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1512.01525
Yezhou Yang
Yezhou Yang and Yiannis Aloimonos and Cornelia Fermuller and Eren Erdal Aksoy
Learning the Semantics of Manipulation Action
null
The 53rd Annual Meeting of the Association for Computational Linguistics (ACL) 1 (2015) 676-686
null
null
cs.RO cs.CL cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present a formal computational framework for modeling manipulation actions. The introduced formalism leads to semantics of manipulation action and has applications to both observing and understanding human manipulation actions as well as executing them with a robotic mechanism (e.g. a humanoid robot). It is based on a Combinatory Categorial Grammar. The goal of the introduced framework is to: (1) represent manipulation actions with both syntax and semantic parts, where the semantic part employs $\lambda$-calculus; (2) enable a probabilistic semantic parsing schema to learn the $\lambda$-calculus representation of manipulation action from an annotated action corpus of videos; (3) use (1) and (2) to develop a system that visually observes manipulation actions and understands their meaning while it can reason beyond observations using propositional logic and axiom schemata. The experiments conducted on a public available large manipulation action dataset validate the theoretical framework and our implementation.
[ { "version": "v1", "created": "Fri, 4 Dec 2015 20:00:08 GMT" } ]
2015-12-07T00:00:00
[ [ "Yang", "Yezhou", "" ], [ "Aloimonos", "Yiannis", "" ], [ "Fermuller", "Cornelia", "" ], [ "Aksoy", "Eren Erdal", "" ] ]
TITLE: Learning the Semantics of Manipulation Action ABSTRACT: In this paper we present a formal computational framework for modeling manipulation actions. The introduced formalism leads to semantics of manipulation action and has applications to both observing and understanding human manipulation actions as well as executing them with a robotic mechanism (e.g. a humanoid robot). It is based on a Combinatory Categorial Grammar. The goal of the introduced framework is to: (1) represent manipulation actions with both syntax and semantic parts, where the semantic part employs $\lambda$-calculus; (2) enable a probabilistic semantic parsing schema to learn the $\lambda$-calculus representation of manipulation action from an annotated action corpus of videos; (3) use (1) and (2) to develop a system that visually observes manipulation actions and understands their meaning while it can reason beyond observations using propositional logic and axiom schemata. The experiments conducted on a public available large manipulation action dataset validate the theoretical framework and our implementation.
no_new_dataset
0.942507
1510.06925
Leigh Robinson
Leigh Robinson, Benjamin Graham
Confusing Deep Convolution Networks by Relabelling
Submitted to BMVC 2015
null
null
null
cs.CV cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep convolutional neural networks have become the gold standard for image recognition tasks, demonstrating many current state-of-the-art results and even achieving near-human level performance on some tasks. Despite this fact it has been shown that their strong generalisation qualities can be fooled to misclassify previously correctly classified natural images and give erroneous high confidence classifications to nonsense synthetic images. In this paper we extend that work, by presenting a straightforward way to perturb an image in such a way as to cause it to acquire any other label from within the dataset while leaving this perturbed image visually indistinguishable from the original.
[ { "version": "v1", "created": "Fri, 23 Oct 2015 13:02:55 GMT" }, { "version": "v2", "created": "Thu, 3 Dec 2015 18:38:08 GMT" } ]
2015-12-04T00:00:00
[ [ "Robinson", "Leigh", "" ], [ "Graham", "Benjamin", "" ] ]
TITLE: Confusing Deep Convolution Networks by Relabelling ABSTRACT: Deep convolutional neural networks have become the gold standard for image recognition tasks, demonstrating many current state-of-the-art results and even achieving near-human level performance on some tasks. Despite this fact it has been shown that their strong generalisation qualities can be fooled to misclassify previously correctly classified natural images and give erroneous high confidence classifications to nonsense synthetic images. In this paper we extend that work, by presenting a straightforward way to perturb an image in such a way as to cause it to acquire any other label from within the dataset while leaving this perturbed image visually indistinguishable from the original.
no_new_dataset
0.947235
1511.06440
Ilya Sutskever
Ilya Sutskever, Rafal Jozefowicz, Karol Gregor, Danilo Rezende, Tim Lillicrap, Oriol Vinyals
Towards Principled Unsupervised Learning
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
General unsupervised learning is a long-standing conceptual problem in machine learning. Supervised learning is successful because it can be solved by the minimization of the training error cost function. Unsupervised learning is not as successful, because the unsupervised objective may be unrelated to the supervised task of interest. For an example, density modelling and reconstruction have often been used for unsupervised learning, but they did not produced the sought-after performance gains, because they have no knowledge of the supervised tasks. In this paper, we present an unsupervised cost function which we name the Output Distribution Matching (ODM) cost, which measures a divergence between the distribution of predictions and distributions of labels. The ODM cost is appealing because it is consistent with the supervised cost in the following sense: a perfect supervised classifier is also perfect according to the ODM cost. Therefore, by aggressively optimizing the ODM cost, we are almost guaranteed to improve our supervised performance whenever the space of possible predictions is exponentially large. We demonstrate that the ODM cost works well on number of small and semi-artificial datasets using no (or almost no) labelled training cases. Finally, we show that the ODM cost can be used for one-shot domain adaptation, which allows the model to classify inputs that differ from the input distribution in significant ways without the need for prior exposure to the new domain.
[ { "version": "v1", "created": "Thu, 19 Nov 2015 23:04:23 GMT" }, { "version": "v2", "created": "Thu, 3 Dec 2015 17:24:22 GMT" } ]
2015-12-04T00:00:00
[ [ "Sutskever", "Ilya", "" ], [ "Jozefowicz", "Rafal", "" ], [ "Gregor", "Karol", "" ], [ "Rezende", "Danilo", "" ], [ "Lillicrap", "Tim", "" ], [ "Vinyals", "Oriol", "" ] ]
TITLE: Towards Principled Unsupervised Learning ABSTRACT: General unsupervised learning is a long-standing conceptual problem in machine learning. Supervised learning is successful because it can be solved by the minimization of the training error cost function. Unsupervised learning is not as successful, because the unsupervised objective may be unrelated to the supervised task of interest. For an example, density modelling and reconstruction have often been used for unsupervised learning, but they did not produced the sought-after performance gains, because they have no knowledge of the supervised tasks. In this paper, we present an unsupervised cost function which we name the Output Distribution Matching (ODM) cost, which measures a divergence between the distribution of predictions and distributions of labels. The ODM cost is appealing because it is consistent with the supervised cost in the following sense: a perfect supervised classifier is also perfect according to the ODM cost. Therefore, by aggressively optimizing the ODM cost, we are almost guaranteed to improve our supervised performance whenever the space of possible predictions is exponentially large. We demonstrate that the ODM cost works well on number of small and semi-artificial datasets using no (or almost no) labelled training cases. Finally, we show that the ODM cost can be used for one-shot domain adaptation, which allows the model to classify inputs that differ from the input distribution in significant ways without the need for prior exposure to the new domain.
no_new_dataset
0.943556
1512.00901
Mingrui Yang
Mingrui Yang, Frank de Hoog, Yuqi Fan, and Wen Hu
Compressive hyperspectral imaging via adaptive sampling and dictionary learning
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose a new sampling strategy for hyperspectral signals that is based on dictionary learning and singular value decomposition (SVD). Specifically, we first learn a sparsifying dictionary from training spectral data using dictionary learning. We then perform an SVD on the dictionary and use the first few left singular vectors as the rows of the measurement matrix to obtain the compressive measurements for reconstruction. The proposed method provides significant improvement over the conventional compressive sensing approaches. The reconstruction performance is further improved by reconditioning the sensing matrix using matrix balancing. We also demonstrate that the combination of dictionary learning and SVD is robust by applying them to different datasets.
[ { "version": "v1", "created": "Wed, 2 Dec 2015 23:13:04 GMT" } ]
2015-12-04T00:00:00
[ [ "Yang", "Mingrui", "" ], [ "de Hoog", "Frank", "" ], [ "Fan", "Yuqi", "" ], [ "Hu", "Wen", "" ] ]
TITLE: Compressive hyperspectral imaging via adaptive sampling and dictionary learning ABSTRACT: In this paper, we propose a new sampling strategy for hyperspectral signals that is based on dictionary learning and singular value decomposition (SVD). Specifically, we first learn a sparsifying dictionary from training spectral data using dictionary learning. We then perform an SVD on the dictionary and use the first few left singular vectors as the rows of the measurement matrix to obtain the compressive measurements for reconstruction. The proposed method provides significant improvement over the conventional compressive sensing approaches. The reconstruction performance is further improved by reconditioning the sensing matrix using matrix balancing. We also demonstrate that the combination of dictionary learning and SVD is robust by applying them to different datasets.
no_new_dataset
0.948394
1512.01055
Ibrahim Radwan Dr.
Ibrahim Radwan, Abhinav Dhall, Roland Goecke
Occlusion-Aware Human Pose Estimation with Mixtures of Sub-Trees
12 pages, 5 figures and 3 Tables
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we study the problem of learning a model for human pose estimation as mixtures of compositional sub-trees in two layers of prediction. This involves estimating the pose of a sub-tree followed by identifying the relationships between sub-trees that are used to handle occlusions between different parts. The mixtures of the sub-trees are learnt utilising both geometric and appearance distances. The Chow-Liu (CL) algorithm is recursively applied to determine the inter-relations between the nodes and to build the structure of the sub-trees. These structures are used to learn the latent parameters of the sub-trees and the inference is done using a standard belief propagation technique. The proposed method handles occlusions during the inference process by identifying overlapping regions between different sub-trees and introducing a penalty term for overlapping parts. Experiments are performed on three different datasets: the Leeds Sports, Image Parse and UIUC People datasets. The results show the robustness of the proposed method to occlusions over the state-of-the-art approaches.
[ { "version": "v1", "created": "Thu, 3 Dec 2015 12:25:33 GMT" } ]
2015-12-04T00:00:00
[ [ "Radwan", "Ibrahim", "" ], [ "Dhall", "Abhinav", "" ], [ "Goecke", "Roland", "" ] ]
TITLE: Occlusion-Aware Human Pose Estimation with Mixtures of Sub-Trees ABSTRACT: In this paper, we study the problem of learning a model for human pose estimation as mixtures of compositional sub-trees in two layers of prediction. This involves estimating the pose of a sub-tree followed by identifying the relationships between sub-trees that are used to handle occlusions between different parts. The mixtures of the sub-trees are learnt utilising both geometric and appearance distances. The Chow-Liu (CL) algorithm is recursively applied to determine the inter-relations between the nodes and to build the structure of the sub-trees. These structures are used to learn the latent parameters of the sub-trees and the inference is done using a standard belief propagation technique. The proposed method handles occlusions during the inference process by identifying overlapping regions between different sub-trees and introducing a penalty term for overlapping parts. Experiments are performed on three different datasets: the Leeds Sports, Image Parse and UIUC People datasets. The results show the robustness of the proposed method to occlusions over the state-of-the-art approaches.
no_new_dataset
0.943452
1512.00537
Anja Gruenheid
Anja Gruenheid and Besmira Nushi and Tim Kraska and Wolfgang Gatterbauer and Donald Kossmann
Fault-Tolerant Entity Resolution with the Crowd
null
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years, crowdsourcing is increasingly applied as a means to enhance data quality. Although the crowd generates insightful information especially for complex problems such as entity resolution (ER), the output quality of crowd workers is often noisy. That is, workers may unintentionally generate false or contradicting data even for simple tasks. The challenge that we address in this paper is how to minimize the cost for task requesters while maximizing ER result quality under the assumption of unreliable input from the crowd. For that purpose, we first establish how to deduce a consistent ER solution from noisy worker answers as part of the data interpretation problem. We then focus on the next-crowdsource problem which is to find the next task that maximizes the information gain of the ER result for the minimal additional cost. We compare our robust data interpretation strategies to alternative state-of-the-art approaches that do not incorporate the notion of fault-tolerance, i.e., the robustness to noise. In our experimental evaluation we show that our approaches yield a quality improvement of at least 20% for two real-world datasets. Furthermore, we examine task-to-worker assignment strategies as well as task parallelization techniques in terms of their cost and quality trade-offs in this paper. Based on both synthetic and crowdsourced datasets, we then draw conclusions on how to minimize cost while maintaining high quality ER results.
[ { "version": "v1", "created": "Wed, 2 Dec 2015 01:03:47 GMT" } ]
2015-12-03T00:00:00
[ [ "Gruenheid", "Anja", "" ], [ "Nushi", "Besmira", "" ], [ "Kraska", "Tim", "" ], [ "Gatterbauer", "Wolfgang", "" ], [ "Kossmann", "Donald", "" ] ]
TITLE: Fault-Tolerant Entity Resolution with the Crowd ABSTRACT: In recent years, crowdsourcing is increasingly applied as a means to enhance data quality. Although the crowd generates insightful information especially for complex problems such as entity resolution (ER), the output quality of crowd workers is often noisy. That is, workers may unintentionally generate false or contradicting data even for simple tasks. The challenge that we address in this paper is how to minimize the cost for task requesters while maximizing ER result quality under the assumption of unreliable input from the crowd. For that purpose, we first establish how to deduce a consistent ER solution from noisy worker answers as part of the data interpretation problem. We then focus on the next-crowdsource problem which is to find the next task that maximizes the information gain of the ER result for the minimal additional cost. We compare our robust data interpretation strategies to alternative state-of-the-art approaches that do not incorporate the notion of fault-tolerance, i.e., the robustness to noise. In our experimental evaluation we show that our approaches yield a quality improvement of at least 20% for two real-world datasets. Furthermore, we examine task-to-worker assignment strategies as well as task parallelization techniques in terms of their cost and quality trade-offs in this paper. Based on both synthetic and crowdsourced datasets, we then draw conclusions on how to minimize cost while maintaining high quality ER results.
no_new_dataset
0.953665
1512.00596
Ira Kemelmacher-Shlizerman
Ira Kemelmacher-Shlizerman and Steve Seitz and Daniel Miller and Evan Brossard
The MegaFace Benchmark: 1 Million Faces for Recognition at Scale
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent face recognition experiments on a major benchmark LFW show stunning performance--a number of algorithms achieve near to perfect score, surpassing human recognition rates. In this paper, we advocate evaluations at the million scale (LFW includes only 13K photos of 5K people). To this end, we have assembled the MegaFace dataset and created the first MegaFace challenge. Our dataset includes One Million photos that capture more than 690K different individuals. The challenge evaluates performance of algorithms with increasing numbers of distractors (going from 10 to 1M) in the gallery set. We present both identification and verification performance, evaluate performance with respect to pose and a person's age, and compare as a function of training data size (number of photos and people). We report results of state of the art and baseline algorithms. Our key observations are that testing at the million scale reveals big performance differences (of algorithms that perform similarly well on smaller scale) and that age invariant recognition as well as pose are still challenging for most. The MegaFace dataset, baseline code, and evaluation scripts, are all publicly released for further experimentations at: megaface.cs.washington.edu.
[ { "version": "v1", "created": "Wed, 2 Dec 2015 07:17:54 GMT" } ]
2015-12-03T00:00:00
[ [ "Kemelmacher-Shlizerman", "Ira", "" ], [ "Seitz", "Steve", "" ], [ "Miller", "Daniel", "" ], [ "Brossard", "Evan", "" ] ]
TITLE: The MegaFace Benchmark: 1 Million Faces for Recognition at Scale ABSTRACT: Recent face recognition experiments on a major benchmark LFW show stunning performance--a number of algorithms achieve near to perfect score, surpassing human recognition rates. In this paper, we advocate evaluations at the million scale (LFW includes only 13K photos of 5K people). To this end, we have assembled the MegaFace dataset and created the first MegaFace challenge. Our dataset includes One Million photos that capture more than 690K different individuals. The challenge evaluates performance of algorithms with increasing numbers of distractors (going from 10 to 1M) in the gallery set. We present both identification and verification performance, evaluate performance with respect to pose and a person's age, and compare as a function of training data size (number of photos and people). We report results of state of the art and baseline algorithms. Our key observations are that testing at the million scale reveals big performance differences (of algorithms that perform similarly well on smaller scale) and that age invariant recognition as well as pose are still challenging for most. The MegaFace dataset, baseline code, and evaluation scripts, are all publicly released for further experimentations at: megaface.cs.washington.edu.
new_dataset
0.955486
1512.00682
Davut Deniz Yavuz
Davut Deniz Yavuz, Osman Abul
Implicit Location Sharing Detection in Social Media from Short Turkish Text
6 pages
null
null
null
cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Social media have become a significant venue for information sharing of live updates. Users of social media are producing and sharing large amount of personal data as a part of the live updates. A significant percentage of this data contains location information that can be used by other people for many purposes. Some of the social media users deliberately share their own location information with other social network users. However, a large number of social media users blindly or implicitly share their location without noticing it or its possible consequences. Implicit location sharing is investigated in the current paper. We perform a large scale study on implicit location sharing for one of the most popular social media platform, namely Twitter. After a careful study, we built a dataset of Turkish tweets and manually tagged them. Using machine learning techniques we built classifiers that are able to classify whether a given tweet contains implicit location sharing or not. The classifiers are shown to be very accurate and efficient. Moreover, the best classifier is employed as a browser add-on tool which warns the user whenever an implicit location sharing is predicted from to be released tweet. The paper provides the methodology and the technical analysis as well. Furthermore, it discusses how these techniques can be extended to different social network services and also to different languages.
[ { "version": "v1", "created": "Wed, 2 Dec 2015 13:10:33 GMT" } ]
2015-12-03T00:00:00
[ [ "Yavuz", "Davut Deniz", "" ], [ "Abul", "Osman", "" ] ]
TITLE: Implicit Location Sharing Detection in Social Media from Short Turkish Text ABSTRACT: Social media have become a significant venue for information sharing of live updates. Users of social media are producing and sharing large amount of personal data as a part of the live updates. A significant percentage of this data contains location information that can be used by other people for many purposes. Some of the social media users deliberately share their own location information with other social network users. However, a large number of social media users blindly or implicitly share their location without noticing it or its possible consequences. Implicit location sharing is investigated in the current paper. We perform a large scale study on implicit location sharing for one of the most popular social media platform, namely Twitter. After a careful study, we built a dataset of Turkish tweets and manually tagged them. Using machine learning techniques we built classifiers that are able to classify whether a given tweet contains implicit location sharing or not. The classifiers are shown to be very accurate and efficient. Moreover, the best classifier is employed as a browser add-on tool which warns the user whenever an implicit location sharing is predicted from to be released tweet. The paper provides the methodology and the technical analysis as well. Furthermore, it discusses how these techniques can be extended to different social network services and also to different languages.
new_dataset
0.957437
1512.00728
David Bamman
Philip Massey, Patrick Xia, David Bamman and Noah A. Smith
Annotating Character Relationships in Literary Texts
null
null
null
null
cs.CL
http://creativecommons.org/licenses/by-nc-sa/4.0/
We present a dataset of manually annotated relationships between characters in literary texts, in order to support the training and evaluation of automatic methods for relation type prediction in this domain (Makazhanov et al., 2014; Kokkinakis, 2013) and the broader computational analysis of literary character (Elson et al., 2010; Bamman et al., 2014; Vala et al., 2015; Flekova and Gurevych, 2015). In this work, we solicit annotations from workers on Amazon Mechanical Turk for 109 texts ranging from Homer's _Iliad_ to Joyce's _Ulysses_ on four dimensions of interest: for a given pair of characters, we collect judgments as to the coarse-grained category (professional, social, familial), fine-grained category (friend, lover, parent, rival, employer), and affinity (positive, negative, neutral) that describes their primary relationship in a text. We do not assume that this relationship is static; we also collect judgments as to whether it changes at any point in the course of the text.
[ { "version": "v1", "created": "Wed, 2 Dec 2015 15:09:31 GMT" } ]
2015-12-03T00:00:00
[ [ "Massey", "Philip", "" ], [ "Xia", "Patrick", "" ], [ "Bamman", "David", "" ], [ "Smith", "Noah A.", "" ] ]
TITLE: Annotating Character Relationships in Literary Texts ABSTRACT: We present a dataset of manually annotated relationships between characters in literary texts, in order to support the training and evaluation of automatic methods for relation type prediction in this domain (Makazhanov et al., 2014; Kokkinakis, 2013) and the broader computational analysis of literary character (Elson et al., 2010; Bamman et al., 2014; Vala et al., 2015; Flekova and Gurevych, 2015). In this work, we solicit annotations from workers on Amazon Mechanical Turk for 109 texts ranging from Homer's _Iliad_ to Joyce's _Ulysses_ on four dimensions of interest: for a given pair of characters, we collect judgments as to the coarse-grained category (professional, social, familial), fine-grained category (friend, lover, parent, rival, employer), and affinity (positive, negative, neutral) that describes their primary relationship in a text. We do not assume that this relationship is static; we also collect judgments as to whether it changes at any point in the course of the text.
new_dataset
0.959875
1512.00747
Agata Mosinska
Agata Mosinska, Raphael Sznitman, Przemys{\l}aw G{\l}owacki, Pascal Fua
Active Learning for Delineation of Curvilinear Structures
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many recent delineation techniques owe much of their increased effectiveness to path classification algorithms that make it possible to distinguish promising paths from others. The downside of this development is that they require annotated training data, which is tedious to produce. In this paper, we propose an Active Learning approach that considerably speeds up the annotation process. Unlike standard ones, it takes advantage of the specificities of the delineation problem. It operates on a graph and can reduce the training set size by up to 80% without compromising the reconstruction quality. We will show that our approach outperforms conventional ones on various biomedical and natural image datasets, thus showing that it is broadly applicable.
[ { "version": "v1", "created": "Wed, 2 Dec 2015 15:57:59 GMT" } ]
2015-12-03T00:00:00
[ [ "Mosinska", "Agata", "" ], [ "Sznitman", "Raphael", "" ], [ "Głowacki", "Przemysław", "" ], [ "Fua", "Pascal", "" ] ]
TITLE: Active Learning for Delineation of Curvilinear Structures ABSTRACT: Many recent delineation techniques owe much of their increased effectiveness to path classification algorithms that make it possible to distinguish promising paths from others. The downside of this development is that they require annotated training data, which is tedious to produce. In this paper, we propose an Active Learning approach that considerably speeds up the annotation process. Unlike standard ones, it takes advantage of the specificities of the delineation problem. It operates on a graph and can reduce the training set size by up to 80% without compromising the reconstruction quality. We will show that our approach outperforms conventional ones on various biomedical and natural image datasets, thus showing that it is broadly applicable.
no_new_dataset
0.947381
1504.04660
Neal Hurlburt
Neal Hurlburt and Steve Jaffey
A spectral optical flow method for determining velocities from digital imagery
12 pages, 5 figures. Submitted to Earth Science Informatics
Earth Science Informatics: Volume 8, Issue 4 (2015), Page 959-965
10.1007/s12145-015-0224-4
null
cs.CV astro-ph.IM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a method for determining surface flows from solar images based upon optical flow techniques. We apply the method to sets of images obtained by a variety of solar imagers to assess its performance. The {\tt opflow3d} procedure is shown to extract accurate velocity estimates when provided perfect test data and quickly generates results consistent with completely distinct methods when applied on global scales. We also validate it in detail by comparing it to an established method when applied to high-resolution datasets and find that it provides comparable results without the need to tune, filter or otherwise preprocess the images before its application.
[ { "version": "v1", "created": "Fri, 17 Apr 2015 23:44:20 GMT" } ]
2015-12-02T00:00:00
[ [ "Hurlburt", "Neal", "" ], [ "Jaffey", "Steve", "" ] ]
TITLE: A spectral optical flow method for determining velocities from digital imagery ABSTRACT: We present a method for determining surface flows from solar images based upon optical flow techniques. We apply the method to sets of images obtained by a variety of solar imagers to assess its performance. The {\tt opflow3d} procedure is shown to extract accurate velocity estimates when provided perfect test data and quickly generates results consistent with completely distinct methods when applied on global scales. We also validate it in detail by comparing it to an established method when applied to high-resolution datasets and find that it provides comparable results without the need to tune, filter or otherwise preprocess the images before its application.
no_new_dataset
0.95253
1512.00001
Stan Hatko
Stan Hatko
k-Nearest Neighbour Classification of Datasets with a Family of Distances
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The $k$-nearest neighbour ($k$-NN) classifier is one of the oldest and most important supervised learning algorithms for classifying datasets. Traditionally the Euclidean norm is used as the distance for the $k$-NN classifier. In this thesis we investigate the use of alternative distances for the $k$-NN classifier. We start by introducing some background notions in statistical machine learning. We define the $k$-NN classifier and discuss Stone's theorem and the proof that $k$-NN is universally consistent on the normed space $R^d$. We then prove that $k$-NN is universally consistent if we take a sequence of random norms (that are independent of the sample and the query) from a family of norms that satisfies a particular boundedness condition. We extend this result by replacing norms with distances based on uniformly locally Lipschitz functions that satisfy certain conditions. We discuss the limitations of Stone's lemma and Stone's theorem, particularly with respect to quasinorms and adaptively choosing a distance for $k$-NN based on the labelled sample. We show the universal consistency of a two stage $k$-NN type classifier where we select the distance adaptively based on a split labelled sample and the query. We conclude by giving some examples of improvements of the accuracy of classifying various datasets using the above techniques.
[ { "version": "v1", "created": "Sun, 29 Nov 2015 01:52:34 GMT" } ]
2015-12-02T00:00:00
[ [ "Hatko", "Stan", "" ] ]
TITLE: k-Nearest Neighbour Classification of Datasets with a Family of Distances ABSTRACT: The $k$-nearest neighbour ($k$-NN) classifier is one of the oldest and most important supervised learning algorithms for classifying datasets. Traditionally the Euclidean norm is used as the distance for the $k$-NN classifier. In this thesis we investigate the use of alternative distances for the $k$-NN classifier. We start by introducing some background notions in statistical machine learning. We define the $k$-NN classifier and discuss Stone's theorem and the proof that $k$-NN is universally consistent on the normed space $R^d$. We then prove that $k$-NN is universally consistent if we take a sequence of random norms (that are independent of the sample and the query) from a family of norms that satisfies a particular boundedness condition. We extend this result by replacing norms with distances based on uniformly locally Lipschitz functions that satisfy certain conditions. We discuss the limitations of Stone's lemma and Stone's theorem, particularly with respect to quasinorms and adaptively choosing a distance for $k$-NN based on the labelled sample. We show the universal consistency of a two stage $k$-NN type classifier where we select the distance adaptively based on a split labelled sample and the query. We conclude by giving some examples of improvements of the accuracy of classifying various datasets using the above techniques.
no_new_dataset
0.946892
1512.00066
Edgar Solomonik
Edgar Solomonik and Torsten Hoefler
Sparse Tensor Algebra as a Parallel Programming Model
null
null
null
null
cs.MS
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dense and sparse tensors allow the representation of most bulk data structures in computational science applications. We show that sparse tensor algebra can also be used to express many of the transformations on these datasets, especially those which are parallelizable. Tensor computations are a natural generalization of matrix and graph computations. We extend the usual basic operations of tensor summation and contraction to arbitrary functions, and further operations such as reductions and mapping. The expression of these transformations in a high-level sparse linear algebra domain specific language allows our framework to understand their properties at runtime to select the preferred communication-avoiding algorithm. To demonstrate the efficacy of our approach, we show how key graph algorithms as well as common numerical kernels can be succinctly expressed using our interface and provide performance results of a general library implementation.
[ { "version": "v1", "created": "Mon, 30 Nov 2015 22:08:23 GMT" } ]
2015-12-02T00:00:00
[ [ "Solomonik", "Edgar", "" ], [ "Hoefler", "Torsten", "" ] ]
TITLE: Sparse Tensor Algebra as a Parallel Programming Model ABSTRACT: Dense and sparse tensors allow the representation of most bulk data structures in computational science applications. We show that sparse tensor algebra can also be used to express many of the transformations on these datasets, especially those which are parallelizable. Tensor computations are a natural generalization of matrix and graph computations. We extend the usual basic operations of tensor summation and contraction to arbitrary functions, and further operations such as reductions and mapping. The expression of these transformations in a high-level sparse linear algebra domain specific language allows our framework to understand their properties at runtime to select the preferred communication-avoiding algorithm. To demonstrate the efficacy of our approach, we show how key graph algorithms as well as common numerical kernels can be succinctly expressed using our interface and provide performance results of a general library implementation.
no_new_dataset
0.939969
1512.00112
Shashank Srivastava
Shashank Srivastava, Snigdha Chaturvedi and Tom Mitchell
Inferring Interpersonal Relations in Narrative Summaries
null
null
null
null
cs.CL cs.AI cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Characterizing relationships between people is fundamental for the understanding of narratives. In this work, we address the problem of inferring the polarity of relationships between people in narrative summaries. We formulate the problem as a joint structured prediction for each narrative, and present a model that combines evidence from linguistic and semantic features, as well as features based on the structure of the social community in the text. We also provide a clustering-based approach that can exploit regularities in narrative types. e.g., learn an affinity for love-triangles in romantic stories. On a dataset of movie summaries from Wikipedia, our structured models provide more than a 30% error-reduction over a competitive baseline that considers pairs of characters in isolation.
