• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.11a
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• pp.196-199
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• 2013

제한수신시스템(Conditional Access System, CAS)은 사용자의 조건에 따라 방송에 대한 접근을 제어하는 시스템으로 유료 방송 시스템에서 인가된 사용자만이 해당 프로그램에 접근할 수 있도록 하는 콘텐츠 보안 기술이다. 최근에는 기존의 하드 웨어 기반 CAS가 가지는 이기종 기기간 호환성과 다른 서비스와의 연동 등의 문제를 해결하고자 CAS 모듈을 소프트웨어로 구현하여 네트워크를 통해 설치하는 교환 가능형 제한수신시스템(eXchangeable CAS, 이하 XCAS) 방식을 도입하여 활발하게 서비스를 제공하고 있다. XCAS는 기존 CableCard방식이 가지는 CAS의 보안성과 분리교환 원칙을 유지하면서도 다양한 단말에 쉽게 설치하여 서비스가 가능하다는 점에서 큰 장점을 가지고 있지만, 방송수신만을 목적으로 하는 DTV(Digtal Television)에 대해 적용하기가 어렵다는 문제점이 존재하였다. 본 논문에서는 케이블방송환경에서 DTV를 통한 유료방송서 비스 제공을 위한 DTV 인증 및 XCAS 서비스에 필요한 SM(Secure Module) 모듈을 다운로드하기 위한 기법을 제안한다.

• Journal of information and communication convergence engineering
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• v.18 no.1
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• pp.22-27
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• 2020

Content centric networking (CCN) is regarded as promising internet architecture because it can provide network efficiency in terms of bandwidth consumption by separating contents from a specific network location and decrease network congestion events. However, the application of a CCN does not widely consider the side effects of mobile devices, particularly mobile content sources. For content source mobility, a full routing update is required. Therefore, in this study, a route optimization scheme is proposed for mobile content sources in a CCN environment to provide low communication overhead, short download time, and low resource consumption. The proposed scheme establishes a direct path between content requesters and a mobile content source for the exchange of interest and data packets using interest-piggybacked data packets. Based on the inherent CCN naming characteristics, the content source does not know the name prefix of the content consumer, and thus the proposed optimized CCN scheme utilizes the content router in the home domain of the content source.

• Annual Conference of KIPS
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• 2003.11b
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• pp.1049-1052
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• 2003

A home network system was implemented using IPv6 and SIP. We integrated different kinds of home devices into IPv6 address system, and built control system independent of controller's address and location, using SIP. Also, controllers can download each device centrol messages without any global definition of handling it. We implemented this system by home device emulator, and PDA controller to control home devices.

• Annual Conference of KIPS
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• 2005.11a
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• pp.1089-1092
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• 2005

1999 년부터 상용화된 무선 인터넷 서비스는 국내의 경우 이동통신 3 사가 각기 독자적인 통신 기법 및 서비스 체제를 가지고 있었다. 이로 인하여 서로 다른 이동통신사의 무선 단말기 플랫폼들은 상호 호환성(interoperability)이 없었다. 이러한 비호환성은 단말기 제조업체나 컨텐츠 제작 업체에게 기술적인 어려움은 물론이고 비용적인 측면에서 여러 가지 문제점을 낳았다. 이러한 문제점을 해결하고자 2002 년부터 WIPI(Wireless Internet Platform for Interoperability)라는 표준화된 무선 인터넷 플랫폼의 개발이 시작되어 현재는 WIPI 2.0 을 탑재한 무선 단말기가 출시된 상황이다. 본 논문에서는 WIPI 플랫폼이 탑재된 무선 단말기가 유료화된 컨텐츠를 다운로드 하여 사용할 수 있도록 해주는 다운로드 시스템의 설계 및 구현에 대해서 기술한다. 이를 위해 컨텐츠 다운로드 프로토콜, 최적화된 컨텐츠의 결정기법, 그리고 COD(Compile On Demand)를 이용한 네이티브 코드 적용 기법에 대해 설명한다.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.2
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• pp.72-74
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• 2006

In this paper, a wireless multimedia service interacting with key input of a phone number is Presented. In the conventional handset, when the key button is pressed, numbers are displayed or the embedded sound is played. Also, the contents are fixed and cannot be changed. In this paper, we propose a wireless multimedia service playing multimedia contents in accordance with the key input of a phone number. The contents can be downloaded from the wireless internet server. To implement this service, file format, fast codec and download structure are proposed. Using the presented structure, this service is being provided by a telecommunication company in Korea. Various applications based on this service are being expected.

