• 조명전기설비학회논문지
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• 제26권10호
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• pp.81-88
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• 2012

Surge protective devices(SPDs) are widely used as a most effective means protecting the electrical and electronic equipment against overvoltages such as lightning and switching surges. When installing SPDs, it is essential that the voltage protection level provided by SPDs should be lower than the withstand voltage of the equipment being protected. But even the proper selection of SPDs are achieved, the voltage at the equipment terminal may be higher than the residual voltage of SPD due to the reflection and oscillation phenomena. This paper was focused on the investigations of the conditions for which the equipment is protected by an SPD taking into account the influences of the protective distance and type of load. The protective effects of SPD with voltage-limiting component were analyzed as functions of types of load and protective distance between the SPD and load. As a result, in the cases of long protective distances, capacitive loads and loads with high resistance, the voltage at the load terminal was significantly higher than the residual voltage of SPD. It was found that the proper installation of SPDs should be carried out by taking into account the protective distance and type of load to achieve reliable protection of electronic equipments against surges.

• KIEAE Journal
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• 제16권6호
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• pp.39-50
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• 2016

Purpose: The purpose of this study is to be performed with studio-type housings among urban life-type housings to investigate the physical characteristic and crime-related factors of studios from the viewpoint of the basic principles of crime prevention through environmental design (CPTED). Method: Eight CPTED guidelines available in Korea were reviewed to select 20 planing factors for actual condition investigation. Five single households in studio-type housings in Gwanak-gu, Seoul, were chosen according to the subject screening criteria to perform the actual condition investigation. Results: First, a lighting plan around a building for natural surveillance should consider the building location, relation with the front road, and surrounding facilities. In a building of a piloti structure, the parking lot and the building gate should be arranged in a manner that enables natural surveillance. Second, the shape of the corridors in studio-type housings should be considered to plan the installation of a lighting at the door of each household, the installation of a viewer window at the door of each household, and the arrangement of the elevator. Third, to support access control, an access control system having the function of video and voice communication is recommended to be installed at the building gate. Criteria for the type of security windows and the floors on which security windows should be installed, and the regulations about the CCTV installation inside and outside the building should be prepared. Fourth, to enhance territoriality in parking lots, ground patterns, parking lot gate, and signs may be installed. Fifth, in view of effective utilization and maintenance, lighting facilities should be installed to increase the usability of ground parking lots, and relevant installation criteria should be prepared regarding the type, number, and brightness of the lightings.

• Journal of Biosystems Engineering
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• 제16권1호
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• pp.83-89
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• 1991

One of the most serious problems in Korean sericulture farms is to improve the adiabatic conditions for the simple silkworm rearing houses which has been widely adapted since early 1980'. Thus, this study is aimed to solve the problems by selecting the thermal screen material and by finding the method of its instalation. For the study, 4 kinds of materials which are (1) TE005,(2) NW60, (3) NW300 and (4) AL110 are selected and 4 different types of methods which are surrounding boundary of rearing bed(type A), surrounding inside of wall and ceiling (type B), installing on inside of wal ony (type C) and installing on ceiling Inly (type D) are installed. Decision criteria of the best combination of screen material and installation methods is made by calculating the heating load coefficients and by testing the application at the simple silkworm rearing houses. The obtained results are summarized as follows ; 1. The effect of thermal screen on reducing the thermal energy is remarkable. It saves energy more 50% than unscreened simple silkworm rearing houses. 2. From a stand point of a good screed material on thermal energy reduction, the NW300, AL110 and PE005 are recommanded materials. However, NW60 and PE005 are regarded as desirable materials from the practical point view. 3. Also, the effect on thermal energy reduction is largely affected by the method of thermal screen installation. The surrounding boundary of the silkworm rearing bed(type A) is the most desirable method to reduce the energy, which saves 56.6% of it. 4. In the practical application, NW60 and type A is considered to be the best combination of material and installation method. By this combination, the level of maximum heating load can be reduced at the rate of 43% for spring season and 40% for autumn season. 5. Another heating method, comparted heating, can be recommended to save the energy.

• 대한토목학회논문집
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• 제36권6호
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• pp.1075-1082
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• 2016

본 연구에서는 과속방지턱과 연속으로 설치된 고원식횡단보도의 적정 설치간격을 산정하기 위하여 최고속도제한이 30km/h로 운영되는 회전교차로의 접근부에서 과속방지턱과 고원식횡단보도 간 서로 다른 간격을 통과하는 차량의 속도를 조사하여 연속으로 설치된 과속방지턱과 고원식횡단보도가 차량의 주행속도에 미치는 영향을 분석하였고, 고원식횡단보도의 적정 설치높이에 대한 시뮬레이션에 다음과 같은 결론을 도출하였다. 첫째, 과속방지턱과 고원식횡단보도는 차량의 속도를 저감시키는 대표적인 교통정온화 기법으로 차량의 속도를 30km/h 이하로 제어하기 위한 과속방지턱과 고원식횡단보도의 적정 간격은 30m로 나타났다. 둘째, 고원식횡단보도를 통과하는 차량의 감속도를 비교한 결과 설치 간격이 65m 이상인 경우 과속방지턱과 고원식횡단보도의 효과가 없는 것으로 나타났다. 따라서 일정 구간의 차량 속도를 제어하기 위한 과속방지턱과 고원식횡단보도의 최대설치 간격은 65m 이내로 설치하는 것이 바람직하다. 셋째, 고원식횡단보도의 설치높이는 차량의 접근부 속도가 20km/h 이하일 때 6~8cm, 30km/h일 때 8~10cm, 30km/h 이상일 때 10cm의 설치가 가장 적정한 것으로 분석되었다. 넷째, 과속방지턱과 고원식횡단보도가 설치된 구간이어도 운전자의 학습효과, 교통상황 등에 의하여 속도감소 효과가 미미한 경우가 있으므로 과속방지턱, 시케인, 초커 등 여러 가지 교통정온화 기법을 동시에 적용할 경우 속도감소 효과가 더 클 것이라 판단된다. 따라서 보행자의 안전을 도모하기 위하여 차량의 속도를 저감시킬 목적으로 교통정온화 기법을 적용하는 경우 여러 가지 기법의 복합 적용을 고려하여야 할 것이다.