[ { "version": "v1", "created": "Tue, 1 Dec 2015 01:11:46 GMT" } ]
2015-12-02T00:00:00
[ [ "Srivastava", "Shashank", "" ], [ "Chaturvedi", "Snigdha", "" ], [ "Mitchell", "Tom", "" ] ]
TITLE: Inferring Interpersonal Relations in Narrative Summaries ABSTRACT: Characterizing relationships between people is fundamental for the understanding of narratives. In this work, we address the problem of inferring the polarity of relationships between people in narrative summaries. We formulate the problem as a joint structured prediction for each narrative, and present a model that combines evidence from linguistic and semantic features, as well as features based on the structure of the social community in the text. We also provide a clustering-based approach that can exploit regularities in narrative types. e.g., learn an affinity for love-triangles in romantic stories. On a dataset of movie summaries from Wikipedia, our structured models provide more than a 30% error-reduction over a competitive baseline that considers pairs of characters in isolation.
no_new_dataset
0.95018
1512.00130
Tyng-Luh Liu
Tsung-Yu Lin, Tsung-Wei Ke, Tyng-Luh Liu
Implicit Sparse Code Hashing
9 pages, 1 figure
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address the problem of converting large-scale high-dimensional image data into binary codes so that approximate nearest-neighbor search over them can be efficiently performed. Different from most of the existing unsupervised approaches for yielding binary codes, our method is based on a dimensionality-reduction criterion that its resulting mapping is designed to preserve the image relationships entailed by the inner products of sparse codes, rather than those implied by the Euclidean distances in the ambient space. While the proposed formulation does not require computing any sparse codes, the underlying computation model still inevitably involves solving an unmanageable eigenproblem when extremely high-dimensional descriptors are used. To overcome the difficulty, we consider the column-sampling technique and presume a special form of rotation matrix to facilitate subproblem decomposition. We test our method on several challenging image datasets and demonstrate its effectiveness by comparing with state-of-the-art binary coding techniques.
[ { "version": "v1", "created": "Tue, 1 Dec 2015 03:12:09 GMT" } ]
2015-12-02T00:00:00
[ [ "Lin", "Tsung-Yu", "" ], [ "Ke", "Tsung-Wei", "" ], [ "Liu", "Tyng-Luh", "" ] ]
TITLE: Implicit Sparse Code Hashing ABSTRACT: We address the problem of converting large-scale high-dimensional image data into binary codes so that approximate nearest-neighbor search over them can be efficiently performed. Different from most of the existing unsupervised approaches for yielding binary codes, our method is based on a dimensionality-reduction criterion that its resulting mapping is designed to preserve the image relationships entailed by the inner products of sparse codes, rather than those implied by the Euclidean distances in the ambient space. While the proposed formulation does not require computing any sparse codes, the underlying computation model still inevitably involves solving an unmanageable eigenproblem when extremely high-dimensional descriptors are used. To overcome the difficulty, we consider the column-sampling technique and presume a special form of rotation matrix to facilitate subproblem decomposition. We test our method on several challenging image datasets and demonstrate its effectiveness by comparing with state-of-the-art binary coding techniques.
no_new_dataset
0.943191
1512.00308
Luiz Capretz Dr.
Faheem Ahmed, Piers Campbell, Ahmad Jaffar, Luiz Fernando Capretz
Managing Support Requests in Open Source Software Project: The Role of Online Forums
arXiv admin note: substantial text overlap with arXiv:1507.06927
2nd IEEE International Conference on Computer Science and Information Technology, pp. 590-594, 2009
10.1109/ICCSIT.2009.5234491
null
cs.SE cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The use of free and open source software is gaining momentum due to the ever increasing availability and use of the Internet. Organizations are also now adopting open source software, despite some reservations in particular regarding the provision and availability of support. One of the greatest concerns about free and open source software is the availability of post release support and the handling of for support. A common belief is that there is no appropriate support available for this class of software, while an alternative argument is that due to the active involvement of Internet users in online forums, there is in fact a large resource available that communicates and manages the management of support requests. The research model of this empirical investigation establishes and studies the relationship between open source software support requests and online public forums. The results of this empirical study provide evidence about the realities of support that is present in open source software projects. We used a dataset consisting of 616 open source software projects covering a broad range of categories in this investigation. The results show that online forums play a significant role in managing support requests in open source software, thus becoming a major source of assistance in maintenance of the open source projects.
[ { "version": "v1", "created": "Tue, 1 Dec 2015 15:51:24 GMT" } ]
2015-12-02T00:00:00
[ [ "Ahmed", "Faheem", "" ], [ "Campbell", "Piers", "" ], [ "Jaffar", "Ahmad", "" ], [ "Capretz", "Luiz Fernando", "" ] ]
TITLE: Managing Support Requests in Open Source Software Project: The Role of Online Forums ABSTRACT: The use of free and open source software is gaining momentum due to the ever increasing availability and use of the Internet. Organizations are also now adopting open source software, despite some reservations in particular regarding the provision and availability of support. One of the greatest concerns about free and open source software is the availability of post release support and the handling of for support. A common belief is that there is no appropriate support available for this class of software, while an alternative argument is that due to the active involvement of Internet users in online forums, there is in fact a large resource available that communicates and manages the management of support requests. The research model of this empirical investigation establishes and studies the relationship between open source software support requests and online public forums. The results of this empirical study provide evidence about the realities of support that is present in open source software projects. We used a dataset consisting of 616 open source software projects covering a broad range of categories in this investigation. The results show that online forums play a significant role in managing support requests in open source software, thus becoming a major source of assistance in maintenance of the open source projects.
new_dataset
0.970743
1412.5687
Abhijit Bendale
Abhijit Bendale, Terrance Boult
Towards Open World Recognition
null
IEEE Conference on Computer Vision and Pattern Recognition (CVPR) (2015) 1893 - 1902
10.1109/CVPR.2015.7298799
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the of advent rich classification models and high computational power visual recognition systems have found many operational applications. Recognition in the real world poses multiple challenges that are not apparent in controlled lab environments. The datasets are dynamic and novel categories must be continuously detected and then added. At prediction time, a trained system has to deal with myriad unseen categories. Operational systems require minimum down time, even to learn. To handle these operational issues, we present the problem of Open World recognition and formally define it. We prove that thresholding sums of monotonically decreasing functions of distances in linearly transformed feature space can balance "open space risk" and empirical risk. Our theory extends existing algorithms for open world recognition. We present a protocol for evaluation of open world recognition systems. We present the Nearest Non-Outlier (NNO) algorithm which evolves model efficiently, adding object categories incrementally while detecting outliers and managing open space risk. We perform experiments on the ImageNet dataset with 1.2M+ images to validate the effectiveness of our method on large scale visual recognition tasks. NNO consistently yields superior results on open world recognition.
[ { "version": "v1", "created": "Thu, 18 Dec 2014 00:07:45 GMT" } ]
2015-12-01T00:00:00
[ [ "Bendale", "Abhijit", "" ], [ "Boult", "Terrance", "" ] ]
TITLE: Towards Open World Recognition ABSTRACT: With the of advent rich classification models and high computational power visual recognition systems have found many operational applications. Recognition in the real world poses multiple challenges that are not apparent in controlled lab environments. The datasets are dynamic and novel categories must be continuously detected and then added. At prediction time, a trained system has to deal with myriad unseen categories. Operational systems require minimum down time, even to learn. To handle these operational issues, we present the problem of Open World recognition and formally define it. We prove that thresholding sums of monotonically decreasing functions of distances in linearly transformed feature space can balance "open space risk" and empirical risk. Our theory extends existing algorithms for open world recognition. We present a protocol for evaluation of open world recognition systems. We present the Nearest Non-Outlier (NNO) algorithm which evolves model efficiently, adding object categories incrementally while detecting outliers and managing open space risk. We perform experiments on the ImageNet dataset with 1.2M+ images to validate the effectiveness of our method on large scale visual recognition tasks. NNO consistently yields superior results on open world recognition.
no_new_dataset
0.945901
1503.09129
Brian Gardner BG
Brian Gardner, Ioana Sporea, Andr\'e Gr\"uning
Encoding Spike Patterns in Multilayer Spiking Neural Networks
31 pages, 14 figures
null
10.1162/NECO_a_00790
null
cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Information encoding in the nervous system is supported through the precise spike-timings of neurons; however, an understanding of the underlying processes by which such representations are formed in the first place remains unclear. Here we examine how networks of spiking neurons can learn to encode for input patterns using a fully temporal coding scheme. To this end, we introduce a learning rule for spiking networks containing hidden neurons which optimizes the likelihood of generating desired output spiking patterns. We show the proposed learning rule allows for a large number of accurate input-output spike pattern mappings to be learnt, which outperforms other existing learning rules for spiking neural networks: both in the number of mappings that can be learnt as well as the complexity of spike train encodings that can be utilised. The learning rule is successful even in the presence of input noise, is demonstrated to solve the linearly non-separable XOR computation and generalizes well on an example dataset. We further present a biologically plausible implementation of backpropagated learning in multilayer spiking networks, and discuss the neural mechanisms that might underlie its function. Our approach contributes both to a systematic understanding of how pattern encodings might take place in the nervous system, and a learning rule that displays strong technical capability.
[ { "version": "v1", "created": "Tue, 31 Mar 2015 17:12:07 GMT" } ]
2015-12-01T00:00:00
[ [ "Gardner", "Brian", "" ], [ "Sporea", "Ioana", "" ], [ "Grüning", "André", "" ] ]
TITLE: Encoding Spike Patterns in Multilayer Spiking Neural Networks ABSTRACT: Information encoding in the nervous system is supported through the precise spike-timings of neurons; however, an understanding of the underlying processes by which such representations are formed in the first place remains unclear. Here we examine how networks of spiking neurons can learn to encode for input patterns using a fully temporal coding scheme. To this end, we introduce a learning rule for spiking networks containing hidden neurons which optimizes the likelihood of generating desired output spiking patterns. We show the proposed learning rule allows for a large number of accurate input-output spike pattern mappings to be learnt, which outperforms other existing learning rules for spiking neural networks: both in the number of mappings that can be learnt as well as the complexity of spike train encodings that can be utilised. The learning rule is successful even in the presence of input noise, is demonstrated to solve the linearly non-separable XOR computation and generalizes well on an example dataset. We further present a biologically plausible implementation of backpropagated learning in multilayer spiking networks, and discuss the neural mechanisms that might underlie its function. Our approach contributes both to a systematic understanding of how pattern encodings might take place in the nervous system, and a learning rule that displays strong technical capability.
no_new_dataset
0.945399
1504.00981
Wu Ai
Wu Ai and Weisheng Chen
ELM-Based Distributed Cooperative Learning Over Networks
This paper has been withdrawn by the authors due to the incorrect proof of Theorem 2
null
null
null
cs.LG math.OC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper investigates distributed cooperative learning algorithms for data processing in a network setting. Specifically, the extreme learning machine (ELM) is introduced to train a set of data distributed across several components, and each component runs a program on a subset of the entire data. In this scheme, there is no requirement for a fusion center in the network due to e.g., practical limitations, security, or privacy reasons. We first reformulate the centralized ELM training problem into a separable form among nodes with consensus constraints. Then, we solve the equivalent problem using distributed optimization tools. A new distributed cooperative learning algorithm based on ELM, called DC-ELM, is proposed. The architecture of this algorithm differs from that of some existing parallel/distributed ELMs based on MapReduce or cloud computing. We also present an online version of the proposed algorithm that can learn data sequentially in a one-by-one or chunk-by-chunk mode. The novel algorithm is well suited for potential applications such as artificial intelligence, computational biology, finance, wireless sensor networks, and so on, involving datasets that are often extremely large, high-dimensional and located on distributed data sources. We show simulation results on both synthetic and real-world data sets.
[ { "version": "v1", "created": "Sat, 4 Apr 2015 04:40:48 GMT" }, { "version": "v2", "created": "Mon, 30 Nov 2015 05:48:56 GMT" } ]
2015-12-01T00:00:00
[ [ "Ai", "Wu", "" ], [ "Chen", "Weisheng", "" ] ]
TITLE: ELM-Based Distributed Cooperative Learning Over Networks ABSTRACT: This paper investigates distributed cooperative learning algorithms for data processing in a network setting. Specifically, the extreme learning machine (ELM) is introduced to train a set of data distributed across several components, and each component runs a program on a subset of the entire data. In this scheme, there is no requirement for a fusion center in the network due to e.g., practical limitations, security, or privacy reasons. We first reformulate the centralized ELM training problem into a separable form among nodes with consensus constraints. Then, we solve the equivalent problem using distributed optimization tools. A new distributed cooperative learning algorithm based on ELM, called DC-ELM, is proposed. The architecture of this algorithm differs from that of some existing parallel/distributed ELMs based on MapReduce or cloud computing. We also present an online version of the proposed algorithm that can learn data sequentially in a one-by-one or chunk-by-chunk mode. The novel algorithm is well suited for potential applications such as artificial intelligence, computational biology, finance, wireless sensor networks, and so on, involving datasets that are often extremely large, high-dimensional and located on distributed data sources. We show simulation results on both synthetic and real-world data sets.
no_new_dataset
0.943034
1505.02074
Mengye Ren
Mengye Ren, Ryan Kiros, Richard Zemel
Exploring Models and Data for Image Question Answering
12 pages. Conference paper at NIPS 2015
null
null
null
cs.LG cs.AI cs.CL cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This work aims to address the problem of image-based question-answering (QA) with new models and datasets. In our work, we propose to use neural networks and visual semantic embeddings, without intermediate stages such as object detection and image segmentation, to predict answers to simple questions about images. Our model performs 1.8 times better than the only published results on an existing image QA dataset. We also present a question generation algorithm that converts image descriptions, which are widely available, into QA form. We used this algorithm to produce an order-of-magnitude larger dataset, with more evenly distributed answers. A suite of baseline results on this new dataset are also presented.
[ { "version": "v1", "created": "Fri, 8 May 2015 15:59:44 GMT" }, { "version": "v2", "created": "Fri, 19 Jun 2015 19:55:07 GMT" }, { "version": "v3", "created": "Thu, 25 Jun 2015 06:44:44 GMT" }, { "version": "v4", "created": "Sun, 29 Nov 2015 22:45:12 GMT" } ]
2015-12-01T00:00:00
[ [ "Ren", "Mengye", "" ], [ "Kiros", "Ryan", "" ], [ "Zemel", "Richard", "" ] ]
TITLE: Exploring Models and Data for Image Question Answering ABSTRACT: This work aims to address the problem of image-based question-answering (QA) with new models and datasets. In our work, we propose to use neural networks and visual semantic embeddings, without intermediate stages such as object detection and image segmentation, to predict answers to simple questions about images. Our model performs 1.8 times better than the only published results on an existing image QA dataset. We also present a question generation algorithm that converts image descriptions, which are widely available, into QA form. We used this algorithm to produce an order-of-magnitude larger dataset, with more evenly distributed answers. A suite of baseline results on this new dataset are also presented.
new_dataset
0.952175
1506.00262
Kyle Beauchamp
Kyle A. Beauchamp, Julie M. Behr, Ari\"en S. Rustenburg, Christopher I. Bayly, Kenneth Kroenlein, John D. Chodera
Towards Automated Benchmarking of Atomistic Forcefields: Neat Liquid Densities and Static Dielectric Constants from the ThermoML Data Archive
null
J. Phys. Chem. B, 2015, 119 (40), pp 12912-12920
10.1021/acs.jpcb.5b06703
null
physics.chem-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Atomistic molecular simulations are a powerful way to make quantitative predictions, but the accuracy of these predictions depends entirely on the quality of the forcefield employed. While experimental measurements of fundamental physical properties offer a straightforward approach for evaluating forcefield quality, the bulk of this information has been tied up in formats that are not machine-readable. Compiling benchmark datasets of physical properties from non-machine-readable sources require substantial human effort and is prone to accumulation of human errors, hindering the development of reproducible benchmarks of forcefield accuracy. Here, we examine the feasibility of benchmarking atomistic forcefields against the NIST ThermoML data archive of physicochemical measurements, which aggregates thousands of experimental measurements in a portable, machine-readable, self-annotating format. As a proof of concept, we present a detailed benchmark of the generalized Amber small molecule forcefield (GAFF) using the AM1-BCC charge model against measurements (specifically bulk liquid densities and static dielectric constants at ambient pressure) automatically extracted from the archive, and discuss the extent of available data. The results of this benchmark highlight a general problem with fixed-charge forcefields in the representation low dielectric environments such as those seen in binding cavities or biological membranes.
[ { "version": "v1", "created": "Sun, 31 May 2015 17:59:03 GMT" } ]
2015-12-01T00:00:00
[ [ "Beauchamp", "Kyle A.", "" ], [ "Behr", "Julie M.", "" ], [ "Rustenburg", "Ariën S.", "" ], [ "Bayly", "Christopher I.", "" ], [ "Kroenlein", "Kenneth", "" ], [ "Chodera", "John D.", "" ] ]
TITLE: Towards Automated Benchmarking of Atomistic Forcefields: Neat Liquid Densities and Static Dielectric Constants from the ThermoML Data Archive ABSTRACT: Atomistic molecular simulations are a powerful way to make quantitative predictions, but the accuracy of these predictions depends entirely on the quality of the forcefield employed. While experimental measurements of fundamental physical properties offer a straightforward approach for evaluating forcefield quality, the bulk of this information has been tied up in formats that are not machine-readable. Compiling benchmark datasets of physical properties from non-machine-readable sources require substantial human effort and is prone to accumulation of human errors, hindering the development of reproducible benchmarks of forcefield accuracy. Here, we examine the feasibility of benchmarking atomistic forcefields against the NIST ThermoML data archive of physicochemical measurements, which aggregates thousands of experimental measurements in a portable, machine-readable, self-annotating format. As a proof of concept, we present a detailed benchmark of the generalized Amber small molecule forcefield (GAFF) using the AM1-BCC charge model against measurements (specifically bulk liquid densities and static dielectric constants at ambient pressure) automatically extracted from the archive, and discuss the extent of available data. The results of this benchmark highlight a general problem with fixed-charge forcefields in the representation low dielectric environments such as those seen in binding cavities or biological membranes.
no_new_dataset
0.931774
1511.08827
Luiz Capretz Dr.
Arif Raza, Luiz Fernando Capretz, Faheem Ahmed
Maintenance Support in Open Source Software Projects
null
null
10.1109/ICDIM.2013.6694005
null
cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Easy and mostly free access to the internet has resulted in the growing use of open source software (OSS). However, it is a common perception that closed proprietary software is still superior in areas such as software maintenance and management. The research model of this study establishes a relationship between maintenance issues (such as user requests and error handling) and support provided by open source software through project forums, mailing lists and trackers. To conduct this research, we have used a dataset consisting of 120 open source software projects, covering a wide range of categories. The results of the study show that project forums and mailing lists play a significant role in addressing user requests in open source software. However according to the empirical investigation, it has been explored that trackers are used as an effective medium for error reporting as well as user requests.
[ { "version": "v1", "created": "Fri, 27 Nov 2015 21:43:39 GMT" } ]
2015-12-01T00:00:00
[ [ "Raza", "Arif", "" ], [ "Capretz", "Luiz Fernando", "" ], [ "Ahmed", "Faheem", "" ] ]
TITLE: Maintenance Support in Open Source Software Projects ABSTRACT: Easy and mostly free access to the internet has resulted in the growing use of open source software (OSS). However, it is a common perception that closed proprietary software is still superior in areas such as software maintenance and management. The research model of this study establishes a relationship between maintenance issues (such as user requests and error handling) and support provided by open source software through project forums, mailing lists and trackers. To conduct this research, we have used a dataset consisting of 120 open source software projects, covering a wide range of categories. The results of the study show that project forums and mailing lists play a significant role in addressing user requests in open source software. However according to the empirical investigation, it has been explored that trackers are used as an effective medium for error reporting as well as user requests.
new_dataset
0.960584
1511.08899
Mohamed Moustafa
Mohamed Moustafa
Applying deep learning to classify pornographic images and videos
PSIVT 2015, the final publication is available at link.springer.com
null
null
null
cs.CV cs.MM cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is no secret that pornographic material is now a one-click-away from everyone, including children and minors. General social media networks are striving to isolate adult images and videos from normal ones. Intelligent image analysis methods can help to automatically detect and isolate questionable images in media. Unfortunately, these methods require vast experience to design the classifier including one or more of the popular computer vision feature descriptors. We propose to build a classifier based on one of the recently flourishing deep learning techniques. Convolutional neural networks contain many layers for both automatic features extraction and classification. The benefit is an easier system to build (no need for hand-crafting features and classifiers). Additionally, our experiments show that it is even more accurate than the state of the art methods on the most recent benchmark dataset.
[ { "version": "v1", "created": "Sat, 28 Nov 2015 13:55:25 GMT" } ]
2015-12-01T00:00:00
[ [ "Moustafa", "Mohamed", "" ] ]
TITLE: Applying deep learning to classify pornographic images and videos ABSTRACT: It is no secret that pornographic material is now a one-click-away from everyone, including children and minors. General social media networks are striving to isolate adult images and videos from normal ones. Intelligent image analysis methods can help to automatically detect and isolate questionable images in media. Unfortunately, these methods require vast experience to design the classifier including one or more of the popular computer vision feature descriptors. We propose to build a classifier based on one of the recently flourishing deep learning techniques. Convolutional neural networks contain many layers for both automatic features extraction and classification. The benefit is an easier system to build (no need for hand-crafting features and classifiers). Additionally, our experiments show that it is even more accurate than the state of the art methods on the most recent benchmark dataset.
no_new_dataset
0.942507
1511.08951
Basura Fernando
Basura Fernando, Efstratios Gavves, Damien Muselet, Tinne Tuytelaars
MidRank: Learning to rank based on subsequences
To appear in ICCV 2015
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a supervised learning to rank algorithm that effectively orders images by exploiting the structure in image sequences. Most often in the supervised learning to rank literature, ranking is approached either by analyzing pairs of images or by optimizing a list-wise surrogate loss function on full sequences. In this work we propose MidRank, which learns from moderately sized sub-sequences instead. These sub-sequences contain useful structural ranking information that leads to better learnability during training and better generalization during testing. By exploiting sub-sequences, the proposed MidRank improves ranking accuracy considerably on an extensive array of image ranking applications and datasets.
[ { "version": "v1", "created": "Sun, 29 Nov 2015 00:47:19 GMT" } ]
2015-12-01T00:00:00
[ [ "Fernando", "Basura", "" ], [ "Gavves", "Efstratios", "" ], [ "Muselet", "Damien", "" ], [ "Tuytelaars", "Tinne", "" ] ]
TITLE: MidRank: Learning to rank based on subsequences ABSTRACT: We present a supervised learning to rank algorithm that effectively orders images by exploiting the structure in image sequences. Most often in the supervised learning to rank literature, ranking is approached either by analyzing pairs of images or by optimizing a list-wise surrogate loss function on full sequences. In this work we propose MidRank, which learns from moderately sized sub-sequences instead. These sub-sequences contain useful structural ranking information that leads to better learnability during training and better generalization during testing. By exploiting sub-sequences, the proposed MidRank improves ranking accuracy considerably on an extensive array of image ranking applications and datasets.
no_new_dataset
0.951997
1511.09066
Richard McClatchey
Kamran Munir, Khawar Hasham Ahmad and Richard McClatchey
Development of a Large-scale Neuroimages and Clinical Variables Data Atlas in the neuGRID4You (N4U) project
35 pages, 15 figures, Journal of Biomedical Informatics, 2015
null
10.1016/j.jbi.2015.08.004
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Exceptional growth in the availability of large-scale clinical imaging datasets has led to the development of computational infrastructures offering scientists access to image repositories and associated clinical variables data. The EU FP7 neuGRID and its follow on neuGRID4You (N4U) project is a leading e-Infrastructure where neuroscientists can find core services and resources for brain image analysis. The core component of this e-Infrastructure is the N4U Virtual Laboratory, which offers an easy access for neuroscientists to a wide range of datasets and algorithms, pipelines, computational resources, services, and associated support services. The foundation of this virtual laboratory is a massive data store plus information services called the Data Atlas that stores datasets, clinical study data, data dictionaries, algorithm/pipeline definitions, and provides interfaces for parameterised querying so that neuroscientists can perform analyses on required datasets. This paper presents the overall design and development of the Data Atlas, its associated datasets and indexing and a set of retrieval services that originated from the development of the N4U Virtual Laboratory in the EU FP7 N4U project in the light of user requirements.
[ { "version": "v1", "created": "Sun, 29 Nov 2015 19:14:53 GMT" } ]
2015-12-01T00:00:00
[ [ "Munir", "Kamran", "" ], [ "Ahmad", "Khawar Hasham", "" ], [ "McClatchey", "Richard", "" ] ]
TITLE: Development of a Large-scale Neuroimages and Clinical Variables Data Atlas in the neuGRID4You (N4U) project ABSTRACT: Exceptional growth in the availability of large-scale clinical imaging datasets has led to the development of computational infrastructures offering scientists access to image repositories and associated clinical variables data. The EU FP7 neuGRID and its follow on neuGRID4You (N4U) project is a leading e-Infrastructure where neuroscientists can find core services and resources for brain image analysis. The core component of this e-Infrastructure is the N4U Virtual Laboratory, which offers an easy access for neuroscientists to a wide range of datasets and algorithms, pipelines, computational resources, services, and associated support services. The foundation of this virtual laboratory is a massive data store plus information services called the Data Atlas that stores datasets, clinical study data, data dictionaries, algorithm/pipeline definitions, and provides interfaces for parameterised querying so that neuroscientists can perform analyses on required datasets. This paper presents the overall design and development of the Data Atlas, its associated datasets and indexing and a set of retrieval services that originated from the development of the N4U Virtual Laboratory in the EU FP7 N4U project in the light of user requirements.
no_new_dataset
0.951278
1511.09067
Mohamed Elawady
Mohamed Elawady
Sparse Coral Classification Using Deep Convolutional Neural Networks
Thesis Submitted for the Degree of MSc Erasmus Mundus in Vision and Robotics (VIBOT 2014)
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Autonomous repair of deep-sea coral reefs is a recent proposed idea to support the oceans ecosystem in which is vital for commercial fishing, tourism and other species. This idea can be operated through using many small autonomous underwater vehicles (AUVs) and swarm intelligence techniques to locate and replace chunks of coral which have been broken off, thus enabling re-growth and maintaining the habitat. The aim of this project is developing machine vision algorithms to enable an underwater robot to locate a coral reef and a chunk of coral on the seabed and prompt the robot to pick it up. Although there is no literature on this particular problem, related work on fish counting may give some insight into the problem. The technical challenges are principally due to the potential lack of clarity of the water and platform stabilization as well as spurious artifacts (rocks, fish, and crabs). We present an efficient sparse classification for coral species using supervised deep learning method called Convolutional Neural Networks (CNNs). We compute Weber Local Descriptor (WLD), Phase Congruency (PC), and Zero Component Analysis (ZCA) Whitening to extract shape and texture feature descriptors, which are employed to be supplementary channels (feature-based maps) besides basic spatial color channels (spatial-based maps) of coral input image, we also experiment state-of-art preprocessing underwater algorithms for image enhancement and color normalization and color conversion adjustment. Our proposed coral classification method is developed under MATLAB platform, and evaluated by two different coral datasets (University of California San Diego's Moorea Labeled Corals, and Heriot-Watt University's Atlantic Deep Sea).
