• Proceedings of the KIEE Conference
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• 대한전기학회 2004년도 추계학술대회 논문집 전기설비전문위원
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• pp.59-62
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• 2004

가스절연개폐장치에서 발생하는 고장을 조기에 예방하기 위해서는 방전신호를 분석하여 방전을 일으키는 결함을 유추하는 것이 핵심 기술이다. 본 논문에서는 UHF 대역에서 알고 있는 결함에 의한 방전신호를 측정하여 다양한 가시화 방법으로 방전유형을 분류, 정리함으로써 미지의 방전신호로부터 방전원인을 추정할 수 있도록 하였다.

• Proceedings of the KIEE Conference
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1691-1693
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• 2002

Acoustic partial discharge detection has been used on GIS testing for more than 10 years. Sensitivities show that most of critical defect types can be detected with a reasonable signal-to-noise ratio. The paper reports on acoustic partial discharge detection comparable to sensitive electrical PD(partial discharge) measuring method.

• Proceedings of the KIEE Conference
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2262-2264
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• 2005

지금까지 변전소나 개폐소에서 전류, 전압을 계측하는 수단으로서 주로 철심과 권선으로 구성되어진 변류기(CT), 계기용 변압기(PT, PD)가 사용되어져 왔다. 최근, 2차측의 계측기나 보호 Relay의 Digital화가 진전되어 또한 이것을 Digital Network으로 총합한 Intelligent 변전소의 구축이 검토되어지고 있으며, Digital Network에 대응한 변성기 관련규격인 IEC 60044가 근래 제정되어짐에 따라 이에 적합한 전자식 변성기가 요구되어지고 있다. 상기와 같은 요구로 인해 당사에서는 IEC 60044를 기반으로 한 전자식변성기 Layout을 구성하였으며, CT는 검출부에 Rogowski Coil을 적용하며 그 후단에 적분기를 설치하였으며, VD는 검출부에 중간 전극을 이용해서 분압하는 방식인 Capacitive Voltage Divider를 사용하고 증폭기를 삽입하여, 각각 요구되는 전압 신호를 얻었다. 이러한 신형 CT/VD의 적용으로 종래의 CT/PT가 차지하는 공간이 필요없게 되어 컴팩트한 GIS의 구조가 가능하게 되어 있다.

• Proceedings of the KIEE Conference
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2066-2068
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• 2005

We developed an on-line Ultra-high frequency partial discharge monitoring system to prevent a catastrophic failure of gas- insulated switchgears. The system has been tested in the laboratory for detection of various UHF PD signals. We also performed detection sensitivity verification tests and compared them with conventional IEC60270 method.

• Journal of the Architectural Institute of Korea Planning & Design
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• 제35권2호
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• pp.115-125
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• 2019

The purpose of this study is to analyze the occurrence characteristics of vacant spaces in the old hillside residential area, focused on 7 areas surrounding old downtown in Busan. This study suggests 3 stages of analysis as following. First, after the overall site survey on the vacant spaces in 7 old hillside residential areas in Busan, this study identifies the difference of types of vacant spaces according to each area. Second, based upon precedent researches, this study set up 3 perspectives and 9 analysis indices to investigate the areal characteristics of vacant space occurrence. Third, through the GIS analysis on the vacant spaces, this study tries to analyze the physical, commercial and social/institutional conditions of the areas in order to disclose the areal characteristics of vacant spaces occurrence.

• Journal of the Korean Association of Geographic Information Studies
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• 제8권2호
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• pp.145-156
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• 2005

An artificial disturbance like forest fragmentation has affected the sustainability of forest ecosystem. Therefore, in order to manage the forest ecosystem efficiently needed to analyze quantity and quality (structural pattern) of forest simultaneously. This study analyzed the structural patterns of forest landscape to provide a basic data for evaluation and management of forest ecosystem in Nakdong River Basin during 10 years from 1980s to 1990s using landscape indices and GIS methods. Forest distribution maps and 6 landscape indices(LPI, PD, ED, MSI, CPLAND, IJI) for the analysis were reconstructed from land-cover maps constructed by Ministry of Environment and pearson correlation analysis. According to the structural analysis of forest landscape using landscape indices, the forest fragmentation of watersheds along the main stream of the Nakdong river was more severe than any other watersheds. Futhermore, the Nakong-sangju and Nakdong-miryang watersheds had unstable forest structures as well as least amount of forest quantity. Thus, these watersheds need significant amount of forest through a new forest management policy considering local environmental conditions. The connectivity between forests in local regions should be considered as well.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제20권9호
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• pp.103-109
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• 2006

