• Journal of Digital Contents Society
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• v.7 no.3
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• pp.207-210
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• 2006

A synchronized multimedia presentation consists of a collection of objects, with each object having one or more rendering intervals within the presentation timeline. These intervals specify the objects' start times and end times relative to the presentation timeline. In this paper we consider the problem of streaming a multimedia presentation from a server to a client over a bandwith-limited communication network. We suppose that each of the static objects is layered-encoded. For a given maximum delay, we consider the problem of finding the optimal number of quality of the presentation. We devise efficient algorithms for determining an optimal policy for several criteria. We also consider the problem of gradual rendering of objects after their start times.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.5 s.311
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• pp.8-16
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• 2006

This paper proposes and implements consistency algorithm that is serviced streaming data efficiently in VOD system. The media data is loaded into each node by Round Robin method. The barrier mechanism is changed into the minimum data factor(SH, GOP) of media data in this paper. In addition in order to fast media data service, the additional features are implemented in the consistency algorithm. Additional feature of the consistency algorithm is added. First, time synchronization algorithm is added the suggested consistency algorithm. Second, the prepaging mechanism supports efficient buffering service. I experimented the suggested consistency algorithm two DSM systems. The performance is good due to the last barrier algorithm.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.577-580
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• 2001

최근 정보통신 기술 발전 및 초고속 통신망의 발달로 인한 인터넷 망(network)상에서의 방송과 통신이 융합되는 추세가 가속화되고 있다. 이에 스트리밍(Streaming) 기술을 기반으로 한 멀티미디어 데이터의 서비스와 데이터 정보의 푸시(push) 기술을 결합하여 인터넷과 고속망상에서의 원활한 실시간 전송 서비스를 위하여 다중 서버를 지원하는 3-tier 방식의 스트리밍 시스템을 구현하였다. 구현된 시스템은 실시간 전송 프로토콜인 RTP(Real-time Transport Protocol)를 이용하여 송신자에게 멀티미디어 스트리밍 서비스를 제공하며, VOD(Video on Demand) 및 실시간 방송 서비스를 제공하는 분산 멀티미디어 스트리밍 전송 시스템이다. 전체 시스템은 인터넷 방송 서비스 제공을 위한 VOD 서버, 실시간 방송 서버 및 푸시 서버와 멀티미디어의 실시간 재생을 위한 클라이언트 인터페이스 등으로 구성되어 있으며, 안정적인 서비스를 위한 미들웨어에서의 부하분배 및 채널 정보의 관리를 가능하게 하였다.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.7
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• pp.231-240
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• 2014

Video transcoding techniques provide an efficient mechanism to make a video content adaptive to the capabilities of a variety of clients. However, it is hard to provide an appropriate quality-of-service(QoS) to the clients owing to heavy workload on transcoding operations. In light of this fact, this paper presents the dual transcoding method in order to guarantee QoS in streaming services by maximizing resource usage in a transcoding server equipped with both CPU and GPU computing units. The CPU and GPU computing units have different architectural features. The proposed method speculates workload of incoming transcoding requests and then schedules the requests either to the CPU or GPU accordingly. From performance evaluation, the proposed dual transcoding method achieved a speedup of 1.84 compared with traditional transcoding approach.

• Journal of the Korea Society of Computer and Information
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• v.17 no.6
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• pp.93-100
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• 2012

In this paper we have proposed a linear time algorithm for solving the minimum sharable-bandwidth tree construction problem. The public-shared network is a user generated infrastructure on which a user can access the Internet and transfer data from any place via access points with sharable bandwidth. Recently, the idea of constructing the SVC video streaming delivery system on public-shared network has been proposed. To send video stream from the stream server to clients on public-shared network, a tree structure is constructed. The problem of constructing a tree structure to serve the video streaming requests by using minimum amount of sharable bandwidth has been shown to be NP-hard. The previously published algorithms for solving this problem are either unable to find solutions frequently or less efficient. The experimental results showed that our algorithm is excellent both in the success rate of finding solutions and in the quality of solutions.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.26-34
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• 2018

