• The KIPS Transactions:PartA
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• v.10A no.6
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• pp.691-700
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• 2003

Due to the fast development of wire&wireless internet and computer hardware, more and more internet services are being developed, such as Internet broadcast, VoD (Video On Demand), etc. So QoS (Qualify of Service) is essentially needed to guarantee the quality of these services. Traditional Internet is Best-Effort service in which all packets are transported in FIFO (First In First Out) style. However, FIFO is not suitable to guarantee the quality of some services, so more research in QoS router and QoS protocol are needed. Researched QoS router and protocol are high cost and inefficient because the existing infra is not used. To solve this problem, a new QoS control method, named Network Adaptive QoS, is introduced and applied to client/server-based streaming systems. Based on network bandwidth monitoring mechanism, network adaptive QoS control method can be used in wire&wireless networks to support QoS in real-time streaming system. In order to reduce application cost, the existing streaming service is used in NAQoS. A new module is integrated into the existing server and client. So the router and network line are not changed. By simulation in heavy traffic network conditions, we proved that stream cannot be seamless without network adaptive QoS method.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.11a
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• pp.353-355
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• 2011

IPTV 서비스는 사업자별로 구성되어 있는 폐쇄적 서비스망에서 VoD 및 방송서비스를 특징으로 하였다. 사업자별 폐쇄성은 사용자의 이용환경의 제약뿐만 아니라 서비스 자원의 이용효율성을 저하시킴으로써, 중복투자 등의 비용적인 부담을 초래하게 되었다. 또한, 다양한 유무선 단말의 수용과 사용자 특성을 고려한 다양한 서비스의 제공요구는 사업자간 또는 서비스 제공자간의 서비스 자원의 상호 공유의 동기를 부여하게 되었다. 이에 본 논문은 오픈 IPTV 서비스 플랫폼에서 제공하는 다양한 서비스 요소들을 융합하여 새로운 융합서비스를 생성하고 제공하는 일련의 구조에 대해 연구하였다. 본 논문에서는 주문형 비디오 서비스를 융합서비스의 예로 삼았으며, 주문형 비디오 서비스를 제공함에 있어, 사용자의 주어진 특성(예를들면, 성별, 연령대 등)에 따른 콘텐츠의 추천을 확장하여, 사용자의 사회적 성향을 반영함으로써, 성별, 연령대에 따른 획일적인 콘텐츠 제공을 극복하고 사용자의 개별적인 성향을 반영하는 콘텐츠 제공방법을 연구하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.7
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• pp.879-884
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• 2020

In the conventional video file system, videos are stored in a high performance server which has mass storage hard disks or disk arrays. For 3D internet broadcasting, real time operations are required to transmit video files to many clients. This paper describes the design of the 3D internet broadcasting system which can provide realtime streaming service to many users in the 5G environment. In reality, unicast is used to transmit multimedia contents over the internet rather than IP multicast since IP multicast has its own drawbacks in deployment, security, maintenance and so on. In addition, multimedia broadcasting service system like VoD has difficulties in applying to 3D internet broadcasting system since it requires a large amount of system and network resources. In this work, we develop a 3D internet broadcasting system which can construct effective data delivery by minimizing performance-degrading factors.

• Journal of Digital Contents Society
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• v.10 no.1
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• pp.61-71
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• 2009

While the broadband network and multimedia technology are being developed, the commercial market on digital contents as well as IPTV has been widely spreading. Especially IPTV is providing various useful services since it makes using multimedia contents easier and more convenient by combining the strong points of both TV and PC system. Until now, IPTV system has been focused on VoD service as a general usages. However, various IPTV services are recently demanded since they can have special features for some specific places and occasions. So in this paper, we propose a design of the download based IPTV system using user-specific channel management. At first, program contents previously scheduled by users are downloaded and are played at settop-box according to the prescribed time table. This system has some advantages of giving users easy access to any wanted media contents in anytime that is IPTV's characteristics. And we can increase stability of services by using time slot distributed download for contents. Because this service can be constructed and maintained at relatively low cost, we confirm that this service model is more suitable to some companies with small infrastructure and special purposes. Accordingly, in this paper, we look into necessary elements and define some protocols for system in order to help other developer build this system.

