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\n\n \n \n \n \n \n \n Human Action Recognition from Inter-Temporal Dictionaries of Key-Sequences.\n \n \n \n \n\n\n \n Alfaro, A.; Mery, D.; and Soto, A.\n\n\n \n\n\n\n In
6th Pacific-Rim Symposium on Image and Video Technology, PSIVT, 2013. \n
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@InProceedings{\t alfaro:etal:2013,\n author\t= { A. Alfaro and D. Mery and A. Soto},\n title\t\t= {Human Action Recognition from Inter-Temporal Dictionaries\n\t\t of Key-Sequences},\n booktitle\t= {6th Pacific-Rim Symposium on Image and Video Technology,\n\t\t PSIVT},\n year\t\t= {2013},\n abstract\t= {This paper addresses the human action recognition in video\n\t\t by proposing a method based on three main processing steps.\n\t\t First, we tackle problems related to intraclass variations\n\t\t and differences in video lengths. We achieve this by\n\t\t reducing an input video to a set of key-sequences that\n\t\t represent atomic meaningful acts of each action class.\n\t\t Second, we use sparse coding techniques to learn a\n\t\t representation for each key-sequence. We then join these\n\t\t representations still preserving information about temporal\n\t\t relationships. We believe that this is a key step of our\n\t\t approach because it provides not only a suitable shared rep\n\t\t resentation to characterize atomic acts, but it also\n\t\t encodes global tem poral consistency among these acts.\n\t\t Accordingly, we call this represen tation inter-temporal\n\t\t acts descriptor. Third, we use this representation and\n\t\t sparse coding techniques to classify new videos. Finally,\n\t\t we show that, our approach outperforms several\n\t\t state-of-the-art methods when is tested using common\n\t\t benchmarks.},\n url\t\t= {http://saturno.ing.puc.cl/media/papers_alvaro/Anali-PSIVT-13.pdf}\n}\n\n
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\n This paper addresses the human action recognition in video by proposing a method based on three main processing steps. First, we tackle problems related to intraclass variations and differences in video lengths. We achieve this by reducing an input video to a set of key-sequences that represent atomic meaningful acts of each action class. Second, we use sparse coding techniques to learn a representation for each key-sequence. We then join these representations still preserving information about temporal relationships. We believe that this is a key step of our approach because it provides not only a suitable shared rep resentation to characterize atomic acts, but it also encodes global tem poral consistency among these acts. Accordingly, we call this represen tation inter-temporal acts descriptor. Third, we use this representation and sparse coding techniques to classify new videos. Finally, we show that, our approach outperforms several state-of-the-art methods when is tested using common benchmarks.\n
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\n\n \n \n \n \n \n \n Proceedings of the Twenty-Seventh AAAI Conference on Artificial Intelligence, July 14-18, 2013, Bellevue, Washington, USA.\n \n \n \n \n\n\n \n desJardins , M.; and Littman, M. L.,\n editors.\n \n\n\n \n\n\n\n AAAI Press. 2013.\n
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@Proceedings{\t dblp:conf/aaai/2013,\n editor\t= {Marie desJardins and Michael L. Littman},\n title\t\t= {Proceedings of the Twenty-Seventh {AAAI} Conference on\n\t\t Artificial Intelligence, July 14-18, 2013, Bellevue,\n\t\t Washington, {USA}},\n publisher\t= {{AAAI} Press},\n year\t\t= {2013},\n url\t\t= {http://www.aaai.org/Library/AAAI/aaai13contents.php},\n isbn\t\t= {978-1-57735-615-8},\n timestamp\t= {Tue, 17 Dec 2013 19:26:12 +0100},\n biburl\t= {https://dblp.org/rec/bib/conf/aaai/2013},\n bibsource\t= {dblp computer science bibliography, https://dblp.org}\n}\n\n
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\n\n \n \n \n \n \n \n Assumption-Based Planning: Generating Plans and Explanations under Incomplete Knowledge.\n \n \n \n \n\n\n \n Davis-Mendelow, S.; Baier, J. A.; and McIlraith, S. A.\n\n\n \n\n\n\n In
Proceedings of the Twenty-Seventh AAAI Conference on Artificial Intelligence, July 14-18, 2013, Bellevue, Washington, USA., 2013. \n
