嶋本 薫　教授SHIMAMOTO, Shigeru　Professor

学術論文誌

1 Jiang Liu, Zhenni Pan, and Shigeru Shimamoto, “Impact of Light Reflection on Indoor Wireless Optical CDMA Systems”,

IEEE/OSA Journal of Optical Communications and Networking, Vol. ４ , No. 12, pp. 989-996, Dec. 2012.【要約】We present a study on evaluating the effects of multipath dispersion on indoor optical code division multiple access （CDMA） systems over optical wireless communication. The indoor propagation channel model which takes multiple reflecting surfaces into account is addressed. Theoretical analysis of the pulse response of direct light and reflected light is given. The bit error rate （BER） of this system is analyzed considering reflected light, background light, avalanche photo-diode noise, thermal noise, and multi-user interference. The results prove that the BER of the system is influenced by reflected light and that the effect of reflected light is related to room size and receiver position. With an increase in the number of users, the effect of reflected light becomes stron-ger and is a significant source of inter-symbol interference. It becomes clear that when optical CDMA is used in an indoor optical wireless system, the effect of reflected light is a key issue to be considered.

2 Jiang Liu, Mianxiong Dong, Laurence T. Yang and Shigeru Shimamoto, “A subcarrier modulation based optical wireless communication system employing transmission diversity,” Journal of Super- computing, Springer Science and Business Media LLC, DOI: 10. 1007/s11227-012-0795-5, July 2012.

【要約】In this paper, we propose an optical wireless communication service for indoor environment. To seamlessly cover the target area and keep the received signal power strength at an acceptable level, we send the signal from multiple diffused optical emitters and achieve possible transmit diversity. With the proposed diversity scheme, the effective coverage range of the proposed system can be significantly enlarged with a guaranteed BER performance. Simulation results show a 13.4 m2 area can be effectively covered by two optical emitters with optical emitter spacing of 3 m and average transmit optical power of 28 dBm.

3 小林 直 , チュウ トン ウー, アルシハーブ アブドラ , 嶋本 薫 ,“定在波比を用いた人体部位形状認識に関する研究”,

IEICE Transactions on Communications （Japanese Edition）, Vol. J95-B, No. 6, pp. 742-750, Jun. 2012.【要約】近年 , ユビキタスコミュニケーションの発展とともに人体通信技術に関する研究が注目を浴びている．その使用用途も携帯端末等に組込むことで医療現場でのヘルスケアシステム , アミューズメントへの適用等多種多様である．本論文では人体通信技術を用いた人体手首の動き及び手部の形状変化識別技術の提案及び検討を行った．手首の動き識別技術では , プローブを装着した被験者の定在波比を計測し , 手首の縦方向及び横方向の動きを識別した．最初に識別を行うにあたり , 人体手部のモデル化を行い , 時間領域差分法を用いた数値計算を行った．その後 , 実験を行い , 本研究の妥当性を示し , 手首の装着箇所における違いを求めた．更に , 手首の動き識別技術の応用として , 手部の形状識別方式を提案し , 実用システムの例として , ジャンケンの識別を行い評価した．結果として , 手首の動き及び形状識別技術が実現可能であることを示した .

4 Chunxiao Li and Shigeru Shimamoto, “ETC Assisted traffic light control scheme for reducing vehicles’ CO2 emissions,”

International Journal of Managing Information Technology （IJMIT）, ISSN: 0975-5586, Vol. 4, No. 2, pp. 1-12, May 2012.

【要約】This paper presents a vehicle’s CO2 emission reduction scheme by an ETC-assisted real-time traffic light control scheme in vehicular networks. Using Electronic Toll Collection （ETC） devices, real-time road conditions can be obtained by wireless com-munication between the ETC devices and the traffic lights. A decision tree classification algorithm is used to assign the changing

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policy for the traffic lights, and then the optimal average waiting time can be calculated. Less waiting time will result in less fuel consumption and fewer CO2 emissions. Compared with the most widely used fixed time control, the ETC-assisted real- time traffic light control scheme has much better performances in reducing the average waiting time, improving non-stop passing rate, and reducing CO2 emission.

国際会議

5 Thomas Bourgeois and Shigeru Shimamoto, “Accurate Subgraph Probabilities in a Random Geometric Graph and Application to Cooperative Multihop Ad-hoc Networks”, Proc. IEEE Global Communications Conference （GLOBECOM 2012）, pp. 506-511, California, USA, 3-7 Dec. 2012.

【要約】In this paper, we propose a new model to determine subgraph probabilities in a Random Geometric Graph （RGG）. A subgraph in a RGG can be used to model various scenarios involving a given number of nodes in a multihop ad hoc network. We determine the probabilities for the two essential cases of complete subgraphs with three and four vertices, respectively, which have not yet been addressed correctly in the literature. Our theoretical results are confirmed by simulation and thus represent a significant step towards the quantitative analysis of complex scenarios, such as cooperative communications, in multi hop ad-hoc networks.

