id
stringlengths
9
16
submitter
stringlengths
3
64
authors
stringlengths
5
6.63k
title
stringlengths
7
245
comments
stringlengths
1
482
journal-ref
stringlengths
4
382
doi
stringlengths
9
151
report-no
stringclasses
984 values
categories
stringlengths
5
108
license
stringclasses
9 values
abstract
stringlengths
83
3.41k
versions
listlengths
1
20
update_date
timestamp[s]date
2007-05-23 00:00:00
2025-04-11 00:00:00
authors_parsed
sequencelengths
1
427
prompt
stringlengths
166
3.49k
label
stringclasses
2 values
prob
float64
0.5
0.98
1603.03656
Nick Feamster
Nick Feamster
Revealing Utilization at Internet Interconnection Points
null
null
null
null
cs.NI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent Internet interconnection disputes have sparked an in- creased interest in developing methods for gathering and collecting data about utilization at interconnection points. One mechanism, developed by DeepField Networks, allows Internet service providers (ISPs) to gather and aggregate utilization information using network flow statistics, standardized in the Internet Engineering Task Force as IPFIX. This report (1) provides an overview of the method that DeepField Networks is using to measure the utilization of various interconnection links between content providers and ISPs or links over which traffic between content and ISPs flow; and (2) surveys the findings from five months of Internet utilization data provided by seven participating ISPs---Bright House Networks, Comcast, Cox, Mediacom, Midco, Suddenlink, and Time Warner Cable---whose access networks represent about 50% of all U.S. broadband subscribers. The dataset includes about 97% of the paid peering, settlement-free peering, and ISP-paid transit links of each of the participating ISPs. Initial analysis of the data---which comprises more than 1,000 link groups, representing the diverse and substitutable available routes---suggests that many interconnects have significant spare capacity, that this spare capacity exists both across ISPs in each region and in aggregate for any individual ISP, and that the aggregate utilization across interconnects interconnects is roughly 50% during peak periods.
[ { "version": "v1", "created": "Fri, 11 Mar 2016 15:06:18 GMT" }, { "version": "v2", "created": "Mon, 5 Sep 2016 01:10:58 GMT" } ]
2016-09-06T00:00:00
[ [ "Feamster", "Nick", "" ] ]
TITLE: Revealing Utilization at Internet Interconnection Points ABSTRACT: Recent Internet interconnection disputes have sparked an in- creased interest in developing methods for gathering and collecting data about utilization at interconnection points. One mechanism, developed by DeepField Networks, allows Internet service providers (ISPs) to gather and aggregate utilization information using network flow statistics, standardized in the Internet Engineering Task Force as IPFIX. This report (1) provides an overview of the method that DeepField Networks is using to measure the utilization of various interconnection links between content providers and ISPs or links over which traffic between content and ISPs flow; and (2) surveys the findings from five months of Internet utilization data provided by seven participating ISPs---Bright House Networks, Comcast, Cox, Mediacom, Midco, Suddenlink, and Time Warner Cable---whose access networks represent about 50% of all U.S. broadband subscribers. The dataset includes about 97% of the paid peering, settlement-free peering, and ISP-paid transit links of each of the participating ISPs. Initial analysis of the data---which comprises more than 1,000 link groups, representing the diverse and substitutable available routes---suggests that many interconnects have significant spare capacity, that this spare capacity exists both across ISPs in each region and in aggregate for any individual ISP, and that the aggregate utilization across interconnects interconnects is roughly 50% during peak periods.
no_new_dataset
0.933915
1607.07959
Ansaf Salleb-Aouissi
Ilia Vovsha, Ansaf Salleb-Aouissi, Anita Raja, Thomas Koch, Alex Rybchuk, Axinia Radeva, Ashwath Rajan, Yiwen Huang, Hatim Diab, Ashish Tomar, and Ronald Wapner
Using Kernel Methods and Model Selection for Prediction of Preterm Birth
Presented at 2016 Machine Learning and Healthcare Conference (MLHC 2016), Los Angeles, CA. In this revision, we updated page 4 by adding the reference Vovsha et al. (2013) (incorrectly referenced as XXX in the previous version due to double blind reviewing). The bibtex entry is now added to the references
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe an application of machine learning to the problem of predicting preterm birth. We conduct a secondary analysis on a clinical trial dataset collected by the National In- stitute of Child Health and Human Development (NICHD) while focusing our attention on predicting different classes of preterm birth. We compare three approaches for deriving predictive models: a support vector machine (SVM) approach with linear and non-linear kernels, logistic regression with different model selection along with a model based on decision rules prescribed by physician experts for prediction of preterm birth. Our approach highlights the pre-processing methods applied to handle the inherent dynamics, noise and gaps in the data and describe techniques used to handle skewed class distributions. Empirical experiments demonstrate significant improvement in predicting preterm birth compared to past work.
[ { "version": "v1", "created": "Wed, 27 Jul 2016 04:56:57 GMT" }, { "version": "v2", "created": "Mon, 5 Sep 2016 12:25:00 GMT" } ]
2016-09-06T00:00:00
[ [ "Vovsha", "Ilia", "" ], [ "Salleb-Aouissi", "Ansaf", "" ], [ "Raja", "Anita", "" ], [ "Koch", "Thomas", "" ], [ "Rybchuk", "Alex", "" ], [ "Radeva", "Axinia", "" ], [ "Rajan", "Ashwath", "" ], [ "Huang", "Yiwen", "" ], [ "Diab", "Hatim", "" ], [ "Tomar", "Ashish", "" ], [ "Wapner", "Ronald", "" ] ]
TITLE: Using Kernel Methods and Model Selection for Prediction of Preterm Birth ABSTRACT: We describe an application of machine learning to the problem of predicting preterm birth. We conduct a secondary analysis on a clinical trial dataset collected by the National In- stitute of Child Health and Human Development (NICHD) while focusing our attention on predicting different classes of preterm birth. We compare three approaches for deriving predictive models: a support vector machine (SVM) approach with linear and non-linear kernels, logistic regression with different model selection along with a model based on decision rules prescribed by physician experts for prediction of preterm birth. Our approach highlights the pre-processing methods applied to handle the inherent dynamics, noise and gaps in the data and describe techniques used to handle skewed class distributions. Empirical experiments demonstrate significant improvement in predicting preterm birth compared to past work.
no_new_dataset
0.945096
1608.02875
Haishan Ye
Haishan Ye, Luo Luo and Zhihua Zhang
Revisiting Sub-sampled Newton Methods
null
null
null
null
math.OC cs.NA
http://creativecommons.org/licenses/by/4.0/
Many machine learning models depend on solving a large scale optimization problem. Recently, sub-sampled Newton methods have emerged to attract much attention for optimization due to their efficiency at each iteration, rectified a weakness in the ordinary Newton method of suffering a high cost at each iteration while commanding a high convergence rate. In this work we propose two new efficient Newton-type methods, Refined Sub-sampled Newton and Refined Sketch Newton. Our methods exhibit a great advantage over existing sub-sampled Newton methods, especially when Hessian-vector multiplication can be calculated efficiently. Specifically, the proposed methods are shown to converge superlinearly in general case and quadratically under a little stronger assumption. The proposed methods can be generalized to a unifying framework for the convergence proof of several existing sub-sampled Newton methods, revealing new convergence properties. Finally, we empirically evaluate the performance of our methods on several standard datasets and the results show consistent improvement in computational efficiency.
[ { "version": "v1", "created": "Mon, 8 Aug 2016 03:30:12 GMT" }, { "version": "v2", "created": "Mon, 5 Sep 2016 03:57:35 GMT" } ]
2016-09-06T00:00:00
[ [ "Ye", "Haishan", "" ], [ "Luo", "Luo", "" ], [ "Zhang", "Zhihua", "" ] ]
TITLE: Revisiting Sub-sampled Newton Methods ABSTRACT: Many machine learning models depend on solving a large scale optimization problem. Recently, sub-sampled Newton methods have emerged to attract much attention for optimization due to their efficiency at each iteration, rectified a weakness in the ordinary Newton method of suffering a high cost at each iteration while commanding a high convergence rate. In this work we propose two new efficient Newton-type methods, Refined Sub-sampled Newton and Refined Sketch Newton. Our methods exhibit a great advantage over existing sub-sampled Newton methods, especially when Hessian-vector multiplication can be calculated efficiently. Specifically, the proposed methods are shown to converge superlinearly in general case and quadratically under a little stronger assumption. The proposed methods can be generalized to a unifying framework for the convergence proof of several existing sub-sampled Newton methods, revealing new convergence properties. Finally, we empirically evaluate the performance of our methods on several standard datasets and the results show consistent improvement in computational efficiency.
no_new_dataset
0.947817
1608.05921
Dongwoo Kim
Dongwoo Kim, Lexing Xie, Cheng Soon Ong
Probabilistic Knowledge Graph Construction: Compositional and Incremental Approaches
The 25th ACM International Conference on Information and Knowledge Management (CIKM 2016)
null
10.1145/2983323.2983677
null
stat.ML cs.AI cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Knowledge graph construction consists of two tasks: extracting information from external resources (knowledge population) and inferring missing information through a statistical analysis on the extracted information (knowledge completion). In many cases, insufficient external resources in the knowledge population hinder the subsequent statistical inference. The gap between these two processes can be reduced by an incremental population approach. We propose a new probabilistic knowledge graph factorisation method that benefits from the path structure of existing knowledge (e.g. syllogism) and enables a common modelling approach to be used for both incremental population and knowledge completion tasks. More specifically, the probabilistic formulation allows us to develop an incremental population algorithm that trades off exploitation-exploration. Experiments on three benchmark datasets show that the balanced exploitation-exploration helps the incremental population, and the additional path structure helps to predict missing information in knowledge completion.
[ { "version": "v1", "created": "Sun, 21 Aug 2016 11:49:53 GMT" }, { "version": "v2", "created": "Mon, 5 Sep 2016 04:52:33 GMT" } ]
2016-09-06T00:00:00
[ [ "Kim", "Dongwoo", "" ], [ "Xie", "Lexing", "" ], [ "Ong", "Cheng Soon", "" ] ]
TITLE: Probabilistic Knowledge Graph Construction: Compositional and Incremental Approaches ABSTRACT: Knowledge graph construction consists of two tasks: extracting information from external resources (knowledge population) and inferring missing information through a statistical analysis on the extracted information (knowledge completion). In many cases, insufficient external resources in the knowledge population hinder the subsequent statistical inference. The gap between these two processes can be reduced by an incremental population approach. We propose a new probabilistic knowledge graph factorisation method that benefits from the path structure of existing knowledge (e.g. syllogism) and enables a common modelling approach to be used for both incremental population and knowledge completion tasks. More specifically, the probabilistic formulation allows us to develop an incremental population algorithm that trades off exploitation-exploration. Experiments on three benchmark datasets show that the balanced exploitation-exploration helps the incremental population, and the additional path structure helps to predict missing information in knowledge completion.
no_new_dataset
0.949153
1608.08435
Rajasekar Venkatesan
Rajasekar Venkatesan, Meng Joo Er
Multi-Label Classification Method Based on Extreme Learning Machines
6 pages, 7 figures, 7 tables, ICARCV
null
10.1109/ICARCV.2014.7064375
null
cs.LG cs.AI cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, an Extreme Learning Machine (ELM) based technique for Multi-label classification problems is proposed and discussed. In multi-label classification, each of the input data samples belongs to one or more than one class labels. The traditional binary and multi-class classification problems are the subset of the multi-label problem with the number of labels corresponding to each sample limited to one. The proposed ELM based multi-label classification technique is evaluated with six different benchmark multi-label datasets from different domains such as multimedia, text and biology. A detailed comparison of the results is made by comparing the proposed method with the results from nine state of the arts techniques for five different evaluation metrics. The nine methods are chosen from different categories of multi-label methods. The comparative results shows that the proposed Extreme Learning Machine based multi-label classification technique is a better alternative than the existing state of the art methods for multi-label problems.
[ { "version": "v1", "created": "Tue, 30 Aug 2016 13:08:06 GMT" } ]
2016-09-06T00:00:00
[ [ "Venkatesan", "Rajasekar", "" ], [ "Er", "Meng Joo", "" ] ]
TITLE: Multi-Label Classification Method Based on Extreme Learning Machines ABSTRACT: In this paper, an Extreme Learning Machine (ELM) based technique for Multi-label classification problems is proposed and discussed. In multi-label classification, each of the input data samples belongs to one or more than one class labels. The traditional binary and multi-class classification problems are the subset of the multi-label problem with the number of labels corresponding to each sample limited to one. The proposed ELM based multi-label classification technique is evaluated with six different benchmark multi-label datasets from different domains such as multimedia, text and biology. A detailed comparison of the results is made by comparing the proposed method with the results from nine state of the arts techniques for five different evaluation metrics. The nine methods are chosen from different categories of multi-label methods. The comparative results shows that the proposed Extreme Learning Machine based multi-label classification technique is a better alternative than the existing state of the art methods for multi-label problems.
no_new_dataset
0.949623
1608.08898
Rajasekar Venkatesan
Meng Joo Er, Rajasekar Venkatesan and Ning Wang
A High Speed Multi-label Classifier based on Extreme Learning Machines
12 pages, 2 figures, 10 tables
null
10.1007/978-3-319-28373-9_37
null
cs.LG cs.AI cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper a high speed neural network classifier based on extreme learning machines for multi-label classification problem is proposed and dis-cussed. Multi-label classification is a superset of traditional binary and multi-class classification problems. The proposed work extends the extreme learning machine technique to adapt to the multi-label problems. As opposed to the single-label problem, both the number of labels the sample belongs to, and each of those target labels are to be identified for multi-label classification resulting in in-creased complexity. The proposed high speed multi-label classifier is applied to six benchmark datasets comprising of different application areas such as multi-media, text and biology. The training time and testing time of the classifier are compared with those of the state-of-the-arts methods. Experimental studies show that for all the six datasets, our proposed technique have faster execution speed and better performance, thereby outperforming all the existing multi-label clas-sification methods.
[ { "version": "v1", "created": "Wed, 31 Aug 2016 14:56:12 GMT" } ]
2016-09-06T00:00:00
[ [ "Er", "Meng Joo", "" ], [ "Venkatesan", "Rajasekar", "" ], [ "Wang", "Ning", "" ] ]
TITLE: A High Speed Multi-label Classifier based on Extreme Learning Machines ABSTRACT: In this paper a high speed neural network classifier based on extreme learning machines for multi-label classification problem is proposed and dis-cussed. Multi-label classification is a superset of traditional binary and multi-class classification problems. The proposed work extends the extreme learning machine technique to adapt to the multi-label problems. As opposed to the single-label problem, both the number of labels the sample belongs to, and each of those target labels are to be identified for multi-label classification resulting in in-creased complexity. The proposed high speed multi-label classifier is applied to six benchmark datasets comprising of different application areas such as multi-media, text and biology. The training time and testing time of the classifier are compared with those of the state-of-the-arts methods. Experimental studies show that for all the six datasets, our proposed technique have faster execution speed and better performance, thereby outperforming all the existing multi-label clas-sification methods.
no_new_dataset
0.947721
1609.00086
Rajasekar Venkatesan
Rajasekar Venkatesan, Meng Joo Er, Mihika Dave, Mahardhika Pratama, Shiqian Wu
A novel online multi-label classifier for high-speed streaming data applications
18 pages, 7 tables, 3 figures. arXiv admin note: text overlap with arXiv:1608.08898
null
10.1007/s12530-016-9162-8
null
cs.LG cs.AI cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, a high-speed online neural network classifier based on extreme learning machines for multi-label classification is proposed. In multi-label classification, each of the input data sample belongs to one or more than one of the target labels. The traditional binary and multi-class classification where each sample belongs to only one target class forms the subset of multi-label classification. Multi-label classification problems are far more complex than binary and multi-class classification problems, as both the number of target labels and each of the target labels corresponding to each of the input samples are to be identified. The proposed work exploits the high-speed nature of the extreme learning machines to achieve real-time multi-label classification of streaming data. A new threshold-based online sequential learning algorithm is proposed for high speed and streaming data classification of multi-label problems. The proposed method is experimented with six different datasets from different application domains such as multimedia, text, and biology. The hamming loss, accuracy, training time and testing time of the proposed technique is compared with nine different state-of-the-art methods. Experimental studies shows that the proposed technique outperforms the existing multi-label classifiers in terms of performance and speed.
[ { "version": "v1", "created": "Thu, 1 Sep 2016 01:58:50 GMT" } ]
2016-09-06T00:00:00
[ [ "Venkatesan", "Rajasekar", "" ], [ "Er", "Meng Joo", "" ], [ "Dave", "Mihika", "" ], [ "Pratama", "Mahardhika", "" ], [ "Wu", "Shiqian", "" ] ]
TITLE: A novel online multi-label classifier for high-speed streaming data applications ABSTRACT: In this paper, a high-speed online neural network classifier based on extreme learning machines for multi-label classification is proposed. In multi-label classification, each of the input data sample belongs to one or more than one of the target labels. The traditional binary and multi-class classification where each sample belongs to only one target class forms the subset of multi-label classification. Multi-label classification problems are far more complex than binary and multi-class classification problems, as both the number of target labels and each of the target labels corresponding to each of the input samples are to be identified. The proposed work exploits the high-speed nature of the extreme learning machines to achieve real-time multi-label classification of streaming data. A new threshold-based online sequential learning algorithm is proposed for high speed and streaming data classification of multi-label problems. The proposed method is experimented with six different datasets from different application domains such as multimedia, text, and biology. The hamming loss, accuracy, training time and testing time of the proposed technique is compared with nine different state-of-the-art methods. Experimental studies shows that the proposed technique outperforms the existing multi-label classifiers in terms of performance and speed.
no_new_dataset
0.948537
1609.00435
David Jurgens
David Jurgens, Srijan Kumar, Raine Hoover, Dan McFarland, Dan Jurafsky
Citation Classification for Behavioral Analysis of a Scientific Field
null
null
null
null
cs.CL cs.DL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Citations are an important indicator of the state of a scientific field, reflecting how authors frame their work, and influencing uptake by future scholars. However, our understanding of citation behavior has been limited to small-scale manual citation analysis. We perform the largest behavioral study of citations to date, analyzing how citations are both framed and taken up by scholars in one entire field: natural language processing. We introduce a new dataset of nearly 2,000 citations annotated for function and centrality, and use it to develop a state-of-the-art classifier and label the entire ACL Reference Corpus. We then study how citations are framed by authors and use both papers and online traces to track how citations are followed by readers. We demonstrate that authors are sensitive to discourse structure and publication venue when citing, that online readers follow temporal links to previous and future work rather than methodological links, and that how a paper cites related work is predictive of its citation count. Finally, we use changes in citation roles to show that the field of NLP is undergoing a significant increase in consensus.
[ { "version": "v1", "created": "Fri, 2 Sep 2016 00:40:15 GMT" } ]
2016-09-06T00:00:00
[ [ "Jurgens", "David", "" ], [ "Kumar", "Srijan", "" ], [ "Hoover", "Raine", "" ], [ "McFarland", "Dan", "" ], [ "Jurafsky", "Dan", "" ] ]
TITLE: Citation Classification for Behavioral Analysis of a Scientific Field ABSTRACT: Citations are an important indicator of the state of a scientific field, reflecting how authors frame their work, and influencing uptake by future scholars. However, our understanding of citation behavior has been limited to small-scale manual citation analysis. We perform the largest behavioral study of citations to date, analyzing how citations are both framed and taken up by scholars in one entire field: natural language processing. We introduce a new dataset of nearly 2,000 citations annotated for function and centrality, and use it to develop a state-of-the-art classifier and label the entire ACL Reference Corpus. We then study how citations are framed by authors and use both papers and online traces to track how citations are followed by readers. We demonstrate that authors are sensitive to discourse structure and publication venue when citing, that online readers follow temporal links to previous and future work rather than methodological links, and that how a paper cites related work is predictive of its citation count. Finally, we use changes in citation roles to show that the field of NLP is undergoing a significant increase in consensus.
new_dataset
0.965152
1609.00843
Rajasekar Venkatesan
Meng Joo Er, Rajasekar Venkatesan, Ning Wang
An Online Universal Classifier for Binary, Multi-class and Multi-label Classification
6 pages, 6 tables
null
null
null
cs.LG cs.AI cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Classification involves the learning of the mapping function that associates input samples to corresponding target label. There are two major categories of classification problems: Single-label classification and Multi-label classification. Traditional binary and multi-class classifications are sub-categories of single-label classification. Several classifiers are developed for binary, multi-class and multi-label classification problems, but there are no classifiers available in the literature capable of performing all three types of classification. In this paper, a novel online universal classifier capable of performing all the three types of classification is proposed. Being a high speed online classifier, the proposed technique can be applied to streaming data applications. The performance of the developed classifier is evaluated using datasets from binary, multi-class and multi-label problems. The results obtained are compared with state-of-the-art techniques from each of the classification types.
[ { "version": "v1", "created": "Sat, 3 Sep 2016 17:03:14 GMT" } ]
2016-09-06T00:00:00
[ [ "Er", "Meng Joo", "" ], [ "Venkatesan", "Rajasekar", "" ], [ "Wang", "Ning", "" ] ]
TITLE: An Online Universal Classifier for Binary, Multi-class and Multi-label Classification ABSTRACT: Classification involves the learning of the mapping function that associates input samples to corresponding target label. There are two major categories of classification problems: Single-label classification and Multi-label classification. Traditional binary and multi-class classifications are sub-categories of single-label classification. Several classifiers are developed for binary, multi-class and multi-label classification problems, but there are no classifiers available in the literature capable of performing all three types of classification. In this paper, a novel online universal classifier capable of performing all the three types of classification is proposed. Being a high speed online classifier, the proposed technique can be applied to streaming data applications. The performance of the developed classifier is evaluated using datasets from binary, multi-class and multi-label problems. The results obtained are compared with state-of-the-art techniques from each of the classification types.
no_new_dataset
0.946001
1609.00845
Kwang-Sung Jun
Kwang-Sung Jun and Robert Nowak
Graph-Based Active Learning: A New Look at Expected Error Minimization
Submitted to GlobalSIP 2016
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In graph-based active learning, algorithms based on expected error minimization (EEM) have been popular and yield good empirical performance. The exact computation of EEM optimally balances exploration and exploitation. In practice, however, EEM-based algorithms employ various approximations due to the computational hardness of exact EEM. This can result in a lack of either exploration or exploitation, which can negatively impact the effectiveness of active learning. We propose a new algorithm TSA (Two-Step Approximation) that balances between exploration and exploitation efficiently while enjoying the same computational complexity as existing approximations. Finally, we empirically show the value of balancing between exploration and exploitation in both toy and real-world datasets where our method outperforms several state-of-the-art methods.
[ { "version": "v1", "created": "Sat, 3 Sep 2016 17:30:15 GMT" } ]
2016-09-06T00:00:00
[ [ "Jun", "Kwang-Sung", "" ], [ "Nowak", "Robert", "" ] ]
TITLE: Graph-Based Active Learning: A New Look at Expected Error Minimization ABSTRACT: In graph-based active learning, algorithms based on expected error minimization (EEM) have been popular and yield good empirical performance. The exact computation of EEM optimally balances exploration and exploitation. In practice, however, EEM-based algorithms employ various approximations due to the computational hardness of exact EEM. This can result in a lack of either exploration or exploitation, which can negatively impact the effectiveness of active learning. We propose a new algorithm TSA (Two-Step Approximation) that balances between exploration and exploitation efficiently while enjoying the same computational complexity as existing approximations. Finally, we empirically show the value of balancing between exploration and exploitation in both toy and real-world datasets where our method outperforms several state-of-the-art methods.
no_new_dataset
0.944536
1609.00878
Joao Papa
Silas E. N. Fernandes, Danillo R. Pereira, Caio C. O. Ramos, Andre N. Souza and Joao P. Papa
A Probabilistic Optimum-Path Forest Classifier for Binary Classification Problems
Submitted to Neural Processing Letters
null
null
null
cs.CV cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Probabilistic-driven classification techniques extend the role of traditional approaches that output labels (usually integer numbers) only. Such techniques are more fruitful when dealing with problems where one is not interested in recognition/identification only, but also into monitoring the behavior of consumers and/or machines, for instance. Therefore, by means of probability estimates, one can take decisions to work better in a number of scenarios. In this paper, we propose a probabilistic-based Optimum Path Forest (OPF) classifier to handle with binary classification problems, and we show it can be more accurate than naive OPF in a number of datasets. In addition to being just more accurate or not, probabilistic OPF turns to be another useful tool to the scientific community.
[ { "version": "v1", "created": "Sun, 4 Sep 2016 00:12:04 GMT" } ]
2016-09-06T00:00:00
[ [ "Fernandes", "Silas E. N.", "" ], [ "Pereira", "Danillo R.", "" ], [ "Ramos", "Caio C. O.", "" ], [ "Souza", "Andre N.", "" ], [ "Papa", "Joao P.", "" ] ]
TITLE: A Probabilistic Optimum-Path Forest Classifier for Binary Classification Problems ABSTRACT: Probabilistic-driven classification techniques extend the role of traditional approaches that output labels (usually integer numbers) only. Such techniques are more fruitful when dealing with problems where one is not interested in recognition/identification only, but also into monitoring the behavior of consumers and/or machines, for instance. Therefore, by means of probability estimates, one can take decisions to work better in a number of scenarios. In this paper, we propose a probabilistic-based Optimum Path Forest (OPF) classifier to handle with binary classification problems, and we show it can be more accurate than naive OPF in a number of datasets. In addition to being just more accurate or not, probabilistic OPF turns to be another useful tool to the scientific community.
no_new_dataset
0.950503
1609.00904
Eric Holloway
Eric Holloway and Robert Marks II
High Dimensional Human Guided Machine Learning
3 pages, 1 figure, HCOMP 2016 submission, work in progress
null
null
null
cs.AI cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Have you ever looked at a machine learning classification model and thought, I could have made that? Well, that is what we test in this project, comparing XGBoost trained on human engineered features to training directly on data. The human engineered features do not outperform XGBoost trained di- rectly on the data, but they are comparable. This project con- tributes a novel method for utilizing human created classifi- cation models on high dimensional datasets.
[ { "version": "v1", "created": "Sun, 4 Sep 2016 08:45:26 GMT" } ]
2016-09-06T00:00:00
[ [ "Holloway", "Eric", "" ], [ "Marks", "Robert", "II" ] ]
TITLE: High Dimensional Human Guided Machine Learning ABSTRACT: Have you ever looked at a machine learning classification model and thought, I could have made that? Well, that is what we test in this project, comparing XGBoost trained on human engineered features to training directly on data. The human engineered features do not outperform XGBoost trained di- rectly on the data, but they are comparable. This project con- tributes a novel method for utilizing human created classifi- cation models on high dimensional datasets.
no_new_dataset
0.948298
1609.00921
Muhammad Yousefnezhad
Muhammad Yousefnezhad and Daoqiang Zhang
Decoding visual stimuli in human brain by using Anatomical Pattern Analysis on fMRI images
The 8th International Conference on Brain Inspired Cognitive Systems (BICS'16), Beijing, China, Nov/28-30/2016
null
null
null
stat.ML cs.LG q-bio.NC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A universal unanswered question in neuroscience and machine learning is whether computers can decode the patterns of the human brain. Multi-Voxels Pattern Analysis (MVPA) is a critical tool for addressing this question. However, there are two challenges in the previous MVPA methods, which include decreasing sparsity and noises in the extracted features and increasing the performance of prediction. In overcoming mentioned challenges, this paper proposes Anatomical Pattern Analysis (APA) for decoding visual stimuli in the human brain. This framework develops a novel anatomical feature extraction method and a new imbalance AdaBoost algorithm for binary classification. Further, it utilizes an Error-Correcting Output Codes (ECOC) method for multi-class prediction. APA can automatically detect active regions for each category of the visual stimuli. Moreover, it enables us to combine homogeneous datasets for applying advanced classification. Experimental studies on 4 visual categories (words, consonants, objects and scrambled photos) demonstrate that the proposed approach achieves superior performance to state-of-the-art methods.
