Tomoharu Iwata

Japanese | English

Tomoharu Iwata
Learning and Intelligent Systems Research Group
Innovative Communication Laboratory
NTT Communication Science Laboratories
NIPPON TELEGRAPH AND TELEPHONE CORPORATION

mail: iwata.tomoharu at lab.ntt.co.jp

He received the B.S. degree in environmental information from Keio University in 2001, the M.S. degree in arts and sciences from the University of Tokyo in 2003, and the Ph.D. degree in informatics from Kyoto University in 2008. In 2003, he joined NTT Communication Science Laboratories, Japan. From 2012 to 2013, he was a visiting researcher at Machine Learning Group, Department of Engineering, University of Cambridge, UK. He is currently a research scientist at Learning and Intelligent Systems Research Group of NTT Communication Science Laboratories, Kyoto, Japan. His research interests include data mining, machine learning, information visualization, and recommender systems.

International Conference

  1. Takeshi Kurashima, Tomoharu Iwata, Noriko Takaya, Hiroshi Sawada:
    "A Probabilistic Behavior Model for Discovering Unrecognized Knowledge,"
    ICDM2013, 2013

  2. Alejandro Marcos Alvarez, Makoto Yamada, Akisato Kimura, Tomoharu Iwata:
    "Clustering-Based Anomaly Detection in Multi-View Data,"
    CIKM2013, poster, 2013

  3. Yuya Yoshikawa, Tomoharu Iwata, Hiroshi Sawada:
    Latent Feature Independent Cascade Model for Social Propagation,
    International Conference on Parallel & Distributed Processing Techniques & Applications (PDPTA), 2013

  4. Tomoharu Iwata, Amar Shah, Zoubin Ghahramani:
    "Discovering Latent Influence in Online Social Activities via Shared Cascade Poisson Processes,"
    Proceedings of the 19th ACM SIGKDD international conference on Knowledge discovery and data mining (KDD2013), 266-274, 2013
    [pdf]

  5. Tsutomu Hirao, Tomoharu Iwata, Masaaki Nagata:
    "Latent Semantic Matching: Application to Cross-language Text Categorization without Alignment Information,"
    ACL2013, short, 2013

  6. Tomoharu Iwata, David Duvenaud, Zoubin Ghahramani:
    "Warped Mixtures for Nonparametric Cluster Shapes,"
    UAI 2013, 2013
    [preprint]

  7. Tomoharu Iwata, Tsutomu Hirao, Naonori Ueda:
    "Unsupervised Cluster Matching via Probabilistic Latent Variable Models,"
    AAAI2013, 2013
    [pdf]

  8. Tomoharu Iwata, Neil Houlsby, Zoubin Ghahramani:
    "Active Learning for Interactive Visualization,"
    AISTATS 2013, JMLR W&CP 31:342-350, 2013
    [pdf]

  9. Takeshi Kurashima, Tomoharu Iwata, Takahide Hoshide, Noriko Takaya, Ko Fujimura:
    "Geo topic model: joint modeling of user's activity area and interests for location recommendation,"
    WSDM 2013, 375-384, 2013

  10. Yutaka Kabutoya, Tomoharu Iwata, Hiroyuki Toda, Hiroyuki Kitagawa:
    "A Probabilistic Model for Diversifying Recommendation Lists,"
    APWeb 2013, April 2013

  11. Tomoharu Iwata, Kevin Duh,
    "Bidirectional Semi-Supervised Learning with Graphs,"
    ECML-PKDD'12, 293-306, 2012
    [pdf]

  12. Yutaka Kabutoya, Robert Sumi, Tomoharu Iwata, Toshio Uchiyama, Ko Fujimura:
    "A Topic Model for Recommending Movies via Linked Open Data,"
    WISE2012, 625-630, 2012

  13. Yasuko Matsubara, Yasushi Sakurai, Christos Faloutsos, Tomoharu Iwata, Masatoshi Yoshikawa:
    ``Fast Mining and Forecasting of Complex Time-Stamped Events,"
    ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD), pp. 271-279, Beijing, China, August 2012

  14. Kevin Duh, Tsutomo Hirao, Akisato Kimura, Katsuhiko Ishiguro, Tomoharu Iwata, Ching-Man Au Yeung,
    "Creating Stories: Social Curation of Twitter Messages,"
    In: ICWSM'12: Proceedings of the 6th International AAAI Conference on Weblogs and Social Media, Dublin, Ireland, 2012

