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1601.03896
Frank Keller
Raffaella Bernardi, Ruket Cakici, Desmond Elliott, Aykut Erdem, Erkut Erdem, Nazli Ikizler-Cinbis, Frank Keller, Adrian Muscat, Barbara Plank
Automatic Description Generation from Images: A Survey of Models, Datasets, and Evaluation Measures
Journal of Artificial Intelligence Research 55, 409-442, 2016
null
null
null
cs.CL cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Automatic description generation from natural images is a challenging problem that has recently received a large amount of interest from the computer vision and natural language processing communities. In this survey, we classify the existing approaches based on how they conceptualize this problem, viz., models that cast description as either generation problem or as a retrieval problem over a visual or multimodal representational space. We provide a detailed review of existing models, highlighting their advantages and disadvantages. Moreover, we give an overview of the benchmark image datasets and the evaluation measures that have been developed to assess the quality of machine-generated image descriptions. Finally we extrapolate future directions in the area of automatic image description generation.
[ { "version": "v1", "created": "Fri, 15 Jan 2016 12:50:32 GMT" }, { "version": "v2", "created": "Mon, 24 Apr 2017 09:47:20 GMT" } ]
2017-04-25T00:00:00
[ [ "Bernardi", "Raffaella", "" ], [ "Cakici", "Ruket", "" ], [ "Elliott", "Desmond", "" ], [ "Erdem", "Aykut", "" ], [ "Erdem", "Erkut", "" ], [ "Ikizler-Cinbis", "Nazli", "" ], [ "Keller", "Frank", "" ], [ "Muscat", "Adrian", "" ], [ "Plank", "Barbara", "" ] ]
TITLE: Automatic Description Generation from Images: A Survey of Models, Datasets, and Evaluation Measures ABSTRACT: Automatic description generation from natural images is a challenging problem that has recently received a large amount of interest from the computer vision and natural language processing communities. In this survey, we classify the existing approaches based on how they conceptualize this problem, viz., models that cast description as either generation problem or as a retrieval problem over a visual or multimodal representational space. We provide a detailed review of existing models, highlighting their advantages and disadvantages. Moreover, we give an overview of the benchmark image datasets and the evaluation measures that have been developed to assess the quality of machine-generated image descriptions. Finally we extrapolate future directions in the area of automatic image description generation.
no_new_dataset
0.954942
1603.02056
Wenqiang Liu
Wenqiang Liu, Jun Liu, Jian Zhang, Haimeng Duan, Bifan Wei
TruthDiscover: Resolving Object Conflicts on Massive Linked Data
This paper had been accepted by Proceedings of the 26th International Conference on World Wide Web Companion. International World Wide Web Conferences Steering Committee, 2017, WWW2017
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Considerable effort has been made to increase the scale of Linked Data. However, because of the openness of the Semantic Web and the ease of extracting Linked Data from semi-structured sources (e.g., Wikipedia) and unstructured sources, many Linked Data sources often provide conflicting objects for a certain predicate of a real-world entity. Existing methods cannot be trivially extended to resolve conflicts in Linked Data because Linked Data has a scale-free property. In this demonstration, we present a novel system called TruthDiscover, to identify the truth in Linked Data with a scale-free property. First, TruthDiscover leverages the topological properties of the Source Belief Graph to estimate the priori beliefs of sources, which are utilized to smooth the trustworthiness of sources. Second, the Hidden Markov Random Field is utilized to model interdependencies among objects for estimating the trust values of objects accurately. TruthDiscover can visualize the process of resolving conflicts in Linked Data. Experiments results on four datasets show that TruthDiscover exhibits satisfactory accuracy when confronted with data having a scale-free property.
[ { "version": "v1", "created": "Mon, 7 Mar 2016 13:34:36 GMT" }, { "version": "v2", "created": "Fri, 21 Apr 2017 22:46:20 GMT" } ]
2017-04-25T00:00:00
[ [ "Liu", "Wenqiang", "" ], [ "Liu", "Jun", "" ], [ "Zhang", "Jian", "" ], [ "Duan", "Haimeng", "" ], [ "Wei", "Bifan", "" ] ]
TITLE: TruthDiscover: Resolving Object Conflicts on Massive Linked Data ABSTRACT: Considerable effort has been made to increase the scale of Linked Data. However, because of the openness of the Semantic Web and the ease of extracting Linked Data from semi-structured sources (e.g., Wikipedia) and unstructured sources, many Linked Data sources often provide conflicting objects for a certain predicate of a real-world entity. Existing methods cannot be trivially extended to resolve conflicts in Linked Data because Linked Data has a scale-free property. In this demonstration, we present a novel system called TruthDiscover, to identify the truth in Linked Data with a scale-free property. First, TruthDiscover leverages the topological properties of the Source Belief Graph to estimate the priori beliefs of sources, which are utilized to smooth the trustworthiness of sources. Second, the Hidden Markov Random Field is utilized to model interdependencies among objects for estimating the trust values of objects accurately. TruthDiscover can visualize the process of resolving conflicts in Linked Data. Experiments results on four datasets show that TruthDiscover exhibits satisfactory accuracy when confronted with data having a scale-free property.
no_new_dataset
0.951051
1604.04562
Tsung-Hsien Wen
Tsung-Hsien Wen, David Vandyke, Nikola Mrksic, Milica Gasic, Lina M. Rojas-Barahona, Pei-Hao Su, Stefan Ultes, Steve Young
A Network-based End-to-End Trainable Task-oriented Dialogue System
published at EACL 2017
null
null
null
cs.CL cs.AI cs.NE stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Teaching machines to accomplish tasks by conversing naturally with humans is challenging. Currently, developing task-oriented dialogue systems requires creating multiple components and typically this involves either a large amount of handcrafting, or acquiring costly labelled datasets to solve a statistical learning problem for each component. In this work we introduce a neural network-based text-in, text-out end-to-end trainable goal-oriented dialogue system along with a new way of collecting dialogue data based on a novel pipe-lined Wizard-of-Oz framework. This approach allows us to develop dialogue systems easily and without making too many assumptions about the task at hand. The results show that the model can converse with human subjects naturally whilst helping them to accomplish tasks in a restaurant search domain.
[ { "version": "v1", "created": "Fri, 15 Apr 2016 16:40:49 GMT" }, { "version": "v2", "created": "Fri, 20 May 2016 14:03:58 GMT" }, { "version": "v3", "created": "Mon, 24 Apr 2017 10:55:12 GMT" } ]
2017-04-25T00:00:00
[ [ "Wen", "Tsung-Hsien", "" ], [ "Vandyke", "David", "" ], [ "Mrksic", "Nikola", "" ], [ "Gasic", "Milica", "" ], [ "Rojas-Barahona", "Lina M.", "" ], [ "Su", "Pei-Hao", "" ], [ "Ultes", "Stefan", "" ], [ "Young", "Steve", "" ] ]
TITLE: A Network-based End-to-End Trainable Task-oriented Dialogue System ABSTRACT: Teaching machines to accomplish tasks by conversing naturally with humans is challenging. Currently, developing task-oriented dialogue systems requires creating multiple components and typically this involves either a large amount of handcrafting, or acquiring costly labelled datasets to solve a statistical learning problem for each component. In this work we introduce a neural network-based text-in, text-out end-to-end trainable goal-oriented dialogue system along with a new way of collecting dialogue data based on a novel pipe-lined Wizard-of-Oz framework. This approach allows us to develop dialogue systems easily and without making too many assumptions about the task at hand. The results show that the model can converse with human subjects naturally whilst helping them to accomplish tasks in a restaurant search domain.
no_new_dataset
0.954009
1604.08407
Wenqiang Liu
Wenqiang Liu, Jun Liu, Haimeng Duan, Xie He, Bifan Wei
Exploiting Source-Object Network to Resolve Object Conflicts in Linked Data
This paper had been accepted by ESWC2017 Research Tracks
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Considerable effort has been made to increase the scale of Linked Data. However, an inevitable problem when dealing with data integration from multiple sources is that multiple different sources often provide conflicting objects for a certain predicate of the same real-world entity, so-called object conflicts problem. Currently, the object conflicts problem has not received sufficient attention in the Linked Data community. In this paper, we first formalize the object conflicts resolution problem as computing the joint distribution of variables on a heterogeneous information network called the Source-Object Network, which successfully captures the all correlations from objects and Linked Data sources. Then, we introduce a novel approach based on network effects called ObResolution(Object Resolution), to identify a true object from multiple conflicting objects. ObResolution adopts a pairwise Markov Random Field (pMRF) to model all evidences under a unified framework. Extensive experimental results on six real-world datasets show that our method exhibits higher accuracy than existing approaches and it is robust and consistent in various domains. \keywords{Linked Data, Object Conflicts, Linked Data Quality, Truth Discovery
[ { "version": "v1", "created": "Thu, 28 Apr 2016 13:22:54 GMT" }, { "version": "v2", "created": "Wed, 22 Feb 2017 21:32:48 GMT" }, { "version": "v3", "created": "Fri, 21 Apr 2017 22:38:10 GMT" } ]
2017-04-25T00:00:00
[ [ "Liu", "Wenqiang", "" ], [ "Liu", "Jun", "" ], [ "Duan", "Haimeng", "" ], [ "He", "Xie", "" ], [ "Wei", "Bifan", "" ] ]
TITLE: Exploiting Source-Object Network to Resolve Object Conflicts in Linked Data ABSTRACT: Considerable effort has been made to increase the scale of Linked Data. However, an inevitable problem when dealing with data integration from multiple sources is that multiple different sources often provide conflicting objects for a certain predicate of the same real-world entity, so-called object conflicts problem. Currently, the object conflicts problem has not received sufficient attention in the Linked Data community. In this paper, we first formalize the object conflicts resolution problem as computing the joint distribution of variables on a heterogeneous information network called the Source-Object Network, which successfully captures the all correlations from objects and Linked Data sources. Then, we introduce a novel approach based on network effects called ObResolution(Object Resolution), to identify a true object from multiple conflicting objects. ObResolution adopts a pairwise Markov Random Field (pMRF) to model all evidences under a unified framework. Extensive experimental results on six real-world datasets show that our method exhibits higher accuracy than existing approaches and it is robust and consistent in various domains. \keywords{Linked Data, Object Conflicts, Linked Data Quality, Truth Discovery
no_new_dataset
0.951639
1606.01549
Bhuwan Dhingra
Bhuwan Dhingra, Hanxiao Liu, Zhilin Yang, William W. Cohen, Ruslan Salakhutdinov
Gated-Attention Readers for Text Comprehension
Accepted at ACL 2017
null
null
null
cs.CL cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we study the problem of answering cloze-style questions over documents. Our model, the Gated-Attention (GA) Reader, integrates a multi-hop architecture with a novel attention mechanism, which is based on multiplicative interactions between the query embedding and the intermediate states of a recurrent neural network document reader. This enables the reader to build query-specific representations of tokens in the document for accurate answer selection. The GA Reader obtains state-of-the-art results on three benchmarks for this task--the CNN \& Daily Mail news stories and the Who Did What dataset. The effectiveness of multiplicative interaction is demonstrated by an ablation study, and by comparing to alternative compositional operators for implementing the gated-attention. The code is available at https://github.com/bdhingra/ga-reader.
[ { "version": "v1", "created": "Sun, 5 Jun 2016 19:30:39 GMT" }, { "version": "v2", "created": "Thu, 1 Dec 2016 19:27:42 GMT" }, { "version": "v3", "created": "Fri, 21 Apr 2017 18:50:05 GMT" } ]
2017-04-25T00:00:00
[ [ "Dhingra", "Bhuwan", "" ], [ "Liu", "Hanxiao", "" ], [ "Yang", "Zhilin", "" ], [ "Cohen", "William W.", "" ], [ "Salakhutdinov", "Ruslan", "" ] ]
TITLE: Gated-Attention Readers for Text Comprehension ABSTRACT: In this paper we study the problem of answering cloze-style questions over documents. Our model, the Gated-Attention (GA) Reader, integrates a multi-hop architecture with a novel attention mechanism, which is based on multiplicative interactions between the query embedding and the intermediate states of a recurrent neural network document reader. This enables the reader to build query-specific representations of tokens in the document for accurate answer selection. The GA Reader obtains state-of-the-art results on three benchmarks for this task--the CNN \& Daily Mail news stories and the Who Did What dataset. The effectiveness of multiplicative interaction is demonstrated by an ablation study, and by comparing to alternative compositional operators for implementing the gated-attention. The code is available at https://github.com/bdhingra/ga-reader.
no_new_dataset
0.949295
1607.07249
Joern Hees
J\"orn Hees, Rouven Bauer, Joachim Folz, Damian Borth and Andreas Dengel
An Evolutionary Algorithm to Learn SPARQL Queries for Source-Target-Pairs: Finding Patterns for Human Associations in DBpedia
15 pages, 2 figures, as of 2016-09-13 6a19d5d7020770dc0711081ce2c1e52f71bf4b86
null
10.1007/978-3-319-49004-5_22
null
cs.AI cs.DB cs.NE stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Efficient usage of the knowledge provided by the Linked Data community is often hindered by the need for domain experts to formulate the right SPARQL queries to answer questions. For new questions they have to decide which datasets are suitable and in which terminology and modelling style to phrase the SPARQL query. In this work we present an evolutionary algorithm to help with this challenging task. Given a training list of source-target node-pair examples our algorithm can learn patterns (SPARQL queries) from a SPARQL endpoint. The learned patterns can be visualised to form the basis for further investigation, or they can be used to predict target nodes for new source nodes. Amongst others, we apply our algorithm to a dataset of several hundred human associations (such as "circle - square") to find patterns for them in DBpedia. We show the scalability of the algorithm by running it against a SPARQL endpoint loaded with > 7.9 billion triples. Further, we use the resulting SPARQL queries to mimic human associations with a Mean Average Precision (MAP) of 39.9 % and a Recall@10 of 63.9 %.
[ { "version": "v1", "created": "Mon, 25 Jul 2016 12:47:38 GMT" }, { "version": "v2", "created": "Tue, 26 Jul 2016 12:13:14 GMT" }, { "version": "v3", "created": "Tue, 13 Sep 2016 10:27:06 GMT" } ]
2017-04-25T00:00:00
[ [ "Hees", "Jörn", "" ], [ "Bauer", "Rouven", "" ], [ "Folz", "Joachim", "" ], [ "Borth", "Damian", "" ], [ "Dengel", "Andreas", "" ] ]
TITLE: An Evolutionary Algorithm to Learn SPARQL Queries for Source-Target-Pairs: Finding Patterns for Human Associations in DBpedia ABSTRACT: Efficient usage of the knowledge provided by the Linked Data community is often hindered by the need for domain experts to formulate the right SPARQL queries to answer questions. For new questions they have to decide which datasets are suitable and in which terminology and modelling style to phrase the SPARQL query. In this work we present an evolutionary algorithm to help with this challenging task. Given a training list of source-target node-pair examples our algorithm can learn patterns (SPARQL queries) from a SPARQL endpoint. The learned patterns can be visualised to form the basis for further investigation, or they can be used to predict target nodes for new source nodes. Amongst others, we apply our algorithm to a dataset of several hundred human associations (such as "circle - square") to find patterns for them in DBpedia. We show the scalability of the algorithm by running it against a SPARQL endpoint loaded with > 7.9 billion triples. Further, we use the resulting SPARQL queries to mimic human associations with a Mean Average Precision (MAP) of 39.9 % and a Recall@10 of 63.9 %.
no_new_dataset
0.769254
1609.02200
Jason Rolfe
Jason Tyler Rolfe
Discrete Variational Autoencoders
Published as a conference paper at ICLR 2017
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Probabilistic models with discrete latent variables naturally capture datasets composed of discrete classes. However, they are difficult to train efficiently, since backpropagation through discrete variables is generally not possible. We present a novel method to train a class of probabilistic models with discrete latent variables using the variational autoencoder framework, including backpropagation through the discrete latent variables. The associated class of probabilistic models comprises an undirected discrete component and a directed hierarchical continuous component. The discrete component captures the distribution over the disconnected smooth manifolds induced by the continuous component. As a result, this class of models efficiently learns both the class of objects in an image, and their specific realization in pixels, from unsupervised data, and outperforms state-of-the-art methods on the permutation-invariant MNIST, Omniglot, and Caltech-101 Silhouettes datasets.
[ { "version": "v1", "created": "Wed, 7 Sep 2016 21:41:32 GMT" }, { "version": "v2", "created": "Sat, 22 Apr 2017 01:23:06 GMT" } ]
2017-04-25T00:00:00
[ [ "Rolfe", "Jason Tyler", "" ] ]
TITLE: Discrete Variational Autoencoders ABSTRACT: Probabilistic models with discrete latent variables naturally capture datasets composed of discrete classes. However, they are difficult to train efficiently, since backpropagation through discrete variables is generally not possible. We present a novel method to train a class of probabilistic models with discrete latent variables using the variational autoencoder framework, including backpropagation through the discrete latent variables. The associated class of probabilistic models comprises an undirected discrete component and a directed hierarchical continuous component. The discrete component captures the distribution over the disconnected smooth manifolds induced by the continuous component. As a result, this class of models efficiently learns both the class of objects in an image, and their specific realization in pixels, from unsupervised data, and outperforms state-of-the-art methods on the permutation-invariant MNIST, Omniglot, and Caltech-101 Silhouettes datasets.
no_new_dataset
0.94868
1611.00020
Chen Liang
Chen Liang, Jonathan Berant, Quoc Le, Kenneth D. Forbus, Ni Lao
Neural Symbolic Machines: Learning Semantic Parsers on Freebase with Weak Supervision
ACL 2017 camera ready version
null
null
null
cs.CL cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Harnessing the statistical power of neural networks to perform language understanding and symbolic reasoning is difficult, when it requires executing efficient discrete operations against a large knowledge-base. In this work, we introduce a Neural Symbolic Machine, which contains (a) a neural "programmer", i.e., a sequence-to-sequence model that maps language utterances to programs and utilizes a key-variable memory to handle compositionality (b) a symbolic "computer", i.e., a Lisp interpreter that performs program execution, and helps find good programs by pruning the search space. We apply REINFORCE to directly optimize the task reward of this structured prediction problem. To train with weak supervision and improve the stability of REINFORCE, we augment it with an iterative maximum-likelihood training process. NSM outperforms the state-of-the-art on the WebQuestionsSP dataset when trained from question-answer pairs only, without requiring any feature engineering or domain-specific knowledge.
[ { "version": "v1", "created": "Mon, 31 Oct 2016 20:07:23 GMT" }, { "version": "v2", "created": "Wed, 2 Nov 2016 05:25:19 GMT" }, { "version": "v3", "created": "Thu, 3 Nov 2016 16:24:24 GMT" }, { "version": "v4", "created": "Sun, 23 Apr 2017 07:16:13 GMT" } ]
2017-04-25T00:00:00
[ [ "Liang", "Chen", "" ], [ "Berant", "Jonathan", "" ], [ "Le", "Quoc", "" ], [ "Forbus", "Kenneth D.", "" ], [ "Lao", "Ni", "" ] ]
TITLE: Neural Symbolic Machines: Learning Semantic Parsers on Freebase with Weak Supervision ABSTRACT: Harnessing the statistical power of neural networks to perform language understanding and symbolic reasoning is difficult, when it requires executing efficient discrete operations against a large knowledge-base. In this work, we introduce a Neural Symbolic Machine, which contains (a) a neural "programmer", i.e., a sequence-to-sequence model that maps language utterances to programs and utilizes a key-variable memory to handle compositionality (b) a symbolic "computer", i.e., a Lisp interpreter that performs program execution, and helps find good programs by pruning the search space. We apply REINFORCE to directly optimize the task reward of this structured prediction problem. To train with weak supervision and improve the stability of REINFORCE, we augment it with an iterative maximum-likelihood training process. NSM outperforms the state-of-the-art on the WebQuestionsSP dataset when trained from question-answer pairs only, without requiring any feature engineering or domain-specific knowledge.
no_new_dataset
0.945197
1611.02261
Rasool Fakoor
Rasool Fakoor, Abdel-rahman Mohamed, Margaret Mitchell, Sing Bing Kang, Pushmeet Kohli
Memory-augmented Attention Modelling for Videos
Revised version, minor changes, add the link for the source codes
null
null
null
cs.CV cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a method to improve video description generation by modeling higher-order interactions between video frames and described concepts. By storing past visual attention in the video associated to previously generated words, the system is able to decide what to look at and describe in light of what it has already looked at and described. This enables not only more effective local attention, but tractable consideration of the video sequence while generating each word. Evaluation on the challenging and popular MSVD and Charades datasets demonstrates that the proposed architecture outperforms previous video description approaches without requiring external temporal video features.
[ { "version": "v1", "created": "Mon, 7 Nov 2016 20:50:08 GMT" }, { "version": "v2", "created": "Mon, 14 Nov 2016 22:39:13 GMT" }, { "version": "v3", "created": "Mon, 13 Feb 2017 02:22:51 GMT" }, { "version": "v4", "created": "Mon, 24 Apr 2017 07:26:01 GMT" } ]
2017-04-25T00:00:00
[ [ "Fakoor", "Rasool", "" ], [ "Mohamed", "Abdel-rahman", "" ], [ "Mitchell", "Margaret", "" ], [ "Kang", "Sing Bing", "" ], [ "Kohli", "Pushmeet", "" ] ]
TITLE: Memory-augmented Attention Modelling for Videos ABSTRACT: We present a method to improve video description generation by modeling higher-order interactions between video frames and described concepts. By storing past visual attention in the video associated to previously generated words, the system is able to decide what to look at and describe in light of what it has already looked at and described. This enables not only more effective local attention, but tractable consideration of the video sequence while generating each word. Evaluation on the challenging and popular MSVD and Charades datasets demonstrates that the proposed architecture outperforms previous video description approaches without requiring external temporal video features.
no_new_dataset
0.947721
1612.01428
Seyed Mohammad Taheri
Seyed Mohammad Taheri, Hamidreza Mahyar, Mohammad Firouzi, Elahe Ghalebi K., Radu Grosu, Ali Movaghar
Extracting Implicit Social Relation for Social Recommendation Techniques in User Rating Prediction
null
null
10.1145/3041021.3051153
null
cs.SI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recommendation plays an increasingly important role in our daily lives. Recommender systems automatically suggest items to users that might be interesting for them. Recent studies illustrate that incorporating social trust in Matrix Factorization methods demonstrably improves accuracy of rating prediction. Such approaches mainly use the trust scores explicitly expressed by users. However, it is often challenging to have users provide explicit trust scores of each other. There exist quite a few works, which propose Trust Metrics to compute and predict trust scores between users based on their interactions. In this paper, first we present how social relation can be extracted from users' ratings to items by describing Hellinger distance between users in recommender systems. Then, we propose to incorporate the predicted trust scores into social matrix factorization models. By analyzing social relation extraction from three well-known real-world datasets, which both: trust and recommendation data available, we conclude that using the implicit social relation in social recommendation techniques has almost the same performance compared to the actual trust scores explicitly expressed by users. Hence, we build our method, called Hell-TrustSVD, on top of the state-of-the-art social recommendation technique to incorporate both the extracted implicit social relations and ratings given by users on the prediction of items for an active user. To the best of our knowledge, this is the first work to extend TrustSVD with extracted social trust information. The experimental results support the idea of employing implicit trust into matrix factorization whenever explicit trust is not available, can perform much better than the state-of-the-art approaches in user rating prediction.
[ { "version": "v1", "created": "Mon, 5 Dec 2016 16:47:02 GMT" }, { "version": "v2", "created": "Fri, 17 Mar 2017 15:23:15 GMT" } ]
2017-04-25T00:00:00
[ [ "Taheri", "Seyed Mohammad", "" ], [ "Mahyar", "Hamidreza", "" ], [ "Firouzi", "Mohammad", "" ], [ "K.", "Elahe Ghalebi", "" ], [ "Grosu", "Radu", "" ], [ "Movaghar", "Ali", "" ] ]
TITLE: Extracting Implicit Social Relation for Social Recommendation Techniques in User Rating Prediction ABSTRACT: Recommendation plays an increasingly important role in our daily lives. Recommender systems automatically suggest items to users that might be interesting for them. Recent studies illustrate that incorporating social trust in Matrix Factorization methods demonstrably improves accuracy of rating prediction. Such approaches mainly use the trust scores explicitly expressed by users. However, it is often challenging to have users provide explicit trust scores of each other. There exist quite a few works, which propose Trust Metrics to compute and predict trust scores between users based on their interactions. In this paper, first we present how social relation can be extracted from users' ratings to items by describing Hellinger distance between users in recommender systems. Then, we propose to incorporate the predicted trust scores into social matrix factorization models. By analyzing social relation extraction from three well-known real-world datasets, which both: trust and recommendation data available, we conclude that using the implicit social relation in social recommendation techniques has almost the same performance compared to the actual trust scores explicitly expressed by users. Hence, we build our method, called Hell-TrustSVD, on top of the state-of-the-art social recommendation technique to incorporate both the extracted implicit social relations and ratings given by users on the prediction of items for an active user. To the best of our knowledge, this is the first work to extend TrustSVD with extracted social trust information. The experimental results support the idea of employing implicit trust into matrix factorization whenever explicit trust is not available, can perform much better than the state-of-the-art approaches in user rating prediction.
no_new_dataset
0.945096
1701.08207
Luis Fern\'andez-Menchero
K. Wang, L. Fern\'andez-Menchero, O. Zatsarinny, and K. Bartschat
Benchmark calculations for electron-impact excitation of Mg$^{4+}$
10 pages, 7 figures, 1 table. Online material
Phys. Rev. A 95, 042709 (2017)
10.1103/PhysRevA.95.042709
null
physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
There are major discrepancies between recent B-spline R-matrix (BSR) and Dirac Atomic R-matrix Code (DARC) calculations regarding electron-impact excitation rates for transitions in Mg$^{4+}$, with claims that the DARC calculations are much more accurate. To identify possible reasons for these discrepancies and to estimate the accuracy of the various results, we carried out independent BSR calculations with the same 86 target states as in the previous calculations, but with a different and more accurate representation of the target structure. We find close agreement with the previous BSR results for the majority of transitions, thereby confirming their accuracy. At the same time the differences with the DARC results are much more pronounced. The discrepancies in the final results for the collision strengths are mainly due to differences in the structure description, specifically the inclusion of correlation effects, and due to the likely occurrence of pseudoresonances. To further check the convergence of the predicted collision rates, we carried out even more extensive calculations involving 316 states of Mg$^{4+}$. Extending the close-coupling expansion results in major corrections for transitions involving the higher-lying states and allows us to assess the likely uncertainties in the existing datasets.
[ { "version": "v1", "created": "Fri, 27 Jan 2017 22:07:39 GMT" }, { "version": "v2", "created": "Mon, 27 Mar 2017 14:57:54 GMT" } ]
2017-04-25T00:00:00
[ [ "Wang", "K.", "" ], [ "Fernández-Menchero", "L.", "" ], [ "Zatsarinny", "O.", "" ], [ "Bartschat", "K.", "" ] ]
TITLE: Benchmark calculations for electron-impact excitation of Mg$^{4+}$ ABSTRACT: There are major discrepancies between recent B-spline R-matrix (BSR) and Dirac Atomic R-matrix Code (DARC) calculations regarding electron-impact excitation rates for transitions in Mg$^{4+}$, with claims that the DARC calculations are much more accurate. To identify possible reasons for these discrepancies and to estimate the accuracy of the various results, we carried out independent BSR calculations with the same 86 target states as in the previous calculations, but with a different and more accurate representation of the target structure. We find close agreement with the previous BSR results for the majority of transitions, thereby confirming their accuracy. At the same time the differences with the DARC results are much more pronounced. The discrepancies in the final results for the collision strengths are mainly due to differences in the structure description, specifically the inclusion of correlation effects, and due to the likely occurrence of pseudoresonances. To further check the convergence of the predicted collision rates, we carried out even more extensive calculations involving 316 states of Mg$^{4+}$. Extending the close-coupling expansion results in major corrections for transitions involving the higher-lying states and allows us to assess the likely uncertainties in the existing datasets.
no_new_dataset
0.950915
1702.03274
Jason Williams
Jason D. Williams, Kavosh Asadi, Geoffrey Zweig
Hybrid Code Networks: practical and efficient end-to-end dialog control with supervised and reinforcement learning
Accepted as a long paper for the 55th Annual Meeting of the Association for Computational Linguistics (ACL 2017)
null
null
null
cs.AI cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
End-to-end learning of recurrent neural networks (RNNs) is an attractive solution for dialog systems; however, current techniques are data-intensive and require thousands of dialogs to learn simple behaviors. We introduce Hybrid Code Networks (HCNs), which combine an RNN with domain-specific knowledge encoded as software and system action templates. Compared to existing end-to-end approaches, HCNs considerably reduce the amount of training data required, while retaining the key benefit of inferring a latent representation of dialog state. In addition, HCNs can be optimized with supervised learning, reinforcement learning, or a mixture of both. HCNs attain state-of-the-art performance on the bAbI dialog dataset, and outperform two commercially deployed customer-facing dialog systems.
