• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2B
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• pp.361-371
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• 2010

To vitalize the terrestrial DMB market, we introduce a personalized DMB(PDMB) service model based on metadata, especially DMB ECG XML standardized by TTA, under the convergence of broadcasting and telecommunications. Also we introduce the personalized DMB service system developed to validate the conformance of DMB ECG XML standard and the usefulness of DMB ECG service. The personalized DMB service system is described in details from the authoring stage to the consumption stage of the contents. The results of experimental tests for the personalized DMB service system are also introduced in this paper. We finally address the possibility of making successful personalized DMB services in mobile multimedia broadcasting market.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.11a
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• pp.7-10
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• 2009

지상파디지털멀티미디어방송(Terrestrial-Digital Multimedia Broadcasting: T-DMB) 시스템 수신기는 이동 환경에서 방송신호의 원활한 수신을 요구한다. 따라서, 일정 레벨 이상의 전계강도와 단일 주파수 망(Single Frequency Network: SFN) 구축을 반드시 요구하게 된다. 본 논문에서는 단일 주파수 망을 통해 T-DMB 신호를 서비스하기 위해 설치하고 있는 등화형 T-DMB 동일채널 중계기(Equalization-Digital Multimedia Broadcasting On-Channel Repeater, E-DMBR)의 성능 및 신호 품질을 측정하기 위한 T-DMB RF 신호 모니터링 장비(T-DMB Monitoring System : DMR)에 대한 요구사항을 고찰하고, 그러한 요구사항을 만족하기 위한 모니터링 장비의 구조 및 구현 방법을 제안하며, 이를 이용한 개발 사례에 대한 결과를 보인다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.07a
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• pp.178-180
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• 2012

본 논문에서는 유럽의 디지털 라디오 전송 규격인 DRM(Digital Radio Mondiale)의 Band II 대역 전송 모드인 모드 E의 전송률 향상 기법을 제안한다. DRM 모드 E는 FM 방송과의 동시방송 등의 문제를 고려하여 100kHz 대역폭에서 186kbps의 전송률을 제공한다. 하지만, 이 전송률은 모바일TV 등 멀티미디어 서비스를 제공하기 위해서는 부족하기 때문에 전송률의 향상이 요구된다. 논문에 제안된 전송률 향상기법은 기존의 DRM 모드에 변조방식 및 부호방식을 추가하는 방식으로 최대 350kbps의 전송률 제공이 가능하며, FAC(Fast Access Channel)의 예약필드에 신규 방식에 대한 정보를 전송함으로써 기존 시스템과 호환성을 유지할 수 있다. 모의실험 결과에서, AWGN(Additive White Gaussian Noise) 채널의 비트오류율 le-4를 기준으로 223kbps의 전송을 위해서는 13dB의 SNR(Signal-to-Noise Ratio)이 요구되며, 351kbps의 전송률 제공을 위해서는 약 18dB의 SNR이 요구됨을 확인할 수 있다. 또한, 다중경로 페이딩 채널환경에서 부호율이 1/2인 경우에는 이동속도보다는 지연확산이 성능에 영향을 주지만, 부호율이 1/2 보다 크며 150Km/h이상 증가하면 오류마루가 발생함을 확인할 수 있다.

• Broadcasting and Media Magazine
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• v.11 no.4
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• pp.104-117
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• 2006

In this Paper, we analyze the application of Interactive Data Broadcasting in DMB(Digital Multimedia Broadcasting) in the accordance with convergence of service and technology. With the acceleration of digital convergence in the Ubiquitous period substantial development of digital media technology and convergence of broadcasting and telecommunication industry are being witnessed. Consequently these results gave rise to newly combined-products such as DMB(Digital Multimedia Broadcasting), WCDMA(Wide-band code division multiple access), Wibro(Wireless Broadband Internet), IP-TV (Internet protocol TV) and HSDPA(High speed downlink packet access). The preparatory stage for the implementation of Interactive Data Broadcasting Service will be reached by the end of December, 2006. DMB is the first result of a successful convergence service between Broadcasting and Telecommunication in new media era. Multimedia technology and services are the core elements of DMB. The Data Broadcasting will not only offer various services of interactive information such News, Weather, Broadcasting Program etc, but also be linked with characteristic function of mobile phone such as calling and SMS(Short Message Service) via Return Channel.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.1B
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• pp.1-12
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• 2002

In the multimedia CDMA mobile communication service, it is required to support various applications, such as voice, video, file transfer, e-mail, and Internet access, with guaranteed QoS. In the mixed traffic environment ,which consists of voice, stream data, and packet data, we analyze the network where preemptive priority is granted to delay-intolerant voice service and a buffer is offered to delay-tolerant stream data service. And, for best-effort packet data service, the access control by transmission permission probability is applied to obtain prominent throughput. To analyze the multimedia CDMA mobile communication system, we build a 2-dimensional markov chain model about prioritized-voice and stream data services and accomplish numerical analysis in combination with packet data traffic based on residual capacity equation.