  15. Ekapol Chuangsuwanich, Shinji Watanabe, Takaaki Hori, Tomoharu Iwata, James Glass,
    "Handling Uncertain Observations in Unsupervised Topic-mixture Language Model Adaptation,"
    ICASSP2012, 2012

  16. Roland Roller, Shinji Watanabe, Tomoharu Iwata,
    "Effect of Dialog Acts on Word Use in Polylogue,"
    ICASSP2012, 2012

  17. Ching-man Au Yeung, Tomoharu Iwata,
    "Modelling User Behaviour and Interactions: Augmented Cognition on the Social Web,"
    HCI (20) 277-287, 2011

  18. Akinori Fujino, Masaaki Nagata, Tomoharu Iwata,
    "Mislabeling Detection with Cross-validation Likelihood Maximization,"
    ACML2011, 2011

  19. Ching Man Au Yeung, Tomoharu Iwata,
    "Extracting Multi-dimensional Relations: A Generative Model of Groups of Entities in a Corpus,"
    CIKM2011, 1203-1208, 2011

  20. Kevin Duh, Katsuhito Sudoh, Tomoharu Iwata, Hajime Tsukada,
    "Alignment Inference and Bayesian Adaptation for Machine Translation,"
    Proceedings of Machine Translation Summit XIII, Xiamen, China, Sep. 2011

  21. Tomoharu Iwata, Shinji Watanabe,
    "Learning Influences from Word Use in Polylogue,"
    Interspeech2011, 3089-3092, 2011
    [pdf]

  22. Yasuhisa Yoshida, Tsutomu Hirao, Tomoharu Iwata, Masaaki Nagata, Yuji Matsumoto,
    "Transfer Learning for Multiple-Domain Sentiment Analysis: Identifying Domain Dependent/Independent Word Polarity,"
    AAAI2011, 2011

  23. Tomoharu Iwata, Shinji Watanabe, Hiroshi Sawada,
    "Fashion Coordinates Recommender System using Photographs from Fashion Magazines,"
    IJCAI2011, 2262-2267, 2011
    [pdf]

  24. Ching Man Au Yeung, Tomoharu Iwata,
    "Strength of Social Influence in Trust Networks in Product Review Sites,"
    WSDM2011, 495-504, 2011

  25. Katsuhiko Ishiguro, Tomoharu Iwata, Naonori Ueda, Josh Tenenbaum,
    "Dynamic Infinite Relational Model for Time-varying Relational Data Analysis,"
    NIPS2010, 910-918, 2010

  26. Takeshi Kurashima, Tomoharu Iwata, Go Irie, Ko Fujimura,
    "Travel Route Recommendation using Geotags in Photo Sharing Sites,"
    CIKM2010, 579-588, 2010

  27. Shinji Watanabe, Tomoharu Iwata, Takaaki Hori, Atsushi Sako, Yasuo Ariki,
    "Application of Topic Tracking Model to Language Model Adaptation and Meeting Analysis,"
    Proc. IEEE Workshop on Spoken Language Technology (SLT'10), 2010

  28. Yutaka Kabutoya, Tomoharu Iwata, Ko Fujimura,
    "Modeling Multiple Users' Purchase over a Single Account for Collaborative Filtering,"
    WISE2010, 2010

  29. Tomoharu Iwata, Takeshi Yamada, Yasushi Sakurai, Naonori Ueda,
    "Online Multiscale Dynamic Topic Models,"
    Proc. of 16th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD2010), 663-672, 2010
    (Best Research Paper Award Honorable Mention)
    [pdf]

  30. Tomoharu Iwata, Daichi Mochihashi, Hiroshi Sawada,
    "Learning Common Grammar from Multilingual Corpus,"
    Proceedings of 48th Annual Meeting of the Association for Computational Linguistics (ACL2010), 184-188, 2010
    [pdf]

  31. Yutaka Kabutoya, Tomoharu Iwata, Hisako Shiohara, Ko Fujimura,
    "Effective Question Recommendation Based on Multiple Features for Question Answering Communities,"
    Proceedings of 4th Int'l AAAI Conference on Weblogs and Social Media (ICWSM2010), 2010

  32. Albert Au Yeung, Tomoharu Iwata,
    "Capturing Implicit User Influence in Online Social Sharing,"
    Proceedings of 21st ACM Conference on Hypertext and Hypermedia (HT2010), 2010