[ { "version": "v1", "created": "Fri, 10 Feb 2017 18:24:13 GMT" }, { "version": "v2", "created": "Mon, 24 Apr 2017 14:39:27 GMT" } ]
2017-04-25T00:00:00
[ [ "Williams", "Jason D.", "" ], [ "Asadi", "Kavosh", "" ], [ "Zweig", "Geoffrey", "" ] ]
TITLE: Hybrid Code Networks: practical and efficient end-to-end dialog control with supervised and reinforcement learning ABSTRACT: End-to-end learning of recurrent neural networks (RNNs) is an attractive solution for dialog systems; however, current techniques are data-intensive and require thousands of dialogs to learn simple behaviors. We introduce Hybrid Code Networks (HCNs), which combine an RNN with domain-specific knowledge encoded as software and system action templates. Compared to existing end-to-end approaches, HCNs considerably reduce the amount of training data required, while retaining the key benefit of inferring a latent representation of dialog state. In addition, HCNs can be optimized with supervised learning, reinforcement learning, or a mixture of both. HCNs attain state-of-the-art performance on the bAbI dialog dataset, and outperform two commercially deployed customer-facing dialog systems.
no_new_dataset
0.950134
1704.06752
Siyuan Qiao
Siyuan Qiao, Wei Shen, Weichao Qiu, Chenxi Liu, Alan Yuille
ScaleNet: Guiding Object Proposal Generation in Supermarkets and Beyond
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by product detection in supermarkets, this paper studies the problem of object proposal generation in supermarket images and other natural images. We argue that estimation of object scales in images is helpful for generating object proposals, especially for supermarket images where object scales are usually within a small range. Therefore, we propose to estimate object scales of images before generating object proposals. The proposed method for predicting object scales is called ScaleNet. To validate the effectiveness of ScaleNet, we build three supermarket datasets, two of which are real-world datasets used for testing and the other one is a synthetic dataset used for training. In short, we extend the previous state-of-the-art object proposal methods by adding a scale prediction phase. The resulted method outperforms the previous state-of-the-art on the supermarket datasets by a large margin. We also show that the approach works for object proposal on other natural images and it outperforms the previous state-of-the-art object proposal methods on the MS COCO dataset. The supermarket datasets, the virtual supermarkets, and the tools for creating more synthetic datasets will be made public.
[ { "version": "v1", "created": "Sat, 22 Apr 2017 06:05:31 GMT" } ]
2017-04-25T00:00:00
[ [ "Qiao", "Siyuan", "" ], [ "Shen", "Wei", "" ], [ "Qiu", "Weichao", "" ], [ "Liu", "Chenxi", "" ], [ "Yuille", "Alan", "" ] ]
TITLE: ScaleNet: Guiding Object Proposal Generation in Supermarkets and Beyond ABSTRACT: Motivated by product detection in supermarkets, this paper studies the problem of object proposal generation in supermarket images and other natural images. We argue that estimation of object scales in images is helpful for generating object proposals, especially for supermarket images where object scales are usually within a small range. Therefore, we propose to estimate object scales of images before generating object proposals. The proposed method for predicting object scales is called ScaleNet. To validate the effectiveness of ScaleNet, we build three supermarket datasets, two of which are real-world datasets used for testing and the other one is a synthetic dataset used for training. In short, we extend the previous state-of-the-art object proposal methods by adding a scale prediction phase. The resulted method outperforms the previous state-of-the-art on the supermarket datasets by a large margin. We also show that the approach works for object proposal on other natural images and it outperforms the previous state-of-the-art object proposal methods on the MS COCO dataset. The supermarket datasets, the virtual supermarkets, and the tools for creating more synthetic datasets will be made public.
new_dataset
0.965218
1704.06779
Nafise Sadat Moosavi
Nafise Sadat Moosavi and Michael Strube
Lexical Features in Coreference Resolution: To be Used With Caution
6 pages, ACL 2017
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lexical features are a major source of information in state-of-the-art coreference resolvers. Lexical features implicitly model some of the linguistic phenomena at a fine granularity level. They are especially useful for representing the context of mentions. In this paper we investigate a drawback of using many lexical features in state-of-the-art coreference resolvers. We show that if coreference resolvers mainly rely on lexical features, they can hardly generalize to unseen domains. Furthermore, we show that the current coreference resolution evaluation is clearly flawed by only evaluating on a specific split of a specific dataset in which there is a notable overlap between the training, development and test sets.
[ { "version": "v1", "created": "Sat, 22 Apr 2017 09:59:42 GMT" } ]
2017-04-25T00:00:00
[ [ "Moosavi", "Nafise Sadat", "" ], [ "Strube", "Michael", "" ] ]
TITLE: Lexical Features in Coreference Resolution: To be Used With Caution ABSTRACT: Lexical features are a major source of information in state-of-the-art coreference resolvers. Lexical features implicitly model some of the linguistic phenomena at a fine granularity level. They are especially useful for representing the context of mentions. In this paper we investigate a drawback of using many lexical features in state-of-the-art coreference resolvers. We show that if coreference resolvers mainly rely on lexical features, they can hardly generalize to unseen domains. Furthermore, we show that the current coreference resolution evaluation is clearly flawed by only evaluating on a specific split of a specific dataset in which there is a notable overlap between the training, development and test sets.
no_new_dataset
0.945147
1704.06803
Federico Monti
Federico Monti, Michael M. Bronstein, Xavier Bresson
Geometric Matrix Completion with Recurrent Multi-Graph Neural Networks
null
null
null
null
cs.LG cs.IR cs.NA stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Matrix completion models are among the most common formulations of recommender systems. Recent works have showed a boost of performance of these techniques when introducing the pairwise relationships between users/items in the form of graphs, and imposing smoothness priors on these graphs. However, such techniques do not fully exploit the local stationarity structures of user/item graphs, and the number of parameters to learn is linear w.r.t. the number of users and items. We propose a novel approach to overcome these limitations by using geometric deep learning on graphs. Our matrix completion architecture combines graph convolutional neural networks and recurrent neural networks to learn meaningful statistical graph-structured patterns and the non-linear diffusion process that generates the known ratings. This neural network system requires a constant number of parameters independent of the matrix size. We apply our method on both synthetic and real datasets, showing that it outperforms state-of-the-art techniques.
[ { "version": "v1", "created": "Sat, 22 Apr 2017 14:02:01 GMT" } ]
2017-04-25T00:00:00
[ [ "Monti", "Federico", "" ], [ "Bronstein", "Michael M.", "" ], [ "Bresson", "Xavier", "" ] ]
TITLE: Geometric Matrix Completion with Recurrent Multi-Graph Neural Networks ABSTRACT: Matrix completion models are among the most common formulations of recommender systems. Recent works have showed a boost of performance of these techniques when introducing the pairwise relationships between users/items in the form of graphs, and imposing smoothness priors on these graphs. However, such techniques do not fully exploit the local stationarity structures of user/item graphs, and the number of parameters to learn is linear w.r.t. the number of users and items. We propose a novel approach to overcome these limitations by using geometric deep learning on graphs. Our matrix completion architecture combines graph convolutional neural networks and recurrent neural networks to learn meaningful statistical graph-structured patterns and the non-linear diffusion process that generates the known ratings. This neural network system requires a constant number of parameters independent of the matrix size. We apply our method on both synthetic and real datasets, showing that it outperforms state-of-the-art techniques.
no_new_dataset
0.941277
1704.06836
Lotem Peled
Lotem Peled and Roi Reichart
Sarcasm SIGN: Interpreting Sarcasm with Sentiment Based Monolingual Machine Translation
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Sarcasm is a form of speech in which speakers say the opposite of what they truly mean in order to convey a strong sentiment. In other words, "Sarcasm is the giant chasm between what I say, and the person who doesn't get it.". In this paper we present the novel task of sarcasm interpretation, defined as the generation of a non-sarcastic utterance conveying the same message as the original sarcastic one. We introduce a novel dataset of 3000 sarcastic tweets, each interpreted by five human judges. Addressing the task as monolingual machine translation (MT), we experiment with MT algorithms and evaluation measures. We then present SIGN: an MT based sarcasm interpretation algorithm that targets sentiment words, a defining element of textual sarcasm. We show that while the scores of n-gram based automatic measures are similar for all interpretation models, SIGN's interpretations are scored higher by humans for adequacy and sentiment polarity. We conclude with a discussion on future research directions for our new task.
[ { "version": "v1", "created": "Sat, 22 Apr 2017 18:59:25 GMT" } ]
2017-04-25T00:00:00
[ [ "Peled", "Lotem", "" ], [ "Reichart", "Roi", "" ] ]
TITLE: Sarcasm SIGN: Interpreting Sarcasm with Sentiment Based Monolingual Machine Translation ABSTRACT: Sarcasm is a form of speech in which speakers say the opposite of what they truly mean in order to convey a strong sentiment. In other words, "Sarcasm is the giant chasm between what I say, and the person who doesn't get it.". In this paper we present the novel task of sarcasm interpretation, defined as the generation of a non-sarcastic utterance conveying the same message as the original sarcastic one. We introduce a novel dataset of 3000 sarcastic tweets, each interpreted by five human judges. Addressing the task as monolingual machine translation (MT), we experiment with MT algorithms and evaluation measures. We then present SIGN: an MT based sarcasm interpretation algorithm that targets sentiment words, a defining element of textual sarcasm. We show that while the scores of n-gram based automatic measures are similar for all interpretation models, SIGN's interpretations are scored higher by humans for adequacy and sentiment polarity. We conclude with a discussion on future research directions for our new task.
new_dataset
0.958148
1704.06841
Toyotaro Suzumura Prof
Mark Hughes, Irene Li, Spyros Kotoulas, Toyotaro Suzumura
Medical Text Classification using Convolutional Neural Networks
null
null
null
null
cs.CL
http://creativecommons.org/licenses/by/4.0/
We present an approach to automatically classify clinical text at a sentence level. We are using deep convolutional neural networks to represent complex features. We train the network on a dataset providing a broad categorization of health information. Through a detailed evaluation, we demonstrate that our method outperforms several approaches widely used in natural language processing tasks by about 15%.
[ { "version": "v1", "created": "Sat, 22 Apr 2017 19:39:32 GMT" } ]
2017-04-25T00:00:00
[ [ "Hughes", "Mark", "" ], [ "Li", "Irene", "" ], [ "Kotoulas", "Spyros", "" ], [ "Suzumura", "Toyotaro", "" ] ]
TITLE: Medical Text Classification using Convolutional Neural Networks ABSTRACT: We present an approach to automatically classify clinical text at a sentence level. We are using deep convolutional neural networks to represent complex features. We train the network on a dataset providing a broad categorization of health information. Through a detailed evaluation, we demonstrate that our method outperforms several approaches widely used in natural language processing tasks by about 15%.
no_new_dataset
0.948965
1704.06843
Cenek Albl
Cenek Albl, Zuzana Kukelova, Andrew Fitzgibbon, Jan Heller, Matej Smid and Tomas Pajdla
On the Two-View Geometry of Unsynchronized Cameras
12 pages, 9 figures, Computer Vision and Pattern Recognition (CVPR) 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present new methods for simultaneously estimating camera geometry and time shift from video sequences from multiple unsynchronized cameras. Algorithms for simultaneous computation of a fundamental matrix or a homography with unknown time shift between images are developed. Our methods use minimal correspondence sets (eight for fundamental matrix and four and a half for homography) and therefore are suitable for robust estimation using RANSAC. Furthermore, we present an iterative algorithm that extends the applicability on sequences which are significantly unsynchronized, finding the correct time shift up to several seconds. We evaluated the methods on synthetic and wide range of real world datasets and the results show a broad applicability to the problem of camera synchronization.
[ { "version": "v1", "created": "Sat, 22 Apr 2017 19:45:46 GMT" } ]
2017-04-25T00:00:00
[ [ "Albl", "Cenek", "" ], [ "Kukelova", "Zuzana", "" ], [ "Fitzgibbon", "Andrew", "" ], [ "Heller", "Jan", "" ], [ "Smid", "Matej", "" ], [ "Pajdla", "Tomas", "" ] ]
TITLE: On the Two-View Geometry of Unsynchronized Cameras ABSTRACT: We present new methods for simultaneously estimating camera geometry and time shift from video sequences from multiple unsynchronized cameras. Algorithms for simultaneous computation of a fundamental matrix or a homography with unknown time shift between images are developed. Our methods use minimal correspondence sets (eight for fundamental matrix and four and a half for homography) and therefore are suitable for robust estimation using RANSAC. Furthermore, we present an iterative algorithm that extends the applicability on sequences which are significantly unsynchronized, finding the correct time shift up to several seconds. We evaluated the methods on synthetic and wide range of real world datasets and the results show a broad applicability to the problem of camera synchronization.
no_new_dataset
0.950411
1704.06857
Alberto Garcia-Garcia
Alberto Garcia-Garcia, Sergio Orts-Escolano, Sergiu Oprea, Victor Villena-Martinez, Jose Garcia-Rodriguez
A Review on Deep Learning Techniques Applied to Semantic Segmentation
Submitted to TPAMI on Apr. 22, 2017
null
null
null
cs.CV cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Image semantic segmentation is more and more being of interest for computer vision and machine learning researchers. Many applications on the rise need accurate and efficient segmentation mechanisms: autonomous driving, indoor navigation, and even virtual or augmented reality systems to name a few. This demand coincides with the rise of deep learning approaches in almost every field or application target related to computer vision, including semantic segmentation or scene understanding. This paper provides a review on deep learning methods for semantic segmentation applied to various application areas. Firstly, we describe the terminology of this field as well as mandatory background concepts. Next, the main datasets and challenges are exposed to help researchers decide which are the ones that best suit their needs and their targets. Then, existing methods are reviewed, highlighting their contributions and their significance in the field. Finally, quantitative results are given for the described methods and the datasets in which they were evaluated, following up with a discussion of the results. At last, we point out a set of promising future works and draw our own conclusions about the state of the art of semantic segmentation using deep learning techniques.
[ { "version": "v1", "created": "Sat, 22 Apr 2017 23:37:43 GMT" } ]
2017-04-25T00:00:00
[ [ "Garcia-Garcia", "Alberto", "" ], [ "Orts-Escolano", "Sergio", "" ], [ "Oprea", "Sergiu", "" ], [ "Villena-Martinez", "Victor", "" ], [ "Garcia-Rodriguez", "Jose", "" ] ]
TITLE: A Review on Deep Learning Techniques Applied to Semantic Segmentation ABSTRACT: Image semantic segmentation is more and more being of interest for computer vision and machine learning researchers. Many applications on the rise need accurate and efficient segmentation mechanisms: autonomous driving, indoor navigation, and even virtual or augmented reality systems to name a few. This demand coincides with the rise of deep learning approaches in almost every field or application target related to computer vision, including semantic segmentation or scene understanding. This paper provides a review on deep learning methods for semantic segmentation applied to various application areas. Firstly, we describe the terminology of this field as well as mandatory background concepts. Next, the main datasets and challenges are exposed to help researchers decide which are the ones that best suit their needs and their targets. Then, existing methods are reviewed, highlighting their contributions and their significance in the field. Finally, quantitative results are given for the described methods and the datasets in which they were evaluated, following up with a discussion of the results. At last, we point out a set of promising future works and draw our own conclusions about the state of the art of semantic segmentation using deep learning techniques.
no_new_dataset
0.949902
1704.06869
Vlad Niculae
Vlad Niculae, Joonsuk Park, Claire Cardie
Argument Mining with Structured SVMs and RNNs
Accepted for publication at ACL 2017. 11 pages, 5 figures. Code at https://github.com/vene/marseille and data at http://joonsuk.org/
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel factor graph model for argument mining, designed for settings in which the argumentative relations in a document do not necessarily form a tree structure. (This is the case in over 20% of the web comments dataset we release.) Our model jointly learns elementary unit type classification and argumentative relation prediction. Moreover, our model supports SVM and RNN parametrizations, can enforce structure constraints (e.g., transitivity), and can express dependencies between adjacent relations and propositions. Our approaches outperform unstructured baselines in both web comments and argumentative essay datasets.
[ { "version": "v1", "created": "Sun, 23 Apr 2017 01:14:55 GMT" } ]
2017-04-25T00:00:00
[ [ "Niculae", "Vlad", "" ], [ "Park", "Joonsuk", "" ], [ "Cardie", "Claire", "" ] ]
TITLE: Argument Mining with Structured SVMs and RNNs ABSTRACT: We propose a novel factor graph model for argument mining, designed for settings in which the argumentative relations in a document do not necessarily form a tree structure. (This is the case in over 20% of the web comments dataset we release.) Our model jointly learns elementary unit type classification and argumentative relation prediction. Moreover, our model supports SVM and RNN parametrizations, can enforce structure constraints (e.g., transitivity), and can express dependencies between adjacent relations and propositions. Our approaches outperform unstructured baselines in both web comments and argumentative essay datasets.
new_dataset
0.930962
1704.06880
Avishek Ghosh
Avishek Ghosh, Sayak Ray Chowdhury, Aditya Gopalan
Misspecified Linear Bandits
Thirty-First AAAI Conference on Artificial Intelligence, 2017
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of online learning in misspecified linear stochastic multi-armed bandit problems. Regret guarantees for state-of-the-art linear bandit algorithms such as Optimism in the Face of Uncertainty Linear bandit (OFUL) hold under the assumption that the arms expected rewards are perfectly linear in their features. It is, however, of interest to investigate the impact of potential misspecification in linear bandit models, where the expected rewards are perturbed away from the linear subspace determined by the arms features. Although OFUL has recently been shown to be robust to relatively small deviations from linearity, we show that any linear bandit algorithm that enjoys optimal regret performance in the perfectly linear setting (e.g., OFUL) must suffer linear regret under a sparse additive perturbation of the linear model. In an attempt to overcome this negative result, we define a natural class of bandit models characterized by a non-sparse deviation from linearity. We argue that the OFUL algorithm can fail to achieve sublinear regret even under models that have non-sparse deviation.We finally develop a novel bandit algorithm, comprising a hypothesis test for linearity followed by a decision to use either the OFUL or Upper Confidence Bound (UCB) algorithm. For perfectly linear bandit models, the algorithm provably exhibits OFULs favorable regret performance, while for misspecified models satisfying the non-sparse deviation property, the algorithm avoids the linear regret phenomenon and falls back on UCBs sublinear regret scaling. Numerical experiments on synthetic data, and on recommendation data from the public Yahoo! Learning to Rank Challenge dataset, empirically support our findings.
[ { "version": "v1", "created": "Sun, 23 Apr 2017 04:37:57 GMT" } ]
2017-04-25T00:00:00
[ [ "Ghosh", "Avishek", "" ], [ "Chowdhury", "Sayak Ray", "" ], [ "Gopalan", "Aditya", "" ] ]
TITLE: Misspecified Linear Bandits ABSTRACT: We consider the problem of online learning in misspecified linear stochastic multi-armed bandit problems. Regret guarantees for state-of-the-art linear bandit algorithms such as Optimism in the Face of Uncertainty Linear bandit (OFUL) hold under the assumption that the arms expected rewards are perfectly linear in their features. It is, however, of interest to investigate the impact of potential misspecification in linear bandit models, where the expected rewards are perturbed away from the linear subspace determined by the arms features. Although OFUL has recently been shown to be robust to relatively small deviations from linearity, we show that any linear bandit algorithm that enjoys optimal regret performance in the perfectly linear setting (e.g., OFUL) must suffer linear regret under a sparse additive perturbation of the linear model. In an attempt to overcome this negative result, we define a natural class of bandit models characterized by a non-sparse deviation from linearity. We argue that the OFUL algorithm can fail to achieve sublinear regret even under models that have non-sparse deviation.We finally develop a novel bandit algorithm, comprising a hypothesis test for linearity followed by a decision to use either the OFUL or Upper Confidence Bound (UCB) algorithm. For perfectly linear bandit models, the algorithm provably exhibits OFULs favorable regret performance, while for misspecified models satisfying the non-sparse deviation property, the algorithm avoids the linear regret phenomenon and falls back on UCBs sublinear regret scaling. Numerical experiments on synthetic data, and on recommendation data from the public Yahoo! Learning to Rank Challenge dataset, empirically support our findings.
no_new_dataset
0.941601
1704.06904
Fei Wang
Fei Wang, Mengqing Jiang, Chen Qian, Shuo Yang, Cheng Li, Honggang Zhang, Xiaogang Wang, Xiaoou Tang
Residual Attention Network for Image Classification
accepted to CVPR2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we propose "Residual Attention Network", a convolutional neural network using attention mechanism which can incorporate with state-of-art feed forward network architecture in an end-to-end training fashion. Our Residual Attention Network is built by stacking Attention Modules which generate attention-aware features. The attention-aware features from different modules change adaptively as layers going deeper. Inside each Attention Module, bottom-up top-down feedforward structure is used to unfold the feedforward and feedback attention process into a single feedforward process. Importantly, we propose attention residual learning to train very deep Residual Attention Networks which can be easily scaled up to hundreds of layers. Extensive analyses are conducted on CIFAR-10 and CIFAR-100 datasets to verify the effectiveness of every module mentioned above. Our Residual Attention Network achieves state-of-the-art object recognition performance on three benchmark datasets including CIFAR-10 (3.90% error), CIFAR-100 (20.45% error) and ImageNet (4.8% single model and single crop, top-5 error). Note that, our method achieves 0.6% top-1 accuracy improvement with 46% trunk depth and 69% forward FLOPs comparing to ResNet-200. The experiment also demonstrates that our network is robust against noisy labels.
[ { "version": "v1", "created": "Sun, 23 Apr 2017 10:03:49 GMT" } ]
2017-04-25T00:00:00
[ [ "Wang", "Fei", "" ], [ "Jiang", "Mengqing", "" ], [ "Qian", "Chen", "" ], [ "Yang", "Shuo", "" ], [ "Li", "Cheng", "" ], [ "Zhang", "Honggang", "" ], [ "Wang", "Xiaogang", "" ], [ "Tang", "Xiaoou", "" ] ]
TITLE: Residual Attention Network for Image Classification ABSTRACT: In this work, we propose "Residual Attention Network", a convolutional neural network using attention mechanism which can incorporate with state-of-art feed forward network architecture in an end-to-end training fashion. Our Residual Attention Network is built by stacking Attention Modules which generate attention-aware features. The attention-aware features from different modules change adaptively as layers going deeper. Inside each Attention Module, bottom-up top-down feedforward structure is used to unfold the feedforward and feedback attention process into a single feedforward process. Importantly, we propose attention residual learning to train very deep Residual Attention Networks which can be easily scaled up to hundreds of layers. Extensive analyses are conducted on CIFAR-10 and CIFAR-100 datasets to verify the effectiveness of every module mentioned above. Our Residual Attention Network achieves state-of-the-art object recognition performance on three benchmark datasets including CIFAR-10 (3.90% error), CIFAR-100 (20.45% error) and ImageNet (4.8% single model and single crop, top-5 error). Note that, our method achieves 0.6% top-1 accuracy improvement with 46% trunk depth and 69% forward FLOPs comparing to ResNet-200. The experiment also demonstrates that our network is robust against noisy labels.
no_new_dataset
0.949669
1704.06972
Yufei Wang
Yufei Wang, Zhe Lin, Xiaohui Shen, Scott Cohen, Garrison W. Cottrell
Skeleton Key: Image Captioning by Skeleton-Attribute Decomposition
Accepted by CVPR 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, there has been a lot of interest in automatically generating descriptions for an image. Most existing language-model based approaches for this task learn to generate an image description word by word in its original word order. However, for humans, it is more natural to locate the objects and their relationships first, and then elaborate on each object, describing notable attributes. We present a coarse-to-fine method that decomposes the original image description into a skeleton sentence and its attributes, and generates the skeleton sentence and attribute phrases separately. By this decomposition, our method can generate more accurate and novel descriptions than the previous state-of-the-art. Experimental results on the MS-COCO and a larger scale Stock3M datasets show that our algorithm yields consistent improvements across different evaluation metrics, especially on the SPICE metric, which has much higher correlation with human ratings than the conventional metrics. Furthermore, our algorithm can generate descriptions with varied length, benefiting from the separate control of the skeleton and attributes. This enables image description generation that better accommodates user preferences.
[ { "version": "v1", "created": "Sun, 23 Apr 2017 20:17:12 GMT" } ]
2017-04-25T00:00:00
[ [ "Wang", "Yufei", "" ], [ "Lin", "Zhe", "" ], [ "Shen", "Xiaohui", "" ], [ "Cohen", "Scott", "" ], [ "Cottrell", "Garrison W.", "" ] ]
TITLE: Skeleton Key: Image Captioning by Skeleton-Attribute Decomposition ABSTRACT: Recently, there has been a lot of interest in automatically generating descriptions for an image. Most existing language-model based approaches for this task learn to generate an image description word by word in its original word order. However, for humans, it is more natural to locate the objects and their relationships first, and then elaborate on each object, describing notable attributes. We present a coarse-to-fine method that decomposes the original image description into a skeleton sentence and its attributes, and generates the skeleton sentence and attribute phrases separately. By this decomposition, our method can generate more accurate and novel descriptions than the previous state-of-the-art. Experimental results on the MS-COCO and a larger scale Stock3M datasets show that our algorithm yields consistent improvements across different evaluation metrics, especially on the SPICE metric, which has much higher correlation with human ratings than the conventional metrics. Furthermore, our algorithm can generate descriptions with varied length, benefiting from the separate control of the skeleton and attributes. This enables image description generation that better accommodates user preferences.
no_new_dataset
0.948251
1704.07047
Deng Cai
Deng Cai, Hai Zhao, Zhisong Zhang, Yuan Xin, Yongjian Wu, Feiyue Huang
Fast and Accurate Neural Word Segmentation for Chinese
To appear in ACL2017
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neural models with minimal feature engineering have achieved competitive performance against traditional methods for the task of Chinese word segmentation. However, both training and working procedures of the current neural models are computationally inefficient. This paper presents a greedy neural word segmenter with balanced word and character embedding inputs to alleviate the existing drawbacks. Our segmenter is truly end-to-end, capable of performing segmentation much faster and even more accurate than state-of-the-art neural models on Chinese benchmark datasets.
[ { "version": "v1", "created": "Mon, 24 Apr 2017 05:50:29 GMT" } ]
2017-04-25T00:00:00
[ [ "Cai", "Deng", "" ], [ "Zhao", "Hai", "" ], [ "Zhang", "Zhisong", "" ], [ "Xin", "Yuan", "" ], [ "Wu", "Yongjian", "" ], [ "Huang", "Feiyue", "" ] ]
TITLE: Fast and Accurate Neural Word Segmentation for Chinese ABSTRACT: Neural models with minimal feature engineering have achieved competitive performance against traditional methods for the task of Chinese word segmentation. However, both training and working procedures of the current neural models are computationally inefficient. This paper presents a greedy neural word segmenter with balanced word and character embedding inputs to alleviate the existing drawbacks. Our segmenter is truly end-to-end, capable of performing segmentation much faster and even more accurate than state-of-the-art neural models on Chinese benchmark datasets.
no_new_dataset
0.949435
1704.07129
Spandana Gella
Spandana Gella, Frank Keller
An Analysis of Action Recognition Datasets for Language and Vision Tasks
To appear in Proceedings of ACL 2017, 8 pages
null
null
null
cs.CL cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A large amount of recent research has focused on tasks that combine language and vision, resulting in a proliferation of datasets and methods. One such task is action recognition, whose applications include image annotation, scene under- standing and image retrieval. In this survey, we categorize the existing ap- proaches based on how they conceptualize this problem and provide a detailed review of existing datasets, highlighting their di- versity as well as advantages and disad- vantages. We focus on recently devel- oped datasets which link visual informa- tion with linguistic resources and provide a fine-grained syntactic and semantic anal- ysis of actions in images.
