• 설비공학논문집
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• 제12권5호
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• pp.431-438
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• 2000

The major irreversibilities in absorption chillers are associated with the transfer of heat into and out from the machine and irreversible process inside the machine. By modeling only external irreversibilities(endo-reversible), a model was formulated to predict the ideal performance of a single-effect absorption chiller. Its actual performance including both external and internal irreversibilities was calculated with a in-house simulation program. The optimization of heat transfer area distribution was performed for both endo-reversible cycle and actual cycle. The equation of endo-reversible modeling was found to give about 2times higher cooling capacity than the simulation program. At optimal distribution, it was found that heat transfer area of the evaporator was about 30% of total area, that of the generator was 20%, and the rest 50% was for the absorber and condenser. The system COP for endo-reversible cycle was slightly higher than that for actual cycle. In the case of LiBr-water single-effect absorption chiller, the maximum cooling capacity was obtained near the condition that LMTD is same at all heat exchangers.

• KEPCO Journal on Electric Power and Energy
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• 제3권2호
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• pp.141-146
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• 2017

In this work, a simulation study on net 500 MW class of Poly-Generation was conducted for the retrofit of an aged natural gas combined cycle. An entrained gasifier which has a capacity of maximum $260,000Nm^3/h$, 50 MW class of a Polymer Electrolyte Membrane Fuel Cell, and H-class Gas Turbine were selected as key processes. After unit design for those employed processes was set up and combined, the simulation was carried out with Gate-Cycle software (Ver. 6.0) for two cases. The selected cases are a retrofit type (Poly-Gen 1) and a new type (Poly-Gen 2). It was found that the efficiency of the retrofit case is 2.7% lower than that of the new case.

• 오토저널
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• 제10권6호
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• pp.72-84
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• 1988

Engine performance is one of the main objectives specified at the beginning of a new engine design project. The cycle simulation for SI engine is based on the zero-dimensional gas exchange model and a heat release expression by Viebe. This program also requires minimum input data and takes only a short time to run. Heat transfer from cylinder transfer formula. The flow coefficient (effective area) is calculated from valve lift using the standard flow coefficient curve and engine friction is calculated from the Millington and Hartles' engine friction formula. The chemical species considered in burned gas are 6 species CO, CO, H$_{2}$, H$_{2}$O, $O_{2}$, N$_{2}$ and the cylinder pressure, homogeneous cylinder temperature, gas composition and burned fraction are calculated at each crank angle through the cycle. To check the validity and accuracy, experimental study was done with 3 engines for measuring cylinder pressure, indicated mean effective pressure, brake mean effective pressure and air flow rate, etc. Despite its simple assumptions, cycle simulation showes excellent breathing and performance correlation when compared with data of tested engines, and have been proved useful in engine design.

• 한국시뮬레이션학회논문지
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• 제15권2호
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• pp.51-57
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• 2006

현재 반도체 산업은 200mm 웨이퍼에서 300mm 웨이퍼 공정으로 기술이 변화하고 있다. 300mm 웨이퍼 제조업체들은 Fabrication Line (FAB Line) 자동화를 비용절감 실현의 방책으로 사용하고 있다. 또한 기술의 확산, 시장 경쟁력의 격화 등으로 생산성 향상에 의한 원가절감이 반도체 산업 성장의 근본요인이 되고 있다. 대부분의 반도체 업체들은 생산성을 높이기 위해 average cycle time을 줄이는데 총력을 기울이고 있다. 본 논문에서는 average cycle time을 줄이는 데 중점을 두고, 300mm 반도체 제조공정을 시뮬레이션 하였다.

• 대한설비공학회지:설비저널
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• 제23권4호
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• pp.282-289
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• 1994

• 한국태양에너지학회 논문집
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• 제26권2호
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• pp.9-18
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• 2006

In this paper, the thermodynamic performance of OTEC cycle was examined. Computer simulation programs were developed for simple Rankine cycle, regenerative Rankine cycle, Kalina cycle, open cycle and hybrid cycle. For the simple Rankine cycle, the results show that newly developed fluids such as R410A and R32 that do not cause stratospheric ozone layer depletion perform as well as R22 and ammonia. Also, simple Rankine cycle OTEC power plant can practically generate electricity when the difference in warm and cold sea water inlet temperatures are greater than $14^{\circ}C$. The regenerative Rankine cycle showed a 1.5 to 2% increase in energy efficiency compared to the simple Rankine cycle while the Kalina cycle employing ammonia/water mixture showed a 2-to-3% increase in energy efficiency, and the overall cycle efficiencies of hybrid cycle and open cycle were 3.35% and 4.86%, respectively.

