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1.
Article
Kyushu Univ. Production Kyushu Univ. Production
Cover image of スケーラビリティを考慮したIPマルチキャストアーキテクチャの設計 — Design of Scalable Inter-Domain IP Multicast Architecture
大森, 幹之; Ohmori, Motoyuki; 岡村, 耕二 ... [et al.]
Publication info: 2000-11-01.
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Abstract: In this paper, we design the scalable inter-domain IP multicast architecture and achieve IP multicast routing over the whole Internet. In our architecture, we propose the dynamical address allocation in order to aggregate addresses efficiently. And for the sake of more flexible address allocation, we define two kind of multicast addresses, which are called VMA(Virtual Multicast Address) and MAR(Multicast Address for Routing). We present amount of routing information with our architecture, and consider inter-operability with other routing protocols. Read more
2.
Article
Kyushu Univ. Production Kyushu Univ. Production
Cover image of ECN Based Multi-path Mechanism for VoIP Transmission
Kang, Joonsuk; Okamura, Koji; 姜, 俊錫 ... [et al.]
Publication info: Research reports on information science and electrical engineering of Kyushu University. 17, (2), pp. 41-48, 2012-09-26. Faculty of Information Science and Electrical Engineering, Kyushu University
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Abstract: By the remarkable improvement of physical performance of networks (such as speed, capacity, etc) which consist of Internet and the diffusion of high-end terminals such as smart-phones, voice over IP (VoIP) is becoming one of the major communication technologies. However current packet networks still can not provide a stable transmission quality and it can cause VoIP call quality degradation. Especially, the main factor affecting VoIP quality is congestion across a network. Multi-homing can be a good solution to avoid points of congestion in the network. We therefore propose Real Time & Multi-path Transmission Protocol (RTMTP), a transport layer protocol in which multiple path real-time transport and effective congestion control are available. Our protocol uses the explicit congestion notification (ECN) mechanism to detect network congestion level and to control transmission rate of VoIP traffic at the sender side. To maximize network bandwidth efficiency of multiple paths, the RTMTP shifts traffic among those paths. Our simulation results show that RTMTP improves VoIP data transmission throughput by effectively utilizing multi-path without voice call quality degradation, and helps users to use more inexpensive access network as much as possible while maintaining an acceptable voice quality. Read more
3.
Article
Kyushu Univ. Production Kyushu Univ. Production
Cover image of Live Surgery and Teleconferencing at the 19th World Congress of the International Association of Surgeons, Gastroenterologists and Oncologists (IASGO) in Beijing
Shimizu, Shuji; Han, HoSeong; Okamura, Koji ... [et al.]
Publication info: Hepato-Gastroenterology. 58, (110), pp. 1427-1429, 2011-09. H.G.E. Update Medical Publishing S.A.
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4.
Article
Kyushu Univ. Production Kyushu Univ. Production
Cover image of Technologic developments in telemedicine : State-of-the-art academic interactions
Shimizu, Shuji; Han, Ho-Seong; Okamura, Koji ... [et al.]
Publication info: Surgery. 147, (5), pp. 597-601, 2010-05-01. Mosby, Inc.
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5.
Article
Kyushu Univ. Production Kyushu Univ. Production
Cover image of A remote surgery experiment between Japan and Thailand over Internet using a low latency CODEC system
Arata, Jumpei; 荒田, 純平; Takahashi, Hiroki ... [et al.]
Publication info: Proceedings of the IEEE International Conference on Robotics and Automation. 2007, pp. 953-959, 2007-04. IEEE
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Abstract: Remote surgery is one of the most desired applications in the context of recent advanced medical technologies. For a future expansion of remote surgery, it is important to use conventional network infrastructures such as Internet. However, using such conventional network infrastructures, we are confronting time-delay problems of data transmission. In this paper, a remote surgery experiment between Japan and Thailand using a Research and Development Internet is presented. In the experiment, the image and audio information was transmitted by a newly developed low latency CODEC system to shorten the time-delay. By introducing the low latency CODEC system, the time-delay was shortened compared with the past remote surgery experiments despite the longer distance. We also conducted several network measurements such as a comparison between TCP/IP and UDP/IP about the control signal transmission. Read more
6.
