Tokushima University / Educator and Researcher Directory --- Kawakami, Hiroshi

Personal Web Page

https://researchmap.jp/read0017407 (researchmap)

Field of Study

○	Electrical and Electronic Engineering

Subject of Study

○	Electronic Engineering, Nonlinear System Analysis, Nonlinear Control (nonlinear systems, chaotic phenomena, bifurcation phenomena, rhythmic phenomena, chaos control, synchronization phenomena) (Qualitative study on nonlinear dynamical systems, Applied analysis of chaotic phenomena and bifurcations, Study on rhythmic phenomena and its biological applications, Kinematic analysis of crane motions, Study on synchronization phenomena of coupled dynamical systems, Study on chaos control and its applications)

Book / Paper

Book:

1.	Hiroshi Kawakami and Takashi Shimamoto : 電気回路の基礎数学, CORONA PUBLISHING CO.,LTD, Tokyo, Oct. 2008. (Summary) 本書は，高校で習った数学を復習し，電気回路，特に「交流回路の定常解析」に出てくる数学を学習するための手引きとして用意した入門書．電気回路に必要な高校数学の復習(三角関数・微積分等)から学習し始め，行列・ベクトル・複素数・正弦波・ラプラス変換等を説明し，電気回路の勉強を始める段階で数学的につまずかないように工夫している．
2.	Hiroshi Kawakami, Takashi Shimamoto and Yoshifumi Nishio : 例題と課題で学ぶ電気回路, CORONA PUBLISHING CO.,LTD, Tokyo, Oct. 2006. (Summary) 大学の初年次で電気回路理論を学ぶ学生向けに，この理論の基本的考え方を身につけることを目的として編集した教科書．1章で直流回路を，2∼4章で交流回路の解析手法と解析ツールの獲得を，5∼8章で多変数・分布になった回路の性質と解析手法の獲得を目的に，本文・例題・課題・演習問題・理解度チェックを繰返し，目標を定めそれに向かって論理的に学習する，いわゆる過程実現型学習が容易にできるよう記述・構成している．
3.	Tetsushi Ueta, Tohru Kawabe, Hiroshi Kawakami and Guanrong Chen : Calculation and Control of Unstable Periodic Orbits in Piecewise-Smooth Dynamical Systems., --- G. Chen, D. J. Hill, and X. Yu (eds), (Chaos and Bifurcation Control: Theory and Applications ---, Springer-Verlag, Berlin, Jul. 2003. (Summary) This chapter describes a simple method for calculating unstable periodic orbits (UPOs) and their control in piecewise smooth autonomous systems. The algorithm can be used to obtain any desired UPO embedded in a chaotic attractor, and the UPO can be stabilized by a simple statefeedback control. Some illustrative examples are shown for demonstration. (Link to Publication Site) ● Publication site (DOI): 10.1007/978-3-540-44986-7_14 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1007/978-3-540-44986-7_14 (DOI: 10.1007/978-3-540-44986-7_14)
4.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcations in synaptically coupled Bonhoeffer-van der Pol neurons, --- G. Chen and T. Ueta (eds), in Chaos in Circuits and Systems ---, World Scientific, Singapore, Jul. 2002.
5.	Tetsushi Ueta and Hiroshi Kawakami : Numerical approaches to bifurcation analysis, --- G. Chen and T. Ueta (eds), in Chaos in Circuits and Systems, Chapter 28 ---, World Scientific, Singapore, Jul. 2002. (Summary) This chapter investigates direct methods for evaluating the bifurcation parameter values of periodic solutions in nonlinear systems. The method can numerically calculate parameter values with high convergence rate and accuracy, at which local bifurcations; tangent, period-doubling, Neimark-Sacker and pitchfork bifurcations are occurred. The method uses some basic properties of the characteristic equation for a fixed point of the corresponding Poincare map. The location and parameter value of the fixed point are used as independent variables in the computation that employs quadratically convergency in Newton method. In addition, in the case of Neimark-Sacker bifurcation, the argument of the complex conjugate multiplier or the other parameter is used as the independent variable. This direct method utilize accurate solution of variational equations with numerical integration, thus implementaion of algorithm becomes very simple. Some numerical examples are given. (Link to Publication Site) ● Publication site (DOI): 10.1142/9789812705303_0028 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1142/9789812705303_0028 (DOI: 10.1142/9789812705303_0028)
6.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Nonlinear dynamical systems with interrupted characteristics: Bifurcation and control, --- G. Chen and T. Ueta (eds), in Chaos in Circuits and Systems, Chapter 19 ---, World Scientific, Singapore, Jul. 2002. (Summary) 断続特性および非線形特性をもつ回路について，生じる周期解の発生，分岐について検討している．回路のクラスを周期外力を加える系，自律系に分けて分岐現象をのべ，分岐パラメータの計算方法を提案し，計算例を示している．区分非線形系の分岐問題について，その数値計算について例題を用いて説明している文献は他に例をみない．ポアンカレ写像の構成方法，不可微分点でのヤコビ行列の求積方法に新規性がある．また，断続系に特有な分岐現象についてもその数値計算方法について述べている． (Link to Publication Site) ● Publication site (DOI): 10.1142/9789812705303_0019 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1142/9789812705303_0019 (DOI: 10.1142/9789812705303_0019)
7.	Hiroshi Kawakami, Tetsuya Yoshinaga, Taishin Nomura, Shinji Doi and Kazuko Terada : 生体リズムの動的モデルとその解析, CORONA PUBLISHING CO.,LTD, Tokyo, Mar. 2001.
8.	Hiroshi Kawakami : Nonlinear Dynamic Phenomena in Circuits, --- Wiley Encyclopedia of Electrical and Electronics Engineering ---, John Wiley & Sons, Inc., New York, Mar. 1999. (Summary) 本書は電気電子工学の各分野について入門から研究の最先端までを適切に事項毎に事典としたものであり，私は Nonlinear Dynamic Phenomena in Circuits の項目を解説した．共同執筆者: J. G. Webster, 川上博他, 総頁数: 20000 担当部分: pp. 525-562
9.	Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcation and chaotic state in forced oscillatory circuits containing saturable inductors, --- L. Pecora and T. Carroll (eds), in Nonlinear Dynamics in Circuits ---, World Scientific, Singapore, Apr. 1995.
10.	Tetsuya Yoshinaga and Hiroshi Kawakami : Codimension-two bifurcation in a forced oscillator, --- K. Shiraiwa, N. Aoki and Y. Takahashi (eds), in Dynamical Systems and Chaos ---, World Scientific, Singapore, Mar. 1995.
11.	Hiroshi Kawakami and Tetsuya Yoshinaga : Codimension two bifurcation and its computational algorithm, --- J. Awrejcewicz (eds), in Bifurcation and Chaos: Theory and Applications ---, Springer-Verlag, Berlin, Feb. 1995.
12.	Hiroshi Kawakami and Tetsushi Ueta : C によるカオス CG, サイエンス社, Tokyo, Apr. 1994. (Summary) 非線形差分方程式で記述されるさまざまな力学系について，パラメータに依存して生じる固定点，周期点，カオスなどのアトラクタを視覚化する．状態空間におけるカオス軌道の表現方法，周期点アトラクタへの吸引集合の視覚化，パラメータにおける分岐集合の計算方法について述べる．C言語のソースをすべて添付し，研究入門者や初学者にも実験できるよう配慮されている．計算結果は高精度グラフィクスにより描画され，多数掲載されている．アトラクタの安定性やその解析方法，分岐パラメータの計算方法もソースコードとともに詳述し，専門家への参考図書としてもなり得る．
13.	Hiroshi Kawakami : Structure and Bifurcations of Dynamical Systems, World Scientific, Singapore, Nov. 1992.
14.	Hiroshi Kawakami : Some Problems on the Theory of Dynamical Systems in Applied Sciences, World Scientific, Singapore, Dec. 1991.
15.	小林邦博 and Hiroshi Kawakami : 電気回路の過渡現象, 産業図書, Tokyo, Sep. 1991.
16.	Hiroshi Kawakami : カオスCGコレクション, サイエンス社, Tokyo, Sep. 1990. (Summary) 本書は，カオス現象をコンピュータを使って実際に体験しながら理解してもらうことを目的に執筆したカオス現象の入門書である．扱っているシステムは，離散時間系に限定している．
17.	Tetsuya Yoshinaga and Hiroshi Kawakami : A property of mean value defined on period doubling cascade, --- H. Kawakami (eds), in Bifurcation phenomena in nonlinear systems and theory of dynamical systems, Advanced Series in Dynamical Systems Vol.8 ---, World Scientific, Singapore, Jul. 1989.
18.	Hiroshi Kawakami : Asymptotic Methods of Mathematical Physics, Kiev Naukova Dumka, Kiev, Oct. 1988.
19.	水上孝一, Hiroshi Kawakami and 坂本明雄 : Basicプログラミング, 朝倉書店, Tokyo, Apr. 1986.
20.	Hiroshi Kawakami : The Theory of Dynamical Systems and Its Application to Nonlinear Problems, World Scientific Publishing Co. Pte. Ltd., Singapore, Dec. 1984. (Summary) 本書は，京都大学数理解析研究所において川上が研究代表者となり開催した共同研究集会「力学系理論とその応用分野における非線形問題」の報告論文集である．21編の論文を収録している．川上はその編集を行い，論文を掲載した．
21.	石黒美種, 仁田工吉, Norio Akamatsu, 生田信晧, Katsuo Isaka, Akio Ushida, Hiroshi Kawakami, Yohsuke Kinouchi, 小林邦博, 島田良作, Takayuki Suzuki, Takeomi Tamesada, 森一郎, Masuo Fukui and 横井良秀 : 電気·電子工学実験(electrical and eiectronic experiments,in japanese), 産業図書, Tokyo, Apr. 1974. (Summary) 本書は，電気電子工学を学ぶ学生のための実験指導書である．内容は基礎実験，材料·能動素子実験，電気機器実験，電力·照明実験，制御及びアナログ演算実験，パルスおよびデジタル回路実験，通信工学実験などの項目で構成されている．第3章:材料および能動素子の実験のホール効果，比抵抗の測定，光電変換素子についての原理，実験方法などを解説した．

Academic Paper (Judged Full Paper):