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@InProceedings{\t dblp:conf/aaai/davis-mendelowbm13,\n author\t= {Sammy Davis{-}Mendelow and Jorge A. Baier and Sheila A.\n\t\t McIlraith},\n title\t\t= {Assumption-Based Planning: Generating Plans and\n\t\t Explanations under Incomplete Knowledge},\n booktitle\t= {Proceedings of the Twenty-Seventh {AAAI} Conference on\n\t\t Artificial Intelligence, July 14-18, 2013, Bellevue,\n\t\t Washington, {USA.}},\n year\t\t= {2013},\n crossref\t= {DBLP:conf/aaai/2013},\n url\t\t= {http://www.aaai.org/ocs/index.php/AAAI/AAAI13/paper/view/6466},\n timestamp\t= {Tue, 17 Dec 2013 19:26:12 +0100},\n biburl\t= {https://dblp.org/rec/bib/conf/aaai/Davis-MendelowBM13},\n bibsource\t= {dblp computer science bibliography, https://dblp.org}\n}\n\n
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\n\n \n \n \n \n \n \n Proceedings of the Twenty-Third International Conference on Automated Planning and Scheduling, ICAPS 2013, Rome, Italy, June 10-14, 2013.\n \n \n \n \n\n\n \n Borrajo, D.; Kambhampati, S.; Oddi, A.; and Fratini, S.,\n editors.\n \n\n\n \n\n\n\n AAAI. 2013.\n
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@Proceedings{\t dblp:conf/aips/2013,\n editor\t= {Daniel Borrajo and Subbarao Kambhampati and Angelo Oddi\n\t\t and Simone Fratini},\n title\t\t= {Proceedings of the Twenty-Third International Conference\n\t\t on Automated Planning and Scheduling, {ICAPS} 2013, Rome,\n\t\t Italy, June 10-14, 2013},\n publisher\t= {{AAAI}},\n year\t\t= {2013},\n url\t\t= {http://www.aaai.org/Library/ICAPS/icaps13contents.php},\n isbn\t\t= {978-1-57735-609-7},\n timestamp\t= {Wed, 29 Mar 2017 16:45:27 +0200},\n biburl\t= {https://dblp.org/rec/bib/conf/aips/2013},\n bibsource\t= {dblp computer science bibliography, https://dblp.org}\n}\n\n
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\n\n \n \n \n \n \n \n Moving Target Search with Compressed Path Databases.\n \n \n \n \n\n\n \n Botea, A.; Baier, J. A.; Harabor, D.; and Hernández, C.\n\n\n \n\n\n\n In
Proceedings of the Twenty-Third International Conference on Automated Planning and Scheduling, ICAPS 2013, Rome, Italy, June 10-14, 2013, 2013. \n
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@InProceedings{\t dblp:conf/aips/boteabhh13,\n author\t= {Adi Botea and Jorge A. Baier and Daniel Harabor and Carlos\n\t\t Hern{\\'{a}}ndez},\n title\t\t= {Moving Target Search with Compressed Path Databases},\n booktitle\t= {Proceedings of the Twenty-Third International Conference\n\t\t on Automated Planning and Scheduling, {ICAPS} 2013, Rome,\n\t\t Italy, June 10-14, 2013},\n year\t\t= {2013},\n crossref\t= {DBLP:conf/aips/2013},\n url\t\t= {http://www.aaai.org/ocs/index.php/ICAPS/ICAPS13/paper/view/6001},\n timestamp\t= {Wed, 29 Mar 2017 16:45:27 +0200},\n biburl\t= {https://dblp.org/rec/bib/conf/aips/BoteaBHH13},\n bibsource\t= {dblp computer science bibliography, https://dblp.org}\n}\n\n
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\n\n \n \n \n \n \n \n International conference on Autonomous Agents and Multi-Agent Systems, AAMAS '13, Saint Paul, MN, USA, May 6-10, 2013.\n \n \n \n \n\n\n \n Gini, M. L.; Shehory, O.; Ito, T.; and Jonker, C. M.,\n editors.\n \n\n\n \n\n\n\n IFAAMAS. 2013.\n
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@Proceedings{\t dblp:conf/atal/2013,\n editor\t= {Maria L. Gini and Onn Shehory and Takayuki Ito and\n\t\t Catholijn M. Jonker},\n title\t\t= {International conference on Autonomous Agents and\n\t\t Multi-Agent Systems, {AAMAS} '13, Saint Paul, MN, USA, May\n\t\t 6-10, 2013},\n publisher\t= {{IFAAMAS}},\n year\t\t= {2013},\n url\t\t= {http://dl.acm.org/citation.cfm?id=2484920},\n isbn\t\t= {978-1-4503-1993-5},\n timestamp\t= {Fri, 28 Jun 2013 12:19:40 +0200},\n biburl\t= {https://dblp.org/rec/bib/conf/atal/2013},\n bibsource\t= {dblp computer science bibliography, https://dblp.org}\n}\n\n
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\n\n \n \n \n \n \n \n Weighted real-time heuristic search.\n \n \n \n \n\n\n \n Rivera, N.; Baier, J. A.; and Hernández, C.\n\n\n \n\n\n\n In
International conference on Autonomous Agents and Multi-Agent Systems, AAMAS '13, Saint Paul, MN, USA, May 6-10, 2013, pages 579–586, 2013. \n
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@InProceedings{\t dblp:conf/atal/riverabh13,\n author\t= {Nicolas Rivera and Jorge A. Baier and Carlos\n\t\t Hern{\\'{a}}ndez},\n title\t\t= {Weighted real-time heuristic search},\n booktitle\t= {International conference on Autonomous Agents and\n\t\t Multi-Agent Systems, {AAMAS} '13, Saint Paul, MN, USA, May\n\t\t 6-10, 2013},\n pages\t\t= {579--586},\n year\t\t= {2013},\n crossref\t= {DBLP:conf/atal/2013},\n url\t\t= {http://dl.acm.org/citation.cfm?id=2485012},\n timestamp\t= {Fri, 28 Jun 2013 12:19:40 +0200},\n biburl\t= {https://dblp.org/rec/bib/conf/atal/RiveraBH13},\n bibsource\t= {dblp computer science bibliography, https://dblp.org}\n}\n\n
