• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.9
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• pp.1780-1787
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• 1992

Experiments have been performed on the thermal behavior in a liquid saturated porous medium in a system to simulate a single well aquifer thermal energy storage system. The principal interests in this study are the combined effects of forced and natural convection. Significant buoyancy flow due to natural convection is developed quickly as the temperature difference between the injection and original aquifer temperature increases. Theoretical model under simplified assumptions (called simple buoyancy flow model in this study) has been developed. The results of this model agree well with the experiments. The effects of buoyancy flow on the recovery factor are also examined in this study.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.2
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• pp.126-131
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• 2001

One of the major obstacles in testing or evaluating precisely the thermal behavior of a machine tool is the difficulty in measuring the heat transfer coefficients on the surfaces by a conventional method. This paper presents a new approach based on the inverse method to identify the values of heat transfer coefficients by using temperature changes measured on the surfaces of a machine tool during a short period in its operating. In the present method, a machine tool structure is modeled by the finite element method and the characteristic curves of the temperature change at several points on machine tool surfaces are theoretically derived in the form that they contain the heat transfer coefficient as an unfixed heat source are approximated so that the theoretical characteristic curves of temperature change fit the measured ones as closely as possible.

• Journal of Korea Fair Competition Federation
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• no.106
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• pp.14-19
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• 2004

공정거래법상 법위반 행위 중지명령의 경우 사업자의 자유로운 사업활동을 제약한다는 측면에서 제재수단에 해당된다는 견해와 동 명령의 경우 법위반 행위 재발에 대한 예방조치로서 사업자에게 특별한 불이익을 주는 것이 아니므로 제재수단에 해당되지 않는다는 견해가 제기될 수 있다. 행정법규 위반행위에 대한 제재수단 또는 행정의사의 실효성 확보수단으로서 강학상 열거되고 있는 수단들은 행정강제, 즉시강제, 행정형벌, 행정질서별, 기타 새로운 의무이행확보수단으로서 공정거래법상 법위반 행위 중지명령의 경우 이들 제재수단들에 언급되지는 않고 있는 것으로 보여진다.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.59-59
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• 2012

의류용 섬유제품은 고유의 기능인 보온성을 비롯하여, 태나 착용감, 또는 패션에 부응하는 다양한 성능이 요구되고 있다. 섬유 직물의 보온기능은 경량 보온과 축열 보온 그리고 발열 등이 중요한 기능으로 인식되고 있으며 특히 적극적인 보온성이 요구된다. 본 연구에서는 그 개선책으로서 패션소재표면에 상전이물질을 코팅하여 보온성을 조사했다. 상전 이물질 (PCM,Phase change materials) 입자를 DSC분석기로 측정하여 열거동을 관찰하였고, 실크직물과 실크혼방 직물에 PCM과 키토산을 농도별로 처리하여 보온성 테스트와 SEM을 측정하였다. 실크직물과 실크혼방 직물에 PCM과 키토산 처리하여 직물의 보온성을 측정해 본 결과, 실크직물 9.1% 실크혼방 직물은 29.9%로 실크혼방 직물이 실크직물보다 우수한 보온성을 보였다. SEM 관찰에서도 실크직물과 실크혼방 직물의 표면에 PCM입자의 침투정도도 확연한 차이를 보였다. 이를 미루어 볼 때 실크직물보다 실크혼방 직물에 PCM과 키토산을 처리하였을 경우 우수한 보온성을 보인다고 생각된다.