[ { "version": "v1", "created": "Mon, 24 Apr 2017 10:38:23 GMT" } ]
2017-04-25T00:00:00
[ [ "Gella", "Spandana", "" ], [ "Keller", "Frank", "" ] ]
TITLE: An Analysis of Action Recognition Datasets for Language and Vision Tasks ABSTRACT: A large amount of recent research has focused on tasks that combine language and vision, resulting in a proliferation of datasets and methods. One such task is action recognition, whose applications include image annotation, scene under- standing and image retrieval. In this survey, we categorize the existing ap- proaches based on how they conceptualize this problem and provide a detailed review of existing datasets, highlighting their di- versity as well as advantages and disad- vantages. We focus on recently devel- oped datasets which link visual informa- tion with linguistic resources and provide a fine-grained syntactic and semantic anal- ysis of actions in images.
no_new_dataset
0.944944
1704.07130
He He
He He and Anusha Balakrishnan and Mihail Eric and Percy Liang
Learning Symmetric Collaborative Dialogue Agents with Dynamic Knowledge Graph Embeddings
ACL 2017
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a symmetric collaborative dialogue setting in which two agents, each with private knowledge, must strategically communicate to achieve a common goal. The open-ended dialogue state in this setting poses new challenges for existing dialogue systems. We collected a dataset of 11K human-human dialogues, which exhibits interesting lexical, semantic, and strategic elements. To model both structured knowledge and unstructured language, we propose a neural model with dynamic knowledge graph embeddings that evolve as the dialogue progresses. Automatic and human evaluations show that our model is both more effective at achieving the goal and more human-like than baseline neural and rule-based models.
[ { "version": "v1", "created": "Mon, 24 Apr 2017 10:38:24 GMT" } ]
2017-04-25T00:00:00
[ [ "He", "He", "" ], [ "Balakrishnan", "Anusha", "" ], [ "Eric", "Mihail", "" ], [ "Liang", "Percy", "" ] ]
TITLE: Learning Symmetric Collaborative Dialogue Agents with Dynamic Knowledge Graph Embeddings ABSTRACT: We study a symmetric collaborative dialogue setting in which two agents, each with private knowledge, must strategically communicate to achieve a common goal. The open-ended dialogue state in this setting poses new challenges for existing dialogue systems. We collected a dataset of 11K human-human dialogues, which exhibits interesting lexical, semantic, and strategic elements. To model both structured knowledge and unstructured language, we propose a neural model with dynamic knowledge graph embeddings that evolve as the dialogue progresses. Automatic and human evaluations show that our model is both more effective at achieving the goal and more human-like than baseline neural and rule-based models.
new_dataset
0.957278
1704.07156
Marek Rei
Marek Rei
Semi-supervised Multitask Learning for Sequence Labeling
ACL 2017
null
null
null
cs.CL cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a sequence labeling framework with a secondary training objective, learning to predict surrounding words for every word in the dataset. This language modeling objective incentivises the system to learn general-purpose patterns of semantic and syntactic composition, which are also useful for improving accuracy on different sequence labeling tasks. The architecture was evaluated on a range of datasets, covering the tasks of error detection in learner texts, named entity recognition, chunking and POS-tagging. The novel language modeling objective provided consistent performance improvements on every benchmark, without requiring any additional annotated or unannotated data.
[ { "version": "v1", "created": "Mon, 24 Apr 2017 11:47:06 GMT" } ]
2017-04-25T00:00:00
[ [ "Rei", "Marek", "" ] ]
TITLE: Semi-supervised Multitask Learning for Sequence Labeling ABSTRACT: We propose a sequence labeling framework with a secondary training objective, learning to predict surrounding words for every word in the dataset. This language modeling objective incentivises the system to learn general-purpose patterns of semantic and syntactic composition, which are also useful for improving accuracy on different sequence labeling tasks. The architecture was evaluated on a range of datasets, covering the tasks of error detection in learner texts, named entity recognition, chunking and POS-tagging. The novel language modeling objective provided consistent performance improvements on every benchmark, without requiring any additional annotated or unannotated data.
no_new_dataset
0.948106
1704.07163
Chang-Ryeol Lee
Chang-Ryeol Lee and Kuk-Jin Yoon
Monocular Visual Odometry with a Rolling Shutter Camera
14 pages, 8 figures
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Rolling Shutter (RS) cameras have become popularized because of low-cost imaging capability. However, the RS cameras suffer from undesirable artifacts when the camera or the subject is moving, or illumination condition changes. For that reason, Monocular Visual Odometry (MVO) with RS cameras produces inaccurate ego-motion estimates. Previous works solve this RS distortion problem with motion prediction from images and/or inertial sensors. However, the MVO still has trouble in handling the RS distortion when the camera motion changes abruptly (e.g. vibration of mobile cameras causes extremely fast motion instantaneously). To address the problem, we propose the novel MVO algorithm in consideration of the geometric characteristics of RS cameras. The key idea of the proposed algorithm is the new RS essential matrix which incorporates the instantaneous angular and linear velocities at each frame. Our algorithm produces accurate and robust ego-motion estimates in an online manner, and is applicable to various mobile applications with RS cameras. The superiority of the proposed algorithm is validated through quantitative and qualitative comparison on both synthetic and real dataset.
[ { "version": "v1", "created": "Mon, 24 Apr 2017 12:02:53 GMT" } ]
2017-04-25T00:00:00
[ [ "Lee", "Chang-Ryeol", "" ], [ "Yoon", "Kuk-Jin", "" ] ]
TITLE: Monocular Visual Odometry with a Rolling Shutter Camera ABSTRACT: Rolling Shutter (RS) cameras have become popularized because of low-cost imaging capability. However, the RS cameras suffer from undesirable artifacts when the camera or the subject is moving, or illumination condition changes. For that reason, Monocular Visual Odometry (MVO) with RS cameras produces inaccurate ego-motion estimates. Previous works solve this RS distortion problem with motion prediction from images and/or inertial sensors. However, the MVO still has trouble in handling the RS distortion when the camera motion changes abruptly (e.g. vibration of mobile cameras causes extremely fast motion instantaneously). To address the problem, we propose the novel MVO algorithm in consideration of the geometric characteristics of RS cameras. The key idea of the proposed algorithm is the new RS essential matrix which incorporates the instantaneous angular and linear velocities at each frame. Our algorithm produces accurate and robust ego-motion estimates in an online manner, and is applicable to various mobile applications with RS cameras. The superiority of the proposed algorithm is validated through quantitative and qualitative comparison on both synthetic and real dataset.
no_new_dataset
0.950915
1504.03440
Georgios Kellaris
Georgios Kellaris, Stavros Papadopoulos, and Dimitris Papadias
Engineering Methods for Differentially Private Histograms: Efficiency Beyond Utility
null
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Publishing histograms with $\epsilon$-differential privacy has been studied extensively in the literature. Existing schemes aim at maximizing the utility of the published data, while previous experimental evaluations analyze the privacy/utility trade-off. In this paper we provide the first experimental evaluation of differentially private methods that goes beyond utility, emphasizing also on another important aspect, namely efficiency. Towards this end, we first observe that all existing schemes are comprised of a small set of common blocks. We then optimize and choose the best implementation for each block, determine the combinations of blocks that capture the entire literature, and propose novel block combinations. We qualitatively assess the quality of the schemes based on the skyline of efficiency and utility, i.e., based on whether a method is dominated on both aspects or not. Using exhaustive experiments on four real datasets with different characteristics, we conclude that there are always trade-offs in terms of utility and efficiency. We demonstrate that the schemes derived from our novel block combinations provide the best trade-offs for time critical applications. Our work can serve as a guide to help practitioners engineer a differentially private histogram scheme depending on their application requirements.
[ { "version": "v1", "created": "Tue, 14 Apr 2015 07:29:25 GMT" }, { "version": "v2", "created": "Thu, 20 Apr 2017 19:27:53 GMT" } ]
2017-04-24T00:00:00
[ [ "Kellaris", "Georgios", "" ], [ "Papadopoulos", "Stavros", "" ], [ "Papadias", "Dimitris", "" ] ]
TITLE: Engineering Methods for Differentially Private Histograms: Efficiency Beyond Utility ABSTRACT: Publishing histograms with $\epsilon$-differential privacy has been studied extensively in the literature. Existing schemes aim at maximizing the utility of the published data, while previous experimental evaluations analyze the privacy/utility trade-off. In this paper we provide the first experimental evaluation of differentially private methods that goes beyond utility, emphasizing also on another important aspect, namely efficiency. Towards this end, we first observe that all existing schemes are comprised of a small set of common blocks. We then optimize and choose the best implementation for each block, determine the combinations of blocks that capture the entire literature, and propose novel block combinations. We qualitatively assess the quality of the schemes based on the skyline of efficiency and utility, i.e., based on whether a method is dominated on both aspects or not. Using exhaustive experiments on four real datasets with different characteristics, we conclude that there are always trade-offs in terms of utility and efficiency. We demonstrate that the schemes derived from our novel block combinations provide the best trade-offs for time critical applications. Our work can serve as a guide to help practitioners engineer a differentially private histogram scheme depending on their application requirements.
no_new_dataset
0.945147
1602.02285
Uri Shaham
Uri Shaham, Xiuyuan Cheng, Omer Dror, Ariel Jaffe, Boaz Nadler, Joseph Chang, Yuval Kluger
A Deep Learning Approach to Unsupervised Ensemble Learning
null
null
null
PMLR 48:30-39
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show how deep learning methods can be applied in the context of crowdsourcing and unsupervised ensemble learning. First, we prove that the popular model of Dawid and Skene, which assumes that all classifiers are conditionally independent, is {\em equivalent} to a Restricted Boltzmann Machine (RBM) with a single hidden node. Hence, under this model, the posterior probabilities of the true labels can be instead estimated via a trained RBM. Next, to address the more general case, where classifiers may strongly violate the conditional independence assumption, we propose to apply RBM-based Deep Neural Net (DNN). Experimental results on various simulated and real-world datasets demonstrate that our proposed DNN approach outperforms other state-of-the-art methods, in particular when the data violates the conditional independence assumption.
[ { "version": "v1", "created": "Sat, 6 Feb 2016 17:56:59 GMT" } ]
2017-04-24T00:00:00
[ [ "Shaham", "Uri", "" ], [ "Cheng", "Xiuyuan", "" ], [ "Dror", "Omer", "" ], [ "Jaffe", "Ariel", "" ], [ "Nadler", "Boaz", "" ], [ "Chang", "Joseph", "" ], [ "Kluger", "Yuval", "" ] ]
TITLE: A Deep Learning Approach to Unsupervised Ensemble Learning ABSTRACT: We show how deep learning methods can be applied in the context of crowdsourcing and unsupervised ensemble learning. First, we prove that the popular model of Dawid and Skene, which assumes that all classifiers are conditionally independent, is {\em equivalent} to a Restricted Boltzmann Machine (RBM) with a single hidden node. Hence, under this model, the posterior probabilities of the true labels can be instead estimated via a trained RBM. Next, to address the more general case, where classifiers may strongly violate the conditional independence assumption, we propose to apply RBM-based Deep Neural Net (DNN). Experimental results on various simulated and real-world datasets demonstrate that our proposed DNN approach outperforms other state-of-the-art methods, in particular when the data violates the conditional independence assumption.
no_new_dataset
0.947721
1603.07188
Pavel Tokmakov
Pavel Tokmakov, Karteek Alahari, Cordelia Schmid
Weakly-Supervised Semantic Segmentation using Motion Cues
Extended version of our ECCV 2016 paper
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fully convolutional neural networks (FCNNs) trained on a large number of images with strong pixel-level annotations have become the new state of the art for the semantic segmentation task. While there have been recent attempts to learn FCNNs from image-level weak annotations, they need additional constraints, such as the size of an object, to obtain reasonable performance. To address this issue, we present motion-CNN (M-CNN), a novel FCNN framework which incorporates motion cues and is learned from video-level weak annotations. Our learning scheme to train the network uses motion segments as soft constraints, thereby handling noisy motion information. When trained on weakly-annotated videos, our method outperforms the state-of-the-art EM-Adapt approach on the PASCAL VOC 2012 image segmentation benchmark. We also demonstrate that the performance of M-CNN learned with 150 weak video annotations is on par with state-of-the-art weakly-supervised methods trained with thousands of images. Finally, M-CNN substantially outperforms recent approaches in a related task of video co-localization on the YouTube-Objects dataset.
[ { "version": "v1", "created": "Wed, 23 Mar 2016 14:01:03 GMT" }, { "version": "v2", "created": "Thu, 28 Jul 2016 12:21:37 GMT" }, { "version": "v3", "created": "Fri, 21 Apr 2017 08:16:06 GMT" } ]
2017-04-24T00:00:00
[ [ "Tokmakov", "Pavel", "" ], [ "Alahari", "Karteek", "" ], [ "Schmid", "Cordelia", "" ] ]
TITLE: Weakly-Supervised Semantic Segmentation using Motion Cues ABSTRACT: Fully convolutional neural networks (FCNNs) trained on a large number of images with strong pixel-level annotations have become the new state of the art for the semantic segmentation task. While there have been recent attempts to learn FCNNs from image-level weak annotations, they need additional constraints, such as the size of an object, to obtain reasonable performance. To address this issue, we present motion-CNN (M-CNN), a novel FCNN framework which incorporates motion cues and is learned from video-level weak annotations. Our learning scheme to train the network uses motion segments as soft constraints, thereby handling noisy motion information. When trained on weakly-annotated videos, our method outperforms the state-of-the-art EM-Adapt approach on the PASCAL VOC 2012 image segmentation benchmark. We also demonstrate that the performance of M-CNN learned with 150 weak video annotations is on par with state-of-the-art weakly-supervised methods trained with thousands of images. Finally, M-CNN substantially outperforms recent approaches in a related task of video co-localization on the YouTube-Objects dataset.
no_new_dataset
0.947381
1606.03777
Nikola Mrk\v{s}i\'c
Nikola Mrk\v{s}i\'c and Diarmuid \'O S\'eaghdha and Tsung-Hsien Wen and Blaise Thomson and Steve Young
Neural Belief Tracker: Data-Driven Dialogue State Tracking
Accepted as a long paper for the 55th Annual Meeting of the Association for Computational Linguistics (ACL 2017)
null
null
null
cs.CL cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One of the core components of modern spoken dialogue systems is the belief tracker, which estimates the user's goal at every step of the dialogue. However, most current approaches have difficulty scaling to larger, more complex dialogue domains. This is due to their dependency on either: a) Spoken Language Understanding models that require large amounts of annotated training data; or b) hand-crafted lexicons for capturing some of the linguistic variation in users' language. We propose a novel Neural Belief Tracking (NBT) framework which overcomes these problems by building on recent advances in representation learning. NBT models reason over pre-trained word vectors, learning to compose them into distributed representations of user utterances and dialogue context. Our evaluation on two datasets shows that this approach surpasses past limitations, matching the performance of state-of-the-art models which rely on hand-crafted semantic lexicons and outperforming them when such lexicons are not provided.
[ { "version": "v1", "created": "Sun, 12 Jun 2016 22:59:14 GMT" }, { "version": "v2", "created": "Fri, 21 Apr 2017 15:15:03 GMT" } ]
2017-04-24T00:00:00
[ [ "Mrkšić", "Nikola", "" ], [ "Séaghdha", "Diarmuid Ó", "" ], [ "Wen", "Tsung-Hsien", "" ], [ "Thomson", "Blaise", "" ], [ "Young", "Steve", "" ] ]
TITLE: Neural Belief Tracker: Data-Driven Dialogue State Tracking ABSTRACT: One of the core components of modern spoken dialogue systems is the belief tracker, which estimates the user's goal at every step of the dialogue. However, most current approaches have difficulty scaling to larger, more complex dialogue domains. This is due to their dependency on either: a) Spoken Language Understanding models that require large amounts of annotated training data; or b) hand-crafted lexicons for capturing some of the linguistic variation in users' language. We propose a novel Neural Belief Tracking (NBT) framework which overcomes these problems by building on recent advances in representation learning. NBT models reason over pre-trained word vectors, learning to compose them into distributed representations of user utterances and dialogue context. Our evaluation on two datasets shows that this approach surpasses past limitations, matching the performance of state-of-the-art models which rely on hand-crafted semantic lexicons and outperforming them when such lexicons are not provided.
no_new_dataset
0.944228
1703.08338
Michael Wray
Michael Wray, Davide Moltisanti, Walterio Mayol-Cuevas and Dima Damen
Improving Classification by Improving Labelling: Introducing Probabilistic Multi-Label Object Interaction Recognition
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This work deviates from easy-to-define class boundaries for object interactions. For the task of object interaction recognition, often captured using an egocentric view, we show that semantic ambiguities in verbs and recognising sub-interactions along with concurrent interactions result in legitimate class overlaps (Figure 1). We thus aim to model the mapping between observations and interaction classes, as well as class overlaps, towards a probabilistic multi-label classifier that emulates human annotators. Given a video segment containing an object interaction, we model the probability for a verb, out of a list of possible verbs, to be used to annotate that interaction. The proba- bility is learnt from crowdsourced annotations, and is tested on two public datasets, comprising 1405 video sequences for which we provide annotations on 90 verbs. We outper- form conventional single-label classification by 11% and 6% on the two datasets respectively, and show that learning from annotation probabilities outperforms majority voting and enables discovery of co-occurring labels.
[ { "version": "v1", "created": "Fri, 24 Mar 2017 10:11:03 GMT" }, { "version": "v2", "created": "Fri, 21 Apr 2017 16:29:22 GMT" } ]
2017-04-24T00:00:00
[ [ "Wray", "Michael", "" ], [ "Moltisanti", "Davide", "" ], [ "Mayol-Cuevas", "Walterio", "" ], [ "Damen", "Dima", "" ] ]
TITLE: Improving Classification by Improving Labelling: Introducing Probabilistic Multi-Label Object Interaction Recognition ABSTRACT: This work deviates from easy-to-define class boundaries for object interactions. For the task of object interaction recognition, often captured using an egocentric view, we show that semantic ambiguities in verbs and recognising sub-interactions along with concurrent interactions result in legitimate class overlaps (Figure 1). We thus aim to model the mapping between observations and interaction classes, as well as class overlaps, towards a probabilistic multi-label classifier that emulates human annotators. Given a video segment containing an object interaction, we model the probability for a verb, out of a list of possible verbs, to be used to annotate that interaction. The proba- bility is learnt from crowdsourced annotations, and is tested on two public datasets, comprising 1405 video sequences for which we provide annotations on 90 verbs. We outper- form conventional single-label classification by 11% and 6% on the two datasets respectively, and show that learning from annotation probabilities outperforms majority voting and enables discovery of co-occurring labels.
no_new_dataset
0.949342
1704.06360
Jason Fries
Jason Fries, Sen Wu, Alex Ratner, Christopher R\'e
SwellShark: A Generative Model for Biomedical Named Entity Recognition without Labeled Data
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present SwellShark, a framework for building biomedical named entity recognition (NER) systems quickly and without hand-labeled data. Our approach views biomedical resources like lexicons as function primitives for autogenerating weak supervision. We then use a generative model to unify and denoise this supervision and construct large-scale, probabilistically labeled datasets for training high-accuracy NER taggers. In three biomedical NER tasks, SwellShark achieves competitive scores with state-of-the-art supervised benchmarks using no hand-labeled training data. In a drug name extraction task using patient medical records, one domain expert using SwellShark achieved within 5.1% of a crowdsourced annotation approach -- which originally utilized 20 teams over the course of several weeks -- in 24 hours.
[ { "version": "v1", "created": "Thu, 20 Apr 2017 23:02:14 GMT" } ]
2017-04-24T00:00:00
[ [ "Fries", "Jason", "" ], [ "Wu", "Sen", "" ], [ "Ratner", "Alex", "" ], [ "Ré", "Christopher", "" ] ]
TITLE: SwellShark: A Generative Model for Biomedical Named Entity Recognition without Labeled Data ABSTRACT: We present SwellShark, a framework for building biomedical named entity recognition (NER) systems quickly and without hand-labeled data. Our approach views biomedical resources like lexicons as function primitives for autogenerating weak supervision. We then use a generative model to unify and denoise this supervision and construct large-scale, probabilistically labeled datasets for training high-accuracy NER taggers. In three biomedical NER tasks, SwellShark achieves competitive scores with state-of-the-art supervised benchmarks using no hand-labeled training data. In a drug name extraction task using patient medical records, one domain expert using SwellShark achieved within 5.1% of a crowdsourced annotation approach -- which originally utilized 20 teams over the course of several weeks -- in 24 hours.
no_new_dataset
0.946498
1704.06363
Arthur Szlam
Sam Gross and Marc'Aurelio Ranzato and Arthur Szlam
Hard Mixtures of Experts for Large Scale Weakly Supervised Vision
Appearing in CVPR 2017
null
null
null
cs.CV stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Training convolutional networks (CNN's) that fit on a single GPU with minibatch stochastic gradient descent has become effective in practice. However, there is still no effective method for training large CNN's that do not fit in the memory of a few GPU cards, or for parallelizing CNN training. In this work we show that a simple hard mixture of experts model can be efficiently trained to good effect on large scale hashtag (multilabel) prediction tasks. Mixture of experts models are not new (Jacobs et. al. 1991, Collobert et. al. 2003), but in the past, researchers have had to devise sophisticated methods to deal with data fragmentation. We show empirically that modern weakly supervised data sets are large enough to support naive partitioning schemes where each data point is assigned to a single expert. Because the experts are independent, training them in parallel is easy, and evaluation is cheap for the size of the model. Furthermore, we show that we can use a single decoding layer for all the experts, allowing a unified feature embedding space. We demonstrate that it is feasible (and in fact relatively painless) to train far larger models than could be practically trained with standard CNN architectures, and that the extra capacity can be well used on current datasets.
[ { "version": "v1", "created": "Thu, 20 Apr 2017 23:45:27 GMT" } ]
2017-04-24T00:00:00
[ [ "Gross", "Sam", "" ], [ "Ranzato", "Marc'Aurelio", "" ], [ "Szlam", "Arthur", "" ] ]
TITLE: Hard Mixtures of Experts for Large Scale Weakly Supervised Vision ABSTRACT: Training convolutional networks (CNN's) that fit on a single GPU with minibatch stochastic gradient descent has become effective in practice. However, there is still no effective method for training large CNN's that do not fit in the memory of a few GPU cards, or for parallelizing CNN training. In this work we show that a simple hard mixture of experts model can be efficiently trained to good effect on large scale hashtag (multilabel) prediction tasks. Mixture of experts models are not new (Jacobs et. al. 1991, Collobert et. al. 2003), but in the past, researchers have had to devise sophisticated methods to deal with data fragmentation. We show empirically that modern weakly supervised data sets are large enough to support naive partitioning schemes where each data point is assigned to a single expert. Because the experts are independent, training them in parallel is easy, and evaluation is cheap for the size of the model. Furthermore, we show that we can use a single decoding layer for all the experts, allowing a unified feature embedding space. We demonstrate that it is feasible (and in fact relatively painless) to train far larger models than could be practically trained with standard CNN architectures, and that the extra capacity can be well used on current datasets.
no_new_dataset
0.945951
1704.06370
Md Zahangir Alom
Md Zahangir Alom and Tarek M. Taha
Robust Multi-view Pedestrian Tracking Using Neural Networks
8 pages, 3 figures
null
null
null
cs.CV
http://creativecommons.org/licenses/by/4.0/
In this paper, we present a real-time robust multi-view pedestrian detection and tracking system for video surveillance using neural networks which can be used in dynamic environments. The proposed system consists of two phases: multi-view pedestrian detection and tracking. First, pedestrian detection utilizes background subtraction to segment the foreground blob. An adaptive background subtraction method where each of the pixel of input image models as a mixture of Gaussians and uses an on-line approximation to update the model applies to extract the foreground region. The Gaussian distributions are then evaluated to determine which are most likely to result from a background process. This method produces a steady, real-time tracker in outdoor environment that consistently deals with changes of lighting condition, and long-term scene change. Second, the Tracking is performed at two phases: pedestrian classification and tracking the individual subject. A sliding window is applied on foreground binary image to select an input window which is used for selecting the input image patches from actually input frame. The neural networks is used for classification with PHOG features. Finally, a Kalman filter is applied to calculate the subsequent step for tracking that aims at finding the exact position of pedestrians in an input image. The experimental result shows that the proposed approach yields promising performance on multi-view pedestrian detection and tracking on different benchmark datasets.
[ { "version": "v1", "created": "Fri, 21 Apr 2017 00:12:23 GMT" } ]
2017-04-24T00:00:00
[ [ "Alom", "Md Zahangir", "" ], [ "Taha", "Tarek M.", "" ] ]
TITLE: Robust Multi-view Pedestrian Tracking Using Neural Networks ABSTRACT: In this paper, we present a real-time robust multi-view pedestrian detection and tracking system for video surveillance using neural networks which can be used in dynamic environments. The proposed system consists of two phases: multi-view pedestrian detection and tracking. First, pedestrian detection utilizes background subtraction to segment the foreground blob. An adaptive background subtraction method where each of the pixel of input image models as a mixture of Gaussians and uses an on-line approximation to update the model applies to extract the foreground region. The Gaussian distributions are then evaluated to determine which are most likely to result from a background process. This method produces a steady, real-time tracker in outdoor environment that consistently deals with changes of lighting condition, and long-term scene change. Second, the Tracking is performed at two phases: pedestrian classification and tracking the individual subject. A sliding window is applied on foreground binary image to select an input window which is used for selecting the input image patches from actually input frame. The neural networks is used for classification with PHOG features. Finally, a Kalman filter is applied to calculate the subsequent step for tracking that aims at finding the exact position of pedestrians in an input image. The experimental result shows that the proposed approach yields promising performance on multi-view pedestrian detection and tracking on different benchmark datasets.
no_new_dataset
0.948202
1704.06382
Holger Roth
Holger R. Roth, Hirohisa Oda, Yuichiro Hayashi, Masahiro Oda, Natsuki Shimizu, Michitaka Fujiwara, Kazunari Misawa, Kensaku Mori
Hierarchical 3D fully convolutional networks for multi-organ segmentation
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent advances in 3D fully convolutional networks (FCN) have made it feasible to produce dense voxel-wise predictions of full volumetric images. In this work, we show that a multi-class 3D FCN trained on manually labeled CT scans of seven abdominal structures (artery, vein, liver, spleen, stomach, gallbladder, and pancreas) can achieve competitive segmentation results, while avoiding the need for handcrafting features or training organ-specific models. To this end, we propose a two-stage, coarse-to-fine approach that trains an FCN model to roughly delineate the organs of interest in the first stage (seeing $\sim$40% of the voxels within a simple, automatically generated binary mask of the patient's body). We then use these predictions of the first-stage FCN to define a candidate region that will be used to train a second FCN. This step reduces the number of voxels the FCN has to classify to $\sim$10% while maintaining a recall high of $>$99%. This second-stage FCN can now focus on more detailed segmentation of the organs. We respectively utilize training and validation sets consisting of 281 and 50 clinical CT images. Our hierarchical approach provides an improved Dice score of 7.5 percentage points per organ on average in our validation set. We furthermore test our models on a completely unseen data collection acquired at a different hospital that includes 150 CT scans with three anatomical labels (liver, spleen, and pancreas). In such challenging organs as the pancreas, our hierarchical approach improves the mean Dice score from 68.5 to 82.2%, achieving the highest reported average score on this dataset.
[ { "version": "v1", "created": "Fri, 21 Apr 2017 03:05:15 GMT" } ]
2017-04-24T00:00:00
[ [ "Roth", "Holger R.", "" ], [ "Oda", "Hirohisa", "" ], [ "Hayashi", "Yuichiro", "" ], [ "Oda", "Masahiro", "" ], [ "Shimizu", "Natsuki", "" ], [ "Fujiwara", "Michitaka", "" ], [ "Misawa", "Kazunari", "" ], [ "Mori", "Kensaku", "" ] ]
TITLE: Hierarchical 3D fully convolutional networks for multi-organ segmentation ABSTRACT: Recent advances in 3D fully convolutional networks (FCN) have made it feasible to produce dense voxel-wise predictions of full volumetric images. In this work, we show that a multi-class 3D FCN trained on manually labeled CT scans of seven abdominal structures (artery, vein, liver, spleen, stomach, gallbladder, and pancreas) can achieve competitive segmentation results, while avoiding the need for handcrafting features or training organ-specific models. To this end, we propose a two-stage, coarse-to-fine approach that trains an FCN model to roughly delineate the organs of interest in the first stage (seeing $\sim$40% of the voxels within a simple, automatically generated binary mask of the patient's body). We then use these predictions of the first-stage FCN to define a candidate region that will be used to train a second FCN. This step reduces the number of voxels the FCN has to classify to $\sim$10% while maintaining a recall high of $>$99%. This second-stage FCN can now focus on more detailed segmentation of the organs. We respectively utilize training and validation sets consisting of 281 and 50 clinical CT images. Our hierarchical approach provides an improved Dice score of 7.5 percentage points per organ on average in our validation set. We furthermore test our models on a completely unseen data collection acquired at a different hospital that includes 150 CT scans with three anatomical labels (liver, spleen, and pancreas). In such challenging organs as the pancreas, our hierarchical approach improves the mean Dice score from 68.5 to 82.2%, achieving the highest reported average score on this dataset.
no_new_dataset
0.94079
1704.06392
Mohamed Elawady
Mohamed Elawady, Olivier Alata, Christophe Ducottet, Cecile Barat, Philippe Colantoni
Multiple Reflection Symmetry Detection via Linear-Directional Kernel Density Estimation
Submitted to CAIP 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Symmetry is an important composition feature by investigating similar sides inside an image plane. It has a crucial effect to recognize man-made or nature objects within the universe. Recent symmetry detection approaches used a smoothing kernel over different voting maps in the polar coordinate system to detect symmetry peaks, which split the regions of symmetry axis candidates in inefficient way. We propose a reliable voting representation based on weighted linear-directional kernel density estimation, to detect multiple symmetries over challenging real-world and synthetic images. Experimental evaluation on two public datasets demonstrates the superior performance of the proposed algorithm to detect global symmetry axes respect to the major image shapes.