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\n\n \n \n \n \n \n Hierarchical Joint Max-Margin Learning of Mid and Top Level Representations for Visual Recognition.\n \n \n \n\n\n \n Lobel, H.; Vidal, R.; and Soto, A.\n\n\n \n\n\n\n In
ICCV, pages 1697–1704, 2013. IEEE Computer Society\n
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@InProceedings{\t dblp:conf/iccv/lobelvs13,\n author\t= {Hans Lobel and Ren{\\'{e}} Vidal and Alvaro Soto},\n title\t\t= {Hierarchical Joint Max-Margin Learning of Mid and Top\n\t\t Level Representations for Visual Recognition},\n booktitle\t= {{ICCV}},\n pages\t\t= {1697--1704},\n publisher\t= {{IEEE} Computer Society},\n year\t\t= {2013}\n}\n\n
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\n\n \n \n \n \n \n Joint Dictionary and Classifier Learning for Categorization of Images Using a Max-margin Framework.\n \n \n \n\n\n \n Lobel, H.; Vidal, R.; Mery, D.; and Soto, A.\n\n\n \n\n\n\n In
PSIVT, volume 8333, of
Lecture Notes in Computer Science, pages 87–98, 2013. Springer\n
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@InProceedings{\t dblp:conf/psivt/lobelvms13,\n author\t= {Hans Lobel and Ren{\\'{e}} Vidal and Domingo Mery and\n\t\t Alvaro Soto},\n title\t\t= {Joint Dictionary and Classifier Learning for\n\t\t Categorization of Images Using a Max-margin Framework},\n booktitle\t= {{PSIVT}},\n series\t= {Lecture Notes in Computer Science},\n volume\t= {8333},\n pages\t\t= {87--98},\n publisher\t= {Springer},\n year\t\t= {2013}\n}\n\n
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\n\n \n \n \n \n \n \n Proceedings of the Sixth Annual Symposium on Combinatorial Search, SOCS 2013, Leavenworth, Washington, USA, July 11-13, 2013.\n \n \n \n \n\n\n \n Helmert, M.; and Röger, G.,\n editors.\n \n\n\n \n\n\n\n AAAI Press. 2013.\n
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@Proceedings{\t dblp:conf/socs/2013,\n editor\t= {Malte Helmert and Gabriele R{\\"{o}}ger},\n title\t\t= {Proceedings of the Sixth Annual Symposium on Combinatorial\n\t\t Search, {SOCS} 2013, Leavenworth, Washington, USA, July\n\t\t 11-13, 2013},\n publisher\t= {{AAAI} Press},\n year\t\t= {2013},\n url\t\t= {http://www.aaai.org/Library/SOCS/socs13contents.php},\n isbn\t\t= {978-1-57735-584-7},\n timestamp\t= {Tue, 20 Aug 2013 16:04:32 +0200},\n biburl\t= {https://dblp.org/rec/bib/conf/socs/2013},\n bibsource\t= {dblp computer science bibliography, https://dblp.org}\n}\n\n
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\n\n \n \n \n \n \n \n Reconnecting with the Ideal Tree: An Alternative to Heuristic Learning in Real-Time Search.\n \n \n \n \n\n\n \n Rivera, N.; Illanes, L.; Baier, J. A.; and Hernández, C.\n\n\n \n\n\n\n In
Proceedings of the Sixth Annual Symposium on Combinatorial Search, SOCS 2013, Leavenworth, Washington, USA, July 11-13, 2013., 2013. \n
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@InProceedings{\t dblp:conf/socs/riveraibh13,\n author\t= {Nicolas Rivera and Leon Illanes and Jorge A. Baier and\n\t\t Carlos Hern{\\'{a}}ndez},\n title\t\t= {Reconnecting with the Ideal Tree: An Alternative to\n\t\t Heuristic Learning in Real-Time Search},\n booktitle\t= {Proceedings of the Sixth Annual Symposium on Combinatorial\n\t\t Search, {SOCS} 2013, Leavenworth, Washington, USA, July\n\t\t 11-13, 2013.},\n year\t\t= {2013},\n crossref\t= {DBLP:conf/socs/2013},\n url\t\t= {http://www.aaai.org/ocs/index.php/SOCS/SOCS13/paper/view/7270},\n timestamp\t= {Tue, 20 Aug 2013 16:04:32 +0200},\n biburl\t= {https://dblp.org/rec/bib/conf/socs/RiveraIBH13},\n bibsource\t= {dblp computer science bibliography, https://dblp.org}\n}\n\n
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\n\n \n \n \n \n \n \n Indoor Scene Recognition by a Mobile Robot Through Adaptive Object Detection.\n \n \n \n \n\n\n \n Espinace, P.; Kollar, T.; Roy, N.; and Soto, A.\n\n\n \n\n\n\n
Robotics and Autonomous Systems, 61(9). 2013.\n
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@Article{\t espinace:etal:2013,\n author\t= {P. Espinace and T. Kollar and N. Roy and A. Soto},\n title\t\t= {Indoor Scene Recognition by a Mobile Robot Through\n\t\t Adaptive Object Detection},\n journal\t= {Robotics and Autonomous Systems},\n volume\t= {61},\n number\t= {9},\n year\t\t= {2013},\n abstract\t= {Mobile Robotics has achieved notably progress, however, to\n\t\t increase the complexity of the tasks that mobile robots can\n\t\t perform in natural environments, we need to provide them\n\t\t with a greater semantic understanding of their surrounding.