• Journal of Communications and Networks
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• v.7 no.2
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• pp.144-156
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• 2005

Video streaming over wireless networks is challenging due to node mobility and high channel error rate. In this paper, we propose a multi-source video streaming (MUVIS) system to support high quality video streaming service over IEEE 802.1l-based wireless networks. We begin by collocating a streaming proxy with the wireless access point to help leverage both the media server and peers in the WLAN. By tracking the peer mobility patterns and performing content discovery among peers, we construct a multi-source sender group and stream video using a rate-distortion optimized scheme. We formulate such a multi-source streaming scenario as a combinatorial packet scheduling problem and introduce the concept of asynchronous clocks to decouple the problem into three steps. First, we decide the membership of the multisource sender group based on the mobility pattern tracking, available video content in each peer and the bandwidth each peer allocates to the multi-source streaming service. Then, we select one sender from the sender group in each optimization instance using asynchronous clocks. Finally, we apply the point-to-point rate-distortion optimization framework between the selected sender-receiver pair. In addition, we implement two different caching strategies, simple caching simple fetching (SCSF) and distortion minimized smart caching (DMSC), in the proxy to investigate the effect of caching on the streaming performance. To design more realistic simulation models, we use the empirical results from corporate wireless networks to generate node mobility. Simulation results show that our proposed multi-source streaming scheme has better performance than the traditional server-only streaming scheme and that proxy-based caching can potentially improve video streaming performance.

• Journal of KIISE
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• v.45 no.2
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• pp.175-186
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• 2018

Recently, HAS (HTTP Adaptive Streaming) has been the subject of much attention to improve the QoE (Quality of Experience). In a high latency network, HAS degrades the QoE due to the lost RTT cycle since it replies with a response of one segment to the request of one segment. The server-push based HAS schemes of downloading multiple segments in one request cause QoE degradation due to the buffer underflow. In this paper, we propose a VSSDS (Video Streaming Scheme based on Dynamic Server-push) scheme to improve the QoE in a high latency network. The proposed scheme adjust video quality by estimating available bandwidth and determine the number of segments to be downloaded for each segment request cycle. Through the simulation, the proposed scheme not only improves the average video bitrate but also alleviates the buffer underflow.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.4
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• pp.677-684
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• 2008

We propose an grid-based research system that replays the experiment by storing and reusing the previous experiment result data in performing remote experiment from a distance. The proposed system was designed for the real-time hybrid test facility which is being built in Korea Construction Engineering Development(KOCED) Project. To provide users with various data, the experiment result data are maintained by the distributed streaming servers based on the publish/subscribe paradigm. Based on the data characteristics of our project, we compared analyzed the performance of the one-streaming-server case and the distributed-multiple-streaming-server case.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.3
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• pp.45-53
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• 2019

Moving image sharing technology has developed various servers and programs for personal broadcasting. In this paper, we propose the method of transmitting the multiple moving image, including the output channel of external streaming server. It also implements and tests multiple real-time broadcast channel automatic transmission systems that assign multiple output channels to automatic output channels. As a result of the experiment, it is easy to allocate moving image to broadcast channels that are output through the external streaming server's output channels regardless of the size of the streaming server, enabling the management of efficient output channels at the time of transmission of multiple moving image. The moving image can be provided through streaming method regardless of the type of moving image from the moving image provider terminal, and the moving image transmission can be controlled in various ways, including adding and changing channels for which the moving image is sent, and sending delayed to the moving image.

• ETRI Journal
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• v.35 no.6
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• pp.960-968
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• 2013

To implement a cloud game service platform supporting multiple users and devices based on real-time streaming, there are many technical needs, including game screen and sound capturing, audio/video encoding in real time created by a high-performance server-generated game screen, and real-time streaming to client devices, such as low-cost PCs, smart devices, and set-top boxes. We therefore present a game service platform for the running and management of the game screen, as well as running the sound on the server, in which the captured and encoded game screen and sound separately provide client devices through real-time streaming. The proposed platform offers Web-based services that allow game play on smaller end devices without requiring the games to be installed locally.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.251-254
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• 2003

