著者

Ryo Shirai Naoki Aoshima Keiji Wada

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Communications Express (ISSN:21870136)

巻号頁・発行日

vol.11, no.9, pp.566-570, 2022-09-01 (Released:2022-09-01)

参考文献数

7

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This paper proposes a platform for electromagnetic interference on Ethernet communication devices due to conducted noise from power conversion circuits, focusing on the electromagnetic near-field coupling between the DC bus and the communication line. The waveforms measured on the platform during switching transients reveal the mechanism of communication failure. The Ethernet performance evaluation by a network protocol analyzer shows that the converter switching frequency impacts the communication error rate.

著者

Tomokazu Okugi Kan Okubo

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Communications Express (ISSN:21870136)

巻号頁・発行日

vol.11, no.4, pp.165-170, 2022-04-01 (Released:2022-04-01)

参考文献数

6

被引用文献数

1

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The propagation analysis of an automotive radar using the finite-difference time-domain (FDTD) method uses tens of billions of analysis cells, and the simulation time is several days to several weeks. This study developed a method of accelerating the FDTD simulation for automotive radar analysis using a cluster-type supercomputer with multiple GPUs. An analysis region was divided into blocks, which were allocated to GPUs. The start time of the operation of each GPU was controlled according to radio wave propagation from a radiation antenna. The proposed method reduced the total simulation time by approximately 34% compared to a conventional method.

著者

小林 和央 風間 一洋 吉田 光男 大向 一輝 佐藤 翔 桂井 麻里衣

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:18804535)

巻号頁・発行日

vol.J105-D, no.5, pp.310-321, 2022-05-01

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本論文では,オルトメトリクスで用いられる論文評価指標の時系列ベクトル表現から検知したバーストの有無や期間・回数などのバースト特性から,多様なユーザによって生み出された論文の評価について多面的に分析する.実際に,2年間のソーシャルメディアの論文言及データから論文言及人数,CiNii Articlesの検索ログから論文閲覧人数を求め,それらの時系列変化から言及バーストと閲覧バーストを検知した.次に,論文とそのバースト特性の関係を,言及バーストと閲覧バーストの対応,閲覧人数の順位,論文の書誌情報,検索語,時系列変化を用いて分析した.その結果,閲覧人数では特定の専門分野の研究者や学生向けよりも,ソーシャルメディア上の情報拡散の影響を強く受けた一般的なユーザ向けの論文がより上位にくることと,ソーシャルメディアの情報拡散と学術イベントが引き起こすバースト特性は異なることがわかった.最後に,バースト特性を用いて,ユーザ属性に応じた学術情報検索を実現する可能性について検討する.

著者

Tomoyuki Sasaki Hidehiro Nakano

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.13, no.2, pp.170-195, 2022 (Released:2022-04-01)

参考文献数

37

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Swarm intelligence (SI) algorithms have been studied in solving real-world optimization problems called black-box optimization problems. Typical features of SI algorithms are: (1) being a population-based metaheuristics; (2) using fitness values of a given objective function; and (3) having very simple search rules which search agents follow. As such, SI algorithms have been applied to various black-box optimization problems. Particle swarm optimization is one of powerful SI algorithms, in which a swarm consists of plural particles as solution candidates. Particles directly fly a search space and share their own information each other, and thus PSO can find good quality of solutions. However, a PSO swarm is easily stuck in solving optimization problems whose search space is high-dimensional and complicated. In order to solve such problems, large numbers of particles and reference frame invariance are needed for PSO algorithms. Herein, we suggest a piecewise-linear particle swarm optimizer (PPSO) which is a deterministic PSO. PPSO has two simple search modes switched to another mode dynamically, whose search dynamics are complex. As such, PPSO algorithm can be implemented on hardware with low hardware costs because PPSO algorithm must not require many random number generators. In addition, PPSO algorithm can find a good quality of solution in solving complex optimization problems. We studied search performances of PPSO compared to PSO algorithms and provide theoretical analysis of reference frame invariance for PPSO. In order to verify search performances and theoretical analysis, we performed numerical simulations.