• Journal of Engineering Education Research
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• v.15 no.6
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• pp.49-57
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• 2012

This paper deals with the individual homework creating and management system. The proposed system can be applied to various types of homeworks such as problem solving, experiment and watching some video material related to lecture. Every authorized student can connect the web server in which the proposed system is implemented and download his assignment which is different from other student's. Also we provide real application examples to show the feasibility and effectiveness of the proposed system regarding 3 types of assignments and expect to help the students to do self-regulated study and improve their professional capability.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.12
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• pp.3135-3148
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• 2013

The popularization of streaming networks and mobile devices brings a new kind of network called mobile peer-assisted streaming network. In this network, service provider not only offers downloading services, but also pre-pushes resources to users for caching. Users can download their demanded resources while working as servers for uploading the cached data. Also the mobile characteristic makes high package losing probability in this network. So we study how the service provider pre-pushes or the user downloads resources efficiently and effectively while considering the package losing in this paper. We build utility models for service provider and user, and solve the models using Bellman's theory to achieve Nash Equilibrium which shows the service provider's optimal pre-pushing speed and user's optimal downloading speed. The numerical simulation demonstrates the efficiency and effectiveness of our proposed pre-pushing and downloading scheme by comparing to the traditional scheme.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2002.11a
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• pp.237-242
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• 2002

DASE(DTV Application Software Environment)는 ATSC의 지상파 방송 표준으로 한국에서는 월드컵과 아시안게임을 거쳐 현재까지 시험방송 중에 있다. 국내에서는 주요한 데이터전송 방식으로 데이터 carousel 프로토콜을 사용하고 있는데, 지금까지는 전송되는 파일의 이름과 content type에 관한 정보가 DST(Data Service Table)에 들어가 있었으나, ATSC 표준이 변경됨에 따라 이 정보가 DII(Download Info Indication)[2]의 descriotor로 위치가 변경되었다. 이로 인해 DII에 삽입해야 하는 데이터의 양이 증가하여 하나의 DII에 삽입 가능한 모듈의 개수가 감소되었고 전송량이 증가하게 되었는데, 본 논문은 base URI와 default content type을 통해 이러한 제약을 완화할 수 있는 방식에 대해 ATSC S13에 제안한 내용을 토대로 기술하였다.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.3
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• pp.141-147
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• 2005

In the field of electrical industry, embedded computing environment including hardware and software is getting more important as the industry shifts to the knowledge-based one. Java could play a great role as bridging technology in such a transition because it provides a lot of benefits like dynamic application download, compatibility of cross platform, and its own security solution. However, the Java technology has a limitation of real-time problem when it is applied to the embedded computing system of the electrical industry. To solve the problem, a novel java-native combination model has been proposed and designed to a firmware level. This scheme has been employed in four kinds of control boards. The result shows that the proposed model has great potential to implement the real-time processing in control of the devices.

• Journal of Digital Contents Society
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• v.8 no.1
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• pp.51-59
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• 2007

In case of the service of the existing PC package game, the production cost and distribution cost is high, the illegal copies by Internet is widespread. To prevent, game production companies and distributors provide a GOD(Games On Demand) service that players download the game content by internet to play games. But, there is little research on current status of GOD service in the country. Therefore, in this paper, we define GOD service, analyse the structure of GOD service, describe domestic current status and research on the problem and solutions of GOD service. This paper gives useful information to companies providing GOD.