Tokushima University / Educator and Researcher Directory --- Yoshinaga, Tetsuya

Personal Web Page

https://ls00.medsci.tokushima-u.ac.jp/cgi-bin/finger?yosinaga

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

https://orcid.org/0000-0003-4994-0522 (ORCID)

Field of Study

○	Medical Engineering, Nonlinear System Engineering

Subject of Study

○	Medical Engineering, Medical Image Equipment Engineering, Nonlinear System Engineering (nonlinear systems, medical image reconstruction, bifurcation phenomena, neuron model, chaos) (Improvement of simultaneous iterative reconstruction technique for computed tomography, based on the nonlinear dynamical system theory. Bifurcation analysis and its applications.)

Book / Paper

Book:

1.	Hiroyuki Kitajima and Tetsuya Yoshinaga : A Method for Constructing a Robust System Against Unexpected Parameter Variation, --- K. Aihara, J. Imura and T. Ueta (eds), Analysis and Control of Complex Dynamical Systems ---, Springer, Tokyo, Mar. 2015. (Keyword) bifurcation (Link to Publication Site) ● Publication site (DOI): 10.1007/978-4-431-55013-6_4 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1007/978-4-431-55013-6_4 (DOI: 10.1007/978-4-431-55013-6_4)
2.	Yasuaki Oishi, Mio Kobayashi and Tetsuya Yoshinaga : Use of a Matrix Inequality Technique for Avoiding Undesirable Bifurcation, --- K. Aihara, J. Imura and T. Ueta (eds), Analysis and Control of Complex Dynamical Systems ---, Springer, Tokyo, Mar. 2015. (Keyword) bifurcation (Link to Publication Site) ● Publication site (DOI): 10.1007/978-4-431-55013-6_3 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1007/978-4-431-55013-6_3 (DOI: 10.1007/978-4-431-55013-6_3)
3.	Hiroyuki Kitajima, Tetsuya Yoshinaga, Jun-ichi Imura and Kazuyuki Aihara : Robust Bifurcation Analysis Based on Degree of Stability, --- K. Aihara, J. Imura and T. Ueta (eds), Analysis and Control of Complex Dynamical Systems ---, Springer, Tokyo, Mar. 2015. (Keyword) bifurcation (Link to Publication Site) ● Publication site (DOI): 10.1007/978-4-431-55013-6_2 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1007/978-4-431-55013-6_2 (DOI: 10.1007/978-4-431-55013-6_2)
4.	Ken'ichi Fujimoto, Tetsuya Yoshinaga, Tetsushi Ueta and Kazuyuki Aihara : Parametric Control to Avoid Bifurcation Based on Maximum Local Lyapunov Exponent, --- K. Aihara, J. Imura and T. Ueta (eds), Analysis and Control of Complex Dynamical Systems ---, Springer, Tokyo, Mar. 2015. (Keyword) bifurcation (Link to Publication Site) ● Publication site (DOI): 10.1007/978-4-431-55013-6_5 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1007/978-4-431-55013-6_5 (DOI: 10.1007/978-4-431-55013-6_5)
5.	Ken'ichi Fujimoto and Tetsuya Yoshinaga : Continuous-Time Image Reconstruction for Computed Tomography in Computed Tomography: New Research (J. H. Park Ed.), Nova Science Publishers, New York, Mar. 2013.
6.	Ken'ichi Fujimoto, Mio Kobayashi and Tetsuya Yoshinaga : Discrete-Time Dynamic Image-Segmentation System in Discrete Time Systems (M. A. Jordán and J. L. Bustamante Eds.), INTECH, Rijeka, Apr. 2011.
7.	田中仁, 他 and Tetsuya Yoshinaga : 新·医用放射線技術実験【基礎編】, KYORITSU SHUPPAN.CO.,LTD, Tokyo, Dec. 2004.
8.	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.
9.	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.
10.	田中仁他 and Tetsuya Yoshinaga : 医用放射線技術実験【基礎編】第3版, KYORITSU SHUPPAN.CO.,LTD, Tokyo, Mar. 1996.
11.	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.
12.	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.
13.	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.
14.	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.

Academic Paper (Judged Full Paper):