1.	Seiya Amoh, Tetsushi Ueta and Hiroshi Kawakami : Transient Responses to Relaxation Oscillations in Multivibrators, IEEE Access, Vol.12, 471-482, 2024. (Summary) The multivibrator is an electronic circuit that has three oscillation states: astable, monostable, and bistable; these circuits typically contain opamps. These states are often modeled using hybrid systems, which contain characteristics of both continuous and discrete time. While an ideal opamp possesses both continuous and discrete characteristics, actual opamps exhibit continuous properties, which necessitate indepth modeling. The relaxation oscillations produced by the multivibrator, characterized by periodic, rapid state changes, are typically modeled by considering slow fast dynamical systems. In these systems, the phenomenon whereby the amplitude of the signal changes rapidly is referred to as a ``canard explosion''. By considering this phenomenon, it is possible to understand the process of relaxation oscillations in the multivibrator. In this work, we model the multivibrator by considering a slow fast dynamical system and observe canard explosions through numerical experiments. This study indicates that the oscillatory changes in the multivibrator are continuous, which explains the onset of relaxation oscillations. Additionally, circuit experiments are conducted using affordable opamps; in this experimental work, canard explosions are observed. (Keyword) bifurcation analysis / canard / multivibrator / singular perturbation / slow-fast dynamical systems (Tokushima University Institutional Repository) ● Metadata: 118852 (Link to Publication Site) ● Publication site (DOI): 10.1109/ACCESS.2023.3345840 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1874242817447351296 ● Summary page in Scopus @ Elsevier: 2-s2.0-85181564229 (Tokushima University Institutional Repository: 118852, DOI: 10.1109/ACCESS.2023.3345840, CiNii: 1874242817447351296, Elsevier: Scopus)
2.	Atsuo Maki, Yuu Miino, Naoya Umeda, Masahiro Sakai, Tetsushi Ueta and Hiroshi Kawakami : Nonlinear dynamics of ship capsizing at sea, Nonlinear Theory and Its Applications, IEICE, Vol.E13-N, No.1, 2-24, 2022. (Summary) Capsizing is one of the worst scenarios in oceangoing vessels. It could lead to a high number of fatalities. A considerable number of studies have been conducted until the 1980s, and one of the discoveries is the weather criterion established by the International Maritime Organization (IMO). In the past, one of the biggest difficulties in revealing the behavior of ship-roll motion was the nonlinearity of the governing equation. On the other hand, after the mid-1980s, the complexity of the capsizing problem was uncovered with the aid of computers. In this study, we present the theoretical backgrounds of the capsizing problem from the viewpoint of nonlinear dynamics. Then, we discuss the theoretical conditions and mechanisms of the bifurcations of periodic solutions and numerical attempts for the bifurcations and capsizing. (Keyword) capsizing / regular sea / safe-basin boundary / global bifurcation (Tokushima University Institutional Repository) ● Metadata: 116263 (Link to Publication Site) ● Publication site (DOI): 10.1587/nolta.13.2 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1390572092345065728 ● Search Scopus @ Elsevier (DOI): 10.1587/nolta.13.2 (Tokushima University Institutional Repository: 116263, DOI: 10.1587/nolta.13.2, CiNii: 1390572092345065728)
3.	Yuu Miino, Daisuke Ito, Tetsushi Ueta and Hiroshi Kawakami : Locating and stabilizing unstable periodic orbits embedded in the horseshoe map, International Journal of Bifurcation and Chaos, Vol.31, No.4, 2150110, 2021. (Summary) Based on the theory of symbolic dynamical systems, we propose a novel computation method to locate and stabilize the unstable periodic points (UPPs) in a two-dimensional dynamical system with a Smale horseshoe. This method directly implies a new framework for controlling chaos. By introducing the subset based correspondence between a planar dynamical system and a symbolic dynamical system, we locate regions sectioned by stable and unstable manifolds comprehensively and identify the speci ed region containing a UPP with the particular period. Then Newton's method compensates the accurate location of the UPP with this region information as an initial guess. On the other hand, the external force control (EFC) is known as an e ective method to stabilize the UPPs. By applying the EFC to the located UPPs, robust controlling chaos is realized. In this framework, we never use ad hoc approaches to nd target UPPs in the given chaotic set. Moreover, the method can stabilize UPPs with the speci ed period regardless of the situation where the targeted chaotic set is attractive or not. As illustrative numerical experiments, we locate and stabilize UPPs and the corresponding unstable periodic orbits in a horseshoe structure of the Du ng equation. In spite of the strong instability of UPPs, the controlled orbit is robust and the control input retains tiny in magnitude. (Keyword) chaos / horseshoe map / symbolic dynamics / unstable periodic point / numerical computation / controlling chaos (Tokushima University Institutional Repository) ● Metadata: 115874 (Link to Publication Site) ● Publication site (DOI): 10.1142/S0218127421501108 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1142/S0218127421501108 (Tokushima University Institutional Repository: 115874, DOI: 10.1142/S0218127421501108)
4.	Yuu Miino, Tetsushi Ueta and Hiroshi Kawakami : Bending angles of a broken line causing bifurcations and chaos, Nonlinear Theory and Its Applications, IEICE, Vol.11, No.3, 359-371, 2020. (Summary) We replace the cubic characteristics in the Duffing equation by two line segments connected at a point and investigate how an angle of that broken line conducts bifurcations to periodic orbits. Firstly we discuss differences in periodic orbits between the Duffing equation and a forced planar system including the broken line. In the latter system, a grazing bifurcation split the parameter space into the linear and nonlinear response domains. Also, we show that bifurcations of non-resonant periodic orbits appeared in the former system are suppressed in the latter system. Secondly, we obtain bifurcation diagrams by changing a slant parameter of the broken line. We also nd the parameter set that a homoclinic bifurcation arises and the corresponding horseshoe map. It is clari ed that a grazing bifurcation and tangent bifurcations form boundaries between linear and nonlinear responses. Finally, we explore the piecewise linear functions that show the minimum bending angles exhibiting bifurcation and chaos. (Keyword) local and global bifurcation analysis / piecewise linear dynamical system / hybrid dynamical system / Duffing equation (Tokushima University Institutional Repository) ● Metadata: 114909 (Link to Publication Site) ● Publication site (DOI): 10.1587/nolta.11.359 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1587/nolta.11.359 (Tokushima University Institutional Repository: 114909, DOI: 10.1587/nolta.11.359)
5.	Atsuo Maki, Lawrence Virgin, Naoya Umeda, Tetsushi Ueta, Yuu Miino and Hiroshi Kawakami : On the loss of stability of periodic oscillations and its relevance to ship capsize, Journal of Marine Science and Technology, 2018. (Summary) This research aims to analytically investigate beam seas roll motion. So far, in the analytical investigation for this topic, the softening Duffing equation has been often utilized because of its similarity to the ship equation of motion, and considerable number of researches have been reported. In this research, we focus on the loss of stability of periodic oscillation and its relevance to ship capsize. In the past researches, the threshold of saddle-node bifurcation, flip bifurcation and heteroclinic bifurcation has been obtained. Among them, the condition with respect to flip was derived from the negative stiffness condition in the variational equation having the form of Mathieus equation. On the other hand, in this paper, the authors reconsider the phenomenon and then that threshold is identical with that of pitchfork bifurcation. Furthermore, the practical capsizing threshold was introduced by using the solution after pitchfork bifurcation. The result shows the fairly good agreement with the numerically obtained capsizing boundary. It means that applying the unsymmetric solution after pitchfork bifurcation into capsizing assessment is reasonable. (Keyword) Nonlinear dynamics / Softening Duffing equation / Capsizing / Pitchfork bifurcation (Tokushima University Institutional Repository) ● Metadata: 113428 (Link to Publication Site) ● Publication site (DOI): 10.1007/s00773-018-0591-x (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1007/s00773-018-0591-x (Tokushima University Institutional Repository: 113428, DOI: 10.1007/s00773-018-0591-x)
6.	Yuu Miino, Tetsushi Ueta and Hiroshi Kawakami : Nonlinear resonance and devil's staircase in a forced planer system containing a piecewise linear hysteresis, Chaos, Solitons & Fractals, Vol.111, 75-85, 2018. (Summary) The Duffing equation describes a periodically forced oscillator model with a nonlinear elasticity. In its circuitry, a saturable-iron core often exhibits a hysteresis. However, a few studies about the Duffing equation has discussed the effects of the hysteresis because of difficulties in their mathematical treatment. In this paper, we investigatea forced planer system demonstrating the Duffing equation containing the hysteresis. For simplicity, we approximate the hysteresis to a piecewise linear function. Since the solutions are expressed by combinations of some dynamical systems and switching conditions, a finite-state machine is derived from the hybrid system approach, and then bifurcation theory can be applied to it. We topologically classify periodic solutions and compute local and grazing bifurcation sets accurately. In comparison with the Duffing equation, we discuss the effects caused by the hysteresis, such as the devil's staircase in resonant solutions. (Keyword) bifurcation analysis / hybrid system / nonlinear resonance / Duffing equation / devil's staircase / chaos (Tokushima University Institutional Repository) ● Metadata: 111897 (Link to Publication Site) ● Publication site (DOI): 10.1016/j.chaos.2018.04.007 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-85045410451 (Tokushima University Institutional Repository: 111897, DOI: 10.1016/j.chaos.2018.04.007, Elsevier: Scopus)
7.	Akinori Tsuji, Norihiko Koori and Hiroshi Kawakami : A Practice for Information Technology Education Using Teaching Materials Based on the Physical Computing, Journal of University Extension, Vol.27, 23-30, 2018. (Tokushima University Institutional Repository) ● Metadata: 112227 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1050020697876711424 (Tokushima University Institutional Repository: 112227, CiNii: 1050020697876711424)
8.	Akinori Tsuji and Hiroshi Kawakami : Practice and Development of the IoT Learning Text for Engineering Education Aimed at Next Generation, Journal of University Extension, Vol.26, 19-26, 2017. (Tokushima University Institutional Repository) ● Metadata: 112221 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1050302172853423616 (Tokushima University Institutional Repository: 112221, CiNii: 1050302172853423616)
9.	Akinori Tsuji and Hiroshi Kawakami : Introduction of the Prototyping Method to Technical Education and Its Effect, Journal of University Extension, Vol.25, 55-63, 2016. (Tokushima University Institutional Repository) ● Metadata: 112218 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1050020697876713600 (Tokushima University Institutional Repository: 112218, CiNii: 1050020697876713600)
10.	Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : Classification of Bifurcations and Oscillations in Coupled BVP Oscillators, Journal of Signal Processing, Vol.18, No.1, 39-48, 2014. (Summary) Bonoh¨oeffer-van der Pol (BVP) oscillator is a planer nonlinear model exhibiting a rich variety of bifurcation phenomena for both equilibria and limit cycles. Since it has two ports regarding its state variables, many topologically different coupled systems are obtained even when two identical BVP oscillators are resistively coupled. Although individual coupled systems have been already studied, it is not able to compare them because models of nonlinearity and normalizations are different. In this paper, we firstly unify them, and investigate their bifurcations of equilibria and synchronization modes of limit cycles. As results, common bifurcations of equilibria for all coupled structures are found, and some properties on parameter ranges, synchronization modes and their stabilities are clarified. (Keyword) coupled BVP oscillator / nonlinear autonomous system / bifurcation phenomenon / chaos attractor / coupled BVP oscillator / nonlinear autonomous system / bifurcation phenomenon / chaos attractor (Link to Publication Site) ● Publication site (DOI): 10.2299/jsp.18.39 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1390001204465040512 ● Search Scopus @ Elsevier (DOI): 10.2299/jsp.18.39 (DOI: 10.2299/jsp.18.39, CiNii: 1390001204465040512)
11.	Kunichika Tsumoto, Tetsushi Ueta, Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcation analyses of nonlinear dynamical systems: From theory to numerical computations, Nonlinear Theory and Its Applications, IEICE, Vol.3, No.4, 458-476, 2012. (Summary) In this paper, we explain how to compute bifurcation parameter values of periodic solutions for non-autonomous nonlinear differential equations. Although various approaches and tools are available for this problem nowadays, we introduce the simplest method composed by computational algorithms appeared in textbooks for beginner's, i.e., the Newton's method and Runge-Kutta method. We formulate the given bifurcation problem as a boundary value problem and use the Newton's method as a solver consistently. All derivatives required in each iteration are obtained by solving variational equations about the state and the parameter. Thank to quadratic convergence ability of the Newton's method, accurate results can be obtained without using any sophisticated mathematical library or software. If a discontinuous periodic force is applied to the system, we can take the same strategy to solve the bifurcation problem. The key point of this method is deriving a differentiable composite map from consideration of the various information about the problem such as the location of sections, the periodicity, the Poincaré mapping, and so on. (Keyword) nonlinear dynamical system / bifurcation / boundary value problem / variational equation / Newton's method (Tokushima University Institutional Repository) ● Metadata: 114910 (Link to Publication Site) ● Publication site (DOI): 10.1587/nolta.3.458 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1587/nolta.3.458 (Tokushima University Institutional Repository: 114910, DOI: 10.1587/nolta.3.458)
12.	Takuji Kousaka, Ken'ichi Fujimoto, YUE MA, Tetsushi Ueta and Hiroshi Kawakami : Bifurcations observed in BVP oscillator with periodically switched RC circuit, Dynamics of Continuous, Discrete and Impulsive Systems. Series A: Mathematical Analysis, Vol.16, No.6, 811-824, 2009. (Summary) Many works have been devoted to the study of the behavior of the Bonhoe er-van der Pol (BVP) oscillator in physiological and biochemical modeling studies. In this paper, bifurcation and chaos in BVP oscillator, which is intermittently connected to a parallel RC load, is investigated. By using the periodicity of switching action we introduce a composite discrete mapping as the Poincar´e mapping that is useful for the analysis of piecewise nonlinear systems. Adjusting the switching period close to the integral multiple of the period of self-oscillation, we find various synchronizations. In particular the fundamental synchronization is discussed. Under the appropriate switching ratios, we illustrate that the synchronized state bifurcates to chaotic states by the period doubling cascades or the torus breaking down. (Keyword) nonlinear circuits / periodic switch / composite Poincare mapping / chaos / bifurcation (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-73249140949 (Elsevier: Scopus)
13.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcation analysis of current coupled BVP oscillators, International Journal of Bifurcation and Chaos, Vol.17, No.3, 837-850, 2007. (Summary) The Bonhöffer van der Pol (BVP) oscillator is a simple circuit implementation describing neuronal dynamics. Lately the diffusive coupling structure of neurons attracts much attention since the existence of the gap-junctional coupling has been confirmed in the brain. Such coupling is easily realized by linear resistors for the circuit implementation, however, there are not enough investigations about diffusively coupled BVP oscillators, even a couple of BVP oscillators. We have considered several types of coupling structure between two BVP oscillators, and discussed their dynamical behavior in preceding works. In this paper, we treat a simple structure called current coupling and study their dynamical properties by the bifurcation theory. We investigate various bifurcation phenomena by computing some bifurcation diagrams in two cases, symmetrically and asymmetrically coupled systems. In symmetrically coupled systems, although all internal elements of two oscillators are the same, we obtain in-phase, anti-phase solution and some chaotic attractors. Moreover, we show that two quasi-periodic solutions disappear simultaneously by the homoclinic bifurcation on the Poincaré map, and that a large quasi-periodic solution is generated by the coalescence of these quasi-periodic solutions, but it disappears by the heteroclinic bifurcation on the Poincaré map. In the other case, we confirm the existence a conspicuous chaotic attractor in the laboratory experiments. (Tokushima University Institutional Repository) ● Metadata: 112115 (Link to Publication Site) ● Publication site (DOI): 10.1142/S0218127407017586 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1142/S0218127407017586 (Tokushima University Institutional Repository: 112115, DOI: 10.1142/S0218127407017586)
14.	Yasuo Miyoshi, Takahiro Oie, Tetsushi Ueta, Masanori Hirotomo, Yoneo Yano and Hiroshi Kawakami : Construction of e-Syllabus Supporting the Discovery of Learning Path by Using EDB, Journal of University Education Research, No.3, 1-9, 2006. (Summary) In Tokushima University, the syllabus has been published and opened on the web using an Educator and Researcher Information Database (EDB). We are now developing an e-Syllabus system that represents graphically and dynamically the relationships between lectures. This development represents one of the improvements of infrastructure for education and learning. In order to construct the e-Syllabus, three new columns have been added to each lecture of the syllabus: keywords, preceding lectures and relational lectures. XML is used as a storage format for EDB; it allows us to represent the structured data within on a text file that can be stored on a CD-ROM. Thus, without accessing the web, it is possible to represent graphically and discover the relations between the lectures. This representation of the syllabus supports the students in the discovery of learning-paths and the definition of learning plan. Thus, the e-Syllabus system improves the convenience of using the syllabus. (Keyword) Learning Path / Syllabus / Lecture Outline / EDB / XML (Tokushima University Institutional Repository) ● Metadata: 82383 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1050020697878043392 (Tokushima University Institutional Repository: 82383, CiNii: 1050020697878043392)
15.	Kunichika Tsumoto, Tetsuya Yoshinaga, Hitoshi Iida, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcations in a mathematical model for circadian oscillations of clock genes, Journal of Theoretical Biology, Vol.239, No.1, 101-122, 2006. (Summary) Circadian oscillations with a period of about 24h are observed in nearly all living organisms as conspicuous biological rhythms. In this paper, we investigate various kinds of bifurcation phenomena produced in a circadian oscillator model of Drosophila. In Drosophila, it is known that circadian oscillations in the levels of two proteins, PER and TIM, result from the negative feedback exerted by a PER-TIM complex on the expression of the per and tim genes that code for the two proteins. For studying circadian oscillations of proteins in Drosophila, a mathematical model has been proposed. The model cannot only account for regular circadian oscillations in environmental conditions such as constant darkness, but also give rise to more complex oscillatory phenomena including chaos and birhythmicity. By calculating bifurcations using Kawakami's method, we obtain detailed bifurcation diagrams related to stable and unstable invariant sets, and identify parameter regions in which the model generates complex oscillations as well as regular circadian oscillations. Moreover, we study bifurcations observed in the model incorporating the effect on a light-dark (LD) cycle and show that the waveform of the periodic variation in the light-induced parameter has a marked influence on the global bifurcation structure or the type of dynamic behavior resulting from the forcing term of the circadian oscillator by the LD cycles. (Keyword) Animals / Biological Clocks / Circadian Rhythm / Drosophila / Gene Expression Regulation / Genes, Insect / Models, Genetic (Link to Publication Site) ● Publication site (DOI): 10.1016/j.jtbi.2005.07.017 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 16143345 ● Search Scopus @ Elsevier (PMID): 16143345 ● Search Scopus @ Elsevier (DOI): 10.1016/j.jtbi.2005.07.017 (DOI: 10.1016/j.jtbi.2005.07.017, PubMed: 16143345)
16.	YUE MA, Chi K. Tse, Takuji Kousaka and Hiroshi Kawakami : General Consideration for Modeling and Bifurcation Analysis of Switched Dynamical Systems, International Journal of Circuit Theory and Applications, Vol.28, No.3, 2006. (Link to Publication Site) ● Publication site (DOI): 10.1142/S0218127406015052 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-33744774205 (DOI: 10.1142/S0218127406015052, Elsevier: Scopus)
17.	Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : Stable torus and its bifurcation phenomena in a Three-Dimensional Autonomous Circuit, Chaos, Solitons & Fractals, Vol.27, No.4, 941-951, 2006. (Summary) It is well known that a stable torus is observed as a result after the system meets the super-critical Neimark Sacker bifurcation for a limit cycle. Although tori are easily observed in two-dimensional and periodically forced dynamical systems, there is a few papers about stable tori in three-dimensional autonomous systems. Besides, as physical circuit implementations, such circuits contain very special active elements, or have difficulty in realizing. In this paper, we show a very simple circuit of three-dimensional autonomous system, an extended Bonhöffer van der Pol (BVP) oscillator, which is demonstrating a stable torus. Firstly we explain a discovery of the torus in a computer simulation of the model equation. To implement it as a circuitry, we design a new nonlinear resistor. Although this contains an FET and an op-amp, it is simpler than any other nonlinear resistors proposed in previous papers. We confirm that this BVP oscillator can generate a stable torus in a real circuitry. We thoroughly investigate the bifurcation phenomena of various limit cycles and tori in this circuit, i.e., a super-critical Neimark Sacker and tangent bifurcations of limit cycles are concretely obtained, furthermore, phase locking and chaos regions are clarified in a bifurcation diagram. (Link to Publication Site) ● Publication site (DOI): 10.1016/j.chaos.2005.04.092 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-24344472635 (DOI: 10.1016/j.chaos.2005.04.092, Elsevier: Scopus)
18.	Takuji Kousaka, Tetsushi Ueta, YUE MA and Hiroshi Kawakami : Control of chaos in a piecewise smooth nonlinear system, Chaos, Solitons & Fractals, Vol.27, No.4, 1019-1025, 2006. (Summary) This paper shows the stabilization of the unstable periodic orbit of any given piecewise smooth system with linear and/or nonlinear characteristics. By utilizing the periodicity of the switching action, we construct the Poincare´ mapping including all information of the original system. This mapping offers a first step toward extending a novel technique for controlling chaos based on the appropriate state feedback in piecewise smooth nonlinear systems. We also apply this approach to Rayleigh type oscillator described by the piecewise smooth nonlinear systems. (Link to Publication Site) ● Publication site (DOI): 10.1016/j.chaos.2005.04.068 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-24344480901 (DOI: 10.1016/j.chaos.2005.04.068, Elsevier: Scopus)
19.	Kunichika Tsumoto, Hiroyuki Kitajima, Tetsuya Yoshinaga, Kazuyuki Aihara and Hiroshi Kawakami : Bifurcations in Morris-Lecar neuron model, Neurocomputing, Vol.69, No.4-6, 293-316, 2006. (Keyword) Morris-Lecar model / classes I and II neuron / saddle-node bifurcation / homoclinic bifurcation / TYROSINE-PHOSPHATASE / SYNCHRONY / channel / EXCITABILITY / EQUATIONS / RESPONSES / biomembrane / SPIKING / CORTEX / AXON (Link to Publication Site) ● Publication site (DOI): 10.1016/j.neucom.2005.03.006 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-29444442155 (DOI: 10.1016/j.neucom.2005.03.006, Elsevier: Scopus)
20.	YUE MA, Chi K. Tse, Takuji Kousaka and Hiroshi Kawakami : Connecting border collision with saddle-node bifurcation in switched dynamical systems, IEEE Transactions on Circuits and Systems II: Express Briefs, Vol.52, No.9, 581-585, 2005. (Link to Publication Site) ● Publication site (DOI): 10.1109/TCSII.2005.850488 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1109/TCSII.2005.850488 (DOI: 10.1109/TCSII.2005.850488)
21.	Takuji Kousaka, Tetsushi Ueta, YUE MA and Hiroshi Kawakami : Bifurcation analysis of a piecewise smooth system with non-linear characteristics, International Journal of Circuit Theory and Applications, Vol.33, No.4, 263-279, 2005. (Summary) In previous works, there are no results about the bifurcation analysis for a piecewise smooth system with non-linear characteristics. The main purpose of this study is to calculate the bifurcation sets for a piecewise smooth system with non-linear characteristics. We first propose a new method to track the bifurcation sets in the system. This method derives the composite discrete mapping, Poincare mapping. As a result, it is possible to obtain the local bifurcation values in the parameter plane. As an illustrated example, we then apply this general methodology to the Rayleigh-type oscillator containing a stateperiod- dependent switch. In the circuit, we can find many subharmonic bifurcation sets including global bifurcations. We also show the bifurcation sets for the border-collision bifurcations. Some theoretical results are verified by laboratory experiments. (Link to Publication Site) ● Publication site (DOI): 10.1002/cta.320 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1002/cta.320 (DOI: 10.1002/cta.320)
22.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcation of synchronization phenomena observed in a coupled neuron model for circadian clock rhythms, Systems and Computers in Japan, Vol.36, No.8, 1-14, 2005. (Link to Publication Site) ● Publication site (DOI): 10.1002/scj.20348 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-20344370478 (DOI: 10.1002/scj.20348, Elsevier: Scopus)
