• JOURNAL OF ELECTRICAL WORLD
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• s.315
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• pp.30-37
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• 2003

오늘날 국민생활에 전기의 의존도는 날로 높아지고 또한 매우 다양하고 고품질의 전력공급을 요구하고 있으며 정보산업사회로의 진입에 따라 고객의 기대수준에 전력공급설비의 발달이 미처 따라주지 못하고 있어 고객에게 감동을 주는 서비스의 실현이 더욱 어려워지고 있는 것이 현실이다. 특히 서울 명동지역은 구건물의 밀집지역으로 상권이 형성되어 있고 외국인 관광객들의 명소로 점차 자리잡아 가고 있는데 반해 전력공급설비는 국내 초기 지중화지역으로 기기설치 공간이 부족하여 노후된 건물 옥상에 다수의 변압기, 케이블이 설치 운영되고 있어 설비관리의 어려움뿐만 아니라 신규전력공급에 부응치 못하는 한계에 도달, 특히 밀집상가의 화재발생 우려 등 많은 문제점으로 안정적 전력공급을 위한 대책이 절실히 요구되는 상황이 되었다. 따라서 이 난해한 문제의 해결과 설비개선을 위해 보다 근원적인 대책을 모색하고자 ‘99년 초 한국전력공사 서울지역본부에 설비혁신 Task-Force를 운영, 명동지역에 가칭 배전 Station 건설을 포함한 종합정비사업을 추진키로 하였다. $\ulcorner$배전 Station$\lrcorner$ 이란 건물 내에 개폐기, 변압기 등 전력기기를 모두 수용하여 전력을 공급하는 소형 배전형 변전소 형태로 국내는 물론 세계적으로도 찾아보기 힘든 경우라 할 것이다. 건울과 설비가 복잡하기로 유명한 유서 깊은 명동지역의 특수한 주변 환경과 조화된 안정적 전력공급의 획기적인 대안으로 실현되고 있는 영동 배전 Station은 현재 3개소를 추진하여 준공단계에 있으며 도심건물 밀집지역의 전력공급에 만전을 다할 것으로 기대하고 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.133-134
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• 2014

이동통신망 내에서 셀룰러 주파수를 공유하여 사용하는 D2D(Device-to-Device) 단말들이 밀집한 지역에서는 D2D 단말이 대부분의 자원을 점유하므로 셀룰러 단말이 통신을 할 수 없는 문제점이 있다. 본 논문에서는 이러한 환경에서 셀룰러 통신을 보장하기 위해 셀룰러 단말과 인접한 범위에 있는 일부 D2D 단말에 대한 모드 선택기법을 제안한다. 제안기법은 밀집된 D2D 단말들로 인해 가용자원이 없는 셀룰러 단말의 주변에 있는 D2D 단말을 셀룰러 모드로 전환한다. 이를 통해 셀룰러 단말은 D2D 단말이 밀집한 지역에서 셀룰러 통신에 사용할 자원을 확보하여 셀룰러 통신을 할 수 있다. 시뮬레이션을 통해 이동통신망에서 D2D 밀집지역에 있는 셀룰러 통신의 성능이 향상되었음을 확인하였다.

• 한국IT서비스학회:학술대회논문집
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• 2009.11a
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• pp.491-496
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• 2009

우리의 생활 속 GPS를 이용한 서비스의 활용분야는 점점 더 넓어지고 있다. 사용자들이 요구하는 GPS 서비스 품질이 높아지면서 GPS의 정확성을 저하시키는 제한적인 상황들은 정확성 제고를 위한 보정을 필요로 한다. 본 연구에서는 도심 내 단층건물 밀집지역이 GPS 정확성을 떨어뜨리는 오차 요인이라고 가정하고 실험을 수행하였다. 평균 2m 간격으로 밀집된 단층 건물들 사이에서의 GPS의 정확성을 측정하였으며 그 결과 밀집된 단층건물에서 다중경로 효과로 인한 위도 경도 상의 오차범위와 절대적 오차범위를 산출할 수 있었다. 이것을 바탕으로 단층건물의 밀집도가 관측점에 위치되어 있는 고층건물보다는 GPS 수신에 더 적은 영향을 미친다는 결론을 도출하였다. 이러한 GPS 정확성은 앞으로 밀집도가 서로 다른 지역에서의 GPS 서비스와 건물의 높이에 따른 GPS 정확성 연구에 활용될 수 있을 것으로 사료된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.40-42
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• 2015

