著者

Sergey V. Dmitriev

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.8, no.2, pp.85-97, 2017 (Released:2017-04-01)

参考文献数

39

被引用文献数

1 2

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It has been rigorously proved that nonlinear lattices can support spatially localized and periodic in time vibrational modes called either discrete breathers (DBs) or intrinsic localized modes (ILMs). DB does not radiate its energy because its frequency does not belong to the spectrum of small-amplitude running waves. Discreteness and nonlinearity are often said to be the two major necessary conditions for the existence of DBs. Interatomic interactions are nonlinear and the discovery of DBs in crystals, which are nonlinear lattices at the atomic scale, was just a question of time. The first successful attempt to excite DB in alkali-halide NaI crystal in molecular dynamics simulations dates back to 1997. However, the first report on DBs in pure metals was delayed till 2011. In this review we discuss the reason of this delay, describe the latest results on DBs in pure metals and ordered alloys, and outline the open problems in this area.

著者

Timothée Leleu Timothée Levi Takashi Kohno Kazuyuki Aihara

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.9, no.2, pp.281-294, 2018 (Released:2018-04-01)

参考文献数

26

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Reconstructing accurately the structure of neural networks from biological data is essential for the analysis of simultaneous recordings from many neurons, and, in turn, for the understanding of neural codes and the design of neural prostheses. Classical techniques are generally based on cross-correlations and cannot reconstruct unambiguously the network structure. Recently, we have proposed a method for which there is one-to-one correspondence between statistical properties of packets of spikes (or avalanches) and the network structure, but this mapping was only proven for simpler neuronal model. In the following, we show using numerical simulation of the Izhikevich model that the proposed method is general, and is particularly well-fitted for the analysis of neural activity recorded from cultured neuronal networks coupled to microelectrode arrays.

著者

Kaori Kuroda Hiroki Kato Song-Ju Kim Makoto Naruse Mikio Hasegawa

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.9, no.1, pp.74-81, 2018 (Released:2018-01-01)

参考文献数

10

被引用文献数

23

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Recently, various mobile communication systems have been widely deployed, and mobile traffic is increasing. However, the bandwidth available for mobile communications is limited, hence the scarcity of radio resources in mobile communications is a serious problem. As an approach to solve this problem, cognitive wireless communication models have been proposed. These model search for vacant time slots in multi-channel wireless communication systems. Although previous studies have shown that frequency utilization efficiency can be improved by multi-armed bandit algorithms, channels are assumed to be independent. However, channels used in 2.4 GHz wireless LANs (such as IEEE802.11b or IEEE802.11g) are not independent because these channels overlap with adjacent channels. In this paper, we propose an extended multi-armed bandit algorithm that uses continuous-valued rewards, which is applicable to wireless communication systems with overlapping channels. We show the effectiveness of the proposed method by experimental demonstrations.

著者

Koji Iwayama Yoshito Hirata Hideyuki Suzuki Kazuyuki Aihara

出版者

一般社団法人 電子情報通信学会

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.4, no.2, pp.160-171, 2013 (Released:2013-04-01)

参考文献数

40

被引用文献数

2 6

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Change-point detection based on an observed time series has emerged as an important method for detecting changes in dynamics of real-world systems. Recently, recurrence networks have been shown to be useful, which are network representations of recurrences, to analyze underlying dynamics. In this paper, we propose a new method for detecting dynamical changes using recurrence networks. The proposed method extracts a group of time indices that share the same dynamics as a community of the recurrence network. In addition, some numerical simulations are presented to verify the validity of this method.

著者

Yuichi Togashi

出版者

一般社団法人 電子情報通信学会

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.7, no.2, pp.190-201, 2016 (Released:2016-04-01)

参考文献数

38

被引用文献数

2

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Owing to recent progress in structural biology, the structures of a number of proteins have been resolved and deposited into databases such as the Protein Data Bank (PDB). Many proteins function as molecular machines or show allosteric effects, which require integrated communication between different parts of the protein structure;however, the general principles underlying such communication are not yet clear. All-atom molecular dynamics simulation is a powerful tool for tracking molecular motion, but is still far too computationally costly to be applied widely. In this paper, we present a simple method for assessing the properties of mechanical communications using coarse-grained steered molecular dynamics simulations with elastic network models. The method was tested by screening for a certain mechanical property among protein structures in the PDB.