[ { "version": "v1", "created": "Sun, 4 Sep 2016 12:01:50 GMT" } ]
2016-09-06T00:00:00
[ [ "Yousefnezhad", "Muhammad", "" ], [ "Zhang", "Daoqiang", "" ] ]
TITLE: Decoding visual stimuli in human brain by using Anatomical Pattern Analysis on fMRI images ABSTRACT: A universal unanswered question in neuroscience and machine learning is whether computers can decode the patterns of the human brain. Multi-Voxels Pattern Analysis (MVPA) is a critical tool for addressing this question. However, there are two challenges in the previous MVPA methods, which include decreasing sparsity and noises in the extracted features and increasing the performance of prediction. In overcoming mentioned challenges, this paper proposes Anatomical Pattern Analysis (APA) for decoding visual stimuli in the human brain. This framework develops a novel anatomical feature extraction method and a new imbalance AdaBoost algorithm for binary classification. Further, it utilizes an Error-Correcting Output Codes (ECOC) method for multi-class prediction. APA can automatically detect active regions for each category of the visual stimuli. Moreover, it enables us to combine homogeneous datasets for applying advanced classification. Experimental studies on 4 visual categories (words, consonants, objects and scrambled photos) demonstrate that the proposed approach achieves superior performance to state-of-the-art methods.
no_new_dataset
0.946843
1609.00969
Christina Lioma Assoc. Prof
Casper Petersen and Jakob Grue Simonsen and Kalervo Jarvelin and Christina Lioma
Adaptive Distributional Extensions to DFR Ranking
null
null
null
null
cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Divergence From Randomness (DFR) ranking models assume that informative terms are distributed in a corpus differently than non-informative terms. Different statistical models (e.g. Poisson, geometric) are used to model the distribution of non-informative terms, producing different DFR models. An informative term is then detected by measuring the divergence of its distribution from the distribution of non-informative terms. However, there is little empirical evidence that the distributions of non-informative terms used in DFR actually fit current datasets. Practically this risks providing a poor separation between informative and non-informative terms, thus compromising the discriminative power of the ranking model. We present a novel extension to DFR, which first detects the best-fitting distribution of non-informative terms in a collection, and then adapts the ranking computation to this best-fitting distribution. We call this model Adaptive Distributional Ranking (ADR) because it adapts the ranking to the statistics of the specific dataset being processed each time. Experiments on TREC data show ADR to outperform DFR models (and their extensions) and be comparable in performance to a query likelihood language model (LM).
[ { "version": "v1", "created": "Sun, 4 Sep 2016 17:55:39 GMT" } ]
2016-09-06T00:00:00
[ [ "Petersen", "Casper", "" ], [ "Simonsen", "Jakob Grue", "" ], [ "Jarvelin", "Kalervo", "" ], [ "Lioma", "Christina", "" ] ]
TITLE: Adaptive Distributional Extensions to DFR Ranking ABSTRACT: Divergence From Randomness (DFR) ranking models assume that informative terms are distributed in a corpus differently than non-informative terms. Different statistical models (e.g. Poisson, geometric) are used to model the distribution of non-informative terms, producing different DFR models. An informative term is then detected by measuring the divergence of its distribution from the distribution of non-informative terms. However, there is little empirical evidence that the distributions of non-informative terms used in DFR actually fit current datasets. Practically this risks providing a poor separation between informative and non-informative terms, thus compromising the discriminative power of the ranking model. We present a novel extension to DFR, which first detects the best-fitting distribution of non-informative terms in a collection, and then adapts the ranking computation to this best-fitting distribution. We call this model Adaptive Distributional Ranking (ADR) because it adapts the ranking to the statistics of the specific dataset being processed each time. Experiments on TREC data show ADR to outperform DFR models (and their extensions) and be comparable in performance to a query likelihood language model (LM).
no_new_dataset
0.946349
1609.00990
Nhien-An Le-Khac
Nhien-An Le-Khac, Sammer Markos, Tahar Kechadi
A data mining-based solution for detecting suspicious money laundering cases in an investment bank
null
null
null
null
cs.DB cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Today, money laundering poses a serious threat not only to financial institutions but also to the nation. This criminal activity is becoming more and more sophisticated and seems to have moved from the clichy of drug trafficking to financing terrorism and surely not forgetting personal gain. Most international financial institutions have been implementing anti-money laundering solutions to fight investment fraud. However, traditional investigative techniques consume numerous man-hours. Recently, data mining approaches have been developed and are considered as well-suited techniques for detecting money laundering activities. Within the scope of a collaboration project for the purpose of developing a new solution for the anti-money laundering Units in an international investment bank, we proposed a simple and efficient data mining-based solution for anti-money laundering. In this paper, we present this solution developed as a tool and show some preliminary experiment results with real transaction datasets.
[ { "version": "v1", "created": "Sun, 4 Sep 2016 21:03:32 GMT" } ]
2016-09-06T00:00:00
[ [ "Le-Khac", "Nhien-An", "" ], [ "Markos", "Sammer", "" ], [ "Kechadi", "Tahar", "" ] ]
TITLE: A data mining-based solution for detecting suspicious money laundering cases in an investment bank ABSTRACT: Today, money laundering poses a serious threat not only to financial institutions but also to the nation. This criminal activity is becoming more and more sophisticated and seems to have moved from the clichy of drug trafficking to financing terrorism and surely not forgetting personal gain. Most international financial institutions have been implementing anti-money laundering solutions to fight investment fraud. However, traditional investigative techniques consume numerous man-hours. Recently, data mining approaches have been developed and are considered as well-suited techniques for detecting money laundering activities. Within the scope of a collaboration project for the purpose of developing a new solution for the anti-money laundering Units in an international investment bank, we proposed a simple and efficient data mining-based solution for anti-money laundering. In this paper, we present this solution developed as a tool and show some preliminary experiment results with real transaction datasets.
no_new_dataset
0.945901
1609.00992
Nhien-An Le-Khac
Maarten Banerveld, Nhien-An Le-Khac, Tahar Kechadi
Performance Evaluation of a Natural Language Processing approach applied in White Collar crime investigation
null
null
null
null
cs.IR cs.CY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In today world we are confronted with increasing amounts of information every day coming from a large variety of sources. People and co-operations are producing data on a large scale, and since the rise of the internet, e-mail and social media the amount of produced data has grown exponentially. From a law enforcement perspective we have to deal with these huge amounts of data when a criminal investigation is launched against an individual or company. Relevant questions need to be answered like who committed the crime, who were involved, what happened and on what time, who were communicating and about what? Not only the amount of available data to investigate has increased enormously, but also the complexity of this data has increased. When these communication patterns need to be combined with for instance a seized financial administration or corporate document shares a complex investigation problem arises. Recently, criminal investigators face a huge challenge when evidence of a crime needs to be found in the Big Data environment where they have to deal with large and complex datasets especially in financial and fraud investigations. To tackle this problem, a financial and fraud investigation unit of a European country has developed a new tool named LES that uses Natural Language Processing (NLP) techniques to help criminal investigators handle large amounts of textual information in a more efficient and faster way. In this paper, we present briefly this tool and we focus on the evaluation its performance in terms of the requirements of forensic investigation: speed, smarter and easier for investigators. In order to evaluate this LES tool, we use different performance metrics. We also show experimental results of our evaluation with large and complex datasets from real-world application.
[ { "version": "v1", "created": "Sun, 4 Sep 2016 21:23:22 GMT" } ]
2016-09-06T00:00:00
[ [ "Banerveld", "Maarten", "" ], [ "Le-Khac", "Nhien-An", "" ], [ "Kechadi", "Tahar", "" ] ]
TITLE: Performance Evaluation of a Natural Language Processing approach applied in White Collar crime investigation ABSTRACT: In today world we are confronted with increasing amounts of information every day coming from a large variety of sources. People and co-operations are producing data on a large scale, and since the rise of the internet, e-mail and social media the amount of produced data has grown exponentially. From a law enforcement perspective we have to deal with these huge amounts of data when a criminal investigation is launched against an individual or company. Relevant questions need to be answered like who committed the crime, who were involved, what happened and on what time, who were communicating and about what? Not only the amount of available data to investigate has increased enormously, but also the complexity of this data has increased. When these communication patterns need to be combined with for instance a seized financial administration or corporate document shares a complex investigation problem arises. Recently, criminal investigators face a huge challenge when evidence of a crime needs to be found in the Big Data environment where they have to deal with large and complex datasets especially in financial and fraud investigations. To tackle this problem, a financial and fraud investigation unit of a European country has developed a new tool named LES that uses Natural Language Processing (NLP) techniques to help criminal investigators handle large amounts of textual information in a more efficient and faster way. In this paper, we present briefly this tool and we focus on the evaluation its performance in terms of the requirements of forensic investigation: speed, smarter and easier for investigators. In order to evaluate this LES tool, we use different performance metrics. We also show experimental results of our evaluation with large and complex datasets from real-world application.
no_new_dataset
0.934395
1609.01228
Michel Fornaciali
Afonso Menegola, Michel Fornaciali, Ramon Pires, Sandra Avila, Eduardo Valle
Towards Automated Melanoma Screening: Exploring Transfer Learning Schemes
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep learning is the current bet for image classification. Its greed for huge amounts of annotated data limits its usage in medical imaging context. In this scenario transfer learning appears as a prominent solution. In this report we aim to clarify how transfer learning schemes may influence classification results. We are particularly focused in the automated melanoma screening problem, a case of medical imaging in which transfer learning is still not widely used. We explored transfer with and without fine-tuning, sequential transfers and usage of pre-trained models in general and specific datasets. Although some issues remain open, our findings may drive future researches.
[ { "version": "v1", "created": "Mon, 5 Sep 2016 17:31:15 GMT" } ]
2016-09-06T00:00:00
[ [ "Menegola", "Afonso", "" ], [ "Fornaciali", "Michel", "" ], [ "Pires", "Ramon", "" ], [ "Avila", "Sandra", "" ], [ "Valle", "Eduardo", "" ] ]
TITLE: Towards Automated Melanoma Screening: Exploring Transfer Learning Schemes ABSTRACT: Deep learning is the current bet for image classification. Its greed for huge amounts of annotated data limits its usage in medical imaging context. In this scenario transfer learning appears as a prominent solution. In this report we aim to clarify how transfer learning schemes may influence classification results. We are particularly focused in the automated melanoma screening problem, a case of medical imaging in which transfer learning is still not widely used. We explored transfer with and without fine-tuning, sequential transfers and usage of pre-trained models in general and specific datasets. Although some issues remain open, our findings may drive future researches.
no_new_dataset
0.942454
1604.06582
Jacopo Cavazza
Jacopo Cavazza, Andrea Zunino, Marco San Biagio and Vittorio Murino
Kernelized Covariance for Action Recognition
Accepted paper at the 23rd International Conference on Pattern Recognition (ICPR), Cancun, Mexico, 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we aim at increasing the descriptive power of the covariance matrix, limited in capturing linear mutual dependencies between variables only. We present a rigorous and principled mathematical pipeline to recover the kernel trick for computing the covariance matrix, enhancing it to model more complex, non-linear relationships conveyed by the raw data. To this end, we propose Kernelized-COV, which generalizes the original covariance representation without compromising the efficiency of the computation. In the experiments, we validate the proposed framework against many previous approaches in the literature, scoring on par or superior with respect to the state of the art on benchmark datasets for 3D action recognition.
[ { "version": "v1", "created": "Fri, 22 Apr 2016 09:16:22 GMT" }, { "version": "v2", "created": "Fri, 2 Sep 2016 12:05:09 GMT" } ]
2016-09-05T00:00:00
[ [ "Cavazza", "Jacopo", "" ], [ "Zunino", "Andrea", "" ], [ "Biagio", "Marco San", "" ], [ "Murino", "Vittorio", "" ] ]
TITLE: Kernelized Covariance for Action Recognition ABSTRACT: In this paper we aim at increasing the descriptive power of the covariance matrix, limited in capturing linear mutual dependencies between variables only. We present a rigorous and principled mathematical pipeline to recover the kernel trick for computing the covariance matrix, enhancing it to model more complex, non-linear relationships conveyed by the raw data. To this end, we propose Kernelized-COV, which generalizes the original covariance representation without compromising the efficiency of the computation. In the experiments, we validate the proposed framework against many previous approaches in the literature, scoring on par or superior with respect to the state of the art on benchmark datasets for 3D action recognition.
no_new_dataset
0.946941
1608.05971
Mohsen Fayyaz
Mohsen Fayyaz, Mohammad Hajizadeh Saffar, Mohammad Sabokrou, Mahmood Fathy, Reinhard Klette, Fay Huang
STFCN: Spatio-Temporal FCN for Semantic Video Segmentation
null
null
null
null
cs.CV
http://creativecommons.org/licenses/by-nc-sa/4.0/
This paper presents a novel method to involve both spatial and temporal features for semantic video segmentation. Current work on convolutional neural networks(CNNs) has shown that CNNs provide advanced spatial features supporting a very good performance of solutions for both image and video analysis, especially for the semantic segmentation task. We investigate how involving temporal features also has a good effect on segmenting video data. We propose a module based on a long short-term memory (LSTM) architecture of a recurrent neural network for interpreting the temporal characteristics of video frames over time. Our system takes as input frames of a video and produces a correspondingly-sized output; for segmenting the video our method combines the use of three components: First, the regional spatial features of frames are extracted using a CNN; then, using LSTM the temporal features are added; finally, by deconvolving the spatio-temporal features we produce pixel-wise predictions. Our key insight is to build spatio-temporal convolutional networks (spatio-temporal CNNs) that have an end-to-end architecture for semantic video segmentation. We adapted fully some known convolutional network architectures (such as FCN-AlexNet and FCN-VGG16), and dilated convolution into our spatio-temporal CNNs. Our spatio-temporal CNNs achieve state-of-the-art semantic segmentation, as demonstrated for the Camvid and NYUDv2 datasets.
[ { "version": "v1", "created": "Sun, 21 Aug 2016 17:34:08 GMT" }, { "version": "v2", "created": "Fri, 2 Sep 2016 15:51:49 GMT" } ]
2016-09-05T00:00:00
[ [ "Fayyaz", "Mohsen", "" ], [ "Saffar", "Mohammad Hajizadeh", "" ], [ "Sabokrou", "Mohammad", "" ], [ "Fathy", "Mahmood", "" ], [ "Klette", "Reinhard", "" ], [ "Huang", "Fay", "" ] ]
TITLE: STFCN: Spatio-Temporal FCN for Semantic Video Segmentation ABSTRACT: This paper presents a novel method to involve both spatial and temporal features for semantic video segmentation. Current work on convolutional neural networks(CNNs) has shown that CNNs provide advanced spatial features supporting a very good performance of solutions for both image and video analysis, especially for the semantic segmentation task. We investigate how involving temporal features also has a good effect on segmenting video data. We propose a module based on a long short-term memory (LSTM) architecture of a recurrent neural network for interpreting the temporal characteristics of video frames over time. Our system takes as input frames of a video and produces a correspondingly-sized output; for segmenting the video our method combines the use of three components: First, the regional spatial features of frames are extracted using a CNN; then, using LSTM the temporal features are added; finally, by deconvolving the spatio-temporal features we produce pixel-wise predictions. Our key insight is to build spatio-temporal convolutional networks (spatio-temporal CNNs) that have an end-to-end architecture for semantic video segmentation. We adapted fully some known convolutional network architectures (such as FCN-AlexNet and FCN-VGG16), and dilated convolution into our spatio-temporal CNNs. Our spatio-temporal CNNs achieve state-of-the-art semantic segmentation, as demonstrated for the Camvid and NYUDv2 datasets.
no_new_dataset
0.951006
1609.00426
Paul M. Aoki
Paul M. Aoki
New Rain Rate Statistics for Emerging Regions: Implications for Wireless Backhaul Planning
14 pages; 3 figures
null
null
null
cs.NI
http://creativecommons.org/licenses/by-nc-sa/4.0/
As demand for broadband service increases in emerging regions, high-capacity wireless links can accelerate and cost-reduce the deployment of new networks (both backhaul and customer site connection). Such links are increasingly common in developed countries, but their reliability in emerging regions is questioned where very heavy tropical rain is present. Here, we investigate the robustness of the standard (ITU-R P.837-6) method for estimating rain rates using an expanded test dataset. We illustrate how bias/variance issues cause problematic predictions at higher rain rates. We confirm (by construction) that an improved rainfall climatology can largely address these prediction issues without compromising standard ITU fit evaluation metrics.
[ { "version": "v1", "created": "Thu, 1 Sep 2016 23:37:04 GMT" } ]
2016-09-05T00:00:00
[ [ "Aoki", "Paul M.", "" ] ]
TITLE: New Rain Rate Statistics for Emerging Regions: Implications for Wireless Backhaul Planning ABSTRACT: As demand for broadband service increases in emerging regions, high-capacity wireless links can accelerate and cost-reduce the deployment of new networks (both backhaul and customer site connection). Such links are increasingly common in developed countries, but their reliability in emerging regions is questioned where very heavy tropical rain is present. Here, we investigate the robustness of the standard (ITU-R P.837-6) method for estimating rain rates using an expanded test dataset. We illustrate how bias/variance issues cause problematic predictions at higher rain rates. We confirm (by construction) that an improved rainfall climatology can largely address these prediction issues without compromising standard ITU fit evaluation metrics.
new_dataset
0.604107
1609.00462
Markus Wagner
Markus Wagner, Marius Lindauer, Mustafa Misir, Samadhi Nallaperuma, Frank Hutter
A case study of algorithm selection for the traveling thief problem
23 pages, this article is underview
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many real-world problems are composed of several interacting components. In order to facilitate research on such interactions, the Traveling Thief Problem (TTP) was created in 2013 as the combination of two well-understood combinatorial optimization problems. With this article, we contribute in four ways. First, we create a comprehensive dataset that comprises the performance data of 21 TTP algorithms on the full original set of 9720 TTP instances. Second, we define 55 characteristics for all TPP instances that can be used to select the best algorithm on a per-instance basis. Third, we use these algorithms and features to construct the first algorithm portfolios for TTP, clearly outperforming the single best algorithm. Finally, we study which algorithms contribute most to this portfolio.
[ { "version": "v1", "created": "Fri, 2 Sep 2016 04:03:22 GMT" } ]
2016-09-05T00:00:00
[ [ "Wagner", "Markus", "" ], [ "Lindauer", "Marius", "" ], [ "Misir", "Mustafa", "" ], [ "Nallaperuma", "Samadhi", "" ], [ "Hutter", "Frank", "" ] ]
TITLE: A case study of algorithm selection for the traveling thief problem ABSTRACT: Many real-world problems are composed of several interacting components. In order to facilitate research on such interactions, the Traveling Thief Problem (TTP) was created in 2013 as the combination of two well-understood combinatorial optimization problems. With this article, we contribute in four ways. First, we create a comprehensive dataset that comprises the performance data of 21 TTP algorithms on the full original set of 9720 TTP instances. Second, we define 55 characteristics for all TPP instances that can be used to select the best algorithm on a per-instance basis. Third, we use these algorithms and features to construct the first algorithm portfolios for TTP, clearly outperforming the single best algorithm. Finally, we study which algorithms contribute most to this portfolio.
new_dataset
0.951278
1609.00683
Alessandro Checco
Alessandro Checco, Gianluca Demartini
Pairwise, Magnitude, or Stars: What's the Best Way for Crowds to Rate?
null
null
null
null
cs.IR cs.HC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compare three popular techniques of rating content: the ubiquitous five star rating, the less used pairwise comparison, and the recently introduced (in crowdsourcing) magnitude estimation approach. Each system has specific advantages and disadvantages, in terms of required user effort, achievable user preference prediction accuracy and number of ratings required. We design an experiment where the three techniques are compared in an unbiased way. We collected 39'000 ratings on a popular crowdsourcing platform, allowing us to release a dataset that will be useful for many related studies on user rating techniques.
[ { "version": "v1", "created": "Fri, 2 Sep 2016 17:50:53 GMT" } ]
2016-09-05T00:00:00
[ [ "Checco", "Alessandro", "" ], [ "Demartini", "Gianluca", "" ] ]
TITLE: Pairwise, Magnitude, or Stars: What's the Best Way for Crowds to Rate? ABSTRACT: We compare three popular techniques of rating content: the ubiquitous five star rating, the less used pairwise comparison, and the recently introduced (in crowdsourcing) magnitude estimation approach. Each system has specific advantages and disadvantages, in terms of required user effort, achievable user preference prediction accuracy and number of ratings required. We design an experiment where the three techniques are compared in an unbiased way. We collected 39'000 ratings on a popular crowdsourcing platform, allowing us to release a dataset that will be useful for many related studies on user rating techniques.
new_dataset
0.941654
1609.00718
Rie Johnson
Rie Johnson and Tong Zhang
Convolutional Neural Networks for Text Categorization: Shallow Word-level vs. Deep Character-level
null
null
null
null
cs.CL cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper reports the performances of shallow word-level convolutional neural networks (CNN), our earlier work (2015), on the eight datasets with relatively large training data that were used for testing the very deep character-level CNN in Conneau et al. (2016). Our findings are as follows. The shallow word-level CNNs achieve better error rates than the error rates reported in Conneau et al., though the results should be interpreted with some consideration due to the unique pre-processing of Conneau et al. The shallow word-level CNN uses more parameters and therefore requires more storage than the deep character-level CNN; however, the shallow word-level CNN computes much faster.
[ { "version": "v1", "created": "Wed, 31 Aug 2016 15:43:27 GMT" } ]
2016-09-05T00:00:00
[ [ "Johnson", "Rie", "" ], [ "Zhang", "Tong", "" ] ]
TITLE: Convolutional Neural Networks for Text Categorization: Shallow Word-level vs. Deep Character-level ABSTRACT: This paper reports the performances of shallow word-level convolutional neural networks (CNN), our earlier work (2015), on the eight datasets with relatively large training data that were used for testing the very deep character-level CNN in Conneau et al. (2016). Our findings are as follows. The shallow word-level CNNs achieve better error rates than the error rates reported in Conneau et al., though the results should be interpreted with some consideration due to the unique pre-processing of Conneau et al. The shallow word-level CNN uses more parameters and therefore requires more storage than the deep character-level CNN; however, the shallow word-level CNN computes much faster.
no_new_dataset
0.956796
1608.08337
Avleen Bijral
Avleen S. Bijral
Data Dependent Convergence for Distributed Stochastic Optimization
PhD thesis
null
null
null
math.OC cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this dissertation we propose alternative analysis of distributed stochastic gradient descent (SGD) algorithms that rely on spectral properties of the data covariance. As a consequence we can relate questions pertaining to speedups and convergence rates for distributed SGD to the data distribution instead of the regularity properties of the objective functions. More precisely we show that this rate depends on the spectral norm of the sample covariance matrix. An estimate of this norm can provide practitioners with guidance towards a potential gain in algorithm performance. For example many sparse datasets with low spectral norm prove to be amenable to gains in distributed settings. Towards establishing this data dependence we first study a distributed consensus-based SGD algorithm and show that the rate of convergence involves the spectral norm of the sample covariance matrix when the underlying data is assumed to be independent and identically distributed (homogenous). This dependence allows us to identify network regimes that prove to be beneficial for datasets with low sample covariance spectral norm. Existing consensus based analyses prove to be sub-optimal in the homogenous setting. Our analysis method also allows us to find data-dependent convergence rates as we limit the amount of communication. Spreading a fixed amount of data across more nodes slows convergence; in the asymptotic regime we show that adding more machines can help when minimizing twice-differentiable losses. Since the mini-batch results don't follow from the consensus results we propose a different data dependent analysis thereby providing theoretical validation for why certain datasets are more amenable to mini-batching. We also provide empirical evidence for results in this thesis.
[ { "version": "v1", "created": "Tue, 30 Aug 2016 05:58:38 GMT" } ]
2016-09-03T00:00:00
[ [ "Bijral", "Avleen S.", "" ] ]
TITLE: Data Dependent Convergence for Distributed Stochastic Optimization ABSTRACT: In this dissertation we propose alternative analysis of distributed stochastic gradient descent (SGD) algorithms that rely on spectral properties of the data covariance. As a consequence we can relate questions pertaining to speedups and convergence rates for distributed SGD to the data distribution instead of the regularity properties of the objective functions. More precisely we show that this rate depends on the spectral norm of the sample covariance matrix. An estimate of this norm can provide practitioners with guidance towards a potential gain in algorithm performance. For example many sparse datasets with low spectral norm prove to be amenable to gains in distributed settings. Towards establishing this data dependence we first study a distributed consensus-based SGD algorithm and show that the rate of convergence involves the spectral norm of the sample covariance matrix when the underlying data is assumed to be independent and identically distributed (homogenous). This dependence allows us to identify network regimes that prove to be beneficial for datasets with low sample covariance spectral norm. Existing consensus based analyses prove to be sub-optimal in the homogenous setting. Our analysis method also allows us to find data-dependent convergence rates as we limit the amount of communication. Spreading a fixed amount of data across more nodes slows convergence; in the asymptotic regime we show that adding more machines can help when minimizing twice-differentiable losses. Since the mini-batch results don't follow from the consensus results we propose a different data dependent analysis thereby providing theoretical validation for why certain datasets are more amenable to mini-batching. We also provide empirical evidence for results in this thesis.
no_new_dataset
0.950778
1603.00275
Korsuk Sirinukunwattana
Korsuk Sirinukunwattana, Josien P. W. Pluim, Hao Chen, Xiaojuan Qi, Pheng-Ann Heng, Yun Bo Guo, Li Yang Wang, Bogdan J. Matuszewski, Elia Bruni, Urko Sanchez, Anton B\"ohm, Olaf Ronneberger, Bassem Ben Cheikh, Daniel Racoceanu, Philipp Kainz, Michael Pfeiffer, Martin Urschler, David R. J. Snead, Nasir M. Rajpoot
Gland Segmentation in Colon Histology Images: The GlaS Challenge Contest
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Colorectal adenocarcinoma originating in intestinal glandular structures is the most common form of colon cancer. In clinical practice, the morphology of intestinal glands, including architectural appearance and glandular formation, is used by pathologists to inform prognosis and plan the treatment of individual patients. However, achieving good inter-observer as well as intra-observer reproducibility of cancer grading is still a major challenge in modern pathology. An automated approach which quantifies the morphology of glands is a solution to the problem. This paper provides an overview to the Gland Segmentation in Colon Histology Images Challenge Contest (GlaS) held at MICCAI'2015. Details of the challenge, including organization, dataset and evaluation criteria, are presented, along with the method descriptions and evaluation results from the top performing methods.
[ { "version": "v1", "created": "Tue, 1 Mar 2016 13:53:48 GMT" }, { "version": "v2", "created": "Thu, 1 Sep 2016 14:18:51 GMT" } ]
2016-09-02T00:00:00
[ [ "Sirinukunwattana", "Korsuk", "" ], [ "Pluim", "Josien P. W.", "" ], [ "Chen", "Hao", "" ], [ "Qi", "Xiaojuan", "" ], [ "Heng", "Pheng-Ann", "" ], [ "Guo", "Yun Bo", "" ], [ "Wang", "Li Yang", "" ], [ "Matuszewski", "Bogdan J.", "" ], [ "Bruni", "Elia", "" ], [ "Sanchez", "Urko", "" ], [ "Böhm", "Anton", "" ], [ "Ronneberger", "Olaf", "" ], [ "Cheikh", "Bassem Ben", "" ], [ "Racoceanu", "Daniel", "" ], [ "Kainz", "Philipp", "" ], [ "Pfeiffer", "Michael", "" ], [ "Urschler", "Martin", "" ], [ "Snead", "David R. J.", "" ], [ "Rajpoot", "Nasir M.", "" ] ]
TITLE: Gland Segmentation in Colon Histology Images: The GlaS Challenge Contest ABSTRACT: Colorectal adenocarcinoma originating in intestinal glandular structures is the most common form of colon cancer. In clinical practice, the morphology of intestinal glands, including architectural appearance and glandular formation, is used by pathologists to inform prognosis and plan the treatment of individual patients. However, achieving good inter-observer as well as intra-observer reproducibility of cancer grading is still a major challenge in modern pathology. An automated approach which quantifies the morphology of glands is a solution to the problem. This paper provides an overview to the Gland Segmentation in Colon Histology Images Challenge Contest (GlaS) held at MICCAI'2015. Details of the challenge, including organization, dataset and evaluation criteria, are presented, along with the method descriptions and evaluation results from the top performing methods.
no_new_dataset
0.939748
1605.01379
Xiao Lin
Xiao Lin, Devi Parikh
Leveraging Visual Question Answering for Image-Caption Ranking
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Visual Question Answering (VQA) is the task of taking as input an image and a free-form natural language question about the image, and producing an accurate answer. In this work we view VQA as a "feature extraction" module to extract image and caption representations. We employ these representations for the task of image-caption ranking. Each feature dimension captures (imagines) whether a fact (question-answer pair) could plausibly be true for the image and caption. This allows the model to interpret images and captions from a wide variety of perspectives. We propose score-level and representation-level fusion models to incorporate VQA knowledge in an existing state-of-the-art VQA-agnostic image-caption ranking model. We find that incorporating and reasoning about consistency between images and captions significantly improves performance. Concretely, our model improves state-of-the-art on caption retrieval by 7.1% and on image retrieval by 4.4% on the MSCOCO dataset.
