• 설비공학논문집
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• 제14권3호
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• pp.191-198
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• 2002

Cooling tower design procedure was set up using conventional Merkel theory, The design data could be different depending on the characteristic curve that the engineer chose. It reveals that the consistent and reasonable criteria are required based on the exact information of the cooling tower Performance. In this study, an off-design performance analysis program for a counterflow-type cooling tower was developed and verified by comparing with experimental data. Also, the off-design performance with various operating conditions was analyzed.

• 설비공학논문집
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• 제13권11호
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• pp.1165-1173
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• 2001

The objectives of this study are to analyze the application of radiant floor cooling and to evaluate the control methods through experiments when the radiant heating system is used for cooling. Through the experiment analysis the control methods such as on/off control, variable flow control and outdoor reset with indoor temperature feedback control are evaluated and compared. The cooling curve (reset ratio) is found for radiant cooling, which shows tole relation between outside air temperature and supply water temperature. Comparison of cooling methods shows that outdoor reset with indoor temperature feedback control is more appropriate than on/off control and variable flow control with regard to prevention of the condensation and thermal comfort.

• 한국추진공학회지
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• 제16권6호
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• pp.16-22
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• 2012

액체로켓 추력실의 성능 예측 및 초음속 노즐부 형상 설계에 활용 중인 in-house 해석 도구를 이용하여 재생냉각 연소기에 대한 성능/냉각 통합해석을 수행하였으며, 막냉각 유량 및 외곽 분사기열의 혼합비 변화에 따른 연소 성능과 냉각 성능 간 trade-off 경향을 고찰하였다. 향후 막냉각 및 주요 설계 인자의 최적화 도구로 활용될 수 있도록 개발 연소기에 대한 시험 결과와의 비교 등을 통하여 수치해석 도구를 검증/개선해나갈 계획이다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2012년도 제38회 춘계학술대회논문집
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• pp.35-41
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• 2012

액체로켓 추력실의 성능 예측 및 초음속 노즐부 형상 설계에 활용 중인 in-house 해석 도구를 이용하여 재생냉각 연소기에 대한 성능/냉각 통합해석을 수행하였으며, 막냉각 유량 및 외곽 분사기열의 혼합비 변화에 따른 연소 성능과 냉각 성능 간 trade-off 경향을 고찰하였다. 향후 막냉각 및 주요 설계인자의 최적화 도구로 활용될 수 있도록 개발 연소기에 대한 시험 결과와의 비교 등을 통하여 수치해석 도구를 검증/개선해나갈 계획이다.

• International Journal of Air-Conditioning and Refrigeration
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• 제11권1호
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• pp.17-23
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• 2003

A design procedure for cooling towers was set up using the Merkel theory In the past, the design data could be different depending on the characteristic curve that the engineer adopted. Therefore, consistent and reasonable criteria are required, which are based on the exact information of the cooling tower performance. In this study, analysis program for both the design and off-design for a counterflow-type cooling tower was developed and verified by comparing with experimental data. The off-design performance with various operating conditions was analyzed, as well.

• 한국응용과학기술학회지
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• 제31권3호
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• pp.402-407
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• 2014

Herein, we describe the effect of the cooling-off condition of a solution-processed 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-pentacene) film on its molecular distribution and the resultant electrical properties. Since the solvent in a TIPS-pentacene droplet gradually evaporates from the rim to the center exhibiting a radial form of solute, for a quenched case, domains of the TIPS-pentacene film are aboriginally spread showing original features of radial shape due to suppressed molecular rearrangement during the momentary cooling period. For the slowly cooled case, however, TIPS-pentacene molecules are randomly rearranged during the long cooling period. As a result, in the lopsided electrodes structure proposed in this work, the charge transport generates more effectively under the case for radial distribution induced by the quenching technique. It was found that the molecular redistribution during the cooling-period plays an important role on the magnitude of the mobility in a solution-processed organic transistor. This work provides at least a scientific basis between the molecular distribution and electrical properties in solution-processed organic devices.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2000년도 춘계 학술발표회 논문집
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• pp.69-74
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• 2000

This paper describes an operation strategy of ice storage systems for energy saving during building cooling. In this study, chiller is assumed not having function of part load control. Thus, it is needed to adopt on-off control with the objective function of summed energy consumption for minimum energy consumption. A conventional control strategy compared with the chiller-on-off control is chiller-priority control. in this control chiller operates as its full capacity and ice storage meets the rest of the cooling load.

• 설비공학논문집
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• 제13권6호
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• pp.532-540
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• 2001

The objectives of this study are to analyze the control variables according to condensation occurrence, to find the range in floor surface temperature and frequency of condensation, and to evaluate the control methods through simulations when the radiant heating system is used for cooling. Through the simulation analysis the control methods such as on/off control, variable flow control and outdoor reset with indoor temperature feedback control are evaluated and compared. The results show that the lowest floor surface temperature is around $23^{\circ}C$, the surface condensation can be prevented by controlling indoor humidity within 20g/kg(DA0, and that outdoor reset with indoor temperature feedback control is more appropriate than on/off control and variable flow control with regard to prevention of the condensation and thermal comfort.

• 통상정보연구
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• 제10권3호
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• pp.75-99
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• 2008

In the commercial transaction sellers use various sales strategies to increase profits, and this kind of sales strategies often causes damage to customers, it, moreover, is true that these examples happen in the electronic commercial market much more than in traditional one because of the characteristics if the electronic commerce. That's why people transact one another without face-to-face meeting in the electronic commerce market, so people one likely to fall for a trick to cheat and deceive. It's no doubt that the frequency of crime is higher than in face-to-face market. For that reason Cooling Off System, Consumer Compensation Insurance, Mutual Aid Association and Billing Payment Deposit System are in force the law related electronic commerce to protect customers' rights. In this paper it will be discussed about the periods of Cooling Off System and a received commodity notice of the Billing Payment Deposit System. Regarding these periods seven days for Cooling Off period and three days for a received commodity notice period are stipulated under the law of related electronic commerce to protect customers' rights, But each period has to be differentiated depending on each goods for this period to be reasonable and proper. Therefore in this study it will be focused on these facts and each period will be classified by the goods' purpose of purchase and quality.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.914-917
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• 2001

Single-shot laser damage of thin Cr films on glass substrates has been studied to understand the cracking and peeling-off mechanism. A numerical model is developed for the calculation of transient heat transfer and thermal stresses in Cr films during excimer laser irradiation and cooling, the transient temperature, and the stress-strain fields are analyzed by using a three-dimensional finite-element model of heat flow. According to the numerical analysis for the experimentally determined cracking and peeling-off conditions, cracking is found to be the result of the tensile brittle fracture due to the excessive thermal stresses formed during the cooling process, while peeling-off is found to be the combined result of films bulging from the softened glass surface at higher temperature and the tensile brittle fracture during the cooling process.