[ { "version": "v1", "created": "Sun, 29 Nov 2015 19:18:36 GMT" } ]
2015-12-01T00:00:00
[ [ "Elawady", "Mohamed", "" ] ]
TITLE: Sparse Coral Classification Using Deep Convolutional Neural Networks ABSTRACT: Autonomous repair of deep-sea coral reefs is a recent proposed idea to support the oceans ecosystem in which is vital for commercial fishing, tourism and other species. This idea can be operated through using many small autonomous underwater vehicles (AUVs) and swarm intelligence techniques to locate and replace chunks of coral which have been broken off, thus enabling re-growth and maintaining the habitat. The aim of this project is developing machine vision algorithms to enable an underwater robot to locate a coral reef and a chunk of coral on the seabed and prompt the robot to pick it up. Although there is no literature on this particular problem, related work on fish counting may give some insight into the problem. The technical challenges are principally due to the potential lack of clarity of the water and platform stabilization as well as spurious artifacts (rocks, fish, and crabs). We present an efficient sparse classification for coral species using supervised deep learning method called Convolutional Neural Networks (CNNs). We compute Weber Local Descriptor (WLD), Phase Congruency (PC), and Zero Component Analysis (ZCA) Whitening to extract shape and texture feature descriptors, which are employed to be supplementary channels (feature-based maps) besides basic spatial color channels (spatial-based maps) of coral input image, we also experiment state-of-art preprocessing underwater algorithms for image enhancement and color normalization and color conversion adjustment. Our proposed coral classification method is developed under MATLAB platform, and evaluated by two different coral datasets (University of California San Diego's Moorea Labeled Corals, and Heriot-Watt University's Atlantic Deep Sea).
no_new_dataset
0.954308
1511.09107
K. Ch. Chatzisavvas
Panagiotis Stalidis, Maria Giatsoglou, Konstantinos Diamantaras, George Sarigiannidis, Konstantinos Ch. Chatzisavvas
Machine Learning Sentiment Prediction based on Hybrid Document Representation
null
null
null
null
cs.CL cs.AI stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Automated sentiment analysis and opinion mining is a complex process concerning the extraction of useful subjective information from text. The explosion of user generated content on the Web, especially the fact that millions of users, on a daily basis, express their opinions on products and services to blogs, wikis, social networks, message boards, etc., render the reliable, automated export of sentiments and opinions from unstructured text crucial for several commercial applications. In this paper, we present a novel hybrid vectorization approach for textual resources that combines a weighted variant of the popular Word2Vec representation (based on Term Frequency-Inverse Document Frequency) representation and with a Bag- of-Words representation and a vector of lexicon-based sentiment values. The proposed text representation approach is assessed through the application of several machine learning classification algorithms on a dataset that is used extensively in literature for sentiment detection. The classification accuracy derived through the proposed hybrid vectorization approach is higher than when its individual components are used for text represenation, and comparable with state-of-the-art sentiment detection methodologies.
[ { "version": "v1", "created": "Sun, 29 Nov 2015 22:41:43 GMT" } ]
2015-12-01T00:00:00
[ [ "Stalidis", "Panagiotis", "" ], [ "Giatsoglou", "Maria", "" ], [ "Diamantaras", "Konstantinos", "" ], [ "Sarigiannidis", "George", "" ], [ "Chatzisavvas", "Konstantinos Ch.", "" ] ]
TITLE: Machine Learning Sentiment Prediction based on Hybrid Document Representation ABSTRACT: Automated sentiment analysis and opinion mining is a complex process concerning the extraction of useful subjective information from text. The explosion of user generated content on the Web, especially the fact that millions of users, on a daily basis, express their opinions on products and services to blogs, wikis, social networks, message boards, etc., render the reliable, automated export of sentiments and opinions from unstructured text crucial for several commercial applications. In this paper, we present a novel hybrid vectorization approach for textual resources that combines a weighted variant of the popular Word2Vec representation (based on Term Frequency-Inverse Document Frequency) representation and with a Bag- of-Words representation and a vector of lexicon-based sentiment values. The proposed text representation approach is assessed through the application of several machine learning classification algorithms on a dataset that is used extensively in literature for sentiment detection. The classification accuracy derived through the proposed hybrid vectorization approach is higher than when its individual components are used for text represenation, and comparable with state-of-the-art sentiment detection methodologies.
no_new_dataset
0.947186
1511.09134
Liu Weiyi
Liu Weiyi, Chen Lingli, Hu Guangmin
Mining Essential Relationships under Multiplex Networks
5 pages, 6 figures
null
null
null
cs.SI physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In big data times, massive datasets often carry different relationships among the same group of nodes, analyzing on these heterogeneous relationships may give us a window to peek the essential relationships among nodes. In this paper, first of all we propose a new metric "similarity rate" in order to capture the changing rate of similarities between node-pairs though all networks; secondly, we try to use this new metric to uncover essential relationships between node-pairs which essential relationships are often hidden and hard to get. From experiments study of Indonesian Terrorists dataset, this new metric similarity rate function well for giving us a way to uncover essential relationships from lots of appearances.
[ { "version": "v1", "created": "Mon, 30 Nov 2015 02:12:13 GMT" } ]
2015-12-01T00:00:00
[ [ "Weiyi", "Liu", "" ], [ "Lingli", "Chen", "" ], [ "Guangmin", "Hu", "" ] ]
TITLE: Mining Essential Relationships under Multiplex Networks ABSTRACT: In big data times, massive datasets often carry different relationships among the same group of nodes, analyzing on these heterogeneous relationships may give us a window to peek the essential relationships among nodes. In this paper, first of all we propose a new metric "similarity rate" in order to capture the changing rate of similarities between node-pairs though all networks; secondly, we try to use this new metric to uncover essential relationships between node-pairs which essential relationships are often hidden and hard to get. From experiments study of Indonesian Terrorists dataset, this new metric similarity rate function well for giving us a way to uncover essential relationships from lots of appearances.
no_new_dataset
0.932913
1511.09150
Rahul Rama Varior Mr.
Rahul Rama Varior, Gang Wang
Hierarchical Invariant Feature Learning with Marginalization for Person Re-Identification
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper addresses the problem of matching pedestrians across multiple camera views, known as person re-identification. Variations in lighting conditions, environment and pose changes across camera views make re-identification a challenging problem. Previous methods address these challenges by designing specific features or by learning a distance function. We propose a hierarchical feature learning framework that learns invariant representations from labeled image pairs. A mapping is learned such that the extracted features are invariant for images belonging to same individual across views. To learn robust representations and to achieve better generalization to unseen data, the system has to be trained with a large amount of data. Critically, most of the person re-identification datasets are small. Manually augmenting the dataset by partial corruption of input data introduces additional computational burden as it requires several training epochs to converge. We propose a hierarchical network which incorporates a marginalization technique that can reap the benefits of training on large datasets without explicit augmentation. We compare our approach with several baseline algorithms as well as popular linear and non-linear metric learning algorithms and demonstrate improved performance on challenging publicly available datasets, VIPeR, CUHK01, CAVIAR4REID and iLIDS. Our approach also achieves the stateof-the-art results on these datasets.
[ { "version": "v1", "created": "Mon, 30 Nov 2015 04:05:21 GMT" } ]
2015-12-01T00:00:00
[ [ "Varior", "Rahul Rama", "" ], [ "Wang", "Gang", "" ] ]
TITLE: Hierarchical Invariant Feature Learning with Marginalization for Person Re-Identification ABSTRACT: This paper addresses the problem of matching pedestrians across multiple camera views, known as person re-identification. Variations in lighting conditions, environment and pose changes across camera views make re-identification a challenging problem. Previous methods address these challenges by designing specific features or by learning a distance function. We propose a hierarchical feature learning framework that learns invariant representations from labeled image pairs. A mapping is learned such that the extracted features are invariant for images belonging to same individual across views. To learn robust representations and to achieve better generalization to unseen data, the system has to be trained with a large amount of data. Critically, most of the person re-identification datasets are small. Manually augmenting the dataset by partial corruption of input data introduces additional computational burden as it requires several training epochs to converge. We propose a hierarchical network which incorporates a marginalization technique that can reap the benefits of training on large datasets without explicit augmentation. We compare our approach with several baseline algorithms as well as popular linear and non-linear metric learning algorithms and demonstrate improved performance on challenging publicly available datasets, VIPeR, CUHK01, CAVIAR4REID and iLIDS. Our approach also achieves the stateof-the-art results on these datasets.
no_new_dataset
0.9463
1511.09159
Yangyang Xu
Yangyang Xu, Ioannis Akrotirianakis, Amit Chakraborty
Proximal gradient method for huberized support vector machine
in Pattern analysis and application, 2015
null
10.1007/s10044-015-0485-z
null
stat.ML cs.LG cs.NA math.NA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Support Vector Machine (SVM) has been used in a wide variety of classification problems. The original SVM uses the hinge loss function, which is non-differentiable and makes the problem difficult to solve in particular for regularized SVMs, such as with $\ell_1$-regularization. This paper considers the Huberized SVM (HSVM), which uses a differentiable approximation of the hinge loss function. We first explore the use of the Proximal Gradient (PG) method to solving binary-class HSVM (B-HSVM) and then generalize it to multi-class HSVM (M-HSVM). Under strong convexity assumptions, we show that our algorithm converges linearly. In addition, we give a finite convergence result about the support of the solution, based on which we further accelerate the algorithm by a two-stage method. We present extensive numerical experiments on both synthetic and real datasets which demonstrate the superiority of our methods over some state-of-the-art methods for both binary- and multi-class SVMs.
[ { "version": "v1", "created": "Mon, 30 Nov 2015 05:02:02 GMT" } ]
2015-12-01T00:00:00
[ [ "Xu", "Yangyang", "" ], [ "Akrotirianakis", "Ioannis", "" ], [ "Chakraborty", "Amit", "" ] ]
TITLE: Proximal gradient method for huberized support vector machine ABSTRACT: The Support Vector Machine (SVM) has been used in a wide variety of classification problems. The original SVM uses the hinge loss function, which is non-differentiable and makes the problem difficult to solve in particular for regularized SVMs, such as with $\ell_1$-regularization. This paper considers the Huberized SVM (HSVM), which uses a differentiable approximation of the hinge loss function. We first explore the use of the Proximal Gradient (PG) method to solving binary-class HSVM (B-HSVM) and then generalize it to multi-class HSVM (M-HSVM). Under strong convexity assumptions, we show that our algorithm converges linearly. In addition, we give a finite convergence result about the support of the solution, based on which we further accelerate the algorithm by a two-stage method. We present extensive numerical experiments on both synthetic and real datasets which demonstrate the superiority of our methods over some state-of-the-art methods for both binary- and multi-class SVMs.
no_new_dataset
0.947914
1511.09209
Zongyuan Ge
ZongYuan Ge and Alex Bewley and Christopher McCool and Ben Upcroft and Peter Corke and Conrad Sanderson
Fine-Grained Classification via Mixture of Deep Convolutional Neural Networks
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a novel deep convolutional neural network (DCNN) system for fine-grained image classification, called a mixture of DCNNs (MixDCNN). The fine-grained image classification problem is characterised by large intra-class variations and small inter-class variations. To overcome these problems our proposed MixDCNN system partitions images into K subsets of similar images and learns an expert DCNN for each subset. The output from each of the K DCNNs is combined to form a single classification decision. In contrast to previous techniques, we provide a formulation to perform joint end-to-end training of the K DCNNs simultaneously. Extensive experiments, on three datasets using two network structures (AlexNet and GoogLeNet), show that the proposed MixDCNN system consistently outperforms other methods. It provides a relative improvement of 12.7% and achieves state-of-the-art results on two datasets.
[ { "version": "v1", "created": "Mon, 30 Nov 2015 09:14:10 GMT" } ]
2015-12-01T00:00:00
[ [ "Ge", "ZongYuan", "" ], [ "Bewley", "Alex", "" ], [ "McCool", "Christopher", "" ], [ "Upcroft", "Ben", "" ], [ "Corke", "Peter", "" ], [ "Sanderson", "Conrad", "" ] ]
TITLE: Fine-Grained Classification via Mixture of Deep Convolutional Neural Networks ABSTRACT: We present a novel deep convolutional neural network (DCNN) system for fine-grained image classification, called a mixture of DCNNs (MixDCNN). The fine-grained image classification problem is characterised by large intra-class variations and small inter-class variations. To overcome these problems our proposed MixDCNN system partitions images into K subsets of similar images and learns an expert DCNN for each subset. The output from each of the K DCNNs is combined to form a single classification decision. In contrast to previous techniques, we provide a formulation to perform joint end-to-end training of the K DCNNs simultaneously. Extensive experiments, on three datasets using two network structures (AlexNet and GoogLeNet), show that the proposed MixDCNN system consistently outperforms other methods. It provides a relative improvement of 12.7% and achieves state-of-the-art results on two datasets.
no_new_dataset
0.948298
1511.09460
Snigdha Chaturvedi
Snigdha Chaturvedi, Dan Goldwasser, Hal Daume III
Ask, and shall you receive?: Understanding Desire Fulfillment in Natural Language Text
null
null
null
null
cs.AI cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ability to comprehend wishes or desires and their fulfillment is important to Natural Language Understanding. This paper introduces the task of identifying if a desire expressed by a subject in a given short piece of text was fulfilled. We propose various unstructured and structured models that capture fulfillment cues such as the subject's emotional state and actions. Our experiments with two different datasets demonstrate the importance of understanding the narrative and discourse structure to address this task.
[ { "version": "v1", "created": "Mon, 30 Nov 2015 20:37:03 GMT" } ]
2015-12-01T00:00:00
[ [ "Chaturvedi", "Snigdha", "" ], [ "Goldwasser", "Dan", "" ], [ "Daume", "Hal", "III" ] ]
TITLE: Ask, and shall you receive?: Understanding Desire Fulfillment in Natural Language Text ABSTRACT: The ability to comprehend wishes or desires and their fulfillment is important to Natural Language Understanding. This paper introduces the task of identifying if a desire expressed by a subject in a given short piece of text was fulfilled. We propose various unstructured and structured models that capture fulfillment cues such as the subject's emotional state and actions. Our experiments with two different datasets demonstrate the importance of understanding the narrative and discourse structure to address this task.
no_new_dataset
0.945147
1505.00853
Bing Xu
Bing Xu, Naiyan Wang, Tianqi Chen, Mu Li
Empirical Evaluation of Rectified Activations in Convolutional Network
null
null
null
null
cs.LG cs.CV stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we investigate the performance of different types of rectified activation functions in convolutional neural network: standard rectified linear unit (ReLU), leaky rectified linear unit (Leaky ReLU), parametric rectified linear unit (PReLU) and a new randomized leaky rectified linear units (RReLU). We evaluate these activation function on standard image classification task. Our experiments suggest that incorporating a non-zero slope for negative part in rectified activation units could consistently improve the results. Thus our findings are negative on the common belief that sparsity is the key of good performance in ReLU. Moreover, on small scale dataset, using deterministic negative slope or learning it are both prone to overfitting. They are not as effective as using their randomized counterpart. By using RReLU, we achieved 75.68\% accuracy on CIFAR-100 test set without multiple test or ensemble.
[ { "version": "v1", "created": "Tue, 5 May 2015 01:16:39 GMT" }, { "version": "v2", "created": "Fri, 27 Nov 2015 06:58:14 GMT" } ]
2015-11-30T00:00:00
[ [ "Xu", "Bing", "" ], [ "Wang", "Naiyan", "" ], [ "Chen", "Tianqi", "" ], [ "Li", "Mu", "" ] ]
TITLE: Empirical Evaluation of Rectified Activations in Convolutional Network ABSTRACT: In this paper we investigate the performance of different types of rectified activation functions in convolutional neural network: standard rectified linear unit (ReLU), leaky rectified linear unit (Leaky ReLU), parametric rectified linear unit (PReLU) and a new randomized leaky rectified linear units (RReLU). We evaluate these activation function on standard image classification task. Our experiments suggest that incorporating a non-zero slope for negative part in rectified activation units could consistently improve the results. Thus our findings are negative on the common belief that sparsity is the key of good performance in ReLU. Moreover, on small scale dataset, using deterministic negative slope or learning it are both prone to overfitting. They are not as effective as using their randomized counterpart. By using RReLU, we achieved 75.68\% accuracy on CIFAR-100 test set without multiple test or ensemble.
no_new_dataset
0.954351
1511.07041
Ankur Handa
Ankur Handa, Viorica Patraucean, Vijay Badrinarayanan, Simon Stent, Roberto Cipolla
SceneNet: Understanding Real World Indoor Scenes With Synthetic Data
null
null
null
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
Scene understanding is a prerequisite to many high level tasks for any automated intelligent machine operating in real world environments. Recent attempts with supervised learning have shown promise in this direction but also highlighted the need for enormous quantity of supervised data --- performance increases in proportion to the amount of data used. However, this quickly becomes prohibitive when considering the manual labour needed to collect such data. In this work, we focus our attention on depth based semantic per-pixel labelling as a scene understanding problem and show the potential of computer graphics to generate virtually unlimited labelled data from synthetic 3D scenes. By carefully synthesizing training data with appropriate noise models we show comparable performance to state-of-the-art RGBD systems on NYUv2 dataset despite using only depth data as input and set a benchmark on depth-based segmentation on SUN RGB-D dataset. Additionally, we offer a route to generating synthesized frame or video data, and understanding of different factors influencing performance gains.
[ { "version": "v1", "created": "Sun, 22 Nov 2015 17:59:49 GMT" }, { "version": "v2", "created": "Thu, 26 Nov 2015 22:09:09 GMT" } ]
2015-11-30T00:00:00
[ [ "Handa", "Ankur", "" ], [ "Patraucean", "Viorica", "" ], [ "Badrinarayanan", "Vijay", "" ], [ "Stent", "Simon", "" ], [ "Cipolla", "Roberto", "" ] ]
TITLE: SceneNet: Understanding Real World Indoor Scenes With Synthetic Data ABSTRACT: Scene understanding is a prerequisite to many high level tasks for any automated intelligent machine operating in real world environments. Recent attempts with supervised learning have shown promise in this direction but also highlighted the need for enormous quantity of supervised data --- performance increases in proportion to the amount of data used. However, this quickly becomes prohibitive when considering the manual labour needed to collect such data. In this work, we focus our attention on depth based semantic per-pixel labelling as a scene understanding problem and show the potential of computer graphics to generate virtually unlimited labelled data from synthetic 3D scenes. By carefully synthesizing training data with appropriate noise models we show comparable performance to state-of-the-art RGBD systems on NYUv2 dataset despite using only depth data as input and set a benchmark on depth-based segmentation on SUN RGB-D dataset. Additionally, we offer a route to generating synthesized frame or video data, and understanding of different factors influencing performance gains.
no_new_dataset
0.949856
1511.08350
Amina Kemmar
Amina Kemmar and Samir Loudni and Yahia Lebbah and Patrice Boizumault and Thierry Charnois
A global Constraint for mining Sequential Patterns with GAP constraint
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Sequential pattern mining (SPM) under gap constraint is a challenging task. Many efficient specialized methods have been developed but they are all suffering from a lack of genericity. The Constraint Programming (CP) approaches are not so effective because of the size of their encodings. In[7], we have proposed the global constraint Prefix-Projection for SPM which remedies to this drawback. However, this global constraint cannot be directly extended to support gap constraint. In this paper, we propose the global constraint GAP-SEQ enabling to handle SPM with or without gap constraint. GAP-SEQ relies on the principle of right pattern extensions. Experiments show that our approach clearly outperforms both CP approaches and the state-of-the-art cSpade method on large datasets.
[ { "version": "v1", "created": "Thu, 26 Nov 2015 10:45:34 GMT" } ]
2015-11-30T00:00:00
[ [ "Kemmar", "Amina", "" ], [ "Loudni", "Samir", "" ], [ "Lebbah", "Yahia", "" ], [ "Boizumault", "Patrice", "" ], [ "Charnois", "Thierry", "" ] ]
TITLE: A global Constraint for mining Sequential Patterns with GAP constraint ABSTRACT: Sequential pattern mining (SPM) under gap constraint is a challenging task. Many efficient specialized methods have been developed but they are all suffering from a lack of genericity. The Constraint Programming (CP) approaches are not so effective because of the size of their encodings. In[7], we have proposed the global constraint Prefix-Projection for SPM which remedies to this drawback. However, this global constraint cannot be directly extended to support gap constraint. In this paper, we propose the global constraint GAP-SEQ enabling to handle SPM with or without gap constraint. GAP-SEQ relies on the principle of right pattern extensions. Experiments show that our approach clearly outperforms both CP approaches and the state-of-the-art cSpade method on large datasets.
no_new_dataset
0.949902
1511.08411
Mostafa Bayomi
Mostafa Bayomi, Killian Levacher, M. Rami Ghorab, S\'eamus Lawless
OntoSeg: a Novel Approach to Text Segmentation using Ontological Similarity
10 pages, IEEE ICDMW 2015 (SENTIRE Workshop)
null
10.1109/ICDMW.2015.6
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Text segmentation (TS) aims at dividing long text into coherent segments which reflect the subtopic structure of the text. It is beneficial to many natural language processing tasks, such as Information Retrieval (IR) and document summarisation. Current approaches to text segmentation are similar in that they all use word-frequency metrics to measure the similarity between two regions of text, so that a document is segmented based on the lexical cohesion between its words. Various NLP tasks are now moving towards the semantic web and ontologies, such as ontology-based IR systems, to capture the conceptualizations associated with user needs and contents. Text segmentation based on lexical cohesion between words is hence not sufficient anymore for such tasks. This paper proposes OntoSeg, a novel approach to text segmentation based on the ontological similarity between text blocks. The proposed method uses ontological similarity to explore conceptual relations between text segments and a Hierarchical Agglomerative Clustering (HAC) algorithm to represent the text as a tree-like hierarchy that is conceptually structured. The rich structure of the created tree further allows the segmentation of text in a linear fashion at various levels of granularity. The proposed method was evaluated on a wellknown dataset, and the results show that using ontological similarity in text segmentation is very promising. Also we enhance the proposed method by combining ontological similarity with lexical similarity and the results show an enhancement of the segmentation quality.
[ { "version": "v1", "created": "Thu, 26 Nov 2015 15:10:18 GMT" } ]
2015-11-30T00:00:00
[ [ "Bayomi", "Mostafa", "" ], [ "Levacher", "Killian", "" ], [ "Ghorab", "M. Rami", "" ], [ "Lawless", "Séamus", "" ] ]
TITLE: OntoSeg: a Novel Approach to Text Segmentation using Ontological Similarity ABSTRACT: Text segmentation (TS) aims at dividing long text into coherent segments which reflect the subtopic structure of the text. It is beneficial to many natural language processing tasks, such as Information Retrieval (IR) and document summarisation. Current approaches to text segmentation are similar in that they all use word-frequency metrics to measure the similarity between two regions of text, so that a document is segmented based on the lexical cohesion between its words. Various NLP tasks are now moving towards the semantic web and ontologies, such as ontology-based IR systems, to capture the conceptualizations associated with user needs and contents. Text segmentation based on lexical cohesion between words is hence not sufficient anymore for such tasks. This paper proposes OntoSeg, a novel approach to text segmentation based on the ontological similarity between text blocks. The proposed method uses ontological similarity to explore conceptual relations between text segments and a Hierarchical Agglomerative Clustering (HAC) algorithm to represent the text as a tree-like hierarchy that is conceptually structured. The rich structure of the created tree further allows the segmentation of text in a linear fashion at various levels of granularity. The proposed method was evaluated on a wellknown dataset, and the results show that using ontological similarity in text segmentation is very promising. Also we enhance the proposed method by combining ontological similarity with lexical similarity and the results show an enhancement of the segmentation quality.
no_new_dataset
0.945298
1511.08417
Ziqiang Cao
Ziqiang Cao, Chengyao Chen, Wenjie Li, Sujian Li, Furu Wei, Ming Zhou
TGSum: Build Tweet Guided Multi-Document Summarization Dataset
7 pages, 1 figure in AAAI 2016
null
null
null
cs.IR cs.CL
http://creativecommons.org/licenses/by-nc-sa/4.0/
The development of summarization research has been significantly hampered by the costly acquisition of reference summaries. This paper proposes an effective way to automatically collect large scales of news-related multi-document summaries with reference to social media's reactions. We utilize two types of social labels in tweets, i.e., hashtags and hyper-links. Hashtags are used to cluster documents into different topic sets. Also, a tweet with a hyper-link often highlights certain key points of the corresponding document. We synthesize a linked document cluster to form a reference summary which can cover most key points. To this aim, we adopt the ROUGE metrics to measure the coverage ratio, and develop an Integer Linear Programming solution to discover the sentence set reaching the upper bound of ROUGE. Since we allow summary sentences to be selected from both documents and high-quality tweets, the generated reference summaries could be abstractive. Both informativeness and readability of the collected summaries are verified by manual judgment. In addition, we train a Support Vector Regression summarizer on DUC generic multi-document summarization benchmarks. With the collected data as extra training resource, the performance of the summarizer improves a lot on all the test sets. We release this dataset for further research.
[ { "version": "v1", "created": "Thu, 26 Nov 2015 15:22:54 GMT" } ]
2015-11-30T00:00:00
[ [ "Cao", "Ziqiang", "" ], [ "Chen", "Chengyao", "" ], [ "Li", "Wenjie", "" ], [ "Li", "Sujian", "" ], [ "Wei", "Furu", "" ], [ "Zhou", "Ming", "" ] ]
TITLE: TGSum: Build Tweet Guided Multi-Document Summarization Dataset ABSTRACT: The development of summarization research has been significantly hampered by the costly acquisition of reference summaries. This paper proposes an effective way to automatically collect large scales of news-related multi-document summaries with reference to social media's reactions. We utilize two types of social labels in tweets, i.e., hashtags and hyper-links. Hashtags are used to cluster documents into different topic sets. Also, a tweet with a hyper-link often highlights certain key points of the corresponding document. We synthesize a linked document cluster to form a reference summary which can cover most key points. To this aim, we adopt the ROUGE metrics to measure the coverage ratio, and develop an Integer Linear Programming solution to discover the sentence set reaching the upper bound of ROUGE. Since we allow summary sentences to be selected from both documents and high-quality tweets, the generated reference summaries could be abstractive. Both informativeness and readability of the collected summaries are verified by manual judgment. In addition, we train a Support Vector Regression summarizer on DUC generic multi-document summarization benchmarks. With the collected data as extra training resource, the performance of the summarizer improves a lot on all the test sets. We release this dataset for further research.
new_dataset
0.957358
1511.08446
Xu Jia
Amir Ghodrati and Xu Jia and Marco Pedersoli and Tinne Tuytelaars
Towards Automatic Image Editing: Learning to See another You
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Learning the distribution of images in order to generate new samples is a challenging task due to the high dimensionality of the data and the highly non-linear relations that are involved. Nevertheless, some promising results have been reported in the literature recently,building on deep network architectures. In this work, we zoom in on a specific type of image generation: given an image and knowing the category of objects it belongs to (e.g. faces), our goal is to generate a similar and plausible image, but with some altered attributes. This is particularly challenging, as the model needs to learn to disentangle the effect of each attribute and to apply a desired attribute change to a given input image, while keeping the other attributes and overall object appearance intact. To this end, we learn a convolutional network, where the desired attribute information is encoded then merged with the encoded image at feature map level. We show promising results, both qualitatively as well as quantitatively, in the context of a retrieval experiment, on two face datasets (MultiPie and CAS-PEAL-R1).
[ { "version": "v1", "created": "Thu, 26 Nov 2015 16:33:10 GMT" } ]
2015-11-30T00:00:00
[ [ "Ghodrati", "Amir", "" ], [ "Jia", "Xu", "" ], [ "Pedersoli", "Marco", "" ], [ "Tuytelaars", "Tinne", "" ] ]
TITLE: Towards Automatic Image Editing: Learning to See another You ABSTRACT: Learning the distribution of images in order to generate new samples is a challenging task due to the high dimensionality of the data and the highly non-linear relations that are involved. Nevertheless, some promising results have been reported in the literature recently,building on deep network architectures. In this work, we zoom in on a specific type of image generation: given an image and knowing the category of objects it belongs to (e.g. faces), our goal is to generate a similar and plausible image, but with some altered attributes. This is particularly challenging, as the model needs to learn to disentangle the effect of each attribute and to apply a desired attribute change to a given input image, while keeping the other attributes and overall object appearance intact. To this end, we learn a convolutional network, where the desired attribute information is encoded then merged with the encoded image at feature map level. We show promising results, both qualitatively as well as quantitatively, in the context of a retrieval experiment, on two face datasets (MultiPie and CAS-PEAL-R1).
no_new_dataset
0.948298
1511.08707
Md Azharuddin
Tripti Tanaya Tejaswi, Md Azharuddin, P. K. Jana
A GA based approach for task scheduling in multi-cloud environment
null
null
null
null
cs.DC
http://creativecommons.org/publicdomain/zero/1.0/
In multi-cloud environment, task scheduling has attracted a lot of attention due to NP-Complete nature of the problem. Moreover, it is very challenging due to heterogeneity of the cloud resources with varying capacities and functionalities. Therefore, minimizing the makespan for task scheduling is a challenging issue. In this paper, we propose a genetic algorithm (GA) based approach for solving task scheduling problem. The algorithm is described with innovative idea of fitness function derivation and mutation. The proposed algorithm is exposed to rigorous testing using various benchmark datasets and its performance is evaluated in terms of total makespan.
