different metrics can often be at odds. In this paper, we approach this task by drawing on the ethical frameworks of utilitarianism and John Rawls. Informally, these two theories of distributive justice measure the `good' as either a population's sum of utility, or worst-off outcomes, respectively. We present a parameterized class of objective functions that interpolates between these two (possibly) conflicting notions of the `good'. This class is shown to represent a relaxation of the Rawlsian `veil of ignorance', and its sequence of optimal solutions converges to both a utilitarian and Rawlsian optimum. Several other properties of this class are studied, including: 1) a relationship to regularized optimization, 2) feasibility of consistent estimation, and 3) algorithmic cost. In several real-world datasets, we compute optimal solutions and construct the tradeoff between utilitarian and Rawlsian notions of the `good'. Empirically, we demonstrate that increasing model complexity can manifest strict improvements to both measures of the `good'. This work suggests that the proper degree of `fairness' can be informed by a designer's preferences over the space of induced utilitarian and Rawlsian `good'.
[ { "created": "Tue, 7 Feb 2023 16:28:10 GMT", "version": "v1" } ]
2023-02-08
[ [ "Rigobon", "Daniel E.", "" ] ]
There is a lack of consensus within the literature as to how `fairness' of algorithmic systems can be measured, and different metrics can often be at odds. In this paper, we approach this task by drawing on the ethical frameworks of utilitarianism and John Rawls. Informally, these two theories of distributive justice measure the `good' as either a population's sum of utility, or worst-off outcomes, respectively. We present a parameterized class of objective functions that interpolates between these two (possibly) conflicting notions of the `good'. This class is shown to represent a relaxation of the Rawlsian `veil of ignorance', and its sequence of optimal solutions converges to both a utilitarian and Rawlsian optimum. Several other properties of this class are studied, including: 1) a relationship to regularized optimization, 2) feasibility of consistent estimation, and 3) algorithmic cost. In several real-world datasets, we compute optimal solutions and construct the tradeoff between utilitarian and Rawlsian notions of the `good'. Empirically, we demonstrate that increasing model complexity can manifest strict improvements to both measures of the `good'. This work suggests that the proper degree of `fairness' can be informed by a designer's preferences over the space of induced utilitarian and Rawlsian `good'.
1303.1747
Emilio Ferrara
Pasquale De Meo, Emilio Ferrara, Giacomo Fiumara, Angela Ricciardello
A Novel Measure of Edge Centrality in Social Networks
28 pages, 5 figures
Knowledge-based Systems, 30:136-150, 2012
10.1016/j.knosys.2012.01.007
null
cs.SI cs.DS physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The problem of assigning centrality values to nodes and edges in graphs has been widely investigated during last years. Recently, a novel measure of node centrality has been proposed, called k-path centrality index, which is based on the propagation of messages inside a network along paths consisting of at most k edges. On the other hand, the importance of computing the centrality of edges has been put into evidence since 1970's by Anthonisse and, subsequently by Girvan and Newman. In this work we propose the generalization of the concept of k-path centrality by defining the k-path edge centrality, a measure of centrality introduced to compute the importance of edges. We provide an efficient algorithm, running in O(k m), being m the number of edges in the graph. Thus, our technique is feasible for large scale network analysis. Finally, the performance of our algorithm is analyzed, discussing the results obtained against large online social network datasets.
[ { "created": "Thu, 7 Mar 2013 16:54:34 GMT", "version": "v1" } ]
2013-03-08
[ [ "De Meo", "Pasquale", "" ], [ "Ferrara", "Emilio", "" ], [ "Fiumara", "Giacomo", "" ], [ "Ricciardello", "Angela", "" ] ]
The problem of assigning centrality values to nodes and edges in graphs has been widely investigated during last years. Recently, a novel measure of node centrality has been proposed, called k-path centrality index, which is based on the propagation of messages inside a network along paths consisting of at most k edges. On the other hand, the importance of computing the centrality of edges has been put into evidence since 1970's by Anthonisse and, subsequently by Girvan and Newman. In this work we propose the generalization of the concept of k-path centrality by defining the k-path edge centrality, a measure of centrality introduced to compute the importance of edges. We provide an efficient algorithm, running in O(k m), being m the number of edges in the graph. Thus, our technique is feasible for large scale network analysis. Finally, the performance of our algorithm is analyzed, discussing the results obtained against large online social network datasets.
2110.09796
Xiaoteng Ma
Xiaoteng Ma, Yiqin Yang, Hao Hu, Qihan Liu, Jun Yang, Chongjie Zhang, Qianchuan Zhao, Bin Liang
Offline Reinforcement Learning with Value-based Episodic Memory
null
null
null
null
cs.LG cs.AI
http://creativecommons.org/licenses/by-nc-sa/4.0/
Offline reinforcement learning (RL) shows promise of applying RL to real-world problems by effectively utilizing previously collected data. Most existing offline RL algorithms use regularization or constraints to suppress extrapolation error for actions outside the dataset. In this paper, we adopt a different framework, which learns the V-function instead of the Q-function to naturally keep the learning procedure within the support of an offline dataset. To enable effective generalization while maintaining proper conservatism in offline learning, we propose Expectile V-Learning (EVL), which smoothly interpolates between the optimal value learning and behavior cloning. Further, we introduce implicit planning along offline trajectories to enhance learned V-values and accelerate convergence. Together, we present a new offline method called Value-based Episodic Memory (VEM). We provide theoretical analysis for the convergence properties of our proposed VEM method, and empirical results in the D4RL benchmark show that our method achieves superior performance in most tasks, particularly in sparse-reward tasks.