• Journal of the Korea Society for Simulation
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• v.21 no.1
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• pp.45-54
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• 2012

Advances in mobile communication and digital video technology enable to commercialize converged multimedia services such as VoD in the mobile networks. Media convergence is evolving into U-Cloud and mobile IP-TV services constituted by high-speed mobile multimedia networks and integrated personal devices. This paper proposes a resource allocation scheme to guarantee QoS of converged mobile multimedia services, and simultaneously maximize legacy services in heterogeneous wireless networks. Performances are analyzed by the simulation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.111-119
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• 2010

With the rapid progress of wireless technologies today, mobile terminals with multiple access interfaces are emerging. In recent years, WLAN (Wireless Local Area Networks) has become the premier choice for many homes and enterprises. WiMAX (Worldwide Interoperability for Microwave Access) has also emerged as the wireless standard that aims to deliver data over long distances. Therefore, it is important to explore efficient integration methods for delivering multimedia data between heterogeneous wireless networks. In this paper, we developed the simulation models and environments for the mobile multihomed node that has both WiMAX and WLAN interfaces and can move around in both networks by using mobile IP. In order to verify the developed models, we designed and constructed several simulation scenarios, e.g. movement in WiMAX/WLAN, group mobility, MANET, and nested MIP under the various traffic environments such as oneway or bothway UDP packets, FTP traffic, and voice with SIP protocol. The simulation results show that the developed models are useful for mobility studies in various integrated wireless networks.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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• pp.325-328
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• 2016

본 논문은 2016 년 6 월 TTA 개정 표준 "HTML5 기반 스마트 TV 플랫폼(TTAK.KO-07.0111/R2)"에서 스마트폰, 태블릿 등 컴패니언 디바이스를 통해 스마트 TV 에 설치된 서비스 애플리케이션(이하, 앱)을 원격으로 조회, 실행, 종료 등의 제어를 지원하는 표준 기술을 소개한다. 이 기술은 표준에서 이미 정의된 멀티스크린 기술을 바탕으로 컴패니언 디바이스(모바일, 테블릿 등)를 통해 스마트 TV 를 인지하고 해당 TV 의 IP 주소 정보를 인식하여 JSON-RPC 프로토콜을 이용한 함수 형식 제어 요청을 통해 정보를 전달하는 방식으로 스마트 TV 수신기는 앱 정보 제공, 특정 앱 실행, 앱 종료 등 다양한 원격 앱 제어 기능을 서비스한다. 또한, 해당 원격 앱 제어 기술을 PC 기반의 가상환경인 스마트 TV 2.0 에뮬레이터 구현으로 표준기술에 유효성 검증과 서비스 응용 사례를 설명한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.1-7
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• 2009

At a Internet service provider(ISP), field human resources visit many customers sites to provide multimedia services to customers in ubiquitous environment. Scheduling the resources is a hard problem because there are many tasks which have to be done by the resources and the number of the resources is not sufficient. To tackle this problem, ISPs had used team-based scheduling system. However, this aporoach was not sufficient to reduce the number of frequent changes of arrival time and could not increase operational efficiency. We also developed an optimal resource selection algorithm based on statistical information when an operator assigns a task to the resource. After we adopted this algorithm to the real world, the resources can do more tasks in a day.

• 전자공학회논문지 IE
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• v.48 no.4
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• pp.19-24
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• 2011

Advances in mobile communications, portable computing and personal electronics have led consumers to demand large viewing area, bright, high resolution, compact and long life portable displays. Pico projectors are the latest technology to prove that big things often do come in small packages. Our goal in this paper was to implement a portable, low power, and highly adaptable miniature pico projector system. The pico projector is designed many functions of the pico projector solutions, multimedia, and T-DMB broadcasting.