1.	Naohiko Inaba, Tsubone Tadashi, Ito Hidetaka, Okazaki Hideaki and Tetsuya Yoshinaga : Nested mixed-mode oscillations, Part III: Comparison of bifurcation structures between a driven Bonhoeffer-van der Pol oscillator and Nagumo-Sato piecewise-linear discontinuous one-dimensional map, Physica D: Nonlinear Phenomena, Vol.446, 2023. (Summary) In our previous studies (Inaba and Kosaka, (2020); Inaba and Tsubone, (2020)), we discovered bifurcation structures represented by nested mixed-mode oscillations (MMOs) generated by a driven Bonhoeffer-van der Pol (BVP) oscillator. BVP oscillators are equivalent to FitzHugh Nagumo models and have been a subject of intense research for the last six decades. In this study, we consider the case in which the diode included in a driven BVP oscillator is assumed to operate as an ideal switch. In this case, Poincaré return maps can be rigorously constructed one-dimensionally, which consist of two downward convex branches. We also consider the Poincaré return map that is approximated as a two-segment piecewise-linear discontinuous one-dimensional map. Such a piecewise-linear map was proposed by Nagumo and Sato and generates nested period-adding bifurcations. We show that the possible solutions of un-nested, singly, and doubly nested period-adding bifurcations generated by the Nagumo-Sato map coincide with those of un-nested, singly, and doubly nested MMO-incrementing bifurcations, respectively, generated with the BVP oscillator. (Link to Publication Site) ● Publication site (DOI): 10.1016/j.physd.2023.133667 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1016/j.physd.2023.133667 (DOI: 10.1016/j.physd.2023.133667)
2.	Takeshi Kojima and Tetsuya Yoshinaga : Iterative Image Reconstruction Algorithm with Parameter Estimation by Neural Network for Computed Tomography, Algorithms, 2023. (Tokushima University Institutional Repository) ● Metadata: 118459 (Link to Publication Site) ● Publication site (DOI): 10.3390/a16010060 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.3390/a16010060 (Tokushima University Institutional Repository: 118459, DOI: 10.3390/a16010060)
3.	Omar M. Abou Al-Ola, Ryosuke Kasai, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Image reconstruction algorithm using weighted mean of ordered-subsets EM and MART for computed tomography, Mathematics, Vol.10, No.22, 4277, 2022. (Tokushima University Institutional Repository) ● Metadata: 118919 (Link to Publication Site) ● Publication site (DOI): 10.3390/math10224277 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.3390/math10224277 (Tokushima University Institutional Repository: 118919, DOI: 10.3390/math10224277)
4.	Kazuki Ishikawa, Yusaku Yamaguchi, Omar M. Abou Al-Ola, Takeshi Kojima and Tetsuya Yoshinaga : Block-iterative reconstruction from dynamically selected sparse projection views using extended power-divergence measure, Entropy, Vol.24, No.5, 1-21, 2022. (Tokushima University Institutional Repository) ● Metadata: 117151 (Link to Publication Site) ● Publication site (DOI): 10.3390/e24050740 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.3390/e24050740 (Tokushima University Institutional Repository: 117151, DOI: 10.3390/e24050740)
5.	Ryosuke Kasai, Yusaku Yamaguchi, Takeshi Kojima, Omar M. Abou Al-Ola and Tetsuya Yoshinaga : Noise-Robust Image Reconstruction Based on Minimizing Extended Class of Power-Divergence Measures, Entropy, Vol.23, No.8, 1-16, 2021. (Tokushima University Institutional Repository) ● Metadata: 116149 (Link to Publication Site) ● Publication site (DOI): 10.3390/e23081005 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.3390/e23081005 (Tokushima University Institutional Repository: 116149, DOI: 10.3390/e23081005)
6.	Ryosei Nakada, Omar M. Abou Al-Ola and Tetsuya Yoshinaga : Intensity-modulated radiation therapy optimization for acceptable and remaining-one unacceptable dose-volume and mean-dose constraint planning, Computational and Mathematical Methods in Medicine, Vol.2020, No.Article ID 3096067, 2020. (Summary) We give a novel approach for obtaining an intensity-modulated radiation therapy (IMRT) optimization solution based on the idea of continuous dynamical methods. The proposed method, which is an iterative algorithm derived from the discretization of a continuous-time dynamical system, can handle not only dose-volume but also mean-dose constraints directly in IMRT treatment planning. A theoretical proof for the convergence to an equilibrium corresponding to the desired IMRT planning is given by using the Lyapunov stability theorem. By introducing the concept of `acceptable', which means the existence of a nonempty set of beam weights satisfying the given dose-volume and mean-dose constraints, and by using the proposed method for an acceptable IMRT planning, one can resolve the issue that the objective and evaluation are different in the conventional planning process. Moreover, in the case where the target planning is totally unacceptable and partly acceptable except for one group of dose constraints, we give a procedure that enables us to obtain a nearly optimal solution close to the desired solution for unacceptable planning. The performance of the proposed approach for an acceptable or unacceptable planning is confirmed through numerical experiments simulating a clinical setup. (Keyword) IMRT optimization / nonlinear dynamical system / Lyapunov theorem (Tokushima University Institutional Repository) ● Metadata: 115639 (Link to Publication Site) ● Publication site (DOI): 10.1155/2020/3096067 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 32963584 ● Summary page in Scopus @ Elsevier: 2-s2.0-85091567152 (Tokushima University Institutional Repository: 115639, DOI: 10.1155/2020/3096067, PubMed: 32963584, Elsevier: Scopus)
7.	Ryosuke Kasai, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Hybrid Euler method for discretizing continuous-time tomographic dynamical system, Journal of Signal Processing, Vol.24, No.4, 183-186, 2020. (Link to Publication Site) ● Publication site (DOI): 10.2299/jsp.24.183 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1390566775151534976 ● Search Scopus @ Elsevier (DOI): 10.2299/jsp.24.183 (DOI: 10.2299/jsp.24.183, CiNii: 1390566775151534976)
8.	Yusaku Yamaguchi, Kudo Moe, Takeshi Kojima and Tetsuya Yoshinaga : Convergence Study of Iterative Image Reconstruction Algorithm with Power Exponent for Computed Tomography, Proc. of NCSP'20, 113-116, 2020.
9.	Ryosuke Kasai, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Hybrid Euler method for discretizing continuous-time tomographic dynamical system, Proc. of NCSP'20, 73-76, 2020.
10.	Yusaku Yamaguchi, Moe Kudo, Ryosuke Kasai, Takeshi Kojima and Tetsuya Yoshinaga : Continuous-time image reconstruction based on Hellinger distance minimization for medical X-ray CT imaging, Basic & Clinical Pharmacology & Toxicology (Abstracts), Vol.125, No.S5, 30-31, 2019.
11.	Ryosuke Kasai, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Hybrid of ML-EM and MART algorithms for X-ray CT image reconstruction, Basic & Clinical Pharmacology & Toxicology (Abstracts), Vol.125, No.S5, 31-32, 2019.
12.	Yusaku Yamaguchi, Moe Kudo, Takeshi Kojima, Omar M. Abou Al-Ola and Tetsuya Yoshinaga : Extended ordered-subsets expectation-maximization algorithm with power exponent for noise-robust image reconstruction in computed tomography, Radiation Environment and Medicine, 2019. (Summary) The maximum-likelihood expectation-maximization (ML-EM) algorithm is the most popular iterative reconstruction method in emission-computed tomography with a noise model based on the Poisson distribution. The ordered-subsets EM (OS-EM) algorithm is known owing to accelerating the convergence of the ML-EM algorithm with the drawback of slow convergence. In this paper, we propose an extended OS-EM algorithm with a power exponent. We theoretically prove the asymptotic stability of an equilibrium corresponding to the solution of the nonlinear hybrid dynamical system whose numerical discretization based on multiplicative calculus coincides with the extended OS-EM algorithm. We provide a numerical experiment to demonstrate the effectiveness of the proposed system and confirm the acceleration of the proposed method and the robustness against noise. The reconstruction of high-quality images made by the method even when the projection data is noisy allows patient dose reduction in clinical practice. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1390011461951749376 (CiNii: 1390011461951749376)
13.	Ryosuke Kasai, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Hybrid algorithm of maximum-likelihood expectation-maximization and multiplicative algebraic reconstruction technique for iterative tomographic image reconstruction, Proceedings Volume 11049, International Workshop on Advanced Image Technology (IWAIT) 2019, No.110491F, 2019. (Link to Publication Site) ● Publication site (DOI): 10.1117/12.2521185 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-85063894959 (DOI: 10.1117/12.2521185, Elsevier: Scopus)
14.	Kimura Masashi, Yusaku Yamaguchi, Omar M. Abou Al-Ola and Tetsuya Yoshinaga : Tomographic Inverse Problem with Estimating Missing Projections, Mathematical Problems in Engineering, Vol.2019, No.Article ID 7932318, 11-pages, 2019. (Tokushima University Institutional Repository) ● Metadata: 114384 (Link to Publication Site) ● Publication site (DOI): 10.1155/2019/7932318 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1155/2019/7932318 (Tokushima University Institutional Repository: 114384, DOI: 10.1155/2019/7932318)
15.	Mio Kobayashi and Tetsuya Yoshinaga : Bifurcation Analysis of Reduced Network Model of Coupled Gaussian Maps for Associative Memory, International Journal of Modern Nonlinear Theory and Application, Vol.8, No.1, 1-16, 2019. (Link to Publication Site) ● Publication site (DOI): 10.4236/ijmnta.2019.81001 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.4236/ijmnta.2019.81001 (DOI: 10.4236/ijmnta.2019.81001)
16.	Ryosuke Kasai, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Tomographic image reconstruction based on minimization of symmetrized Kullback-Leibler divergence, Mathematical Problems in Engineering, Vol.2018, No.Article ID 8973131, 9-pages, 2018. (Tokushima University Institutional Repository) ● Metadata: 114383 (Link to Publication Site) ● Publication site (DOI): 10.1155/2018/8973131 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1155/2018/8973131 (Tokushima University Institutional Repository: 114383, DOI: 10.1155/2018/8973131)
17.	Mio Kobayashi and Tetsuya Yoshinaga : Chaotic Itinerancy Observed in Mutually Coupled Gaussian Maps, International Journal of Bifurcation and Chaos, Vol.28, No.4, 12-pages, 2018. (Tokushima University Institutional Repository) ● Metadata: 116194 (Link to Publication Site) ● Publication site (DOI): 10.1142/S0218127418300112 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-85046659223 (Tokushima University Institutional Repository: 116194, DOI: 10.1142/S0218127418300112, Elsevier: Scopus)
18.	Yuta Nagata, Naohiko Inaba, Munehisa Sekikawa, Tetsuro Endo, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Remarkable similarities of two pairs of stable and saddle canards in a van der Pol oscillator under extremely weak periodic perturbation, Progress of Theoretical and Experimental Physics, Vol.2018, No.1, 2018. (Tokushima University Institutional Repository) ● Metadata: 115701 (Link to Publication Site) ● Publication site (DOI): 10.1093/ptep/ptx172 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1093/ptep/ptx172 (Tokushima University Institutional Repository: 115701, DOI: 10.1093/ptep/ptx172)
19.	Takeshi Kojima, Tetsushi Ueta and Tetsuya Yoshinaga : Multivalued discrete tomography using dynamical system that describes competition, Mathematical Problems in Engineering, Vol.2017, No.Article ID 8160354, 9-pages, 2017. (Summary) Multivalued discrete tomography involves reconstructing images composed of three or more gray levels from projections. We propose a method based on the continuous-time optimization approach with a nonlinear dynamical system that effectively utilizes competition dynamics to solve the problem of multivalued discrete tomography. We perform theoretical analysis to understand how the system obtains the desired multivalued reconstructed image. Numerical experiments illustrate that the proposed method also works well when the number of pixels is comparatively high even if the exact labels are unknown. (Tokushima University Institutional Repository) ● Metadata: 114381 (Link to Publication Site) ● Publication site (DOI): 10.1155/2017/8160354 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1155/2017/8160354 (Tokushima University Institutional Repository: 114381, DOI: 10.1155/2017/8160354)
20.	Kiyoko Tateishi, Yusaku Yamaguchi, Omar M. Abou Al-Ola and Tetsuya Yoshinaga : Continuous analog of accelerated OS-EM algorithm for computed tomography, Mathematical Problems in Engineering, Vol.2017, No.Article ID 1564123, 1-8, 2017. (Tokushima University Institutional Repository) ● Metadata: 113352 (Link to Publication Site) ● Publication site (DOI): 10.1155/2017/1564123 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1155/2017/1564123 (Tokushima University Institutional Repository: 113352, DOI: 10.1155/2017/1564123)
21.	Mio Kobayashi and Tetsuya Yoshinaga : Discrete-Time Dynamic Image Segmentation Using Oscillators with Adaptive Coupling, International Journal of Modern Nonlinear Theory and Application, Vol.5, No.2, 93-103, 2016. (Link to Publication Site) ● Publication site (DOI): 10.4236/ijmnta.2016.52010 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.4236/ijmnta.2016.52010 (DOI: 10.4236/ijmnta.2016.52010)
22.	Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Noise reduction in computed tomography using a multiplicative continuous-time image reconstruction method, Progress in Biomedical Optics and Imaging - Proceedings of SPIE, Vol.9783, 2016. (Link to Publication Site) ● Publication site (DOI): 10.1117/12.2216439 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1117/12.2216439 (DOI: 10.1117/12.2216439)
23.	Kiyoko Tateishi, Yusaku Yamaguchi, Omar M. Abou Al-Ola, Takeshi Kojima and Tetsuya Yoshinaga : Continuous analog of multiplicative algebraic reconstruction technique for computed tomography, Progress in Biomedical Optics and Imaging - Proceedings of SPIE, Vol.9783, 2016. (Link to Publication Site) ● Publication site (DOI): 10.1117/12.2214598 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1117/12.2214598 (DOI: 10.1117/12.2214598)
24.	Yasuaki Oishi, Mio Kobayashi and Tetsuya Yoshinaga : Robustification of a Nonlinear Dynamical System with a Stability Index and a Matrix Inequality, SICE Journal of Control, Measurement, and System Integration, Vol.8, No.3, 209-213, 2015. (Summary) A problem in the field of nonlinear dynamics is considered with a technique of control theory. In particular, for preventing a nonlinear dynamical system from making undesirable bifurcation, it is proposed to control its parameter with a stability index and a matrix inequality. A basic idea is to update the parameter of the system so as to minimize the stability index. Since the stability index is not differentiable as a function of the parameter, its minimization is carried out through equivalent transformation to a smooth minimization problem, where a matrix inequality is used. The proposed method is applied to a simple dynamical system and shown to be effective. Its generalization is also considered for driving a system to avoid chaos. (Keyword) stability index / matrix inequality / penalty function method / local expansion rate (Link to Publication Site) ● Publication site (DOI): 10.9746/jcmsi.8.209 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1360283696380759936 ● Search Scopus @ Elsevier (DOI): 10.9746/jcmsi.8.209 (DOI: 10.9746/jcmsi.8.209, CiNii: 1360283696380759936)
25.	Yoshihiro Tanaka, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Dose-volume constrained optimization in intensity-modulated radiation therapy treatment planning, Journal of Inequalities and Applications, Vol.1, No.2015:122, 2015. (Summary) We present a novel optimization method to handle dose-volume constraints (DVCs) directly in intensity-modulated radiation therapy (IMRT) treatment planning based on the idea of continuous dynamical methods. Most of the conventional methods are constructed for solving inconsistent inverse problems with, e.g., dose-volume based objective functions, and one expects to obtain a feasible solution that minimally violates the DVCs. We introduce the concept of `acceptable' meaning that there exists a nonempty set of radiation beam weights satisfying the given DVCs and resolve the issue that the objective and evaluation are different in the conventional planning approach. We apply the initial-value problem of the proposed dynamical system to an acceptable and inconsistent inverse problem and prove that the convergence to an equilibrium in the acceptable set of solutions is theoretically guaranteed by using the Lyapunov theorem. Indeed, we confirmed that we can obtain acceptable beam weights through numerical experiments using phantom data simulating a clinical setup for an acceptable and inconsistent IMRT planning system. (Keyword) Intensity-modulated radiation therapy treatment planning / Dose-volume constraints / Dose-volume constrained optimization / inverse problem / Stability of solution (Tokushima University Institutional Repository) ● Metadata: 109514 (Link to Publication Site) ● Publication site (DOI): 10.1186/s13660-015-0643-2 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-84927163770 (Tokushima University Institutional Repository: 109514, DOI: 10.1186/s13660-015-0643-2, Elsevier: Scopus)
26.	Hiroyuki Kitajima, Tetsuya Yoshinaga, Imura Jun-ichi and Kazuyuki Aihara : Robust bifurcation analysis based on optimization of degree of stability, International Journal of Innovative Computing, Information and Control, Vol.11, No.1, 153-162, 2015. (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-84922020044 (Elsevier: Scopus)
27.	Hiroyuki Kitajima and Tetsuya Yoshinaga : A Method for Finding Optimal Parameter Values Using Bifurcation-Based Procedure, International Journal of Modern Nonlinear Theory and Application, Vol.3, No.2, 37-43, 2014. (Link to Publication Site) ● Publication site (DOI): 10.4236/ijmnta.2014.32006 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.4236/ijmnta.2014.32006 (DOI: 10.4236/ijmnta.2014.32006)
28.	Ken'ichi Fujimoto, Yoshihiro Tanaka, Omar M. Abou Al-Ola and Tetsuya Yoshinaga : Continuous-time method and its discretization to inverse problem of intensity-modulated radiation therapy treatment planning, Communications in Nonlinear Science and Numerical Simulation, Vol.19, No.6, 1996-2004, 2014. (Summary) We propose a novel approach for solving box-constrained inverse problems in intensity-modulated radiation therapy (IMRT) treatment planning based on the idea of continuous dynamical methods and split-feasibility algorithms. Our method can compute a feasible solution without the second derivative of an objective function, which is required for gradient-based optimization algorithms. We prove theoretically that a double Kullback Leibler divergence can be used as the Lyapunov function for the IMRT planning system. Moreover, we propose a non-negatively constrained iterative method formulated by discretizing a differential equation in the continuous method. We give proof for the convergence of a desired solution in the discretized system, theoretically. The proposed method not only reduces computational costs but also does not produce a solution with an unphysical negative radiation beam weight in solving IMRT planning inverse problems. The convergence properties of solutions for an ill-posed case are confirmed by numerical experiments using phantom data simulating a clinical setup. (Keyword) Intensity-modulated radiation therapy treatment planning / inverse problem / Stability of solution / Kullback-Leibler divergence (Link to Publication Site) ● Publication site (DOI): 10.1016/j.cnsns.2013.10.026 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-84890787448 (DOI: 10.1016/j.cnsns.2013.10.026, Elsevier: Scopus)
29.	Naohiko Inaba, Munehisa Sekikawa, Yoshimasa Shinotsuka, Kyohei Kamiyama, Ken'ichi Fujimoto, Tetsuya Yoshinaga and Tetsuro Endo : Bifurcation scenarios for a 3D torus and torus-doubling, Progress of Theoretical and Experimental Physics, Vol.2014, No.2, 2014. (Summary) Bifurcation transitions between a 1D invariant closed curve (ICC), corresponding to a 2D torus in vector fields, and a 2D invariant torus (IT), corresponding to a 3D torus in vector fields, have been the subjects of intensive research in recent years. An existing hypothesis involves the bifurcation boundary between a region generating an ICC and a region generating an IT. It asserts that an IT would be generated from a stable fixed point as a consequence of two Hopf (or two Neimark Sacker) bifurcations. We assume that this hypothesis may puzzle many researchers because it is difficult to assess its validity, although it seems to be a reasonable bifurcation scenario at first glance. To verify this hypothesis, we conduct a detailed Lyapunov analysis for a coupled delayed logistic map that can generate an IT, and indicate that this hypothesis does not hold according to numerical results. Furthermore, we show that a saddle-node bifurcation of unstable periodic points does not coincide with the bifurcation boundary between an ICC and an IT. In addition, the bifurcation boundaries of torus doubling do not coincide with a period-doubling bifurcation of unstable periodic points. To conclude, torus bifurcations have no relation with the bifurcations of unstable periodic points. Additionally, we exactly derive a quasi-periodic Hopf bifurcation boundary introducing a double Poincaré map. (Tokushima University Institutional Repository) ● Metadata: 115703 (Link to Publication Site) ● Publication site (DOI): 10.1093/ptep/ptt122 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-84898464224 (Tokushima University Institutional Repository: 115703, DOI: 10.1093/ptep/ptt122, Elsevier: Scopus)