\n\t\t In particular, identifying indoor scenes, such as an office\n\t\t or a kitchen, is a highly valuable perceptual ability for\n\t\t an indoor mobile robot, and in this paper we propose a new\n\t\t technique to achieve this goal. As a distinguishing\n\t\t feature, we use common objects, such as doors or\n\t\t furnitures, as a key intermediate representation to\n\t\t recognize indoor scenes. We frame our method as a\n\t\t generative probabilistic hierarchical model, where we use\n\t\t object category classifiers to associate low-level visual\n\t\t features to objects, and contextual relations to associate\n\t\t objects to scenes. The inherent seman- tic interpretation\n\t\t of common objects allows us to use rich sources of online\n\t\t data to populate the probabilistic terms of our model. In\n\t\t contrast to alterna- tive computer vision based methods, we\n\t\t boost performance by exploiting the embedded and dynamic\n\t\t nature of a mobile robot. In particular, we increase\n\t\t detection accuracy and efficiency by using a 3D range\n\t\t sensor that allows us to implement a focus of attention\n\t\t mechanism based on geometric and struc- tural information.\n\t\t Furthermore, we use concepts from information theory to\n\t\t propose an adaptive scheme that limits computational load\n\t\t by selectively guiding the search for informative objects.\n\t\t The operation of this scheme is facilitated by the dynamic\n\t\t nature of a mobile robot that is constantly changing its\n\t\t field of view. We test our approach using real data\n\t\t captured by a mo- bile robot navigating in office and home\n\t\t environments. Our results indicate that the proposed\n\t\t approach outperforms several state-of-the-art techniques },\n url\t\t= {http://saturno.ing.puc.cl/media/papers_alvaro/Final-RAS-2013.pdf}\n}\n\n
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\n Mobile Robotics has achieved notably progress, however, to increase the complexity of the tasks that mobile robots can perform in natural environments, we need to provide them with a greater semantic understanding of their surrounding. In particular, identifying indoor scenes, such as an office or a kitchen, is a highly valuable perceptual ability for an indoor mobile robot, and in this paper we propose a new technique to achieve this goal. As a distinguishing feature, we use common objects, such as doors or furnitures, as a key intermediate representation to recognize indoor scenes. We frame our method as a generative probabilistic hierarchical model, where we use object category classifiers to associate low-level visual features to objects, and contextual relations to associate objects to scenes. The inherent seman- tic interpretation of common objects allows us to use rich sources of online data to populate the probabilistic terms of our model. In contrast to alterna- tive computer vision based methods, we boost performance by exploiting the embedded and dynamic nature of a mobile robot. In particular, we increase detection accuracy and efficiency by using a 3D range sensor that allows us to implement a focus of attention mechanism based on geometric and struc- tural information. Furthermore, we use concepts from information theory to propose an adaptive scheme that limits computational load by selectively guiding the search for informative objects. The operation of this scheme is facilitated by the dynamic nature of a mobile robot that is constantly changing its field of view. We test our approach using real data captured by a mo- bile robot navigating in office and home environments. Our results indicate that the proposed approach outperforms several state-of-the-art techniques \n
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\n\n \n \n \n \n \n Encouraging Online Student Reading with Social Visualization Support.\n \n \n \n\n\n \n Guerra, J.; Parra, D.; and Brusilovsky, P.\n\n\n \n\n\n\n In
2nd Workshop on Intelligent Support for Learning in Groups - AIED 2013, 2013. \n
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@InProceedings{\t guerra2013encouraging,\n author\t= {Guerra, Julio and Parra, Denis and Brusilovsky, Peter},\n booktitle\t= {2nd Workshop on Intelligent Support for Learning in Groups\n\t\t - AIED 2013},\n title\t\t= {Encouraging Online Student Reading with Social\n\t\t Visualization Support},\n year\t\t= {2013}\n}\n\n
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\n\n \n \n \n \n \n \n Hierarchical Joint Max-Margin Learning of Mid and Top Level Representations for Visual Recognition.\n \n \n \n \n\n\n \n Lobel, H.; Vidal, R.; and Soto, A.\n\n\n \n\n\n\n In
ICCV, 2013. \n
