Misc - TANAKA Gouhei
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リザバーコンピューティング Invited
田中剛平
106 ( 6 ) 2023.06
Authorship：Lead author, Last author, Corresponding author Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (scientific journal)
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リザバーコンピューティングの概念と最近の動向
タナカ ゴウヘイ
電子情報通信学会誌 102 ( 2 ) 108 - 113 2019.02
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Reservoir computing utilizing spin waves: enhancement of computational performance through a practical approach for on-chip devices
応用物理学会春季学術講演会講演予稿集(CD-ROM) 70th 2023.03
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Guest Editorial Special Issue on New Frontiers in Extremely Efficient Reservoir Computing
Gouhei Tanaka, Claudio Gallicchio, Alessio Micheli, Juan Pablo Ortega, Akira Hirose
IEEE Transactions on Neural Networks and Learning Systems 33 ( 6 ) 2571 - 2574 2022.06
Publishing type：Book review, literature introduction, etc.
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Reservoir Computing utilizing spin waves propagating through magnetic domains
中根了昌, 廣瀬明, 田中剛平, 田中剛平, 田中剛平
応用物理学会春季学術講演会講演予稿集(CD-ROM) 69th 2022
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Reservoir computing with spiking neural networks and reward-modulated STDP
鶴海杭之, 田中剛平, 田中剛平
電子情報通信学会技術研究報告(Web) 122 ( 65(NLP2022 1-25) ) 2022
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Experiments of Reconstructive Reservoir Computing to Detect Anomaly in Time-series Signals
加藤准也, 田中剛平, 田中剛平, 中根了昌, 廣瀬明
電子情報通信学会技術研究報告(Web) 121 ( 390(NC2021 46-78) ) 2022
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Relationship between Computational Performance and Task Difficulty of Reinforcement Learning Methods Using Reward Machines
渡邊隆二, 田中剛平
電子情報通信学会技術研究報告(Web) 121 ( 444(NLP2021 126-152) ) 2022
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Effects of sparse connections in spiking neural networks for unsupervised pattern recognition
品川大樹, 藤原寛太郎, 田中剛平, 田中剛平
電子情報通信学会技術研究報告(Web) 121 ( 444(NLP2021 126-152) ) 2022
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Neural network hardware and spin-wave reservoir computing
廣瀬明, 田中剛平, 中根了昌
日本物理学会講演概要集(CD-ROM) 76 ( 1 ) 2021
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Influence of regularity in readout electrode arrangement on the performance of a spin-wave reservoir computing chip
市村剛大, 中根了昌, 田中剛平, 廣瀬明
日本神経回路学会全国大会講演論文集 31st (CD-ROM) 2021
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Physical reservoir computing chip and complex-valued neural networks framework to realize ultra low power consumption information processing
廣瀬明, 中根了昌, 田中剛平
応用物理学会秋季学術講演会講演予稿集(CD-ROM) 81st 214 - 214 2020.08
Language：Japanese Publisher：The Japan Society of Applied Physics
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知っておきたいキーワード(第136回)リザバーコンピューティング—Keywords you should know : Reservoir Computing
田中 剛平
74 ( 3 ) 532 - 534 2020.05
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Analysis of epidemic disease control using metapopulation models
MATSUKI Akari, TANAKA Gouhei
SEISAN KENKYU 72 ( 2 ) 129 - 135 2020.03
Language：English Publisher：Institute of Industrial Science The University of Tokyo
Mathematical models of epidemic diseases are used for understanding complex spreading processes of diseases and assessing the efficacy of countermeasures to epidemics. Among them, metapopulation epidemic models consider populations distributed in spatially distant patches and migration of individuals between patches. These models can be theoretically analyzed to some extent as well as can incorporate realistic factors. In this review, we focus on local interventions to a fraction of patches for reducing the effective transmission rates in the patches. We explain the analytical derivation of the minimum fraction of patches (or the intervention threshold） that is necessary for prevention of global epidemic outbreaks and numerical simulations for validating the efficacy of targeted intervention.
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Mathematical aspects and device implementation of reservoir computing
Tanaka Gouhei
JSAP Annual Meetings Extended Abstracts 2020.1 49 - 49 2020.02
Language：Japanese Publisher：The Japan Society of Applied Physics
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ネットワークと脳科学
タナカ ゴウヘイ, アイハラ カズユキ
58 ( 2 ) 59 - 65 2020.02
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Spatial distribution of information effective for logic function learning in spin-wave reservoir computing chip utilizing spatiotemporal physical dynamics.
