• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.12
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• pp.1352-1370
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• 2010

In this paper, we investigated the shadow area of radio programs which are currently being broadcast via FM 102.5 MHz in Jeollabuk-do consisting of 6 cities and 8-guns. The field strength data of FM 102.5 MHz was used with criterion of shadow area. As a result, the field strength of the eastern mountainous area in Jeollabuk-do was very low. We also measured, compared and analyzed the field strength of 102.5 MHz(TBN-Jeonju), 100.7 MHz(KBS) and 99.1 MHz (MBC) in Jeollabuk-do. Based on the field strength data, we tried to find what correlation exists and how much influence is between difference of antenna output power and solution of shadow area. In result, enhancement of antenna output power is not solution in terms of reducing the shadow Area of 102.5 MHz(TBN-Jeonju). In addition, we measured, compared and analyzed the field strength of 102.5 MHz(TBN-Jeonju) and 106.9 MHz(EBS). In fact, the relay stations with 104.1 MHz, 104.9 MHz, 105.3 MHz and 107.5 MHz of EBS FM has a number of FM relay stations in the eastern mountainous area of Jeollabuk-do. As a result, we confirmed that EBS almost did not have shadow area in the eastern mountainous area of Jeollabuk-do based on the field strength data. As in the case of EBS and KBS, we suggest installing TBN-Jeonju FM relay station with the best solution to reducing the shadow area to extend the audible range of TBN-Jeonju.

• Journal of Convergence for Information Technology
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• v.11 no.4
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• pp.26-34
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• 2021

In the era of the Fourth Industrial Revolution, the future battlefield will carry out multi-area operations with hyper-connected, high-speed and mobile systems. In order to prepare for changes in the future, the Korean military intends to develop various weapons systems and form a multi-layer tactical network to support On The Move communication. However, current tactical networks are limited in support of On The Move communications. In other words, the operation of multi-beam antennas is necessary to efficiently construct a multi-layer tactical network in future warfare. Therefore, in this paper, we look at the need for multi-beam antennas through the operational scenario of a multi-layer tactical network. In addition, based on development consideration factors, features of rotary-wing and fixed-wing aircraft, we present the location and operation of airborne relay drone installations of multi-beam antennas.

• Journal of Korean Port Research
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• v.13 no.1
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• pp.1-10
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• 1999

Port competition is generally classified into two type of inter-domestic ports and intermational ports and the latter is measured how to secure the function of intermediacy for foreign cargoes among competing parts. In the Northeast Asia top 20 world container ports such as Pusan, Kobe, Yokohama and Kaohsiung are struggling to induce transshipment containers generated in the North China region. This paper aims to analyze and evaluate the competitive factors of the said ports such as port site facilities expenses service level and flexibility of management and operations and suggest the feasible strategies that the Pusan Port to be viable transshipment center in the region. The evaluation is attempted twice. First attempt is evaluated by present conditions of each port and second attempt by upgraded conditions of evaluation value such as port service level and flexibility of port management and operations resulted from the implementation of the ON-DOCK service system. The results of evaluation are as follows; (1) Port competitiveness of first evaluation is ranked in Kobe=Kaohsiung >Pusan>Yokohama. (2) Second evaluation is resulted in Kobe> Pusan= Kaohsiung>Yokohama. According to this results the competitiveness edge of the Pusan Port is able to strengthen by implementation of the ON-DOCk system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.1
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• pp.196-205
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• 1996

Severice allocation to satellite transponders under consideration of interference caused by inter-satellite and intra-satellite systems is one of the most important issue in terms of optimal usage of satellite network resource. In this paper, we present a new and show several simulation results to verify the proposed method. Especially, our concerns are concentrated on the cost (interference) matrix which is believed to be optimal in obtaining the service allocation plan. The method and concepts presented in this paper may be well applicable to making a plan for service assignment of the satellite communication systems.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.06a
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• pp.26-28
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• 2017

스마트폰 보유율과 모바일 이용 행태가 급변함에 따라 방송사에서는 양방향 서비스를 포함한 다양한 방송 서비스를 제공하려고 노력하고 있다. 양방향 서비스 방송에서 시청자가 보낸 문구를 실제 화면에 보여주기까지 PD 와 담당자들의 수작업이 필요하다. 하지만 하루 평균 약 7,200 건 (MBC 오늘아침 소통중계)의 양방향 서비스 관련 로그가 남게 되어, PD 가 일일이 판별하기에는 많은 노력이 따른다. 이러한 불필요한 노력을 줄이기 위해 본 논문에서는 감정 분석을 이용한 딥러닝 인공지능 기반 양방향 서비스 방송 소프트웨어 시스템을 제안한다. 첫째, 시청자들이 전송한 의견, 건의사항, 내용 등을 전처리 과정을 진행한다. 둘째, 감정 사전을 이용해 전처리 된 단어와 비교하여 시청자가 보낸 문구의 감정 점수를 계산한다. 셋째, 과거 실제 방송에 송출된 시청자 문구를 감정 점수와 함께 딥러닝을 이용하여 훈련시킨다. 본 논문의 성능을 평가하기 위해, 2017 년 생방송 오늘아침 소통중계에 사례연구를 진행하였고 효율성을 보였다. 앞으로 이러한 양방향 서비스 방송 소프트웨어 시스템 도입으로, PD 가 방송 제작에 더욱 집중 할 수 있도록 차별화된 방송을 준비하는데 크게 기여할 것이라 기대한다.