[ { "version": "v1", "created": "Fri, 27 Nov 2015 15:30:13 GMT" } ]
2015-11-30T00:00:00
[ [ "Tejaswi", "Tripti Tanaya", "" ], [ "Azharuddin", "Md", "" ], [ "Jana", "P. K.", "" ] ]
TITLE: A GA based approach for task scheduling in multi-cloud environment ABSTRACT: In multi-cloud environment, task scheduling has attracted a lot of attention due to NP-Complete nature of the problem. Moreover, it is very challenging due to heterogeneity of the cloud resources with varying capacities and functionalities. Therefore, minimizing the makespan for task scheduling is a challenging issue. In this paper, we propose a genetic algorithm (GA) based approach for solving task scheduling problem. The algorithm is described with innovative idea of fitness function derivation and mutation. The proposed algorithm is exposed to rigorous testing using various benchmark datasets and its performance is evaluated in terms of total makespan.
no_new_dataset
0.952131
1508.03881
Fangting Xia
Fangting Xia, Jun Zhu, Peng Wang, Alan Yuille
Pose-Guided Human Parsing with Deep Learned Features
12 pages, 10 figures, a shortened version of this paper was accepted by AAAI 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Parsing human body into semantic regions is crucial to human-centric analysis. In this paper, we propose a segment-based parsing pipeline that explores human pose information, i.e. the joint location of a human model, which improves the part proposal, accelerates the inference and regularizes the parsing process at the same time. Specifically, we first generate part segment proposals with respect to human joints predicted by a deep model, then part- specific ranking models are trained for segment selection using both pose-based features and deep-learned part potential features. Finally, the best ensemble of the proposed part segments are inferred though an And-Or Graph. We evaluate our approach on the popular Penn-Fudan pedestrian parsing dataset, and demonstrate the effectiveness of using the pose information for each stage of the parsing pipeline. Finally, we show that our approach yields superior part segmentation accuracy comparing to the state-of-the-art methods.
[ { "version": "v1", "created": "Mon, 17 Aug 2015 00:05:38 GMT" }, { "version": "v2", "created": "Wed, 25 Nov 2015 02:07:11 GMT" } ]
2015-11-26T00:00:00
[ [ "Xia", "Fangting", "" ], [ "Zhu", "Jun", "" ], [ "Wang", "Peng", "" ], [ "Yuille", "Alan", "" ] ]
TITLE: Pose-Guided Human Parsing with Deep Learned Features ABSTRACT: Parsing human body into semantic regions is crucial to human-centric analysis. In this paper, we propose a segment-based parsing pipeline that explores human pose information, i.e. the joint location of a human model, which improves the part proposal, accelerates the inference and regularizes the parsing process at the same time. Specifically, we first generate part segment proposals with respect to human joints predicted by a deep model, then part- specific ranking models are trained for segment selection using both pose-based features and deep-learned part potential features. Finally, the best ensemble of the proposed part segments are inferred though an And-Or Graph. We evaluate our approach on the popular Penn-Fudan pedestrian parsing dataset, and demonstrate the effectiveness of using the pose information for each stage of the parsing pipeline. Finally, we show that our approach yields superior part segmentation accuracy comparing to the state-of-the-art methods.
no_new_dataset
0.952131
1511.05121
Rahul Gopal Krishnan
Rahul G. Krishnan, Uri Shalit, David Sontag
Deep Kalman Filters
17 pages, 14 figures: Fixed typo in Fig. 1(b) and added reference
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Kalman Filters are one of the most influential models of time-varying phenomena. They admit an intuitive probabilistic interpretation, have a simple functional form, and enjoy widespread adoption in a variety of disciplines. Motivated by recent variational methods for learning deep generative models, we introduce a unified algorithm to efficiently learn a broad spectrum of Kalman filters. Of particular interest is the use of temporal generative models for counterfactual inference. We investigate the efficacy of such models for counterfactual inference, and to that end we introduce the "Healing MNIST" dataset where long-term structure, noise and actions are applied to sequences of digits. We show the efficacy of our method for modeling this dataset. We further show how our model can be used for counterfactual inference for patients, based on electronic health record data of 8,000 patients over 4.5 years.
[ { "version": "v1", "created": "Mon, 16 Nov 2015 20:46:38 GMT" }, { "version": "v2", "created": "Wed, 25 Nov 2015 20:47:00 GMT" } ]
2015-11-26T00:00:00
[ [ "Krishnan", "Rahul G.", "" ], [ "Shalit", "Uri", "" ], [ "Sontag", "David", "" ] ]
TITLE: Deep Kalman Filters ABSTRACT: Kalman Filters are one of the most influential models of time-varying phenomena. They admit an intuitive probabilistic interpretation, have a simple functional form, and enjoy widespread adoption in a variety of disciplines. Motivated by recent variational methods for learning deep generative models, we introduce a unified algorithm to efficiently learn a broad spectrum of Kalman filters. Of particular interest is the use of temporal generative models for counterfactual inference. We investigate the efficacy of such models for counterfactual inference, and to that end we introduce the "Healing MNIST" dataset where long-term structure, noise and actions are applied to sequences of digits. We show the efficacy of our method for modeling this dataset. We further show how our model can be used for counterfactual inference for patients, based on electronic health record data of 8,000 patients over 4.5 years.
new_dataset
0.96157
1511.07917
Anton Osokin
Tuan-Hung Vu, Anton Osokin, Ivan Laptev
Context-aware CNNs for person head detection
To appear in International Conference on Computer Vision (ICCV), 2015
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Person detection is a key problem for many computer vision tasks. While face detection has reached maturity, detecting people under a full variation of camera view-points, human poses, lighting conditions and occlusions is still a difficult challenge. In this work we focus on detecting human heads in natural scenes. Starting from the recent local R-CNN object detector, we extend it with two types of contextual cues. First, we leverage person-scene relations and propose a Global CNN model trained to predict positions and scales of heads directly from the full image. Second, we explicitly model pairwise relations among objects and train a Pairwise CNN model using a structured-output surrogate loss. The Local, Global and Pairwise models are combined into a joint CNN framework. To train and test our full model, we introduce a large dataset composed of 369,846 human heads annotated in 224,740 movie frames. We evaluate our method and demonstrate improvements of person head detection against several recent baselines in three datasets. We also show improvements of the detection speed provided by our model.
[ { "version": "v1", "created": "Tue, 24 Nov 2015 23:23:18 GMT" } ]
2015-11-26T00:00:00
[ [ "Vu", "Tuan-Hung", "" ], [ "Osokin", "Anton", "" ], [ "Laptev", "Ivan", "" ] ]
TITLE: Context-aware CNNs for person head detection ABSTRACT: Person detection is a key problem for many computer vision tasks. While face detection has reached maturity, detecting people under a full variation of camera view-points, human poses, lighting conditions and occlusions is still a difficult challenge. In this work we focus on detecting human heads in natural scenes. Starting from the recent local R-CNN object detector, we extend it with two types of contextual cues. First, we leverage person-scene relations and propose a Global CNN model trained to predict positions and scales of heads directly from the full image. Second, we explicitly model pairwise relations among objects and train a Pairwise CNN model using a structured-output surrogate loss. The Local, Global and Pairwise models are combined into a joint CNN framework. To train and test our full model, we introduce a large dataset composed of 369,846 human heads annotated in 224,740 movie frames. We evaluate our method and demonstrate improvements of person head detection against several recent baselines in three datasets. We also show improvements of the detection speed provided by our model.
new_dataset
0.957912
1511.07951
Vittal Premachandran
Vittal Premachandran, Boyan Bonev, Alan L. Yuille
PASCAL Boundaries: A Class-Agnostic Semantic Boundary Dataset
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we address the boundary detection task motivated by the ambiguities in current definition of edge detection. To this end, we generate a large database consisting of more than 10k images (which is 20x bigger than existing edge detection databases) along with ground truth boundaries between 459 semantic classes including both foreground objects and different types of background, and call it the PASCAL Boundaries dataset, which will be released to the community. In addition, we propose a novel deep network-based multi-scale semantic boundary detector and name it Multi-scale Deep Semantic Boundary Detector (M-DSBD). We provide baselines using models that were trained on edge detection and show that they transfer reasonably to the task of boundary detection. Finally, we point to various important research problems that this dataset can be used for.
[ { "version": "v1", "created": "Wed, 25 Nov 2015 05:12:38 GMT" } ]
2015-11-26T00:00:00
[ [ "Premachandran", "Vittal", "" ], [ "Bonev", "Boyan", "" ], [ "Yuille", "Alan L.", "" ] ]
TITLE: PASCAL Boundaries: A Class-Agnostic Semantic Boundary Dataset ABSTRACT: In this paper, we address the boundary detection task motivated by the ambiguities in current definition of edge detection. To this end, we generate a large database consisting of more than 10k images (which is 20x bigger than existing edge detection databases) along with ground truth boundaries between 459 semantic classes including both foreground objects and different types of background, and call it the PASCAL Boundaries dataset, which will be released to the community. In addition, we propose a novel deep network-based multi-scale semantic boundary detector and name it Multi-scale Deep Semantic Boundary Detector (M-DSBD). We provide baselines using models that were trained on edge detection and show that they transfer reasonably to the task of boundary detection. Finally, we point to various important research problems that this dataset can be used for.
new_dataset
0.955026
1511.08032
Christos Tzelepis
Christos Tzelepis, Damianos Galanopoulos, Vasileios Mezaris, Ioannis Patras
Learning to detect video events from zero or very few video examples
Image and Vision Computing Journal, Elsevier, 2015, accepted for publication
Image and Vision Computing Journal, Elsevier, 2015
10.1016/j.imavis.2015.09.005
null
cs.LG cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we deal with the problem of high-level event detection in video. Specifically, we study the challenging problems of i) learning to detect video events from solely a textual description of the event, without using any positive video examples, and ii) additionally exploiting very few positive training samples together with a small number of ``related'' videos. For learning only from an event's textual description, we first identify a general learning framework and then study the impact of different design choices for various stages of this framework. For additionally learning from example videos, when true positive training samples are scarce, we employ an extension of the Support Vector Machine that allows us to exploit ``related'' event videos by automatically introducing different weights for subsets of the videos in the overall training set. Experimental evaluations performed on the large-scale TRECVID MED 2014 video dataset provide insight on the effectiveness of the proposed methods.
[ { "version": "v1", "created": "Wed, 25 Nov 2015 12:17:50 GMT" } ]
2015-11-26T00:00:00
[ [ "Tzelepis", "Christos", "" ], [ "Galanopoulos", "Damianos", "" ], [ "Mezaris", "Vasileios", "" ], [ "Patras", "Ioannis", "" ] ]
TITLE: Learning to detect video events from zero or very few video examples ABSTRACT: In this work we deal with the problem of high-level event detection in video. Specifically, we study the challenging problems of i) learning to detect video events from solely a textual description of the event, without using any positive video examples, and ii) additionally exploiting very few positive training samples together with a small number of ``related'' videos. For learning only from an event's textual description, we first identify a general learning framework and then study the impact of different design choices for various stages of this framework. For additionally learning from example videos, when true positive training samples are scarce, we employ an extension of the Support Vector Machine that allows us to exploit ``related'' event videos by automatically introducing different weights for subsets of the videos in the overall training set. Experimental evaluations performed on the large-scale TRECVID MED 2014 video dataset provide insight on the effectiveness of the proposed methods.
no_new_dataset
0.950595
1511.08177
Saurabh Gupta
Saurabh Gupta, Bharath Hariharan, Jitendra Malik
Exploring Person Context and Local Scene Context for Object Detection
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we explore two ways of using context for object detection. The first model focusses on people and the objects they commonly interact with, such as fashion and sports accessories. The second model considers more general object detection and uses the spatial relationships between objects and between objects and scenes. Our models are able to capture precise spatial relationships between the context and the object of interest, and make effective use of the appearance of the contextual region. On the newly released COCO dataset, our models provide relative improvements of up to 5% over CNN-based state-of-the-art detectors, with the gains concentrated on hard cases such as small objects (10% relative improvement).
[ { "version": "v1", "created": "Wed, 25 Nov 2015 19:45:03 GMT" } ]
2015-11-26T00:00:00
[ [ "Gupta", "Saurabh", "" ], [ "Hariharan", "Bharath", "" ], [ "Malik", "Jitendra", "" ] ]
TITLE: Exploring Person Context and Local Scene Context for Object Detection ABSTRACT: In this paper we explore two ways of using context for object detection. The first model focusses on people and the objects they commonly interact with, such as fashion and sports accessories. The second model considers more general object detection and uses the spatial relationships between objects and between objects and scenes. Our models are able to capture precise spatial relationships between the context and the object of interest, and make effective use of the appearance of the contextual region. On the newly released COCO dataset, our models provide relative improvements of up to 5% over CNN-based state-of-the-art detectors, with the gains concentrated on hard cases such as small objects (10% relative improvement).
new_dataset
0.951953
1412.1526
Xianjie Chen
Xianjie Chen, Alan Yuille
Parsing Occluded People by Flexible Compositions
CVPR 15 Camera Ready
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents an approach to parsing humans when there is significant occlusion. We model humans using a graphical model which has a tree structure building on recent work [32, 6] and exploit the connectivity prior that, even in presence of occlusion, the visible nodes form a connected subtree of the graphical model. We call each connected subtree a flexible composition of object parts. This involves a novel method for learning occlusion cues. During inference we need to search over a mixture of different flexible models. By exploiting part sharing, we show that this inference can be done extremely efficiently requiring only twice as many computations as searching for the entire object (i.e., not modeling occlusion). We evaluate our model on the standard benchmarked "We Are Family" Stickmen dataset and obtain significant performance improvements over the best alternative algorithms.
[ { "version": "v1", "created": "Thu, 4 Dec 2014 00:45:14 GMT" }, { "version": "v2", "created": "Tue, 24 Nov 2015 07:57:19 GMT" } ]
2015-11-25T00:00:00
[ [ "Chen", "Xianjie", "" ], [ "Yuille", "Alan", "" ] ]
TITLE: Parsing Occluded People by Flexible Compositions ABSTRACT: This paper presents an approach to parsing humans when there is significant occlusion. We model humans using a graphical model which has a tree structure building on recent work [32, 6] and exploit the connectivity prior that, even in presence of occlusion, the visible nodes form a connected subtree of the graphical model. We call each connected subtree a flexible composition of object parts. This involves a novel method for learning occlusion cues. During inference we need to search over a mixture of different flexible models. By exploiting part sharing, we show that this inference can be done extremely efficiently requiring only twice as many computations as searching for the entire object (i.e., not modeling occlusion). We evaluate our model on the standard benchmarked "We Are Family" Stickmen dataset and obtain significant performance improvements over the best alternative algorithms.
no_new_dataset
0.947575
1503.08895
Sainbayar Sukhbaatar
Sainbayar Sukhbaatar, Arthur Szlam, Jason Weston and Rob Fergus
End-To-End Memory Networks
Accepted to NIPS 2015
null
null
null
cs.NE cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a neural network with a recurrent attention model over a possibly large external memory. The architecture is a form of Memory Network (Weston et al., 2015) but unlike the model in that work, it is trained end-to-end, and hence requires significantly less supervision during training, making it more generally applicable in realistic settings. It can also be seen as an extension of RNNsearch to the case where multiple computational steps (hops) are performed per output symbol. The flexibility of the model allows us to apply it to tasks as diverse as (synthetic) question answering and to language modeling. For the former our approach is competitive with Memory Networks, but with less supervision. For the latter, on the Penn TreeBank and Text8 datasets our approach demonstrates comparable performance to RNNs and LSTMs. In both cases we show that the key concept of multiple computational hops yields improved results.
[ { "version": "v1", "created": "Tue, 31 Mar 2015 03:05:37 GMT" }, { "version": "v2", "created": "Fri, 3 Apr 2015 02:23:20 GMT" }, { "version": "v3", "created": "Sun, 12 Apr 2015 04:19:33 GMT" }, { "version": "v4", "created": "Mon, 8 Jun 2015 21:42:20 GMT" }, { "version": "v5", "created": "Tue, 24 Nov 2015 19:41:57 GMT" } ]
2015-11-25T00:00:00
[ [ "Sukhbaatar", "Sainbayar", "" ], [ "Szlam", "Arthur", "" ], [ "Weston", "Jason", "" ], [ "Fergus", "Rob", "" ] ]
TITLE: End-To-End Memory Networks ABSTRACT: We introduce a neural network with a recurrent attention model over a possibly large external memory. The architecture is a form of Memory Network (Weston et al., 2015) but unlike the model in that work, it is trained end-to-end, and hence requires significantly less supervision during training, making it more generally applicable in realistic settings. It can also be seen as an extension of RNNsearch to the case where multiple computational steps (hops) are performed per output symbol. The flexibility of the model allows us to apply it to tasks as diverse as (synthetic) question answering and to language modeling. For the former our approach is competitive with Memory Networks, but with less supervision. For the latter, on the Penn TreeBank and Text8 datasets our approach demonstrates comparable performance to RNNs and LSTMs. In both cases we show that the key concept of multiple computational hops yields improved results.
no_new_dataset
0.953708
1505.02438
Stavros Tsogkas
S. Tsogkas, I. Kokkinos, G. Papandreou, A. Vedaldi
Deep Learning for Semantic Part Segmentation with High-Level Guidance
11 pages (including references), 3 figures, 2 tables
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we address the task of segmenting an object into its parts, or semantic part segmentation. We start by adapting a state-of-the-art semantic segmentation system to this task, and show that a combination of a fully-convolutional Deep CNN system coupled with Dense CRF labelling provides excellent results for a broad range of object categories. Still, this approach remains agnostic to high-level constraints between object parts. We introduce such prior information by means of the Restricted Boltzmann Machine, adapted to our task and train our model in an discriminative fashion, as a hidden CRF, demonstrating that prior information can yield additional improvements. We also investigate the performance of our approach ``in the wild'', without information concerning the objects' bounding boxes, using an object detector to guide a multi-scale segmentation scheme. We evaluate the performance of our approach on the Penn-Fudan and LFW datasets for the tasks of pedestrian parsing and face labelling respectively. We show superior performance with respect to competitive methods that have been extensively engineered on these benchmarks, as well as realistic qualitative results on part segmentation, even for occluded or deformable objects. We also provide quantitative and extensive qualitative results on three classes from the PASCAL Parts dataset. Finally, we show that our multi-scale segmentation scheme can boost accuracy, recovering segmentations for finer parts.
[ { "version": "v1", "created": "Sun, 10 May 2015 21:12:31 GMT" }, { "version": "v2", "created": "Tue, 24 Nov 2015 14:22:43 GMT" } ]
2015-11-25T00:00:00
[ [ "Tsogkas", "S.", "" ], [ "Kokkinos", "I.", "" ], [ "Papandreou", "G.", "" ], [ "Vedaldi", "A.", "" ] ]
TITLE: Deep Learning for Semantic Part Segmentation with High-Level Guidance ABSTRACT: In this work we address the task of segmenting an object into its parts, or semantic part segmentation. We start by adapting a state-of-the-art semantic segmentation system to this task, and show that a combination of a fully-convolutional Deep CNN system coupled with Dense CRF labelling provides excellent results for a broad range of object categories. Still, this approach remains agnostic to high-level constraints between object parts. We introduce such prior information by means of the Restricted Boltzmann Machine, adapted to our task and train our model in an discriminative fashion, as a hidden CRF, demonstrating that prior information can yield additional improvements. We also investigate the performance of our approach ``in the wild'', without information concerning the objects' bounding boxes, using an object detector to guide a multi-scale segmentation scheme. We evaluate the performance of our approach on the Penn-Fudan and LFW datasets for the tasks of pedestrian parsing and face labelling respectively. We show superior performance with respect to competitive methods that have been extensively engineered on these benchmarks, as well as realistic qualitative results on part segmentation, even for occluded or deformable objects. We also provide quantitative and extensive qualitative results on three classes from the PASCAL Parts dataset. Finally, we show that our multi-scale segmentation scheme can boost accuracy, recovering segmentations for finer parts.
no_new_dataset
0.946448
1511.03371
Jack Hessel
Jack Hessel, Alexandra Schofield, Lillian Lee, David Mimno
What do Vegans do in their Spare Time? Latent Interest Detection in Multi-Community Networks
NIPS 2015 Network Workshop
null
null
null
cs.SI physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most social network analysis works at the level of interactions between users. But the vast growth in size and complexity of social networks enables us to examine interactions at larger scale. In this work we use a dataset of 76M submissions to the social network Reddit, which is organized into distinct sub-communities called subreddits. We measure the similarity between entire subreddits both in terms of user similarity and topical similarity. Our goal is to find community pairs with similar userbases, but dissimilar content; we refer to this type of relationship as a "latent interest." Detection of latent interests not only provides a perspective on individual users as they shift between roles (student, sports fan, political activist) but also gives insight into the dynamics of Reddit as a whole. Latent interest detection also has potential applications for recommendation systems and for researchers examining community evolution.
[ { "version": "v1", "created": "Wed, 11 Nov 2015 03:07:00 GMT" }, { "version": "v2", "created": "Tue, 24 Nov 2015 05:11:11 GMT" } ]
2015-11-25T00:00:00
[ [ "Hessel", "Jack", "" ], [ "Schofield", "Alexandra", "" ], [ "Lee", "Lillian", "" ], [ "Mimno", "David", "" ] ]
TITLE: What do Vegans do in their Spare Time? Latent Interest Detection in Multi-Community Networks ABSTRACT: Most social network analysis works at the level of interactions between users. But the vast growth in size and complexity of social networks enables us to examine interactions at larger scale. In this work we use a dataset of 76M submissions to the social network Reddit, which is organized into distinct sub-communities called subreddits. We measure the similarity between entire subreddits both in terms of user similarity and topical similarity. Our goal is to find community pairs with similar userbases, but dissimilar content; we refer to this type of relationship as a "latent interest." Detection of latent interests not only provides a perspective on individual users as they shift between roles (student, sports fan, political activist) but also gives insight into the dynamics of Reddit as a whole. Latent interest detection also has potential applications for recommendation systems and for researchers examining community evolution.
no_new_dataset
0.903038
1511.06891
Kian Hsiang Low
Yehong Zhang, Trong Nghia Hoang, Kian Hsiang Low, Mohan Kankanhalli
Near-Optimal Active Learning of Multi-Output Gaussian Processes
30th AAAI Conference on Artificial Intelligence (AAAI 2016), Extended version with proofs, 13 pages
null
null
null
stat.ML cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper addresses the problem of active learning of a multi-output Gaussian process (MOGP) model representing multiple types of coexisting correlated environmental phenomena. In contrast to existing works, our active learning problem involves selecting not just the most informative sampling locations to be observed but also the types of measurements at each selected location for minimizing the predictive uncertainty (i.e., posterior joint entropy) of a target phenomenon of interest given a sampling budget. Unfortunately, such an entropy criterion scales poorly in the numbers of candidate sampling locations and selected observations when optimized. To resolve this issue, we first exploit a structure common to sparse MOGP models for deriving a novel active learning criterion. Then, we exploit a relaxed form of submodularity property of our new criterion for devising a polynomial-time approximation algorithm that guarantees a constant-factor approximation of that achieved by the optimal set of selected observations. Empirical evaluation on real-world datasets shows that our proposed approach outperforms existing algorithms for active learning of MOGP and single-output GP models.
[ { "version": "v1", "created": "Sat, 21 Nov 2015 15:08:53 GMT" }, { "version": "v2", "created": "Tue, 24 Nov 2015 08:45:36 GMT" } ]
2015-11-25T00:00:00
[ [ "Zhang", "Yehong", "" ], [ "Hoang", "Trong Nghia", "" ], [ "Low", "Kian Hsiang", "" ], [ "Kankanhalli", "Mohan", "" ] ]
TITLE: Near-Optimal Active Learning of Multi-Output Gaussian Processes ABSTRACT: This paper addresses the problem of active learning of a multi-output Gaussian process (MOGP) model representing multiple types of coexisting correlated environmental phenomena. In contrast to existing works, our active learning problem involves selecting not just the most informative sampling locations to be observed but also the types of measurements at each selected location for minimizing the predictive uncertainty (i.e., posterior joint entropy) of a target phenomenon of interest given a sampling budget. Unfortunately, such an entropy criterion scales poorly in the numbers of candidate sampling locations and selected observations when optimized. To resolve this issue, we first exploit a structure common to sparse MOGP models for deriving a novel active learning criterion. Then, we exploit a relaxed form of submodularity property of our new criterion for devising a polynomial-time approximation algorithm that guarantees a constant-factor approximation of that achieved by the optimal set of selected observations. Empirical evaluation on real-world datasets shows that our proposed approach outperforms existing algorithms for active learning of MOGP and single-output GP models.
no_new_dataset
0.945951
1511.07528
Nicolas Papernot
Nicolas Papernot and Patrick McDaniel and Somesh Jha and Matt Fredrikson and Z. Berkay Celik and Ananthram Swami
The Limitations of Deep Learning in Adversarial Settings
Accepted to the 1st IEEE European Symposium on Security & Privacy, IEEE 2016. Saarbrucken, Germany
null
null
null
cs.CR cs.LG cs.NE stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep learning takes advantage of large datasets and computationally efficient training algorithms to outperform other approaches at various machine learning tasks. However, imperfections in the training phase of deep neural networks make them vulnerable to adversarial samples: inputs crafted by adversaries with the intent of causing deep neural networks to misclassify. In this work, we formalize the space of adversaries against deep neural networks (DNNs) and introduce a novel class of algorithms to craft adversarial samples based on a precise understanding of the mapping between inputs and outputs of DNNs. In an application to computer vision, we show that our algorithms can reliably produce samples correctly classified by human subjects but misclassified in specific targets by a DNN with a 97% adversarial success rate while only modifying on average 4.02% of the input features per sample. We then evaluate the vulnerability of different sample classes to adversarial perturbations by defining a hardness measure. Finally, we describe preliminary work outlining defenses against adversarial samples by defining a predictive measure of distance between a benign input and a target classification.
[ { "version": "v1", "created": "Tue, 24 Nov 2015 01:07:08 GMT" } ]
2015-11-25T00:00:00
[ [ "Papernot", "Nicolas", "" ], [ "McDaniel", "Patrick", "" ], [ "Jha", "Somesh", "" ], [ "Fredrikson", "Matt", "" ], [ "Celik", "Z. Berkay", "" ], [ "Swami", "Ananthram", "" ] ]
TITLE: The Limitations of Deep Learning in Adversarial Settings ABSTRACT: Deep learning takes advantage of large datasets and computationally efficient training algorithms to outperform other approaches at various machine learning tasks. However, imperfections in the training phase of deep neural networks make them vulnerable to adversarial samples: inputs crafted by adversaries with the intent of causing deep neural networks to misclassify. In this work, we formalize the space of adversaries against deep neural networks (DNNs) and introduce a novel class of algorithms to craft adversarial samples based on a precise understanding of the mapping between inputs and outputs of DNNs. In an application to computer vision, we show that our algorithms can reliably produce samples correctly classified by human subjects but misclassified in specific targets by a DNN with a 97% adversarial success rate while only modifying on average 4.02% of the input features per sample. We then evaluate the vulnerability of different sample classes to adversarial perturbations by defining a hardness measure. Finally, we describe preliminary work outlining defenses against adversarial samples by defining a predictive measure of distance between a benign input and a target classification.
no_new_dataset
0.942135
1511.07571
Justin Johnson
Justin Johnson and Andrej Karpathy and Li Fei-Fei
DenseCap: Fully Convolutional Localization Networks for Dense Captioning
null
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce the dense captioning task, which requires a computer vision system to both localize and describe salient regions in images in natural language. The dense captioning task generalizes object detection when the descriptions consist of a single word, and Image Captioning when one predicted region covers the full image. To address the localization and description task jointly we propose a Fully Convolutional Localization Network (FCLN) architecture that processes an image with a single, efficient forward pass, requires no external regions proposals, and can be trained end-to-end with a single round of optimization. The architecture is composed of a Convolutional Network, a novel dense localization layer, and Recurrent Neural Network language model that generates the label sequences. We evaluate our network on the Visual Genome dataset, which comprises 94,000 images and 4,100,000 region-grounded captions. We observe both speed and accuracy improvements over baselines based on current state of the art approaches in both generation and retrieval settings.