Article
Kyushu Univ. Production Kyushu Univ. Production
Cover image of 日本-タイ遠隔手術実験 — Remote Surgery Experiment between Japan-Thailand
荒田, 純平; Arata, Jumpei; 高橋, 弘樹 ... [et al.]
Publication info: 日本ロボット学会学術講演会予稿集. 24, 2006-09. The Robotics Society of Japan
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Abstract: In this paper, a remote surgery experiment, which was conducted between Japan and Thailand by using the developed minimally surgical system is described. In the experiment, a laparoscopic cholecystectomy was successfully performed on a pig. Various network measurements were conducted for the evaluation of the remote surgery. Read more
7.
Article
Kyushu Univ. Production Kyushu Univ. Production
Cover image of 日韓遠隔医療システムの構築 : 超高速遠隔医療システムの意義
清水, 周次; Shimizu, Shuji; 中島, 直樹 ... [et al.]
Publication info: 月刊新医療. 32, (2), pp. 125-127, 2005-02-01. エムイー振興協会
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Abstract: We have established a high-quality teleconference system between Korea and Japan through submarine optic cable on big broadband Internet. Broadcasting real-time surgery and teleconference with medical-quality videos was so useful to learn surgical techniques and other medical procedures. With these experiences and current achievements, we hope to extend this advanced network system to whole Asian countries to share our medical skills and international friendship. Read more
8.
Article
Kyushu Univ. Production Kyushu Univ. Production
Cover image of 日韓遠隔医療システムの構築 : 非圧縮デジタル動画像のインターネット配信 — High-Quaity Telemedicine via Korea-Japan Cable Network : Digital Video Transport System over Internet Protocol
清水, 周次; Shimizu, Shuji; 中島, 直樹 ... [et al.]
Publication info: 遠隔医療研究会論文集. 8, pp. 54-55, 2004-08-21. 遠隔医療システム研究会
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Abstract: A broad-banded medical network was established between Korea and Japan using Digital Video Transport System (DVTS) over Internet protocol. We used Kyushu GigaPOP (QGPOP) (Japanese side), the Korea Advanced Research Network (Korean side), and the Korea-Japan Cable Network (international line). The teleconferences with real-time transmission of laparoscopic surgery, neurosurgery, and endoscopic examination were successfully performed. The bandwidth was 30 Mbps for a line of transmission and two lines of DVTS were utilized. The uncompressed moving image had the rate of 30 per second. The security software was also used to protect patient privacy. This international telecommunication using high-quality moving image is very helpful for the exchange of new medical techniques among different countries. Read more
9.
Article
Kyushu Univ. Production Kyushu Univ. Production
Cover image of 超高速インターネットを介した日韓手術支援 — Telesurgery between Korea and Japan over Broadband Internet
川本, 雅彦; Kawamoto, Masahiko; 清水, 周次 ... [et al.]
Publication info: 九州大学アジア総合研究センターNewsletter. 3, pp. 7-7, 2004-03-31. Kyushu University Asia Center
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10.
Article
Kyushu Univ. Production Kyushu Univ. Production
Cover image of International Collaborations using Next Generation Internet in Asia
Okamura, Koji ; 岡村, 耕二
Publication info: 2005, pp. 1-8, 2005. Proceedings of International Workshop on Applied Information Technology || 2005 || p1-8
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Abstract: Currently, Japan and Korea progress vary active International Collaborations about NGI (Next Generation Internet) project between countries, named "Core Program Project of NGI". In this paper, the project's history and current detailed activities are introduced. And technical issues from these activities are explained. Finally future plan about International Collaborations among Asian Countries over Asian NGI extended from this project will be shown. Read more