23.	Munehisa Sekikawa, Naohiko Inaba, Tetsuya Yoshinaga and Hiroshi Kawakami : Collapse of duck solution in a circuit driven by an extremely small periodic force, Electronics and Communications in Japan, Part 3 : Fundamental Electronic Science, Vol.88, No.4, 51-59, 2005. (Keyword) nonlinear oscillations / duck solutions / chaos / SINGULAR HOPF-BIFURCATION / DYNAMICAL-SYSTEMS / COMPUTATION (Link to Publication Site) ● Publication site (DOI): 10.1002/ecjc.20093 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1002/ecjc.20093 (DOI: 10.1002/ecjc.20093)
24.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcation of Synchronization Phenomena Observed in a Coupled Neuron Model for Circadian Clock Rhythms, The Transactions of the Institute of Electronics, Information and Communication Engineers D-II, Vol.J87-D-II, No.7, 1516-1528, 2004. (Summary) 本研究では,2個のMorris-Lecarニューロンモデルが電気シナプス(gap-junction)と化学シナプス(a関数)により相互結合し,かつ,周期の異なる正弦波外力が個々のニューロンに印加された系を解析する.このモデルは時計遺伝子リズムに起因したニューロン相互の同調を説明するために提案した力学系であり,実際,平均発火率リズム(発火/非発火応答の持続時間変動)の相互同調及び周期外力への同調現象が観察された.系に見られる分岐現象の解析により,生理実験で報告されている同調/脱同調の発生メカニズムが説明できることを明らかにする. (Keyword) 結合系 / サーカディアン発火リズム / 同調 / 分岐 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520853832533522560 (CiNii: 1520853832533522560)
25.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : A design method of bursting using 2-parameter bifurcation diagrams in FitzHugh-Nagumo model, International Journal of Bifurcation and Chaos, Vol.14, No.7, 2241-2252, 2004. (Summary) Spiking and bursting observed in nerve membranes seem to be important when we investigate information representation model in the brain. Many topologically different bursting responses are observed in the mathematical models and their related bifurcation mechanisms have been clarified. In this paper, we propose a design method to generate bursting responses in FitzHugh Nagumo model with a simple periodic external force based on bifurcation analysis. Some effective parameter perturbations for the amplitude of the external input are given from the two-parameter bifurcation diagram. (Keyword) bifurcation / bursting / FitzHugh-Nagumo model / periodic external force / OSCILLATIONS (Tokushima University Institutional Repository) ● Metadata: 112113 (Link to Publication Site) ● Publication site (DOI): 10.1142/S0218127404010564 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1142/S0218127404010564 (Tokushima University Institutional Repository: 112113, DOI: 10.1142/S0218127404010564)
26.	YUE MA, Hiroshi Kawakami and Chi K. Tse : Bifurcation analysis of switched dynamical systems with periodically moving borders, IEEE Transactions on Circuits and Systems I: Regular Papers, Vol.51, No.6, 1184-1193, 2004. (Link to Publication Site) ● Publication site (DOI): 10.1109/TCSI.2004.829240 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1109/TCSI.2004.829240 (DOI: 10.1109/TCSI.2004.829240)
27.	Munehisa Sekikawa, Naohiko Inaba, Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcation structure of fractional harmonic entrainments in the forced Rayleigh oscillator, Electronics and Communications in Japan, Part 3 : Fundamental Electronic Science, Vol.87, No.3, 30-40, 2004. (Link to Publication Site) ● Publication site (DOI): 10.1002/ecjc.10126 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1002/ecjc.10126 (DOI: 10.1002/ecjc.10126)
28.	Tetsushi Ueta, Hisayo Miyazaki, Takuji Kousaka and Hiroshi Kawakami : Bifurcation and chaos in coupled BVP oscillators, International Journal of Bifurcation and Chaos, Vol.14, No.4, 1305-1324, 2004. (Summary) Bonh¨offer van der Pol(BVP) oscillator is a classic model exhibiting typical nonlinear phenomena in the planar autonomous system. This paper gives an analysis of equilibria, periodic solutions, strange attractors of two BVP oscillators coupled by a resister. When an oscillator is fixed its parameter values in nonoscillatory region and the others in oscillatory region, create the double scroll attractor due to the coupling. Bifurcation diagrams are obtained numerically from the mathematical model and chaotic parameter regions are clarified. We also confirm the existence of period-doubling cascades and chaotic attractors in the experimental laboratory. (Keyword) bifurcation / chaos / BVP oscillator / coupling (Tokushima University Institutional Repository) ● Metadata: 112055 (Link to Publication Site) ● Publication site (DOI): 10.1142/S0218127404009983 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1142/S0218127404009983 (Tokushima University Institutional Repository: 112055, DOI: 10.1142/S0218127404009983)
29.	Munehisa Sekikawa, Naohiko Inaba, Tetsuya Yoshinaga and Hiroshi Kawakami : 超微小な周期外力の印加によるあひる解の崩壊とカオス, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J87-A, No.2, 199-207, 2004. (Summary) 本論文では,あひる解を発生するvan der Po1発振器に超微小な周期的外力を印加した場合にどのような分岐現象が生じるのかを調べた.分岐ダイアグラムを作成し,基本調波引込領域,1/2分数調波引込領域,1/3分数調波引込領域の分岐の構造を明らかにした.各々の領域において,周期外力が超微小な領域において周期倍分岐の連鎖的発生が観察され,カオスが発生することが分かった.また,超微小周期外力の印加のもとで二つのあひる解が共存するという興味深い現象も見られた. (Keyword) 非線形振動 / あひる解 / カオス (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520009407120112896 (CiNii: 1520009407120112896)
30.	Takuji Kousaka, Yasuhara Yoshihito, Tetsushi Ueta and Hiroshi Kawakami : Experimental Investigation of Controlling Chaos using Pole Assignment in the Forced BVP Oscillator, IEEJ Transactions on Electronics, Information and Systems, Vol.124-C, No.2, 495-501, 2004. (Summary) In previous work(1), we proposed a control method of the chaotic attractor in the non-autonomous systems and stabilized the unstable periodic orbits observed in the Duffing's equation. Our method can be used as a general technique for controlling chaos, however, the control function was not demonstrated in the laboratory experiments. With this in mind, in this paper, we consider the experimental control of the chaotic behavior in the circuit model, called the forced BVP oscillator. The pole assignment for the corresponding discrete system derived from such a non-autonomous system via Poincaré mapping works effectively, and the control unit is easily realized by the window comparator, sample-hold circuits, and so on. In particular, we try to stabilize the unstable 1 and 3-periodic orbits in the chaotic attractor in the numerical and experimental simulations. (Keyword) non-autonomous system / forced BVP oscillator / controlling chaos / circuit implementation / forced BVP oscillator / controlling chaos / circuit implementation (Link to Publication Site) ● Publication site (DOI): 10.1541/ieejeiss.124.495 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1390282679582944384 ● Search Scopus @ Elsevier (DOI): 10.1541/ieejeiss.124.495 (DOI: 10.1541/ieejeiss.124.495, CiNii: 1390282679582944384)
31.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcation of Burst Response in an Amari-Hopfield Neuron Pair with a Periodic External Force, Electrical Engineering in Japan, Vol.146, No.2, 43-53, 2004. (Keyword) excitatory-inhibitory neuron pair model / bifurcation / a periodic external force / burst response / MODEL / OSCILLATIONS (Link to Publication Site) ● Publication site (DOI): 10.1002/eej.10217 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1002/eej.10217 (DOI: 10.1002/eej.10217)
32.	Hiroyuki Kitajima, Tetsuya Yoshinaga, Kazuyuki Aihara and Hiroshi Kawakami : Itinerant memory dynamics and global bifurcations in chaotic neural networks, Chaos, Vol.13, No.3, 1122-1132, 2003. (Keyword) 2-DIMENSIONAL NONINVERTIBLE MAPS / TRAVELING SALESMAN PROBLEMS / HOMOCLINIC POINTS / MODEL (Link to Publication Site) ● Publication site (DOI): 10.1063/1.1601912 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1063/1.1601912 (DOI: 10.1063/1.1601912)
33.	YUE MA and Hiroshi Kawakami : Combinatorial resonances in a coupled Duffing's crcuit with asymmetry, IEICE Transactions on Fundamentals, Vol.E86-A, No.9, 2340-2346, 2003.
34.	Kunichika Tsumoto, Tetsuya Yoshinaga, Kazuyuki Aihara and Hiroshi Kawakami : Bifurcations in synaptically coupled Hodgkin-Huxley neurons with a periodic input, International Journal of Bifurcation and Chaos, Vol.13, No.3, 653-666, 2003. (Keyword) Hodgkin-Huxley neuron / bifurcation analysis / synaptically coupled neurons / subthreshold and suprathreshold dynamics / phase locked oscillation / SUBTHRESHOLD DYNAMICS / CORTEX (Link to Publication Site) ● Publication site (DOI): 10.1142/S0218127403006832 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1142/S0218127403006832 (DOI: 10.1142/S0218127403006832)
35.	Munehisa Sekikawa, Naohiko Inaba, Tetsuya Yoshinaga and Hiroshi Kawakami : 強制レイリー発振器の分数調波引き込み領域にみられる分岐の構造, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J86-A, No.3, 213-222, 2003. (Summary) 本論文では,強制レイリー方程式の分数調波引込領域の分岐の構造を系の対称性と関連づけて解析する.系の対称性により,状態空間上において原点について対称な形状をしたアトラクタが発生する場合と,原点について非対称な形状をした二つのアトラクタが互いに原点対称な位置に発生する場合の2種類の分数調波周期解の引込領域が存在する.それらの分岐集合のパラメータ平面上での形状を調べたところ,前者と後者の分数調波引込領域は基本調波周明解のネイマルク・サッカー分岐曲線の近傍で異なった構造をもっていることが明らかになった. (Keyword) 強制レイリー発振器 / カオス / 分岐現象 / 分数調波引込領域 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520853833067003776 (CiNii: 1520853833067003776)
36.	Takuji Kousaka, Tetsushi Ueta, Hiroshi Kawakami and Minoru Abe : Implementation and Analysis of a Simple Circuit Causing Border-Collision Bifurcation, IEEJ Transactions on Electronics, Information and Systems, Vol.122-C, No.11, 1908-1916, 2002. (Summary) ecently, a new type of bifurcation phenomena called Border-Collision (abbr. BC) bifurcation has been discovered for one or two-dimensional one-parameter families of discrete-time systems. A skewed tent map is the simplest model exhibiting the BC bifurcation and the existence of break point (undifferentiable point) in the map is an essential for BC bifurcation. In some continuous systems, BC bifurcation is also confirmed. In particular, many interesting bifurcation phenomena including BC bifurcation are observed in the power electronic systems. Since power electronic circuits with current or voltage feedback have wide industrial ap plications, indeed, theoretical and experimental analysis in such systems are very important in practical point of view. In this paper, we propose a system interrupted by own state and a periodic interval, and show that the system has much variety of bifurcation phenomena, including BC bifurcation. To analyze properties of the dynamics, we derive a one-dimensional map explicitly. We show some theorem and the regions of periodic solution within two parameter space. Some of theoretical results are verified by laboratory experiments. (Keyword) Border-Collision bifurcation / Return map / Bifurcation diagram (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1390282679587897600 (CiNii: 1390282679587897600)
37.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcation of Burst Response in Amari-Hopfield Neuron Pair with a Periodic External Force, IEEJ Transactions on Electronics, Information and Systems, Vol.122-C, No.9, 1506-1514, 2002. (Summary) 本論文では一般的な解析によく用いられている Amari-Hopfield 型ニューロンモデルについて，バースト応答の分類と対応を調べ，バースト発生機構を構築している．入力は周期外力とし，これがパラメータ分岐図における各種分岐曲線をまたがって摂動する場合，さまざまなバーストが発生する．周期外力をパラメータとし，その振幅と周波数による分岐図を求めた．バースト発振の発生·消滅·バーストのパルス数は主に接線分岐により増減することを示した．分岐のパターンによって，バースト発振を分類した．これにより，バースト応答の設計が可能となり，仕様を満たすバースト応答を自由に実現できる． (Keyword) excitatory-inhibitory neuron pair model / bifurcation / a periodic external force / burst response (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1390001204609985536 (CiNii: 1390001204609985536)
38.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Controlling chaos in a state-dependent nonlinear system, International Journal of Bifurcation and Chaos, Vol.12, No.5, 1111-1119, 2002. (Summary) In this paper, we propose a general method for controlling chaos in a nonlinear dynamical system containing a state-dependent switch. The pole assignment for the corresponding discrete system derived from such a nonsmooth system via Poincar e mapping works effectively. As an illustrative example, we consider controlling the chaos in the Rayleigh-type oscillator with a state-dependent switch, which is changed by the hysteresis comparator. The unstable one- and two-periodic orbits in the chaotic attractor are stabilized in both numerical and experimental simulations. (Tokushima University Institutional Repository) ● Metadata: 112109 (Link to Publication Site) ● Publication site (DOI): 10.1142/S0218127402004942 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1142/S0218127402004942 (Tokushima University Institutional Repository: 112109, DOI: 10.1142/S0218127402004942)
39.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcations of synchronized responses in synaptically coupled Bonhoeffer-van der Pol neuronss, Physical Review E, Statistical, Nonlinear, and Soft Matter Physics, Vol.65, No.036230, 1-9, 2002. (Summary) The Bonhöffer-van der Pol (BvdP) equation is considered as an important model for studying dynamics in a single neuron. In this paper, we investigate bifurcations of periodic solutions in model equations of four and five BvdP neurons coupled through the characteristics of synaptic transmissions with a time delay. The model can be considered as a dynamical system whose solution includes jumps depending on a condition related to the behavior of the trajectory. Although the solution is discontinuous, we can define the Poincaré map as a synthesis of successive submaps, and give its derivatives for obtaining periodic points and their bifurcations. Using our proposed numerical method, we clarify mechanisms of bifurcations among synchronized oscillations with phase-locking patterns by analyzing periodic solutions observed in the coupling system and its subsystems. Moreover, we show that a global behavior of chaotic itinerancy or a phenomenon of chaotic transitions among several quasiattracting states can be observed in higher-dimensional systems of the synaptically four and five coupled neurons. (Link to Publication Site) ● Publication site (DOI): 10.1103/PhysRevE.65.036230 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 11909235 ● Search Scopus @ Elsevier (PMID): 11909235 ● Search Scopus @ Elsevier (DOI): 10.1103/PhysRevE.65.036230 (DOI: 10.1103/PhysRevE.65.036230, PubMed: 11909235)
40.	YUE MA and Hiroshi Kawakami : Combinatorial resonances in coupled Duffing's circuits, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E85-A, No.3, 648-654, 2002. (Summary) In this paper, we study the fundamental combinatorial nonlinear resonances of a system consisting of two identical periodic forced circuits coupled by a linear resistor. The circuit equations are described by a system of coupled Duffing's equations. We discuss two cases of external periodic force, i.e., in-phase and anti-phase, and obtain the bifurcation diagram of each case. Periodic solutions are classified according to the symmetrical property of the circuit. Resonances in the coupled system are explained from the combinatorial standpoint. That is, we introduce the definition of combinatorial resonances and investigate the patterns of combinatorial solutions in this system. (Keyword) coupled Duffing's circuits / bifurcation / combinatorial pattern (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1570009752558501632 ● Summary page in Scopus @ Elsevier: 2-s2.0-0036522885 (CiNii: 1570009752558501632, Elsevier: Scopus)
41.	Tetsuya Yoshinaga and Hiroshi Kawakami : Chaotic wandering and bifurcations in coupled chaotic neurons, Nonlinear Analysis: Theory, Methods & Applications, Vol.47, No.8, 5357-5365, 2001. (Link to Publication Site) ● Publication site (DOI): 10.1016/S0362-546X(01)00640-X (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0035421592 (DOI: 10.1016/S0362-546X(01)00640-X, Elsevier: Scopus)
42.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Chaos and Control of Periodically Switched Nonlinear Systems, The Latin American Applied Research Journal, Vol.1, No.31, 211-218, 2001. (Summary) This paper discusses chaos and its control in periodically switched nonlinear systems. Since the trajectory of the system is not differentiable at break points, the Poincar sections should be naturally attached at these points and then the Poincar mapping is derived as a composite of local mappings defined among these sections. This map enable us to calculate the location and its stabilities of the periodic points in the chaotic attractor. We also consider chaos control problem based on the Poincar map. The controlled system is fully described as the differentiable map, there fore the controller can be designed by using conventional pole assignment technique. As an illustrated example, we consider a Rayleigh type oscillator containing a periodic switch. We firstly discuss bifurcation sets of the system. The dynamic properties of periodic or bits and chaotic attractors e clarified. We also investigate bifurcation structure of phase locked regions along a Neimark-Sacker bifurcation set. Some theoretical results are con firmed by laboratory experiments. Secondly we try to stabilize one and two-period unstable periodic orbits by using the proposed method. The controller is calculated easily because all information can be obtained from the Poincar map. The results of numerical simulations are demonstrated.
43.	Hiroyuki Kitajima, Tetsuya Yoshinaga, Kazuyuki Aihara and Hiroshi Kawakami : Burst firing and bifurcation in chaotic neural networks with ring structure, International Journal of Bifurcation and Chaos, Vol.11, No.6, 1631-1643, 2001. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1571417125568330752 (CiNii: 1571417125568330752)
44.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcations in synaptically coupled BVP neurons, International Journal of Bifurcation and Chaos, Vol.11, No.4, 1053-1064, 2001. (Link to Publication Site) ● Publication site (DOI): 10.1142/S0218127401002651 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0035593396 (DOI: 10.1142/S0218127401002651, Elsevier: Scopus)
45.	Tetsushi Ueta, Eiji Izumida and Hiroshi Kawakami : Visualization of Bifurcation Surfaces of Periodic Solutions in Nonlinear Dynamical Systems, Transactions of the Visualization Society of Japan, Vol.21, No.4, 65-70, 2001. (Summary) 本論文では， n次元非線形常微分方程式系に含まれる3次元パラメータ空間において，周期解に関する分岐集合(分岐曲面)を計算し， CG として視覚化する方法について述べる．分岐曲面は一種の等値面とみなせるが，一般の等値面構成問題とは異なり，数値積分とn+3 次元方程式の求解を要し，ボクセル判定法は計算コストの観点から用いることができない．そこで，計算コストの削減を念頭においた分岐曲面の構成方法を二つ提案する．構成方法 I は，第 3 パラメータのさまざまな値で第 1, 2 パラメータによる平面で分岐集合をもとめ，それらを接続してポリゴンを生成する手法である．また，構成方法IIは，初期値となるパラメータ平面の分岐集合から自律的に 3次元分岐曲面を探索してゆく手法である．両手法の詳細を述べ，特徴を比較した．これらの可視化手法よって，パラメータ空間中における各種解の存在領域の形状，その発生消滅，カオスの存在位置などの大域的性質が理解でき，系の設計，解析の手助けとなる． (Link to Publication Site) ● Publication site (DOI): 10.3154/tvsj.21.65 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.3154/tvsj.21.65 (DOI: 10.3154/tvsj.21.65)
46.	Tetsushi Ueta, Tetsuya Yoshinaga, Hiroshi Kawakami and Guanrong Chen : A Method to Calculate Neimark-Sacker Bifurcation in Autonomous Systems, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J83-A, No.10, 1141-1147, 2000. (Summary) 自律系にみられるリミットサイクルにおいて，パラメータの変化により特性乗数が複素単位円を横切る場合， Neimark-Sacker 分岐を生じる．本論文ではこの分岐パラメータ値を求める新しい計算方法を提案する．固定点条件，ポアンカレ断面条件に加えて，共役複素数の特性乗数を代入した特性方程式を実部と虚部に分離し，それぞれを独立した条件として採用する．これら条件式を連立させ，ニュートン法により解く．新たな独立変数として，共役複素な特性乗数の偏角を用いた．ニュートン法のヤコビ行列の各要素は，複素数演算，数値微分を用いることなく，変分方程式の解と行列操作によって求めることができるため，ニュートン法の収束性もよい．例として8次元自律系のリミットサイクルのNeimark-Sacker分岐の計算結果を挙げる． (Tokushima University Institutional Repository) ● Metadata: 110721 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1050020697877288832 (Tokushima University Institutional Repository: 110721, CiNii: 1050020697877288832)
47.	Hiroyuki Kitajima, Hiroshi Kawakami and Christian Mira : A method to calculate bifurcation sets for a two-dimensional noninvertible map, International Journal of Bifurcation and Chaos, Vol.10, No.8, 2001-2014, 2000.
48.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : Nonlinear Phenomena on a Two-Link Planer Manipulator with a Free Joint, Transactions of the Institute of Systems, Control and Information Engineers, Vol.13, No.8, 369-376, 2000. (Link to Publication Site) ● Publication site (DOI): 10.5687/iscie.13.8_369 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1390282680141947520 ● Search Scopus @ Elsevier (DOI): 10.5687/iscie.13.8_369 (DOI: 10.5687/iscie.13.8_369, CiNii: 1390282680141947520)
49.	Naohiko Inaba, Ryo Fujimoto, Hiroshi Kawakami and Tetsuya Yoshinaga : Period doubling bifurcation and chaos observed in regions of higher-harmonic entrainment in the forced Rayleigh oscillator, Electronics and Communications in Japan (Part II: Electronics), Vol.83, No.2, 35-43, 2000. (Link to Publication Site) ● Publication site (DOI): 10.1002/(sici)1520-6432(200002)83:2<35::aid-ecjb5>3.0.co;2-c (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0347074610 (DOI: 10.1002/(sici)1520-6432(200002)83:2<35::aid-ecjb5>3.0.co;2-c, Elsevier: Scopus)
50.	Ken-ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : Forced Oscillatory Phenomena of a Two-Link Planer Manipulator with a Free Joint under Repetitive Motion, Transactions of the Institute of Systems, Control and Information Engineers, Vol.12, No.10, 596-603, 1999.
51.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : Forced Oscillatory Phenomena of a Two-Link Planer Manipulator with a Free Joint under Repetitive Motion, Transactions of the Institute of Systems, Control and Information Engineers, Vol.12, No.10, 596-603, 1999. (Link to Publication Site) ● Publication site (DOI): 10.5687/iscie.12.596 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1390282680142346112 ● Search Scopus @ Elsevier (DOI): 10.5687/iscie.12.596 (DOI: 10.5687/iscie.12.596, CiNii: 1390282680142346112)
52.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcation of a modified BVP circuit model for neurons generating rectangular waves, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E82-A, No.9, 1729-1736, 1999. (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0033184957 (Elsevier: Scopus)
53.	Christian Mira, Qriouet Touzani and Hiroshi Kawakami : Bifurcation structures generated by the nonautonomous Duffing equation, International Journal of Bifurcation and Chaos, Vol.9, No.7, 1363-1379, 1999.
54.	Tetsuya Yoshinaga, Yasuhiko Sano and Hiroshi Kawakami : A method to calculate bifurcations in synaptically coupled Hodgkin-Huxley equations, International Journal of Bifurcation and Chaos, Vol.9, No.7, 1451-1458, 1999. (Link to Publication Site) ● Publication site (DOI): 10.1142/S0218127499001000 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0033164101 (DOI: 10.1142/S0218127499001000, Elsevier: Scopus)
55.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Bifurcation of Switched Nonlinear Dynamical Systems, IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, Vol.CAS-2, No.7, 878-885, 1999. (Summary) This paper proposes a method to trace bifurcation sets for a piecewise-defined differential equation. In this system, the trajectory is continuous, but it is not differentiable at break points of the characteristics. We define the Poincare mapping by suitable local sections and local mappings, and thereby it is possible to calculate bifurcation parameter values. As an illustrated example, we analyze the behavior of a two-dimensional nonlinear autonomous system whose state space is constrained on two half planes concerned with state dependent switching characteristics. From investigation of bifurcation diagrams, we conclude that the tangent and global bifurcations play an important role for generating various periodic solutions and chaos. Some theoretical results are confirmed by laboratory experiments (Link to Publication Site) ● Publication site (DOI): 10.1109/82.775383 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1109/82.775383 (DOI: 10.1109/82.775383)
56.	Yoshio Tanaka, Hiroshi Kawakami and Ken'ichi Fujimoto : Swing-Up Control of a Inverted Pendulum Using Chaotic Motion, Transactions of The Japan Society of Mechanical Engineers, Series C, Vol.65, No.634, 2338-2344, 1999. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1390282681303755008 (CiNii: 1390282681303755008)
57.	Pierre Jean Carcasses and Hiroshi Kawakami : Existence of a cusp point on a fold bifurcation curve and stability of the associated fixed point, --- Case of an n-dimensional map ---, International Journal of Bifurcation and Chaos, Vol.9, No.5, 875-894, 1999.
58.	Hiroyuki Kitajima, Yasushi Noumi and Hiroshi Kawakami : Forced Synchronization of Coupled Oscillators, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E82-A, No.4, 700-703, 1999. (Summary) 本論文は，電圧結合した2個の発振器系に正弦波入力を印加した場合にみられる基本調波引き込み現象を解析したものである．
59.	Yuichi Nakamura, Yoshihiro Nakamo and Hiroshi Kawakami : ねじれ環状構造に結合されたニューラル発振器のN相振動, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J82-A, No.2, 228-238, 1999. (Summary) 本論文は，ニューラル発振器の入出力をねじって結合させることにより任意のN相振動が得られることを提案したものである．
60.	Yuichi Nakamura and Hiroshi Kawakami : 3 成分系アナログニューラル発振器の分岐現象とカオスアトラクタ, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J81-A, No.11, 1345-1351, 1998. (Summary) 本論文は，3 成分系アナログニューラル発振器にみられる硬い発振現象と周期振動の周期倍分岐現象を解析し，カオス振動の発生することを示したものである．
61.	Naohiko Inaba, Tooru Fujimoto, Hiroshi Kawakami and Tetsuya Yoshinaga : 強制レイリー発振器の高調波引込領域にみられる周期倍分岐とカオス, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J81-A, No.8, 1134-1141, 1998. (Summary) 本論文は，強制レイリー発振器の高調波引込領域にみられる周期倍分岐とカオスについて分岐理論を用いて解析したものである． (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520009410296484096 (CiNii: 1520009410296484096)
62.	Tetsuya Yoshinaga and Hiroshi Kawakami : 睡眠覚醒リズムの結合発振器モデルにみられる分岐現象, 日本ME学会誌, Vol.12, No.5, 3-10, 1998. (Summary) 本論文は，睡眠覚醒と体温のリズムに関する結合発振器モデルにみられる分岐現象を解析したものである． (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1571698599600161792 (CiNii: 1571698599600161792)
63.	Takuji Kosaka, Yutaka Umakoshi, Tetsushi Ueta and Hiroshi Kawakami : Bifurcation of Nonlinear Circuits with Periodically Operating Switch, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J81-A, No.5, 836-843, 1998. (Summary) 本論文では，レイリー型の発振器部分とスイッチで制御される直流電源部分から構成される Alpazur 発振器の分岐集合を数値計算により求めた．従来法による分岐パラメータの計算方法では，スイッチの断続条件が軌道の連続微分性を失わせていしまい，そのままの適用はできない．そこでスイッチング動作の周期性を利用して，たくみにポアンカレ写像を構成し，分岐パラメータを計算することに成功した．定式化とアルゴリズムについて述べる．さらには Neimark-Sacker 分岐に沿って生じる位相同期解とカオスについて詳細に解析した． (Tokushima University Institutional Repository) ● Metadata: 110720 (Tokushima University Institutional Repository: 110720)
64.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Synchronization of Electric Fireflies by using Square Wave Generators, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E81-A, No.5, 656-663, 1998. (Summary) In this article, we propose a square wave generator whose switching threshold values are switched by external inputs. This circuit is designed to simulate the synchronized luminescence of coupled fireflies. We investigate the behavior of the solutions in two coupled oscillators. The dynamics are demonstrated by a linear autonomous equation piecewisely, therefore, a one-dimensional return map is derived. We also prove the existence of stable in-phase synchronization in the coupled oscillator by using the return map, and we show the existence of regions of periodic solutions within a parameter space. Some theoretical results are confirmed by laboratory measurements. (Tokushima University Institutional Repository) ● Metadata: 110701 (Tokushima University Institutional Repository: 110701)
65.	Hiroyuki Kitajima, Yuji Katsuta and Hiroshi Kawakami : Bifurcations of Periodic Solutions in a Coupled Oscillator with Voltage Ports, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E81-A, No.3, 476-482, 1998. (Summary) 本論文は，抵抗により電圧結合した結合発振器にみられる対称な周期振動を分類し，解析したものである．
