• Proceedings of the Korea Society for Industrial Systems Conference
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• 2003.11a
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• pp.49-71
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• 2003

Due to rapid development of internet, it is easy to use extensive information networks of all over the world. Also development of information technology made all entities share information. Before internet websites were only used to give informations. If primary functions of research center's website are composed of supply of research data, exchange of information, and management of information, it is essential that efficient evaluation and reliable evaluation standards should be set up. This study's purposes are as follows. First, this investigates current status of RRC(Regional Research Center)'s websites. And deducted evaluation models, which can be applied to RRC based on literature study. By using the evaluation models, conducted evalution of websites both from internet users view and from outside experts view, and compared the two groups test results. Second, this study provides current problems of RRC's websites by analyzing the test results. Third, this study presents problems of RRC's websites management of primary funtions and management plans of RRC's websites.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.49.1-49.1
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• 2011

집광채광 설비는 건축물의 조명에너지 절감 및 자연광의 실내 유입을 위해 적용 가능한 태양에너지설비로써 다른 신 재생 에너지 설비와 다르게 연간에너지생산에 대한 정량적 데이터가 아직까지 부재하다. 집광채광 설비의 설치효과를 판단하기 위해서는 집광채광 설비 설치에 따른 연간 에너지생산량 산출이 필요하며, 이를 위해서는 각 구성부분(집광부, 전송부 및 산광부)의 광전송 효율에 대한 데이터가 구축되어야 한다. 본 연구는 집광채광 설비의 효율 분석에 관한 첫 번째 단계로써 외부광속에 대한 집광부 통과 직후의 내부광속의 비율을 예측하였다. 국내에 보급된 집광채광 설비는 대부분 프리즘형과 광덕트형이며, 우선적으로 집광부 입사면의 경사각과 방위각이 다양하여 내부광속 산출방법론이 매우 복잡한 프리즘형을 분석대상으로 삼았다. 전일사량, 외부조도 및 집광부 내부조도가 측정되었으며, 외부광속으로부터 내부광속을 산출하는 공식을 유도하기 위해 천공상태에 따라 전일사량 측정치가 직산분리 되었다. Perez model과 Liu and Jordon에 의해 제시된 계산식과 입사면 및 집광부 면적을 고려하여 수평면 외부조도 측정치로부터 외부광속이 그리고 내부조도로부터 내부광속이 산출되었다. 입사면의 투과율이 동일하다는 전제 하에 천공상태에 따른 태양광 투과 비율을 도출한 결과, 담천공(Kt ${\leq}$ 0.3)에서 0.39, 부분담천공(0.3${\geq}$ 0.78)에서 1.0으로 나타났다. 도출된 투과비율을 외부광속에 적용하여 내부광속을 계산한 결과치와 측정치는 약 ${\pm}9%$ 정도의 차이를 보였다. 연간 기상데이터에 위와 같은 방법론이 적용되면 프리즘형 집광부의 연간 내부광속이 산출될 수 있다. 또한 기존 연구에서 제시된 발광효율 산출식과 일사 파장에 따른 시감도를 고려하면 매 시간별 외부조도도 산출이 가능하다. 일사량 측정치와 외부조도 측정치 사이의 상관관계를 분석한 결과 결정계수 $R^2$이 0.99인데 반해 일사량 측정치와 외부조도 계산치 사이의 상관관계 결정계수는 0.95로 측정치 보다 약간 작은 값을 갖는다. 이렇게 산출된 외부조도는 각 입사면의 면적을 반영하여 외부광속으로 변환되고, 앞서 산출된 천공상태별 투과비율이 적용됨으로써 내부광속이 도출될 수 있다. 이와 같은 집광부에 대한 연구를 바탕으로 향후 전송부와 산광부 효율을 도출하고 궁극적으로 집광채광 설비를 통해 실내에 전달되는 연간 빛에너지를 예측할 수 있을 것이다. 또한 본 연구의 방법론은 다른 형태의 집광채광 설비에도 적용이 가능할 것으로 판단되며, 국내 집광채광 설비의 연간 에너지생산량에 대한 폭 넓은 데이터 구축이 가능할 것으로 기대된다.

