• Journal of Korea Multimedia Society
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• v.11 no.5
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• pp.685-691
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• 2008

Recently with the rapid evolution of the mobile computing and communication technologies, mobile VOD service becomes increasingly important for wireless mobile users. The VOD service is being widely used in various areas of application, such as education, entertainment and business, because it provides users convenience in easily having access to video information at any time in any places. However, in reality, the mobile system has many difficulties in providing the smooth VOD service owing to frequent transfers and cutoffs of clients. The importance of a technique to transmit broadcasting is being stressed as a method for providing stabler mobile VOD service to a large number of clients. This paper is aimed at showing how to reduce demands for server bandwidth and delay of earlier service through performance analysis by suggesting an effective VOD broadcasting transmission technique through channel division in the mobile atmosphere. Many researches have been made about regular broadcasting techniques in particular. This study divides the methods used for assigning channels which have been decided by the size of segments into a group of regular channels and assistant channels using wireless gap-fillers to provide effective VOD services to a large number of clients at the mobile environment using small bandwidth resources. The regular channels transfer regular streams, while assistant channels repeatedly transfer the first segment to reduce early service delay time to receive regular streams. In this way, the study suggests a technique to reduce server bandwidth demand and early service delay time. Through the proposed technique, the server bandwidth demand could be reduced by more than 30 percent and the study continuously shows reduced early service delay time through conducting performance analysis.

• Convergence Security Journal
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• v.17 no.3
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• pp.51-57
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• 2017

VOD service provides an additional revenue for broadcasting companies in addition to the existing subscription fees and advertisement-based revenue. Therefore, each broadcasting company develops its own VOD service and performs frequent improvement work. This leads to the development of new VOD services, so developers are considering ways to effectively handle the frequent development needs. In this background, we conducted an underlying research to apply the feature-oriented analysis model to the development of VOD service. The feature-oriented analysis model used in this study is the Feature-Oriented Domain Analysis (FODA) developed by SEI of Carnegie Mellon University. FODA provides a tool for specifying a feature model of a software domain, based on which developers determine the configuration of a software with customers. This study developed a feature model of the VOD service domain and devised the functionalities and testcases in an integrated manner with the feature model. Additionally, we proposed a VOD service development process utilizing the feature model, function specification, and testcases.

• The KIPS Transactions:PartB
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• v.8B no.5
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• pp.507-514
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• 2001

In VOD(Video-on-Demand) system, the real-time interactive service is one of the most important factor to determine the degree of QoS(Quality of Service). In this paper, we propose the head-end system consisted of switching agent and head-end node, which needs to receive the only video stream for multiple users which have requested the same video, to serve the unlimited interactive service which has no service delay and block. The unlimited VCR services can be served by storing the video stream with buffer at client and head-end node. And the proposed algorithm presents the method to enhance the efficiency by buffer, offer the true interactive VOD services to users because all of service requested by clients are processed immediately. In this paper, we implemented the VOD system which has the VCR functions without service delay and block. Simulation results indicate that the proposed algorithm has better performance in the number of service request and time interval.

• Journal of Digital Contents Society
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• v.18 no.3
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• pp.457-463
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• 2017

VOD service provides an additional revenue model for digital broadcasting companies in addition to the existing subscription fees and advertisement-based revenue models. Therefore, each digital broadcasting company develops its own VOD service and performs frequent improvement work. In this circumstance, the developer is seeking to improve the efficiency of the VOD service development. To address the needs of such developers, this study conducted a basic study to apply the feature-oriented analysis model to the development of VOD services. The feature-oriented analysis model is recognized (through a number of case studies) as an effective tool for analyzing the requirements of softwares with the functions that are interconnected organically. In this paper, we developed a feature model of VOD service and designed the primary functions of each feature and the test-cases that can test the these functions, laying the foundation for developing VOD services based on feature-oriented analysis model.

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.3
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• pp.299-310
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• 2000

In this paper, we designed and implemented a personal VOD server using multi-thread for the real-time services of video data to the users. The system consists of service manager, disk manager, and network manager. The service manager controls the user admission to the system using the VBR(Variable Bit Rate) characteristics of MPEG (Moving Picture Experts Group) video data. The disk manager provides the functions for VCR-like operations. The disk manager reads blocks from the disk by the size of GOP(Group of Pictures) and buffers the data to the user's thread. The network manager uses TCP/IP for the communication between the server and the client. The communication starts from the client and the VOD server must respond to this request. The implemented personal VOD system shows an acceptable performance.

