Updated on 2024/10/07

写真b

 
OHNISHI Takaaki
 
*Items subject to periodic update by Rikkyo University (The rest are reprinted from information registered on researchmap.)
Affiliation*
Graduate School of Artificial Intelligence and Science Master's Program in Artificial Intelligence and Science
College of Economics Department of Economics
Graduate School of Artificial Intelligence and Science Doctoral Program in Artificial Intelligence and Science
Title*
Professor
Degree
博士（科学） （ 東京大学 ）
Research Theme*

  • データ科学、機械学習、社会・経済物理学、ネットワーク科学、超並列計算の手法を用いて店舗・施設・人の地理空間情報、金融市場・脳波・人間行動の時系列、TV・ニュース・ウェブのテキストデータ、市場間相関・取引関係・共起関係ネットワークなどのビッグデータを実証科学の視点から解析することで、価値ある新たな知見の創出を目指した研究を行っている。【略歴】2001年東京大学大学院工学系研究科修士課程修了。2004年同大学院新領域創成科学研究科博士課程修了。博士（科学）。2004年同大学院法学政治学研究科助手、2007年同研究科助教、2009年キヤノングローバル戦略研究所研究員、2012年同研究所主任研究員、2013年東京大学大学院情報理工学系研究科准教授を経て2020年より現職。

    • Campus Career*
    • 4 2022 - Present 
      Graduate School of Artificial Intelligence and Science   Master's Program in Artificial Intelligence and Science   Professor
    • 4 2022 - Present 
      Graduate School of Artificial Intelligence and Science   Doctoral Program in Artificial Intelligence and Science   Professor
    • 4 2020 - Present 
      College of Economics   Department of Economics   Professor
    • 4 2020 - 3 2022 
      Graduate School of Artificial Intelligence and Science   Artificial Intelligence and Science   Professor
     

    Research Areas

    • Others / Others

    Research History

    • 4 2020 - Present 
      立教大学大学院人工知能科学研究科 教授

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    • 11 2013 - 3 2020 
      The University of Tokyo   The Graduate School of Information Science and Technology, Department of Mathematical Informatics

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    • 10 2013 - 3 2020 
      The University of Tokyo   The Graduate School of Information Science and Technology

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    • 8 2013 - 9 2013 
      Institute of Statistical Research

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    • 1 2012 - 9 2013 
      一般財団法人キヤノングローバル戦略研究所   主任研究員

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    • 10 2009 - 7 2013 
      The University of Tokyo   Division of Economics, Graduate School

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    • 6 2009 - 12 2011 
      一般財団法人キヤノングローバル戦略研究所   研究員

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    • 6 2009 - 10 2009 
      The University of Tokyo   School of Legal and Political Studies, Graduate Schools for Law and Politics

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    • 4 2004 - 5 2009 
      The University of Tokyo   School of Legal and Political Studies, Graduate Schools for Law and Politics

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    Education

    • 4 2001 - 3 2004 
      The University of Tokyo   Graduate School of Frontier Sciences   Department of Complexity Science and Engineering

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    • 4 1999 - 3 2001 
      The University of Tokyo   The Graduate School of Engineering

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    • 4 1995 - 3 1999 
      University of Tsukuba

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    Papers

    • A Noise-Robust Approach to Estimate Dimension of Sleep EEG in Mice Using Permutation Entropy Peer-reviewed

      Kazuki Koyama, Masanori Sakaguchi, Takaaki Ohnishi

      2024 IEEE International Conference on Fuzzy Systems (FUZZ-IEEE)   1 - 8   30 6 2024

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      Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

      DOI： 10.1109/fuzz-ieee60900.2024.10611847

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    • Exogenous and endogenous factors affecting stock market transactions: A Hawkes process analysis of the Tokyo Stock Exchange during the COVID-19 pandemic

      Mariko I. Ito, Yudai Honma, Takaaki Ohnishi, Tsutomu Watanabe, Kazuyuki Aihara

      PLOS ONE19 ( 4 ) e0301462 - e0301462   17 4 2024

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      Publishing type：Research paper (scientific journal)   Publisher：Public Library of Science (PLoS)  

      Transactions in financial markets are not evenly spaced but can be concentrated within a short period of time. In this study, we investigated the factors that determine the transaction frequency in financial markets. Specifically, we employed the Hawkes process model to identify exogenous and endogenous forces governing transactions of individual stocks in the Tokyo Stock Exchange during the COVID-19 pandemic. To enhance the accuracy of our analysis, we introduced a novel EM algorithm for the estimation of exogenous and endogenous factors that specifically addresses the interdependence of the values of these factors over time. We detected a substantial change in the transaction frequency in response to policy change announcements. Moreover, there is significant heterogeneity in the transaction frequency among individual stocks. We also found a tendency where stocks with high market capitalization tend to significantly respond to external news, while their excitation relationship between transactions is weak. This suggests the capability of quantifying the market state from the viewpoint of the exogenous and endogenous factors generating transactions for various stocks.

      DOI： 10.1371/journal.pone.0301462

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    • Gaussian hierarchical latent Dirichlet allocation: Bringing polysemy back

      Takahiro Yoshida, Ryohei Hisano, Takaaki Ohnishi

      PLOS ONE18 ( 7 ) e0288274 - e0288274   12 7 2023

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      Publishing type：Research paper (scientific journal)   Publisher：Public Library of Science (PLoS)  

      Topic models are widely used to discover the latent representation of a set of documents. The two canonical models are latent Dirichlet allocation, and Gaussian latent Dirichlet allocation, where the former uses multinomial distributions over words, and the latter uses multivariate Gaussian distributions over pre-trained word embedding vectors as the latent topic representations, respectively. Compared with latent Dirichlet allocation, Gaussian latent Dirichlet allocation is limited in the sense that it does not capture the polysemy of a word such as “bank.” In this paper, we show that Gaussian latent Dirichlet allocation could recover the ability to capture polysemy by introducing a hierarchical structure in the set of topics that the model can use to represent a given document. Our Gaussian hierarchical latent Dirichlet allocation significantly improves polysemy detection compared with Gaussian-based models and provides more parsimonious topic representations compared with hierarchical latent Dirichlet allocation. Our extensive quantitative experiments show that our model also achieves better topic coherence and held-out document predictive accuracy over a wide range of corpus and word embedding vectors which significantly improves the capture of polysemy compared with GLDA and CGTM. Our model learns the underlying topic distribution and hierarchical structure among topics simultaneously, which can be further used to understand the correlation among topics. Moreover, the added flexibility of our model does not necessarily increase the time complexity compared with GLDA and CGTM, which makes our model a good competitor to GLDA.

      DOI： 10.1371/journal.pone.0288274

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    • Fluctuation in Grocery Sales by Brand: An Analysis Using Taylor’s Law Peer-reviewed

      Kazuki Koyama, Mariko I. Ito, Takaaki Ohnishi

      The Review of Socionetwork Strategies16 ( 2 ) 417 - 430   10 2022

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      Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

      Abstract

      In recent years, Taylor’s law describing the power function relationship between the mean and standard deviation of certain phenomena has found an increasing number of applications. We studied the characteristics of Taylor’s law for branded product sales using point-of-sale (POS) data for brands sold in 72 grocery stores in the Greater Tokyo area. A previous study found that product sales follow Taylor’s law with a scaling exponent of 0.5 for low sales quantities and 1.0 for large sales quantities. In the current study, we observed Taylor’s law with cross-over for 54 product brands and estimated the value of the two coefficients in the theoretical curve to characterize the cross-over. The coefficients represent the fluctuations in the number of items purchased per consumer and the number of consumers in one store and in all stores. The estimated coefficients suggested the dependence of the features of Taylor’s law on the category to which the brands belong. We found that brands in the same category tend to share similar features under Taylor’s law. However, some brands exhibited specific features that differed from others in the same category. For example, for many brands in the Laundry Detergent and Instant Noodles categories, the number of customers purchasing the products in each store fluctuated significantly, whereas the number of purchased items per customer varied widely in the Japanese Tea category. In the coffee category, our results indicated that the degree of fluctuation in the number of purchasing customers largely depends on the brand.

      DOI： 10.1007/s12626-022-00119-7

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      Other Link： https://link.springer.com/article/10.1007/s12626-022-00119-7/fulltext.html

    • Fluctuations in the Number of Stores by Industry During the COVID-19 Pandemic Based on Japanese Phone Book Entries Peer-reviewed

      Saki Saito, Mariko I. Ito, Takaaki Ohnishi

      The Review of Socionetwork Strategies16 ( 2 ) 545 - 557   10 2022

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      Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

      Abstract

      Currently in Japan, summaries of the number of bankruptcies due to the spread of COVID-19 can only be obtained from surveys conducted by a few research firms targeting particular companies. In this study, we used Japanese telephone directory data containing detailed information on the location and industrial category of stores/facilities nationwide in an effort to infer the influence of COVID-19 on businesses in Japan. We analyzed the temporal change in the number of stores before and after the COVID-19 outbreak. Among other findings, the analysis revealed that the number of travel agencies and facilities offering karaoke and other forms of entertainment declined significantly after the outbreak in some prefectures, with the largest declines in Ibaraki, Osaka, and Hyogo prefectures, and a relatively small decline in Tochigi prefecture. Among the stores and facilities categorized as restaurants and travel-related services, the decline was particularly significant in urban areas such as Tokyo and Osaka prefectures.