• Journal of the Korea Concrete Institute
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• v.21 no.4
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• pp.513-521
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• 2009

Recently, the externally prestressed unbonded concrete structures are increasingly being built. The mechanical behavior of prestressed concrete beams with external unbonded tendon is different from that of normal bonded PSC beams in that the slip of tendons at deviators and the change of tendon eccentricity occurs as external loads are applied in external unbonded PSC beams. The purpose of the present paper is therefore to evaluate the flexural behavior by performing static flexural test according to tendon area and tendon force. From experimental results, before flexural cracking, there was no difference between external members and bonded members. However, after cracking, yielding load of reinforcement, ultimate load, and the tendon stress of external members was lower than that of bonded members. For the relationship of load-tendon stress, the increasing of tendon strain was inversely proportional to the initial tendon force. However, even if the initial tendon force was large, the tendon strain with small effective stress was smaller than that with large effective stress. The concrete compressive strain was proportional to the effective stress of external tendon. From the comparison between test results and codes, the ACI-318 could not consider the effect of tendon force or effective stress, and especially the results of ACI-318 were very small, so it was very conservative. And the AASHTO 1994 could be influenced on the tendon area, initial force and effective stress, but as it was made on the basis of internal unbonded tendon, its results were much larger than the test results. For this reason, the new correct predict equation of external tendon stress will be needed.

• 대한공업교육학회지
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• v.44 no.2
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• pp.28-46
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• 2019

The purpose of this study is to use as a basic data of establishing operating Course-based National Technical Qualification(CNTQ) support program by examining the educational needs for operating CNTQ of vocational school teachers, and to contribute to the vocational school settlement of CNTQ course. To achieve those purposes, this study drew 27 tasks performed by teachers operating CNTQ. Also, it surveyed the perceived importance and the performance. The findings of this study are as follows. First, it is showed that 'selection of qualification fields and confirmation of organization criteria, organization of educational training time by competency unit, organization of subjects and establishment of competency unit operating plan by grade and semester, selection of teaching materials, implementation of education and training, establishment of evaluation plan, implementation of evaluation, re-education and re-evaluation students with grades under 40%, guidance of paper evaluation, guidance of practical evaluation, guidance of interview evaluation' are the first priority tasks in the result of the need analysis. Second, it is indicated that 'application of external evaluation, guidance to retake an exam for failure' are the secondary priority tasks. According to these results, the following conclusions were made. First, it will be more positive effects if the educational needs in the next CNTQ support program include contents of the first priority tasks. Second, it is indicated that the priority of the educational needs for tasks of operating plan stages is commonly high. In particular, the highest ranking in the result means that it is completely supported from the first step on operating course. It is expected that the program which teachers on operating the course of similar qualification fields share each operating experience is effective. Third, the priority of the educational needs for external evaluation step ranked high. External evaluation has a different level of difficulty and a form of practical evaluation output according to qualification fields, so the method of guidance has to be different. It needs the program constructed by similar fields.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1998.10a
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• pp.26-26
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• 1998

다련장 로켓과 같이 무유도로서 대량 발사하는 탄을 설계함에 있어서 탄의 성능을 예측하기 위해서는 사거리와 고도 해석을 통해 체계 성능을 분석하고 탄의 특성 및 외부요소의 변화 가능성을 고려하여 탄착 정확도에 대한 해석을 수행하여야 한다. 탄착 정확도는 설계하고자하는 무기체계의 신뢰성을 평가하는 최종단계이므로 매우 중요한 factor이다. 다련장 로켓과 같은 무유도 로켓의 탄착 정확도를 평가하는 가장 좋은 방법은 많은 발수의 시료를 발사하여 획득한 데이터를 바탕으로 평가하는 것이다. 그러나 이 방법은 예비 설계시에는 적용할 수 없으며 제작이 되었다 하더라도 비용이 많이 들기 때문에 적용하기 무척 어렵다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.254-255
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• 2000