• Korean Journal of Applied Biomechanics
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• v.13 no.3
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• pp.231-239
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• 2003

본 연구의 목적은 2002년 한 일 월드컵에서 우승을 차지한 브라질의 7경기를 대상으로 축구 경기를 분석하는 것이다. 본 연구에 사용된 경기 분석용 비디오테이프는 FIFA에서 인정한 공식 중계방송사인 한국방송공사(KBS)의 중계 자료를 사용하였다. 본 연구의 통계 처리는 SPSS프로그램을 이용하여 상관관계분석(Pearson Correlation)을 실시하였다. 본 연구를 통한 결론은 다음과 같다. 첫째, 브라질 팀은 득점할 수 있는 비율이 높은 수비에서 최종공격수로 바로 연결되는 역습에 의한 공격(20.0%), 미더필드를 통한 빠른 공격(20.0%), 세트 플레이에 의한 공격(15.5%), 공격지역에서 볼을 뺏은 후 공격(18.5%)으로 다양한 공격 전술을 구사하여 상대 팀보다 많은 득점기회를 얻었다. 둘째, 브라질 팀은 골키퍼를 제외한 전 선수의 볼 소유 횟수가 비슷하게 나타나서, 전 선수가 고르게 활약했다. 경기의 질을 나타내는 지수인 인덱스에서는 수비수 중에는 중앙 수비수가 3.3, 미드필더 중에는 왼쪽 중앙 미드필더가 5.0, 공격수 중에는 중앙 공격수가 1.4로 포지션별로 제일 높게 나타나서 경기에서 중요한 역할을 수행하였다. 셋째, 브라질 팀은 세트플레이 성공률과 공격지역에서의 볼 점유율의 증가를 통하여 골당공격성공률을 높인 것으로 나타났다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.401-405
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• 2007

In sensor network, cluster based routing protocol about efficient energy usage method has researched variously. But existing cluster based routing protocol have problems. one of the problem is sensor nodes's imbalance energy consumption problem at cluster reconstruction. anther is non- connection problem between header node and spc node when they are far from each other, not properly connected. We propose cluster re-division and header node of multihop transmission method in this paper. The cluster re-division method is the method that re-divides existing routing protocol with the small-scale cluster and multihop transmission method is the method regarding the relay transmission between the header nodes. Through the simulation, the proposed routing mechanism shows more excellent than exiting routing protocol in balance energy consumption and energy efficiency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.10A
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• pp.997-1005
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• 2008

In this paper, we propose an efficient space-time block coding (STBC) scheme in a cooperative satellite-terrestrial system. The proposed STBC scheme has code rate 1 for a 3 transmit antenna scheme. Because the channel matrix of the proposed scheme is orthogonal, we can use a simple linear decoding algorithm and also can expect improved performance over the conventional scheme. The simulation results demonstrate that the proposed scheme has improved performance for bit error rates (BER) than several conventional STBC schemes. In addition, we investigate performance simulation results by power imbalance between the terrestrial repeaters and satellite.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9B
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• pp.1518-1526
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• 2000

This paper proposes an optical transmission link design method based on an optimum compensation scheme using dispersion compensating fiber (DCF), so that high-speed long-distance optical transmission would be possible over the conventional standard single mode fiber (SMF) link. The proposed design method provides the maximized transmission distances according to the signal speeds, where the amplifier spacing and repeater spacing are optimized wit respect to self-phase modulation(SPM) due to fiber nonlinearity and amplified spontaneous emission (ASE) noises caused by optical amplifies. It is also shown that there exists an optimum input signal power range balancing the effects of ASE noise and SPM for the given amplifier spacing and repeater spacing.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.3
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• pp.405-412
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• 2010

The purpose of this paper is to compare complexity and to assess flexibility of competing transponder architectures for satellite communication services. For performance comparison, we consider three channelization techniques: digital down converter(DDC) based on the use of the cascaded integrator-comb(CIC) filter, tuneable pipeline frequency transform(T-PFT) based on the tree-structure(TS) and variable oversampled complex-modulated filter banks(OCM-FB) based on the polyphase FFT(P-FFT). The comparison begins by presenting a basic architecture of each channelization method and includes analytical expressions of the number of multiplications as a computational complexity perspective. The analytical results show that DDC with CIC filter requires the heavy computational burden and the perfect flexibility. T-PFT based on the TS provides the almost perfect flexibility with the low complexity over DDC with the CIC filter for a large number of sub-channels. OCM-FB based on the P-FFT shows the high flexibility and the best computational complexity performance compared with other approaches.