• 한국ITS학회 논문지
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• 제19권6호
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• pp.49-60
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• 2020

교통사고 예방을 위해 설치되는 무인교통단속장비의 운영대수는 매년 경찰청과 지방자치단체의 지속적인 설치로 해마다 증가하고 있다. 하지만 공학적, 체계적인 분석결과가 아닌 민원 위주의 정성적인 판단을 기반으로 설치하고 있어 정량적인 설치기준이 필요한 실정이다. 따라서 본 논문에서는 도로 유형별 사고 심각도를 고려한 설치 판단기준을 제시하고 필요 설치대수를 산출하여 향후 추가 설치대수를 도출하는 것을 목표로 하였다. 사고건수와 KSI를 활용하여 교통사고 심각도를 나타낼 수 있는 ARI 지표를 개발하였으며, 일원배치 분산분석과 군집분석을 통해 도로유형을 4가지 유형으로 분류하고, 도로 유형별 사고 잦은 곳의 사고정보를 분석하여 교통사고 심각도가 높은 군집의 ARI를 도출하였다. 도로 유형별 단속장비의 설치 판단을 위한 ARI 값을 제시하였고, 사고 잦은 곳 중 교통단속장비가 기 설치된 구간을 제외하고 5,244대의 추가 설치가 필요한 것으로 분석되었다.

• 한국조명전기설비학회지:조명전기설비
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• 제7권4호
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• pp.26-33
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• 1993

트리열화 현상을 감지하기 위한 노력으로 음향방출 펄스를 계측할 수 있는 자동계측 시스템을 자체 개발하였다.가교 폴리에틸렌(이하 XLPE라 부른다)시편에 교번전압 15[kV]을 인가했을 때 수초형 트리(bush-type tree)로의 개시 및 진전시 수초형에서 가지형(branch-type tree)으로 진전할 때는 음향방출 평균펄스 진폭(이하 펄스평균 진폭이라 부른다)이 작은 펄스가 많이 발생하였고, 가지형에서 수초형 트리로 진전할 때에는 큰 펄스진폭을 갖는 작은 수의 펄스수를 계측할 수 있다. 이로써 작은 진폭을 갖는 많은 펄스진폭 및 펄스수에 대한 3차원의 분포양상으로서 왜도(Skewness)가 방전의 특성량임을 확인하였고, 왜도를 이용한 S-평면상의 궤적(Trajectory) 변화시 원점에서 멀어질수록 파괴에 가까워짐을 알았다.

• 조명전기설비학회논문지
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• 제25권5호
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• pp.39-44
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• 2011

Automatic fire alarm system is set up to automatically detect fire on buildings. Because of economic reasons, P-type receiver and a conventional type fire detector is normally used for automatic fire alarm system in Korea. Because early detection of fire is regarded as important, the need of finding technique of fire location increases. This paper is studied a method to improve a reliability and add a function of fire location detection on a conventional type fire detector and P-type receiver. Fire location is detected by a method that controller attached on the receiver and the detector is read with a time lag. A reliability of fire detection alarm system is improved with a method that false fire alarm is able to decrease using two different principle detector together. This paper is studied for basic data of improvement of low-cost addressable automatic fire alarm system.

• 조명전기설비학회논문지
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• 제25권1호
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• pp.113-117
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• 2011

As one of the countermeasures to solve the increase of the fault current in a power system, the superconducting fault current limiter (SFCL) has been noticed together with the development of a various types of SFCL, which has accelerated the researches to apply a SFCL into a power system. Among the developed SFCLs, the transformer type SFCL is expected to be available for adjusting the voltage and the current ratings of the SFCL. In this paper, the fault current limiting and the bus line‘s voltage sag suppressing effect by the transformer type SFCL were investigated and the case without the transformer type SFCL was compared as well. Through the analysis on the results of the short-circuit tests, the fault current limiting and the bus-line voltage suppressing characteristics of the transformer type SFCL could be confirmed to be effectively performed.

• 조명전기설비학회논문지
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• 제28권8호
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• pp.62-68
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• 2014

The series connection type superconducting fault current limiter (SFCL) with added third winding, which was magnetically coupled in one iron core, was proposed. The proposed SFCL was expected to be more improved by just adding third winding into the conventional series connection type SFCL with two coils. To analyze the contribution of the third winding for the current limiting and the recovery characteristics of the SFCL, the short-circuit tests for the series connection type SFCL with the added third winding were performed together with the analysis on its electrical equivalent circuit. From the comparative analysis on the amplitude of the limited fault current and the power burden of the high-TC superconducting (HTSC) element comprising this SFCL, the improved current limiting and recovery characteristics of the series connection type SFCL using the third winding could be confirmed.

• 조명전기설비학회논문지
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• 제25권4호
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• pp.71-78
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• 2011

This paper contains the selection of operation parameters for protection and control of steam turbine in a Korea Standard Type Nuclear Power Plant. The safety of nuclear reactor must be ensured which generates nuclear energy and produces steam. Also, the safety of turbine, which consume the nuclear energy as a core machine, must be ensured. For the purpose of this, we describe how the operating parameters were selected, reviewed, implemented into the operator console and finally put into actual operation of the system.