[ { "version": "v1", "created": "Tue, 24 Nov 2015 05:13:54 GMT" } ]
2015-11-25T00:00:00
[ [ "Johnson", "Justin", "" ], [ "Karpathy", "Andrej", "" ], [ "Fei-Fei", "Li", "" ] ]
TITLE: DenseCap: Fully Convolutional Localization Networks for Dense Captioning ABSTRACT: We introduce the dense captioning task, which requires a computer vision system to both localize and describe salient regions in images in natural language. The dense captioning task generalizes object detection when the descriptions consist of a single word, and Image Captioning when one predicted region covers the full image. To address the localization and description task jointly we propose a Fully Convolutional Localization Network (FCLN) architecture that processes an image with a single, efficient forward pass, requires no external regions proposals, and can be trained end-to-end with a single round of optimization. The architecture is composed of a Convolutional Network, a novel dense localization layer, and Recurrent Neural Network language model that generates the label sequences. We evaluate our network on the Visual Genome dataset, which comprises 94,000 images and 4,100,000 region-grounded captions. We observe both speed and accuracy improvements over baselines based on current state of the art approaches in both generation and retrieval settings.
no_new_dataset
0.948442
1511.07732
Thiago Santini
Thiago Santini, Wolfgang Fuhl, Thomas K\"ubler, and Enkelejda Kasneci
Bayesian Identification of Fixations, Saccades, and Smooth Pursuits
8 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Smooth pursuit eye movements provide meaningful insights and information on subject's behavior and health and may, in particular situations, disturb the performance of typical fixation/saccade classification algorithms. Thus, an automatic and efficient algorithm to identify these eye movements is paramount for eye-tracking research involving dynamic stimuli. In this paper, we propose the Bayesian Decision Theory Identification (I-BDT) algorithm, a novel algorithm for ternary classification of eye movements that is able to reliably separate fixations, saccades, and smooth pursuits in an online fashion, even for low-resolution eye trackers. The proposed algorithm is evaluated on four datasets with distinct mixtures of eye movements, including fixations, saccades, as well as straight and circular smooth pursuits; data was collected with a sample rate of 30 Hz from six subjects, totaling 24 evaluation datasets. The algorithm exhibits high and consistent performance across all datasets and movements relative to a manual annotation by a domain expert (recall: \mu = 91.42%, \sigma = 9.52%; precision: \mu = 95.60%, \sigma = 5.29%; specificity \mu = 95.41%, \sigma = 7.02%) and displays a significant improvement when compared to I-VDT, an state-of-the-art algorithm (recall: \mu = 87.67%, \sigma = 14.73%; precision: \mu = 89.57%, \sigma = 8.05%; specificity \mu = 92.10%, \sigma = 11.21%). For algorithm implementation and annotated datasets, please contact the first author.
[ { "version": "v1", "created": "Tue, 24 Nov 2015 14:40:05 GMT" } ]
2015-11-25T00:00:00
[ [ "Santini", "Thiago", "" ], [ "Fuhl", "Wolfgang", "" ], [ "Kübler", "Thomas", "" ], [ "Kasneci", "Enkelejda", "" ] ]
TITLE: Bayesian Identification of Fixations, Saccades, and Smooth Pursuits ABSTRACT: Smooth pursuit eye movements provide meaningful insights and information on subject's behavior and health and may, in particular situations, disturb the performance of typical fixation/saccade classification algorithms. Thus, an automatic and efficient algorithm to identify these eye movements is paramount for eye-tracking research involving dynamic stimuli. In this paper, we propose the Bayesian Decision Theory Identification (I-BDT) algorithm, a novel algorithm for ternary classification of eye movements that is able to reliably separate fixations, saccades, and smooth pursuits in an online fashion, even for low-resolution eye trackers. The proposed algorithm is evaluated on four datasets with distinct mixtures of eye movements, including fixations, saccades, as well as straight and circular smooth pursuits; data was collected with a sample rate of 30 Hz from six subjects, totaling 24 evaluation datasets. The algorithm exhibits high and consistent performance across all datasets and movements relative to a manual annotation by a domain expert (recall: \mu = 91.42%, \sigma = 9.52%; precision: \mu = 95.60%, \sigma = 5.29%; specificity \mu = 95.41%, \sigma = 7.02%) and displays a significant improvement when compared to I-VDT, an state-of-the-art algorithm (recall: \mu = 87.67%, \sigma = 14.73%; precision: \mu = 89.57%, \sigma = 8.05%; specificity \mu = 92.10%, \sigma = 11.21%). For algorithm implementation and annotated datasets, please contact the first author.
no_new_dataset
0.954393
1501.04709
Boleslaw Szymanski
Chris Gaiteri, Mingming Chen, Boleslaw Szymanski, Konstantin Kuzmin, Jierui Xie, Changkyu Lee, Timothy Blanche, Elias Chaibub Neto, Su-Chun Huang, Thomas Grabowski, Tara Madhyastha, Vitalina Komashko
Identifying robust communities and multi-community nodes by combining top-down and bottom-up approaches to clustering
null
Scientific Reports 5, Article number: 16361 (2015)
10.1038/srep16361
null
cs.CE cs.SI physics.bio-ph q-bio.MN
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Biological functions are carried out by groups of interacting molecules, cells or tissues, known as communities. Membership in these communities may overlap when biological components are involved in multiple functions. However, traditional clustering methods detect non-overlapping communities. These detected communities may also be unstable and difficult to replicate, because traditional methods are sensitive to noise and parameter settings. These aspects of traditional clustering methods limit our ability to detect biological communities, and therefore our ability to understand biological functions. To address these limitations and detect robust overlapping biological communities, we propose an unorthodox clustering method called SpeakEasy which identifies communities using top-down and bottom-up approaches simultaneously. Specifically, nodes join communities based on their local connections, as well as global information about the network structure. This method can quantify the stability of each community, automatically identify the number of communities, and quickly cluster networks with hundreds of thousands of nodes. SpeakEasy shows top performance on synthetic clustering benchmarks and accurately identifies meaningful biological communities in a range of datasets, including: gene microarrays, protein interactions, sorted cell populations, electrophysiology and fMRI brain imaging.
[ { "version": "v1", "created": "Tue, 20 Jan 2015 04:15:17 GMT" }, { "version": "v2", "created": "Thu, 26 Feb 2015 00:30:22 GMT" } ]
2015-11-24T00:00:00
[ [ "Gaiteri", "Chris", "" ], [ "Chen", "Mingming", "" ], [ "Szymanski", "Boleslaw", "" ], [ "Kuzmin", "Konstantin", "" ], [ "Xie", "Jierui", "" ], [ "Lee", "Changkyu", "" ], [ "Blanche", "Timothy", "" ], [ "Neto", "Elias Chaibub", "" ], [ "Huang", "Su-Chun", "" ], [ "Grabowski", "Thomas", "" ], [ "Madhyastha", "Tara", "" ], [ "Komashko", "Vitalina", "" ] ]
TITLE: Identifying robust communities and multi-community nodes by combining top-down and bottom-up approaches to clustering ABSTRACT: Biological functions are carried out by groups of interacting molecules, cells or tissues, known as communities. Membership in these communities may overlap when biological components are involved in multiple functions. However, traditional clustering methods detect non-overlapping communities. These detected communities may also be unstable and difficult to replicate, because traditional methods are sensitive to noise and parameter settings. These aspects of traditional clustering methods limit our ability to detect biological communities, and therefore our ability to understand biological functions. To address these limitations and detect robust overlapping biological communities, we propose an unorthodox clustering method called SpeakEasy which identifies communities using top-down and bottom-up approaches simultaneously. Specifically, nodes join communities based on their local connections, as well as global information about the network structure. This method can quantify the stability of each community, automatically identify the number of communities, and quickly cluster networks with hundreds of thousands of nodes. SpeakEasy shows top performance on synthetic clustering benchmarks and accurately identifies meaningful biological communities in a range of datasets, including: gene microarrays, protein interactions, sorted cell populations, electrophysiology and fMRI brain imaging.
no_new_dataset
0.945349
1505.05836
Aroma Mahendru
Neelima Chavali, Harsh Agrawal, Aroma Mahendru, Dhruv Batra
Object-Proposal Evaluation Protocol is 'Gameable'
15 pages, 11 figures, 4 tables
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Object proposals have quickly become the de-facto pre-processing step in a number of vision pipelines (for object detection, object discovery, and other tasks). Their performance is usually evaluated on partially annotated datasets. In this paper, we argue that the choice of using a partially annotated dataset for evaluation of object proposals is problematic -- as we demonstrate via a thought experiment, the evaluation protocol is 'gameable', in the sense that progress under this protocol does not necessarily correspond to a "better" category independent object proposal algorithm. To alleviate this problem, we: (1) Introduce a nearly-fully annotated version of PASCAL VOC dataset, which serves as a test-bed to check if object proposal techniques are overfitting to a particular list of categories. (2) Perform an exhaustive evaluation of object proposal methods on our introduced nearly-fully annotated PASCAL dataset and perform cross-dataset generalization experiments; and (3) Introduce a diagnostic experiment to detect the bias capacity in an object proposal algorithm. This tool circumvents the need to collect a densely annotated dataset, which can be expensive and cumbersome to collect. Finally, we plan to release an easy-to-use toolbox which combines various publicly available implementations of object proposal algorithms which standardizes the proposal generation and evaluation so that new methods can be added and evaluated on different datasets. We hope that the results presented in the paper will motivate the community to test the category independence of various object proposal methods by carefully choosing the evaluation protocol.
[ { "version": "v1", "created": "Thu, 21 May 2015 18:53:45 GMT" }, { "version": "v2", "created": "Fri, 22 May 2015 04:23:57 GMT" }, { "version": "v3", "created": "Mon, 25 May 2015 05:14:53 GMT" }, { "version": "v4", "created": "Mon, 23 Nov 2015 07:16:16 GMT" } ]
2015-11-24T00:00:00
[ [ "Chavali", "Neelima", "" ], [ "Agrawal", "Harsh", "" ], [ "Mahendru", "Aroma", "" ], [ "Batra", "Dhruv", "" ] ]
TITLE: Object-Proposal Evaluation Protocol is 'Gameable' ABSTRACT: Object proposals have quickly become the de-facto pre-processing step in a number of vision pipelines (for object detection, object discovery, and other tasks). Their performance is usually evaluated on partially annotated datasets. In this paper, we argue that the choice of using a partially annotated dataset for evaluation of object proposals is problematic -- as we demonstrate via a thought experiment, the evaluation protocol is 'gameable', in the sense that progress under this protocol does not necessarily correspond to a "better" category independent object proposal algorithm. To alleviate this problem, we: (1) Introduce a nearly-fully annotated version of PASCAL VOC dataset, which serves as a test-bed to check if object proposal techniques are overfitting to a particular list of categories. (2) Perform an exhaustive evaluation of object proposal methods on our introduced nearly-fully annotated PASCAL dataset and perform cross-dataset generalization experiments; and (3) Introduce a diagnostic experiment to detect the bias capacity in an object proposal algorithm. This tool circumvents the need to collect a densely annotated dataset, which can be expensive and cumbersome to collect. Finally, we plan to release an easy-to-use toolbox which combines various publicly available implementations of object proposal algorithms which standardizes the proposal generation and evaluation so that new methods can be added and evaluated on different datasets. We hope that the results presented in the paper will motivate the community to test the category independence of various object proposal methods by carefully choosing the evaluation protocol.
new_dataset
0.969699
1507.03060
Hongkai Yu
Hongkai Yu, Youjie Zhou, Hui Qian, Min Xian, Yuewei Lin, Dazhou Guo, Kang Zheng, Kareem Abdelfatah, Song Wang
LooseCut: Interactive Image Segmentation with Loosely Bounded Boxes
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One popular approach to interactively segment the foreground object of interest from an image is to annotate a bounding box that covers the foreground object. Then, a binary labeling is performed to achieve a refined segmentation. One major issue of the existing algorithms for such interactive image segmentation is their preference of an input bounding box that tightly encloses the foreground object. This increases the annotation burden, and prevents these algorithms from utilizing automatically detected bounding boxes. In this paper, we develop a new LooseCut algorithm that can handle cases where the input bounding box only loosely covers the foreground object. We propose a new Markov Random Fields (MRF) model for segmentation with loosely bounded boxes, including a global similarity constraint to better distinguish the foreground and background, and an additional energy term to encourage consistent labeling of similar-appearance pixels. This MRF model is then solved by an iterated max-flow algorithm. In the experiments, we evaluate LooseCut in three publicly-available image datasets, and compare its performance against several state-of-the-art interactive image segmentation algorithms. We also show that LooseCut can be used for enhancing the performance of unsupervised video segmentation and image saliency detection.
[ { "version": "v1", "created": "Sat, 11 Jul 2015 03:04:36 GMT" }, { "version": "v2", "created": "Sun, 22 Nov 2015 03:54:17 GMT" } ]
2015-11-24T00:00:00
[ [ "Yu", "Hongkai", "" ], [ "Zhou", "Youjie", "" ], [ "Qian", "Hui", "" ], [ "Xian", "Min", "" ], [ "Lin", "Yuewei", "" ], [ "Guo", "Dazhou", "" ], [ "Zheng", "Kang", "" ], [ "Abdelfatah", "Kareem", "" ], [ "Wang", "Song", "" ] ]
TITLE: LooseCut: Interactive Image Segmentation with Loosely Bounded Boxes ABSTRACT: One popular approach to interactively segment the foreground object of interest from an image is to annotate a bounding box that covers the foreground object. Then, a binary labeling is performed to achieve a refined segmentation. One major issue of the existing algorithms for such interactive image segmentation is their preference of an input bounding box that tightly encloses the foreground object. This increases the annotation burden, and prevents these algorithms from utilizing automatically detected bounding boxes. In this paper, we develop a new LooseCut algorithm that can handle cases where the input bounding box only loosely covers the foreground object. We propose a new Markov Random Fields (MRF) model for segmentation with loosely bounded boxes, including a global similarity constraint to better distinguish the foreground and background, and an additional energy term to encourage consistent labeling of similar-appearance pixels. This MRF model is then solved by an iterated max-flow algorithm. In the experiments, we evaluate LooseCut in three publicly-available image datasets, and compare its performance against several state-of-the-art interactive image segmentation algorithms. We also show that LooseCut can be used for enhancing the performance of unsupervised video segmentation and image saliency detection.
no_new_dataset
0.949856
1508.01292
Ilya Kalinowski
Ilya Kalinovskii, Vladimir Spitsyn
Compact Convolutional Neural Network Cascade for Face Detection
Demo video and test results available at http://github.com/Bkmz21/FD-Evaluation
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The problem of faces detection in images or video streams is a classical problem of computer vision. The multiple solutions of this problem have been proposed, but the question of their optimality is still open. Many algorithms achieve a high quality face detection, but at the cost of high computational complexity. This restricts their application in the real-time systems. This paper presents a new solution of the frontal face detection problem based on compact convolutional neural networks cascade. The test results on FDDB dataset show that it is competitive with state-of-the-art algorithms. This proposed detector is implemented using three technologies: SSE/AVX/AVX2 instruction sets for Intel CPUs, Nvidia CUDA, OpenCL. The detection speed of our approach considerably exceeds all the existing CPU-based and GPU-based algorithms. Because of high computational efficiency, our detector can processing 4K Ultra HD video stream in real time (up to 27 fps) on mobile platforms (Intel Ivy Bridge CPUs and Nvidia Kepler GPUs) in searching objects with the dimension 60x60 pixels or higher. At the same time its performance weakly dependent on the background and number of objects in scene. This is achieved by the asynchronous computation of stages in the cascade.
[ { "version": "v1", "created": "Thu, 6 Aug 2015 07:01:55 GMT" }, { "version": "v2", "created": "Wed, 12 Aug 2015 09:10:27 GMT" }, { "version": "v3", "created": "Mon, 23 Nov 2015 20:01:06 GMT" } ]
2015-11-24T00:00:00
[ [ "Kalinovskii", "Ilya", "" ], [ "Spitsyn", "Vladimir", "" ] ]
TITLE: Compact Convolutional Neural Network Cascade for Face Detection ABSTRACT: The problem of faces detection in images or video streams is a classical problem of computer vision. The multiple solutions of this problem have been proposed, but the question of their optimality is still open. Many algorithms achieve a high quality face detection, but at the cost of high computational complexity. This restricts their application in the real-time systems. This paper presents a new solution of the frontal face detection problem based on compact convolutional neural networks cascade. The test results on FDDB dataset show that it is competitive with state-of-the-art algorithms. This proposed detector is implemented using three technologies: SSE/AVX/AVX2 instruction sets for Intel CPUs, Nvidia CUDA, OpenCL. The detection speed of our approach considerably exceeds all the existing CPU-based and GPU-based algorithms. Because of high computational efficiency, our detector can processing 4K Ultra HD video stream in real time (up to 27 fps) on mobile platforms (Intel Ivy Bridge CPUs and Nvidia Kepler GPUs) in searching objects with the dimension 60x60 pixels or higher. At the same time its performance weakly dependent on the background and number of objects in scene. This is achieved by the asynchronous computation of stages in the cascade.
no_new_dataset
0.946399
1511.05296
Jinghua Wang
Jinghua Wang, Abrar Abdul Nabi, Gang Wang, Chengde Wan, Tian-Tsong Ng
Towards Predicting the Likeability of Fashion Images
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose a method for ranking fashion images to find the ones which might be liked by more people. We collect two new datasets from image sharing websites (Pinterest and Polyvore). We represent fashion images based on attributes: semantic attributes and data-driven attributes. To learn semantic attributes from limited training data, we use an algorithm on multi-task convolutional neural networks to share visual knowledge among different semantic attribute categories. To discover data-driven attributes unsupervisedly, we propose an algorithm to simultaneously discover visual clusters and learn fashion-specific feature representations. Given attributes as representations, we propose to learn a ranking SPN (sum product networks) to rank pairs of fashion images. The proposed ranking SPN can capture the high-order correlations of the attributes. We show the effectiveness of our method on our two newly collected datasets.
[ { "version": "v1", "created": "Tue, 17 Nov 2015 07:31:36 GMT" }, { "version": "v2", "created": "Mon, 23 Nov 2015 07:26:25 GMT" } ]
2015-11-24T00:00:00
[ [ "Wang", "Jinghua", "" ], [ "Nabi", "Abrar Abdul", "" ], [ "Wang", "Gang", "" ], [ "Wan", "Chengde", "" ], [ "Ng", "Tian-Tsong", "" ] ]
TITLE: Towards Predicting the Likeability of Fashion Images ABSTRACT: In this paper, we propose a method for ranking fashion images to find the ones which might be liked by more people. We collect two new datasets from image sharing websites (Pinterest and Polyvore). We represent fashion images based on attributes: semantic attributes and data-driven attributes. To learn semantic attributes from limited training data, we use an algorithm on multi-task convolutional neural networks to share visual knowledge among different semantic attribute categories. To discover data-driven attributes unsupervisedly, we propose an algorithm to simultaneously discover visual clusters and learn fashion-specific feature representations. Given attributes as representations, we propose to learn a ranking SPN (sum product networks) to rank pairs of fashion images. The proposed ranking SPN can capture the high-order correlations of the attributes. We show the effectiveness of our method on our two newly collected datasets.
new_dataset
0.927495
1511.06833
Thenmalar S
S. Thenmalar, J. Balaji, and T.V. Geetha
Semi-supervised Bootstrapping approach for Named Entity Recognition
13 pages, 2 figures, 5 tables
null
null
null
cs.CL cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The aim of Named Entity Recognition (NER) is to identify references of named entities in unstructured documents, and to classify them into pre-defined semantic categories. NER often aids from added background knowledge in the form of gazetteers. However using such a collection does not deal with name variants and cannot resolve ambiguities associated in identifying the entities in context and associating them with predefined categories. We present a semi-supervised NER approach that starts with identifying named entities with a small set of training data. Using the identified named entities, the word and the context features are used to define the pattern. This pattern of each named entity category is used as a seed pattern to identify the named entities in the test set. Pattern scoring and tuple value score enables the generation of the new patterns to identify the named entity categories. We have evaluated the proposed system for English language with the dataset of tagged (IEER) and untagged (CoNLL 2003) named entity corpus and for Tamil language with the documents from the FIRE corpus and yield an average f-measure of 75% for both the languages.
[ { "version": "v1", "created": "Sat, 21 Nov 2015 04:11:44 GMT" } ]
2015-11-24T00:00:00
[ [ "Thenmalar", "S.", "" ], [ "Balaji", "J.", "" ], [ "Geetha", "T. V.", "" ] ]
TITLE: Semi-supervised Bootstrapping approach for Named Entity Recognition ABSTRACT: The aim of Named Entity Recognition (NER) is to identify references of named entities in unstructured documents, and to classify them into pre-defined semantic categories. NER often aids from added background knowledge in the form of gazetteers. However using such a collection does not deal with name variants and cannot resolve ambiguities associated in identifying the entities in context and associating them with predefined categories. We present a semi-supervised NER approach that starts with identifying named entities with a small set of training data. Using the identified named entities, the word and the context features are used to define the pattern. This pattern of each named entity category is used as a seed pattern to identify the named entities in the test set. Pattern scoring and tuple value score enables the generation of the new patterns to identify the named entity categories. We have evaluated the proposed system for English language with the dataset of tagged (IEER) and untagged (CoNLL 2003) named entity corpus and for Tamil language with the documents from the FIRE corpus and yield an average f-measure of 75% for both the languages.
no_new_dataset
0.9463
1511.06838
Stella Yu
Takuya Narihira, Damian Borth, Stella X. Yu, Karl Ni, Trevor Darrell
Mapping Images to Sentiment Adjective Noun Pairs with Factorized Neural Nets
null
null
null
null
cs.CV cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the visual sentiment task of mapping an image to an adjective noun pair (ANP) such as "cute baby". To capture the two-factor structure of our ANP semantics as well as to overcome annotation noise and ambiguity, we propose a novel factorized CNN model which learns separate representations for adjectives and nouns but optimizes the classification performance over their product. Our experiments on the publicly available SentiBank dataset show that our model significantly outperforms not only independent ANP classifiers on unseen ANPs and on retrieving images of novel ANPs, but also image captioning models which capture word semantics from co-occurrence of natural text; the latter turn out to be surprisingly poor at capturing the sentiment evoked by pure visual experience. That is, our factorized ANP CNN not only trains better from noisy labels, generalizes better to new images, but can also expands the ANP vocabulary on its own.
[ { "version": "v1", "created": "Sat, 21 Nov 2015 04:58:46 GMT" } ]
2015-11-24T00:00:00
[ [ "Narihira", "Takuya", "" ], [ "Borth", "Damian", "" ], [ "Yu", "Stella X.", "" ], [ "Ni", "Karl", "" ], [ "Darrell", "Trevor", "" ] ]
TITLE: Mapping Images to Sentiment Adjective Noun Pairs with Factorized Neural Nets ABSTRACT: We consider the visual sentiment task of mapping an image to an adjective noun pair (ANP) such as "cute baby". To capture the two-factor structure of our ANP semantics as well as to overcome annotation noise and ambiguity, we propose a novel factorized CNN model which learns separate representations for adjectives and nouns but optimizes the classification performance over their product. Our experiments on the publicly available SentiBank dataset show that our model significantly outperforms not only independent ANP classifiers on unseen ANPs and on retrieving images of novel ANPs, but also image captioning models which capture word semantics from co-occurrence of natural text; the latter turn out to be surprisingly poor at capturing the sentiment evoked by pure visual experience. That is, our factorized ANP CNN not only trains better from noisy labels, generalizes better to new images, but can also expands the ANP vocabulary on its own.
no_new_dataset
0.950869
1511.06853
Yichao Xu
Yichao Xu, Hajime Nagahara, Atsushi Shimada, Rin-ichiro Taniguchi
TransCut: Transparent Object Segmentation from a Light-Field Image
9 pages, 14 figures, 2 tables, ICCV 2015
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The segmentation of transparent objects can be very useful in computer vision applications. However, because they borrow texture from their background and have a similar appearance to their surroundings, transparent objects are not handled well by regular image segmentation methods. We propose a method that overcomes these problems using the consistency and distortion properties of a light-field image. Graph-cut optimization is applied for the pixel labeling problem. The light-field linearity is used to estimate the likelihood of a pixel belonging to the transparent object or Lambertian background, and the occlusion detector is used to find the occlusion boundary. We acquire a light field dataset for the transparent object, and use this dataset to evaluate our method. The results demonstrate that the proposed method successfully segments transparent objects from the background.
[ { "version": "v1", "created": "Sat, 21 Nov 2015 08:33:18 GMT" } ]
2015-11-24T00:00:00
[ [ "Xu", "Yichao", "" ], [ "Nagahara", "Hajime", "" ], [ "Shimada", "Atsushi", "" ], [ "Taniguchi", "Rin-ichiro", "" ] ]
TITLE: TransCut: Transparent Object Segmentation from a Light-Field Image ABSTRACT: The segmentation of transparent objects can be very useful in computer vision applications. However, because they borrow texture from their background and have a similar appearance to their surroundings, transparent objects are not handled well by regular image segmentation methods. We propose a method that overcomes these problems using the consistency and distortion properties of a light-field image. Graph-cut optimization is applied for the pixel labeling problem. The light-field linearity is used to estimate the likelihood of a pixel belonging to the transparent object or Lambertian background, and the occlusion detector is used to find the occlusion boundary. We acquire a light field dataset for the transparent object, and use this dataset to evaluate our method. The results demonstrate that the proposed method successfully segments transparent objects from the background.
new_dataset
0.542515
1511.06951
Leslie Smith
Leslie N. Smith, Emily M. Hand, Timothy Doster
Gradual DropIn of Layers to Train Very Deep Neural Networks
null
null
null
null
cs.NE cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce the concept of dynamically growing a neural network during training. In particular, an untrainable deep network starts as a trainable shallow network and newly added layers are slowly, organically added during training, thereby increasing the network's depth. This is accomplished by a new layer, which we call DropIn. The DropIn layer starts by passing the output from a previous layer (effectively skipping over the newly added layers), then increasingly including units from the new layers for both feedforward and backpropagation. We show that deep networks, which are untrainable with conventional methods, will converge with DropIn layers interspersed in the architecture. In addition, we demonstrate that DropIn provides regularization during training in an analogous way as dropout. Experiments are described with the MNIST dataset and various expanded LeNet architectures, CIFAR-10 dataset with its architecture expanded from 3 to 11 layers, and on the ImageNet dataset with the AlexNet architecture expanded to 13 layers and the VGG 16-layer architecture.
[ { "version": "v1", "created": "Sun, 22 Nov 2015 02:33:08 GMT" } ]
2015-11-24T00:00:00
[ [ "Smith", "Leslie N.", "" ], [ "Hand", "Emily M.", "" ], [ "Doster", "Timothy", "" ] ]
TITLE: Gradual DropIn of Layers to Train Very Deep Neural Networks ABSTRACT: We introduce the concept of dynamically growing a neural network during training. In particular, an untrainable deep network starts as a trainable shallow network and newly added layers are slowly, organically added during training, thereby increasing the network's depth. This is accomplished by a new layer, which we call DropIn. The DropIn layer starts by passing the output from a previous layer (effectively skipping over the newly added layers), then increasingly including units from the new layers for both feedforward and backpropagation. We show that deep networks, which are untrainable with conventional methods, will converge with DropIn layers interspersed in the architecture. In addition, we demonstrate that DropIn provides regularization during training in an analogous way as dropout. Experiments are described with the MNIST dataset and various expanded LeNet architectures, CIFAR-10 dataset with its architecture expanded from 3 to 11 layers, and on the ImageNet dataset with the AlexNet architecture expanded to 13 layers and the VGG 16-layer architecture.
no_new_dataset
0.952882
1511.06988
Haitian Zheng
Haitian Zheng, Yebin Liu, Mengqi Ji, Feng Wu, Lu Fang
Learning High-level Prior with Convolutional Neural Networks for Semantic Segmentation
9 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper proposes a convolutional neural network that can fuse high-level prior for semantic image segmentation. Motivated by humans' vision recognition system, our key design is a three-layer generative structure consisting of high-level coding, middle-level segmentation and low-level image to introduce global prior for semantic segmentation. Based on this structure, we proposed a generative model called conditional variational auto-encoder (CVAE) that can build up the links behind these three layers. These important links include an image encoder that extracts high level info from image, a segmentation encoder that extracts high level info from segmentation, and a hybrid decoder that outputs semantic segmentation from the high level prior and input image. We theoretically derive the semantic segmentation as an optimization problem parameterized by these links. Finally, the optimization problem enables us to take advantage of state-of-the-art fully convolutional network structure for the implementation of the above encoders and decoder. Experimental results on several representative datasets demonstrate our supreme performance for semantic segmentation.
[ { "version": "v1", "created": "Sun, 22 Nov 2015 10:25:02 GMT" } ]
2015-11-24T00:00:00
[ [ "Zheng", "Haitian", "" ], [ "Liu", "Yebin", "" ], [ "Ji", "Mengqi", "" ], [ "Wu", "Feng", "" ], [ "Fang", "Lu", "" ] ]
TITLE: Learning High-level Prior with Convolutional Neural Networks for Semantic Segmentation ABSTRACT: This paper proposes a convolutional neural network that can fuse high-level prior for semantic image segmentation. Motivated by humans' vision recognition system, our key design is a three-layer generative structure consisting of high-level coding, middle-level segmentation and low-level image to introduce global prior for semantic segmentation. Based on this structure, we proposed a generative model called conditional variational auto-encoder (CVAE) that can build up the links behind these three layers. These important links include an image encoder that extracts high level info from image, a segmentation encoder that extracts high level info from segmentation, and a hybrid decoder that outputs semantic segmentation from the high level prior and input image. We theoretically derive the semantic segmentation as an optimization problem parameterized by these links. Finally, the optimization problem enables us to take advantage of state-of-the-art fully convolutional network structure for the implementation of the above encoders and decoder. Experimental results on several representative datasets demonstrate our supreme performance for semantic segmentation.
no_new_dataset
0.948632
1511.07004
Keunwoo Choi Mr
Keunwoo Choi, George Fazekas, Mark Sandler
Understanding Music Playlists
International Conference on Machine Learning (ICML) 2015, Machine Learning for Music Discovery Workshop
null
null
null
cs.MM cs.IR
http://creativecommons.org/licenses/by/4.0/
As music streaming services dominate the music industry, the playlist is becoming an increasingly crucial element of music consumption. Con- sequently, the music recommendation problem is often casted as a playlist generation prob- lem. Better understanding of the playlist is there- fore necessary for developing better playlist gen- eration algorithms. In this work, we analyse two playlist datasets to investigate some com- monly assumed hypotheses about playlists. Our findings indicate that deeper understanding of playlists is needed to provide better prior infor- mation and improve machine learning algorithms in the design of recommendation systems.
