• 전기학회논문지
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• 제57권11호
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• pp.1933-1937
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• 2008

XLPE insulated power cables are introduced in Korea in 1980s. The cable installation test has been carried out according to the Korean Technical Reference of Electrical Facilities. But recent research results shows DC Hipot test cannot detect the serious defects in XLPE insulated cables. VLF test is recommended as a installation test of XLPE insulated cables by CENELEC and IEEE standards in 1996 and 2001 respectively. We suggest to apply VLF test as an installation test for XLPE insulated MV cables in Korea.

• 조명전기설비학회논문지
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• 제29권9호
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• pp.59-64
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• 2015

IEC is an international standards which are used in many countries with Europe as the center. IEC standard is introduced in Korea according to WTO/TBT agreements, however until now there are no buildings in Korea which are designed applying IEC standard. Therefore, KEA(Korea Electric Association) is scheduled to construct Korean low voltage electrical installation integration test site which is designed applying IEC standard. In this paper, before being under construction of Korean low voltage electrical installation integration test site, power substation is modeled based on real design parameters and method to select circuit breakers and cables is presented applying IEC standard in the modeled power substation. EMTP(ElctroMagnetic Transient Program) is used for simulation program. EMTP which is power system analysis program is easy to model power system and power substation.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.978-985
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• 2004

Geogrid may be damaged during its installation in the filed. The installation damage mainly depends on two factors, which are materials used and construction activities. Materials relate to geogrid and soils, and construction activities are mainly related to installation of geogrid and compaction of soils. This paper describes the results of a series of field tests, which were conducted to assess the installation damage of the various geogrids according to different fill materials. After field installation damage tests, the change in tensile strength of geogrids was determined from wide width tensile tests using both damaged and undamaged specimens.

• 안보군사학연구
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• 통권8호
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• pp.383-420
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• 2010

This article is focusing on the improvement of weapon system test & evaluation, aimed at the weapon system in the research development stage. This article suggests improvement directions in three aspects(organization and system, skilled manpower and technology, test facilities of weapon system test & evaluation) as follows. 1) Weapon system test & evaluation organization and system a. Establishment of comprehensive test & evaluation system b. Making regulation for comprehensive test infrastructure management. c. Standardization of test & evaluation process, which can be used in special subject to army, navy and air force. 2) Skilled manpower and technology of weapon system test & evaluation a. Training & education, management of test & evaluation experts. b. Establishment of skill management system of test & evaluation. 3) Test facilities of weapon system test & evaluation a. Establishment of comprehensive improvement direction of test & evaluation installation and equipment. b. Consideration of counter measures to prevent overlapping investment, and to use the test & evaluation resources efficiently. c. Establishment of organic network for the effective use of test & evaluation installation and equipment. d. Establishment of detailed cooperation plan for the commonage of test & evaluation facility and equipment.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.293-302
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• 2010

2 types of geogrids and geotextiles was used to evaluate shear behaviors after installation damage test. Shear behaviors were compared after installation damage test and coefficient of resistance to direct sliding($f_{ds}$) was estimated by theoretical shear analysis. Shear strength of damaged geogrid decreased under high normal stress of 150kPa and shear strength of geotextile decreased with increasing normal stress. It is seen that $f_{ds}$ values after installation damage decreased than before installation damage through comparison calculated $f_{ds}$ by direct theoretical shear analysis. $f_{ds}$ values to be calculated by theoretical shear analysis were changed with before and after installation damage.

• 한국환경복원기술학회지
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• 제8권1호
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• pp.27-36
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• 2005

Geosynthetic reinforcements may be damaged during its installation in the filed. The installation damage mainly depends on two factors such as materials used and construction activities. This paper describes the results of a series of field tests, which are conducted to assess the installation damage of geogrid according to different maximum grain sizes of fills (40, 60, and 80 mm). These tests are done in three sites for twelve different kinds of geogrids. After field tests, the changes in tensile strength of the geogrids is determined from wide width tensile tests using both damaged and undamaged specimens. In the results of tests, tensile strength of the relatively flexible geogrids after field installation tests was decreased about from 20% to 40% according to the increment of the maximum grain size. On the other hand, for the relatively stiff geogrids, the loss of the tensile strength after site installation was examined below 5.2% independent of the maximum grain size of the soils. The results of this study show that the installation damage significantly depends on the stiffness of geogrid and is more obvious to a flexible geogrid and a fill material having higher maximum grain size.

