• Journal of Digital Contents Society
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• v.16 no.2
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• pp.291-298
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• 2015

In a fast-paced information technology environment, consumption of video content is changing from one-way television viewing to VOD (Video on Demand) playing anywhere, anytime, on any device. This video-watching trend gives additional importance to videos with fine-speed-control, in addition to the strength of the digital video signal. Currently, many video players provide a fine-speed-control function which can speed up the video to skip a boring part, or slow it down to focus on an exciting scene. The audio information is just as important as the visual information for understanding the content of the speed-controlled video. Thus, a number of algorithms for fine-speed-control video-playing technologies have been proposed to solve the pitch distortion in the audio-processing area. In this study, well-known techniques for prosodic modification of speech signals, WSOLA (Waveform-Similarity-Based Overlap-Add), have been applied to analyze users' needs for fine-speed-control video playing. By surveying the users' preferred speeds on categorized video content and analyzing the results, this paper proposes that various fine-speed adjustments are needed to accommodate users' preferred video consumption.

• The Transactions of the Korea Information Processing Society
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• v.7 no.12
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• pp.3794-3803
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• 2000

In a Video-on-Demand system, admission control that is used to serve multimedia data efficiently has to be perfonned by an accurate grasp of the condition of surplus resources. Most of all. we need to adaptable admission control mechanism because the disk has irregular response time caused by external elements of disk, and also has high deviation of amount demanded. In previous admission control schemes, they determined whether a new user is granted or not through a theoretical value. Although they based on the measurement, they left much to be desired in dealing with the service state. Measurement ~based statistical admission control scheme, as we su~~ested in this research, perfonns 2 processes of off-line process and on-line process in real service environment. Through this processes, we can grasp the accurate resource state of system and adaptive!y detennine the admission according to circumstances. Therefore, it can guarantee both maximum resource utilization and QoS(Quality of Service). On performance evaluations, we show that the video server can utilize maximum resource utilization with QoS guarantee through precision of perfonnance by measurement and adaptable admission control according to the requested bandwidth.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.884-888
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• 2009

Vehicular Adhoc Networks (VANET), a Vehicle-to-Infrastucture or Vehicle-to-Vehicle communication technology, is an area that makes more specific use of Mobile Adhoc Networks(MANET). VANET's Quality of Service(QoS) focuses on preventing possible emergencies like car crash from happening by immediately transmitting information to the cars around, while MANET's QoS is being studied for the quality of multimedia data such as Video on Demand(VoD), Video streaming, Voice over IP(VoIP), etc. In this paper, I structure the actual network configuration using Link State Routing(LSR), implement QoS Provisioning Model using Common Open Policy Service(COPS), and suggest more effective k-hop Cluster and inter-domain policy negotiation which fit better to the characteristics of VANET.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.1052-1059
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• 2016

Video-on-Demand(VoD) is one of the most popular media streaming which attracted many researchers' attention. VMesh is one of the most cited works in the field of the VoD system. VMesh is proposed to solve the problem of random seeking functionality. However, a large number of the DHT(Distributed Hash Table) searches in VMesh is sill the main problem which needs to be solved. In order to reduce the number of the DHT searches, the clustered segment index(CSI) scheme is proposed. In this scheme, the video segments are divided into clusters. The segment information of the video segments, which are clustered into the same cluster, are stored in the same clustered segment index that can be searched by using the hash key. Each peer also can request the required segments by using this clustered segment index. The experiment results show that the number of the DHT searches in the proposed scheme is less than that of VMesh even in case of peers leave and join the network or peers perform the fast forward/backward operations.

• ETRI Journal
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• v.37 no.4
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• pp.685-695
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• 2015

This paper proposes a novel video delivery scheme that reduces the bandwidth consumption cost from a video server to terminals in Long-Term Evolution networks. This proposed scheme combines optimized hybrid multicast with a segment-based caching strategy for use in environments where the maximum number of multicast channels is limited. The optimized hybrid multicast, allocation of multicast channels, and cache allocation are determined on the basis of a video's request rate, the related video's length, and the variable cost per unit size of a segment belonging to the related video. Performance evaluation results show that the proposed scheme reduces a video's delivery costs. This work is applicable to on-demand TV services that feature asynchronous video content requests.

• Journal of the Korea Society of Computer and Information
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• v.3 no.4
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• pp.10-18
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• 1998

Video information is an important component of multimedia system such as Digital Library. World-Wide Web(WWW) and Video-On-Demand(VOD) service system. It can support various types of information because of including audio-visual, spatial-temporal and semantics information. In addition, it requires the ability of retrieving the specific scene of video instead of entire retrieval of video document. Therefore, so as to support a variety of retrieval, this paper models metadata using video document structure information that consists of hierarchical structure, and designs database schema that can manipulate video document.

• Journal of the Semiconductor & Display Technology
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• v.16 no.1
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• pp.75-80
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• 2017

Nowadays, smart phone is being popularly used for communication, entertainment, and information retrieval. While demands on video traffic over mobile networks increases sharply, the wireless link capacity is often limited to fully support the traffic demand. Therefore, the size of video data needs to be reduced to provide high quality video with limited capacity. To handle this issue, we propose a video editing system using the ffmpeg library. The proposed system can provide a high quality video with a relatively small data size, thereby facilitating the mobile streaming services and live-video games.

• Journal of Broadcast Engineering
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• v.3 no.1
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• pp.100-109
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• 1998

The coding of video sequences has been the focus of research in recent years. High Definition TV(HDTV), video conferencing and video on demand(VOD) are some of the well known applications. In the moving picture compression, motion estimation algorithm plays a very important role, but due to its high computational complexity, there has been many approaches to overcome this difficulty. We propose a new block matching criterion that uses modified cost functions. This new block matching criterion classifies pixels into 2-levels, 4-levels and 8-levels with a suitable thresholding method. We also show that our new proposed algorithms can easily be combined with many other fast motion estimation algorithms with good performance.

• The Magazine of the IEIE
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• v.22 no.7
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• pp.51-59
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• 1995

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.635-637
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• 1999

기존의 인터넷 기반 데이터 서비스는 'Best-effort' 정책으로 멀티미디어 서비스를 위한 트래픽 제어(traffic control) 기능을 제공하지 못한다. 그러므로 실시간 데이터 전송을 기반으로 제공되는 VOD(Video-on-Demand) 서비스는 사용자가 원하는 QoS(Quality of Service)를 제공할 수 없다. 따라서 인터넷 상에서 트래픽 제어 기능을 갖춘 중개자를 두어 VOD 서비스를 제공하는 방법에 대해 제안한다. 중개자의 주요 기능은 비디오 서버와 클라이언트 사이에 비디오 데이터의 버퍼링 기능을 이용하여 실시간 트래픽 제어를 수행한다. 이런 기능을 가진 중개자를 에이전트라 부르고, 에이전트에 대한 설계 및 구현에 대해 기술한다.