66.	Tetsuya Yoshinaga, Hiroyuki Kitajima, Hiroshi Kawakami and Christian Mira : A Method to Calculate Homoclinic Points of a Two Dimensional Noninvertible Map, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E80-A, No.9, 1560-1566, 1997. (Summary) 本論文は，非可逆写像のホモクリニック点を求めるアルゴリズムを提案したものである．具体的な計算例もあげられている． (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0031220523 (Elsevier: Scopus)
67.	Yoshio Tanaka, Hiroshi Kawakami and Tetsushi Ueta : Nonlinear Phenomena in Overhead-Crane-Type One-Link Manipulator, Transactions of The Japan Society of Mechanical Engineers, Series C, Vol.63, No.7, 2360-2367, 1997. (Summary) The dynamics of an overhead-crane-type one-link manipulator with a passive joint is essentially described by nonlinear ordinary differential equations including trigonometric functions. Under certain conditions, therefore, it is predicted that a manipulator performing repetitive tasks will exhibit typical nonlinear phenomena, such as the coexistence of several periodic vibrations and chaotic states of vibrations. In this paper, periodic motions of the manipulator are studied numerically, and their bifurcation diagrams in several parameter planes are calculated using the algorithms based on the geometric approach of ordinary differential equations. Period-doubling bifurcation leading to chaotic motions are observed in some parameter areas.
68.	北島博之 and Hiroshi Kawakami : 周期倍分岐と Neimark-Sacker 分岐列について, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J80-A, No.3, 491-498, 1997.
69.	T Mihara and Hiroshi Kawakami : Synchronization and Chaos of Coupled Duffing-Rayleigh Oscillators, IEICE Transactions, Vol.E79-A, No.10, 1581-1586, 1996.
70.	Olivier Papy and Hiroshi Kawakami : Symmetry Breaking and Recovering in a System of n Hybridly Coupled Oscillators, IEICE Transactions, Vol.E79-A, No.10, 1568-1574, 1996.
71.	Hiroyuki Kitajima, Tetsuya Yoshinaga and Hiroshi Kawakami : Codimension two bifurcation observed in a phase converter circuit, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E79-A, No.10, 1563-1567, 1996. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1572543027348377216 ● Summary page in Scopus @ Elsevier: 2-s2.0-0030264015 (CiNii: 1572543027348377216, Elsevier: Scopus)
72.	Tetsushi Ueta and Hiroshi Kawakami : Bifurcation phenomena in the Josephson junction circuit coupled by a resistor, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E79-A, No.10, 1546-1550, 1996. (Summary) Bifurcation phenomena observed in a circuit containing two Josephson junctions coupled by a resistor are investigated. This circuit model has a mechanical analogue; Two damped pendular linked by a clutch exchanging kinetic energy of each pendulum. In this paper, firstly we study equilibria of the system. Bifurcations and topological properties of the equilibria are clarified. Secondly we analyse periodic solutions in the system by using suitable Poincare mapping and obtain a bifurcation diagram. There are two types of limit cycles distinguished by whether the motion is in S1 * R3 or T2 * R2, since at most two cyclic coordinates are included in the state space. There is a typical structure of tangent bifurcation for 2-periodic solutions with a cusp point. We found chaotic orbits via the period-doubling cascade, and a long-period stepwise orbit. (Tokushima University Institutional Repository) ● Metadata: 110695 (Tokushima University Institutional Repository: 110695)
73.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : A Method to Generatr a Chaotic Attractor by Destabilization, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J79-A, No.8, 1418-1426, 1996. (Summary) 本論文では，自律系にみられる安定平衡点やリミットサイクルに対し，不安定化制御を行う．これは，線形制御理論の極配置法において，不安定極を指定することによって達成され，結果としてカオスアトラクタを得ることができる．安定平衡点の場合は，安定平衡点周りの特性方程式の極を不安定に指定した制御器を取り付け，制御を印加する時間を適当に与える．また，リミットサイクルに対しては，ポアンカレ写像を定義し，それによって得られる差分方程式系の固定点を不安定化し, カオスを発生させる．これらの手法の適用例として，勾配系回路, van der Pol方程式，拡張BVP発振器のモデルにそれぞれ不安定化制御を施し，得られたカオスについて検討した． (Tokushima University Institutional Repository) ● Metadata: 110719 (Tokushima University Institutional Repository: 110719)
74.	北島博之 and Hiroshi Kawakami : 固定点多様体を追跡する 1 アルゴリズムについて, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J79-A, No.5, 1122-1124, 1996.
75.	Olivier Papy and Hiroshi Kawakami : Symmetrical Properties and Bifurcations of the Equilibria for a Resistively Coupled Oscillator with Hybrid Connection, IEICE Transactions, Vol.E 78-A, No.12, 1822-1827, 1995.
76.	Olivier Papy and Hiroshi Kawakami : Symmetrical Properties and Bifurcations of the Periodic Solutions for Hybridly Coupled Oscillator, IEICE Transactions, Vol.E 78-A, No.1253, 1816-1821, 1995.
77.	中村雄一 and Hiroshi Kawakami : 硬い発振器にみられる同期振動の分岐, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J78-A, No.11, 1460-1467, 1995.
78.	Tetsuya Yoshinaga, Hiroyuki Kitajima and Hiroshi Kawakami : Bifurcations in a coupled Roessler system, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E78-A, No.10, 1276-1280, 1995. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1572543027239220096 (CiNii: 1572543027239220096)
79.	Tetsushi Ueta, Hiroshi Kawakami and Ikuro Morita : A Study of the Pendulum Equation with a Periodic Impulsive Force, --- Bifurcation and Control ---, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E78-A, No.10, 1269-1275, 1995. (Summary) The pendulum equation with a periodic impulsive force is investigated. This model described by a second order differential equation is also derived from dynamics of the stepping motor. In this paper, firstly, we analyze bifurcation phenomena of periodic solutions observed in a generalized pendulum equation with a periodic impulsive force. There exist two topologically different kinds of solution which can be chaotic by changing system parameters. We try to stabilize an unstable periodic orbit embedded in the chaotic attractor by small perturbations for the parameters. Secondly, we investigate the intermittent drive characteristics of two-phase hybrid stepping motor. We suggest that the unstable operations called pull-out are caused by bifurcations. Finally, we proposed a control method to avoid the pull-out by changing the repetitive frequency and stepping rate. (Tokushima University Institutional Repository) ● Metadata: 110694 (Tokushima University Institutional Repository: 110694)
80.	Mozammel Hoque and Hiroshi Kawakami : Resistively Coupled Oscillators with Hybrid Connection, IEICE Transactions, Vol.E 78-A, No.9, 1253-1256, 1995.
81.	勝田祐司 and Hiroshi Kawakami : 環状に 5 個結合した発振器回路の対称性を有する周期解について, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J78-A, No.8, 984-991, 1995.
82.	Yoshio Tanaka, Tetsushi Ueta, Hiroshi Kawakami and Takashi Sumitomo : A Robotic Truck Crane with Vibration Sensors, Journal of Robotics and Mechatronics, Vol.7, No.3, 213-217, 1995. (Summary) To solve the problems of the shortage and increasing age of skilled operators in Japan, we propose a new concept of "robotic crane system" or "intelligent crane system" and develop the prototype system under laboratory conditions. This paper describes the hardware of the robotic crane system, control design of the flexible rotary crane using vibration sensors, and the first experimental results. In order to simulate the crane's load swing efficiently and develop a 3-D simulator for cranes with a spherical pendulum such as a rotary crane, an efficient dynamic simulation method is also presented. This method was applied to the prototype system.
83.	Tetsushi Ueta and Hiroshi Kawakami : Composite dynamical system for controlling chaos, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E78-A, No.6, 708-714, 1995. (Summary) We propose a stabilization method of unstable periodic orbits embedded in a chaotic attractor of continuous-time system by using discrete state feedback controller. The controller is designed systematically by the Poincare mapping and its derivatives. Although the output of the controller is applied periodically to system parameter as small perturbations discontinuously, the controlled orbit accomplishes C^0. As the stability of a specific orbit is completely determined by the design of controller, we can also use the method to destabilize a stable periodic orbit. The destabilization method may be effectively applied to . escape from a local minimum in various optimization problems. As an example of the stabilization and destabilization, some numerical results of Duffing's equation are illustrated. (Tokushima University Institutional Repository) ● Metadata: 110693 (Tokushima University Institutional Repository: 110693)
84.	北島博之 and Hiroshi Kawakami : 接線分岐曲線を自動追跡できるアルゴリズムとそのDuffing方程式への応用, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J78-A, No.7, 806-810, 1995.
85.	Mozammel Hoque and Hiroshi Kawakami : Controlling the Stability of Resistively Coupled Oscillators, IEICE Transactions, Vol.E 78-A, No.4, 541-544, 1995.
86.	Mozammel Hoque and Hiroshi Kawakami : Resistively Coupled Wien Bridge Oscillators, IEICE Transactions, Vol.E 78-A, No.4, 498-505, 1995.
87.	Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcations of quasi-periodic responses in coupled van der Pol oscillators with external force, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E77-A, No.11, 1783-1787, 1994. (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0028548174 (Elsevier: Scopus)
88.	小針憲一, 斉藤利通 and Hiroshi Kawakami : しきい値が周期的に変化する弛張発振器に見られるカオスと基本的な分岐現象について, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J77-A, No.12, 1477-1485, 1994.
89.	田中芳夫 and Hiroshi Kawakami : 天井走行形 1 リンクマニピュレータに見られる非線形現象, Transactions of The Japan Society of Mechanical Engineers, Series C, Vol.61, No.583, 791-798, 1994.
90.	Takahiro Oie, Tadamitsu Iritani and Hiroshi Kawakami : Response of PLL Demodulator by Two Sinusoidal Inputs, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E 77-A, No.11, 1771-1776, 1994. (Summary) 本論文では周波数ホッピングスペクトル拡散(FH-SS)通信において周波数シフトキーキング(FSK)変調された信号をPLL (Phase Locked Loop)によって復調する場合を想定し，目的局信号以外に干渉信号が受信信号に混入する状況における復調性能を調べるため，2つの正弦波が入力されたときのPLLの応答を調べた．まず，2つの正弦波が入力されたときのPLLの同期ダイアグラムを作成し，目的局のFSK変調指数を変化させたときの干渉信号による同期外れの影響を調べた．その結果，目的局のFSK変調指数を十分に小さくしたとしても許容できる目的-干渉信号比の大きさには限界があることを示した．
91.	Olivier Papy and Hiroshi Kawakami : Bifurcations of the Quasi-Periodic Solutions of a Coupled van der Pol Oscillator, IEICE Transactions, Vol.E 77-A, No.11, 1788-1793, 1994.
92.	Tetsushi Ueta and Hiroshi Kawakami : Bifurcation of an inductively coupled Josephson junction circuit, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E77-A, No.11, 1758-1763, 1994. (Summary) Some qualitative properties of an inductively coupled circuit containing two Josephson junction elements with a dc source are investigated. The system is described by a four-dimensional autonomous differential equation. However, the phase space can be regarded as S^1×R^3 because the system has a periodicity for the invariant transformation. In this paper, we study the properties of periodic solutions winding around S^1 as a bifurcation problem. Firstly, we analyze equilibria in this system. The bifurcation diagram of equilibria and its topological classification are given. Secondly, the bifurcation diagram of the periodic solutions winding around S^1 are calculated by using a suitable Poincare mapping, and some properties of periodic solutions are discussed. From these analyses, we clarify that a periodic solution so-called "caterpillar solution" [1] is observed when the two Josephson junction circuits are weakly coupled. (Tokushima University Institutional Repository) ● Metadata: 110689 (Tokushima University Institutional Repository: 110689)
93.	吉川研一 and Hiroshi Kawakami : 化学反応系の非線形ダイナミクス - 結合振動系を中心に -, 応用数理, Vol.4, No.3, 238-258, 1994.
94.	勝田祐司 and Hiroshi Kawakami : 環状に結合した発振器回路の周期解の対称性について, 宇部高専研究報告, Vol.40, 21-24, 1994.
95.	Christian Mira, Daniel Fournier, Leon Bardini, Hiroshi Kawakami and Jean Cathala : Basin Bifurcations of Two-dimensional Noninvertible Maps: Fractalization of Basins, International Journal of Bifurcation and Chaos, Vol.4, No.2, 343-381, 1994.
96.	Tetsushi Ueta and Hiroshi Kawakami : Bifurcation of heteroclinic orbits in a circuit containing a Josephson junction element, Electronics and Communications in Japan, Part 3 : Fundamental Electronic Science, Vol.77, No.2, 85-93, 1994. (Summary) The circuit equation of the circuit containing a Josephson junction and the equation of motion of a pendulum in which an elastic restoring force is applied in the direction of rotation are described in terms of a second-order ordinary differential equation containing the sum of a trigonometric term on the state and a linear term. In such a dynamic system, the number of saddles and sinks changes according to the parameter values and no periodicity exists with respect to the location of the saddles and sinks, thus analysis is difficult. In this paper, a circuit containing a Josephson junction is chosen as an example of such a dynamic system. Classification by the tangent bifurcation of the saddles and sinks and the results of the analysis based on the heteroclinic orbits on the phase plane are presented. The heteroclinic orbit presents a global bifurcation on the phase plane due to its structural instability. The parameters generated by this orbit are used as the values for the bifurcation, and the bifurcation set was derived on the parameter plane. As a result, the unique linking number is defined for a particular parameter region surrounded by the bifurcation curve. This value can be used as a guideline for rotation of the orbit on the phase plane. Further, by combining it with the bifurcation ensemble, a classification of the stable sinks in the basin is made possible. (Link to Publication Site) ● Publication site (DOI): 10.1002/ecjc.4430770209 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1002/ecjc.4430770209 (DOI: 10.1002/ecjc.4430770209)
97.	Ken'ichi Kohari, Toshimichi Saito and Hiroshi Kawakami : On a Hysteresis Oscillator Including Periodic Thresholds, IEICE Transactions, Vol.E 76-A, No.12, 2102-2107, 1993.
98.	勝田祐司 and Hiroshi Kawakami : 対称性をもつ非線形非自律系に見られる周期解の分岐, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.J76-A, No.12, 1753-1760, 1993.
99.	Tetsushi Ueta and Hiroshi Kawakami : Bifurcation of Heteroclinic Orbits in a Circuit Containing a Josephson Junction Element, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J76-A, No.10, 1450-1456, 1993. (Summary) ジョセフソン接合素子を含む回路の回路方程式や，回転方向に弾性復元力の働く振り子の運動方程式などは，状態に関する三角関数の項と線形項の和を含んだ2階の常微分方程式で記述される．このような力学系は，平衡点の数がパラメータの値によって変わり，平衡点の位置に関して周期性を持たなくなるため解析が難しい．本論文では，この力学系の例としてジョセフソン接合素子を含む回路を取り上げ，平衡点の接線分岐による分類，および相平面上に生じるヘテロクリニック軌道に着目した解析の結果を述べる．ヘテロクリニック軌道は，その構造不安定性により，相平面上での大域的な分岐を表す．この軌道の生じるパラメータを分岐の値として，パラメータ平面で分岐集合を求めた．その際，分岐曲線によって囲まれる1つのパラメータ領域に，唯一決まるまつわり数を定義した．これは，軌道の相平面での回転の指標として用いることができ，さらに分岐集合と組み合わせることによって，安定平衡点の引力圏の分類を可能にした． (Tokushima University Institutional Repository) ● Metadata: 110718 (Tokushima University Institutional Repository: 110718)
100.	Christian Mira, Hiroshi Kawakami and Rene Allam : The Dovetail Bifurcation Structure and Its Qualitative Changes, International Journal of Bifurcation and Chaos, Vol.3, No.4, 903-919, 1993.
101.	Hiroshi Kawakami : CG によるカオスの可視化, 可視化情報学会論文誌, Vol.13, No.50, 32-37, 1993.
102.	Yoshisuke Kaneda, 中田聡 and Hiroshi Kawakami : 化学種によってパターンを変える電気化学振動子, Chemistry and Education, Vol.41, No.6, 400-403, 1993.
103.	Yoshio Tanaka, Yasuo Yoshida, Tetsushi Ueta and Hiroshi Kawakami : Vibration suppressing control of flexible rotary crane using tip position sensor, Journal of Robotics and Mechatronics, Vol.4, No.6, 520-525, 1993. (Summary) For vibration suppressing control of flexible rotary cranes, two control methods by the use of a tip position sensor have been proposed. One is a control system that suppresses transient vibrations generated by the impact of switching of driving speeds when Bang-Bang control, open-loop anti-swing control, is completed. The other is a servo system to which vibration suppressing feedback is added. Experiments have confirmed that either system is remarkably effective in suppressing vibration.
104.	Tetsuya Yoshinaga and Hiroshi Kawakami : Synchronized quasi-periodic oscillations in a ring of coupled oscillators with hard characteristics, Electronics and Communications in Japan, Part 3 : Fundamental Electronic Science, Vol.76, No.5, 110-120, 1993. (Link to Publication Site) ● Publication site (DOI): 10.1002/ecjc.4430760511 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0027599689 (DOI: 10.1002/ecjc.4430760511, Elsevier: Scopus)
105.	Yoshio Tanaka, Tetsushi Ueta and Hiroshi Kawakami : Efficient Dynamic Simulation Method of Cranes with a Spherical Pendulum, Transactions of The Japan Society of Mechanical Engineers, Series C, Vol.59, No.3, 186-190, 1993. (Summary) 旋回型クレーンにおいて，クレーン本体と吊り荷を一つの開ループリンク機構としてモデリングを行うことを提案している．受動関節と仮想リンクという新しい概念を導入し，従来使用されている開ループリンク機構ロボット用に開発された高速シミュレーション方法が適用可能となった．本文ではリンクの構成問題の詳述と，適用例，それらの数値計算結果を示している．適用例では，実験用に製作したクレーンの実パラメータを用いてシミュレーションを行い，実機とシミュレーションとの差違についても検討している．また，結果の3次元ソリッドモデルによるグラフィクス表示も試みている．
106.	Toshihiro Okamoto, Masanobu Haraguchi, Masuo Fukui, Hiroshi Kawakami and Samir J. Al-Bader : Optical Bistability in Prism / Ag Film / Nonlinear Film / Air Geometry by Utilizing Surface Plasmon and Guided Wave Characteristics, Journal of the Physical Society of Japan, Vol.62, No.3, 918-925, 1993. (Summary) 表面プラズモンと導波光を励起することによって発生する光双安定性現象を理論検討した．非線形媒質としてはカー効果を示す4BCMU膜を用いた．TEおよびTM偏光に対する解析および数値計算を行った．導波光の方が光双安定現象を生じさせる臨界入力光強度Pcが小さい．条件を選べば，Pcを1W/cm²以下にすることが可能であることがわかった．
107.	Tetsuya Yoshinaga and Hiroshi Kawakami : 環状に結合した硬い発振器に見られる同期した準周期振動, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J75-A, No.12, 1811-1818, 1992. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520290885258275200 (CiNii: 1520290885258275200)
108.	Pierre Jean Carcasses, Hiroshi Kawakami and Christian Mira : Singular points with two multipliers, S1=-S2=1, in the bifurcation curves of maps, International Journal of Bifurcation and Chaos, Vol.2, No.4, 1001-1004, 1992.
109.	Ken'ichi Yoshikawa, Tetsuya Yoshinaga, Hiroshi Kawakami and Satoshi Nakata : New strategy of informational processing: utilization of nonlinear dynamics to chemical sensing, Physica A: Statistical Mechanics and its Applications, Vol.188, No.3, 243-250, 1992. (Link to Publication Site) ● Publication site (DOI): 10.1016/0378-4371(92)90270-Z (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0010423359 (DOI: 10.1016/0378-4371(92)90270-Z, Elsevier: Scopus)
110.	Hiroshi Kawakami : Bifurcation and Chaotic State in Forced Oscillatory Circuits Containing Saturable Inductors, International Journal of Applied Electromagnetics in Materials, Vol.3, 215-220, 1992.
111.	Satoshi Nakata, Ken'ichi Yoshikawa and Hiroshi Kawakami : Entrainment in an Electrochemical Forced Oscillator as a Method of Classification of Chemical Species - a New Strategy to Develop a Chemical Sensor -, Physica D, Vol.59, No.6, 169-176, 1992.
112.	Yuji Katsuta and Hiroshi Kawakami : 対称性を持つ非線形自律系にみられる平衡点と周期解の分岐, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.J75-A, No.6, 1035-1044, 1992.
113.	Ken'ichi Yoshikawa and Hiroshi Kawakami : 化学モデルと不動点-化学反応によるリズムとパターン, Journal of Information Processing Society of Japan, Vol.33, No.4, 334-341, 1992.
114.	Tetsuya Yoshinaga, Hiroshi Kawakami and Ken'ichi Yoshikawa : Mode bifurcations in diffusively coupled van der Pol equations, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E-74, No.6, 1420-1427, 1991. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1573950401429853696 (CiNii: 1573950401429853696)
115.	Ken'ichi Yoshikawa, Kenji Fukunaga and Hiroshi Kawakami : A tri-phasic mode is stable when three non-linear oscillators interact with each other, Chemical Physics Letters, Vol.174, No.2, 203-207, 1990.
116.	Tetsuya Yoshinaga and Hiroshi Kawakami : Codimension two bifurcation problems in forced nonlinear circuits, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E-73, No.6, 817-824, 1990.
117.	Tetsuya Yoshinaga and Hiroshi Kawakami : 周期的外力を加えた非線形回路にみられる余次元2の分岐, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J72-A, No.11, 1821-1828, 1989. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520572360255593472 (CiNii: 1520572360255593472)
118.	Hiroshi Kawakami : Computation of Bifurcation Diagram: A Case Study for Duffing's Equation, Computer Theoretikum und Practikum fur Physiker, No.4, 69-916, 1989.
119.	Satoshi Nakata, Ken'ichi Yoshikawa, Mamoru Shoji, Hiroshi Kawakami and Takashi Ishii : Characteristic response to taste stimuli of the intensities of higher harmonics in an electrochemical oscillatory system, Biophysical Chemistry, Vol.34, No.3, 201-210, 1989.
120.	Tetsuya Yoshinaga, Hiroshi Kawakami and Ken'ichi Yoshikawa : 水·油界面に生じる化学的非線形振動の回路モデル, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J71-A, No.10, 1843-1851, 1988. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520009410276212224 (CiNii: 1520009410276212224)
121.	Ken'ichi Yoshikawa, Satoru Maeda and Hiroshi Kawakami : Various Oscillatory Regimes and Bifurcations in a Dynamic Chemical System at an Interface, Ferroelectrics, Vol.86, No.10, 281-298, 1988.
122.	Akio Sakamoto, Hiroshi Kawakami and Ken'ichi Yoshikawa : A Graph Theoretical Approachto Complex Reaction Networks, Chemical Physics Letters, Vol.146, No.5, 444-448, 1988.
123.	Ken'ichi Yoshikawa, Mamoru Shoji, Satoshi Nakata, Satoru Maeda and Hiroshi Kawakami : An Excitable Liquid Membrane Possibly Mimikingthe Sensing Mechanism of Taste, Langmuir, Vol.4, No.3, 759-762, 1988.
124.	Yoneo Yamamoto, Keiji Ozaki, Takashi Tojo, Akio Sakamoto and Hiroshi Kawakami : パーソナルコンピュータによるカリキュラム相談システム, Transactions of Information Processing Society of Japan, Vol.27, No.7, 736-743, 1986.
125.	Daniel Fournier, Hiroshi Kawakami and Christian Mira : La chaine de laisons:image symbolique d'un ensemble complet de communications entre feuillets du plan des bifurcations d'un diffeo-morphisme bidimensionnel, Comptes rendus des seances de l'Academie des sciences. Serie D, Sciences narurelles, Vol.303-I, No.7, 315-320, 1986.
126.	Hiroshi Kawakami : Algorithme optimal definissantles suites de rotations de yn+1=yn2 - l, Notion de cycle adjoint, C. R. Acad. Sc. Paris, Vol.301-I, No.12, 643-648, 1985.
127.	Daniel Fournier, Hiroshi Kawakami and Christian Mira : Sequencess de Myrberg et communications entre feuilletsdes bifurcations d'un diffeo-morphisme bidimensionnel, Comptes rendus des seances de l'Academie des sciences. Serie D, Sciences narurelles, Vol.301-I, No.6, 325-328, 1985.
128.	Daniel Fournier, Hiroshi Kawakami and Christian Mira : Feuilletage du plan des bifurcations d'un diffeomorphisme bidimensionnel. Doublement de l'ordre(periode) des zones sources et des zones echangeurs, C. R. Acad. Sc. Paris, Vol.301-I, No.5, 223-228, 1985.
129.	Daniel Fournier, Hiroshi Kawakami and Christian Mira : Sur les bifurcations d'un diffeomorphisme quadratique bi-dimensionnel. Situations homoclines et heteroclines. Zone Morse-Smale, C. R. Acad. Sc. Paris, Vol.298-I, No.11, 253-256, 1984.
130.	Hiroshi Kawakami and 尾崎安彦 : n次元自律系方程式のセパラトリクス閉路の解析, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J67-A, No.11, 1098-1099, 1984.
131.	Hiroshi Kawakami : Bifurcation of Periodic Responses in Forced Dynamic Nonlinear Circuits: Computation of Bifurcation Values of the System Parameters, IEEE Transactions on Circuits and Systems, Vol.CAS-31, No.3, 248-260, 1984. (Link to Publication Site) ● Publication site (DOI): 10.1109/TCS.1984.1085495 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1109/TCS.1984.1085495 (DOI: 10.1109/TCS.1984.1085495)
132.	Hiroshi Kawakami and 松尾次郎 : 非線形方程式にみられる準周期解の計算, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J65-A, No.7, 723-724, 1982.
133.	Hiroshi Kawakami and 勝田祐司 : まつわり数を考慮したリミットサイクルの分岐, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J65-A, No.7, 723-724, 1982.
134.	Hiroshi Kawakami and 松尾次郎 : 非線形系にみられる二重漸近運動の分岐, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J65-A, No.7, 647-654, 1982.
135.	Hiroshi Kawakami and 勝田祐司 : 同期化問題に関連した2次元自律系の動的性質, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J65-A, No.4, 269-276, 1982.
136.	Hiroshi Kawakami and 松尾次郎 : 2重漸近運動の一計算法, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J64-A, No.12, 1058-1059, 1981.
137.	Hiroshi Kawakami and 松尾次郎 : ダフィング方程式にみられる周期解の分岐集合, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J64-A, No.12, 1018-1025, 1981.
138.	Hiroshi Kawakami and 勝田祐司 : 3階ダフィング形方程式のホッフ分岐とカオス, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J64-A, No.11, 940-947, 1981.
139.	Hiroshi Kawakami : シリンダ(円筒形)相曲面上の強制振動に関する定性的性質, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J64-A, No.11, 916-923, 1981.
140.	Hiroshi Kawakami, 松尾次郎 and 勝田祐司 : I形分岐により生じる周期運動の安定性基準, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J64-A, No.11, 958-959, 1981.
141.	Hiroshi Kawakami and 勝田祐司 : くら形平衡点のセパラトリクス閉路の計算, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J64-A, No.10, 860-861, 1981.
142.	Hiroshi Kawakami : 非線形回路にみられる分岐集合の大域的性質, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J64-A, No.9, 699-706, 1981.
143.	Hiroshi Kawakami and 小林邦博 : 多項式非線形方程式の周期解の一計算法, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J64-A, No.8, 614-621, 1981.
144.	Hiroshi Kawakami : 指定したωー極限集合を持つ発振器の合成, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J64-A, No.7, 590-591, 1981.
145.	Takashi Matsumoto, Leon Chua, Hiroshi Kawakami and Shigeo Ichiraku : Geometric Properties of Dynamic Nonlinear Networks: Transversality, Local-Solvability and Eventual Passivity, IEEE Transactions on Circuits and Systems, Vol.CAS-28, No.6, 406-428, 1981. (Link to Publication Site) ● Publication site (DOI): 10.1109/TCS.1981.1085003 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1109/TCS.1981.1085003 (DOI: 10.1109/TCS.1981.1085003)
146.	Hiroshi Kawakami : Algorithme numerique definissant la bifurcation d'un point homocline, C. R. Acad. Sc. Paris, Vol.293, No.I, 401-403, 1981.
147.	Hiroshi Kawakami and 小林邦博 : 非線形方程式に現れる分岐集合の計算, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J64-A, No.1, 88-89, 1981.
148.	Hiroshi Kawakami and 小林邦博 : 周期的外力を加えた非線形回路にみられる周期振動とその分岐, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.63-A, No.11, 753-760, 1980.
149.	Hiroshi Kawakami and Kunihiro Kobayashi : Computer Experiments on Chaotic Solutions of x(t+2) - ax(t+1) - x2(t) = b, Bulletin of Faculty of Engineering, The University of Tokushima, Vol.16, No.10, 29-46, 1979.
150.	Hiroshi Kawakami, 松村利夫 and 小林邦博 : 非線形自律方程式における周期解の一計算法, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.61-A, No.10, 713-715, 1978.
151.	松本隆 and Hiroshi Kawakami : 周期解を持つ非線形RC相反回路網について, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.61-A, No.1, 71-72, 1978.
152.	Hiroshi Kawakami, 松村利夫 and 小林邦博 : 電圧制御形非線形抵抗素子の一構成法, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.60-A, No.10, 990-991, 1977.
153.	Hiroshi Kawakami and 小林邦博 : スカラ値関数による電気回路の状態方程式の標準形, Bulletin of Faculty of Engineering, The University of Tokushima, Vol.21, No.1, 155-168, 1976.
154.	Hiroshi Kawakami, Tadamitsu Iritani and 小林邦博 : マイクロプログラムの手法によるアナログ計算機の演算制御, Bulletin of Faculty of Engineering, The University of Tokushima, Vol.20, No.1, 85-90, 1975.
155.	Hiroshi Kawakami : Sur les points fixes des iteres d'un diffeomorphisme dans le voisinage d'un point homocline, Journal of Differential Equations, Vol.14, No.3, 442-461, 1973. (Link to Publication Site) ● Publication site (DOI): 10.1016/0022-0396(73)90060-0 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-49549167284 (DOI: 10.1016/0022-0396(73)90060-0, Elsevier: Scopus)
156.	Chihiro Hayashi, Yoshisuke Ueda and Hiroshi Kawakami : Transformation Theory as Applied to the Solutions of Non-Linear Differential Equations of the Second Order, International Journal of NonLinear Mechanics, Vol.4, No.3, 235-255, 1969. (Link to Publication Site) ● Publication site (DOI): 10.1016/0020-7462(69)90003-1 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0014568130 (DOI: 10.1016/0020-7462(69)90003-1, Elsevier: Scopus)