Our D2D (Device-to-Device) advertisement dissemination algorithm based on the convergence of a D2D communication and a social commerce service is able to efficiently deliver advertisement messages of small business owners. We here assume high user-density areas as target-areas, and these target areas can form several target-groups based on geographical proximity. Also, the isolated target-areas which are not included in the target-groups may have the opportunities for forming a new target-group in consideration of the maximum distance with AP. In this paper, we evaluate performances with respect to the total number of successfully received users and the average number of relay users in accordance with variation in the maximum distance for isolated target-areas.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.6D
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• pp.655-662
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• 2012

The aim of this study is to analyze tthe pattern of compacted area and the distribution characteristics in one-person household. Through ArcGis, we collect the basic data and classify the compact area in accordance with the pattern employing Ward method out of cluster analysis. The main results are found as follows; First, the station sphere type is located around Seomyun and Nampo-dong, which are the main CBD( Central Business District) This type must be essentially considered in residential plan for one-person household location. Second, the district oriented type is located around the subway and it has relatively better residential facilities and environments. Third, it is found that the younger worker including students resided in one room and villa in the type around university. Forth, the foreign workers and domestic workers in small and medium factory resided in the factory centered type which is far from the station sphere. Lastly, it is dormitory type which is isolated from the CBD, and insteadly amenable and well natural environment area, but students and workers in this area where there are lacking life-related facilities and aside from accessibilities feel uncomfortable.

• Economic and Environmental Geology
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• v.38 no.3 s.172
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• pp.221-236
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• 2005

In order to investigate the contamination levels and dispersion patterns of heavy metals such as Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn by urbanization, soils beneath roadside-trees and leaves of Ginkgo biloba were collected from Seoul area during October to November in 2001. All tree leaves were grouped into washed and unwashed ones. The pH of most soil ranges from 6 to 9 indicating a weak acidic and alkaline. The element couples of Cd-Co, Cr-Ni and Zn-Cu-Pb have good correlation in soils, and contamination sources of Cd-Co, Cr-Ni and Zn-Cu-Pb could be similar. High correlation coefficients among Pb, Cu and Zn in G. biloba indicates that these elements show the similar behavior during the metabolism processes. From the results of pollution index calculation for soils, industrialized and heavy traffic area were severly polluted by heavy metals such as Cd, Cu, Pb and Zn. By the discriminant analysis, industrialized and heavy traffic areas are enriched in the order of Ni> Cr> Pb. Cadmium is useful to discriminate between industrialized and heavy traffic areas, Co and Pb are highly enhanced in heavy traffic area.

• JOURNAL OF ELECTRICAL WORLD
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• s.316
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• pp.35-43
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• 2003

• Journal of Korean Society of Environmental Engineers
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• v.37 no.6
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• pp.380-386
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• 2015

In this study, the spatial and temporal distribution of volatile organic compounds (VOCs) in an industrial shipbuilding complex was monitored, and the local characteristics estimated. The major VOC component measured at all of the sampling sites were almost the same as those found at an indoor painting facility, indicating that painting works conducted in the shipyards were a significant source of VOCs in the vicinity of shipbuilding areas. The main parameters affecting the VOCs distribution were the distance between the sampling site and painting work place, and the intensity of the painting works. A quite broad range of VOC concentrations were observed in all of the sampling sites, depending on the intensity of painting works in nearby areas suppressing the typical seasonal and temporal variation trends in VOCs observed in urban areas.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.7
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• pp.694-700
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• 2013

Urban area is a representative environment of wireless channels in the mobile communication, building density has a different distribution depending on the location. Building density has affect to propagation prediction For this reason, building density is expected to affect to the channel characteristics, we need to analyze it. We measured channel characteristics in urban areas of Jeju island by channel sounder and $4{\times}4$ antenna. Channel characteristics considering the building density were derived based on the measured data in the urban area. In this paper, the measurement data is analyzed and channel characteristics are derived through MIMO Channel measurements at 700 MHz considering the building density in the urban area.

• Journal of the Korean Regional Science Association
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• v.35 no.1
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• pp.19-31
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• 2019

This study examines the effect of national identity and threat awareness on the multi-cultural acceptability and whether contact theory actually work. For the analysis, this study used '2013 Korea General Social Survey' data and compared two groups divided according to whether or not they live in ethnic places using structural equation modeling. The empirical analysis shows that national identity does not have a direct effect on multi-cultural acceptability, and threat awareness has a full mediating effect between national identity and multi-cultural acceptability. In addition, the negative effect of the threat awareness on multi-cultural acceptability was greater in groups living in ethnic places. The findings suggest that multi-cultural awareness education is necessary to reduce the threat awareness toward foreigners, and that community-level programs are needed to prevent and coordinate conflicts arising from contact between foreigners and Koreans.