研究者詳細 - 山里　敬也

論文 - 山里　敬也

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Cooperative Transmission Scheme with Inactive Node Reactivation Condition for Solar-Powered Wireless Sensor Networks 査読有り

Ota Kentaro, Kobayashi Kentaro, Yamazato Takaya, Katayama Masaaki

2011 IEEE 22ND INTERNATIONAL SYMPOSIUM ON PERSONAL INDOOR AND MOBILE RADIO COMMUNICATIONS (PIMRC) 頁： 2384 - 2388 2011年

Cooperative transmission scheme with inactive node reactivation condition for solar-powered wireless sensor networks 査読有り

Ota K.

IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 頁： 2384 - 2388 2011年

LED Traffic Light Detection Using High-speed-camera Image Processing for Visible Light Communication 査読有り

Premachandra H. Chinthaka N., Yendo Tomohiro, Tehrani Mehrdad Panahpour, Yamazato Takaya, Okada Hiraku, Fujii Toshiaki, Tanimoto Masayuki

Information and Media Technologies 6 巻 ( 3 ) 頁： 785 - 791 2011年

掲載種別：研究論文（学術雑誌）出版者・発行元：Information and Media Technologies 編集運営会議

We propose a visible light road-to-vehicle communication system at intersections as an ITS(Intelligent Transport System) technique. In this system, the communication between a vehicle and an LED traffic light is conducted using an LED traffic light as a transmitter and an on-vehicle high-speed camera as a receiver. The LEDs in the transmitter emit light at high frequency, and those emitted light is captured by the high-speed camera for communication. Here, the luminance value of the LEDs in the transmitter should be captured in consecutive frames to achieve communication. For this purpose, first the transmitter should be found, and then it should be tracked in consecutive frames while the vehicle is moving by processing the images from the high-speed camera. In this paper, we propose new algorithms for finding and tracking the transmitter, which result in increased communication speed and data rate compared to the previous methods. Experiments using appropriate images showed the effectiveness of the proposals.

DOI： 10.11185/imt.6.785

LEDアレイ送信機追跡のための反転信号を用いた路車間可視光通信の特性改善(ITS画像処理,映像メディア,視覚及び一般) 査読有り

名倉徹, 山里敬也, 圓道知博, 藤井俊彰, 岡田啓

映像情報メディア学会技術報告 35 巻 ( 0 ) 頁： 95 - 99 2011年

掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人映像情報メディア学会

本稿ではLEDアレイを送信機に,車載高速度カメラを受信機に用いた路車間可視光通信について考える。路車間可視光通信において受信車両は走行しているため,LEDアレイ送信機をカメラで追跡しながら,送信された情報を復号する必要がある。筆者らはこれまで,反転信号を用いた信号機追跡手法を提案することでLEDアレイの追跡を実現した。本稿では,反転信号を信号機追跡だけではなく,復号にも用いることにより,雑音を軽減し誤り率特性を改善できることを示す。また,反転信号を用いることで,LEDアレイのちらつきを軽減できることを定量的に評価する。

DOI： 10.11485/itetr.35.9.0_95

LEDアレイと高速度カメラを用いた可視光通信のための優先度重畳符号化(ITS画像処理,映像メディア,視覚及び一般) 査読有り

西本早耶香, 名倉徹, 山里敬也, 圓道知博, 藤井俊彰, 岡田啓, 荒井伸太郎

映像情報メディア学会技術報告 35 巻 ( 0 ) 頁： 89 - 94 2011年

掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人映像情報メディア学会

本稿では送信機にLEDアレイ,受信機に高速度カメラを用いた可視光通信を考える.送受信機間の距離が長くなるほど受信画像の解像度が劣化する問題に対して,画像の空間周波数が劣化しにくい低周波成分に優先度の高いデータを割り当てることで,距離が長くても優先度の高いデータの取得を可能にした.その際に従来用いていたウェーブレット変換はデータを割り当てるLEDの数や配置が制限されるなど,設計の自由度が低い,そこで設計の自由度の向上を目指して,データを割り当てるLEDの配置や数に制限のない優先度重畳符号化を提案し,その特性を評価する.

DOI： 10.11485/itetr.35.9.0_89

Overlay Coding for Road-to-Vehicle Visible Light Communication using LED Array and High-Speed Camera 査読有り

Nishimoto Sayaka, Nagura Toru, Yamazato Takaya, Yendo Tomohiro, Fujii Toshiaki, Okada Hiraku, Arai Shintaro

2011 14TH INTERNATIONAL IEEE CONFERENCE ON INTELLIGENT TRANSPORTATION SYSTEMS (ITSC) 頁： 1704 - 1709 2011年

Overlay coding for road-to-vehicle visible light communication using LED array and high-speed camera 査読有り

Nishimoto S.