  33. Tomoharu Iwata, Takeshi Yamada, Naonori Ueda,
    "Modeling Social Annotation Data with Content Relevance using a Topic Model,"
    Advances in Neural Information Processing Systems (NIPS2009), 835-843, 2009
    [pdf (revised version)]

  34. Takuya Goto, Tomoko Kojiri, Toyohide Watanabe, Tomoharu Iwata, Takeshi Yamada,
    "An Automatic Generation of Multiple-choice Cloze Questions Based on Statistical Learning,"
    The 17th International Conference on Computers in Education (ICCE2009), 415-422, 2009 (Nomination for Best Student Paper Award)

  35. Tomoharu Iwata, Shinji Watanabe, Takeshi Yamada, Naonori Ueda,
    "Topic Tracking Model for Analyzing Consumer Purchase Behavior,"
    Proc. of 21st International Joint Conference on Artificial Intelligence (IJCAI-09), 1427-1432, 2009
    [pdf]

  36. Tomoharu Iwata, Tomoko Kojiri, Takeshi Yamada, Toyohide Watanabe,
    "Recommendation Algorithm for Learning Materials that Maximizes Expected Test Scores,"
    Proc. of 10th Pacific Rim International Conference on Artificial Intelligence (PRICAI2008), 965-970, 2008
    [pdf]

  37. Takuya Goto, Tomoko Kojiri, Toyohide Watanabe, Takeshi Yamada, Tomoharu Iwata,
    "English Grammar Learning System Based on Knowledge Network of Fill-in-the-Blank Exercises,"
    Proc. of 12th International Conference on Knowledge-Based and Intelligent Information & Engineering Systems (KES2008), Part III, LNAI 5179, 588-595, 2008

  38. Tomoharu Iwata, Takeshi Yamada, Naonori Ueda,
    "Probabilistic Latent Semantic Visualization: Topic Model for Visualizing Documents,"
    Proc. of 14th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD2008), 363-371, 2008
    [pdf] © ACM, 2008. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution.

  39. Masahide Kakehi, Tomoko Kojiri, Toyohide Watanabe, Takeshi Yamada, Tomoharu Iwata,
    "Organization of Discussion Knowledge Graph from Collaborative Learning Record,"
    Proc. of 11th International Conference on Knowledge-Based Intelligent Information & Engineering Systems (KES2007), LNAI 4694 III, 600-607, 2007

  40. Tomoharu Iwata, Kazumi Saito, Takeshi Yamada,
    "Modeling User Behavior in Recommender Systems based on Maximum Entropy,"
    Proc. of 16th International World Wide Web Conference (WWW2007), poster, 1281-1282, 2007
    [pdf] © ACM, 2007. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution.

  41. Tomoharu Iwata, Kazumi Saito, Takeshi Yamada,
    "Recommendation Method for Extending Subscription Periods,"
    Proc. of 12th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD2006), 574-579, 2006
    [pdf] © ACM, 2006. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution.

  42. Tomoharu Iwata, Kazumi Saito, Naonori Ueda,
    "Visual Nonlinear Discriminant Analysis for Classifier Design,"
    Proc. of 14th European Symposium on Artificial Neural Networks (ESANN2006), 283-288, 2006
    [pdf]

  43. Tomoharu Iwata, Kazumi Saito, Naonori Ueda, Sean Stromsten, Thomas L. Griffiths, Joshua B. Tenenbaum,
    Parametric Embedding for Class Visualization
    Advances in Neural Information Processing Systems 17 (NIPS2004), 617-624, 2005
    [pdf]

  44. Tomoharu Iwata, Kazumi Saito,
    "Visualization of Anomaly using Mixture Model,"
    Proc. of 8th International Conference on Knowledge-Based Intelligent Information & Engineering Systems (KES2004), Part 2, 624-631, 2004

  45. Takashi Ikegami, Tomoharu Iwata, Koh Hashimoto,
    A Network of Dynamic Keystone Species
    Proc. of Artificial Life VIII, 216-222, 2002

  46. Kouichi Takahashi, Yusuke Saito, Tomohiko Aikawa, Tomoharu Iwata, Motohiro Yoneda, Masayuki Okayama, Masaru Tomita,
    "E-Cell: Software Environment for Whole Cell Simulation and Analysis,"
    4th Annual International Conference on Computational Molecular Biology (RECOMB2000), 2000

