• 한국환경과학회지
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• 제12권4호
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• pp.503-510
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• 2003

How to plan the energy system is one of the keys f3r constructing the Environment -Friendly City. for this reason, a great number of surveys for utilizing unused energy have conducted by a planner. In regard to unused energy, the heat from incineration plants classify as a unused energy having high-exergy-energy. From this point of view, It is studied about the plant systems providing heat to district heating & cooling(D.H.C) and producing electric power. It is divided four system models as system I (10K [kgf/cm$^2$) vapor as outlet of boiler, supply far 10K vapor and return to 60$^{\circ}C$ as supply condition of district heating), system II (30 K vapor as outlet of boiler, supply for 5t vapor and return to 60f as supply condition of district heating), system 111 (30 K vapor as outlet of boiler, supply for 85$^{\circ}C$ hot water and return to 60$^{\circ}C$ as supply condition of district heating), system IV (30 K vapor as outlet of boiler, supply for 47$^{\circ}C$ hot water and return to 40t as supply condition of district heating). The results from the upper condition of four system, System II got a proper on economical benefits and system IV calculated as benefiting on energy saving effects, and suggest indifference curve as the total evaluation method of both economical benefits and energy saving.

• Journal of Electrical Engineering and Technology
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• 제11권1호
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• pp.47-54
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• 2016

Microgrids offer several reliability benefits, such as the improvement of load-point reliability and the opportunity for reliability-differentiated services. The primary goal of this work is to investigate the impacts of operating condition on the reliability index for microgrid system. It relies on a component failure rate model which quantifies the relationship between component failure rate and state variables. Some parameters involved are characterized by subjective uncertainty. Thus, fuzzy numbers are introduced to represent such parameters, and an optimization model based on Fuzzy Chance Constrained Programming (FCCP) is established for reliability index calculation. In addition, we present a hybrid algorithm which combines scenario enumeration and fuzzy simulation as a solution tool. The simulations in a microgrid test system show that reliability indices without considering operating condition can often prove to be optimistic. We also investigate two groups of situations, which include the different penetration levels of microsource and different confidence levels. The results support the necessity of considering operating condition for achieving accurate reliability evaluation.

• 한국문헌정보학회지
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• 제21권
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• pp.141-168
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• 1991

The Purpose of this study is to explore and analyse ways of enhancing the effectiveness of reference service through reference evaluation. Marketing research technique combined with pre-evaluation theory was applied in this study to find out information for practice the service based on current concept of reference service. Aims and results of this study can be summarised as follows: First, the evaluation of effectiveness of reference service should be conducted for the purpose of finding out the ways of increasing user's satisfaction. Second, the policy evaluation was understood as the appropriated evaluation concept. The policy evaluation in principle coincides with reference service in sense that the satisfaction of public should have priority and hence be the criterion of the evaluation. Third, marketing research based on recently developed 'marketing concept', which concentrates all its efforts to meet user's demand and attempt to acquire the information for better marketing management of non-profit organization such as library, is examined to find out the evaluation method practically applicable to the pre-evaluation of reference service. In this study , conjoint analysis was adopted as the method of pre-evaluation about reference service. The Reference Room of the Central Library Yonsei University, was selected as the arget sample to find out the expected condition for the maximization of the user's satisfaction from the reference service. Based on this example study, the analysis indicates as the most desirable combination for reference service in terms of the user's satisfaction is following condition: the younger librarian with aimable personality who displays willingness In his/her assistance, plus as the method of reference service, sufficient and practical introduction to the reference materials available, plus immediate and satisfactory result of the service, and finally a library equipped with inter-library use system.

• 한국환경생태학회지
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• 제26권6호
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• pp.970-979
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• 2012

본 연구는 생물학적 보전지수(IBI, Index of Biotic Integrity) 평가와 이화학적 수질 분석, 물리적 서식지 평가(QHEI, Qualitative habitate evaluation index)를 이용하여 하천 건강성을 평가하고자 남천의 10개 지점을 대상으로 2006년 8월과 2006년 11월, 2007년 2월, 2007년 4월까지 총 4회에 걸쳐 부착규조 조사를 실시하였다. IBI, QHEI값을 산정하기 위하여 USEPA(1999) 가 제시한 항목 중 우리나라의 환경적 특성에 맞게 수정 보안하여 사용하여 평가하였다. 남천의 하천 생태 건강도 평가 결과, IBI 등급은 '보통', QHEI등급은 '열악', BOD값에 의거한 이화학적 수질등급은 II등급 기준인 '약간좋음'으로 나타나 총체적인 하천생태계 건강도는 '보통'상태로 나타났다. 이는 수 환경에 대한 교란은 적고 생물들이 서식하기에 비교적 양호한 수질임을 시사한다. 정점별로는 St. 6과 St. 7, St. 8, St. 9는 물리적 서식지 지수가 가장 '열악'한 상태로 대부분이 하천의 흐름을 방해하는 교각이나 인공보가 곳곳에 설치되어 있으며, 하상구조가 대부분 단순화되어 있어 수생태계 심각한 교란이 예상되는 정점이다. 또한 St. 10은 전체적으로 서식 환경은 좋으나 생활하수 유입과 함께 하수종말처리장으로부터 배출되는 영양염으로 인한 수생태계의 교란을 초래할 것으로 예상되므로 추후 영양염 유입에 대한 관리가 필요한 것으로 판단된다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.181-183
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• 2013

수문관측시스템 설비의 수명은 설비별 사용빈도와 운영환경에 따라 상이하나, 설비 개대체시 내용 년수만을 고려하고 있는 실정이다. 따라서, 설비의 성능분석을 통한 상태평가 및 의사결정에 따른 과학적 근거를 기초로 한 경제적인 자산관리가 필요하다. 본 연구에서는 K-water에서 사용하고 있는 수문관측시스템의 우량국, 수위국, 경보국 등 단말국 설비에 대하여 성능분석을 통한 과학적인 상태평가방안을 제안하였으며, 이를 통한 합리적인 개대체 방안을 수립하였다.