Takehiro Ichimura, Ryosho Nakane, Gouhei Tanaka, Akira Hirose
2020 International Joint Conference on Neural Networks(IJCNN) 118 ( 470(NC2018 44-88)(Web) ) 1 - 8 2020
Language：Japanese Publisher：IEEE
This paper investigates the spatial distribution of information effective for function learning in a spin-wave reservoir-computing garnet chip. We map the neural weights of a readout neuron virtually connected massively and densely to the reservoir chip. We find that the spatial weight distribution shows wavefront-like lines, suggesting the importance of concurrent and time-different interferences of the spin waves. We also estimate the size of reservoir output electrodes required for the proper information extraction. These results are significantly useful for designing spin reservoir chips in the near future energy efficient devices.
DOI： 10.1109/IJCNN48605.2020.9207629
Other Link： https://dblp.uni-trier.de/db/conf/ijcnn/ijcnn2020.html#IchimuraNTH20
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パターン情報表現およびパターン情報処理を物理的に実現するニューラルネットワークデバイス
廣瀬明, 廣瀬明, 田中剛平, 田中剛平, 武田征士, 山根敏志, 沼田秀俊, 金澤直輝, HEROUX J. B, 中野大樹, 中根了昌, 中根了昌
電子情報通信学会大会講演論文集(CD-ROM) 2019 ROMBUNNO.CS‐2‐7 2019.03
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スピン波を用いたリザバーコンピューティングデバイスにおける荷重の空間分布
市村剛大, 中根了昌, 中根了昌, 田中剛平, 田中剛平, 廣瀬明, 廣瀬明, 廣瀬明
電子情報通信学会大会講演論文集(CD-ROM) 2019 ROMBUNNO.CS‐2‐8 2019.03
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Reservoir computing devices that realize pattern information representation and processing directly in physics: Its advantages
廣瀬明, 田中剛平, 武田征士, 山根敏志, 沼田秀俊, 金澤直輝, HEROUX J. B, 中野大樹, 中根了昌
電子情報通信学会技術研究報告 118 ( 470(NC2018 44-88)(Web) ) 117‐120 (WEB ONLY) 2019.02
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スピン波リザバーコンピューティングチップデバイス
中根了昌, 田中剛平, 廣瀬明
応用物理学会春季学術講演会講演予稿集(CD-ROM) 66th ROMBUNNO.12p‐W933‐10 2019.02
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「ニューロ的」ハードウエアと物理リザバーコンピューティング
廣瀬明, 武田征士, ヘロー ジャンベノ, 金澤直輝, 沼田英俊, 山根敏志, 中野大樹, 中根了昌, 田中剛平
29th 2019
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Physical rsssrvoir computing using lightwavss
廣瀬明, 武田征士, HEROUX Jean Benoit, 沼田英俊, 金澤直輝, 山根敏行, 中野大樹, 中根了昌, 田中剛平
Optics & Photonics Japan講演予稿集(CD-ROM) 2019 2019
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スピン波を用いた機械学習チップデバイス
ナカネ リョウショウ, タナカ ゴウヘイ, ヒロセ アキラ
14 ( 6 ) 329 - 334 2019
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スピン波リザバーコンピューティングチップにおける実空間情報分布
市村剛大, 中根了昌, 田中剛平, 廣瀬明, 中根了昌, 田中剛平, 廣瀬明
29th 2019
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招待講演 複雑ネットワークの動的頑強性
タナカ ゴウヘイ
電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 118 ( 316 ) 33 - 38 2018.11
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Dynamical robustness of complex networks
田中剛平
電子情報通信学会技術研究報告 118 ( 316(CCS2018 33-45) ) 33‐38 2018.11
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Nonlinear Time Series Prediction using Multi‐Step Learning Echo State Networks
秋山貴則, 田中剛平, 田中剛平
電子情報通信学会技術研究報告 118 ( 284(IBISML2018 44-104)(Web) ) 293‐299 (WEB ONLY) 2018.10
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ハードウェアで実現するリザバーコンピューティング
中野大樹, 沼田英俊, 山根敏志, 武田征士, HEROUX Jean Benoit, 金澤直樹, 田中剛平, 中根了昌, 廣瀬明
電気学会全国大会講演論文集(CD-ROM) 2018 ROMBUNNO.S16‐4 2018.03
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大規模停電を想定した電力系統モデルにおけるカスケード故障
117 ( 121 ) 63 - 66 2017.07
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リザーバ・コンピューティングにおける複素ニューラルネットワーク
廣瀬明, 武田征士, 田中剛平, 中根了昌, 山根敏志, 中野大樹, 中川茂
2017 2017
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Spontaneous Oscillation in coupled system composed of excitable units
Morino Kai, Tanaka Gouhei, Aihara Kazuyuki
Meeting Abstracts of the Physical Society of Japan 72.1 ( 0 ) 3035 - 3035 2017
Language：Japanese Publisher：The Physical Society of Japan
<p>今回の発表では，興奮性を示す位相振動子を結合した系において，結合強度を強化することで起こる自発的振動現象の解析結果について報告する．今回の系では結合強度を上げることで安定平衡点がサドルノード分岐により消失して自発的な振動が生じるが，全ての素子が振動を開始する場合と一部の素子のみが振動を開始する場合がパラメータにより分かれる．この振動開始のメカニズムを分岐解析によって詳細に解析した結果を報告する．</p>