[ { "version": "v1", "created": "Fri, 21 Apr 2017 04:15:15 GMT" } ]
2017-04-24T00:00:00
[ [ "Elawady", "Mohamed", "" ], [ "Alata", "Olivier", "" ], [ "Ducottet", "Christophe", "" ], [ "Barat", "Cecile", "" ], [ "Colantoni", "Philippe", "" ] ]
TITLE: Multiple Reflection Symmetry Detection via Linear-Directional Kernel Density Estimation ABSTRACT: Symmetry is an important composition feature by investigating similar sides inside an image plane. It has a crucial effect to recognize man-made or nature objects within the universe. Recent symmetry detection approaches used a smoothing kernel over different voting maps in the polar coordinate system to detect symmetry peaks, which split the regions of symmetry axis candidates in inefficient way. We propose a reliable voting representation based on weighted linear-directional kernel density estimation, to detect multiple symmetries over challenging real-world and synthetic images. Experimental evaluation on two public datasets demonstrates the superior performance of the proposed algorithm to detect global symmetry axes respect to the major image shapes.
no_new_dataset
0.953708
1704.06456
Qianru Sun
Qianru Sun, Bernt Schiele and Mario Fritz
A Domain Based Approach to Social Relation Recognition
To appear in CVPR 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Social relations are the foundation of human daily life. Developing techniques to analyze such relations from visual data bears great potential to build machines that better understand us and are capable of interacting with us at a social level. Previous investigations have remained partial due to the overwhelming diversity and complexity of the topic and consequently have only focused on a handful of social relations. In this paper, we argue that the domain-based theory from social psychology is a great starting point to systematically approach this problem. The theory provides coverage of all aspects of social relations and equally is concrete and predictive about the visual attributes and behaviors defining the relations included in each domain. We provide the first dataset built on this holistic conceptualization of social life that is composed of a hierarchical label space of social domains and social relations. We also contribute the first models to recognize such domains and relations and find superior performance for attribute based features. Beyond the encouraging performance of the attribute based approach, we also find interpretable features that are in accordance with the predictions from social psychology literature. Beyond our findings, we believe that our contributions more tightly interleave visual recognition and social psychology theory that has the potential to complement the theoretical work in the area with empirical and data-driven models of social life.
[ { "version": "v1", "created": "Fri, 21 Apr 2017 09:27:32 GMT" } ]
2017-04-24T00:00:00
[ [ "Sun", "Qianru", "" ], [ "Schiele", "Bernt", "" ], [ "Fritz", "Mario", "" ] ]
TITLE: A Domain Based Approach to Social Relation Recognition ABSTRACT: Social relations are the foundation of human daily life. Developing techniques to analyze such relations from visual data bears great potential to build machines that better understand us and are capable of interacting with us at a social level. Previous investigations have remained partial due to the overwhelming diversity and complexity of the topic and consequently have only focused on a handful of social relations. In this paper, we argue that the domain-based theory from social psychology is a great starting point to systematically approach this problem. The theory provides coverage of all aspects of social relations and equally is concrete and predictive about the visual attributes and behaviors defining the relations included in each domain. We provide the first dataset built on this holistic conceptualization of social life that is composed of a hierarchical label space of social domains and social relations. We also contribute the first models to recognize such domains and relations and find superior performance for attribute based features. Beyond the encouraging performance of the attribute based approach, we also find interpretable features that are in accordance with the predictions from social psychology literature. Beyond our findings, we believe that our contributions more tightly interleave visual recognition and social psychology theory that has the potential to complement the theoretical work in the area with empirical and data-driven models of social life.
new_dataset
0.958187
1704.06569
Caiyun Huang
Caiyun Huang, Peng Zhang, Junpeng Liu, Yong Sun, Xueqiang Zou
SFCSD: A Self-Feedback Correction System for DNS Based on Active and Passive Measurement
7 pages, 3 figures, 7 tables, submitted to GlobeCOM 2017
null
null
null
cs.NI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Domain Name System (DNS), one of the important infrastructure in the Internet, was vulnerable to attacks, for the DNS designer didn't take security issues into consideration at the beginning. The defects of DNS may lead to users' failure of access to the websites, what's worse, users might suffer a huge economic loss. In order to correct the DNS wrong resource records, we propose a Self-Feedback Correction System for DNS (SFCSD), which can find and track a large number of common websites' domain name and IP address correct correspondences to provide users with a real-time auto-updated correct (IP, Domain) binary tuple list. By matching specific strings with SSL, DNS and HTTP traffic passively, filtering with the CDN CNAME and non-homepage URL feature strings, verifying with webpage fingerprint algorithm, SFCSD obtains a large number of highly possibly correct IP addresses to make an active manual correction in the end. Its self-feedback mechanism can expand search range and improve performance. Experiments show that, SFCSD can achieve 94.3% precision and 93.07% recall rate with the optimal threshold selection in the test dataset. It has 8Gbps processing speed stand-alone to find almost 1000 possibly correct (IP, Domain) per day for the each specific string and to correct almost 200.
[ { "version": "v1", "created": "Fri, 21 Apr 2017 14:41:10 GMT" } ]
2017-04-24T00:00:00
[ [ "Huang", "Caiyun", "" ], [ "Zhang", "Peng", "" ], [ "Liu", "Junpeng", "" ], [ "Sun", "Yong", "" ], [ "Zou", "Xueqiang", "" ] ]
TITLE: SFCSD: A Self-Feedback Correction System for DNS Based on Active and Passive Measurement ABSTRACT: Domain Name System (DNS), one of the important infrastructure in the Internet, was vulnerable to attacks, for the DNS designer didn't take security issues into consideration at the beginning. The defects of DNS may lead to users' failure of access to the websites, what's worse, users might suffer a huge economic loss. In order to correct the DNS wrong resource records, we propose a Self-Feedback Correction System for DNS (SFCSD), which can find and track a large number of common websites' domain name and IP address correct correspondences to provide users with a real-time auto-updated correct (IP, Domain) binary tuple list. By matching specific strings with SSL, DNS and HTTP traffic passively, filtering with the CDN CNAME and non-homepage URL feature strings, verifying with webpage fingerprint algorithm, SFCSD obtains a large number of highly possibly correct IP addresses to make an active manual correction in the end. Its self-feedback mechanism can expand search range and improve performance. Experiments show that, SFCSD can achieve 94.3% precision and 93.07% recall rate with the optimal threshold selection in the test dataset. It has 8Gbps processing speed stand-alone to find almost 1000 possibly correct (IP, Domain) per day for the each specific string and to correct almost 200.
no_new_dataset
0.940735
1704.06591
Ahmet Iscen
Ahmet Iscen, Giorgos Tolias, Yannis Avrithis, Teddy Furon, Ondrej Chum
Panorama to panorama matching for location recognition
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Location recognition is commonly treated as visual instance retrieval on "street view" imagery. The dataset items and queries are panoramic views, i.e. groups of images taken at a single location. This work introduces a novel panorama-to-panorama matching process, either by aggregating features of individual images in a group or by explicitly constructing a larger panorama. In either case, multiple views are used as queries. We reach near perfect location recognition on a standard benchmark with only four query views.
[ { "version": "v1", "created": "Fri, 21 Apr 2017 15:23:29 GMT" } ]
2017-04-24T00:00:00
[ [ "Iscen", "Ahmet", "" ], [ "Tolias", "Giorgos", "" ], [ "Avrithis", "Yannis", "" ], [ "Furon", "Teddy", "" ], [ "Chum", "Ondrej", "" ] ]
TITLE: Panorama to panorama matching for location recognition ABSTRACT: Location recognition is commonly treated as visual instance retrieval on "street view" imagery. The dataset items and queries are panoramic views, i.e. groups of images taken at a single location. This work introduces a novel panorama-to-panorama matching process, either by aggregating features of individual images in a group or by explicitly constructing a larger panorama. In either case, multiple views are used as queries. We reach near perfect location recognition on a standard benchmark with only four query views.
no_new_dataset
0.94743
1704.06610
Jose Oramas
Jose Oramas and Luc De Raedt and Tinne Tuytelaars
Context-based Object Viewpoint Estimation: A 2D Relational Approach
Computer Vision and Image Understanding (CVIU)
null
10.1016/j.cviu.2017.04.005
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The task of object viewpoint estimation has been a challenge since the early days of computer vision. To estimate the viewpoint (or pose) of an object, people have mostly looked at object intrinsic features, such as shape or appearance. Surprisingly, informative features provided by other, extrinsic elements in the scene, have so far mostly been ignored. At the same time, contextual cues have been proven to be of great benefit for related tasks such as object detection or action recognition. In this paper, we explore how information from other objects in the scene can be exploited for viewpoint estimation. In particular, we look at object configurations by following a relational neighbor-based approach for reasoning about object relations. We show that, starting from noisy object detections and viewpoint estimates, exploiting the estimated viewpoint and location of other objects in the scene can lead to improved object viewpoint predictions. Experiments on the KITTI dataset demonstrate that object configurations can indeed be used as a complementary cue to appearance-based viewpoint estimation. Our analysis reveals that the proposed context-based method can improve object viewpoint estimation by reducing specific types of viewpoint estimation errors commonly made by methods that only consider local information. Moreover, considering contextual information produces superior performance in scenes where a high number of object instances occur. Finally, our results suggest that, following a cautious relational neighbor formulation brings improvements over its aggressive counterpart for the task of object viewpoint estimation.
[ { "version": "v1", "created": "Fri, 21 Apr 2017 15:55:54 GMT" } ]
2017-04-24T00:00:00
[ [ "Oramas", "Jose", "" ], [ "De Raedt", "Luc", "" ], [ "Tuytelaars", "Tinne", "" ] ]
TITLE: Context-based Object Viewpoint Estimation: A 2D Relational Approach ABSTRACT: The task of object viewpoint estimation has been a challenge since the early days of computer vision. To estimate the viewpoint (or pose) of an object, people have mostly looked at object intrinsic features, such as shape or appearance. Surprisingly, informative features provided by other, extrinsic elements in the scene, have so far mostly been ignored. At the same time, contextual cues have been proven to be of great benefit for related tasks such as object detection or action recognition. In this paper, we explore how information from other objects in the scene can be exploited for viewpoint estimation. In particular, we look at object configurations by following a relational neighbor-based approach for reasoning about object relations. We show that, starting from noisy object detections and viewpoint estimates, exploiting the estimated viewpoint and location of other objects in the scene can lead to improved object viewpoint predictions. Experiments on the KITTI dataset demonstrate that object configurations can indeed be used as a complementary cue to appearance-based viewpoint estimation. Our analysis reveals that the proposed context-based method can improve object viewpoint estimation by reducing specific types of viewpoint estimation errors commonly made by methods that only consider local information. Moreover, considering contextual information produces superior performance in scenes where a high number of object instances occur. Finally, our results suggest that, following a cautious relational neighbor formulation brings improvements over its aggressive counterpart for the task of object viewpoint estimation.
no_new_dataset
0.948106
1704.06619
Arman Cohan
Arman Cohan and Nazli Goharian
Scientific Article Summarization Using Citation-Context and Article's Discourse Structure
EMNLP 2015
null
null
null
cs.CL cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a summarization approach for scientific articles which takes advantage of citation-context and the document discourse model. While citations have been previously used in generating scientific summaries, they lack the related context from the referenced article and therefore do not accurately reflect the article's content. Our method overcomes the problem of inconsistency between the citation summary and the article's content by providing context for each citation. We also leverage the inherent scientific article's discourse for producing better summaries. We show that our proposed method effectively improves over existing summarization approaches (greater than 30% improvement over the best performing baseline) in terms of \textsc{Rouge} scores on TAC2014 scientific summarization dataset. While the dataset we use for evaluation is in the biomedical domain, most of our approaches are general and therefore adaptable to other domains.
[ { "version": "v1", "created": "Fri, 21 Apr 2017 16:17:58 GMT" } ]
2017-04-24T00:00:00
[ [ "Cohan", "Arman", "" ], [ "Goharian", "Nazli", "" ] ]
TITLE: Scientific Article Summarization Using Citation-Context and Article's Discourse Structure ABSTRACT: We propose a summarization approach for scientific articles which takes advantage of citation-context and the document discourse model. While citations have been previously used in generating scientific summaries, they lack the related context from the referenced article and therefore do not accurately reflect the article's content. Our method overcomes the problem of inconsistency between the citation summary and the article's content by providing context for each citation. We also leverage the inherent scientific article's discourse for producing better summaries. We show that our proposed method effectively improves over existing summarization approaches (greater than 30% improvement over the best performing baseline) in terms of \textsc{Rouge} scores on TAC2014 scientific summarization dataset. While the dataset we use for evaluation is in the biomedical domain, most of our approaches are general and therefore adaptable to other domains.
no_new_dataset
0.949763
1512.03155
Erkan Bostanci
Erkan Bostanci
Enhanced image feature coverage: Key-point selection using genetic algorithms
14 pages, journal
null
10.1080/13682199.2016.1254939
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Coverage of image features play an important role in many vision algorithms since their distribution affect the estimated homography. This paper presents a Genetic Algorithm (GA) in order to select the optimal set of features yielding maximum coverage of the image which is measured by a robust method based on spatial statistics. It is shown with statistical tests on two datasets that the metric yields better coverage and this is also confirmed by an accuracy test on the computed homography for the original set and the newly selected set of features. Results have demonstrated that the new set has similar performance in terms of the accuracy of the computed homography with the original one with an extra benefit of using fewer number of features ultimately reducing the time required for descriptor calculation and matching.
[ { "version": "v1", "created": "Thu, 10 Dec 2015 06:51:28 GMT" } ]
2017-04-21T00:00:00
[ [ "Bostanci", "Erkan", "" ] ]
TITLE: Enhanced image feature coverage: Key-point selection using genetic algorithms ABSTRACT: Coverage of image features play an important role in many vision algorithms since their distribution affect the estimated homography. This paper presents a Genetic Algorithm (GA) in order to select the optimal set of features yielding maximum coverage of the image which is measured by a robust method based on spatial statistics. It is shown with statistical tests on two datasets that the metric yields better coverage and this is also confirmed by an accuracy test on the computed homography for the original set and the newly selected set of features. Results have demonstrated that the new set has similar performance in terms of the accuracy of the computed homography with the original one with an extra benefit of using fewer number of features ultimately reducing the time required for descriptor calculation and matching.
no_new_dataset
0.953837
1610.07448
Simone Scardapane
Simone Scardapane and Paolo Di Lorenzo
A Framework for Parallel and Distributed Training of Neural Networks
Published on Neural Networks (Elsevier), in press
null
10.1016/j.neunet.2017.04.004
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The aim of this paper is to develop a general framework for training neural networks (NNs) in a distributed environment, where training data is partitioned over a set of agents that communicate with each other through a sparse, possibly time-varying, connectivity pattern. In such distributed scenario, the training problem can be formulated as the (regularized) optimization of a non-convex social cost function, given by the sum of local (non-convex) costs, where each agent contributes with a single error term defined with respect to its local dataset. To devise a flexible and efficient solution, we customize a recently proposed framework for non-convex optimization over networks, which hinges on a (primal) convexification-decomposition technique to handle non-convexity, and a dynamic consensus procedure to diffuse information among the agents. Several typical choices for the training criterion (e.g., squared loss, cross entropy, etc.) and regularization (e.g., $\ell_2$ norm, sparsity inducing penalties, etc.) are included in the framework and explored along the paper. Convergence to a stationary solution of the social non-convex problem is guaranteed under mild assumptions. Additionally, we show a principled way allowing each agent to exploit a possible multi-core architecture (e.g., a local cloud) in order to parallelize its local optimization step, resulting in strategies that are both distributed (across the agents) and parallel (inside each agent) in nature. A comprehensive set of experimental results validate the proposed approach.
[ { "version": "v1", "created": "Mon, 24 Oct 2016 14:58:56 GMT" }, { "version": "v2", "created": "Mon, 30 Jan 2017 11:00:58 GMT" }, { "version": "v3", "created": "Thu, 20 Apr 2017 08:55:19 GMT" } ]
2017-04-21T00:00:00
[ [ "Scardapane", "Simone", "" ], [ "Di Lorenzo", "Paolo", "" ] ]
TITLE: A Framework for Parallel and Distributed Training of Neural Networks ABSTRACT: The aim of this paper is to develop a general framework for training neural networks (NNs) in a distributed environment, where training data is partitioned over a set of agents that communicate with each other through a sparse, possibly time-varying, connectivity pattern. In such distributed scenario, the training problem can be formulated as the (regularized) optimization of a non-convex social cost function, given by the sum of local (non-convex) costs, where each agent contributes with a single error term defined with respect to its local dataset. To devise a flexible and efficient solution, we customize a recently proposed framework for non-convex optimization over networks, which hinges on a (primal) convexification-decomposition technique to handle non-convexity, and a dynamic consensus procedure to diffuse information among the agents. Several typical choices for the training criterion (e.g., squared loss, cross entropy, etc.) and regularization (e.g., $\ell_2$ norm, sparsity inducing penalties, etc.) are included in the framework and explored along the paper. Convergence to a stationary solution of the social non-convex problem is guaranteed under mild assumptions. Additionally, we show a principled way allowing each agent to exploit a possible multi-core architecture (e.g., a local cloud) in order to parallelize its local optimization step, resulting in strategies that are both distributed (across the agents) and parallel (inside each agent) in nature. A comprehensive set of experimental results validate the proposed approach.
no_new_dataset
0.943556
1612.03925
Jose Dolz
J. Dolz, C. Desrosiers, I. Ben Ayed
3D fully convolutional networks for subcortical segmentation in MRI: A large-scale study
Accepted in the special issue of Neuroimage: "Brain Segmentation and Parcellation"
null
10.1016/j.neuroimage.2017.04.039
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This study investigates a 3D and fully convolutional neural network (CNN) for subcortical brain structure segmentation in MRI. 3D CNN architectures have been generally avoided due to their computational and memory requirements during inference. We address the problem via small kernels, allowing deeper architectures. We further model both local and global context by embedding intermediate-layer outputs in the final prediction, which encourages consistency between features extracted at different scales and embeds fine-grained information directly in the segmentation process. Our model is efficiently trained end-to-end on a graphics processing unit (GPU), in a single stage, exploiting the dense inference capabilities of fully CNNs. We performed comprehensive experiments over two publicly available datasets. First, we demonstrate a state-of-the-art performance on the ISBR dataset. Then, we report a {\em large-scale} multi-site evaluation over 1112 unregistered subject datasets acquired from 17 different sites (ABIDE dataset), with ages ranging from 7 to 64 years, showing that our method is robust to various acquisition protocols, demographics and clinical factors. Our method yielded segmentations that are highly consistent with a standard atlas-based approach, while running in a fraction of the time needed by atlas-based methods and avoiding registration/normalization steps. This makes it convenient for massive multi-site neuroanatomical imaging studies. To the best of our knowledge, our work is the first to study subcortical structure segmentation on such large-scale and heterogeneous data.
[ { "version": "v1", "created": "Mon, 12 Dec 2016 21:09:06 GMT" }, { "version": "v2", "created": "Thu, 20 Apr 2017 02:03:35 GMT" } ]
2017-04-21T00:00:00
[ [ "Dolz", "J.", "" ], [ "Desrosiers", "C.", "" ], [ "Ayed", "I. Ben", "" ] ]
TITLE: 3D fully convolutional networks for subcortical segmentation in MRI: A large-scale study ABSTRACT: This study investigates a 3D and fully convolutional neural network (CNN) for subcortical brain structure segmentation in MRI. 3D CNN architectures have been generally avoided due to their computational and memory requirements during inference. We address the problem via small kernels, allowing deeper architectures. We further model both local and global context by embedding intermediate-layer outputs in the final prediction, which encourages consistency between features extracted at different scales and embeds fine-grained information directly in the segmentation process. Our model is efficiently trained end-to-end on a graphics processing unit (GPU), in a single stage, exploiting the dense inference capabilities of fully CNNs. We performed comprehensive experiments over two publicly available datasets. First, we demonstrate a state-of-the-art performance on the ISBR dataset. Then, we report a {\em large-scale} multi-site evaluation over 1112 unregistered subject datasets acquired from 17 different sites (ABIDE dataset), with ages ranging from 7 to 64 years, showing that our method is robust to various acquisition protocols, demographics and clinical factors. Our method yielded segmentations that are highly consistent with a standard atlas-based approach, while running in a fraction of the time needed by atlas-based methods and avoiding registration/normalization steps. This makes it convenient for massive multi-site neuroanatomical imaging studies. To the best of our knowledge, our work is the first to study subcortical structure segmentation on such large-scale and heterogeneous data.
no_new_dataset
0.950227
1701.08251
Nasrin Mostafazadeh
Nasrin Mostafazadeh, Chris Brockett, Bill Dolan, Michel Galley, Jianfeng Gao, Georgios P. Spithourakis, Lucy Vanderwende
Image-Grounded Conversations: Multimodal Context for Natural Question and Response Generation
null
null
null
null
cs.CL cs.AI cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The popularity of image sharing on social media and the engagement it creates between users reflects the important role that visual context plays in everyday conversations. We present a novel task, Image-Grounded Conversations (IGC), in which natural-sounding conversations are generated about a shared image. To benchmark progress, we introduce a new multiple-reference dataset of crowd-sourced, event-centric conversations on images. IGC falls on the continuum between chit-chat and goal-directed conversation models, where visual grounding constrains the topic of conversation to event-driven utterances. Experiments with models trained on social media data show that the combination of visual and textual context enhances the quality of generated conversational turns. In human evaluation, the gap between human performance and that of both neural and retrieval architectures suggests that multi-modal IGC presents an interesting challenge for dialogue research.
[ { "version": "v1", "created": "Sat, 28 Jan 2017 05:06:11 GMT" }, { "version": "v2", "created": "Thu, 20 Apr 2017 00:36:35 GMT" } ]
2017-04-21T00:00:00
[ [ "Mostafazadeh", "Nasrin", "" ], [ "Brockett", "Chris", "" ], [ "Dolan", "Bill", "" ], [ "Galley", "Michel", "" ], [ "Gao", "Jianfeng", "" ], [ "Spithourakis", "Georgios P.", "" ], [ "Vanderwende", "Lucy", "" ] ]
TITLE: Image-Grounded Conversations: Multimodal Context for Natural Question and Response Generation ABSTRACT: The popularity of image sharing on social media and the engagement it creates between users reflects the important role that visual context plays in everyday conversations. We present a novel task, Image-Grounded Conversations (IGC), in which natural-sounding conversations are generated about a shared image. To benchmark progress, we introduce a new multiple-reference dataset of crowd-sourced, event-centric conversations on images. IGC falls on the continuum between chit-chat and goal-directed conversation models, where visual grounding constrains the topic of conversation to event-driven utterances. Experiments with models trained on social media data show that the combination of visual and textual context enhances the quality of generated conversational turns. In human evaluation, the gap between human performance and that of both neural and retrieval architectures suggests that multi-modal IGC presents an interesting challenge for dialogue research.
new_dataset
0.959573
1704.02259
Mireya Paredes Ms.
Mireya Paredes, Graham Riley and Mikel Lujan
Vectorization of Hybrid Breadth First Search on the Intel Xeon Phi
9 pages
null
null
null
cs.DC
http://creativecommons.org/licenses/by/4.0/
The Breadth-First Search (BFS) algorithm is an important building block for graph analysis of large datasets. The BFS parallelisation has been shown to be challenging because of its inherent characteristics, including irregular memory access patterns, data dependencies and workload imbalance, that limit its scalability. We investigate the optimisation and vectorisation of the hybrid BFS (a combination of top-down and bottom-up approaches for BFS) on the Xeon Phi, which has advanced vector processing capabilities. The results show that our new implementation improves by 33\%, for a one million vertices graph, compared to the state-of-the-art.
[ { "version": "v1", "created": "Fri, 7 Apr 2017 15:12:05 GMT" }, { "version": "v2", "created": "Thu, 20 Apr 2017 03:59:33 GMT" } ]
2017-04-21T00:00:00
[ [ "Paredes", "Mireya", "" ], [ "Riley", "Graham", "" ], [ "Lujan", "Mikel", "" ] ]
TITLE: Vectorization of Hybrid Breadth First Search on the Intel Xeon Phi ABSTRACT: The Breadth-First Search (BFS) algorithm is an important building block for graph analysis of large datasets. The BFS parallelisation has been shown to be challenging because of its inherent characteristics, including irregular memory access patterns, data dependencies and workload imbalance, that limit its scalability. We investigate the optimisation and vectorisation of the hybrid BFS (a combination of top-down and bottom-up approaches for BFS) on the Xeon Phi, which has advanced vector processing capabilities. The results show that our new implementation improves by 33\%, for a one million vertices graph, compared to the state-of-the-art.
no_new_dataset
0.948442
1704.05420
Cem Subakan
Y. Cem Subakan, Paris Smaragdis
Diagonal RNNs in Symbolic Music Modeling
Submitted to Waspaa 2017
null
null
null
cs.NE cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose a new Recurrent Neural Network (RNN) architecture. The novelty is simple: We use diagonal recurrent matrices instead of full. This results in better test likelihood and faster convergence compared to regular full RNNs in most of our experiments. We show the benefits of using diagonal recurrent matrices with popularly used LSTM and GRU architectures as well as with the vanilla RNN architecture, on four standard symbolic music datasets.
[ { "version": "v1", "created": "Tue, 18 Apr 2017 16:47:38 GMT" }, { "version": "v2", "created": "Wed, 19 Apr 2017 23:36:18 GMT" } ]
2017-04-21T00:00:00
[ [ "Subakan", "Y. Cem", "" ], [ "Smaragdis", "Paris", "" ] ]
TITLE: Diagonal RNNs in Symbolic Music Modeling ABSTRACT: In this paper, we propose a new Recurrent Neural Network (RNN) architecture. The novelty is simple: We use diagonal recurrent matrices instead of full. This results in better test likelihood and faster convergence compared to regular full RNNs in most of our experiments. We show the benefits of using diagonal recurrent matrices with popularly used LSTM and GRU architectures as well as with the vanilla RNN architecture, on four standard symbolic music datasets.
no_new_dataset
0.952926
1704.05860
Junye Wang
Mihal Miu, Xiaokun Zhang, M. Ali Akber Dewan, Junye Wang
Aggregation and visualization of spatial data with application to classification of land use and land cover
null
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Aggregation and visualization of geographical data are an important part of environmental data mining, environmental modelling, and agricultural management. However, it is difficult to aggregate geospatial data of the various formats, such as maps, census and survey data. This paper presents a framework named PlaniSphere, which can aggregate the various geospatial datasets, and synthesizes raw data. We developed an algorithm in PlaniSphere to aggregate remote sensing images with census data for classification and visualization of land use and land cover (LULC). The results show that the framework is able to classify geospatial data sets of LULC from multiple formats. National census data sets can be used for calibration of remote sensing LULC classifications. This provides a new approach for the classification of remote sensing data. This approach proposed in this paper should be useful for LULC classification in environmental spatial analysis.