[ { "version": "v1", "created": "Sun, 22 Nov 2015 12:33:08 GMT" } ]
2015-11-24T00:00:00
[ [ "Choi", "Keunwoo", "" ], [ "Fazekas", "George", "" ], [ "Sandler", "Mark", "" ] ]
TITLE: Understanding Music Playlists ABSTRACT: As music streaming services dominate the music industry, the playlist is becoming an increasingly crucial element of music consumption. Con- sequently, the music recommendation problem is often casted as a playlist generation prob- lem. Better understanding of the playlist is there- fore necessary for developing better playlist gen- eration algorithms. In this work, we analyse two playlist datasets to investigate some com- monly assumed hypotheses about playlists. Our findings indicate that deeper understanding of playlists is needed to provide better prior infor- mation and improve machine learning algorithms in the design of recommendation systems.
no_new_dataset
0.95222
1511.07017
Sudhakar Singh
Sudhakar Singh, Rakhi Garg, P. K. Mishra
Performance Analysis of Apriori Algorithm with Different Data Structures on Hadoop Cluster
2009-2015 International Journal of Computer Applications, FCS(Foundation of Computer Science)
null
10.5120/ijca2015906632
null
cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mining frequent itemsets from massive datasets is always being a most important problem of data mining. Apriori is the most popular and simplest algorithm for frequent itemset mining. To enhance the efficiency and scalability of Apriori, a number of algorithms have been proposed addressing the design of efficient data structures, minimizing database scan and parallel and distributed processing. MapReduce is the emerging parallel and distributed technology to process big datasets on Hadoop Cluster. To mine big datasets it is essential to re-design the data mining algorithm on this new paradigm. In this paper, we implement three variations of Apriori algorithm using data structures hash tree, trie and hash table trie i.e. trie with hash technique on MapReduce paradigm. We emphasize and investigate the significance of these three data structures for Apriori algorithm on Hadoop cluster, which has not been given attention yet. Experiments are carried out on both real life and synthetic datasets which shows that hash table trie data structures performs far better than trie and hash tree in terms of execution time. Moreover the performance in case of hash tree becomes worst.
[ { "version": "v1", "created": "Sun, 22 Nov 2015 14:40:06 GMT" } ]
2015-11-24T00:00:00
[ [ "Singh", "Sudhakar", "" ], [ "Garg", "Rakhi", "" ], [ "Mishra", "P. K.", "" ] ]
TITLE: Performance Analysis of Apriori Algorithm with Different Data Structures on Hadoop Cluster ABSTRACT: Mining frequent itemsets from massive datasets is always being a most important problem of data mining. Apriori is the most popular and simplest algorithm for frequent itemset mining. To enhance the efficiency and scalability of Apriori, a number of algorithms have been proposed addressing the design of efficient data structures, minimizing database scan and parallel and distributed processing. MapReduce is the emerging parallel and distributed technology to process big datasets on Hadoop Cluster. To mine big datasets it is essential to re-design the data mining algorithm on this new paradigm. In this paper, we implement three variations of Apriori algorithm using data structures hash tree, trie and hash table trie i.e. trie with hash technique on MapReduce paradigm. We emphasize and investigate the significance of these three data structures for Apriori algorithm on Hadoop cluster, which has not been given attention yet. Experiments are carried out on both real life and synthetic datasets which shows that hash table trie data structures performs far better than trie and hash tree in terms of execution time. Moreover the performance in case of hash tree becomes worst.
no_new_dataset
0.949342
1511.07063
Ning Zhang
Ning Zhang, Evan Shelhamer, Yang Gao, Trevor Darrell
Fine-grained pose prediction, normalization, and recognition
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Pose variation and subtle differences in appearance are key challenges to fine-grained classification. While deep networks have markedly improved general recognition, many approaches to fine-grained recognition rely on anchoring networks to parts for better accuracy. Identifying parts to find correspondence discounts pose variation so that features can be tuned to appearance. To this end previous methods have examined how to find parts and extract pose-normalized features. These methods have generally separated fine-grained recognition into stages which first localize parts using hand-engineered and coarsely-localized proposal features, and then separately learn deep descriptors centered on inferred part positions. We unify these steps in an end-to-end trainable network supervised by keypoint locations and class labels that localizes parts by a fully convolutional network to focus the learning of feature representations for the fine-grained classification task. Experiments on the popular CUB200 dataset show that our method is state-of-the-art and suggest a continuing role for strong supervision.
[ { "version": "v1", "created": "Sun, 22 Nov 2015 20:32:45 GMT" } ]
2015-11-24T00:00:00
[ [ "Zhang", "Ning", "" ], [ "Shelhamer", "Evan", "" ], [ "Gao", "Yang", "" ], [ "Darrell", "Trevor", "" ] ]
TITLE: Fine-grained pose prediction, normalization, and recognition ABSTRACT: Pose variation and subtle differences in appearance are key challenges to fine-grained classification. While deep networks have markedly improved general recognition, many approaches to fine-grained recognition rely on anchoring networks to parts for better accuracy. Identifying parts to find correspondence discounts pose variation so that features can be tuned to appearance. To this end previous methods have examined how to find parts and extract pose-normalized features. These methods have generally separated fine-grained recognition into stages which first localize parts using hand-engineered and coarsely-localized proposal features, and then separately learn deep descriptors centered on inferred part positions. We unify these steps in an end-to-end trainable network supervised by keypoint locations and class labels that localizes parts by a fully convolutional network to focus the learning of feature representations for the fine-grained classification task. Experiments on the popular CUB200 dataset show that our method is state-of-the-art and suggest a continuing role for strong supervision.
no_new_dataset
0.947769
1511.07340
Henry WJ Reeve
Henry W J Reeve and Gavin Brown
Modular Autoencoders for Ensemble Feature Extraction
18 pages, 8 figures, to appear in a special issue of The Journal Of Machine Learning Research (vol.44, Dec 2015)
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce the concept of a Modular Autoencoder (MAE), capable of learning a set of diverse but complementary representations from unlabelled data, that can later be used for supervised tasks. The learning of the representations is controlled by a trade off parameter, and we show on six benchmark datasets the optimum lies between two extremes: a set of smaller, independent autoencoders each with low capacity, versus a single monolithic encoding, outperforming an appropriate baseline. In the present paper we explore the special case of linear MAE, and derive an SVD-based algorithm which converges several orders of magnitude faster than gradient descent.
[ { "version": "v1", "created": "Mon, 23 Nov 2015 17:51:18 GMT" } ]
2015-11-24T00:00:00
[ [ "Reeve", "Henry W J", "" ], [ "Brown", "Gavin", "" ] ]
TITLE: Modular Autoencoders for Ensemble Feature Extraction ABSTRACT: We introduce the concept of a Modular Autoencoder (MAE), capable of learning a set of diverse but complementary representations from unlabelled data, that can later be used for supervised tasks. The learning of the representations is controlled by a trade off parameter, and we show on six benchmark datasets the optimum lies between two extremes: a set of smaller, independent autoencoders each with low capacity, versus a single monolithic encoding, outperforming an appropriate baseline. In the present paper we explore the special case of linear MAE, and derive an SVD-based algorithm which converges several orders of magnitude faster than gradient descent.
no_new_dataset
0.946597
1511.07353
Ahmed Bin Shafaat Ahmed Bin Shafaat
Kamran Shaukat, Nayyer Masood, Ahmed Bin Shafaat, Kamran Jabbar, Hassan Shabbir and Shakir Shabbir
Dengue Fever in Perspective of Clustering Algorithms
null
null
null
null
cs.CY
http://creativecommons.org/licenses/by/4.0/
Dengue fever is a disease which is transmitted and caused by Aedes Aegypti mosquitos. Dengue has become a serious health issue in all over the world especially in those countries who are situated in tropical or subtropical regions because rain is an important factor for growth and increase in the population of dengue transmitting mosquitos. For a long time, data mining algorithms have been used by the scientists for the diagnosis and prognosis of different diseases which includes dengue as well. This was a study to analyses the attack of dengue fever in different areas of district Jhelum, Pakistan in 2011. As per our knowledge, we are unaware of any kind of research study in the area of district Jhelum for diagnosis or analysis of dengue fever. According to our information, we are the first one researching and analyzing dengue fever in this specific area. Dataset was obtained from the office of Executive District Officer EDO (health) District Jhelum. We applied DBSCAN algorithm for the clustering of dengue fever. First we showed overall behavior of dengue in the district Jhelum. Then we explained dengue fever at tehsil level with the help of geographical pictures. After that we have elaborated comparison of different clustering algorithms with the help of graphs based on our dataset. Those algorithms include k-means, K-mediods, DBSCAN and OPTICS.
[ { "version": "v1", "created": "Mon, 23 Nov 2015 18:27:21 GMT" } ]
2015-11-24T00:00:00
[ [ "Shaukat", "Kamran", "" ], [ "Masood", "Nayyer", "" ], [ "Shafaat", "Ahmed Bin", "" ], [ "Jabbar", "Kamran", "" ], [ "Shabbir", "Hassan", "" ], [ "Shabbir", "Shakir", "" ] ]
TITLE: Dengue Fever in Perspective of Clustering Algorithms ABSTRACT: Dengue fever is a disease which is transmitted and caused by Aedes Aegypti mosquitos. Dengue has become a serious health issue in all over the world especially in those countries who are situated in tropical or subtropical regions because rain is an important factor for growth and increase in the population of dengue transmitting mosquitos. For a long time, data mining algorithms have been used by the scientists for the diagnosis and prognosis of different diseases which includes dengue as well. This was a study to analyses the attack of dengue fever in different areas of district Jhelum, Pakistan in 2011. As per our knowledge, we are unaware of any kind of research study in the area of district Jhelum for diagnosis or analysis of dengue fever. According to our information, we are the first one researching and analyzing dengue fever in this specific area. Dataset was obtained from the office of Executive District Officer EDO (health) District Jhelum. We applied DBSCAN algorithm for the clustering of dengue fever. First we showed overall behavior of dengue in the district Jhelum. Then we explained dengue fever at tehsil level with the help of geographical pictures. After that we have elaborated comparison of different clustering algorithms with the help of graphs based on our dataset. Those algorithms include k-means, K-mediods, DBSCAN and OPTICS.
no_new_dataset
0.927953
1511.07357
Sariel Har-Peled
Sariel Har-Peled and Sepideh Mahabadi
Proximity in the Age of Distraction: Robust Approximate Nearest Neighbor Search
null
null
null
null
cs.CG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a new variant of the nearest neighbor search problem, which allows for some coordinates of the dataset to be arbitrarily corrupted or unknown. Formally, given a dataset of $n$ points $P=\{ x_1,\ldots, x_n\}$ in high-dimensions, and a parameter $k$, the goal is to preprocess the dataset, such that given a query point $q$, one can compute quickly a point $x \in P$, such that the distance of the query to the point $x$ is minimized, when ignoring the "optimal" $k$ coordinates. Note, that the coordinates being ignored are a function of both the query point and the point returned. We present a general reduction from this problem to answering ANN queries, which is similar in spirit to LSH (locality sensitive hashing) [IM98]. Specifically, we give a sampling technique which achieves a bi-criterion approximation for this problem. If the distance to the nearest neighbor after ignoring $k$ coordinates is $r$, the data-structure returns a point that is within a distance of $O(r)$ after ignoring $O(k)$ coordinates. We also present other applications and further extensions and refinements of the above result. The new data-structures are simple and (arguably) elegant, and should be practical -- specifically, all bounds are polynomial in all relevant parameters (including the dimension of the space, and the robustness parameter $k$).
[ { "version": "v1", "created": "Mon, 23 Nov 2015 18:45:12 GMT" } ]
2015-11-24T00:00:00
[ [ "Har-Peled", "Sariel", "" ], [ "Mahabadi", "Sepideh", "" ] ]
TITLE: Proximity in the Age of Distraction: Robust Approximate Nearest Neighbor Search ABSTRACT: We introduce a new variant of the nearest neighbor search problem, which allows for some coordinates of the dataset to be arbitrarily corrupted or unknown. Formally, given a dataset of $n$ points $P=\{ x_1,\ldots, x_n\}$ in high-dimensions, and a parameter $k$, the goal is to preprocess the dataset, such that given a query point $q$, one can compute quickly a point $x \in P$, such that the distance of the query to the point $x$ is minimized, when ignoring the "optimal" $k$ coordinates. Note, that the coordinates being ignored are a function of both the query point and the point returned. We present a general reduction from this problem to answering ANN queries, which is similar in spirit to LSH (locality sensitive hashing) [IM98]. Specifically, we give a sampling technique which achieves a bi-criterion approximation for this problem. If the distance to the nearest neighbor after ignoring $k$ coordinates is $r$, the data-structure returns a point that is within a distance of $O(r)$ after ignoring $O(k)$ coordinates. We also present other applications and further extensions and refinements of the above result. The new data-structures are simple and (arguably) elegant, and should be practical -- specifically, all bounds are polynomial in all relevant parameters (including the dimension of the space, and the robustness parameter $k$).
no_new_dataset
0.938067
1511.07397
Gabriele Farina
Gabriele Farina, Nicola Gatti
Ad auctions and cascade model: GSP inefficiency and algorithms
AAAI16, to appear
null
null
null
cs.GT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The design of the best economic mechanism for Sponsored Search Auctions (SSAs) is a central task in computational mechanism design/game theory. Two open questions concern the adoption of user models more accurate than that one currently used and the choice between Generalized Second Price auction (GSP) and Vickrey-Clark-Groves mechanism (VCG). In this paper, we provide some contributions to answer these questions. We study Price of Anarchy (PoA) and Price of Stability (PoS) over social welfare and auctioneer's revenue of GSP w.r.t. the VCG when the users follow the famous cascade model. Furthermore, we provide exact, randomized, and approximate algorithms, showing that in real-world settings (Yahoo! Webscope A3 dataset, 10 available slots) optimal allocations can be found in less than 1s with up to 1000 ads, and can be approximated in less than 20ms even with more than 1000 ads with an average accuracy greater than 99%.
[ { "version": "v1", "created": "Mon, 23 Nov 2015 20:19:55 GMT" } ]
2015-11-24T00:00:00
[ [ "Farina", "Gabriele", "" ], [ "Gatti", "Nicola", "" ] ]
TITLE: Ad auctions and cascade model: GSP inefficiency and algorithms ABSTRACT: The design of the best economic mechanism for Sponsored Search Auctions (SSAs) is a central task in computational mechanism design/game theory. Two open questions concern the adoption of user models more accurate than that one currently used and the choice between Generalized Second Price auction (GSP) and Vickrey-Clark-Groves mechanism (VCG). In this paper, we provide some contributions to answer these questions. We study Price of Anarchy (PoA) and Price of Stability (PoS) over social welfare and auctioneer's revenue of GSP w.r.t. the VCG when the users follow the famous cascade model. Furthermore, we provide exact, randomized, and approximate algorithms, showing that in real-world settings (Yahoo! Webscope A3 dataset, 10 available slots) optimal allocations can be found in less than 1s with up to 1000 ads, and can be approximated in less than 20ms even with more than 1000 ads with an average accuracy greater than 99%.
no_new_dataset
0.945399
1412.5474
Jonghoon Jin
Jonghoon Jin, Aysegul Dundar, Eugenio Culurciello
Flattened Convolutional Neural Networks for Feedforward Acceleration
International Conference on Learning Representations (ICLR) 2015
null
null
null
cs.NE cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present flattened convolutional neural networks that are designed for fast feedforward execution. The redundancy of the parameters, especially weights of the convolutional filters in convolutional neural networks has been extensively studied and different heuristics have been proposed to construct a low rank basis of the filters after training. In this work, we train flattened networks that consist of consecutive sequence of one-dimensional filters across all directions in 3D space to obtain comparable performance as conventional convolutional networks. We tested flattened model on different datasets and found that the flattened layer can effectively substitute for the 3D filters without loss of accuracy. The flattened convolution pipelines provide around two times speed-up during feedforward pass compared to the baseline model due to the significant reduction of learning parameters. Furthermore, the proposed method does not require efforts in manual tuning or post processing once the model is trained.
[ { "version": "v1", "created": "Wed, 17 Dec 2014 16:48:54 GMT" }, { "version": "v2", "created": "Fri, 27 Feb 2015 20:36:05 GMT" }, { "version": "v3", "created": "Mon, 6 Apr 2015 01:40:08 GMT" }, { "version": "v4", "created": "Fri, 20 Nov 2015 05:50:23 GMT" } ]
2015-11-23T00:00:00
[ [ "Jin", "Jonghoon", "" ], [ "Dundar", "Aysegul", "" ], [ "Culurciello", "Eugenio", "" ] ]
TITLE: Flattened Convolutional Neural Networks for Feedforward Acceleration ABSTRACT: We present flattened convolutional neural networks that are designed for fast feedforward execution. The redundancy of the parameters, especially weights of the convolutional filters in convolutional neural networks has been extensively studied and different heuristics have been proposed to construct a low rank basis of the filters after training. In this work, we train flattened networks that consist of consecutive sequence of one-dimensional filters across all directions in 3D space to obtain comparable performance as conventional convolutional networks. We tested flattened model on different datasets and found that the flattened layer can effectively substitute for the 3D filters without loss of accuracy. The flattened convolution pipelines provide around two times speed-up during feedforward pass compared to the baseline model due to the significant reduction of learning parameters. Furthermore, the proposed method does not require efforts in manual tuning or post processing once the model is trained.
no_new_dataset
0.950869
1412.7957
Sezer Karaoglu
Sezer Karaoglu, Yang Liu, Theo Gevers
Detect2Rank : Combining Object Detectors Using Learning to Rank
null
null
10.1109/TIP.2015.2499702
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Object detection is an important research area in the field of computer vision. Many detection algorithms have been proposed. However, each object detector relies on specific assumptions of the object appearance and imaging conditions. As a consequence, no algorithm can be considered as universal. With the large variety of object detectors, the subsequent question is how to select and combine them. In this paper, we propose a framework to learn how to combine object detectors. The proposed method uses (single) detectors like DPM, CN and EES, and exploits their correlation by high level contextual features to yield a combined detection list. Experiments on the PASCAL VOC07 and VOC10 datasets show that the proposed method significantly outperforms single object detectors, DPM (8.4%), CN (6.8%) and EES (17.0%) on VOC07 and DPM (6.5%), CN (5.5%) and EES (16.2%) on VOC10.
[ { "version": "v1", "created": "Fri, 26 Dec 2014 16:46:52 GMT" } ]
2015-11-23T00:00:00
[ [ "Karaoglu", "Sezer", "" ], [ "Liu", "Yang", "" ], [ "Gevers", "Theo", "" ] ]
TITLE: Detect2Rank : Combining Object Detectors Using Learning to Rank ABSTRACT: Object detection is an important research area in the field of computer vision. Many detection algorithms have been proposed. However, each object detector relies on specific assumptions of the object appearance and imaging conditions. As a consequence, no algorithm can be considered as universal. With the large variety of object detectors, the subsequent question is how to select and combine them. In this paper, we propose a framework to learn how to combine object detectors. The proposed method uses (single) detectors like DPM, CN and EES, and exploits their correlation by high level contextual features to yield a combined detection list. Experiments on the PASCAL VOC07 and VOC10 datasets show that the proposed method significantly outperforms single object detectors, DPM (8.4%), CN (6.8%) and EES (17.0%) on VOC07 and DPM (6.5%), CN (5.5%) and EES (16.2%) on VOC10.
no_new_dataset
0.951818
1501.05928
John L. Rubinstein
Jianhua Zhao, Marcus A. Brubaker, Samir Benlekbir, John L. Rubinstein
Description and comparison of algorithms for correcting anisotropic magnification in cryo-EM images
9 pages, 4 figures
J Struct Biol. 2015 Nov;192(2):209-15. doi: 10.1016/j.jsb.2015.06.014
null
null
physics.ins-det q-bio.BM q-bio.QM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Single particle electron cryomicroscopy (cryo-EM) allows for structures of proteins and protein complexes to be determined from images of non-crystalline specimens. Cryo-EM data analysis requires electron microscope images of randomly oriented ice-embedded protein particles to be rotated and translated to allow for coherent averaging when calculating three-dimensional (3D) structures. Rotation of 2D images is usually done with the assumption that the magnification of the electron microscope is the same in all directions. However, due to electron optical aberrations, this condition is not met with some electron microscopes when used with the settings necessary for cryo-EM with a direct detector device (DDD) camera. Correction of images by linear interpolation in real space has allowed high-resolution structures to be calculated from cryo-EM images for symmetric particles. Here we describe and compare a simple real space method, a simple Fourier space method, and a somewhat more sophisticated Fourier space method to correct images for a measured anisotropy in magnification. Further, anisotropic magnification causes contrast transfer function (CTF) parameters estimated from image power spectra to have an apparent systematic astigmatism. To address this problem we develop an approach to adjust CTF parameters measured from distorted images so that they can be used with corrected images. The effect of anisotropic magnification on CTF parameters provides a simple way of detecting magnification anisotropy in cryo-EM datasets.
[ { "version": "v1", "created": "Fri, 23 Jan 2015 19:51:40 GMT" }, { "version": "v2", "created": "Tue, 27 Jan 2015 22:56:39 GMT" }, { "version": "v3", "created": "Fri, 7 Aug 2015 21:06:45 GMT" } ]
2015-11-23T00:00:00
[ [ "Zhao", "Jianhua", "" ], [ "Brubaker", "Marcus A.", "" ], [ "Benlekbir", "Samir", "" ], [ "Rubinstein", "John L.", "" ] ]
TITLE: Description and comparison of algorithms for correcting anisotropic magnification in cryo-EM images ABSTRACT: Single particle electron cryomicroscopy (cryo-EM) allows for structures of proteins and protein complexes to be determined from images of non-crystalline specimens. Cryo-EM data analysis requires electron microscope images of randomly oriented ice-embedded protein particles to be rotated and translated to allow for coherent averaging when calculating three-dimensional (3D) structures. Rotation of 2D images is usually done with the assumption that the magnification of the electron microscope is the same in all directions. However, due to electron optical aberrations, this condition is not met with some electron microscopes when used with the settings necessary for cryo-EM with a direct detector device (DDD) camera. Correction of images by linear interpolation in real space has allowed high-resolution structures to be calculated from cryo-EM images for symmetric particles. Here we describe and compare a simple real space method, a simple Fourier space method, and a somewhat more sophisticated Fourier space method to correct images for a measured anisotropy in magnification. Further, anisotropic magnification causes contrast transfer function (CTF) parameters estimated from image power spectra to have an apparent systematic astigmatism. To address this problem we develop an approach to adjust CTF parameters measured from distorted images so that they can be used with corrected images. The effect of anisotropic magnification on CTF parameters provides a simple way of detecting magnification anisotropy in cryo-EM datasets.
no_new_dataset
0.954308
1511.05688
Ameen Eetemadi
Ameen Eetemadi, Ilias Tagkopoulos
A Distribution Adaptive Framework for Prediction Interval Estimation Using Nominal Variables
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Proposed methods for prediction interval estimation so far focus on cases where input variables are numerical. In datasets with solely nominal input variables, we observe records with the exact same input $x^u$, but different real valued outputs due to the inherent noise in the system. Existing prediction interval estimation methods do not use representations that can accurately model such inherent noise in the case of nominal inputs. We propose a new prediction interval estimation method tailored for this type of data, which is prevalent in biology and medicine. We call this method Distribution Adaptive Prediction Interval Estimation given Nominal inputs (DAPIEN) and has four main phases. First, we select a distribution function that can best represent the inherent noise of the system for all unique inputs. Then we infer the parameters $\theta_i$ (e.g. $\theta_i=[mean_i, variance_i]$) of the selected distribution function for all unique input vectors $x^u_i$ and generate a new corresponding training set using pairs of $x^u_i, \theta_i$. III). Then, we train a model to predict $\theta$ given a new $x_u$. Finally, we calculate the prediction interval for a new sample using the inverse of the cumulative distribution function once the parameters $\theta$ is predicted by the trained model. We compared DAPIEN to the commonly used Bootstrap method on three synthetic datasets. Our results show that DAPIEN provides tighter prediction intervals while preserving the requested coverage when compared to Bootstrap. This work can facilitate broader usage of regression methods in medicine and biology where it is necessary to provide tight prediction intervals while preserving coverage when input variables are nominal.
[ { "version": "v1", "created": "Wed, 18 Nov 2015 08:13:35 GMT" }, { "version": "v2", "created": "Fri, 20 Nov 2015 08:12:23 GMT" } ]
2015-11-23T00:00:00
[ [ "Eetemadi", "Ameen", "" ], [ "Tagkopoulos", "Ilias", "" ] ]
TITLE: A Distribution Adaptive Framework for Prediction Interval Estimation Using Nominal Variables ABSTRACT: Proposed methods for prediction interval estimation so far focus on cases where input variables are numerical. In datasets with solely nominal input variables, we observe records with the exact same input $x^u$, but different real valued outputs due to the inherent noise in the system. Existing prediction interval estimation methods do not use representations that can accurately model such inherent noise in the case of nominal inputs. We propose a new prediction interval estimation method tailored for this type of data, which is prevalent in biology and medicine. We call this method Distribution Adaptive Prediction Interval Estimation given Nominal inputs (DAPIEN) and has four main phases. First, we select a distribution function that can best represent the inherent noise of the system for all unique inputs. Then we infer the parameters $\theta_i$ (e.g. $\theta_i=[mean_i, variance_i]$) of the selected distribution function for all unique input vectors $x^u_i$ and generate a new corresponding training set using pairs of $x^u_i, \theta_i$. III). Then, we train a model to predict $\theta$ given a new $x_u$. Finally, we calculate the prediction interval for a new sample using the inverse of the cumulative distribution function once the parameters $\theta$ is predicted by the trained model. We compared DAPIEN to the commonly used Bootstrap method on three synthetic datasets. Our results show that DAPIEN provides tighter prediction intervals while preserving the requested coverage when compared to Bootstrap. This work can facilitate broader usage of regression methods in medicine and biology where it is necessary to provide tight prediction intervals while preserving coverage when input variables are nominal.
no_new_dataset
0.948585
1511.06379
Richard Searle Dr
Richard Searle, Megan Bingham-Walker
Dynamic Adaptive Network Intelligence
8 pages, 2 figures, 3 tables, ICLR 2016 conference paper submission
null
null
null
cs.CL cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Accurate representational learning of both the explicit and implicit relationships within data is critical to the ability of machines to perform more complex and abstract reasoning tasks. We describe the efficient weakly supervised learning of such inferences by our Dynamic Adaptive Network Intelligence (DANI) model. We report state-of-the-art results for DANI over question answering tasks in the bAbI dataset that have proved difficult for contemporary approaches to learning representation (Weston et al., 2015).
[ { "version": "v1", "created": "Thu, 19 Nov 2015 21:07:27 GMT" } ]
2015-11-23T00:00:00
[ [ "Searle", "Richard", "" ], [ "Bingham-Walker", "Megan", "" ] ]
TITLE: Dynamic Adaptive Network Intelligence ABSTRACT: Accurate representational learning of both the explicit and implicit relationships within data is critical to the ability of machines to perform more complex and abstract reasoning tasks. We describe the efficient weakly supervised learning of such inferences by our Dynamic Adaptive Network Intelligence (DANI) model. We report state-of-the-art results for DANI over question answering tasks in the bAbI dataset that have proved difficult for contemporary approaches to learning representation (Weston et al., 2015).
no_new_dataset
0.942771
1511.06438
Danushka Bollegala
Danushka Bollegala, Alsuhaibani Mohammed, Takanori Maehara, Ken-ichi Kawarabayashi
Joint Word Representation Learning using a Corpus and a Semantic Lexicon
Accepted to AAAI-2016
Proceedings of the AAAI 2016
null
null
cs.CL cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Methods for learning word representations using large text corpora have received much attention lately due to their impressive performance in numerous natural language processing (NLP) tasks such as, semantic similarity measurement, and word analogy detection. Despite their success, these data-driven word representation learning methods do not consider the rich semantic relational structure between words in a co-occurring context. On the other hand, already much manual effort has gone into the construction of semantic lexicons such as the WordNet that represent the meanings of words by defining the various relationships that exist among the words in a language. We consider the question, can we improve the word representations learnt using a corpora by integrating the knowledge from semantic lexicons?. For this purpose, we propose a joint word representation learning method that simultaneously predicts the co-occurrences of two words in a sentence subject to the relational constrains given by the semantic lexicon. We use relations that exist between words in the lexicon to regularize the word representations learnt from the corpus. Our proposed method statistically significantly outperforms previously proposed methods for incorporating semantic lexicons into word representations on several benchmark datasets for semantic similarity and word analogy.
