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 3

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
Takeshi Fujino Takaya Kubota Mitsuru Shiozaki
出版者
一般社団法人 電子情報通信学会
雑誌
IEICE Electronics Express (ISSN:13492543)
巻号頁・発行日
vol.14, no.2, pp.20162004-20162004, 2017 (Released:2017-01-25)
参考文献数
20

Cryptosystems are widely used for achieving data confidentiality and authenticated access control. Recent cryptographic algorithms such as AES or RSA are computationally safe in the sense that it is practically impossible to reveal key information from a pair of plain and cipher texts if a key of sufficient length is used. A malicious attacker aims to reveal a key by exploiting implementation flaws in cryptographic modules. Even if there are no flaws in the software, the attacker will try to extract a secret key stored in the security hardware. The side-channel attacks (SCAs) are low cost and powerful against cryptographic hardware. The attacker exploits side-channel information such as power or electro-magnetic emission traces on the cryptographic circuits. In this paper, we will introduce the principle of SCAs and the countermeasures against SCAs.
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
1

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
植松 友彦
出版者
一般社団法人 電子情報通信学会
雑誌
電子情報通信学会 基礎・境界ソサイエティ Fundamentals Review (ISSN:18820875)
巻号頁・発行日
vol.4, no.2, pp.123-128, 2010-10-01 (Released:2010-12-01)
参考文献数
62

シャノンによる情報通信のマグナカルタ “A mathematical theory of communication” が発表されてから60年以上を経た.本稿では,シャノンが最初に創造した情報理論の枠組みについて解説した後,いつだれによって基本定理の厳密な証明がなされたか,並びに情報理論がどのような発展の経路をたどってシャノンの後にどこまで到達したかについて解説している.
著者
鳥屋尾 博 小林 準人 安藤 利和 半杭 英二
出版者
一般社団法人 電子情報通信学会
雑誌
電子情報通信学会 通信ソサイエティマガジン (ISSN:21860661)
巻号頁・発行日
vol.9, no.1, pp.27-32, 2015-06-01 (Released:2015-06-01)
参考文献数
7

小形化が進む無線機器の内部では,電磁ノイズによって生じる干渉の低減が課題となっている.メタマテリアルの一種である電磁バンドギャップ (EBG) 構造は,この電磁ノイズの放射を抑制する新たな技術として注目を集めている.本稿では,メタマテリアル技術の産業応用の例として,これまでに提案されているEBG構造の種類や原理を中心に,筆者らによるEBG構造の応用事例も含めて紹介する.更に試作機レベルでの電磁ノイズ抑制効果についても評価結果を示して解説する.
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

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
Shuhei AMAKAWA
出版者
一般社団法人 電子情報通信学会
雑誌
IEICE Transactions on Electronics (ISSN:09168524)
巻号頁・発行日
vol.E99.C, no.10, pp.1100-1112, 2016-10-01 (Released:2016-10-01)
参考文献数
79

The most commonly used scattering parameters (S parameters) are normalized to a real reference resistance, typically 50Ω. In some cases, the use of S parameters normalized to some complex reference impedance is essential or convenient. But there are different definitions of complex-referenced S parameters that are incompatible with each other and serve different purposes. To make matters worse, different simulators implement different ones and which ones are implemented is rarely properly documented. What are possible scenarios in which using the right one matters? This tutorial-style paper is meant as an informal and not overly technical exposition of some such confusing aspects of S parameters, for those who have a basic familiarity with the ordinary, real-referenced S parameters.
著者
IWAMOTO Chuzo MATSUI Yuta
出版者
一般社団法人 電子情報通信学会
雑誌
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)
巻号頁・発行日
vol.99, no.6, pp.1145-1148, 2016
被引用文献数
1

The Building puzzle is played on an N×N grid of cells. Initially, some numbers are given around the border of the grid. The object of the puzzle is to fill out blank cells such that every row and column contains the numbers 1 through N. The number written in each cell represents the height of the building. The numbers around the border indicate the number of buildings which a person can see from that direction. A shorter building behind a taller one cannot be seen by him. It is shown that deciding whether the Building puzzle has a solution is NP-complete.
著者
S. S. Gupta R. Senani
出版者
一般社団法人 電子情報通信学会
雑誌
IEICE Electronics Express (ISSN:13492543)
巻号頁・発行日
vol.1, no.16, pp.507-512, 2004 (Released:2004-11-25)
参考文献数
15
被引用文献数
10 12