Academic Letter:

1.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami, Hiroshi Fujii and Kazuyuki Aihara : Bifurcations in two-dimensional Hindmarsh-Rose type model, International Journal of Bifurcation and Chaos, Vol.17, No.3, 985-998, 2007. (Summary) We analyze a two-dimensional Hindmarsh Rose type model exhibiting properties of both Class 1 and Class 2 neurons. Although the system is two-dimensional and contains only four parameters, the obtained bifurcation diagrams show that the bifurcation structure satisfies conditions for emergence of both features with constant stimuli. (Tokushima University Institutional Repository) ● Metadata: 112116 (Link to Publication Site) ● Publication site (DOI): 10.1142/S0218127407017707 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1142/S0218127407017707 (Tokushima University Institutional Repository: 112116, DOI: 10.1142/S0218127407017707)
2.	Tetsushi Ueta and Hiroshi Kawakami : Chaos in cross-coupled BVP oscillators, International Journal of Bifurcation and Chaos, Vol.15, No.10, 3359-3366, 2005. (Summary) In this letter, we investigate the cross-coupled BVP oscillators. A single BVP oscillator has two terminals which can extract an independent state variable, so in the preceding works, several coupling systems have been studied. Synchronization modes and chaos in these systems are classified as results of bifurcation problems. We revisit a coupled oscillator, and clarify new results which have not been reported before, i.e. stable tori and its breakdown, and chaotic motions. Also classification of synchronized periodic solutions is done by a bifurcation diagram. (Tokushima University Institutional Repository) ● Metadata: 112058 (Link to Publication Site) ● Publication site (DOI): 10.1142/S0218127405013940 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1142/S0218127405013940 (Tokushima University Institutional Repository: 112058, DOI: 10.1142/S0218127405013940)
3.	Takuji Kousaka, Yoshihito Yasuhara, Tetsushi Ueta and Hiroshi Kawakami : Experimental Realization of Controlling Chaos in the Periodically Switched Nonlinear Circuit, International Journal of Bifurcation and Chaos, Vol.14, No.10, 3655-3660, 2004. (Summary) This letter presents an experimental confirmation of controlling the chaotic behavior of a target unstable periodic orbit when the periodically switched nonlinear circuit has a chaotic attractor. The pole assignment for the corresponding discrete system derived from such a nonautonomous system via Poincar´e mapping works effectively, and the control unit is easily realized by the window comparator, sample-hold circuits, and so on. (Tokushima University Institutional Repository) ● Metadata: 112114 (Link to Publication Site) ● Publication site (DOI): 10.1142/S0218127404011508 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1142/S0218127404011508 (Tokushima University Institutional Repository: 112114, DOI: 10.1142/S0218127404011508)
4.	Tetsushi Ueta and Hiroshi Kawakami : Bifurcation in asymmetrically coupled BVP oscillators, International Journal of Bifurcation and Chaos, Vol.13, No.5, 1319-1327, 2003. (Summary) BVP oscillator is the simplest mathematical model describing dynamical behavior of the neural activity. The large scale neural network can often be described naturally by coupled systems of BVP oscillators. However, even if two BVP oscillators are merely coupled by a linear element, the whole system exhibits a complicated behavior. In this paper, we analyze coupled BVP oscillators with asymmetrical coupling structure, with each oscillator having a different internal resistance. We present a complete four-dimensional system, which shows a rich variety of bifurcation phenomena, and strange attractors. We calculate bifurcation diagrams and confirm relaxation phenomena in the laboratory experiments. We also briefly report a conspicuous strange attractor. (Tokushima University Institutional Repository) ● Metadata: 112053 (Link to Publication Site) ● Publication site (DOI): 10.1142/S0218127403007199 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1142/S0218127403007199 (Tokushima University Institutional Repository: 112053, DOI: 10.1142/S0218127403007199)
5.	Shigeki Tsuji, Tetsushi Ueta, Tetsuya Yoshinaga and Hiroshi Kawakami : A Calculation Method of the Fixed Point with a Specified Argument and Its Application, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J84-A, No.3, 441-443, 2001. (Summary) 非線形力学系において，系に含まれるパラメータが変化し，固定点の特性乗数が複素単位円外に出ることにより各種の局所的分岐現象を生じる．本報告では，複素共役な特性乗数をもつ固定点に対して，偏角を指定してその位置，動径，パラメータ値を数値計算する方法を述べる．また，その応用として，Neimark-Sacker 分岐パラメータ値を求める計算方法を提案する．本稿では，連続力学系のポアンカレ写像または離散力学系を対象とし，指定した偏角をもつ固定点(周期点)の等高線をパラメータ平面で計算する方法を提案する．固定点条件，共役複素数の特性乗数を代入した特性方程式を実部と虚部に分離し，それぞれを独立した条件として連立させ，ニュートン法で固定点位置，パラメータ値について解く．また，この手法の応用として，指定した偏角をもつNS分岐を求める手法について述べる．これらのツールにより，固定点とNS分岐，周期引き込み領域との関係をより直接的に調べることができる． (Keyword) 固定点 / 偏角 / Neimark-Sacker 分岐 / ニュートン法 (Tokushima University Institutional Repository) ● Metadata: 110723 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1050583647830709760 (Tokushima University Institutional Repository: 110723, CiNii: 1050583647830709760)
6.	Takuji Kousaka, Shoichi Tahara, Tetsushi Ueta, Hiroshi Kawakami and Minoru Abe : Chaos in a Simple Hybrid System and its Control, Electronics Letters, Vol.37, No.1, 1-2, 2001. (Summary) A simple hybrid system exhibiting chaos is developed and a chaos control method realised. It is shown that, since the dynamics can be expressed by a return map, the system has an observable chaos. The control method, which is based on the pole assignment technique, can stabilise any unstable periodic orbit in the chaos. The theoretical result is verified by laboratory experiments. (Link to Publication Site) ● Publication site (DOI): 10.1049/el:20010033 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1049/el:20010033 (DOI: 10.1049/el:20010033)
7.	Tetsushi Ueta, Masafumi Tsueike, Hiroshi Kawakami, Tetsuya Yoshinaga and Yuji Katsuta : A computation of bifurcation parameter values for limit cycles, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.EA80, No.9, 1725-1728, 1997. (Summary) This letter describes a new computational method to obtain the bifurcation parameter value of a limit cycle in nonlinear autonomous systems. The method can calculate a parameter value at which local bifurcations; tangent, period-doubling and Neimark-Sacker bifurcations are occurred by using properties of the characteristic equation for a fixed point of the Poincare mapping. Conventionally a period of the limit cycle is not used explicitly since the Poincare mapping needs only whether the orbit reaches a cross-section or not. In our method, the period is treated as an independent variable for Newton's method, so an accurate location of the fixed point, its period and the bifurcation parameter value can be calculated simultaneously. Although the number of variables increases, the Jacobian matrix becomes simple and the recurrence procedure converges rapidly compared with conventional methods. (Tokushima University Institutional Repository) ● Metadata: 110699 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0031220919 (Tokushima University Institutional Repository: 110699, Elsevier: Scopus)
8.	Tetsushi Ueta and Hiroshi Kawakami : On Unstable Saddle-Node Connecting Orbit in a Planer Autonomous System, IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E79-A, No.11, 1581-1586, 1996. (Summary) We found a novel connecting orbit in the averaged Duffing-Rayleigh equation. The orbit starts from an unstable manifold of a saddle type equilibrium point and reaches to a stable manifold of a node type equilibrium. Although the connecting orbit is structurally stable in terms of the conventional definition of structural stability, it is structually unstable since a one-dimensional manifold into which the connecting orbit flows is unstable. We can consider the orbit is one of global bifurcations governing the differentiability of the closed orbit. (Keyword) saddle-node connecting orbit / bifurcation / topological classification of flows (Tokushima University Institutional Repository) ● Metadata: 110696 (Tokushima University Institutional Repository: 110696)
9.	Tetsuya Yoshinaga and Hiroshi Kawakami : 周期倍分岐列に生じる樹状パターン, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J73-A, No.3, 639-641, 1990.

Review, Commentary:

1.	Hiroshi Kawakami, Tetsushi Ueta and Tetsuya Yoshinaga : 区分非線形系にみられる不連続応答の分岐とカオス制御, Journal of Signal Processing, Vol.3, No.6, 367-371, Jun. 1999.
2.	Hiroshi Kawakami, Tetsuya Yoshinaga and Tetsushi Ueta : 力学系の計算機シミュレーション, 応用数理, Vol.3, No.6, 49-57, Dec. 1997.
3.	Hiroshi Kawakami and Tetsuya Yoshinaga : 非線形振動現象とカオス, 数理科学, No.407, 71-77, May 1997.
4.	Hiroshi Kawakami and Tetsuya Yoshinaga : 連続力学系のカオスの数値解析, The Journal of the Institute of Electronics, Information and Communication Engineers, Vol.79, 590-596, Jun. 1996. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520572360230886400 (CiNii: 1520572360230886400)
5.	Tetsuya Yoshinaga and Hiroshi Kawakami : 非線形力学系の分岐問題, Journal of the Society of Instrument and Control Engineers, Vol.34, No.10, 817-823, Oct. 1995.

