• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9A
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• pp.704-711
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• 2009

In this paper, we report the results of the field trial test of 1GbpsX16channels Injection locking FP-LD based WDM-PON system which could guarantee 40Mbps minimum bandwidth per subscriber, We have confirmed the system reliability, also verified that the system could reliably deliver the service such as internet, VoD through the systems during the field trial test.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.10
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• pp.684-690
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• 2014

In this work we investigate the benefit of multicast in the delivery of video data over the mobile MBMS network. In order to quantify the benefit in a practical aspect, this work proposes an analytic framework that employs a combined statistical and queuing model, where a queuing model represents the behavior of user's access to the video service and the statistical model captures the popularity of the video contents, via which we draw out a more realistic intuition for the expected benefit from multicast. Finally, we present results of numerical experiment that illustrates the validity of the proposed work.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.675-678
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• 2006

IPTV (Internet Protocol Television) is an efficient system which serves various contents to subscribing consumers by using the IP over a broadband connection. The IPTV services can be multi-channel broadcasting service, VoD, T-Commerce, video conference, on-line game and so on. TV Anytime metadata provides various description tools for TV program contents by which TV program contents can serve more information. In this paper, we mention about the overview and feature of IPTV and TV Anytime metadata, propose the essential functions in the EPG program of IPTV and survey the description tools for the proposed functions in EPG. Finally, we show the authored metadata and the implementation of advanced EPG application.

• Proceedings of the Optical Society of Korea Conference
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• 2008.07a
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• pp.421-422
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• 2008

In this paper, we will present the results of 1Gbps x 16 channels RSOA remodulation based WMD-PON field trial test. We have confirmed the system reliability, also verified the system could reliably deliver the service such as internet, VoD through the system during the field trial test.

• 한국IT서비스학회:학술대회논문집
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• 2006.11a
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• pp.329-334
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• 2006

최근 방송통신융합 기술에 대한 관심이 높아지고 있는 상황에서 주문형비디오 서비스에 대한 관심도 증가하고 있다. 본 논문에서는 주문형비디오 서비스의 구현을 위해 기존의 배칭 기법 중 Fast Data broadcasting 방식을 활용한 패칭 기법을 제안한다. 대역폭이 제한되어 있는 통신 환경에서 사용자는 요청한 비디오를 시청하기까지 일정 시간을 기다려야 하는데, 사용자 요청 시점 이전 데이터를 Fast Data broadcasting 방식을 적용한 패칭 채널을 통해 전송함으로써 대기 시간을 크게 줄이는 효과를 얻을 수 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4360-4366
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• 2010

It is impossible for all athletes to be satisfied with a single training program due to the fact that they have different physiological characteristics and needs. However, paucity studies have been introduced a specific training program for high school sprinters. Therefore, this study was designed to help develop and introduce the training program with a physical examination to enhance sprinting performance for experienced high school sprinters. VO2max, muscular strength, basic physical ability, and body composition were measured before and after a 24 week training program. The following are the conclusions based on the results of this study: 1) body fat percentage was increased after 24 weeks of training. Fat free mass and the amount of water in the body increased by 1.5% and 1.1% respectively, 2) $VO_2$maxand anaerobic threshold level showed a significant increase after 24 weeks of training, 3) exercise duration and anaerobic threshold duration were also increased after 24 weeks of training, but not statistically significant, and 4) muscular strength significantly increased due to the execution of combined weight training and circuit training. Development and implementation of the training program in this study made sprinters' physical capacities better in VO2max, anaerobic threshold, and muscular strength and body composition. Also, sprinters were able to increase fat free mass through 24 weeks of training due to increased muscle mass. Therefore, a training program for high school sprinters should include a physical examination to enhance sprinting performance and prevent sports injuries.

• Journal of KIISE:Information Networking
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• v.34 no.6
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• pp.525-532
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• 2007

Recently, broadband access networks have been competitively deployed all over the world with the development of various multimedia services for such a network. ETRI(Electronics and Telecommunications Research Institute) built the FTTH(Fiber-to-the-Home) service center to develop a next-generation equipment and a high-quality service/platform as well as to promote domestic industry in the field of optical communication. The FTTH service center has a variety of test equipments such as FTTH standard testbed for a BMT(Bench Mark Test), a network operation center, and IPTV service equipments. Also, ETRI deployed a new type of commercial optical access networks cooperating with ISP(Internet service provider). In this paper, we analyzed the quality degradation appeared in QoE(Quality of Experience), when IP data broadcasted from the FTTH service center is transmitted to subscribers through the commercial optical access network. Moreover, we proposed a noble solution to address this problem.

• Journal of the Korea Society of Computer and Information
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• v.17 no.6
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• pp.183-190
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• 2012

Internet Protocol Television(IPTV) is the use of an IP broadband network to deliver television (cable TV type) services to the end user. Traditional telecommunications service providers as well as alternate service providers and Internet service providers can utilize their IP networks (and broadband consumer access) to deliver broadcast TV, Video on Demand (VOD) and other Internet services to the consumer. As digital technologies progress, illegal copy and redistribution of IPTV content become easier and simpler. Therefore it is required to protect IPTV content or service. In this paper, we analyze the security threats and requirements. We also discuss related issues and solutions for IPTV.

• Proceedings of the KAIS Fall Conference
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• 2010.11b
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• pp.988-991
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• 2010

본 연구에서는 고등학교 단거리 선수의 심폐능력, 신체조성, 그리고 각 부위별 근력이 24주간 운동을 통하여 어떠한 변화가 있는지 규명하였다. D 고등학교에 재학중이며 운동경력이 최소 4년이상된 남자 단거리 선수 8명을 연구대상자로 선정하였다. 운동 전 후 연구대상자들의 심폐능력, 신체조성, 그리고 근력을 측정하여 자료처리 하였다. 본 연구결과, 체지방률, 체지방량, 제지방량, 그리고 체수분량 모두 훈련 후 통계적으로 유의한 증가가 있었다(p<0.05). $VO_2$max와 aerobic threshold는 운동전보다 향상되었으며 통계적으로 매우 유의한 변화가 나타났다 (p<0.05). 근력 또한 통계적으로 유의한 상승 변화을 보였다 (p<0.05.) 본 연구결과 24주간의 훈련 프로그램은 남자 고등학교 단거리 선수들의 총체적 체력 향상을 도모하였다. 단거리 훈련 프로그램 작성 시 전통적인 방법으로 훈련을 계획하고 실천하기 보다는 경기력 향상 및 부상 예방을 위하여 훈련 전 종합적인 신체검사 및 체력 검사를 전문가와 같이 실시 및 평가하여 이를 토대로 개인의 체력에 맞게 훈련 프로그램을 계획 실천할 필요가 있을 것이다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.781-784
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• 2009

IPTV, which is convergence of Communication and Broadcasting, has improved quickly recently. This service can provide high quality and various services to their customers, such as choosing channels freely, VOD and many kinds of Interactive service. As the technology of IPTV rapid development, more and more people worry about its disadvantages during the spread and apply, for instance, the illegal application, illegal copy, access authority abuse and the danger of the IPTV contents. This paper will provide the solution to solve these problems, through the Public Key Certificate of PKI(Public Key Infrastructure) and the Attribute Certificate of PMI(Privilege Management Infrastructure).