[ { "version": "v1", "created": "Wed, 4 May 2016 18:54:09 GMT" }, { "version": "v2", "created": "Wed, 31 Aug 2016 20:14:12 GMT" } ]
2016-09-02T00:00:00
[ [ "Lin", "Xiao", "" ], [ "Parikh", "Devi", "" ] ]
TITLE: Leveraging Visual Question Answering for Image-Caption Ranking ABSTRACT: Visual Question Answering (VQA) is the task of taking as input an image and a free-form natural language question about the image, and producing an accurate answer. In this work we view VQA as a "feature extraction" module to extract image and caption representations. We employ these representations for the task of image-caption ranking. Each feature dimension captures (imagines) whether a fact (question-answer pair) could plausibly be true for the image and caption. This allows the model to interpret images and captions from a wide variety of perspectives. We propose score-level and representation-level fusion models to incorporate VQA knowledge in an existing state-of-the-art VQA-agnostic image-caption ranking model. We find that incorporating and reasoning about consistency between images and captions significantly improves performance. Concretely, our model improves state-of-the-art on caption retrieval by 7.1% and on image retrieval by 4.4% on the MSCOCO dataset.
no_new_dataset
0.948394
1607.06275
Peng Li
Peng Li, Wei Li, Zhengyan He, Xuguang Wang, Ying Cao, Jie Zhou, Wei Xu
Dataset and Neural Recurrent Sequence Labeling Model for Open-Domain Factoid Question Answering
10 pages, 3 figures, withdraw experimental results on CNN/Daily Mail datasets
null
null
null
cs.CL cs.AI cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
While question answering (QA) with neural network, i.e. neural QA, has achieved promising results in recent years, lacking of large scale real-word QA dataset is still a challenge for developing and evaluating neural QA system. To alleviate this problem, we propose a large scale human annotated real-world QA dataset WebQA with more than 42k questions and 556k evidences. As existing neural QA methods resolve QA either as sequence generation or classification/ranking problem, they face challenges of expensive softmax computation, unseen answers handling or separate candidate answer generation component. In this work, we cast neural QA as a sequence labeling problem and propose an end-to-end sequence labeling model, which overcomes all the above challenges. Experimental results on WebQA show that our model outperforms the baselines significantly with an F1 score of 74.69% with word-based input, and the performance drops only 3.72 F1 points with more challenging character-based input.
[ { "version": "v1", "created": "Thu, 21 Jul 2016 11:40:50 GMT" }, { "version": "v2", "created": "Thu, 1 Sep 2016 10:56:45 GMT" } ]
2016-09-02T00:00:00
[ [ "Li", "Peng", "" ], [ "Li", "Wei", "" ], [ "He", "Zhengyan", "" ], [ "Wang", "Xuguang", "" ], [ "Cao", "Ying", "" ], [ "Zhou", "Jie", "" ], [ "Xu", "Wei", "" ] ]
TITLE: Dataset and Neural Recurrent Sequence Labeling Model for Open-Domain Factoid Question Answering ABSTRACT: While question answering (QA) with neural network, i.e. neural QA, has achieved promising results in recent years, lacking of large scale real-word QA dataset is still a challenge for developing and evaluating neural QA system. To alleviate this problem, we propose a large scale human annotated real-world QA dataset WebQA with more than 42k questions and 556k evidences. As existing neural QA methods resolve QA either as sequence generation or classification/ranking problem, they face challenges of expensive softmax computation, unseen answers handling or separate candidate answer generation component. In this work, we cast neural QA as a sequence labeling problem and propose an end-to-end sequence labeling model, which overcomes all the above challenges. Experimental results on WebQA show that our model outperforms the baselines significantly with an F1 score of 74.69% with word-based input, and the performance drops only 3.72 F1 points with more challenging character-based input.
new_dataset
0.750827
1608.07793
Zhongqi Lu
Zhongqi Lu, Qiang Yang
Partially Observable Markov Decision Process for Recommender Systems
null
null
null
null
cs.AI cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We report the "Recurrent Deterioration" (RD) phenomenon observed in online recommender systems. The RD phenomenon is reflected by the trend of performance degradation when the recommendation model is always trained based on users' feedbacks of the previous recommendations. There are several reasons for the recommender systems to encounter the RD phenomenon, including the lack of negative training data and the evolution of users' interests, etc. Motivated to tackle the problems causing the RD phenomenon, we propose the POMDP-Rec framework, which is a neural-optimized Partially Observable Markov Decision Process algorithm for recommender systems. We show that the POMDP-Rec framework effectively uses the accumulated historical data from real-world recommender systems and automatically achieves comparable results with those models fine-tuned exhaustively by domain exports on public datasets.
[ { "version": "v1", "created": "Sun, 28 Aug 2016 09:42:52 GMT" }, { "version": "v2", "created": "Thu, 1 Sep 2016 15:41:02 GMT" } ]
2016-09-02T00:00:00
[ [ "Lu", "Zhongqi", "" ], [ "Yang", "Qiang", "" ] ]
TITLE: Partially Observable Markov Decision Process for Recommender Systems ABSTRACT: We report the "Recurrent Deterioration" (RD) phenomenon observed in online recommender systems. The RD phenomenon is reflected by the trend of performance degradation when the recommendation model is always trained based on users' feedbacks of the previous recommendations. There are several reasons for the recommender systems to encounter the RD phenomenon, including the lack of negative training data and the evolution of users' interests, etc. Motivated to tackle the problems causing the RD phenomenon, we propose the POMDP-Rec framework, which is a neural-optimized Partially Observable Markov Decision Process algorithm for recommender systems. We show that the POMDP-Rec framework effectively uses the accumulated historical data from real-world recommender systems and automatically achieves comparable results with those models fine-tuned exhaustively by domain exports on public datasets.
no_new_dataset
0.949623
1608.08967
Seyed-Mohsen Moosavi-Dezfooli
Alhussein Fawzi, Seyed-Mohsen Moosavi-Dezfooli, Pascal Frossard
Robustness of classifiers: from adversarial to random noise
Accepted to NIPS 2016
null
null
null
cs.LG cs.CV stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Several recent works have shown that state-of-the-art classifiers are vulnerable to worst-case (i.e., adversarial) perturbations of the datapoints. On the other hand, it has been empirically observed that these same classifiers are relatively robust to random noise. In this paper, we propose to study a \textit{semi-random} noise regime that generalizes both the random and worst-case noise regimes. We propose the first quantitative analysis of the robustness of nonlinear classifiers in this general noise regime. We establish precise theoretical bounds on the robustness of classifiers in this general regime, which depend on the curvature of the classifier's decision boundary. Our bounds confirm and quantify the empirical observations that classifiers satisfying curvature constraints are robust to random noise. Moreover, we quantify the robustness of classifiers in terms of the subspace dimension in the semi-random noise regime, and show that our bounds remarkably interpolate between the worst-case and random noise regimes. We perform experiments and show that the derived bounds provide very accurate estimates when applied to various state-of-the-art deep neural networks and datasets. This result suggests bounds on the curvature of the classifiers' decision boundaries that we support experimentally, and more generally offers important insights onto the geometry of high dimensional classification problems.
[ { "version": "v1", "created": "Wed, 31 Aug 2016 17:54:34 GMT" } ]
2016-09-02T00:00:00
[ [ "Fawzi", "Alhussein", "" ], [ "Moosavi-Dezfooli", "Seyed-Mohsen", "" ], [ "Frossard", "Pascal", "" ] ]
TITLE: Robustness of classifiers: from adversarial to random noise ABSTRACT: Several recent works have shown that state-of-the-art classifiers are vulnerable to worst-case (i.e., adversarial) perturbations of the datapoints. On the other hand, it has been empirically observed that these same classifiers are relatively robust to random noise. In this paper, we propose to study a \textit{semi-random} noise regime that generalizes both the random and worst-case noise regimes. We propose the first quantitative analysis of the robustness of nonlinear classifiers in this general noise regime. We establish precise theoretical bounds on the robustness of classifiers in this general regime, which depend on the curvature of the classifier's decision boundary. Our bounds confirm and quantify the empirical observations that classifiers satisfying curvature constraints are robust to random noise. Moreover, we quantify the robustness of classifiers in terms of the subspace dimension in the semi-random noise regime, and show that our bounds remarkably interpolate between the worst-case and random noise regimes. We perform experiments and show that the derived bounds provide very accurate estimates when applied to various state-of-the-art deep neural networks and datasets. This result suggests bounds on the curvature of the classifiers' decision boundaries that we support experimentally, and more generally offers important insights onto the geometry of high dimensional classification problems.
no_new_dataset
0.950134
1609.00017
Gordon Christie
Gordon Christie, Adam Shoemaker, Kevin Kochersberger, Pratap Tokekar, Lance McLean, Alexander Leonessa
Radiation Search Operations using Scene Understanding with Autonomous UAV and UGV
null
null
null
null
cs.RO cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Autonomously searching for hazardous radiation sources requires the ability of the aerial and ground systems to understand the scene they are scouting. In this paper, we present systems, algorithms, and experiments to perform radiation search using unmanned aerial vehicles (UAV) and unmanned ground vehicles (UGV) by employing semantic scene segmentation. The aerial data is used to identify radiological points of interest, generate an orthophoto along with a digital elevation model (DEM) of the scene, and perform semantic segmentation to assign a category (e.g. road, grass) to each pixel in the orthophoto. We perform semantic segmentation by training a model on a dataset of images we collected and annotated, using the model to perform inference on images of the test area unseen to the model, and then refining the results with the DEM to better reason about category predictions at each pixel. We then use all of these outputs to plan a path for a UGV carrying a LiDAR to map the environment and avoid obstacles not present during the flight, and a radiation detector to collect more precise radiation measurements from the ground. Results of the analysis for each scenario tested favorably. We also note that our approach is general and has the potential to work for a variety of different sensing tasks.
[ { "version": "v1", "created": "Wed, 31 Aug 2016 20:00:46 GMT" } ]
2016-09-02T00:00:00
[ [ "Christie", "Gordon", "" ], [ "Shoemaker", "Adam", "" ], [ "Kochersberger", "Kevin", "" ], [ "Tokekar", "Pratap", "" ], [ "McLean", "Lance", "" ], [ "Leonessa", "Alexander", "" ] ]
TITLE: Radiation Search Operations using Scene Understanding with Autonomous UAV and UGV ABSTRACT: Autonomously searching for hazardous radiation sources requires the ability of the aerial and ground systems to understand the scene they are scouting. In this paper, we present systems, algorithms, and experiments to perform radiation search using unmanned aerial vehicles (UAV) and unmanned ground vehicles (UGV) by employing semantic scene segmentation. The aerial data is used to identify radiological points of interest, generate an orthophoto along with a digital elevation model (DEM) of the scene, and perform semantic segmentation to assign a category (e.g. road, grass) to each pixel in the orthophoto. We perform semantic segmentation by training a model on a dataset of images we collected and annotated, using the model to perform inference on images of the test area unseen to the model, and then refining the results with the DEM to better reason about category predictions at each pixel. We then use all of these outputs to plan a path for a UGV carrying a LiDAR to map the environment and avoid obstacles not present during the flight, and a radiation detector to collect more precise radiation measurements from the ground. Results of the analysis for each scenario tested favorably. We also note that our approach is general and has the potential to work for a variety of different sensing tasks.
no_new_dataset
0.815673
1609.00070
Arun Tejasvi Chaganty
Arun Tejasvi Chaganty and Percy Liang
How Much is 131 Million Dollars? Putting Numbers in Perspective with Compositional Descriptions
null
ACL (2016), 578-587
10.18653/v1/P16-1055
null
cs.CL
http://creativecommons.org/licenses/by-sa/4.0/
How much is 131 million US dollars? To help readers put such numbers in context, we propose a new task of automatically generating short descriptions known as perspectives, e.g. "$131 million is about the cost to employ everyone in Texas over a lunch period". First, we collect a dataset of numeric mentions in news articles, where each mention is labeled with a set of rated perspectives. We then propose a system to generate these descriptions consisting of two steps: formula construction and description generation. In construction, we compose formulae from numeric facts in a knowledge base and rank the resulting formulas based on familiarity, numeric proximity and semantic compatibility. In generation, we convert a formula into natural language using a sequence-to-sequence recurrent neural network. Our system obtains a 15.2% F1 improvement over a non-compositional baseline at formula construction and a 12.5 BLEU point improvement over a baseline description generation.
[ { "version": "v1", "created": "Thu, 1 Sep 2016 00:20:41 GMT" } ]
2016-09-02T00:00:00
[ [ "Chaganty", "Arun Tejasvi", "" ], [ "Liang", "Percy", "" ] ]
TITLE: How Much is 131 Million Dollars? Putting Numbers in Perspective with Compositional Descriptions ABSTRACT: How much is 131 million US dollars? To help readers put such numbers in context, we propose a new task of automatically generating short descriptions known as perspectives, e.g. "$131 million is about the cost to employ everyone in Texas over a lunch period". First, we collect a dataset of numeric mentions in news articles, where each mention is labeled with a set of rated perspectives. We then propose a system to generate these descriptions consisting of two steps: formula construction and description generation. In construction, we compose formulae from numeric facts in a knowledge base and rank the resulting formulas based on familiarity, numeric proximity and semantic compatibility. In generation, we convert a formula into natural language using a sequence-to-sequence recurrent neural network. Our system obtains a 15.2% F1 improvement over a non-compositional baseline at formula construction and a 12.5 BLEU point improvement over a baseline description generation.
no_new_dataset
0.733452
1609.00081
Tanmoy Chakraborty
Tanmoy Chakraborty and Ramasuri Narayanam
All Fingers are not Equal: Intensity of References in Scientific Articles
11 pages, 4 figures, 4 tables, Conference on Empirical Methods in Natural Language Processing (EMNLP 2016)
null
null
null
cs.CL cs.DL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Research accomplishment is usually measured by considering all citations with equal importance, thus ignoring the wide variety of purposes an article is being cited for. Here, we posit that measuring the intensity of a reference is crucial not only to perceive better understanding of research endeavor, but also to improve the quality of citation-based applications. To this end, we collect a rich annotated dataset with references labeled by the intensity, and propose a novel graph-based semi-supervised model, GraLap to label the intensity of references. Experiments with AAN datasets show a significant improvement compared to the baselines to achieve the true labels of the references (46% better correlation). Finally, we provide four applications to demonstrate how the knowledge of reference intensity leads to design better real-world applications.
[ { "version": "v1", "created": "Thu, 1 Sep 2016 01:34:56 GMT" } ]
2016-09-02T00:00:00
[ [ "Chakraborty", "Tanmoy", "" ], [ "Narayanam", "Ramasuri", "" ] ]
TITLE: All Fingers are not Equal: Intensity of References in Scientific Articles ABSTRACT: Research accomplishment is usually measured by considering all citations with equal importance, thus ignoring the wide variety of purposes an article is being cited for. Here, we posit that measuring the intensity of a reference is crucial not only to perceive better understanding of research endeavor, but also to improve the quality of citation-based applications. To this end, we collect a rich annotated dataset with references labeled by the intensity, and propose a novel graph-based semi-supervised model, GraLap to label the intensity of references. Experiments with AAN datasets show a significant improvement compared to the baselines to achieve the true labels of the references (46% better correlation). Finally, we provide four applications to demonstrate how the knowledge of reference intensity leads to design better real-world applications.
new_dataset
0.962108
1609.00130
Roberto Rigamonti
Roberto Rigamonti and Baptiste Delporte and Anthony Convers and Alberto Dassatti
Transparent Live Code Offloading on FPGA
9 pages in FPGAs for Software Programmers (FSP 2016)
null
null
null
cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Even though it seems that FPGAs have finally made the transition from research labs to the consumer devices' market, programming them remains challenging. Despite the improvements made by High-Level Synthesis (HLS), which removed the language and paradigm barriers that prevented many computer scientists from working with them, producing a new design typically requires at least several hours, making data- and context-dependent adaptations virtually impossible. In this paper we present a new framework that off-loads, on-the-fly and transparently to both the user and the developer, computationally-intensive code fragments to FPGAs. While the performance should not surpass that of hand-crafted HDL code, or even code produced by HLS, our results come with no additional development costs and do not require producing and deploying a new bit-stream to the FPGA each time a change is made. Moreover, since optimizations are made at run-time, they may fit particular datasets or usage scenarios, something which is rarely foreseeable at design or compile time. Our proposal revolves around an overlay architecture that is pre-programmed on the FPGA and dynamically reconfigured by our framework to execute code fragments extracted from the Data Flow Graph (DFG) of computational intensive routines. We validated our solution using standard benchmarks and proved we are able to off-load to FPGAs without developer's intervention.
[ { "version": "v1", "created": "Thu, 1 Sep 2016 07:18:41 GMT" } ]
2016-09-02T00:00:00
[ [ "Rigamonti", "Roberto", "" ], [ "Delporte", "Baptiste", "" ], [ "Convers", "Anthony", "" ], [ "Dassatti", "Alberto", "" ] ]
TITLE: Transparent Live Code Offloading on FPGA ABSTRACT: Even though it seems that FPGAs have finally made the transition from research labs to the consumer devices' market, programming them remains challenging. Despite the improvements made by High-Level Synthesis (HLS), which removed the language and paradigm barriers that prevented many computer scientists from working with them, producing a new design typically requires at least several hours, making data- and context-dependent adaptations virtually impossible. In this paper we present a new framework that off-loads, on-the-fly and transparently to both the user and the developer, computationally-intensive code fragments to FPGAs. While the performance should not surpass that of hand-crafted HDL code, or even code produced by HLS, our results come with no additional development costs and do not require producing and deploying a new bit-stream to the FPGA each time a change is made. Moreover, since optimizations are made at run-time, they may fit particular datasets or usage scenarios, something which is rarely foreseeable at design or compile time. Our proposal revolves around an overlay architecture that is pre-programmed on the FPGA and dynamically reconfigured by our framework to execute code fragments extracted from the Data Flow Graph (DFG) of computational intensive routines. We validated our solution using standard benchmarks and proved we are able to off-load to FPGAs without developer's intervention.
no_new_dataset
0.940463
1609.00154
Sebastian Sippel
Sebastian Sippel and Jakob Zscheischler and Martin Heimann and Holger Lange and Miguel D. Mahecha and Geert Jan van Oldenborgh and Friederike E.L. Otto and Markus Reichstein
Have precipitation extremes and annual totals been increasing in the world's dry regions over the last 60 years?
null
null
null
null
physics.geo-ph physics.ao-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Daily rainfall extremes and annual totals have increased in large parts of the global land area over the last decades. These observations are consistent with theoretical considerations of a warming climate. However, until recently these global tendencies have not been shown to consistently affect land regions with limited moisture availability. A recent study, published by Donat et al. (2016, Nature Climate Change, doi:10.1038/nclimate2941), now identified rapid increases in globally aggregated dry region daily extreme rainfall and annual rainfall totals. Here, we reassess the respective analysis and find that a) statistical artifacts introduced by the choice of the reference period prior to data standardization lead to an overestimation of the reported trends by up to 40%, and also that b) the definition of `dry regions of the globe' affect the reported globally aggregated trends in extreme rainfall. Using the same observational dataset, but accounting for the statistical artifacts and using alternative, well-established dryness definitions, we find no significant increases in heavy precipitation in the world's dry regions. Adequate data pre-processing approaches and accounting for uncertainties regarding the definition of dryness are crucial to the quantification of spatially aggregated trends in the world's dry regions. In view of the high relevance of the question to many potentially affected stakeholders, we call for a cautionary consideration of specific data processing methods, including issues related to the definition of dry areas, to guarantee robustness of communicated climate change relevant findings.
[ { "version": "v1", "created": "Thu, 1 Sep 2016 09:20:20 GMT" } ]
2016-09-02T00:00:00
[ [ "Sippel", "Sebastian", "" ], [ "Zscheischler", "Jakob", "" ], [ "Heimann", "Martin", "" ], [ "Lange", "Holger", "" ], [ "Mahecha", "Miguel D.", "" ], [ "van Oldenborgh", "Geert Jan", "" ], [ "Otto", "Friederike E. L.", "" ], [ "Reichstein", "Markus", "" ] ]
TITLE: Have precipitation extremes and annual totals been increasing in the world's dry regions over the last 60 years? ABSTRACT: Daily rainfall extremes and annual totals have increased in large parts of the global land area over the last decades. These observations are consistent with theoretical considerations of a warming climate. However, until recently these global tendencies have not been shown to consistently affect land regions with limited moisture availability. A recent study, published by Donat et al. (2016, Nature Climate Change, doi:10.1038/nclimate2941), now identified rapid increases in globally aggregated dry region daily extreme rainfall and annual rainfall totals. Here, we reassess the respective analysis and find that a) statistical artifacts introduced by the choice of the reference period prior to data standardization lead to an overestimation of the reported trends by up to 40%, and also that b) the definition of `dry regions of the globe' affect the reported globally aggregated trends in extreme rainfall. Using the same observational dataset, but accounting for the statistical artifacts and using alternative, well-established dryness definitions, we find no significant increases in heavy precipitation in the world's dry regions. Adequate data pre-processing approaches and accounting for uncertainties regarding the definition of dryness are crucial to the quantification of spatially aggregated trends in the world's dry regions. In view of the high relevance of the question to many potentially affected stakeholders, we call for a cautionary consideration of specific data processing methods, including issues related to the definition of dry areas, to guarantee robustness of communicated climate change relevant findings.
no_new_dataset
0.941007
1609.00162
Limin Wang
Limin Wang, Zhe Wang, Yu Qiao, Luc Van Gool
Transferring Object-Scene Convolutional Neural Networks for Event Recognition in Still Images
20 pages
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Event recognition in still images is an intriguing problem and has potential for real applications. This paper addresses the problem of event recognition by proposing a convolutional neural network that exploits knowledge of objects and scenes for event classification (OS2E-CNN). Intuitively, it stands to reason that there exists a correlation among the concepts of objects, scenes, and events. We empirically demonstrate that the recognition of objects and scenes substantially contributes to the recognition of events. Meanwhile, we propose an iterative selection method to identify a subset of object and scene classes, which help to more efficiently and effectively transfer their deep representations to event recognition. Specifically, we develop three types of transferring techniques: (1) initialization-based transferring, (2) knowledge-based transferring, and (3) data-based transferring. These newly designed transferring techniques exploit multi-task learning frameworks to incorporate extra knowledge from other networks and additional datasets into the training procedure of event CNNs. These multi-task learning frameworks turn out to be effective in reducing the effect of over-fitting and improving the generalization ability of the learned CNNs. With OS2E-CNN, we design a multi-ratio and multi-scale cropping strategy, and propose an end-to-end event recognition pipeline. We perform experiments on three event recognition benchmarks: the ChaLearn Cultural Event Recognition dataset, the Web Image Dataset for Event Recognition (WIDER), and the UIUC Sports Event dataset. The experimental results show that our proposed algorithm successfully adapts object and scene representations towards the event dataset and that it achieves the current state-of-the-art performance on these challenging datasets.
[ { "version": "v1", "created": "Thu, 1 Sep 2016 09:47:22 GMT" } ]
2016-09-02T00:00:00
[ [ "Wang", "Limin", "" ], [ "Wang", "Zhe", "" ], [ "Qiao", "Yu", "" ], [ "Van Gool", "Luc", "" ] ]
TITLE: Transferring Object-Scene Convolutional Neural Networks for Event Recognition in Still Images ABSTRACT: Event recognition in still images is an intriguing problem and has potential for real applications. This paper addresses the problem of event recognition by proposing a convolutional neural network that exploits knowledge of objects and scenes for event classification (OS2E-CNN). Intuitively, it stands to reason that there exists a correlation among the concepts of objects, scenes, and events. We empirically demonstrate that the recognition of objects and scenes substantially contributes to the recognition of events. Meanwhile, we propose an iterative selection method to identify a subset of object and scene classes, which help to more efficiently and effectively transfer their deep representations to event recognition. Specifically, we develop three types of transferring techniques: (1) initialization-based transferring, (2) knowledge-based transferring, and (3) data-based transferring. These newly designed transferring techniques exploit multi-task learning frameworks to incorporate extra knowledge from other networks and additional datasets into the training procedure of event CNNs. These multi-task learning frameworks turn out to be effective in reducing the effect of over-fitting and improving the generalization ability of the learned CNNs. With OS2E-CNN, we design a multi-ratio and multi-scale cropping strategy, and propose an end-to-end event recognition pipeline. We perform experiments on three event recognition benchmarks: the ChaLearn Cultural Event Recognition dataset, the Web Image Dataset for Event Recognition (WIDER), and the UIUC Sports Event dataset. The experimental results show that our proposed algorithm successfully adapts object and scene representations towards the event dataset and that it achieves the current state-of-the-art performance on these challenging datasets.
no_new_dataset
0.948489
1609.00203
Angelos Valsamis
Angelos Valsamis, Konstantinos Tserpes, Dimitrios Zissis, Dimosthenis Anagnostopoulos, Theodora Varvarigou
Employing traditional machine learning algorithms for big data streams analysis: the case of object trajectory prediction
14 pages, 2 figures, 3 tables, 31 references
null
10.1016/j.jss.2016.06.016
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we model the trajectory of sea vessels and provide a service that predicts in near-real time the position of any given vessel in 4', 10', 20' and 40' time intervals. We explore the necessary tradeoffs between accuracy, performance and resource utilization are explored given the large volume and update rates of input data. We start with building models based on well-established machine learning algorithms using static datasets and multi-scan training approaches and identify the best candidate to be used in implementing a single-pass predictive approach, under real-time constraints. The results are measured in terms of accuracy and performance and are compared against the baseline kinematic equations. Results show that it is possible to efficiently model the trajectory of multiple vessels using a single model, which is trained and evaluated using an adequately large, static dataset, thus achieving a significant gain in terms of resource usage while not compromising accuracy.
[ { "version": "v1", "created": "Thu, 1 Sep 2016 12:06:20 GMT" } ]
2016-09-02T00:00:00
[ [ "Valsamis", "Angelos", "" ], [ "Tserpes", "Konstantinos", "" ], [ "Zissis", "Dimitrios", "" ], [ "Anagnostopoulos", "Dimosthenis", "" ], [ "Varvarigou", "Theodora", "" ] ]
TITLE: Employing traditional machine learning algorithms for big data streams analysis: the case of object trajectory prediction ABSTRACT: In this paper, we model the trajectory of sea vessels and provide a service that predicts in near-real time the position of any given vessel in 4', 10', 20' and 40' time intervals. We explore the necessary tradeoffs between accuracy, performance and resource utilization are explored given the large volume and update rates of input data. We start with building models based on well-established machine learning algorithms using static datasets and multi-scan training approaches and identify the best candidate to be used in implementing a single-pass predictive approach, under real-time constraints. The results are measured in terms of accuracy and performance and are compared against the baseline kinematic equations. Results show that it is possible to efficiently model the trajectory of multiple vessels using a single model, which is trained and evaluated using an adequately large, static dataset, thus achieving a significant gain in terms of resource usage while not compromising accuracy.
no_new_dataset
0.943608
1609.00221
Federico Becattini
Giovanni Cuffaro, Federico Becattini, Claudio Baecchi, Lorenzo Seidenari, Alberto Del Bimbo
Segmentation Free Object Discovery in Video
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present a simple yet effective approach to extend without supervision any object proposal from static images to videos. Unlike previous methods, these spatio-temporal proposals, to which we refer as tracks, are generated relying on little or no visual content by only exploiting bounding boxes spatial correlations through time. The tracks that we obtain are likely to represent objects and are a general-purpose tool to represent meaningful video content for a wide variety of tasks. For unannotated videos, tracks can be used to discover content without any supervision. As further contribution we also propose a novel and dataset-independent method to evaluate a generic object proposal based on the entropy of a classifier output response. We experiment on two competitive datasets, namely YouTube Objects and ILSVRC-2015 VID.
[ { "version": "v1", "created": "Thu, 1 Sep 2016 13:08:39 GMT" } ]
2016-09-02T00:00:00
[ [ "Cuffaro", "Giovanni", "" ], [ "Becattini", "Federico", "" ], [ "Baecchi", "Claudio", "" ], [ "Seidenari", "Lorenzo", "" ], [ "Del Bimbo", "Alberto", "" ] ]
TITLE: Segmentation Free Object Discovery in Video ABSTRACT: In this paper we present a simple yet effective approach to extend without supervision any object proposal from static images to videos. Unlike previous methods, these spatio-temporal proposals, to which we refer as tracks, are generated relying on little or no visual content by only exploiting bounding boxes spatial correlations through time. The tracks that we obtain are likely to represent objects and are a general-purpose tool to represent meaningful video content for a wide variety of tasks. For unannotated videos, tracks can be used to discover content without any supervision. As further contribution we also propose a novel and dataset-independent method to evaluate a generic object proposal based on the entropy of a classifier output response. We experiment on two competitive datasets, namely YouTube Objects and ILSVRC-2015 VID.
no_new_dataset
0.951369
1609.00278
Arsalan Mousavian
Arsalan Mousavian, Jana Kosecka
Semantic Image Based Geolocation Given a Map
null
null
null
null
cs.CV cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The problem visual place recognition is commonly used strategy for localization. Most successful appearance based methods typically rely on a large database of views endowed with local or global image descriptors and strive to retrieve the views of the same location. The quality of the results is often affected by the density of the reference views and the robustness of the image representation with respect to viewpoint variations, clutter and seasonal changes. In this work we present an approach for geo-locating a novel view and determining camera location and orientation using a map and a sparse set of geo-tagged reference views. We propose a novel technique for detection and identification of building facades from geo-tagged reference view using the map and geometry of the building facades. We compute the likelihood of camera location and orientation of the query images using the detected landmark (building) identities from reference views, 2D map of the environment, and geometry of building facades. We evaluate our approach for building identification and geo-localization on a new challenging outdoors urban dataset exhibiting large variations in appearance and viewpoint.