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外部フィードバック・レーザを用いたリザーバコンピューティング
武田征士, 山根敏志, 中野大樹, 田中剛平, 中根了昌, 廣瀬明, 中川茂
2017 2017
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ニューロン特性の不均一性を考慮したエコーステートネットワーク
田中剛平, 中根了昌, 山根敏志, 中野大樹, 武田征士, 中川茂, 廣瀬明
2017 2017
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Dynamics of Cellular Systems and Bifurcation Theory
TANAKA Gouhei
Seibutsu Butsuri 56 ( 6 ) 340 - 344 2016
Language：Japanese Publisher：The Biophysical Society of Japan General Incorporated Association
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A pruning method based on weight variation information for feedforward neural networks
Zhiqiang Tong, Gouhei Tanaka
IFAC-PapersOnLine 28 ( 18 ) 221 - 226 2015.11
Language：English
Artificial neural networks are powerful tools for many information processing tasks such as pattern recognition, data mining, optimization, and prediction. It is a significant problem to find optimal structures of artificial neural networks for drawing out their high computational performance. Downsizing of network structure is also an issue to be considered for hardware implementation of largescale neural networks. In this study, we propose a pruning method to find a compact structure of feedforward neural networks with high generalization ability in classification problems. Our method evaluates the significance of neuron nodes using the information on weight variation in the training process and prune the insignificant nodes preferentially unless the classification accuracy is degraded. Numerical experiments with several benchmark datasets show that the proposed method is effective compared with other methods.
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A hybrid model for hepatitis B virus
Ben-Gong Zhang, Gouhei Tanaka, Kazuyuki Aihara, Masao Honda, Shuichi Kaneko, Luonan Chen
IFAC-PapersOnLine 28 ( 18 ) 37 - 40 2015.11
Language：English
The hepatitis B virus (HBV) is a kind of pandemic infectious disease. It is becoming a major health problem in Asian and African countries, however, less so in other areas around the world. There is a vast background for studying HBV. However, some problems still require further study. For example, when the patient is infected by HBV, how to arrange the treatment schedule? Using long term continuous treatment or others? Therefore, we wish to readdress the study of HBV. First, we propose a new hybrid model that contains both continuous and discrete variables. Second, we analyze its dynamical behavior. We hope that this study may provide some new insight for HBV disease and some new guidance for the therapy.
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Dynamical robustness of complex biological networks
Gouhei Tanaka, Kai Morino, Kazuyuki Aihara
Mathematical Approaches to Biological Systems: Networks, Oscillations, and Collective Motions 29 - 53 2015.01
Language：English Publisher：Springer Japan
Dynamical behavior of biological systems is maintained by interactions between biological units such as neurons, cells, proteins, and molecules. It is a challenging issue to understand robustness of biological interaction networks from a viewpoint of dynamical systems. In this chapter, we introduce the concept of dynamical robustness in complex networks and demonstrate its application to biological networks. First, we introduce the framework for studying the dynamical robustness through analyses of coupled Stuart-Landau oscillators with various types of network structures. Second, based on the framework, we examine the dynamical robustness of neuronal firing activity in networks of synaptically coupled Morris- Lecar neuron models. Our analyses suggest that a consideration of both network structure and dynamics is crucial in elucidating biological robustness.