일반적으로 노출 평가(exposure assessment)는 발생원과 그 발생원으로부터 배출되는 발생량의 추정에서부터 시작한다. 그리고 발생된 오염물질의 환경중 소멸 과정(fate, chemical process) 및 이동 경로(transport, physical process) 추적 등으로 이어진다. 또한 이들 물질의 수용체인 인체나 혹은 인구 집단의 생활 행태(activity patterns)와 연결·지어 최종적으로 수용체 외부의 노출량 평가 그리고, 수용체 내부 전체 혹은 각각의 장기에서의 오염물질의 정량 등을 고찰하게 된다(Patrick, 1994). (중략)

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.801-805
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• 1998

1000 MWe 국내 표준형 원전을 대상으로 노심이 손상되는 각종 중대사고 시나리오에 대하여 방사선원항 특성을 평가하기 위하여, 2단계 확률론적 안전성 평가 방법론에 따라 방사선원 방출군을 정의하고 원전 중대사고 발생시 격납건물 손상을 가정하여 각 방출군별로 격납건물 외부로 방출되는 방사능 방출율을 정량화하였다. 도출된 19개의 그룹중에서 방출률이 작거나 발생빈도가 낮은 7개를 제외하고 12가지 대표 사고경위에 대하여 계산을 수행하였으며, 분석결과는 격납건물 내에서 감쇄효과가 작은 증기발생기 세관 파단사고, 격납건물 격리 실패사고 및 조기 격납건물 파손사고 둥이 상대적으로 큰 방사능 방출량을 보여주었다

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4375-4380
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• 2015

This study was performed to evaluate a newly proposed heating process of blank, which was used for Crank throw in the diesel engine, and provide design guidelines of heating processes. Non-linear numerical analyses were done using ANSYS program to investigate temperature and thermal stress distributions of blank during heating processes. The heating process consists of two stages; one is a heating stage with 20 hours, and the other is a holding stage with 12 hours, totaling 32-hour heating time. Based on analysis results, it was found that the temperature difference between the center and the surface of blank increased linearly during the heating stage but decreased gradually during the holding stage of heating processes, while max. equivalent stress, $12.5kg/mm^2$, was found at the center of blank after 10-hour heating time. As the guideline of blank heating process, it was recommended to keep the temperature difference between the center and the surface of blank to be within $150^{\circ}C$ when the environment temperature in furnace reaches $650^{\circ}C$ during a heating stage.

• Journal of the Korean Geotechnical Society
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• v.18 no.2
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• pp.23-37
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• 2002

Failure of the cut slope is triggered by combination of internal and extemal failure factors. Internal failure factors are related to geological and geometrical conditions of slope itself, and natural and/or artificial loadings on slope can be the external failure factors. Influences of these failure factors show different intensity according to the ground condition and are controlled by behavior characters of the slope. In this study, the soil depth ratio(SR), block size ratio(BR) and rock strength are used as the criteria to divide ground condition based on behavior characteristics. Ground condition of the slope is divided into discontinuous jointed rock mass and continuos soil-like mass, highly fractured rock mass and massive rock mass by the criteria(SR and BR). The SFi-system is a rating system to determine the slope failure index(SFi) by analyzing internal and external factors based on classification of the ground condition. The results of the SFi-system application to the real cut slopes show close relationship between the SFi value and potential or dimension of the failure. Therefore, the SFi-system can be used as a useful tool to predict and analyze the characteristic of the slope failure.

• Journal of Korea Port Economic Association
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• v.23 no.2
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• pp.121-144
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• 2007

In general, the design of container yard and container handling system on container terminal are focused on operation of shipside than service about chassis from outside(C/O). It is not efficient for chassis from outside. The purpose of this paper is functional assessment of efficient container terminal and for higher performance of container terminal. first, the items which are concerned with container handling at the planning of container terminal are investigated and extracted through the practical data analysis of container terminal. Also, verified problems of planning and present condition through the functional assessment. Secondly, the improvements for container throughput in container yard are proposed and examined the effectiveness of improvements about queuing time of chassis from outside and service time of transfer crane by the evaluation decision model based upon multi criteria objectives.