[ { "version": "v1", "created": "Thu, 1 Sep 2016 15:27:02 GMT" } ]
2016-09-02T00:00:00
[ [ "Mousavian", "Arsalan", "" ], [ "Kosecka", "Jana", "" ] ]
TITLE: Semantic Image Based Geolocation Given a Map ABSTRACT: The problem visual place recognition is commonly used strategy for localization. Most successful appearance based methods typically rely on a large database of views endowed with local or global image descriptors and strive to retrieve the views of the same location. The quality of the results is often affected by the density of the reference views and the robustness of the image representation with respect to viewpoint variations, clutter and seasonal changes. In this work we present an approach for geo-locating a novel view and determining camera location and orientation using a map and a sparse set of geo-tagged reference views. We propose a novel technique for detection and identification of building facades from geo-tagged reference view using the map and geometry of the building facades. We compute the likelihood of camera location and orientation of the query images using the detected landmark (building) identities from reference views, 2D map of the environment, and geometry of building facades. We evaluate our approach for building identification and geo-localization on a new challenging outdoors urban dataset exhibiting large variations in appearance and viewpoint.
new_dataset
0.958187
1602.08751
Jacopo Iacovacci
Jacopo Iacovacci and Ginestra Bianconi
Extracting Information from Multiplex Networks
11 pages; 5 figures
Chaos: An Interdisciplinary Journal of Nonlinear Science 26.6 (2016): 065306
10.1063/1.4953161
null
physics.soc-ph cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Multiplex networks are generalized network structures that are able to describe networks in which the same set of nodes are connected by links that have different connotations. Multiplex networks are ubiquitous since they describe social, financial, engineering and biological networks as well. Extending our ability to analyze complex networks to multiplex network structures increases greatly the level of information that is possible to extract from Big Data. For these reasons characterizing the centrality of nodes in multiplex networks and finding new ways to solve challenging inference problems defined on multiplex networks are fundamental questions of network science. In this paper we discuss the relevance of the Multiplex PageRank algorithm for measuring the centrality of nodes in multilayer networks and we characterize the utility of the recently introduced indicator function $\widetilde{\Theta}^{S}$ for describing their mesoscale organization and community structure. As working examples for studying these measures we consider three multiplex network datasets coming for social science.
[ { "version": "v1", "created": "Sun, 28 Feb 2016 18:32:14 GMT" }, { "version": "v2", "created": "Mon, 16 May 2016 19:04:56 GMT" } ]
2016-09-01T00:00:00
[ [ "Iacovacci", "Jacopo", "" ], [ "Bianconi", "Ginestra", "" ] ]
TITLE: Extracting Information from Multiplex Networks ABSTRACT: Multiplex networks are generalized network structures that are able to describe networks in which the same set of nodes are connected by links that have different connotations. Multiplex networks are ubiquitous since they describe social, financial, engineering and biological networks as well. Extending our ability to analyze complex networks to multiplex network structures increases greatly the level of information that is possible to extract from Big Data. For these reasons characterizing the centrality of nodes in multiplex networks and finding new ways to solve challenging inference problems defined on multiplex networks are fundamental questions of network science. In this paper we discuss the relevance of the Multiplex PageRank algorithm for measuring the centrality of nodes in multilayer networks and we characterize the utility of the recently introduced indicator function $\widetilde{\Theta}^{S}$ for describing their mesoscale organization and community structure. As working examples for studying these measures we consider three multiplex network datasets coming for social science.
no_new_dataset
0.953188
1606.01455
Jin-Hwa Kim
Jin-Hwa Kim, Sang-Woo Lee, Dong-Hyun Kwak, Min-Oh Heo, Jeonghee Kim, Jung-Woo Ha, Byoung-Tak Zhang
Multimodal Residual Learning for Visual QA
13 pages, 7 figures, accepted for NIPS 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deep neural networks continue to advance the state-of-the-art of image recognition tasks with various methods. However, applications of these methods to multimodality remain limited. We present Multimodal Residual Networks (MRN) for the multimodal residual learning of visual question-answering, which extends the idea of the deep residual learning. Unlike the deep residual learning, MRN effectively learns the joint representation from vision and language information. The main idea is to use element-wise multiplication for the joint residual mappings exploiting the residual learning of the attentional models in recent studies. Various alternative models introduced by multimodality are explored based on our study. We achieve the state-of-the-art results on the Visual QA dataset for both Open-Ended and Multiple-Choice tasks. Moreover, we introduce a novel method to visualize the attention effect of the joint representations for each learning block using back-propagation algorithm, even though the visual features are collapsed without spatial information.
[ { "version": "v1", "created": "Sun, 5 Jun 2016 02:38:20 GMT" }, { "version": "v2", "created": "Wed, 31 Aug 2016 08:28:38 GMT" } ]
2016-09-01T00:00:00
[ [ "Kim", "Jin-Hwa", "" ], [ "Lee", "Sang-Woo", "" ], [ "Kwak", "Dong-Hyun", "" ], [ "Heo", "Min-Oh", "" ], [ "Kim", "Jeonghee", "" ], [ "Ha", "Jung-Woo", "" ], [ "Zhang", "Byoung-Tak", "" ] ]
TITLE: Multimodal Residual Learning for Visual QA ABSTRACT: Deep neural networks continue to advance the state-of-the-art of image recognition tasks with various methods. However, applications of these methods to multimodality remain limited. We present Multimodal Residual Networks (MRN) for the multimodal residual learning of visual question-answering, which extends the idea of the deep residual learning. Unlike the deep residual learning, MRN effectively learns the joint representation from vision and language information. The main idea is to use element-wise multiplication for the joint residual mappings exploiting the residual learning of the attentional models in recent studies. Various alternative models introduced by multimodality are explored based on our study. We achieve the state-of-the-art results on the Visual QA dataset for both Open-Ended and Multiple-Choice tasks. Moreover, we introduce a novel method to visualize the attention effect of the joint representations for each learning block using back-propagation algorithm, even though the visual features are collapsed without spatial information.
no_new_dataset
0.9434
1608.08526
Umar Iqbal
Umar Iqbal and Juergen Gall
Multi-Person Pose Estimation with Local Joint-to-Person Associations
Accepted to European Conference on Computer Vision (ECCV) Workshops, Crowd Understanding, 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Despite of the recent success of neural networks for human pose estimation, current approaches are limited to pose estimation of a single person and cannot handle humans in groups or crowds. In this work, we propose a method that estimates the poses of multiple persons in an image in which a person can be occluded by another person or might be truncated. To this end, we consider multi-person pose estimation as a joint-to-person association problem. We construct a fully connected graph from a set of detected joint candidates in an image and resolve the joint-to-person association and outlier detection using integer linear programming. Since solving joint-to-person association jointly for all persons in an image is an NP-hard problem and even approximations are expensive, we solve the problem locally for each person. On the challenging MPII Human Pose Dataset for multiple persons, our approach achieves the accuracy of a state-of-the-art method, but it is 6,000 to 19,000 times faster.
[ { "version": "v1", "created": "Tue, 30 Aug 2016 16:00:42 GMT" }, { "version": "v2", "created": "Wed, 31 Aug 2016 09:26:57 GMT" } ]
2016-09-01T00:00:00
[ [ "Iqbal", "Umar", "" ], [ "Gall", "Juergen", "" ] ]
TITLE: Multi-Person Pose Estimation with Local Joint-to-Person Associations ABSTRACT: Despite of the recent success of neural networks for human pose estimation, current approaches are limited to pose estimation of a single person and cannot handle humans in groups or crowds. In this work, we propose a method that estimates the poses of multiple persons in an image in which a person can be occluded by another person or might be truncated. To this end, we consider multi-person pose estimation as a joint-to-person association problem. We construct a fully connected graph from a set of detected joint candidates in an image and resolve the joint-to-person association and outlier detection using integer linear programming. Since solving joint-to-person association jointly for all persons in an image is an NP-hard problem and even approximations are expensive, we solve the problem locally for each person. On the challenging MPII Human Pose Dataset for multiple persons, our approach achieves the accuracy of a state-of-the-art method, but it is 6,000 to 19,000 times faster.
no_new_dataset
0.9463
1608.08716
Aishwarya Agrawal
C. Lawrence Zitnick, Aishwarya Agrawal, Stanislaw Antol, Margaret Mitchell, Dhruv Batra, Devi Parikh
Measuring Machine Intelligence Through Visual Question Answering
AI Magazine, 2016
null
null
null
cs.AI cs.CL cs.CV cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As machines have become more intelligent, there has been a renewed interest in methods for measuring their intelligence. A common approach is to propose tasks for which a human excels, but one which machines find difficult. However, an ideal task should also be easy to evaluate and not be easily gameable. We begin with a case study exploring the recently popular task of image captioning and its limitations as a task for measuring machine intelligence. An alternative and more promising task is Visual Question Answering that tests a machine's ability to reason about language and vision. We describe a dataset unprecedented in size created for the task that contains over 760,000 human generated questions about images. Using around 10 million human generated answers, machines may be easily evaluated.
[ { "version": "v1", "created": "Wed, 31 Aug 2016 02:56:00 GMT" } ]
2016-09-01T00:00:00
[ [ "Zitnick", "C. Lawrence", "" ], [ "Agrawal", "Aishwarya", "" ], [ "Antol", "Stanislaw", "" ], [ "Mitchell", "Margaret", "" ], [ "Batra", "Dhruv", "" ], [ "Parikh", "Devi", "" ] ]
TITLE: Measuring Machine Intelligence Through Visual Question Answering ABSTRACT: As machines have become more intelligent, there has been a renewed interest in methods for measuring their intelligence. A common approach is to propose tasks for which a human excels, but one which machines find difficult. However, an ideal task should also be easy to evaluate and not be easily gameable. We begin with a case study exploring the recently popular task of image captioning and its limitations as a task for measuring machine intelligence. An alternative and more promising task is Visual Question Answering that tests a machine's ability to reason about language and vision. We describe a dataset unprecedented in size created for the task that contains over 760,000 human generated questions about images. Using around 10 million human generated answers, machines may be easily evaluated.
new_dataset
0.954393
1608.09002
Prantik Bhattacharyya
Nemanja Spasojevic, Prantik Bhattacharyya, Adithya Rao
Mining Half a Billion Topical Experts Across Multiple Social Networks
20 pages, 9 figures, 6 tables
null
10.1007/s13278-016-0356-7
null
cs.IR cs.SI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mining topical experts on social media is a problem that has gained significant attention due to its wide-ranging applications. Here we present the first study that combines data from four major social networks -- Twitter, Facebook, Google+ and LinkedIn, along with the Wikipedia graph and internet webpage text and metadata, to rank topical experts across the global population of users. We perform an in-depth analysis of 37 features derived from various data sources such as message text, user lists, webpages, social graphs and wikipedia. This large-scale study includes more than 12 billion messages over a 90-day sliding window and 58 billion social graph edges. Comparison reveals that features derived from Twitter Lists, Wikipedia, internet webpages and Twitter Followers are especially good indicators of expertise. We train an expertise ranking model using these features on a large ground truth dataset containing almost 90,000 labels. This model is applied within a production system that ranks over 650 million experts in more than 9,000 topical domains on a daily basis. We provide results and examples on the effectiveness of our expert ranking system, along with empirical validation. Finally, we make the topical expertise data available through open REST APIs for wider use.
[ { "version": "v1", "created": "Wed, 31 Aug 2016 19:14:03 GMT" } ]
2016-09-01T00:00:00
[ [ "Spasojevic", "Nemanja", "" ], [ "Bhattacharyya", "Prantik", "" ], [ "Rao", "Adithya", "" ] ]
TITLE: Mining Half a Billion Topical Experts Across Multiple Social Networks ABSTRACT: Mining topical experts on social media is a problem that has gained significant attention due to its wide-ranging applications. Here we present the first study that combines data from four major social networks -- Twitter, Facebook, Google+ and LinkedIn, along with the Wikipedia graph and internet webpage text and metadata, to rank topical experts across the global population of users. We perform an in-depth analysis of 37 features derived from various data sources such as message text, user lists, webpages, social graphs and wikipedia. This large-scale study includes more than 12 billion messages over a 90-day sliding window and 58 billion social graph edges. Comparison reveals that features derived from Twitter Lists, Wikipedia, internet webpages and Twitter Followers are especially good indicators of expertise. We train an expertise ranking model using these features on a large ground truth dataset containing almost 90,000 labels. This model is applied within a production system that ranks over 650 million experts in more than 9,000 topical domains on a daily basis. We provide results and examples on the effectiveness of our expert ranking system, along with empirical validation. Finally, we make the topical expertise data available through open REST APIs for wider use.
new_dataset
0.828037
1604.06506
Roeland De Geest
Roeland De Geest, Efstratios Gavves, Amir Ghodrati, Zhenyang Li, Cees Snoek, Tinne Tuytelaars
Online Action Detection
Project page: http://homes.esat.kuleuven.be/~rdegeest/OnlineActionDetection.html
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In online action detection, the goal is to detect the start of an action in a video stream as soon as it happens. For instance, if a child is chasing a ball, an autonomous car should recognize what is going on and respond immediately. This is a very challenging problem for four reasons. First, only partial actions are observed. Second, there is a large variability in negative data. Third, the start of the action is unknown, so it is unclear over what time window the information should be integrated. Finally, in real world data, large within-class variability exists. This problem has been addressed before, but only to some extent. Our contributions to online action detection are threefold. First, we introduce a realistic dataset composed of 27 episodes from 6 popular TV series. The dataset spans over 16 hours of footage annotated with 30 action classes, totaling 6,231 action instances. Second, we analyze and compare various baseline methods, showing this is a challenging problem for which none of the methods provides a good solution. Third, we analyze the change in performance when there is a variation in viewpoint, occlusion, truncation, etc. We introduce an evaluation protocol for fair comparison. The dataset, the baselines and the models will all be made publicly available to encourage (much needed) further research on online action detection on realistic data.
[ { "version": "v1", "created": "Thu, 21 Apr 2016 22:02:50 GMT" }, { "version": "v2", "created": "Tue, 30 Aug 2016 09:29:39 GMT" } ]
2016-08-31T00:00:00
[ [ "De Geest", "Roeland", "" ], [ "Gavves", "Efstratios", "" ], [ "Ghodrati", "Amir", "" ], [ "Li", "Zhenyang", "" ], [ "Snoek", "Cees", "" ], [ "Tuytelaars", "Tinne", "" ] ]
TITLE: Online Action Detection ABSTRACT: In online action detection, the goal is to detect the start of an action in a video stream as soon as it happens. For instance, if a child is chasing a ball, an autonomous car should recognize what is going on and respond immediately. This is a very challenging problem for four reasons. First, only partial actions are observed. Second, there is a large variability in negative data. Third, the start of the action is unknown, so it is unclear over what time window the information should be integrated. Finally, in real world data, large within-class variability exists. This problem has been addressed before, but only to some extent. Our contributions to online action detection are threefold. First, we introduce a realistic dataset composed of 27 episodes from 6 popular TV series. The dataset spans over 16 hours of footage annotated with 30 action classes, totaling 6,231 action instances. Second, we analyze and compare various baseline methods, showing this is a challenging problem for which none of the methods provides a good solution. Third, we analyze the change in performance when there is a variation in viewpoint, occlusion, truncation, etc. We introduce an evaluation protocol for fair comparison. The dataset, the baselines and the models will all be made publicly available to encourage (much needed) further research on online action detection on realistic data.
new_dataset
0.965803
1608.07550
Joyce Fang
Joyce Fang, Dmitry Savransky
Automated alignment of a reconfigurable optical system using focal-plane sensing and Kalman filtering
null
null
10.1364/AO.55.005967
null
astro-ph.IM physics.optics
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Automation of alignment tasks can provide improved efficiency and greatly increase the flexibility of an optical system. Current optical systems with automated alignment capabilities are typically designed to include a dedicated wavefront sensor. Here, we demonstrate a self-aligning method for a reconfigurable system using only focal plane images. We define a two lens optical system with eight degrees of freedom. Images are simulated given misalignment parameters using ZEMAX software. We perform a principal component analysis (PCA) on the simulated dataset to obtain Karhunen-Lo\`eve (KL) modes, which form the basis set whose weights are the system measurements. A model function which maps the state to the measurement is learned using nonlinear least squares fitting and serves as the measurement function for the nonlinear estimator (Extended and Unscented Kalman filters) used to calculate control inputs to align the system. We present and discuss both simulated and experimental results of the full system in operation.
[ { "version": "v1", "created": "Fri, 26 Aug 2016 18:24:18 GMT" } ]
2016-08-31T00:00:00
[ [ "Fang", "Joyce", "" ], [ "Savransky", "Dmitry", "" ] ]
TITLE: Automated alignment of a reconfigurable optical system using focal-plane sensing and Kalman filtering ABSTRACT: Automation of alignment tasks can provide improved efficiency and greatly increase the flexibility of an optical system. Current optical systems with automated alignment capabilities are typically designed to include a dedicated wavefront sensor. Here, we demonstrate a self-aligning method for a reconfigurable system using only focal plane images. We define a two lens optical system with eight degrees of freedom. Images are simulated given misalignment parameters using ZEMAX software. We perform a principal component analysis (PCA) on the simulated dataset to obtain Karhunen-Lo\`eve (KL) modes, which form the basis set whose weights are the system measurements. A model function which maps the state to the measurement is learned using nonlinear least squares fitting and serves as the measurement function for the nonlinear estimator (Extended and Unscented Kalman filters) used to calculate control inputs to align the system. We present and discuss both simulated and experimental results of the full system in operation.
no_new_dataset
0.947769
1608.08148
Olaf Hartig
Olaf Hartig and Carlos Buil-Aranda
brTPF: Bindings-Restricted Triple Pattern Fragments (Extended Preprint)
This document is an extended preprint of a paper published in the proceedings of the ODBASE 2016 conference. In contrast to the proceedings version, this document contains Appendixes A and B which present additional experimental results
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Triple Pattern Fragment (TPF) interface is a recent proposal for reducing server load in Web-based approaches to execute SPARQL queries over public RDF datasets. The price for less overloaded servers is a higher client-side load and a substantial increase in network load (in terms of both the number of HTTP requests and data transfer). In this paper, we propose a slightly extended interface that allows clients to attach intermediate results to triple pattern requests. The response to such a request is expected to contain triples from the underlying dataset that do not only match the given triple pattern (as in the case of TPF), but that are guaranteed to contribute in a join with the given intermediate result. Our hypothesis is that a distributed query execution using this extended interface can reduce the network load (in comparison to a pure TPF-based query execution) without reducing the overall throughput of the client-server system significantly. Our main contribution in this paper is twofold: we empirically verify the hypothesis and provide an extensive experimental comparison of our proposal and TPF.
[ { "version": "v1", "created": "Mon, 29 Aug 2016 17:09:53 GMT" }, { "version": "v2", "created": "Tue, 30 Aug 2016 15:49:29 GMT" } ]
2016-08-31T00:00:00
[ [ "Hartig", "Olaf", "" ], [ "Buil-Aranda", "Carlos", "" ] ]
TITLE: brTPF: Bindings-Restricted Triple Pattern Fragments (Extended Preprint) ABSTRACT: The Triple Pattern Fragment (TPF) interface is a recent proposal for reducing server load in Web-based approaches to execute SPARQL queries over public RDF datasets. The price for less overloaded servers is a higher client-side load and a substantial increase in network load (in terms of both the number of HTTP requests and data transfer). In this paper, we propose a slightly extended interface that allows clients to attach intermediate results to triple pattern requests. The response to such a request is expected to contain triples from the underlying dataset that do not only match the given triple pattern (as in the case of TPF), but that are guaranteed to contribute in a join with the given intermediate result. Our hypothesis is that a distributed query execution using this extended interface can reduce the network load (in comparison to a pure TPF-based query execution) without reducing the overall throughput of the client-server system significantly. Our main contribution in this paper is twofold: we empirically verify the hypothesis and provide an extensive experimental comparison of our proposal and TPF.
no_new_dataset
0.948917
1608.08242
Colin Lea
Colin Lea, Rene Vidal, Austin Reiter, Gregory D. Hager
Temporal Convolutional Networks: A Unified Approach to Action Segmentation
Submitted to the ECCV workshop on "Brave new ideas for motion representations in videos" (http://bravenewmotion.github.io/)
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The dominant paradigm for video-based action segmentation is composed of two steps: first, for each frame, compute low-level features using Dense Trajectories or a Convolutional Neural Network that encode spatiotemporal information locally, and second, input these features into a classifier that captures high-level temporal relationships, such as a Recurrent Neural Network (RNN). While often effective, this decoupling requires specifying two separate models, each with their own complexities, and prevents capturing more nuanced long-range spatiotemporal relationships. We propose a unified approach, as demonstrated by our Temporal Convolutional Network (TCN), that hierarchically captures relationships at low-, intermediate-, and high-level time-scales. Our model achieves superior or competitive performance using video or sensor data on three public action segmentation datasets and can be trained in a fraction of the time it takes to train an RNN.
[ { "version": "v1", "created": "Mon, 29 Aug 2016 20:48:15 GMT" } ]
2016-08-31T00:00:00
[ [ "Lea", "Colin", "" ], [ "Vidal", "Rene", "" ], [ "Reiter", "Austin", "" ], [ "Hager", "Gregory D.", "" ] ]
TITLE: Temporal Convolutional Networks: A Unified Approach to Action Segmentation ABSTRACT: The dominant paradigm for video-based action segmentation is composed of two steps: first, for each frame, compute low-level features using Dense Trajectories or a Convolutional Neural Network that encode spatiotemporal information locally, and second, input these features into a classifier that captures high-level temporal relationships, such as a Recurrent Neural Network (RNN). While often effective, this decoupling requires specifying two separate models, each with their own complexities, and prevents capturing more nuanced long-range spatiotemporal relationships. We propose a unified approach, as demonstrated by our Temporal Convolutional Network (TCN), that hierarchically captures relationships at low-, intermediate-, and high-level time-scales. Our model achieves superior or competitive performance using video or sensor data on three public action segmentation datasets and can be trained in a fraction of the time it takes to train an RNN.
no_new_dataset
0.950134
1608.08305
Ronghang Hu
Ronghang Hu, Marcus Rohrbach, Subhashini Venugopalan, Trevor Darrell
Utilizing Large Scale Vision and Text Datasets for Image Segmentation from Referring Expressions
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Image segmentation from referring expressions is a joint vision and language modeling task, where the input is an image and a textual expression describing a particular region in the image; and the goal is to localize and segment the specific image region based on the given expression. One major difficulty to train such language-based image segmentation systems is the lack of datasets with joint vision and text annotations. Although existing vision datasets such as MS COCO provide image captions, there are few datasets with region-level textual annotations for images, and these are often smaller in scale. In this paper, we explore how existing large scale vision-only and text-only datasets can be utilized to train models for image segmentation from referring expressions. We propose a method to address this problem, and show in experiments that our method can help this joint vision and language modeling task with vision-only and text-only data and outperforms previous results.
[ { "version": "v1", "created": "Tue, 30 Aug 2016 02:27:41 GMT" } ]
2016-08-31T00:00:00
[ [ "Hu", "Ronghang", "" ], [ "Rohrbach", "Marcus", "" ], [ "Venugopalan", "Subhashini", "" ], [ "Darrell", "Trevor", "" ] ]
TITLE: Utilizing Large Scale Vision and Text Datasets for Image Segmentation from Referring Expressions ABSTRACT: Image segmentation from referring expressions is a joint vision and language modeling task, where the input is an image and a textual expression describing a particular region in the image; and the goal is to localize and segment the specific image region based on the given expression. One major difficulty to train such language-based image segmentation systems is the lack of datasets with joint vision and text annotations. Although existing vision datasets such as MS COCO provide image captions, there are few datasets with region-level textual annotations for images, and these are often smaller in scale. In this paper, we explore how existing large scale vision-only and text-only datasets can be utilized to train models for image segmentation from referring expressions. We propose a method to address this problem, and show in experiments that our method can help this joint vision and language modeling task with vision-only and text-only data and outperforms previous results.
no_new_dataset
0.949856
1608.08471
Johannes Stegmaier
Johannes Stegmaier
New Methods to Improve Large-Scale Microscopy Image Analysis with Prior Knowledge and Uncertainty
218 pages, 58 figures, PhD thesis, Department of Mechanical Engineering, Karlsruhe Institute of Technology, published online with KITopen (License: CC BY-SA 3.0, http://dx.doi.org/10.5445/IR/1000057821)
null
10.5445/IR/1000057821
null
cs.CV
http://creativecommons.org/licenses/by-sa/4.0/
Multidimensional imaging techniques provide powerful ways to examine various kinds of scientific questions. The routinely produced datasets in the terabyte-range, however, can hardly be analyzed manually and require an extensive use of automated image analysis. The present thesis introduces a new concept for the estimation and propagation of uncertainty involved in image analysis operators and new segmentation algorithms that are suitable for terabyte-scale analyses of 3D+t microscopy images.
[ { "version": "v1", "created": "Tue, 30 Aug 2016 14:21:55 GMT" } ]
2016-08-31T00:00:00
[ [ "Stegmaier", "Johannes", "" ] ]
TITLE: New Methods to Improve Large-Scale Microscopy Image Analysis with Prior Knowledge and Uncertainty ABSTRACT: Multidimensional imaging techniques provide powerful ways to examine various kinds of scientific questions. The routinely produced datasets in the terabyte-range, however, can hardly be analyzed manually and require an extensive use of automated image analysis. The present thesis introduces a new concept for the estimation and propagation of uncertainty involved in image analysis operators and new segmentation algorithms that are suitable for terabyte-scale analyses of 3D+t microscopy images.
no_new_dataset
0.944791
1511.04599
Seyed-Mohsen Moosavi-Dezfooli
Seyed-Mohsen Moosavi-Dezfooli, Alhussein Fawzi, Pascal Frossard
DeepFool: a simple and accurate method to fool deep neural networks
In Proceedings of IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2016
null
null
null
cs.LG cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
State-of-the-art deep neural networks have achieved impressive results on many image classification tasks. However, these same architectures have been shown to be unstable to small, well sought, perturbations of the images. Despite the importance of this phenomenon, no effective methods have been proposed to accurately compute the robustness of state-of-the-art deep classifiers to such perturbations on large-scale datasets. In this paper, we fill this gap and propose the DeepFool algorithm to efficiently compute perturbations that fool deep networks, and thus reliably quantify the robustness of these classifiers. Extensive experimental results show that our approach outperforms recent methods in the task of computing adversarial perturbations and making classifiers more robust.
[ { "version": "v1", "created": "Sat, 14 Nov 2015 18:50:00 GMT" }, { "version": "v2", "created": "Thu, 14 Apr 2016 09:33:23 GMT" }, { "version": "v3", "created": "Mon, 4 Jul 2016 04:49:44 GMT" } ]
2016-08-30T00:00:00
[ [ "Moosavi-Dezfooli", "Seyed-Mohsen", "" ], [ "Fawzi", "Alhussein", "" ], [ "Frossard", "Pascal", "" ] ]
TITLE: DeepFool: a simple and accurate method to fool deep neural networks ABSTRACT: State-of-the-art deep neural networks have achieved impressive results on many image classification tasks. However, these same architectures have been shown to be unstable to small, well sought, perturbations of the images. Despite the importance of this phenomenon, no effective methods have been proposed to accurately compute the robustness of state-of-the-art deep classifiers to such perturbations on large-scale datasets. In this paper, we fill this gap and propose the DeepFool algorithm to efficiently compute perturbations that fool deep networks, and thus reliably quantify the robustness of these classifiers. Extensive experimental results show that our approach outperforms recent methods in the task of computing adversarial perturbations and making classifiers more robust.
no_new_dataset
0.947088
1601.06579
Dong Nguyen
Dong Nguyen, Jacob Eisenstein
A Kernel Independence Test for Geographical Language Variation
In submission. 26 pages
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quantifying the degree of spatial dependence for linguistic variables is a key task for analyzing dialectal variation. However, existing approaches have important drawbacks. First, they are based on parametric models of dependence, which limits their power in cases where the underlying parametric assumptions are violated. Second, they are not applicable to all types of linguistic data: some approaches apply only to frequencies, others to boolean indicators of whether a linguistic variable is present. We present a new method for measuring geographical language variation, which solves both of these problems. Our approach builds on Reproducing Kernel Hilbert space (RKHS) representations for nonparametric statistics, and takes the form of a test statistic that is computed from pairs of individual geotagged observations without aggregation into predefined geographical bins. We compare this test with prior work using synthetic data as well as a diverse set of real datasets: a corpus of Dutch tweets, a Dutch syntactic atlas, and a dataset of letters to the editor in North American newspapers. Our proposed test is shown to support robust inferences across a broad range of scenarios and types of data.