[ { "version": "v1", "created": "Wed, 19 Apr 2017 18:01:29 GMT" } ]
2017-04-21T00:00:00
[ [ "Miu", "Mihal", "" ], [ "Zhang", "Xiaokun", "" ], [ "Dewan", "M. Ali Akber", "" ], [ "Wang", "Junye", "" ] ]
TITLE: Aggregation and visualization of spatial data with application to classification of land use and land cover ABSTRACT: Aggregation and visualization of geographical data are an important part of environmental data mining, environmental modelling, and agricultural management. However, it is difficult to aggregate geospatial data of the various formats, such as maps, census and survey data. This paper presents a framework named PlaniSphere, which can aggregate the various geospatial datasets, and synthesizes raw data. We developed an algorithm in PlaniSphere to aggregate remote sensing images with census data for classification and visualization of land use and land cover (LULC). The results show that the framework is able to classify geospatial data sets of LULC from multiple formats. National census data sets can be used for calibration of remote sensing LULC classifications. This provides a new approach for the classification of remote sensing data. This approach proposed in this paper should be useful for LULC classification in environmental spatial analysis.
no_new_dataset
0.949763
1704.05921
Dat Tran
Dat Tran and Christof Teuscher
Memcapacitive Devices in Logic and Crossbar Applications
null
null
null
null
cs.ET
http://creativecommons.org/publicdomain/zero/1.0/
Over the last decade, memristive devices have been widely adopted in computing for various conventional and unconventional applications. While the integration density, memory property, and nonlinear characteristics have many benefits, reducing the energy consumption is limited by the resistive nature of the devices. Memcapacitors would address that limitation while still having all the benefits of memristors. Recent work has shown that with adjusted parameters during the fabrication process, a metal-oxide device can indeed exhibit a memcapacitive behavior. We introduce novel memcapacitive logic gates and memcapacitive crossbar classifiers as a proof of concept that such applications can outperform memristor-based architectures. The results illustrate that, compared to memristive logic gates, our memcapacitive gates consume about 7x less power. The memcapacitive crossbar classifier achieves similar classification performance but reduces the power consumption by a factor of about 1,500x for the MNIST dataset and a factor of about 1,000x for the CIFAR-10 dataset compared to a memristive crossbar. Our simulation results demonstrate that memcapacitive devices have great potential for both Boolean logic and analog low-power applications.
[ { "version": "v1", "created": "Wed, 19 Apr 2017 20:13:41 GMT" } ]
2017-04-21T00:00:00
[ [ "Tran", "Dat", "" ], [ "Teuscher", "Christof", "" ] ]
TITLE: Memcapacitive Devices in Logic and Crossbar Applications ABSTRACT: Over the last decade, memristive devices have been widely adopted in computing for various conventional and unconventional applications. While the integration density, memory property, and nonlinear characteristics have many benefits, reducing the energy consumption is limited by the resistive nature of the devices. Memcapacitors would address that limitation while still having all the benefits of memristors. Recent work has shown that with adjusted parameters during the fabrication process, a metal-oxide device can indeed exhibit a memcapacitive behavior. We introduce novel memcapacitive logic gates and memcapacitive crossbar classifiers as a proof of concept that such applications can outperform memristor-based architectures. The results illustrate that, compared to memristive logic gates, our memcapacitive gates consume about 7x less power. The memcapacitive crossbar classifier achieves similar classification performance but reduces the power consumption by a factor of about 1,500x for the MNIST dataset and a factor of about 1,000x for the CIFAR-10 dataset compared to a memristive crossbar. Our simulation results demonstrate that memcapacitive devices have great potential for both Boolean logic and analog low-power applications.
no_new_dataset
0.948775
1704.05939
Karel Lenc
Vassileios Balntas and Karel Lenc and Andrea Vedaldi and Krystian Mikolajczyk
HPatches: A benchmark and evaluation of handcrafted and learned local descriptors
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose a novel benchmark for evaluating local image descriptors. We demonstrate that the existing datasets and evaluation protocols do not specify unambiguously all aspects of evaluation, leading to ambiguities and inconsistencies in results reported in the literature. Furthermore, these datasets are nearly saturated due to the recent improvements in local descriptors obtained by learning them from large annotated datasets. Therefore, we introduce a new large dataset suitable for training and testing modern descriptors, together with strictly defined evaluation protocols in several tasks such as matching, retrieval and classification. This allows for more realistic, and thus more reliable comparisons in different application scenarios. We evaluate the performance of several state-of-the-art descriptors and analyse their properties. We show that a simple normalisation of traditional hand-crafted descriptors can boost their performance to the level of deep learning based descriptors within a realistic benchmarks evaluation.
[ { "version": "v1", "created": "Wed, 19 Apr 2017 21:37:03 GMT" } ]
2017-04-21T00:00:00
[ [ "Balntas", "Vassileios", "" ], [ "Lenc", "Karel", "" ], [ "Vedaldi", "Andrea", "" ], [ "Mikolajczyk", "Krystian", "" ] ]
TITLE: HPatches: A benchmark and evaluation of handcrafted and learned local descriptors ABSTRACT: In this paper, we propose a novel benchmark for evaluating local image descriptors. We demonstrate that the existing datasets and evaluation protocols do not specify unambiguously all aspects of evaluation, leading to ambiguities and inconsistencies in results reported in the literature. Furthermore, these datasets are nearly saturated due to the recent improvements in local descriptors obtained by learning them from large annotated datasets. Therefore, we introduce a new large dataset suitable for training and testing modern descriptors, together with strictly defined evaluation protocols in several tasks such as matching, retrieval and classification. This allows for more realistic, and thus more reliable comparisons in different application scenarios. We evaluate the performance of several state-of-the-art descriptors and analyse their properties. We show that a simple normalisation of traditional hand-crafted descriptors can boost their performance to the level of deep learning based descriptors within a realistic benchmarks evaluation.
new_dataset
0.966789
1704.05963
Daniel R. Jiang
Daniel R. Jiang, Lina Al-Kanj, Warren B. Powell
Monte Carlo Tree Search with Sampled Information Relaxation Dual Bounds
33 pages, 6 figures
null
null
null
math.OC cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Monte Carlo Tree Search (MCTS), most famously used in game-play artificial intelligence (e.g., the game of Go), is a well-known strategy for constructing approximate solutions to sequential decision problems. Its primary innovation is the use of a heuristic, known as a default policy, to obtain Monte Carlo estimates of downstream values for states in a decision tree. This information is used to iteratively expand the tree towards regions of states and actions that an optimal policy might visit. However, to guarantee convergence to the optimal action, MCTS requires the entire tree to be expanded asymptotically. In this paper, we propose a new technique called Primal-Dual MCTS that utilizes sampled information relaxation upper bounds on potential actions, creating the possibility of "ignoring" parts of the tree that stem from highly suboptimal choices. This allows us to prove that despite converging to a partial decision tree in the limit, the recommended action from Primal-Dual MCTS is optimal. The new approach shows significant promise when used to optimize the behavior of a single driver navigating a graph while operating on a ride-sharing platform. Numerical experiments on a real dataset of 7,000 trips in New Jersey suggest that Primal-Dual MCTS improves upon standard MCTS by producing deeper decision trees and exhibits a reduced sensitivity to the size of the action space.
[ { "version": "v1", "created": "Thu, 20 Apr 2017 00:16:01 GMT" } ]
2017-04-21T00:00:00
[ [ "Jiang", "Daniel R.", "" ], [ "Al-Kanj", "Lina", "" ], [ "Powell", "Warren B.", "" ] ]
TITLE: Monte Carlo Tree Search with Sampled Information Relaxation Dual Bounds ABSTRACT: Monte Carlo Tree Search (MCTS), most famously used in game-play artificial intelligence (e.g., the game of Go), is a well-known strategy for constructing approximate solutions to sequential decision problems. Its primary innovation is the use of a heuristic, known as a default policy, to obtain Monte Carlo estimates of downstream values for states in a decision tree. This information is used to iteratively expand the tree towards regions of states and actions that an optimal policy might visit. However, to guarantee convergence to the optimal action, MCTS requires the entire tree to be expanded asymptotically. In this paper, we propose a new technique called Primal-Dual MCTS that utilizes sampled information relaxation upper bounds on potential actions, creating the possibility of "ignoring" parts of the tree that stem from highly suboptimal choices. This allows us to prove that despite converging to a partial decision tree in the limit, the recommended action from Primal-Dual MCTS is optimal. The new approach shows significant promise when used to optimize the behavior of a single driver navigating a graph while operating on a ride-sharing platform. Numerical experiments on a real dataset of 7,000 trips in New Jersey suggest that Primal-Dual MCTS improves upon standard MCTS by producing deeper decision trees and exhibits a reduced sensitivity to the size of the action space.
no_new_dataset
0.946646
1704.05972
Leon Derczynski
Leon Derczynski and Kalina Bontcheva and Maria Liakata and Rob Procter and Geraldine Wong Sak Hoi and Arkaitz Zubiaga
SemEval-2017 Task 8: RumourEval: Determining rumour veracity and support for rumours
null
null
null
null
cs.CL cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Media is full of false claims. Even Oxford Dictionaries named "post-truth" as the word of 2016. This makes it more important than ever to build systems that can identify the veracity of a story, and the kind of discourse there is around it. RumourEval is a SemEval shared task that aims to identify and handle rumours and reactions to them, in text. We present an annotation scheme, a large dataset covering multiple topics - each having their own families of claims and replies - and use these to pose two concrete challenges as well as the results achieved by participants on these challenges.
[ { "version": "v1", "created": "Thu, 20 Apr 2017 01:21:20 GMT" } ]
2017-04-21T00:00:00
[ [ "Derczynski", "Leon", "" ], [ "Bontcheva", "Kalina", "" ], [ "Liakata", "Maria", "" ], [ "Procter", "Rob", "" ], [ "Hoi", "Geraldine Wong Sak", "" ], [ "Zubiaga", "Arkaitz", "" ] ]
TITLE: SemEval-2017 Task 8: RumourEval: Determining rumour veracity and support for rumours ABSTRACT: Media is full of false claims. Even Oxford Dictionaries named "post-truth" as the word of 2016. This makes it more important than ever to build systems that can identify the veracity of a story, and the kind of discourse there is around it. RumourEval is a SemEval shared task that aims to identify and handle rumours and reactions to them, in text. We present an annotation scheme, a large dataset covering multiple topics - each having their own families of claims and replies - and use these to pose two concrete challenges as well as the results achieved by participants on these challenges.
new_dataset
0.95096
1704.05973
Lin Wu
Tong Chen, Lin Wu, Xue Li, Jun Zhang, Hongzhi Yin, Yang Wang
Call Attention to Rumors: Deep Attention Based Recurrent Neural Networks for Early Rumor Detection
9 pages
null
null
null
cs.CL cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The proliferation of social media in communication and information dissemination has made it an ideal platform for spreading rumors. Automatically debunking rumors at their stage of diffusion is known as \textit{early rumor detection}, which refers to dealing with sequential posts regarding disputed factual claims with certain variations and highly textual duplication over time. Thus, identifying trending rumors demands an efficient yet flexible model that is able to capture long-range dependencies among postings and produce distinct representations for the accurate early detection. However, it is a challenging task to apply conventional classification algorithms to rumor detection in earliness since they rely on hand-crafted features which require intensive manual efforts in the case of large amount of posts. This paper presents a deep attention model on the basis of recurrent neural networks (RNN) to learn \textit{selectively} temporal hidden representations of sequential posts for identifying rumors. The proposed model delves soft-attention into the recurrence to simultaneously pool out distinct features with particular focus and produce hidden representations that capture contextual variations of relevant posts over time. Extensive experiments on real datasets collected from social media websites demonstrate that (1) the deep attention based RNN model outperforms state-of-the-arts that rely on hand-crafted features; (2) the introduction of soft attention mechanism can effectively distill relevant parts to rumors from original posts in advance; (3) the proposed method detects rumors more quickly and accurately than competitors.
[ { "version": "v1", "created": "Thu, 20 Apr 2017 01:22:57 GMT" } ]
2017-04-21T00:00:00
[ [ "Chen", "Tong", "" ], [ "Wu", "Lin", "" ], [ "Li", "Xue", "" ], [ "Zhang", "Jun", "" ], [ "Yin", "Hongzhi", "" ], [ "Wang", "Yang", "" ] ]
TITLE: Call Attention to Rumors: Deep Attention Based Recurrent Neural Networks for Early Rumor Detection ABSTRACT: The proliferation of social media in communication and information dissemination has made it an ideal platform for spreading rumors. Automatically debunking rumors at their stage of diffusion is known as \textit{early rumor detection}, which refers to dealing with sequential posts regarding disputed factual claims with certain variations and highly textual duplication over time. Thus, identifying trending rumors demands an efficient yet flexible model that is able to capture long-range dependencies among postings and produce distinct representations for the accurate early detection. However, it is a challenging task to apply conventional classification algorithms to rumor detection in earliness since they rely on hand-crafted features which require intensive manual efforts in the case of large amount of posts. This paper presents a deep attention model on the basis of recurrent neural networks (RNN) to learn \textit{selectively} temporal hidden representations of sequential posts for identifying rumors. The proposed model delves soft-attention into the recurrence to simultaneously pool out distinct features with particular focus and produce hidden representations that capture contextual variations of relevant posts over time. Extensive experiments on real datasets collected from social media websites demonstrate that (1) the deep attention based RNN model outperforms state-of-the-arts that rely on hand-crafted features; (2) the introduction of soft attention mechanism can effectively distill relevant parts to rumors from original posts in advance; (3) the proposed method detects rumors more quickly and accurately than competitors.
no_new_dataset
0.948822
1704.05982
Tao Wu
Tao Wu and David Gleich
Retrospective Higher-Order Markov Processes for User Trails
null
null
null
null
cs.SI cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Users form information trails as they browse the web, checkin with a geolocation, rate items, or consume media. A common problem is to predict what a user might do next for the purposes of guidance, recommendation, or prefetching. First-order and higher-order Markov chains have been widely used methods to study such sequences of data. First-order Markov chains are easy to estimate, but lack accuracy when history matters. Higher-order Markov chains, in contrast, have too many parameters and suffer from overfitting the training data. Fitting these parameters with regularization and smoothing only offers mild improvements. In this paper we propose the retrospective higher-order Markov process (RHOMP) as a low-parameter model for such sequences. This model is a special case of a higher-order Markov chain where the transitions depend retrospectively on a single history state instead of an arbitrary combination of history states. There are two immediate computational advantages: the number of parameters is linear in the order of the Markov chain and the model can be fit to large state spaces. Furthermore, by providing a specific structure to the higher-order chain, RHOMPs improve the model accuracy by efficiently utilizing history states without risks of overfitting the data. We demonstrate how to estimate a RHOMP from data and we demonstrate the effectiveness of our method on various real application datasets spanning geolocation data, review sequences, and business locations. The RHOMP model uniformly outperforms higher-order Markov chains, Kneser-Ney regularization, and tensor factorizations in terms of prediction accuracy.
[ { "version": "v1", "created": "Thu, 20 Apr 2017 02:14:17 GMT" } ]
2017-04-21T00:00:00
[ [ "Wu", "Tao", "" ], [ "Gleich", "David", "" ] ]
TITLE: Retrospective Higher-Order Markov Processes for User Trails ABSTRACT: Users form information trails as they browse the web, checkin with a geolocation, rate items, or consume media. A common problem is to predict what a user might do next for the purposes of guidance, recommendation, or prefetching. First-order and higher-order Markov chains have been widely used methods to study such sequences of data. First-order Markov chains are easy to estimate, but lack accuracy when history matters. Higher-order Markov chains, in contrast, have too many parameters and suffer from overfitting the training data. Fitting these parameters with regularization and smoothing only offers mild improvements. In this paper we propose the retrospective higher-order Markov process (RHOMP) as a low-parameter model for such sequences. This model is a special case of a higher-order Markov chain where the transitions depend retrospectively on a single history state instead of an arbitrary combination of history states. There are two immediate computational advantages: the number of parameters is linear in the order of the Markov chain and the model can be fit to large state spaces. Furthermore, by providing a specific structure to the higher-order chain, RHOMPs improve the model accuracy by efficiently utilizing history states without risks of overfitting the data. We demonstrate how to estimate a RHOMP from data and we demonstrate the effectiveness of our method on various real application datasets spanning geolocation data, review sequences, and business locations. The RHOMP model uniformly outperforms higher-order Markov chains, Kneser-Ney regularization, and tensor factorizations in terms of prediction accuracy.
no_new_dataset
0.951953
1704.06033
Hongyoon Choi Dr
Hongyoon Choi, Kyong Hwan Jin
Predicting Cognitive Decline with Deep Learning of Brain Metabolism and Amyloid Imaging
24 pages
null
null
null
cs.CV cs.AI stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For effective treatment of Alzheimer disease (AD), it is important to identify subjects who are most likely to exhibit rapid cognitive decline. Herein, we developed a novel framework based on a deep convolutional neural network which can predict future cognitive decline in mild cognitive impairment (MCI) patients using flurodeoxyglucose and florbetapir positron emission tomography (PET). The architecture of the network only relies on baseline PET studies of AD and normal subjects as the training dataset. Feature extraction and complicated image preprocessing including nonlinear warping are unnecessary for our approach. Accuracy of prediction (84.2%) for conversion to AD in MCI patients outperformed conventional feature-based quantification approaches. ROC analyses revealed that performance of CNN-based approach was significantly higher than that of the conventional quantification methods (p < 0.05). Output scores of the network were strongly correlated with the longitudinal change in cognitive measurements. These results show the feasibility of deep learning as a tool for predicting disease outcome using brain images.
[ { "version": "v1", "created": "Thu, 20 Apr 2017 07:33:18 GMT" } ]
2017-04-21T00:00:00
[ [ "Choi", "Hongyoon", "" ], [ "Jin", "Kyong Hwan", "" ] ]
TITLE: Predicting Cognitive Decline with Deep Learning of Brain Metabolism and Amyloid Imaging ABSTRACT: For effective treatment of Alzheimer disease (AD), it is important to identify subjects who are most likely to exhibit rapid cognitive decline. Herein, we developed a novel framework based on a deep convolutional neural network which can predict future cognitive decline in mild cognitive impairment (MCI) patients using flurodeoxyglucose and florbetapir positron emission tomography (PET). The architecture of the network only relies on baseline PET studies of AD and normal subjects as the training dataset. Feature extraction and complicated image preprocessing including nonlinear warping are unnecessary for our approach. Accuracy of prediction (84.2%) for conversion to AD in MCI patients outperformed conventional feature-based quantification approaches. ROC analyses revealed that performance of CNN-based approach was significantly higher than that of the conventional quantification methods (p < 0.05). Output scores of the network were strongly correlated with the longitudinal change in cognitive measurements. These results show the feasibility of deep learning as a tool for predicting disease outcome using brain images.
no_new_dataset
0.945399
1704.06062
Yehezkel Resheff
Yehezkel S. Resheff, Amit Mandelbaum, Daphna Weinshall
Every Untrue Label is Untrue in its Own Way: Controlling Error Type with the Log Bilinear Loss
null
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep learning has become the method of choice in many application domains of machine learning in recent years, especially for multi-class classification tasks. The most common loss function used in this context is the cross-entropy loss, which reduces to the log loss in the typical case when there is a single correct response label. While this loss is insensitive to the identity of the assigned class in the case of misclassification, in practice it is often the case that some errors may be more detrimental than others. Here we present the bilinear-loss (and related log-bilinear-loss) which differentially penalizes the different wrong assignments of the model. We thoroughly test this method using standard models and benchmark image datasets. As one application, we show the ability of this method to better contain error within the correct super-class, in the hierarchically labeled CIFAR100 dataset, without affecting the overall performance of the classifier.
[ { "version": "v1", "created": "Thu, 20 Apr 2017 09:29:09 GMT" } ]
2017-04-21T00:00:00
[ [ "Resheff", "Yehezkel S.", "" ], [ "Mandelbaum", "Amit", "" ], [ "Weinshall", "Daphna", "" ] ]
TITLE: Every Untrue Label is Untrue in its Own Way: Controlling Error Type with the Log Bilinear Loss ABSTRACT: Deep learning has become the method of choice in many application domains of machine learning in recent years, especially for multi-class classification tasks. The most common loss function used in this context is the cross-entropy loss, which reduces to the log loss in the typical case when there is a single correct response label. While this loss is insensitive to the identity of the assigned class in the case of misclassification, in practice it is often the case that some errors may be more detrimental than others. Here we present the bilinear-loss (and related log-bilinear-loss) which differentially penalizes the different wrong assignments of the model. We thoroughly test this method using standard models and benchmark image datasets. As one application, we show the ability of this method to better contain error within the correct super-class, in the hierarchically labeled CIFAR100 dataset, without affecting the overall performance of the classifier.
no_new_dataset
0.945349
1704.06125
Mathieu Cliche
Mathieu Cliche
BB_twtr at SemEval-2017 Task 4: Twitter Sentiment Analysis with CNNs and LSTMs
Published in Proceedings of SemEval-2017, 8 pages
null
null
null
cs.CL stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we describe our attempt at producing a state-of-the-art Twitter sentiment classifier using Convolutional Neural Networks (CNNs) and Long Short Term Memory (LSTMs) networks. Our system leverages a large amount of unlabeled data to pre-train word embeddings. We then use a subset of the unlabeled data to fine tune the embeddings using distant supervision. The final CNNs and LSTMs are trained on the SemEval-2017 Twitter dataset where the embeddings are fined tuned again. To boost performances we ensemble several CNNs and LSTMs together. Our approach achieved first rank on all of the five English subtasks amongst 40 teams.
[ { "version": "v1", "created": "Thu, 20 Apr 2017 13:10:25 GMT" } ]
2017-04-21T00:00:00
[ [ "Cliche", "Mathieu", "" ] ]
TITLE: BB_twtr at SemEval-2017 Task 4: Twitter Sentiment Analysis with CNNs and LSTMs ABSTRACT: In this paper we describe our attempt at producing a state-of-the-art Twitter sentiment classifier using Convolutional Neural Networks (CNNs) and Long Short Term Memory (LSTMs) networks. Our system leverages a large amount of unlabeled data to pre-train word embeddings. We then use a subset of the unlabeled data to fine tune the embeddings using distant supervision. The final CNNs and LSTMs are trained on the SemEval-2017 Twitter dataset where the embeddings are fined tuned again. To boost performances we ensemble several CNNs and LSTMs together. Our approach achieved first rank on all of the five English subtasks amongst 40 teams.
no_new_dataset
0.953708
1704.06254
Shubham Tulsiani
Shubham Tulsiani, Tinghui Zhou, Alexei A. Efros, Jitendra Malik
Multi-view Supervision for Single-view Reconstruction via Differentiable Ray Consistency
To appear at CVPR 2017. Project webpage : https://shubhtuls.github.io/drc/
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the notion of consistency between a 3D shape and a 2D observation and propose a differentiable formulation which allows computing gradients of the 3D shape given an observation from an arbitrary view. We do so by reformulating view consistency using a differentiable ray consistency (DRC) term. We show that this formulation can be incorporated in a learning framework to leverage different types of multi-view observations e.g. foreground masks, depth, color images, semantics etc. as supervision for learning single-view 3D prediction. We present empirical analysis of our technique in a controlled setting. We also show that this approach allows us to improve over existing techniques for single-view reconstruction of objects from the PASCAL VOC dataset.
[ { "version": "v1", "created": "Thu, 20 Apr 2017 17:56:53 GMT" } ]
2017-04-21T00:00:00
[ [ "Tulsiani", "Shubham", "" ], [ "Zhou", "Tinghui", "" ], [ "Efros", "Alexei A.", "" ], [ "Malik", "Jitendra", "" ] ]
TITLE: Multi-view Supervision for Single-view Reconstruction via Differentiable Ray Consistency ABSTRACT: We study the notion of consistency between a 3D shape and a 2D observation and propose a differentiable formulation which allows computing gradients of the 3D shape given an observation from an arbitrary view. We do so by reformulating view consistency using a differentiable ray consistency (DRC) term. We show that this formulation can be incorporated in a learning framework to leverage different types of multi-view observations e.g. foreground masks, depth, color images, semantics etc. as supervision for learning single-view 3D prediction. We present empirical analysis of our technique in a controlled setting. We also show that this approach allows us to improve over existing techniques for single-view reconstruction of objects from the PASCAL VOC dataset.
no_new_dataset
0.949529
1504.05773
Kitty Meeks
Jessica Enright and Kitty Meeks
Deleting edges to restrict the size of an epidemic
Author final version of article to appear in Algorithmica (funding details updated from previous version)
null
null
null
cs.DS math.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by applications in network epidemiology, we consider the problem of determining whether it is possible to delete at most $k$ edges from a given input graph (of small treewidth) so that the resulting graph avoids a set $\mathcal{F}$ of forbidden subgraphs; of particular interest is the problem of determining whether it is possible to delete at most $k$ edges so that the resulting graph has no connected component of more than $h$ vertices, as this bounds the worst-case size of an epidemic. While even this special case of the problem is NP-complete in general (even when $h=3$), we provide evidence that many of the real-world networks of interest are likely to have small treewidth, and we describe an algorithm which solves the general problem in time \genruntime ~on an input graph having $n$ vertices and whose treewidth is bounded by a fixed constant $w$, if each of the subgraphs we wish to avoid has at most $r$ vertices. For the special case in which we wish only to ensure that no component has more than $h$ vertices, we improve on this to give an algorithm running in time $O((wh)^{2w}n)$, which we have implemented and tested on real datasets based on cattle movements.
[ { "version": "v1", "created": "Wed, 22 Apr 2015 12:58:59 GMT" }, { "version": "v2", "created": "Fri, 17 Jul 2015 11:26:21 GMT" }, { "version": "v3", "created": "Tue, 10 May 2016 16:17:49 GMT" }, { "version": "v4", "created": "Wed, 12 Apr 2017 12:45:24 GMT" }, { "version": "v5", "created": "Wed, 19 Apr 2017 09:30:38 GMT" } ]
2017-04-20T00:00:00
[ [ "Enright", "Jessica", "" ], [ "Meeks", "Kitty", "" ] ]
TITLE: Deleting edges to restrict the size of an epidemic ABSTRACT: Motivated by applications in network epidemiology, we consider the problem of determining whether it is possible to delete at most $k$ edges from a given input graph (of small treewidth) so that the resulting graph avoids a set $\mathcal{F}$ of forbidden subgraphs; of particular interest is the problem of determining whether it is possible to delete at most $k$ edges so that the resulting graph has no connected component of more than $h$ vertices, as this bounds the worst-case size of an epidemic. While even this special case of the problem is NP-complete in general (even when $h=3$), we provide evidence that many of the real-world networks of interest are likely to have small treewidth, and we describe an algorithm which solves the general problem in time \genruntime ~on an input graph having $n$ vertices and whose treewidth is bounded by a fixed constant $w$, if each of the subgraphs we wish to avoid has at most $r$ vertices. For the special case in which we wish only to ensure that no component has more than $h$ vertices, we improve on this to give an algorithm running in time $O((wh)^{2w}n)$, which we have implemented and tested on real datasets based on cattle movements.
no_new_dataset
0.946448
1608.07433
Hossein Ziaei Nafchi
Hossein Ziaei Nafchi, Atena Shahkolaei, Rachid Hedjam, Mohamed Cheriet
Mean Deviation Similarity Index: Efficient and Reliable Full-Reference Image Quality Evaluator
11 pages, 8 figures, 6 tables
null
10.1109/ACCESS.2016.2604042
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Applications of perceptual image quality assessment (IQA) in image and video processing, such as image acquisition, image compression, image restoration and multimedia communication, have led to the development of many IQA metrics. In this paper, a reliable full reference IQA model is proposed that utilize gradient similarity (GS), chromaticity similarity (CS), and deviation pooling (DP). By considering the shortcomings of the commonly used GS to model human visual system (HVS), a new GS is proposed through a fusion technique that is more likely to follow HVS. We propose an efficient and effective formulation to calculate the joint similarity map of two chromatic channels for the purpose of measuring color changes. In comparison with a commonly used formulation in the literature, the proposed CS map is shown to be more efficient and provide comparable or better quality predictions. Motivated by a recent work that utilizes the standard deviation pooling, a general formulation of the DP is presented in this paper and used to compute a final score from the proposed GS and CS maps. This proposed formulation of DP benefits from the Minkowski pooling and a proposed power pooling as well. The experimental results on six datasets of natural images, a synthetic dataset, and a digitally retouched dataset show that the proposed index provides comparable or better quality predictions than the most recent and competing state-of-the-art IQA metrics in the literature, it is reliable and has low complexity. The MATLAB source code of the proposed metric is available at https://www.mathworks.com/matlabcentral/fileexchange/59809.