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@InProceedings{\t lobel-a:etal:2013,\n author\t= {H. Lobel and R. Vidal and A. Soto},\n title\t\t= {Hierarchical Joint Max-Margin Learning of Mid and Top\n\t\t Level Representations for Visual Recognition},\n booktitle\t= {{ICCV}},\n year\t\t= {2013},\n abstract\t= {Currently, Bag-of-Visual-Words (BoVW) and part-based\n\t\t methods are the most popular approaches for visual\n\t\t recognition. In both cases, a mid-level representation is\n\t\t build on top of low level image descriptors while top\n\t\t levels classifiers use this mid-level representation to\n\t\t achieve visual recognition. While in current part-based\n\t\t approaches, mid and top level representations are usually\n\t\t jointly trained, this is not the usual case for BoVW\n\t\t schemes. A main reason is the complex data association\n\t\t problem associated to the larger size of the visual\n\t\t dictionary usually needed by BoVW approaches at the\n\t\t mid-level layer. As a further observation, typical\n\t\t solutions based on BoVW and part-based representations are\n\t\t usually limited to binary classification problems, a\n\t\t strategy that ignores relevant correlations among classes.\n\t\t In this work we propose a novel hierarchical approach for\n\t\t visual recognition that, in the context of a BoVW scheme,\n\t\t jointly learns suitable mid and top level representations.\n\t\t Furthermore, using a max-margin learning framework, the\n\t\t proposed approach directly handles the multiclass case at\n\t\t both levels of abstraction. We test our proposed method\n\t\t using several popular benchmarks datasets. As our main\n\t\t result, we demonstrate that by coupling learning of mid and\n\t\t top level representations, the proposed approach fosters\n\t\t sharing of discriminativity words among target classes,\n\t\t being able to achieve state-of-the-art recognition\n\t\t performance using far less visual words than previous\n\t\t approaches.},\n url\t\t= {http://saturno.ing.puc.cl/media/papers_alvaro/finalHans-ICCV-13.pdf}\n}\n\n
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\n Currently, Bag-of-Visual-Words (BoVW) and part-based methods are the most popular approaches for visual recognition. In both cases, a mid-level representation is build on top of low level image descriptors while top levels classifiers use this mid-level representation to achieve visual recognition. While in current part-based approaches, mid and top level representations are usually jointly trained, this is not the usual case for BoVW schemes. A main reason is the complex data association problem associated to the larger size of the visual dictionary usually needed by BoVW approaches at the mid-level layer. As a further observation, typical solutions based on BoVW and part-based representations are usually limited to binary classification problems, a strategy that ignores relevant correlations among classes. In this work we propose a novel hierarchical approach for visual recognition that, in the context of a BoVW scheme, jointly learns suitable mid and top level representations. Furthermore, using a max-margin learning framework, the proposed approach directly handles the multiclass case at both levels of abstraction. We test our proposed method using several popular benchmarks datasets. As our main result, we demonstrate that by coupling learning of mid and top level representations, the proposed approach fosters sharing of discriminativity words among target classes, being able to achieve state-of-the-art recognition performance using far less visual words than previous approaches.\n
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\n\n \n \n \n \n \n \n Joint Dictionary and Classifier learning for Categorization of Images using a Max-margin Framework.\n \n \n \n \n\n\n \n Lobel, H.; Vidal, R.; Mery, D.; and Soto., A.\n\n\n \n\n\n\n In
6th Pacific-Rim Symposium on Image and Video Technology, PSIVT, 2013. \n
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@InProceedings{\t lobel-b:etal:2013,\n author\t= {H. Lobel and R. Vidal and D. Mery and A. Soto.},\n title\t\t= {Joint Dictionary and Classifier learning for\n\t\t Categorization of Images using a Max-margin Framework},\n booktitle\t= {6th Pacific-Rim Symposium on Image and Video Technology,\n\t\t PSIVT},\n year\t\t= {2013},\n abstract\t= {The Bag-of-Visual-Words (BoVW) model is a popular approach\n\t\t for visual recognition. Used successfully in many different\n\t\t tasks, simplicity and good performance are the main reasons\n\t\t for its popularity. The central aspect of this model, the\n\t\t visual dictionary, is used to build mid-level\n\t\t representations based on low level image descriptors.