• The KIPS Transactions:PartB
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• v.8B no.1
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• pp.74-80
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• 2001

본 논문에서는 환경에서 VOD(Video On Demand) 서비스를 위한 적응적 멀티미디어 동기화 알고리즘을 제안하였다. 제안된 방식은 망의 상태에 따른 패킷 손실과 지연에 대해서 각각 적응적으로 서버의 전송률과 클라이언트의 재생예정시간을 조절한다. 그리고 망에서 발생하는 손실뿐만 아니라, 클라이언트의 재생 처리능력을 동시에 고려한 선택적 픽처 폐기를 통하여 서버의 전송률을 조절한다. 성능 평가를 통해 제안된 방식이 기존 방식보다 더 나은 서비스 품질을 제공함을 알 수 있었다.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.123-126
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• 1998

Generally, in a VOD(video on Demand) system, batching technique is oten used to improve throughput. Since subscribers to VOD servives tend to withdraw their requests as the latency becomes large, an optimal scheduling scheme should consider not only batching size but also withdrawal rae, service latency and fairness between different programs. In this paper, we propose a new scheduling scheme, which shows improvement in fairness and reduction in withdrawal rate and service latency compared with other well known schemes. When there are 2 or more streams are available in the VOD server, proposed scheme apply different program selection policies to each streams. Using this approach effectiveness of stream usage can be improved.

• Journal of the Korea Computer Industry Society
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• v.5 no.2
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• pp.293-300
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• 2004

In this paper, we devise both methods supporting interactive VCR-like functions for MPEG stream and minimizing the storage space. Specifically, we proposed both methods to efficiently stripe MPEG stream into multiple disks, and an access strategy to retrieve the distributed streams over the disks. To accurately locate the streams to be referred to, we introduce a table indexing the location. When client request Fast Forward(FF)/Fast Backward(FB), VOD(Video on Demand) server refer to this index table supporting FF/FB functions. Experimental result shows that the proposed method can reduce the additional storage space needed when VOD server services FF/FB functions.

• Journal of the Korea Society of Computer and Information
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• v.19 no.12
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• pp.257-266
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• 2014

In this paper, we propose the development of an eBook Service System based on VOD Broadcasting Contents(eBSS-VOD) which protects the illegal copy through the effective DRM strategy. Here, eBSS-VOD is composed of three sub-systems - eBook server management system, ePub Builder, and eBook App - according to the functional points of view. The eBook server management system operates to manage the eBooks, the encription keys, the VOD contents, the membership and the history of users' viewing log. The ePub Builder assists to produce eBooks by DRM strategy. The eBook App provides users with the utility services of VOD viewing and eBook purchase processing. The proposed eBSS-VOD, differently from the current eBook systems, helps to increase the users' interests in reading books and to motivate the users' purchasing needs and it also makes new distribution channel for eBooks based on VOD broadcasting contents through smart applications. We provides the differentiated eBook builder which are based on ePub3.0 and DRM strategy. Through empirical survey results on users' interests and purchase intention for eBooks, we show that the proposed eBSS-VOD has the comparative effects compared to the current systems.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.6
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• pp.173-178
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• 2008

With the discontinuation of analog broadcasting in 2012, the cable broadcasters are investing in the conversion to DCATV (Digital Cable TV). DCATV is providing various broadcast of high quality to audiences through paid broadcasting called PPV (Pay Per View). Such services are using various kinds of CASs (Conditional Access System) in order to verify the viewing rights of subscriber. In addition, to respond to the fast changing environment of digital broadcast, not only simple digitalization of broadcast but also services such as PVR (Personal Video Recorder) and VOD (Video On Demand) are provided to subscribers. Because these additional services have many difficult areas to cover with traditional CAS alone, a new plan has become necessary. With the improvement of related regulations in 2008, the test service of IPTV (Internet Protocol TV) which is a broadcast service through the internet started. Because like DCATV, IPTV also sets the real time broadcast and the VOD service as the basic services, the use of appropriate CAS is required. In this study, the CASs for DCATV and IPTV undergo comparative analysis, and the development direction which will benefit both subscribers and broadcasting companies is suggested.