[ { "version": "v1", "created": "Fri, 26 Aug 2016 12:16:09 GMT" }, { "version": "v2", "created": "Mon, 29 Aug 2016 12:10:59 GMT" }, { "version": "v3", "created": "Fri, 16 Sep 2016 08:17:07 GMT" }, { "version": "v4", "created": "Wed, 19 Apr 2017 05:41:11 GMT" } ]
2017-04-20T00:00:00
[ [ "Nafchi", "Hossein Ziaei", "" ], [ "Shahkolaei", "Atena", "" ], [ "Hedjam", "Rachid", "" ], [ "Cheriet", "Mohamed", "" ] ]
TITLE: Mean Deviation Similarity Index: Efficient and Reliable Full-Reference Image Quality Evaluator ABSTRACT: Applications of perceptual image quality assessment (IQA) in image and video processing, such as image acquisition, image compression, image restoration and multimedia communication, have led to the development of many IQA metrics. In this paper, a reliable full reference IQA model is proposed that utilize gradient similarity (GS), chromaticity similarity (CS), and deviation pooling (DP). By considering the shortcomings of the commonly used GS to model human visual system (HVS), a new GS is proposed through a fusion technique that is more likely to follow HVS. We propose an efficient and effective formulation to calculate the joint similarity map of two chromatic channels for the purpose of measuring color changes. In comparison with a commonly used formulation in the literature, the proposed CS map is shown to be more efficient and provide comparable or better quality predictions. Motivated by a recent work that utilizes the standard deviation pooling, a general formulation of the DP is presented in this paper and used to compute a final score from the proposed GS and CS maps. This proposed formulation of DP benefits from the Minkowski pooling and a proposed power pooling as well. The experimental results on six datasets of natural images, a synthetic dataset, and a digitally retouched dataset show that the proposed index provides comparable or better quality predictions than the most recent and competing state-of-the-art IQA metrics in the literature, it is reliable and has low complexity. The MATLAB source code of the proposed metric is available at https://www.mathworks.com/matlabcentral/fileexchange/59809.
no_new_dataset
0.948442
1609.08913
George Monta\~nez
George D. Montanez
The Famine of Forte: Few Search Problems Greatly Favor Your Algorithm
null
null
null
null
stat.ML cs.IT cs.LG math.IT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Casting machine learning as a type of search, we demonstrate that the proportion of problems that are favorable for a fixed algorithm is strictly bounded, such that no single algorithm can perform well over a large fraction of them. Our results explain why we must either continue to develop new learning methods year after year or move towards highly parameterized models that are both flexible and sensitive to their hyperparameters. We further give an upper bound on the expected performance for a search algorithm as a function of the mutual information between the target and the information resource (e.g., training dataset), proving the importance of certain types of dependence for machine learning. Lastly, we show that the expected per-query probability of success for an algorithm is mathematically equivalent to a single-query probability of success under a distribution (called a search strategy), and prove that the proportion of favorable strategies is also strictly bounded. Thus, whether one holds fixed the search algorithm and considers all possible problems or one fixes the search problem and looks at all possible search strategies, favorable matches are exceedingly rare. The forte (strength) of any algorithm is quantifiably restricted.
[ { "version": "v1", "created": "Wed, 28 Sep 2016 13:52:17 GMT" }, { "version": "v2", "created": "Wed, 19 Apr 2017 14:21:53 GMT" } ]
2017-04-20T00:00:00
[ [ "Montanez", "George D.", "" ] ]
TITLE: The Famine of Forte: Few Search Problems Greatly Favor Your Algorithm ABSTRACT: Casting machine learning as a type of search, we demonstrate that the proportion of problems that are favorable for a fixed algorithm is strictly bounded, such that no single algorithm can perform well over a large fraction of them. Our results explain why we must either continue to develop new learning methods year after year or move towards highly parameterized models that are both flexible and sensitive to their hyperparameters. We further give an upper bound on the expected performance for a search algorithm as a function of the mutual information between the target and the information resource (e.g., training dataset), proving the importance of certain types of dependence for machine learning. Lastly, we show that the expected per-query probability of success for an algorithm is mathematically equivalent to a single-query probability of success under a distribution (called a search strategy), and prove that the proportion of favorable strategies is also strictly bounded. Thus, whether one holds fixed the search algorithm and considers all possible problems or one fixes the search problem and looks at all possible search strategies, favorable matches are exceedingly rare. The forte (strength) of any algorithm is quantifiably restricted.
no_new_dataset
0.946794
1703.04454
Chao Zhang
Chao Zhang, Sergi Pujades, Michael Black, and Gerard Pons-Moll
Detailed, accurate, human shape estimation from clothed 3D scan sequences
CVPR 2017, camera ready
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address the problem of estimating human pose and body shape from 3D scans over time. Reliable estimation of 3D body shape is necessary for many applications including virtual try-on, health monitoring, and avatar creation for virtual reality. Scanning bodies in minimal clothing, however, presents a practical barrier to these applications. We address this problem by estimating body shape under clothing from a sequence of 3D scans. Previous methods that have exploited body models produce smooth shapes lacking personalized details. We contribute a new approach to recover a personalized shape of the person. The estimated shape deviates from a parametric model to fit the 3D scans. We demonstrate the method using high quality 4D data as well as sequences of visual hulls extracted from multi-view images. We also make available BUFF, a new 4D dataset that enables quantitative evaluation (http://buff.is.tue.mpg.de). Our method outperforms the state of the art in both pose estimation and shape estimation, qualitatively and quantitatively.
[ { "version": "v1", "created": "Mon, 13 Mar 2017 15:41:36 GMT" }, { "version": "v2", "created": "Wed, 19 Apr 2017 12:26:27 GMT" } ]
2017-04-20T00:00:00
[ [ "Zhang", "Chao", "" ], [ "Pujades", "Sergi", "" ], [ "Black", "Michael", "" ], [ "Pons-Moll", "Gerard", "" ] ]
TITLE: Detailed, accurate, human shape estimation from clothed 3D scan sequences ABSTRACT: We address the problem of estimating human pose and body shape from 3D scans over time. Reliable estimation of 3D body shape is necessary for many applications including virtual try-on, health monitoring, and avatar creation for virtual reality. Scanning bodies in minimal clothing, however, presents a practical barrier to these applications. We address this problem by estimating body shape under clothing from a sequence of 3D scans. Previous methods that have exploited body models produce smooth shapes lacking personalized details. We contribute a new approach to recover a personalized shape of the person. The estimated shape deviates from a parametric model to fit the 3D scans. We demonstrate the method using high quality 4D data as well as sequences of visual hulls extracted from multi-view images. We also make available BUFF, a new 4D dataset that enables quantitative evaluation (http://buff.is.tue.mpg.de). Our method outperforms the state of the art in both pose estimation and shape estimation, qualitatively and quantitatively.
new_dataset
0.958304
1704.05548
Lluis Castrejon
Lluis Castrejon, Kaustav Kundu, Raquel Urtasun, Sanja Fidler
Annotating Object Instances with a Polygon-RNN
null
CVPR 2017
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an approach for semi-automatic annotation of object instances. While most current methods treat object segmentation as a pixel-labeling problem, we here cast it as a polygon prediction task, mimicking how most current datasets have been annotated. In particular, our approach takes as input an image crop and sequentially produces vertices of the polygon outlining the object. This allows a human annotator to interfere at any time and correct a vertex if needed, producing as accurate segmentation as desired by the annotator. We show that our approach speeds up the annotation process by a factor of 4.7 across all classes in Cityscapes, while achieving 78.4% agreement in IoU with original ground-truth, matching the typical agreement between human annotators. For cars, our speed-up factor is 7.3 for an agreement of 82.2%. We further show generalization capabilities of our approach to unseen datasets.
[ { "version": "v1", "created": "Tue, 18 Apr 2017 22:17:28 GMT" } ]
2017-04-20T00:00:00
[ [ "Castrejon", "Lluis", "" ], [ "Kundu", "Kaustav", "" ], [ "Urtasun", "Raquel", "" ], [ "Fidler", "Sanja", "" ] ]
TITLE: Annotating Object Instances with a Polygon-RNN ABSTRACT: We propose an approach for semi-automatic annotation of object instances. While most current methods treat object segmentation as a pixel-labeling problem, we here cast it as a polygon prediction task, mimicking how most current datasets have been annotated. In particular, our approach takes as input an image crop and sequentially produces vertices of the polygon outlining the object. This allows a human annotator to interfere at any time and correct a vertex if needed, producing as accurate segmentation as desired by the annotator. We show that our approach speeds up the annotation process by a factor of 4.7 across all classes in Cityscapes, while achieving 78.4% agreement in IoU with original ground-truth, matching the typical agreement between human annotators. For cars, our speed-up factor is 7.3 for an agreement of 82.2%. We further show generalization capabilities of our approach to unseen datasets.
no_new_dataset
0.953319
1704.05566
Jeremy Morton
Jeremy Morton and Mykel J. Kochenderfer
Simultaneous Policy Learning and Latent State Inference for Imitating Driver Behavior
7 pages, 6 figures, 2 tables
null
null
null
cs.LG cs.AI stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we propose a method for learning driver models that account for variables that cannot be observed directly. When trained on a synthetic dataset, our models are able to learn encodings for vehicle trajectories that distinguish between four distinct classes of driver behavior. Such encodings are learned without any knowledge of the number of driver classes or any objective that directly requires the models to learn encodings for each class. We show that driving policies trained with knowledge of latent variables are more effective than baseline methods at imitating the driver behavior that they are trained to replicate. Furthermore, we demonstrate that the actions chosen by our policy are heavily influenced by the latent variable settings that are provided to them.
[ { "version": "v1", "created": "Wed, 19 Apr 2017 00:23:59 GMT" } ]
2017-04-20T00:00:00
[ [ "Morton", "Jeremy", "" ], [ "Kochenderfer", "Mykel J.", "" ] ]
TITLE: Simultaneous Policy Learning and Latent State Inference for Imitating Driver Behavior ABSTRACT: In this work, we propose a method for learning driver models that account for variables that cannot be observed directly. When trained on a synthetic dataset, our models are able to learn encodings for vehicle trajectories that distinguish between four distinct classes of driver behavior. Such encodings are learned without any knowledge of the number of driver classes or any objective that directly requires the models to learn encodings for each class. We show that driving policies trained with knowledge of latent variables are more effective than baseline methods at imitating the driver behavior that they are trained to replicate. Furthermore, we demonstrate that the actions chosen by our policy are heavily influenced by the latent variable settings that are provided to them.
no_new_dataset
0.944893
1704.05617
Chun-Nan Hsu
Sanjeev Shenoy, Tsung-Ting Kuo, Rodney Gabriel, Julian McAuley and Chun-Nan Hsu
Deduplication in a massive clinical note dataset
Extended from the Master project report of Sanjeev Shenoy, Department of Computer Science and Engineering, University of California, San Diego. June 2016
null
null
null
cs.DB cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Duplication, whether exact or partial, is a common issue in many datasets. In clinical notes data, duplication (and near duplication) can arise for many reasons, such as the pervasive use of templates, copy-pasting, or notes being generated by automated procedures. A key challenge in removing such near duplicates is the size of such datasets; our own dataset consists of more than 10 million notes. To detect and correct such duplicates requires algorithms that both accurate and highly scalable. We describe a solution based on Minhashing with Locality Sensitive Hashing. In this paper, we present the theory behind this method and present a database-inspired approach to make the method scalable. We also present a clustering technique using disjoint sets to produce dense clusters, which speeds up our algorithm.
[ { "version": "v1", "created": "Wed, 19 Apr 2017 05:33:21 GMT" } ]
2017-04-20T00:00:00
[ [ "Shenoy", "Sanjeev", "" ], [ "Kuo", "Tsung-Ting", "" ], [ "Gabriel", "Rodney", "" ], [ "McAuley", "Julian", "" ], [ "Hsu", "Chun-Nan", "" ] ]
TITLE: Deduplication in a massive clinical note dataset ABSTRACT: Duplication, whether exact or partial, is a common issue in many datasets. In clinical notes data, duplication (and near duplication) can arise for many reasons, such as the pervasive use of templates, copy-pasting, or notes being generated by automated procedures. A key challenge in removing such near duplicates is the size of such datasets; our own dataset consists of more than 10 million notes. To detect and correct such duplicates requires algorithms that both accurate and highly scalable. We describe a solution based on Minhashing with Locality Sensitive Hashing. In this paper, we present the theory behind this method and present a database-inspired approach to make the method scalable. We also present a clustering technique using disjoint sets to produce dense clusters, which speeds up our algorithm.
no_new_dataset
0.721792
1704.05643
Bo Li
Bo Li, Huahui Chen, Yucheng Chen, Yuchao Dai, Mingyi He
Skeleton Boxes: Solving skeleton based action detection with a single deep convolutional neural network
4 pages,3 figures, icmew 2017
icmew 2017
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Action recognition from well-segmented 3D skeleton video has been intensively studied. However, due to the difficulty in representing the 3D skeleton video and the lack of training data, action detection from streaming 3D skeleton video still lags far behind its recognition counterpart and image based object detection. In this paper, we propose a novel approach for this problem, which leverages both effective skeleton video encoding and deep regression based object detection from images. Our framework consists of two parts: skeleton-based video image mapping, which encodes a skeleton video to a color image in a temporal preserving way, and an end-to-end trainable fast skeleton action detector (Skeleton Boxes) based on image detection. Experimental results on the latest and largest PKU-MMD benchmark dataset demonstrate that our method outperforms the state-of-the-art methods with a large margin. We believe our idea would inspire and benefit future research in this important area.
[ { "version": "v1", "created": "Wed, 19 Apr 2017 08:16:13 GMT" } ]
2017-04-20T00:00:00
[ [ "Li", "Bo", "" ], [ "Chen", "Huahui", "" ], [ "Chen", "Yucheng", "" ], [ "Dai", "Yuchao", "" ], [ "He", "Mingyi", "" ] ]
TITLE: Skeleton Boxes: Solving skeleton based action detection with a single deep convolutional neural network ABSTRACT: Action recognition from well-segmented 3D skeleton video has been intensively studied. However, due to the difficulty in representing the 3D skeleton video and the lack of training data, action detection from streaming 3D skeleton video still lags far behind its recognition counterpart and image based object detection. In this paper, we propose a novel approach for this problem, which leverages both effective skeleton video encoding and deep regression based object detection from images. Our framework consists of two parts: skeleton-based video image mapping, which encodes a skeleton video to a color image in a temporal preserving way, and an end-to-end trainable fast skeleton action detector (Skeleton Boxes) based on image detection. Experimental results on the latest and largest PKU-MMD benchmark dataset demonstrate that our method outperforms the state-of-the-art methods with a large margin. We believe our idea would inspire and benefit future research in this important area.
no_new_dataset
0.949763
1704.05646
Lech Szymanski
Lech Szymanski, Brendan McCane, Wei Gao, Zhi-Hua Zhou
Effects of the optimisation of the margin distribution on generalisation in deep architectures
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Despite being so vital to success of Support Vector Machines, the principle of separating margin maximisation is not used in deep learning. We show that minimisation of margin variance and not maximisation of the margin is more suitable for improving generalisation in deep architectures. We propose the Halfway loss function that minimises the Normalised Margin Variance (NMV) at the output of a deep learning models and evaluate its performance against the Softmax Cross-Entropy loss on the MNIST, smallNORB and CIFAR-10 datasets.
[ { "version": "v1", "created": "Wed, 19 Apr 2017 08:31:20 GMT" } ]
2017-04-20T00:00:00
[ [ "Szymanski", "Lech", "" ], [ "McCane", "Brendan", "" ], [ "Gao", "Wei", "" ], [ "Zhou", "Zhi-Hua", "" ] ]
TITLE: Effects of the optimisation of the margin distribution on generalisation in deep architectures ABSTRACT: Despite being so vital to success of Support Vector Machines, the principle of separating margin maximisation is not used in deep learning. We show that minimisation of margin variance and not maximisation of the margin is more suitable for improving generalisation in deep architectures. We propose the Halfway loss function that minimises the Normalised Margin Variance (NMV) at the output of a deep learning models and evaluate its performance against the Softmax Cross-Entropy loss on the MNIST, smallNORB and CIFAR-10 datasets.
no_new_dataset
0.946892
1704.05665
Qingcai Chen
Xin Liu, Qingcai Chen, Xiangping Wu, Yan Liu, Yang Liu
CNN based music emotion classification
7 pages, 4 figures
null
null
null
cs.MM cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Music emotion recognition (MER) is usually regarded as a multi-label tagging task, and each segment of music can inspire specific emotion tags. Most researchers extract acoustic features from music and explore the relations between these features and their corresponding emotion tags. Considering the inconsistency of emotions inspired by the same music segment for human beings, seeking for the key acoustic features that really affect on emotions is really a challenging task. In this paper, we propose a novel MER method by using deep convolutional neural network (CNN) on the music spectrograms that contains both the original time and frequency domain information. By the proposed method, no additional effort on extracting specific features required, which is left to the training procedure of the CNN model. Experiments are conducted on the standard CAL500 and CAL500exp dataset. Results show that, for both datasets, the proposed method outperforms state-of-the-art methods.
[ { "version": "v1", "created": "Wed, 19 Apr 2017 09:28:39 GMT" } ]
2017-04-20T00:00:00
[ [ "Liu", "Xin", "" ], [ "Chen", "Qingcai", "" ], [ "Wu", "Xiangping", "" ], [ "Liu", "Yan", "" ], [ "Liu", "Yang", "" ] ]
TITLE: CNN based music emotion classification ABSTRACT: Music emotion recognition (MER) is usually regarded as a multi-label tagging task, and each segment of music can inspire specific emotion tags. Most researchers extract acoustic features from music and explore the relations between these features and their corresponding emotion tags. Considering the inconsistency of emotions inspired by the same music segment for human beings, seeking for the key acoustic features that really affect on emotions is really a challenging task. In this paper, we propose a novel MER method by using deep convolutional neural network (CNN) on the music spectrograms that contains both the original time and frequency domain information. By the proposed method, no additional effort on extracting specific features required, which is left to the training procedure of the CNN model. Experiments are conducted on the standard CAL500 and CAL500exp dataset. Results show that, for both datasets, the proposed method outperforms state-of-the-art methods.
no_new_dataset
0.950088
1704.05674
Emanuela Haller
Emanuela Haller and Marius Leordeanu
Unsupervised object segmentation in video by efficient selection of highly probable positive features
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address an essential problem in computer vision, that of unsupervised object segmentation in video, where a main object of interest in a video sequence should be automatically separated from its background. An efficient solution to this task would enable large-scale video interpretation at a high semantic level in the absence of the costly manually labeled ground truth. We propose an efficient unsupervised method for generating foreground object soft-segmentation masks based on automatic selection and learning from highly probable positive features. We show that such features can be selected efficiently by taking into consideration the spatio-temporal, appearance and motion consistency of the object during the whole observed sequence. We also emphasize the role of the contrasting properties between the foreground object and its background. Our model is created in two stages: we start from pixel level analysis, on top of which we add a regression model trained on a descriptor that considers information over groups of pixels and is both discriminative and invariant to many changes that the object undergoes throughout the video. We also present theoretical properties of our unsupervised learning method, that under some mild constraints is guaranteed to learn a correct discriminative classifier even in the unsupervised case. Our method achieves competitive and even state of the art results on the challenging Youtube-Objects and SegTrack datasets, while being at least one order of magnitude faster than the competition. We believe that the competitive performance of our method in practice, along with its theoretical properties, constitute an important step towards solving unsupervised discovery in video.
[ { "version": "v1", "created": "Wed, 19 Apr 2017 10:00:46 GMT" } ]
2017-04-20T00:00:00
[ [ "Haller", "Emanuela", "" ], [ "Leordeanu", "Marius", "" ] ]
TITLE: Unsupervised object segmentation in video by efficient selection of highly probable positive features ABSTRACT: We address an essential problem in computer vision, that of unsupervised object segmentation in video, where a main object of interest in a video sequence should be automatically separated from its background. An efficient solution to this task would enable large-scale video interpretation at a high semantic level in the absence of the costly manually labeled ground truth. We propose an efficient unsupervised method for generating foreground object soft-segmentation masks based on automatic selection and learning from highly probable positive features. We show that such features can be selected efficiently by taking into consideration the spatio-temporal, appearance and motion consistency of the object during the whole observed sequence. We also emphasize the role of the contrasting properties between the foreground object and its background. Our model is created in two stages: we start from pixel level analysis, on top of which we add a regression model trained on a descriptor that considers information over groups of pixels and is both discriminative and invariant to many changes that the object undergoes throughout the video. We also present theoretical properties of our unsupervised learning method, that under some mild constraints is guaranteed to learn a correct discriminative classifier even in the unsupervised case. Our method achieves competitive and even state of the art results on the challenging Youtube-Objects and SegTrack datasets, while being at least one order of magnitude faster than the competition. We believe that the competitive performance of our method in practice, along with its theoretical properties, constitute an important step towards solving unsupervised discovery in video.
no_new_dataset
0.948106
1704.05708
Usman Mahmood Khan Usman Mahmood Khan
U. M. Khan, Z. Kabir, S. A. Hassan, S. H. Ahmed
A Deep Learning Framework using Passive WiFi Sensing for Respiration Monitoring
7 pages, 11 figures
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents an end-to-end deep learning framework using passive WiFi sensing to classify and estimate human respiration activity. A passive radar test-bed is used with two channels where the first channel provides the reference WiFi signal, whereas the other channel provides a surveillance signal that contains reflections from the human target. Adaptive filtering is performed to make the surveillance signal source-data invariant by eliminating the echoes of the direct transmitted signal. We propose a novel convolutional neural network to classify the complex time series data and determine if it corresponds to a breathing activity, followed by a random forest estimator to determine breathing rate. We collect an extensive dataset to train the learning models and develop reference benchmarks for the future studies in the field. Based on the results, we conclude that deep learning techniques coupled with passive radars offer great potential for end-to-end human activity recognition.
[ { "version": "v1", "created": "Wed, 19 Apr 2017 12:35:17 GMT" } ]
2017-04-20T00:00:00
[ [ "Khan", "U. M.", "" ], [ "Kabir", "Z.", "" ], [ "Hassan", "S. A.", "" ], [ "Ahmed", "S. H.", "" ] ]
TITLE: A Deep Learning Framework using Passive WiFi Sensing for Respiration Monitoring ABSTRACT: This paper presents an end-to-end deep learning framework using passive WiFi sensing to classify and estimate human respiration activity. A passive radar test-bed is used with two channels where the first channel provides the reference WiFi signal, whereas the other channel provides a surveillance signal that contains reflections from the human target. Adaptive filtering is performed to make the surveillance signal source-data invariant by eliminating the echoes of the direct transmitted signal. We propose a novel convolutional neural network to classify the complex time series data and determine if it corresponds to a breathing activity, followed by a random forest estimator to determine breathing rate. We collect an extensive dataset to train the learning models and develop reference benchmarks for the future studies in the field. Based on the results, we conclude that deep learning techniques coupled with passive radars offer great potential for end-to-end human activity recognition.
no_new_dataset
0.950641
1704.05742
Pengfei Liu
Pengfei Liu and Xipeng Qiu and Xuanjing Huang
Adversarial Multi-task Learning for Text Classification
Accepted by ACL2017
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neural network models have shown their promising opportunities for multi-task learning, which focus on learning the shared layers to extract the common and task-invariant features. However, in most existing approaches, the extracted shared features are prone to be contaminated by task-specific features or the noise brought by other tasks. In this paper, we propose an adversarial multi-task learning framework, alleviating the shared and private latent feature spaces from interfering with each other. We conduct extensive experiments on 16 different text classification tasks, which demonstrates the benefits of our approach. Besides, we show that the shared knowledge learned by our proposed model can be regarded as off-the-shelf knowledge and easily transferred to new tasks. The datasets of all 16 tasks are publicly available at \url{http://nlp.fudan.edu.cn/data/}
[ { "version": "v1", "created": "Wed, 19 Apr 2017 14:17:25 GMT" } ]
2017-04-20T00:00:00
[ [ "Liu", "Pengfei", "" ], [ "Qiu", "Xipeng", "" ], [ "Huang", "Xuanjing", "" ] ]
TITLE: Adversarial Multi-task Learning for Text Classification ABSTRACT: Neural network models have shown their promising opportunities for multi-task learning, which focus on learning the shared layers to extract the common and task-invariant features. However, in most existing approaches, the extracted shared features are prone to be contaminated by task-specific features or the noise brought by other tasks. In this paper, we propose an adversarial multi-task learning framework, alleviating the shared and private latent feature spaces from interfering with each other. We conduct extensive experiments on 16 different text classification tasks, which demonstrates the benefits of our approach. Besides, we show that the shared knowledge learned by our proposed model can be regarded as off-the-shelf knowledge and easily transferred to new tasks. The datasets of all 16 tasks are publicly available at \url{http://nlp.fudan.edu.cn/data/}
no_new_dataset
0.945551
1704.05754
Federico Magliani
Federico Magliani, Navid Mahmoudian Bidgoli, Andrea Prati
A location-aware embedding technique for accurate landmark recognition
6 pages, 5 figures, ICDSC 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The current state of the research in landmark recognition highlights the good accuracy which can be achieved by embedding techniques, such as Fisher vector and VLAD. All these techniques do not exploit spatial information, i.e. consider all the features and the corresponding descriptors without embedding their location in the image. This paper presents a new variant of the well-known VLAD (Vector of Locally Aggregated Descriptors) embedding technique which accounts, at a certain degree, for the location of features. The driving motivation comes from the observation that, usually, the most interesting part of an image (e.g., the landmark to be recognized) is almost at the center of the image, while the features at the borders are irrelevant features which do no depend on the landmark. The proposed variant, called locVLAD (location-aware VLAD), computes the mean of the two global descriptors: the VLAD executed on the entire original image, and the one computed on a cropped image which removes a certain percentage of the image borders. This simple variant shows an accuracy greater than the existing state-of-the-art approach. Experiments are conducted on two public datasets (ZuBuD and Holidays) which are used both for training and testing. Morever a more balanced version of ZuBuD is proposed.
[ { "version": "v1", "created": "Wed, 19 Apr 2017 14:45:23 GMT" } ]
2017-04-20T00:00:00
[ [ "Magliani", "Federico", "" ], [ "Bidgoli", "Navid Mahmoudian", "" ], [ "Prati", "Andrea", "" ] ]
TITLE: A location-aware embedding technique for accurate landmark recognition ABSTRACT: The current state of the research in landmark recognition highlights the good accuracy which can be achieved by embedding techniques, such as Fisher vector and VLAD. All these techniques do not exploit spatial information, i.e. consider all the features and the corresponding descriptors without embedding their location in the image. This paper presents a new variant of the well-known VLAD (Vector of Locally Aggregated Descriptors) embedding technique which accounts, at a certain degree, for the location of features. The driving motivation comes from the observation that, usually, the most interesting part of an image (e.g., the landmark to be recognized) is almost at the center of the image, while the features at the borders are irrelevant features which do no depend on the landmark. The proposed variant, called locVLAD (location-aware VLAD), computes the mean of the two global descriptors: the VLAD executed on the entire original image, and the one computed on a cropped image which removes a certain percentage of the image borders. This simple variant shows an accuracy greater than the existing state-of-the-art approach. Experiments are conducted on two public datasets (ZuBuD and Holidays) which are used both for training and testing. Morever a more balanced version of ZuBuD is proposed.
no_new_dataset
0.949012
1704.05776
Jimmy Ren
Jimmy Ren, Xiaohao Chen, Jianbo Liu, Wenxiu Sun, Jiahao Pang, Qiong Yan, Yu-Wing Tai, Li Xu
Accurate Single Stage Detector Using Recurrent Rolling Convolution
CVPR 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most of the recent successful methods in accurate object detection and localization used some variants of R-CNN style two stage Convolutional Neural Networks (CNN) where plausible regions were proposed in the first stage then followed by a second stage for decision refinement. Despite the simplicity of training and the efficiency in deployment, the single stage detection methods have not been as competitive when evaluated in benchmarks consider mAP for high IoU thresholds. In this paper, we proposed a novel single stage end-to-end trainable object detection network to overcome this limitation. We achieved this by introducing Recurrent Rolling Convolution (RRC) architecture over multi-scale feature maps to construct object classifiers and bounding box regressors which are "deep in context". We evaluated our method in the challenging KITTI dataset which measures methods under IoU threshold of 0.7. We showed that with RRC, a single reduced VGG-16 based model already significantly outperformed all the previously published results. At the time this paper was written our models ranked the first in KITTI car detection (the hard level), the first in cyclist detection and the second in pedestrian detection. These results were not reached by the previous single stage methods. The code is publicly available.