• 한국산학기술학회논문지
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• 제20권11호
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• pp.44-55
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• 2019

본 연구는 간호사를 대상으로 초기 심정지 5분 간 수행능력, 자신감 향상을 위해 전통적 시뮬레이션 교육 방법과 Rapid Cycle Deliberate Practice(RCDP) 시뮬레이션 교육 방법을 받은 전·후 변화를 확인하고 두 그룹 간의 수행 능력, 자신감, 만족도를 비교 하고자 시도되었으며 연구 대상자는 서울 소재 병원의 간호사로 그룹 1은 62명으로 RCDP 시뮬레이션 방법을 그룹 2는 60명으로 전통적 시뮬레이션 교육 방법으로 총 122명의 간호사에게 전문 소생술 교육을 진행 하였다. 2019년 3월 18일부터 29일 까지 자료 수집을 하였으며 자료 분석은 SPSS Version 23.0 프로그램으로 서술적 통계, Fisher's exact test, t-test, Wilcoxon sign rank test, Mann-Whitney U-test를 활용하여 분석하였다. 연구 결과 RCDP와 전통적 시뮬레이션 교육의 두 그룹 간에는 수행 능력의 일부 항목(z=-2.02, p=0.044 / z=-2.42, p=0.015 / z=-3.03, p=0.002)은 유의한 차이를 보였으나 수행 자신감(z=0.388, p=0.699)과 만족도(t=.72, p=0.476)에서 두 그룹간의 차이는 없었다. 본 연구는 전통적 시뮬레이션 교육 방법과 RCDP 시뮬레이션 교육 방법 모두 간호사의 전문 소생술 수행 능력 및 자신감을 높이는데 효과적인 교육 방법임을 확인하였다. 따라서 간호사 대상 전문 소생술 교육시 교육 대상 및 내용에 따라 적절한 시뮬레이션 방법을 적용하고 다양한 분야에 RCDP 시뮬레이션 교육 방법을 활용하여 효과성을 확인 해 볼 것을 제언한다.

• 한국시뮬레이션학회논문지
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• 제21권2호
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• pp.41-50
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• 2012

본 연구에서는 반도체 제조공정 및 클러스터 장비에 대한 상세히 설명하고 현 팹 레이아웃 및 클러스터 장비 아키텍처상의 문제점을 제시하였다. 또한 현 아키텍처상의 대안으로서 클러스터 장비간의 웨이퍼 이동이 상호 연결된 인라인 EFEM(Equipment Front End Module) 을 통해 이루어지는 ILE (In-Line EFEM) 아키텍처의 개념을 제시하였다. 마지막으로 해당 아키텍처를 실제 적용하여 구현된 파일럿 시스템을 시뮬레이션 을 통해 사이클 타임 관점에서 비교 분석하였다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 추계학술발표대회 개요집
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• pp.150-152
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• 2003

This simulation was carried out to estimate the process time and to improve the operation efficiency. The subassembly process consists of piece arrangement, tack welding, robot welding, manual welding and the robot welding of them was the focus of the simulation. Robot welding stage was analyzed by UML and IDEFø method, and then it was represented as the three-dimensional model(simulator) based on the analysis. The output of this simulation was the cycle time for one day's work. The cycle time for the different torch and the different piece arrangement was investigated by the 3-dimensional simulation.

• 대한기계학회논문집B
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• 제31권10호
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• pp.860-867
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• 2007

Heat pump drying has a great potential for energy saving due to its high energy efficiency in comparison with conventional air drying. In the present study, the performance simulation for the basic design of a heat pump dryer has been carried out. The simulation includes one-stage heat pump cycle, simple drying process using the drying efficiency. As an example, the heat pump cycle with Refrigerant 134a has been investigated. For the operating conditions such as the average temperature of the condenser, the heat rate released in the condenser, the flow rate of drying air, and drying efficiency, the simulation has been carried out to figure out the performance of the dryer. The parameters considered in the design of the dryer are COP, MER, SMER, the rate of dehumidification, the temperature and humidity of drying air and those parameters are compared for different conditions after carrying out the simulation.