[ { "version": "v1", "created": "Thu, 19 Nov 2015 22:58:10 GMT" } ]
2015-11-23T00:00:00
[ [ "Bollegala", "Danushka", "" ], [ "Mohammed", "Alsuhaibani", "" ], [ "Maehara", "Takanori", "" ], [ "Kawarabayashi", "Ken-ichi", "" ] ]
TITLE: Joint Word Representation Learning using a Corpus and a Semantic Lexicon ABSTRACT: Methods for learning word representations using large text corpora have received much attention lately due to their impressive performance in numerous natural language processing (NLP) tasks such as, semantic similarity measurement, and word analogy detection. Despite their success, these data-driven word representation learning methods do not consider the rich semantic relational structure between words in a co-occurring context. On the other hand, already much manual effort has gone into the construction of semantic lexicons such as the WordNet that represent the meanings of words by defining the various relationships that exist among the words in a language. We consider the question, can we improve the word representations learnt using a corpora by integrating the knowledge from semantic lexicons?. For this purpose, we propose a joint word representation learning method that simultaneously predicts the co-occurrences of two words in a sentence subject to the relational constrains given by the semantic lexicon. We use relations that exist between words in the lexicon to regularize the word representations learnt from the corpus. Our proposed method statistically significantly outperforms previously proposed methods for incorporating semantic lexicons into word representations on several benchmark datasets for semantic similarity and word analogy.
no_new_dataset
0.944689
1511.06452
Hyun Oh Song
Hyun Oh Song, Yu Xiang, Stefanie Jegelka, Silvio Savarese
Deep Metric Learning via Lifted Structured Feature Embedding
11 pages
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Learning the distance metric between pairs of examples is of great importance for learning and visual recognition. With the remarkable success from the state of the art convolutional neural networks, recent works have shown promising results on discriminatively training the networks to learn semantic feature embeddings where similar examples are mapped close to each other and dissimilar examples are mapped farther apart. In this paper, we describe an algorithm for taking full advantage of the training batches in the neural network training by lifting the vector of pairwise distances within the batch to the matrix of pairwise distances. This step enables the algorithm to learn the state of the art feature embedding by optimizing a novel structured prediction objective on the lifted problem. Additionally, we collected Online Products dataset: 120k images of 23k classes of online products for metric learning. Our experiments on the CUB-200-2011, CARS196, and Online Products datasets demonstrate significant improvement over existing deep feature embedding methods on all experimented embedding sizes with the GoogLeNet network.
[ { "version": "v1", "created": "Thu, 19 Nov 2015 23:41:11 GMT" } ]
2015-11-23T00:00:00
[ [ "Song", "Hyun Oh", "" ], [ "Xiang", "Yu", "" ], [ "Jegelka", "Stefanie", "" ], [ "Savarese", "Silvio", "" ] ]
TITLE: Deep Metric Learning via Lifted Structured Feature Embedding ABSTRACT: Learning the distance metric between pairs of examples is of great importance for learning and visual recognition. With the remarkable success from the state of the art convolutional neural networks, recent works have shown promising results on discriminatively training the networks to learn semantic feature embeddings where similar examples are mapped close to each other and dissimilar examples are mapped farther apart. In this paper, we describe an algorithm for taking full advantage of the training batches in the neural network training by lifting the vector of pairwise distances within the batch to the matrix of pairwise distances. This step enables the algorithm to learn the state of the art feature embedding by optimizing a novel structured prediction objective on the lifted problem. Additionally, we collected Online Products dataset: 120k images of 23k classes of online products for metric learning. Our experiments on the CUB-200-2011, CARS196, and Online Products datasets demonstrate significant improvement over existing deep feature embedding methods on all experimented embedding sizes with the GoogLeNet network.
new_dataset
0.963265
1511.06463
Sucheta Soundarajan
Sucheta Soundarajan, Tina Eliassi-Rad, Brian Gallagher, Ali Pinar
MaxOutProbe: An Algorithm for Increasing the Size of Partially Observed Networks
NIPS Workshop on Networks in the Social and Information Sciences
null
null
LLNL-CONF-677677
cs.SI physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Networked representations of real-world phenomena are often partially observed, which lead to incomplete networks. Analysis of such incomplete networks can lead to skewed results. We examine the following problem: given an incomplete network, which $b$ nodes should be probed to bring the largest number of new nodes into the observed network? Many graph-mining tasks require having observed a considerable amount of the network. Examples include community discovery, belief propagation, influence maximization, etc. For instance, consider someone who has observed a portion (say 1%) of the Twitter retweet network via random tweet sampling. She wants to estimate the size of the largest connected component of the fully observed retweet network. To improve her estimate, how should she use her limited budget to reduce the incompleteness of the network? In this work, we propose a novel algorithm, called MaxOutProbe, which uses a budget $b$ (on nodes probed) to increase the size of the observed network in terms of the number of nodes. Our experiments, across a range of datasets and conditions, demonstrate the advantages of MaxOutProbe over existing methods.
[ { "version": "v1", "created": "Fri, 20 Nov 2015 00:26:27 GMT" } ]
2015-11-23T00:00:00
[ [ "Soundarajan", "Sucheta", "" ], [ "Eliassi-Rad", "Tina", "" ], [ "Gallagher", "Brian", "" ], [ "Pinar", "Ali", "" ] ]
TITLE: MaxOutProbe: An Algorithm for Increasing the Size of Partially Observed Networks ABSTRACT: Networked representations of real-world phenomena are often partially observed, which lead to incomplete networks. Analysis of such incomplete networks can lead to skewed results. We examine the following problem: given an incomplete network, which $b$ nodes should be probed to bring the largest number of new nodes into the observed network? Many graph-mining tasks require having observed a considerable amount of the network. Examples include community discovery, belief propagation, influence maximization, etc. For instance, consider someone who has observed a portion (say 1%) of the Twitter retweet network via random tweet sampling. She wants to estimate the size of the largest connected component of the fully observed retweet network. To improve her estimate, how should she use her limited budget to reduce the incompleteness of the network? In this work, we propose a novel algorithm, called MaxOutProbe, which uses a budget $b$ (on nodes probed) to increase the size of the observed network in terms of the number of nodes. Our experiments, across a range of datasets and conditions, demonstrate the advantages of MaxOutProbe over existing methods.
no_new_dataset
0.947235
1511.06523
Shuo Yang
Shuo Yang, Ping Luo, Chen Change Loy, and Xiaoou Tang
WIDER FACE: A Face Detection Benchmark
12 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Face detection is one of the most studied topics in the computer vision community. Much of the progresses have been made by the availability of face detection benchmark datasets. We show that there is a gap between current face detection performance and the real world requirements. To facilitate future face detection research, we introduce the WIDER FACE dataset, which is 10 times larger than existing datasets. The dataset contains rich annotations, including occlusions, poses, event categories, and face bounding boxes. Faces in the proposed dataset are extremely challenging due to large variations in scale, pose and occlusion, as shown in Fig. 1. Furthermore, we show that WIDER FACE dataset is an effective training source for face detection. We benchmark several representative detection systems, providing an overview of state-of-the-art performance and propose a solution to deal with large scale variation. Finally, we discuss common failure cases that worth to be further investigated. Dataset can be downloaded at: mmlab.ie.cuhk.edu.hk/projects/WIDERFace
[ { "version": "v1", "created": "Fri, 20 Nov 2015 08:33:57 GMT" } ]
2015-11-23T00:00:00
[ [ "Yang", "Shuo", "" ], [ "Luo", "Ping", "" ], [ "Loy", "Chen Change", "" ], [ "Tang", "Xiaoou", "" ] ]
TITLE: WIDER FACE: A Face Detection Benchmark ABSTRACT: Face detection is one of the most studied topics in the computer vision community. Much of the progresses have been made by the availability of face detection benchmark datasets. We show that there is a gap between current face detection performance and the real world requirements. To facilitate future face detection research, we introduce the WIDER FACE dataset, which is 10 times larger than existing datasets. The dataset contains rich annotations, including occlusions, poses, event categories, and face bounding boxes. Faces in the proposed dataset are extremely challenging due to large variations in scale, pose and occlusion, as shown in Fig. 1. Furthermore, we show that WIDER FACE dataset is an effective training source for face detection. We benchmark several representative detection systems, providing an overview of state-of-the-art performance and propose a solution to deal with large scale variation. Finally, we discuss common failure cases that worth to be further investigated. Dataset can be downloaded at: mmlab.ie.cuhk.edu.hk/projects/WIDERFace
new_dataset
0.959988
1511.06554
Li Li
Li Li, Tegawend\'e F. Bissyand\'e, Jacques Klein, Yves Le Traon
An Investigation into the Use of Common Libraries in Android Apps
null
null
null
null
cs.SE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The packaging model of Android apps requires the entire code necessary for the execution of an app to be shipped into one single apk file. Thus, an analysis of Android apps often visits code which is not part of the functionality delivered by the app. Such code is often contributed by the common libraries which are used pervasively by all apps. Unfortunately, Android analyses, e.g., for piggybacking detection and malware detection, can produce inaccurate results if they do not take into account the case of library code, which constitute noise in app features. Despite some efforts on investigating Android libraries, the momentum of Android research has not yet produced a complete set of common libraries to further support in-depth analysis of Android apps. In this paper, we leverage a dataset of about 1.5 million apps from Google Play to harvest potential common libraries, including advertisement libraries. With several steps of refinements, we finally collect by far the largest set of 1,113 libraries supporting common functionalities and 240 libraries for advertisement. We use the dataset to investigates several aspects of Android libraries, including their popularity and their proportion in Android app code. Based on these datasets, we have further performed several empirical investigations to confirm the motivations behind our work.
[ { "version": "v1", "created": "Fri, 20 Nov 2015 10:49:27 GMT" } ]
2015-11-23T00:00:00
[ [ "Li", "Li", "" ], [ "Bissyandé", "Tegawendé F.", "" ], [ "Klein", "Jacques", "" ], [ "Traon", "Yves Le", "" ] ]
TITLE: An Investigation into the Use of Common Libraries in Android Apps ABSTRACT: The packaging model of Android apps requires the entire code necessary for the execution of an app to be shipped into one single apk file. Thus, an analysis of Android apps often visits code which is not part of the functionality delivered by the app. Such code is often contributed by the common libraries which are used pervasively by all apps. Unfortunately, Android analyses, e.g., for piggybacking detection and malware detection, can produce inaccurate results if they do not take into account the case of library code, which constitute noise in app features. Despite some efforts on investigating Android libraries, the momentum of Android research has not yet produced a complete set of common libraries to further support in-depth analysis of Android apps. In this paper, we leverage a dataset of about 1.5 million apps from Google Play to harvest potential common libraries, including advertisement libraries. With several steps of refinements, we finally collect by far the largest set of 1,113 libraries supporting common functionalities and 240 libraries for advertisement. We use the dataset to investigates several aspects of Android libraries, including their popularity and their proportion in Android app code. Based on these datasets, we have further performed several empirical investigations to confirm the motivations behind our work.
no_new_dataset
0.784979
1511.06627
Zhu Shizhan
Shizhan Zhu, Cheng Li, Chen Change Loy, Xiaoou Tang
Towards Arbitrary-View Face Alignment by Recommendation Trees
This is our original submission to ICCV 2015
null
null
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
Learning to simultaneously handle face alignment of arbitrary views, e.g. frontal and profile views, appears to be more challenging than we thought. The difficulties lay in i) accommodating the complex appearance-shape relations exhibited in different views, and ii) encompassing the varying landmark point sets due to self-occlusion and different landmark protocols. Most existing studies approach this problem via training multiple viewpoint-specific models, and conduct head pose estimation for model selection. This solution is intuitive but the performance is highly susceptible to inaccurate head pose estimation. In this study, we address this shortcoming through learning an Ensemble of Model Recommendation Trees (EMRT), which is capable of selecting optimal model configuration without prior head pose estimation. The unified framework seamlessly handles different viewpoints and landmark protocols, and it is trained by optimising directly on landmark locations, thus yielding superior results on arbitrary-view face alignment. This is the first study that performs face alignment on the full AFLWdataset with faces of different views including profile view. State-of-the-art performances are also reported on MultiPIE and AFW datasets containing both frontaland profile-view faces.
[ { "version": "v1", "created": "Fri, 20 Nov 2015 15:01:21 GMT" } ]
2015-11-23T00:00:00
[ [ "Zhu", "Shizhan", "" ], [ "Li", "Cheng", "" ], [ "Loy", "Chen Change", "" ], [ "Tang", "Xiaoou", "" ] ]
TITLE: Towards Arbitrary-View Face Alignment by Recommendation Trees ABSTRACT: Learning to simultaneously handle face alignment of arbitrary views, e.g. frontal and profile views, appears to be more challenging than we thought. The difficulties lay in i) accommodating the complex appearance-shape relations exhibited in different views, and ii) encompassing the varying landmark point sets due to self-occlusion and different landmark protocols. Most existing studies approach this problem via training multiple viewpoint-specific models, and conduct head pose estimation for model selection. This solution is intuitive but the performance is highly susceptible to inaccurate head pose estimation. In this study, we address this shortcoming through learning an Ensemble of Model Recommendation Trees (EMRT), which is capable of selecting optimal model configuration without prior head pose estimation. The unified framework seamlessly handles different viewpoints and landmark protocols, and it is trained by optimising directly on landmark locations, thus yielding superior results on arbitrary-view face alignment. This is the first study that performs face alignment on the full AFLWdataset with faces of different views including profile view. State-of-the-art performances are also reported on MultiPIE and AFW datasets containing both frontaland profile-view faces.
no_new_dataset
0.946892
1511.06656
Carlos Sarraute
Carlos Sarraute, Pablo Blanc, Javier Burroni
A Study of Age and Gender seen through Mobile Phone Usage Patterns in Mexico
null
Proc. 2014 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM), Beijing, China, 17-20 August 2014, pp. 836 - 843
10.1109/ASONAM.2014.6921683
null
cs.SI physics.soc-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
Mobile phone usage provides a wealth of information, which can be used to better understand the demographic structure of a population. In this paper we focus on the population of Mexican mobile phone users. Our first contribution is an observational study of mobile phone usage according to gender and age groups. We were able to detect significant differences in phone usage among different subgroups of the population. Our second contribution is to provide a novel methodology to predict demographic features (namely age and gender) of unlabeled users by leveraging individual calling patterns, as well as the structure of the communication graph. We provide details of the methodology and show experimental results on a real world dataset that involves millions of users.
[ { "version": "v1", "created": "Fri, 20 Nov 2015 15:53:52 GMT" } ]
2015-11-23T00:00:00
[ [ "Sarraute", "Carlos", "" ], [ "Blanc", "Pablo", "" ], [ "Burroni", "Javier", "" ] ]
TITLE: A Study of Age and Gender seen through Mobile Phone Usage Patterns in Mexico ABSTRACT: Mobile phone usage provides a wealth of information, which can be used to better understand the demographic structure of a population. In this paper we focus on the population of Mexican mobile phone users. Our first contribution is an observational study of mobile phone usage according to gender and age groups. We were able to detect significant differences in phone usage among different subgroups of the population. Our second contribution is to provide a novel methodology to predict demographic features (namely age and gender) of unlabeled users by leveraging individual calling patterns, as well as the structure of the communication graph. We provide details of the methodology and show experimental results on a real world dataset that involves millions of users.
no_new_dataset
0.902007
1511.06663
Cecilia Damon
Luca Talenti, Margaux Luck, Anastasia Yartseva, Nicolas Argy, Sandrine Houz\'e and Cecilia Damon
L1 logistic regression as a feature selection step for training stable classification trees for the prediction of severity criteria in imported malaria
18 pages, 10 figures, ICLR, computational science - Learning, Imported Malaria, L1 logistic regression, Decision tree
null
null
null
cs.LG q-bio.QM stat.AP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Multivariate classification methods using explanatory and predictive models are necessary for characterizing subgroups of patients according to their risk profiles. Popular methods include logistic regression and classification trees with performances that vary according to the nature and the characteristics of the dataset. In the context of imported malaria, we aimed at classifying severity criteria based on a heterogeneous patient population. We investigated these approaches by implementing two different strategies: L1 logistic regression (L1LR) that models a single global solution and classification trees that model multiple local solutions corresponding to discriminant subregions of the feature space. For each strategy, we built a standard model, and a sparser version of it. As an alternative to pruning, we explore a promising approach that first constrains the tree model with an L1LR-based feature selection, an approach we called L1LR-Tree. The objective is to decrease its vulnerability to small data variations by removing variables corresponding to unstable local phenomena. Our study is twofold: i) from a methodological perspective comparing the performances and the stability of the three previous methods, i.e L1LR, classification trees and L1LR-Tree, for the classification of severe forms of imported malaria, and ii) from an applied perspective improving the actual classification of severe forms of imported malaria by identifying more personalized profiles predictive of several clinical criteria based on variables dismissed for the clinical definition of the disease. The main methodological results show that the combined method L1LR-Tree builds sparse and stable models that significantly predicts the different severity criteria and outperforms all the other methods in terms of accuracy.
[ { "version": "v1", "created": "Fri, 20 Nov 2015 16:12:59 GMT" } ]
2015-11-23T00:00:00
[ [ "Talenti", "Luca", "" ], [ "Luck", "Margaux", "" ], [ "Yartseva", "Anastasia", "" ], [ "Argy", "Nicolas", "" ], [ "Houzé", "Sandrine", "" ], [ "Damon", "Cecilia", "" ] ]
TITLE: L1 logistic regression as a feature selection step for training stable classification trees for the prediction of severity criteria in imported malaria ABSTRACT: Multivariate classification methods using explanatory and predictive models are necessary for characterizing subgroups of patients according to their risk profiles. Popular methods include logistic regression and classification trees with performances that vary according to the nature and the characteristics of the dataset. In the context of imported malaria, we aimed at classifying severity criteria based on a heterogeneous patient population. We investigated these approaches by implementing two different strategies: L1 logistic regression (L1LR) that models a single global solution and classification trees that model multiple local solutions corresponding to discriminant subregions of the feature space. For each strategy, we built a standard model, and a sparser version of it. As an alternative to pruning, we explore a promising approach that first constrains the tree model with an L1LR-based feature selection, an approach we called L1LR-Tree. The objective is to decrease its vulnerability to small data variations by removing variables corresponding to unstable local phenomena. Our study is twofold: i) from a methodological perspective comparing the performances and the stability of the three previous methods, i.e L1LR, classification trees and L1LR-Tree, for the classification of severe forms of imported malaria, and ii) from an applied perspective improving the actual classification of severe forms of imported malaria by identifying more personalized profiles predictive of several clinical criteria based on variables dismissed for the clinical definition of the disease. The main methodological results show that the combined method L1LR-Tree builds sparse and stable models that significantly predicts the different severity criteria and outperforms all the other methods in terms of accuracy.
no_new_dataset
0.952618
1511.06674
Marius Leordeanu
Anirudh Goyal and Marius Leordeanu
Stories in the Eye: Contextual Visual Interactions for Efficient Video to Language Translation
null
null
null
null
cs.CV cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Integrating higher level visual and linguistic interpretations is at the heart of human intelligence. As automatic visual category recognition in images is approaching human performance, the high level understanding in the dynamic spatiotemporal domain of videos and its translation into natural language is still far from being solved. While most works on vision-to-text translations use pre-learned or pre-established computational linguistic models, in this paper we present an approach that uses vision alone to efficiently learn how to translate into language the video content. We discover, in simple form, the story played by main actors, while using only visual cues for representing objects and their interactions. Our method learns in a hierarchical manner higher level representations for recognizing subjects, actions and objects involved, their relevant contextual background and their interaction to one another over time. We have a three stage approach: first we take in consideration features of the individual entities at the local level of appearance, then we consider the relationship between these objects and actions and their video background, and third, we consider their spatiotemporal relations as inputs to classifiers at the highest level of interpretation. Thus, our approach finds a coherent linguistic description of videos in the form of a subject, verb and object based on their role played in the overall visual story learned directly from training data, without using a known language model. We test the efficiency of our approach on a large scale dataset containing YouTube clips taken in the wild and demonstrate state-of-the-art performance, often superior to current approaches that use more complex, pre-learned linguistic knowledge.
[ { "version": "v1", "created": "Fri, 20 Nov 2015 16:33:13 GMT" } ]
2015-11-23T00:00:00
[ [ "Goyal", "Anirudh", "" ], [ "Leordeanu", "Marius", "" ] ]
TITLE: Stories in the Eye: Contextual Visual Interactions for Efficient Video to Language Translation ABSTRACT: Integrating higher level visual and linguistic interpretations is at the heart of human intelligence. As automatic visual category recognition in images is approaching human performance, the high level understanding in the dynamic spatiotemporal domain of videos and its translation into natural language is still far from being solved. While most works on vision-to-text translations use pre-learned or pre-established computational linguistic models, in this paper we present an approach that uses vision alone to efficiently learn how to translate into language the video content. We discover, in simple form, the story played by main actors, while using only visual cues for representing objects and their interactions. Our method learns in a hierarchical manner higher level representations for recognizing subjects, actions and objects involved, their relevant contextual background and their interaction to one another over time. We have a three stage approach: first we take in consideration features of the individual entities at the local level of appearance, then we consider the relationship between these objects and actions and their video background, and third, we consider their spatiotemporal relations as inputs to classifiers at the highest level of interpretation. Thus, our approach finds a coherent linguistic description of videos in the form of a subject, verb and object based on their role played in the overall visual story learned directly from training data, without using a known language model. We test the efficiency of our approach on a large scale dataset containing YouTube clips taken in the wild and demonstrate state-of-the-art performance, often superior to current approaches that use more complex, pre-learned linguistic knowledge.
no_new_dataset
0.947817
1511.06683
Maksim Lapin
Maksim Lapin, Matthias Hein and Bernt Schiele
Top-k Multiclass SVM
NIPS 2015
null
null
null
stat.ML cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Class ambiguity is typical in image classification problems with a large number of classes. When classes are difficult to discriminate, it makes sense to allow k guesses and evaluate classifiers based on the top-k error instead of the standard zero-one loss. We propose top-k multiclass SVM as a direct method to optimize for top-k performance. Our generalization of the well-known multiclass SVM is based on a tight convex upper bound of the top-k error. We propose a fast optimization scheme based on an efficient projection onto the top-k simplex, which is of its own interest. Experiments on five datasets show consistent improvements in top-k accuracy compared to various baselines.
[ { "version": "v1", "created": "Fri, 20 Nov 2015 16:49:33 GMT" } ]
2015-11-23T00:00:00
[ [ "Lapin", "Maksim", "" ], [ "Hein", "Matthias", "" ], [ "Schiele", "Bernt", "" ] ]
TITLE: Top-k Multiclass SVM ABSTRACT: Class ambiguity is typical in image classification problems with a large number of classes. When classes are difficult to discriminate, it makes sense to allow k guesses and evaluate classifiers based on the top-k error instead of the standard zero-one loss. We propose top-k multiclass SVM as a direct method to optimize for top-k performance. Our generalization of the well-known multiclass SVM is based on a tight convex upper bound of the top-k error. We propose a fast optimization scheme based on an efficient projection onto the top-k simplex, which is of its own interest. Experiments on five datasets show consistent improvements in top-k accuracy compared to various baselines.
no_new_dataset
0.954393
1409.7794
Steven C.H. Hoi
Yue Wu, Steven C. H. Hoi, Tao Mei, Nenghai Yu
Large-scale Online Feature Selection for Ultra-high Dimensional Sparse Data
13 pages
null
null
null
cs.LG cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Feature selection with large-scale high-dimensional data is important yet very challenging in machine learning and data mining. Online feature selection is a promising new paradigm that is more efficient and scalable than batch feature section methods, but the existing online approaches usually fall short in their inferior efficacy as compared with batch approaches. In this paper, we present a novel second-order online feature selection scheme that is simple yet effective, very fast and extremely scalable to deal with large-scale ultra-high dimensional sparse data streams. The basic idea is to improve the existing first-order online feature selection methods by exploiting second-order information for choosing the subset of important features with high confidence weights. However, unlike many second-order learning methods that often suffer from extra high computational cost, we devise a novel smart algorithm for second-order online feature selection using a MaxHeap-based approach, which is not only more effective than the existing first-order approaches, but also significantly more efficient and scalable for large-scale feature selection with ultra-high dimensional sparse data, as validated from our extensive experiments. Impressively, on a billion-scale synthetic dataset (1-billion dimensions, 1-billion nonzero features, and 1-million samples), our new algorithm took only 8 minutes on a single PC, which is orders of magnitudes faster than traditional batch approaches. \url{http://arxiv.org/abs/1409.7794}
[ { "version": "v1", "created": "Sat, 27 Sep 2014 10:58:09 GMT" }, { "version": "v2", "created": "Wed, 18 Nov 2015 12:49:16 GMT" }, { "version": "v3", "created": "Thu, 19 Nov 2015 14:21:21 GMT" } ]
2015-11-20T00:00:00
[ [ "Wu", "Yue", "" ], [ "Hoi", "Steven C. H.", "" ], [ "Mei", "Tao", "" ], [ "Yu", "Nenghai", "" ] ]
TITLE: Large-scale Online Feature Selection for Ultra-high Dimensional Sparse Data ABSTRACT: Feature selection with large-scale high-dimensional data is important yet very challenging in machine learning and data mining. Online feature selection is a promising new paradigm that is more efficient and scalable than batch feature section methods, but the existing online approaches usually fall short in their inferior efficacy as compared with batch approaches. In this paper, we present a novel second-order online feature selection scheme that is simple yet effective, very fast and extremely scalable to deal with large-scale ultra-high dimensional sparse data streams. The basic idea is to improve the existing first-order online feature selection methods by exploiting second-order information for choosing the subset of important features with high confidence weights. However, unlike many second-order learning methods that often suffer from extra high computational cost, we devise a novel smart algorithm for second-order online feature selection using a MaxHeap-based approach, which is not only more effective than the existing first-order approaches, but also significantly more efficient and scalable for large-scale feature selection with ultra-high dimensional sparse data, as validated from our extensive experiments. Impressively, on a billion-scale synthetic dataset (1-billion dimensions, 1-billion nonzero features, and 1-million samples), our new algorithm took only 8 minutes on a single PC, which is orders of magnitudes faster than traditional batch approaches. \url{http://arxiv.org/abs/1409.7794}
no_new_dataset
0.950273
1506.03340
Karl Moritz Hermann
Karl Moritz Hermann, Tom\'a\v{s} Ko\v{c}isk\'y, Edward Grefenstette, Lasse Espeholt, Will Kay, Mustafa Suleyman and Phil Blunsom
Teaching Machines to Read and Comprehend
Appears in: Advances in Neural Information Processing Systems 28 (NIPS 2015). 14 pages, 13 figures
null
null
null
cs.CL cs.AI cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Teaching machines to read natural language documents remains an elusive challenge. Machine reading systems can be tested on their ability to answer questions posed on the contents of documents that they have seen, but until now large scale training and test datasets have been missing for this type of evaluation. In this work we define a new methodology that resolves this bottleneck and provides large scale supervised reading comprehension data. This allows us to develop a class of attention based deep neural networks that learn to read real documents and answer complex questions with minimal prior knowledge of language structure.
[ { "version": "v1", "created": "Wed, 10 Jun 2015 14:54:39 GMT" }, { "version": "v2", "created": "Thu, 1 Oct 2015 15:04:49 GMT" }, { "version": "v3", "created": "Thu, 19 Nov 2015 15:43:23 GMT" } ]
2015-11-20T00:00:00
[ [ "Hermann", "Karl Moritz", "" ], [ "Kočiský", "Tomáš", "" ], [ "Grefenstette", "Edward", "" ], [ "Espeholt", "Lasse", "" ], [ "Kay", "Will", "" ], [ "Suleyman", "Mustafa", "" ], [ "Blunsom", "Phil", "" ] ]
TITLE: Teaching Machines to Read and Comprehend ABSTRACT: Teaching machines to read natural language documents remains an elusive challenge. Machine reading systems can be tested on their ability to answer questions posed on the contents of documents that they have seen, but until now large scale training and test datasets have been missing for this type of evaluation. In this work we define a new methodology that resolves this bottleneck and provides large scale supervised reading comprehension data. This allows us to develop a class of attention based deep neural networks that learn to read real documents and answer complex questions with minimal prior knowledge of language structure.
no_new_dataset
0.950778
1507.02620
Mircea Cimpoi
Mircea Cimpoi, Subhransu Maji, Iasonas Kokkinos, Andrea Vedaldi
Deep filter banks for texture recognition, description, and segmentation
29 pages; 13 figures; 8 tables
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Visual textures have played a key role in image understanding because they convey important semantics of images, and because texture representations that pool local image descriptors in an orderless manner have had a tremendous impact in diverse applications. In this paper we make several contributions to texture understanding. First, instead of focusing on texture instance and material category recognition, we propose a human-interpretable vocabulary of texture attributes to describe common texture patterns, complemented by a new describable texture dataset for benchmarking. Second, we look at the problem of recognizing materials and texture attributes in realistic imaging conditions, including when textures appear in clutter, developing corresponding benchmarks on top of the recently proposed OpenSurfaces dataset. Third, we revisit classic texture representations, including bag-of-visual-words and the Fisher vectors, in the context of deep learning and show that these have excellent efficiency and generalization properties if the convolutional layers of a deep model are used as filter banks. We obtain in this manner state-of-the-art performance in numerous datasets well beyond textures, an efficient method to apply deep features to image regions, as well as benefit in transferring features from one domain to another.