Proceeding of International Conference:

1.	Yuu Miino, Tetsushi Ueta, Hiroshi Kawakami, Atsuo Maki and Naoya Umeda : Local stability and bifurcation analysis of the softening Duffing equation by numerical computation, Proc. 13th International Conference on the Stability of Ships and Ocean Vehicles, 397-403, Osaka, Sep. 2018.
2.	Yuu Miino, Tetsushi Ueta and Hiroshi Kawakami : Bifurcations in a sinusoidally driven LCR circuit with a hysteresis, Proc. NOLTA 2018, 247-250, Tarragona, Spain, Sep. 2018. (Summary) We investigate a driven LCR circuit with ahysteresis. We describe the circuit by a hybrid dynamicalsystem. The coil is modeled by a piecewise linear hysteresis, and the changes of the condition of the coil (magnetizedor not) are described by a finite state machine. We computelocal bifurcations accurately by taking a suitable Poincaremapping. Appearance patterns of the tangent and grazingbifurcations characterize this model.
3.	Yuu Miino, Tetsushi Ueta and Hiroshi Kawakami : Global bifurcation analysis in a simple piecewise linear non-autonomous dynamical system, Proc. NOLTA 2017, 629-632, Cancun, Mexico, Dec. 2017. (Summary) In this study, we construct a simple piecewise linear dynamical system and analyze their global bifurcation phenomena. From the parameter dependency, we derive the scenario of local and global bifurcation phenomena.
4.	Kyosuke Miyamoto, Daisuke Ito, Hiroyuki Asahara, Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Circuit Experiments for Bifurcation of TimeWaveforms on Forced LED Fireflies, Proc. NOLTA 2015, 836-839, Hong Kong, Dec. 2015. (Summary) Creatures with rhythm phenomenon is shown mutual emphasis and combination, this is called synchronization phenomenon that is one of typical phenomenon in nonlinear systems. As the example of creatures causing synchronization phenomenon, there are group emissions of light of fireflies and chorus of crickets [1] [2] [3]. In this paper, we observe bifurcation phenomenon of periodic solutions on forced LED fireflies that constructed from an RC square wave generator with a periodic external force in order to simulate the synchronization of fireflies. On forced LED fireflies, characteristic periodic solutions called isolation periodic solution is observed at broad parameter regions. It can be considered these solutions causes synchronization phenomenon. Waveforms and periods of them are changed by border-collision bifurcations that are occurred by varying the frequency of an external force. Moreover, chaotic waveforms are observed at certain parameters. There can observe chaos waveform by a certain parameter. (Keyword) LED / fireflies
5.	Daisuke Ito, Munehisa Sekikawa, Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Bursting of transition dynamics on series coupled two operational amplifiers, Proc. NOLTA 2015, 181-184, Hong Kong, Dec. 2015. (Summary) Abstract\|An operation ampli er (op-amp) is used in various electrical circuits and one of the most famous electronic devices. In general applications, op-amps behave as differential amplifiers, but in parameter miss matching or miss connections, the op-amp occurs complex high frequency oscillations. We nd complex oscillation phenomena in the modi ed simple oscillator with the op-amp, and that these phenomena depend on the dynamics of circuits and throughrates of op-amps. (Keyword) firefly
6.	Munehisa Sekikawa, Akinori Tsuji, Keiko Kimoto, Ikku Aihara, Daisuke Ito, Tetsushi Ueta, Kazuyuki Aihara and Hiroshi Kawakami : Optically coupled oscillators (OCOs) -- LED fireflies, Proceedings of the 2012 ACM Multimedia Conference, MM'12, 1485-1486, Nara, Oct. 2012.
7.	Daisuke Ito, Nakanishi Takaya, Akinori Tsuji, Tetsushi Ueta and Hiroshi Kawakami : Bifurcation Phenomena of a Light Coupled Oscillator with a Clock Pulse Input, Proc. NCSP 2012, 675-679, Honolulu, Mar. 2012.
8.	Kazutoshi Kinoshita, Tetsushi Ueta, Hiroshi Kawakami, Jun'ichi Imura and Kazuyuki Aihara : Bifurcation phenomena of coupled piecewise affine system with hysteresis properties, Proc. NOLTA 2011, 407-410, Kobe, Sep. 2011.
9.	Kazutoshi Kinoshita, Tetsushi Ueta, Hiroshi Kawakami, Jun'ichi Imura, Kazuyuki Aihara and Kazuyuki Aihara : Bifurcation phenomena of piecewise affine systems with hysteresis properties, Proc. ISIMM2011, 109, Tokyo, Mar. 2011.
10.	Tetsushi Ueta and Hiroshi Kawakami : Visualization of unstable periodic points embedded in chaotic attractors by the directional coloring, Proc. NOMA'07, 25-28, Toulouse, Dec. 2007. (Summary) We propose a new visualization method called directional coloring for chaotic attractors in two-dimensional discrete systems. The argument defined by the current point of the solution orbit and its n-th mapped point is assigned into the hue circle in the HSV color system. For a given system, the vector field of the n-th powered system is visualized by this method. As singular points, n-periodic points are emerged as concentrating points of colors. We also reduce the computation time by featuring the brute-force method for the directional coloring, and illustrate a detection method of unstable periodic points in a chaotic attractor as an application.
11.	Masaaki Mizumoto, Tetsushi Ueta and Hiroshi Kawakami : Bifurcation Analysis of Duffing-Rayleigh Equation, Proc. NDES2007, 90-93, Tokushima, Jul. 2007. (Summary) This paper deals with the bifurcation of the periodic solution and the generation of chaotic states of the solution for Duffing-Rayleigh equation. We calculate bifurcation diagram under both of increasing and decreasing time and calculate stable and unstable manifolds. From these analysis, we explain the generation of crisis.
12.	Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : Bifurcation Structure of Capacitive Coupled BVP, Proc. NDES2007, 90-93, Tokushima, Jul. 2007. (Summary) We have investigated a variety of coupled two oscillators. In previous reports, we explained many bifurcation structures of coupling types when two BVP oscillators are connected by linear resistor. In this report we investigate a bifurcation structure, when two BVP oscillators are connected by capacitor. Additionally, each current Port of oscillators is connected. This system becomes five-dimensional autonomous system unlike other coupling. We illustrate attractors and bifurcation phenomena of this system, and we compare bifurcation structures of coupled oscillators.
13.	Yasuo Miyoshi, Takahiro Oie, Hiroshi Kawakami, Tetsushi Ueta and Yoneo Yano : e-Syllabus System Supporting the Discovery of Learning Paths, Proceedings of E-Learn 2006, 784-789, Honolulu, Oct. 2006. (Summary) We have developed an e-Syllabus system that represents graphically and dynamically the relationships between lectures. This development represents one of the improvements of infrastructure for education and learning. In order to construct the e-Syllabus, three new columns have been added to each lecture of the syllabus: keywords, preceding lectures and relational lectures. XML is used as a storage format; it allows us to represent the structured data within on a text file that can be stored on a CD-ROM. Thus, without accessing the web, it is possible to represent graphically and discover the relations between the lectures. This representation of the syllabus supports the students in the discovery of learning-paths and the definition of learning plan. Thus, the e-Syllabus system improves the convenience of using the syllabus.
14.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : Dependence of Synchronous Activities in Coupled Inhibitory Neurons upon Excitability Classes, Proc. of NOLTA2006, Bologna, Italy, Sep. 2006.
15.	Toshiyuki Kumano, Tetsushi Ueta and Hiroshi Kawakami : Pattern Emergence in Strange Attractor by Directions of Mappings, Proc. of ISCAS2006, 2737-2740, Island of Kos, Greece, May 2006. (Summary) This paper proposes a new visualization method to given chaotic attractors in discrete nonlinear dynamical systems. Conventionally it is expressed by plotting the solution orbit into a plane as a set of dots. In the case of color figures, a pixel is colored by the location of the orbit, histogram of hitting, and so on. We use an argument defined by a current orbit and an n-time mapped point is utilized for coloring. This can depict orientation or tendency of the orbit within the chaotic attractor. In this visualization process, an remarkable pattern emergence phenomenon is observed. We illustrate these color figures and discuss similarity to basins of attraction.
16.	Kimiyasu Shiotsu, Tetsuya Kobayashi, Tetsushi Ueta, Shigeki Tsuji, Kazuyuki Aihara and Hiroshi Kawakami : Bifurcations of periodic solutions in the forced genetic toggle switch system, Proc. of NCSP2006, 251-254, Honolulu, Mar. 2006.
17.	Hirokazu Komatsu, Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcational classification for type-I and II activities in a forced planar H-R model, Proc. of NCSP2006, 325-328, Honolulu, Mar. 2006.
18.	Hiroki Yoshii, Tetsushi Ueta and Hiroshi Kawakami : Visualization and stereolithography system of bifurcation sets, Proc. of NCSP2006, 361-364, Honolulu, Mar. 2006.
19.	Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : Bifurcation phenomena of capacitive coupled BVP oscillators, Proc. of NCSP2006, 243-246, Honolulu, Mar. 2006.
20.	Toshiyuki Kumano, Masaaki Mizumoto, Yusuke Nishiuchi, Kunichika Tsumoto, Shigeki Tsuji, Tetsushi Ueta, Tetsuya Yoshinaga, Hiroshi Kawakami and Kazuyuki Aihara : Development of an ODE solver orienting a bifurcation analysis package, Proc. of NCSP'06, 297-300, Honolulu, Mar. 2006.
21.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : Design of Controllers Based on Symmetry of Inverted Pendulum, Proc. of 2006 RISP International Workshop on Nonlinear Circuits and Signal Processing, 207-210, Honolulu, Mar. 2006.
22.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcations in Class 1 neuron models interconnected by inhibitory and electrical synapses, Proc. of NOLTA'05, Vol.1, 317-320, Bruges, Oct. 2005.
23.	Kunichika Tsumoto, Tetsuya Yoshinaga, Hitoshi Iida, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcation Analyses in a Circadian Oscillator Model of Clock Genes, Abstract book of International Workshop on Gene-Protein Dynamics of Circadian Clocks, 89-130, Tokyo, Sep. 2005.
24.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcations in Modified BVP Neurons Connected by Inhibitory and Electrical Coupling, Proc. ISCAS2005, 6058-6061, Kobe, May 2005.
25.	YUE MA, Chi K. Tse, Takuji Kousaka and Hiroshi Kawakami : A Subtle Link in Switched Dynamical Systems: Saddle-Node Bifurcation Meets Border Collision, Proceedings of The 2005 IEEE International Symposium on Circuits and Systems, 6050-6053, Kobe, May 2005.
26.	Yusuke Nishiuchi, Shigeki Tsuji, Tetsushi Ueta and Hiroshi Kawakami : On Synchronization in Cross Coupled BVP Oscillators, Proc. NCSP2005, 109-112, Honolulu, Mar. 2005.
27.	Hiroki Yoshii, Tetsushi Ueta and Hiroshi Kawakami : A New Scheme for Construction of 3D Bifurcation Diagrams, Proc. of NCSP2005, 65-68, Honolulu, Mar. 2005.
28.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : Spatio-Temporal Complex Behavior in Inhibitory Modified BVP Neurons Connected by Gap-Junction, Proc. NCSP2005, 29-32, Honolulu, Mar. 2005.
29.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : Stabilization of Unstable Periodic Motion Existed in an Inverted Pendulum using Discrete Controllers, Proc. of 2005 RISP International Workshop on Nonlinear Circuits and Signal Processing, 491-494, Honolulu, Mar. 2005.
30.	YUE MA and Hiroshi Kawakami : Control of Bifurcation in DC/DC PWM Switching Converters, Proceedings of 8th International Conference on Control, Automation, Robotics and Vision 2004, 1421-1426, Kunming, Dec. 2004.
31.	YUE MA, Takuji Kousaka, Chi K. Tse and Hiroshi Kawakami : General Consideration for Modeling and Analyzing Switched Dynamical Systems, Proceedings of International Symposium on Nonlinear Theory and its Applications 2004, 59-62, Fukuoka, Nov. 2004.
32.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcations in current coupled BVP oscillators, Proc. NDES2004, 348-351, Evora, Portugal, May 2004.
33.	Tetsushi Ueta and Hiroshi Kawakami : An aspect of oscillatory conditions in linear systems and Hopf bifurcations in nonlinear systems, Proc. NDES2004, 352-355, Evora, Portugal, May 2004.
34.	YUE MA, Hiroshi Kawakami and Chi K. Tse : Analysis of bifurcation in switched dynamical systems with periodically moving borders: application to power converters, IEEE International Symposium on Circuits and Systems 2004, Vancouver, May 2004. (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-4344591379 (Elsevier: Scopus)
35.	Munehisa Sekikawa, Naohiko Inaba, Tetsuya Yoshinaga and Hiroshi Kawakami : Collapse and Coexistence of Duck Solution in a Circuit Driven by an Extremely Small Periodic Force, Proc. International IEEE Workshop on Nonlinear Dynamics of Electronic Systems, 308-311, Evora, Portugal, May 2004.
36.	Tetsuya Yoshinaga, Kunichika Tsumoto, Hitoshi Iida and Hiroshi Kawakami : Bifurcation in a circadian oscillator model, Abstracts of International Symposium on Dynamical Systems Theory and Its Applications to Biology and Environmental Sciences, 167, Shizuoka, Mar. 2004.
37.	Kunichika Tsumoto, Tetsuya Yoshinaga, Kazuyuki Aihara and Hiroshi Kawakami : Bifurcations in a mathematical model for circadian oscillations of clock genes, Proc. of 2004 RISP International Workshop on Nonlinear Circuits and Signal Processing, 403-406, Hawaii, USA, Mar. 2004.
38.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcations in Modified BVP Neurons Coupled by Gap-Junctions, Proc. of NCSP'04, 495-498, Honolulu, Mar. 2004.
39.	Atsushi Tsuda, Shigeki Tsuji, Tetsushi Ueta and Hiroshi Kawakami : On Basin Boundary of Composite Dynamical System with Pole Assignment, Proc. of NCSP'04, 363-366, Honolulu, Mar. 2004.
40.	Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : A Blurred Boundary and its Manifolds in the Extended BVP oscillator, Proc. of NCSP'04, 515-518, Honolulu, Mar. 2004.
41.	YUE MA, Hiroshi Kawakami and Chi K. Tse : Bifurcation analysis of switched dynamical systems with periodically moving borders, ShangHai International Symposium on Nonlinear Science and Applications, Shanghai, Nov. 2003.
42.	Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : On a stable torus in a three dimensional autonomous system, Proc. of ECCTD'03, Vol.1, 82-85, Cracow, Sep. 2003.
43.	Tetsushi Ueta and Hiroshi Kawakami : Chaos in cross-coupled BVP oscillator, Proc. ISCAS2003, Vol.3, 68-72, Bangkok, May 2003.
44.	Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : On basin boundary of the extended BVP oscillator, Proc. of NOLTA'02, Vol.1, 311-314, Xi'an, Oct. 2002.
45.	Shigeki Tsuji, Tetsushi Ueta, Tetsuya Yoshinaga, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcations in gap-junctionally coupled BVP neurons driven by periodic external force, Proc. of NOLTA'02, Vol.1, 307-310, Xi'an, Oct. 2002.
46.	Kunichika Tsumoto, Tetsuya Yoshinaga, Kazuyuki Aihara and Hiroshi Kawakami : Bifurcations in Morris-Lecar neuron model, Proc. of NOLTA 2002, 363-366, Xi'an, Oct. 2002.
47.	YUE MA and Hiroshi Kawakami : Combinatorial resonances in a coupled Duffing's circuit with asymmetry, Proceedings of International Symposium on Nonlinear Theory and its Applications 2002, 4148-4152, Xi'an, Oct. 2002.
48.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : Stabilization of Unstable Periodic Motions in Parallel-Type Double Inverted Pendulum, Proc. of the 4th Asian Control Conference, 567-571, Singapore, Sep. 2002.
49.	YUE MA and Hiroshi Kawakami : Bifurcation of combinatorial oscillations in coupled Duffing's circuits, Proceedings of International Technical Conference on Circuits/Systems, Computers and Communications 2002, 1622-1625, Phuket, Thailand, Jul. 2002.
50.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Bifurcation behavior in a nonlinear circuit with a state-period dependent switch, Proc. NDES2002, 3-1-3-4, Izmir, Turkey, Jun. 2002.
51.	Tetsushi Ueta and Hiroshi Kawakami : Bifurcation and chaos in the extended BVP oscillator, Proc. NDES2002, 3-5-3-8, Izmir, Turkey, Jun. 2002.
52.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : An advanced design method of bursting in FitzHugh-Nagumo model, Proc. ISCAS2002, Vol.1, 389-392, Phoenix, AZ, May 2002.
53.	Tetsushi Ueta and Hiroshi Kawakami : Bifurcation and chaos in asymmetrically coupled BVP oscillators, Proc. ISCAS2002, Vol.2, 544-547, Phoenix, AZ, May 2002.
54.	Shouichi Tahara, Takuji Kousaka, Tetsushi Ueta, Minoru Abe and Hiroshi Kawakami : Experimental Control of Chaotic Behavior in State-Dependent Nonlinear Circuit, Proc. of NOLTA2001, Zaou, Miyagi, Japan, Oct. 2001.
55.	Kunichika Tsumoto, Tetsuya Yoshinaga, Kazuyuki Aihara and Hiroshi Kawakami : Bifurcations in a synaptically coupled system of Hodgkin-Huxley neurons with a periodic alpha-function train, Proc. of 2001 International Workshop on Neuronal Coding, 105-108, U.K., Oct. 2001.
56.	YUE MA and Hiroshi Kawakami : 1/3 combinatorial subharmonics in coupled Duffing's circuits, Proceedings of International Symposium on Nonlinear Theory and its Applications 2001, 199-202, Zao, Japan, Oct. 2001.
57.	Munehisa Sekikawa, Naohiko Inaba, Tetsuya Yoshinaga and Hiroshi Kawakami : The Bifurcation Structure of Fractional-Harmonic Entrainments in the Forced Rayleigh Oscillator, Proceedings of IEEE International Conference on Electronics, Circuits and Systems, 1269-1272, Sep. 2001.
58.	Takahiro Oie, Youji Ochi, Tetsushi Ueta, Yoneo Yano and Hiroshi Kawakami : A Database Orienting Information Disclosure on Campus Network, Proceedings of 2nd International Conference on Information Technology Based Higher Education and Training, Kumamoto, Jul. 2001.
59.	Tetsushi Ueta, Takuji Kousaka and Hiroshi Kawakami : Strange attractor in resistively coupled BVP oscillators, Proc. of Progress on Nonlinear Science, Nizhny Novgorod, Jun. 2001.
60.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Controlling chaos in a state-dependent nonlinear circuit, Proc. of First Asia-Pacific Workshop on Chaos Control and Synchronization, 26-27, Shanghai, Jun. 2001.
61.	Hiroshi Kawakami, Tetsuya Yoshinaga and Tetsushi Ueta : Counting and classifying synchronized patterns in symmetrical network, Proc. of First Asia-Pacific Workshop on Chaos Control and Synchronization, 3, Shanghai, Jun. 2001.
62.	YUE MA, ChiPing Zhang and Hiroshi Kawakami : Bifurcation of combinatorial subharmonic in coupled Duffing's circuit, Proceedings of International Technical Conference on Circuits/Systems, Computers and Communications 2001, 865-868, Tokushima, Jun. 2001.
63.	Tetsushi Ueta, Shigeki Tsuji, Tetsuya Yoshinaga and Hiroshi Kawakami : Calculation of the isocline for the fixed point with a specified argument of complex multipliers, Proc. ISCAS2001, Vol.III, 281-284, Sydney, May 2001.
64.	Takuji Kousaka, M Matsumoto, Tetsushi Ueta and Hiroshi Kawakami : Bifurcation Analysis in Hybrid Nonlinear Dynamical Systems, Proc. ISCAS2001, Vol.III, 281-284, Sydney, May 2001.
65.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : A route to chaos with a chain of homoclinic bifurcations in a modified Bonhoeffer-van der Pol equation, CD-ROM of 2000 IEEE ISIECI, Vol.00CH37141C, 2064-2069, Nagoya, Oct. 2000.
66.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcation of Burst response in Forced Wilson-Cowan Neuron Model, Proc. NOLTA'00, Vol.1, 285-288, Dresden, Germany, Sep. 2000.
67.	Yusuke Kawabata, Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcation in a two-coupled oscillator with periodic pulse train and sinusoidal force, Proc. of NOLTA' 2000, Vol.2, 563-566, Dresden, Sep. 2000.
68.	Yuji Yamawaka, Hiroyuki Kitajima and Hiroshi Kawakami : Bifurcation of synchronized states in oscillators with hard characteristics and state coupling, Proc. of NOLTA' 2000, Vol.2, 559-562, Dresden, Sep. 2000.
69.	Yoshio Tanaka, Hiroshi Kawakami and Ken'ichi Fujimoto : Utilizing chaos for selective swing-up of a parallel-type double inverted pendulum, Proc. of 2000 International Symposium on Nonlinear Theory and its Applications, Vol.2, 539-542, Dresden, Sep. 2000.
70.	Tatsunobu Sugita, Kunichika Tsumoto and Hiroshi Kawakami : Resonance phenomena in a tri-phase Duffing circuit, Proc. of NOLTA' 2000, Vol.2, 453-456, Dresden, Sep. 2000.
71.	Hiroyuki Kudo, Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : Stabilizing methods of an unstable periodic oscillation in an inverted pendulum, Proc. of 2000 International Symposium on Nonlinear Theory and its Applications, Vol.2, 429-432, Dresden, Sep. 2000.
72.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : Control of Unstable Periodic Motion on a Two-link Planer UAM, Proc. of 2000 International Symposium on Nonlinear Theory and its Applications, Vol.2, 425-428, Dresden, Sep. 2000.
73.	Yuichi Nakamura, Daisuke Sato, Yoko Uwate and Hiroshi Kawakami : Realization of chaotic orbits by recurrent neural networks, Proc. of NOLTA' 2000, Vol.1, 27-30, Dresden, Sep. 2000.
74.	Kunichika Tsumoto, Tetsuya Yoshinaga, Kazuyuki Aihara and Hiroshi Kawakami : Bifurcation in synaptically coupled BVP neurons, part II, Proc. of NOLTA' 2000, Vol.1, 269-272, Dresden, Sep. 2000.
75.	Hiroyuki Kitajima and Hiroshi Kawakami : Bifurcation of periodic states in coupled BVP neurons with external impulsive forces, Proc. of NOLTA' 2000, Vol.1, 265-268, Dresden, Sep. 2000.
76.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : A chain of homoclinic bifurcations in a modified Bonhoeffer-van der Pol equation, Proc. of the third World Congress of Nonlinear Analysts, Catania, Italy, Jul. 2000.
77.	Tetsuya Yoshinaga, Hiroyuki Kitajima, Kazuyuki Aihara and Hiroshi Kawakami : Bifurcations in coupled chaotic neurons, Proc. of the third World Congress of Nonlinear Analysts, Catania, Italy, Jul. 2000.
78.	Tetsushi Ueta, Guranrong Chen, Hiroshi Kawakami and Tetsuya Yoshinaga : Bifurcation and Bursting Response in Coupled Neural Oscillators, Proc. ISCAS00, Vol.3, 475-478, Geneva, May 2000. (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0033714204 (Elsevier: Scopus)
79.	Takuji Kousaka, Takashi Kido, Tetsushi Ueta, Hiroshi Kawakami and Minoru Abe : Analysis of Border-Collision Bifurcation in a Simple Circuit, Proc. ISCAS00, Vol.2, 481-484, Geneva, May 2000.
80.	Takuji Kousaka, Shouichi Tahara, Tetsushi Ueta, Hiroshi Kawakami and Minoru Abe : Controlling Chaos of Nonlinear Hybrid System with a State-Period Depended Switch, AFSS 2000, Vol.1, 363-368, Tsukuba, Japan, May 2000.
81.	Takashi Kido, Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Efficient Construction of 3D Bifurcation Diagrams for Nonlinear Dynamical Systems, Proc. NOLTA'99, Vol.1, 93-96, Hawaii, USA, Dec. 1999.
82.	Eiji Izumida, Tetsushi Ueta and Hiroshi Kawakami : Efficient Construction of 3D Bifurcation Diagrams for Nonlinear Dynamical Systems, Proc. NOLTA'99, Vol.1, 257-260, Hawaii, USA, Dec. 1999.
83.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcations in synaptically coupled BVP neurons, Proc. of NOLTA'99, Vol.1, 211-214, Hawaii, U.S.A., Nov. 1999.
84.	Yasuhiko Sano, Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcations in an impulsivelly forced Hodgkin-Huxley equation, Proc. of NOLTA'99, Vol.1, 207-210, Hawaii, U.S.A., Nov. 1999.
85.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : Observed Behavior on a Two-link Planer Manipulator with a Free joint, Proc. of 1999 International Symposium on Nonlinear Theory and its Applications, Vol.1, 362-365, Kona, Nov. 1999.
86.	Tetsuya Yoshinaga, Yasuhiko Sano and Hiroshi Kawakami : Bifurcations in two synaptically coupled Hodgkin-Huxley neurons, Proc. of Intl Workshop on Neuronal Coding, 61-64, Osaka, Oct. 1999.
87.	Ei'ichiro Okahisa, Hiroyuki Kitajima, Tetsushi Ueta and Hiroshi Kawakami : Spatiotemporal Chaotic Motion in Lower Dimensional Coupled Maps, Proc. KES'99, Vol.1, 867-870, Aderade, Australia, Aug. 1999.
88.	Tetsushi Ueta, Guanrong Chen, Tetsuya Yoshinaga and Hiroshi Kawakami : A Numerical Algorithm for Computing Neimark-Sacker Bifurcation Parameters, Proc. ISCAS'99, Vol.5, 503-506, Orlando, FL, USA, May 1999. (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0032673064 (Elsevier: Scopus)
89.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Bifurcation of a Nonlinear Circuit with a State-Dependent Switch, Proc. NOLTA'98, Vol.1, 867-870, Crans-Montana, Switzerland, Sep. 1998.
90.	Inuma Yasusuke, Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcation and chaotic itinerancy in a chaotic neural network, part II, Proc. of NOLTA'98, Vol.2, 699-702, Crans-Montana, Switzerland, Sep. 1998.
91.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : A chain of homoclinic bifurcations to infinity in a modified BVP equation, Proc. of NOLTA'98, Vol.2, 643-646, Crans-Montana, Switzerland, Sep. 1998.
92.	Tetsuya Yoshinaga, Ooshita Tetsuo and Hiroshi Kawakami : Bifurcations in a ring of coupled chaotic neurons, Proc. of NOLTA'98, Vol.2, 743-746, Crans-Montana, Switzerland, Sep. 1998.
93.	Yoshio Tanaka, Hiroshi Kawakami and Ken'ichi Fujimoto : Control of Periodic States in a Manipulator with a Free-Joint, Proc. of 1998 International Symposium on Nonlinear Theory and its Applications, Vol.2, 535-538, Crans-Montana, Switzerland, Sep. 1998.
94.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : Forced Oscillatory Phenomena of a Two-link Planer Manipulator With a Free Joint, Proc. of 1998 International Symposium on Nonlinear Theory and its Applications, Vol.3, 1043-1046, Crans-Montana, Switzerland, Sep. 1998.
95.	Tetsushi Ueta, Takuji Kousaka and Hiroshi Kawakami : Bifurcation of Switched Nonlinear Dynamical Systems, Proc. of ISCAS'98, Vol.3, 465-468, Monterey, CA, USA, May 1998.
96.	Tetsuya Yoshinaga, Inuma Yasusuke and Hiroshi Kawakami : A mechanism of the generation of chaotic itinerancy in a chaotic neural network, Proc. of 2nd R.I.E.C., 261-264, Sendai, Mar. 1998.
97.	Tetsushi Ueta, T Okubo and Hiroshi Kawakami : Nonlinear resonant circuit with phase-controlled periodic signal, Proc. NOLTA'97, 487-490, Hawaill, USA, Nov. 1997.
98.	Ken'ichi Fujimoto, Takuji Kousaka, Hiroyuki Kitajima, Tetsushi Ueta and Hiroshi Kawakami : BVP oscillator with periodically switched RC circuit, Proc. of 1997 International Symposium on Nonlinear Theory and its Applications, 479-482, Hawaii, USA, Nov. 1997.
99.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Controlling chaos in nonlinear dynamical systems with non-smooth characteristics, Proc. NOLTA'97, 471-474, Hawaii, USA, Nov. 1997.
100.	Makoto Shiota, Tetsushi Ueta and Hiroshi Kawakami : Computation of three-dimensional bifurcation diagrams for dynamical systems, Proc. NOLTA'97, 69-72, Hawaill, USA, Nov. 1997.
101.	Yuichi Nakamura and Hiroshi Kawakami : Hard Oscillation and Chaotic State in Neural Oscillator with Three Neurons, Proc. of NOLTA'97, 1197-1200, Hawaii, Nov. 1997.
102.	Hiroyuki Kitajima, Y Noumi and Hiroshi Kawakami : Forced synchronization of coupled oscillators, Proc. of NOLTA'97, 573-576, Hawaii, Nov. 1997.
103.	Hiroyuki Kitajima and Hiroshi Kawakami : Bifurcations and chaos in unidirectionally coupled oscillators, Proc. of NOLTA'97, 65-68, Hawaii, Nov. 1997.
104.	Yoshio Tanaka, Hiroshi Kawakami and Ken'ichi Fujimoto : Nonlinear Phenomena Observed in a Manipulator with a Passive Joint, Proc. of 1997 International Symposium on Nonlinear Theory and its Applications, 49-52, Hawaii, Nov. 1997.
105.	T Mishima and Hiroshi Kawakami : Bifurcation of Equilibrium Points and Synchronized Periodic Solution in Four Coupled Oscillations, Proc. of NOLTA'97, 37-40, Hawaii, Nov. 1997.
106.	K Ochi and Hiroshi Kawakami : Bifurcation of Periodic Oscillations in A Tri-phase Duffing Circuit, Proc. of NOLTA'97, 33-36, Hawaii, Nov. 1997.
107.	Tetsuya Yoshinaga, Yasusuke Inuma and Hiroshi Kawakami : Bifurcation and chaotic itinerancy in a chaotic neural network, Proc. of NOLTA'97, 53-56, Hawaii, Nov. 1997.
108.	Tetsushi Ueta and Hiroshi Kawakami : Chaos synchronizing control in the invariant subspaces, Proc. COC'97, 69-72, St. Petersbrug, Russia, Aug. 1997.
109.	Tetsushi Ueta, Hiroshi Kawakami, Tetsuya Yoshinaga and Yuuji Katsuta : A computation of bifurcation parameter values for limit cycles, Proc. of ISCAS'97, Vol.2, 801-804, Hong Kong, Jun. 1997. (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0030700186 (Elsevier: Scopus)
110.	Christian Mira and Hiroshi Kawakami : Qualitative Modifications of the Lip Bifurcation Structure, Proc. of European Conf. of Iteration Theory, 199-206, Wien, Nov. 1996.
111.	Masafumi Tsueike, Tetsushi Ueta and Hiroshi Kawakami : Bifurcations of Coupled Neural Oscillators, Proc. of NOLTA'96, 365-368, Kochi, Oct. 1996.
112.	Takuji Kousaka, Hiroshi Kawakami and Tetsushi Ueta : Synchronization of Electric Fireflies of Square Wave Generators, Proc. of NOLTA'96, 321-324, Kochi, Oct. 1996.
113.	K Ochi, Pierre Jean Carcasses and Hiroshi Kawakami : A Method for Detecting Codimension Two Bifurcation Points, Proc. of NOLTA'96, 317-320, Kochi, Oct. 1996.
114.	Y Umakoshi and Hiroshi Kawakami : Bifurcation and Chaos of Periodically Interrupted Nonlinear Circuits, Proc. of NOLTA'96, 133-136, Kochi, Oct. 1996.
115.	Tetsushi Ueta and Hiroshi Kawakami : A Control to Enlarge the Region of Frequency Entrainment in a Nonautonomous System, Proc. of NOLTA'96, 73-74, Kochi, Oct. 1996.
116.	Hiroyuki Kitajima and Hiroshi Kawakami : Bifurcation of a unidirectional coupled oscillator, Proc. of NOLTA'96, 21-24, Kochi, Oct. 1996.
117.	Tetsuya Yoshinaga, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcations in two coupled chaotic neurons, Proc. of NOLTA'96, 105-108, Kochi, Oct. 1996.
118.	Yuichi Nakamura and Hiroshi Kawakami : Oscillatory Modes in a Coupled System of Simple Neural Oscillators, Proc. NOLTA'96, 9-12, Kochi, Oct. 1996.
119.	Tetsuya Yoshinaga and Hiroshi Kawakami : A method to calculate homoclinic points of a noninvertible map, Proc. of ICNBC, 267-271, Lodz-Dobieszkow, Sep. 1996.
120.	Tetsushi Ueta and Hiroshi Kawakami : Unstable saddle-node connecting orbits in the averaged Duffing-Rayleigh equation, Proc. of ISCAS'96, Vol.3, 288-291, Atlanta, May 1996.
121.	Hiroyuki Kitajima, Tetsuya Yoshinaga and Hiroshi Kawakami : Codimension two bifurcation observed in a phase converter circuit, Proc. of NOLTA'95, Vol.2G-3, 335-338, Las Vegas, Dec. 1995.
122.	Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcations in a BVP equation with periodic impulsive force, Proc. of NOLTA'95, 331-334, Las Vegas, Dec. 1995.
123.	Hiroshi Kawakami : Nonlinear Oscillations: Applications to electrical circuits and electronics, Proc. of Bifurcations, Chaos, Noninvertible Maps and Applications, 61-77, Grenoble, Dec. 1995.
124.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Destabilizing control of stable orbits, Proc. NOLTA'95, Vol.2, 997-1000, Las Vegas, Nov. 1995.
125.	Masafumi Tsueike, Tetsushi Ueta and Hiroshi Kawakami : Basin of attractions in controlled chaotic system, Proc. NOLTA'95, Vol.2, 985-988, Las Vegas, Nov. 1995.
126.	Olivier Papy and Hiroshi Kawakami : Synchronization of three hybridly coupled oscillators, Proc. NOLTA'95, Vol.2, 933-936, Las Vegas, Nov. 1995.
127.	T Mihara and Hiroshi Kawakami : Synchronization and chaos of a coupled Duffing-Rayleigh oscillator, Proc. NOLTA'95, Vol.2, 925-928, Las Vegas, Nov. 1995.
128.	Yuichi Nakamura and Hiroshi Kawakami : Hard oscillation and its synchronization of a simple neural oscillator, Proc. NOLTA'95, Vol.1, 351-354, Las Vegas, Nov. 1995.
129.	Tetsushi Ueta and Hiroshi Kawakami : Bifurcation phenomena in the Josephson junction circuit coupled by a resistor, Proc. NOLTA'95, Vol.1, 343-346, Las Vegas, Nov. 1995. (Summary) Bifurcation phenomena observed in a circuit containing two Josephson junctions coupled by a resistor are investigated. This circuit model has a mechanical analogue: Two damped pendula linked by a clutch exchanging kinetic energy of each pendulum. In this paper, firstly we study equilibria of the system. Bifurcations and topological properties of the equilibria are clarified. Secondly we analyze periodic solutions in the system by using suitable Poincare mapping and obtain a bifurcation diagram. There are two types of limit cycles distinguished by whether the motion is in S^1 x R^3 or T^2 x R^2, since at most two cyclic coordinates are included in the state space. There is a typical structure of tangent bifurcation for 2-periodic solutions with a cusp point. We found chaotic orbits via the period-doubling cascade, and a long-period stepwise orbit.
130.	Hiroshi Kawakami and Tetsushi Ueta : Stabilization and Destbilization of Chaotic Systems, Proceedings of ICIAM 95 in Zeitschrift fur Angewandte Mathematik und Mechanik, 210-213, Hamburg, Jul. 1995.
131.	Olivier Papy and Hiroshi Kawakami : Synchronization of a Resistively Coupled Oscillator with a Hybrid Connection, Proc. NOLTA'94, 209-212, Kagoshima, Dec. 1994.
132.	Osamu Morimoto and Hiroshi Kawakami : Bifurcation Diagram of a BVP Equation with Impulsive External Force, Proc. NOLTA'94, 205-208, Kagoshima, Dec. 1994.
133.	Mozammel Hoque and Hiroshi Kawakami : Resistively Coupled Oscillators: Four Oscillators Case, Proc. NOLTA'94, 197-200, Kagoshima, Dec. 1994.
134.	Hiroyuki Kitajima, Tetsuya Yoshinaga and Hiroshi Kawakami : Synchronization in two coupled oscillators with three ports, Proc. of NOLTA'94, 89-92, Kagoshima, Oct. 1994.
135.	Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcations of a coupled Roessler system, Proc. of NOLTA'94, 109-112, Kagoshima, Oct. 1994.
136.	Yoshio Tanaka, Tetsushi Ueta and Hiroshi Kawakami : A robotic truck crane with vibration sensors, Proc. JFCM'04, 731-734, Takamatsu, Jun. 1994.
137.	Tetsuya Yoshinaga and Hiroshi Kawakami : Codimension two bifurcation in a coupled oscillator, Abst. of ICDSC'94, 83, Tokyo, May 1994.
138.	Takahiro Oie, Tadamitsu Iritani and Hiroshi Kawakami : Response of PLL Demodulator by Two Sinusoidal Inputs, Proceedings of 1993 International Symposium on Nonlinear Theory and its Applications, Vol.1.3, No.2, 67-70, Honolulu, Dec. 1993.
139.	Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcations of quasi-periodic responses in coupled van der Pol oscillators with external force, Proc. of NOLTA'93, Vol.2, 487-490, Honolulu, Dec. 1993.
140.	Tetsushi Ueta and Hiroshi Kawakami : Bifurcation of an inductively coupled Josephson junction circuit, Proc. NOLTA'93, Vol.3, 1019-1022, Honolulu, Dec. 1993.
141.	H Fijiwara and Hiroshi Kawakami : Harmonic synchronization and unstable chaos in Duffing-Rayleigh oscillator with hard characteristics, Proc. NOLTA'93, Vol.3, 1019-1022, Honolulu, Nov. 1993.
142.	Olivier Papy and Hiroshi Kawakami : Phase trapped properties of a coupled van der Pol oscillator, Proc. NOLTA'93, Vol.2, 617-620, Honolulu, Nov. 1993.
143.	Kenichi Kohari, Toshimichi Saito and Hiroshi Kawakami : Chaos and Hysteretic Fractals from a Hysteresis Oscillator with Periodic Thresholds, Proc. NOLTA'92, 13-16, Kanagawa, Oct. 1992.
144.	Hiroshi Kawakami : Bifurcation and Chaotic State in Forced Oscillatory Circuits Containing Saturable Inductors, Proc. of Nonlinear Phenomena in Electomagnetic Fields, 213-216, Nagoya, Sep. 1992.
145.	Tetsuya Yoshinaga and Hiroshi Kawakami : Synchronized quasi-periodic oscillations in mutually coupled oscillators with hard characteristics, Proc. of NOLTA'92, 13-16, Kanagawa, Jul. 1992.
146.	Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcations in coupled BVP equations with forcing term, Proc. of ISCAS'91, Vol.5, 2697-2700, Singapore, Jun. 1991. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1573668926473963264 ● Summary page in Scopus @ Elsevier: 2-s2.0-0026405153 (CiNii: 1573668926473963264, Elsevier: Scopus)
147.	Hiroshi Kawakami : Dynamic Gyrator: An Interface Element for Modeling Lumped Electro-Magnetic Networks, Proc. Int. Symp. on Mathematical Theory of Networks and Systems, 234-236, Kobe, Jun. 1991.
148.	Tetsuya Yoshinaga and Hiroshi Kawakami : Mode bifurcations observed in coupled oscillators, Proc. of ITC-CSCC'90, 211-216, Cheju, Dec. 1990.
149.	Tetsuya Yoshinaga and Hiroshi Kawakami : Codimension two bifurcation problems in forced nonlinear circuits, Proc. of ISCAS'89, 209-212, Jan. 1989.
150.	M Shoji, S Maeda, Satoshi Nakata, Hiroshi Kawakami and Ken'ichi Yoshikawa : Oscillation and Bifurcation at an Oil-Water Interface, 6th. Int. Conf. on Surface and Colloid Science, 825-831, New York, Mar. 1988.
151.	Hiroshi Kawakami : Bifurcation Phenomena in Duffing-Rayleigh Equation, Proc.11th Int. Conf. on Non-linear Oscillations, 267-270, Budapest, Sep. 1987.
152.	Hiroshi Kawakami : Fuzzy Boundary of Domain of Attraction in Forced Oscillatory Circuit, Proc. ECCTD87, 393-398, Paris, Sep. 1987.
153.	Hiroshi Kawakami and Go Shichino : An Invariant of Chaotic Response in a Josephson Junction Circuit, Proc. of ISCAS'85, 843-846, Kyoto, Oct. 1985.
154.	Hiroshi Kawakami : Recurrence : Construction Numerique Dans le Cas D'un Systeme Continu, Conf. du Traitement Numerique des Attracteurs Etranges, 53-66, Grenoble, Sep. 1985.
155.	Chihiro Hayashi and Hiroshi Kawakami : Behavior of Solutions for Duffing-Van der Pol Equation, Proc. 10th Int. Conf. on Non-linear Oscillations, 164-167, Varna, Oct. 1984.
156.	Hiroshi Kawakami : Bifurcations and Chaotic States of Forced Dymamic Nonlinear Circuits, Proc. of ISCAS'83, Vol.1982, 378-381, Los Angeles, Sep. 1983.
157.	Hiroshi Kawakami : Bifurcations and Chaotic States Obserbed in Duffing-van der Pol Equation, Int. Conf. on Iteration Theory, 219-226, Toulouse, Sep. 1982.
158.	Chihiro Hayashi and Hiroshi Kawakami : Bifurcatoins and the Generation of Chaotic States in the Solutions of Nonlinear Differential Equations, Proc. 4th Conf. on Theoretical and Applied Mechanics, Vol.1981, 537-542, Varna, Nov. 1981.
159.	Hiroshi Kawakami and Chihiro Hayashi : Bifurcations and Chaotic States of the Solutions of Duffing-Van der Pol Equation, 26. Int. Wiss. Koll., Vol.1, No.A1, 15-18, Ilmenau, Nov. 1981.
160.	Hiroshi Kawakami : The Bifurcation Pattern of Periodic Solutions Observed in Duffing's Equation, Proc. 9th Int. Conf. on Non-linear Oscillations, Vol.2, 40-44, Kiev, Oct. 1981.
161.	Chihiro Hayashi, Minoru Abe, Kenji Oshima and Hiroshi Kawakami : The Method of Mapping as Applied to the Solution for Certain Types of Nonlinear Differential Equations, Proc. 9th Int. Conf. on Non-linear Oscillations, Vol.1979, 40-44, Kiev, Oct. 1981.
162.	Hiroshi Kawakami and Kunihiro Kobayashi : A Computation of Periodic Solutions of Nonlinear Autonomous Systems, Proc. of ISCAS'79, Vol.1, 44-45, Tokyo, Sep. 1979.
163.	Hiroshi Kawakami : Elementary Bifurcation Phenomena in Forced Oscillatory Circuits, Proc. 8th Int. Conf. on Non-linear Oscillations, Vol.1977, No.1977, 379-384, Prague, Oct. 1978.
164.	Hiroshi Kawakami : Sur la bifurcation des solutions periodiques des equations differentielles periodiques du deuxieme ordre et leur application aux oscillation parametriques, Proc. 7th Int. Conf. on Non-linear Oscillations, Vol.2, No.1970, 155-168, Berlin, Sep. 1977.
165.	Chihiro Hayashi, Yoshisuke Ueda and Hiroshi Kawakami : Periodic Solutions of Duffing's Equation with Reference to Doubly Asymptotic Solutions, Proc. 5th Int. Conf. on Non-linear Oscillations, Vol.2, No.1, 507-521, Kiev, Oct. 1970.
166.	Chihiro Hayashi, Yoshisuke Ueda and Hiroshi Kawakami : Solution of Duffing's Equation Using Mapping Concepts, Proc. 4th Int. Conf. on Non-linear Oscillations, Vol.1, No.1, 25-40, Prague, Sep. 1968.

