• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2002년도 춘계공동학술발표회요약집
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• pp.76-76
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• 2002

• Nuclear Engineering and Technology
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• 제49권5호
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• pp.979-988
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• 2017

The feasibility of cooling in a pressurized heavy water reactor after a large break loss-of-coolant accident has been analyzed using Multidimensional Analysis of Reactor Safety-KINS Standard code during the recirculation phase. Through evaluation of sensitivity of the fuel channel temperature to various effective recirculation flow areas, it is determined that proper cooling of the fuel channels in the broken loop is feasible if the effective flow area remains above approximately 70% of the nominal flow area. When the flow area is reduced by more than approximately 25% of the nominal value, however, incipience of boiling is expected, after which the thermal integrity of the fuel channel can be threatened. In addition, if a dramatic reduction of the recirculation flow occurs, excursions and frequent fluctuations of temperature in the fuel channels are likely to be unavoidable, and thus damage to the fuel channels would be anticipated. To resolve this, emergency coolant supply through the newly installed external injection path can be used as one alternative means of cooling, enabling fuel channel integrity to be maintained and permanently preventing severe accident conditions. Thus, the external injection flow required to guarantee fuel channel coolability has been estimated.

• 한국산림과학회지
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• 제81권4호
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• pp.357-362
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• 1992

아까시나무와 산돌배나무의 수분이동(水分移動) 경로(經路)를 이해하고, 수분이동(水分移動) 경로(經路)를 이용한 무늬목을 생산하기 위하여, 염료침투경로(染料浸透經路)를 0.5% acidic fuchasin 용액과 0.5% fast green 용액을 수목(樹木)에 주입시켰다. 환공재(環孔材)이면서 타이로시스를 갖고있는 아까시나무와 산공재(散孔材)이면서 목섬유(木纖維)에 많은 벽공(壁孔)이 존재하는 산돌배나무의 목부구조(木部構造)와 수분이동(水分移動) 경로(經路)를 비교했다. 그 결과 아까시나무의 수분통도(水分通導)는 당해년도(當該年度)와 전년도(前年度)에 형성된 조재부(早材部)의 대도관(大導管)에 의해서 주도되었다. 그리고 타이로시스가 도관(導管) 내강(內腔)을 폐쇄(閉鎖)하고 있는 심재(心材)와 이행재(移行材)에는 염료침투(染料浸透)가 되지 않았다. 산돌배나무는 수(髓)를 제외하고 전부위에 염색되었으며, 특히 도관(導管)이외에 목섬유(木纖維)의 벽(壁)에 염료(染料)의 침착이 이루어졌다.

• 한국산학기술학회논문지
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• 제15권5호
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• pp.2628-2634
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• 2014

동절기에 차량 전면유리의 결빙이나 이물질을 제거하기 위하여 워셔액 가열시스템 적용이 점차 늘어나고 있다. 이 워셔액 가열 시스템은 짧은 시간동안 목표온도까지 워셔액이 가열되도록 설계되어야 한다. 본 연구에서는 급속하게 워셔액을 가열하기 위하여 차량 워셔액 가열 시스템의 내부 부품의 재질에 따라 열전달 특성을 해석하였다. 해석을 위해 열유동 전산해석에서 사용하고 있는 CFD(Computational Fluid Dynamics) 상용코드인 ANSYS-FLUENT 소프트웨어를 이용하였다. 본 모델은 3차원 비정상상태의 축대칭 모델로 Fluent에서 제공하는 압력기반(Pressure-Based) 기법 중의 하나인 Coupled 기법을 적용하였다. 이 결과를 통하여 충전재 및 유로의 최적화된 재질을 찾게 되었다. 충전재 재질은 낮은 밀도를 가진 공기가 실리콘카바이드보다 빠르게 가열되었다. 유로재질은 니켈보다 열전달계수가 약 4배 정도 큰 구리가 내부에 열을 균일하게 전달되어 메탄올의 가열 시간을 단축하여 효율이 더 높게 나왔다.