著者

Yota Tsukamoto Honami Tsushima Tohru Ikeguchi

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.13, no.2, pp.367-372, 2022 (Released:2022-04-01)

参考文献数

9

被引用文献数

3

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In the field of neuroscience, it is widely acknowledged that neurons exhibit periodic, quasi-periodic, and chaotic responses to periodic inputs. In this study, we evaluated the responses of the Izhikevich neuron model stimulated by sinusoidal inputs. First, we analyzed the dynamical behavior of the Izhikevich neuron model to the sinusoidal inputs in the state space and found two types of responses: periodic and non-periodic. Next, we obtained the domains of the periodic and non-periodic responses on the frequency-amplitude plane of the sinusoidal inputs by evaluating the diversity index of the inter-spike intervals. Finally, we analyzed the responses of the Izhikevich neuron model using the stroboscopic plot. Consequently, we clarified that a periodic response is a limit cycle and an irregular response is a torus, which implies that the irregular responses of the Izhikevich neuron model stimulated by sinusoidal inputs are quasi-periodic responses.

著者

岩本 孝太 坂本 雅弥 岩城 昴琉 黒木 太司

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 C (ISSN:13452827)

巻号頁・発行日

vol.J105-C, no.3, pp.81-86, 2022-03-01

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農業人口の高齢化に伴いスマート農業システムの概念が提唱されており,高齢農業者が手探りで土中農作物を収穫している現状にあっては,新しい土中生育農作物探知機の導入が望まれている.とりわけ土中で収穫されたタケノコは酸化などによるえぐみが無く,生の状態で食することができることから市場では高額で取引される.そこで本論では低価格で実現可能な土中タケノコ探知機の試作を目的として,タケノコの実,皮,及びタケノコ農園の土壌の複素誘電率をUHF帯で測定し,その結果をもとに共振型電極を用いて地表から5 cm程度に生育するタケノコの探知を理論・実験両面から検討することによりその可能性を示した.

著者

山元 翔 橋本 拓也 神戸 健寛 吉田 裕太 前田 一誠 平嶋 宗

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 D (ISSN:18804535)

巻号頁・発行日

vol.J99-D, no.2, pp.232-235, 2016-02-01

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筆者らはこれまでに,1回の加減で解決できる算数文章題を対象として,三文構成モデルによる作問学習支援システムを開発している.本研究では,システムを小学校2年生で学習する乗算の領域へと拡張するものであり,システムの拡張から1クラス9時限の実践利用までを行ったので,報告する.結果としては,システムを利用することで問題解決能力はあっても,構造の理解が浅い学習者に対して,構造理解を深められることを示唆する結果が得られた.

著者

Yosuke MUKASA Tomoya WAKAIZUMI Shu TANAKA Nozomu TOGAWA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E104-D, no.10, pp.1592-1600, 2021-10-01

被引用文献数

5

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In an amusement park, an attraction-visiting route considering the waiting time and traveling time improves visitors' satisfaction and experience. We focus on Ising machines to solve the problem, which are recently expected to solve combinatorial optimization problems at high speed by mapping the problems to Ising models or quadratic unconstrained binary optimization (QUBO) models. We propose a mapping of the visiting-route recommendation problem in amusement parks to a QUBO model for solving it using Ising machines. By using an actual Ising machine, we could obtain feasible solutions one order of magnitude faster with almost the same accuracy as the simulated annealing method for the visiting-route recommendation problem.