      DOI： 10.1007/s12626-022-00120-0

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      Other Link： https://link.springer.com/article/10.1007/s12626-022-00120-0/fulltext.html

    • ID-POS Data Analysis Using TV Commercial Viewership Data Peer-reviewed

      Taizo Horikomi, Mariko I. Ito, Takaaki Ohnishi

      The Review of Socionetwork Strategies16 ( 2 ) 431 - 451   10 2022

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      Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

      DOI： 10.1007/s12626-022-00116-w

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      Other Link： https://link.springer.com/article/10.1007/s12626-022-00116-w/fulltext.html

    • Visualizing Social and Behavior Change due to the Outbreak of COVID-19 Using Mobile Phone Location Data Peer-reviewed

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      New Generation Computing39 ( 3-4 ) 453 - 468   11 2021

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      Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

      Abstract

      We visualize the rates of stay-home for residents by region using the difference between day-time and night-time populations to detect residential areas, and then observing the numbers of people leaving residential areas. There are issues with measuring stay-home rates by observing numbers of people visiting downtown areas, such as central urban shopping centers and major train stations. The first is that we cannot eliminate the possibility that people will avoid areas being observed and go to other areas. The second is that for people visiting downtown areas, we cannot know where they reside. These issues can be resolved if we quantify the degree of stay-home using the number of people leaving residential areas. There are significant differences in stay-home levels by region throughout Japan. By this visualization, residents of each region can see whether their level of stay-home is adequate or not, and this can provide incentive toward compliance suited to the residents of the region.

      DOI： 10.1007/s00354-021-00139-x

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      Other Link： https://link.springer.com/article/10.1007/s00354-021-00139-x/fulltext.html

    • Co-occurrence network of TV advertisements revealing Japanese lifestyle Peer-reviewed

      Mariko I. Ito, Takaaki Ohnishi

      Applied Network Science6 ( 1 ) 1 - 19   7 2021

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      Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

      Abstract

      The relationship between culture and the appeals in TV advertisements has been extensively studied. We attempted to reveal the image structure produced by TV commercials in Japan, which may show the cultural features of the country, and to evaluate its temporal change. For this purpose, we constructed and analysed a co-occurrence network of keywords related to TV commercials by using immense data that include the records of all TV commercials aired in the Kanto area in Japan including Tokyo for a period of 15 years. We found a strong heterogeneity of the co-occurrence relationship, where a few keywords, e.g., ‘woman’, ‘man’, ‘animation’, and ‘logo’, co-occur with a huge number of other keywords every year. A community on a co-occurrence network can be regarded as a set of keywords that are mutually associated with each other through TV commercials. We examined the characteristics of the communities by associating them with categories of advertised products and found a temporal change in which the relationship between the communities possessing the image of entertainment and children and the category of PC and A/V gradually increases in strength. However, there was a consistent tendency in the examined period for the product categories related to communities that include ‘man’ to be less associated with those that include ‘woman’ and vice versa, which implicates a gender role inequality underlying the various appeals in TV commercials.

      DOI： 10.1007/s41109-021-00393-4

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      Other Link： https://link.springer.com/article/10.1007/s41109-021-00393-4/fulltext.html

    • Metabolic fingerprints of fear memory consolidation during sleep Peer-reviewed

      Iyo Koyanagi, Kazuhiro Sonomura, Toshie Naoi, Takaaki Ohnishi, Naoko Kaneko, Kazunobu Sawamoto, Tak-Aki Sato, Masanori Sakaguchi

      Molecular Brain14 ( 30 )   2 2021

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    • Uncovering the Image Structure of Japanese TV Commercials Through a Co-occurrence Network Representation Peer-reviewed

      Mariko I. Ito, Takaaki Ohnishi

      In: Complex Networks and Their Applications IX. COMPLEX NETWORKS 2020. Studies in Computational Intelligence, Springer943   273 - 283   2021

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      Publishing type：Part of collection (book)   Publisher：Springer International Publishing  

      DOI： 10.1007/978-3-030-65347-7_23

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    • Nondiagonal Mixture of Dirichlet Network Distributions for Analyzing a Stock Ownership Network Peer-reviewed

      Wenning Zhang, Ryohei Hisano, Takaaki Ohnishi, Takayuki Mizuno

      In: Complex Networks and Their Applications IX. COMPLEX NETWORKS 2020. Studies in Computational Intelligence, Springer943   75 - 86   2021

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    • Topological Data Analysis of Microdomain Patterns of Block Copolymer Peer-reviewed

      Y. Mototake, S. Yamanaka, T. Aoyagi, T. Ohnishi, K. Fukumizu

      Proceedings of the 2020 International Symposium on Nonlinear Theory and its Applications (NOLTA2020)   517 - 520   11 2020

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    • Quantification of microphase separated structures from the viewpoint of multifractal Peer-reviewed

      Proceedings of the 2020 International Symposium on Nonlinear Theory and its Applications (NOLTA2020)   480 - 483   11 2020

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    • Complex Network Representation of the Structure-Mechanical Property Relationships in Elastomers with Heterogeneous Connectivity Peer-reviewed

      Yoshifumi Amamoto, Ken Kojio, Atsushi Takahara, Yuichi Masubuchi, Takaaki Ohnishi

      Patterns1 ( 8 ) 100135 - 100135   11 2020

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      Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

      The complicated structure-property relationships of materials have recently been described using a methodology of data science that is recognized as the fourth paradigm in materials science. In network polymers or elastomers, the manner of connection of the polymer chains among the crosslinking points has a significant effect on the material properties. In this study, we quantitatively evaluate the structural heterogeneity of elastomers at the mesoscopic scale based on complex network, one of the methods used in data science, to describe the elastic properties. It was determined that a unified parameter with topological and spatial information universally describes some parameters related to the stresses. This approach enables us to uncover the role of individual crosslinking points for the stresses, even in complicated structures. Based on the data science, we anticipate that the structure-property relationships of heterogeneous materials can be interpretatively represented using this type of "white box" approach.

      DOI： 10.1016/j.patter.2020.100135

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    • House price dispersion in boom–bust cycles: evidence from Tokyo Peer-reviewed

      Takaaki Ohnishi, Takayuki Mizuno, Tsutomu Watanabe

      The Japanese Economic Review71 ( 4 ) 511 - 539   10 2020

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      Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

      DOI： 10.1007/s42973-019-00019-6

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      Other Link： http://link.springer.com/article/10.1007/s42973-019-00019-6/fulltext.html

    • Evaluation of the Heterogeneous Spatial Distribution of Population and Stores/Facilities by Multifractal Analysis Peer-reviewed

      Mariko I. Ito, Takaaki Ohnishi

      Frontiers in Physics8 ( 291 ) 1 - 12   4 8 2020

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      Publishing type：Research paper (scientific journal)   Publisher：Frontiers Media SA  

      DOI： 10.3389/fphy.2020.00291

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    • Sparse Activity of Hippocampal Adult-Born Neurons during REM Sleep Is Necessary for Memory Consolidation Peer-reviewed International journal

      Deependra Kumar, Iyo Koyanagi, Alvaro Carrier-Ruiz, Pablo Vergara, Sakthivel Srinivasan, Yuki Sugaya, Masatoshi Kasuya, Tzong-Shiue Yu, Kaspar E. Vogt, Masafumi Muratani, Takaaki Ohnishi, Sima Singh, Catia M. Teixeira, Yoan Chérasse, Toshie Naoi, Szu-Han Wang, Pimpimon Nondhalee, Boran A.H. Osman, Naoko Kaneko, Kazunobu Sawamoto, Steven G. Kernie, Takeshi Sakurai, Thomas J. McHugh, Masanobu Kano, Masashi Yanagisawa, Masanori Sakaguchi

      Neuron107 ( 3 ) 552 - 565.e10   8 2020

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      Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

      The occurrence of dreaming during rapid eye movement (REM) sleep prompts interest in the role of REM sleep in hippocampal-dependent episodic memory. Within the mammalian hippocampus, the dentate gyrus (DG) has the unique characteristic of exhibiting neurogenesis persisting into adulthood. Despite their small numbers and sparse activity, adult-born neurons (ABNs) in the DG play critical roles in memory; however, their memory function during sleep is unknown. Here, we investigate whether young ABN activity contributes to memory consolidation during sleep using Ca2+ imaging in freely moving mice. We found that contextual fear learning recruits a population of young ABNs that are reactivated during subsequent REM sleep against a backdrop of overall reduced ABN activity. Optogenetic silencing of this sparse ABN activity during REM sleep alters the structural remodeling of spines on ABN dendrites and impairs memory consolidation. These findings provide a causal link between ABN activity during REM sleep and memory consolidation.

      DOI： 10.1016/j.neuron.2020.05.008

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    • Weighted Network Analysis for Computer-Aided Drug Discovery Peer-reviewed

      Mariko I. Ito, Takaaki Ohnishi

      In: Czarnowski, I., Howlett, R., Jain, L. (eds) Intelligent Decision Technologies. IDT 2020. Smart Innovation, Systems and Technologies193   27 - 36   6 2020

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      Publishing type：Part of collection (book)   Publisher：Springer Singapore  

      DOI： 10.1007/978-981-15-5925-9_3

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    • Detecting stock market bubbles based on the cross-sectional dispersion of stock prices Peer-reviewed

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      In: Sato H., Iwanaga S., Ishii A. (eds) Proceedings of the 23rd Asia Pacific Symposium on Intelligent and Evolutionary Systems. IES 2019. Proceedings in Adaptation, Learning and Optimization, Springer, Cham.2   194 - 202   12 2019

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    • Novel and topical business news and their impact on stock market activity

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      EPJ Data Science6 ( 26 )   12 2017

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      Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

      DOI： 10.1140/epjds/s13688-017-0123-7

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      Other Link： http://link.springer.com/article/10.1140/epjds/s13688-017-0123-7/fulltext.html

    • Revealing Persistent Structure of International Trade by Nonnegative Matrix Factorization Peer-reviewed

      Chikara Mizokami, Takaaki Ohnishi

      In: Cherifi C., Cherifi H., Karsai M., Musolesi M. (eds) Complex Networks & Their Applications VI. COMPLEX NETWORKS 2017. Studies in Computational Intelligence (Springer, Cham)689   1088 - 1099   11 2017

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    • Relationship between population density and population movement in inhabitable lands Peer-reviewed

      Shouji Fujimoto, Takayuki Mizuno, Takaaki Ohnishi, Chihiro Shimizu, Tsutomu Watanabe

      Evolutionary and Institutional Economics Review14 ( 1 ) 117 - 130   6 2017

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      Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

      DOI： 10.1007/s40844-016-0064-z

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      Other Link： http://link.springer.com/content/pdf/10.1007/s40844-016-0064-z.pdf