著者

Ikkyu Aihara Yasufumi Yamada Emyo Fujioka Shizuko Hiryu

出版者

一般社団法人 電子情報通信学会

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.6, no.2, pp.313-328, 2015 (Released:2015-04-01)

参考文献数

14

被引用文献数

3

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A mathematical model is proposed to describe the nonlinear dynamics of the echolocation behavior of a bat during free flight in an enclosed chamber. In the model, a bat dynamically controls its flight and pulse directions (φf and φp respectively), to avoid collision with multiple walls of the chamber; namely, the bat varies φf and φp repulsively from the closest wall, minimizing the difference between φf and φp. Numerical simulation of the model with specific parameter values demonstrates that the bat can successfully fly in the chamber while emitting pulses along the inner periphery of an eight-shaped flight path, which is consistent with the results of a behavioral experiment conducted by using a Japanese house bat (Pipistrellus abramus).

著者

Naoyuki Kizaki Hiroshi Yoshino Hiroaki Kurokawa

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.6, no.2, pp.226-236, 2015 (Released:2015-04-01)

参考文献数

19

被引用文献数

1 2

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The regulatory interactions among genes are summarized by the gene regulatory network. Recently, the gene regulatory network that is described by the differential equations is widely used, and a lot of inference methods using time course data of the gene expression levels have been proposed. One of the successful inference methods of the gene regulatory network is the method using the neural network. In this study, as a method to improve a performance of the gene regulatory network inference using the neural networks, we propose the method to apply a kind of majority rule to the conventional method. Our proposed method infers the regulatory interactions in the gene network based on the results of a lot of trials of the inference using neural networks. In the simulations, we evaluate our proposed method using artificially defined gene regulatory networks. The results show the validity of the proposed method. The results also suggest that the strategy of the proposed method is applicable to various methods using the heuristic solver.

著者

Shinji Nakaoka

出版者

一般社団法人 電子情報通信学会

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.6, no.1, pp.54-70, 2015 (Released:2015-01-01)

参考文献数

34

被引用文献数

1 3 3

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Immunotherapy for cancer is a forthcoming therapeutic option in cancer treatment. A variety of approaches, including adoptive cell transfer, adjuvant therapy, and monoclonal antibody therapy, are currently used as complementary or alternative cancer treatments. Since immunity against tumors is established as a result of complex interactions among tumors and immune cells, a theoretical framework to elucidate the dynamics of tumor killing by immune cells initiated by clinical intervention needs to be developed. We construct a simple mathematical model that describes the killing of tumors by T cells. We focus on a mathematical characterization of the effect of adoptive cell transfer therapy, the injection of a patient's own ex vivo activated T cells to initiate tumor immunity. On the basis of rigorous mathematical analyses and numerical computations, we provide biological interpretations for the possible outcomes of adoptive cell transfer under three different scenarios in terms of proliferation. In our modeling framework, adoptive cell transfer therapy can be understood as a driving force that potentially operates to shift the state of an immune response from inactive to active. On the other hand, our modeling framework suggests the possibility that a tumor can exploit a self-augmenting proliferation of T cells mediated by autocrine/paracrine signaling as an escape strategy from an immune response.

著者

Hisashi Kada Hiromasa Hojyo Isao T. Tokuda

出版者

一般社団法人 電子情報通信学会

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.5, no.4, pp.466-475, 2014 (Released:2014-10-01)

参考文献数

24

被引用文献数

3

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Because of an increasing demand on electric power and limited resources for conventional fuels, highly efficient engine that is capable of converting energy resource to electric power with a small loss is awaited. In this respect, Stirling engine provides a strong potential because of its efficient thermodynamic cycle, which is ideally close to the theoretical limit of the Carnot cycle. Practical use of the Stirling engine, however, has been limited because of its low output power. Towards its wider applicability, simultaneous operation of many individual Stirling engines is indispensable to increase the output power. This paper presents an experimental study of synchronized dynamics of two coupled Stirling engines. It is shown that the synchronized operation of the population of engines provides a key technology to extend the system size so as to produce a large-scale electric energy.