• Preventive Nutrition and Food Science
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• 제15권4호
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• pp.309-315
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• 2010

A grilled-type shrimp flavor was developed through the Maillard reaction to reduce or mask fish odor or off-flavor in seafood. Model systems were created by using enzymatic hydrolysate of shrimp and adding precursors to increase flavor quality and stability. Amino acid precursors such as cysteine and methionine, sugar precursors such as glucose, xylose, ribose, and sucrose, and one particular compound of glucosamine were tried and their flavor qualities were tested by sensory evaluation. Also, the optimum reaction condition was investigated using the pH values of pH 5, 6, 7, and 8 with reaction times of 1 hr, 2 hr and 3 hr after the best precursors were determined. The best condition of the precursors for grilled-type shrimp flavor was the mixtures of methionine, threonine, xylose, and glucosamine. The optimum reaction condition was at pH 8.0 and 2 hr reaction time.

• 한국안전학회지
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• 제28권3호
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• pp.1-5
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• 2013

In order to evaluate fatigue endurance for an MTB(mountain bike) frame, FEM(finite element method) analysis was performed. For evaluating the fatigue endurance of the MTB frame, the S-N data for Al-6061 fillet weldment were compared with the stress analysis results through FEM analysis of the frame. Three loading condition, pedalling, horizontal and vertical loading conditions were considered for fatigue endurance evaluation. Horizontal loading(+1200 N) condition was found to be the most severe to the frame. The maximum von Mises stress of the frame under horizontal loading(+1200 N) condition was determined 294 MPa through FEM analysis of the frame. Conclusively, on the basis of fatigue strength of 200 MPa at the number of cycles of 50,000, the MTB frame has an improper safety factor of approximately 0.25, suggesting that this frame needs reinforcement.

• 한국터널지하공간학회 논문집
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• 제3권3호
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• pp.45-56
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• 2001

터널 시공에 영향을 주는 지질구조에 대한 정확한 정보를 얻기 위해서는 시공 중의 탐사기법이 중요한 역할을 한다. 국내에서 막장 전방 지질조건을 예측하기 위한 터널내 탄성파 반사법 탐사로는 TSP(Tunnel Seismic Prediction)법을 주로 적용했으나, 본고에서는 HSP(Horizontal Seismic Profiling)법을 수행하였다. 현장 적용결과 소규모의 불연속면의 존재가 예측되었으며, 또한 지반 조사에서 추정된 RMR 값과 터널내 반사법 탐사를 통하여 얻은 암반조건과 거의 일치하는 결과를 얻었으며, 시공 중 평가되는 암반 분류 및 평가 결과와 비교 검증하였다.

• Geomechanics and Engineering
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• 제33권5호
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• pp.463-475
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• 2023

Tunnel construction activity, conducted mainly in mountains and within urban centres, causes soil settlement, thus requiring the relevant management of slopes and structures as well as evaluations of risk and stability. Accordingly, in this study we performed a three-dimensional finite element analysis to examine the behaviour of piles and pile cap stability when a tunnel passes near the bottom of the foundation of a pile group connected by a pile cap. We examined the results via numerical analysis considering different conditions for reinforcement of the ground between the tunnel and the pile foundation. The numerical analysis assessed the angular distortion of the pile cap, pile settlement, axial force, shear stress, relative displacement, and volume loss due to tunnel excavation, and pile cap stability was evaluated based on Son and Cording's evaluation criterion for damage to adjacent structures. The pile located closest to the tunnel under the condition of no ground reinforcement exhibited pile head settlement approximately 70% greater than that of the pile located farthest from the tunnel under the condition of greatest ground reinforcement. Additionally, pile head settlement was greatest when the largest volume loss occurred, being approximately 18% greater than pile head settlement under the condition having the smallest volume loss. This paper closely examines the main factors influencing the behaviour of a pile group connected by a pile cap for three ground reinforcement conditions and presents an evaluation of pile cap stability.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.465-466
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• 2002

In any mechanical system consisting of gears, shafts and/or bearings, the majority of metallic particles deposited into and carried by the lubrication system originate from the deterioration of oil-wetted working surfaces, even in proper lubrication system, due to failure mechanism (s) such as wear, fatigue and fretting corrosion. Determination of the point at which transition from normal to abnormal or to actual damage occurs has become a focus of attention in research activities for years, because it has been recognized that reliable, economic operation can be achieved through appropriate preventative measures. Known collectively from 'all size wear debris analysis' as early failure detection, the methods of testing for damage differ considerably, range from a micron or a submicron size debris analysis to Magnetic Chip Detector (MCD) ferrous debris analysis. This paper will be focused on the utilization of the low-cost analysis techniques for evaluation of industrial machinery condition.