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21aPS-5 Robustness of Coupled Heterogeneous Excitable and Periodic Oscillators
Morino Kai, Tanaka Gouhei, Aihara Kazuyuki
Meeting Abstracts of the Physical Society of Japan 70.1 ( 0 ) 2853 2015
Language：Japanese Publisher：The Physical Society of Japan
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17pPSA-52 Complex Phase Diagram of Coupled Heterogeneous Excitable and Periodic Phase Oscillators
Morino Kai, Tanaka Gouhei, Aihara Kazuyuki
Meeting Abstracts of the Physical Society of Japan 70.2 ( 0 ) 2704 2015
Language：Japanese Publisher：The Physical Society of Japan
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Wave-Based Device Scaling Concept for Brain-Like Energy Efficiency and Integration
Y. Katayama, T. Yamane, D. Nakano, R. Nakane, G. Tanaka
PROCEEDINGS OF THE 2015 IEEE/ACM INTERNATIONAL SYMPOSIUM ON NANOSCALE ARCHITECTURES (NANOARCH 15) 23 - 24 2015
Language：English Publisher：IEEE
Aiming at achieving brain-like capabilities and efficiencies with nano-scale integration, this paper proposes a new scaling concept for wave-based neuromorphic devices. Our scaling approach shows that v(g) the group velocity of a signaling wave is one of the essential parameters that can account for the orders-of-magnitude gaps in the efficiency of the human brain and VLSIs for cognitive tasks.
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Wave-Based Neuromorphic Computing Framework for Brain-Like Energy Efficiency and Integration
Y. Katayama, T. Yamane, D. Nakano, R. Nakane, G. Tanaka
2015 IEEE 15TH INTERNATIONAL CONFERENCE ON NANOTECHNOLOGY (IEEE-NANO) 1210 - 1213 2015
Language：English Publisher：IEEE
We present a framework of wave-based neuromorphic computing aiming at brain-like capabilities and efficiencies with nano-scale device integration. We take advantage of the unique nature of elastic wave dynamics in both computations and the IO communications in between as a means to efficiently implement and execute neuromorphic computing. We point out that the group velocity of a wave is one of the essential design parameters.
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疎結合を持つモジュラー型自己連想ニューラルネットワークの特性解析
ヤマネ トシユキ, タナカ ゴウヘイ, ナカノ ダイジュ
電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 114 ( 306 ) 351 - 356 2014.11
Language：Japanese Publisher：The Institute of Electronics, Information and Communication Engineers
We report the performance analysis of auto-associative neural networks on modular structures. We focus on the sparse modules to reduce the wiring complexity for hardware implementation. The local iterative Hebbian rules is employed which can be applied to arbitrary network topologies and the relations between modular structures and auto-associative capability is investigated.
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Hopfield-type associative memory with sparse modular networks
Gouhei Tanaka, Toshiyuki Yamane, Daiju Nakano, Ryosho Nakane, Yasunao Katayama
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 8834 255 - 262 2014.01
© Springer International Publishing Switzerland 2014. Modular structures are ubiquitously found in the brain and neural networks. Inspired by the biological networks, we explore Hopfieldtype recurrent neural networks with sparse modular connectivity for associative memory. We first show that an iterative learning algorithm, which determines the connection weights depending on the network topology, yields better performance than the one-shot learning rule. We then examine the topological factors which govern the memory capacity of the sparse modular neural network. Numerical results suggest that the uniformity of the number of connections per neuron is an essential condition for good performance. We discuss a method to design an energy-efficient neural network.
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On the analysis of the bifurcation sets of equilibrium points in parameter space
G. Chesi, G. Tanaka, Y. Hirata, K. Aihara
2013 European Control Conference, ECC 2013 670 - 675 2013.12
This paper addresses the problems of characterizing and estimating the bifurcation sets of equilibrium points in multi-parameter space of a class of nonlinear dynamical systems. Specifically, we investigate the sets of parameters that lead to saddle-node bifurcations and Hopf bifurcations at an equilibrium point of interest. First, a characterization of these sets is provided in terms of the zeros of some functions. Second, this characterization is exploited to estimate such sets through convex programming for the case of polynomial dynamical systems. In particular, two conditions are proposed for establishing whether a sublevel set of a given polynomial does not contain parameters that lead to bifurcations. By using these conditions, the largest of such sublevel sets can be estimated by solving an eigenvalue problem. Some numerical examples illustrate the proposed results. © 2013 EUCA.
