• Proceedings of the Korea Information Assurance Society Conference
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• 2004.05a
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• pp.269-274
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• 2004

중앙집중 구조의 멀티미디어 콘텐트 서비스에서는 서버의 과부하 문제와 네트워크 트래픽의 급격한 증가 문제가 발생한다. 최근에는 이러한 문제점을 해결하기 위한 디지털콘텐트 전송기술로 CDN에 대한 연구가 활발히 진행되고 있다. 본 연구의 목적은 CDN을 통한 디지털콘텐트의 서비스에서 안전하고 효율적인 전송 성능을 지닌 시스템을 설계하는 것이다. 본 연구에서는 CDN을 기반으로 대규모의 디지털콘텐트의 전송 및 관리 시스템에서, 디지털콘텐트의 그룹별 관리를 통한 디지털콘텐트의 안전성과 전송성능을 개선한 시스템을 설계하였다.

• The KIPS Transactions:PartD
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• v.12D no.2 s.98
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• pp.303-308
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• 2005

Generally, the overloaded server problem and the rapidly increased network traffic problem are happened in a center concentrated multimedia digital content service. Recently, a study about the CDN which is a digital content transmission technology to solve these problems are performed actively. In this study, we proposed the SDCDS which improved a process latency time and a security performance on a digital content delivery and management. The goal of the SDCDS is the digital content security and the improvement of the processing time. For that, we have to design the security and the caching method considering the architecture characteristics of the CDN. In the SDCDS, the public key encryption method is designed by considering the architecture characteristics of CDN. And we improved the processing latency time by improved the caching method which uses the grouped caching method on the encrypted DC and the general DC. And in the experiment, we veryfy the performance of the proposed system.

• Journal of the Korea Society of Computer and Information
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• v.25 no.4
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• pp.87-95
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• 2020

In this paper, we examine the problems of the current Internet due to the development of network services and the expansion of network bandwidth. The current Internet has been used for a long time because it is composed of TCP / IP, but fundamental problems such as bandwidth, transmission rate, and security have not been solved. Therefore, the future network must be prepared through continuous investment and maintenance. In order to overcome this problem, we will propose a way to overcome the above problems and upgrade by converting the current Internet Protocol into the next generation network. Currently, many researches on next-generation networks have been conducted, but there are not many studies in Korea, and research on next-generation networks will be a very important task for the future development of the Internet service industry at the national level. In this paper, we propose an advanced internet environment through the advantages of various next generation protocols.

• Journal of KIISE:Information Networking
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• v.36 no.6
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• pp.492-504
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• 2009

The delivery of multimedia that efficiently adapts its bit-rate to changing network characteristics and conditions is one of the important challenging tasks in the design of today's real-time multimedia streaming systems such as IPTV, Mobile IPTV and so on. In these work, the primary focus is on network congestion, to improve network stability and inter-protocol fairness. However, these existing works have problems which do not support QoE (Quality of Experience), because they did not consider essential characteristics of contents playback such as the media continuity. In this paper, we propose a novel rate control scheme for improving the QoE of multimedia streaming service in the Internet congestion, called NCAR (Network and Client-Aware Rate control), which is based on network-aware congestion control and client-aware flow control scheme. Network-aware congestion control of the NCAR offers an improving reliability and fairness of multimedia streaming, and reduces the rate oscillation as well as keeping high link utilization. Client-aware flow control of NCAR offers a removing the media discontinuity and a suitable receiver buffer allocation, and provides a good combination of low playback delay. Simulation results demonstrate the effectiveness of our proposed schemes.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.216-219
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• 2011

DASH(Dynamic Adaptive Streaming over HTTP)는 MPEG(Moving Picture Experts Group)에서 표준화 중인 HTTP를 이용한 적응형 비디오 스트리밍 기술이다. 일반적으로 HTTP를 이용한 적응형 비디오 스트리밍에서 클라이언트가 사용할 수 있는 기능은 파일 전체 또는 그 일부를 다운로드하는 것이다. 따라서 전체 콘텐트를 작은 파일 조각 즉, 세그먼트(segment)로 분할하여 세그먼트들을 순차적으로 다운로드함으로써 마치 스트리밍이 달성되는 것과 같은 효과를 낼 수 있다. 네트워크의 상태에 따라 전송률을 조절하기 위해서는 서버에 서로 다른 비트율로 부호화된 세그먼트들을 함께 보관해 두어 클라이언트로 하여금 선택할 수 있게 한다. DASH에서는 MPEG-2 TS 또는 MPEG-4 파일 포맷(MP4)를 기반으로 하는 두 가지 형태의 서버 콘텐트를 제공할 수 있다. MP4 기반 DASH의 경우, 클라이언트가 수신한 세그먼트들을 순차적으로 이어 붙여 저장한다 하더라도 특별한 조건을 만족하는 경우를 제외하고는 MP4 파일을 재생할 수 있는 기존 미디어 플레이어가 이를 재생하지 못한다. 본 논문에서는 이러한 특별한 조건을 제시하고 이를 검증하였다. 이 조건은 서버에서 제공하는 세그먼트들에 대한 조건이다.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.1051-1056
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• 2007

In current web-based systems, it is generally recognized that one way flow of information from providers to users can cause the static problem of document structure. Therefore, information update frequency and interaction between providers and users are quiet slow. Monopolized information can obstruct the free user's access and heterogeneous format and different protocols also make users difficult to retrieve and to collect information. To resolve these problems, in this study, we introduce the Web 2.0 to move toward the user's participation and share based on the social network and the OAI protocol to improve the free access and the interoperability on bibliographic information for Life Science and then design the bibliographic information network for life science. This network has four main functions such as: 1) Open Repository function that can make up user community for sharing and data exchange. Data such as article, seminar material, research note and research report are considered in design. 2) Open Collection function that can collect and store the metadata on distributed bibliographic information networks, 3) Open Access function that can manage the metadata in the open access environment, and 4) Administration function that can monitor the user activity and statistics and can inspect the registered data.