Proceeding of Domestic Conference:

1.	Akinori Tsuji, Norihiko Koori and Hiroshi Kawakami : 3Dプリンタを活用したAI / IoT実習用ロボット教材の開発, 令和4年度全学FD推進プログラム大学教育カンファレンスin徳島発表抄録集, 54-55, Dec. 2022.
2.	Seiya Amoh, Tetsushi Ueta and Hiroshi Kawakami : マルチバイブレータとカナール, NOLTAソサイエティ大会, No.NLS-019, Jun. 2022.
3.	Akinori Tsuji, Norihiko Koori and Hiroshi Kawakami : AI/IoTオリジナル教材を用いた実験・演習プログラムの開発, 令和3年度全学FD推進プログラム大学教育カンファレンスin徳島発表抄録集, 46-47, Jan. 2022.
4.	Seiya Amoh, Tetsushi Ueta and Hiroshi Kawakami : マルチバイブレータのカナール発生機序, Proc. SJCIEE 2021, 12, Sep. 2021.
5.	Akinori Tsuji, Norihiko Koori and Hiroshi Kawakami : AI/IoT基礎力養成-課題解決・アイデア創出に繋がる教材開発―, 令和2年度全学FD推進プログラム大学教育カンファレンスin徳島発表抄録集, 52-53, Jan. 2021.
6.	Akinori Tsuji, Norihiko Koori and Hiroshi Kawakami : 実践して学ぶAI/IoT技術-公開講座「AI/IoTセンサのしくみを知ろう」ー, 令和元年度全学FD推進プログラム大学教育カンファレンスin徳島発表抄録集, 54-55, Dec. 2019.
7.	Akinori Tsuji, Norihiko Koori and Hiroshi Kawakami : IoT対応2輪駆動型ロボットの開発-公開講座での活用事例-, 平成30年度全学FD推進プログラム大学教育カンファレンスin徳島発表抄録集, 48-49, Dec. 2018.
8.	Akinori Tsuji and Hiroshi Kawakami : ゲンジボタルの集団同期明滅における発光個体数の周波数解析, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 10, Sep. 2018.
9.	Miino Yuu, Tetsushi Ueta, Hiroshi Kawakami, Atsuo Maki and Naoya Umeda : Local stability and bifurcation phenomena in the softening Duffing equation, NOLTAソサイエティ大会, No.NLS-25, Jun. 2018.
10.	Akinori Tsuji, Norihiko Koori and Hiroshi Kawakami : 情報技術の習得を目的としたプログラミング学習用教材の開発, 平成29年度全学FD推進プログラム大学教育カンファレンスin徳島発表抄録集, 48-49, Jan. 2018.
11.	Akinori Tsuji and Hiroshi Kawakami : 発光パタン解析によるゲンジボタル雌のバースト発光の観測, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 26, Sep. 2017.
12.	Miino Yuu, Tetsushi Ueta and Hiroshi Kawakami : Bifurcation phenomena and homoclinic states of a simple piecewise linear dynamical system, NOLTAソサイエティ大会, No.NLS-18, Jun. 2017.
13.	Akinori Tsuji and Hiroshi Kawakami : プロトタイピング手法を用いたIoT教材の開発-公開講座「気象モニターを作ろう」-, 平成28年度全学FD推進プログラム大学教育カンファレンスin徳島発表抄録集, 40-41, Dec. 2016.
14.	Akinori Tsuji and Hiroshi Kawakami : ダブルプロット法によるゲンジボタル雌雄の発光同期パタンの解析, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 8, Sep. 2016.
15.	Akinori Tsuji and Hiroshi Kawakami : 公開講座におけるプロトタイピング手法を用いた体験型教育の実践, 平成27年度全学FD推進プログラム大学教育カンファレンスin徳島発表抄録集, 64-65, Jan. 2016.
16.	Akinori Tsuji and Hiroshi Kawakami : ゲンジボタル雄雌の相互結合における発光同期パタン, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 23, Sep. 2015.
17.	宮本恭介, Tetsushi Ueta and Hiroshi Kawakami : 2 つのコンパレータを用いたRC 方形波発振回路, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 300, Sep. 2015.
18.	Akinori Tsuji, 藤岡慧明, Daisuke Ito, 木本圭子, 合原一究, 関川宗久, Tetsushi Ueta, Kazuyuki Aihara and Hiroshi Kawakami : LEDホタルによる自然ホタルの強制同期, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 12, Sep. 2014.
19.	Akinori Tsuji, Daisuke Ito, 木本圭子, 合原一究, 関川宗久, Tetsushi Ueta, Kazuyuki Aihara and Hiroshi Kawakami : LEDホタルによるゲンジボタルの発光同期パタンの解析, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 3, Sep. 2013.
20.	Jumpei Inaba, Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : ある4次元発振器で見られるバースト発振について, 平成25年度電気関係学会四国支部連合大会講演論文集, 2, Sep. 2013.
21.	Daisuke Ito, Akinori Tsuji, 木本圭子, 合原一究, 関川宗久, Tetsushi Ueta, 合原一幸 and Hiroshi Kawakami : LEDホタルの引き込み現象:ホタルはエッジで同期する, LED総合フォーラム2013 in徳島論文集, 87-88, Apr. 2013.
22.	Akinori Tsuji, Daisuke Ito, 木本圭子, 関川宗久, 喜多順三, Tetsushi Ueta, 合原一幸 and Hiroshi Kawakami : LEDホタルの同期現象:自律的に動く光パタンの生成, LED総合フォーラム2012 in徳島論文集, 99-100, Apr. 2012.
23.	Kazutoshi Kinoshita, Tetsushi Ueta, Hiroshi Kawakami, Jun'ichi Imura and Kazuyuki Aihara : Bifurcation Phenomena of a Piecewise Affine Map with Hysteresis Properties, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, No.1-10, 10, Sep. 2011.
24.	Masaaki Mizumoto, Tetsushi Ueta and Hiroshi Kawakami : Bifurcation Analysis of Duffing-Rayleigh Equation, 平成19年度電気関係学会四国支部連合大会講演論文集, No.17-58, 388, Sep. 2007.
25.	Masaaki Mizumoto, Tetsushi Ueta and Hiroshi Kawakami : Bifurcation analysis of modified Duffing-van der Pol equation, 平成18年度電気関係学会四国支部連合大会講演論文集, No.17-3, 299, Sep. 2006.
26.	Toshiyuki Kumano, Tetsushi Ueta and Hiroshi Kawakami : A detection of repelles by applied computation for basin of attractions, 平成18年度電気関係学会四国支部連合大会講演論文集, No.17-2, 298, Sep. 2006.
27.	Masayasu Shiotsu, Tetsushi Ueta, Tetsuya Kobayashi, Shigeki Tsuji, Kazuyuki Aihara and Hiroshi Kawakami : On bistability of forced gene toggle switch, 平成18年度電気関係学会四国支部連合大会講演論文集, No.17-5, 301, Sep. 2006.
28.	Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : Bifurcation and Chaos in Simplification Circuit of `v`-`i` Coupled BVP Oscillators, 平成18年度電気関係学会四国支部連合大会講演論文集, No.17-4, 300, Sep. 2006.
29.	Yasuo Miyoshi, Takahiro Oie, Tetsushi Ueta, Masanori Hirotomo, Yoneo Yano and Hiroshi Kawakami : Support for Finding Learning Path by Relevant Lectures in e-Syllabus, JSiSE Research Report, Vol.20, No.4, 7-12, Nov. 2005. (Summary) 徳島大学では教育·研究者情報データベース (EDB) を利用してシラバスを作成してきた．現在，EDBに登録されたXML形式のシラバス情報を元に科目間の関連性をグラフ表示するLearning Path Finderの開発を行っている．これにより履修時の学習経路検索が支援されシラバスの使い勝手が向上する． (Keyword) Learning Path / Syllabus / XML / XML / Relational Database
30.	Kimiyasu Shiotsu, Tetsushi Ueta, Shigeki Tsuji, Kazuyuki Aihara and Hiroshi Kawakami : 遺伝子スイッチモデルの強制系に見られる周期解とその分岐現象, 平成17年度電気関係学会四国支部連合大会講演論文集, 4, Oct. 2005.
31.	Hirokazu Komatsu, Shigeki Tsuji, Tetsushi Ueta and Hiroshi Kawakami : 2次元ニューロンモデルの発火特性とその分類, 平成17年度電気関係学会四国支部連合大会講演論文集, 5, Oct. 2005.
32.	Toshiyuki Kumano, Tetsushi Ueta and Hiroshi Kawakami : カオスアトラクタ内の軌道履歴の視覚化, 平成17年度電気関係学会四国支部連合大会講演論文集, 12, Oct. 2005.
33.	Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : 変形BVP発振器でみられる引力圏境消失について, 平成17年度電気関係学会四国支部連合大会講演論文集, 10, Oct. 2005.
34.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : 倒立振子における力学系の対称性を利用した不安定周期運動の安定化制御器設計法, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 103, Sep. 2005.
35.	Hiroki Yoshii, Shigeki Tsuji, Tetsushi Ueta and Hiroshi Kawakami : Homotopy法をもちいた分岐局面の自動追跡, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, Sep. 2005.
36.	Yoshihiro Imakura, Tetsushi Ueta and Hiroshi Kawakami : Brusselator にみられるカオス現象, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, Sep. 2005.
37.	Tetsuya Yoshinaga, Hitoshi Iida, Kunichika Tsumoto and Hiroshi Kawakami : Analysis of a circadian oscillator model based on clock gene rhythms, 電気学会電子·情報·システム部門大会論文集, 114-118, Sep. 2005.
38.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : 倒立振子における不安定周期運動の安定化可能領域についての考察, National Convention Record I.E.E. Japan, Vol.3, 37, Mar. 2005.
39.	Tetsuya Yoshinaga, Kunichika Tsumoto, Hitoshi Iida and Hiroshi Kawakami : サーカディアンリズムの結合振動子モデルと時計遺伝子モデルの分岐解析, Transactions of the Japanese Society for Medical and Biological Engineering, Vol.42, No.2, 178, Nov. 2004.
40.	Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : ネットワークルータの輻輳制御における非線形性の導入, Proceedings of IEICE Society Conference, Vol.A, Sep. 2004.
41.	Hitoshi Iida, Tetsuya Yoshinaga and Hiroshi Kawakami : サーカディアン振動子モデルにみられる矩形波外力への同期化現象, 電子情報通信学会総合大会講演論文集, A-2-18, Mar. 2004.
42.	Tetsushi Ueta and Hiroshi Kawakami : 拡張BVP発振器における振動停止現象について, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 14, Oct. 2003.
43.	Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : 変形BVP発振器でみられるトーラス, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 13, Oct. 2003.
44.	Shigeki Tsuji, Tetsushi Ueta and Hiroshi Kawakami : 電流結合型 BVP発振器対の分岐とカオス, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 11, Oct. 2003.
45.	Atsushi Tsuda, Tetsushi Ueta, Takuji Kousaka and Hiroshi Kawakami : 極配置法カオス制御におけるベイスンについて, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 10, Oct. 2003.
46.	Hitoshi Iida, Hiroshi Kawakami, Tomohiro Kubo and Tetsuya Yoshinaga : 周期的矩形波列を注入した睡眠覚醒振動子モデルの分岐解析, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, Oct. 2003.
47.	Hitoshi Takagi, Kazuya Kusaka, Takao Hanabusa and Hiroshi Kawakami : Trial of task inquiring class named "Find Its Root", 平成15年度工学·工業教育研究講演会講演論文集, 417-418, Sep. 2003.
48.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : 並列型倒立振子における不安定周期運動の一安定化法, 平成15年度全国工業高等専門学校パワーエレクトロニクスセミナー(第8回)講演論文集, 69-72, Aug. 2003.
49.	俟野淳, Tomohiro Kubo and Hiroshi Kawakami : Robust stabilization of systems with time-delay in the states by delayed feedback, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 107, Oct. 2002.
50.	高橋昌宏, Tomohiro Kubo and Hiroshi Kawakami : Stabilization of uncertain discrete-time systems with prescribed stability, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 106, Oct. 2002.
51.	Tetsuya Yoshinaga, Kunichika Tsumoto and Hiroshi Kawakami : 動的結合ニューロンにみられる分岐と大域的挙動, 電子情報通信学会総合大会講演論文集, 442-443, Mar. 2002.
52.	Yoshihito Yasuhara, Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : 周期開閉スイッチを有する非線形回路に発生するカオスの制御, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 17, Oct. 2001.
53.	Shoichi Tahara, Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : ハイブリッドシステムに発生するカオスの制御, 電気関係学会中国支部連合大会論文集, 10, Oct. 2001.
54.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : 状態依存型断続特性を有する非線形力学系に発生するカオスの実験的制御, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 12, Oct. 2001.
55.	Hisayo Miyazaki, Tetsushi Ueta and Hiroshi Kawakami : 非対称結合BVP発振器の分岐とカオス, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 13, Oct. 2001.
56.	高橋昌宏, Tomohiro Kubo and Hiroshi Kawakami : 安定度を指定した離散時間最適レギュレータ, 平成13年電気関係学会四国支部連合大会講演論文集, No.8-24, 134, Sep. 2001.
57.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : 2本並列型倒立振子の安定化制御に関する一考察, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 121, Sep. 2001.
58.	Tetsuya Yoshinaga, Kunichika Tsumoto and Hiroshi Kawakami : 拡張BVP方程式にみられるホモクリニック分岐の連鎖, RIMS Kokyuroku, Jul. 2001.
59.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : 周期的α関数列を印加したHodgkin-Huxley方程式の分岐, 電子情報通信学会総合大会講演論文集, 67, Mar. 2001.
60.	Shoichi Tahara, Takuji Kousaka, Tetsushi Ueta, Hiroshi Kawakami and Minoru Abe : On an Electric Circuit Interrupted by Own State and a Periodic Interval, --- Control ---, IEICE Technical Report, Vol.NLP2000, No.100, 57-62, Nov. 2000. (Summary) In this report, we propose a control method of chaos in nonlinear dynamical system interrupted by own state and a periodic interval. We derive the composite discrete mapping as Poincare mapping. It enable us to calculate the unstable fixed or periodic point in a chaotic attractor. The controller is designed with the pole assignment technique which is usually applied in many linear control system. As an illustrate examples, we try to control the chaos in the system which has an observable chaos. This system is described by one dimensional piecewise linear system interrupted by own state and a periodic interval. Some theoretical results are verified by laboratory experiment.
61.	Kunichika Tsumoto, Tetsuya Yoshinaga, Kazuyuki Aihara and Hiroshi Kawakami : Bifurcations in a Model of Synaptically Coupled Neurons, Proc. International Conference on Dynamical Aspects in Complex Systems from Cells to Brain, Nov. 2000.
62.	岩尾続雄, Tomohiro Kubo and Hiroshi Kawakami : 状態にむだ時間を含む系が不確かさをもつ場合に対する最適メモリーレスレギュレータの構成, 平成12年電気関係学会四国支部連合大会, No.8-8, 111, Oct. 2000.
63.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : 周期外力を印加したニューロン対におけるバースト応答とその分岐, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 10, Oct. 2000.
64.	Shoichi Tahara, Takuji Kousaka, Tetsushi Ueta, Hiroshi Kawakami and Minoru Abe : ハイブリッドシステムに発生するカオスの制御, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 5, Oct. 2000.
65.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : 周期的α関数列を印加したBVP ニューロンにみられる分岐, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 7, Oct. 2000.
66.	Tetsuya Yoshinaga, Yuusuke Kawabata and Hiroshi Kawakami : 睡眠覚醒リズムにみられる季節依存性の結合発振器モデル, 日本エム·イー学会秋季大会論文集, 21, Oct. 2000.
67.	Yuusuke Kawabata, Tetsuya Yoshinaga and Hiroshi Kawakami : 睡眠覚醒リズムにみられる季節病の光治療を考慮した結合発振器モデルの分岐解析, 日本エム·イー学会中国四国支部大会論文集, 48, Oct. 2000.
68.	Takashi Minakuchi, Ken'ichi Fujimoto and Hiroshi Kawakami : 2リンク垂直型マニピュレータに見られる周期運動, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 18, Oct. 2000.
69.	Hiroaki Kudo, Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : 倒立振子における不安定回転運動の安定化に関する一考察, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 17, Oct. 2000.
70.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : 2リンク平面型UAMにおける不安定周期運動を用いた軌道設計, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 115, Oct. 2000.
71.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : 2リンク平面UAMにおける不安定周期運動の安定化可能領域, 電気学会電子·情報システム部門大会講演予稿集, 301-304, Sep. 2000.
72.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : UAMにおける周期運動の制御, ロボティクス·メカトロニクス講演会予稿集, 2P1-57-094, May 2000.
73.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : ニューロン対発振器の周期外力応答, 電子情報通信学会総合大会講演論文集, Vol.A, 61, Mar. 2000.
74.	Tetsushi Ueta, Guanrong Chen, Tetsuya Yoshinaga and Hiroshi Kawakami : 強結合ニューロン対に生じるneimark-sacker分岐と同期モード, 電子情報通信学会総合大会講演論文集, Vol.A, 412-413, Mar. 2000.
75.	Hiroaki Kudo, Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : 倒立振子における不安定周期振動の安定化, 電子情報通信学会総合大会講演論文集, 57, Mar. 2000.
76.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : 平面マニピュレータに見られる周期運動の運動学的考察, 第42回自動制御連合講演会予稿集, 221-222, Nov. 1999.
77.	西村泰治, Tomohiro Kubo and Hiroshi Kawakami : 入力にむだ時間を含む系における非干渉制御, 平成11年電気関係学会四国支部連合大会講演論文集, No.8-8, 122, Oct. 1999.
78.	Eiji Izumida, Tetsushi Ueta and Hiroshi Kawakami : 非線形力学系における3次元分岐図の自動作成, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 14, Oct. 1999.
79.	Takashi Kido, Takuji Kousaka, Hiroshi Kawakami and Tetsushi Ueta : Border-Collision分岐を生じる簡素な回路, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 13, Oct. 1999.
80.	Hiroaki Kudo, Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : 3本並列型倒立振子の選択的振り上げの一方法, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 22, Oct. 1999.
81.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : 平面マニピュレータに見られる周期運動の引力圏, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 120, Oct. 1999.
82.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : 平面マニピュレータの分岐現象における粘性摩擦変動の影響, 四国工業技術研究所研究成果発表予稿集, 25, Jul. 1999.
83.	Yoshio Tanaka, Ken'ichi Fujimoto and Hiroshi Kawakami : カオスによる並列型倒立振子の選択的振り上げ, 第38回計測自動制御学会学術講演会予稿集, Vol.2, 707-708, Jul. 1999.
84.	Eiji Izumida, Tetsushi Ueta and Hiroshi Kawakami : 非線形力学系における3パラメータ分岐曲面求解の自動化, National Convention Record I.E.E. Japan, Vol.1, 31, Mar. 1999.
85.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : 2リンク平面マニピュレータにおける運動の力学的性質, 電子情報通信学会総合大会講演論文集, 86, Mar. 1999.
86.	Eiji Izumida, Tetsushi Ueta and Hiroshi Kawakami : 3-パラメータ空間における非線形力学系の分岐構造の視覚化, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 10, Oct. 1998.
87.	Takashi Kido, Takuji Kousaka, Hiroshi Kawakami and Tetsushi Ueta : 方形波発振器の同期現象の解析, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 15, Oct. 1998.
88.	Takuji Kousaka, Hiroshi Kawakami and Tetsushi Ueta : DC-DCコンバータ回路における分岐計算法, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 82, Oct. 1998.
89.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : 1自由関節を持つ2平面リンクマニピュレータにおける強制振動現象の解析, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 11, Oct. 1998.
90.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : 状態に依存したスイッチで制御される非線形断続回路のカオス制御, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 115, Oct. 1997.
91.	Makoto Shiota, Tetsushi Ueta and Hiroshi Kawakami : Duffing方程式における分岐集合曲面の3次元表示, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 34, Oct. 1997.
92.	Tetsushi Ueta and Hiroshi Kawakami : 3個の結合された2次写像の時空カオス的挙動, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 21, Oct. 1997.
93.	Ken'ichi Fujimoto, Takuji Kousaka, Yasuyuki Hayashi and Hiroshi Kawakami : スイッチで制御されるRC回路を付加したBVP発振器, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 27, Oct. 1997.
94.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : 不連続な非線形特性を持つ系にみられるリミットサイクルの分岐, 電子情報通信学会総合大会講演論文集, Vol.A, 93, Mar. 1997.
95.	Makoto Shiota, Tetsushi Ueta and Hiroshi Kawakami : 2 次元離散力学系における周期アトラクタ領域の σ-等高線による解析, 電子情報通信学会総合大会講演論文集, Vol.A, 92, Mar. 1997.
96.	Masafumi Tsueike, Tetsushi Ueta and Hiroshi Kawakami : 結合ニューロン発振器の同期現象, 電子情報通信学会総合大会講演論文集, Vol.A, 76, Mar. 1997.
97.	Makoto Shiota, Tetsushi Ueta and Hiroshi Kawakami : 2次元離散系における σ-等高線の計算, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 21, Oct. 1996.
98.	Takuji Kousaka, Hiroshi Kawakami and Tetsushi Ueta : 方形波発振器を用いた電子ホタルの同期現象, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 20, Oct. 1996.
99.	Tetsushi Ueta and Hiroshi Kawakami : On saddle-node connectiong orbit in nonlinear dynamical systems, 電子情報通信学会総合大会講演論文集, Vol.A, 435-436, Mar. 1996.
100.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Destabilizing orbits by controlling chaos, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 125, Oct. 1995.
101.	Tetsushi Ueta and Hiroshi Kawakami : A control to enlarge the synchronized region of nonlinear dynamics, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 124, Oct. 1995.
102.	Tetsushi Ueta and Hiroshi Kawakami : 周期外力を印加した倒立振子のカオスとその制御, 電子情報通信学会総合大会講演論文集, Vol.A, 75, Mar. 1995.
103.	Takuji Kosaka, Tetsushi Ueta and Hiroshi Kawakami : BVP発信器に見られる分岐現象の解析, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 13, Oct. 1994.
104.	Tetsushi Ueta and Hiroshi Kawakami : Stabilizing periodic orbits embedded in a chaotic attractor of continuous dynamical systems, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 129, Oct. 1994.
105.	Hiroshi Kawakami and Tetsushi Ueta : Controlling unstable fixed point in chaotic state of discrete dynamical systems, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 128, Oct. 1994.
106.	Tetsushi Ueta and Hiroshi Kawakami : Bifurcation phenomena in a Josephson junction circuit coupled by a resistor, 電子情報通信学会春季全国大会講演論文集, Vol.A, 75, Mar. 1994.
107.	Tetsushi Ueta and Hiroshi Kawakami : Bifurcation of an inductively coupled Josephson junction circuit, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 13-14, Oct. 1993.
108.	Takahiro Oie, Tadamitsu Iritani and Hiroshi Kawakami : 2つの正弦波入力に対するPLLの応答, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, No.12-5, 206, Oct. 1993.
109.	Tetsushi Ueta and Hiroshi Kawakami : 準回転力学系のヘテロクリニック軌道, 電子情報通信学会春季全国大会講演論文集, A85, Mar. 1993.
110.	Tetsushi Ueta and Hiroshi Kawakami : 準回転運動を行なう力学系の解析, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 13-14, Oct. 1992.
111.	Yoshio Tanaka, Masato Tanaka, Yasuo Yoshida, Tetsushi Ueta and Hiroshi Kawakami : 振動センサを利用した旋回型クレーンの振動制御, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 287-288, Oct. 1991.
112.	Tetsushi Ueta, Yoshio Tanaka and Hiroshi Kawakami : クレーンの吊り荷揺れと揺れのパラメトリック制御, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 277-278, Oct. 1991.
113.	Tetsushi Ueta, Yoshio Tanaka and Hiroshi Kawakami : クレーンの本体と吊り荷揺れの統一的解析法Ⅱ, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 213-214, Oct. 1990.
114.	Yoshio Tanaka, Tetsushi Ueta and Hiroshi Kawakami : クレーンの本体と吊り荷揺れの統一的解析法I, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 211-212, Oct. 1990.
115.	Yoneo Yano, Hiroshi Kawakami and 森崎雅念 : タートルグラフィックスの一方法とその電気回路への応用, 昭和59年度電気関係学会四国支部連合大会, 1-249-1-250, Mar. 1984.
116.	東條隆, Yoneo Yano, 坂本明雄 and Hiroshi Kawakami : Course Guidance Systemの開発, 昭和59年度電気関係学会四国支部連合大会, 7-295, Mar. 1984.
117.	東條隆, Yoneo Yano, 坂本明雄 and Hiroshi Kawakami : Course Guidance System(COGS)における相談過程, 第8回CAI学会研究発表大会論文集, 91-94, Oct. 1983.
118.	東條隆, Yoneo Yano, 坂本明雄 and Hiroshi Kawakami : 履修科目選択のための相談システム, 電気関係学会四国支部連合大会, Vol.12-1, 235-236, Oct. 1982.

Et cetera, Workshop:

1.	Seiya Amoh, Tetsushi Ueta and Hiroshi Kawakami : Multivibrator and Slow-fast Dynamics, --- Basic bifurcation phenomena and Canard solutions ---, IEICE Technical Report, Vol.NLP2022, No.15, 72-77, Jun. 2022. (Summary) Slow-fast dynamical systems are systems of ordinary differential equations involving different time constants. Systems with slow-fast characteristics may have a characteristic solution called the Canard solution. The evolution of the solution depending on the parameter change is interesting. In this paper, we treat a multivibrator, which is a slow-fast dynamical system that can be easily implemented as an electronic circuit. If the operational amplifiers of the multivibrator have dynamic output characteristics, the system behaves as a slow dynamics system. We investigate the basic bifurcation phenomena that occur at the equilibrium point and the process of generating Canard solutions. (Keyword) Slow-fast dynamics / canard / multivibrator / bifurcation
2.	Shohei Miyazaki, Yuu Miino, Tetsushi Ueta and Hiroshi Kawakami : 馬蹄型写像の同定とカオス制御, IEICE Technical Report, Vol.NLP2019, No.58, 117-122, Sep. 2019. (Summary) 1 つのサドル型固定点から伸びる安定多様体と不安定多様体の交わりであるホモクリニック点が存在するとき，馬蹄形写像が存在している．馬蹄形写像内部には可算無限個の不安定周期点が存在しており，ホモクリニック点をNewton 法の初期値として任意周期の不安定周期点を計算することができる．本研究では，導出した不安定周期点を用いたExternal Force Control で馬蹄形写像内部の不安定周期点を制御することを目的とする． (Keyword) Henon map / horse shoe map / unstable periodic orbit / homoclinic point / かおすせいぎょ
3.	Shohei Miyazaki, Yuu Miino, Tetsushi Ueta and Hiroshi Kawakami : エノン写像における馬蹄形写像のホモクリニック点と不安定周期点との位置関係, IEICE Technical Report, Vol.NLP2018, No.70, 91-96, Aug. 2018. (Summary) 馬蹄形写像内部の不安定周期点をあるホモクリニック点の座標情報を用いて計算する手法が開発されている．しかし，両者の位置的関係についての調査は未だ行われていなかった．本研究では，馬蹄形写像に埋め込まれた不安定周期点を6周期点まで算出し，これらと算出に用いるホモクリニック点との位置関係を調査する．Hénon 写像を例に取り，ホモクリニック点及び周期点は数値的に導出し，極座標形式による座標評価を行う． (Keyword) Henon map / horse shoe map / unstable periodic orbit / homoclinic point
4.	Yuu Miino, Tetsushi Ueta, Hiroshi Kawakami, Atsuo Maki and Naoya Umeda : 船舶転覆問題にみられる分岐現象, IEICE Technical Report, Vol.NLP2018, No.55, 15-19, Aug. 2018. (Summary) 船舶の運動安定性の分野においては，船舶転覆問題を議論するために軟化型Duffing 方程式が用いられる．しかしながら，軟化型Duffing 方程式を扱う多くの研究は近似的解法を用いており，実際の物理系の振る舞いにそぐわない結果を導くことも少なくない．本報では，非線形分野で古くから発展してきた数値的解法を用いて，軟化型 Duffing 方程式を解析する．適切なPoincaré 写像を定義し，系で観測される周期解の安定性や安定・不安定多様体を導出し，局所または大域分岐について議論する．結果として，系の二次元パラメタ空間における分岐構造を明らかにし，分岐現象が状態空間のベイスンに及ぼす影響について議論する． (Keyword) 軟化型Duffing方程式 / numerical computation / local stability / local bifurcation / global bifurcation
5.	Yuu Miino, Tetsushi Ueta and Hiroshi Kawakami : 簡素な区分線形力学系に発現するホモクリニック点の分岐, IEICE Technical Report, Vol.NLP2017-15, No.18, 73-76, May 2017. (Summary) In a certain case, a piecewise linear dynamical system shows rich nonlinear phenomena. In this study, we discuss the homoclinic point and its bifurcation observed in a simple piecewise linear dynamical system. We adapt the hybrid system approach and calculate the homoclinic point and its bifurcation sets. (Keyword) piecewise linear / bifurcation analysis / hybrid system / homoclinic point
6.	Yuu Miino, Tetsushi Ueta and Hiroshi Kawakami : Nonlinear phenomena observed in the piecewise hysteresis Duffing equation, IEICE Technical Report, Vol.NLP2016, No.50, 31-36, Sep. 2016. (Keyword) hysteresis phenomena / Duffing equation / bifurcation analysis / hybrid system / nonlinear resonance
7.	Kyosuke Miyamoto, Tetsushi Ueta and Hiroshi Kawakami : Synchronization mechanism of optical-coupled oscillators, IEICE Technical Report, Vol.NLP2016, No.10, 45-50, May 2016. (Keyword) LED firefly / synchronization
8.	Daisuke Ito, Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : 周期外力を印加した電子ホタルにみられる時間応答波形, IEICE Technical Report, Vol.114, No.414, 113-116, Jan. 2015. (Keyword) Electronic firefly / isolated periodic orbit / quasi-periodic orbit
9.	Jumpei Inaba, Yusuke NIshiuchi, Tetsushi Ueta and Hiroshi Kawakami : An analysis of bursting oscillations in a 4D autonomous system, IEICE Technical Report, Vol.113, No.271, 199-204, Oct. 2013. (Summary) Bursting oscillations are important in considering the behavior of neuron,the mathematical models are devised variously.And bursting oscillations are realized by a coupling or applying an external periodic forcing to the system,however,what can be implemented easily in actual circuit is not many. In the studying for the BVP oscillator for generating a quasi-periodic, we were able to propose the bursting oscillator of 4-dimensional autonomous system. whose number of components is small and be easy to implement.In this paper, we showed periodic orbits, quasi-periodic orbits, and let compared with the responses of the actual circuit and numerical simulations on how to change burst oscillations are dependent on the parameters. Next we analyzed the bifurcation of periodic solutions, and characterized the topological properties of the bursting oscillations. (Keyword) バースト発振 / 4次元発振器 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520853834200712192 (CiNii: 1520853834200712192)
10.	Yusuke NIshiuchi, Tetsushi Ueta and Hiroshi Kawakami : Characteristics of bifurcations and oscillations in coupled BVP oscillators, IEICE Technical Report, Vol.113, No.271, 117-122, Oct. 2013. (Summary) BVP 発振器は単純な回路構成で発振状態を観測できる有名な非線形モデルである．BVP 発振器は二つの状態変数に関係したポートを持つため，二つの同一 BVP 振器を結合する場合でも，結合方式の違う結合発振器が複数存在する．これらの結合発振器のうち，基本的なものは既に研究されているが，非線形特性や正規化手法が違うため，その結果を単純に比較し特徴を求めることはできない．そこで，本研究では基本的な結合方式について，同一条件で平衡点やリミットサイクルの分岐，同期発振の状態を調べ，結合方式による特徴を明らかにする． (Keyword) 結合BVP発振器 / nonlinear systems / bifurcation phenomena
11.	Daisuke Ito, Akinori Tsuji, Tetsushi Ueta and Hiroshi Kawakami : 周期外力を加えた電子ホタルにおける分岐と同期現象, IEICE Technical Report, Vol.NLP2011-138, No.111, 81-86, Jan. 2012. (Summary) Cooperative or conjoint action of creatures with autonomous oscillation can be considered as synchronization phenomena which are one of typical nonlinear dynamic properties. For example, there are a group singing of crickets, self-organized light synchronizations of fireflies and so on. Especially, fireflies can be modeled as optically coupled oscillators(OCOs) by using LEDs and photo interruptor. Synchronization phenomena of a couple of these oscillators were already investigated, however, synchronization of the single oscillator is not discussed. In this study, we model the firefly as OCO, and add the periodic external force input for one. (Keyword) electrical firefly / interrupt dynamical system / bifurcation phenomena (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520572357095635328 (CiNii: 1520572357095635328)
12.	Takaya Nakanishi, Daisuke Ito, Tetsushi Ueta, Hiroshi Kawakami, Jun'ichi Imura and Kazuyuki Aihara : 馬蹄形写像を利用した周期点の特定と制御, IEICE Technical Report, Vol.NLP2011-120, No.111, 19-24, Dec. 2011.
13.	Kazutoshi Kinoshita, Tetsushi Ueta, Hiroshi Kawakami, Jun'ichi Imura and Kazuyuki Aihara : ヒステリシス特性を持つ区分的アファインシステムについての分岐現象, IEICE Technical Report, Vol.NLP2011-13, No.62, 62-64, May 2011.
14.	Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : 特異な応答における Basin Boundary 構造の消失と数値演算誤差について, IEICE Technical Report, Vol.NLP2008, No.29, 53-56, Jul. 2008.
15.	Kimiyasu Shiotsu, Tetsushi Ueta, Shigeki Tsuji, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcations in a gene toggle switch model, IEICE Technical Report, Vol.NLP2005, No.114, 93-98, Jan. 2006.
16.	Hirokazu Komatsu, Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : Analysis of type-I and II characteristics of a forced two-dimentional HR neuron model, IEICE Technical Report, Vol.NLP2005, No.113, 87-92, Jan. 2006.
17.	Hiroki Yoshii, Tetsushi Ueta and Hiroshi Kawakami : Automatic Tracking Scheme of 3D Bifurcation Diagrams for Nonlinear Dynamical Systems, IEICE Technical Report, Vol.NLP2005, No.103, 55-60, Jan. 2006.
18.	Toshiyuki Kumano, Tetsushi Ueta and Hiroshi Kawakami : Information Extraction by Visualization of Transient States in Chaotic Attractors, IEICE Technical Report, Vol.NLP2005, No.107, 55-60, Jan. 2006.
19.	Hirokazu Komatsu, Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcational classification for type-I and II activities in a forced planar H-R model, Int. Symp. Complexity Modelling and its Applications, Nov. 2005.
20.	Hitoshi Iida, Tetsuya Yoshinaga and Hiroshi Kawakami : Analysis on sets of equal phase differences for synchronized rhythms in a circadian oscillator model, IEICE Technical Report, Vol.NLP2004-89, 5-8, Jan. 2005.
21.	Hiroki Yoshii, Tetsushi Ueta and Hiroshi Kawakami : ニュートンホモトピー法を応用した3次元分岐局面の構成法について, IEICE Technical Report, Vol.NLP2004, No.91, 15-20, Jan. 2005.
22.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : 電気シナプスと抑制性シナプスによって結合される変形BVPニューロンモデルにみられる同期現象について, IEICE Technical Report, Vol.NLP2004, No.84, 49-54, Nov. 2004. (Summary) Electrical coupling among inhibitory interneurons has been discovered in various regions of the brain. Since these local networks indicate the sophisticated activity by the interplay between electrical and inhibitory synapses, the emergence of synchronous phenomena have been investigated by many researchers. We propose coupled neuronal models connected by both inhibitory and electrical synapses and investigate the emergence of various synchronous phenomena and its bifurcational structures by the bifurcation analysis.Although it is generally known that strong gap junction synchronize coupled neurons, we show in-phase and anti-phase phenomena in coupled neurons connected by both inhibitory and electrical synapses, and they change to chaotic solutions via period-doubling and pitchfork bifurcations.
23.	Hitoshi Iida, Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcations in a circadian oscillator model with periodic force, IEICE Technical Report, Vol.104, No.179, 33-36, Jul. 2004.
24.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : Gapjunction 結合ニューロンモデルにみられる分岐現象について, IEICE Technical Report, Vol.NLP2003, No.139, 5-10, Dec. 2003.
25.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : 時計遺伝子サーカディアンモデルの分岐現象, IEICE Technical Report, Vol.103, No.503, 61-66, Dec. 2003.
26.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcation in a Morris-Lecar neuron model, IEICE Technical Report, Vol.103, No.464, 13-18, Nov. 2003.
27.	Tetsushi Ueta and Hiroshi Kawakami : 線形回路の発振条件と非線形回路の Hopf 分岐に関する考察, IEICE Technical Report, Vol.NLP2003, No.84, 7-12, Oct. 2003.
28.	Atsushi Tsuda, Shigeki Tsuji, Tetsushi Ueta and Hiroshi Kawakami : 極配置法カオス制御におけるベイスンについて, IEICE Technical Report, Vol.NLP2003, No.78, 49-54, Sep. 2003.
29.	Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : 単純な3次元自律系に生じるトーラス, IEICE Technical Report, Vol.NLP2003, No.52, 41-46, Jul. 2003.
30.	Shigeki Tsuji, Tetsushi Ueta and Hiroshi Kawakami : 電流結合型BVP発振器対にみられる分岐現象とカオス, IEICE Technical Report, Vol.NLP2003, No.49, 23-28, Jul. 2003.
31.	Hiroyuki Kitajima, Tetsuya Yoshinaga, Kazuyuki Aihara and Hiroshi Kawakami : カオスニューロン結合系にみられるカオス遍歴とα-枝の交差, IEICE Technical Report, Vol.103, No.183, 37-40, Jul. 2003.
32.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : シナプス伝達により結合した Morris-Lecar ニューロンにみられる同調現象の分岐解析, IEICE Technical Report, Vol.103, No.183, 29-32, Jul. 2003.
33.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : 時計遺伝子リズムのニューロンモデルにみられる同調現象の分岐, IEICE Technical Report, Vol.103, No.137, 31-36, Jun. 2003.
34.	Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : 変形BVP発振器における引力圏形成モデル, IEICE Technical Report, Vol.NLP2003, No.3, 13-18, May 2003.
35.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : 3次元自律系ニューロンモデルにみられるバースト発火とその分岐, IEICE Technical Report, Vol.NLP2003, No.5, 25-30, May 2003.
36.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcations analysis of synchronization phenomena observedin a coupled neuronal model for circadian clock rhythms, Proc. of Symposium on Nonlinear-linear Information processing, Vol.1, 13-20, Nov. 2002.
37.	Yoshihito Yasuhara, Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : 状態と時刻に依存したスイッチを有する非線形回路の解析, IEICE Technical Report, Vol.NLP2002, No.76, 43-48, Nov. 2002.
38.	Yusuke Nishiuchi, Tetsushi Ueta and Hiroshi Kawakami : 変形BVP発振器にみられる特異な応答とその Basin Boundary について, IEICE Technical Report, Vol.NLP2002, No.15, 45-50, Jun. 2002.
39.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : 周期外力で駆動される Gap Junction 結合 BVP 発振器, IEICE Technical Report, Vol.NLP2002, No.14, 39-44, Jun. 2002.
40.	Hideaki Harada, Takuji Kousaka, Minoru Abe, Hiroshi Kawakami and Tetsushi Ueta : Calculation of the Bifurcation sets in the Buck Converter, IEICE Technical Report, Vol.NLP2002, No.100, 472-54, Jan. 2002. (Summary) Recently, various bifurcation phenomena have been observed in the simple power electronics circuits. Since current or voltage controlled converters have wide industrial application, it is a important problem to clarity the property of the power electronics systems in the mathematical point of view. However, there are very few methods being developed in the literature for the bifurcation analysis and its property. In this paper, we investigate the bifurcation phenomena in a simple DC-DC buck converter. We have also propose a method to trace the local bifurcation sets in such converters. Some of theoretical results are verified by laboratory experiments.
41.	Tetsushi Ueta and Hiroshi Kawakami : Bifurcation and Chaos of Periodic Solutions in the Custom BVP Oscillator, IEICE Technical Report, Vol.NLP2001, No.63, 71-78, Nov. 2001.
42.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : The design and its implementation of the bursting in BVP oscillator, IEICE Technical Report, Vol.NLP2001, No.57, 27-34, Nov. 2001. (Summary) Bursting observed in nerve membranes is regarded to be important when the information representation problem in brain is considered. Until now, various bursting responses are illustrated in the mathematical model, and accordingly their related bifurcation mechanisms have been clarified. In this paper, we propose an oscillator showing bursting response with a simple circuitry, the circuit equation is represented as a BVP(FitzHugh-Nagumo)model equation. Firstly we investigate bifurcation structure in the autonomous system. Then an effective and reasonable perturbation of theh external force to this bifurcation structure to generate various bursting responses. Secondly we show various burst oscillations are observed by changing the frequency and amplitude of sinusoidal wave. Finally we show a laboratory experiments of the circuit.
43.	Tsutomu Enomoto, Tetsuya Yoshinaga and Hiroshi Kawakami : 逐次的CT画像再構成法の高速化, IEICE Technical Report, Vol.NLP2001-59, 43-49, Nov. 2001.
44.	Hisayo Miyazaki, Tetsushi Ueta, Takuji Kousaka and Hiroshi Kawakami : Bifurcation in Coupled BVP Oscillators, IEICE Technical Report, Vol.NLP2001, No.56, 35-42, Sep. 2001. (Summary) BVP oscillator is the simplest mathematical model describing a neural activity. However, even if two BVP oscillators are merely compled by a linear element, the whole system exhibits complicated behavior. For studying such coupled system, identical oscillators are often used as an oscillator unit since symmetrical properties sometimes reduce the bifurcation problem about equilibria and periodic solutions. In this paper, we analyze a coupled BVP oscillators with asymmetrical coupling structure, besides, each oscillator has different internal registance. We should the whole four-dimensional system, but the system shows strange attractors. We calculate bifurcation diagrams and confirm relevant phenomena in the laboratory experiments. Furthermore, we try to reduce the system dimension by removing passive and active elements.
45.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : The generating mechanism of bursting in FitzHugh-Nagumo model and design of its external force, IEICE Technical Report, Vol.NLP2001, No.44, 27-34, Sep. 2001. (Summary) Firing phenomenon called spiking and bursting observed in nerve cell membranes are regarded to be important when the information representation problem in brain is considered. Until now, various bursting responses observed in the mathematical model have been classified, and accordingly their related bifurcation mechanisms on have been clarified. In this papaer, we propse a FitzHugh-Nagumo model with a simple periodic external force. The external input gives periodic activity to the autonomous system, and it is expected that the generating mechanism of bursting is constructed. The parameter regions sectioned by bifurcation curves are obtained as bursting or spiking regions.
46.	Tsutomu Enomoto, Tetsuya Yoshinaga and Hiroshi Kawakami : CT画像の代数的再構成法に対する高速化, IEICE Technical Report, Vol.MBE2001-63, 63-69, Jul. 2001.
47.	Yoshihito Yasuhara, Takuji Kousaka, Tetsushi Ueta, Minoru Abe and Hiroshi Kawakami : Experimental Control of Chaotic Behavior in a State-Dependent Nonlinear Circuit, IEICE Technical Report, Vol.NLP2001, No.8, 51-58, May 2001. (Summary) There have been numerous theoretical and experimental investigations on the controlling chaos in the piecewise linear systems. This paper reports a method for controlling chaos in the nonlinear dynamical systems with interrupted characteristics. Some of theoretical results are confirmed by experiment al laboratory.
48.	Kunichika Tsumoto, Tetsuya Yoshinaga, Kazuyuki Aihara and Hiroshi Kawakami : 周期的α関数を注入した結合Hodgkin-Huxleyニューロン対にみられる分岐現象, IEICE Technical Report, Vol.NLP2001-7, 43-50, May 2001.
49.	Shigeki Tsuji, Tetsushi Ueta, Hiroshi Kawakami and Kazuyuki Aihara : 周期外力を付加したAmari-Hopfieldニューロン対におけるバースト応答の分岐, IEICE Technical Report, Vol.NLP2000, No.167, 25-32, Mar. 2001. (Summary) When considering the mechanism of an information processing mechanism in the brain of a living body, the problem of information coding of a neuron, etc., the mathematical model of a neuron is indispensable. According to a point of view and the purpose, various models are formulized until now, and analysis is advanced. In this paper, correspondence is investigated about a classification of bifuracation by Izhikevich et al., and a burst response in an Amari-Hopfield model. It is thought that it is important to investigate the various burst response type which realizes a burst response of the given specification, and it becomes information useful as a design problem of a burst response to solve the bifurcation diagram according to the parameter of external force.
50.	Tetsushi Ueta, Takuji Kousaka, Hisayo Miyazaki and Hiroshi Kawakami : Bifurcation and Chaos in Coupled BVP Oscillators, IEICE Technical Report, Vol.NLP2000, No.166, 17-24, Mar. 2001. (Summary) BVP oscillator is one of classic model exhibiting typical nonlinear phenomena in the planar autonomous system and it has been studied for last three decades. This report shows bifurcation and chaos in resistively coupled BVP oscillators. Each oscillator has different value of internal resister, i.e., different frequency oscillators are coupled. Bifurcation diagrams are obtained numerically from mathematical model and chaotic parameter regions are clarified. This result also points out that the coupling system of identical oscillators does not behave chaotically with reasonable parameter range. We also confirm the existence of period-doubling cascades and chaotic attractors in experimental laboratory.
51.	Takuji Kousaka, Tetsushi Ueta, Hiroshi Kawakami, Shoichi Tahara and Minoru Abe : On an Electric Circuit Interrupted by Own State and a Periodic Interval, --- Control ---, IEICE Technical Report, Vol.NLP2000, No.100, 57-62, Nov. 2000. (Summary) This report consider a system interrupted by own state and a periodic interval. We know above system has prospects of occurrence of border-collision bifurcation. Firstly, we propose a simple model that occurs border-collision bifurcation, and consider periodic orbits, their stabilities and bifurcations. Some of theoretical results are verified by laboratory experiments. Secondly, we analyze dc-dc converter. Finally, We propose a method to trace bifurcation sets for a piecewise nonlinear equation interrupted by own state and periodic interval.
52.	Shigeki Tsuji, Hisayo Miyazaki, Tetsushi Ueta and Hiroshi Kawakami : Calculation of the Isocline for the Fixed Point with a specifiled Argument of Complex Multipliers, IEICE Technical Report, Vol.NLP2000, No.102, 69-74, Nov. 2000. (Summary) This paper proposes a calculation method to obtain the location of the fixed point in given nonlinear discrete system when the argument of complex multipliers is specified. We can calculate isoclines corresponding to the specified arguments, then the stability and instantaneous phase around the fixed point is clarified. As an application, we also propose a new calculation method of NS bifurcation parameter values with specified argument. In addition, cross points of a cusp in a periodic entrainment region and the NS bifurcation curve is identified by this application.
53.	Hiroaki Kudo, Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : Swing-Up Control of a Parallel-Type Triple Inverted Pendulum, IEICE Technical Report, Vol.NLP100, No.469, 51-56, Nov. 2000.
54.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : 周期的α関数を注入したBVPニューロンにみられる分岐, IEICE Technical Report, Vol.NLP2000-106, 97-104, Nov. 2000.
55.	Yusuke Kawabata, Tetsuya Yoshinaga and Hiroshi Kawakami : 周期的パルス列を注入した相互結合発振器の分岐解析, IEICE Technical Report, Vol.NLP2000-113, 37-44, Nov. 2000.
56.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : シナプス伝達により結合した4個のBVPニューロンにみられる分岐現象, IEICE Technical Report, Vol.NLP2000-3, 17-24, May 2000.
57.	Takuji Kousaka, Takashi Kido, Tetsushi Ueta and Hiroshi Kawakami : On an Electric Circuit Interrupted by Own State and a Periodic Interval, --- Bifurcation ---, IEICE Technical Report, Vol.NLP99, No.123, 31-38, Nov. 1999. (Summary) This report consider a system interrupted by own state and a periodic interval. We know above system has prospects of occurrence of border-collision bifurcation. Firstly, we propose a simple model that occurs border-collision bifurcation, and consider periodic orbits, their stabilities and bifurcations. Some of theoretical results are verified by laboratory experiments. Secondly, we analyze dc-dc converter. Finally, We propose a method to trace bifurcation sets for a piecewise nonlinear equation interrupted by own state and periodic interval.
58.	Yusuke Kawabata, Tetsuya Yoshinaga and Hiroshi Kawakami : 睡眠覚醒モデルの平均化方程式にみられる分岐現象の解析, IEICE Technical Report, Vol.MBE99-47, 69-76, Jul. 1999.
59.	Hiroaki Kudo, Tetsuya Yoshinaga and Hiroshi Kawakami : α関数による自己結合BVP方程式の分岐解析, IEICE Technical Report, Vol.NLP99-55, 69-76, Jul. 1999.
60.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : シナプス伝達により結合した2個のBVPニューロンにみられる分岐現象(2), IEICE Technical Report, Vol.NLP99-52, 45-52, Jul. 1999.
61.	Ken'ichi Fujimoto, Yoshio Tanaka and Hiroshi Kawakami : A Study of Identifying Parameters of a Planer Manipulator, IEICE Technical Report, Vol.NLP99, No.134, 91-97, Jun. 1999.
62.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : シナプス伝達により結合した2個のBVPニューロンにみられる分岐現象, IEICE Technical Report, Vol.NLP99-43, 115-122, Jun. 1999.
63.	Yasuhiko Sano, Tetsuya Yoshinaga and Hiroshi Kawakami : 周期的インパルス列を印加したHodgkin-Huxley方程式にみられる分岐, IEICE Technical Report, Vol.NLP99-44, 123-130, Jun. 1999.
64.	Takashi Kido, Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Border-collision 分岐を生じる簡素な構成の回路について, IEICE Technical Report, Vol.NLP99, No.123, 31-38, May 1999.
65.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : ニューロンモデルとしての拡張BVP方程式にみられる矩型波バースト振動の分岐, IEICE Technical Report, Vol.NLP98-102, 43-50, Feb. 1999.
66.	Tetsuya Yoshinaga and Hiroshi Kawakami : カオス·ニューロンを用いた離散時間自己想起形連想記憶モデルの解析, RIMS Kokyuroku, Vol.1072, 144-161, Dec. 1998.
67.	Tetsuya Yoshinaga, Kunichika Tsumoto, Yasuhiko Sano and Hiroshi Kawakami : ニューロンモデルにみられる振動現象の分岐解析, The Papers of Technical Meeting, IEE JAPAN, Vol.ECT-98-108, 41-46, Dec. 1998.
68.	Yasuhiko Sano, Tetsuya Yoshinaga and Hiroshi Kawakami : シナプス結合Hodgkin-Huxley方程式にみられる分岐, IEICE Technical Report, Vol.NLP98-83, 43-50, Nov. 1998.
69.	Takuji Kousaka, Hiroyuki Kitajima, Tetsushi Ueta, Tetsuya Yoshinaga and Hiroshi Kawakami : 不連続性をもつ力学系における分岐計算法, IEICE Technical Report, Vol.NLP98, No.30, 1-8, Jul. 1998.
70.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : 拡張BVP方程式の相互結合系にみられる同期と分岐, IEICE Technical Report, Vol.NLP98-52, 37-44, Jul. 1998.
71.	Takashi Kido, Takuji Kousaka, Hiroshi Kawakami and Tetsushi Ueta : 抵抗で結合した方形波発振器の同期現象, IEICE Technical Report, Vol.NLP98, No.92, 9-16, May 1998.
72.	Tetsuya Yoshinaga, Yasuhiro Inuma and Hiroshi Kawakami : あるカオス·ニューラル·ネットワークにみられるカオス的遍歴現象の解析(II), IEICE Technical Report, Vol.NLP97-164, 23-30, Mar. 1998.
73.	塩田真, Tetsushi Ueta and Hiroshi Kawakami : 3次元パラメータ空間における分岐図の構成と視覚化, IEICE Technical Report, Vol.NLP97, No.97, 93-100, Oct. 1997.
74.	高坂拓司, Tetsushi Ueta, Hiroshi Kawakami, Ken'ichi Fujimoto and 林保幸 : 断続RC回路を持つBVP発振器について, IEICE Technical Report, Vol.NLP97, No.112, 103-108, Oct. 1997.
75.	Yasuhiro Inuma, Tetsuya Yoshinaga and Hiroshi Kawakami : あるカオス·ニューラル·ネットワークにみられるカオス的遍歴現象の解析, IEICE Technical Report, Vol.NLP97-102, 25-32, Oct. 1997.
76.	Kunichika Tsumoto, Tetsuya Yoshinaga and Hiroshi Kawakami : 拡張BVP方程式のカオス発生に至る分岐, 1997年非線形理論とその応用ワークショップ報告集, 34-37, Oct. 1997.
77.	高坂拓司, 馬越豊, Tetsushi Ueta and Hiroshi Kawakami : 状態に依存したスイッチで切り替わる非線形系の分岐, IEICE Technical Report, Vol.NLP97, No.14, 97-104, May 1997.
78.	Tetsushi Ueta and Hiroshi Kawakami : 2自由度マニュピュレータの繰り返し動作にみられるカオス的振動, IEICE Technical Report, Vol.NLP97, No.112, 103-108, May 1997.
79.	馬越豊, 高坂拓司, Tetsushi Ueta and Hiroshi Kawakami : 外力と状態で動作するスイッチを含む発振回路の解析, IEICE Technical Report, Vol.NLP96, No.169, 77-84, Mar. 1997.
80.	Takuji Kousaka, Hiroshi Kawakami and Tetsushi Ueta : 結合した2つの異なる方形波発振器に生じる周期解の解析, IEICE Technical Report, Vol.NLP96, No.145, 33-40, Feb. 1997.
81.	杖池雅史, Tetsushi Ueta and Hiroshi Kawakami : 結合ニューロン発振器の同期現象, IEICE Technical Report, Vol.NLP96, No.137, 101-107, Feb. 1997.
82.	杖池雅史, Tetsushi Ueta and Hiroshi Kawakami : 結合した興奮抑制対ニューロン回路の同期, IEICE Technical Report, Vol.NLP96, No.61, 23-28, Jul. 1996.
83.	Tetsushi Ueta and Hiroshi Kawakami : 2次元自律系における解軌道の位相的分類, IEICE Technical Report, Vol.NLP96, No.25, 105-110, May 1996.
84.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : 方形波発振器を用いた電子ホタルの同期現象, IEICE Technical Report, Vol.NLP96, No.5, 27-32, May 1996.
85.	Tetsushi Ueta and Hiroshi Kawakami : 結合系のカオス制御, IEICE Technical Report, Vol.NLP95, No.81, 133-139, Oct. 1995.
86.	Tetsushi Ueta and Hiroshi Kawakami : リミットサイクルに関する分岐の一計算法, IEICE Technical Report, Vol.NLP95, No.43, 47-52, Oct. 1995.
87.	Takuji Kousaka, Tetsushi Ueta and Hiroshi Kawakami : Destabilization of Stable Orbits by Controlling Chaos, IEICE Technical Report, Vol.NLP94, No.102, 51-58, Mar. 1995. (Summary) We propose a method of destabilizing stable equilibria and limit cycles by using controlling chaos.A chaotic state can be easily generated from stable states by our method.A stable orbit is destabilized by a linear feedback technique with unstable pole assignment.As illustrated examples,a stable limit cycle of the van der Pol equation and stable equilibria of BVP equation are destabilized to chaos.Gradient system is also destabilized and a technique to escape from local minimum is discussed.
88.	Tetsushi Ueta and Hiroshi Kawakami : 高階自律系におけるカオス制御, IEICE Technical Report, Vol.NLP94, No.79, 71-78, Dec. 1994.
89.	Hiroshi Kawakami and Tetsushi Ueta : Control theory as applied to controlling discrete chaotic dynamical systems, IEICE Technical Report, Vol.NLP94, No.63, 175-182, Oct. 1994.
90.	Tetsushi Ueta and Hiroshi Kawakami : Stabilization method of controlling chaotic systems, IEICE Technical Report, Vol.NLP94, No.62, 167-174, Oct. 1994.
91.	森本修, Tetsushi Ueta and Hiroshi Kawakami : 不連続波形を印加した非線形系の分岐現象の追跡法とそのBVP方程式への応用, IEICE Technical Report, Vol.NLP94, No.2, 9-14, May 1994.
92.	Tetsushi Ueta and Hiroshi Kawakami : Bifurcation phenomena in a Josephson junction circuit coupled by a resistor, IEICE Technical Report, Vol.NLP93, No.91, 47-54, Mar. 1994.
93.	Tetsushi Ueta and Hiroshi Kawakami : Bifurcation of Heteroclinic Orbits in a Circuit containing a Jasephson Junction Element, IEICE Technical Report, Vol.NLP92, No.105, 43-48, Mar. 1993. (Summary) Similar equation is obtained from a simple pendulum with an elastic restoring force.In such a system there exist many saddles and sinks affected by the sinusoidal restoring term.In this paper we investigate heteroclinic bifurcations correlated with separatrices of the saddle points.The topological classification of the heteroclinic orbit is achieved by defining a linking number between the heteroclinic orbit and a suitable cross section.

Report:

1.	Hiroshi Kawakami, Tetsuya Yoshinaga and Tetsushi Ueta : Nonlinear Science Laboratory, Supplemental report of Kaken, Tokushima, Feb. 2002.
2.	Hiroshi Kawakami, Tetsuya Yoshinaga and Tetsushi Ueta : 有限群の表現を用いた対称結合非線形回路の合成法に関する研究, 平成11-13年度科学研究費補助金(基盤研究(C)(2))研究成果報告書, Tokushima, Feb. 2002.
3.	Hiroshi Kawakami, Tetsuya Yoshinaga and Tetsushi Ueta : 系の構造に基づく非線形回路の解析法に関する研究, 平成8-9年度科学研究費補助金(基盤研究(C)(2))研究成果報告書, Tokushima, Feb. 1998.

Patent:

1.	Yoshio Tanaka, Hiroshi Kawakami and Ken'ichi Fujimoto : マニピュレータの動的制御方法, H11-114172 (Apr. 1999), 2000-301480 (Oct. 2000), 3208425 (Jul. 2001).

Grants-in-Aid for Scientific Research (KAKEN Grants Database @ NII.ac.jp)

Synthesis of Symmetrical Nonlinear-Circuits with Finite Group Representaion (Project/Area Number: 11650383 )
Study on Methods of Analysis of Nonlinear Circuits with Symmetrical Structure (Project/Area Number: 08650431 )
Analysis of Coupled Oscillator Networks and Application to Chemical Reaction Oscillations and Biological Rhythms (Project/Area Number: 03805028 )
Studies on Analysis of Generation Process of Chaos in Nonlinear Circuits and on Systematic Construction of Chaos Generation Circuits (Project/Area Number: 63302032 )
Search by Researcher Number (60035631)

Professor Emeritus : Kawakami, Hiroshi

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Grants-in-Aid for Scientific Research (KAKEN Grants Database @ NII.ac.jp)