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Oscillatory behavior of complex networks composed of active and selectively-inactivated phase oscillators.
Morino Kai, Tanaka Gouhei, Aihara Kazuyuki
Meeting Abstracts of the Physical Society of Japan 68 ( 0 ) 284 2013
Language：Japanese Publisher：The Physical Society of Japan
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27pXM-6 Non-standard scaling law of fluctuations in globally coupled oscillators
Nishikawa I.
Meeting Abstracts of the Physical Society of Japan 68.1.2 ( 0 ) 359 2013
Language：Japanese Publisher：The Physical Society of Japan
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A mathematical model of rubella with heterogeneity of vaccination
Urabe Chiyori, Tanaka Gouhei, Mitsudo Tetsuya, Misaki Takako, Maruyama Aya, Oshima Takahiro, Okabe Nobuhiko, Aihara Kazuyuki
Meeting Abstracts of the Physical Society of Japan 68 ( 0 ) 281 2013
Language：Japanese Publisher：The Physical Society of Japan
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Analysis of Frequency Synchronization of the Power Grid in East Japan Using the Phase Model
NAGATA Motoki, FUJIWARA Naoya, NISHIKAWA Isao, TANAKA Gouhei, SUZUKI Hideyuki, AIHARA Kazuyuki
SEISAN KENKYU 65 ( 3 ) 295 - 299 2013
Language：Japanese Publisher：Institute of Industrial Science The University of Tokyo
After the Tohoku earthquake, it is becoming very important to ensure a stable energy supply because of the recent developments in renewable and decentralized energy. In order to stabilize the supply of power grids, it is useful to analyze mathematical models which describe the essence of dynamical processes of the grids. In this paper, we replicated the topology of the power grid in Eastern Japan and described power grids by phase models. We used the minimum coupling strength for global frequency synchronizationas a stability measure in power grids. Further, we identify transmission lines which contribute to a stable supply.
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An optimal control problem of dynamical vaccine allocation in an influenza epidemic model
山本 浩貴, 田中 剛平, 合原 一幸
生産研究 64 ( 3 ) 313 - 318 2012.05
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Dynamical modeling of chronic myeloid leukemia progression and the development of mutations
Ben-gong Zhang, Gouhei Tanaka, Luonan Chen, Kazuyuki Aihara
2012 IEEE INTERNATIONAL CONFERENCE ON BIOINFORMATICS AND BIOMEDICINE WORKSHOPS (BIBMW) 130 - 135 2012
Language：English Publisher：IEEE
Mathematical models have already been developed to describe the dynamics of the chronic myeloid leukemia (CML). However, most of them mainly focus on the short term dynamics and response to the treatment with drugs such as imatinib or the relapse upon cessation of treatment. In this paper, we aim to study the dynamics of CML which represents the first human cancer for the molecularly targeted therapy again. First, we propose a new mathematical model of CML which based on the known biology know ledges. And then we analyze its qualitative and dynamical properties. Combining the clinical data and theoretical analysis, we demonstrate that our model is biologically plausible and also computationally viable. Second, we demonstrate that this model can characterize the dynamics of the CML infection and the development of mutation, and is also validated by clinical data.