    • The gradual evolution of buyer-seller networks and their role in aggregate fluctuations Peer-reviewed

      Ryohei Hisano, Tsutomu Watanabe, Takayuki Mizuno, Takaaki Ohnishi, Didier Sornette

      Applied Network Science2   9   5 2017

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    • Structure of global buyer-supplier networks and its implications for conflict minerals regulations

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      EPJ Data Science5 ( 1 )   12 2016

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      Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

      DOI： 10.1140/epjds/s13688-016-0063-7

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      Other Link： http://link.springer.com/article/10.1140/epjds/s13688-016-0063-7/fulltext.html

    • Power laws in market capitalization during the Dot-com and Shanghai bubble periods Peer-reviewed

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      Evolutionary and Institutional Economics Review13 ( 2 ) 445 - 454   9 2016

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    • Simulating customer-To-customer interaction in a B2B financial service business by empirical agent-based modeling Peer-reviewed

      Makoto Mizuno, Yutaro Nemoto, Keisuke Oura, Keiko Toya, Shintaro Tanno, Akira Ishii, Kana Ozawa, Kohei Arai, Takaaki Ohnishi

      BICT 2015 - 9th EAI International Conference on Bio-Inspired Information and Communications Technologies3 ( 8 ) e1   24 5 2016

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      Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Association for Computing Machinery, Inc  

      Service research has emphasized triad relationships between a firm, employees and customers. To coordinate these stakeholders effectively, it is highly important to understand what service activities are beneficial to all or some of these stakeholders. Yet, the recent increase in C2C interaction may make the problem more complex. This study proposes a methodology combining statistical techniques and agent-based modeling, which makes it possible to assess the joint impact of each service value and C2C interaction on the payoffs.

      DOI： 10.4108/eai.3-12-2015.2262497

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    • Econophysics Point of View of Trade Liberalization: Community dynamics, synchronization, and controllability as example of collective motions Peer-reviewed

      Y. Ikeda, H. Aoyama, H. Iyetomi, T. Mizuno, T. Ohnishi, Y. Sakamoto, T. Watanabe

      RIETI Discussion Paper Series 16-E-026   1 - 35   3 2016

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    • Geographic Dependency of Population Distribution Peer-reviewed

      Shouji Fujimoto, Takayuki Mizuno, Takaaki Ohnishi, Chihiro Shimizu, Tsutomu Watanabe

      Proceedings of the International Conference on Social Modeling and Simulation, plus Econophysics Colloquium 2014   151 - 162   10 2015

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      Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer International Publishing  

      DOI： 10.1007/978-3-319-20591-5_14

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    • The Structure of Global Inter-firm Networks Peer-reviewed

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      Social Informatics8852   334 - 338   2015

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      Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：SPRINGER-VERLAG BERLIN  

      We investigate the structure of global inter-firm relationships using a unique dataset containing information on customers, suppliers, licensors, licensees and strategic alliances for each of 412,814 major incorporated non-financial firms in the world. We focus on three different networks: customer-supplier network, licensee-licensor network, and strategic alliance network. In/out-degree distribution of these networks follows a Pareto distribution with an exponent of 1.5. The shortest path length on the networks for any pair of firms is around six links. The networks have a scale-free property. We also find that stock price returns tend to be more highly correlated the closer two listed firms are to each other in the networks. This suggests that a non-negligible portion of price fluctuations stems from the propagation of a particular firm's shocks through inter-firm relationships.

      DOI： 10.1007/978-3-319-15168-7_42

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    • Relationship between Job Opportunities and Economic Environments Measured from Data in Internet Job Searching Sites Peer-reviewed

      Aki-Hiro Sato, Chihiro Shimizu, Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      Procedia Computer Science60   1255 - 1262   2015

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      Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

      DOI： 10.1016/j.procs.2015.08.191

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    • Community Structure and Dynamics of the Industry Sector-Specific International-Trade-Network Peer-reviewed

      Y. Ikeda, H. Iyetomi, T. Mizuno, T. Ohnishi, T. Watanabe

      2014 Tenth International Conference on Signal-Image Technology and Internet-Based Systems   456 - 461   11 2014

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      Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

      DOI： 10.1109/sitis.2014.67

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    • Ecosystems perspective on financial networks: Diagnostic tools Peer-reviewed

      Eduardo Viegas, Misako Takayasu, Wataru Miura, Koutarou Tamura, Takaaki Ohnishi, Hideki Takayasu, Henrik Jeldtoft Jensen

      Complexity19 ( 1 ) 22 - 36   9 2013

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      Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

      The world economy consists of highly interconnected and interdependent commercial and financial networks. Here, we develop temporal and structural network tools to analyze the state of the economy and the financial markets. Our analysis indicates that a strong clustering can be a warning sign. Reduction in diversity, which was an essential aspect of the dynamics surrounding the financial markets crisis of 2008, is seen as a key emergent feature arising naturally from the evolutionary and adaptive dynamics inherent to the financial markets. Similarly, collusion amongst construction firms in a number of regions in Japan in the 2000s can be identified with the formation of clusters of anomalous highly connected companies. (c) 2013 Wiley Periodicals, Inc. Complexity 19: 22-36, 2013

      DOI： 10.1002/cplx.21452

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      Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/cplx.21452

    • High Quality Topic Extraction from Business News Explains Abnormal Financial Market Volatility Peer-reviewed

      Ryohei Hisano, Didier Sornette, Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      PLoS ONE8 ( 6 ) e64846 - e64846   6 6 2013

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      Publishing type：Research paper (scientific journal)   Publisher：Public Library of Science (PLoS)  

      DOI： 10.1371/journal.pone.0064846

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    • Replication of non-trivial directional motion in multi-scales observed by the runs test Peer-reviewed

      Yoshihiro Yura, Takaaki Ohnishi, Hideki Takayasu, Misako Takayasu

      International Journal of Modern Physics: Conference Series16   136 - 148   9 2012

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    • Power Laws in Real Estate Prices during Bubble Periods Peer-reviewed

      Takaaki Ohnishi, Takayuki Mizuno, Chihiro Shimizu, Tsutomu Watanabe

      International Journal of Modern Physics: Conference Series16   61 - 81   9 2012

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    • Random walk or a run. Market microstructure analysis of foreign exchange rate movements based on conditional probability Peer-reviewed

      Yuko Hashimoto, Takatoshi Ito, Takaaki Ohnishi, Misako Takayasu, Hideki Takayasu, Tsutomu Watanabe

      Quantitative Finance12 ( 6 ) 893 - 905   6 2012

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      Publishing type：Research paper (scientific journal)   Publisher：Informa UK Limited  

      DOI： 10.1080/14697681003792237

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    • On the nonstationarity of the exchange rate process Peer-reviewed

      Takaaki Ohnishi, Hideki Takayasu, Takatoshi Ito, Yuko Hashimoto, Tsutomu Watanabe, Misako Takayasu

      International Review of Financial Analysis23   30 - 34   6 2012

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      Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

      DOI： 10.1016/j.irfa.2011.06.010

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    • Power Laws in Real Estate Prices During Bubble Periods Peer-reviewed

      TAKAAKI OHNISHI, TAKAYUKI MIZUNO, CHIHIRO SHIMIZU, TSUTOMU WATANABE

      International Journal of Modern Physics: Conference Series16   61 - 81   1 2012

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      Language：English   Publishing type：Research paper (scientific journal)   Publisher：World Scientific Pub Co Pte Lt  

      How can we detect real estate bubbles? In this paper, we propose making use of information on the cross-sectional dispersion of real estate prices. During bubble periods, prices tend to go up considerably for some properties, but less so for others, so that price inequality across properties increases. In other words, a key characteristic of real estate bubbles is not the rapid price hike itself but a rise in price dispersion. Given this, the purpose of this paper is to examine whether developments in the dispersion in real estate prices can be used to detect bubbles in property markets as they arise, using data from Japan and the U.S. First, we show that the land price distribution in Tokyo had a power-law tail during the bubble period in the late 1980s, while it was very close to a lognormal before and after the bubble period. Second, in the U.S. data we find that the tail of the house price distribution tends to be heavier in those states which experienced a housing bubble. We also provide evidence suggesting that the power-law tail observed during bubble periods arises due to the lack of price arbitrage across regions.

      DOI： 10.1142/s2010194512007787

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    • Temporal and Cross Correlations in Business News Peer-reviewed

      Takayuki Mizuno, Kazumasa Takei, Takaaki Ohnishi, Tsutomu Watanabe

      Progress of Theoretical Physics Supplement194   181 - 192   2012

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      Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press (OUP)  

      DOI： 10.1143/ptps.194.181

      CiNii Article

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    • The dynamics and distribution of the area price in the Nord Pool Peer-reviewed

      Tsuruhiko Nambu, Takaaki Ohnishi

      Journal of Economic Interaction and Coordination5 ( 2 ) 181 - 189   12 2010

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      Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

      DOI： 10.1007/s11403-010-0067-5

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      Other Link： http://link.springer.com/article/10.1007/s11403-010-0067-5/fulltext.html

    • Network motifs in an inter-firm network Peer-reviewed

      Takaaki Ohnishi, Hideki Takayasu, Misako Takayasu

      Journal of Economic Interaction and Coordination5 ( 2 ) 171 - 180   12 2010

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      Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

      DOI： 10.1007/s11403-010-0066-6

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      Other Link： http://link.springer.com/article/10.1007/s11403-010-0066-6/fulltext.html

    • Structure analyses of a large-scale transaction network through visualization based on molecular dynamics Peer-reviewed

      K. Kamehama, T. Iino, H. Iyetomi, Y. Ikeda, T. Ohnishi, H. Takayasu, M. Takayasu

      Journal of Physics: Conference Series221 ( 1 ) 012013   2010

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      Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Physics Publishing  

      We shed light on industrial structure of the economic system in Japan by combining visualization technique and community analysis in this and an accompanying paper. Here we focus on visualization of a production network comprising submillion nodes (firms) and three million links (transaction relations). A network structure is optimized through molecular dynamics simulation with a spring-electrical model in a three-dimensional space. The lowest-energy state in the model, corresponding to a crystalline state in a physical system, is expected to give a comprehensible view on the network. Then we discuss how firms are distributed in the optimized network structure by classifying them according to sectors, sizes or regions. The distributions of firms reflect characteristics of individual classifications. Also propagation of the shock due to a recent economic scandal over the network is visualized. © 2010 IOP Publishing Ltd.

