電気学会論文誌C(電子・情報・システム部門誌)
Online ISSN : 1348-8155
Print ISSN : 0385-4221
ISSN-L : 0385-4221
138 巻 , 3 号
選択された号の論文の15件中1~15を表示しています
特集:新たなセンサネットワーク社会を拓くIoT/M2M情報通信技術
特集論文
<情報通信工学>
  • 川口 貴正, 藤井 健二郎, 谷川原 誠, 久保 信明
    2018 年 138 巻 3 号 p. 193-203
    発行日: 2018/03/01
    公開日: 2018/03/01
    ジャーナル 認証あり

    Indoor Messaging System (IMES) is a seamless positioning technology in the indoor and outdoor environment, IMES signal transmitter in indoor environment broadcasts the location information instead of the GPS navigation message. A positioning system of IMES is the range-free positioning system. However, it was not easy to construct the range-free positioning system of IMES. This paper attempts to use a 1/2λ whip antenna instead of an RHCP patch antenna. Moreover, a transmission diversity method is also proposed to mitigate the influence of multipath interference. A transmitter based on this method is developed and experimentally evaluated in a practical setup The experimental results show that the proposed method can improve the availability of the cell of the IMES signal service area. These findings contribute further to development of a practical IMES transmitter and receiver.

  • 白戸 裕史, 石岡 諒汰, 村口 正弘
    2018 年 138 巻 3 号 p. 204-209
    発行日: 2018/03/01
    公開日: 2018/03/01
    ジャーナル 認証あり

    The authors propose the transmission system which uses the CAZAC equalizer in order to reduce the PAPR and enhance power added efficiency (PAE) of the transmitter PA. In this paper, we firstly show that the proposed CAZAC-OFDM signal have the same PAPR as single carrier signals theoretically, then we discuss about the spectrum design, the frame structure design and the synchronization issues assuming a WiFi-based wireless system in which the CAZAC equalizer is used. Finally, we show the effectiveness of the proposed CAZAC equalizer by computer simulations. It is confirmed that the proposed receiver performs well under both AWGN channels and fading channels. It is also demonstrated that the proposed CAZAC-OFDM shows much better BER than the conventional OFDM under the frequency selective fading channels. It may be caused by some kind of frequency diversity gain obtained inclusively in the CAZAC-OFDM.

<音声画像処理・認識>
  • 北島 利浩, 村上 エドワード, 吉元 俊輔, 黒田 嘉宏, 大城 理
    2018 年 138 巻 3 号 p. 210-220
    発行日: 2018/03/01
    公開日: 2018/03/01
    ジャーナル 認証あり

    People sensing occurs everywhere, in the Internet of Things (IoT). Cameras are being increasingly used because they provide inexpensive and effective sensing devices. However, the camera acquires the information that identifies an individual, there is a problem that the privacy of the person is invaded. Furthermore, since home appliances are increasingly being connected to the Internet via the IoT, it has become possible for user images to leak out unintentionally. With these concerns in mind, we propose a face detection method that protects user privacy by using intentionally blurred images. In this method, the presence of a human being is determined by dividing an image into several regions and then calculating the heart rate detected in each region. In our performance evaluation, the proposed method showed dominant performance results when compared with an existing face detection method, and was confirmed to be an effective method for detecting faces in both normal and blurred images. We confirmed the influence of the performance in the proposed method when changing the sharpness of the images. The proposed method also showed high accuracy position detection performance results. Furthermore, we confirmed the effectiveness of the proposed method in near-infrared images and distorted images.

論文
<生体医工学・福祉工学>
  • 浅見 直弥, 山﨑 陽一, 神山 斉己
    2018 年 138 巻 3 号 p. 221-227
    発行日: 2018/03/01
    公開日: 2018/03/01
    ジャーナル 認証あり

    Endothelial dysfunction is known to be the early stage of arteriosclerosis. The flow-mediated dilation (FMD) test is the most commonly used method to diagnose the endothelial function. The test measures the maximum vasodilation (FMD response) on the brachial artery induced by the increases in blood flow after cuff deflation on the forearm. The vessel diameter must be captured clearly with the ultrasonic probe during the test. The vasodilation is induced in response to changes in the mechanical property of the vessel wall due to the blood flow stimulation. The changes are supposed to affect the pulsatile flow, but the influence of continuous behavior of vascular property on hemodynamics has not been clarified. In this study, in order to clarify the influence of the FMD response on hemodynamics, we propose a mathematical model that can simulate hemodynamics and vasomotor responses. As a result, it was shown that vessel wall dynamics affected the pulsatile flow. This result suggests that the endothelial function can be evaluated from blood flow.

<知能,ロボティクス>
  • 井手 広康, 奥田 隆史
    2018 年 138 巻 3 号 p. 228-233
    発行日: 2018/03/01
    公開日: 2018/03/01
    ジャーナル 認証あり

    The number of bullying recognition at school is increasing every year, and it is a very serious problem in Japan. It is said that the cause of bullying is attributed to the fact that students have independent values in groups and they interact in a complicated way. In this research, we added some special agents into the agent-based model of bullying, and verified what behavioral characteristics are most effective in suppressing bullying by using multi-agent simulation. As a result, it was found that the behavioral characteristic “take the tuning action to an agent with a small number of selected values when the number of bullying candidates exceeds the threshold value, and take the tuning action to an agent who is a bullying candidate when the number of bullying candidates is less than or equal to the threshold value” of special agents is most effective in suppressing bullying.

<メディア情報,ユーザ・インタフェース>
<音声画像処理・認識>
  • 中山 仁史, 石光 俊介, 山下 公子, 石井 かおり, 葛西 一貴, 堀畑 聡
    2018 年 138 巻 3 号 p. 242-248
    発行日: 2018/03/01
    公開日: 2018/03/01
    ジャーナル 認証あり

    Oral habits are tongue protrusion in malocclusions, causing deterioration of oral functions necessary for feeding, chewing, swallowing, and vocalization. In order to realize a non-invasive measurement of the habits, we propose and experiment acoustic feature analysis to discriminate tongue habits. Compared to normal speech, tongue-protruded speech is pronounced between the frontal teeth. Therefore, the speech is emphasized at a wide-range band of frequency components due to turbulence, as can be heard in the pronunciation of consonants. In this paper, we confirm these differences in acoustic features, such as zero-crossing which can capture the characteristics of voiced and unvoiced sounds and Mel Frequency Cepstrum Coefficient (MFCC) which is a filter bank analysis for front-end processing at speech recognition. We collect samples for that focus on the differences in oral habits of subjects, and significant of acoustic features which measured from the samples are confirmed. Finally, tongue habit discrimination using k-nearest neighbor algorithm (k-NN) achieved discrimination rate of about 85 to 98% on the databases.

<情報処理・ソフトウェア>
資料
<システム・計測・制御>
研究開発レター
<電気回路・電子回路>
<情報通信工学>
部門記事
 
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