IEEE Conference on Intelligent Transportation Systems, Proceedings, ITSC 頁： 1704 - 1709 2011年

部分高速読み出し可能な撮像素子を用いたLED信号機の高速追尾手法の研究(ITS画像処理,映像メディア,視覚及び一般) 査読有り

前野恵太, 圓道知博, パナヒプルテヘラニメヒルダド, 藤井俊彰, 山里敬也, 岡田啓, 谷本正幸

映像情報メディア学会技術報告 35 巻 ( 0 ) 頁： 101 - 106 2011年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人映像情報メディア学会

LEDを用いた無線通信システムである可視光通信が提案されている.本研究では,送信機にLED信号機,受信機に部分高速読み出し可能な撮像素子を用いた可視光通信システムの提案を行う.その為には,先行研究で達成されなかった走行環境での送信機の追尾手法を実現することが不可欠である.本稿では,撮像素子の特性を活かした送信機の高速追尾手法についての提案を行う.

DOI： 10.11485/itetr.35.9.0_101

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TDOA UWB positioning with three receivers using known indoor features 査読有り

Kietlinski-Zaleski J.

2010 IEEE International Conference on Ultra-Wideband, ICUWB2010 - Proceedings 2 巻 2010年12月

Dynamic Bandwidth Allocation of Satellite/Terrestrial Integrated Mobile Communication System 査読有り

T. Yamazato, T. Aman, M. Katayama

IEEE Global Communications Conference 頁： CD-ROM 2010年12月

記述言語：英語

In this paper, we propose two dynamic bandwidth allocation (DBA) schemes, a game theory based DBA and a successive DBA, for satellite/terrestrial integrated mobile communication system (STICS). The game theory based DBA allocate the bandwidth according to a utility function based on a weighted demand bandwidth of both satellite and terrestrial system. The successive DBA recursively allocates an unit of bandwidth according to a weighted number of bandwidth unfilled cells of both satellite and terrestrial systems, until the total bandwidth is fulfilled. As results, both DBA outperform the conventional fixed bandwidth allocation scheme. Between two proposed DBA, the successive DBA shows better spectral improvement ratio than the game theory based DBA.

LED Traffic Light Detection Using High-speed-camera Image Processing for Visible Light Communication System, 査読有り

H. C. N. Premachandra, T. Yendo, M. P. Tehrani, T. Yamazato, H. Okada, T. Fujii, M. Tanimoto

Workshop on Picture Coding and Image Processing, PCSJ2010/IMPS2010 頁： CD-ROM 2010年12月

記述言語：英語

Intelligent transport system has been introduced to reduce traffic problems such traffic accidents and traffic congestions. In this paper, we introduce a receiver for a road to vehicle Visible Light Communication (VLC) system which is proposed as an Intelligent Transport System (ITS) technique. In this system, an on-vehicle high-speed camera is used as a receiver and an LED array is used as a transmitter. VLC is a wireless communication using luminance. Here, transmitter send information by emitting light and receiver receive them by capturing the luminance of emitting LEDs in the array(Luminance: whether each LED is on or off). For capturing the Luminance, it is necessary to find the transmitter and track it in consecutive frames. In our previous works we introduced methods for finding and tracking. In this paper, we shortly explain the proposed transmitter finding and tracking methods and then a new method is proposed for capturing the luminance of LEDs to achieve communication.

Hierarchical Encoding System for Road-to-Vehicle Communication Using LED Traffic Light 査読有り

T. Masuda, T. Yendo, T. Yamazato, H. Okada, M. P. Tehrani, T. Fujii, M. Tanimoto

Workshop on Picture Coding and Image Processing, PCSJ2010/IMPS2010 (2010-12-7) 頁： CD-ROM 2010年12月

記述言語：英語

This paper discusses the visible light road-to-vehicle communication system at intersection as one of ITS (Intelligent Transport System) technique. The communication between a vehicle and an LED traffic light is approached using an LED traffic light as a transmitter, and on-vehicle high-speed camera as a receiver. In this system, it is able to send data by blinking the LEDs of the traffic light in two dimensional patterns, and able to receive them by high-speed camera with image processing [1]. Here, we aim to conduct long-distance high-speed visible light communication. When the distance between transmitter and receiver is far, the image of the LED traffic light captured by on-vehicle high-speed camera is very small. So, if the data are put on two dimension patterns without modification, data would be mistaken, because the two dimension patterns can’t be realized correctly. To solve this problem, data are encoded hierarchically before they are lighted by the LED traffic light. This is called as hierarchical encoding that the data are assigned with each spatial frequency.