30.	Kaoru Itoh, Kuniyasu Shimizu, Naohiko Inaba, Ken'ichi Fujimoto, Tetsuya Yoshinaga and Tetsuro Endo : Behavior of MMOs in the extended BVP oscillator under weak periodic perturbation, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J97-A, No.1, 14-22, 2014. (Summary) Mixed-mode oscillatons (MMOs) are complicated oscillations found in chemical experiments. In this study, to investigate the fragility of MMOs in the presence of noise, the extended BVP oscillator under weak periodic perturbation is investigated. MMOs are sensitive to extremely weak perturbation. This is clarified by calculating the Lyapunov exponents, observing the attractors, and drawing a two-parameter bifurcation diagram. Furthermore, by choosing one inductor to be large, the extended BVP oscillator be- comes one of three time-scale systems. In this case, the physical mechanisms of the generation of MMOs can be explained by the construction of the oscillator. (Keyword) MMOs / canard / chaos / 拡張BVP発振器 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520009407417972736 (CiNii: 1520009407417972736)
31.	Hiroyuki Fujii, Yoko Hoshi, Shinpei Okawa, Tetsuya Yoshinaga, Satoru Kohno and Yukio Yamada : A coupling model of light propagation based on the radiative transfer and diffusion equations, AIP Conference Proceedings, Vol.1558, 2528-2531, 2013. (Link to Publication Site) ● Publication site (DOI): 10.1063/1.4826055 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-84887507679 (DOI: 10.1063/1.4826055, Elsevier: Scopus)
32.	Yusaku Yamaguchi, Ken'ichi Fujimoto, Omar M. Abou Al-Ola and Tetsuya Yoshinaga : Continuous-Time Image Reconstruction for Binary Tomography, Communications in Nonlinear Science and Numerical Simulation, Vol.18, No.8, 2081-2087, 2013. (Summary) Binary tomography is the process of reconstructing a binary image from a finite number of projections. We present a novel method for solving binary tomographic inverse problems using a continuous-time image reconstruction (CIR) system described by nonlinear differ- ential equations based on the minimization of a double Kullback Leibler divergence. We prove theoretically that the divergence measure monotonically decreases in time. More- over, we demonstrate numerically that the quality of the reconstructed images of the non- linear CIR system is better than those from an iterative reconstruction method. (Keyword) Binary tomography / Continuous-time image reconstruction / ordinary differential equation / Stability of solution / Kullback Leibler divergence (Tokushima University Institutional Repository) ● Metadata: 109383 (Link to Publication Site) ● Publication site (DOI): 10.1016/j.cnsns.2013.01.001 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1016/j.cnsns.2013.01.001 (Tokushima University Institutional Repository: 109383, DOI: 10.1016/j.cnsns.2013.01.001)
33.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Extended Continuous-Time Image Reconstruction System for Binary and Continuous Tomography, Journal of Signal Processing, Vol.17, No.4, 163-166, 2013. (Link to Publication Site) ● Publication site (DOI): 10.2299/jsp.17.163 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.2299/jsp.17.163 (DOI: 10.2299/jsp.17.163)
34.	Ken'ichi Fujimoto, Mio Kobayashi and Tetsuya Yoshinaga : GPU Implementation of Oscillator Network System with Plastic Coupling for Dynamic Image Segmentation, Journal of Electronic Systems, Vol.3, No.1, 17-24, 2013.
35.	Ken'ichi Fujimoto, Mio Kobayashi, Tetsuya Yoshinaga and Kazuyuki Aihara : Identification of target image regions based on bifurcations of a fixed point in a discrete-time oscillator network, International Journal of Innovative Computing, Information and Control, Vol.9, No.1, 355-363, 2013. (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-84872166316 (Elsevier: Scopus)
36.	Kiyoko Tateishi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Convergence of Iterative Method as Discretization of Continuous-Time Image Reconstruction System for Computed Tomography, Journal of Signal Processing, Vol.16, No.6, 617-621, 2012. (Link to Publication Site) ● Publication site (DOI): 10.2299/jsp.16.617 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.2299/jsp.16.617 (DOI: 10.2299/jsp.16.617)
37.	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)
38.	Munehisa Sekikawa, Kuniyasu Shimizu, Naohiko Inaba, Hiroki Kita, Tetsuro Endo, Ken'ichi Fujimoto, Tetsuya Yoshinaga and Kazuyuki Aihara : Sudden change from chaos to oscillation death in the Bonhoeffer-van der Pol oscillator under weak periodic perturbation, Physical Review E, Statistical, Nonlinear, and Soft Matter Physics, Vol.84, No.5, 056209, 2011. (Link to Publication Site) ● Publication site (DOI): 10.1103/PhysRevE.84.056209 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1103/PhysRevE.84.056209 (DOI: 10.1103/PhysRevE.84.056209)
39.	Ken'ichi Fujimoto, Mio Kobayashi and Tetsuya Yoshinaga : Discrete-Time Dynamic Image Segmentation Based on Oscillations by Destabilizing a Fixed Point, IEEJ Transactions on Electrical and Electronic Engineering (TEEE), Vol.6, No.5, 468-473, 2011. (Keyword) chaotic neuron / oscillatory response / dynamic image segmentation / stable fixed point / destabilizer (Link to Publication Site) ● Publication site (DOI): 10.1002/tee.20683 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1570572700034435968 ● Search Scopus @ Elsevier (DOI): 10.1002/tee.20683 (DOI: 10.1002/tee.20683, CiNii: 1570572700034435968)
40.	Kunichika Tsumoto, Gen Kurosawa, Tetsuya Yoshinaga and Kazuyuki Aihara : Modeling Light Adaptation in Circadian Clock: Prediction of the Response That Stabilizes Entrainment, PLoS ONE, Vol.6, No.6, e20880, 2011. (Summary) Periods of biological clocks are close to but often different from the rotation period of the earth. Thus, the clocks of organisms must be adjusted to synchronize with day-night cycles. The primary signal that adjusts the clocks is light. In Neurospora, light transiently up-regulates the expression of specific clock genes. This molecular response to light is called light adaptation. Does light adaptation occur in other organisms? Using published experimental data, we first estimated the time course of the up-regulation rate of gene expression by light. Intriguingly, the estimated up-regulation rate was transient during light period in mice as well as Neurospora. Next, we constructed a computational model to consider how light adaptation had an effect on the entrainment of circadian oscillation to 24-h light-dark cycles. We found that cellular oscillations are more likely to be destabilized without light adaption especially when light intensity is very high. From the present results, we predict that the instability of circadian oscillations under 24-h light-dark cycles can be experimentally observed if light adaptation is altered. We conclude that the functional consequence of light adaptation is to increase the adjustability to 24-h light-dark cycles and then adapt to fluctuating environments in nature. (Keyword) Adaptation, Physiological / Animals / Circadian Clocks / Light / Mice / RNA, Messenger (Link to Publication Site) ● Publication site (DOI): 10.1371/journal.pone.0020880 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 21698191 ● Search Scopus @ Elsevier (PMID): 21698191 ● Search Scopus @ Elsevier (DOI): 10.1371/journal.pone.0020880 (DOI: 10.1371/journal.pone.0020880, PubMed: 21698191)
41.	Omar M. Abou Al-Ola, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Common Lyapunov function based on Kullback-Leibler divergence for a switched nonlinear system, Mathematical Problems in Engineering, Vol.2011, No.723509, 1-12, 2011. (Link to Publication Site) ● Publication site (DOI): 10.1155/2011/723509 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-79959280105 (DOI: 10.1155/2011/723509, Elsevier: Scopus)
42.	Ken'ichi Fujimoto, Omar M. Abou Al-Ola and Tetsuya Yoshinaga : Implementation of continuous-time image reconstruction system in analog electronic circuit, Far East Journal of Electronics and Communications, Vol.6, No.1, 13-25, 2011.
43.	Ken'ichi Fujimoto, Mio Musashi and Tetsuya Yoshinaga : FPGA Implementation of Discrete-Time Neuronal Network for Dynamic Image Segmentation, IEEJ Transactions on Electronics, Information and Systems, Vol.131, No.3, 604-605, 2011. (Summary) We have developed a discrete-time dynamical system for dynamic image segmentation. It consists of a global inhibitor and modified chaotic neurons that can generate oscillatory responses. Dynamic image segmentation is performed using its oscillatory responses. This letter presents an implementation of our system in a field programmable gate array (FPGA) device and a successful result of dynamic image segmentation. (Keyword) Discrete-time neuronal network system / oscillatory response / dynamic image segmentation / FPGA (Link to Publication Site) ● Publication site (DOI): 10.1541/ieejeiss.131.604 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1390282679586157824 ● Search Scopus @ Elsevier (DOI): 10.1541/ieejeiss.131.604 (DOI: 10.1541/ieejeiss.131.604, CiNii: 1390282679586157824)
44.	Mio Kobayashi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Bifurcations of Oscillatory Responses Observed in Discrete-Time Coupled Neuronal System for Dynamic Image Segmentation, Journal of Signal Processing, Vol.15, No.2, 145-153, 2011. (Keyword) discrete-time dynamical system / coupled neurons / oscillatory response / bifurcation / dynamic image segmentation (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1523388080594270208 (CiNii: 1523388080594270208)
45.	Omar M. Abou Al-Ola, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Block continuous-time image reconstruction for computed tomography, Far East Journal of Dynamical Systems, Vol.14, No.1, 51-70, 2010.
46.	Munehisa Sekikawa, Naohiko Inaba, Tetsuya Yoshinaga and Takashi Hikihara : Period-Doubling Cascades of Canards from the Extended Bonhoeffer-van der Pol Oscillator, Physics Letters A, Vol.374, No.36, 3745-3751, 2010. (Summary) This Letter investigates the period-doubling cascades of canards, generated in the extended Bonhoeffer–van der Pol oscillator. Canards appear by Andronov–Hopf bifurcations (AHBs) and it is confirmed that these AHBs are always supercritical in our system. The cascades of period-doubling bifurcation are followed by mixed-mode oscillations. The detailed two-parameter bifurcation diagrams are derived, and it is clarified that the period-doubling bifurcations arise from a narrow parameter value range at which the original canard in the non-extended equation is observed. (Keyword) Andronov–Hopf bifurcations / Mixed-mode oscillations / Canards / Chaos (Link to Publication Site) ● Publication site (DOI): 10.1016/j.physleta.2010.07.033 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1050001202113506688 ● Search Scopus @ Elsevier (DOI): 10.1016/j.physleta.2010.07.033 (DOI: 10.1016/j.physleta.2010.07.033, CiNii: 1050001202113506688)
47.	Chika Ueda, Omar M. Abou Al-Ola, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Iterative Method Based on a Discretization of Continuous-Time Image Reconstruction for Computed Tomography, Journal of Signal Processing, Vol.14, No.4, 293-296, 2010. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1522543654762709504 (CiNii: 1522543654762709504)
48.	Tadashi Tsubone, Naohiko Inaba, Takashi Tsubouchi and Tetsuya Yoshinaga : 極めて簡素な区分定数強制発振器にみられる同期現象, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J93-A, No.5, 375-383, 2010. (Summary) 本論文では,極めて簡素な区分定数強制発振器を解析し,この回路に見られる同期現象を写像法によって調べた.この方程式においては,ポアンカレ写像は区分線形サークル写像として陽に導出できる.このポアンカレ写像を解析することにより,基本調波引込領域から奇数次の分数調波引込領域の境界が陽に求められることを明らかにした. (Keyword) 非線形回路 / アーノルドの舌 / 同期現象 / 区分定数回路 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520853833339035904 (CiNii: 1520853833339035904)
49.	Ken'ichi Fujimoto, Omar M. Abou Al-Ola and Tetsuya Yoshinaga : Continuous-Time Image Reconstruction Using Differential Equations for Computed Tomography, Communications in Nonlinear Science and Numerical Simulation, Vol.15, No.6, 1648-1654, 2010. (Link to Publication Site) ● Publication site (DOI): 10.1016/j.cnsns.2009.06.025 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1016/j.cnsns.2009.06.025 (DOI: 10.1016/j.cnsns.2009.06.025)
50.	Ken'ichi Fujimoto, Mio Musashi and Tetsuya Yoshinaga : Reduced Model of Discrete-time Dynamic Image Segmentation System and its Bifurcation Analysis, International Journal of Imaging Systems and Technology, Vol.19, No.4, 283-289, 2009. (Link to Publication Site) ● Publication site (DOI): 10.1002/ima.20204 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1002/ima.20204 (DOI: 10.1002/ima.20204)
51.	Mio Musashi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Bifurcation Phenomena of Periodic Points With High Order of Period Observed in Discrete-Time Two-Coupled Chaotic Neurons, Journal of Signal Processing, Vol.13, No.4, 311-314, 2009. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1523951030168547840 (CiNii: 1523951030168547840)
52.	Ken'ichi Fujimoto and Tetsuya Yoshinaga : Bifurcations in an Iterative Optimization Process for Intensity Modulated Radiation Therapy, International Journal of Bifurcation and Chaos, Vol.19, No.3, 1087-1095, 2009. (Link to Publication Site) ● Publication site (DOI): 10.1142/S0218127409023512 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1142/S0218127409023512 (DOI: 10.1142/S0218127409023512)
53.	Ken'ichi Fujimoto, Mio Musashi and Tetsuya Yoshinaga : Discrete-time dynamic image segmentation system, Electronics Letters, Vol.44, No.12, 727-729, 2008. (Link to Publication Site) ● Publication site (DOI): 10.1049/el:20080546 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1572261551361119488 ● Search Scopus @ Elsevier (DOI): 10.1049/el:20080546 (DOI: 10.1049/el:20080546, CiNii: 1572261551361119488)
54.	Tetsuya Yoshinaga, Yoshihiro Imakura, Ken'ichi Fujimoto and Tetsushi Ueta : Bifurcation Analysis of Iterative Image Reconstruction Method for Computed Tomography, International Journal of Bifurcation and Chaos, Vol.18, No.4, 1219-1225, 2008. (Summary) Of the iterative image reconstruction algorithms for computed tomography (CT), the power multiplicative algebraic reconstruction technique (PMART) is known to have good properties for speeding convergence and maximizing entropy. We analyze here bifurcations of fixed and periodic points that correspond to reconstructed images observed using PMART with an image made of multiple pixels and we investigate an extended PMART, which is a dynamical class for accelerating convergence. The convergence process for the state in the neighborhood of the true reconstructed image can be reduced to the property of a fixed point observed in the dynamical system. To investigate the speed of convergence, we present a computational method of obtaining parameter sets in which the given real or absolute values of the characteristic multiplier are equal. The advantage of the extended PMART is verified by comparing it with the standard multiplicative algebraic reconstruction technique (MART) using numerical experiments. (Link to Publication Site) ● Publication site (DOI): 10.1142/S021812740802094X (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1142/S021812740802094X (DOI: 10.1142/S021812740802094X)
55.	Ken'ichi Fujimoto and Tetsuya Yoshinaga : Bifurcations in an Oscillator Network with Synaptic Coupling for Improving Image Segmentation, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J90-A, No.11, 817-825, 2007. (Summary) 振動子ネットワーク系に見られる時空ダイナミックスを画像領域分割に応用した処理系としてLEGION (Locally-Excitatory Globally-Inhibitory Oscillator Network)が知られている.本論文では,まず,LEGION力学系に生じる現象の本質的な発生機構を解明するために低次元系(低画素数の画像)を解析対象とし,画像領域分割を実現する現象が入力画像に応じた多様な対称・非対称パターンの周期解に対応していることを示す.次に,非連結画像領域に対応した複数個の振動子の挙動が,初期値によっては同相で同期することを明らかにし,同相周期解が画像領域分割にとって不適切な挙動であることを示す.また,周期解の分岐解析を通じて,同相周期解が比較的広いパラメータ範囲で存在していることも明らかにする.更に,同相周期解の発生を回避する方法としてシナプス結合を有するLEGION処理系を提案し,定性的分岐理論に基づいた解析を通じ,同相周期解の不安定化にとってシナプス結合が有効であることを例証する. (Keyword) 画像領域分割 / 結合振動子 / シナプス結合 / 力学系 / 分岐 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520572358839907840 (CiNii: 1520572358839907840)
56.	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)
57.	Munehisa Sekikawa, Naohiko Inaba, Tetsuya Yoshinaga and Takashi Tsubouchi : Bifurcation structure of successive torus doubling, Physics Letters A, Vol.348, No.3, 187-194, 2006. (Keyword) torus / torus doubling / bifurcation / chaos / system (Link to Publication Site) ● Publication site (DOI): 10.1016/j.physleta.2005.08.089 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-29144484650 (DOI: 10.1016/j.physleta.2005.08.089, Elsevier: Scopus)
58.	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)
59.	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)
60.	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)
61.	Tetsuya Yoshinaga : A method to accelerate the convergence of the PMART for computed tomography, WSEAS Transactions on Systems, Vol.3, No.10, 2981-2984, 2005. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1573950400136705792 (CiNii: 1573950400136705792)
62.	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)
63.	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)
64.	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)
65.	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)
66.	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)
67.	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)
68.	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)
69.	Hiroo Sekiya, Tetsuya Yoshinaga, Seiichiro Moro, Shinsaku Mori and Iwao Sasase : Investigation of not-in-phase synchronization on coupled system of four oscillators, Electronics and Communications in Japan, Part 3 : Fundamental Electronic Science, Vol.85, No.2, 1-12, 2002. (Keyword) oscillator / not-in-phase synchronization / an independent pair of anti-phase synchronization / four-phase synchronization / in- and anti-phase synchronization (Link to Publication Site) ● Publication site (DOI): 10.1002/ecjc.1066 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0036147090 (DOI: 10.1002/ecjc.1066, Elsevier: Scopus)
70.	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)
71.	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)
72.	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)
73.	Hiroo Sekiya, Tetsuya Yoshinaga, Seiichiro Moro, Shinsaku Mori and Iwao Sasase : 4個の発振器の結合系に生じる非同期同相同期現象の考察, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J84-A, No.1, 42-52, 2001. (Keyword) 独立逆相同期 / 4相同期 / 交互逆相同期 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520572359388942592 (CiNii: 1520572359388942592)
74.	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): 1050564287419583872 (Tokushima University Institutional Repository: 110721, CiNii: 1050564287419583872)
75.	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)
76.	Tetsuya Yoshinaga : A fast convergence method with simultaneous iterative reconstruction technique for computerized tomography, International Journal of Imaging Systems and Technology, Vol.10, No.6, 432-436, 2000. (Link to Publication Site) ● Publication site (DOI): 10.1002/(SICI)1098-1098(1999)10:6<432::AID-IMA4>3.0.CO;2-I (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-0033339730 (DOI: 10.1002/(SICI)1098-1098(1999)10:6<432::AID-IMA4>3.0.CO;2-I, Elsevier: Scopus)
77.	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)
78.	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)
79.	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)
80.	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)
81.	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)
82.	Tetsuya Yoshinaga : ウェーブレット変換を用いたMRIの体動アーチファクト削減方法, Japanese Journal of Medical Electronics and Biological Engineering, Vol.35, No.3, 313-319, 1997. (Link to Publication Site) ● Publication site (DOI): 10.11239/jsmbe1963.35.313 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.11239/jsmbe1963.35.313 (DOI: 10.11239/jsmbe1963.35.313)
83.	Sumiko Tsuchihashi, Toshiko Terao, Tetsuya Yoshinaga, Sachiko Kawano, Yoshihiro Takegawa, Mika Kurokawa, Tadashi Nakayama and Susumu Yasuoka : ヒト気道トリプターゼによるフィブリノーンの分解, The Japanese Journal of Thoracic Diseases, Vol.35, No.1, 49-55, 1997. (Link to Publication Site) ● Publication site (DOI): 10.11389/jjrs1963.35.49 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.11389/jjrs1963.35.49 (DOI: 10.11389/jjrs1963.35.49)
84.	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)
85.	Susumu Yasuoka, Sumiko Tsuchihashi, Mika Kurokawa, Toshiko Terao, Tetsuya Yoshinaga, Sachiko Kawano, Yoshihiro Takegawa, Tdashi Nakayama and Mitsumasa Ogawara : ヒト喀痰から分離した気道トリプターゼと肥満細胞トリプターゼの性質の比較, The Japanese Journal of Thoracic Diseases, Vol.34, No.6, 678-684, 1996.
86.	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)
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.	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)
89.	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)
90.	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)
91.	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)
92.	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.
93.	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)
94.	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)
95.	Tetsuya Yoshinaga, Atsumi Hattori and Kunihiro Kobayashi : 多変数系の測定出力と達成可能な外部特性のクラス, Transactions of the Society of Instrument and Control Engineers, Vol.22, No.3, 291-295, 1986. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520290885165954432 (CiNii: 1520290885165954432)