著者

Sho TSUGAWA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Communications (ISSN:09168516)

巻号頁・発行日

vol.E102-B, no.1, pp.17-39, 2019-01-01

被引用文献数

16

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Socially aware networking is an emerging research field that aims to improve the current networking technologies and realize novel network services by applying social network analysis (SNA) techniques. Conducting socially aware networking studies requires knowledge of both SNA and communication networking, but it is not easy for communication networking researchers who are unfamiliar with SNA to obtain comprehensive knowledge of SNA due to its interdisciplinary nature. This paper therefore aims to fill the knowledge gap for networking researchers who are interested in socially aware networking but are not familiar with SNA. This paper surveys three types of important SNA techniques for socially aware networking: identification of influential nodes, link prediction, and community detection. Then, this paper introduces how SNA techniques are used in socially aware networking and discusses research trends in socially aware networking.

著者

山中 直明 西村 光弘 石黒 正揮 岡崎 義勝 川西 哲也 釣谷 剛宏 中尾 彰宏 原井 洋明 廣岡 俊彦 古川 英昭 宮澤 雅典 山本 直克 吉野 修一

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 B (ISSN:13444697)

巻号頁・発行日

vol.J104-B, no.3, pp.315-336, 2021-03-01

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2020年に我が国でも5G商用サービスが本格開始され,2021年の東京オリンピック・パラリンピックでは,5Gを応用したサービスのトライアルが行われる.一方,同時に将来の技術やニーズを先取りしたBeyond 5G/6Gの研究開発スタートの年となる.Beyond 5G/6Gを検討する際は,将来を予想して必要となるサービスを左手とするならば,ブレークスルーにより発展する基盤技術を右手として,それらを融合するネットワークアーキテクチャを面的に考え,同時に時間軸のステップを考える必要がある.そのため,総務省が主体となり「Beyond 5G時代の有線ネットワーク検討会」を発足させ,キャリア,国立研究機関,アカデミアに加え,本分野の代表的な電子情報通信学会研究専門委員会の委員長,コンソーシアムの主導者にも参加頂き,Beyond 5Gのオーバービューとブレークスルー技術等の取りまとめを行った.本論文では,そこで取りまとめた「ネットワークビジョン2030」を電子情報通信学会の多くの読者,研究者に提供することにより,自らのビジネスや研究へのヒントを得ると同時に,各分野の最新動向をフィードバック頂くことで,常に最新のビジョンへブラッシュアップすることを目指し,執筆を行った.

著者

Kensho HARA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)

巻号頁・発行日

pp.2020IMP0012, (Released:2020-12-07)

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The performance of video action recognition has improved significantly in recent decades. Current recognition approaches mainly utilize convolutional neural networks to acquire video feature representations. In addition to the spatial information of video frames, temporal information such as motions and changes is important for recognizing videos. Therefore, the use of convolutions in a spatiotemporal three-dimensional (3D) space for representing spatiotemporal features has garnered significant attention. Herein, we introduce recent advances in 3D convolutions for video action recognition.

著者

Ryohei Nakamura Hisaya Hadama

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Communications Express (ISSN:21870136)

巻号頁・発行日

vol.6, no.9, pp.530-534, 2017 (Released:2017-09-01)

参考文献数

8

被引用文献数

6 26

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This letter proposes to use an ultra-wideband (UWB) radar for drone detection and experimentally investigates feasibility of the proposal. First, the radar cross section (RCS) of a typical quadrotor drone is clarified. Next, radar range profiles of a flying drone are discussed. As a result, we have confirmed that an UWB radar with high range resolution can detect a drone and observed a unique feature of the echoes reflected from the drone’s rotor blades. The feature will enable us to distinguish a drone from other flying objects.

著者

Hironori KIYA Katsuki OHTO Hirotaka ONO

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)

巻号頁・発行日

pp.2020DMP0026, (Released:2021-02-10)

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DAIHINMIN, which means Grand Pauper, is a popular playing-card game in Japan. TANHINMIN is a simplified variant of DAIHINMIN, which was proposed by Nishino in 2007 in order to investigate the mathematical properties of DAIHINMIN. In this paper, we consider a 2-player generalized TANHINMIN, where the deck size is arbitrary n. We present a linear-time algorithm that determines which player has a winning strategy after all cards are distributed to the players.

