• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제8권2호
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• pp.43-50
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• 2002

By reason of development of anesthesia, advent of new surgical operation type and change of hygiene criterion and economical index is increasing recently request about alteration of existing unit or new surgical operation-unit type. The purpose of this study is to provide of architectural planning program for the type decision and the scale computation of operating-unit in healthcare facilities. As a result of this study, presented program of six type according to surgical operation process including space and time side.

• 한국초전도ㆍ저온공학회논문지
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• 제10권1호
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• pp.67-70
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• 2008

Performance of integral type Stirling refrigerator used for cooling infrared detector is affected by principal factors such as design factors and operating factors. Operating factors include charging pressure and operating frequency. The purpose of this paper is to examine the basic design analysis on the integral type Stirling refrigerator and the changes in performance through experiments on operating factors.

• Journal of Mechanical Science and Technology
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• 제19권4호
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• pp.1018-1026
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• 2005

The proton exchange membrane (PEM) fuel cell system consisting of stack and balance of plant (BOP) was modeled in a MATLAB/Simulink environment. High-pressure operating (compressor type) and low-pressure operating (air blower type) fuel cell systems were con­sidered. The effects of two main operating parameters (humidity and the pressure of the supplied gas) on the power distribution characteristics of BOP and the net system efficiency of the two systems mentioned above were compared and discussed. The simulation determines an optimum condition regarding parameters such as the cathode air pressure and the relative humidity for maximum net system efficiency for the operating fuel cell systems. This study contributes to get a basic insight into the fuel cell stack and BOP component sizing. Further research using muli­object variable optimization packages and the approach developed by this study can effectively contribute to an operating strategy for the practical use of fuel cell systems for vehicles.

• 동력기계공학회지
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• 제18권6호
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• pp.99-105
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• 2014

This paper presents a comparison of operating characteristics for industrial water cooler with variation control methods. The performance analysis regarding the characteristics of condensation capacity, evaporation capacity, compressor load, COP of an on-off type cooler, a hot gas-bypass control type cooler and an inverter control type cooler with respect to the system load is reviewed, respectively. The primary results are as following: the variation of required compressor load of an on-off type cooler with respect to load is 5%, that of hot gas-bypass type is 18% and 66% for an inverter control type cooler. As the result shows, an inverter control type yields relatively huge difference of required compressor load compared to other types of control system. In terms of partial load, COP of an inverter control type cooler presents the highest value, and is considered as the optimized type for the used of the system involving frequent partial load.

• Journal of Power Electronics
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• 제6권4호
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• pp.356-365
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• 2006

This paper presents an improved three-phase PFC power rectifier with a three-phase diode rectifier cascaded four-switch boost converter. Its operating principle contains the operating principle of two conventional three-phase PFC power rectifiers: one switch boost converter type and a two switch boost converter type. The operating characteristics of the four switch boost converter type three-phase PFC power rectifier are evaluated from a practical point of view, being compared with one switch boost converter type and two switch boost converter topologies.

• Korean Chemical Engineering Research
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• 제58권3호
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• pp.493-497
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• 2020

Hazardous area classification is designed to prevent chemical plant explosions in advance. Generally, the duration of the explosive atmosphere is used for zone type classification. Herein, IEC code, a quantitative zone type classification methodology, was used to achieve Zone 2 NE, which indicates a practical non-explosion condition. This study analyzed the operating pressure of a vessel handling propane to achieve Zone 2 NE by applying the IEC code via MATLAB. The resulting zone type and hazardous area grades were compared with the results from other design standards, namely API and EI codes. According to the IEC code, the operating pressure of vessels handling propane should be between 101325-116560.59 Pa. In contrast, the zone type classification criteria used by API and EI codes are abstract. Therefore, since these codes could interpret excessively explosive atmospheres, care is required while using them for hazardous area classification design.

• Journal of Advanced Marine Engineering and Technology
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• 제22권6호
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• pp.782-791
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• 1998

This paper presents a computer simulation of five types of triple effect absorption cycles employ-ing the refrigerant absorbent combinations of NH3/LiNO3 low-pressure type NH3/LiNO3+H2O/LiBr binary two-stage type series flow cycle and two types of parallel flow cycle for H2O/LiBr. The absorption systems is investigated through cycle simulation to obtain the system characteristics with the cooling water inlet temperature approach temperature of absorber loss temperature of absorber and chilled water outlet temperature. The most important characteristic temperature of absorber and chilled water outlet temperature. The most important characteristic of NH3/LiNO3 low-pressure type and a NH3/LINO3+H2O/LiBr binary two-stage type is that it obtains a coefficient of performance higher than the sum of the performance coefficients of its part operating independently. As a result of this analysis the optimum designs and operating conditions were determined based on the operating conditions and the coefficient of performance.

• 교육시설 논문지
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• 제20권5호
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• pp.3-10
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• 2013

This study was carried out to obtain basic data for architectural plans on the facilities relocation needed in operating the departmentalized classroom system at the latest built middle schools. For this, floor plans of ten middle schools built in Gwangju after 2009 were analyzed about space configuration and area holding state. The process of this study is as follows: (1) To investigate proper area holding state for operating variation type, this study analyzed area of departmentalized classrooms, homebases and teachers' offices. (2) To investigate space configuration for operating variation type, this study analyzed composition of departmentalized classrooms, learning-support facilities and homebases. (3) On the base of those analyses, this study proposed some directions for architectural plans on the facilities relocation.

• 한국전기전자재료학회논문지
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• 제36권5호
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• pp.474-481
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• 2023

This paper is an experimental study on the optimal operating conditions of direct charging type electrospray for particulate matter collection. To perform the research, a direct charging type electrospray visualization system was configured to photograph the spray shape of microdroplets, and experiments were performed with varying electrode distance, flow rate, and applied voltage, which are the main factors affecting the particulate matter collection efficacy. Through image processing, the total number of microdroplets according to each condition was analyzed, and the number of microdroplets with a diameter of 1.5 mm or less was confirmed. In addition, by calculating the number of microdroplets per power consumption according to the applied voltage, the optimal operating conditions were derived in terms of energy consumption efficacy, and the microdroplet size distribution was analyzed under the optimal operating conditions. As a result of the experiment, it was confirmed that the optimal operating condition was at a flow rate of 10 mL/min and a voltage of -20 kV in case of 5 mm electrode distance, and at a flow rate of 15 mL/min and a voltage of -30 kV in case of 100 mm electrode distance.

• 대한교통학회지
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• 제25권1호
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• pp.133-141
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• 2007

승용차 부문의 에너지수요 또는 대기오염물 배출에 대해 영향을 미치는 정책의 효과를 정확히 예측하기 위해서는 소비자의 승용차 보유 및 이용행태에 대한 분석 및 예측이 선행되어야 한다. 이를 위해 본 연구는 네스티드로짓모형 을 활용한 가계의 자동차 보유대수 및 차종선택에 대한 연구로서 2003년 에너지경제연구원에서 수행한 에너지간이 조사 자료를 이용하여 추정을 시도하였다. 모형의 추정결과를 요약하면 모형의 적합도(goodness of fit)를 나타내는 ${\rho}^2$ 값과 포괄값이 모두 통계적으로 유의한 범위 내에 있어 네스티드로짓모형을 활용한 방법이 더 우수하다고 할 수 있다. 또한 운행비용의 탄력성이 1보다 커서 가구의 차량보유대수 및 차종선택은 운행비용에 대해 매우 민감하다는 것과 소득계층별로는 저소득 계층이 고소득 계층보다 더 민감하게 반응한다는 것을 알 수 있었다.