• 한국지진공학회논문집
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• 제24권2호
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• pp.95-102
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• 2020

Electrical instruments and devices contained in cabinets for controlling nuclear power plants require seismic qualification; likewise, in-cabinet response spectrum (ICRS) is necessary. Gupta et al. (1999) suggested the Ritz method, where rocking, frame bending, and plate bending behaviors of cabinets are considered, as a method for determining ICRS. This research proposes a method to determine the rocking stiffness of cabinets, which represents its rocking behavior. The cabinet is fixed on mounting frames and is connected to the base concrete by anchors. When horizontal excitation is applied to the cabinet, the mounting frames at anchors are locally deformed, the mounting frames are bent, and then rocking in the cabinet becomes evident. A method to determine equivalent vertical spring stiffness representing the local deformation of the mounting frames at anchors is then proposed. Subsequently, the rocking stiffness of this mounting frame is calculated upon assumption of the mounting frame as an indeterminate beam.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.224-227
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• 2007

This paper introduces the results of acoustic loads test conducted on the upper stage assembly of KSLV-I, which is the first Korea space launch vehicle. A launch vehicle and its payloads are subjected to severe acoustic pressure loading when they lift off and ascent during the transonic periods. Acoustic loadings are spreaded out broad frequncy-spectrum up to 10,000Hz. Acoustic loads are a primary source of structural random vibration of the upper stage and payloads. Therefore, in order to verify the structural integrity of the upper stage assembly of KSLV-I and the survivability of its components under severe random vibration environment, acoustic loads test is conducted in the high intensity acoustic chamber with 142dB (overall SPL). The results show the structural design and component random vibration specifications well meet with the environmental requirements.

• 품질경영학회지
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• 제30권1호
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• pp.74-96
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• 2002

The objectives of this study is to suggest the rectifying sampling inspection plan considering quality cost. Limiting quality level(LQL) plans(also called LTPD plans) and outgoing quality(OQ) plans are considered. The Hald's linear cost model is discussed with and without a beta prior for the distribution of the fraction of nonconforming items in a lot. It is assumed that the sampling inspection is error free. We consider the design of reliability acceptance sampling plan (RASP) for failure rate level qualification at selected confidence level. The lifetime distribution of products is assumed to be exponential. MIL-STD-690C and K C 6032 standards provide this procedures. But these procedures have some questions to apply in the field. The cost of test and confidence level(1-$\beta$ risk) are the problem between supplier and user. So, we suggest that the optimal life test sampling inspection plans using simple linear cost model considering product cost, capability of environment chamber, environmental test cost, and etc. Especially, we consider a reliability of lots that contain some nonconforming items. In this case we assumed that a nonconforming item fail after environmental life test. Finally, we develope the algorithm of the optimal sampling inspection plan based on minimum costs for rectifying inspection and RASP. And computer application programs are developed So, it is shown how the desired sampling plan can be easily found.

• 농촌계획
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• 제6권1호
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• pp.10-18
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• 2000

The objective of this study is to analyze 1) the law system in relation with the development permissions 2) characteristics of the development permissions change 3) especially focusing on the development permissions changes in agricultural, forestry and fisheries facilities in light of socio - economic conditions in Korea Greenbelt. The following results were obtained: 1) The purpose of Greenbelt in Korea is to control the land use in order to protect the surrounding areas from urbanization. 2) During the 1990s, the number of formulated development regulations increased one and half times than that of the previous decades(1970s 1980s). The main reasons are advancements of local autonomy and democratization. 3) Three patterns were observed with respect to ease the regulations in agricultural, forestry and fisheries facilities those are: (1) increase in types of businesses ; (2) increase the maximum area permitted ; (3) decrease in qualification for establishing facilities. 4) There were few development permissions in a agricultural, forestry and fisheries facilities in consideration to the regional agricultural condition. The development permissions were only during the period of restricted to use ($1979.12{\sim}1993.11$). We propose that the authority of development permission should be given to the local autonomy government, because the local government has the knowledge of its individual agricultural conditions.