Academic Paper (Unrefereed Paper):

1.	Ken'ichi Fujimoto, Tetsuya Yoshinaga, Takahiro Oie and Yasuo Miyoshi : EDB/CMSと汎用LMSを用いたe-ラーニングシステムの構築, 大学教育研究ジャーナル(別冊), No.3, 43-44, 2006.
2.	Sumiko Tsuchihashi, Toyota Akiko, Toshiko Terao, Toshiko Tada, Tetsuya Yoshinaga, Kawano Sachiko, Yoshihiro Takegawa, Kurokawa Mika, Hiroto Akiyoshi and Yasuoka Susumu : A research of subjective complaints in expectoration of sputum in patients with chronic airway diseases through a questionnaire, Bulletin of School of Medical Sciences, the University of Tokushima, Vol.5, 67-74, 1995. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1572261551772663040 (CiNii: 1572261551772663040)
3.	Sumiko Tsuchihashi, Toyota Akiko, Toshiko Terao, Toshiko Tada, Tetsuya Yoshinaga, Kawano Sachiko, Yoshihiro Takegawa, Kurokawa Mika, Hiroto Akiyoshi and Yasuoka Susumu : Comparison of biochemical characteristics of human airway tryptase and that of lung mast cell tryptase, Bulletin of School of Medical Sciences, the University of Tokushima, Vol.5, 59-65, 1995. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1570291226935692032 (CiNii: 1570291226935692032)
4.	Tetsuya Yoshinaga, Takuya Hiramoto and Shinobu Ikawa : MRIの位相エンコード方向に生じた体動アーチファクトの削減II, Bulletin of School of Medical Sciences, the University of Tokushima, Vol.4, 221-227, 1994. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1572543026791888640 (CiNii: 1572543026791888640)
5.	Sumiko Tsuchihashi, Tetsuya Yoshinaga, 大島一志, Toshiko Tada, 大西敏男 and 安岡劭 : 慢性気道感染症患者の臨床像と喀痰の特徴, Bulletin of School of Medical Sciences, the University of Tokushima, Vol.3, 107-114, 1993. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1571980076838573184 (CiNii: 1571980076838573184)
6.	Tetsuya Yoshinaga : MRIの位相エンコード方向に生じた体動アーチファクトの削減, Bulletin of School of Medical Sciences, the University of Tokushima, Vol.3, 189-195, 1993. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1571135651908429696 (CiNii: 1571135651908429696)
7.	Tetsuya Yoshinaga and Hiroshi Asano : MRIにおけるスピン密度変化の検出, Bulletin of School of Medical Sciences, the University of Tokushima, Vol.2, 159-165, 1992. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1572261551823079808 (CiNii: 1572261551823079808)

Academic Letter:

1.	Munehisa Sekikawa, Naohiko Inaba and Tetsuya Yoshinaga : On the Trick of Taming CHaos Phenomenon, The Transactions of the Institute of Electronics, Information and Communication Engineers A, Vol.J88-A, No.6, 788-792, 2005. (Summary) 近年, 微小高調波外力の印加によるTaming Chaosと呼ばれるnon-feedbackカオス制御方式が大きな注目を集め, 活発な議論が行われている. これに対し, 筆者らはTaming Chaos現象は微小周期外力の印加により, 分岐曲線がわずかにシフトして生じる単なる分岐現象であることを主張している. 本論文では, その仮説が正しいことを強制BvP方程式を例にとり検証する. (Keyword) 強制BvP方程式 / Chaos / Taming Chaos / 分岐現象 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520290884449501312 (CiNii: 1520290884449501312)
2.	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): 1050282812442873856 (Tokushima University Institutional Repository: 110723, CiNii: 1050282812442873856)
3.	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)
4.	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.	Ken'ichi Fujimoto, Mio Musashi and Tetsuya Yoshinaga : Image Segmentation System Using Discrete-Time Dynamics of Coupled Chaotic Neurons, Systems, Control and Information, Vol.54, No.1, 9-14, Jan. 2010. (Keyword) discrete-time dynamics / coupled system / chaotic neuron / oscillatory response / bifurcation / dynamic image segmentation (Link to Publication Site) ● Publication site (DOI): 10.11509/isciesci.54.1_9 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1390282679278625152 ● Search Scopus @ Elsevier (DOI): 10.11509/isciesci.54.1_9 (DOI: 10.11509/isciesci.54.1_9, CiNii: 1390282679278625152)
2.	Ken'ichi Fujimoto, Mio Musashi and Tetsuya Yoshinaga : 領域分割とその時系列表示が可能な動的画像領域分割システム, Chemical Engineering, Vol.54, No.2, 29-35, Feb. 2009. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1523669554792099328 (CiNii: 1523669554792099328)
3.	Tetsuya Yoshinaga : Bifurcation analysis of synaptically coupled neuronal model, Shikoku Acta Medica, Vol.59, No.4,5, 228-234, Oct. 2003. (Summary) We investigate bifurcations of periodic solutions in model equations of 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 Poincare map as a synthesis of successive submaps, and give its derivatives for obtaining periodic points and their bifurcations.Using our proposed method, we clarify mechanisms of bifurcations among synchronized oscillations with phase-locking patterns by analyzing periodic solutions observed in a model of coupled Hodgkin-Huxley equations. Moreover we illustrate a mechanism of the generation of chaotic itinerancy or the phenomenon of chaotic transitions among several quasi-stable states, which corresponds to associative dynamics or memory searching process in real neurons, by the analysis of four-coupled Bonhoffer-van der Pol equations. (Keyword) coupled neuron model / synaptic transmission / bifurcation / nonlinear dynamical system (Tokushima University Institutional Repository) ● Metadata: 110620 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1050564287419552256 (Tokushima University Institutional Repository: 110620, CiNii: 1050564287419552256)
4.	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.
5.	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.
6.	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.
7.	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)
8.	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.
9.	Kenji Matsuzaki, Tetsuya Yoshinaga, Noboru Niki, Masafumi Harada, Hiromu Nishitani and Junji Ueno : 三次元画像情報を利用した総合診療支援システムの試み, 映像情報Medical, Vol.23, No.7, 307-310, 1991.