6 Jiang Liu, P.W.C. Chan, D.W.K. Ng, E.S. Lo, and Shigeru Shimamoto, “Hybrid visible light communications in Intelligent Transportation Systems with position based

services”Proc. IEEE Global Communications Conference Workshops （GLOBECOM Workshops 2012）, pp. 1254-1259, California, USA, 3-7 Dec. 2012.

【要約】This paper proposes a hybrid communication system for Intelligent Transportation System （ITS） utilizing visible light and radio communications for position-based services. The directionality of light communication is used to distribute position-based keys to vehicles such that they can extract information related only to their desired lanes. The extended coverage of radio communica-tion is used to provide stable data communication complementing the visible light communications （VLC） systems. This paper provides system models and important parameters for designing a hybrid ITS system. The system performance is evaluated by simulation, and the results demonstrate a considerable increase of the effective communication area and receivable information using the proposed hybrid ITS system compared with a VLC system.

7 Dac-Tu Ho, E.I. Grotli, Shigeru Shimamoto, T.A. Johansen,“Optimal relay path selection and cooperative communication protocol for a swarm of UAVs”

Proc. IEEE Global Communications Conference Workshops （GLOBECOM Workshops 2012）, pp. 1585-1590, California, USA, 3-7 Dec. 2012.

【要約】In many applications based on the use of unmanned aerial vehicles （UAVs）, it is possible to establish a cluster of UAVs in which each UAV knows the other vehicle’s position. Assuming that the common channel condition between any two nodes of UAVs is line-of-sight （LOS）, the time and energy consumption for data transmission on each path that connecting two nodes may be estimated by a node itself. In this paper, we use a modified Bellman-Ford algorithm to find the best selection of relay nodes in order to minimize the time and energy consumption for data transmission between any UAV node in the cluster and the UAV acting as the cluster head. This algorithm is applied with a proposed cooperative MAC protocol that is compatible with the IEEE 802.11 standard. The evaluations under data saturation conditions illustrate noticeable benefits in successful packet delivery ratio, average delay, and in particular the cost of time and energy.

8 Nan Gao, and Shigeru Shimamoto, “FDTD Simulations for Ultrasonic Communication System Employing Metal Plates”,

Proc. 31st JSST Annual Conference, JSST 2012 international conference on simulation technology, vol. 31, pp. RS1-5, Kobe, Japan, 27-28 Sep. 2012.

【要約】Nowadays, there have no identified ideas for sand digital information across conductors material, such as metal, water and so

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on. But in some cases, it will not be a good idea to make some holes in such materials. So we need other sensor system which can send the information directly through them. But conventional wireless communication system cannot be applied because of the shielding provided by the conductors material, however the ultrasound propagates readily through them and it also can be used to convey information. In this paper, we choose the Finite Difference Time Domain method to simulate the ultrasound wave behavior. This method can be used easily to simulate ultrasound propagation in the conductors material. It can lead to better un-derstanding of the effect of ultrasound signal. In this work, an implementation of FDTD into an application for ultrasonic com-munication is described.

9 Jin Qi, and Shigeru Shimamoto, “A Cognitive Data Gathering Scheme for Gas Monitoring Employing Mobile Phone based

Wireless Sensor Networks”,Proc. 31st JSST Annual Conference, JSST 2012 international conference on simulation technology, vol. 31, pp. RS1-5, 27-28 Sep. 2012.

【要約】With the progressing of industrialization and urbanization, the leakage of gas or other chemicals has been a serious threat to the safety of humans. In the paper, mobile phone based wireless sensor networks are proposed for gas monitoring. In the network, each mobile terminal is equipped with a sensor, which senses gas data from surrounding environment using such mobile devices as sensors, significant advantages can be achieved over unattended wireless sensor networks. First, mobile phones can provide coverage where static sensors are hard to deploy and maintain. Second, mobile phones and cellular networks have already ex-isted around the world, providing the physical sensing infrastructure. Third, each mobile phone is associated with a human user, whose assistance can sometimes be used to enhance application functionality.

10 Jiang Liu, Zhenni Pan, Wasinee Noonpakdee, and Shigeru Shimamoto, “Performance Analysis of Image Sensor Communication over Free Space Optical Channel”,

Proc. IEEE International Conference on Imaging Systems and Techniques （IST）, Manchester, UK, 16-17 July, 2012.【要約】This paper presents a free space visible light communication （VLC） system using an image sensor as a receiver to acquire posi-tion related timely information. Since the atmospheric turbulence affects the communication quality, the analysis of atmospheric turbulence is very important for designing a practical communication system. In this paper, the atmospheric turbulence channel is analyzed. The method of characterizing and quantifying the influence of atmospheric effect to image sensor communication is presented. The noise model of the system using CMOS image sensor as a receiver is given. Furthermore, the bit error probability of the system using OOK modulation considering atmospheric turbulence is studied.

