• 대한기계학회논문집B
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• 제25권11호
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• pp.1640-1649
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• 2001

The present study investigates the effects of various rib arrangements on heat/mass transfer in the cooling passage of gas turbine blades. A complex flow structure occurs in the cooling passage with rib turbulators which promote heat transfer on the wall. It is important to increase not only the heat transfer rates but also the uniformity of heat transfer in the cooling passage. A numerical computation is performed using a commercial code to calculate the flow structures and experiments are conducted to measure heat/mass transfer coefficients using a naphthalene sublimation technique. A square channel (50 mm $\times$ 50 mm) with rectangular ribs (4 mm $\times$ 5 mm) is used fur the stationary duct test. The experiments focus on the effects of rib arrangements and gap positions in the discrete ribs on the heat/mass transfer on the duct wall. The rib angle of attack is 60°and the rib-to-rib pitch is 32 mm, that is 8 times of the rib height. With the inclined rib angle of attack (60°), the parallel rib arrangements make a pair of counter rotating secondary flows in the cross section, but the cross rib arrangements make a single large secondary flow including a small secondary vortex. These secondary flow patterns affect significantly the heat/mass transfer on the ribbed wall. The heat/mass transfer in the parallel arrangements is 1.5 ∼2 times higher than that in the cross arrangements. However, the shifted rib arrangements change little the heat/mass transfer from the inline rib arrangements. The gap position in the discrete rib affects significantly the heat/mass transfer because a strong flow acceleration occurs locally through the gap.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3395-3400
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• 2007

Heat transfer experiments at a vertical annulus passage were carried out in the SPHINX(Supercritical Pressure Heat Transfer Investigation for NeXt Generation) to investigate the heat transfer behaviors of supercritical $CO_2$. The collected test data are to be used for the reactor core design of the SCWR (SuperCritical Water-cooled Reactor). The mass flux was in the range of 400${\sim}$1200 kg/$m^2$s and the heat flux was chosen up to 150 kW/$m^2$. The selected pressures were 7.75 and 8.12 MPa. The heat transfer data were analyzed and compared with the previous tube test data. The test results showed that the heat transfer characteristics were similar to those of the tube in case of a normal heat transfer mode and degree of heat transfer deterioration became smaller than that in the tube. Comparison of the experimental heat transfer coefficients with the predicted ones by the existing correlations showed that there was not a distinct difference between the correlations.

• Asia pacific journal of information systems
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• 제10권4호
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• pp.57-75
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• 2000

Most current literature on knowledge and technology transfer(Appropriability Model, Dissemination Model, and Knowledge Utilization Model), describe the process of transfer in details, but has limitation in terms of their application in contemporary high-tech industries since most studies have not provided plausible explanation on levels and factors affecting transfer of knowledge and/or technology. To overcome these limitations, the four levels of knowledge and technology transfer are suggested: Knowledge and Technology Creation(Level I), Sharing(Level II), Implementation(Level III), and Commercialization(Level IV). Comprehensive literature identifies sixteen variables affecting the process and results of knowledge and technology transfer. The survey results show four key factors in knowledge and technology transfer: Communication, Distance, Equivocality, and Motivation, Communication refers to the degree to which a medium is able to efficiently and accurately conveys task-relevant information and media while distance involves both physical and cultural proximity. Equivocality refers to the degree of concreteness of knowledge and technology to be transferred while motivation involves incentives for and the recognition of the importance of knowledge and technology transfer activities. Further analysis shows that there are four distinctive clusters and they show very contrasting characteristics in terms of four key factors. The careful mapping of the four clusters on the four key factors show very informative knowledge and technology transfer patterns, the Knowledge and Technology Transfer Grid. Finally, actions to increase communication interactivity and motivation, and to reduce cultural distance and equivocality are suggested.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.39-44
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• 2008

In this paper, heat transfer coefficients were measured in a channel with one side dimpled surface. The sphere type dimples were fabricated and the diameter and depth of dimple was 16mm and 4mm, respectively. Two channel heights of about 0.6 and 1.2 time of the dimple diameter, two dimple configuration were tested. The Reynolds numbers based on the channel hydraulic diameter was varied from 30000 to 50000. The improved hue detection based transient liquid crystal technique was used in the heat transfer measurement. Heat transfer measurement results showed that high heat transfer was induced downstream of dimples due to flow reattachment. Due to the flow recirculation on the upstream side in the dimple, the heat transfer coefficient was very low. As the Reynolds increased, the overall heat transfer coefficients also increased. With same dimple arrangement, the heat transfer coefficients and the thermal performance factor were higher for the lower channel height. As the distance between dimples became smaller, the overall heat transfer coefficient and the thermal performance factor were increased.

• Journal of Advanced Marine Engineering and Technology
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• 제21권3호
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• pp.229-235
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• 1997

The comparison of radiative and convective heat transfer in a room air ventilation is investi¬gated by a numerical simulation. The room air temperature distributions with radiation are appeared more uniform than without radiation at Gr= 1460 and Re=50. The mean Nusselt number in the radiative heat transfer shows less value than convective heat transfer. The total mean Nusselt number is found Wall 1> Wall 3${\fallingdotseq}$Wall 2 7 Wall 4.

• 한국수정란이식학회지
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• 제2권1호
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• pp.22-26
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• 1987

When the dairy cattle are genetically improved by embryo transfer, generation intervals can be reduced since sires are selected by their full-sister's records rather than by their daughter's records and selection intensity increases because only donor cows and sires for them are selected. In addition by embryo transfer many number of full-sisters and full-sisters are produced at the same time, resulting in the increase in the accuracy of selection.

