• Korean Management Science Review
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• v.22 no.1
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• pp.179-197
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• 2005

This study examines market acceptance for DMB service, one of the touted new business models in Korea's next-generation mobile communications service market, using adoption end diffusion of innovation as the theoretical framework. Market acceptance for DMB service was assessed by predicting the demand for the service using the Bass model, and the demand variability over time was then analyzed by integrating the innovation adoption model proposed by Rogers (2003). In our estimation of the Bass model, we derived the coefficient of innovation and coefficient of imitation, using actual diffusion data from the mobile telephone service market. The maximum number of subscribers was estimated based on the result of a survey on satellite DMB service. Furthermore, to test the difference in diffusion pattern between mobile phone service and satellite DMB service, we reorganized the demand data along the diffusion timeline according to Rogers' innovation adoption model, using the responses by survey subjects concerning their respective projected time of adoption. The comparison of the two demand prediction models revealed that diffusion for both took place forming a classical S-curve. Concerning variability in demand for DMB service, our findings, much in agreement with Rogers' view, indicated that demand was highly variable over time and depending on the adopter group. In distinguishing adopters into different groups by time of adoption of innovation, we found that income and lifestyle (opinion leadership, novelty seeking tendency and independent decision-making) were variables with measurable impact. Among the managerial variables, price of reception device, contents type, subscription fees were the variables resulting in statistically significant differences. This study, as an attempt to measure the market acceptance for satellite DMB service, a leading next-generation mobile communications service product, stands out from related studies in that it estimates the nature and level of acceptance for specific customer categories, using theories of innovation adoption and diffusion and based on the result of a survey conducted through one-to-one interviews. The authors of this paper believe that the theoretical framework elaborated in this study and its findings can be fruitfully reused in future attempts to predict demand for new mobile communications service products.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.138-144
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• 2008

In this paper, we propose a novel single-feed dual-band circular polarization square patch antenna for GPS(global positioning system)/DMB(digital multimedia broadcasting) receiver. The proposed antenna has folded slots at the 4 corners and a diagonal slot at the center of the square patch. The measured -10 dB impedance bandwidths of the proposed antenna were 84 MHz ranging from 1.516 GHz to 1.600 GHz for the low frequency band(GPS) and 109 MHz ranging from 2.596 GHz to 2.705 GHz for the high frequency band(DMB). The measured peak linear antenna gains of the proposed antenna were 6.23 dBi at 1.575 GHz for GPS and 6.97 dBi at 2.642 GHz for DMB band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.11
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• pp.1130-1137
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• 2009

This paper proposes a new clock routing design for suppressing clock harmonic effects in a Printed Circuit Board (PCB) for a terrestrial Digital Multimedia Broadcasting(DMB) system. Typical crystal reference frequencies that are widely used in DMB tuners are 16.384 MHz, 19.2 MHz, 24.576 MHz. When the high-order harmonic components of these reference frequencies fall near the RF channel frequencies, receiver sensitivity of the tuners is seriously degraded. In this work, we propose a new clock routing design in order to address the clock harmonic coupling issue. The proposed design incorporates two inductors for isolating the clock ground from the main ground, and adopts a new strip line-style routing instead of the conventional microstrip line style routing to minimize the overlap area with the main ground. As a result, the RF sensitivity of the T-DMB tuner is improved by 2 dB.

• Journal of Broadcast Engineering
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• v.12 no.3
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• pp.214-221
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• 2007

In this paper, we presents conformance test tools for the broadcast web site (BWS) service which is one of the data services for terrestrial digital multimedia broadcasting (T-DMB). First, the methodology for the conformance test is established for both transmitters and receivers of T-DMB BWS services. The test tools consist of three parts: BWS bitstream analyzer, BWS reference decoder (software) module, and BWS test bitstreams. For testing transmitted BWS bitstreams, we developed the bitstream analyzer. For testing BWS receivers, we developed the reference Ifecoder module and created the test bitstreams. Actually the bitstream analyzer developed in this paper was used for the verification of the test bitstreams. The same test bitstreams are fed to a BWS decoder module under test and the reference decoder module and the results from the two are compared for verification. The test tools can be used for the test of all the protocol and textual/image specifications related to BWS including MOT protocol, HTML, PNG, MNG, JPEG, and Ecma Script.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.2 s.117
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• pp.227-232
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• 2007

In this paper, we propose Triple-band antenna, which is practicable for the transmission and the reception of the frequency band used in mobile broadcast and mobile internet. We choose T-DMB(Band-III), DAB(L-Band) for a mobile broadcast and Wibro for a mobile internet. The size of proposal antenna measures $10{\times}74{\times}0.6[mm^3]$. Although being defective in that T-DMB bandwidth is rather narrow, the antenna, considering the reception environment, has an advantage of a realistic possibility of reception in 8 channel($180{\sim}186$ MHz)and 12 channel($206{\sim}210$ MHz) of T-DMB band, being given broadcast services. Also It has gains similar characteristics of ideal dipole antenna in DAB and Wibro band.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.5
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• pp.629-636
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• 2011

This paper presents the design of a novel integrated T-DMB/GPS/Mobile antenna for vehicular application. The T-DMB antenna is designed with a modified meander-type microstrip patch providing linearly a polarized broadside radiation pattern. The GPS antenna is designed with an inserted slot in the patch antenna providing circularly polarized broadside radiation pattern. The Mobile (GSM, AMPS, DCS, PCS, UMTS, etc.) antenna is designed as a modified G-type patch antenna providing multi-band operation. Experimental results indicate that the impedance bandwidth (VSWR 1:2.5) of the proposed T-DMB /GPS/Mobile antenna satisfactorily matches that of the simulation results. The 2D and 3D radiation patterns and gains according to the results of the experiment are also presented and discussed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.4
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• pp.351-356
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• 2009