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21aAE-10 Oscillatory behavior of mixed populations of active and inactive phase oscillators depends on the degrees in complex networks
Morino Kai, Tanaka Gouhei, Aihara Kazuyuki
Meeting Abstracts of the Physical Society of Japan 67 ( 0 ) 309 2012
Language：Japanese Publisher：The Physical Society of Japan
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1SC-04 Mathematical analysis of dynamical robustness in biological networks(1SC Frontiers in mathematical methods in biology,Symposium,The 50th Annual Meeting of the Biophysical Society of Japan)
Tanaka Gouhei, Morino Kai, Aihara Kazuyuki
Seibutsu Butsuri 52 ( 0 ) S3 - S4 2012
Language：English Publisher：The Biophysical Society of Japan General Incorporated Association
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An optimal control problem of dynamical vaccine allocation in an influenza epidemic model
YAMAMOTO Hiroki, TANAKA Gouhei, AIHARA Kazuyuki
SEISAN KENKYU 64 ( 3 ) 313 - 318 2012
Language：Japanese Publisher：Institute of Industrial Science The University of Tokyo
When a new influenza epidemic is going on, it is important to promptly plan the schedule of production and allocation of vaccines in order to mitigate the severity of the influenza. Because the production of vaccines starts after identification of the antigenic type of the spreading influenza virus, it is almost impossible to store adequate amounts of vaccines in advance. Therefore, it is necessary to timely produce and distribute the available vaccines under a daily and total limit. In this study, we formulate an optimal control problem on dynamical vaccine allocation that minimizes the number of fatalities or that of infections in an age-structured influenza epidemic model. By numerically solving this problem, we can obtain the optimal amount of vaccines allocated to each age-group on a moment-to-moment basis. We also demonstrate that the framework for optimal control of dynamical vaccine allocation is applicable to the concurrent epidemic model of seasonal and pandemic influenza.[This abstract is not included in the PDF]
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Mathematical Modelling of Complex Systems and Simulation
TANAKA Gouhei, OKU Makito, AIHARA Kazuyuki
シミュレーション 30 ( 4 ) 236 - 241 2011.12
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Analysis of a learning algorithm for a single phasor neuron (Research on complex dynamics and related fields)
Tanaka Gouhei
RIMS Kokyuroku 1762 ( 1762 ) 1 - 12 2011.09
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Complex-Sigmoid Function for Complex-Valued Neural Networks (Dynamical Systems : Theories to Applications and Applications to Theories)
Tanaka Gouhei
RIMS Kokyuroku 1742 ( 1742 ) 145 - 157 2011.05
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Mathematical modelling of prostate cancer growth and its application to hormone therapy (vol 368, pg 5029, 2010)
Gouhei Tanaka, Yoshito Hirata, S. Larry Goldenberg, Nicholas Bruchovsky, Kazuyuki Aihara
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES 369 ( 1935 ) 495 - 495 2011.01
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25pTF-2 Aging transitions in multi-layer oscillator networks
Morino Kai, Tanaka Gouhei, Aihara Kazuyuki
Meeting Abstracts of the Physical Society of Japan 66 ( 0 ) 296 2011
Language：Japanese Publisher：The Physical Society of Japan
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23pGU-4 Recovery of global oscillations in coupled oscillator networks
Morino Kai, Tanaka Gouhei, Aihara Kazuyuki
Meeting Abstracts of the Physical Society of Japan 66 ( 0 ) 286 2011
Language：Japanese Publisher：The Physical Society of Japan
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Numerical Analysis on Coupled Systems of Period-1 and Period-2 Limit Cycle Oscillators
OKADA Yusuke, TANAKA Gouhei, KOHNO Takashi, AIHARA Kazuyuki
IEICE technical report 109 ( 269 ) 203 - 208 2009.11
Language：Japanese Publisher：The Institute of Electronics, Information and Communication Engineers
Coupled oscillators have been widely studied, for instance, as a mathematical model to investigate the mechanism of emergence of biological rhythms generated by an ensemble of interacting biological cells. In this study, we focus on network dynamics in a coupled system of inhomogeneous dynamical oscillators. In particular, we consider the case in which each oscillator is given as the same dynamical system while heterogeneity of oscillators lies in different parameter values. Recently, Daido and Nakanishi (2004) investigated network dynamics in a coupled system of active elements with a parameter value corresponding to a limit cycle and inactive elements with a parameter value corresponding to an equilibrium, and studied aging transition which occurs as the proportion of the inactive elements is varied. Motivated by this work, we numerically investigate a diffusively coupled system of period-1 and period-2 limit cycle oscillators. We show phase diagrams where the coupling strength and the proportion of the period-1 oscillators are varied.
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Backpropagation Learning Algorithm for Multi layer Phasor Neural Networks
Gouhei Tanaka, Kazuyuki Aihara
NEURAL INFORMATION PROCESSING, PT 1, PROCEEDINGS 5863 484 - 493 2009
Language：English Publisher：SPRINGER-VERLAG BERLIN
We present a backpropagation learning algorithm for multi-layer feedforward phasor neural networks using a gradient descent method. The state of a phasor neuron takes a complex-valued state on the unit circle in the complex domain. Namely, the state can be identified only by its phase component because the amplitude component is fixed. Due to the circularity of the phase variable, phasor neural networks are useful to deal with periodic and multivalued variables. Under the assumption that the weight coefficients are complex numbers and the activation function is a continuous and differentiable function of a phase variable, we derive an iterative learning algorithm to minimize the output error. In each step of the algorithm, the weight coefficients are updated in the gradient descent direction of the error function landscape. The proposed algorithm is numerically tested in function approximation task. The numerical results suggest that the proposed method has a better generalization ability compared with the other backpropagation algorithm based on linear correction rule.
