• 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.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.101-105
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• 2011

This paper calculates protection distance to protect WiBro service from ISM(Industrial Scientific Medical) equipment which is used in the same frequency with WiBro. We analyze with a scenario that WiBro receiver is closed to ISM equipment which has interfering power of CISPR(International Special Committee on Radio Interference) 11 limit. As a result, the protection distance of 14 m was calculated by using MCL (Minimum Coupling Loss) for the worst case. And, the protection distance of 10 m was calculated to meet 5 % interference probability below by using MC(Monte Carlo) for statistic analysis in case of a interferer.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.2
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• pp.72-80
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• 1998

Most cellsite are operated by 3-sector system in these days. Due to the weak propagating signal caused by peculiar topography, there exist weak or shadow regions. To solve this problem, we need double beam in a sector, thus we have to design 4-sector cellisite even if investment cost and maintenance cost gets high. We propose here using the dual TX-ANT instead of designing 4-sector cellsite to reduse investment cost and to improve call quality. We choose YangPeong and Gepo cellisite in Seoul and DuckCheon cellsite in Pusan to run the experiments. And we verified the practicality by comparing data before and before and after the installation of dual TX-ANT.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.5
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• pp.755-762
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• 2017

In railway communication, LTE based railway wireless communication systems have been developed to support high data rate and reliable communication link. In this paper, the testbed of LTE based railway wireless communication systems is introduced. Then, we describe measurement results of communication performance such as radiation strength, communication coverage, call setup time, handover success rate, and data transmission rate in the testbed. We also consider requirements for commercialization based on measurement results.

• Journal of Broadcast Engineering
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• v.21 no.1
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• pp.97-104
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• 2016

In this paper, in order to relieve the area of terrestrial DTV broadcasting, we watch the same channel DTV Repeater output ICS using nano field test and analysis of effect was proven. Interspersed throughout the blanket area(natural) and buildings(artificially) 7 established the field selected as the test area, and each station(KBS1, KBS2, MBC, SBS, EBS) Extremely Low Power ICS Repeater the same channel of the receiving field strength and after install, SNR(Signal to Noise Ratios) verify the equipment to measure the efficacy and minimal output for future ICS type nav should you wish to provide a research-based for the spread.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.4
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• pp.221-225
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• 2014

In modern times, threat of high power electromagnetic wave is increasing. When the electrical grid and communication network are attacked by these high power electromagnetic wave, the whole infrastructure is paralyzed. To protect the infrastructure from these high power electromagnetic wave threat, the shielding facility that can block high power electromagnetic wave is constructed. Also shielding effectiveness evaluation about the constructed facility is important. But, because of space efficiency and saving of construction cost to construct the actual shielding facility, the shielding room wall is generally adjacent to exterior concrete structures. As space between shielding facility wall and concrete structures is very small, arranging the transmitting antenna exterior shielding facility is realistically difficult. Therefore, in this research, The shielding effectiveness measurement plan in the state of exterior narrow space of HEMP shielding facility is presented. And to apply this plan, The influence of shielding effectiveness according to the size of the shielding facility is analyzed.

• Journal of Broadcast Engineering
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• v.23 no.5
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• pp.693-700
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• 2018

In this paper, we propose a wireless video transmission scheme, providing medium and long range communication in the 2.4GHz band with beamforming. With this scheme, it is shown that the transmission rate of 32Mbps and received signal power of -77dBm is achieved with 4 antennas of 5dBi and 16dBm transmit power at each antenna connection for the distance of 3.6km. The scheme also provides transmission distance of 20km for 10~12Mbps with the 4 omni-directional antennas of 5dBi.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2138.1_2139.1
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• 2009

COS 조작봉은 선로의 사고나 설비교체 또는 수리 등이 필요할 때 활선상태에서 COS를 개폐하기 위한 장비로서 보통 절연특성 및 강도가 우수하고 경량소재인 FRP(Fiberglass Reinforced Plastics)로 제작된다. 따라서 특고압 선로에서 작업 중 안전사고를 예방하기 위해 사용되는 장비인 만큼 안전거리 확보와 작업의 편리성을 고려하여 직접 조작봉을 연장하여 사용할 수 있도록 다단으로 제작되며, 조작봉의 크기는 작업조건에 따라 길이를 선택하여 사용할 수 있도록 2, 4, 6m급 등 길이에 따른 종류별로 생산되고 있다. 이러한 COS 조작봉의 사용특징은 장소와 시간에 관계없이 사용이 가능해야 하고, 특정한 사정에 의해선 작업자 혼자서 사용할 수 있도록 조작봉과 일체된 조명장치의 필요성이 항상 제기되어 왔던 문제이다. 본 논문에서는 이러한 문제점에 주안을 두고 조작봉과 일체된 전계검출에 의한 발광동작을 제어할 수 있는 발광형 COS 조작봉에 대해 각각의 구성별 요소들을 분석하고자 한다.

• 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 KIEE Conference
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• 2008.04b
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• pp.28-30
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• 2008

본 논문은 국내 실정에 적합한 초고압 가공 직류 송전(HVDC)선로 설계를 위해서 세계적으로 처음 시도되는 가변 기능을 지닌 Proto Type HVDC 실규모 시험선로의 설계와 구축에 대해 소개한다. 시험선로는 초고압 직류송전시 발생하는 이온의 흐름에 의한 이온전류 밀도, 대전 전압, 지표면 전계강도 등 이온류(Ion류(流))에 의한 전기환경장애 및 코로나 영향을 검토하여 환경 친화적 HVDC 송전선로 설계기준을 도출하는데 있다. 이에 따라 HVDC 실규모 시험선로는 요크, 특수 애자련, 특수 arm을 사용하여 철탑의 극간 배치, 도체 배치 변경 및 지상고 변경이 가능하도록 winch를 채용하여 절연설계 조건의 유동성, 환경, 지지물, 송전기자재, 경제성 및 운용의 효율성을 종합적으로 고려할 수 있도록 특수한 형태로 설계되었으며, 본 논문은 상용 가공 HVDC 송전방식의 적용에 앞서 현재의 상황을 고려한 가공 HVDC 실증시험을 수행하기 위한 시험선로의 설계 및 구축에 대하여 기술하였다.