      DOI： 10.1088/1742-6596/221/1/012013

      Scopus

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    • Community structure in a large-scale transaction network and visualization Peer-reviewed

      T. Iino, K. Kamehama, H. Iyetomi, Y. Ikeda, T. Ohnishi, H. Takayasu, M. Takayasu

      Journal of Physics: Conference Series221 ( 1 ) 012012   2010

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      Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Physics Publishing  

      We analyze a transaction network of about 800 thousand Japanese firms to elucidate its community structure. Finding community in networks means the appearance of dense connected groups of vertices and sparse connections between groups. We adopt modularity as a quality function of communities introduced by Newman. The modularity optimization is one of effective approaches to find community. We first use a bottom-up algorithm, which makes the optimization fast by using a greedy algorithm. For the community extraction, the greedy algorithm is widely used, however, may not sufficiently optimize modularity because the optimization tends to be trapped by a local maximum especially for large-scale networks. Alternatively we propose a top-down algorithm with implementation of an annealing method and compare effectiveness of the two algorithms. We also compare the results of the community analysis with images of network structure visualized by molecular dynamics method. The vertices belonging to the same community are spatially located close to each other. The community structure determined by the modularity optimization is well reproduced in the network structure obtained by molecular dynamics. © 2010 IOP Publishing Ltd.

      DOI： 10.1088/1742-6596/221/1/012012

      Scopus

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    • Elucidation of Industrial Structure of the Japanese Economy through Visualization and Community Analysis

      H. Iyetomi, K. Kamehama, T. Iino, Y. Ikeda, T. Ohnishi, H. Takayasu, M. Takayasu

      In: Nakamatsu, K., Phillips-Wren, G., Jain, L.C., Howlett, R.J. (eds) New Advances in Intelligent Decision Technologies. Studies in Computational Intelligence199   645 - 652   2009

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      Publishing type：Part of collection (book)   Publisher：Springer Berlin Heidelberg  

      DOI： 10.1007/978-3-642-00909-9_62

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    • Hubs and Authorities on Japanese Inter-Firm Network: Characterization of Nodes in Very Large Directed Networks

      Takaaki Ohnishi, Hideki Takayasu, Misako Takayasu

      Progress of Theoretical Physics Supplement179   157 - 166   2009

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      Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press (OUP)  

      DOI： 10.1143/ptps.179.157

      CiNii Article

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    • Multicommunity weight-driven bipartite network model Peer-reviewed

      H. Fan, Z. Wang, T. Ohnishi, H. Saito, K. Aihara

      Physical Review E78 ( 2 ) 026103   8 8 2008

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      Publishing type：Research paper (scientific journal)   Publisher：American Physical Society (APS)  

      DOI： 10.1103/physreve.78.026103

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      Other Link： http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevE.78.026103/fulltext

    • Dynamics of quote and deal prices in the foreign exchange market Peer-reviewed

      Takaaki Ohnishi, Hideki Takayasu, Takatoshi Ito, Yuko Hashimoto, Tsutomu Watanabe, Misako Takayasu

      Journal of Economic Interaction and Coordination3 ( 1 ) 99 - 106   6 2008

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      Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

      DOI： 10.1007/s11403-008-0033-7

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      Other Link： http://link.springer.com/article/10.1007/s11403-008-0033-7/fulltext.html

    • Temporal characteristics of moving average of foreign exchange markets Peer-reviewed

      Misako Takayasu, Takayuki Mizuno, Takaaki Ohnishi, Hideki Takayasu

      in: Practical Fruits of Econophysics (Springer Verlag, 2006)   29 - 32   1 2006

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      Language：English   Publishing type：Research paper (scientific journal)  

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    • Systematic tuning of optimal weighted-moving-average of yen-dollar market data Peer-reviewed

      Takaaki Ohnishi, Takayuki Mizuno, Kazuyuki Aihara, Misako Takayasu, Hideki Takayasu

      in: Practical Fruits of Econophysics (Springer Verlag, 2006)   62 - 66   1 2006

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      Language：English   Publishing type：Research paper (scientific journal)  

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    • Statistical properties of the moving average price in dollar–yen exchange rates Peer-reviewed

      Takaaki Ohnishi, Takayuki Mizuno, Kazuyuki Aihara, Misako Takayasu, Hideki Takayasu

      Physica A: Statistical Mechanics and its Applications344 ( 1-2 ) 207 - 210   12 2004

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      Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

      DOI： 10.1016/j.physa.2004.06.118

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    ▼display all

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      大西立顕

      社会保障研究9 ( 1 ) 33 - 44   7 2024

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    • 遅れ時間座標系におけるマウスの脳波時系列データの順列エントロピーによる評価

      小山一樹, 坂口昌徳, 大西立顕

      信学技報 NLP2023-148123 ( 428 ) 119 - 122   3 2024

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      Authorship：Last author  

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    • ネット掲示板発言小町のLDAによるトピック分析

      川口 裕靖, 大西 立顕

      研究報告人文科学とコンピュータ（CH）2024-CH-134 ( 6 ) 1 - 8   2 2024

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      Authorship：Corresponding author  

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      小山一樹, 坂口昌徳, 大西立顕

      研究報告数理モデル化と問題解決（MPS）2024-MPS-147 ( 27 ) 1 - 6   2 2024

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      Authorship：Corresponding author  

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      土屋 健, 大西 立顕

      信学技報 NLP2023-102123 ( NLP-354 ) 90 - 93   1 2024

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      小山一樹, 坂口昌徳, 大西立顕

      信学技報 NLP2022-122122 ( 436 ) 75 - 80   3 2023

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      川口裕靖, 大西立顯

      進化経済学会論集 第27集   34 - 46   3 2023

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    • 中古マンションの価格と面積の関係の地域性

      柴田紘希, 大⻄立顕

      進化経済学会論集 第27集   18 - 33   3 2023

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    • 東証の株式市場における取引点過程の時系列解析

      伊藤真利子, 大西立顕, 本間裕大

      進化経済学会論集 第27集   1 - 16   3 2023

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    • 銀行送金ネットワークの内在的構造と時間変化 Invited

      久野 遼平, 長澤 達也, 高橋 秀, 近藤 亮磨, 大西 立顕

      人工知能38 ( 2 ) 131 - 138   1 3 2023

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    • 料理レシピに使用された材料時系列データのNMFによる解析

      小山一樹, 大西立顕

      研究報告人文科学とコンピュータ（CH）2023-CH-131 ( 5 ) 1 - 8   11 2 2023

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    • Correlation structure between time series of topics in newspaper articles and economic indicators

          33 - 49   3 2022

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    • Changes in the number of stores due to the influence of the new coronavirus using phone book data

          25 - 32   3 2022

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    • コロナ禍における電話帳データの登録店舗数の都道府県別変動調査

      齋藤紗季, 伊藤真利子, 大西立顕

      情報処理学会 第84回全国大会講演論文集4   863 - 864   3 2022

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    • 国勢調査とモバイル空間統計を用いた診療所の診療圏内の人口分布の推定

      伊藤毅, 大西立顕, 伊藤真利子

      情報処理学会 第84回全国大会講演論文集4   945 - 946   3 2022

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    • 畳み込みニューラルネットワークによるマウス脳波時系列からの睡眠ステージ分類

      宮城周, 伊藤真利子, 坂口昌徳, 大西立顕

      情報処理学会 第84回全国大会講演論文集4   993 - 994   3 2022

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    • 非負値行列因子分解によるマウス脳波のパワースペクトルの分類

      小山一樹, 伊藤真利子, 坂口昌徳, 大西立顕

      信学技報 NLP2021-147121 ( 444 ) 111 - 116   3 2022

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      Authorship：Last author  

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    • Taylor則を用いた属性別・時期別のPOSデータの解析

      小山一樹, 伊藤真利子, 大西立顕

      信学技報 NLP2021-57121 ( 307 ) 61 - 66   12 2021

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      Authorship：Last author  

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    • 離散幾何学とその周辺

      大西立顕

      数理科学 2021年12月号 No.70259 ( 12 ) 66 - 72   11 2021

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    • Random Forest Analysis of X-ray Diffraction and Scattering Data on Crystalline Polymer

      Kazuki K. TAKAHASHI, Yoshifumi AMAMOTO, Hiroteru KIKUTAKE, Mariko I. ITO, Atsushi TAKAHARA, Takaaki OHNISHI

      Journal of Computer Chemistry, Japan20 ( 3 ) 103 - 105   11 2021

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      Publisher：Society of Computer Chemistry Japan  

      DOI： 10.2477/jccj.2021-0042

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    • Prediction of Stress-Strain Curve of Block Copolymers Using Transfer Learning of 3D Convolutional Neural Network.