본 논문의 목표는 디지털방송과 인터넷의 융합에 따른 MPEG-2/4/7 방송 및 인터넷 콘텐츠을 비롯한 게임등과 같은 다양한 멀티미디어 서비스를 제공하기 위한 차세대 지능형 고품질 홈 엔터테인먼트 시스템 Platform 개발이다. 디지털 방송과 데이터방송 수신이 가능한 Set-Top Box기능, 수신된 방송의 저장 및 재생이 가능한 PDR 기능, MPEG-2 형식을 MPEG-4 형식으로 변환하는 Transcoding 기능, VOD 서비스를 제공하기 위한 Streaming 기능 등을 지원할 수 있는 시스템의 구조를 설계하였다. 이러한 지능형 고품질 서비스를 지원하기 일해 고성능 시스템이 필요하다. 시스템 제어를 위한 CPU 로는 PMC-Sierra사의 MIPS Architecture에 기반을 둔 RM5231 을 채택하고, MPEC-4 Decoding, BIFS Presentation Engine과 Streaming 서비스와 MPEC-7 Metadata Generator/Parser 을 위해 ARM Architecture에 기반을 둔 Intel80200 Processor 를 채택하였다. 또한, 디지털방송을 위한 MPEC-2 Decoder Chip 인 Teraloglc 사의 TL811 System Controller 와 TL851 Graphics& Display Processor 를 채택하였다. 개발된 시스템을 테스트하기 위하여 DVB-MHP Server와 MPEG-4 IP Streaming Server 를 구축하여 디지털 방송과 Streaming 서비스를 테스트하였다.

• Journal of the Semiconductor & Display Technology
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• v.15 no.2
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• pp.66-69
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• 2016

Recently, augmented reality and virtual reality in the ICT sector have been highlighted. So also interested in related HMD areas to facilitate contact with the VR content is being attend. This paper proposes a method for implementing to the virtual reality through the mobile HMD device with the real time 360 image. This system is required the real time 360 image streaming server configuration and image processing for augmented reality and virtual reality. The configuration of the streaming server is configured the DB server to store images and the relay server that can relay images to other devices. Augmented image processing module is composed based on markerless tracking, and there are four modules that are recognition, tracking, detecting and learning module. Also, the purpose of this paper is shown the augmented 360 image processing through the Mobile HMD.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.07a
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• pp.51-52
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• 2015

근래에 인터넷 방송이 활기차게 서비스되고 있다. 기관과 단체뿐 아니라 개인까지도 인터넷 방송 서비스를 제공하는 실정이다. 인터넷 방송 이용자는 스트리밍 서버에 접속하여, 서버가 송출하는 멀티미디어 스트림을 실시간으로 받아 재생한다. 그래서 스트리밍 서버가 인터넷 방송 시스템의 핵심 장비다. 스트리밍 서버에는 와우자 서버, 다윈 스트리밍 서버 등이 있는데, 그 중 와우자 서버 설치 방법을 설명한다.

• The KIPS Transactions:PartA
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• v.11A no.3
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• pp.207-212
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• 2004

This paper provides the higher user QoS(Quality of Service) by analyzing media service model between server and client in single VoD(Video on Demand) environment and applying it to parallel VoD environment. Media service model is divided into the Client Pull, Server Push, and IPP(Interleaving Pull & Push) model. A server sends data based on client's request in the Client Pull Model. A server one-sidedly sends data without client's request in the Server Pull model. And the WP model unites above two models. For a parallel VoD environment, We built the PMSS system which provides the parallel media streaming services that one client is simultaneously served by several servers. In the single and parallel VoD environment, We compare and analyze the performance of service models with respect to network delay and data size in buffer. In this experiment, we found that IPP service model keeps the least network delay and stable client buffer in the parallel VoD environment. This result shows that PMSS can provide the more quality of service.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.893-901
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• 2013

This paper suggests a method of developing live media streaming service through Linux server system on android system environment. The android application constructed in the experiment is able to record media while sending it to Linux server. Generated real time media data is send to linux server through Multipart Request class of Apache Tomcat server constructed on Linux system. Also in this research, by utilizing Android video player and media player class, development of android application structures was accomplished, which has methods of; playing live media stream data on video server, or playing live media stream data while saving stream data in cache. The structure and function of suggested system and application is confirmed by series of experiments.