[ { "version": "v1", "created": "Mon, 25 Jan 2016 12:45:59 GMT" }, { "version": "v2", "created": "Mon, 29 Aug 2016 13:16:42 GMT" } ]
2016-08-30T00:00:00
[ [ "Nguyen", "Dong", "" ], [ "Eisenstein", "Jacob", "" ] ]
TITLE: A Kernel Independence Test for Geographical Language Variation ABSTRACT: Quantifying the degree of spatial dependence for linguistic variables is a key task for analyzing dialectal variation. However, existing approaches have important drawbacks. First, they are based on parametric models of dependence, which limits their power in cases where the underlying parametric assumptions are violated. Second, they are not applicable to all types of linguistic data: some approaches apply only to frequencies, others to boolean indicators of whether a linguistic variable is present. We present a new method for measuring geographical language variation, which solves both of these problems. Our approach builds on Reproducing Kernel Hilbert space (RKHS) representations for nonparametric statistics, and takes the form of a test statistic that is computed from pairs of individual geotagged observations without aggregation into predefined geographical bins. We compare this test with prior work using synthetic data as well as a diverse set of real datasets: a corpus of Dutch tweets, a Dutch syntactic atlas, and a dataset of letters to the editor in North American newspapers. Our proposed test is shown to support robust inferences across a broad range of scenarios and types of data.
no_new_dataset
0.92944
1605.04457
Alexandre Mauroy
Alexandre Mauroy and Jorge Goncalves
Linear identification of nonlinear systems: A lifting technique based on the Koopman operator
6 pages
null
null
null
cs.SY
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We exploit the key idea that nonlinear system identification is equivalent to linear identification of the socalled Koopman operator. Instead of considering nonlinear system identification in the state space, we obtain a novel linear identification technique by recasting the problem in the infinite-dimensional space of observables. This technique can be described in two main steps. In the first step, similar to the socalled Extended Dynamic Mode Decomposition algorithm, the data are lifted to the infinite-dimensional space and used for linear identification of the Koopman operator. In the second step, the obtained Koopman operator is "projected back" to the finite-dimensional state space, and identified to the nonlinear vector field through a linear least squares problem. The proposed technique is efficient to recover (polynomial) vector fields of different classes of systems, including unstable, chaotic, and open systems. In addition, it is robust to noise, well-suited to model low sampling rate datasets, and able to infer network topology and dynamics.
[ { "version": "v1", "created": "Sat, 14 May 2016 19:05:18 GMT" }, { "version": "v2", "created": "Sat, 27 Aug 2016 18:21:39 GMT" } ]
2016-08-30T00:00:00
[ [ "Mauroy", "Alexandre", "" ], [ "Goncalves", "Jorge", "" ] ]
TITLE: Linear identification of nonlinear systems: A lifting technique based on the Koopman operator ABSTRACT: We exploit the key idea that nonlinear system identification is equivalent to linear identification of the socalled Koopman operator. Instead of considering nonlinear system identification in the state space, we obtain a novel linear identification technique by recasting the problem in the infinite-dimensional space of observables. This technique can be described in two main steps. In the first step, similar to the socalled Extended Dynamic Mode Decomposition algorithm, the data are lifted to the infinite-dimensional space and used for linear identification of the Koopman operator. In the second step, the obtained Koopman operator is "projected back" to the finite-dimensional state space, and identified to the nonlinear vector field through a linear least squares problem. The proposed technique is efficient to recover (polynomial) vector fields of different classes of systems, including unstable, chaotic, and open systems. In addition, it is robust to noise, well-suited to model low sampling rate datasets, and able to infer network topology and dynamics.
no_new_dataset
0.948106
1606.00850
Tianfu Wu
Yunzhu Li, Benyuan Sun, Tianfu Wu and Yizhou Wang
Face Detection with End-to-End Integration of a ConvNet and a 3D Model
16 pages, Y. Li and B. Sun contributed equally to this work
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents a method for face detection in the wild, which integrates a ConvNet and a 3D mean face model in an end-to-end multi-task discriminative learning framework. The 3D mean face model is predefined and fixed (e.g., we used the one provided in the AFLW dataset). The ConvNet consists of two components: (i) The face pro- posal component computes face bounding box proposals via estimating facial key-points and the 3D transformation (rotation and translation) parameters for each predicted key-point w.r.t. the 3D mean face model. (ii) The face verification component computes detection results by prun- ing and refining proposals based on facial key-points based configuration pooling. The proposed method addresses two issues in adapting state- of-the-art generic object detection ConvNets (e.g., faster R-CNN) for face detection: (i) One is to eliminate the heuristic design of prede- fined anchor boxes in the region proposals network (RPN) by exploit- ing a 3D mean face model. (ii) The other is to replace the generic RoI (Region-of-Interest) pooling layer with a configuration pooling layer to respect underlying object structures. The multi-task loss consists of three terms: the classification Softmax loss and the location smooth l1 -losses [14] of both the facial key-points and the face bounding boxes. In ex- periments, our ConvNet is trained on the AFLW dataset only and tested on the FDDB benchmark with fine-tuning and on the AFW benchmark without fine-tuning. The proposed method obtains very competitive state-of-the-art performance in the two benchmarks.
[ { "version": "v1", "created": "Thu, 2 Jun 2016 20:08:28 GMT" }, { "version": "v2", "created": "Tue, 26 Jul 2016 03:49:44 GMT" }, { "version": "v3", "created": "Mon, 29 Aug 2016 14:57:17 GMT" } ]
2016-08-30T00:00:00
[ [ "Li", "Yunzhu", "" ], [ "Sun", "Benyuan", "" ], [ "Wu", "Tianfu", "" ], [ "Wang", "Yizhou", "" ] ]
TITLE: Face Detection with End-to-End Integration of a ConvNet and a 3D Model ABSTRACT: This paper presents a method for face detection in the wild, which integrates a ConvNet and a 3D mean face model in an end-to-end multi-task discriminative learning framework. The 3D mean face model is predefined and fixed (e.g., we used the one provided in the AFLW dataset). The ConvNet consists of two components: (i) The face pro- posal component computes face bounding box proposals via estimating facial key-points and the 3D transformation (rotation and translation) parameters for each predicted key-point w.r.t. the 3D mean face model. (ii) The face verification component computes detection results by prun- ing and refining proposals based on facial key-points based configuration pooling. The proposed method addresses two issues in adapting state- of-the-art generic object detection ConvNets (e.g., faster R-CNN) for face detection: (i) One is to eliminate the heuristic design of prede- fined anchor boxes in the region proposals network (RPN) by exploit- ing a 3D mean face model. (ii) The other is to replace the generic RoI (Region-of-Interest) pooling layer with a configuration pooling layer to respect underlying object structures. The multi-task loss consists of three terms: the classification Softmax loss and the location smooth l1 -losses [14] of both the facial key-points and the face bounding boxes. In ex- periments, our ConvNet is trained on the AFLW dataset only and tested on the FDDB benchmark with fine-tuning and on the AFW benchmark without fine-tuning. The proposed method obtains very competitive state-of-the-art performance in the two benchmarks.
no_new_dataset
0.952309
1607.00669
Charbel Sakr
Charbel Sakr, Ameya Patil, Sai Zhang, Yongjune Kim, Naresh Shanbhag
Understanding the Energy and Precision Requirements for Online Learning
14 pages, 5 figures 4 of which have 2 subfigures
null
null
null
stat.ML cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is well-known that the precision of data, hyperparameters, and internal representations employed in learning systems directly impacts its energy, throughput, and latency. The precision requirements for the training algorithm are also important for systems that learn on-the-fly. Prior work has shown that the data and hyperparameters can be quantized heavily without incurring much penalty in classification accuracy when compared to floating point implementations. These works suffer from two key limitations. First, they assume uniform precision for the classifier and for the training algorithm and thus miss out on the opportunity to further reduce precision. Second, prior works are empirical studies. In this article, we overcome both these limitations by deriving analytical lower bounds on the precision requirements of the commonly employed stochastic gradient descent (SGD) on-line learning algorithm in the specific context of a support vector machine (SVM). Lower bounds on the data precision are derived in terms of the the desired classification accuracy and precision of the hyperparameters used in the classifier. Additionally, lower bounds on the hyperparameter precision in the SGD training algorithm are obtained. These bounds are validated using both synthetic and the UCI breast cancer dataset. Additionally, the impact of these precisions on the energy consumption of a fixed-point SVM with on-line training is studied.
[ { "version": "v1", "created": "Sun, 3 Jul 2016 18:54:25 GMT" }, { "version": "v2", "created": "Mon, 15 Aug 2016 23:01:12 GMT" }, { "version": "v3", "created": "Fri, 26 Aug 2016 21:56:03 GMT" } ]
2016-08-30T00:00:00
[ [ "Sakr", "Charbel", "" ], [ "Patil", "Ameya", "" ], [ "Zhang", "Sai", "" ], [ "Kim", "Yongjune", "" ], [ "Shanbhag", "Naresh", "" ] ]
TITLE: Understanding the Energy and Precision Requirements for Online Learning ABSTRACT: It is well-known that the precision of data, hyperparameters, and internal representations employed in learning systems directly impacts its energy, throughput, and latency. The precision requirements for the training algorithm are also important for systems that learn on-the-fly. Prior work has shown that the data and hyperparameters can be quantized heavily without incurring much penalty in classification accuracy when compared to floating point implementations. These works suffer from two key limitations. First, they assume uniform precision for the classifier and for the training algorithm and thus miss out on the opportunity to further reduce precision. Second, prior works are empirical studies. In this article, we overcome both these limitations by deriving analytical lower bounds on the precision requirements of the commonly employed stochastic gradient descent (SGD) on-line learning algorithm in the specific context of a support vector machine (SVM). Lower bounds on the data precision are derived in terms of the the desired classification accuracy and precision of the hyperparameters used in the classifier. Additionally, lower bounds on the hyperparameter precision in the SGD training algorithm are obtained. These bounds are validated using both synthetic and the UCI breast cancer dataset. Additionally, the impact of these precisions on the energy consumption of a fixed-point SVM with on-line training is studied.
no_new_dataset
0.952706
1608.06148
Chandrajit M
Chandrajit M, Girisha R and Vasudev T
Multiple objects tracking in surveillance video using color and Hu moments
13 pages, Signal & Image Processing : An International Journal (SIPIJ) Vol.7, No.3, June 2016
null
10.5121/sipij.2016.7302
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Multiple objects tracking finds its applications in many high level vision analysis like object behaviour interpretation and gait recognition. In this paper, a feature based method to track the multiple moving objects in surveillance video sequence is proposed. Object tracking is done by extracting the color and Hu moments features from the motion segmented object blob and establishing the association of objects in the successive frames of the video sequence based on Chi-Square dissimilarity measure and nearest neighbor classifier. The benchmark IEEE PETS and IEEE Change Detection datasets has been used to show the robustness of the proposed method. The proposed method is assessed quantitatively using the precision and recall accuracy metrics. Further, comparative evaluation with related works has been carried out to exhibit the efficacy of the proposed method.
[ { "version": "v1", "created": "Mon, 22 Aug 2016 12:42:46 GMT" }, { "version": "v2", "created": "Sun, 28 Aug 2016 13:11:35 GMT" } ]
2016-08-30T00:00:00
[ [ "M", "Chandrajit", "" ], [ "R", "Girisha", "" ], [ "T", "Vasudev", "" ] ]
TITLE: Multiple objects tracking in surveillance video using color and Hu moments ABSTRACT: Multiple objects tracking finds its applications in many high level vision analysis like object behaviour interpretation and gait recognition. In this paper, a feature based method to track the multiple moving objects in surveillance video sequence is proposed. Object tracking is done by extracting the color and Hu moments features from the motion segmented object blob and establishing the association of objects in the successive frames of the video sequence based on Chi-Square dissimilarity measure and nearest neighbor classifier. The benchmark IEEE PETS and IEEE Change Detection datasets has been used to show the robustness of the proposed method. The proposed method is assessed quantitatively using the precision and recall accuracy metrics. Further, comparative evaluation with related works has been carried out to exhibit the efficacy of the proposed method.
no_new_dataset
0.954858
1608.06347
Shikai Jin
Shikai Jin, Yuxuan Cui, Chunli Yu
A New Parallelization Method for K-means
null
null
null
null
cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
K-means is a popular clustering method used in data mining area. To work with large datasets, researchers propose PKMeans, which is a parallel k-means on MapReduce. However, the existing k-means parallelization methods including PKMeans have many limitations. PKMeans can't finish all its iterations in one MapReduce job, so it has to repeat cascading MapReduce jobs in a loop until convergence. On the most popular MapReduce platform, Hadoop, every MapReduce job introduces significant I/O overheads and extra execution time at stages of job start-up and shuffling. Even worse, it has been proved that in the worst case, k-means needs $2^{{\Omega}(n)}$ MapReduce jobs to converge, where n is the number of data instances, which means huge overheads for large datasets. Additionally, in PKMeans, at most one reducer can be assigned to and update each centroid, so PKMeans can only make use of limited number of parallel reducers. In this paper, we propose an improved parallel method for k-means, IPKMeans, which has a parallel preprocessing stage using k-d tree and can finish k-means in one single MapReduce job with much more reducers working in parallel and lower I/O overheads than PKMeans and has a fast post-processing stage generating the final result. In our method, both k-d tree and the new improved parallel k-means are implemented using MapReduce and tested on Hadoop. Our experiments show that with same dataset and initial centroids, our method has up to 2/3 lower I/O overheads and consumes less amount of time than PKMeans to get a very close clustering result.
[ { "version": "v1", "created": "Tue, 23 Aug 2016 00:35:10 GMT" }, { "version": "v2", "created": "Fri, 26 Aug 2016 21:11:34 GMT" } ]
2016-08-30T00:00:00
[ [ "Jin", "Shikai", "" ], [ "Cui", "Yuxuan", "" ], [ "Yu", "Chunli", "" ] ]
TITLE: A New Parallelization Method for K-means ABSTRACT: K-means is a popular clustering method used in data mining area. To work with large datasets, researchers propose PKMeans, which is a parallel k-means on MapReduce. However, the existing k-means parallelization methods including PKMeans have many limitations. PKMeans can't finish all its iterations in one MapReduce job, so it has to repeat cascading MapReduce jobs in a loop until convergence. On the most popular MapReduce platform, Hadoop, every MapReduce job introduces significant I/O overheads and extra execution time at stages of job start-up and shuffling. Even worse, it has been proved that in the worst case, k-means needs $2^{{\Omega}(n)}$ MapReduce jobs to converge, where n is the number of data instances, which means huge overheads for large datasets. Additionally, in PKMeans, at most one reducer can be assigned to and update each centroid, so PKMeans can only make use of limited number of parallel reducers. In this paper, we propose an improved parallel method for k-means, IPKMeans, which has a parallel preprocessing stage using k-d tree and can finish k-means in one single MapReduce job with much more reducers working in parallel and lower I/O overheads than PKMeans and has a fast post-processing stage generating the final result. In our method, both k-d tree and the new improved parallel k-means are implemented using MapReduce and tested on Hadoop. Our experiments show that with same dataset and initial centroids, our method has up to 2/3 lower I/O overheads and consumes less amount of time than PKMeans to get a very close clustering result.
no_new_dataset
0.94625
1608.07636
Hossein Hosseini
Hossein Hosseini, Sreeram Kannan, Baosen Zhang and Radha Poovendran
Learning Temporal Dependence from Time-Series Data with Latent Variables
null
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the setting where a collection of time series, modeled as random processes, evolve in a causal manner, and one is interested in learning the graph governing the relationships of these processes. A special case of wide interest and applicability is the setting where the noise is Gaussian and relationships are Markov and linear. We study this setting with two additional features: firstly, each random process has a hidden (latent) state, which we use to model the internal memory possessed by the variables (similar to hidden Markov models). Secondly, each variable can depend on its latent memory state through a random lag (rather than a fixed lag), thus modeling memory recall with differing lags at distinct times. Under this setting, we develop an estimator and prove that under a genericity assumption, the parameters of the model can be learned consistently. We also propose a practical adaption of this estimator, which demonstrates significant performance gains in both synthetic and real-world datasets.
[ { "version": "v1", "created": "Sat, 27 Aug 2016 00:25:54 GMT" } ]
2016-08-30T00:00:00
[ [ "Hosseini", "Hossein", "" ], [ "Kannan", "Sreeram", "" ], [ "Zhang", "Baosen", "" ], [ "Poovendran", "Radha", "" ] ]
TITLE: Learning Temporal Dependence from Time-Series Data with Latent Variables ABSTRACT: We consider the setting where a collection of time series, modeled as random processes, evolve in a causal manner, and one is interested in learning the graph governing the relationships of these processes. A special case of wide interest and applicability is the setting where the noise is Gaussian and relationships are Markov and linear. We study this setting with two additional features: firstly, each random process has a hidden (latent) state, which we use to model the internal memory possessed by the variables (similar to hidden Markov models). Secondly, each variable can depend on its latent memory state through a random lag (rather than a fixed lag), thus modeling memory recall with differing lags at distinct times. Under this setting, we develop an estimator and prove that under a genericity assumption, the parameters of the model can be learned consistently. We also propose a practical adaption of this estimator, which demonstrates significant performance gains in both synthetic and real-world datasets.
no_new_dataset
0.949059
1608.07639
Yuval Atzmon
Yuval Atzmon, Jonathan Berant, Vahid Kezami, Amir Globerson and Gal Chechik
Learning to generalize to new compositions in image understanding
null
null
null
null
cs.CV cs.AI cs.CL cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recurrent neural networks have recently been used for learning to describe images using natural language. However, it has been observed that these models generalize poorly to scenes that were not observed during training, possibly depending too strongly on the statistics of the text in the training data. Here we propose to describe images using short structured representations, aiming to capture the crux of a description. These structured representations allow us to tease-out and evaluate separately two types of generalization: standard generalization to new images with similar scenes, and generalization to new combinations of known entities. We compare two learning approaches on the MS-COCO dataset: a state-of-the-art recurrent network based on an LSTM (Show, Attend and Tell), and a simple structured prediction model on top of a deep network. We find that the structured model generalizes to new compositions substantially better than the LSTM, ~7 times the accuracy of predicting structured representations. By providing a concrete method to quantify generalization for unseen combinations, we argue that structured representations and compositional splits are a useful benchmark for image captioning, and advocate compositional models that capture linguistic and visual structure.
[ { "version": "v1", "created": "Sat, 27 Aug 2016 00:34:00 GMT" } ]
2016-08-30T00:00:00
[ [ "Atzmon", "Yuval", "" ], [ "Berant", "Jonathan", "" ], [ "Kezami", "Vahid", "" ], [ "Globerson", "Amir", "" ], [ "Chechik", "Gal", "" ] ]
TITLE: Learning to generalize to new compositions in image understanding ABSTRACT: Recurrent neural networks have recently been used for learning to describe images using natural language. However, it has been observed that these models generalize poorly to scenes that were not observed during training, possibly depending too strongly on the statistics of the text in the training data. Here we propose to describe images using short structured representations, aiming to capture the crux of a description. These structured representations allow us to tease-out and evaluate separately two types of generalization: standard generalization to new images with similar scenes, and generalization to new combinations of known entities. We compare two learning approaches on the MS-COCO dataset: a state-of-the-art recurrent network based on an LSTM (Show, Attend and Tell), and a simple structured prediction model on top of a deep network. We find that the structured model generalizes to new compositions substantially better than the LSTM, ~7 times the accuracy of predicting structured representations. By providing a concrete method to quantify generalization for unseen combinations, we argue that structured representations and compositional splits are a useful benchmark for image captioning, and advocate compositional models that capture linguistic and visual structure.
no_new_dataset
0.946892
1608.07664
Tian Lan
Jianhong Wang, Tian Lan, Xu Zhang, Limin Luo
Spatio-temporal Aware Non-negative Component Representation for Action Recognition
11 pages, 5 figures, 6 tables
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents a novel mid-level representation for action recognition, named spatio-temporal aware non-negative component representation (STANNCR). The proposed STANNCR is based on action component and incorporates the spatial-temporal information. We first introduce a spatial-temporal distribution vector (STDV) to model the distributions of local feature locations in a compact and discriminative manner. Then we employ non-negative matrix factorization (NMF) to learn the action components and encode the video samples. The action component considers the correlations of visual words, which effectively bridge the sematic gap in action recognition. To incorporate the spatial-temporal cues for final representation, the STDV is used as the part of graph regularization for NMF. The fusion of spatial-temporal information makes the STANNCR more discriminative, and our fusion manner is more compact than traditional method of concatenating vectors. The proposed approach is extensively evaluated on three public datasets. The experimental results demonstrate the effectiveness of STANNCR for action recognition.
[ { "version": "v1", "created": "Sat, 27 Aug 2016 06:30:34 GMT" } ]
2016-08-30T00:00:00
[ [ "Wang", "Jianhong", "" ], [ "Lan", "Tian", "" ], [ "Zhang", "Xu", "" ], [ "Luo", "Limin", "" ] ]
TITLE: Spatio-temporal Aware Non-negative Component Representation for Action Recognition ABSTRACT: This paper presents a novel mid-level representation for action recognition, named spatio-temporal aware non-negative component representation (STANNCR). The proposed STANNCR is based on action component and incorporates the spatial-temporal information. We first introduce a spatial-temporal distribution vector (STDV) to model the distributions of local feature locations in a compact and discriminative manner. Then we employ non-negative matrix factorization (NMF) to learn the action components and encode the video samples. The action component considers the correlations of visual words, which effectively bridge the sematic gap in action recognition. To incorporate the spatial-temporal cues for final representation, the STDV is used as the part of graph regularization for NMF. The fusion of spatial-temporal information makes the STANNCR more discriminative, and our fusion manner is more compact than traditional method of concatenating vectors. The proposed approach is extensively evaluated on three public datasets. The experimental results demonstrate the effectiveness of STANNCR for action recognition.
no_new_dataset
0.945399
1608.07720
Fei Li
Fei Li, Meishan Zhang, Guohong Fu, Tao Qian, Donghong Ji
A Bi-LSTM-RNN Model for Relation Classification Using Low-Cost Sequence Features
null
null
null
null
cs.CL
http://creativecommons.org/publicdomain/zero/1.0/
Relation classification is associated with many potential applications in the artificial intelligence area. Recent approaches usually leverage neural networks based on structure features such as syntactic or dependency features to solve this problem. However, high-cost structure features make such approaches inconvenient to be directly used. In addition, structure features are probably domain-dependent. Therefore, this paper proposes a bi-directional long-short-term-memory recurrent-neural-network (Bi-LSTM-RNN) model based on low-cost sequence features to address relation classification. This model divides a sentence or text segment into five parts, namely two target entities and their three contexts. It learns the representations of entities and their contexts, and uses them to classify relations. We evaluate our model on two standard benchmark datasets in different domains, namely SemEval-2010 Task 8 and BioNLP-ST 2016 Task BB3. In the former dataset, our model achieves comparable performance compared with other models using sequence features. In the latter dataset, our model obtains the third best results compared with other models in the official evaluation. Moreover, we find that the context between two target entities plays the most important role in relation classification. Furthermore, statistic experiments show that the context between two target entities can be used as an approximate replacement of the shortest dependency path when dependency parsing is not used.
[ { "version": "v1", "created": "Sat, 27 Aug 2016 15:41:22 GMT" } ]
2016-08-30T00:00:00
[ [ "Li", "Fei", "" ], [ "Zhang", "Meishan", "" ], [ "Fu", "Guohong", "" ], [ "Qian", "Tao", "" ], [ "Ji", "Donghong", "" ] ]
TITLE: A Bi-LSTM-RNN Model for Relation Classification Using Low-Cost Sequence Features ABSTRACT: Relation classification is associated with many potential applications in the artificial intelligence area. Recent approaches usually leverage neural networks based on structure features such as syntactic or dependency features to solve this problem. However, high-cost structure features make such approaches inconvenient to be directly used. In addition, structure features are probably domain-dependent. Therefore, this paper proposes a bi-directional long-short-term-memory recurrent-neural-network (Bi-LSTM-RNN) model based on low-cost sequence features to address relation classification. This model divides a sentence or text segment into five parts, namely two target entities and their three contexts. It learns the representations of entities and their contexts, and uses them to classify relations. We evaluate our model on two standard benchmark datasets in different domains, namely SemEval-2010 Task 8 and BioNLP-ST 2016 Task BB3. In the former dataset, our model achieves comparable performance compared with other models using sequence features. In the latter dataset, our model obtains the third best results compared with other models in the official evaluation. Moreover, we find that the context between two target entities plays the most important role in relation classification. Furthermore, statistic experiments show that the context between two target entities can be used as an approximate replacement of the shortest dependency path when dependency parsing is not used.
no_new_dataset
0.952042
1608.07807
Chandrajit M
Chandrajit M, Girisha R, Vasudev T and Ashok C B
Cast and Self Shadow Segmentation in Video Sequences using Interval based Eigen Value Representation
6 pages journal article
International Journal of Computer Applications 142(4):27-32, May 2016
10.5120/ijca2016909752
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Tracking of motion objects in the surveillance videos is useful for the monitoring and analysis. The performance of the surveillance system will deteriorate when shadows are detected as moving objects. Therefore, shadow detection and elimination usually benefits the next stages. To overcome this issue, a method for detection and elimination of shadows is proposed. This paper presents a method for segmenting moving objects in video sequences based on determining the Euclidian distance between two pixels considering neighborhood values in temporal domain. Further, a method that segments cast and self shadows in video sequences by computing the Eigen values for the neighborhood of each pixel is proposed. The dual-map for cast and self shadow pixels is represented based on the interval of Eigen values. The proposed methods are tested on the benchmark IEEE CHANGE DETECTION 2014 dataset.
[ { "version": "v1", "created": "Sun, 28 Aug 2016 13:07:16 GMT" } ]
2016-08-30T00:00:00
[ [ "M", "Chandrajit", "" ], [ "R", "Girisha", "" ], [ "T", "Vasudev", "" ], [ "B", "Ashok C", "" ] ]
TITLE: Cast and Self Shadow Segmentation in Video Sequences using Interval based Eigen Value Representation ABSTRACT: Tracking of motion objects in the surveillance videos is useful for the monitoring and analysis. The performance of the surveillance system will deteriorate when shadows are detected as moving objects. Therefore, shadow detection and elimination usually benefits the next stages. To overcome this issue, a method for detection and elimination of shadows is proposed. This paper presents a method for segmenting moving objects in video sequences based on determining the Euclidian distance between two pixels considering neighborhood values in temporal domain. Further, a method that segments cast and self shadows in video sequences by computing the Eigen values for the neighborhood of each pixel is proposed. The dual-map for cast and self shadow pixels is represented based on the interval of Eigen values. The proposed methods are tested on the benchmark IEEE CHANGE DETECTION 2014 dataset.
no_new_dataset
0.951863
1608.07916
Bo Li
Bo Li, Tianlei Zhang, Tian Xia
Vehicle Detection from 3D Lidar Using Fully Convolutional Network
Robotics: Science and Systems, 2016
null
null
null
cs.CV cs.RO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Convolutional network techniques have recently achieved great success in vision based detection tasks. This paper introduces the recent development of our research on transplanting the fully convolutional network technique to the detection tasks on 3D range scan data. Specifically, the scenario is set as the vehicle detection task from the range data of Velodyne 64E lidar. We proposes to present the data in a 2D point map and use a single 2D end-to-end fully convolutional network to predict the objectness confidence and the bounding boxes simultaneously. By carefully design the bounding box encoding, it is able to predict full 3D bounding boxes even using a 2D convolutional network. Experiments on the KITTI dataset shows the state-of-the-art performance of the proposed method.
[ { "version": "v1", "created": "Mon, 29 Aug 2016 05:57:36 GMT" } ]
2016-08-30T00:00:00
[ [ "Li", "Bo", "" ], [ "Zhang", "Tianlei", "" ], [ "Xia", "Tian", "" ] ]
TITLE: Vehicle Detection from 3D Lidar Using Fully Convolutional Network ABSTRACT: Convolutional network techniques have recently achieved great success in vision based detection tasks. This paper introduces the recent development of our research on transplanting the fully convolutional network technique to the detection tasks on 3D range scan data. Specifically, the scenario is set as the vehicle detection task from the range data of Velodyne 64E lidar. We proposes to present the data in a 2D point map and use a single 2D end-to-end fully convolutional network to predict the objectness confidence and the bounding boxes simultaneously. By carefully design the bounding box encoding, it is able to predict full 3D bounding boxes even using a 2D convolutional network. Experiments on the KITTI dataset shows the state-of-the-art performance of the proposed method.
no_new_dataset
0.948965
1608.07934
Hadi Zare
Hadi Zare and Mojtaba Niazi
Relevant based structure learning for feature selection
29 pages, 11 figures
Eng. Appl. Artif. Intel. 55 (2016) 93-102
10.1016/j.engappai.2016.06.001
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Feature selection is an important task in many problems occurring in pattern recognition, bioinformatics, machine learning and data mining applications. The feature selection approach enables us to reduce the computation burden and the falling accuracy effect of dealing with huge number of features in typical learning problems. There is a variety of techniques for feature selection in supervised learning problems based on different selection metrics. In this paper, we propose a novel unified framework for feature selection built on the graphical models and information theoretic tools. The proposed approach exploits the structure learning among features to select more relevant and less redundant features to the predictive modeling problem according to a primary novel likelihood based criterion. In line with the selection of the optimal subset of features through the proposed method, it provides us the Bayesian network classifier without the additional cost of model training on the selected subset of features. The optimal properties of our method are established through empirical studies and computational complexity analysis. Furthermore the proposed approach is evaluated on a bunch of benchmark datasets based on the well-known classification algorithms. Extensive experiments confirm the significant improvement of the proposed approach compared to the earlier works.