• 에너지공학
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• 제24권2호
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• pp.103-109
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• 2015

배열회수 보일러는 입구 확관 덕트와 전열관군으로 이루어져 있는데 전열관군에서 열전달 효율을 향상하기 위해서는 전열관군 전에서 배기가스 유동이 균일하게 되어야 한다. 본 연구에서는 전열관군 전의 배열회수 보일러 입구 덕트에서 유동 특성을 살펴보았고 전열관군의 열전달 메커니즘을 지금까지 다른 연구들에서 적용하였던 일정한 열전달 량으로 한 경우와 전열관군 배관의 내부와 외부의 대류열전달을 고려한 열전달 메커니즘을 적용한 경우의 해석에서 온도 분포를 비교하여 배열회수 보일러의 전열관군에서 실제 현상에 보다 적합한 열전달 메커니즘을 정립하는 것을 목적으로 하였다. 본 연구를 통하여 전열관군 배관의 내부와 외부의 대류열전달을 고려한 열전달 메커니즘을 적용한 해석이 일정한 열전달 량을 적용한 경우보다 온도 분포가 타당한 결과를 도출하였고 이렇게 적용한 경우는 배열회수 보일러 탈질설비 전단에서 온도 분포가 설계 기준 ${\pm}10^{\circ}C$에 만족함을 알 수 있었다.

• 한국직업건강간호학회지
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• 제29권4호
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• pp.354-362
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• 2020

Purpose: This study aimed to define and clarify learning transfer in nursing. Methods: This study used a hybrid model to analyze the concept of learning transfer in nursing through three phases. For the theoretical phase, learning transfer attributes were identified through a scoping literature review. In the fieldwork phase, in-depth focus group interviews were conducted to develop attributes. Purposive sampling was performed with ten participants(five nursing students, two nurses, three nursing faculty members). In the analysis phase, the attributes and final analysis of learning transfer in nursing were extracted and integrated from the previous two phases. Results: According to the analysis, learning transfer was represented in two dimensions with eight attributes. The development of competency dimension had three attributes: 1) theory acquisition, nursing skills, professional attitude, 2) integration, and 3) analysis competency. The competency change dimension had five attributes: 1) appropriateness in patient care, 2) proficiency in patient care, 3) satisfaction, 4) achievement, and 5) confidence. Conclusion: The concept analysis might provide a basic understanding of learning transfer, a development framework toward a measurement of nursing learning transfer and effective educational nursing strategies.

• 대한기계학회논문집B
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• 제33권1호
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• pp.17-27
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• 2009

Water jet impingement cooling is used to remove heat from high-temperature surfaces such as hot steel plates in the steel manufacturing process (thermo-mechanical cooling process; TMCP). In those processes, uniform cooling is the most critical factor to ensure high strength steel and good quality. In this study, experiments are performed to measure the heat transfer coefficient together with the inverse heat conduction problem (IHCP) analysis for a plate cooled by planar water jet. In the inverse heat transfer analysis, spatial and temporal variations of heat transfer coefficient, with no information regarding its functional form, are determined by employing the conjugate gradient method with an adjoint problem. To estimate the two dimensional distribution of heat transfer coefficient and heat flux for planar waterjet cooling, eight thermo-couple are installed inside the plate. The results show that heat transfer coefficient is approximately uniform in the span-wise direction in the early stage of cooling. In the later stage where the forced-convection effect is important, the heat transfer coefficient becomes larger in the edge region. The surface temperature vs. heat flux characteristics are also investigated for the entire boiling regimes. In addition, the heat transfer rate for the two different plate geometries are compared at the same Reynolds number.

• 벤처창업연구
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• 제7권1호
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• pp.165-175
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• 2012

최근 21세기 세계 경제가 지속적인 성장을 유지하기 위한 핵심요소로서 기술의 축적, 이전, 흡수, 상용화 등이 중요하게 인식되고 있으며, 정부는 공공연구기관에서 개발된 기술이 민간부문으로 이전되어 사업화되는 것을 촉진하고 민간부문에서 개발된 기술이 원활히 거래되고 사업화되는 것을 촉진하기 위해'기술의 이전 및 사업화 촉진에 관한 법률'을 마련했다. 또한 동 법률 제14조에서는 기술거래사의 등록 육성 및 지원에 관한 사항으로 '기술거래사' 자격제도를 도입하여 국가에서 등록, 운영, 관리하고 있으며 대부분의 선진국은 기술거래중개 기관을 민간에 이양하여 기술중개기관 또는 기술브러커로 지칭하고 있다. 국내에서는 이러한 자격제도 도입과 시장 활성화 촉진을 위한 다양한 조직과 기술중개시스템을 구축하였음에도 불구하고 기술거래사 등록제도와 사후관리에 대한 법률적 근거와 체계가 미흡하여 문제점이 발생되고 있다. 일례로 최근 기술거래관련 실적면제로 기술거래사 등록 활성화는 달성하였으나, 실적 검증을 통한 일정수준 이상의 전문가 선별에는 한계점이 나타나고 있다. 이에 경력증명서 기재 내용만으로 업무 경력 보유 여부를 판단하기에는 심사의 한계점이 드러나고 있어 이에 대한 대책이 시급하다. 또한 기술거래사 등록 시 의무적 교육이수제도가 2010년도에 법 개정 및 고시 개정으로 마련되었으나, 소양교육수준의 단기 교육과정 운영으로 신청자에게 다양한 전문지식 취득의 기회 제공이 어려움이 있는 것이다. 이에 본 연구에서는 한국과 중국의 기술거래사 제도 비교를 통해 기술거래사 제도개선에 대해 고찰해 보았다. 이를 통해 기술이전 사업화 시장 확대와 기술거래사 전문가의 업무영역 보장과 전문가로서의 입지확보 등 경쟁력을 강화하는데 활용될 수 있도록 개선안을 제시하였다.