• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10B
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• pp.900-908
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• 2006

This paper studied on the future market competitive structure among mobile multimedia services that offer a variety of multimedia services and contents through wireless networks. In the past, forecasting methods based on market data would be used popularly in telecommunications industry. However, methods must focus on not market data but customer preferences. In this reason, paper use to forecast the market competitive structure and offer firm strategies and policies using a customer choice probability model.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.2 s.93
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• pp.211-216
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• 2005

In this paper, GPS/PCS/Satellite DMB compact chip antenna is designed using stacked meander line for mobile communication handset. The fabricated antenna size is $12.52mm\times19.95\times1.05mm$. The coupling is adjusted by via and arrangement among meander lines to improve FR(Frequency Ratio) and return-loss. The fabricated antenna achieve triple-band. The resonance frequencies are 1.696 GHz, 1.888 GHz and 2.680 GHz. The impedance bandwidths are 150 MHz, 120 MHz and 60 MHz. The maximum gains of antenna are 0.08 dBi, 1.70 dBi and -1.27 dBi at resonance frequencies.

• The Journal of Society for e-Business Studies
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• v.11 no.2
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• pp.111-134
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• 2006

This paper analyzes the resistance to mobile commerce services in consumer adoption process. Relative advantage, compatibility, perceived risk, complexity, self-efficacy, innovativeness and attitude for competing service have been chosen as independent variables. This paper also investigates on the significant factors which resist against adoption of mobile commerce service according to adoption phase. The results show that relative advantage, self-efficacy, perceived risk, attitude for competing service are significant factors to affect resistance to mobile commerce services. Relative advantage, perceived risk, attitude for competing service are significant resistance to mobile commerce services for consumers in before-adoption group and compatibility, complexity, self-efficacy are significant factors for consumers in after-adoption group. This study can be extended to new communication services such as Wibro and DMB to reduce resistances in early adoption phase.

• The KIPS Transactions:PartB
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• v.12B no.6 s.102
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• pp.637-646
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• 2005

Most of the multimedia contents for DBM services art provided as MPEG-2 bit streams. However, they have to be transcoded to H.264 bit streams for practical services because the standard video codec for DMB is H.264. The existing transcoder architecture is Cascaded Pixel-Domain Transcoding Architecture, which consists of the MPEG-2 dacoding phase and the H.264 encoding phase. This architecture can be easily implemented using MPEG-2 decoder and H.264 encoder without source modifying. However. It has disadvantages in transcoding time and DCT-mismatch problem. In this paper, we propose two kinds of transcoder architecture, DCT-OPEN and DCT-CLOSED, to complement the CPDT architecture. Although DCT-OPEN has lower PSNR than CPDT due to drift problem, it is efficient for real-time transcoding. On the contrary, the DCT-CLOSED architecture has the advantage of PSNR over CPDT at the cost of transcoding time.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.2 s.5
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• pp.1-8
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• 2004

Characteristics of digital broadcasting are multi-channel, high-definition and multi-function. especially, multi-function is enable us to do a variety of services except for an image and a voice. This paper, therefore, is analyzed propagation environment in Busan into ETRI model application about 지상파 DMB service. It takes to be simulated in Busan area around the mountains area and high building. So it measures the electric field strength in standards. Distribution pattern are similar with mutually in the 이론 and real measurement. Even areas are almost the same, but urban areas and mountains are different with mutually. Therefore, we conclude that ETRI propagation model and theoretical modeling in a free space in Busan area is not suitable.

• Journal of KIISE:Information Networking
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• v.33 no.5
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• pp.380-394
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• 2006

Traditional Internet services provide the same level of qualify to all users without considering about their application's QoS (quality of service) requirements. Because the wireless and Internet technologies are evolving rapidly, the powerful mobile devices are more widely used. Therefore, the new applications such as DMB (digital multimedia broadcasting), VoD (video on demand), telemedicine, and etc. demand appropriate QoS and host mobility. To satisfy free mobility and QoS, we deploy Diffserv (differentiated services) model to the mobile IPv6 networks. We propose the operational procedures and cost analyzing models for providing an MN's mobility and QoS. Also its performance is presented by cost analyzing and the future works are described.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.525-528
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• 2009

This paper attempts to conceptually examine the potential of IPTV(Internet Protocol Television). First, this paper reviews the concept of a bridging telecommunication service and a gap-filling telecommunications service. Second, the current status of various emerging telecommunications services including mobile WiMax, called WiBro, and both satellite and terrestrial digital multimedia broadcasting service, called DMB are comprehensively analyzed. Based on those analysis, this paper analyzes whether IPTV is regared as a bridging telecommunications service or a gap-filling telecommunications service and examine the potential growth possibility of IPTV. Finally, the suggestions for policy makers are discussed.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.5
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• pp.325-330
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• 2014

The era of convergence is being applied to all areas of Information and Communication Technology (ICT). The convergence of broadcasting service and communication service almost occurs on smart devices including smartphone. The smart hybrid Digital Multimedia Broadcasting (DMB) is a typical example of the convergence of broadcasting and wireless communication service. The hybrid mobile broadcasting service can support seamless video, 3D, high quality, and additional data services based on network connection between the broadcasting and wireless network. The gateway and terminal (including apps on the smartphone) take the role of the main components on the hybrid service. This paper presents the service concept, main components structure, the implementation of gateway and terminals, and field test to the urban areas for the mobile hybrid system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3C
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• pp.245-249
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• 2006

In general, a large number of the memory accesses are required to decode the CAVLC in H.264/AVC. This is a serious problem for applications such as a DMB and videophone services because of the considerable amount of power that is consumed in accessing the memory. In order to overcome this problem, we propose an efficient run_before decoding method, In the proposed method, the memory access is removed by using a FSM with arithmetic operations. The simulation results show that the proposed algorithm does not degrade video quality is not degraded as well as the power is saved.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.11a
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• pp.249-251
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• 2012

최근 대형 재난의 증가로 안전에 대한 관심이 증가하고 있는데 이러한 재난을 대비하기 위해서는 효과적, 효율적인 재난방송이 필요하다. 재난방송을 수신할 수 있는 단말 중에 휴대전화, 내비게이션 등의 휴대용 단말은 정전 상황에서도 이용할 수 있어 특히 유용하다. 본 논문에서는 휴대용 단말에서 이용할 수 있는 재난정보전달 기술을 분석하여 장단점을 평가하였다. 이를 위해 지상파DMB 재난경보방송과 스마트폰 어플리케이션, CBS(Cell Broadcasting System) 재난문자방송과 최근 연구 중인 자동인지 T-DMB 재난방송을 분석하고, 재난방송에서 중요한 특성인 안정성, 효율성, 자동인지(wake-up), 지역맞춤 서비스 등의 항목에 대해 평가하였다. 평가 결과 모든 특성을 만족하는 기술은 없어 복수의 기술을 동시에 적용하여 장점을 활용하는 방안과, 이에 따른 중복 수신 문제를 해결하기 위한 연구 및 협력이 필요하다는 결론과 차세대 재난방송 서비스인 자동인지 T-DMB 재난방송에서 이와 같은 특성을 만족시키고 빠른 시일 내에 보급 및 확산이 필요하다는 결론을 도출하였다.