Parallel Visible Light Communication Using Visually Non-Lighting LEDs 査読有り

K. Maeno, T. Yendo, M. P. Tehrani, T. Fujii, T. Yamazato, H. Okada, M. Tanimoto

Workshop on Picture Coding and Image Processing, PCSJ2010/IMPS2010 (2010-12-7) 頁： CD-ROM 2010年12月

記述言語：英語

The proposed visible light communication method uses visually non-lighting LEDs, which enables us to communicate in different situations, e.g. using visually non- lighting tail lamps of cars or visually non-lighting traffic lights. We realize visually non-lighting LEDs by reducing luminescence energy of LEDs according to the brightness in the environment. Experimental results demonstrate that it is possible to make communication using visually non-lighting LEDs.

［奨励講演］無線センサネットワークにおけるセンサADC出力の空間的相関を利用した分散誤り訂正符号化・統合復号法招待有り

小林健太郎，山里敬也，片山正昭

電子情報通信学会技術研究報告 WBS2010-39 巻頁： 23-28 2010年12月

記述言語：日本語

無線センサネットワークでは，高い観測精度を得るために複数のセンサノードを密に配置することが多く，各ノードの観測データは空間的に相関を有する．本稿では，複数センサノードの観測値の相関を誤り訂正に利用できる統合復号法について検討を行う．提案方式は，観測値の相関をADC出力のビットレベルごとに推定して復号に利用する．さらに，ADC出力に生じるビットの繰り上がりをグレイ符号を用いて回避することで誤り訂正の性能向上を図る．屋内にて実際に測定した観測データをシミュレーションで利用し，提案方式の性能を評価する．

EXIT Analysis for MAP-based Joint Iterative Decoding of Separately Encoded Correlated Sources 査読有り

K. Kobayashi, T. Yamazato, M. Katayama

電子情報通信学会英文論文誌 E93-B 巻 ( 12 ) 頁： 3509-3513 2010年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

We develop a mathematical framework for the extrinsic information transfer (EXIT) analysis to assess the convergence behavior of maximum a posteriori (MAP)-based joint iterative decoding of correlated sources, which are separately encoded and transmitted over noisy channels. Unlike the previous work, side information about the correlation is not perfectly given at the joint decoder but is extracted from decoder output and updated in an iterative manner. The presented framework provides a convenient way to compare between schemes. We show that it allows us to easily and accurately predict joint decoding gain and turbo cliff position.

TOA UWB Positioning with Two Receivers Using Known Indoor Features 査読有り

J. Kietlinski-Zaleski, T. Yamazato, M. Katayama

電子情報通信学会英文論文誌 E93-B 巻 ( 12 ) 頁： 3624-3631 2010年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

Ultra-Wideband is an attractive technology for short range positioning, especially indoors. However, for normal Time of Arrival (ToA) positioning, at least three receivers with unblocked direct path to the transmitter are required. A requirement that is not always met. In this work, a novel algorithm for ToA positioning using only two receivers is presented. This is possible by exploiting the knowledge of some of the indoor features, namely positions of big flat reflective surfaces, for example ceiling and walls. The proposed algorithm was tested using data from a measurement campaign.

EXIT Analysis for MAP-Based Joint Iterative Decoding of Separately Encoded Correlated Sources 査読有り

Kobayashi Kentaro, Yamazato Takaya, Katayama Masaaki

IEICE TRANSACTIONS ON COMMUNICATIONS E93B 巻 ( 12 ) 頁： 3509 - 3513 2010年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人電子情報通信学会

We develop a mathematical framework for the extrinsic information transfer (EXIT) analysis to assess the convergence behavior of maximum a posteriori (MAP)-based joint iterative decoding of correlated sources, which are separately encoded and transmitted over noisy channels. Unlike the previous work, our approach focuses on the case side information about the correlation is not perfectly given at the joint decoder but is extracted from decoder output and updated in an iterative manner. The presented framework provides a convenient way to compare between schemes. We show that it allows us to easily and accurately predict joint decoding gain and turbo cliff position.

DOI： 10.1587/transcom.E93.B.3509

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Recent Advances in Satellite and Space Communications 査読有り

Bisio Igor, De Gaudenzi Riccardo, Nguyen Hung, Pavlidou Fotini-Niovi, Yamazato Takaya

JOURNAL OF COMMUNICATIONS AND NETWORKS 12 巻 ( 6 ) 頁： 523 - 528 2010年12月