[ { "version": "v1", "created": "Wed, 19 Apr 2017 15:31:01 GMT" } ]
2017-04-20T00:00:00
[ [ "Ren", "Jimmy", "" ], [ "Chen", "Xiaohao", "" ], [ "Liu", "Jianbo", "" ], [ "Sun", "Wenxiu", "" ], [ "Pang", "Jiahao", "" ], [ "Yan", "Qiong", "" ], [ "Tai", "Yu-Wing", "" ], [ "Xu", "Li", "" ] ]
TITLE: Accurate Single Stage Detector Using Recurrent Rolling Convolution ABSTRACT: Most of the recent successful methods in accurate object detection and localization used some variants of R-CNN style two stage Convolutional Neural Networks (CNN) where plausible regions were proposed in the first stage then followed by a second stage for decision refinement. Despite the simplicity of training and the efficiency in deployment, the single stage detection methods have not been as competitive when evaluated in benchmarks consider mAP for high IoU thresholds. In this paper, we proposed a novel single stage end-to-end trainable object detection network to overcome this limitation. We achieved this by introducing Recurrent Rolling Convolution (RRC) architecture over multi-scale feature maps to construct object classifiers and bounding box regressors which are "deep in context". We evaluated our method in the challenging KITTI dataset which measures methods under IoU threshold of 0.7. We showed that with RRC, a single reduced VGG-16 based model already significantly outperformed all the previously published results. At the time this paper was written our models ranked the first in KITTI car detection (the hard level), the first in cyclist detection and the second in pedestrian detection. These results were not reached by the previous single stage methods. The code is publicly available.
no_new_dataset
0.949716
1704.05815
Thomas Louail
Thomas Louail and Marc Barthelemy
Headphones on the wire
10 pages, 4 figures + SI (13 pages and 13 Supplementary figures)
null
null
null
physics.soc-ph cs.CY cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze a dataset providing the complete information on the effective plays of thousands of music listeners during several months. Our analysis confirms a number of properties previously highlighted by research based on interviews and questionnaires, but also uncover new statistical patterns, both at the individual and collective levels. In particular, we show that individuals follow common listening rhythms characterized by the same fluctuations, alternating heavy and light listening periods, and can be classified in four groups of similar sizes according to their temporal habits --- 'early birds', 'working hours listeners', 'evening listeners' and 'night owls'. We provide a detailed radioscopy of the listeners' interplay between repeated listening and discovery of new content. We show that different genres encourage different listening habits, from Classical or Jazz music with a more balanced listening among different songs, to Hip Hop and Dance with a more heterogeneous distribution of plays. Finally, we provide measures of how distant people are from each other in terms of common songs. In particular, we show that the number of songs $S$ a DJ should play to a random audience of size $N$ such that everyone hears at least one song he/she currently listens to, is of the form $S\sim N^\alpha$ where the exponent depends on the music genre and is in the range $[0.5,0.8]$. More generally, our results show that the recent access to virtually infinite catalogs of songs does not promote exploration for novelty, but that most users favor repetition of the same songs.
[ { "version": "v1", "created": "Wed, 19 Apr 2017 16:51:32 GMT" } ]
2017-04-20T00:00:00
[ [ "Louail", "Thomas", "" ], [ "Barthelemy", "Marc", "" ] ]
TITLE: Headphones on the wire ABSTRACT: We analyze a dataset providing the complete information on the effective plays of thousands of music listeners during several months. Our analysis confirms a number of properties previously highlighted by research based on interviews and questionnaires, but also uncover new statistical patterns, both at the individual and collective levels. In particular, we show that individuals follow common listening rhythms characterized by the same fluctuations, alternating heavy and light listening periods, and can be classified in four groups of similar sizes according to their temporal habits --- 'early birds', 'working hours listeners', 'evening listeners' and 'night owls'. We provide a detailed radioscopy of the listeners' interplay between repeated listening and discovery of new content. We show that different genres encourage different listening habits, from Classical or Jazz music with a more balanced listening among different songs, to Hip Hop and Dance with a more heterogeneous distribution of plays. Finally, we provide measures of how distant people are from each other in terms of common songs. In particular, we show that the number of songs $S$ a DJ should play to a random audience of size $N$ such that everyone hears at least one song he/she currently listens to, is of the form $S\sim N^\alpha$ where the exponent depends on the music genre and is in the range $[0.5,0.8]$. More generally, our results show that the recent access to virtually infinite catalogs of songs does not promote exploration for novelty, but that most users favor repetition of the same songs.
no_new_dataset
0.918334
1704.05817
Wenbin Li
Wenbin Li, Da Chen, Zhihan Lv, Yan Yan, Darren Cosker
Learn to Model Motion from Blurry Footages
Preprint of our paper accepted by Pattern Recognition
null
null
null
cs.CV
http://creativecommons.org/licenses/by-nc-sa/4.0/
It is difficult to recover the motion field from a real-world footage given a mixture of camera shake and other photometric effects. In this paper we propose a hybrid framework by interleaving a Convolutional Neural Network (CNN) and a traditional optical flow energy. We first conduct a CNN architecture using a novel learnable directional filtering layer. Such layer encodes the angle and distance similarity matrix between blur and camera motion, which is able to enhance the blur features of the camera-shake footages. The proposed CNNs are then integrated into an iterative optical flow framework, which enable the capability of modelling and solving both the blind deconvolution and the optical flow estimation problems simultaneously. Our framework is trained end-to-end on a synthetic dataset and yields competitive precision and performance against the state-of-the-art approaches.
[ { "version": "v1", "created": "Wed, 19 Apr 2017 16:54:54 GMT" } ]
2017-04-20T00:00:00
[ [ "Li", "Wenbin", "" ], [ "Chen", "Da", "" ], [ "Lv", "Zhihan", "" ], [ "Yan", "Yan", "" ], [ "Cosker", "Darren", "" ] ]
TITLE: Learn to Model Motion from Blurry Footages ABSTRACT: It is difficult to recover the motion field from a real-world footage given a mixture of camera shake and other photometric effects. In this paper we propose a hybrid framework by interleaving a Convolutional Neural Network (CNN) and a traditional optical flow energy. We first conduct a CNN architecture using a novel learnable directional filtering layer. Such layer encodes the angle and distance similarity matrix between blur and camera motion, which is able to enhance the blur features of the camera-shake footages. The proposed CNNs are then integrated into an iterative optical flow framework, which enable the capability of modelling and solving both the blind deconvolution and the optical flow estimation problems simultaneously. Our framework is trained end-to-end on a synthetic dataset and yields competitive precision and performance against the state-of-the-art approaches.
no_new_dataset
0.948106
1612.09542
Licheng Yu
Licheng Yu, Hao Tan, Mohit Bansal, Tamara L. Berg
A Joint Speaker-Listener-Reinforcer Model for Referring Expressions
Some typo fixed; comprehension results on refcocog updated; more human evaluation results added
null
null
null
cs.CV cs.AI cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Referring expressions are natural language constructions used to identify particular objects within a scene. In this paper, we propose a unified framework for the tasks of referring expression comprehension and generation. Our model is composed of three modules: speaker, listener, and reinforcer. The speaker generates referring expressions, the listener comprehends referring expressions, and the reinforcer introduces a reward function to guide sampling of more discriminative expressions. The listener-speaker modules are trained jointly in an end-to-end learning framework, allowing the modules to be aware of one another during learning while also benefiting from the discriminative reinforcer's feedback. We demonstrate that this unified framework and training achieves state-of-the-art results for both comprehension and generation on three referring expression datasets. Project and demo page: https://vision.cs.unc.edu/refer
[ { "version": "v1", "created": "Fri, 30 Dec 2016 17:39:19 GMT" }, { "version": "v2", "created": "Mon, 17 Apr 2017 20:13:49 GMT" } ]
2017-04-19T00:00:00
[ [ "Yu", "Licheng", "" ], [ "Tan", "Hao", "" ], [ "Bansal", "Mohit", "" ], [ "Berg", "Tamara L.", "" ] ]
TITLE: A Joint Speaker-Listener-Reinforcer Model for Referring Expressions ABSTRACT: Referring expressions are natural language constructions used to identify particular objects within a scene. In this paper, we propose a unified framework for the tasks of referring expression comprehension and generation. Our model is composed of three modules: speaker, listener, and reinforcer. The speaker generates referring expressions, the listener comprehends referring expressions, and the reinforcer introduces a reward function to guide sampling of more discriminative expressions. The listener-speaker modules are trained jointly in an end-to-end learning framework, allowing the modules to be aware of one another during learning while also benefiting from the discriminative reinforcer's feedback. We demonstrate that this unified framework and training achieves state-of-the-art results for both comprehension and generation on three referring expression datasets. Project and demo page: https://vision.cs.unc.edu/refer
no_new_dataset
0.951639
1702.01072
Giovanni Bussi
Vojt\v{e}ch Ml\'ynsk\'y and Giovanni Bussi
Understanding In-line Probing Experiments by Modeling Cleavage of Non-reactive RNA Nucleotides
null
RNA 2017, 23, 712-720
10.1261/rna.060442.116
null
q-bio.BM physics.bio-ph physics.chem-ph physics.comp-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ribonucleic acid (RNA) is involved in many regulatory and catalytic processes in the cell. The function of any RNA molecule is intimately related with its structure. In-line probing experiments provide valuable structural datasets for a variety of RNAs and are used to characterize conformational changes in riboswitches. However, the structural determinants that lead to differential reactivities in unpaired nucleotides have not been investigated yet. In this work we used a combination of theoretical approaches, i.e., classical molecular dynamics simulations, multiscale quantum mechanical/molecular mechanical calculations, and enhanced sampling techniques in order to compute and interpret the differential reactivity of individual residues in several RNA motifs including members of the most important GNRA and UNCG tetraloop families. Simulations on the multi ns timescale are required to converge the related free-energy landscapes. The results for uGAAAg and cUUCGg tetraloops and double helices are compared with available data from in-line probing experiments and show that the introduced technique is able to distinguish between nucleotides of the uGAAAg tetraloop based on their structural predispositions towards phosphodiester backbone cleavage. For the cUUCGg tetraloop, more advanced ab initio calculations would be required. This study is the first attempt to computationally classify chemical probing experiments and paves the way for an identification of tertiary structures based on the measured reactivity of non-reactive nucleotides.
[ { "version": "v1", "created": "Fri, 3 Feb 2017 16:42:09 GMT" } ]
2017-04-19T00:00:00
[ [ "Mlýnský", "Vojtěch", "" ], [ "Bussi", "Giovanni", "" ] ]
TITLE: Understanding In-line Probing Experiments by Modeling Cleavage of Non-reactive RNA Nucleotides ABSTRACT: Ribonucleic acid (RNA) is involved in many regulatory and catalytic processes in the cell. The function of any RNA molecule is intimately related with its structure. In-line probing experiments provide valuable structural datasets for a variety of RNAs and are used to characterize conformational changes in riboswitches. However, the structural determinants that lead to differential reactivities in unpaired nucleotides have not been investigated yet. In this work we used a combination of theoretical approaches, i.e., classical molecular dynamics simulations, multiscale quantum mechanical/molecular mechanical calculations, and enhanced sampling techniques in order to compute and interpret the differential reactivity of individual residues in several RNA motifs including members of the most important GNRA and UNCG tetraloop families. Simulations on the multi ns timescale are required to converge the related free-energy landscapes. The results for uGAAAg and cUUCGg tetraloops and double helices are compared with available data from in-line probing experiments and show that the introduced technique is able to distinguish between nucleotides of the uGAAAg tetraloop based on their structural predispositions towards phosphodiester backbone cleavage. For the cUUCGg tetraloop, more advanced ab initio calculations would be required. This study is the first attempt to computationally classify chemical probing experiments and paves the way for an identification of tertiary structures based on the measured reactivity of non-reactive nucleotides.
no_new_dataset
0.944893
1704.01792
Qingyu Zhou
Qingyu Zhou, Nan Yang, Furu Wei, Chuanqi Tan, Hangbo Bao, Ming Zhou
Neural Question Generation from Text: A Preliminary Study
Submitted to EMNLP 2017
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Automatic question generation aims to generate questions from a text passage where the generated questions can be answered by certain sub-spans of the given passage. Traditional methods mainly use rigid heuristic rules to transform a sentence into related questions. In this work, we propose to apply the neural encoder-decoder model to generate meaningful and diverse questions from natural language sentences. The encoder reads the input text and the answer position, to produce an answer-aware input representation, which is fed to the decoder to generate an answer focused question. We conduct a preliminary study on neural question generation from text with the SQuAD dataset, and the experiment results show that our method can produce fluent and diverse questions.
[ { "version": "v1", "created": "Thu, 6 Apr 2017 11:44:07 GMT" }, { "version": "v2", "created": "Sun, 16 Apr 2017 03:27:15 GMT" }, { "version": "v3", "created": "Tue, 18 Apr 2017 07:54:52 GMT" } ]
2017-04-19T00:00:00
[ [ "Zhou", "Qingyu", "" ], [ "Yang", "Nan", "" ], [ "Wei", "Furu", "" ], [ "Tan", "Chuanqi", "" ], [ "Bao", "Hangbo", "" ], [ "Zhou", "Ming", "" ] ]
TITLE: Neural Question Generation from Text: A Preliminary Study ABSTRACT: Automatic question generation aims to generate questions from a text passage where the generated questions can be answered by certain sub-spans of the given passage. Traditional methods mainly use rigid heuristic rules to transform a sentence into related questions. In this work, we propose to apply the neural encoder-decoder model to generate meaningful and diverse questions from natural language sentences. The encoder reads the input text and the answer position, to produce an answer-aware input representation, which is fed to the decoder to generate an answer focused question. We conduct a preliminary study on neural question generation from text with the SQuAD dataset, and the experiment results show that our method can produce fluent and diverse questions.
no_new_dataset
0.947527
1704.05165
Brent Griffin
Brent A. Griffin and Jason J. Corso
Video Object Segmentation using Supervoxel-Based Gerrymandering
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Pixels operate locally. Superpixels have some potential to collect information across many pixels; supervoxels have more potential by implicitly operating across time. In this paper, we explore this well established notion thoroughly analyzing how supervoxels can be used in place of and in conjunction with other means of aggregating information across space-time. Focusing on the problem of strictly unsupervised video object segmentation, we devise a method called supervoxel gerrymandering that links masks of foregroundness and backgroundness via local and non-local consensus measures. We pose and answer a series of critical questions about the ability of supervoxels to adequately sway local voting; the questions regard type and scale of supervoxels as well as local versus non-local consensus, and the questions are posed in a general way so as to impact the broader knowledge of the use of supervoxels in video understanding. We work with the DAVIS dataset and find that our analysis yields an unsupervised method that outperforms all other known unsupervised methods and even many supervised ones.
[ { "version": "v1", "created": "Tue, 18 Apr 2017 01:11:35 GMT" } ]
2017-04-19T00:00:00
[ [ "Griffin", "Brent A.", "" ], [ "Corso", "Jason J.", "" ] ]
TITLE: Video Object Segmentation using Supervoxel-Based Gerrymandering ABSTRACT: Pixels operate locally. Superpixels have some potential to collect information across many pixels; supervoxels have more potential by implicitly operating across time. In this paper, we explore this well established notion thoroughly analyzing how supervoxels can be used in place of and in conjunction with other means of aggregating information across space-time. Focusing on the problem of strictly unsupervised video object segmentation, we devise a method called supervoxel gerrymandering that links masks of foregroundness and backgroundness via local and non-local consensus measures. We pose and answer a series of critical questions about the ability of supervoxels to adequately sway local voting; the questions regard type and scale of supervoxels as well as local versus non-local consensus, and the questions are posed in a general way so as to impact the broader knowledge of the use of supervoxels in video understanding. We work with the DAVIS dataset and find that our analysis yields an unsupervised method that outperforms all other known unsupervised methods and even many supervised ones.
no_new_dataset
0.947527
1704.05215
Ashwin Mathur Mr.
Ashwin Mathur, Fei Han, and Hao Zhang
Multisensory Omni-directional Long-term Place Recognition: Benchmark Dataset and Analysis
15 pages
null
null
null
cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recognizing a previously visited place, also known as place recognition (or loop closure detection) is the key towards fully autonomous mobile robots and self-driving vehicle navigation. Augmented with various Simultaneous Localization and Mapping techniques (SLAM), loop closure detection allows for incremental pose correction and can bolster efficient and accurate map creation. However, repeated and similar scenes (perceptual aliasing) and long term appearance changes (e.g. weather variations) are major challenges for current place recognition algorithms. We introduce a new dataset Multisensory Omnidirectional Long-term Place recognition (MOLP) comprising omnidirectional intensity and disparity images. This dataset presents many of the challenges faced by outdoor mobile robots and current place recognition algorithms. Using MOLP dataset, we formulate the place recognition problem as a regularized sparse convex optimization problem. We conclude that information extracted from intensity image is superior to disparity image in isolating discriminative features for successful long term place recognition. Furthermore, when these discriminative features are extracted from an omnidirectional vision sensor, a robust bidirectional loop closure detection approach is established, allowing mobile robots to close the loop, regardless of the difference in the direction when revisiting a place.
[ { "version": "v1", "created": "Tue, 18 Apr 2017 06:36:48 GMT" } ]
2017-04-19T00:00:00
[ [ "Mathur", "Ashwin", "" ], [ "Han", "Fei", "" ], [ "Zhang", "Hao", "" ] ]
TITLE: Multisensory Omni-directional Long-term Place Recognition: Benchmark Dataset and Analysis ABSTRACT: Recognizing a previously visited place, also known as place recognition (or loop closure detection) is the key towards fully autonomous mobile robots and self-driving vehicle navigation. Augmented with various Simultaneous Localization and Mapping techniques (SLAM), loop closure detection allows for incremental pose correction and can bolster efficient and accurate map creation. However, repeated and similar scenes (perceptual aliasing) and long term appearance changes (e.g. weather variations) are major challenges for current place recognition algorithms. We introduce a new dataset Multisensory Omnidirectional Long-term Place recognition (MOLP) comprising omnidirectional intensity and disparity images. This dataset presents many of the challenges faced by outdoor mobile robots and current place recognition algorithms. Using MOLP dataset, we formulate the place recognition problem as a regularized sparse convex optimization problem. We conclude that information extracted from intensity image is superior to disparity image in isolating discriminative features for successful long term place recognition. Furthermore, when these discriminative features are extracted from an omnidirectional vision sensor, a robust bidirectional loop closure detection approach is established, allowing mobile robots to close the loop, regardless of the difference in the direction when revisiting a place.
new_dataset
0.961425
1704.05358
Jiaqi Mu
Jiaqi Mu, Suma Bhat, Pramod Viswanath
Representing Sentences as Low-Rank Subspaces
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Sentences are important semantic units of natural language. A generic, distributional representation of sentences that can capture the latent semantics is beneficial to multiple downstream applications. We observe a simple geometry of sentences -- the word representations of a given sentence (on average 10.23 words in all SemEval datasets with a standard deviation 4.84) roughly lie in a low-rank subspace (roughly, rank 4). Motivated by this observation, we represent a sentence by the low-rank subspace spanned by its word vectors. Such an unsupervised representation is empirically validated via semantic textual similarity tasks on 19 different datasets, where it outperforms the sophisticated neural network models, including skip-thought vectors, by 15% on average.
[ { "version": "v1", "created": "Tue, 18 Apr 2017 14:30:32 GMT" } ]
2017-04-19T00:00:00
[ [ "Mu", "Jiaqi", "" ], [ "Bhat", "Suma", "" ], [ "Viswanath", "Pramod", "" ] ]
TITLE: Representing Sentences as Low-Rank Subspaces ABSTRACT: Sentences are important semantic units of natural language. A generic, distributional representation of sentences that can capture the latent semantics is beneficial to multiple downstream applications. We observe a simple geometry of sentences -- the word representations of a given sentence (on average 10.23 words in all SemEval datasets with a standard deviation 4.84) roughly lie in a low-rank subspace (roughly, rank 4). Motivated by this observation, we represent a sentence by the low-rank subspace spanned by its word vectors. Such an unsupervised representation is empirically validated via semantic textual similarity tasks on 19 different datasets, where it outperforms the sophisticated neural network models, including skip-thought vectors, by 15% on average.
no_new_dataset
0.945399
1704.05368
Jan Egger
Jan Egger, Dieter Schmalstieg, Xiaojun Chen, Wolfram G. Zoller, Alexander Hann
Interactive Outlining of Pancreatic Cancer Liver Metastases in Ultrasound Images
15 pages, 16 figures, 2 tables, 58 references
Sci. Rep. 7, 892, 2017
10.1038/s41598-017-00940-z
null
cs.CV cs.GR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ultrasound (US) is the most commonly used liver imaging modality worldwide. Due to its low cost, it is increasingly used in the follow-up of cancer patients with metastases localized in the liver. In this contribution, we present the results of an interactive segmentation approach for liver metastases in US acquisitions. A (semi-) automatic segmentation is still very challenging because of the low image quality and the low contrast between the metastasis and the surrounding liver tissue. Thus, the state of the art in clinical practice is still manual measurement and outlining of the metastases in the US images. We tackle the problem by providing an interactive segmentation approach providing real-time feedback of the segmentation results. The approach has been evaluated with typical US acquisitions from the clinical routine, and the datasets consisted of pancreatic cancer metastases. Even for difficult cases, satisfying segmentations results could be achieved because of the interactive real-time behavior of the approach. In total, 40 clinical images have been evaluated with our method by comparing the results against manual ground truth segmentations. This evaluation yielded to an average Dice Score of 85% and an average Hausdorff Distance of 13 pixels.
[ { "version": "v1", "created": "Tue, 18 Apr 2017 14:45:20 GMT" } ]
2017-04-19T00:00:00
[ [ "Egger", "Jan", "" ], [ "Schmalstieg", "Dieter", "" ], [ "Chen", "Xiaojun", "" ], [ "Zoller", "Wolfram G.", "" ], [ "Hann", "Alexander", "" ] ]
TITLE: Interactive Outlining of Pancreatic Cancer Liver Metastases in Ultrasound Images ABSTRACT: Ultrasound (US) is the most commonly used liver imaging modality worldwide. Due to its low cost, it is increasingly used in the follow-up of cancer patients with metastases localized in the liver. In this contribution, we present the results of an interactive segmentation approach for liver metastases in US acquisitions. A (semi-) automatic segmentation is still very challenging because of the low image quality and the low contrast between the metastasis and the surrounding liver tissue. Thus, the state of the art in clinical practice is still manual measurement and outlining of the metastases in the US images. We tackle the problem by providing an interactive segmentation approach providing real-time feedback of the segmentation results. The approach has been evaluated with typical US acquisitions from the clinical routine, and the datasets consisted of pancreatic cancer metastases. Even for difficult cases, satisfying segmentations results could be achieved because of the interactive real-time behavior of the approach. In total, 40 clinical images have been evaluated with our method by comparing the results against manual ground truth segmentations. This evaluation yielded to an average Dice Score of 85% and an average Hausdorff Distance of 13 pixels.
no_new_dataset
0.946151
1704.05393
Michela Fazzolari
Michela Fazzolari, Marinella Petrocchi, Alessandro Tommasi, Cesare Zavattari
Mining Worse and Better Opinions. Unsupervised and Agnostic Aggregation of Online Reviews
null
null
null
null
cs.SI cs.CL cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose a novel approach for aggregating online reviews, according to the opinions they express. Our methodology is unsupervised - due to the fact that it does not rely on pre-labeled reviews - and it is agnostic - since it does not make any assumption about the domain or the language of the review content. We measure the adherence of a review content to the domain terminology extracted from a review set. First, we demonstrate the informativeness of the adherence metric with respect to the score associated with a review. Then, we exploit the metric values to group reviews, according to the opinions they express. Our experimental campaign has been carried out on two large datasets collected from Booking and Amazon, respectively.
[ { "version": "v1", "created": "Tue, 18 Apr 2017 15:20:25 GMT" } ]
2017-04-19T00:00:00
[ [ "Fazzolari", "Michela", "" ], [ "Petrocchi", "Marinella", "" ], [ "Tommasi", "Alessandro", "" ], [ "Zavattari", "Cesare", "" ] ]
TITLE: Mining Worse and Better Opinions. Unsupervised and Agnostic Aggregation of Online Reviews ABSTRACT: In this paper, we propose a novel approach for aggregating online reviews, according to the opinions they express. Our methodology is unsupervised - due to the fact that it does not rely on pre-labeled reviews - and it is agnostic - since it does not make any assumption about the domain or the language of the review content. We measure the adherence of a review content to the domain terminology extracted from a review set. First, we demonstrate the informativeness of the adherence metric with respect to the score associated with a review. Then, we exploit the metric values to group reviews, according to the opinions they express. Our experimental campaign has been carried out on two large datasets collected from Booking and Amazon, respectively.
no_new_dataset
0.949201
1704.05409
Giorgio Roffo
Giorgio Roffo and Simone Melzi
Ranking to Learn: Feature Ranking and Selection via Eigenvector Centrality
Preprint version - Lecture Notes in Computer Science - Springer 2017
New Frontiers in Mining Complex Patterns, Fifth International workshop, nfMCP2016. Lecture Notes in Computer Science - Springer
null
null
cs.CV cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In an era where accumulating data is easy and storing it inexpensive, feature selection plays a central role in helping to reduce the high-dimensionality of huge amounts of otherwise meaningless data. In this paper, we propose a graph-based method for feature selection that ranks features by identifying the most important ones into arbitrary set of cues. Mapping the problem on an affinity graph-where features are the nodes-the solution is given by assessing the importance of nodes through some indicators of centrality, in particular, the Eigen-vector Centrality (EC). The gist of EC is to estimate the importance of a feature as a function of the importance of its neighbors. Ranking central nodes individuates candidate features, which turn out to be effective from a classification point of view, as proved by a thoroughly experimental section. Our approach has been tested on 7 diverse datasets from recent literature (e.g., biological data and object recognition, among others), and compared against filter, embedded and wrappers methods. The results are remarkable in terms of accuracy, stability and low execution time.
[ { "version": "v1", "created": "Tue, 18 Apr 2017 16:21:05 GMT" } ]
2017-04-19T00:00:00
[ [ "Roffo", "Giorgio", "" ], [ "Melzi", "Simone", "" ] ]
TITLE: Ranking to Learn: Feature Ranking and Selection via Eigenvector Centrality ABSTRACT: In an era where accumulating data is easy and storing it inexpensive, feature selection plays a central role in helping to reduce the high-dimensionality of huge amounts of otherwise meaningless data. In this paper, we propose a graph-based method for feature selection that ranks features by identifying the most important ones into arbitrary set of cues. Mapping the problem on an affinity graph-where features are the nodes-the solution is given by assessing the importance of nodes through some indicators of centrality, in particular, the Eigen-vector Centrality (EC). The gist of EC is to estimate the importance of a feature as a function of the importance of its neighbors. Ranking central nodes individuates candidate features, which turn out to be effective from a classification point of view, as proved by a thoroughly experimental section. Our approach has been tested on 7 diverse datasets from recent literature (e.g., biological data and object recognition, among others), and compared against filter, embedded and wrappers methods. The results are remarkable in terms of accuracy, stability and low execution time.
no_new_dataset
0.945349
1608.03016
Yuncheng Li
Yuncheng Li, LiangLiang Cao, Jiang Zhu, Jiebo Luo
Mining Fashion Outfit Composition Using An End-to-End Deep Learning Approach on Set Data
IEEE TMM
null
10.1109/TMM.2017.2690144
null
cs.MM cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Composing fashion outfits involves deep understanding of fashion standards while incorporating creativity for choosing multiple fashion items (e.g., Jewelry, Bag, Pants, Dress). In fashion websites, popular or high-quality fashion outfits are usually designed by fashion experts and followed by large audiences. In this paper, we propose a machine learning system to compose fashion outfits automatically. The core of the proposed automatic composition system is to score fashion outfit candidates based on the appearances and meta-data. We propose to leverage outfit popularity on fashion oriented websites to supervise the scoring component. The scoring component is a multi-modal multi-instance deep learning system that evaluates instance aesthetics and set compatibility simultaneously. In order to train and evaluate the proposed composition system, we have collected a large scale fashion outfit dataset with 195K outfits and 368K fashion items from Polyvore. Although the fashion outfit scoring and composition is rather challenging, we have achieved an AUC of 85% for the scoring component, and an accuracy of 77% for a constrained composition task.
[ { "version": "v1", "created": "Wed, 10 Aug 2016 01:11:32 GMT" }, { "version": "v2", "created": "Sat, 15 Apr 2017 05:26:23 GMT" } ]
2017-04-18T00:00:00
[ [ "Li", "Yuncheng", "" ], [ "Cao", "LiangLiang", "" ], [ "Zhu", "Jiang", "" ], [ "Luo", "Jiebo", "" ] ]
TITLE: Mining Fashion Outfit Composition Using An End-to-End Deep Learning Approach on Set Data ABSTRACT: Composing fashion outfits involves deep understanding of fashion standards while incorporating creativity for choosing multiple fashion items (e.g., Jewelry, Bag, Pants, Dress). In fashion websites, popular or high-quality fashion outfits are usually designed by fashion experts and followed by large audiences. In this paper, we propose a machine learning system to compose fashion outfits automatically. The core of the proposed automatic composition system is to score fashion outfit candidates based on the appearances and meta-data. We propose to leverage outfit popularity on fashion oriented websites to supervise the scoring component. The scoring component is a multi-modal multi-instance deep learning system that evaluates instance aesthetics and set compatibility simultaneously. In order to train and evaluate the proposed composition system, we have collected a large scale fashion outfit dataset with 195K outfits and 368K fashion items from Polyvore. Although the fashion outfit scoring and composition is rather challenging, we have achieved an AUC of 85% for the scoring component, and an accuracy of 77% for a constrained composition task.
new_dataset
0.854095
1612.03216
Peter Potash
Peter Potash, Alexey Romanov, Anna Rumshisky
#HashtagWars: Learning a Sense of Humor
10 Pages
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we present a new dataset for computational humor, specifically comparative humor ranking, which attempts to eschew the ubiquitous binary approach to humor detection. The dataset consists of tweets that are humorous responses to a given hashtag. We describe the motivation for this new dataset, as well as the collection process, which includes a description of our semi-automated system for data collection. We also present initial experiments for this dataset using both unsupervised and supervised approaches. Our best supervised system achieved 63.7% accuracy, suggesting that this task is much more difficult than comparable humor detection tasks. Initial experiments indicate that a character-level model is more suitable for this task than a token-level model, likely due to a large amount of puns that can be captured by a character-level model.