[ { "version": "v1", "created": "Thu, 9 Jul 2015 17:55:30 GMT" }, { "version": "v2", "created": "Wed, 18 Nov 2015 23:10:52 GMT" } ]
2015-11-20T00:00:00
[ [ "Cimpoi", "Mircea", "" ], [ "Maji", "Subhransu", "" ], [ "Kokkinos", "Iasonas", "" ], [ "Vedaldi", "Andrea", "" ] ]
TITLE: Deep filter banks for texture recognition, description, and segmentation ABSTRACT: Visual textures have played a key role in image understanding because they convey important semantics of images, and because texture representations that pool local image descriptors in an orderless manner have had a tremendous impact in diverse applications. In this paper we make several contributions to texture understanding. First, instead of focusing on texture instance and material category recognition, we propose a human-interpretable vocabulary of texture attributes to describe common texture patterns, complemented by a new describable texture dataset for benchmarking. Second, we look at the problem of recognizing materials and texture attributes in realistic imaging conditions, including when textures appear in clutter, developing corresponding benchmarks on top of the recently proposed OpenSurfaces dataset. Third, we revisit classic texture representations, including bag-of-visual-words and the Fisher vectors, in the context of deep learning and show that these have excellent efficiency and generalization properties if the convolutional layers of a deep model are used as filter banks. We obtain in this manner state-of-the-art performance in numerous datasets well beyond textures, an efficient method to apply deep features to image regions, as well as benefit in transferring features from one domain to another.
new_dataset
0.964855
1510.06492
Linus Hermansson
Linus Hermansson, Fredrik D. Johansson, and Osamu Watanabe
Generalized Shortest Path Kernel on Graphs
Short version presented at Discovery Science 2015 in Banff
null
null
null
cs.DS cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of classifying graphs using graph kernels. We define a new graph kernel, called the generalized shortest path kernel, based on the number and length of shortest paths between nodes. For our example classification problem, we consider the task of classifying random graphs from two well-known families, by the number of clusters they contain. We verify empirically that the generalized shortest path kernel outperforms the original shortest path kernel on a number of datasets. We give a theoretical analysis for explaining our experimental results. In particular, we estimate distributions of the expected feature vectors for the shortest path kernel and the generalized shortest path kernel, and we show some evidence explaining why our graph kernel outperforms the shortest path kernel for our graph classification problem.
[ { "version": "v1", "created": "Thu, 22 Oct 2015 05:49:31 GMT" } ]
2015-11-20T00:00:00
[ [ "Hermansson", "Linus", "" ], [ "Johansson", "Fredrik D.", "" ], [ "Watanabe", "Osamu", "" ] ]
TITLE: Generalized Shortest Path Kernel on Graphs ABSTRACT: We consider the problem of classifying graphs using graph kernels. We define a new graph kernel, called the generalized shortest path kernel, based on the number and length of shortest paths between nodes. For our example classification problem, we consider the task of classifying random graphs from two well-known families, by the number of clusters they contain. We verify empirically that the generalized shortest path kernel outperforms the original shortest path kernel on a number of datasets. We give a theoretical analysis for explaining our experimental results. In particular, we estimate distributions of the expected feature vectors for the shortest path kernel and the generalized shortest path kernel, and we show some evidence explaining why our graph kernel outperforms the shortest path kernel for our graph classification problem.
no_new_dataset
0.948251
1511.05788
Michael Edwards
Michael Edwards and Jingjing Deng and Xianghua Xie
From Pose to Activity: Surveying Datasets and Introducing CONVERSE
Presentation of pose-based conversational human interaction dataset, review of current appearance and depth based action recognition datasets, public dataset, 38 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a review on the current state of publicly available datasets within the human action recognition community; highlighting the revival of pose based methods and recent progress of understanding person-person interaction modeling. We categorize datasets regarding several key properties for usage as a benchmark dataset; including the number of class labels, ground truths provided, and application domain they occupy. We also consider the level of abstraction of each dataset; grouping those that present actions, interactions and higher level semantic activities. The survey identifies key appearance and pose based datasets, noting a tendency for simplistic, emphasized, or scripted action classes that are often readily definable by a stable collection of sub-action gestures. There is a clear lack of datasets that provide closely related actions, those that are not implicitly identified via a series of poses and gestures, but rather a dynamic set of interactions. We therefore propose a novel dataset that represents complex conversational interactions between two individuals via 3D pose. 8 pairwise interactions describing 7 separate conversation based scenarios were collected using two Kinect depth sensors. The intention is to provide events that are constructed from numerous primitive actions, interactions and motions, over a period of time; providing a set of subtle action classes that are more representative of the real world, and a challenge to currently developed recognition methodologies. We believe this is among one of the first datasets devoted to conversational interaction classification using 3D pose features and the attributed papers show this task is indeed possible. The full dataset is made publicly available to the research community at www.csvision.swansea.ac.uk/converse.
[ { "version": "v1", "created": "Wed, 18 Nov 2015 14:03:55 GMT" }, { "version": "v2", "created": "Thu, 19 Nov 2015 13:04:09 GMT" } ]
2015-11-20T00:00:00
[ [ "Edwards", "Michael", "" ], [ "Deng", "Jingjing", "" ], [ "Xie", "Xianghua", "" ] ]
TITLE: From Pose to Activity: Surveying Datasets and Introducing CONVERSE ABSTRACT: We present a review on the current state of publicly available datasets within the human action recognition community; highlighting the revival of pose based methods and recent progress of understanding person-person interaction modeling. We categorize datasets regarding several key properties for usage as a benchmark dataset; including the number of class labels, ground truths provided, and application domain they occupy. We also consider the level of abstraction of each dataset; grouping those that present actions, interactions and higher level semantic activities. The survey identifies key appearance and pose based datasets, noting a tendency for simplistic, emphasized, or scripted action classes that are often readily definable by a stable collection of sub-action gestures. There is a clear lack of datasets that provide closely related actions, those that are not implicitly identified via a series of poses and gestures, but rather a dynamic set of interactions. We therefore propose a novel dataset that represents complex conversational interactions between two individuals via 3D pose. 8 pairwise interactions describing 7 separate conversation based scenarios were collected using two Kinect depth sensors. The intention is to provide events that are constructed from numerous primitive actions, interactions and motions, over a period of time; providing a set of subtle action classes that are more representative of the real world, and a challenge to currently developed recognition methodologies. We believe this is among one of the first datasets devoted to conversational interaction classification using 3D pose features and the attributed papers show this task is indeed possible. The full dataset is made publicly available to the research community at www.csvision.swansea.ac.uk/converse.
new_dataset
0.965674
1511.06015
Juan C. Caicedo
Juan C. Caicedo and Svetlana Lazebnik
Active Object Localization with Deep Reinforcement Learning
IEEE ICCV 2015
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an active detection model for localizing objects in scenes. The model is class-specific and allows an agent to focus attention on candidate regions for identifying the correct location of a target object. This agent learns to deform a bounding box using simple transformation actions, with the goal of determining the most specific location of target objects following top-down reasoning. The proposed localization agent is trained using deep reinforcement learning, and evaluated on the Pascal VOC 2007 dataset. We show that agents guided by the proposed model are able to localize a single instance of an object after analyzing only between 11 and 25 regions in an image, and obtain the best detection results among systems that do not use object proposals for object localization.
[ { "version": "v1", "created": "Wed, 18 Nov 2015 22:55:46 GMT" } ]
2015-11-20T00:00:00
[ [ "Caicedo", "Juan C.", "" ], [ "Lazebnik", "Svetlana", "" ] ]
TITLE: Active Object Localization with Deep Reinforcement Learning ABSTRACT: We present an active detection model for localizing objects in scenes. The model is class-specific and allows an agent to focus attention on candidate regions for identifying the correct location of a target object. This agent learns to deform a bounding box using simple transformation actions, with the goal of determining the most specific location of target objects following top-down reasoning. The proposed localization agent is trained using deep reinforcement learning, and evaluated on the Pascal VOC 2007 dataset. We show that agents guided by the proposed model are able to localize a single instance of an object after analyzing only between 11 and 25 regions in an image, and obtain the best detection results among systems that do not use object proposals for object localization.
no_new_dataset
0.949529
1511.06072
Sebastian Agethen
Sebastian Agethen, Winston H. Hsu
Mediated Experts for Deep Convolutional Networks
null
null
null
null
cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new supervised architecture termed Mediated Mixture-of-Experts (MMoE) that allows us to improve classification accuracy of Deep Convolutional Networks (DCN). Our architecture achieves this with the help of expert networks: A network is trained on a disjoint subset of a given dataset and then run in parallel to other experts during deployment. A mediator is employed if experts contradict each other. This allows our framework to naturally support incremental learning, as adding new classes requires (re-)training of the new expert only. We also propose two measures to control computational complexity: An early-stopping mechanism halts experts that have low confidence in their prediction. The system allows to trade-off accuracy and complexity without further retraining. We also suggest to share low-level convolutional layers between experts in an effort to avoid computation of a near-duplicate feature set. We evaluate our system on a popular dataset and report improved accuracy compared to a single model of same configuration.
[ { "version": "v1", "created": "Thu, 19 Nov 2015 07:01:36 GMT" } ]
2015-11-20T00:00:00
[ [ "Agethen", "Sebastian", "" ], [ "Hsu", "Winston H.", "" ] ]
TITLE: Mediated Experts for Deep Convolutional Networks ABSTRACT: We present a new supervised architecture termed Mediated Mixture-of-Experts (MMoE) that allows us to improve classification accuracy of Deep Convolutional Networks (DCN). Our architecture achieves this with the help of expert networks: A network is trained on a disjoint subset of a given dataset and then run in parallel to other experts during deployment. A mediator is employed if experts contradict each other. This allows our framework to naturally support incremental learning, as adding new classes requires (re-)training of the new expert only. We also propose two measures to control computational complexity: An early-stopping mechanism halts experts that have low confidence in their prediction. The system allows to trade-off accuracy and complexity without further retraining. We also suggest to share low-level convolutional layers between experts in an effort to avoid computation of a near-duplicate feature set. We evaluate our system on a popular dataset and report improved accuracy compared to a single model of same configuration.
no_new_dataset
0.95018
1511.06147
Abhimanyu Dubey
Abhimanyu Dubey, Nikhil Naik, Dan Raviv, Rahul Sukthankar and Ramesh Raskar
Coreset-Based Adaptive Tracking
8 pages, 5 figures, In submission to IEEE TPAMI (Transactions on Pattern Analysis and Machine Intelligence)
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a method for learning from streaming visual data using a compact, constant size representation of all the data that was seen until a given moment. Specifically, we construct a 'coreset' representation of streaming data using a parallelized algorithm, which is an approximation of a set with relation to the squared distances between this set and all other points in its ambient space. We learn an adaptive object appearance model from the coreset tree in constant time and logarithmic space and use it for object tracking by detection. Our method obtains excellent results for object tracking on three standard datasets over more than 100 videos. The ability to summarize data efficiently makes our method ideally suited for tracking in long videos in presence of space and time constraints. We demonstrate this ability by outperforming a variety of algorithms on the TLD dataset with 2685 frames on average. This coreset based learning approach can be applied for both real-time learning of small, varied data and fast learning of big data.
[ { "version": "v1", "created": "Thu, 19 Nov 2015 12:59:20 GMT" } ]
2015-11-20T00:00:00
[ [ "Dubey", "Abhimanyu", "" ], [ "Naik", "Nikhil", "" ], [ "Raviv", "Dan", "" ], [ "Sukthankar", "Rahul", "" ], [ "Raskar", "Ramesh", "" ] ]
TITLE: Coreset-Based Adaptive Tracking ABSTRACT: We propose a method for learning from streaming visual data using a compact, constant size representation of all the data that was seen until a given moment. Specifically, we construct a 'coreset' representation of streaming data using a parallelized algorithm, which is an approximation of a set with relation to the squared distances between this set and all other points in its ambient space. We learn an adaptive object appearance model from the coreset tree in constant time and logarithmic space and use it for object tracking by detection. Our method obtains excellent results for object tracking on three standard datasets over more than 100 videos. The ability to summarize data efficiently makes our method ideally suited for tracking in long videos in presence of space and time constraints. We demonstrate this ability by outperforming a variety of algorithms on the TLD dataset with 2685 frames on average. This coreset based learning approach can be applied for both real-time learning of small, varied data and fast learning of big data.
no_new_dataset
0.94887
1511.06201
Zhirong Wu
Zhirong Wu, Dahua Lin, Xiaoou Tang
Adjustable Bounded Rectifiers: Towards Deep Binary Representations
Under review as a conference paper at ICLR 2016
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Binary representation is desirable for its memory efficiency, computation speed and robustness. In this paper, we propose adjustable bounded rectifiers to learn binary representations for deep neural networks. While hard constraining representations across layers to be binary makes training unreasonably difficult, we softly encourage activations to diverge from real values to binary by approximating step functions. Our final representation is completely binary. We test our approach on MNIST, CIFAR10, and ILSVRC2012 dataset, and systematically study the training dynamics of the binarization process. Our approach can binarize the last layer representation without loss of performance and binarize all the layers with reasonably small degradations. The memory space that it saves may allow more sophisticated models to be deployed, thus compensating the loss. To the best of our knowledge, this is the first work to report results on current deep network architectures using complete binary middle representations. Given the learned representations, we find that the firing or inhibition of a binary neuron is usually associated with a meaningful interpretation across different classes. This suggests that the semantic structure of a neural network may be manifested through a guided binarization process.
[ { "version": "v1", "created": "Thu, 19 Nov 2015 15:14:02 GMT" } ]
2015-11-20T00:00:00
[ [ "Wu", "Zhirong", "" ], [ "Lin", "Dahua", "" ], [ "Tang", "Xiaoou", "" ] ]
TITLE: Adjustable Bounded Rectifiers: Towards Deep Binary Representations ABSTRACT: Binary representation is desirable for its memory efficiency, computation speed and robustness. In this paper, we propose adjustable bounded rectifiers to learn binary representations for deep neural networks. While hard constraining representations across layers to be binary makes training unreasonably difficult, we softly encourage activations to diverge from real values to binary by approximating step functions. Our final representation is completely binary. We test our approach on MNIST, CIFAR10, and ILSVRC2012 dataset, and systematically study the training dynamics of the binarization process. Our approach can binarize the last layer representation without loss of performance and binarize all the layers with reasonably small degradations. The memory space that it saves may allow more sophisticated models to be deployed, thus compensating the loss. To the best of our knowledge, this is the first work to report results on current deep network architectures using complete binary middle representations. Given the learned representations, we find that the firing or inhibition of a binary neuron is usually associated with a meaningful interpretation across different classes. This suggests that the semantic structure of a neural network may be manifested through a guided binarization process.
no_new_dataset
0.947039
1511.06208
Moshe Salhov
Moshe Salhov and Amit Bermanis and Guy Wolf and Amir Averbuch
Diffusion Representations
null
null
null
null
stat.ML cs.LG math.SP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Diffusion Maps framework is a kernel based method for manifold learning and data analysis that defines diffusion similarities by imposing a Markovian process on the given dataset. Analysis by this process uncovers the intrinsic geometric structures in the data. Recently, it was suggested to replace the standard kernel by a measure-based kernel that incorporates information about the density of the data. Thus, the manifold assumption is replaced by a more general measure-based assumption. The measure-based diffusion kernel incorporates two separate independent representations. The first determines a measure that correlates with a density that represents normal behaviors and patterns in the data. The second consists of the analyzed multidimensional data points. In this paper, we present a representation framework for data analysis of datasets that is based on a closed-form decomposition of the measure-based kernel. The proposed representation preserves pairwise diffusion distances that does not depend on the data size while being invariant to scale. For a stationary data, no out-of-sample extension is needed for embedding newly arrived data points in the representation space. Several aspects of the presented methodology are demonstrated on analytically generated data.
[ { "version": "v1", "created": "Thu, 19 Nov 2015 15:30:39 GMT" } ]
2015-11-20T00:00:00
[ [ "Salhov", "Moshe", "" ], [ "Bermanis", "Amit", "" ], [ "Wolf", "Guy", "" ], [ "Averbuch", "Amir", "" ] ]
TITLE: Diffusion Representations ABSTRACT: Diffusion Maps framework is a kernel based method for manifold learning and data analysis that defines diffusion similarities by imposing a Markovian process on the given dataset. Analysis by this process uncovers the intrinsic geometric structures in the data. Recently, it was suggested to replace the standard kernel by a measure-based kernel that incorporates information about the density of the data. Thus, the manifold assumption is replaced by a more general measure-based assumption. The measure-based diffusion kernel incorporates two separate independent representations. The first determines a measure that correlates with a density that represents normal behaviors and patterns in the data. The second consists of the analyzed multidimensional data points. In this paper, we present a representation framework for data analysis of datasets that is based on a closed-form decomposition of the measure-based kernel. The proposed representation preserves pairwise diffusion distances that does not depend on the data size while being invariant to scale. For a stationary data, no out-of-sample extension is needed for embedding newly arrived data points in the representation space. Several aspects of the presented methodology are demonstrated on analytically generated data.
no_new_dataset
0.948106
1511.06316
Zinelabidine Boulkenafet Mr
Zinelabidine Boulkenafet, Jukka Komulainen, Abdenour Hadid
face anti-spoofing based on color texture analysis
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Research on face spoofing detection has mainly been focused on analyzing the luminance of the face images, hence discarding the chrominance information which can be useful for discriminating fake faces from genuine ones. In this work, we propose a new face anti-spoofing method based on color texture analysis. We analyze the joint color-texture information from the luminance and the chrominance channels using a color local binary pattern descriptor. More specifically, the feature histograms are extracted from each image band separately. Extensive experiments on two benchmark datasets, namely CASIA face anti-spoofing and Replay-Attack databases, showed excellent results compared to the state-of-the-art. Most importantly, our inter-database evaluation depicts that the proposed approach showed very promising generalization capabilities.
[ { "version": "v1", "created": "Thu, 19 Nov 2015 19:28:20 GMT" } ]
2015-11-20T00:00:00
[ [ "Boulkenafet", "Zinelabidine", "" ], [ "Komulainen", "Jukka", "" ], [ "Hadid", "Abdenour", "" ] ]
TITLE: face anti-spoofing based on color texture analysis ABSTRACT: Research on face spoofing detection has mainly been focused on analyzing the luminance of the face images, hence discarding the chrominance information which can be useful for discriminating fake faces from genuine ones. In this work, we propose a new face anti-spoofing method based on color texture analysis. We analyze the joint color-texture information from the luminance and the chrominance channels using a color local binary pattern descriptor. More specifically, the feature histograms are extracted from each image band separately. Extensive experiments on two benchmark datasets, namely CASIA face anti-spoofing and Replay-Attack databases, showed excellent results compared to the state-of-the-art. Most importantly, our inter-database evaluation depicts that the proposed approach showed very promising generalization capabilities.
no_new_dataset
0.948442
1506.03736
Joseph Salmon
Eugene Ndiaye, Olivier Fercoq, Alexandre Gramfort, Joseph Salmon
GAP Safe screening rules for sparse multi-task and multi-class models
in Proceedings of the 29-th Conference on Neural Information Processing Systems (NIPS), 2015
null
null
null
stat.ML cs.LG math.OC stat.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
High dimensional regression benefits from sparsity promoting regularizations. Screening rules leverage the known sparsity of the solution by ignoring some variables in the optimization, hence speeding up solvers. When the procedure is proven not to discard features wrongly the rules are said to be \emph{safe}. In this paper we derive new safe rules for generalized linear models regularized with $\ell_1$ and $\ell_1/\ell_2$ norms. The rules are based on duality gap computations and spherical safe regions whose diameters converge to zero. This allows to discard safely more variables, in particular for low regularization parameters. The GAP Safe rule can cope with any iterative solver and we illustrate its performance on coordinate descent for multi-task Lasso, binary and multinomial logistic regression, demonstrating significant speed ups on all tested datasets with respect to previous safe rules.
[ { "version": "v1", "created": "Thu, 11 Jun 2015 16:25:36 GMT" }, { "version": "v2", "created": "Wed, 18 Nov 2015 10:07:20 GMT" } ]
2015-11-19T00:00:00
[ [ "Ndiaye", "Eugene", "" ], [ "Fercoq", "Olivier", "" ], [ "Gramfort", "Alexandre", "" ], [ "Salmon", "Joseph", "" ] ]
TITLE: GAP Safe screening rules for sparse multi-task and multi-class models ABSTRACT: High dimensional regression benefits from sparsity promoting regularizations. Screening rules leverage the known sparsity of the solution by ignoring some variables in the optimization, hence speeding up solvers. When the procedure is proven not to discard features wrongly the rules are said to be \emph{safe}. In this paper we derive new safe rules for generalized linear models regularized with $\ell_1$ and $\ell_1/\ell_2$ norms. The rules are based on duality gap computations and spherical safe regions whose diameters converge to zero. This allows to discard safely more variables, in particular for low regularization parameters. The GAP Safe rule can cope with any iterative solver and we illustrate its performance on coordinate descent for multi-task Lasso, binary and multinomial logistic regression, demonstrating significant speed ups on all tested datasets with respect to previous safe rules.
no_new_dataset
0.945701
1506.04132
Yingzhen Li
Yingzhen Li, Jose Miguel Hernandez-Lobato, Richard E. Turner
Stochastic Expectation Propagation
Published at NIPS 2015. 18 pages including supplementary
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Expectation propagation (EP) is a deterministic approximation algorithm that is often used to perform approximate Bayesian parameter learning. EP approximates the full intractable posterior distribution through a set of local approximations that are iteratively refined for each datapoint. EP can offer analytic and computational advantages over other approximations, such as Variational Inference (VI), and is the method of choice for a number of models. The local nature of EP appears to make it an ideal candidate for performing Bayesian learning on large models in large-scale dataset settings. However, EP has a crucial limitation in this context: the number of approximating factors needs to increase with the number of data-points, N, which often entails a prohibitively large memory overhead. This paper presents an extension to EP, called stochastic expectation propagation (SEP), that maintains a global posterior approximation (like VI) but updates it in a local way (like EP). Experiments on a number of canonical learning problems using synthetic and real-world datasets indicate that SEP performs almost as well as full EP, but reduces the memory consumption by a factor of $N$. SEP is therefore ideally suited to performing approximate Bayesian learning in the large model, large dataset setting.
[ { "version": "v1", "created": "Fri, 12 Jun 2015 19:51:06 GMT" }, { "version": "v2", "created": "Wed, 18 Nov 2015 10:52:17 GMT" } ]
2015-11-19T00:00:00
[ [ "Li", "Yingzhen", "" ], [ "Hernandez-Lobato", "Jose Miguel", "" ], [ "Turner", "Richard E.", "" ] ]
TITLE: Stochastic Expectation Propagation ABSTRACT: Expectation propagation (EP) is a deterministic approximation algorithm that is often used to perform approximate Bayesian parameter learning. EP approximates the full intractable posterior distribution through a set of local approximations that are iteratively refined for each datapoint. EP can offer analytic and computational advantages over other approximations, such as Variational Inference (VI), and is the method of choice for a number of models. The local nature of EP appears to make it an ideal candidate for performing Bayesian learning on large models in large-scale dataset settings. However, EP has a crucial limitation in this context: the number of approximating factors needs to increase with the number of data-points, N, which often entails a prohibitively large memory overhead. This paper presents an extension to EP, called stochastic expectation propagation (SEP), that maintains a global posterior approximation (like VI) but updates it in a local way (like EP). Experiments on a number of canonical learning problems using synthetic and real-world datasets indicate that SEP performs almost as well as full EP, but reduces the memory consumption by a factor of $N$. SEP is therefore ideally suited to performing approximate Bayesian learning in the large model, large dataset setting.
no_new_dataset
0.948489
1510.04709
Desmond Elliott
Desmond Elliott, Stella Frank, Eva Hasler
Multilingual Image Description with Neural Sequence Models
Under review as a conference paper at ICLR 2016
null
null
null
cs.CL cs.CV cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present an approach to multi-language image description bringing together insights from neural machine translation and neural image description. To create a description of an image for a given target language, our sequence generation models condition on feature vectors from the image, the description from the source language, and/or a multimodal vector computed over the image and a description in the source language. In image description experiments on the IAPR-TC12 dataset of images aligned with English and German sentences, we find significant and substantial improvements in BLEU4 and Meteor scores for models trained over multiple languages, compared to a monolingual baseline.
[ { "version": "v1", "created": "Thu, 15 Oct 2015 20:29:21 GMT" }, { "version": "v2", "created": "Wed, 18 Nov 2015 17:04:35 GMT" } ]
2015-11-19T00:00:00
[ [ "Elliott", "Desmond", "" ], [ "Frank", "Stella", "" ], [ "Hasler", "Eva", "" ] ]
TITLE: Multilingual Image Description with Neural Sequence Models ABSTRACT: In this paper we present an approach to multi-language image description bringing together insights from neural machine translation and neural image description. To create a description of an image for a given target language, our sequence generation models condition on feature vectors from the image, the description from the source language, and/or a multimodal vector computed over the image and a description in the source language. In image description experiments on the IAPR-TC12 dataset of images aligned with English and German sentences, we find significant and substantial improvements in BLEU4 and Meteor scores for models trained over multiple languages, compared to a monolingual baseline.
no_new_dataset
0.945147
1511.04813
Jing Lu
Jing Lu, Steven C.H. Hoi, Doyen Sahoo, Peilin Zhao
Budget Online Multiple Kernel Learning
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Online learning with multiple kernels has gained increasing interests in recent years and found many applications. For classification tasks, Online Multiple Kernel Classification (OMKC), which learns a kernel based classifier by seeking the optimal linear combination of a pool of single kernel classifiers in an online fashion, achieves superior accuracy and enjoys great flexibility compared with traditional single-kernel classifiers. Despite being studied extensively, existing OMKC algorithms suffer from high computational cost due to their unbounded numbers of support vectors. To overcome this drawback, we present a novel framework of Budget Online Multiple Kernel Learning (BOMKL) and propose a new Sparse Passive Aggressive learning to perform effective budget online learning. Specifically, we adopt a simple yet effective Bernoulli sampling to decide if an incoming instance should be added to the current set of support vectors. By limiting the number of support vectors, our method can significantly accelerate OMKC while maintaining satisfactory accuracy that is comparable to that of the existing OMKC algorithms. We theoretically prove that our new method achieves an optimal regret bound in expectation, and empirically found that the proposed algorithm outperforms various OMKC algorithms and can easily scale up to large-scale datasets.
[ { "version": "v1", "created": "Mon, 16 Nov 2015 03:40:50 GMT" }, { "version": "v2", "created": "Wed, 18 Nov 2015 08:08:43 GMT" } ]
2015-11-19T00:00:00
[ [ "Lu", "Jing", "" ], [ "Hoi", "Steven C. H.", "" ], [ "Sahoo", "Doyen", "" ], [ "Zhao", "Peilin", "" ] ]
TITLE: Budget Online Multiple Kernel Learning ABSTRACT: Online learning with multiple kernels has gained increasing interests in recent years and found many applications. For classification tasks, Online Multiple Kernel Classification (OMKC), which learns a kernel based classifier by seeking the optimal linear combination of a pool of single kernel classifiers in an online fashion, achieves superior accuracy and enjoys great flexibility compared with traditional single-kernel classifiers. Despite being studied extensively, existing OMKC algorithms suffer from high computational cost due to their unbounded numbers of support vectors. To overcome this drawback, we present a novel framework of Budget Online Multiple Kernel Learning (BOMKL) and propose a new Sparse Passive Aggressive learning to perform effective budget online learning. Specifically, we adopt a simple yet effective Bernoulli sampling to decide if an incoming instance should be added to the current set of support vectors. By limiting the number of support vectors, our method can significantly accelerate OMKC while maintaining satisfactory accuracy that is comparable to that of the existing OMKC algorithms. We theoretically prove that our new method achieves an optimal regret bound in expectation, and empirically found that the proposed algorithm outperforms various OMKC algorithms and can easily scale up to large-scale datasets.
no_new_dataset
0.947332