      Hironobu KAWAGUCHI, Mariko I. ITO, Takeshi AOYAGI, Takaaki OHNISHI

      Journal of Computer Chemistry, Japan20 ( 3 ) 100 - 102   11 2021

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      Publisher：Society of Computer Chemistry Japan  

      DOI： 10.2477/jccj.2021-0037

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      Mariko I. ITO, Yoshifumi AMAMOTO, Takaaki OHNISHI

      Journal of Computer Chemistry, Japan20 ( 3 ) 89 - 91   11 2021

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      Publisher：Society of Computer Chemistry Japan  

      DOI： 10.2477/jccj.2021-0040

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      Hironobu KAWAGUCHI, Mariko I. ITO, Sadato YAMANAKA, Takeshi AOYAGI, Takaaki OHNISHI

      Journal of Computer Chemistry, Japan19 ( 4 ) 136 - 138   4 2021

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      Publisher：Society of Computer Chemistry Japan  

      DOI： 10.2477/jccj.2021-0001

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    • 医療施設の診療圏内の年齢階級別人口分布とその時空間変化

      伊藤 毅, 伊藤 真利子, 大西 立顕

      情報処理学会 第83回全国大会講演論文集2021 ( 1 ) 447 - 448   3 2021

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    • LDAで求めた新聞記事のトピック割合と株価指数の関係性

      竹澤譲, 伊藤真利子, 大西立顕

      人工知能学会研究会資料 SIG-FIN-026   1 - 8   3 2021

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    • 高分子の高次構造特徴量ー物性相関としてのサイバーポリマー

      天本義史, 菊武裕晃, 大西立顕

      高分子70 ( 3 ) 133 - 134   3 2021

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    • 流動人口ビッグデータによる外出の自粛率の見える化

      水野 貴之, 大西 立顕, 渡辺 努

      人工知能35 ( 5 ) 667 - 672   9 2020

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    • ブロック共重合体のミクロ相分離構造に対するマルチフラクタル解析

      伊藤 真利子, 山中 貞人, 青柳 岳司, 大西 立顕

      Journal of Computer Chemistry, Japan18 ( 5 ) 214 - 216   1 2020

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    • 化合物空間の重み付きネットワーク解析

      伊藤 真利子, 大西 立顕

      ケモインフォマティクス討論会予稿集2019   1P19   10 2019

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    • トピック間の階層構造を考慮したGaussian LDAの構成

      吉田崇裕, 久野遼平, 大西立顕

      研究報告自然言語処理（NL)2019-NL-241 ( 6 ) 1 - 8   8 2019

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      大西立顕, 渡辺努

      数理科学 2019年6月号 No.67257 ( 6 ) 15 - 21   6 2019

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    • 不動産分野へのデータ解析と人工知能技術の応用

      和泉潔, 諏訪博彦, 大西立顕, 坂地泰紀, 松島裕康

      不動産テックを考える，赤木正幸，浅見泰司，谷山智彦編，プログレス   75 - 89   5 2019

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    • 電話帳データを活用した買い物・医療困難地域の検出

      大西立顕, 水野貴之, 渡辺努

      計測自動制御学会 システム・情報部門社会システム部会 第18回社会システム部会研究会資料   174   3 2019

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    • 隠れマルコフモデルとランダムフォレストによるマウスの睡眠ステージ判定

      松崎舜, 坂口昌徳, 大西立顕

      信学技報 NLP2018-123118 ( 413 ) 143 - 148   1 2019

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      Language：Japanese  

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    • 物理による社会学

      F. シュヴァイツァー著, 大西立顕訳

      パリティ 2018年12月号33 ( 12 ) 30 - 38   12 2018

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    • ランダムフォレストによるマウス脳波時系列を用いた睡眠ステージ判定

      松崎舜, 坂口昌徳, 大西 立顕

      研究報告数理モデル化と問題解決（MPS）2018-MPS-120 ( 12 ) 1 - 6   9 2018

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    • 国勢調査と電話帳データから推定した全国における高齢者の生活環境の地域差

      大西立顕, 水野貴之, 渡辺努

      研究報告高齢社会デザイン（ASD）2018-ASD-12 ( 2 ) 1 - 5   6 2018

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    • 臨界現象の研究による経済制御の可能性

      大西立顕

      全・地球学1996-2017 フォーラム「地球学の世紀」22年 134人の知の試み，松井孝典監修   446 - 447   3 2018

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    • 電話帳データから観測した都市の成長・衰退のダイナミクス

      大西立顕, 水野貴之, 渡辺努

      計測自動制御学会 システム・情報部門社会システム部会 第15回社会システム部会研究会資料   247   3 2018

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    • 位置情報ビッグデータによるデモ参加者の人流解析

      水野貴之, 大西立顕, 渡辺努

      計測自動制御学会 システム・情報部門社会システム部会 第15回社会システム部会研究会資料   9 - 13   3 2018

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    • 金融ビッグデータによるバブルの早期警戒技術

      水野 貴之, 大西 立顕, 渡辺 努

      情報処理学会 第79回全国大会講演論文集2017 ( 1 ) 219 - 220   3 2017

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    • 類似企業の株価差を利用した株式バブルのナウキャスト

      水野貴之, 大西立顕, 渡辺努

      計測自動制御学会 システム・情報部門社会システム部会 第12回社会システム部会研究会資料   107   3 2017

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    • 世界の株式市場の相関構造分析

      木村笙子, 大西立顕

      計測自動制御学会 システム・情報部門社会システム部会 第12回社会システム部会研究会資料   169 - 176   3 2017

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    • 位置情報付きTwitterデータから算出した都市間の人の移動ネットワーク

      大西立顕, 水野貴之, 渡辺努

      計測自動制御学会 システム・情報部門社会システム部会 第12回社会システム部会研究会資料   246   3 2017

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    • 正規分布とベキ分布 経済物理学の基礎知識

      大西立顕

      週刊エコノミスト2016年5月31日号   26   5 2016

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    • 経済学が目を背けてきたバブル ゆらぎで定量化に成功

      大西立顕

      週刊エコノミスト2016年5月31日号   30 - 31   5 2016

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    • 電話帳データを活用した都市のスケーリング指数の観測

      大西 立顕, 水野 貴之, 清水 千弘, 渡辺 努

      人工知能学会第二種研究会資料2016 ( BI-004 ) 8   3 2016

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    • 移住と人口密度の相関の普遍性

      藤本祥二, 大西立顕, 清水千弘, 水野貴之, 渡辺努

      統計数理研究所共同研究リポート360 経済物理とその周辺(360)   39 - 47   3 2016

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    • k近傍法による中古マンション売買価格の分析

      大西立顕, 水野貴之, 清水千弘, 渡辺努

      統計数理研究所共同研究リポート360 経済物理とその周辺(360)   66 - 69   3 2016

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    • データサイエンティスト育成と利活用のベスト・プラクティス

      丸山宏, 神谷直樹, 樋口知之, 竹村彰道, 大西立顕

      情報処理学会デジタルプラクティス6 ( 3 ) 223 - 229   7 2015

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    • 中古マンション売買データを用いた同一需給圏と不動産バブルの推定

      大西立顕, 水野貴之, 清水千弘, 家富洋, 渡辺努

      SICEシステム・情報部門社会システム部会第8回社会システム部会研究会資料   107 - 112   3 2015

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    • 実データを用いた企業間振込ネットワークにおけるページランクと振込総額の統計性とその応用

      石井晃, 大西立顕, 新井康平, 大浦啓輔, 戸谷圭子

      SICEシステム・情報部門社会システム部会第7回社会システム部会研究会資料   53 - 58   9 2014

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    • 日本の人口分布と可住地面積分布のスケーリング則と河川地形の関係

      藤本祥二, 大西立顕, 清水千弘, 水野貴之, 渡辺努

      統計数理研究所共同研究リポート311 経済物理とその周辺(10)   82 - 90   3 2014

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    • 企業間振込ネットワークにおけるページランクと振込総額の統計性

      大西立顕, 石井晃

      統計数理研究所共同研究リポート311 経済物理とその周辺(10)   64 - 68   3 2014

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    • スケールフリーネットワーク

      大西立顕

      応用数理ハンドブック，薩摩順吉，大石進一，杉原正顕編，朝倉書店   248 - 249   11 2013

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    • 経済ネットワークの数理

      大西立顕

      横幹7 ( 2 ) 100 - 107   10 2013

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    • 米国における住宅の価格分布と差押え率

      大西立顕, 水野貴之, 清水千弘, 家富洋, 渡辺努

      統計数理研究所共同研究リポート292 経済物理とその周辺(9)   8 - 11   3 2013

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    • 日本の人口分布と可住地面積分布のスケーリング則

      藤本祥二, 大西立顕, 清水千弘, 水野貴之, 渡辺努

      統計数理研究所共同研究リポート292 経済物理とその周辺(9)   12 - 18   3 2013

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    • 非定常性に挑む外国為替市場の科学

      大西立顕

      システム/制御/情報:システム制御情報学会誌56 ( 10 ) 550 - 555   10 2012

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    • 日本に於ける人口分布・可住地分布のクラスタ解析

      藤本祥二, 大西立顕, 清水千弘, 水野貴之, 渡辺努

      統計数理研究所共同研究リポート271 経済物理とその周辺(8)   57 - 63   3 2012

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    • 円ドル為替レートの非定常性

      大西立顕, 高安秀樹, 伊藤隆敏, 橋本優子, 渡辺努, 高安美佐子

      統計数理研究所共同研究リポート271 経済物理とその周辺(8)   64 - 69   3 2012

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    • 企業間取引ネットワークの role 解析

      大西立顕, 高安秀樹, 高安美佐子

      統計数理研究所共同研究リポート259 経済物理とその周辺(7)   55 - 59   3 2011

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    • 最適移動平均で求める変動の実相

      大西立顕

      金融財政ビジネス, 時事通信社, 2010年12月9日 第10128号   10 - 12   12 2010

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    • 企業間取引ネットワークのページランク

      大西立顕, 高安秀樹, 高安美佐子

      情報処理学会研究報告2010-MPS-81   1 - 3   12 2010

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    • 企業間ネットワークの数理構造

      大西立顕, 高安秀樹, 高安美佐子

      応用数理20 ( 3 ) 37 - 49   9 2010

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    • 企業間取引ネットワークのモチーフ構造

      大西立顕, 高安秀樹, 高安美佐子

      統計数理研究所共同研究リポート241 経済物理とその周辺(6)   63 - 67   3 2010

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    • 企業の評価 新たな視点で

      大西立顕

      日経・経済教室セレクション2, 日本経済新聞社編, 日本経済新聞出版社   418 - 422   3 2010

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    • 企業間取引の大規模ネットワーク構造からみた企業の特徴

      大西立顕

      東京大学情報基盤センター・スーパーコンピューティングニュース12 ( Special Issue 1 ) 95 - 106   2 2010

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    • Mathematical analysis of large-scale business and economic data（大規模データから探る経済現象の数理）

      Takaaki Ohnishi

      Mathematical Bulletin of the Graduate School of Science Josai University（城西大学大学院理学研究科研究業績集（数学専攻））11   97 - 131   5 2009