Proceeding of International Conference:

1.	Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Enhanced Image Reconstruction in Emission Tomography through Minimization of Extended Power-Divergence Measures, 2024 SNMMI Annual Meeting, Toronto,
2.	Ryosuke Kasai, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Hybrid Euler method for discretizing continuous-time tomographic dynamical system, Proc. of NCSP'20, 73-76, Honolulu, Feb. 2020.
3.	Yusaku Yamaguchi, Kudo Moe, Takeshi Kojima and Tetsuya Yoshinaga : Convergence Study of Iterative Image Reconstruction Algorithm with Power Exponent for Computed Tomography, Proc. of NCSP'20, 113-116, Honolulu, Feb. 2020.
4.	Yusaku Yamaguchi, Moe Kudoh, Ryosuke Kasai, Takeshi Kojima and Tetsuya Yoshinaga : Continuous-time image reconstruction based on Hellinger distance minimization for medical X-ray CT imaging, Abstract Proceeding of the 8th International Conference on Biomedical Engineering and Biotechnology, 30-31, Seoul, Oct. 2019.
5.	Ryosuke Kasai, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Hybrid of ML-EM and MART algorithms for X-ray CT image reconstruction, Abstract Proceeding of the 8th International Conference on Biomedical Engineering and Biotechnology, 31-32, Seoul, Oct. 2019.
6.	Ryosuke Kasai, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Hybrid algorithm of maximum-likelihood expectation-maximization and multiplicative algebraic reconstruction technique for iterative tomographic image reconstruction, Proceedings of SPIE, Vol.11049, Singapore, Jan. 2019. (Link to Publication Site) ● Publication site (DOI): 10.1117/12.2521185 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-85063894959 (DOI: 10.1117/12.2521185, Elsevier: Scopus)
7.	Yusaku Yamaguchi, Michiko Mori, Takeshi Kojima and Tetsuya Yoshinaga : Nonautonomous Nonlinear Dynamical System for Reconstructing Magnetic Resonance Image, Proc. of NOLTA 2018, 200-203, Tarragona, Spain, Sep. 2018.
8.	Takeshi Kojima, Kiyoko Tateishi, Yusaku Yamaguchi and Tetsuya Yoshinaga : Discretization of Continuous Analog to Accelerated Expectation-Maximization Algorithm for Computed Tomography, Proc. of NOLTA 2018, 136-139, Tarragona, Spain, Sep. 2018.
9.	Ryosei Nakada, Takeshi Kojima and Tetsuya Yoshinaga : Nonlinear Dynamical System with Order-Preserving Function for Inverse Problem of Intensity-Modulated Radiation Therapy Treatment Planning, Proc. of NOLTA 2018, 192-195, Tarragona, Spain, Sep. 2018.
10.	Masashi Kimura, Akira Kinokiri, Takeshi Kojima, Yusaku Yamaguchi and Tetsuya Yoshinaga : Total-Variation Minimization with Regularization for Continuous-Time Dynamical Image Reconstruction in Computed Tomography, Proc. of NOLTA 2018, 143-146, Tarragona, Spain, Sep. 2018.
11.	Mio Kobayashi and Tetsuya Yoshinaga : Associative Memory by Using Coupled Gaussian Maps, 2018 5th International Conference on Advanced Informatics: Concept Theory and Applications (ICAICTA), Krabi, Thailand, Aug. 2018. (Link to Publication Site) ● Publication site (DOI): 10.1109/ICAICTA.2018.8541291 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-85059960216 (DOI: 10.1109/ICAICTA.2018.8541291, Elsevier: Scopus)
12.	Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Tomographic Image Reconstruction via Chi-Square Minimization, Proc. of NCSP'18, 600-603, Honolulu, Mar. 2018.
13.	Takeshi Kojima, Tetsushi Ueta and Tetsuya Yoshinaga : An attempt to enlarge basin in discrete tomographic dynamics with a competitive term, Proc. of NCSP'18, 604-607, Honolulu, Mar. 2018.
14.	Tetsuya Yoshinaga : A novel method of dose-volume-constrained and equivalent-uniform-dose-based optimization in intensity-modulated radiation therapy treatment planning, The ECR 2018 Book of Abstracts is a Supplement to Insights into Imaging, Wien, Feb. 2018.
15.	Tetsuya Yoshinaga : A novel image reconstruction method based on minimization of Hellinger distance, The ECR 2017 Book of Abstracts is a Supplement to Insights into Imaging, Wien, Mar. 2017.
16.	Keita Nakahama, Takeshi Kojima and Tetsuya Yoshinaga : Applying dynamical method of discrete tomography to X-ray CT imaging, Proceedings of International Forum of Medical Imaging in Asia, 81-84, Okinawa, Jan. 2017.
17.	Yusaku Yamaguchi, Omar M. Abou Al-Ola, Shintaro Harano, Takeshi Kojima and Tetsuya Yoshinaga : Evaluation of metal artifact reduction using dynamical image reconstruction in X-ray CT, Proceedings of International Forum of Medical Imaging in Asia, 221-224, Okinawa, Jan. 2017.
18.	Kohsuke Yamato, Akihito Kawabata, Mio Kobayashi and Tetsuya Yoshinaga : Control of Avoidance for Chaos by using Downhill Simplex Method, Proc. NOLTA 2016, Yugawara, Sep. 2016.
19.	Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Noise reduction in computed tomography using a multiplicative continuous-time image reconstruction method, Progress in Biomedical Optics and Imaging - Proceedings of SPIE, Vol.9783, San Diego, Feb. 2016. (Link to Publication Site) ● Publication site (DOI): 10.1117/12.2216439 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-84978828225 (DOI: 10.1117/12.2216439, Elsevier: Scopus)
20.	Kiyoko Tateishi, Yusaku Yamaguchi, Omar M. Abou Al-Ola, Takeshi Kojima and Tetsuya Yoshinaga : Continuous analog of multiplicative algebraic reconstruction technique for computed tomography, Progress in Biomedical Optics and Imaging - Proceedings of SPIE, Vol.9783, San Diego, Feb. 2016. (Link to Publication Site) ● Publication site (DOI): 10.1117/12.2214598 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-84978923868 (DOI: 10.1117/12.2214598, Elsevier: Scopus)
21.	K. Hashimoto, Satoru Kohno, H. Fujii, E. Okada, S. Okawa, Y. Tanikawa, Tetsuya Yoshinaga and Y. Hoshi : Numerical simulation of iterative reconstruction for optical tomography and detection of tumor in human neck based on the time-dependent 3D radiative transfer equation., ISEM 2015, Sep. 2015.
22.	Y. Hoshi, E. Okada, S. Okawa, Y. Tanikawa, Tetsuya Yoshinaga, H. Fijii, K. Fujimoto, K. Hashimoto and Satoru Kohno : Diffuse optical tomography: how to improve image quality?, ICM2015, Jun. 2015.
23.	K. Hashimoto, H. Fujii, Satoru Kohno, E. Okada, S. Okawa, Y. Tanikawa, Tetsuya Yoshinaga and Y. Hoshi : Numerical simulation of iterative reconstruction for optical tomography and detection of tumor in human neck based on the time-dependent 3D radiative transfer equation., 5th Asian and Pacific-Rim Symposium on Biophotonics, Yokohama, Apr. 2015.
24.	Tetsuya Yoshinaga, Yoshihiro Tanaka and Ken'ichi Fujimoto : Iterative method as discretization of continuous-time method based on dose-volume constrained optimization for intensity-modulated radiation therapy treatment planning, EPOS in European Congress of Radiology 2015, Wien, Mar. 2015.
25.	Mio Kobayashi and Tetsuya Yoshinaga : Discrete-time Dynamic Image Segmentation based on Oscillations in a Coupled System with Adaptive Coupling, Proc. of 2015 RISP International Workshop on Nonlinear Circuits, Communications and Signal Processing, 599-602, Kuala Lumpur, Feb. 2015. (Summary) We propose a novel discrete-time coupled model generating oscillatory responses by periodic points with high order of pe- riod or non-periodic points. The coupled system consists of one-dimensional oscillators on the basis of the Rulkov map and a globally coupled oscillator. Since the waveform of the one-dimensional oscillator has the precipitous peaks, the cou- pled system is effective when we use the system for the dy- namic image segmentation. The proposed system transforms the coupling of each oscillator as iteration by depending on the input value which corresponds to the pixel value of an in- put image. It enables the system to segment image regions in which pixel values change gradually as the connected re- gion. In this study, we show the bifurcation analysis of three- coupled model. In addition, we demonstrated that the system could work well for a gray-level image with three isolated image regions.
26.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Improving image quality using an extended continuous-time CT image reconstruction system, International Journal of Computer Assisted Radiology and Surgery, Vol.9, No.Supplement 1, S372, Fukuoka, Jun. 2014. (Keyword) computed tomography / inverse problem / reconstructed image quality / binary tomography
27.	Tetsuya Yoshinaga, Yoshihiro Tanaka and Ken'ichi Fujimoto : Continuous-time method based on dose optimization for intensity-modulated radiation therapy treatment planning, The ECR 2014 Book of Abstracts is a Supplement to Insights into Imaging, Wien, Mar. 2014. (Link to Publication Site) ● Publication site (DOI): 10.1594/ecr2014/C-2322 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1594/ecr2014/C-2322 (DOI: 10.1594/ecr2014/C-2322)
28.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Magnetic resonance image reconstruction using nonlinear continuous-time dynamical system, Proc. of 2014 RISP International Workshop on Nonlinear Circuits, Communications and Signal Processing, 586-589, Honolulu, Feb. 2014. (Summary) The basic problem of image reconstruction in magnetic resonance imaging (MRI) is to estimate a tomographic image by performing a pulse sequence that produces signals representing k-space. In this paper, for solving inverse problems in MRI, we present a novel approach for MRI reconstruction involving a spiral k-space scanning, based on the continuous method using a nonlinear continuous-time dynamical system. We found that the nonlinear continuous method produced better results than a linear continuous method as well as a gradient iterative method with respect to the convergence property of reconstructed images, through numerical experiments using simulated noisy phantom data.
29.	Fujii Hiroyuki, Okawa Shinpei, Tetsuya Yoshinaga, Yamada Yukio, Hoshi Yoko and Satoru Kohno : Image errors of timeresolved optical tomography based on the radiative transfer and diffusion equations, Proceedings of the 9th International Conference on Optics-photonics Design & Fabrication, Tokyo, Feb. 2014.
30.	Ken'ichi Fujimoto, Mio Kobayashi and Tetsuya Yoshinaga : Successive Algorithm Using Discrete-Time Oscillator Network for Three-Dimensional Image Segmentation, IIE Int'l Conference Proceedings of International Conference on Innovations in Engineering and Technology (ICIET'2013), 62-63, Bangkok, Dec. 2013.
31.	Ken'ichi Fujimoto, Tomohiro Otsu, Tetsuya Yoshinaga, Tetsushi Ueta, Hiroyuki Kitajima and Kazuyuki Aihara : Controlling Method to Avoid Bifurcations of Periodic Points Using Maximum Lyapunov Exponent, Proc. of 2013 International Symposium on Nonlinear Theory and its Applications, 158-161, Santa Fe, Sep. 2013. (Link to Publication Site) ● Publication site (DOI): 10.15248/proc.2.158 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.15248/proc.2.158 (DOI: 10.15248/proc.2.158)
32.	Yoshihiro Tanaka, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Nonlinear continuous method for non-negatively constrained inverse problem of IMRT planning, Medical Physics, Vol.40, No.6, 358, Indianapolis, Aug. 2013. (Link to Publication Site) ● Publication site (DOI): 10.1118/1.4815088 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1118/1.4815088 (DOI: 10.1118/1.4815088)
33.	Ken'ichi Fujimoto, Mio Kobayashi and Tetsuya Yoshinaga : GPU Implementation of Oscillator Network System with Plastic Coupling for Dynamic Image Segmentation, Abstract Proceedings of The International Conference on Signal Processing and Telecommunications, 23, Sousse, Mar. 2013.
34.	Ken'ichi Fujimoto and Tetsuya Yoshinaga : Continuous-Time Method to Inverse Problem of Intensity-Modulated Radiation Therapy Treatment Planning, EPOS in European Congress of Radiology 2013, Wien, Mar. 2013.
35.	Yoshiaki Akaishi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Electronic Circuit Design of a Block Continuous-Time Image Reconstruction System, Proc. of 2013 RISP International Workshop on Nonlinear Circuits, Communications and Signal Processing, 217-220, Kona, Mar. 2013.
36.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Extended Continuous-Time Image Reconstruction System for Binary and Continuous Tomography, Proc. of 2013 RISP International Workshop on Nonlinear Circuits, Communications and Signal Processing, 309-312, Kona, Mar. 2013.
37.	Kiyoko Tateishi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Convergence of Iterative Method as Discretization of Continuous-Time Image Reconstruction System for Computed Tomography, Proc. of 2012 RISP International Workshop on Nonlinear Circuits, Communications and Signal Processing, 489-492, Honolulu, Mar. 2012.
38.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Theoretical and Experimental Study of Continuous-Time Image Reconstruction System for Computed Tomography, Proc. of 2012 RISP International Workshop on Nonlinear Circuits, Communications and Signal Processing, 485-488, Honolulu, Mar. 2012.
39.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Extended Continuous-Time Image Reconstruction for Computed Tomography, EPOS in European Congress of Radiology 2012, Wien, Mar. 2012.
40.	Ken'ichi Fujimoto, Mio Kobayashi and Tetsuya Yoshinaga : Coupled Neuronal System with Plastic Coupling for Dynamic Image Segmentation, IFMBE Proceedings, Vol.37, 643-646, Budapest, Sep. 2011.
41.	Ken'ichi Fujimoto, Mio Kobayashi, Tetsuya Yoshinaga and Kazuyuki Aihara : Identification of Number of Target Image Regions Based on Bifurcation of Fixed Point in Discrete-Time Coupled Neuronal System, Proc. of 2011 International Symposium on Nonlinear Theory and its Applications, 156-159, Kobe, Sep. 2011.
42.	Naohiko Inaba, Tetsuro Endo, Tetsuya Yoshinaga and Ken'ichi Fujimoto : Collapse of Mixed-Mode Oscillations and Chaos in the Extended Bonhoeffer-van Der Pol Oscillator Under Weak Periodic Perturbation, Proc. of the 20th European Conference on Circuit Theory and Design, 374-377, Linköping, Aug. 2011.
43.	Hiroki Kita, Tetsuro Endo, Kuniyasu Shimizu, Munehisa Sekikawa, Naohiko Inaba, Tetsuya Yoshinaga and Ken'ichi Fujimoto : Amplitude Death and Chaos from the BVP Oscillator Under Weak Periodic Perturbation, Proc. of the 26th International Technical Conference on Circuits/Systems, Computers and Communications, 764-767, Gyounju, Jun. 2011.
44.	Naohiko Inaba, Munehisa Sekikawa, Tetsuya Yoshinaga and Tetsuro Endo : Coexisting two pairs of stable canards and unstable canards and their remarkable resemblances in the van der Pol oscillator under extremely weak periodic perturbation, Proceedings of International Technical Conference on Circuits/Systems, Computers and Communications, 760-763, Jun. 2011.
45.	Yusaku Yamaguchi, Omar M. Abou Al-Ola, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Numerical Study of Continuous-Time Image Reconstruction for Computed Tomography, EPOS in European Congress of Radiology 2011, Wien, Mar. 2011.
46.	Mio Kobayashi, Ken'ichi Fujimoto, Tetsuya Yoshinaga and Kazuyuki Aihara : Bifurcation analysis for designing dynamic image segmentation system, Proc. of the 1st International Symposium on Innovative Mathematical Modelling, 93, Tokyo, Feb. 2011.
47.	Omar M. Abou Al-Ola, Ken'ichi Fujimoto, Tetsuya Yoshinaga and Kazuyuki Aihara : Common Lyapunov function for a switched nonlinear dynamical system, Proc. of the 1st International Symposium on Innovative Mathematical Modelling, 94, Tokyo, Feb. 2011.
48.	Omar M. Abou Al-Ola, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Stability of a Switched System for Continuous-time Tomographic Image Reconstruction, Proc. of 2010 International Symposium on Nonlinear Theory and its Applications, 115-118, Krakow, Sep. 2010.
49.	Mio Musashi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Extraction of image regions using oscillatory responses in chaotic neuronal network, Proc. of 2010 International Symposium on Nonlinear Theory and its Applications, 169-172, Krakow, Sep. 2010.
50.	Chika Ueda, Omar M. Abou Al-Ola, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Iterative method based on a discretization of continuous-time image reconstruction for computed tomography, Proc. of the 2010 RISP International Workshop on Nonlinear Circuits, Communications and Signal Processing, 223-226, Honolulu, Mar. 2010.
51.	Omar M. Abou Al-Ola, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Properties of a switched system for continuous-time tomographic image reconstruction, Proc. of the 2010 RISP International Workshop on Nonlinear Circuits, Communications and Signal Processing, 219-222, Honolulu, Mar. 2010.
52.	Mio Musashi, Masayoshi Fujiwara, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Analysis of four-phase oscillatory periodic points for discrete-time dynamic image segmentation, Proc. of the 2010 RISP International Workshop on Nonlinear Circuits, Communications and Signal Processing, 57-60, Honolulu, Mar. 2010.
53.	Ken'ichi Fujimoto, Mio Musashi and Tetsuya Yoshinaga : Dynamic image segmentation system with multi-scaling system for gray scale image, Proc. of the Third International Conference on Bio-inspired Systems and Signal Processing, 159-162, Valencia, Jan. 2010.
54.	Omar M. Abou Al-Ola, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Dynamics of Continuous-Time Image Reconstruction System for Computed Tomography, Proc. of 2009 International Symposium on Nonlinear Theory and its Applications, 627-630, Sapporo, Oct. 2009.
55.	Ken'ichi Fujimoto, Mio Musashi and Tetsuya Yoshinaga : Dynamic Image Segmentation System for Ultrasonic B-Mode Image Based on its Multi-Scaled Feature Maps, Proc. of 2009 International Symposium on Nonlinear Theory and its Applications, 495-498, Sapporo, Oct. 2009.
56.	Mio Musashi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Bifurcation Phenomena Observed in Discrete-Time Coupled Chaotic Neurons Generating Oscillatory Responses with High Order of Period, Proc. of the 2009 RISP International Workshop on Nonlinear Circuits and Signal Processing, 201-204, Honolulu, Mar. 2009.
57.	Ken'ichi Fujimoto, Mio Musashi and Tetsuya Yoshinaga : A Design of Destabilizer for Stable Fixed Point Observed in Chaotic Neural Network Generating Oscillations for Dynamic Image Segmentation, Proc. of the 2009 RISP International Workshop on Nonlinear Circuits and Signal Processing, 475-478, Honolulu, Mar. 2009.
58.	Mio Musashi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Bifurcations in a coupled system of chaotic neurons generating oscillatory responses, Proc. of International Conference on Systems, Signals and Image Processing 2008, 149-152, Bratislava, Jun. 2008.
59.	Shota Takemoto, Masahisa Onoguchi and Tetsuya Yoshinaga : The evaluation of the SPECT image using PMART reconstruction, 2008 SNM Annual Meeting, New Orleans, Jun. 2008.
60.	Ken'ichi Fujimoto, Mio Musashi and Tetsuya Yoshinaga : Discrete-time Chaotic Neural Network Generating Oscillations for Dynamic Image Segmentation, Proc. of 2008 RISP International Workshop on Nonlinear Circuits and Signal Processing, 208-211, Gold Coast, Mar. 2008.
61.	Tetsuya Yoshinaga and Ken'ichi Fujimoto : Dynamical Property of Periodic Oscillations Observed in a Coupled Neural Oscillator Network for Image Segmentation, Proc. of International Conference on Bio-inspired Systems and Signal Processing, Vol.2, 141-146, Funchal, Jan. 2008.
62.	Kenji Yamada, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Bifurcation Phenomena in an Iterative Optimization Process for Intensity Modulated Radiation Therapy, Proc. of The 15th IEEE International Workshop on Nonlinear Dynamics of Electronic Systems, 229-232, Tokushima, Jul. 2007.
63.	Ken'ichi Fujimoto and Tetsuya Yoshinaga : Bifurcations in a Synaptic Coupled Oscillator Network for Image Segmentation, International Workshop on Synchronization: Phenomena and Analyses 2006, 147, Tokyo, Oct. 2006.
64.	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.
65.	Tetsuya Yoshinaga : Analysis of an Extended PMART for CT Image Reconstruction as a Nonlinear Dynamical System, Proc. of the 1st International Conference on Computer Vision Theory and Applications, Vol.1, 440-444, Setubal, Feb. 2006.
66.	Yoshihiro Imakura, Tetsushi Ueta and Tetsuya Yoshinaga : Bifurcations of a Dynamical System Defined by PMART, Proc. of NOLTA'05, Vol.1, 38-51, Bruges, Oct. 2005.
67.	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.
68.	Tetsuya Yoshinaga : A method to accelerate the convergence of the PMART for computed tomography, Proc. of the 3rd WSEAS Int. Conf. on NON-LINEAR ANALYSIS, NON-LINEAR SYSTEMS AND CHAOS, 2981-2984, Athens, Dec. 2004.
69.	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.
70.	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.
71.	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.
72.	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.
73.	Tetsuya Yoshinaga : A fast iterative method with algebraic reconstruction technique for computerized tomography, Proc. of NOLTA 2002, Xi'an, Oct. 2002.
74.	Munehisa Sekikawa, Tetsuya Yoshinaga and Naohiko Inaba : The bifurcation set of swollen shape type bifurcation, Proc. of NOLTA 2002, Xi'an, Oct. 2002.
75.	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.
76.	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.
77.	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.
78.	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.
79.	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.
80.	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.
81.	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.
82.	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.
83.	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.
84.	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.
85.	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)
86.	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.
87.	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.
88.	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.
89.	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)
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.	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.
94.	Takashi Ikemoto, Hirofumi Nagashino, Yohsuke Kinouchi and Tetsuya Yoshinaga : Oscillatory mode transitions in a four coupled neural oscillator model, Proceedings of 1997 International Symposium on Nonlinear Theory and its Applications, Vol.1, 561-564, Honolulu, Dec. 1997.
95.	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.
96.	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)
97.	Tetsuya Yoshinaga, Hiroshi Kawakami and Kazuyuki Aihara : Bifurcations in two coupled chaotic neurons, Proc. of NOLTA'96, 105-108, Kochi, Oct. 1996.
98.	Tetsuya Yoshinaga and Hiroshi Kawakami : A method to calculate homoclinic points of a noninvertible map, Proc. of ICNBC, 267-271, Lodz-Dobieszkow, Sep. 1996.
99.	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.
100.	Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcations in a BVP equation with periodic impulsive force, Proc. of NOLTA'95, 331-334, Las Vegas, Dec. 1995.
101.	Hiroyuki Kitajima, Tetsuya Yoshinaga and Hiroshi Kawakami : Synchronization in two coupled oscillators with three ports, Proc. of NOLTA'94, 89-92, Kagoshima, Oct. 1994.
102.	Tetsuya Yoshinaga and Hiroshi Kawakami : Bifurcations of a coupled Roessler system, Proc. of NOLTA'94, 109-112, Kagoshima, Oct. 1994.
103.	Tetsuya Yoshinaga and Hiroshi Kawakami : Codimension two bifurcation in a coupled oscillator, Abst. of ICDSC'94, 83, Tokyo, May 1994.
104.	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.
105.	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.
106.	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)
107.	Tetsuya Yoshinaga and Hiroshi Kawakami : Mode bifurcations observed in coupled oscillators, Proc. of ITC-CSCC'90, 211-216, Cheju, Dec. 1990.
108.	Tetsuya Yoshinaga and Hiroshi Kawakami : Codimension two bifurcation problems in forced nonlinear circuits, Proc. of ISCAS'89, 209-212, Jan. 1989.