\n\t\t Classifiers are then trained using these mid-level\n\t\t representations to perform categorization. While most works\n\t\t based on BoVW models have been focused on learning a\n\t\t suitable dictionary or on proposing a suitable pooling\n\t\t strategy, little effort has been devoted to explore and\n\t\t improve the coupling between the dictionary and the\n\t\t top-level classifiers, in order to gen- erate more\n\t\t discriminative models. This problem can be highly complex\n\t\t due to the large dictionary size usually needed by these\n\t\t methods. Also, most BoVW based systems usually perform\n\t\t multiclass categorization using a one-vs-all strat- egy,\n\t\t ignoring relevant correlations among classes. To tackle the\n\t\t previous issues, we propose a novel approach that jointly\n\t\t learns dictionary words and a proper top- level multiclass\n\t\t classifier. We use a max-margin learning framework to\n\t\t minimize a regularized energy formulation, allowing us to\n\t\t propagate labeled information to guide the commonly\n\t\t unsupervised dictionary learning process. As a result we\n\t\t produce a dictionary that is more compact and\n\t\t discriminative. We test our method on several popular\n\t\t datasets, where we demonstrate that our joint optimization\n\t\t strategy induces a word sharing behavior among the target\n\t\t classes, being able to achieve state-of-the-art performance\n\t\t using far less visual words than previous approaches. },\n url\t\t= {http://saturno.ing.puc.cl/media/papers_alvaro/Hans-PSIVT-13.pdf}\n}\n\n
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\n The Bag-of-Visual-Words (BoVW) model is a popular approach for visual recognition. Used successfully in many different tasks, simplicity and good performance are the main reasons for its popularity. The central aspect of this model, the visual dictionary, is used to build mid-level representations based on low level image descriptors. Classifiers are then trained using these mid-level representations to perform categorization. While most works based on BoVW models have been focused on learning a suitable dictionary or on proposing a suitable pooling strategy, little effort has been devoted to explore and improve the coupling between the dictionary and the top-level classifiers, in order to gen- erate more discriminative models. This problem can be highly complex due to the large dictionary size usually needed by these methods. Also, most BoVW based systems usually perform multiclass categorization using a one-vs-all strat- egy, ignoring relevant correlations among classes. To tackle the previous issues, we propose a novel approach that jointly learns dictionary words and a proper top- level multiclass classifier. We use a max-margin learning framework to minimize a regularized energy formulation, allowing us to propagate labeled information to guide the commonly unsupervised dictionary learning process. As a result we produce a dictionary that is more compact and discriminative. We test our method on several popular datasets, where we demonstrate that our joint optimization strategy induces a word sharing behavior among the target classes, being able to achieve state-of-the-art performance using far less visual words than previous approaches. \n
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\n\n \n \n \n \n \n \n Automated Design of a Computer Vision System for Food Quality Evaluation.\n \n \n \n \n\n\n \n Mery, D.; Pedreschi, F.; and Soto, A.\n\n\n \n\n\n\n
Food and Bioprocess Technology, 6(8): 2093-2108. 2013.\n
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@Article{\t mery:etal:2013,\n author\t= {D. Mery and F. Pedreschi and A. Soto},\n title\t\t= {Automated Design of a Computer Vision System for Food\n\t\t Quality Evaluation},\n journal\t= {Food and Bioprocess Technology},\n volume\t= {6},\n number\t= {8},\n pages\t\t= {2093-2108},\n year\t\t= {2013},\n abstract\t= {Considerable research efforts in computer classifiers for\n\t\t a given application avoiding the classical vision applied\n\t\t to food quality evaluation have been trial and error\n\t\t framework commonly used by human developed in the last\n\t\t years; however, they have been designers. The key idea of\n\t\t the proposed framework concentrated on using or developing\n\t\t tailored methods is to select—automatically—from a\n\t\t large set of fea- based on visual features that are able to\n\t\t solve a specific tures and a bank of classifiers those\n\t\t features and clas- task. Nevertheless, today’s computer\n\t\t capabilities are sifiers that achieve the highest\n\t\t performance. We tested giving us new ways to solve complex\n\t\t computer