著者

Kunihiro OGATA Tomoki MITA Takeshi SHIMIZU Nobuya YAMASAKI

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Transactions on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E98.D, no.11, pp.1916-1922, 2015-11-01 (Released:2015-11-01)

参考文献数

19

被引用文献数

5

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Some unilateral lower-limb amputees, have through continued exertion, increase the foot reaction force of the sound leg. The asymmetric gait with a prosthetic leg may thus negatively affect the musculoskeletal health of the leg on the healthy side. Therefore, it is important for these amputees to learn how to adjust the balance of each foot load in training. The aim of this study is to develop a training support system visualizing floor-reaction forces using a color-depth sensor. The pose of the entire body of the amputee is measured by the depth sensor, and the floor reaction force is estimated based on Zero Moment Point (ZMP), which is calculated using the center of mass of the amputee. Evaluation experiments of the proposed method were performed and they confirmed the effectiveness of the estimation method and the training with the visualization of reaction force.

著者

園田 潤 木本 智幸

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

電子情報通信学会論文誌 C (ISSN:13452827)

巻号頁・発行日

vol.J104-C, no.3, pp.60-66, 2021-03-01

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地中レーダは,地上から入射した電波が地中の誘電率差で反射することを利用して地中物体を検出する技術であり,近年劣化が社会問題化している道路や橋梁等の社会インフラの異常検出に有効な技術である.しかしながら,地中レーダで得られるレーダ画像から地中物体の材質や大きさを推定することが課題であった.本論文では,レーダ画像からの地中モデル逆推定を目的に,深層学習による画像生成手法である敵対的生成ネットワークGANを用いたモデル逆推定手法について述べる.

著者

Toshimichi Saito

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.11, no.4, pp.373-390, 2020 (Released:2020-10-01)

参考文献数

71

被引用文献数

2

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This review paper introduces piecewise linear switched dynamical systems in three topics. In the first topic of autonomous chaotic circuits, we introduce the manifold piecewise linear system and chaotic spiking oscillator. Using piecewise exact solutions and mapping procedure, we obtain rigorous proof of chaos generation. In the second topic of recurrent neural networks, we introduce the hysteresis neural network and its application to associative memories. Performing theoretical analysis based on the piecewise exact solutions, we obtain parameter conditions for guaranteed storage of any desired memories. In the third topic of multiobjective optimization problems, we introduce a two-objective problem in a piecewise linear model of switching power converter with photovoltaic input. Applying a simple multiobjective evolutionary algorithm, we clarify existence of a trade-off between the maximum input power and circuit stability.

著者

Natsuki UENO Shoichi KOYAMA Hiroshi SARUWATARI

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences (ISSN:09168508)

巻号頁・発行日

pp.2021EAP1004, (Released:2021-02-25)

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We propose a useful formulation for ill-posed inverse problems in Hilbert spaces with nonlinear clipping effects. Ill-posed inverse problems are often formulated as optimization problems, and nonlinear clipping effects may cause nonconvexity or nondifferentiability of the objective functions in the case of commonly used regularized least squares. To overcome these difficulties, we present a tractable formulation in which the objective function is convex and differentiable with respect to optimization variables, on the basis of the Bregman divergence associated with the primitive function of the clipping function. By using this formulation in combination with the representer theorem, we need only to deal with a finite-dimensional, convex, and differentiable optimization problem, which can be solved by well-established algorithms. We also show two practical examples of inverse problems where our theory can be applied, estimation of band-limited signals and time-harmonic acoustic fields, and evaluate the validity of our theory by numerical simulations.