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    • 分子動力学法を用いた企業間取引の有向ネットワーク構造の可視化

      亀浜紘祐, 飯野隆史, 家富洋, 池田裕一, 大西立顕, 高安秀樹, 高安美佐子

      統計数理研究所共同研究リポート226 経済物理とその周辺(5)   74 - 86   3 2009

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    • 大規模取引ネットワークのコミュニティ分析

      飯野隆史, 小林祐貴, 亀浜紘祐, 家富洋, 池田裕一, 大西立顕, 高安秀樹, 高安美佐子

      統計数理研究所共同研究リポート226 経済物理とその周辺(5)   56 - 63   3 2009

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    • 円ドル為替市場における指値価格と約定価格の統計性

      大西立顕, 高安秀樹, 伊藤隆敏, 橋本優子, 渡辺努, 高安美佐子

      統計数理研究所共同研究リポート226 経済物理とその周辺(5)   32 - 39   3 2009

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    • ページランクとオーソリティ・ハブによる企業間取引の有向ネットワーク解析

      大西立顕, 高安秀樹, 高安美佐子

      統計数理研究所共同研究リポート226 経済物理とその周辺(5)   23 - 31   3 2009

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    • Unscented Kalman Filterを用いた外国為替時系列の非線形性の考察と局所２次近似予測法の提案

      永田育真, 大西立顕, 合原一幸

      統計数理研究所共同研究リポート226 経済物理とその周辺(5)   9 - 22   3 2009

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    • 経済データの数理

      大西立顕

      社会を変える驚きの数学, 合原一幸編著, ウェッジ選書   216 - 220   6 2008

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    • 市場分断が常態化するノルドプールの卸電力価格形成の実状

      南部鶴彦, 大西立顕

      エネルギーフォーラム 第54巻641号   70 - 74   5 2008

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    • 北欧電力卸売市場の経済物理学的解析

      大西立顕, 水野貴之, 大藤健太, 南部鶴彦

      社会経済研究56   15 - 24   2 2008

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    • 市場価格時系列のトレンド抽出

      大西立顕, 合原一幸, 高安美佐子, 高安秀樹

      統計数理研究所共同研究リポート187 経済物理とその周辺(2)   1 - 9   3 2006

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    • 最適移動平均した為替レートの統計性

      水野貴之, 大西立顕, 中野徹, 高安美佐子, 高安秀樹

      第５９回日本物理学会講演概要集、第２分冊2   p.199   9 2004

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    • 為替の移動平均価格の統計的特性

      大西立顕, 合原一幸, 高安美佐子, 高安秀樹

      素粒子論研究108 ( 4 ) D24   1 2004

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    • 市場価格変動のスピンモデル

      大西立顕, 合原一幸

      信学技報 NLP2002-19   69 - 72   6 2002

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    • 株価変動のマルチフラクタル解析

      大西立顕, 合原一幸

      信学技報 NLP2001-114   93 - 100   3 2002

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    • 時空間学習とニューロンの応答特性

      大西立顕, 合原一幸

      信学技報 NLP2000-42 NC2000-36   87 - 94   6 2000

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    Books and Other Publications

    • ネットワーク学習から経済と法分析へ

      久野, 遼平, 大西, 立顕, 渡辺, 努

      サイエンス社  6 2024  （ ISBN:9784781916040 ）

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      Total pages：xi, 215p   Language：Japanese

      CiNii Books

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    Presentations

    • Indicator of the Number of Stores and Facilities Suitable for Urban Population Using Scaling Exponents

      Takaaki Ohnishi, Takayuki Mizuno, Tsutomu Watanabe

      Social Informatics 2019  11 2019 

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    • Applying a Change-point Detection Method to Housing Market Data

      Takaaki Ohnishi, Takayuki Mizuno, Tsutomu Watanabe

      Conference on Complex Systems 2019  10 2019 

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    • Dimension Reduction of Molecular Fingerprints

      Takaaki Ohnishi, Mariko Ito

      Conference on Complex Systems 2019  10 2019 

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    • Using two-dimensional Kolmogorov-Smirnov statistics to characterize allometric scaling between population and number of facilities

      Takaaki Ohnishi, Takayuki Mizuno, Tsutomu Watanabe

      FENS 2019 - 10th Polish Symposium on Physics in Economy and Social Sciences  7 2019 

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    • Continuous increases or decreases in city sizes observed in Japanese telephone directory data

      Takaaki Ohnishi, Takayuki Mizuno, Tsutomu Watanabe

      DPG Spring Meeting  2 4 2019 

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    • Directional patterns of city size changes in Japan International conference

      Takaaki Ohnishi, Takayuki Mizuno, Tsutomu Watanabe

      The Computational Social Science Society of the Americas CSS 2018  10 2018 

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      Language：English   Presentation type：Poster presentation  

      Venue：Santa Fe, NM  

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    • The dynamics of city growth observed in Japanese telephone directory data International conference

      Takaaki Ohnishi, Takayuki Mizuno, Tsutomu Watanabe

      Conference on Complex Systems 2018  9 2018 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Thessaloniki, Greece  

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    • Statistical laws of urban development and decline International conference

      Takaaki Ohnishi, Takayuki Mizuno, Tsutomu Watanabe

      The 23rd Annual Workshop on Economic Science with Heterogeneous Interacting Agents (WEHIA 2018)  6 2018 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：International Christian University (ICU), Japan  

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    • Quantification of spatial collocation patterns of shops and facilities using the two-dimensional Kolmogorov-Smirnov statistic International conference

      Takaaki Ohnishi, Takayuki Mizuno, Tsutomu Watanabe

      13th German Probability and Statistics Days 2018  2 2018 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Freiburg, Germany  

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    • Three State Model for Temporal Network Change Detection International conference

      Chikara Mizokami, Takaaki Ohnishi

      NetSci-X 2018: International School and Conference on Network Science  1 2018 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Hangzhou, China  

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    • Use of the two-dimensional Kolmogorov-Smirnov test to measure spatial concentration in geospatial data International conference

      Takaaki Ohnishi, Takayuki Mizuno, Tsutomu Watanabe

      11th International Conference on Computational and Financial Econometrics (CFE 2017)  12 2017 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：London, UK  

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    • Revealing Persistent Structure of International Trade by Nonnegative Matrix Factorization International conference

      Chikara Mizokami, Takaaki Ohnishi

      COMPLEX NETWORKS 2017: The 6th International Conference on Complex Networks and Their Applications  11 2017 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Lyon, France  

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    • Irresponsible communities in global supply chain International conference

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      COMPLEX NETWORKS 2017: The 6th International Conference on Complex Networks and Their Applications  11 2017 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Lyon, France  

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    • International Trade Relationship from a Multilateral Point of View International conference

      Hiroshi Iyetomi, Yuichi Ikeda, Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      COMPLEX NETWORKS 2017: The 6th International Conference on Complex Networks and Their Applications  11 2017 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Lyon, France  

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    • How to guard company's supply-chain risks by global inter-firm relationships International conference

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      Conference on Complex Systems 2017  9 2017 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Cancun, Mexico  

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    • Characteristic Spatial Interaction between Shops and Facilities in Japan International conference

      Takaaki Ohnishi, Takayuki Mizuno, Tsutomu Watanabe

      Conference on Complex Systems 2017  9 2017 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Cancun, Mexico  

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    • Using Network Motif Analysis to Characterize the International Trade Network International conference

      T. Ohnishi, T. Mizuno, Y. Ikeda, H. Iyetomi, T. Watanabe

      SigmaPhi2017  7 2017 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Corfu, Greece  

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    • Exploiting global buyer-supplier networks to improve supply chain due diligence International conference

      T. Mizuno, T. Ohnishi, T. Watanabe

      SigmaPhi2017  7 2017 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Corfu, Greece  

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    • A countermeasure for supply-chain risks based on structure of global buyer-supplier network International conference

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      8th Conference on Complex Networks (CompleNet'17)  3 2017 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Dubrovnik, Croatia  

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    • Daily living area detection using mobility network map equation International conference

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      COMPLEX NETWORKS 2016: The 5th International Conference on Complex Networks and Their Applications  11 2016 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Milan, Italy  

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    • Scaling relations between population and number of facilities International conference

      Takaaki Ohnishi, Takayuki Mizuno, Tsutomu Watanabe

      Dynamics Days Latin America and the Caribbean  10 2016 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Puebla, Mexico  

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    • Scaling analysis of urban agglomeration observed in Japanese phone directory data International conference

      Takaaki Ohnishi, Takayuki Mizuno, Tsutomu Watanabe

      Conference on Complex Systems 2016  9 2016 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Amsterdam, Netherlands  

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    • Study of Quantitative Indicators for Urban Renewal by Utilizing Cultural Policy in Depopulated Areas International conference

      Yasuko Kawahata, Takaaki Ohnishi

      Asia-Pacific Econophysics Conference 2016  8 2016 

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      Language：English   Presentation type：Poster presentation  

      Venue：Tokyo, Japan  

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    • Characterizing industry agglomeration in Japan using urban allometric scaling International conference

      Takaaki Ohnishi, Takayuki Mizuno, Tsutomu Watanabe

      Challenges in Data Science  7 2016 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Matera, Italy  

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    • Power Law of Market Capitalization and Stock Market Bubble International conference

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      22nd International Conference on Computing in Economics and Finance (CEF 2016)  6 2016 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Bordeaux, France  

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    • Urban scaling observed in Japanese telephone book data International conference

      Takaaki Ohnishi, Takayuki Mizuno, Chihiro Shimizu, Tsutomu Watanabe

      80th Annual Conference of the DPG  3 2016 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Regensburg, Germany  

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    • Real estate valuation using k-nearest neighbor regression International conference

      Takaaki Ohnishi, Takayuki Mizuno, Chihiro Shimizu, Hiroshi Iyetomi, Tsutomu Watanabe

      Econophysics-2015  12 2015 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：New Delhi, India  

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    • Inter-firm money transfers: a weighted network analysis International conference

      Michiaki Nakaya, Takaaki Ohnishi, Akira Ishii, Keiko Toya

      Challenges in Data Science: a Complex Systems Perspective  10 2015 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Torino, Italy  