[ { "version": "v1", "created": "Mon, 29 Aug 2016 07:21:20 GMT" } ]
2016-08-30T00:00:00
[ [ "Zare", "Hadi", "" ], [ "Niazi", "Mojtaba", "" ] ]
TITLE: Relevant based structure learning for feature selection ABSTRACT: Feature selection is an important task in many problems occurring in pattern recognition, bioinformatics, machine learning and data mining applications. The feature selection approach enables us to reduce the computation burden and the falling accuracy effect of dealing with huge number of features in typical learning problems. There is a variety of techniques for feature selection in supervised learning problems based on different selection metrics. In this paper, we propose a novel unified framework for feature selection built on the graphical models and information theoretic tools. The proposed approach exploits the structure learning among features to select more relevant and less redundant features to the predictive modeling problem according to a primary novel likelihood based criterion. In line with the selection of the optimal subset of features through the proposed method, it provides us the Bayesian network classifier without the additional cost of model training on the selected subset of features. The optimal properties of our method are established through empirical studies and computational complexity analysis. Furthermore the proposed approach is evaluated on a bunch of benchmark datasets based on the well-known classification algorithms. Extensive experiments confirm the significant improvement of the proposed approach compared to the earlier works.
no_new_dataset
0.948632
1608.07951
Seoung Wug Oh
Seoung Wug Oh and Seon Joo Kim
Approaching the Computational Color Constancy as a Classification Problem through Deep Learning
This is a preprint of an article accepted for publication in Pattern Recognition, ELSEVIER
Pattern Recognition, Volume 61, January 2017, Pages 405 to 416
10.1016/j.patcog.2016.08.013
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Computational color constancy refers to the problem of computing the illuminant color so that the images of a scene under varying illumination can be normalized to an image under the canonical illumination. In this paper, we adopt a deep learning framework for the illumination estimation problem. The proposed method works under the assumption of uniform illumination over the scene and aims for the accurate illuminant color computation. Specifically, we trained the convolutional neural network to solve the problem by casting the color constancy problem as an illumination classification problem. We designed the deep learning architecture so that the output of the network can be directly used for computing the color of the illumination. Experimental results show that our deep network is able to extract useful features for the illumination estimation and our method outperforms all previous color constancy methods on multiple test datasets.
[ { "version": "v1", "created": "Mon, 29 Aug 2016 08:41:55 GMT" } ]
2016-08-30T00:00:00
[ [ "Oh", "Seoung Wug", "" ], [ "Kim", "Seon Joo", "" ] ]
TITLE: Approaching the Computational Color Constancy as a Classification Problem through Deep Learning ABSTRACT: Computational color constancy refers to the problem of computing the illuminant color so that the images of a scene under varying illumination can be normalized to an image under the canonical illumination. In this paper, we adopt a deep learning framework for the illumination estimation problem. The proposed method works under the assumption of uniform illumination over the scene and aims for the accurate illuminant color computation. Specifically, we trained the convolutional neural network to solve the problem by casting the color constancy problem as an illumination classification problem. We designed the deep learning architecture so that the output of the network can be directly used for computing the color of the illumination. Experimental results show that our deep network is able to extract useful features for the illumination estimation and our method outperforms all previous color constancy methods on multiple test datasets.
no_new_dataset
0.948202
1608.08130
Olaf Hartig
Magnus Knuth and Olaf Hartig and Harald Sack
Scheduling Refresh Queries for Keeping Results from a SPARQL Endpoint Up-to-Date (Extended Version)
This document is an extended version of a paper published in ODBASE 2016
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many datasets change over time. As a consequence, long-running applications that cache and repeatedly use query results obtained from a SPARQL endpoint may resubmit the queries regularly to ensure up-to-dateness of the results. While this approach may be feasible if the number of such regular refresh queries is manageable, with an increasing number of applications adopting this approach, the SPARQL endpoint may become overloaded with such refresh queries. A more scalable approach would be to use a middle-ware component at which the applications register their queries and get notified with updated query results once the results have changed. Then, this middle-ware can schedule the repeated execution of the refresh queries without overloading the endpoint. In this paper, we study the problem of scheduling refresh queries for a large number of registered queries by assuming an overload-avoiding upper bound on the length of a regular time slot available for testing refresh queries. We investigate a variety of scheduling strategies and compare them experimentally in terms of time slots needed before they recognize changes and number of changes that they miss.
[ { "version": "v1", "created": "Mon, 29 Aug 2016 16:16:36 GMT" } ]
2016-08-30T00:00:00
[ [ "Knuth", "Magnus", "" ], [ "Hartig", "Olaf", "" ], [ "Sack", "Harald", "" ] ]
TITLE: Scheduling Refresh Queries for Keeping Results from a SPARQL Endpoint Up-to-Date (Extended Version) ABSTRACT: Many datasets change over time. As a consequence, long-running applications that cache and repeatedly use query results obtained from a SPARQL endpoint may resubmit the queries regularly to ensure up-to-dateness of the results. While this approach may be feasible if the number of such regular refresh queries is manageable, with an increasing number of applications adopting this approach, the SPARQL endpoint may become overloaded with such refresh queries. A more scalable approach would be to use a middle-ware component at which the applications register their queries and get notified with updated query results once the results have changed. Then, this middle-ware can schedule the repeated execution of the refresh queries without overloading the endpoint. In this paper, we study the problem of scheduling refresh queries for a large number of registered queries by assuming an overload-avoiding upper bound on the length of a regular time slot available for testing refresh queries. We investigate a variety of scheduling strategies and compare them experimentally in terms of time slots needed before they recognize changes and number of changes that they miss.
no_new_dataset
0.940079
1512.07071
Lutz Bornmann Dr.
Lutz Bornmann, Robin Haunschild, Werner Marx
Policy documents as sources for measuring societal impact: How often is climate change research mentioned in policy-related documents?
in press at Scientometrics
null
null
null
physics.soc-ph cs.DL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the current UK Research Excellence Framework (REF) and the Excellence in Research for Australia (ERA) societal impact measurements are inherent parts of the national evaluation systems. In this study, we deal with a relatively new form of societal impact measurements. Recently, Altmetric - a start-up providing publication level metrics - started to make data for publications available which have been mentioned in policy documents. We regard this data source as an interesting possibility to specifically measure the (societal) impact of research. Using a comprehensive dataset with publications on climate change as an example, we study the usefulness of the new data source for impact measurement. Only 1.2% (n=2,341) out of 191,276 publications on climate change in the dataset have at least one policy mention. We further reveal that papers published in Nature and Science as well as from the areas "Earth and related environmental sciences" and "Social and economic geography" are especially relevant in the policy context. Given the low coverage of the climate change literature in policy documents, this study can be only a first attempt to study this new source of altmetric data. Further empirical studies are necessary in upcoming years, because mentions in policy documents are of special interest in the use of altmetric data for measuring target-oriented the broader impact of research.
[ { "version": "v1", "created": "Tue, 22 Dec 2015 13:09:52 GMT" }, { "version": "v2", "created": "Fri, 26 Aug 2016 13:04:34 GMT" } ]
2016-08-29T00:00:00
[ [ "Bornmann", "Lutz", "" ], [ "Haunschild", "Robin", "" ], [ "Marx", "Werner", "" ] ]
TITLE: Policy documents as sources for measuring societal impact: How often is climate change research mentioned in policy-related documents? ABSTRACT: In the current UK Research Excellence Framework (REF) and the Excellence in Research for Australia (ERA) societal impact measurements are inherent parts of the national evaluation systems. In this study, we deal with a relatively new form of societal impact measurements. Recently, Altmetric - a start-up providing publication level metrics - started to make data for publications available which have been mentioned in policy documents. We regard this data source as an interesting possibility to specifically measure the (societal) impact of research. Using a comprehensive dataset with publications on climate change as an example, we study the usefulness of the new data source for impact measurement. Only 1.2% (n=2,341) out of 191,276 publications on climate change in the dataset have at least one policy mention. We further reveal that papers published in Nature and Science as well as from the areas "Earth and related environmental sciences" and "Social and economic geography" are especially relevant in the policy context. Given the low coverage of the climate change literature in policy documents, this study can be only a first attempt to study this new source of altmetric data. Further empirical studies are necessary in upcoming years, because mentions in policy documents are of special interest in the use of altmetric data for measuring target-oriented the broader impact of research.
no_new_dataset
0.932576
1602.06023
Ramesh Nallapati
Ramesh Nallapati, Bowen Zhou, Cicero Nogueira dos santos, Caglar Gulcehre, Bing Xiang
Abstractive Text Summarization Using Sequence-to-Sequence RNNs and Beyond
null
The SIGNLL Conference on Computational Natural Language Learning (CoNLL), 2016
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we model abstractive text summarization using Attentional Encoder-Decoder Recurrent Neural Networks, and show that they achieve state-of-the-art performance on two different corpora. We propose several novel models that address critical problems in summarization that are not adequately modeled by the basic architecture, such as modeling key-words, capturing the hierarchy of sentence-to-word structure, and emitting words that are rare or unseen at training time. Our work shows that many of our proposed models contribute to further improvement in performance. We also propose a new dataset consisting of multi-sentence summaries, and establish performance benchmarks for further research.
[ { "version": "v1", "created": "Fri, 19 Feb 2016 02:04:18 GMT" }, { "version": "v2", "created": "Mon, 11 Apr 2016 22:50:03 GMT" }, { "version": "v3", "created": "Sat, 23 Apr 2016 02:38:01 GMT" }, { "version": "v4", "created": "Wed, 10 Aug 2016 22:56:10 GMT" }, { "version": "v5", "created": "Fri, 26 Aug 2016 16:13:13 GMT" } ]
2016-08-29T00:00:00
[ [ "Nallapati", "Ramesh", "" ], [ "Zhou", "Bowen", "" ], [ "santos", "Cicero Nogueira dos", "" ], [ "Gulcehre", "Caglar", "" ], [ "Xiang", "Bing", "" ] ]
TITLE: Abstractive Text Summarization Using Sequence-to-Sequence RNNs and Beyond ABSTRACT: In this work, we model abstractive text summarization using Attentional Encoder-Decoder Recurrent Neural Networks, and show that they achieve state-of-the-art performance on two different corpora. We propose several novel models that address critical problems in summarization that are not adequately modeled by the basic architecture, such as modeling key-words, capturing the hierarchy of sentence-to-word structure, and emitting words that are rare or unseen at training time. Our work shows that many of our proposed models contribute to further improvement in performance. We also propose a new dataset consisting of multi-sentence summaries, and establish performance benchmarks for further research.
new_dataset
0.955569
1608.06010
Yun Wang
Yun Wang, Xu Chen and Peter J. Ramadge
Feedback-Controlled Sequential Lasso Screening
null
null
null
null
cs.LG cs.AI cs.CV stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
One way to solve lasso problems when the dictionary does not fit into available memory is to first screen the dictionary to remove unneeded features. Prior research has shown that sequential screening methods offer the greatest promise in this endeavor. Most existing work on sequential screening targets the context of tuning parameter selection, where one screens and solves a sequence of $N$ lasso problems with a fixed grid of geometrically spaced regularization parameters. In contrast, we focus on the scenario where a target regularization parameter has already been chosen via cross-validated model selection, and we then need to solve many lasso instances using this fixed value. In this context, we propose and explore a feedback controlled sequential screening scheme. Feedback is used at each iteration to select the next problem to be solved. This allows the sequence of problems to be adapted to the instance presented and the number of intermediate problems to be automatically selected. We demonstrate our feedback scheme using several datasets including a dictionary of approximate size 100,000 by 300,000.
[ { "version": "v1", "created": "Sun, 21 Aug 2016 23:40:56 GMT" }, { "version": "v2", "created": "Thu, 25 Aug 2016 22:52:30 GMT" } ]
2016-08-29T00:00:00
[ [ "Wang", "Yun", "" ], [ "Chen", "Xu", "" ], [ "Ramadge", "Peter J.", "" ] ]
TITLE: Feedback-Controlled Sequential Lasso Screening ABSTRACT: One way to solve lasso problems when the dictionary does not fit into available memory is to first screen the dictionary to remove unneeded features. Prior research has shown that sequential screening methods offer the greatest promise in this endeavor. Most existing work on sequential screening targets the context of tuning parameter selection, where one screens and solves a sequence of $N$ lasso problems with a fixed grid of geometrically spaced regularization parameters. In contrast, we focus on the scenario where a target regularization parameter has already been chosen via cross-validated model selection, and we then need to solve many lasso instances using this fixed value. In this context, we propose and explore a feedback controlled sequential screening scheme. Feedback is used at each iteration to select the next problem to be solved. This allows the sequence of problems to be adapted to the instance presented and the number of intermediate problems to be automatically selected. We demonstrate our feedback scheme using several datasets including a dictionary of approximate size 100,000 by 300,000.
no_new_dataset
0.946448
1608.06014
Yun Wang
Yun Wang and Peter J. Ramadge
The Symmetry of a Simple Optimization Problem in Lasso Screening
null
null
null
null
cs.LG cs.AI cs.CV stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently dictionary screening has been proposed as an effective way to improve the computational efficiency of solving the lasso problem, which is one of the most commonly used method for learning sparse representations. To address today's ever increasing large dataset, effective screening relies on a tight region bound on the solution to the dual lasso. Typical region bounds are in the form of an intersection of a sphere and multiple half spaces. One way to tighten the region bound is using more half spaces, which however, adds to the overhead of solving the high dimensional optimization problem in lasso screening. This paper reveals the interesting property that the optimization problem only depends on the projection of features onto the subspace spanned by the normals of the half spaces. This property converts an optimization problem in high dimension to much lower dimension, and thus sheds light on reducing the computation overhead of lasso screening based on tighter region bounds.
[ { "version": "v1", "created": "Sun, 21 Aug 2016 23:48:43 GMT" }, { "version": "v2", "created": "Thu, 25 Aug 2016 22:05:24 GMT" } ]
2016-08-29T00:00:00
[ [ "Wang", "Yun", "" ], [ "Ramadge", "Peter J.", "" ] ]
TITLE: The Symmetry of a Simple Optimization Problem in Lasso Screening ABSTRACT: Recently dictionary screening has been proposed as an effective way to improve the computational efficiency of solving the lasso problem, which is one of the most commonly used method for learning sparse representations. To address today's ever increasing large dataset, effective screening relies on a tight region bound on the solution to the dual lasso. Typical region bounds are in the form of an intersection of a sphere and multiple half spaces. One way to tighten the region bound is using more half spaces, which however, adds to the overhead of solving the high dimensional optimization problem in lasso screening. This paper reveals the interesting property that the optimization problem only depends on the projection of features onto the subspace spanned by the normals of the half spaces. This property converts an optimization problem in high dimension to much lower dimension, and thus sheds light on reducing the computation overhead of lasso screening based on tighter region bounds.
no_new_dataset
0.952175
1608.07411
Wadim Kehl
Wadim Kehl, Tobias Holl, Federico Tombari, Slobodan Ilic, Nassir Navab
An Octree-Based Approach towards Efficient Variational Range Data Fusion
BMVC 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Volume-based reconstruction is usually expensive both in terms of memory consumption and runtime. Especially for sparse geometric structures, volumetric representations produce a huge computational overhead. We present an efficient way to fuse range data via a variational Octree-based minimization approach by taking the actual range data geometry into account. We transform the data into Octree-based truncated signed distance fields and show how the optimization can be conducted on the newly created structures. The main challenge is to uphold speed and a low memory footprint without sacrificing the solutions' accuracy during optimization. We explain how to dynamically adjust the optimizer's geometric structure via joining/splitting of Octree nodes and how to define the operators. We evaluate on various datasets and outline the suitability in terms of performance and geometric accuracy.
[ { "version": "v1", "created": "Fri, 26 Aug 2016 10:01:51 GMT" } ]
2016-08-29T00:00:00
[ [ "Kehl", "Wadim", "" ], [ "Holl", "Tobias", "" ], [ "Tombari", "Federico", "" ], [ "Ilic", "Slobodan", "" ], [ "Navab", "Nassir", "" ] ]
TITLE: An Octree-Based Approach towards Efficient Variational Range Data Fusion ABSTRACT: Volume-based reconstruction is usually expensive both in terms of memory consumption and runtime. Especially for sparse geometric structures, volumetric representations produce a huge computational overhead. We present an efficient way to fuse range data via a variational Octree-based minimization approach by taking the actual range data geometry into account. We transform the data into Octree-based truncated signed distance fields and show how the optimization can be conducted on the newly created structures. The main challenge is to uphold speed and a low memory footprint without sacrificing the solutions' accuracy during optimization. We explain how to dynamically adjust the optimizer's geometric structure via joining/splitting of Octree nodes and how to define the operators. We evaluate on various datasets and outline the suitability in terms of performance and geometric accuracy.
no_new_dataset
0.950365
1608.07441
Maxime Bucher
Maxime Bucher (Palaiseau), St\'ephane Herbin (Palaiseau), Fr\'ed\'eric Jurie
Hard Negative Mining for Metric Learning Based Zero-Shot Classification
null
ECCV 16 WS TASK-CV: Transferring and Adapting Source Knowledge in Computer Vision, Oct 2016, Amsterdam, Netherlands. ECCV 16 WS TASK-CV: Transferring and Adapting Source Knowledge in Computer Vision
null
null
cs.LG cs.AI cs.CV stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Zero-Shot learning has been shown to be an efficient strategy for domain adaptation. In this context, this paper builds on the recent work of Bucher et al. [1], which proposed an approach to solve Zero-Shot classification problems (ZSC) by introducing a novel metric learning based objective function. This objective function allows to learn an optimal embedding of the attributes jointly with a measure of similarity between images and attributes. This paper extends their approach by proposing several schemes to control the generation of the negative pairs, resulting in a significant improvement of the performance and giving above state-of-the-art results on three challenging ZSC datasets.
[ { "version": "v1", "created": "Fri, 26 Aug 2016 12:42:43 GMT" } ]
2016-08-29T00:00:00
[ [ "Bucher", "Maxime", "", "Palaiseau" ], [ "Herbin", "Stéphane", "", "Palaiseau" ], [ "Jurie", "Frédéric", "" ] ]
TITLE: Hard Negative Mining for Metric Learning Based Zero-Shot Classification ABSTRACT: Zero-Shot learning has been shown to be an efficient strategy for domain adaptation. In this context, this paper builds on the recent work of Bucher et al. [1], which proposed an approach to solve Zero-Shot classification problems (ZSC) by introducing a novel metric learning based objective function. This objective function allows to learn an optimal embedding of the attributes jointly with a measure of similarity between images and attributes. This paper extends their approach by proposing several schemes to control the generation of the negative pairs, resulting in a significant improvement of the performance and giving above state-of-the-art results on three challenging ZSC datasets.
no_new_dataset
0.951639
1608.07454
Vincent Lepetit
Tadej Vodopivec, Vincent Lepetit, Peter Peer
Fine Hand Segmentation using Convolutional Neural Networks
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a method for extracting very accurate masks of hands in egocentric views. Our method is based on a novel Deep Learning architecture: In contrast with current Deep Learning methods, we do not use upscaling layers applied to a low-dimensional representation of the input image. Instead, we extract features with convolutional layers and map them directly to a segmentation mask with a fully connected layer. We show that this approach, when applied in a multi-scale fashion, is both accurate and efficient enough for real-time. We demonstrate it on a new dataset made of images captured in various environments, from the outdoors to offices.
[ { "version": "v1", "created": "Fri, 26 Aug 2016 13:40:08 GMT" } ]
2016-08-29T00:00:00
[ [ "Vodopivec", "Tadej", "" ], [ "Lepetit", "Vincent", "" ], [ "Peer", "Peter", "" ] ]
TITLE: Fine Hand Segmentation using Convolutional Neural Networks ABSTRACT: We propose a method for extracting very accurate masks of hands in egocentric views. Our method is based on a novel Deep Learning architecture: In contrast with current Deep Learning methods, we do not use upscaling layers applied to a low-dimensional representation of the input image. Instead, we extract features with convolutional layers and map them directly to a segmentation mask with a fully connected layer. We show that this approach, when applied in a multi-scale fashion, is both accurate and efficient enough for real-time. We demonstrate it on a new dataset made of images captured in various environments, from the outdoors to offices.
new_dataset
0.950041
1510.01098
Boshra Rajaei
Boshra Rajaei, Eric W. Tramel, Sylvain Gigan, Florent Krzakala, Laurent Daudet
Intensity-only optical compressive imaging using a multiply scattering material and a double phase retrieval approach
null
Proceedings of the 2016 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) pages: 4054 - 4058
10.1109/ICASSP.2016.7472439
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, the problem of compressive imaging is addressed using natural randomization by means of a multiply scattering medium. To utilize the medium in this way, its corresponding transmission matrix must be estimated. To calibrate the imager, we use a digital micromirror device (DMD) as a simple, cheap, and high-resolution binary intensity modulator. We propose a phase retrieval algorithm which is well adapted to intensity-only measurements on the camera, and to the input binary intensity patterns, both to estimate the complex transmission matrix as well as image reconstruction. We demonstrate promising experimental results for the proposed algorithm using the MNIST dataset of handwritten digits as example images.
[ { "version": "v1", "created": "Mon, 5 Oct 2015 11:07:30 GMT" }, { "version": "v2", "created": "Mon, 25 Jan 2016 14:35:44 GMT" } ]
2016-08-26T00:00:00
[ [ "Rajaei", "Boshra", "" ], [ "Tramel", "Eric W.", "" ], [ "Gigan", "Sylvain", "" ], [ "Krzakala", "Florent", "" ], [ "Daudet", "Laurent", "" ] ]
TITLE: Intensity-only optical compressive imaging using a multiply scattering material and a double phase retrieval approach ABSTRACT: In this paper, the problem of compressive imaging is addressed using natural randomization by means of a multiply scattering medium. To utilize the medium in this way, its corresponding transmission matrix must be estimated. To calibrate the imager, we use a digital micromirror device (DMD) as a simple, cheap, and high-resolution binary intensity modulator. We propose a phase retrieval algorithm which is well adapted to intensity-only measurements on the camera, and to the input binary intensity patterns, both to estimate the complex transmission matrix as well as image reconstruction. We demonstrate promising experimental results for the proposed algorithm using the MNIST dataset of handwritten digits as example images.
no_new_dataset
0.952442
1603.07445
Michael (Micky) Fire
Michael Fire and Carlos Guestrin
Time Is of the Essence: Analyzing the Effect of Vertex-Joining Time on Complex Network Evolution
null
null
null
null
cs.SI physics.soc-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Complex networks have non-trivial characteristics and appear in many real-world systems. Such networks are vitally important, but their full underlying dynamics are not completely understood. Utilizing new data sources, however, can unveil the evolution process of these networks. This study uses the recently published Reddit dataset, containing over 1.65 billion comments, to construct the largest publicly available social network corpus to date. We used this dataset to deeply examine the network evolution process, which resulted in two key observations: First, links are more likely to be created among users who join a network at a similar time. Second, the rate in which new users join a network is a central factor in molding a network's topology; i.e., different user-join patterns create different topological properties. Based on these observations, we developed the \textit{Temporal Preferential Attachment} random network generation model. This model produces not only scale-free networks that have relative high clustering coefficients, but also networks that are sensitive to both the rate and the time in which users join the network. This results in a more accurate and flexible model of how complex networks evolve, one which more closely represents real-world data.
[ { "version": "v1", "created": "Thu, 24 Mar 2016 05:32:31 GMT" }, { "version": "v2", "created": "Thu, 25 Aug 2016 05:48:36 GMT" } ]
2016-08-26T00:00:00
[ [ "Fire", "Michael", "" ], [ "Guestrin", "Carlos", "" ] ]
TITLE: Time Is of the Essence: Analyzing the Effect of Vertex-Joining Time on Complex Network Evolution ABSTRACT: Complex networks have non-trivial characteristics and appear in many real-world systems. Such networks are vitally important, but their full underlying dynamics are not completely understood. Utilizing new data sources, however, can unveil the evolution process of these networks. This study uses the recently published Reddit dataset, containing over 1.65 billion comments, to construct the largest publicly available social network corpus to date. We used this dataset to deeply examine the network evolution process, which resulted in two key observations: First, links are more likely to be created among users who join a network at a similar time. Second, the rate in which new users join a network is a central factor in molding a network's topology; i.e., different user-join patterns create different topological properties. Based on these observations, we developed the \textit{Temporal Preferential Attachment} random network generation model. This model produces not only scale-free networks that have relative high clustering coefficients, but also networks that are sensitive to both the rate and the time in which users join the network. This results in a more accurate and flexible model of how complex networks evolve, one which more closely represents real-world data.
no_new_dataset
0.921428
1608.06985
Ting-Chun Wang
Ting-Chun Wang, Jun-Yan Zhu, Ebi Hiroaki, Manmohan Chandraker, Alexei A. Efros, Ravi Ramamoorthi
A 4D Light-Field Dataset and CNN Architectures for Material Recognition
European Conference on Computer Vision (ECCV) 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce a new light-field dataset of materials, and take advantage of the recent success of deep learning to perform material recognition on the 4D light-field. Our dataset contains 12 material categories, each with 100 images taken with a Lytro Illum, from which we extract about 30,000 patches in total. To the best of our knowledge, this is the first mid-size dataset for light-field images. Our main goal is to investigate whether the additional information in a light-field (such as multiple sub-aperture views and view-dependent reflectance effects) can aid material recognition. Since recognition networks have not been trained on 4D images before, we propose and compare several novel CNN architectures to train on light-field images. In our experiments, the best performing CNN architecture achieves a 7% boost compared with 2D image classification (70% to 77%). These results constitute important baselines that can spur further research in the use of CNNs for light-field applications. Upon publication, our dataset also enables other novel applications of light-fields, including object detection, image segmentation and view interpolation.
[ { "version": "v1", "created": "Wed, 24 Aug 2016 23:30:22 GMT" } ]
2016-08-26T00:00:00
[ [ "Wang", "Ting-Chun", "" ], [ "Zhu", "Jun-Yan", "" ], [ "Hiroaki", "Ebi", "" ], [ "Chandraker", "Manmohan", "" ], [ "Efros", "Alexei A.", "" ], [ "Ramamoorthi", "Ravi", "" ] ]
TITLE: A 4D Light-Field Dataset and CNN Architectures for Material Recognition ABSTRACT: We introduce a new light-field dataset of materials, and take advantage of the recent success of deep learning to perform material recognition on the 4D light-field. Our dataset contains 12 material categories, each with 100 images taken with a Lytro Illum, from which we extract about 30,000 patches in total. To the best of our knowledge, this is the first mid-size dataset for light-field images. Our main goal is to investigate whether the additional information in a light-field (such as multiple sub-aperture views and view-dependent reflectance effects) can aid material recognition. Since recognition networks have not been trained on 4D images before, we propose and compare several novel CNN architectures to train on light-field images. In our experiments, the best performing CNN architecture achieves a 7% boost compared with 2D image classification (70% to 77%). These results constitute important baselines that can spur further research in the use of CNNs for light-field applications. Upon publication, our dataset also enables other novel applications of light-fields, including object detection, image segmentation and view interpolation.
new_dataset
0.960805
1608.07138
Cesar Roberto de Souza
C\'esar Roberto de Souza, Adrien Gaidon, Eleonora Vig, Antonio Manuel L\'opez
Sympathy for the Details: Dense Trajectories and Hybrid Classification Architectures for Action Recognition
Accepted for publication in the 14th European Conference on Computer Vision (ECCV), Amsterdam, 2016, plus supplementary material
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Action recognition in videos is a challenging task due to the complexity of the spatio-temporal patterns to model and the difficulty to acquire and learn on large quantities of video data. Deep learning, although a breakthrough for image classification and showing promise for videos, has still not clearly superseded action recognition methods using hand-crafted features, even when training on massive datasets. In this paper, we introduce hybrid video classification architectures based on carefully designed unsupervised representations of hand-crafted spatio-temporal features classified by supervised deep networks. As we show in our experiments on five popular benchmarks for action recognition, our hybrid model combines the best of both worlds: it is data efficient (trained on 150 to 10000 short clips) and yet improves significantly on the state of the art, including recent deep models trained on millions of manually labelled images and videos.