• 한국화재소방학회논문지
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• 제30권4호
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• pp.1-5
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• 2016

본 논문은 영상화재감지기(Video Fire Detector)의 시험 및 설치기준에 관한 연구로서 FM Approvals, UL, ISO7240 및 NFPA 72 기준들을 서로 비교분석하여 국가화재안전기준 203 (NFSC 203)에 반영되어야 할 기준들을 제안하였다. 영상화재감지기의 시험과 관계된 FM Approvals 기준에는 연기형, 불꽃형으로 분류되고 비화재보시험이 있었으나 UL 기준에는 연기형만 제시되어 있었다. 외국 기준인 ISO 7240에서는 화재현상 검출유형 등 6가지를, NFPA 72에서는 화재현상 검출유형 등 3가지를 조사하였다. CCTV 설치 표준공법에서는 영상화재감지기의 설치기준에 필요한 항목이 15가지가 있었으며 설치방법에 따라 각 분야별 기준이 제시되어 있었다. 영상화재감지기 적용을 위해서는 감지기 시험항목 중 용어의 정의, 감지기의 구분, 구조 및 기능에 관련항목을 삽입하고 감도조정, 비화재보방지, 주위온도시험, 유효감지거리 및 감도와 시야각, 노화시험, 살수시험, 내화시험의 7개 항목의 적용이 필요하다. 현장 설치를 위해서는 국가화재안전기준 203 (NFSC 203)에 작동환경 및 조도기준을 설정하고 음향장치, 표시등의 설치거리 등의 기준을 삽입하여야 한다.

• 한국농공학회논문집
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• 제52권3호
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• pp.113-120
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• 2010

Reduction factor for installation damage required to calculate design strength of geogrid used in MSEW(mechanically stabilized earth wall) design is usually obtained in the field test simulating real construction condition. However, damages occurred in geogrid during backfill work are influenced by many factors such as polymer types, unit weight per area, backfill construction method and gradation of backfill material and field test considering these factors demand lots of time and costs. In this study, factors affecting installation damage are analyzed and empirical method to evaluate reduction factor for installation damage using maximum particle size in backfill material is suggested.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 가을 학술발표회 논문집
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• pp.305-306
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• 2003

In the case of the geosynthetics usage to soil structure, there are some damages by compaction. And these damages by the installation compaction result in the unexpected changes of short and long term properties of the structure. So in the case of index test, there are some problems to the exact evaluation on the installation damage. Therefore, to the more definite evaluation on the installation damage of geosynthetics, the real site installation damage test is encouraged. (omitted)

• Safety and Health at Work
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• 제11권4호
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• pp.405-417
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• 2020

Background: Electrical socket outlets are used continuously until a failure occurs because they have no indication of manufacturing date or exchange specifications. For this reason, 659 electrical fires related to electrical socket outlets broke out in the Republic of Korea at 2018 only, an increase year on year. To reduce electrical fires from electrical socket outlets, it is necessary to perform an accelerated test and analyze the thermal, insulation resistance, and material properties of electrical socket outlets by installation years. Methods: Thermal characteristics were investigated by measured the temperature increase of electrical socket outlets classified according to year with variation of the current level. Insulation resistance characteristics was measured according to temperature for an electrical socket outlets by their years of use. Finally, to investigate the thermal and insulation resistance characteristics in relation to outlet aging, this study analyzed electrical socket outlets' conductor surface and content, insulator weight, and thermal deformation temperature. Results: Analysis showed, regarding the thermal characteristics, that electrical socket outlet temperature rose when the current value increased. Moreover, the longer the time that had elapsed since an accelerated test and installation, the higher the electrical socket outlet temperature was. With respect to the insulation resistance properties, the accelerated test (30 years) showed that insulation resistance decreased from 110 ℃. In relation to the installation year (30 years), insulation resistance decreased from 70 ℃, which is as much as 40 ℃ lower than the result found by the accelerated test. Regarding the material properties, the longer the elapsed time since installation, the rougher the surface of conductor contact point was, and cracks increased. Conclusion: The 30-year-old electrical socket outlet exceeded the allowable temperature which is 65 ℃ of the electrical contacts at 10 A, and the insulation resistance began to decrease at 70 ℃. It is necessary to manage electrical socket outlets that have been installed for a long time.