[ { "created": "Tue, 19 Oct 2021 08:20:11 GMT", "version": "v1" } ]
2021-10-20
[ [ "Ma", "Xiaoteng", "" ], [ "Yang", "Yiqin", "" ], [ "Hu", "Hao", "" ], [ "Liu", "Qihan", "" ], [ "Yang", "Jun", "" ], [ "Zhang", "Chongjie", "" ], [ "Zhao", "Qianchuan", "" ], [ "Liang", "Bin", "" ] ]
Offline reinforcement learning (RL) shows promise of applying RL to real-world problems by effectively utilizing previously collected data. Most existing offline RL algorithms use regularization or constraints to suppress extrapolation error for actions outside the dataset. In this paper, we adopt a different framework, which learns the V-function instead of the Q-function to naturally keep the learning procedure within the support of an offline dataset. To enable effective generalization while maintaining proper conservatism in offline learning, we propose Expectile V-Learning (EVL), which smoothly interpolates between the optimal value learning and behavior cloning. Further, we introduce implicit planning along offline trajectories to enhance learned V-values and accelerate convergence. Together, we present a new offline method called Value-based Episodic Memory (VEM). We provide theoretical analysis for the convergence properties of our proposed VEM method, and empirical results in the D4RL benchmark show that our method achieves superior performance in most tasks, particularly in sparse-reward tasks.
1108.3632
EPTCS
Thierry Monteil (CNRS - Universit\'e Montpellier 2)
The complexity of tangent words
In Proceedings WORDS 2011, arXiv:1108.3412
EPTCS 63, 2011, pp. 152-157
10.4204/EPTCS.63.21
null
cs.DM cs.CG cs.FL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a previous paper, we described the set of words that appear in the coding of smooth (resp. analytic) curves at arbitrary small scale. The aim of this paper is to compute the complexity of those languages.
[ { "created": "Thu, 18 Aug 2011 03:54:08 GMT", "version": "v1" } ]
2011-08-19
[ [ "Monteil", "Thierry", "", "CNRS - Université Montpellier 2" ] ]
In a previous paper, we described the set of words that appear in the coding of smooth (resp. analytic) curves at arbitrary small scale. The aim of this paper is to compute the complexity of those languages.
2407.04106
Asma Alkhaldi
Asma Alkhaldi, Raneem Alnajim, Layan Alabdullatef, Rawan Alyahya, Jun Chen, Deyao Zhu, Ahmed Alsinan, Mohamed Elhoseiny
MiniGPT-Med: Large Language Model as a General Interface for Radiology Diagnosis
null
null
null
null
cs.AI cs.CL cs.CV
http://creativecommons.org/licenses/by/4.0/
Recent advancements in artificial intelligence (AI) have precipitated significant breakthroughs in healthcare, particularly in refining diagnostic procedures. However, previous studies have often been constrained to limited functionalities. This study introduces MiniGPT-Med, a vision-language model derived from large-scale language models and tailored for medical applications. MiniGPT-Med demonstrates remarkable versatility across various imaging modalities, including X-rays, CT scans, and MRIs, enhancing its utility. The model is capable of performing tasks such as medical report generation, visual question answering (VQA), and disease identification within medical imagery. Its integrated processing of both image and textual clinical data markedly improves diagnostic accuracy. Our empirical assessments confirm MiniGPT-Med's superior performance in disease grounding, medical report generation, and VQA benchmarks, representing a significant step towards reducing the gap in assisting radiology practice. Furthermore, it achieves state-of-the-art performance on medical report generation, higher than the previous best model by 19\% accuracy. MiniGPT-Med promises to become a general interface for radiology diagnoses, enhancing diagnostic efficiency across a wide range of medical imaging applications.
[ { "created": "Thu, 4 Jul 2024 18:21:10 GMT", "version": "v1" } ]
2024-07-08
[ [ "Alkhaldi", "Asma", "" ], [ "Alnajim", "Raneem", "" ], [ "Alabdullatef", "Layan", "" ], [ "Alyahya", "Rawan", "" ], [ "Chen", "Jun", "" ], [ "Zhu", "Deyao", "" ], [ "Alsinan", "Ahmed", "" ], [ "Elhoseiny", "Mohamed", "" ] ]
Recent advancements in artificial intelligence (AI) have precipitated significant breakthroughs in healthcare, particularly in refining diagnostic procedures. However, previous studies have often been constrained to limited functionalities. This study introduces MiniGPT-Med, a vision-language model derived from large-scale language models and tailored for medical applications. MiniGPT-Med demonstrates remarkable versatility across various imaging modalities, including X-rays, CT scans, and MRIs, enhancing its utility. The model is capable of performing tasks such as medical report generation, visual question answering (VQA), and disease identification within medical imagery. Its integrated processing of both image and textual clinical data markedly improves diagnostic accuracy. Our empirical assessments confirm MiniGPT-Med's superior performance in disease grounding, medical report generation, and VQA benchmarks, representing a significant step towards reducing the gap in assisting radiology practice. Furthermore, it achieves state-of-the-art performance on medical report generation, higher than the previous best model by 19\% accuracy. MiniGPT-Med promises to become a general interface for radiology diagnoses, enhancing diagnostic efficiency across a wide range of medical imaging applications.