[ { "version": "v1", "created": "Thu, 25 Aug 2016 13:37:15 GMT" } ]
2016-08-26T00:00:00
[ [ "de Souza", "César Roberto", "" ], [ "Gaidon", "Adrien", "" ], [ "Vig", "Eleonora", "" ], [ "López", "Antonio Manuel", "" ] ]
TITLE: Sympathy for the Details: Dense Trajectories and Hybrid Classification Architectures for Action Recognition ABSTRACT: Action recognition in videos is a challenging task due to the complexity of the spatio-temporal patterns to model and the difficulty to acquire and learn on large quantities of video data. Deep learning, although a breakthrough for image classification and showing promise for videos, has still not clearly superseded action recognition methods using hand-crafted features, even when training on massive datasets. In this paper, we introduce hybrid video classification architectures based on carefully designed unsupervised representations of hand-crafted spatio-temporal features classified by supervised deep networks. As we show in our experiments on five popular benchmarks for action recognition, our hybrid model combines the best of both worlds: it is data efficient (trained on 150 to 10000 short clips) and yet improves significantly on the state of the art, including recent deep models trained on millions of manually labelled images and videos.
no_new_dataset
0.945096
1608.07242
Mooyeol Baek
Hyeonseob Nam, Mooyeol Baek, Bohyung Han
Modeling and Propagating CNNs in a Tree Structure for Visual Tracking
10 pages, Hyeonseob Nam and Mooyeol Baek have equal contribution
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an online visual tracking algorithm by managing multiple target appearance models in a tree structure. The proposed algorithm employs Convolutional Neural Networks (CNNs) to represent target appearances, where multiple CNNs collaborate to estimate target states and determine the desirable paths for online model updates in the tree. By maintaining multiple CNNs in diverse branches of tree structure, it is convenient to deal with multi-modality in target appearances and preserve model reliability through smooth updates along tree paths. Since multiple CNNs share all parameters in convolutional layers, it takes advantage of multiple models with little extra cost by saving memory space and avoiding redundant network evaluations. The final target state is estimated by sampling target candidates around the state in the previous frame and identifying the best sample in terms of a weighted average score from a set of active CNNs. Our algorithm illustrates outstanding performance compared to the state-of-the-art techniques in challenging datasets such as online tracking benchmark and visual object tracking challenge.
[ { "version": "v1", "created": "Thu, 25 Aug 2016 18:29:53 GMT" } ]
2016-08-26T00:00:00
[ [ "Nam", "Hyeonseob", "" ], [ "Baek", "Mooyeol", "" ], [ "Han", "Bohyung", "" ] ]
TITLE: Modeling and Propagating CNNs in a Tree Structure for Visual Tracking ABSTRACT: We present an online visual tracking algorithm by managing multiple target appearance models in a tree structure. The proposed algorithm employs Convolutional Neural Networks (CNNs) to represent target appearances, where multiple CNNs collaborate to estimate target states and determine the desirable paths for online model updates in the tree. By maintaining multiple CNNs in diverse branches of tree structure, it is convenient to deal with multi-modality in target appearances and preserve model reliability through smooth updates along tree paths. Since multiple CNNs share all parameters in convolutional layers, it takes advantage of multiple models with little extra cost by saving memory space and avoiding redundant network evaluations. The final target state is estimated by sampling target candidates around the state in the previous frame and identifying the best sample in terms of a weighted average score from a set of active CNNs. Our algorithm illustrates outstanding performance compared to the state-of-the-art techniques in challenging datasets such as online tracking benchmark and visual object tracking challenge.
no_new_dataset
0.950319
1608.06757
Sebastian Arnold
Sebastian Arnold, Felix A. Gers, Torsten Kilias, Alexander L\"oser
Robust Named Entity Recognition in Idiosyncratic Domains
8 pages, 1 figure
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Named entity recognition often fails in idiosyncratic domains. That causes a problem for depending tasks, such as entity linking and relation extraction. We propose a generic and robust approach for high-recall named entity recognition. Our approach is easy to train and offers strong generalization over diverse domain-specific language, such as news documents (e.g. Reuters) or biomedical text (e.g. Medline). Our approach is based on deep contextual sequence learning and utilizes stacked bidirectional LSTM networks. Our model is trained with only few hundred labeled sentences and does not rely on further external knowledge. We report from our results F1 scores in the range of 84-94% on standard datasets.
[ { "version": "v1", "created": "Wed, 24 Aug 2016 09:06:14 GMT" } ]
2016-08-25T00:00:00
[ [ "Arnold", "Sebastian", "" ], [ "Gers", "Felix A.", "" ], [ "Kilias", "Torsten", "" ], [ "Löser", "Alexander", "" ] ]
TITLE: Robust Named Entity Recognition in Idiosyncratic Domains ABSTRACT: Named entity recognition often fails in idiosyncratic domains. That causes a problem for depending tasks, such as entity linking and relation extraction. We propose a generic and robust approach for high-recall named entity recognition. Our approach is easy to train and offers strong generalization over diverse domain-specific language, such as news documents (e.g. Reuters) or biomedical text (e.g. Medline). Our approach is based on deep contextual sequence learning and utilizes stacked bidirectional LSTM networks. Our model is trained with only few hundred labeled sentences and does not rely on further external knowledge. We report from our results F1 scores in the range of 84-94% on standard datasets.
no_new_dataset
0.95388
1608.06761
Geetanjali Kale
Geetanjali Vinayak Kale and Varsha Hemant Patil
A Study of Vision based Human Motion Recognition and Analysis
5 Figures, 18 Pages, International Journal of Ambient Computing and Intelligence, Volume 7 Issue 2,July-December 2016
null
10.4018/IJACI.2016070104
null
cs.CV
http://creativecommons.org/licenses/by-nc-sa/4.0/
Vision based human motion recognition has fascinated many researchers due to its critical challenges and a variety of applications. The applications range from simple gesture recognition to complicated behaviour understanding in surveillance system. This leads to major development in the techniques related to human motion representation and recognition. This paper discusses applications, general framework of human motion recognition, and the details of each of its components. The paper emphasizes on human motion representation and the recognition methods along with their advantages and disadvantages. This study also discusses the selected literature, popular datasets, and concludes with the challenges in the domain along with a future direction. The human motion recognition domain has been active for more than two decades, and has provided a large amount of literature. A bird's eye view for new researchers in the domain is presented in the paper.
[ { "version": "v1", "created": "Wed, 24 Aug 2016 09:23:14 GMT" } ]
2016-08-25T00:00:00
[ [ "Kale", "Geetanjali Vinayak", "" ], [ "Patil", "Varsha Hemant", "" ] ]
TITLE: A Study of Vision based Human Motion Recognition and Analysis ABSTRACT: Vision based human motion recognition has fascinated many researchers due to its critical challenges and a variety of applications. The applications range from simple gesture recognition to complicated behaviour understanding in surveillance system. This leads to major development in the techniques related to human motion representation and recognition. This paper discusses applications, general framework of human motion recognition, and the details of each of its components. The paper emphasizes on human motion representation and the recognition methods along with their advantages and disadvantages. This study also discusses the selected literature, popular datasets, and concludes with the challenges in the domain along with a future direction. The human motion recognition domain has been active for more than two decades, and has provided a large amount of literature. A bird's eye view for new researchers in the domain is presented in the paper.
no_new_dataset
0.950088
1608.06800
Javier Alejandro Aldana Iuit
Javier Aldana-Iuit, Dmytro Mishkin, Ondrej Chum, Jiri Matas
In the Saddle: Chasing Fast and Repeatable Features
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A novel similarity-covariant feature detector that extracts points whose neighbourhoods, when treated as a 3D intensity surface, have a saddle-like intensity profile. The saddle condition is verified efficiently by intensity comparisons on two concentric rings that must have exactly two dark-to-bright and two bright-to-dark transitions satisfying certain geometric constraints. Experiments show that the Saddle features are general, evenly spread and appearing in high density in a range of images. The Saddle detector is among the fastest proposed. In comparison with detector with similar speed, the Saddle features show superior matching performance on number of challenging datasets.
[ { "version": "v1", "created": "Wed, 24 Aug 2016 12:57:34 GMT" } ]
2016-08-25T00:00:00
[ [ "Aldana-Iuit", "Javier", "" ], [ "Mishkin", "Dmytro", "" ], [ "Chum", "Ondrej", "" ], [ "Matas", "Jiri", "" ] ]
TITLE: In the Saddle: Chasing Fast and Repeatable Features ABSTRACT: A novel similarity-covariant feature detector that extracts points whose neighbourhoods, when treated as a 3D intensity surface, have a saddle-like intensity profile. The saddle condition is verified efficiently by intensity comparisons on two concentric rings that must have exactly two dark-to-bright and two bright-to-dark transitions satisfying certain geometric constraints. Experiments show that the Saddle features are general, evenly spread and appearing in high density in a range of images. The Saddle detector is among the fastest proposed. In comparison with detector with similar speed, the Saddle features show superior matching performance on number of challenging datasets.
no_new_dataset
0.920647
1608.06861
Jun Yue
Xia Yue, Wang Man, Jun Yue, Guangcao Liu
Parallel K-Medoids++ Spatial Clustering Algorithm Based on MapReduce
null
null
null
null
cs.DC
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Clustering analysis has received considerable attention in spatial data mining for several years. With the rapid development of the geospatial information technologies, the size of spatial information data is growing exponentially which makes clustering massive spatial data a challenging task. In order to improve the efficiency of spatial clustering for large scale data, many researchers proposed several efficient clustering algorithms in parallel. In this paper, a new K-Medoids++ spatial clustering algorithm based on MapReduce for clustering massive spatial data is proposed. The initialization algorithm to decrease the number of iterations is combined with the MapReduce framework. Comparative Experiments conducted over different dataset and different number of nodes indicate that the proposed K-Medoids spatial clustering algorithm provides better efficiency than traditional K-Medoids and scales well while processing massive spatial data on commodity hardware.
[ { "version": "v1", "created": "Wed, 24 Aug 2016 15:21:24 GMT" } ]
2016-08-25T00:00:00
[ [ "Yue", "Xia", "" ], [ "Man", "Wang", "" ], [ "Yue", "Jun", "" ], [ "Liu", "Guangcao", "" ] ]
TITLE: Parallel K-Medoids++ Spatial Clustering Algorithm Based on MapReduce ABSTRACT: Clustering analysis has received considerable attention in spatial data mining for several years. With the rapid development of the geospatial information technologies, the size of spatial information data is growing exponentially which makes clustering massive spatial data a challenging task. In order to improve the efficiency of spatial clustering for large scale data, many researchers proposed several efficient clustering algorithms in parallel. In this paper, a new K-Medoids++ spatial clustering algorithm based on MapReduce for clustering massive spatial data is proposed. The initialization algorithm to decrease the number of iterations is combined with the MapReduce framework. Comparative Experiments conducted over different dataset and different number of nodes indicate that the proposed K-Medoids spatial clustering algorithm provides better efficiency than traditional K-Medoids and scales well while processing massive spatial data on commodity hardware.
no_new_dataset
0.955152
1608.06863
Victoria Peterson Mrs
Victoria Peterson, Hugo Leonardo Rufiner, Ruben Daniel Spies
Kullback-Leibler Penalized Sparse Discriminant Analysis for Event-Related Potential Classification
27 pages, 4 figures
null
null
null
cs.CV cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A brain computer interface (BCI) is a system which provides direct communication between the mind of a person and the outside world by using only brain activity (EEG). The event-related potential (ERP)-based BCI problem consists of a binary pattern recognition. Linear discriminant analysis (LDA) is widely used to solve this type of classification problems, but it fails when the number of features is large relative to the number of observations. In this work we propose a penalized version of the sparse discriminant analysis (SDA), called Kullback-Leibler penalized sparse discriminant analysis (KLSDA). This method inherits both the discriminative feature selection and classification properties of SDA and it also improves SDA performance through the addition of Kullback-Leibler class discrepancy information. The KLSDA method is design to automatically select the optimal regularization parameters. Numerical experiments with two real ERP-EEG datasets show that this new method outperforms standard SDA.
[ { "version": "v1", "created": "Wed, 24 Aug 2016 15:32:51 GMT" } ]
2016-08-25T00:00:00
[ [ "Peterson", "Victoria", "" ], [ "Rufiner", "Hugo Leonardo", "" ], [ "Spies", "Ruben Daniel", "" ] ]
TITLE: Kullback-Leibler Penalized Sparse Discriminant Analysis for Event-Related Potential Classification ABSTRACT: A brain computer interface (BCI) is a system which provides direct communication between the mind of a person and the outside world by using only brain activity (EEG). The event-related potential (ERP)-based BCI problem consists of a binary pattern recognition. Linear discriminant analysis (LDA) is widely used to solve this type of classification problems, but it fails when the number of features is large relative to the number of observations. In this work we propose a penalized version of the sparse discriminant analysis (SDA), called Kullback-Leibler penalized sparse discriminant analysis (KLSDA). This method inherits both the discriminative feature selection and classification properties of SDA and it also improves SDA performance through the addition of Kullback-Leibler class discrepancy information. The KLSDA method is design to automatically select the optimal regularization parameters. Numerical experiments with two real ERP-EEG datasets show that this new method outperforms standard SDA.
no_new_dataset
0.94625
1505.07717
Rodrigo Cabral Farias
Rodrigo Cabral Farias, Jeremy Emile Cohen and Pierre Comon
Exploring multimodal data fusion through joint decompositions with flexible couplings
15 pages, 7 figures, revised version
null
10.1109/TSP.2016.2576425
null
cs.IT math.IT
http://creativecommons.org/licenses/by-nc-sa/4.0/
A Bayesian framework is proposed to define flexible coupling models for joint tensor decompositions of multiple data sets. Under this framework, a natural formulation of the data fusion problem is to cast it in terms of a joint maximum a posteriori (MAP) estimator. Data driven scenarios of joint posterior distributions are provided, including general Gaussian priors and non Gaussian coupling priors. We present and discuss implementation issues of algorithms used to obtain the joint MAP estimator. We also show how this framework can be adapted to tackle the problem of joint decompositions of large datasets. In the case of a conditional Gaussian coupling with a linear transformation, we give theoretical bounds on the data fusion performance using the Bayesian Cramer-Rao bound. Simulations are reported for hybrid coupling models ranging from simple additive Gaussian models, to Gamma-type models with positive variables and to the coupling of data sets which are inherently of different size due to different resolution of the measurement devices.
[ { "version": "v1", "created": "Thu, 28 May 2015 15:07:14 GMT" }, { "version": "v2", "created": "Thu, 8 Oct 2015 07:01:43 GMT" }, { "version": "v3", "created": "Wed, 25 May 2016 12:03:01 GMT" } ]
2016-08-24T00:00:00
[ [ "Farias", "Rodrigo Cabral", "" ], [ "Cohen", "Jeremy Emile", "" ], [ "Comon", "Pierre", "" ] ]
TITLE: Exploring multimodal data fusion through joint decompositions with flexible couplings ABSTRACT: A Bayesian framework is proposed to define flexible coupling models for joint tensor decompositions of multiple data sets. Under this framework, a natural formulation of the data fusion problem is to cast it in terms of a joint maximum a posteriori (MAP) estimator. Data driven scenarios of joint posterior distributions are provided, including general Gaussian priors and non Gaussian coupling priors. We present and discuss implementation issues of algorithms used to obtain the joint MAP estimator. We also show how this framework can be adapted to tackle the problem of joint decompositions of large datasets. In the case of a conditional Gaussian coupling with a linear transformation, we give theoretical bounds on the data fusion performance using the Bayesian Cramer-Rao bound. Simulations are reported for hybrid coupling models ranging from simple additive Gaussian models, to Gamma-type models with positive variables and to the coupling of data sets which are inherently of different size due to different resolution of the measurement devices.
no_new_dataset
0.94474
1508.00842
Sougata Chaudhuri
Sougata Chaudhuri and Ambuj Tewari
Perceptron like Algorithms for Online Learning to Rank
Under review in Journal of Artificial Intelligence Research (JAIR)
null
null
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Perceptron is a classic online algorithm for learning a classification function. In this paper, we provide a novel extension of the perceptron algorithm to the learning to rank problem in information retrieval. We consider popular listwise performance measures such as Normalized Discounted Cumulative Gain (NDCG) and Average Precision (AP). A modern perspective on perceptron for classification is that it is simply an instance of online gradient descent (OGD), during mistake rounds, using the hinge loss function. Motivated by this interpretation, we propose a novel family of listwise, large margin ranking surrogates. Members of this family can be thought of as analogs of the hinge loss. Exploiting a certain self-bounding property of the proposed family, we provide a guarantee on the cumulative NDCG (or AP) induced loss incurred by our perceptron-like algorithm. We show that, if there exists a perfect oracle ranker which can correctly rank each instance in an online sequence of ranking data, with some margin, the cumulative loss of perceptron algorithm on that sequence is bounded by a constant, irrespective of the length of the sequence. This result is reminiscent of Novikoff's convergence theorem for the classification perceptron. Moreover, we prove a lower bound on the cumulative loss achievable by any deterministic algorithm, under the assumption of existence of perfect oracle ranker. The lower bound shows that our perceptron bound is not tight, and we propose another, \emph{purely online}, algorithm which achieves the lower bound. We provide empirical results on simulated and large commercial datasets to corroborate our theoretical results.
[ { "version": "v1", "created": "Tue, 4 Aug 2015 17:23:46 GMT" }, { "version": "v2", "created": "Sun, 6 Mar 2016 20:32:04 GMT" }, { "version": "v3", "created": "Sun, 27 Mar 2016 00:29:55 GMT" }, { "version": "v4", "created": "Tue, 23 Aug 2016 06:52:04 GMT" } ]
2016-08-24T00:00:00
[ [ "Chaudhuri", "Sougata", "" ], [ "Tewari", "Ambuj", "" ] ]
TITLE: Perceptron like Algorithms for Online Learning to Rank ABSTRACT: Perceptron is a classic online algorithm for learning a classification function. In this paper, we provide a novel extension of the perceptron algorithm to the learning to rank problem in information retrieval. We consider popular listwise performance measures such as Normalized Discounted Cumulative Gain (NDCG) and Average Precision (AP). A modern perspective on perceptron for classification is that it is simply an instance of online gradient descent (OGD), during mistake rounds, using the hinge loss function. Motivated by this interpretation, we propose a novel family of listwise, large margin ranking surrogates. Members of this family can be thought of as analogs of the hinge loss. Exploiting a certain self-bounding property of the proposed family, we provide a guarantee on the cumulative NDCG (or AP) induced loss incurred by our perceptron-like algorithm. We show that, if there exists a perfect oracle ranker which can correctly rank each instance in an online sequence of ranking data, with some margin, the cumulative loss of perceptron algorithm on that sequence is bounded by a constant, irrespective of the length of the sequence. This result is reminiscent of Novikoff's convergence theorem for the classification perceptron. Moreover, we prove a lower bound on the cumulative loss achievable by any deterministic algorithm, under the assumption of existence of perfect oracle ranker. The lower bound shows that our perceptron bound is not tight, and we propose another, \emph{purely online}, algorithm which achieves the lower bound. We provide empirical results on simulated and large commercial datasets to corroborate our theoretical results.
no_new_dataset
0.942295
1511.04695
Linxiao Yang
Linxiao Yang and Jun Fang and Hongbin Li and Bing Zeng
An Iterative Reweighted Method for Tucker Decomposition of Incomplete Multiway Tensors
null
null
10.1109/TSP.2016.2572047
null
cs.NA cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of low-rank decomposition of incomplete multiway tensors. Since many real-world data lie on an intrinsically low dimensional subspace, tensor low-rank decomposition with missing entries has applications in many data analysis problems such as recommender systems and image inpainting. In this paper, we focus on Tucker decomposition which represents an Nth-order tensor in terms of N factor matrices and a core tensor via multilinear operations. To exploit the underlying multilinear low-rank structure in high-dimensional datasets, we propose a group-based log-sum penalty functional to place structural sparsity over the core tensor, which leads to a compact representation with smallest core tensor. The method for Tucker decomposition is developed by iteratively minimizing a surrogate function that majorizes the original objective function, which results in an iterative reweighted process. In addition, to reduce the computational complexity, an over-relaxed monotone fast iterative shrinkage-thresholding technique is adapted and embedded in the iterative reweighted process. The proposed method is able to determine the model complexity (i.e. multilinear rank) in an automatic way. Simulation results show that the proposed algorithm offers competitive performance compared with other existing algorithms.
[ { "version": "v1", "created": "Sun, 15 Nov 2015 12:56:36 GMT" } ]
2016-08-24T00:00:00
[ [ "Yang", "Linxiao", "" ], [ "Fang", "Jun", "" ], [ "Li", "Hongbin", "" ], [ "Zeng", "Bing", "" ] ]
TITLE: An Iterative Reweighted Method for Tucker Decomposition of Incomplete Multiway Tensors ABSTRACT: We consider the problem of low-rank decomposition of incomplete multiway tensors. Since many real-world data lie on an intrinsically low dimensional subspace, tensor low-rank decomposition with missing entries has applications in many data analysis problems such as recommender systems and image inpainting. In this paper, we focus on Tucker decomposition which represents an Nth-order tensor in terms of N factor matrices and a core tensor via multilinear operations. To exploit the underlying multilinear low-rank structure in high-dimensional datasets, we propose a group-based log-sum penalty functional to place structural sparsity over the core tensor, which leads to a compact representation with smallest core tensor. The method for Tucker decomposition is developed by iteratively minimizing a surrogate function that majorizes the original objective function, which results in an iterative reweighted process. In addition, to reduce the computational complexity, an over-relaxed monotone fast iterative shrinkage-thresholding technique is adapted and embedded in the iterative reweighted process. The proposed method is able to determine the model complexity (i.e. multilinear rank) in an automatic way. Simulation results show that the proposed algorithm offers competitive performance compared with other existing algorithms.
no_new_dataset
0.944791
1603.00961
Jan Egger
Tobias L\"uddemann, Jan Egger
Interactive and Scale Invariant Segmentation of the Rectum/Sigmoid via User-Defined Templates
6 pages, 4 figures, 1 table, 43 references
SPIE Medical Imaging Conference 2016, Paper 9784-113
10.1117/12.2216226
null
cs.CV cs.GR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Among all types of cancer, gynecological malignancies belong to the 4th most frequent type of cancer among women. Besides chemotherapy and external beam radiation, brachytherapy is the standard procedure for the treatment of these malignancies. In the progress of treatment planning, localization of the tumor as the target volume and adjacent organs of risks by segmentation is crucial to accomplish an optimal radiation distribution to the tumor while simultaneously preserving healthy tissue. Segmentation is performed manually and represents a time-consuming task in clinical daily routine. This study focuses on the segmentation of the rectum/sigmoid colon as an Organ-At-Risk in gynecological brachytherapy. The proposed segmentation method uses an interactive, graph-based segmentation scheme with a user-defined template. The scheme creates a directed two dimensional graph, followed by the minimal cost closed set computation on the graph, resulting in an outlining of the rectum. The graphs outline is dynamically adapted to the last calculated cut. Evaluation was performed by comparing manual segmentations of the rectum/sigmoid colon to results achieved with the proposed method. The comparison of the algorithmic to manual results yielded to a Dice Similarity Coefficient value of 83.85+/-4.08%, in comparison to 83.97+/-8.08% for the comparison of two manual segmentations of the same physician. Utilizing the proposed methodology resulted in a median time of 128 seconds per dataset, compared to 300 seconds needed for pure manual segmentation.
[ { "version": "v1", "created": "Thu, 3 Mar 2016 03:39:59 GMT" } ]
2016-08-24T00:00:00
[ [ "Lüddemann", "Tobias", "" ], [ "Egger", "Jan", "" ] ]
TITLE: Interactive and Scale Invariant Segmentation of the Rectum/Sigmoid via User-Defined Templates ABSTRACT: Among all types of cancer, gynecological malignancies belong to the 4th most frequent type of cancer among women. Besides chemotherapy and external beam radiation, brachytherapy is the standard procedure for the treatment of these malignancies. In the progress of treatment planning, localization of the tumor as the target volume and adjacent organs of risks by segmentation is crucial to accomplish an optimal radiation distribution to the tumor while simultaneously preserving healthy tissue. Segmentation is performed manually and represents a time-consuming task in clinical daily routine. This study focuses on the segmentation of the rectum/sigmoid colon as an Organ-At-Risk in gynecological brachytherapy. The proposed segmentation method uses an interactive, graph-based segmentation scheme with a user-defined template. The scheme creates a directed two dimensional graph, followed by the minimal cost closed set computation on the graph, resulting in an outlining of the rectum. The graphs outline is dynamically adapted to the last calculated cut. Evaluation was performed by comparing manual segmentations of the rectum/sigmoid colon to results achieved with the proposed method. The comparison of the algorithmic to manual results yielded to a Dice Similarity Coefficient value of 83.85+/-4.08%, in comparison to 83.97+/-8.08% for the comparison of two manual segmentations of the same physician. Utilizing the proposed methodology resulted in a median time of 128 seconds per dataset, compared to 300 seconds needed for pure manual segmentation.
no_new_dataset
0.953319
1603.01855
Sougata Chaudhuri
Sougata Chaudhuri and Ambuj Tewari
Online Learning to Rank with Feedback at the Top
Appearing in AISTATS 2016
AISTATS 16, volume 51 of JMLR Workshop and Conference Proceedings, pg.-277-285, 2016
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider an online learning to rank setting in which, at each round, an oblivious adversary generates a list of $m$ documents, pertaining to a query, and the learner produces scores to rank the documents. The adversary then generates a relevance vector and the learner updates its ranker according to the feedback received. We consider the setting where the feedback is restricted to be the relevance levels of only the top $k$ documents in the ranked list for $k \ll m$. However, the performance of learner is judged based on the unrevealed full relevance vectors, using an appropriate learning to rank loss function. We develop efficient algorithms for well known losses in the pointwise, pairwise and listwise families. We also prove that no online algorithm can have sublinear regret, with top-1 feedback, for any loss that is calibrated with respect to NDCG. We apply our algorithms on benchmark datasets demonstrating efficient online learning of a ranking function from highly restricted feedback.
[ { "version": "v1", "created": "Sun, 6 Mar 2016 18:43:54 GMT" } ]
2016-08-24T00:00:00
[ [ "Chaudhuri", "Sougata", "" ], [ "Tewari", "Ambuj", "" ] ]
TITLE: Online Learning to Rank with Feedback at the Top ABSTRACT: We consider an online learning to rank setting in which, at each round, an oblivious adversary generates a list of $m$ documents, pertaining to a query, and the learner produces scores to rank the documents. The adversary then generates a relevance vector and the learner updates its ranker according to the feedback received. We consider the setting where the feedback is restricted to be the relevance levels of only the top $k$ documents in the ranked list for $k \ll m$. However, the performance of learner is judged based on the unrevealed full relevance vectors, using an appropriate learning to rank loss function. We develop efficient algorithms for well known losses in the pointwise, pairwise and listwise families. We also prove that no online algorithm can have sublinear regret, with top-1 feedback, for any loss that is calibrated with respect to NDCG. We apply our algorithms on benchmark datasets demonstrating efficient online learning of a ranking function from highly restricted feedback.
no_new_dataset
0.942823
1608.05477
Xi Peng
Xi Peng, Rogerio S. Feris, Xiaoyu Wang, Dimitris N. Metaxas
A Recurrent Encoder-Decoder Network for Sequential Face Alignment
European Conference on Computer Vision (ECCV), 2016
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel recurrent encoder-decoder network model for real-time video-based face alignment. Our proposed model predicts 2D facial point maps regularized by a regression loss, while uniquely exploiting recurrent learning at both spatial and temporal dimensions. At the spatial level, we add a feedback loop connection between the combined output response map and the input, in order to enable iterative coarse-to-fine face alignment using a single network model. At the temporal level, we first decouple the features in the bottleneck of the network into temporal-variant factors, such as pose and expression, and temporal-invariant factors, such as identity information. Temporal recurrent learning is then applied to the decoupled temporal-variant features, yielding better generalization and significantly more accurate results at test time. We perform a comprehensive experimental analysis, showing the importance of each component of our proposed model, as well as superior results over the state-of-the-art in standard datasets.
[ { "version": "v1", "created": "Fri, 19 Aug 2016 02:28:50 GMT" }, { "version": "v2", "created": "Tue, 23 Aug 2016 01:23:48 GMT" } ]
2016-08-24T00:00:00
[ [ "Peng", "Xi", "" ], [ "Feris", "Rogerio S.", "" ], [ "Wang", "Xiaoyu", "" ], [ "Metaxas", "Dimitris N.", "" ] ]
TITLE: A Recurrent Encoder-Decoder Network for Sequential Face Alignment ABSTRACT: We propose a novel recurrent encoder-decoder network model for real-time video-based face alignment. Our proposed model predicts 2D facial point maps regularized by a regression loss, while uniquely exploiting recurrent learning at both spatial and temporal dimensions. At the spatial level, we add a feedback loop connection between the combined output response map and the input, in order to enable iterative coarse-to-fine face alignment using a single network model. At the temporal level, we first decouple the features in the bottleneck of the network into temporal-variant factors, such as pose and expression, and temporal-invariant factors, such as identity information. Temporal recurrent learning is then applied to the decoupled temporal-variant features, yielding better generalization and significantly more accurate results at test time. We perform a comprehensive experimental analysis, showing the importance of each component of our proposed model, as well as superior results over the state-of-the-art in standard datasets.
no_new_dataset
0.949482
1608.06169
Jaroslaw Szlichta
Jaroslaw Szlichta, Parke Godfrey, Lukasz Golab, Mehdi Kargar, Divesh Srivastava
Effective and Complete Discovery of Order Dependencies via Set-based Axiomatization
14 pages
null
null
null
cs.DB
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Integrity constraints (ICs) provide a valuable tool for expressing and enforcing application semantics. However, formulating constraints manually requires domain expertise, is prone to human errors, and may be excessively time consuming, especially on large datasets. Hence, proposals for automatic discovery have been made for some classes of ICs, such as functional dependencies (FDs), and recently, order dependencies (ODs). ODs properly subsume FDs, as they can additionally express business rules involving order; e.g., an employee never has a higher salary while paying lower taxes compared with another employee. We address the limitations of prior work on OD discovery which has factorial complexity in the number of attributes, is incomplete (i.e., it does not discover valid ODs that cannot be inferred from the ones found) and is not concise (i.e., it can result in "redundant" discovery and overly large discovery sets). We improve significantly on complexity, offer completeness, and define a compact canonical form. This is based on a novel polynomial mapping to a canonical form for ODs, and a sound and complete set of axioms (inference rules) for canonical ODs. This allows us to develop an efficient set-containment, lattice-driven OD discovery algorithm that uses the inference rules to prune the search space. Our algorithm has exponential worst-case time complexity in the number of attributes and linear complexity in the number of tuples. We prove that it produces a complete, minimal set of ODs (i.e., minimal with regards to the canonical representation). Finally, using real and synthetic datasets, we experimentally show orders-of-magnitude performance improvements over the current state-of-the-art algorithm and demonstrate effectiveness of our techniques.