A dual-mode annular ring antenna for both global positioning system(GPS) and satellite digital multimedia broad-casting(DMB) is designed. The proposed antenna consists of a coupling feed line and four slots on the annular ring patch. The gap between the feed line and the annular ring patch is used for an input impedance matching, and the slot length is used for adjusting the resonant frequency of the $TM_{21}$ mode at the DMB frequency. The antenna was fabricated and measured. The experimental results show that the antenna resonants at the GPS and DMB frequencies with suitable bandwidths, and had a broadside radiation pattern at the GPS band and a conical beam radiation pattern at the DMB band.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.21-27
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• 2014

The broadcasting of the analog TV was terminated in 2012 and was converted into the broadcasting of the digital TV, so methods for arrival of DAB(Digital Audio Broadcasting) are planned recently. Thus, with digitization of analog broadcasting and appearance of new service, it takes effort to improve efficiency of broadcasting frequency. T-DMB which came in 2005 uses existing analog TV band and its channel is allocated inefficiently in order to avoid interference between mutual services. However, the foundation which can afresh reorganize T-DMB channel is building up because the broadcasting of the analog TV was terminated. So, this paper proposes the method for national SFN composition of T-DMB considering existing local broadcasting in order to provide better service to users as well as improve efficiency of broadcasting frequency.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2008.11a
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• pp.41-44
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• 2008

디지털 컨버전스와 유비쿼터스 시대의 시작은 디지털 미디어 기술의 발전과 방송 통신 사업의 컨버전스를 가속화 시켰으며, 그 결과로DMB, WCDMA, Wibro, IP-TV, HSDPA 등의 새로운 형태의 차세대 제품과 서비스들이 뉴미디어 매체의 핵심으로 등장하고 있다. 국내에서 방송 통신의 컨버전스의 빠른 진행은 세계 최초로 디지털 멀티미디어 방송(DMB) 서비스 시작을 가능하게 하였다. DMB 서비스는 멀티미디어 서비스가 핵심이다. DMB 데이터 서비스인 Broadcasting Website Service(BWS)는 현재 지상파 DMB방송 사업자인 KBS, MBC, SBS, YTNDMB가 본방송 준비 막바지 단계이며, 삼성전자와 LG전자를 비롯한 단말기 개발사들도 데이터 서비스를 위한 제품 출시에 서두르고 있는 등 DMB 산업의 활성화의 주역이 될 것으로 예상된다. DMB의 데이터 서비스는 뉴스, 날씨, 프로그램 정보 등의 단순 정보보기 수준에 그치지 않고, 리턴 채널을 이용한 양방향 서비스와, SMS, 전화걸기 등 휴대전화 단말의 고유기능과의 연계를 통한 다양한 서비스도 선보일 것이다. 더 나아가 향후 T-Commerce와 개인 광고 등 새로운 비즈니스 모델과 사업영역으로 확산시켜 나갈 수 있을 것이다. 그러나, 아직까지 DMB와 데이터 서비스는 초기단계로서, 표준 기술의 규격 작업, 이론적 논의들, 관련 사업자들의 비즈니스 준비 등에서 검토되어, 실제 사용자들을 대상으로한 연구 분석이 이루어 지지 않았다는 연구의 한계를 가지고 있다. 본격적으로 방송, 통신 컨버전스 데이터 서비스가 시작되면서, 사용자들에 초점을 맞춘 많은 연구가 이루어지길 바라며, 이러한 연구의 분석을 통해 또 다른 새로운 서비스와 비즈니스 기회의 창출을 기대해 본다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2007.02a
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• pp.29-32
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• 2007

지상파 DMB 상용 서비스가 시작된 지 1년이 경과함에 따라 DMB 시청자의 수가 급격히 증가하였다. 그러나 DMB와 융합된 새로운 서비스가 활성화가 활발하지 못하고, 따라서 여러 가지 부가 수익서비스가 창출되지 못하고 있다. 그 이유 중의 하나는 기존에 제안된 양방향 데이터 서비스들은 모바일 홈페이지로의 연결하는 방식이라, 시청자가 DMB 단말기의 작은 화면에서 단말기의 버튼이나 터치스크린을 사용하기 불편하고, 방송시청이 불편하다. 또한, 기존의 방송참여 방식인 ARS, SMS 방식을 포용하지 못한다. 본 논문은 기존의 시청자 참여 방식을 분석하고 기존 방식의 약점을 보안하여 URL 방식 명령을 통한 양방향 서비스를 제안한다. 이 방법은 작은 디스플레이를 통해 홈페이지 방식을 고집하지 않고, 기존의 ARS, SMS를 포용하며, 단순한 동작으로 시청자 참여가 가능하다. 본 논문이 제안하는 방법은 서비스 방식 및 구조에 따라 ARS 서비스를 제공하는 URL방식 명령, SMS 서비스를 제공하는 URL 명령, 서버응용 호출서비스를 위한 URL방식 명령(SERVER-URL), 클라이언트 응용호출 서비스를 위한 URL방식 명령(CLIENT-URL)으로 분류된다. 본 방법들은 사용자의 참여가 단순하게 이루어지도록 방송시 송출되며, 이러한 방법은 ol동 방송에 특히 적합할 것으로 사료되어, 앞으로 보다 실용적인 DMB 기반의 융합 서비스에 사용될 것으로 사료된다.