• International Journal of Advanced Culture Technology
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• v.2 no.1
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• pp.14-19
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• 2014

In this paper, we propose a stream based patching technique in order to reduce demands of network output bandwidth required to provide the true video-on-demand (VoD) service in a Multimedia server. The proposed scheme calculates required streams to clients accurately by analyzing temporal relationships between already arrived requests in a multimedia server and still progressing streams, and then transmits streams freshly. Since our stream based patching technique induces new linking stream which is playing a link role between long and short patching streams, it reduces demand of network output bandwidth required to provide the true VoD service in a multimedia server. Accordingly, we know that the proposed scheme improves service latency and defection rate than those of existing patching technique by a simulation study.

• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.367-376
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• 1999

A variable bit-rate based video services have much limitation for bandwidth management, since its trarfic has a some variances in frame level. In particular, the bandwidth management for video which has characteristics of VBR traffic such a MPEG video could be more complicated. Also, it is difficult to manage the bandwidth effectively for proving a VCR function from VOD service, since we don't know the traffic variance exactly at that time. In this paper, we proposed the dynamic bandwidth allocation a scheme based on VBR traffic based stored video such as MPEG for interactive video service. This scheme can maximize the given total bandwidth through the prefetch based variable length bandwidth allocation scheme and dynamic bandwidth management scheme for multiple streams. Also, our scheme can be used for a MPEG-based bandwidth allocation scheme, and provides the method that can maximize the utilization of network resource for multiple stream by using a dynamic bandwidth management.

• Journal of Information Management
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• v.40 no.2
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• pp.117-134
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• 2009

Most of the colleges run their own broadcasting stations. They provide diverse types of content, and nowadays many colleges even provide video content. This paper deals with the concept of multicast service as a solution to provide efficient broadcasting service on the college campus. For this purpose, it examines concept and characteristics of the multicast service. It also reviews the actually case of such service provided by S college in Seoul, focusing on its platform, major functions, and scenario. I expect what's discussed in this paper contribute to effective implementing and operating of a college broadcasting service. Also, multicast service introduced in this paper is applicable to the various organizational environment such as private companies and institutions as well as colleges.

• Korean journal of communication and information
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• v.64
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• pp.31-58
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• 2013

With the expansion of digital media platform, there has been a new conceptualization about public function of public broadcasting in and around European countries. Although there are differences between countries, Universal Access including smart and Internet media has been emphasized in Britain and France. However, there is lack of public discussion on service strategy of Internet and smart media platform when public function of public broadcasting is discussed. Therefore, this study tried to investigate not only the public function of public broadcasting in the field of Internet and smart media through audience research but also how the national public broadcasting stations ensure public interest and competitiveness in the field of Internet and smart media platform. The results suggested that smart phone users evaluated real-time broadcasting and VOD are the most important services among the public functions which public broadcasting stations have to persue. Futhermore, the users showed high intension to use when the free real-time broadcasting service is offered. Therefore, public broadcasting stations have to improve the social recognition on necessity and public interest of public broadcasting stations through the free real-time broadcasting services on Internet and smart media platform. And policies which can ensure competitiveness in the era of digital media are needed to become important broadcasting institute.

• The Journal of the Korea Contents Association
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• v.10 no.3
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• pp.413-422
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• 2010

With the beginning of foreign workers' immigration since 1990, Korea has faced multi-cultural society. At the same time, the number of female marriage immigrants have constantly increased. But the social services for immigrants are not yet prepared. According to the research on the actual condition of immigrants' culture enjoyment, which was done by Ministry of Culture, Sports and Tourism of Korea, the most preferable leisure activity of immigrants is 'sightseeing'. So this study focused on improvement of web contents of tourism information to satisfy the information needs of immigrants. Concretely, this study analysed the present condition of the existing tourism web contents, and analysed deeply the web site 'Tourism Busan' for special reference. Especially this study tried to analyse VOD images among web contents of 'Tourism Busan', and provided concrete improvement plan for that. And also this study processed interview with marriage immigrants to provide web site evaluation at the level of immigrants' eyes. As a result of evaluation, immigrants was the most dissatisfied with 'contents quality', and showed lower dissatisfaction at 'service quality', 'interface quality' factors.