11 David Donald Mrema, and Shigeru Shimamoto,“Performance of Quadrifilar Helix Antenna on EAD Channel Model for UAV to LEO Satellite

link.”Proc. 2012 International Conference on Collaboration Technologies and Systems （CTS）, Denver Colorado USA, 21-25 May 2012.

【要約】In this paper we explore the performance of our designed Quadrifilar Helix Antenna （QHA） for Unmanned Aerial Vehicle （UAV） to be used in data transmission to Low Orbit Earth （LEO） Satellite. Elevation Angle Dependent （EAD） channel mod-el was technique used to analyze the channel fading and Bit Error Ratio （BER） values were used to quantify the performance of this long distance communication channel. A Cylindrical shape （21.2mm, 94.2mm） diameter and height, Quadrifilar Helix An-tenna （QHA） was designed with Voltage Stand Wave Ratio （VSWR） ＜2 at 2.4GHz. QHA was designed with proper pattern which has high directivity gain at low elevation angles so as to mitigate the fading effects on this long distance data transmission link from UAV to LEO Satellite.

12 Zhenni Pan, and Shigeru Shimamoto,“Cyclic Activated Power-efficient Scheme based upon Dynamic Cell Configuration”,

Proc. IEEE Wireless Communications and Networking Conference （WCNC 2012）, Paris, France, 1-4 Apr. 2012. 【要約】In this paper, we propose an energy saving solution for mobile systems based upon dynamic cell configuration for different

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scenarios. To characterize the optimal energy savings of base stations, we propose an active cell rotating scheme to control the number of active cells with regard to different work patterns switching among three states （active, receive and sleep）. A recov-ery mechanism is enabled by scheduling a receiving-only function if sudden traffic occurs within the cell group. We consider an improved-Markov based birth-death process in order to modeling the instantaneous random traffic variance and state transitions, which is used to evaluate the performance of the proposed approach with a positive influence on power savings, especially during the night zone.

国内大会

13 呉 宇鎮 , 麻生 健斗 , 周 牧野 , David Donald Mrema, 劉 江 , 嶋本 薫 ,“UAVを用いた行方不明者探索システムに関する考察”,電子情報通信学会 総合大会 BI-2-13 2013年３月 .

【要約】先の東日本大震災のような自然災害下で多大な被害を受けたが , 中でも行方不明者が多かった事が挙げられ , このような災害地で行方不明者を迅速に発見する事が今後の重要な課題となっている．本研究の提案システムでは腕時計型のトランスポンダを人体に装着し , UAVからの信号を受けて IDや簡単なバイタルデータを送信するものである．これにより , 被災者の位置や状況を一括して把握可能なシステムの構築を目指す．実験ではUAVとのデータ通信に必要な所要電力 , 有効的にデータ収集可能な飛行高度 , 飛行速度 , アクセス方式 , アンテナ指向性等に関して考察を行う．更に , 衛星と組み合わせた広域なネットワークに関する研究も行う .

14 Khemry Khourn, Jiang Liu, Wasinee Noonpakdee and Shigeru Shimamoto, “Energy Harvesting Based Optical Wireless Identification Scheme Employing Thinfilm Corner

Cube Retroreflector”,Proc. IEICE General Conference, Gifu, Japan, 19-22 March, 2013.

【要約】This paper presents an optical wireless identification （OWID） scheme utilizing high-energy harvesting thinfilm embedded with the corner cube retroreflector （CCR）. We apply optical wireless communication （OWC） for transmitting information. The thin-film act as a rechargeable battery that absorbs the power when the incident light beam goes through the CCR while reflects on-off-keying modulated signals back to the reader. The energy harvested during the transmission is used to drive the CCR inside the tag to modulate the OWC signals back to the reader. The proposed system is proved to be more secure with much higher available stored energy.

15 Sokha Heng, and Shigeru Shimamoto,“Performance of Time Division Multiple Access and Slotted Aloha with Capture Effect in Cognitive Radio Environment”,Proc. IEICE Society Conference, BS-5, pp. S. 86-S. 87, Toyama, Japan, September, 2012.

【要約】Cognitive Radio provides opportunity and takes advantage of spectrum hole from licensed users （primary users） to allow unli-censed users （secondary Users） to use the frequency spectrum. In this paper, we investigate a system in which primary users with Time Division Multiple Access （TDMA） and secondary users with Slotted Aloha transmit theirs packets to a common access point in a fading channel with Capture Effect and we off higher power for primary users. From a result of simulation, Primary Users get higher performance when power increases.

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