著者

Yuki SAITO Kei AKUZAWA Kentaro TACHIBANA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Transactions on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E103.D, no.9, pp.1978-1987, 2020-09-01 (Released:2020-09-01)

参考文献数

53

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This paper presents a method for many-to-one voice conversion using phonetic posteriorgrams (PPGs) based on an adversarial training of deep neural networks (DNNs). A conventional method for many-to-one VC can learn a mapping function from input acoustic features to target acoustic features through separately trained DNN-based speech recognition and synthesis models. However, 1) the differences among speakers observed in PPGs and 2) an over-smoothing effect of generated acoustic features degrade the converted speech quality. Our method performs a domain-adversarial training of the recognition model for reducing the PPG differences. In addition, it incorporates a generative adversarial network into the training of the synthesis model for alleviating the over-smoothing effect. Unlike the conventional method, ours jointly trains the recognition and synthesis models so that they are optimized for many-to-one VC. Experimental evaluation demonstrates that the proposed method significantly improves the converted speech quality compared with conventional VC methods.

著者

Junya KOGUCHI Shinnosuke TAKAMICHI Masanori MORISE Hiroshi SARUWATARI Shigeki SAGAYAMA

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE TRANSACTIONS on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E103-D, no.12, pp.2673-2681, 2020-12-01

被引用文献数

2

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We propose a speech analysis-synthesis and deep neural network (DNN)-based text-to-speech (TTS) synthesis framework using Gaussian mixture model (GMM)-based approximation of full-band spectral envelopes. GMMs have excellent properties as acoustic features in statistic parametric speech synthesis. Each Gaussian function of a GMM fits the local resonance of the spectrum. The GMM retains the fine spectral envelope and achieve high controllability of the structure. However, since conventional speech analysis methods (i.e., GMM parameter estimation) have been formulated for a narrow-band speech, they degrade the quality of synthetic speech. Moreover, a DNN-based TTS synthesis method using GMM-based approximation has not been formulated in spite of its excellent expressive ability. Therefore, we employ peak-picking-based initialization for full-band speech analysis to provide better initialization for iterative estimation of the GMM parameters. We introduce not only prediction error of GMM parameters but also reconstruction error of the spectral envelopes as objective criteria for training DNN. Furthermore, we propose a method for multi-task learning based on minimizing these errors simultaneously. We also propose a post-filter based on variance scaling of the GMM for our framework to enhance synthetic speech. Experimental results from evaluating our framework indicated that 1) the initialization method of our framework outperformed the conventional one in the quality of analysis-synthesized speech; 2) introducing the reconstruction error in DNN training significantly improved the synthetic speech; 3) our variance-scaling-based post-filter further improved the synthetic speech.

著者

Mohammed Salah AL-RADHI Tamás Gábor CSAPÓ Géza NÉMETH

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Transactions on Information and Systems (ISSN:09168532)

巻号頁・発行日

vol.E103.D, no.5, pp.1099-1107, 2020-05-01 (Released:2020-05-01)

参考文献数

36

被引用文献数

2

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In this article, we propose a method called “continuous noise masking (cNM)” that allows eliminating residual buzziness in a continuous vocoder, i.e. of which all parameters are continuous and offers a simple and flexible speech analysis and synthesis system. Traditional parametric vocoders generally show a perceptible deterioration in the quality of the synthesized speech due to different processing algorithms. Furthermore, an inaccurate noise resynthesis (e.g. in breathiness or hoarseness) is also considered to be one of the main underlying causes of performance degradation, leading to noisy transients and temporal discontinuity in the synthesized speech. To overcome these issues, a new cNM is developed based on the phase distortion deviation in order to reduce the perceptual effect of the residual noise, allowing a proper reconstruction of noise characteristics, and model better the creaky voice segments that may happen in natural speech. To this end, the cNM is designed to keep only voice components under a condition of the cNM threshold while discarding others. We evaluate the proposed approach and compare with state-of-the-art vocoders using objective and subjective listening tests. Experimental results show that the proposed method can reduce the effect of residual noise and can reach the quality of other sophisticated approaches like STRAIGHT and log domain pulse model (PML).