• 공학교육연구
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• 제6권1호
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• pp.42-55
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• 2003

이 연구는 환경분야 이공계 대학의 교육과정 실태를 분석하고, 환경분야 이공계 대학의 교육과정 개선 방안을 제시하는데 목적이 있다. 이에 따라 환경분야 이공계 대학의 교육과정을 분석 제시하고자 각 대학의 교과목을 분석하였으며, 그에 따른 문제점과 시사점을 도출하였다. 또한 환경분야 이공계 대학의 교육과정 개선 방안으로 환경분야 산업체 전문가들이 참여한 가운데 직무분석 작업 실시, 산업현장에서 요구하는 교육과정 신설, 산업체 연수프로그램 등을 제시하여 환경교육과정이 현장위주로 개선되어야 함을 제시하였다. 연구 방법으로는 관련 자료의 수집 및 분석, 환경관련 학과의 교육과정 실태분석, 환경관련 교수전공 실태 등을 인터넷, 자료 및 문헌조사를 통해 실시하였다.

• Nuclear Engineering and Technology
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• 제43권6호
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• pp.573-582
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• 2011

The in-cabinet response spectrum is used to define the input motion in the seismic qualification of instruments and devices mounted inside an electrical cabinet. This paper presents a procedure for generating the in-cabinet response spectrum for electrical equipment based on in-situ testing by an impact hammer. The proposed procedure includes an algorithm to build the relationship between the impact forces and the measured acceleration responses of cabinet structures by estimating the state-space model. This model is used to predict seismic responses to the equivalent earthquake forces. Three types of structural model are analyzed for numerical verification of the proposed method. A comparison of predicted and simulated response spectra shows good convergence, demonstrating the potential of the proposed method to predict the response spectra for real cabinet structures using vibration tests. The presented procedure eliminates the uncertainty associated with constructing an analytical model of the electrical cabinet, which has complex mass distribution and stiffness.

• 에너지공학
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• 제23권1호
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• pp.90-94
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• 2014

본 논문은 원자력발전소의 내환경기기검증(EQ)을 위한 HVAC 과도분석 방법에 대한 내용을 기술하고 있다. 분석 대상 격실은 비안전관련 HVAC 계통에 의해 공급되는 격실 중에 원자로 안전정지를 담당하는 중요기기가 위치한 구역/격실을 선정하였다. 그리고 해당 HVAC 계통이 공급되는 건물별로 HVAC 과도시 온도조건을 분석하였다. 본 분석을 위해서 GOTHIC 전산코드를 사용하였다. 온도분석 결과는 원자로 보조건물 환기계통(DVN)의 W315/W415 격실에서 $82.2^{\circ}C$로 가장 높은 온도값을 나타내며, 제어봉구동장치 전원공급건물 및 보조급수펌프실(DVG) 계통의 W229 (Auxiliary feedwater pump room) 격실에서 $52.7^{\circ}C$, 기기냉각건물 환기계통(DVI)의 전 격실에서 $42.9^{\circ}C$, 전기건물 주환기 계통(DVL)의 L207 (Hot workshop) 격실에서 $57.3^{\circ}C$를 각각 나타났다. 이러한 온도값은 일반적인 원전의 기기검증 제한값인 $171^{\circ}C$이하이므로 내환경검증 요건을 만족하는 온도이다.

• 한국산업보건학회지
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• 제15권3호
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• pp.232-238
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• 2005

There are growing needs for improving the general performances of the domestic working environment evaluation organizations. For this purpose, introduction of laboratory accreditation program has been suggested. This study was conducted as a part of this effort. With a questionnaire developed in accordance with the ISO/IEC 17025, the current status of industrial hygiene (IH) laboratories in terms of manpower, management and technical aspects. The results of this study were as follows: 1. The average working staffs' number of the working environment evaluation organizations was $6.8{\pm}3.3$ persons. In addition, 49% of all organizations are run by less than 5 persons. This suggests that manpower of Korean IH laboratories is very limited. 2. IH laboratories surveyed in this study obtained 53% of the points by the international standard. And there is significant correlation between the number of staffing and total scores (P<0.05). 3. The period of work experience is one of the most important factors to determine the working capability. The average year of work experience of the laboratories' directors was $13.5{\pm}5.3$ years. Directors with more wok experiences obtained higher scores on the questions that ask to prove the appropriateness of the research methodology (p<0.05). 4. As for academic qualifications of laboratory directors, 14% had Ph.D., 31% with Master's, 29% with Bachelor's, and 4% had Associate degree. There was significant correlation between the total scores and the general managers' academic background (p<0.05). The 27% of laboratory directors have majored in either industrial hygiene or health, 8% majored in medicine, another 8% majored environmental studies, and 6% majored in chemistry. 5. Only 14% of all IH laboratories surveyed employ directors with Certified Industrial Hygienist licence, 41% have general managers with Certified Associate Industrial Hygienist (Level 1) licence, and 45% of all laboratories either employ directors without relevant qualification or did not respond. When the laboratory manger holds relevant qualification, laboratory health and safety management was better (p<0.05). 6. When compared to the general international standard in terms of the management, and 55% in terms of technological level.