This research is contents about output characteristic of optic current sensor that use faraday effect. optic current sensor used in an experiment is consisted of three parts.(1) Source of light used laser diode of 1310[nm].(2) Sensor section manufactured circularly according to gas insulated switchgear. And $9/125[{\mu}m]$ standard single mode optical fiber for communication was installed winding 20 [turn] on sensor section core surroundings of diameter 31 [cm].(3) Electrical signal of PD(Photo detector) is collected using NI company's 16bit DAQ board via terminal block. Collected data analyzed by different three signal processing methods. NI company's $Labview^{TM}$ was used to signal processing software. As a result, In signal processing of optic current sensor, we could know that noise greatly more influences the error generation than fluctuation of light intensity. also, 1 class CT(current transformer) manufacture that have error rate less than 1[%] was available by removing these

• Journal of The Korean Society of Agricultural Engineers
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• 제49권6호
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• pp.65-76
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• 2007

Studies in landscape ecology have emphasized on the relationship between landscape patterns and shapes. A variety of landscape metrics has been developed so far to quantify landscape structures. Therefore, their developments and widespread applications become possible with the advent of spatial information systems including geographic information systems(GIS) and remote sensing. This study is to grasp the change of land use and landscape ecology indices, and to analyze the change of landscape structure in a part of Gyeonggi-do during 15 years from 1985 to 2000. Green-area distribution maps and agricultural-area distribution maps for the analysis were reconstructed from land cover maps constructed by WAMIS(Water Management Information System). And then, 4 landscape ecology indices(TA, LPI, SHAPE_AM, CAI_MN) for the green-area and 5 landscape ecology indices(TA, PD, LPI, LSI, CAI_MN) for the agricultural-area were selected by using pearson correlation analysis. According to the spatio-temporal change analysis using landscape ecology indices, the green-area fragmentation of Yongin was the most severe of the study area and the agricultural-area fragmentation of Gwangju and Namyangju was more severe than any other regions.

• Journal of the Architectural Institute of Korea Planning & Design
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• 제34권3호
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• pp.93-104
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• 2018

This study is about occurrence pattern of vacant spaces as a urban decline indicator to consider a decline of old hillside residential area from spatial structure perspective. For investigation based upon vacant space and the street structure, this study selects Ami Chojang-dong in Seo-gu, Busan, of which 79.7% of total area is over a gradient of $10^{\circ}$. Focused on relationship between occurrence pattern of vacant spaces and 'vertical alleys(link)' serving as main movement path of local residents in hillside residential area, the length, numbers, slopes, and use characteristic of vertical alleys were analyzed using Arc GIS 9.3 program to classify characteristic zone types of spacial structure in hillside residential area. After the occurrence pattern of vacant space are interpreted in relation with building density, vertical alleys' number length slope, the social and economic issues have been considered as well. After analyzing the occurrence pattern of vacant space, this study argues that the occurrence pattern of vacant space in old hillside residential area is rather affected by street structure system consisting of vertical alleys than the impacts of social economical issues.

• Journal of the Architectural Institute of Korea Planning & Design
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• 제35권1호
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• pp.117-125
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• 2019

The purpose of this study is to examine urban built environments associated with the walking behavior in order to identify the problem of urban infrastructure from the perspective of Universal design theory. Using the walkability criteria developed based on the findings of previous studies on Universal design theory and walking environment, the urban built environments in old town area of Seoul were evaluated. The results of the evaluation indicated that the pedestrian infrastructure in the study area had several shortcomings to improve in order to provide walking-friendly environments. First, the pedestrian infrastructure for visually impaired people were severely limited. Second, walking traffics in large portion of the street networks were interrupted by a variety of obstacles such as parked cars, signboards, and illegal street shops. Third, there were certain areas where the quality of pavement was not properly managed. In summary, this study provides an empirical data to understand the current situation of pedestrian infrastructure in the urban areas. Improvement of pedestrian infrastructure is needed to address the issues related to the mobility of the disabled people. It is also recommended to construct the GIS data on walking environment in order to develop and mange a long-term public investment plan for walking-friendly urban environments.