In this paper, we propose a scheduling scheme that can efficiently serve I/O requests having deadlines in flash storage. The I/O requests with deadlines, namely, real-time requests, are assumed to be issued for streaming services of continuous media. Since a Web-based streaming server commonly supports downloads of HTMLs or images, we also aim to quickly process non-real-time I/O requests, together with real-time ones. For this purpose, we adopt the well-known rate-reservation EDF (RR-EDF) algorithm for determining scheduling priorities among mixed I/O requests. In fact, for the use of an EDF-style algorithm, overhead of task's switching should be low and predictable, as with its application of CPU scheduling. In other words, the EDF algorithm is inherently unsuitable for scheduling I/O requests in HDD storage because of highly varying latency times of HDD. Unlike HDD, time for reading a block in flash storage is almost uniform with respect to its physical location. This is because flash storage has no mechanical component, differently from HDD. By capitalizing on this uniform block read time, we compute bandwidth utilization rates of real-time requests from streams. Then, the RR-EDF algorithm is applied for determining how much storage bandwidth can be assigned to non-real-time requests, while meeting deadlines of real-time requests. From this, we can improve the service times of non-real-time requests, which are issued for downloads of static files. Because the proposed scheme can expand flexibly the scheduling periods of streams, it can provide a full usage of slack times, thereby improving the overall throughput of flash storage significantly.

• KIPS Transactions on Computer and Communication Systems
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• v.3 no.2
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• pp.57-62
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• 2014

In order to provide real-time multimedia streaming service, a lot of system resources and network bandwidth required. Thus each computer is any computer other equivalent has the ability to act as a client and a server Peer-to-Peer(P2P) architecture with much interest. In this paper, techniques of P2P content that requires a user to efficiently retrieve the desired time in the streaming service have placed the focus of the research techniques. In a number present in the P2P contents, the user requests to find out the desired amount of time the content streaming services in order to provide seamless lookup latency contents search algorithm to minimize the study. P2P based smart network system and the structure of the super-node and the peer node is composed of super-gateway. Smart network system architecture proposed by performing a content search algorithm. The user requests a desired content, the service can be retrieved within the provided the flexibility.

• Journal of the Korea Society of Computer and Information
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• v.16 no.10
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• pp.147-153
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• 2011

In this paper, we present a new video management technique using forward timeline to efficiently store and delete the videos on a local server. The proposed method is based on capturing the changing preference of the videos according to recentness, frequency, and playback length of the requested videos. For this purpose, we utilize the forward timeline which represents the time area within a number of predefined intervals. The local server periodically measures time popularity and request segment of all videos. Based on the measured data, time popularity and request segment, the local server calculates the mean time popularity and mean request segment of a video using forward timeline. Using mean time popularity and mean request segment of video, we estimate the ranking and allocated storage space of a video. The ranking represents the priority of deletion when the storage area of local server is running out of space and the allocated storage space means the maximum size of storage space to be allocated to a video. In addition, we propose an efficient storage space partitioning technique in order to stably store videos and present a time based free-up storage space technique using the expected variation of video data in order for avoiding the overflow on a local server in advance. The simulation results show that the proposed method performs better than other methods in terms of hit rate and number of deletion. Therefore, our video management technique for local server provides the lowest user start-up latency and the highest bandwidth saving significantly.

• Journal of Korea Game Society
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• v.12 no.3
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• pp.59-68
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• 2012

This paper describes the design and implementation of a network-adaptive N-screen game system to be used in cloud computing. The system we are considering needs to generate game video in a cloud server and transmit the video to multiple game devices over an in-home wireless network via a home game server. It is difficult to support multiple screens which have different resolutions with a single bitstream of game video. Therefore, we developed a new network-adaptive game-video extraction and transmission method using (1) scalable video coding and (2) Raptor code techniques. The simulation, conducted with real game-video, verified the efficiency of the proposed video streaming system.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.12 no.2
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• pp.38-44
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• 2013

In this paper, we designed and implemented a mobile video transmission device with 1080i resolution and 30fps frame rate using wireless multi-access technologies. The video acquisition delay time of 16us and jitter of 21ms for this equipment were obtained, respectively. The device is designed to access various communication networks. In order to evaluate the performance of its video transmission capability, a server and monitoring viewer are implemented. In the performance test using LTE network, 211ms delay time was obtained at 3Mbps transmission. Rendering of 1fps frame rate at the 265kbps transmission was confirmed for the transmission test using Inmarsat network.