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    • Footprints of conflict minerals on global supply-chain network International conference

      Takayuki Mizuno, Takaaki Ohnishi, Hiroshi Iyetomi, Yuichi Ikeda, Tsutomu Watanabe

      Challenges in Data Science: a Complex Systems Perspective  10 2015 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Torino, Italy  

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    • Using k-nearest neighbor method to estimate real estate prices International conference

      Takaaki Ohnishi, Takayuki Mizuno, Chihiro Shimizu, Hiroshi Iyetomi, Tsutomu Watanabe

      Econophysics Colloquium 2015  9 2015 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Prague, Czech Republic  

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    • Structure of global buyer-supplier networks and its implications for conflict minerals regulations International conference

      Takayuki Mizuno, Takaaki Ohnishi, Hiroshi Iyetomi, Yuichi Ikeda, Tsutomu Watanabe

      CCS'15  9 2015 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Tempe, Arizona  

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    • Relationship between job opportunities and economic environments measured from data in internet job searching sites International conference

      Aki-Hiro Sato, Chihiro Shimizu, Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      19th International Conference on Knowledge-Based and Intelligent Information & Engineering Systems (KES2015)  9 2015 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Singapore  

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    • Estimating the Size of Market Areas and Bubbles in the Japanese Housing Market International conference

      Takaaki Ohnishi, Takayuki Mizuno, Chihiro Shimizu, Hiroshi Iyetomi, Tsutomu Watanabe

      CCS'15  9 2015 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Tempe, Arizona  

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    • Probable contribution of Data-driven investigation to solve problems in aging society International conference

      Aki-Hiro Sato, Chihiro Shimizu, Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      Asia-Pacific Econophysics Conference 2015  7 2015 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Singapore  

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    • Network Motifs in the World Trade Network International conference

      Takaaki Ohnishi, Takayuki Mizuno, Yuichi Ikeda, Hiroshi Iyetomi, Tsutomu Watanabe

      NetSci2015  6 2015 

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      Language：English   Presentation type：Poster presentation  

      Venue：Zaragoza, Spain  

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    • Estimating firm-level risk in global inter-firm networks International conference

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      NetSci2015  6 2015 

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      Language：English   Presentation type：Poster presentation  

      Venue：Zaragoza, Spain  

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    • Community Structure and Synchronization of the Industry Sector Specific Trade Network International conference

      Yuichi Ikeda, Hiroshi Iyetomi, Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      NetSci2015  6 2015 

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      Language：English   Presentation type：Poster presentation  

      Venue：Zaragoza, Spain  

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    • Global inter-firm networks and stock price correlations International conference

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      6th Workshop on Complex Networks  3 2015 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：New York City, New York  

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    • Identification of network effect in the buyer-seller network International conference

      R. Hisano, T. Mizuno, T. Ohnishi, T. Watanabe

      8th International Conference on Computational and Financial Econometrics (CFE 2014)  12 2014 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Pisa, Italy  

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    • Financial bubble detection using cross-sectional dispersion of price earnings ratios International conference

      T. Mizuno, T. Ohnishi, T. Watanabe

      8th International Conference on Computational and Financial Econometrics (CFE 2014)  12 2014 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Pisa, Italy  

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    • The structure of global inter-firm networks International conference

      Takayuki Mizuno, Takaaki Ohnishi, Tsutom Watanabe

      SEDNAM: Socio-Economic Dynamics, Networks and Agent-based Models  11 2014 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Barcelona, Spain  

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    • Community Structure and Dynamics of the Industry Sector Specific International Trade Network International conference

      Yuichi Ikeda, Hiroshi Iyetomi, Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      The 10th International Conference on Signal Image Technology & Internet Based Systems  11 2014 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Marrakesh, Morocco  

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    • Empirical Agent-Based Modeling for Customer Portfolio Management: A Case of a Regional B2B Financial Service in Japan International conference

      Makoto Mizuno, Kohei Arai, Akira Ishii, Yutaro Nemoto, Takaaki Ohnishi, Kosuke Oura, Kanako Ozawa, Keiko Toya

      6th Annual Complexity in Business Conference  10 2014 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Washington, D.C.  

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    • The structure of global inter-firm networks International conference

      Takayuki Mizuno, Takaaki Ohnishi, Tsutom Watanabe

      Complex Networks in International Economics (Satellite meeting of ECCS'14)  9 2014 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Lucca, Italy  

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    • Simulating Value Co-Creation in B2B Financial Service: An Application of Empirical Agent-Based Modeling International conference

      Makoto Mizuno, Keiko Toya, Kana Ozawa, Mayomi Haga, Yutaro Nemoto, Kohei Arai, Keisuke Oura, Akira Ishii, Takaaki Ohnishi

      Social Simulation Conference 2014 (SSC2014)  9 2014 

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      Language：English   Presentation type：Poster presentation  

      Venue：Barcelona, Spain  

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    • Network Analysis of inter-firm payment flows using real monetary transaction records between firms International conference

      T. Ohnishi, A. Ishii, K. Arai, K. Oura, K. Toya

      The 2nd international conference on Serviceology (ICServ2014)  9 2014 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Yokohama, Japan  

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    • Locality and universality of population distribution International conference

      S. Fujimoto, T. Mizuno, T. Ohnishi, C. Shimizu, T. Watanabe

      Computationally Intensive Methods in Statistics and Econometrics (Satellite meeting of COMPSTAT 2014)  8 2014 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Neuchtel, Switzerland  

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    • Large scale empirical analysis of buyer-seller network and its role in the business cycle International conference

      R. Hisano, T. Mizuno, T. Ohnishi, T. Watanabe

      Computationally Intensive Methods in Statistics and Econometrics (Satellite meeting of COMPSTAT 2014)  8 2014 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Neuchtel, Switzerland  

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    • Forecasting volatility using financial big data sets International conference

      T. Mizuno, T. Ohnishi, T. Watanabe

      Computationally Intensive Methods in Statistics and Econometrics (Satellite meeting of COMPSTAT 2014)  8 2014 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Neuchtel, Switzerland  

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    • Network analysis of inter-firm payment flows using real monetary transaction records between firms International conference

      T. Ohnishi, A. Ishii, K. Arai, K. Oura, K. Toya

      International Conference on Statistical Physics (SigmaPhi 2014)  7 2014 

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      Language：English   Presentation type：Poster presentation  

      Venue：Rhodes, Greece  

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    • Exogenous shocks in financial markets: Novelty and topicality detection in business news International conference

      T. Mizuno, T. Ohnishi, T. Watanabe

      International Conference on Statistical Physics (SigmaPhi 2014)  7 2014 

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      Language：English   Presentation type：Poster presentation  

      Venue：Rhodes, Greece  

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    • Community Structure and Wealth Transfer on Trade Network International conference

      Yuichi Ikeda, Hiroshi Iyetomi, Tsutomu Watanabe, Takaaki Ohnishi, Takayuki Mizuno

      NetSci2014  6 2014 

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      Language：English   Presentation type：Poster presentation  

      Venue：Berkeley, California  

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    • Applying PageRank to interfirm money transfer network International conference

      Takaaki Ohnishi, Akira Ishii, Keiko Toya

      NetSci2014  6 2014 

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      Language：English   Presentation type：Poster presentation  

      Venue：Berkeley, California  

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    • Use of house price distribution for estimating a local bubble indicator International conference

      Takaaki Ohnishi, Takayuki Mizuno, Chihiro Shimizu, Hiroshi Iyetomi, Tsutomu Watanabe

      11th German Probability and Statistics Days 2014  3 2014 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Ulm, Germany  

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    • Financial market reactions to exogenous shocks International conference

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      ECONOPHYS-KOLKATA VIII  3 2014 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Kolkata, India  

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    • Exogenous shocks in financial markets: Statistical analysis using business news International conference

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      11th German Probability and Statistics Days 2014  3 2014 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Ulm, Germany  

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    • Network analysis of inter-firm payment flows International conference

      Takaaki Ohnishi, Akira Ishii

      ESHIA Winter Workshop 2013  11 2013 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Singapore  

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    • Estimating the Effects of Exogenous Shocks Using Business News and Stock Market Data International conference

      Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      ESHIA Winter Workshop 2013  11 2013 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Singapore  

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    • Measuring the likelihood of housing bubbles: a spatio-temporal analysis International conference

      Takaaki Ohnishi, Takayuki Mizuno, Chihiro Shimizu, Hiroshi Iyetomi, Tsutomu Watanabe

      European Conference on Complex Systems 2013  9 2013 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Barcelona, Spain  

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    • The Mechanism behind Power-Law Distribution of Housing Prices International conference

      Takaaki Ohnishi, Takayuki Mizuno, Chihiro Shimizu, Hiroshi Iyetomi, Tsutomu Watanabe

      Statphys 25  7 2013 

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      Language：English   Presentation type：Poster presentation  

      Venue：Seoul, Korea  

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    • Colored Motifs in Japanese Inter-firm Network International conference

      Takaaki Ohnishi, Hideki Takayasu, Misako Takayasu

      4th Workshop on Complex Networks  3 2013 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Berlin, Germany  

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    • Using Property Price Distribution to Detect Real Estate Bubbles International conference

      Takaaki Ohnishi, Takayuki Mizuno, Chihiro Shimizu, Tsutomu Watanabe

      6th CSDA International Conference on Computational and Financial Econometrics (CFE 2012)  12 2012 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Oviedo, Spain  

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    • Spatial Heterogeneity and Real Estate Bubble Invited International conference

      Takaaki Ohnishi

      ECONOPHYS-KOLKATA VII  11 2012 

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      Language：English   Presentation type：Oral presentation (invited, special)  

      Venue：Kolkata, India  

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    • Structure and function of inter-firm relationships revealed by network motif analysis International conference

      Takaaki Ohnishi, Hideki Takayasu, Misako Takayasu

      XXXII Dynamics Days Europe  9 2012 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Gothenburg, Sweden  

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    • Replication of Non-Trivial Directional Motion in Multi-Scales Observed by Runs Test International conference