• International journal of advanced smart convergence
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• v.4 no.1
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• pp.18-30
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• 2015

As the speed of networks that subscribers can use has greatly increased, demand for high-quality broadcast content, such as from Internet Protocol Television (IPTV) and Video on Demand (VoD), is likewise increasing. Therefore, while broadcasters are increasing content and channels, they are striving to improve consumer quality of experience (QoE) to differentiate themselves from competitors, including by producing higher physical-quality content. Recently, subjective measurement methods have been internationally standardized as the most reliable approach for measuring and evaluating IPTV QoE. However, a majority of these methods are performed in experimental environments and are based on the extremely brief viewing period of approximately ten seconds using original reference videos. It is actually difficult to apply standard evaluation methods based on a ten-second viewing interval to assess real broadcast watching of IPTV or other services that involve a longer time (i.e., more than thirty minutes). In this paper, we therefore propose a method that accommodates actual viewing environments. Using the mean opinion score, we experimentally analyze the effects of evaluation interval changes under actual conditions in which IPTV service is provided. In addition, we propose improvements by applying the results into actual live broadcast IPTV service and by analyzing consumer service QoE.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.1
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• pp.69-75
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• 2002

The important issues of facility database management in GIS are to collect up-to-date information and to update information in accordance with new-establishment, repair and replacement of the facilities. Therefore, it is necessary to develop a system which has capability of monitoring facilities as well as managing database efficiently. The purpose of this study is to propose possibility of implementation of mobile GIS solution for the facility management. In order to achieve the goal, to process existing digital maps and to receive on-site information through the wireless communication service are required. In addition, the system is required to process spatial information obtained by GPS and digital photogrammetric technique with real-time updating database in server. The system increases efficiency both in work flow and monitoring for facility management by providing optimal routing information to the sites and real-time two-way communication using VoIP(Voice over Internet Protocol). The system is expected to perform real-time database management effectively. In consequence, the system could appropriately response on-site situations in various practical applications. The proposed technology could contribute to improve nation's leading-edge technology.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.8
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• pp.59-66
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• 2009

Recently, as the expectation about the IPTV (Internet Protocol TV) service quality is rapidly increased by the development of the national high-speed internet and TPS (the Triple Play Service : data + image + audio) service Therefore, the enactment of the national quality standards about the IPTV service quality guaranteeing the real time video quality of a subscriber and the international standards are hastily needed. This paper built a test bed with the network domain and the subscriber set-top box domain including the headend area and commercial network characteristic in order to test in the environment which is similar to the characteristic of the service business network. And by using the constructed environment, the characteristics required for SLA(service Level Agreement) of the IPTV service are presented as the quality test according to the service environment change.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06d
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• pp.229-231
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• 2006

VoD(Video on Demand)나 IP 텔레폰, 화상채팅과 같은 멀티미디어 서비스는 일정한 대역폭의 자원을 요구하고 지터, 전송 지연에 매우 민감한 데이터이다. 멀티미디어 서비스의 QoS 보장과 TCP와 형평성을 위하여 TFRC, RAP, TLFC 와 같은 흐름제어 기법이 사용되고 있다. 하지만 흐름제어 기법에서 네트워크 판단을 위해서 사용하고 있는 RTT값은 서버와 클라이언트 사이의 왕복 전송 지연시간을 측정한 값으로써 클라이언트에서 서버로 전송되는 피드백 정보의 전송 지연시간에 따라서 오차가 발생한다. 본 논문에서는 서버에서 클라이언트로 단방향으로 데이터가 전송되는 특징을 가진 스트리밍 서비스를 위하여 RTP/RTCP를 이용한 단방향 전송 지연 측정을 제안한다.

• Journal of information and communication convergence engineering
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• v.18 no.2
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• pp.100-105
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• 2020

With the advent of the 5G era, the rapid growth in demand for mobile content services has increased the need for additional backhaul investment. To meet this demand, employing a content delivery network (CDN) and optical access solution near the last mile has become essential for the configuration of 5G networks. In this paper, a cache-enabled architecture using the passive optical network (PON) is presented to serve video on demand (VoD) for users. For efficient use of mobile backhaul, I propose a request deduplication scheme (RDS) that can provide all the requested services missed in cache with minimum bandwidth by eliminating duplicate requests for movies within tolerable range of the quality of service (QoS). The performance of the proposed architecture is compared with and without RDS in terms of the number of requests arriving at the origin server (OS), hit ratio, and improvement ratio according to user requests and cache sizes.

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.437-440
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• 2011

IP 기반은 VoD, 인터넷 등의 통신 서비스와 실시간 방송 프로그램을 제공하는 통신과 방송의 속성을 모두 가진 융합서비스를 의미한다. 이러한 IP 기반을 통해 본 논문은 사용자의 요청에 따라 양방향으로 다양한 멀티미디어 콘텐츠를 제공할 수 있도록 미디어 데이터의 유연성과 적응성이 고려된 멀티미디어 시스템 설계 및 구현을 하고자 한다.