Proceeding of Domestic Conference:

1.	Kohei Hayashi, OBATA Norihisa, Ryosei Nakada, Takeshi Kojima and Tetsuya Yoshinaga : 多目的線量体積制約に基づく動的IMRT計画法の高精度化, 第37回高精度放射線外部照射部会学術大会, Mar. 2024.
2.	Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : 冪指数を導入した逐次CT画像再構成アルゴリズムのパラメータ推定, 第62回日本生体医工学会大会, May 2023.
3.	Kohei Hayashi, OBATA Norihisa, Ryosei Nakada, Takeshi Kojima and Tetsuya Yoshinaga : 多目的線量体積制約に基づく動的高精度IMRT計画のための新しい反復則, 第62回日本生体医工学会大会, May 2023.
4.	ISHIKAWA Kazuki, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : 冪指数型に拡張した期待値最大化に基づくウィーディング・ブロック反復CT画像再構成法, 第62回日本生体医工学会大会, May 2023.
5.	Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : パラメータを含む逐次CT画像再構成アルゴリズムの性能評価最適化法, 中四国放射線医療技術フォーラム, Oct. 2022.
6.	HANADA Ryoya, Takeshi Kojima and Tetsuya Yoshinaga : 拡張指数型測度族の最適化に基づく医用CT画像再構成法の効果的な指数パラメータ自動探索, 中四国放射線医療技術フォーラム, Oct. 2022.
7.	OBATA Norihisa, Kohei Hayashi, Ryosei Nakada, Takeshi Kojima and Tetsuya Yoshinaga : 多目的線量体積制約に基づく動的強度変調放射線治療計画法, 中四国放射線医療技術フォーラム, Oct. 2022.
8.	ISHIKAWA Kazuki, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : ウィーディング・ブロック反復CT画像再構成アルゴリズムの特性, 中四国放射線医療技術フォーラム, Oct. 2022.
9.	Ryosuke Kasai, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : 拡張指数型ダイバージェンス測度族の最適化に基づく逐次CT画像再構成, 中四国放射線医療技術フォーラム, Oct. 2022.
10.	Ryosei Nakada, Omar M. Abou Al-Ola, Takeshi Kojima and Tetsuya Yoshinaga : 線量体積制約に基づく強度変調放射線治療計画の最適化, 日本放射線腫瘍学会第34回高精度放射線外部照射部会学術大会, Mar. 2021.
11.	Akira Kinokiri, Masashi Kimura, Takeshi Kojima and Tetsuya Yoshinaga : ヘリンガー距離の全変動に基づく正則化を考慮した連続時間CT画像再構成法, 中四国放射線医療技術フォーラム, Nov. 2018. (Summary) 【背景と目的】筆者の一部らは，CT逆問題が適切性を満たす場合に真の画像への収束が理論的に保証された微分方程式系を提案している．診断に用いられる条件の非適切逆問題に対しても品質の高い画像が得られることを例証する研究を進めているが，一般的に，劣決定逆問題に対しては，高品質な再構成画像を得るために正則化が効果的である．本報告では，平面画像における全変動距離の最小化を期待した正則化法を考え，近傍画素値の距離を測る関数としてヘリンガー距離の平方で与える方法を提案する．連続時間断層画像再構成系に合った効果的な正則化法を見出すことが本研究の目的である．【方法】通常，全変動の評価にはL1-ノルムを距離とした関数が用いられる．ただし，L1-ノルムには微分が不可能な点があり，連続時間勾配系の最適化評価関数に用いるのは不適切である．そこで，L1-ノルムと密接な不等式関係を持つヘリンガー距離を全変動の距離関数に用いることとした．提案法をユークリッド距離の平方に基づく正則化と比較した数値実験を行い，測定雑音の程度や正則化の重み係数等を変化させて再構成画像の品質を評価した．【結果と結論】再構成画像の全変動距離が同じ値となるよう正則化係数を調整したとき，提案法は対照法と比べ，辺縁の急峻さよりもコントラストの保持や乱雑性を抑制する効果が高いことがわかった．金属アーチファクトの削減などを目的とした用途に適切である．
12.	Ryosuke Kasai, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : 期待値最大化法と乗法的代数的再構成法を拡張した新しい逐次CT画像再構成法の特性, 中四国放射線医療技術フォーラム, Nov. 2018. (Summary) 【背景と目的】医用CT画像診断装置の画像再構成原理として，近年，多くの種類の逐次再構成(IR)法が提案され利用されている．最適化を導く評価関数の特性を反映して収束性能や画像の品質に特徴が生じる．種々の評価関数に基づき微分方程式系を構成し，系の離散化によりIR法を導出する接近法が提案されている．筆者らは，最近，期待値最大化(EM)法と乗法的代数的再構成法(MART)を混合して拡張したIR法を提案している．このときの数値離散には加法的および乗法的算法の混成による離散化法を考案して適用した．本報告では，提案したIR法の特長を実験により検証している．【方法】EM法とMARTの混合拡張系は，投影と順投影の対称カルバック・ライブラー距離(SKLD)を最適化の評価関数として導出した逐次法である．CT逆問題が適切性を満たすとき，微分方程式系にみられる平衡点の安定性を理論的に証明することが可能である．臨床例を模擬した数値実験および実際の画像診断装置から得られた投影データによる実験を通して，提案法の性能を評価する．【結果と結論】まず，ハイブリッド算法を用いた場合のみが数値演算の安定性が高いことを確認した．次に，適切性を満たす設定において，解に沿ったSKLDの時間変化が単調に減少することを検証した．さらに，複数の実験結果から，提案法はEM法とMARTよりも評価関数による定量的な性能が高いことがわかった．
13.	Moe Kudoh, Yusaku Yamaguchi, Omar M. Abou Al-Ola, Takeshi Kojima and Tetsuya Yoshinaga : 一般化ヘリンガー距離の最小化に基づく逐次画像再構成法, Proceedings of the 116th Scientific Meeting of JSMP, Vol.38, No.3, Sep. 2018. (Summary) [Purpose] We present a novel method of image reconstruction in computed tomography on the basis of minimizing a generalized Hellinger distance. The Hellinger distance has good properties for evaluating images, meaning that it gives an upper bound of the L-1 norm. The purpose of this paper is to show advantages of using the image reconstruction method compared with conventional methods, through theoretical and experimental investigations. [Method] We have previously proposed an approach for solving non-negatively constrained tomographic inverse problems based on the idea of dynamical methods using nonlinear differential equations. We applied the methodology to the optimization of the generalized Hellinger distance and derived an iterative image reconstruction algorithm by discretizing the continuous-time system. Then we performed numerical experiments comparing the proposed method with the maximum-likelihood expectation-maximization (ML-EM) method, using simulated projection data with white Gaussian noise. [Result] The convergence of the dynamical image reconstruction system to a desired reconstruction image has been theoretically proved by the Lyapunov stability theorem using squared Hellinger distance with a power exponent as a Lyapunov function. We found that the proposed iterative method having a relatively small value of the power exponent was able to reconstruct a better quality image with fewer artifacts for projection data with low signal-to-noise ratios (SNRs) compared with that by using the ML-EM method. This fact was quantitatively confirmed by several kinds of measures between the true and reconstructed images at each iteration. [Conclusion] The proposed method produces images that have better quality and are more robust to lower SNRs or higher noise levels. The advantage of the proposed method is due to the theoretical inequality property that the Hellinger distance minimization means the minimization of L-1 norm. The reconstruction of high-quality images made by our method even for noisy projection data allows patient dose reduction in clinical practice.
14.	Yusaku Yamaguchi, Ryosuke Kasai, Takeshi Kojima and Tetsuya Yoshinaga : 連続時間断層画像再構成法の加法的・乗法的及びその混成による離散化, Proceedings of the 116th Scientific Meeting of JSMP, Vol.38, No.3, Sep. 2018. (Summary) 【目的】高品質な断層画像を高速に再構成する方法の開発を目指し，筆者らは，種々の評価関数に基づく微分方程式系とハイブリッド力学系を提案している(連続時間再構成法と呼ぶ)．これまでに提示した系は，断層逆問題が適切性を満たす場合，画素値としての制約を満たしながら理想解の漸近安定性が理論的に保証されている特長を持つ．本報告では，連続時間再構成法の離散化算法に着目し，精度の高い効果的な逐次再構成(IR)法を構成するアプローチを提案する．【方法】連続時間再構成法は非線形微分方程式系の初期値問題を用いる方法である．まず，方程式系にみられる平衡点の漸近安定性を非線形力学系理論の安定性定理を用いて証明する．次に，IR法を導出するための離散化を実施する．非適切な場合や雑音が測定に含まれる場合の逆問題設定に対する数値実験を通して，離散化算法の種類と系のパラメタに依存したIR法の性能を評価する．【結果】連続時間系にみられる平衡点の安定性証明はリアプノフ定理を用いた．加法系，乗法系だけでなく，加法と乗法の混成系に基づきIR法を構成する．数値実験により，系の特性に応じた適切な離散化算法が存在することがわかった．投影と順投影の比に係る冪指数を測定雑音に含まれる雑音の程度に応じて適切に選ぶことで，最も品質の高い画像を与える効果的な再構成を実現できることが明らかとなった．【結論】断層画像再構成法として望ましい最適化評価関数に基づく微分方程式系を構成し，乗法的・加法的算法，及び，それらの混成による離散化算法からIR法を導出する手順を提示した．品質の高い画像を高速に演算できるIR法の構成アプローチとして有効である．
15.	Moe Kudo, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : 一般化 Hellinger 距離の最小化に基づくCT画像再構成, 第40回日本生体医工学会中国四国支部大会プログラム講演抄録, Oct. 2017. (Summary) 【背景】医用CT画像再構成法として変換法と逐次再構成(IR)法がある．IR法は演算コストが高いが非適切な逆問題において変換法よりも品質の高い画像が得られる特長を持つ．筆者等の一部は，CT逆問題の解法として微分方程式系の初期値問題を与え，系の数値離散によりIR法を導出するアプローチを提案している．以前に，Hellinger 距離(HD)の最小化を導く再構成法を提案し，全変動距離の最小化を反映した良質な画像が得られることを例証した．【目的】本報告では，HDを一般化させた評価関数の最小化に基づく画像再構成法を提案し，理論および数値実験により有効性を示す．【結果】提案した非線形微分方程式系において，真の画像に対応した平衡点の大域的安定性を理論的に証明した．すなわち，逆問題が適切性を満たすとき，任意の正の画素値から出発した解軌道は投影と逆投影の一般化HDを単調減少させながら真の画素値に収束する．この性質は，系に含まれるパラメタとしての冪指数が1未満の任意の正値に対して成立する．数値実験により性能を評価し，一般化HDの最小化法は，測定雑音の再構成画像への影響を期待値最大化法よりも低く抑える良好な特性があることを例証している．
16.	Mio Kobayashi and Tetsuya Yoshinaga : Analysis of Bifurcation Phenomena Observed in Coupled Gauss Map, Proc. of the Electronics, Information and Systems Conference Electronics, Information and Systems Society, I.E.E. of Japan, 1123-1127, Sep. 2017.
17.	Tetsuya Yoshinaga : Tomographic image reconstruction using nonlinear differential equation with analog electronic circuit, Proc. of the Electronics, Information and Systems Conference Electronics, Information and Systems Society, I.E.E. of Japan, 437-441, Sep. 2017.
18.	Daisuke Ikeda, Kisaki Mizuta, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Applying Dynamical Reconstruction Method Based on Hellinger Distance Minimization to X-ray CT Imaging, 日本放射線技術学会第73回総会学術大会予稿集, Apr. 2017. (Summary) 【背景】医用X線CTの画像再構成法にはフィルタ補正逆投影法(変換法)が専ら利用されてきたが，画像の高品質化や被ばく線量の低減を目的として，近年，逐次再構成(IR)法を実装した装置も普及しつつある．変換法よりも性能の良いIR法が広く活用されるようになるには，演算の高速化だけでなく，より品質の高い画像が得られる方法の理論と技術開発が求められている．筆者等の一部は，CT逆問題の解法として非線形微分方程式系の初期値問題を与え，系の数値離散により新しいIRアルゴリズムを導出するアプローチを提案している．【目的】最近，ヘリンガー距離の最小化に基づく動的画像再構成法を提案し，逆問題が適切性を満たす場合，解(画素値)が真値へ向かう大域的収束性の理論証明に成功している．ヘリンガー距離は，全変動(TV)距離の上限を与える不等式関係があり，TV距離の最小化による画像再構成が期待できる．実用的な条件下での実験を通して提案法の性能を検証することが本報告の目的である．【方法】再構成を与える微分方程式系をオイラー法により離散化したIR法を提案法とする．医用X線CT装置を用いて人体模擬ファントムを撮影し，取得した投影データから期待値最大化(EM)法と提案法により再構成を実施した．再構成画像の濃度プロファイル，反復解の収束特性などを用いて性能を評価した．【結果】提案法はEM法と比較して，投影と逆投影のヘリンガー距離(およびTV距離)が各反復において小さく，画像に含まれる特徴領域のエッジをシャープに再構成することがわかった．ヘリンガー距離の最小化に基づく動的方法により導出したIR法は，TV最小化を反映した特徴をもつ品質の高い再構成画像が得られることが明らかとなった．EM法を導く評価関数もTV距離の上限を与えるが，へリンガー距離の方がより近い上限値となっていることが，提案法の優位な性質を結論づけているといえる．
19.	Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Magnetic Resonance Image Reconstruction Based on Nonautonomous Nonlinear Differential Equation, 日本放射線技術学会第73回総会学術大会予稿集, Apr. 2017. (Summary) 【背景】空間周波数領域(k 空間)に配置された受信信号から磁気共鳴画像(MRI)を再構成する手続きは，線形代数方程式に対する最確値を求める問題に定式化される．ダイナミックMRIなど高い時間分解能を要する高速撮像のためのパルスシーケンスにおいて，k 空間の中心付近，すなわち，低周波数成分を高密度で得られるように空間周波数データが非デカルト軌道状にサンプリングされることがある．いま，離散的に観測された非デカルト軌道の受信信号と画像の関係は実部と虚部からなる複素係数の線形代数方程式で記述されるが，MR信号に含まれる測定雑音等の影響を受け，MR画像再構成問題は一般に非適切逆問題となる．【目的】筆者等は以前に，MR画像再構成の逆問題を非線形微分方程式系の初期値問題に帰着させ，高品質画像が高速に得られる再構成法(非線形微分方程式系)を提案している．先行法では，複素係数代数方程式を実部と虚部の連立方程式として扱い画素値の実部成分のみの最適化問題に帰着させていたが，本研究では，虚部が満たすべき代数方程式を緩く満たしながら，時間経過に伴って零ベクトルへ漸近させる機能を微分方程式系に導入した再構成法(非自律系非線形微分方程式系)を提案し，効果を検証することが本報告の目的である．【方法】提案法の性能を評価するため，ディジタル・ファントムをもとに数値実験を実施した．対照系は先行法および共役勾配法とし，それぞれの再構成画像を定量的に評価するために各種距離関数を用いて比較を行った．【結果】提案法は，望ましい解への収束が理論的に保証されており，定常状態の解をもとに品質の高い画像を演算することが可能であると期待される．数値実験を通し，提案系に含まれるパラメータを最適に設定することで，収束性の良い性質を保ったまま，先行法および共役勾配法よりもアーチファクトの少ない高品質な再構成画像が得られることがわかった．
20.	Kisaki Mizuta, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Hellinger 距離の最小化に基づくCT画像再構成, 第39回日本生体医工学会中国四国支部大会プログラム講演抄録, Oct. 2016. (Summary) 【背景】医用CT画像再構成法としてフィルタ補正逆投影法(変換法)と逐次再構成(IR)法がある．IR法は演算コストが高いが非適切な逆問題において変換法よりも高い品質の画像が得られる特長がある．筆者等の一部は，CT逆問題の解法として微分方程式系の初期値問題を与え，系の数値離散によりIRアルゴリズムを導出するアプローチを提案している．【目的】Hellinger 距離の最小化に基づく画像再構成法を提案し，理論および数値実験により有用性を示す．Hellinger 距離は，全変動(TV)距離の上限を与える不等式関係があり，TV 最小化による画像再構成が期待できる．【結果】提案した非線形微分方程式系において，真の画像に対応した平衡点の大域的安定性を理論的に証明した．すなわち，CT逆問題が適切性を満たすとき，任意の正の初期値(画素値)から出発した解軌道は投影と逆投影の Hellinger 距離を単調減少させながら平衡点(真の画素値)に収束する．数値実験およびX線CT装置を用いた実機実験により性能を評価し，実際，提案法は TV 最小化を反映した特徴をもつ品質の高い画像再構成が可能であることが例証された．
21.	Keita Nakahama, Takeshi Kojima and Tetsuya Yoshinaga : 微分方程式を用いた離散トモグラフィのX線CT画像への適用, 第39回日本生体医工学会中国四国支部大会プログラム講演抄録, Oct. 2016. (Summary) 離散トモグラフィ画像再構成は，複数レベルの濃度値を持つ画像を投影から再構成する問題であり，医用画像における特徴領域の自動抽出を可能とする原理として画像診断装置の基盤技術である．筆者等は，一般化ロトカ・ヴォルテラ型の競争モデルに基づく非線形微分方程式系を構成し，真の画像に対応した安定平衡点への解の収束によって，目的の再構成を達成させる新しい方法を提案している．従来法として，逐次再構成法に画像領域分割やエネルギー関数最適化を併用した方法が知られているが，提案法のように，競争モデルの力学を用いた接近法は本研究が最初である．微分方程式系には複数の安定・不安定平衡点が共存し，実験により，安定平衡点へ収束する状態の初期値集合が存在することがわかっている．本報告において，数値実験およびX線CT装置を用いた実機実験により提案法の性能と有用性を検討する．まず，数値ファントムを用いた実験を行い，画像を濃度レベルごとに正しく分割した再構成が実現できることを示す．次に，特性評価ファントムと人体模擬ファントムをX線CT装置で撮影し，サイノグラムから再構成を実施した．実用的な条件での提案法の有用性を検証している．
22.	Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : Magnetic resonance image reconstruction for non-Cartesian sampling schemes, 第44回日本磁気共鳴医学会大会, Sep. 2016. (Summary) Image reconstruction problem in magnetic resonance imaging (MRI) is formulated as a problem of finding a solution satisfying linear equations derived from signals sampled in k-space according to a pulse sequence. When sampling signals are taken at the Cartesian locations using the ordinary pulse sequences represented by, e.g., the spin echo sequence, it is possible to reconstruct an image using the method of two-dimensional Fourier transformation. However, spatial frequency data in the pulse sequence for an ultrafast MRI sequence may be provided with non-Cartesian k-space sampling schemes such as spiral or radial trajectories. The relation between image pixel densities and sampled signals is described through a set of linear equations and the problem of MRI reconstruction becomes a linear inverse problem, which may be generally ill-posed due to the presence of noise and detection error. In this study, we present a novel approach for MRI reconstruction involving a spiral k-space scanning on the basis of the idea of continuous dynamical methods using the minimization of Kullback-Leibler (KL) divergence. Our proposed system is described by nonlinear differential equations and it can not only reconstruct non-negatively constrained tomographic images but also has the property that the KL-divergence measure monotonically decreases along the solution. To evaluate the performance of the proposed method, we compare numerically the convergence properties of proposed method with the conjugate gradient iterative method using simulated noisy phantom data. We demonstrated that the proposed method is more effective than the conventional iterative method in convergence quality, through numerical experiments in the case of noisy phantom data with lower signal-to-noise ratios.
23.	Kiyoko Tateishi, Yusaku Yamaguchi, Takeshi Kojima and Tetsuya Yoshinaga : 逐次CT画像再構成アルゴリズム構築の新しいアプローチ, 医用画像情報学会(MII)平成28年度年次(第175回)大会誌, 28, Jun. 2016.
24.	Yusaku Yamaguchi, Michiko Mori, Takeshi Kojima and Tetsuya Yoshinaga : 非線形微分方程式に基づく磁気共鳴画像再構成, 医用画像情報学会(MII)平成28年度年次(第175回)大会誌, 23, Jun. 2016.
25.	Shintaro Harano, Takeshi Kojima and Tetsuya Yoshinaga : Effect of metal artifact reduction using continuous-time CT image reconstruction method, 第111回日本医学物理学会学術大会, Apr. 2016. (Summary) 【背景】X線CTの撮影領域において吸収率が極端に高い物体が存在するとき，通常の再構成法を用いると画像にスポーク状のアーチファクトが発生する．原因の一つには，金属を通過するX線ビーム上に存在する吸収係数の線積分が正しく得られず，投影に欠損が生じることが挙げられる．特に，複数の金属が存在する場合には診断画像の品質の劣化が問題となっている．アーチファクト削減方法として現在知られているのは，画像上で金属の存在する領域をサイノグラムのフィルタ処理から推定する方法などが原理として用いられている．【目的】CT画像再構成は，既知の投影から画像の濃度値を推定する逆問題である．筆者等は，金属アーチファクト削減に応用可能なCT逆問題の新しい解法を提案している．すなわち，画素値だけでなく欠損した箇所の投影も未知変数に含めた連立非線形微分方程式系を最適化原理に基づき構成し，微分方程式の初期値問題により，再構成画像と投影が同時に得られることを期待する．本報告の目的は，ディジタル・ファントムを用いた数値実験を通して，理論の検証とアーチファクト削減効果を評価することにある．【方法】複数の金属片を仮定した濃淡画像ファントムの投影データをもとに提案法による画像再構成を実施する．金属領域の大きさや測定雑音の程度を変化させ，濃度プロファイルにより再構成画像の品質を検討する．【結果】投影と逆投影との違いを評価する関数は系の解に沿って単調に減少する良い性質が確認できた．複数の金属を含む場合でもアーチファクトの少ない再構成画像，及び欠損を補完した投影を求めることができ，提案法がアーチファクト削減に有用であることが示された．
26.	Keita Nakahama, Takeshi Kojima and Tetsuya Yoshinaga : Discrete tomographic image reconstruction using differential equation, 第111回日本医学物理学会学術大会, Apr. 2016. (Summary) 【背景】離散トモグラフィ画像再構成は，複数レベルの濃度値を持つ画像を投影データから再構成する問題であり，医用 CT 画像における特徴領域の自動抽出を可能とする原理として画像診断装置の重要な基盤技術である．筆者等は，一般化 Lotka-Volterra 型の競争モデルに基づく非線形微分方程式系を構成し，真の画像に対応した安定平衡点への解軌道の収束によって，目的の画像再構成を達成させる新しい方法を提案している．【目的】非線形微分方程式系の初期値問題を用いる離散トモグラフィの解法を与え，数値実験により提案法の性能と有用性を検討する．【方法】投影と投影作用素だけでなく，濃度レベル値とレベル数が既知のもとで断層画像の各画素値を推定する逆問題として離散トモグラフィの問題を定式化する．提案法の微分方程式系には複数の安定及び不安定平衡点が共存することを示す．ディジタル・ファントムを用いた数値実験を実施し，次の検討を行う．まず，真の画像に対応した安定平衡点へ解が漸近する初期値条件と平衡点の位相的性質を調べる．さらに，濃度レベル毎に正しく分割した再構成画像が得られるための条件を検討する．【結果】提案系にみられる安定及び不安定平衡点の位相的性質を調べた．数値実験を通し，初期値を出発した解が真値に対応した安定平衡点へ至る収束過程には，サドル型平衡点の安定多様体が重要な役割を果たしていることが明らかとなった．濃度レベル値やレベル数だけでなく画素数との相互関係も含め，正しい再構成画像が得られるための条件を検討した．適切な初期値を選ぶことにより，画像を濃度レベル毎に分割した再構成が実現できることを例証した．
27.	Keita Nakahama, Takeshi Kojima and Tetsuya Yoshinaga : 微分方程式を用いた離散トモグラフィ画像再構成法の数値実験による検討, 島根県診療放射線技師会平成27年度春季学術大会, Mar. 2016.
28.	Shintaro Harano, Takeshi Kojima and Tetsuya Yoshinaga : 金属アーチファクト削減のための連続時間 CT 画像再構成法, 第38回日本生体医工学会中国四国支部大会プログラム講演抄録, Nov. 2015. (Summary) 医用X線CTの撮像領域において金属のような極端にX線吸収率の高い物体が存在するとき，通常の再構成法を用いると画像にスポーク状のアーチファクトが発生する．原因は，金属を通過するX線ビーム上の組織に対応した吸収係数の線積分が正しく得られず，投影に欠損が生じることにあり，複数の金属が存在するときには特に画像の品質の劣化が問題となっている．現在，金属の存在する画像領域をサイノグラムのフィルタ処理から推定することでアーチファクト削減を図る方法などが知られている．本報告において，画素値だけでなく，欠損した箇所の投影も未知変数に含めた連立非線形微分方程式系を最適化原理に基づき構成し，微分方程式の初期値問題により，再構成画像と投影の一部を同時に求めるアプローチを提案する．さらに，ディジタル・ファントムを用いた数値実験結果を報告する．複数の金属片を仮定した濃淡画像ファントムの投影データをもとに提案法による画像再構成を行い，次の結果を得た．すなわち，投影と逆投影との違いを評価する関数は微分方程式系の解軌道に沿って単調に減少し，アーチファクトの少ない再構成画像，および欠損を補完した投影を求めることができた．
29.	Keita Nakahama, Takeshi Kojima and Tetsuya Yoshinaga : 非線形微分方程式を用いた離散トモグラフィ, 第38回日本生体医工学会中国四国支部大会プログラム講演抄録, Nov. 2015. (Summary) 離散トモグラフィは，複数レベルの濃度値を持つ画像を投影データから再構成する問題であり，医用CT画像の特徴領域の抽出を可能とする画像診断装置の基盤技術である．筆者等の一部は，一般化ロトカ・ボルテラ(Lotka-Volterra)型の競争モデルに基づく非線形微分方程式系を構成し，真の画像に対応した安定平衡点への解軌道の収束によって目的の画像再構成を達成させる方法を提案している．従来法として，逐次画像再構成法に画像領域分割やエネルギー関数最適化を併用した方法が知られているが，近年，精度の高い方法の開発を目指した研究が進められている．提案法のように，競争モデルのダイナミクスに動機づけられて導出した微分方程式を原理に用いたアプローチは本研究が最初である．微分方程式系には複数の安定および不安定平衡点が共存することを理論的に示すことができ，実験により，安定平衡点へ収束する状態変数の初期値集合が存在することが明らかとなった．ディジタル・ファントムを用いた数値実験を行い，適切な初期値を選ぶことにより，画像を濃度レベルごとに正しく分割した再構成が達成できることを例証する．
30.	Yoshihiro Tanaka and Tetsuya Yoshinaga : Utility of an intensity-modulated radiation therapy planning method based on dose-volume constrained optimization, Proceedings of the 110th Scientific Meeting of Japan Society of Medical Physics, Sep. 2015.
31.	Kiyoko Tateishi, Yusaku Yamaguchi and Tetsuya Yoshinaga : Continuous-time CT image reconstruction method and its multiplicative discretization, Proceedings of the 110th Scientific Meeting of Japan Society of Medical Physics, Sep. 2015.