[ { "version": "v1", "created": "Fri, 9 Dec 2016 23:28:16 GMT" }, { "version": "v2", "created": "Sat, 15 Apr 2017 18:41:44 GMT" } ]
2017-04-18T00:00:00
[ [ "Potash", "Peter", "" ], [ "Romanov", "Alexey", "" ], [ "Rumshisky", "Anna", "" ] ]
TITLE: #HashtagWars: Learning a Sense of Humor ABSTRACT: In this work, we present a new dataset for computational humor, specifically comparative humor ranking, which attempts to eschew the ubiquitous binary approach to humor detection. The dataset consists of tweets that are humorous responses to a given hashtag. We describe the motivation for this new dataset, as well as the collection process, which includes a description of our semi-automated system for data collection. We also present initial experiments for this dataset using both unsupervised and supervised approaches. Our best supervised system achieved 63.7% accuracy, suggesting that this task is much more difficult than comparable humor detection tasks. Initial experiments indicate that a character-level model is more suitable for this task than a token-level model, likely due to a large amount of puns that can be captured by a character-level model.
new_dataset
0.956431
1612.04402
Peiyun Hu
Peiyun Hu, Deva Ramanan
Finding Tiny Faces
CVPR 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Though tremendous strides have been made in object recognition, one of the remaining open challenges is detecting small objects. We explore three aspects of the problem in the context of finding small faces: the role of scale invariance, image resolution, and contextual reasoning. While most recognition approaches aim to be scale-invariant, the cues for recognizing a 3px tall face are fundamentally different than those for recognizing a 300px tall face. We take a different approach and train separate detectors for different scales. To maintain efficiency, detectors are trained in a multi-task fashion: they make use of features extracted from multiple layers of single (deep) feature hierarchy. While training detectors for large objects is straightforward, the crucial challenge remains training detectors for small objects. We show that context is crucial, and define templates that make use of massively-large receptive fields (where 99% of the template extends beyond the object of interest). Finally, we explore the role of scale in pre-trained deep networks, providing ways to extrapolate networks tuned for limited scales to rather extreme ranges. We demonstrate state-of-the-art results on massively-benchmarked face datasets (FDDB and WIDER FACE). In particular, when compared to prior art on WIDER FACE, our results reduce error by a factor of 2 (our models produce an AP of 82% while prior art ranges from 29-64%).
[ { "version": "v1", "created": "Tue, 13 Dec 2016 21:28:02 GMT" }, { "version": "v2", "created": "Sat, 15 Apr 2017 06:18:08 GMT" } ]
2017-04-18T00:00:00
[ [ "Hu", "Peiyun", "" ], [ "Ramanan", "Deva", "" ] ]
TITLE: Finding Tiny Faces ABSTRACT: Though tremendous strides have been made in object recognition, one of the remaining open challenges is detecting small objects. We explore three aspects of the problem in the context of finding small faces: the role of scale invariance, image resolution, and contextual reasoning. While most recognition approaches aim to be scale-invariant, the cues for recognizing a 3px tall face are fundamentally different than those for recognizing a 300px tall face. We take a different approach and train separate detectors for different scales. To maintain efficiency, detectors are trained in a multi-task fashion: they make use of features extracted from multiple layers of single (deep) feature hierarchy. While training detectors for large objects is straightforward, the crucial challenge remains training detectors for small objects. We show that context is crucial, and define templates that make use of massively-large receptive fields (where 99% of the template extends beyond the object of interest). Finally, we explore the role of scale in pre-trained deep networks, providing ways to extrapolate networks tuned for limited scales to rather extreme ranges. We demonstrate state-of-the-art results on massively-benchmarked face datasets (FDDB and WIDER FACE). In particular, when compared to prior art on WIDER FACE, our results reduce error by a factor of 2 (our models produce an AP of 82% while prior art ranges from 29-64%).
no_new_dataset
0.948298
1701.01779
George Papandreou
George Papandreou, Tyler Zhu, Nori Kanazawa, Alexander Toshev, Jonathan Tompson, Chris Bregler, Kevin Murphy
Towards Accurate Multi-person Pose Estimation in the Wild
Paper describing an improved version of the G-RMI entry to the 2016 COCO keypoints challenge (http://image-net.org/challenges/ilsvrc+coco2016). Camera ready version to appear in the Proceedings of CVPR 2017
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a method for multi-person detection and 2-D pose estimation that achieves state-of-art results on the challenging COCO keypoints task. It is a simple, yet powerful, top-down approach consisting of two stages. In the first stage, we predict the location and scale of boxes which are likely to contain people; for this we use the Faster RCNN detector. In the second stage, we estimate the keypoints of the person potentially contained in each proposed bounding box. For each keypoint type we predict dense heatmaps and offsets using a fully convolutional ResNet. To combine these outputs we introduce a novel aggregation procedure to obtain highly localized keypoint predictions. We also use a novel form of keypoint-based Non-Maximum-Suppression (NMS), instead of the cruder box-level NMS, and a novel form of keypoint-based confidence score estimation, instead of box-level scoring. Trained on COCO data alone, our final system achieves average precision of 0.649 on the COCO test-dev set and the 0.643 test-standard sets, outperforming the winner of the 2016 COCO keypoints challenge and other recent state-of-art. Further, by using additional in-house labeled data we obtain an even higher average precision of 0.685 on the test-dev set and 0.673 on the test-standard set, more than 5% absolute improvement compared to the previous best performing method on the same dataset.
[ { "version": "v1", "created": "Fri, 6 Jan 2017 23:56:02 GMT" }, { "version": "v2", "created": "Fri, 14 Apr 2017 18:30:58 GMT" } ]
2017-04-18T00:00:00
[ [ "Papandreou", "George", "" ], [ "Zhu", "Tyler", "" ], [ "Kanazawa", "Nori", "" ], [ "Toshev", "Alexander", "" ], [ "Tompson", "Jonathan", "" ], [ "Bregler", "Chris", "" ], [ "Murphy", "Kevin", "" ] ]
TITLE: Towards Accurate Multi-person Pose Estimation in the Wild ABSTRACT: We propose a method for multi-person detection and 2-D pose estimation that achieves state-of-art results on the challenging COCO keypoints task. It is a simple, yet powerful, top-down approach consisting of two stages. In the first stage, we predict the location and scale of boxes which are likely to contain people; for this we use the Faster RCNN detector. In the second stage, we estimate the keypoints of the person potentially contained in each proposed bounding box. For each keypoint type we predict dense heatmaps and offsets using a fully convolutional ResNet. To combine these outputs we introduce a novel aggregation procedure to obtain highly localized keypoint predictions. We also use a novel form of keypoint-based Non-Maximum-Suppression (NMS), instead of the cruder box-level NMS, and a novel form of keypoint-based confidence score estimation, instead of box-level scoring. Trained on COCO data alone, our final system achieves average precision of 0.649 on the COCO test-dev set and the 0.643 test-standard sets, outperforming the winner of the 2016 COCO keypoints challenge and other recent state-of-art. Further, by using additional in-house labeled data we obtain an even higher average precision of 0.685 on the test-dev set and 0.673 on the test-standard set, more than 5% absolute improvement compared to the previous best performing method on the same dataset.
no_new_dataset
0.94699
1704.03944
Yuting Zhang
Yuting Zhang, Luyao Yuan, Yijie Guo, Zhiyuan He, I-An Huang, Honglak Lee
Discriminative Bimodal Networks for Visual Localization and Detection with Natural Language Queries
IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2017
null
null
null
cs.CV stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Associating image regions with text queries has been recently explored as a new way to bridge visual and linguistic representations. A few pioneering approaches have been proposed based on recurrent neural language models trained generatively (e.g., generating captions), but achieving somewhat limited localization accuracy. To better address natural-language-based visual entity localization, we propose a discriminative approach. We formulate a discriminative bimodal neural network (DBNet), which can be trained by a classifier with extensive use of negative samples. Our training objective encourages better localization on single images, incorporates text phrases in a broad range, and properly pairs image regions with text phrases into positive and negative examples. Experiments on the Visual Genome dataset demonstrate the proposed DBNet significantly outperforms previous state-of-the-art methods both for localization on single images and for detection on multiple images. We we also establish an evaluation protocol for natural-language visual detection.
[ { "version": "v1", "created": "Wed, 12 Apr 2017 22:09:36 GMT" }, { "version": "v2", "created": "Mon, 17 Apr 2017 07:22:14 GMT" } ]
2017-04-18T00:00:00
[ [ "Zhang", "Yuting", "" ], [ "Yuan", "Luyao", "" ], [ "Guo", "Yijie", "" ], [ "He", "Zhiyuan", "" ], [ "Huang", "I-An", "" ], [ "Lee", "Honglak", "" ] ]
TITLE: Discriminative Bimodal Networks for Visual Localization and Detection with Natural Language Queries ABSTRACT: Associating image regions with text queries has been recently explored as a new way to bridge visual and linguistic representations. A few pioneering approaches have been proposed based on recurrent neural language models trained generatively (e.g., generating captions), but achieving somewhat limited localization accuracy. To better address natural-language-based visual entity localization, we propose a discriminative approach. We formulate a discriminative bimodal neural network (DBNet), which can be trained by a classifier with extensive use of negative samples. Our training objective encourages better localization on single images, incorporates text phrases in a broad range, and properly pairs image regions with text phrases into positive and negative examples. Experiments on the Visual Genome dataset demonstrate the proposed DBNet significantly outperforms previous state-of-the-art methods both for localization on single images and for detection on multiple images. We we also establish an evaluation protocol for natural-language visual detection.
no_new_dataset
0.946448
1704.04516
Tae Soo Kim
Tae Soo Kim, Austin Reiter
Interpretable 3D Human Action Analysis with Temporal Convolutional Networks
8 pages, 5 figures, BNMW CVPR 2017 Submission
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The discriminative power of modern deep learning models for 3D human action recognition is growing ever so potent. In conjunction with the recent resurgence of 3D human action representation with 3D skeletons, the quality and the pace of recent progress have been significant. However, the inner workings of state-of-the-art learning based methods in 3D human action recognition still remain mostly black-box. In this work, we propose to use a new class of models known as Temporal Convolutional Neural Networks (TCN) for 3D human action recognition. Compared to popular LSTM-based Recurrent Neural Network models, given interpretable input such as 3D skeletons, TCN provides us a way to explicitly learn readily interpretable spatio-temporal representations for 3D human action recognition. We provide our strategy in re-designing the TCN with interpretability in mind and how such characteristics of the model is leveraged to construct a powerful 3D activity recognition method. Through this work, we wish to take a step towards a spatio-temporal model that is easier to understand, explain and interpret. The resulting model, Res-TCN, achieves state-of-the-art results on the largest 3D human action recognition dataset, NTU-RGBD.
[ { "version": "v1", "created": "Fri, 14 Apr 2017 19:00:36 GMT" } ]
2017-04-18T00:00:00
[ [ "Kim", "Tae Soo", "" ], [ "Reiter", "Austin", "" ] ]
TITLE: Interpretable 3D Human Action Analysis with Temporal Convolutional Networks ABSTRACT: The discriminative power of modern deep learning models for 3D human action recognition is growing ever so potent. In conjunction with the recent resurgence of 3D human action representation with 3D skeletons, the quality and the pace of recent progress have been significant. However, the inner workings of state-of-the-art learning based methods in 3D human action recognition still remain mostly black-box. In this work, we propose to use a new class of models known as Temporal Convolutional Neural Networks (TCN) for 3D human action recognition. Compared to popular LSTM-based Recurrent Neural Network models, given interpretable input such as 3D skeletons, TCN provides us a way to explicitly learn readily interpretable spatio-temporal representations for 3D human action recognition. We provide our strategy in re-designing the TCN with interpretability in mind and how such characteristics of the model is leveraged to construct a powerful 3D activity recognition method. Through this work, we wish to take a step towards a spatio-temporal model that is easier to understand, explain and interpret. The resulting model, Res-TCN, achieves state-of-the-art results on the largest 3D human action recognition dataset, NTU-RGBD.
no_new_dataset
0.939081
1704.04723
Jalal Mahmud
Jalal Mahmud, Geli Fei, Anbang Xu, Aditya Pal, Michelle Zhou
Computational Models for Attitude and Actions Prediction
This is an extended version of a previously published IUI 2016 paper from same authors. http://dl.acm.org/citation.cfm?id=2856800
null
null
null
cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we present computational models to predict Twitter users' attitude towards a specific brand through their personal and social characteristics. We also predict their likelihood to take different actions based on their attitudes. In order to operationalize our research on users' attitude and actions, we collected ground-truth data through surveys of Twitter users. We have conducted experiments using two real world datasets to validate the effectiveness of our attitude and action prediction framework. Finally, we show how our models can be integrated with a visual analytics system for customer intervention.
[ { "version": "v1", "created": "Sun, 16 Apr 2017 05:03:22 GMT" } ]
2017-04-18T00:00:00
[ [ "Mahmud", "Jalal", "" ], [ "Fei", "Geli", "" ], [ "Xu", "Anbang", "" ], [ "Pal", "Aditya", "" ], [ "Zhou", "Michelle", "" ] ]
TITLE: Computational Models for Attitude and Actions Prediction ABSTRACT: In this paper, we present computational models to predict Twitter users' attitude towards a specific brand through their personal and social characteristics. We also predict their likelihood to take different actions based on their attitudes. In order to operationalize our research on users' attitude and actions, we collected ground-truth data through surveys of Twitter users. We have conducted experiments using two real world datasets to validate the effectiveness of our attitude and action prediction framework. Finally, we show how our models can be integrated with a visual analytics system for customer intervention.
no_new_dataset
0.943815
1704.04799
Alexander Jung
Saeed Basirian and Alexander Jung
Random Walk Sampling for Big Data over Networks
null
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has been shown recently that graph signals with small total variation can be accurately recovered from only few samples if the sampling set satisfies a certain condition, referred to as the network nullspace property. Based on this recovery condition, we propose a sampling strategy for smooth graph signals based on random walks. Numerical experiments demonstrate the effectiveness of this approach for graph signals obtained from a synthetic random graph model as well as a real-world dataset.
[ { "version": "v1", "created": "Sun, 16 Apr 2017 17:43:38 GMT" } ]
2017-04-18T00:00:00
[ [ "Basirian", "Saeed", "" ], [ "Jung", "Alexander", "" ] ]
TITLE: Random Walk Sampling for Big Data over Networks ABSTRACT: It has been shown recently that graph signals with small total variation can be accurately recovered from only few samples if the sampling set satisfies a certain condition, referred to as the network nullspace property. Based on this recovery condition, we propose a sampling strategy for smooth graph signals based on random walks. Numerical experiments demonstrate the effectiveness of this approach for graph signals obtained from a synthetic random graph model as well as a real-world dataset.
no_new_dataset
0.954095
1704.04865
Felix Juefei-Xu
Felix Juefei-Xu, Vishnu Naresh Boddeti, Marios Savvides
Gang of GANs: Generative Adversarial Networks with Maximum Margin Ranking
16 pages. 11 figures
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Traditional generative adversarial networks (GAN) and many of its variants are trained by minimizing the KL or JS-divergence loss that measures how close the generated data distribution is from the true data distribution. A recent advance called the WGAN based on Wasserstein distance can improve on the KL and JS-divergence based GANs, and alleviate the gradient vanishing, instability, and mode collapse issues that are common in the GAN training. In this work, we aim at improving on the WGAN by first generalizing its discriminator loss to a margin-based one, which leads to a better discriminator, and in turn a better generator, and then carrying out a progressive training paradigm involving multiple GANs to contribute to the maximum margin ranking loss so that the GAN at later stages will improve upon early stages. We call this method Gang of GANs (GoGAN). We have shown theoretically that the proposed GoGAN can reduce the gap between the true data distribution and the generated data distribution by at least half in an optimally trained WGAN. We have also proposed a new way of measuring GAN quality which is based on image completion tasks. We have evaluated our method on four visual datasets: CelebA, LSUN Bedroom, CIFAR-10, and 50K-SSFF, and have seen both visual and quantitative improvement over baseline WGAN.
[ { "version": "v1", "created": "Mon, 17 Apr 2017 04:42:56 GMT" } ]
2017-04-18T00:00:00
[ [ "Juefei-Xu", "Felix", "" ], [ "Boddeti", "Vishnu Naresh", "" ], [ "Savvides", "Marios", "" ] ]
TITLE: Gang of GANs: Generative Adversarial Networks with Maximum Margin Ranking ABSTRACT: Traditional generative adversarial networks (GAN) and many of its variants are trained by minimizing the KL or JS-divergence loss that measures how close the generated data distribution is from the true data distribution. A recent advance called the WGAN based on Wasserstein distance can improve on the KL and JS-divergence based GANs, and alleviate the gradient vanishing, instability, and mode collapse issues that are common in the GAN training. In this work, we aim at improving on the WGAN by first generalizing its discriminator loss to a margin-based one, which leads to a better discriminator, and in turn a better generator, and then carrying out a progressive training paradigm involving multiple GANs to contribute to the maximum margin ranking loss so that the GAN at later stages will improve upon early stages. We call this method Gang of GANs (GoGAN). We have shown theoretically that the proposed GoGAN can reduce the gap between the true data distribution and the generated data distribution by at least half in an optimally trained WGAN. We have also proposed a new way of measuring GAN quality which is based on image completion tasks. We have evaluated our method on four visual datasets: CelebA, LSUN Bedroom, CIFAR-10, and 50K-SSFF, and have seen both visual and quantitative improvement over baseline WGAN.
no_new_dataset
0.948585
1704.04962
Thomas Brouwer
Thomas Brouwer, Pietro Li\'o
Bayesian Hybrid Matrix Factorisation for Data Integration
Proceedings of the 20th International Conference on Artificial Intelligence and Statistics (AISTATS 2017)
PMLR 54:557-566, 2017
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a novel Bayesian hybrid matrix factorisation model (HMF) for data integration, based on combining multiple matrix factorisation methods, that can be used for in- and out-of-matrix prediction of missing values. The model is very general and can be used to integrate many datasets across different entity types, including repeated experiments, similarity matrices, and very sparse datasets. We apply our method on two biological applications, and extensively compare it to state-of-the-art machine learning and matrix factorisation models. For in-matrix predictions on drug sensitivity datasets we obtain consistently better performances than existing methods. This is especially the case when we increase the sparsity of the datasets. Furthermore, we perform out-of-matrix predictions on methylation and gene expression datasets, and obtain the best results on two of the three datasets, especially when the predictivity of datasets is high.
[ { "version": "v1", "created": "Mon, 17 Apr 2017 13:39:29 GMT" } ]
2017-04-18T00:00:00
[ [ "Brouwer", "Thomas", "" ], [ "Lió", "Pietro", "" ] ]
TITLE: Bayesian Hybrid Matrix Factorisation for Data Integration ABSTRACT: We introduce a novel Bayesian hybrid matrix factorisation model (HMF) for data integration, based on combining multiple matrix factorisation methods, that can be used for in- and out-of-matrix prediction of missing values. The model is very general and can be used to integrate many datasets across different entity types, including repeated experiments, similarity matrices, and very sparse datasets. We apply our method on two biological applications, and extensively compare it to state-of-the-art machine learning and matrix factorisation models. For in-matrix predictions on drug sensitivity datasets we obtain consistently better performances than existing methods. This is especially the case when we increase the sparsity of the datasets. Furthermore, we perform out-of-matrix predictions on methylation and gene expression datasets, and obtain the best results on two of the three datasets, especially when the predictivity of datasets is high.
no_new_dataset
0.950041
1704.05017
Mathieu Galtier
Mathieu Galtier and Camille Marini
Morpheo: Traceable Machine Learning on Hidden data
whitepaper, 9 pages, 6 figures
null
null
null
cs.AI cs.CR cs.DC stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Morpheo is a transparent and secure machine learning platform collecting and analysing large datasets. It aims at building state-of-the art prediction models in various fields where data are sensitive. Indeed, it offers strong privacy of data and algorithm, by preventing anyone to read the data, apart from the owner and the chosen algorithms. Computations in Morpheo are orchestrated by a blockchain infrastructure, thus offering total traceability of operations. Morpheo aims at building an attractive economic ecosystem around data prediction by channelling crypto-money from prediction requests to useful data and algorithms providers. Morpheo is designed to handle multiple data sources in a transfer learning approach in order to mutualize knowledge acquired from large datasets for applications with smaller but similar datasets.
[ { "version": "v1", "created": "Mon, 17 Apr 2017 16:24:29 GMT" } ]
2017-04-18T00:00:00
[ [ "Galtier", "Mathieu", "" ], [ "Marini", "Camille", "" ] ]
TITLE: Morpheo: Traceable Machine Learning on Hidden data ABSTRACT: Morpheo is a transparent and secure machine learning platform collecting and analysing large datasets. It aims at building state-of-the art prediction models in various fields where data are sensitive. Indeed, it offers strong privacy of data and algorithm, by preventing anyone to read the data, apart from the owner and the chosen algorithms. Computations in Morpheo are orchestrated by a blockchain infrastructure, thus offering total traceability of operations. Morpheo aims at building an attractive economic ecosystem around data prediction by channelling crypto-money from prediction requests to useful data and algorithms providers. Morpheo is designed to handle multiple data sources in a transfer learning approach in order to mutualize knowledge acquired from large datasets for applications with smaller but similar datasets.
no_new_dataset
0.945298
1112.6209
Quoc Le
Quoc V. Le, Marc'Aurelio Ranzato, Rajat Monga, Matthieu Devin, Kai Chen, Greg S. Corrado, Jeff Dean, Andrew Y. Ng
Building high-level features using large scale unsupervised learning
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of building high-level, class-specific feature detectors from only unlabeled data. For example, is it possible to learn a face detector using only unlabeled images? To answer this, we train a 9-layered locally connected sparse autoencoder with pooling and local contrast normalization on a large dataset of images (the model has 1 billion connections, the dataset has 10 million 200x200 pixel images downloaded from the Internet). We train this network using model parallelism and asynchronous SGD on a cluster with 1,000 machines (16,000 cores) for three days. Contrary to what appears to be a widely-held intuition, our experimental results reveal that it is possible to train a face detector without having to label images as containing a face or not. Control experiments show that this feature detector is robust not only to translation but also to scaling and out-of-plane rotation. We also find that the same network is sensitive to other high-level concepts such as cat faces and human bodies. Starting with these learned features, we trained our network to obtain 15.8% accuracy in recognizing 20,000 object categories from ImageNet, a leap of 70% relative improvement over the previous state-of-the-art.
[ { "version": "v1", "created": "Thu, 29 Dec 2011 00:26:54 GMT" }, { "version": "v2", "created": "Tue, 22 May 2012 08:12:49 GMT" }, { "version": "v3", "created": "Tue, 12 Jun 2012 05:12:56 GMT" }, { "version": "v4", "created": "Wed, 11 Jul 2012 04:40:33 GMT" }, { "version": "v5", "created": "Thu, 12 Jul 2012 04:32:50 GMT" } ]
2017-04-17T00:00:00
[ [ "Le", "Quoc V.", "" ], [ "Ranzato", "Marc'Aurelio", "" ], [ "Monga", "Rajat", "" ], [ "Devin", "Matthieu", "" ], [ "Chen", "Kai", "" ], [ "Corrado", "Greg S.", "" ], [ "Dean", "Jeff", "" ], [ "Ng", "Andrew Y.", "" ] ]
TITLE: Building high-level features using large scale unsupervised learning ABSTRACT: We consider the problem of building high-level, class-specific feature detectors from only unlabeled data. For example, is it possible to learn a face detector using only unlabeled images? To answer this, we train a 9-layered locally connected sparse autoencoder with pooling and local contrast normalization on a large dataset of images (the model has 1 billion connections, the dataset has 10 million 200x200 pixel images downloaded from the Internet). We train this network using model parallelism and asynchronous SGD on a cluster with 1,000 machines (16,000 cores) for three days. Contrary to what appears to be a widely-held intuition, our experimental results reveal that it is possible to train a face detector without having to label images as containing a face or not. Control experiments show that this feature detector is robust not only to translation but also to scaling and out-of-plane rotation. We also find that the same network is sensitive to other high-level concepts such as cat faces and human bodies. Starting with these learned features, we trained our network to obtain 15.8% accuracy in recognizing 20,000 object categories from ImageNet, a leap of 70% relative improvement over the previous state-of-the-art.
no_new_dataset
0.939192
1703.05593
Ignacio Rocco
Ignacio Rocco, Relja Arandjelovi\'c, Josef Sivic
Convolutional neural network architecture for geometric matching
In 2017 IEEE Conference on Computer Vision and Pattern Recognition (CVPR 2017)
null
null
null
cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address the problem of determining correspondences between two images in agreement with a geometric model such as an affine or thin-plate spline transformation, and estimating its parameters. The contributions of this work are three-fold. First, we propose a convolutional neural network architecture for geometric matching. The architecture is based on three main components that mimic the standard steps of feature extraction, matching and simultaneous inlier detection and model parameter estimation, while being trainable end-to-end. Second, we demonstrate that the network parameters can be trained from synthetically generated imagery without the need for manual annotation and that our matching layer significantly increases generalization capabilities to never seen before images. Finally, we show that the same model can perform both instance-level and category-level matching giving state-of-the-art results on the challenging Proposal Flow dataset.
[ { "version": "v1", "created": "Thu, 16 Mar 2017 13:03:54 GMT" }, { "version": "v2", "created": "Thu, 13 Apr 2017 22:32:43 GMT" } ]
2017-04-17T00:00:00
[ [ "Rocco", "Ignacio", "" ], [ "Arandjelović", "Relja", "" ], [ "Sivic", "Josef", "" ] ]
TITLE: Convolutional neural network architecture for geometric matching ABSTRACT: We address the problem of determining correspondences between two images in agreement with a geometric model such as an affine or thin-plate spline transformation, and estimating its parameters. The contributions of this work are three-fold. First, we propose a convolutional neural network architecture for geometric matching. The architecture is based on three main components that mimic the standard steps of feature extraction, matching and simultaneous inlier detection and model parameter estimation, while being trainable end-to-end. Second, we demonstrate that the network parameters can be trained from synthetically generated imagery without the need for manual annotation and that our matching layer significantly increases generalization capabilities to never seen before images. Finally, we show that the same model can perform both instance-level and category-level matching giving state-of-the-art results on the challenging Proposal Flow dataset.
no_new_dataset
0.952574
1704.00057
Layla El Asri
Layla El Asri and Hannes Schulz and Shikhar Sharma and Jeremie Zumer and Justin Harris and Emery Fine and Rahul Mehrotra and Kaheer Suleman
Frames: A Corpus for Adding Memory to Goal-Oriented Dialogue Systems
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents the Frames dataset (Frames is available at http://datasets.maluuba.com/Frames), a corpus of 1369 human-human dialogues with an average of 15 turns per dialogue. We developed this dataset to study the role of memory in goal-oriented dialogue systems. Based on Frames, we introduce a task called frame tracking, which extends state tracking to a setting where several states are tracked simultaneously. We propose a baseline model for this task. We show that Frames can also be used to study memory in dialogue management and information presentation through natural language generation.
[ { "version": "v1", "created": "Fri, 31 Mar 2017 21:03:58 GMT" }, { "version": "v2", "created": "Thu, 13 Apr 2017 18:22:49 GMT" } ]
2017-04-17T00:00:00
[ [ "Asri", "Layla El", "" ], [ "Schulz", "Hannes", "" ], [ "Sharma", "Shikhar", "" ], [ "Zumer", "Jeremie", "" ], [ "Harris", "Justin", "" ], [ "Fine", "Emery", "" ], [ "Mehrotra", "Rahul", "" ], [ "Suleman", "Kaheer", "" ] ]
TITLE: Frames: A Corpus for Adding Memory to Goal-Oriented Dialogue Systems ABSTRACT: This paper presents the Frames dataset (Frames is available at http://datasets.maluuba.com/Frames), a corpus of 1369 human-human dialogues with an average of 15 turns per dialogue. We developed this dataset to study the role of memory in goal-oriented dialogue systems. Based on Frames, we introduce a task called frame tracking, which extends state tracking to a setting where several states are tracked simultaneously. We propose a baseline model for this task. We show that Frames can also be used to study memory in dialogue management and information presentation through natural language generation.
new_dataset
0.958538