Recently, the authors introduced two new second-order single-resistance-controlled oscillators (SRCO) employing four/three unity-gain cells (unity-gain voltage followers and unity-gain current followers). In this communication, a novel family of SRCOs has been presented which employ a reduced number of (only two) unity-gain cells as active elements. The workability of the new circuits has been confirmed by the SPICE simulations of their CMOS-implementable versions.
著者
Kazunori AKABANE Nobuaki MOCHIZUKI Shigeru TERUHI Mamoru KOBAYASHI Shuichi YOSHINO Masashi SHIMIZU Kazuhiro UEHARA
出版者
一般社団法人 電子情報通信学会
雑誌
IEICE Transactions on Communications (ISSN:09168516)
巻号頁・発行日
vol.E99.B, no.9, pp.1920-1929, 2016-09-01 (Released:2016-09-01)
参考文献数
27

In the near future, many sensors and terminals will be connected to the public network to provide various convenient IoT/M2M services. In order to connect many sensors to the network efficiently, wireless communication systems in the 920MHz band are seen as attractive solutions. We are focusing on the 920MHz band to research and develop high-capacity protocols that can accommodate many terminals, and low power consumption technologies for battery-driven terminals. In this paper, we describe the following three concrete wireless systems that use our proposals. (1) A physical distribution pallet management system that can handle thousands of pallet-embedded sensors and a wireless module with a battery lifetime of about ten years. (2) Water leakage monitoring system for underground pipes by using sensors and a wireless module in each valve box. (3) A wide-area and high-capacity radio relay system for smart metering services like the reading of gas meters. The radio relay system can accommodate various sensors and terminals and has large potential for providing various IoT/M2M services in conjunction with smart metering services.
著者
Rong-Long WANG Li-Qing ZHAO Xiao-Fan ZHOU
出版者
一般社団法人 電子情報通信学会
雑誌
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)
巻号頁・発行日
vol.E95.A, no.3, pp.639-645, 2012-03-01 (Released:2012-03-01)
参考文献数
24
被引用文献数
1 3

Ant Colony Optimization (ACO) is one of the most recent techniques for solving combinatorial optimization problems, and has been unexpectedly successful. Therefore, many improvements have been proposed to improve the performance of the ACO algorithm. In this paper an ant colony optimization with memory is proposed, which is applied to the classical traveling salesman problem (TSP). In the proposed algorithm, each ant searches the solution not only according to the pheromone and heuristic information but also based on the memory which is from the solution of the last iteration. A large number of simulation runs are performed, and simulation results illustrate that the proposed algorithm performs better than the compared algorithms.
著者
石浦 菜岐佐
出版者
一般社団法人 電子情報通信学会
雑誌
電子情報通信学会 基礎・境界ソサイエティ Fundamentals Review (ISSN:18820875)
巻号頁・発行日
vol.9, no.3, pp.188-196, 2016-01-01 (Released:2016-01-01)
参考文献数
21

コンパイラはソフトウェア開発の基盤ツールであり,その信頼性確保は重要な課題である.コンパイラのテストは数千本から数十万本のテストプログラムから成るテストスイートを用いて行われるが,テストの数が有限である以上,どうしても不具合の見逃しは防げず,最新のGCC やLLVM/Clang などの比較的品質が高いとされるコンパイラにも多くの不具合が報告されている.近年,ランダムに生成したプログラムによりそのような不具合を検出するコンパイラ・ファジングのツールが幾つか開発され,成果を挙げている.本稿では,これまでに開発された手法やツールの狙いや課題について概観し,今後の方向性についての所感を述べる.
著者
Takaaki DEGUCHI Yoshiaki TANIGUCHI Go HASEGAWA Yutaka NAKAMURA Norimichi UKITA Kazuhiro MATSUDA Morito MATSUOKA
出版者
一般社団法人 電子情報通信学会
雑誌
IEICE Transactions on Communications (ISSN:09168516)
巻号頁・発行日
vol.E99.B, no.2, pp.347-355, 2016-02-01 (Released:2016-02-01)
参考文献数
17
被引用文献数
1 1

In this paper, we propose a workload assignment policy for reducing power consumption by air conditioners in data centers. In the proposed policy, to reduce the air conditioner power consumption by raising the temperature set points of the air conditioners, the temperatures of all server back-planes are equalized by moving workload from the servers with the highest temperatures to the servers with the lowest temperatures. To evaluate the proposed policy, we use a computational fluid dynamics simulator for obtaining airflow and air temperature in data centers, and an air conditioner model based on experimental results from actual data center. Through evaluation, we show that the air conditioners' power consumption is reduced by 10.4% in a conventional data center. In addition, in a tandem data center proposed in our research group, the air conditioners' power consumption is reduced by 53%, and the total power consumption of the whole data center is exhibited to be reduced by 23% by reusing the exhaust heat from the servers.
著者
Ken Umeno
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.1, pp.14-20, 2016 (Released:2016-01-01)
参考文献数
11
被引用文献数
2

We consider a family of ergodic transformations on the real line R preserving Cauchy laws. A dualistic nature between the ergodic transformation and the associated transformation of the scale parameter of a Cauchy law is proven to be hold, which provides a systematic view of explicit mixing property with the ergodic transformation having the Cauchy law as the limiting distribution.