[ { "version": "v1", "created": "Mon, 22 Aug 2016 14:03:46 GMT" }, { "version": "v2", "created": "Tue, 23 Aug 2016 19:54:06 GMT" } ]
2016-08-24T00:00:00
[ [ "Szlichta", "Jaroslaw", "" ], [ "Godfrey", "Parke", "" ], [ "Golab", "Lukasz", "" ], [ "Kargar", "Mehdi", "" ], [ "Srivastava", "Divesh", "" ] ]
TITLE: Effective and Complete Discovery of Order Dependencies via Set-based Axiomatization ABSTRACT: Integrity constraints (ICs) provide a valuable tool for expressing and enforcing application semantics. However, formulating constraints manually requires domain expertise, is prone to human errors, and may be excessively time consuming, especially on large datasets. Hence, proposals for automatic discovery have been made for some classes of ICs, such as functional dependencies (FDs), and recently, order dependencies (ODs). ODs properly subsume FDs, as they can additionally express business rules involving order; e.g., an employee never has a higher salary while paying lower taxes compared with another employee. We address the limitations of prior work on OD discovery which has factorial complexity in the number of attributes, is incomplete (i.e., it does not discover valid ODs that cannot be inferred from the ones found) and is not concise (i.e., it can result in "redundant" discovery and overly large discovery sets). We improve significantly on complexity, offer completeness, and define a compact canonical form. This is based on a novel polynomial mapping to a canonical form for ODs, and a sound and complete set of axioms (inference rules) for canonical ODs. This allows us to develop an efficient set-containment, lattice-driven OD discovery algorithm that uses the inference rules to prune the search space. Our algorithm has exponential worst-case time complexity in the number of attributes and linear complexity in the number of tuples. We prove that it produces a complete, minimal set of ODs (i.e., minimal with regards to the canonical representation). Finally, using real and synthetic datasets, we experimentally show orders-of-magnitude performance improvements over the current state-of-the-art algorithm and demonstrate effectiveness of our techniques.
no_new_dataset
0.943971
1608.06298
Jonathan Gemmell Jonathan Gemmell
Greg Zanotti, Miller Horvath, Lucas Nunes Barbosa, Venkata Trinadh Kumar Gupta Immedisetty, Jonathan Gemmell
Infusing Collaborative Recommenders with Distributed Representations
null
null
null
null
cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recommender systems assist users in navigating complex information spaces and focus their attention on the content most relevant to their needs. Often these systems rely on user activity or descriptions of the content. Social annotation systems, in which users collaboratively assign tags to items, provide another means to capture information about users and items. Each of these data sources provides unique benefits, capturing different relationships. In this paper, we propose leveraging multiple sources of data: ratings data as users report their affinity toward an item, tagging data as users assign annotations to items, and item data collected from an online database. Taken together, these datasets provide the opportunity to learn rich distributed representations by exploiting recent advances in neural network architectures. We first produce representations that subjectively capture interesting relationships among the data. We then empirically evaluate the utility of the representations to predict a user's rating on an item and show that it outperforms more traditional representations. Finally, we demonstrate that traditional representations can be combined with representations trained through a neural network to achieve even better results.
[ { "version": "v1", "created": "Mon, 22 Aug 2016 20:05:01 GMT" } ]
2016-08-24T00:00:00
[ [ "Zanotti", "Greg", "" ], [ "Horvath", "Miller", "" ], [ "Barbosa", "Lucas Nunes", "" ], [ "Immedisetty", "Venkata Trinadh Kumar Gupta", "" ], [ "Gemmell", "Jonathan", "" ] ]
TITLE: Infusing Collaborative Recommenders with Distributed Representations ABSTRACT: Recommender systems assist users in navigating complex information spaces and focus their attention on the content most relevant to their needs. Often these systems rely on user activity or descriptions of the content. Social annotation systems, in which users collaboratively assign tags to items, provide another means to capture information about users and items. Each of these data sources provides unique benefits, capturing different relationships. In this paper, we propose leveraging multiple sources of data: ratings data as users report their affinity toward an item, tagging data as users assign annotations to items, and item data collected from an online database. Taken together, these datasets provide the opportunity to learn rich distributed representations by exploiting recent advances in neural network architectures. We first produce representations that subjectively capture interesting relationships among the data. We then empirically evaluate the utility of the representations to predict a user's rating on an item and show that it outperforms more traditional representations. Finally, we demonstrate that traditional representations can be combined with representations trained through a neural network to achieve even better results.
no_new_dataset
0.943504
1608.06408
Sougata Chaudhuri
Sougata Chaudhuri and Ambuj Tewari
Online Learning to Rank with Top-k Feedback
Under review in JMLR
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider two settings of online learning to rank where feedback is restricted to top ranked items. The problem is cast as an online game between a learner and sequence of users, over $T$ rounds. In both settings, the learners objective is to present ranked list of items to the users. The learner's performance is judged on the entire ranked list and true relevances of the items. However, the learner receives highly restricted feedback at end of each round, in form of relevances of only the top $k$ ranked items, where $k \ll m$. The first setting is \emph{non-contextual}, where the list of items to be ranked is fixed. The second setting is \emph{contextual}, where lists of items vary, in form of traditional query-document lists. No stochastic assumption is made on the generation process of relevances of items and contexts. We provide efficient ranking strategies for both the settings. The strategies achieve $O(T^{2/3})$ regret, where regret is based on popular ranking measures in first setting and ranking surrogates in second setting. We also provide impossibility results for certain ranking measures and a certain class of surrogates, when feedback is restricted to the top ranked item, i.e. $k=1$. We empirically demonstrate the performance of our algorithms on simulated and real world datasets.
[ { "version": "v1", "created": "Tue, 23 Aug 2016 07:40:08 GMT" } ]
2016-08-24T00:00:00
[ [ "Chaudhuri", "Sougata", "" ], [ "Tewari", "Ambuj", "" ] ]
TITLE: Online Learning to Rank with Top-k Feedback ABSTRACT: We consider two settings of online learning to rank where feedback is restricted to top ranked items. The problem is cast as an online game between a learner and sequence of users, over $T$ rounds. In both settings, the learners objective is to present ranked list of items to the users. The learner's performance is judged on the entire ranked list and true relevances of the items. However, the learner receives highly restricted feedback at end of each round, in form of relevances of only the top $k$ ranked items, where $k \ll m$. The first setting is \emph{non-contextual}, where the list of items to be ranked is fixed. The second setting is \emph{contextual}, where lists of items vary, in form of traditional query-document lists. No stochastic assumption is made on the generation process of relevances of items and contexts. We provide efficient ranking strategies for both the settings. The strategies achieve $O(T^{2/3})$ regret, where regret is based on popular ranking measures in first setting and ranking surrogates in second setting. We also provide impossibility results for certain ranking measures and a certain class of surrogates, when feedback is restricted to the top ranked item, i.e. $k=1$. We empirically demonstrate the performance of our algorithms on simulated and real world datasets.
no_new_dataset
0.950227
1608.06495
Dan Xu
Nannan Li, Dan Xu, Zhenqiang Ying, Zhihao Li, Ge Li
Searching Action Proposals via Spatial Actionness Estimation and Temporal Path Inference and Tracking
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we address the problem of searching action proposals in unconstrained video clips. Our approach starts from actionness estimation on frame-level bounding boxes, and then aggregates the bounding boxes belonging to the same actor across frames via linking, associating, tracking to generate spatial-temporal continuous action paths. To achieve the target, a novel actionness estimation method is firstly proposed by utilizing both human appearance and motion cues. Then, the association of the action paths is formulated as a maximum set coverage problem with the results of actionness estimation as a priori. To further promote the performance, we design an improved optimization objective for the problem and provide a greedy search algorithm to solve it. Finally, a tracking-by-detection scheme is designed to further refine the searched action paths. Extensive experiments on two challenging datasets, UCF-Sports and UCF-101, show that the proposed approach advances state-of-the-art proposal generation performance in terms of both accuracy and proposal quantity.
[ { "version": "v1", "created": "Tue, 23 Aug 2016 13:08:30 GMT" } ]
2016-08-24T00:00:00
[ [ "Li", "Nannan", "" ], [ "Xu", "Dan", "" ], [ "Ying", "Zhenqiang", "" ], [ "Li", "Zhihao", "" ], [ "Li", "Ge", "" ] ]
TITLE: Searching Action Proposals via Spatial Actionness Estimation and Temporal Path Inference and Tracking ABSTRACT: In this paper, we address the problem of searching action proposals in unconstrained video clips. Our approach starts from actionness estimation on frame-level bounding boxes, and then aggregates the bounding boxes belonging to the same actor across frames via linking, associating, tracking to generate spatial-temporal continuous action paths. To achieve the target, a novel actionness estimation method is firstly proposed by utilizing both human appearance and motion cues. Then, the association of the action paths is formulated as a maximum set coverage problem with the results of actionness estimation as a priori. To further promote the performance, we design an improved optimization objective for the problem and provide a greedy search algorithm to solve it. Finally, a tracking-by-detection scheme is designed to further refine the searched action paths. Extensive experiments on two challenging datasets, UCF-Sports and UCF-101, show that the proposed approach advances state-of-the-art proposal generation performance in terms of both accuracy and proposal quantity.
no_new_dataset
0.945651
1608.06557
Le Hou
Le Hou, Dimitris Samaras, Tahsin M. Kurc, Yi Gao, Joel H. Saltz
Neural Networks with Smooth Adaptive Activation Functions for Regression
null
null
null
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In Neural Networks (NN), Adaptive Activation Functions (AAF) have parameters that control the shapes of activation functions. These parameters are trained along with other parameters in the NN. AAFs have improved performance of Neural Networks (NN) in multiple classification tasks. In this paper, we propose and apply AAFs on feedforward NNs for regression tasks. We argue that applying AAFs in the regression (second-to-last) layer of a NN can significantly decrease the bias of the regression NN. However, using existing AAFs may lead to overfitting. To address this problem, we propose a Smooth Adaptive Activation Function (SAAF) with piecewise polynomial form which can approximate any continuous function to arbitrary degree of error. NNs with SAAFs can avoid overfitting by simply regularizing the parameters. In particular, an NN with SAAFs is Lipschitz continuous given a bounded magnitude of the NN parameters. We prove an upper-bound for model complexity in terms of fat-shattering dimension for any Lipschitz continuous regression model. Thus, regularizing the parameters in NNs with SAAFs avoids overfitting. We empirically evaluated NNs with SAAFs and achieved state-of-the-art results on multiple regression datasets.
[ { "version": "v1", "created": "Tue, 23 Aug 2016 15:56:08 GMT" } ]
2016-08-24T00:00:00
[ [ "Hou", "Le", "" ], [ "Samaras", "Dimitris", "" ], [ "Kurc", "Tahsin M.", "" ], [ "Gao", "Yi", "" ], [ "Saltz", "Joel H.", "" ] ]
TITLE: Neural Networks with Smooth Adaptive Activation Functions for Regression ABSTRACT: In Neural Networks (NN), Adaptive Activation Functions (AAF) have parameters that control the shapes of activation functions. These parameters are trained along with other parameters in the NN. AAFs have improved performance of Neural Networks (NN) in multiple classification tasks. In this paper, we propose and apply AAFs on feedforward NNs for regression tasks. We argue that applying AAFs in the regression (second-to-last) layer of a NN can significantly decrease the bias of the regression NN. However, using existing AAFs may lead to overfitting. To address this problem, we propose a Smooth Adaptive Activation Function (SAAF) with piecewise polynomial form which can approximate any continuous function to arbitrary degree of error. NNs with SAAFs can avoid overfitting by simply regularizing the parameters. In particular, an NN with SAAFs is Lipschitz continuous given a bounded magnitude of the NN parameters. We prove an upper-bound for model complexity in terms of fat-shattering dimension for any Lipschitz continuous regression model. Thus, regularizing the parameters in NNs with SAAFs avoids overfitting. We empirically evaluated NNs with SAAFs and achieved state-of-the-art results on multiple regression datasets.
no_new_dataset
0.950503
1405.4897
Yun Wang
Zhen James Xiang, Yun Wang and Peter J. Ramadge
Screening Tests for Lasso Problems
Accepted to IEEE Transactions on Pattern Analysis and Machine Intelligence
null
10.1109/TPAMI.2016.2568185
null
cs.LG stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper is a survey of dictionary screening for the lasso problem. The lasso problem seeks a sparse linear combination of the columns of a dictionary to best match a given target vector. This sparse representation has proven useful in a variety of subsequent processing and decision tasks. For a given target vector, dictionary screening quickly identifies a subset of dictionary columns that will receive zero weight in a solution of the corresponding lasso problem. These columns can be removed from the dictionary prior to solving the lasso problem without impacting the optimality of the solution obtained. This has two potential advantages: it reduces the size of the dictionary, allowing the lasso problem to be solved with less resources, and it may speed up obtaining a solution. Using a geometrically intuitive framework, we provide basic insights for understanding useful lasso screening tests and their limitations. We also provide illustrative numerical studies on several datasets.
[ { "version": "v1", "created": "Mon, 19 May 2014 21:07:08 GMT" }, { "version": "v2", "created": "Sun, 21 Aug 2016 22:04:31 GMT" } ]
2016-08-23T00:00:00
[ [ "Xiang", "Zhen James", "" ], [ "Wang", "Yun", "" ], [ "Ramadge", "Peter J.", "" ] ]
TITLE: Screening Tests for Lasso Problems ABSTRACT: This paper is a survey of dictionary screening for the lasso problem. The lasso problem seeks a sparse linear combination of the columns of a dictionary to best match a given target vector. This sparse representation has proven useful in a variety of subsequent processing and decision tasks. For a given target vector, dictionary screening quickly identifies a subset of dictionary columns that will receive zero weight in a solution of the corresponding lasso problem. These columns can be removed from the dictionary prior to solving the lasso problem without impacting the optimality of the solution obtained. This has two potential advantages: it reduces the size of the dictionary, allowing the lasso problem to be solved with less resources, and it may speed up obtaining a solution. Using a geometrically intuitive framework, we provide basic insights for understanding useful lasso screening tests and their limitations. We also provide illustrative numerical studies on several datasets.
no_new_dataset
0.95275
1508.02848
Yunjin Chen
Yunjin Chen and Thomas Pock
Trainable Nonlinear Reaction Diffusion: A Flexible Framework for Fast and Effective Image Restoration
14 pages, 13 figures, to appear in IEEE Transactions on Pattern Analysis and Machine Intelligence (TPAMI)
null
10.1109/TPAMI.2016.2596743
null
cs.CV
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Image restoration is a long-standing problem in low-level computer vision with many interesting applications. We describe a flexible learning framework based on the concept of nonlinear reaction diffusion models for various image restoration problems. By embodying recent improvements in nonlinear diffusion models, we propose a dynamic nonlinear reaction diffusion model with time-dependent parameters (\ie, linear filters and influence functions). In contrast to previous nonlinear diffusion models, all the parameters, including the filters and the influence functions, are simultaneously learned from training data through a loss based approach. We call this approach TNRD -- \textit{Trainable Nonlinear Reaction Diffusion}. The TNRD approach is applicable for a variety of image restoration tasks by incorporating appropriate reaction force. We demonstrate its capabilities with three representative applications, Gaussian image denoising, single image super resolution and JPEG deblocking. Experiments show that our trained nonlinear diffusion models largely benefit from the training of the parameters and finally lead to the best reported performance on common test datasets for the tested applications. Our trained models preserve the structural simplicity of diffusion models and take only a small number of diffusion steps, thus are highly efficient. Moreover, they are also well-suited for parallel computation on GPUs, which makes the inference procedure extremely fast.
[ { "version": "v1", "created": "Wed, 12 Aug 2015 08:40:48 GMT" }, { "version": "v2", "created": "Sat, 20 Aug 2016 04:48:54 GMT" } ]
2016-08-23T00:00:00
[ [ "Chen", "Yunjin", "" ], [ "Pock", "Thomas", "" ] ]
TITLE: Trainable Nonlinear Reaction Diffusion: A Flexible Framework for Fast and Effective Image Restoration ABSTRACT: Image restoration is a long-standing problem in low-level computer vision with many interesting applications. We describe a flexible learning framework based on the concept of nonlinear reaction diffusion models for various image restoration problems. By embodying recent improvements in nonlinear diffusion models, we propose a dynamic nonlinear reaction diffusion model with time-dependent parameters (\ie, linear filters and influence functions). In contrast to previous nonlinear diffusion models, all the parameters, including the filters and the influence functions, are simultaneously learned from training data through a loss based approach. We call this approach TNRD -- \textit{Trainable Nonlinear Reaction Diffusion}. The TNRD approach is applicable for a variety of image restoration tasks by incorporating appropriate reaction force. We demonstrate its capabilities with three representative applications, Gaussian image denoising, single image super resolution and JPEG deblocking. Experiments show that our trained nonlinear diffusion models largely benefit from the training of the parameters and finally lead to the best reported performance on common test datasets for the tested applications. Our trained models preserve the structural simplicity of diffusion models and take only a small number of diffusion steps, thus are highly efficient. Moreover, they are also well-suited for parallel computation on GPUs, which makes the inference procedure extremely fast.
no_new_dataset
0.949201
1511.00792
Sayantan Dasgupta
Sayantan Dasgupta
Fast Collaborative Filtering from Implicit Feedback with Provable Guarantees
null
null
null
null
cs.LG
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Building recommendation algorithms is one of the most challenging tasks in Machine Learning. Although most of the recommendation systems are built on explicit feedback available from the users in terms of rating or text, a majority of the applications do not receive such feedback. Here we consider the recommendation task where the only available data is the records of user-item interaction over web applications over time, in terms of subscription or purchase of items; this is known as implicit feedback recommendation. There is usually a massive amount of such user-item interaction available for any web applications. Algorithms like PLSI or Matrix Factorization runs several iterations through the dataset, and may prove very expensive for large datasets. Here we propose a recommendation algorithm based on Method of Moment, which involves factorization of second and third order moments of the dataset. Our algorithm can be proven to be globally convergent using PAC learning theory. Further, we show how to extract the parameters using only three passes through the entire dataset. This results in a highly scalable algorithm that scales up to million of users even on a machine with a single-core processor and 8 GB RAM and produces competitive performance in comparison with existing algorithms.
[ { "version": "v1", "created": "Tue, 3 Nov 2015 06:43:54 GMT" }, { "version": "v10", "created": "Sun, 21 Aug 2016 08:00:15 GMT" }, { "version": "v2", "created": "Wed, 4 Nov 2015 06:26:04 GMT" }, { "version": "v3", "created": "Thu, 5 Nov 2015 13:06:07 GMT" }, { "version": "v4", "created": "Tue, 10 Nov 2015 12:05:40 GMT" }, { "version": "v5", "created": "Mon, 23 Nov 2015 10:05:40 GMT" }, { "version": "v6", "created": "Thu, 24 Dec 2015 20:33:13 GMT" }, { "version": "v7", "created": "Fri, 15 Jan 2016 15:44:30 GMT" }, { "version": "v8", "created": "Sat, 6 Feb 2016 10:28:25 GMT" }, { "version": "v9", "created": "Wed, 8 Jun 2016 16:33:38 GMT" } ]
2016-08-23T00:00:00
[ [ "Dasgupta", "Sayantan", "" ] ]
TITLE: Fast Collaborative Filtering from Implicit Feedback with Provable Guarantees ABSTRACT: Building recommendation algorithms is one of the most challenging tasks in Machine Learning. Although most of the recommendation systems are built on explicit feedback available from the users in terms of rating or text, a majority of the applications do not receive such feedback. Here we consider the recommendation task where the only available data is the records of user-item interaction over web applications over time, in terms of subscription or purchase of items; this is known as implicit feedback recommendation. There is usually a massive amount of such user-item interaction available for any web applications. Algorithms like PLSI or Matrix Factorization runs several iterations through the dataset, and may prove very expensive for large datasets. Here we propose a recommendation algorithm based on Method of Moment, which involves factorization of second and third order moments of the dataset. Our algorithm can be proven to be globally convergent using PAC learning theory. Further, we show how to extract the parameters using only three passes through the entire dataset. This results in a highly scalable algorithm that scales up to million of users even on a machine with a single-core processor and 8 GB RAM and produces competitive performance in comparison with existing algorithms.
no_new_dataset
0.937897
1603.08148
\c{C}a\u{g}lar G\"ul\c{c}ehre
Caglar Gulcehre, Sungjin Ahn, Ramesh Nallapati, Bowen Zhou and Yoshua Bengio
Pointing the Unknown Words
ACL 2016 Oral Paper
null
null
null
cs.CL cs.LG cs.NE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The problem of rare and unknown words is an important issue that can potentially influence the performance of many NLP systems, including both the traditional count-based and the deep learning models. We propose a novel way to deal with the rare and unseen words for the neural network models using attention. Our model uses two softmax layers in order to predict the next word in conditional language models: one predicts the location of a word in the source sentence, and the other predicts a word in the shortlist vocabulary. At each time-step, the decision of which softmax layer to use choose adaptively made by an MLP which is conditioned on the context.~We motivate our work from a psychological evidence that humans naturally have a tendency to point towards objects in the context or the environment when the name of an object is not known.~We observe improvements on two tasks, neural machine translation on the Europarl English to French parallel corpora and text summarization on the Gigaword dataset using our proposed model.
[ { "version": "v1", "created": "Sat, 26 Mar 2016 22:31:57 GMT" }, { "version": "v2", "created": "Sun, 3 Apr 2016 21:12:57 GMT" }, { "version": "v3", "created": "Sun, 21 Aug 2016 20:03:39 GMT" } ]
2016-08-23T00:00:00
[ [ "Gulcehre", "Caglar", "" ], [ "Ahn", "Sungjin", "" ], [ "Nallapati", "Ramesh", "" ], [ "Zhou", "Bowen", "" ], [ "Bengio", "Yoshua", "" ] ]
TITLE: Pointing the Unknown Words ABSTRACT: The problem of rare and unknown words is an important issue that can potentially influence the performance of many NLP systems, including both the traditional count-based and the deep learning models. We propose a novel way to deal with the rare and unseen words for the neural network models using attention. Our model uses two softmax layers in order to predict the next word in conditional language models: one predicts the location of a word in the source sentence, and the other predicts a word in the shortlist vocabulary. At each time-step, the decision of which softmax layer to use choose adaptively made by an MLP which is conditioned on the context.~We motivate our work from a psychological evidence that humans naturally have a tendency to point towards objects in the context or the environment when the name of an object is not known.~We observe improvements on two tasks, neural machine translation on the Europarl English to French parallel corpora and text summarization on the Gigaword dataset using our proposed model.
no_new_dataset
0.951051
1608.00276
Jeroen Vuurens
Jeroen B. P. Vuurens, Martha Larson, Arjen P. de Vries
Exploring Deep Space: Learning Personalized Ranking in a Semantic Space
6 pages, RecSys 2016 RSDL workshop
null
10.1145/2988450.2988457
null
cs.IR
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recommender systems leverage both content and user interactions to generate recommendations that fit users' preferences. The recent surge of interest in deep learning presents new opportunities for exploiting these two sources of information. To recommend items we propose to first learn a user-independent high-dimensional semantic space in which items are positioned according to their substitutability, and then learn a user-specific transformation function to transform this space into a ranking according to the user's past preferences. An advantage of the proposed architecture is that it can be used to effectively recommend items using either content that describes the items or user-item ratings. We show that this approach significantly outperforms state-of-the-art recommender systems on the MovieLens 1M dataset.
[ { "version": "v1", "created": "Sun, 31 Jul 2016 22:38:46 GMT" }, { "version": "v2", "created": "Mon, 22 Aug 2016 18:43:04 GMT" } ]
2016-08-23T00:00:00
[ [ "Vuurens", "Jeroen B. P.", "" ], [ "Larson", "Martha", "" ], [ "de Vries", "Arjen P.", "" ] ]
TITLE: Exploring Deep Space: Learning Personalized Ranking in a Semantic Space ABSTRACT: Recommender systems leverage both content and user interactions to generate recommendations that fit users' preferences. The recent surge of interest in deep learning presents new opportunities for exploiting these two sources of information. To recommend items we propose to first learn a user-independent high-dimensional semantic space in which items are positioned according to their substitutability, and then learn a user-specific transformation function to transform this space into a ranking according to the user's past preferences. An advantage of the proposed architecture is that it can be used to effectively recommend items using either content that describes the items or user-item ratings. We show that this approach significantly outperforms state-of-the-art recommender systems on the MovieLens 1M dataset.
no_new_dataset
0.953362
1608.01413
Subhro Roy
Subhro Roy and Dan Roth
Solving General Arithmetic Word Problems
EMNLP 2015
null
null
null
cs.CL
http://creativecommons.org/licenses/by/4.0/
This paper presents a novel approach to automatically solving arithmetic word problems. This is the first algorithmic approach that can handle arithmetic problems with multiple steps and operations, without depending on additional annotations or predefined templates. We develop a theory for expression trees that can be used to represent and evaluate the target arithmetic expressions; we use it to uniquely decompose the target arithmetic problem to multiple classification problems; we then compose an expression tree, combining these with world knowledge through a constrained inference framework. Our classifiers gain from the use of {\em quantity schemas} that supports better extraction of features. Experimental results show that our method outperforms existing systems, achieving state of the art performance on benchmark datasets of arithmetic word problems.
[ { "version": "v1", "created": "Thu, 4 Aug 2016 01:47:23 GMT" }, { "version": "v2", "created": "Sat, 20 Aug 2016 11:50:41 GMT" } ]
2016-08-23T00:00:00
[ [ "Roy", "Subhro", "" ], [ "Roth", "Dan", "" ] ]
TITLE: Solving General Arithmetic Word Problems ABSTRACT: This paper presents a novel approach to automatically solving arithmetic word problems. This is the first algorithmic approach that can handle arithmetic problems with multiple steps and operations, without depending on additional annotations or predefined templates. We develop a theory for expression trees that can be used to represent and evaluate the target arithmetic expressions; we use it to uniquely decompose the target arithmetic problem to multiple classification problems; we then compose an expression tree, combining these with world knowledge through a constrained inference framework. Our classifiers gain from the use of {\em quantity schemas} that supports better extraction of features. Experimental results show that our method outperforms existing systems, achieving state of the art performance on benchmark datasets of arithmetic word problems.
no_new_dataset
0.941975
1608.05777
Lei Xu
Lei Xu, Ziyun Wang, Ayana, Zhiyuan Liu, Maosong Sun
Topic Sensitive Neural Headline Generation
null
null
null
null
cs.CL
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neural models have recently been used in text summarization including headline generation. The model can be trained using a set of document-headline pairs. However, the model does not explicitly consider topical similarities and differences of documents. We suggest to categorizing documents into various topics so that documents within the same topic are similar in content and share similar summarization patterns. Taking advantage of topic information of documents, we propose topic sensitive neural headline generation model. Our model can generate more accurate summaries guided by document topics. We test our model on LCSTS dataset, and experiments show that our method outperforms other baselines on each topic and achieves the state-of-art performance.
[ { "version": "v1", "created": "Sat, 20 Aug 2016 03:43:29 GMT" } ]
2016-08-23T00:00:00
[ [ "Xu", "Lei", "" ], [ "Wang", "Ziyun", "" ], [ "Ayana", "", "" ], [ "Liu", "Zhiyuan", "" ], [ "Sun", "Maosong", "" ] ]
TITLE: Topic Sensitive Neural Headline Generation ABSTRACT: Neural models have recently been used in text summarization including headline generation. The model can be trained using a set of document-headline pairs. However, the model does not explicitly consider topical similarities and differences of documents. We suggest to categorizing documents into various topics so that documents within the same topic are similar in content and share similar summarization patterns. Taking advantage of topic information of documents, we propose topic sensitive neural headline generation model. Our model can generate more accurate summaries guided by document topics. We test our model on LCSTS dataset, and experiments show that our method outperforms other baselines on each topic and achieves the state-of-art performance.
no_new_dataset
0.949153