32.	Yusaku Yamaguchi and Tetsuya Yoshinaga : Noise reduction in CT using a multiplicative continuous-time image reconstruction method, Proceedings of the 110th Scientific Meeting of Japan Society of Medical Physics, Sep. 2015.
33.	Kiyoko Tateishi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : 微分方程式の離散化に基づくCT画像再構成法, 第37回日本生体医工学会中国四国支部大会プログラム講演抄録, 34, Oct. 2014. (Summary) 医用CT画像の再構成は投影から断層画像を推定する逆問題として定式化できる．筆者等の一部は，CT逆問題を微分方程式系の求解問題に帰着させ，高品質画像が得られる再構成法(連続法)を提案している．従来の逐次法として，代数的再構成法(ART)とブロック型期待値最大化(OSEM)法が用いられているが，ARTでは不適切な負の画素値が生じたり，準周期解に収束する欠点がある．OSEM法ではバランス条件が満たされていないとき収束に失敗することがある．本研究では，連続法の離散化に基づく新しい逐次法を構成し，高精細画像をソフトウェアで簡便に得ることのできる再構成法の開発を目指す．連続法の良好な性質を保持して離散化を行う方法として画素値の非負と単調収束を保証する逐次法を与える．まず，反復解の正値性と安定固定点への単調な収束性を理論的に証明する．次に，数値実験により提案法の収束性及び再構成画像の品質を従来法と比較した．理論で得られた設定条件をもとに，数値例及び実機から取得した投影を用いて再構成を行った結果，提案法の評価関数は単調に減少する性質を持ち，偽像の発生が抑制されること等，提案法の有用性が明らかになった．
34.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : 非線形微分方程式を用いた磁気共鳴画像再構成, 第37回日本生体医工学会中国四国支部大会プログラム講演抄録, 35, Oct. 2014. (Summary) 磁気共鳴画像(MRI)の再構成は，信号計測空間(k-空間)を適切に充填するようパルスシーケンスを構成し，解析的方法または線形逆問題解法によって断層画像を求める問題である．受信信号をk-空間で直角格子状に配置したとき，再構成画像は2次元フーリエ変換により解析的に得られる．一方，信号計測データが非デカルト軌道のサンプリング点で与えられるパルスシーケンスは高速撮像として用いられる．受信信号と画像の関係は線形複素代数方程式で記述されるが，測定雑音等の影響を受け，解を求める逆問題は一般に非適切となる．本研究では，逆問題から導かれた最小化問題を微分方程式の初期値問題に帰着させて再構成を行う方法(非線形連続法)を提案する．提案法の勾配系は，状態と真値との Kullback-Leibler divergence に基づく非線形微分方程式で与えられる．雑音を加えた受信信号が螺旋軌道上の点列で与えられる数値データを設定し，非線形連続法の性能を測定誤差の2次形式に基づく線形連続法と比較検討した．非線形連続法は解に沿った目標関数が単調減少し，線形連続法で求めた画像よりも品質の高い画像が得られることがわかった．
35.	岡田英史, 大川晋平, 谷川ゆかり, Tetsuya Yoshinaga, Ken'ichi Fujimoto, 橋本康, 岩瀬正, Satoru Kohno and 星詳子 : ヒト生体イメージングを目指した革新的バイオフォトニクス技術の構築, 第53回日本生体医工学会学会大会.シンポジウム, Jul. 2014.
36.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Dual-energy CT image reconstruction using continuous-time method, 日本放射線技術学会第70回総会学術大会予稿集, 165-166, Apr. 2014. (Summary) 【目的】Dual-energy CT (DECT) 画像再構成は，相異なる2種類のX線エネルギーを使用して投影データを収集し，物質が持つ線減弱係数のエネルギー依存性を利用することにより，物質弁別画像や仮想単色画像を生成する技術である．一方，筆者等は，医用CT画像の再構成法として，CT逆問題を非線形微分方程式の求解問題に帰着させ，高品質画像が得られる新しい方法(連続時間CT画像再構成法または連続時間法)を提案している．低被曝・高品質なDECT画像が得られる再構成法の開発を目的とし，数値実験により，DECT画像再構成に対する連続時間法の有効性を検討する．【方法】異なる管電圧を模擬して得られた2種類の投影データを入力として，連続時間法とフィルタ補正逆投影法を用いて再構成演算を行い，画像の分解能，雑音特性などに着目して比較を行った．【結果】再構成画像をフィルタ補正逆投影法と比較した結果，連続時間法では，画像に生じるアーチファクトが少なく，高コントラストで高品質な画像が得られた．また，投影方向数が少数の場合においても高品質画像が得られることから，被曝低減にも効果が期待できることが明らかになった．
37.	Yoshihiro Tanaka, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Optimization by continuous-time method for intensity-modulated radiation therapy treatment planning, 日本放射線技術学会第70回総会学術大会予稿集, 182, Apr. 2014. (Summary) 【目的】強度変調放射線治療(IMRT)計画は，照射ビーム係数に関する評価関数の最適化問題に帰着できる．最適化法として，CG法やNewton法などの反復法が一般的に用いられている．ただし，問題によっては反復解が負値となることなど，計画にとって不都合な状況が生じる可能性がある．筆者等は，IMRT計画の最適化問題を非線形微分方程式の初期値問題に帰着させ，評価関数の極小解を求める方法(連続時間法)を提案している．連続時間法は評価関数のヘッセ行列を必要とせず，ビームの制約としての解の正値性を保ちながら，解に沿った Kullback-Leibler ダイバージェンスの単調減少性が理論的に保証される特長がある．本報告では，連続時間法によるIMRT計画の有効性を評価する．【方法】臨床例に基づく最適化問題に対して連続時間法により極小解を求め，多角的に結果を評価した．【結果】解に対応した線量分布は，リスク臓器を低線量に抑え，標的体積のみに高線量が集中し，与えられた線量制約を満たしていることが確認できた．望ましいIMRT計画が得られることが理論と実験により検証され，連続時間法の臨床応用への有効性が示された．
38.	Daisuke Ito, Tomohiro Otsu, Ken'ichi Fujimoto, Tetsushi Ueta, Kazuyuki Aihara and Tetsuya Yoshinaga : Avoidance of Bifurcations of Stable Fixed Point Using the Maximum Lyapunov Exponent, Proceedings of 1st Multi Symposium on Control Systems, 742-745, Mar. 2014. (Summary) Topological properties of the limit set are characterized by the Lyapunov exponent of the orbit on the dynamical system. In discrete-time dynamical system is described by ordinary differential equations, authors translate avoidance of bifurcations controlling problem of a stable fixed point, periodic point into minimization problem that the evaluation function the maximum Lyapunov exponent. The authors had proposed the controller to avoid the unbeseeming bifurcation phenomena that is caused by the variation of system parameters by change in environment. We have reported results that it is applied to the period- doubling bifurcation of the periodic point on the H enon map. In this paper, avoidance of bifurcations method is applied to the Kawakami map. We confirm that the controller can avoid the tangent bifurcation and Neimark-Sacker bifurcation. (Keyword) Avoidance of bifurcation / Maximum Lyapunov exponent
39.	Mio Kobayashi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Control to avoid chaos using robust bifurcation analysis method, Proceedings of 1st Multi Symposium on Control Systems, 746, Mar. 2014. (Summary) Robust bifurcation analysis for parameterized dynamical systems provides a direct method for finding the values of system parameters at which the system has a steady-state with a high degree of stability using an optimization methodite{KY2013}. We extend the method with a matrix inequalityite{O2013} to enable us to treat non-periodic points of the system by using the local expansion rates as the stability index. We illustrate that the method can be applicable to the control of system parameters for the purpose of avoiding chaos. (Keyword) Robust bifurcation analysis / Matrix inequality / Non-periodic point / Local expansion rates
40.	Mio Kobayashi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Avoidance of chaotic state using method based on robust bifurcation analysis, Proceedings of the 2014 IEICE General Conference, SS61-SS62, Mar. 2014. (Summary) ロバスト分岐解析とは，数理モデル系にみられる極限集合に安定度を定義し，環境変化に頑健で回復力を持つシステムの構築を目的とした解析手法である．筆者等は以前に，離散力学系にみられる周期点の最大特性乗数を安定度として定義し，特性多項式に基づく非線形勾配系を用いて，安定度が高くなるよう自動的にパラメータを探索する方法を考案した．一方，最大特性乗数がパラメータに対して微分不可能となる問題を解決させるため，制御理論に基づく行列不等式アプローチが提案されている．本稿では，この手法を非周期解に拡張し，局所軌道拡大率を安定度指標とすることで，カオス状態を回避する制御が実現できることを示す．実際，提案法を Henon写像に適用し，安定度の低いカオス状態や分岐曲線近傍の周期点が自動的に回避されるパラメータ変化が求められることを例証する．
41.	Tomohiro Otsu, Ken'ichi Fujimoto, Tetsushi Ueta, Kazuyuki Aihara and Tetsuya Yoshinaga : Avoidance of Bifurcations of Stable Fixed Point Using the Maximum Lyapunov Exponent, Proceedings of the 2014 IEICE General Conference, SS49-SS50, Mar. 2014. (Summary) 動的システムにみられる極限集合の位相的性質は解軌道のリアプノフ指数によって特徴づけられる．著者らは，常差分方程式で記述される離散時間力学系において，安定な固定点・周期点の分岐回避制御問題を最大リアプノフ指数を評価関数とした最小化問題に帰着させ，環境変動等に起因するシステムパラメータ変化によって発生しうる不適切な分岐を回避するための制御系を提案し，Henon写像にみられる安定固定点・周期点の周期倍分岐回避に適用した実験結果を報告している．本稿では，その分岐回避制御系を川上写像に適用し，安定固定点の接線分岐とNeimark-Sacker分岐が回避できることを例証する．
42.	Yoshiaki Akaishi, Hitoshi Iida, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Circuit Implementation of Block Continuous-Time Reconstruction System for Computed Tomography, Proceedings of the 26th Workshop on Circuits and Systems, 293-298, Jul. 2013.
43.	Ken'ichi Fujimoto, Tetsuya Yoshinaga, Tetsushi Ueta, Hiroyuki Kitajima and Kazuyuki Aihara : Control to Avoid Bifurcations of Periodic Points Using Maximum Lyapunov Exponent, Proceedings of the 2013 IEICE General Conference, SS50-SS51, Mar. 2013. (Summary) 動的システムにみられる極限集合の位相的性質は解軌道のリアプノフ指数によって特徴づけられる．本稿では，安定な固定点・周期点の分岐回避制御問題を最大リアプノフ指数を評価関数とした最小化問題に帰着させ，環境変動等に起因するシステムパラメータ変化によって発生しうる不適切な分岐を回避するための制御系を提案する．
44.	Hiroyuki Kitajima, Ken'ichi Fujimoto, Tetsuya Yoshinaga and Kazuyuki Aihara : Robust bifurcation analysis and a calculation method, Proceedings of the 2013 IEICE General Conference, SS46-SS47, Mar. 2013. (Summary) ロバスト分岐解析とは，数理モデル系にみられる極限集合に安定度を定義し，環境変化に頑健で回復力を持つシステムの構築を目的とした解析手法である．安定度が高くなるよう系のパラメータを自動探索する原理に基き，予測を超えた環境変動や重大事故に対してもなるべく高い安定度を保つよう自己回復するレジリエントなシステムを設計できる可能性がある．系の固定点に関するロバスト分岐解析の一手法を提案し，数値例を示す．
45.	Yoshihiro Tanaka, Ken'ichi Fujimoto and Tetsuya Yoshinaga : 強度変調放射線治療計画のための離散化連続法, 日本放射線技術学会近畿部会第56回学術大会誌, 24, Jan. 2013.
46.	Yoshiaki Akaishi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : 連続法を用いた電気インピーダンス・トモグラフィ, 第35回日本生体医工学会中国四国支部大会プログラム講演抄録, 26, Oct. 2012.
47.	Kousuke Hashido, Ken'ichi Fujimoto and Tetsuya Yoshinaga : 強度変調放射線治療計画のためのスイッチト連続法, Chugoku-Shikoku Forum for Radiological Technology 2012, 77, Oct. 2012.
48.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : 高品質CT画像再構成を目的とした拡張連続法の収束性, Chugoku-Shikoku Forum for Radiological Technology 2012, 73, Oct. 2012.
49.	Kousuke Hashido, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Intensity modulated radiation therapy planning using an extended continuous method, Proceedings of the 104th Scientific Meeting of Japan Society of Medical Physics, Vol.32, No.3, 198-199, Sep. 2012.
50.	Kiyoko Tateishi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Iterative CT image reconstruction method ensuring properties of non-negative pixels and monotonic convergence, Proceedings of the 104th Scientific Meeting of Japan Society of Medical Physics, Vol.32, No.3, 269-270, Sep. 2012.
51.	Yoshihiro Tanaka, Kousuke Hashido, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Intensity modulated radiation therapy planning using iterative method as discretization of continuous method, Proceedings of the 104th Scientific Meeting of Japan Society of Medical Physics, Vol.32, No.3, 200-201, Sep. 2012.
52.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Binary tomography using an extension of continuous-time CT image reconstruction method, Proceedings of the 104th Scientific Meeting of Japan Society of Medical Physics, Vol.32, No.3, 137-138, Sep. 2012.
53.	Yoshihiro Tanaka, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Convergence of Intensity Modulated Radiation Therapy Planning as Discretization of Continuous Method, Proceedings of the 25th Workshop on Circuits and Systems, 239-244, Jul. 2012.
54.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : 連続CT画像再構成法の拡張による効果, Chugoku-Shikoku Forum for Radiological Technology 2011, 75, Nov. 2011.
55.	Tetsuya Yoshinaga : 先端数理に基づく CT 画像再構成, Oct. 2011.
56.	Kiyoko Tateishi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : 拡張連続法の離散化に基づくCT画像再構成, 第34回日本生体医工学会中国四国支部大会プログラム講演抄録, 18, Oct. 2011.
57.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : 拡張連続法を用いた少数方向投影からのCT画像再構成, 第34回日本生体医工学会中国四国支部大会プログラム講演抄録, 17, Oct. 2011.
58.	Ken'ichi Fujimoto, Mio Kobayashi and Tetsuya Yoshinaga : Discrete-Time Neuronal Network with Plastic Coupling for Dynamic Image Segmentation, Proceedings of the 24th Workshop on Circuits and Systems, 274-278, Aug. 2011.
59.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Convergence of Objective Function in Continuous-Time CT Image Reconstruction, Proceedings of the 101st Scientific Meeting of Japan Society of Medical Physics, Vol.31, No.1, 144, May 2011.
60.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : 連続CT 画像再構成法の性能評価, 医用画像情報学会平成22年度春季(第159回)大会, Feb. 2011.
61.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : 連続法を用いたCT画像再構成の特徴, Chugoku-Shikoku Forum for Radiological Technology 2010, 82, Oct. 2010.
62.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Properties of reconstructed images using a continuous method for computed tomography, 第33回日本生体医工学会中国四国支部大会プログラム講演抄録, 20, Sep. 2010.
63.	Ken'ichi Fujimoto and Tetsuya Yoshinaga : Circuit Implementation of Continuous-Time Dynamical System for Reconstructing Tomography Image, Proc. of the 25th Symposium on Biological and Physiological Engineering, 277-280, Sep. 2010.
64.	Chika Ueda, Ken'ichi Fujimoto and Tetsuya Yoshinaga : 連続CT画像再構成法の離散化に基づく逐次法, 第32回日本生体医工学会中国四国支部大会プログラム講演抄録, 17, Nov. 2009.
65.	Ken'ichi Fujimoto, Mio Musashi and Tetsuya Yoshinaga : A Trial Study on FPGA Implementation of Coupled System of Chaotic Neuron, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 19, Sep. 2009.
66.	Omar M. Abou Al-Ola, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Property of Equilibrium Existed in Continuous-Time Image Reconstruction System With Subsets for Medical Tomographic Image, Proc. of the Electronics, Information and Systems Conference Electronics, Information and Systems Society, I.E.E. of Japan, 951-956, Sep. 2009.
67.	Ken'ichi Fujimoto, Omar M. Abou Al-Ola and Tetsuya Yoshinaga : Continuous Image Reconstruction for Computed Tomography Using Electronic Circuit, Proc. of the Electronics, Information and Systems Conference Electronics, Information and Systems Society, I.E.E. of Japan, 67-72, Sep. 2009.
68.	Mio Musashi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Basin of Oscillatory Responses Observed in a Discrete-Time Chaotic Neural Network, Proc. of the Electronics, Information and Systems Conference Electronics, Information and Systems Society, I.E.E. of Japan, 941-946, Sep. 2009.
69.	Ken'ichi Fujimoto, Mio Musashi and Tetsuya Yoshinaga : Generating Out-of-Phase Oscillatory Response by Destabilizing Fixed Point Observed in Two-Coupled Chaotic Neurons, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 6, Sep. 2008.
70.	Ai Fukunaga, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Dynamical Properties of Gradient Systems for Optimizing EUD-based IMRT, The 21st Workshop on Circuits and Systems in Karuizawa, 353-358, Apr. 2008.
71.	Mio Musashi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : A Coupled System of Chaotic Neurons Generating Oscillatory Responses and its Bifurcation Phenomena, The 21st Workshop on Circuits and Systems in Karuizawa, 363-368, Apr. 2008.
72.	Tetsuya Yoshinaga, Ken'ichi Fujimoto and Mio Musashi : 領域分割とその時系列表示が可能な画像領域分割システム, 四国地区四大学発新技術説明会資料集, 49-53, Apr. 2008.
73.	Norihiko Koori, Takahito Saito, Kazuhide Kanenishi, Tetsuya Yoshinaga, Ken'ichi Fujimoto, Toshio Gotoh and Seiichi Wakaizumi : eコンテンツ開発の現状とコース管理システムMoodle, 平成19年度全学FD 徳島大学教育カンファレンス発表抄録集, 44-45, Jan. 2008. (Summary) 大学教育委員会のeコンテンツ実用化WGは，オープンコースウェアの開発と大学内におけるICTを利用した教育改善を目指して，活動している．昨年来，高大接続教育，初年次教育にはeコンテンツが有用であろうと，徳大で要望のある高大接続のための物理と生物のeコンテンツを開発してきている．また，基礎物理学の自習・演習課題のeコンテンツも作成している．これらのeコンテンツは，オープンソースのコース管理システムMoodleの元に置かれて，学生への便宜を図っている．発表では，全体的な現状についてポスターで発表する． (Keyword) eコンテンツ
74.	Takahito Saito, Norihiko Koori, Kazuhide Kanenishi, Tetsuya Yoshinaga and Ken'ichi Fujimoto : 全学共通教育におけるCMS/Moodleの活用報告, 平成19年度全学FD 徳島大学教育カンファレンス発表抄録集, 22-23, Jan. 2008. (Summary) Web環境上でeラーニングを提供する管理システム(CMS)の一つとしてフリーソフトウェアで提供されているMoodleの利用が全国的に広がりつつある．徳島大学においても，数台のサーバーが設置され，また利用講習会が開かれており，いくつかの授業で利用がスタートした．この発表では，Moodleの利用方法を解説するとともに，全学共通教育における実施状況を報告する． (Keyword) e-learning / Moodle / 全学共通教育
75.	Ken'ichi Fujimoto, Kenji Yamada and Tetsuya Yoshinaga : A Bifurcation Phenomenon Observed in Optimizing of IMRT Plan, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 12, Sep. 2007.
76.	Mio Musashi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : A Discrete-Time Coupled Model of Two Chaotic Neurons Generating Oscillatory Responses with High Order of Period, Journal of Shikoku-Section Joint Convention of the Institutes of Electrical and Related Engineers, 11, Sep. 2007.
77.	Kenji Yamada, Ken'ichi Fujimoto and Tetsuya Yoshinaga : CT における測定誤差を考慮した拡張 PMART 画像再構成力学系の解析, 日本放射線技術学会第63回総会学術大会予稿集, 150, Apr. 2007.
78.	Kenji Yamada, Ken'ichi Fujimoto and Tetsuya Yoshinaga : IMRT 最適化アルゴリズムの非線形力学系としての性質, 日本放射線技術学会第63回総会学術大会予稿集, 131, Apr. 2007.
79.	Norihiko Koori, Takahito Saito, Makoto Ohashi, Seiichi Wakaizumi, Toshio Gotoh, Tetsuya Yoshinaga and Ken'ichi Fujimoto : 2006年問題に対するeコンテンツ開発と学習環境の整備, 平成18年度全学FD 徳島大学教育カンファレンス発表抄録集, 51-52, Mar. 2007. (Summary) 昨年度，大学教育委員会の下で「2006年問題検討WG」により，高校の新指導要領に基づく教育を受けた学生に対する高大接続の在り方，具体的対応策などが検討された．その中で指摘，提案された事項の内，本年度，「eコンテンツによる初年次学生の学習支援」のプロジェクトとして，インテリジェント・ラボにおいて高校での未履修科目のeコンテンツの開発，基礎科目の自習教材，それらを提供する学習環境(CMS)の整備などを行っているので，状況を報告する．
80.	Shota Takemoto, Tetsuya Yoshinaga and Ken'ichi Fujimoto : Emission CT Image Reconstruction Using an Extended PMART, 第29回日本生体医工学会中国四国支部大会講演抄録, 29, Oct. 2006.
81.	Yoshihiro Imakura, Tetsushi Ueta and Tetsuya Yoshinaga : PMART力学系の分岐, 平成17年度電気関係学会四国支部連合大会講演論文集, Oct. 2005.
82.	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.
83.	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.
84.	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.
85.	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.
86.	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.
87.	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.
88.	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.
89.	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.
90.	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.
91.	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.
92.	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.
93.	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.
94.	小河原光正, Sumiko Tsuchihashi, 黒川美香, Yoshihiro Takegawa, Tetsuya Yoshinaga, Toshio Ohnishi, Susumu Yasuoka, 朝田完二, 中山正 and 土居裕幸 : ヒト気道トリプターゼ(HAT)の慢性気道疾患における変動, 第36回日本胸部疾患学会総会(宇都宮), Apr. 1996.
95.	Sumiko Tsuchihashi, Toshiko Terao, Toshiko Tada, 河野幸子, Yoshihiro Takegawa, Tetsuya Yoshinaga, Toshio Ohnishi, Susumu Yasuoka, 小河原光正, 中山正 and 土居裕幸 : 呼吸器系のトリプターゼに関する研究, 第36回日本胸部疾患学会総会(宇都宮), Apr. 1996.
96.	Sumiko Tsuchihashi, Tetsuya Yoshinaga, Hirofumi Yagi, 河野幸子, Yoshihiro Takegawa and Susumu Yasuoka : ブレオマイシン肺障害における肺組織と気管支肺胞洗浄液のセリンプロテアーゼ活性の変動, 第35回日本胸部疾患学会総会(名古屋), May 1995.