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Estimation on effects of preventive measures reducing force of infection based on an epidemic model
TANAKA Gouhei, AIHARA Kazuyuki
SEISAN KENKYU 61 ( 6 ) 1081 - 1084 2009
Language：Japanese Publisher：Institute of Industrial Science The University of Tokyo
&nbsp;&nbsp;&nbsp;It is estimated that the Pandemic influenza A (H1N1) 2009 emerging all over the world in this year would further spread. Although production of pandemic vaccines is intensively promoted, its maximum amount is limited. Therefore, preventive measures other than the vaccination are also considered to be significant for decreasing the number of patients. In this study, under the assumption that the force of infection can be reduced by patients wearing a mask and staying at home, air ventilation, careful gargle and hand-wash etc., we estimate the effects of them using an epidemic model. For instance, in the case that the basic reproduction number is 1.4, reduction of the force of infection by 10% corresponds to approximately 16 million pandemic vaccines and results in decreasing the morbidity by about 25%. [This abstract is not included in the PDF]<br>
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カオス工学は何を可能にするか
タナカ ゴウヘイ
78 ( 11 ) 1242 - 1245 2008.11
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Complex-Valued Multistate Associative Memory with Nonlinear Multilevel Function
TANAKA Gouhei, AIHARA Kazuyuki
IEICE technical report 107 ( 478 ) 13 - 18 2008.02
Language：Japanese Publisher：The Institute of Electronics, Information and Communication Engineers
A complex-valued neural network can be used for multistate associative memory by quantizing a neuronal state into a multivalued state with an appropriate threshold function. The complex-signum function used in conventional multistate associative memory models is a transformation including a multilevel signum function in essence. In the present report, we propose a complex-valued threshold function based on nonlinear multilevel functions and show the recall performance of the multistate associative memory based on the proposed method. Numerical experiments clarify how the recall capability is influenced by the parameter controlling the nonlinearity of the multilevel function, the number of the stored patterns, and the number of quantized states. We also demonstrate gray-level image reconstruction with the proposed method.
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MP-533 前立腺癌の間欠的ホルモン療法の数理モデルによる解析(一般演題ポスター,第94回日本泌尿器科学会総会)
島田 尚, 合原 一幸, 出田 亜位子, 津本 国親, 辻 繁樹, 平田 祥人, 鈴木 大慈, 田中 剛平, 武内 功, 北村 唯一
97 ( 2 ) 500 2006
Language：Japanese Publisher：一般社団法人 日本泌尿器科学会
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Multistate associative memory with parametrically coupled map networks
Gouhei Tanaka, Kazuyuki Aihara
IEEE Asia-Pacific Conference on Circuits and Systems, Proceedings, APCCAS 2 1017 - 1020 2004.12
The present paper proposes two types of multistate associative memory models using circle maps coupled through a parameter in the individual map. Each network utilizes a circle map with a specific bifurcation property as its component and realizes self-organizing chaotic dynamics in a memory association. The performance of the proposed networks is compared with that of a conventional multistate neural network in multistate associative memory tests. © 2004 IEEE.
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Analysis of Bursting Cell Model with 2D Maps
TANAKA Gouhei, AIHARA Kazuyuki
IEICE technical report. Circuits and systems 103 ( 334 ) 73 - 78 2003.09
Language：Japanese Publisher：The Institute of Electronics, Information and Communication Engineers
From the viewpoint of biological information processing, bursting responses of excitable cells may play an important role in the interaction of the cells. In several experiments and model simulations, two coupled bursting cells with electrical synapses often display in-phase and anti-phase burst synchronization depending on the coupling strength. To clarify an essential mechanism of the change between the two types of burst synchronization, this report investigates a coupled system of identical cells, each of which is described as a 2D bursting mapping. We show that the in-phase and anti-phase synchronized bursting solutions are stable for positive and negative coupling coefficients, respectively. The transition concerns with the change of local transverse stability of an invariant subspace. Moreover, the parameter region of bursting responses in a single cell is compared with that in the coupled cell system.
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