vision our framework on eight different food\n\t\t quality evalua- problems. In particular, a new paradigm on\n\t\t machine tion problems yielding a classification performance\n\t\t of learning techniques has emerged posing the task of 95 %\n\t\t or more in every case. The proposed framework recognizing\n\t\t visual patterns as a search problem based was implemented\n\t\t as a Matlab Toolbox available for on training data and a\n\t\t hypothesis space composed by noncommercial purposes. visual\n\t\t features and suitable classifiers. Furthermore, now we are\n\t\t able to extract, process, and test in the same time more\n\t\t image features and classifiers than before. Thus, we\n\t\t propose a general framework that designs a computer vision\n\t\t system automatically, i.e., it finds— without human\n\t\t interaction—the features and the classifiers for a given\n\t\t application avoiding the classical trial and error\n\t\t framework commonly used by human designers. The key idea of\n\t\t the proposed framework is to select—automatically—from\n\t\t a large set of fea- tures and a bank of classifiers those\n\t\t features and clas- sifiers that achieve the highest\n\t\t performance. We tested our framework on eight different\n\t\t food quality evalua- tion problems yielding a\n\t\t classification performance of 95% or more in every case.\n\t\t The proposed framework was implemented as a Matlab Toolbox\n\t\t available for noncommercial purposes.\n\t\t \n\t\t },\n url\t\t= {http://saturno.ing.puc.cl/media/papers_alvaro/Food-Mery-2012.pdf}\n}\n\n
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\n Considerable research efforts in computer classifiers for a given application avoiding the classical vision applied to food quality evaluation have been trial and error framework commonly used by human developed in the last years; however, they have been designers. The key idea of the proposed framework concentrated on using or developing tailored methods is to select—automatically—from a large set of fea- based on visual features that are able to solve a specific tures and a bank of classifiers those features and clas- task. Nevertheless, today’s computer capabilities are sifiers that achieve the highest performance. We tested giving us new ways to solve complex computer vision our framework on eight different food quality evalua- problems. In particular, a new paradigm on machine tion problems yielding a classification performance of learning techniques has emerged posing the task of 95 % or more in every case. The proposed framework recognizing visual patterns as a search problem based was implemented as a Matlab Toolbox available for on training data and a hypothesis space composed by noncommercial purposes. visual features and suitable classifiers. Furthermore, now we are able to extract, process, and test in the same time more image features and classifiers than before. Thus, we propose a general framework that designs a computer vision system automatically, i.e., it finds— without human interaction—the features and the classifiers for a given application avoiding the classical trial and error framework commonly used by human designers. The key idea of the proposed framework is to select—automatically—from a large set of fea- tures and a bank of classifiers those features and clas- sifiers that achieve the highest performance. We tested our framework on eight different food quality evalua- tion problems yielding a classification performance of 95% or more in every case. The proposed framework was implemented as a Matlab Toolbox available for noncommercial purposes. \n
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\n\n \n \n \n \n \n A field study of a visual controllable talk recommender.\n \n \n \n\n\n \n Parra, D.; and Brusilovsky, P.\n\n\n \n\n\n\n In
Proceedings of the 2013 Chilean Conference on Human-Computer Interaction, pages 56–59, 2013. ACM\n
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@InProceedings{\t parra2013field,\n author\t= {Parra, Denis and Brusilovsky, Peter},\n booktitle\t= {Proceedings of the 2013 Chilean Conference on\n\t\t Human-Computer Interaction},\n organization\t= {ACM},\n pages\t\t= {56--59},\n title\t\t= {A field study of a visual controllable talk recommender},\n year\t\t= {2013}\n}\n\n
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\n\n \n \n \n \n \n USER CONTROLLABILITY IN A HYBRID RECOMMENDER SYSTEM.\n \n \n \n\n\n \n Parra, D.\n\n\n \n\n\n\n Ph.D. Thesis, University of Pittsburgh, 2013.\n