Et cetera, Workshop:

1.	谷川ゆかり, 川口拓之, 岡田英史, Satoru Kohno, 藤井宏之, 橋本康, Tetsuya Yoshinaga, 大川晋平 and 星詳子 : 時間分解計測を用いた生体の in vivo 光学特性計測, 第15回産総研・産技連 LS-BT合同研究発表会「ビッグデータとビッグシミュレーションによる生命医科学の未来」, Feb. 2016.
2.	谷川ゆかり, 川口拓之, 岡田英史, Satoru Kohno, 藤井宏之, 橋本康, Tetsuya Yoshinaga, 大川晋平 and 星詳子 : 時間分解計測を用いた生体の光学特性計測, つくば医工連携フォーラム, Jan. 2016.
3.	谷川ゆかり, 川口拓之, 岡田英史, Satoru Kohno, 藤井宏之, 橋本康, Tetsuya Yoshinaga, 大川晋平 and 星詳子 : バイオメディカル光イメージングにおける数理モデルと画像再構成における光学特性のin vivo計測, 産業技術総合研究所人間情報研究部門シンポジウム, Dec. 2015.
4.	Takeshi Kojima and Tetsuya Yoshinaga : Discrete tomography based on competition model, The Papers of Technical Meeting, IEE JAPAN, Nov. 2015. (Summary) We consider the problem of multi-valued discrete tomography and propose a reconstruction method of using nonlinear differential equations. The dynamical system is based on the continuous-time image reconstruction system for binary tomography and is inspired by the Lotka-Volterra competition model. Some theoretical and experimental results are presented to show the validity of solving the tomographic inverse problem. (Keyword) medical image reconstruction / inverse problem
5.	Mio Kobayashi and Tetsuya Yoshinaga : Dynamic Image Segmentation using Oscillatory Responses Observed in a Coupled System of One-dimensional Discrete-time Oscillators, IEICE Technical Report, Vol.NLP2014-53, No.2014-10, 43-48, Oct. 2014.
6.	Ken'ichi Fujimoto, Yoshiaki Akaishi, Hitoshi Iida and Tetsuya Yoshinaga : Circuit Design and Implementation of Block Continuous-Time Image Reconstruction System for Computed Tomography, The Papers of Technical Meeting, IEE JAPAN, Vol.ECT-13, 69-74, Nov. 2013. (Summary) We previously proposed a block continuous-time image-reconstruction system (block CIR system) that is described by switched ordinary differential equations. In this report, we present the design and implementation of the block CIR system to an electronic circuit. We also demonstrated that the block CIR circuit implemented to solve a preliminary CT problem worked well. (Keyword) CT image reconstruction / Optimization problem / Switched continuous-time dynamical system / Mixed analog-digital circuit
7.	Yoshihiro Tanaka, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Continuous-time method based on dose-volume constrained optimization for intensity-modulated radiation therapy treatment planning, IEICE Technical Report, Vol.114, No.258, 25-29, Jul. 2013. (Summary) The intensity-modulated radiation therapy (IMRT) plans include an optimization strategy for minimizing an objective function of radiation beam weights. In this study, we consider the concept meaning the condition that satisfies the dose-volume constraints in the IMRT planning system. For this purpose, we present a nonlinear dynamical system based on a dose-volume constrained optimization, which enables us to decrease an objective function monotonically by applying an initial-value problem for the differential equation to the IMRT inverse problems. The performance of the proposed system is confirmed by means of numerical experiments using a phantom under conditions simulating clinical radiation therapy. (Keyword) intensity-modulated radiation therapy planning / dose-volume constraints / inverse problem / stability / Kullback-Leibler divergence (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520009407074341760 (CiNii: 1520009407074341760)
8.	Yoshihiro Tanaka, Ken'ichi Fujimoto and Tetsuya Yoshinaga : A method of intensity-modulated radiation therapy planning using nonlinear dynamical system, IEICE Technical Report, Vol.113, No.147, 47-52, Jul. 2013. (Summary) The intensity-modulated radiation therapy (IMRT) plans include an optimization strategy for minimizing an objective function of radiation beam weights. Some of the authors have presented an approach to obtain a feasible solution of an objective function by applying an initial-value problem for the nonlinear differential equation to IMRT planning inverse problems. In this study, we propose a nonlinear dynamical system that a dose based objective function decreases monotonically, which is different from the conventional system. We first consider the stability of an equilibrium, which corresponds to the consistent planning in the IMRT system. Next, we confirm the performance of the proposed system for the inconsistent planning in the IMRT system by means of numerical experiments using phantom data simulating a clinical setup. (Keyword) 強度変調放射線治療計画 / inverse problem / nonlinear dynamical system / stability / Kullback Leibler divergence (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520009407091090304 (CiNii: 1520009407091090304)
9.	Munehisa Sekikawa, Sumito Fujiwara, Naohiko Inaba, Tetsuya Yoshinaga, Ken'ichi Fujimoto and Tetsuro Endo : Invariant Torus and Arnold tongue in a discrete dynamics, IEICE Technical Report, Vol.113, No.69, 39-42, May 2013.
10.	Yusaku Yamaguchi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Binary tomography using a nonlinear switched system, IEICE Technical Report, Vol.113, No.15, 13-18, Apr. 2013.
11.	Sumito Fujiwara, Naohiko Inaba, Munehisa Sekikawa, Ken'ichi Fujimoto, Tetsuya Yoshinaga and Tetsuro Endo : Bifurcation boundary between 2-torus and 3-torus, IEICE Technical Report, Vol.112, No.487, 77-80, Mar. 2013.
12.	Ken'ichi Fujimoto, Tomohiro Otsu, Daisuke Ito, Tetsushi Ueta and Tetsuya Yoshinaga : Evaluation and comparison of controlling costs on controlling chaos, IEICE Technical Report, Vol.112, No.301, 1-6, Nov. 2012. (Summary) OGY and delayed-feedback methods proposed at the beginning of 1990s are well known as the original methods of controlling chaos. One of the authors et al. also proposed a method of controlling chaos using Poincare map and linear control theory. All the methods can stabilize unstable periodic motions by making small perturbations of available system parameters. However, from the viewpoint of controlling energy needed to stabilize such motions, to evaluate the amount of required parameter perturbations has not been reported as far as the authors know. In this report, using three indices based on state variables, control input, and electric power (i.e. energy), we evaluated controlling costs to stabilize an unstable periodic motion observed in a continuous-time dynamical system such that the amount of parameter perturbations can be converted to electric power.
13.	Ken'ichi Fujimoto, Yusaku Yamaguchi and Tetsuya Yoshinaga : Circuit Design of Block Continuous-Time Image Reconstruction System for Computed Tomography, The Papers of Technical Meeting, IEE JAPAN, Vol.ECT-11, 9-14, Nov. 2011.
14.	Mio Kobayashi, Masayoshi Fujiwara, Ken'ichi Fujimoto, Tetsuya Yoshinaga and Kazuyuki Aihara : Bifurcation and Chaotic Phenomena in Discrete-Time Star-Coupled Oscillatiors, IEICE Technical Report, Vol.111, No.276, 1-5, Nov. 2011.
15.	Mio Kobayashi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Analysis of synchronization in a discrete-time coupled neuronal system, IEICE Technical Report, Vol.111, No.62, 79-84, May 2011.
16.	Kousuke Hashido, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Continuous-Time Planning System for Intensity Modulated Radiation Therapy, IEICE Technical Report, Vol.111, No.62, 105-110, May 2011.
17.	Munehisa Sekikawa, Naohiko Inaba, Tetsuya Yoshinaga and Kazuyuki Aihara : Remarkable resemblances between two pair of stable and saddle canards, IEICE Technical Report, Vol.110, No.165, 39-42, Jul. 2010.
18.	Masayoshi Fujiwara, Mio Musashi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Bifurcation of oscillatory responses observed in a three-coupled system of discrete-time neurons, IEICE Technical Report, Vol.110, No.165, 123-128, Jul. 2010.
19.	Chika Ueda, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Property of an iterative method based on discretization of continuous-time image reconstruction for computed tomography, IEICE Technical Report, Vol.110, No.165, 5-9, Jul. 2010.
20.	Naohiko Inaba, Munehisa Sekikawa, Tetsuya Yoshinaga, Ken'ichi Fujimoto, Takashi Tsubouchi and Tetsuro Endo : Experimental Study of Mixed-Mode Oscillations in a Slow-Fast Dynamical Circuit, IEICE Technical Report, Vol.110, No.165, 35-38, Jul. 2010.
21.	Naohiko Inaba, Tetsuya Yoshinaga, Ken'ichi Fujimoto, Takashi Tsubouchi and Tetsuro Endo : Breakdown of Mixed-Mode Oscillations in a Slow-Fast Dynamical System, IEICE Technical Report, Vol.109, No.458, 43-46, Mar. 2010.
22.	Mio Musashi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Bifurcation and Basin of Oscillatory Responses Observed in a Discrete-Time Chaotic Neural Network, IEICE Technical Report, Vol.109, No.167, 65-70, Jul. 2009.
23.	Ken'ichi Fujimoto, Mio Musashi and Tetsuya Yoshinaga : Multi-Scaling of Gray Level Image and its Dynamic Image Segmentation Using Discrete-time Dynamical Systems, IEICE Technical Report, Vol.109, No.167, 49-52, Jul. 2009.
24.	Ken'ichi Fujimoto, Omar M. Abou Al-Ola and Tetsuya Yoshinaga : Continuous-Time Dynamical System for Reconstructing Computed Tomography Image, IEICE Technical Report, Vol.108, No.477, 41-46, Mar. 2009.
25.	Mio Musashi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Bifurcations in Discrete-Time Coupled Chaotic Neurons Generating Oscillatory Responses with High Order of Period, Part II, IEICE Technical Report, Vol.108, No.174, 27-31, Jul. 2008.
26.	Mio Musashi, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Bifurcations in Discrete-Time Coupled Chaotic Neurons Generating Oscillatory Responses with High Order of Period, IEICE Technical Report, Vol.107, No.265, 1-6, Oct. 2007.
27.	Ken'ichi Fujimoto, Kenji Yamada and Tetsuya Yoshinaga : A Study of Diagonal Newton's Method for Optimizing EUD-Based IMRT Plans, IEICE Technical Report, Vol.107, No.154, 59-62, Jul. 2007.
28.	Kenji Yamada, Ken'ichi Fujimoto and Tetsuya Yoshinaga : Bifurcations in an Extended PMART With Noisy Pro jection Data for CT Image Reconstruction, IEICE Technical Report, Vol.106, No.452, 73-78, Jan. 2007.
29.	Ken'ichi Fujimoto and Tetsuya Yoshinaga : Dynamical Property of an Iterative Optimization Method for Intensity Modulated Radiation Therapy, IEICE Technical Report, Vol.106, No.452, 17-21, Jan. 2007.
30.	Ken'ichi Fujimoto and Tetsuya Yoshinaga : Periodic Oscillations Observed in a Synaptic Coupled Oscillator Network for Image Segmentation, IEICE Technical Report, Vol.106, No.272, 7-11, Oct. 2006.
31.	Yoshihiro Imakura, Tetsushi Ueta and Tetsuya Yoshinaga : Estimating Suitable Parameter of Dynamical System Defined by PMART with Eigenvalue, IEICE Technical Report, Vol.NLP2005, No.106, 49-54, Jan. 2006.
32.	Tetsuya Yoshinaga : はじめよう，eラーニング授業∼目的に合ったLMSの選択とウェブ教材の作成∼, Jan. 2006.
33.	Tetsuya Yoshinaga and Ken'ichi Fujimoto : Dynamical Property of Periodic Oscillations Observed in a Coupled Oscillator Network for Image Segmentation, The Papers of Technical Meeting, IEE JAPAN, Vol.ECT-05, 51-55, Nov. 2005.
34.	Megumi Matsushita and Tetsuya Yoshinaga : Properties of an Extended PMART for CT Image Reconstruction as a Nonlinear Dynamical System, IEICE Technical Report, Vol.105, 33-36, Oct. 2005.
35.	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.
36.	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.
37.	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.
38.	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.
39.	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.
40.	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.
41.	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.
42.	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.
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.	Munehisa Sekikawa, Naohiko Inaba and Tetsuya Yoshinaga : 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.NLP2001-54, 7-12, Nov. 2001.
45.	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.
46.	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.
47.	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.
48.	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.
49.	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.
50.	Hiroo Sekiya, Tetsuya Yoshinaga, Seiichiro Moro, Shinsaku Mori and Iwao Sasase : 4個の3次元発振器の結合系に生じる非同相同期現象, IEICE Technical Report, Vol.NLP99-104, 9-16, Jul. 1999.
51.	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.
52.	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.
53.	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.
54.	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.
55.	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.
56.	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.
57.	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.
58.	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.
59.	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.
60.	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.
61.	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.
62.	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.
63.	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.
64.	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.

Report:

1.	Norihiko Koori, Takahito Saito, Makoto Ohashi, 若泉誠一, 後藤寿夫, Tetsuya Yoshinaga and Ken'ichi Fujimoto : 高大接続eコンテンツ開発プロジェクト「eコンテンツによる初年次学生の学習支援」報告, Journal of University Education Research, No.4, 48-54, Tokushima, Mar. 2007. (Keyword) 全学共通教育 / 学習支援 / eコンテンツ (Tokushima University Institutional Repository) ● Metadata: 82398 (Tokushima University Institutional Repository: 82398)
2.	Tetsuya Yoshinaga : 非線形力学系理論に基づく代数的CT画像再構成の高速化, 平成14∼15年度科学研究費補助金(基盤研究(C)(2))研究成果報告書, Tokushima, Mar. 2004.
3.	Hiroshi Kawakami, Tetsuya Yoshinaga and Tetsushi Ueta : Nonlinear Science Laboratory, Supplemental report of Kaken, Tokushima, Feb. 2002.
4.	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.
5.	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.	Tetsuya Yoshinaga and Ken'ichi Fujimoto : 強度変調放射線治療計画装置，強度変調放射線照射装置の放射線ビーム係数演算方法，強度変調放射線治療計画プログラム及びコンピュータで読み取り可能な記録媒体並びに記録した機器, 2012-166589 (Jul. 2012), 2014-23741 (Feb. 2014), .
2.	Tetsuya Yoshinaga and Ken'ichi Fujimoto : CT装置，CT装置における画像再構成方法，及び電子回路部品, 2008-317758 (Dec. 2008), 2010-136958 (Jun. 2010), 5493072 (Mar. 2014).
3.	Tetsuya Yoshinaga, Ken'ichi Fujimoto and Mio Musashi : 動的画像領域分割方法，動的画像領域分割装置，および動的画像領域分割プログラム, 2008-054151 (Mar. 2008), 2009-211439 (Sep. 2009), .

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

可変線量制約法を用いた高精度強度変調放射線治療計画法の開発 (Project/Area Number: 24K07507 )
多目的線量体積制約に基づく動的強度変調放射線治療計画法の開発 (Project/Area Number: 21K04080 )
Development of intensity-modulated radiation therapy treatment planning by actively utilizing nonlinear dynamics (Project/Area Number: 18K04169 )
Development of intensity-modulated radiation therapy treatment planning based on dose-volume constraints (Project/Area Number: 15K06110 )
Development of a continuous-time method for intensity-modulated radiation therapy treatment planning (Project/Area Number: 24560522 )
Regulatory Network for Expression of Antibiotic Tolerance in Pseudomonas aeruginosa (Project/Area Number: 21590627 )
Development of Continuous-Time Dynamical Reconstruction Method for High-Quality CT Image (Project/Area Number: 21560449 )
Development of fast image reconstruction technique for CT image using active nonlinear dynamics of iterative method (Project/Area Number: 18560412 )
Construction and Bifurcation Analysis in a Mathematical Model for Circadian Oscillations of Clock Genes (Project/Area Number: 16500132 )
A Fast Iterative Method with Algebraic CT Image Reconstruction Technique Based on Dynamical System Theory (Project/Area Number: 14550420 )
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 )
The development of techniques for easing pains of delivery by the quantitative measurement of pain (Project/Area Number: 07672527 )
核磁気共鳴画像の撮像中に生じた被写体の動きによる偽像を除去する方法の開発 (Project/Area Number: 06858095 )
Analysis of Coupled Oscillator Networks and Application to Chemical Reaction Oscillations and Biological Rhythms (Project/Area Number: 03805028 )
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Professor : Yoshinaga, Tetsuya

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