  47. Yusuke Saito, Kouichi Takahashi, Tomoharu Iwata, Tomohiko Aikawa, Masaru Tomita,
    "Parameter Estimation Mechanism of E-Cell Simulation Environment,"
    Genome Informatics (GIW99), 1999

Journal

  1. Yuya Yoshikawa, Tomoharu Iwata, Hiroshi Sawada
    "Collaboration on Social Media: Analyzing Successful projects in Social Coding,"
    DBSJ Journal, Vol.12, No.3, Feb. 2014, to appear

  2. Akisato Kimura, Kevin Duh, Tsutomu Hirao, Katsuhiko Ishiguro, Tomoharu Iwata, Ching-man Au Yeung,
    "Creating stories from socially curated microblog messages,"
    IEICE Transactions on Information and Systems, to appear

  3. Yasuko Matsubara, Yasushi Sakurai, Christos Faloutsos, Tomoharu Iwata, Masatoshi Yoshikawa:
    IEICE, to appear

  4. Yuya Yoshikawa, Tomoharu Iwata, Hiroshi Sawada
    "Information Diffusion Models with Latent features of Users on Social Networks," IPSJ Transaction on Database (TOD), , Vol. 6, No. 5, 85-94, Dec. 2013

  5. Tomoharu Iwata, Takeshi Yamada, Naonori Ueda,
    "Modeling Noisy Annotated Data with Application to Social Annotation,"
    IEEE Transactions on Knowledge and Data Engineering, 25 (7), 1601-1613, 2013

  6. Takeshi Kurashima, Tomoharu Iwata, Go Irie, Ko Fujimura,
    "Travel Route Recommendation Using Geotagged Photos,"
    Knowledge and Information Systems (KAIS) journal, Volume 37, Issue 1, 37-60, 2013

  7. Takeshi Kurashima, Tomoharu Iwata, Takahide Hoshide, Noriko Takaya, Ko Fujimura,
    "Joint modeling of user's activity area and interests for location recommendation,"
    IPSJ Transaction on Database (TOD), Vol. 6, No. 2, 30-41, 2013

  8. Kevin Duh, Ching-Man Au Yeung, Tomoharu Iwata, Masaaki Nagata:
    "Managing information disparity in multilingual document collections,"
    ACM Trans. Speech Lang. Process. 10, 1, Article 1, March 2013

  9. Tomoharu Iwata, Shinji Watanabe,
    "Influence Relation Estimation based on Lexical Entrainment in Conversation,"
    Speech Communication, 55, 2, 329-339, 2013

  10. Tomoharu Iwata, Hiroshi Sawada,
    "Topic Model for Analyzing Purchase Data with Price Information,"
    Data Mining and Knowledge Discovery, 26, 3, 559-573, 2013
    [pdf]

  11. Tomoharu Iwata, Takeshi Yamada, Yasushi Sakurai, Naonori Ueda,
    "Sequential Modeling of Topic Dynamics with Multiple Timescales,"
    ACM Transactions on Knowledge Discovery from Data (TKDD), Volume 5 Issue 4, 19:1-19:27, 2012
    [pdf]

  12. Yutaka Kabutoya, Tomoharu Iwata, Ko Fujimura,
    "Collaborative Filtering based on Topic Models Considering an Account Shared by Multiple Users,"
    DBSJ Journal, Vol.9, No.3, 7-12, 2011

  13. Tomoharu Iwata, Tomoko Kojiri, Takeshi Yamada, Toyohide Watanabe,
    "Recommendation for English Multiple-choice Cloze Questions Based on Expected Test Scores,"
    International Journal of Knowledge-based and Intelligent Engineering Systems, Volume 15, Number 1, 2011
    [pdf]

  14. Shinji Watanabe, Tomoharu Iwata, Takaaki Hori, Atsushi Sako, Yasuo Ariki,
    "Topic Tracking Language Model for Speech Recognition,"
    Computer Speech & Language, Volume 25, Issue 22, 440-461, 2011

  15. Tomoharu Iwata, Toshiyuki Tanaka, Takeshi Yamada, Naonori Ueda,
    "Improving Classifier Performance using Data with Different Taxonomies,"
    IEEE Transactions on Knowledge and Data Engineering (TKDE), Vol. 23, No. 11, 1668-1677, 2011
    [pdf]