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@PhDThesis{\t parra2013user,\n author\t= {Parra, Denis},\n school\t= {University of Pittsburgh},\n title\t\t= {USER CONTROLLABILITY IN A HYBRID RECOMMENDER SYSTEM},\n year\t\t= {2013}\n}\n\n
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\n\n \n \n \n \n \n \n Enhancing K-Means Using Class Labels.\n \n \n \n \n\n\n \n Peralta, B.; Espinace, P.; and Soto, A.\n\n\n \n\n\n\n
Intelligent Data Analysis (IDA), 17(6): 1023-1039. 2013.\n
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@Article{\t peralta:etal:2013,\n author\t= {B. Peralta and P. Espinace and A. Soto},\n title\t\t= {Enhancing K-Means Using Class Labels},\n journal\t= {Intelligent Data Analysis (IDA)},\n volume\t= {17},\n number\t= {6},\n pages\t\t= {1023-1039},\n year\t\t= {2013},\n abstract\t= {Clustering is a relevant problem in machine learning where\n\t\t the main goal is to locate meaningful partitions of\n\t\t unlabeled data. In the case of labeled data, a related\n\t\t problem is supervised clustering, where the objective is to\n\t\t locate class- uniform clusters. Most current approaches to\n\t\t supervised clustering optimize a score related to cluster\n\t\t purity with respect to class labels. In particular, we\n\t\t present Labeled K-Means (LK-Means), an algorithm for\n\t\t supervised clustering based on a variant of K-Means that\n\t\t incorporates information about class labels. LK-Means\n\t\t replaces the classical cost function of K-Means by a convex\n\t\t combination of the joint cost associated to: (i) A\n\t\t discriminative score based on class labels, and (ii) A\n\t\t generative score based on a traditional metric for\n\t\t unsupervised clustering. We test the performance of\n\t\t LK-Means using standard real datasets and an application\n\t\t for object recognition. Moreover, we also compare its\n\t\t performance against classical K-Means and a popular\n\t\t K-Medoids-based supervised clustering method. Our\n\t\t experiments show that, in most cases, LK-Means outperforms\n\t\t the alternative techniques by a considerable margin.\n\t\t Furthermore, LK-Means presents execution times considerably\n\t\t lower than the alternative supervised clustering method\n\t\t under evaluation. },\n url\t\t= {http://saturno.ing.puc.cl/media/papers_alvaro/supClustering.pdf}\n}\n\n
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\n Clustering is a relevant problem in machine learning where the main goal is to locate meaningful partitions of unlabeled data. In the case of labeled data, a related problem is supervised clustering, where the objective is to locate class- uniform clusters. Most current approaches to supervised clustering optimize a score related to cluster purity with respect to class labels. In particular, we present Labeled K-Means (LK-Means), an algorithm for supervised clustering based on a variant of K-Means that incorporates information about class labels. LK-Means replaces the classical cost function of K-Means by a convex combination of the joint cost associated to: (i) A discriminative score based on class labels, and (ii) A generative score based on a traditional metric for unsupervised clustering. We test the performance of LK-Means using standard real datasets and an application for object recognition. Moreover, we also compare its performance against classical K-Means and a popular K-Medoids-based supervised clustering method. Our experiments show that, in most cases, LK-Means outperforms the alternative techniques by a considerable margin. Furthermore, LK-Means presents execution times considerably lower than the alternative supervised clustering method under evaluation. \n
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\n\n \n \n \n \n \n \n Visualizing recommendations to support exploration, transparency and controllability.\n \n \n \n \n\n\n \n Verbert, K.; Parra, D.; Brusilovsky, P.; and Duval, E.\n\n\n \n\n\n\n In
Proceedings of the 2013 international conference on Intelligent user interfaces, pages 351–362, 2013. ACM\n
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@InProceedings{\t verbert2013visualizing,\n author\t= {Verbert, Katrien and Parra, Denis and Brusilovsky, Peter\n\t\t and Duval, Erik},\n booktitle\t= {Proceedings of the 2013 international conference on\n\t\t Intelligent user interfaces},\n organization\t= {ACM},\n pages\t\t= {351--362},\n title\t\t= {Visualizing recommendations to support exploration,\n\t\t transparency and controllability},\n url\t\t= {http://web.ing.puc.cl/~dparra/pdfs/IUI13-aduna-v5.5-notcameraready.pdf},\n year\t\t= {2013},\n bdsk-url-1\t= {http://web.ing.puc.cl/~dparra/pdfs/IUI13-aduna-v5.5-notcameraready.pdf}\n}\n\n
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