• Journal of Digital Contents Society
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• v.2 no.1
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• pp.73-79
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• 2001

Most of the existing algorithms try to disseminate the multimedia contents of internet service provider(ISP), without taking into account the needs and characteristics of specific websites including e-learning systems with web-based .educational contents. Sometimes the client must select the best one among the replicated repositories. However, this is a less reliable approach because clients' selections are made without prior information on server load capacity. In this paper we propose an agent system inspired by the need of improving QoS of delivering web-based educational multimedia contents without incurring long access delays. This agent system consists of three components, Analyzer, Knowledge Base, and Automaton embedded the capacity algorithm. It analyzes and investigates traffic information collected from individual replicated server by learners' requests, and selects a server which is available and is expected to provide the fastest latency time and the lowest loaded capacity, and achieves high performance by dynamic replicating web resources among multiple repositories.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.6
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• pp.3074-3091
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• 2019

With the widespread use of the Internet, services for providing large-capacity multimedia data such as video-on-demand (VOD) services and video uploading sites have greatly increased. VOD service providers want to be able to provide users with high-quality keyframes of high quality videos within a few minutes after the broadcast ends. However, existing keyframe extraction tends to select keyframes whose quality as a keyframe is insufficiently considered, and it takes a long computation time because it does not consider an HD class image. In this paper, we propose a keyframe selection method that flexibly applies multiple keyframe quality metrics and improves the computation time. The main procedure is as follows. After shot boundary detection is performed, the first frames are extracted as initial keyframes. The user sets evaluation metrics and priorities by considering the genre and attributes of the video. According to the evaluation metrics and the priority, the low-quality keyframe is selected as a replacement target. The replacement target keyframe is replaced with a high-quality frame in the shot. The proposed method was subjectively evaluated by 23 votes. Approximately 45% of the replaced keyframes were improved and about 18% of the replaced keyframes were adversely affected. Also, it took about 10 minutes to complete the summary of one hour video, which resulted in a reduction of more than 44.5% of the execution time.

• Journal of the Korea Convergence Society
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• v.10 no.8
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• pp.137-144
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• 2019

This paper deals with the longitudinal study on the supply & demand-side diversity of digital media service. The purpose of this study is to measure the diversity of contents supply and demand-side of digital media platform providers by longitudinal data and discuss the implication. In the approval and re-authorization of pay-TV broadcasters, there were attempts to measure diversity indicators as items to evaluate the publicness and public interest of broadcasting, but they are mainly limited to the method of measuring diversity in the short-term supply side. Thus researcher wants to confirm the evaluation of two aspects through this study. First, researcher proposes a demand-side measurement methodology that utilizes actual audience data from users, and second, a longitudinal evaluation methodology that evaluates long-term trends of diversity change. Researcher has secured the actual supply and demand data of the platform player and confirmed trends of longitudinal diversification indexing for 50 months from 2012 to 2017. Through this research, researcher expects that the supply and demand-side and the longitudinal diversity evaluation will be utilized in a balanced way of publicness and public interest evaluation of broadcasting.

• ETRI Journal
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• v.27 no.5
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• pp.595-607
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• 2005

The widespread use of the Internet has led to the problem of intellectual property and copyright infringement. Digital rights management (DRM) technologies have been developed to protect digital content items. Digital content can be classified into static content (for example, text or media files) and dynamic content (for example, VOD or multicast streams). This paper deals with the protection of a multicast stream on set-top boxes connected to an IP network. In this paper, we examine the following design and architectural issues to be considered when applying DRM functions to multicast streaming service environments: transparent streaming service and large-scale user environments. To address the transparency issue, we introduce a 'selective encryption scheme'. To address the second issue, a 'key packet insertion scheme' and 'hierarchical key management scheme' are introduced. Based on the above design and architecture, we developed a prototype of a multicasting DRM system. The analysis of our implementation shows that it supports transparent and scalable DRM multicasting service in a large-scale user environment.

• Journal of the Korea Computer Industry Society
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• v.3 no.9
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• pp.1223-1234
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• 2002

RTP payload must be encrypted for providing commercial VOD service or private video conference over the Internet. Encryption/decryption delay is minimized because there are constraints in transporting a multimedia data through the Internet. Therefore, encryption algorithm is changed with considering network traffic md load. During many users participate in the same multimedia service, an user who already left the service can receive and decrypt the RTP payload because of knowing the encryption key. In this paper, Security Control Protocol for RTP is designed and implemented for changing the encryption algorithm and the key.