• Journal of applied mathematics & informatics
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• 제15권1_2호
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• pp.53-75
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• 2004

First, we present two classes of sequential algorithms for minimum flow problem: decreasing path algorithms and preflow algorithms. Then we describe another approach of the minimum flow problem, that consists of applying any maximum flow algorithm in a modified network. In section 5 we present several parallel preflow algorithms that solve the minimum flow problem. Finally, we present an application of the minimum flow problem.

• Journal of Nutrition and Health
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• 제34권6호
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• pp.701-714
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• 2001

The purpose of this study was to apply a PERT-type system, a combination of the project evaluation and review technique(PERT) and critical path method(CPM) on the employees' work time management of flood preparation, assembly, transportation and cleaning in home-delivered meals program for elderly The resources allotment heuristic program was developed by considering the number of employees and cooking utilities, being limited resources of home- delivered meals program. This program could assign the employees to perform the works included in flood preparation, assembly, transportation ind cleaning. Critical path and activities ware identified by PERT-type system on the basic of work time investigation in five senior centers. Work sheets were invented to perform the work by the shortest path with flexible employees'maximum flow As a result of the work time investigation, the most prevalent activities were ones of preparation in center C and E. Besides, the preparation(over fifty percent) was the most proportion among flood preparation, assembly, transportation and cleaning in center C and E. Critical path and activities of 'C'center were cucumber in sauce preparation path and assembly, wrapping in assembly path and case delivery in transportation path. Critical path and activities of 'E'center were Pan-fried Potato Preparation Path and assembly, case covering, wrapping in assembly Path. The work sheet invented by the heuristic program and PERT-type system reduced the work completion time and man hours in both centers.

• 설비공학논문집
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• 제16권4호
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• pp.340-348
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• 2004

The air and refrigerant side heat transfer performances are key parameters to improve heat transfer efficiency of the heat exchanger including the fan performance. Design of the fins, treatment of the tube inside, tube diameter and tube array effect heat transfer performance of the heat exchanger. The heat exchanger is used as a condenser at cooling mode and used as an evaporator at heating mode in the heat pump system. The heat pump system uses R410A as the refrigerant. The heat exchangers are consisted with 7 mm diameter tubes with slit-type fins. The study was conducted with variation of arrangement of the refrigerant path and air flow rate and refrigerant pressure drop and heat transfer rate were measured with a code tester. The capacity of the 3 path heat exchanger is more efficient than 2 or 4 path heat exchangers in heating or cooling modes.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2001년도 가을 학술발표논문집 Vol.28 No.2 (3)
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• pp.805-807
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• 2001

네트워크상의 자원을 효율적으로 사용하기 위한 방범의 하나로 다중 경로 라우팅(multi-path routine)이 있다. 트래픽 엔지니어링(traffic engineering)을 위하여 다중 경로 라우팅을 이용하면 트래픽(traffic) 을 여러 경로로 분산 시켜 트래픽이 한 곳으로 집중하는 현상은 제거 할 수 있을 뿐 아니라 네트워크 상의 유휴자원을 효율적으로 사용할 수 있는 장점이 있다. 본 논문에서는MPLS환경 하에서 다중 경로 라우팅을 효율적으로 사용하기 위해 제안 되었던 알고리즘에 대하여 분석 하고 각 알고리즘들의 장단점을 비교한다. 그리고 효율적인 다중 경로 라우팅을 위해 추가적으로 필요한 요소를 기술하고, 새로운 다중 경로 라우팅을 위한 구조를 제안한다.

• 산업경영시스템학회지
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• 제26권4호
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• pp.23-30
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• 2003

This study develops an efficient heuristic which is based on genetic approach for AGVs flow path layout problem. The suggested solution approach uses a algorithm to replace two 0-1 integer programming models and a branch-and-bound search algorithm. Genetic algorithms are a class of heuristic and optimization techniques that imitate the natural selection and evolutionary process. The solution is to determine the flow direction of line in network AGVs. The encoding of the solutions into binary strings is presented, as well as the genetic operators used by the algorithm. Genetic algorithm procedure is suggested, and a simple illustrative example is shown to explain the procedure.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.687-688
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• 2012