  16. Yutaka Kabutoya, Tomoharu Iwata, Hisako Shiohara, Ko Fujimura,
    "Effective Question Recommendation using Multiple Features for Question Answering Communities,"
    IPSJ Transaction on Database (TOD), Vol.3, No. 4, 34-47, 2010

  17. Takuya Goto, Tomoko Kojiri, Toyohide Watanabe, Tomoharu Iwata, Takeshi Yamada,
    "Automatic Generation System of Multiple-choice Cloze Questions and its Evaluation,"
    Knowledge Management & E-Learning: An International Journal (KM&EL), Vol 2, No 3, 2010

  18. Tomoharu Iwata, Shinji Watanabe, Takeshi Yamada, Naonori Ueda
    "Topic Tracking Model for Purchase Behavior Analysis,"
    Transactions of IEICEJ, Vol.J93-D, No.6, pp.978-987, 2010

  19. Katsuhiko Ishiguro, Tomoharu Iwata, Naonori Ueda,
    "Dynamic infinite relational model for time-dependent relational data analysis,"
    Journal of Information Processing Society of Japan, Vol. 3, No.1, 1-12, 2010

  20. Takuya Goto, Tomoko Kojiri, Toyohide Watanabe, Tomoharu Iwata, Takeshi Yamada,
    "Knowledge Network for English Grammar Learning Support System,"
    International Journal of Advanced Intelligence Paradigms, Vol.2, No.1, 64-77, 2009

  21. Tomoharu Iwata, Takeshi Yamada, Naonori Ueda,
    "Visualizing Documents based on Topic Models,"
    Journal of Information Processing Society of Japan, Vol.50, No.6, 1649-1659, 2009

  22. Tomoharu Iwata, Toshiyuki Tanaka, Takeshi Yamada, Naonori Ueda,
    "Model Learning when Distributions Differ over Time,"
    Transactions of IEICEJ, Vol.J92-D, No.3, 361-370, 2009

  23. Tomoharu Iwata, Kazumi Saito, Takeshi Yamada,
    "Recommendation Method for Improving Customer Lifetime Value,"
    IEEE Transactions on Knowledge and Data Engineering, Vol.20, No.9, 1254-1263, 2008
    [pdf] © 2008 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. *IEEE

  24. Tomoharu Iwata, Takeshi Yamada, Naonori Ueda,
    "Collaborative filtering efficiently using purchase orders,"
    Transaction of Information Processing Society of Japan, Vol.49, No.SIG4 (TOM20), 125-134, 2008
    [pdf]*IPSJ

  25. Tomoharu Iwata, Kazumi Saito,
    "Visual Classifier Analysis using Parametric Embedding,"
    Journal of Information Processing Society of Japan, Vol.48, No.12, 2007
    [pdf]*IPSJ

  26. Tomoharu Iwata, Kazumi Saito, Takeshi Yamada,
    "Recommendation Method for Extending Subscription Periods,"
    Transaction of Information Processing Society of Japan, Vol.48, No.SIG6 (TOM17), 65-74, 2007
    [pdf]*IPSJ

  27. Tomoharu Iwata, Kazumi Saito, Naonori Ueda, Sean Stromsten, Thomas L. Griffiths, Joshua B. Tenenbaum,
    "Parametric Embedding for Class Visualization,"
    Neural Computation, Vol.19, No.9, 2536-2556, 2007
    [pdf]

  28. Tomoharu Iwata, Kazumi Saito,
    "Visualization of Anomalies using Mixture Models,"
    Journal of Intelligent Manufacturing, Vol.16, 635-643, 2005
    [pdf]

  29. Tomoharu Iwata, Kazumi Saito, Naonori Ueda,
    "Class Structure Visualization by Parametric Embedding,"
    Journal of Information Processing Society of Japan, vol.46, 2337-2346, 2005
    [pdf]*IPSJ

Letter

  1. Tomoharu Iwata, Kazumi Saito, Takeshi Yamada,
    "Recommendation to Extend Subscription Periods,"
    Information Technology Letters, vol.5, 109-112, 2006
    [pdf]

  2. Tomoharu Iwata, Kazumi Saito, Naonori Ueda,
    "Visualization via Posterior Preserving Embedding,"
    Information Technology Letters, Vol.3, 119-120, 2004
    [pdf]

Thesis

    Tomoharu Iwata,
    "Probabilistic User Behavior Models in Online Stores for Recommender Systems,"
    Doctoral Thesis, Graduate School of Informatics, Kyoto University, 2008
    [pdf]

last update 19/Feb/2014