• 분석과학
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• 제17권2호
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• pp.117-129
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• 2004

본 연구에서는 극성이 높고, 휘발성이 낮아 GC나 GC/MS로 분석이 곤란한 환경매체 중의 아미트롤을 LC/ESI/MS를 사용하여 분석한 결과 다음과 같은 결론을 얻었다. 분자량이 84인 아미트롤은 LC/ESI/MS 방식에서는 m/z 85인$(M+H)^+$형태로 나타났으며, 피크강도는 30V에서 (SIR mode) 최대를 나타내었다. 질량 스펙트럼 비를 정성확인에 적용하기 위하여 실험한 결과 아미트롤은 m/z 85 와 m/z 58 이온으로 나타났으며, 50V에서 이 비는 1 : 7.03~7.58 로 나타났다. 동위원소 비를 이용한 정성확인은 isotope MS나 HR/MS가 주로 사용되나, 본 연구에서는 정성확인을 위한 보조수단으로 이용하고자 실험한 결과 아미트롤의 동위원소는 $86([M+H])^+$ 형태로 나타났으며, 시료에서(30V) m/z 85와 m/z 86의 질량 스펙트럼 비는 27.1~28.6 : 1(이론적 비 26.6 : 1)로 나타났다. 단계별 표준액을 시료의 전 처리 방법과 동일하게 처리하여 분석한 검량선의 직선성은 $y=1.09354e^6X+26947.2$이었으며, $r^2=0.99$로 나타났다. 분석의 정도관리를 위한 회수율검정과 반복 재현성을 알아보기 위한 실험에서 수질시료의 회수율은 77.64~83.44%, 토양시료에서는71.11~79.44%로 나타났으며, 각 농도 단계별 반복(5회)실험결과 상대표준편차 값은 10%이하를 나타내었다.

• 대한환경공학회지
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• 제27권4호
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• pp.369-376
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• 2005

이 연구는 환경분야의 자격에 대한 이론적 배경을 바탕으로 환경분야 자격의 효과를 조사하고 이를 실증적으로 검정하는데 목적이 있다. 따라서 이 연구는 이론적 배경을 바탕으로 기업에서의 자격의 효과를 경제적 효과(생산성 향상, 품질 향상)와 비경제적 효과(직무수행시 신뢰성, 기술 기능인력의 전문성, 기업가치평가지표, 직무배치 활용)로 구분하여 연구의 모형을 설정했으며, 연구의 모형을 바탕으로 설문지를 구성하여 설문조사를 실시하였다 가설을 검정한 결과는 다음과 같다. 첫째, 가설 1(환경분야 자격은 기업의 경제적 효과에 긍정적인 영향을 미칠 것이다)의 검정결과, 환경분야 자격은 기업의 경제적 효과에 긍정적인 영향을 미친다고 분석되었다. 기업의 경제적인 효과를 생산성 향상과 품질 향상으로 제시하였는데 2가지 변인 모두에게서 환경분야 자격은 기업의 경제적인 효과에 긍정적인 영향을 미쳤다. 둘째, 가설 2(환경분야 자격은 기업의 비경제적 효과에 긍정적인 영향을 미칠 것이다)의 검정결과, 환경분야 자격은 직무수행시 신뢰성 효과, 기술 기능 인력 전문성 효과, 기업가치평가지표 효과, 직무배치 활용 효과에 있어서 기업의 비경제적 효과에 긍정적인 영향을 미쳤다. 이와 같이 환경분야 자격은 환경산업체에서 기업의 경제적 효과와 비경제적인 효과가 있었다.