      Yoshihiro Yura, Takaaki Ohnishi, Hideki Takayasu, Misako Takayasu

      Latsis Symposium 2012  9 2012 

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      Language：English   Presentation type：Poster presentation  

      Venue：Zurich, Switzerland  

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    • Habitable Area Distributions as a External Factor of the Population Distributions in Japan International conference

      Shouji Fujimoto, Takayuki Mizuno, Takaaki Ohnishi, Chihiro Shimizu, Tsutomu Watanabe

      XXXII Dynamics Days Europe  9 2012 

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      Language：English   Presentation type：Poster presentation  

      Venue：Gothenburg, Sweden  

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    • Using Network Motif Analysis to Characterize Inter-firm Transactions International conference

      Takaaki Ohnishi, Hideki Takayasu, Misako Takayasu

      NetSci2012  6 2012 

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      Language：English   Presentation type：Poster presentation  

      Venue：Evanston, Ilinois  

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    • Social Networks in Business News International conference

      Takayuki Mizuno, Ryohei Hisano, Takaaki Ohnishi, Tsutomu Watanabe

      17th Annual Workshop on Economic Heterogeneous Interacting Agents  6 2012 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Paris, France  

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    • Habitable Area Distribution as Conditional of Population Distribution International conference

      Shouji Fujimoto, Takayuki Mizuno, Takaaki Ohnishi, Chihiro Shimizu, Tsutomu Watanabe

      17th Annual Workshop on Economic Heterogeneous Interacting Agents  6 2012 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Paris, France  

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    • House price distribution and bubbles in Japan and the U.S. International conference

      Takaaki Ohnishi, Takayuki Mizuno, Chihiro Shimizu, Tsutomu Watanabe

      10th German Probability and Statistics Days 2012  3 2012 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Mainz, Germany  

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    • Time-frequency analysis of company news International conference

      Takayuki Mizuno, Kazumasa Takei, Takaaki Ohnishi, Tsutomu Watanabe

      European Conference on Complex Systems 2011  9 2011 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Vienna, Austria  

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    • Recurrence interval analysis of high-frequency returns on foreign exchange International conference

      Takaaki Ohnishi, Hideki Takayasu, Takatoshi Ito, Yuko Hashimoto, Tsutomu Watanabe, Misako Takayasu

      European Conference on Complex Systems 2011  9 2011 

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      Language：English   Presentation type：Poster presentation  

      Venue：Vienna, Austria  

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    • Cluster analysis of the population in Japan International conference

      Shouji Fujimoto, Chihiro Shimizu, Takayuki Mizuno, Takaaki Ohnishi, Tsutomu Watanabe

      European Conference on Complex Systems 2011  9 2011 

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      Language：English   Presentation type：Poster presentation  

      Venue：Vienna, Austria  

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    • On the evolution of the house price distribution Invited International conference

      Takaaki Ohnishi

      the 58th World Statistics Congress of the International Statistical Institute (ISI)  8 2011 

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      Language：English   Presentation type：Oral presentation (invited, special)  

      Venue：Dublin, Ireland  

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    • Characteristics of bubble in house price distribution of Japan International conference

      Takaaki Ohnishi, Takayuki Mizuno, Chihiro Shimizu, Tsutomu Watanabe

      International Conference on Statistical Physics (SigmaPhi 2011)  7 2011 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Larnaca, Cyprus  

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    • Time-frequency analysis of company news International conference

      Takayuki Mizuno, Kazumasa Takei, Takaaki Ohnishi, Tsutomu Watanabe

      International Workshop on Coping Crises in Complex Socio-Economic Systems  6 2011 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Zurich, Switzerland  

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    • Detection of bubbles in Japanese house prices International conference

      Takaaki Ohnishi, Takayuki Mizuno, Chihiro Shimizu, Tsutomu Watanabe

      International Workshop on Coping with Crises in Complex Socio-Economic Systems 2011  6 2011 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Zurich, Switzerland  

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    • A comprehensive directional motion analysis of market fluctuations International conference

      Takaaki Ohnishi, Hideki Takayasu, Takatoshi Ito, Yuko Hashimoto, Tsutomu Watanabe, Misako Takayasu

      International Conference on Econophysics 2011  6 2011 

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      Language：English   Presentation type：Poster presentation  

      Venue：Shanghai, China  

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    • The market impact of company news in NYSE International conference

      Takayuki Mizuno, Kazumasa Takei, Takaaki Ohnishi, Tsutomu Watanabe

      First Workshop on Quantitative Finance and Economics  2 2011 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Tokyo, Japan  

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    • Detecting and analyzing nonstationarity in foreign exchange market International conference

      Takaaki Ohnishi, Hideki Takayasu, Takatoshi Ito, Yuko Hashimoto, Tsutomu Watanabe, Misako Takayasu

      Econophysics Colloquium 2010  11 2010 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Taipei, Taiwan  

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    • PageRank for characterizing growth possibility in Japanese inter-firm network International conference

      Takaaki Ohnishi, Hideki Takayasu, Misako Takayasu

      2nd Workshop on Complex Networks  10 2010 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Rio de Janeiro, Brazil  

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    • Structural motif-based classification of nodes in Japanese inter-firm network International conference

      Takaaki Ohnishi, Hideki Takayasu, Misako Takayasu

      Statphys 24  7 2010 

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      Language：English   Presentation type：Poster presentation  

      Venue：Cairns, Australia  

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    • The role of strongly-connected components in the network of Japanese companies International conference

      S. Sameshima, T. Ohnishi, H. Takayasu, M. Takayasu

      Applications of Physics in Financial Analysis 7  3 2009 

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      Language：English   Presentation type：Poster presentation  

      Venue：Tokyo, Japan  

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    • Network Motifs in Inter-firm Network International conference

      T. Ohnishi, H. Takayasu, M. Takayasu

      Applications of Physics in Financial Analysis 7  3 2009 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Tokyo, Japan  

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    • Dynamics of deal price in foreign exchange market International conference

      Takaaki Ohnishi, Hideki Takayasu, Takatoshi Ito, Yuko Hashimoto, Tsutomu Watanabe, Misako Takayasu

      Econophysics Colloquium and Third Bonzenfreies Colloquium  11 2006 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Tokyo, Japan  

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    • Characterization of Temporal Behavior of Foreign Exchange Markets International conference

      Misako Takayasu, Takaaki Ohnishi, Takayuki Mizuno, Hideki Takayasu

      First International Workshop on Intelligent Finance, A Convergence of Mathematical Finance with Technical and Fundamental Analysis  12 2004 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Melbourne, Australia  

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    • Systematic tuning of optimal weighted-moving-average of yen-dollar market data International conference

      Takaaki Ohnishi, Takayuki Mizuno, Kazuyuki Aihara, Misako Takayasu, Hideki Takayasu

      The Third Nikkei Econophysics Symposium -Practical Fruits of Econophysics-  11 2004 

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      Language：English   Presentation type：Poster presentation  

      Venue：Tokyo, Japan  

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    • Statistical properties of the moving average price in dollar-yen exchange rates International conference

      Takaaki Ohnishi, Kazuyuki Aihara, Misako Takayasu, Hideki Takayasu

      Applications of Physics in Financial Analysis 4  11 2003 

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      Language：English   Presentation type：Poster presentation  

      Venue：Warsaw, Poland  

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    • Neural Response and Spatio-temporal Learning International conference

      Takaaki Ohnishi, Kazuyuki Aihara

      International Symposium on Nonlinear Theory and its Applications 2001  10 2001 

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      Language：English   Presentation type：Oral presentation (general)  

      Venue：Miyagi, Japan  

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    Professional Memberships

    •  
      JAPAN ASSOCIATION FOR EVOLUTIONARY ECONOMICS

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      INFORMATION PROCESSING SOCIETY OF JAPAN

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      JAPANESE ECONOMIC ASSOCIATION

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      THE PHYSICAL SOCIETY OF JAPAN

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    Research Projects

    • 地理空間ビッグデータとスパコンを用いた高齢者の生活基盤評価

      日本学術振興会  科学研究費補助金 挑戦的研究(萌芽) 

      大西 立顕

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      6 2019 - 3 2022

      Authorship：Principal investigator  Grant type：Competitive

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    • 複雑ネットワーク解析に基づく物質・材料探索

      文部科学省  科学研究費補助金 新学術領域研究(研究領域提案型) 

      大西立顕

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      4 2017 - 3 2022

      Authorship：Principal investigator  Grant type：Competitive

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    • 人口・産業集積の時空間ビッグデータにみられる相転移挙動の計算科学的研究

      日本学術振興会  科学研究費補助金 基盤研究(B) (一般) 

      大西立顕

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      4 2016 - 3 2020

      Authorship：Principal investigator  Grant type：Competitive

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    • 地域社会における生活基盤の持続可能性指標の開発

      日本学術振興会  課題設定による先導的人文学・社会科学研究推進事業 実社会対応プログラム 

      大西立顕

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      10 2015 - 9 2018

      Authorship：Principal investigator  Grant type：Competitive

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    • データ駆動型統計学の可能性：動的で複雑な経済・社会現象の帰納的理解に挑む

      日本学術振興会  科学研究費補助金 挑戦的萌芽研究 

      大西立顕

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      4 2014 - 3 2016

      Authorship：Principal investigator  Grant type：Competitive

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    • 大規模経済データにみられる相転移挙動の計算科学的研究

      日本学術振興会  科学研究費補助金 若手研究(A) 

      大西立顕

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      4 2011 - 3 2015

      Authorship：Principal investigator  Grant type：Competitive

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    • 計算集約的経済分析の可能性:大変動・非定常・非線形を前提とした正確な実証分析

      日本学術振興会  科学研究費補助金 挑戦的萌芽研究 

      大西立顕

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      4 2012 - 3 2013

      Authorship：Principal investigator  Grant type：Competitive

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    • 経済現象に潜む静的・動的臨界ゆらぎの実証的観測と発生機構の解明

      日本学術振興会  科学研究費補助金 若手研究(B) 

      大西立顕

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      4 2008 - 3 2011

      Authorship：Principal investigator  Grant type：Competitive

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