• Journal of Hydrogen and New Energy
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• v.22 no.2
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• pp.178-183
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• 2011

Metal hydride alloys are a promising type of material in hydrogen storage applications, allowing for low-pressure, high-density storage. However, while many studies are being performed on enhancing the hydrogen storage properties of such alloys, there has been little research on large-scale storage vessels which make use of the alloys. In particular, large-scale, high-density storage devices must make allowances for the inevitable generation or absorption of heat during use, which may negatively impact functioning properties of the alloys. In this study, we develop a numerical model of the discharge properties of a high-density MH hydrogen storage device. Discharge behavior for a pilot system is observed in terms of temperature and hydrogen flow rates. These results are then used to build a numerical model and verify its calculated predictions. The proposed model may be applied to scaled-up applications of the device, as well as for analyses to enhance future device designs.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.550-554
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• 2007

A one-dimensional heat transfer model coupled with parameter estimation is developed in this study to predict the effective thermal conductivities of soil formation and borehole resistances from in situ field test data. In this application a new method of using initial ignoring time(IIT) obtained from error estimation is tried and turned out to be successful in determining soil thermal conductivities. The validity of this model is accomplished through comparison of the predicted temperature profiles of the model with the data from laboratory scale experimental setting. Eleven test boreholes were constructed in Ochang, Chungcheong Buk Do, and thermal response test was carried out with each borehole. The results of the in situ tests were analyzed with our 1-D numerical model and compared with the results of line source method. The comparison shows that the thermal properties from line source method is a little lower (${\sim}95%$)than those from numerical method. The reason of such result seems to be the lower thermal conductivity of grout material, which is not counted in line source method.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.426-427
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• 2008

전력의 안정적 공급, 공급 신뢰도 향상 및 도심지 인구밀집 지역의 전력공급 및 미화 등의 축면에서 송전분야에서의 지중화는 필수적이며 지속적으로 증가추세에 있다. 그러나 제한적인 지중공간을 활용함에 따른 여러 문제가 발생하고 있다. 지중선로 고장상황으로 1선 지락, 2선지락, 선간단락, 3상단락 등의 사고가 있으며 이러한 고장상황에서 발생하는 고장전류에 의한 열거동은 지중선로에 악영향을 준다. 그러므로 각 고장상황에 따른 지중선로의 영향에 대한 세부적인 검토가 필요하다. 본 논문에서는 각 고장상황에 따른 검토조건으로 1회선과 2회 선일 경우와 상배열이 정삼각배열, 수평/수직배열, 직각배열일 경우를 선정하여 지중선로에 미치는 영향을 EMTP, IDEARS, MARC를 활용하여 분석하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.9
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• pp.1499-1507
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• 2003

Physical importance of cutting temperatures has long been recognized. Cutting temperatures have strongly influenced both the tool life and the metallurgical state of machined surfaces. Temperatures in drilling processes are particularly important, because chips remain in contact with the tool for a relatively long time in a hole. Tool temperatures tend to be higher in drilling processes than in other in machining processes. This paper concerns with modeling of thermal behaviors in drilling processes as well as estimation of the cutting temperature distribution based on remote temperature measurements. One- and two-dimensional estimation problems are proposed to analyze drilling temperatures. The proposed thermal models are compared with solutions of finite element methods. Observer algorithms are developed to solve inverse heat conduction problems. In order to apply the estimation of cutting temperatures, approximation methods are proposed by using the solution of the finite element method. In two-dimensional analysis, a moving heat source according to feedrate of the drilling process is regarded as a fixed heat source with respect to the drilling location. Simulation results confirm the application of the proposed methods.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.191-191
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• 2009

In this paper, we have confirmed the temperature of LED chip and McPCB with thermal simulation program which is CFDedign V10 for analysis the thermal flow of HP LED package. we have known that the heat from LED chip is transferred through heat slug to copper layer of McPCB. the temperature of LED chip shows 85.11 [$^{\circ}C$], which shows the temperature gap of 7.52 [$^{\circ}C$] against McPCB. the gap of temperature affect reliability of the wire bonding and die attachment. therefore, copper layer of heat slug on the McPCB should designed with the largest dimension.

• Convergence Security Journal
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• v.15 no.6_2
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• pp.55-63
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• 2015

Like a violence occurred by security guardians in the Yoosung or SJM Enterprise, a series of security company in Korea has repeated illegal conduct. So human rights violations are getting to be very heavy. The National Police Agency, the controller of the Security Services Industry Act, requires stricter regulations for the defense industry direction. here followed the research about some provisions in the Security Services Industry Act relating to 'the collective civil appeals spot' examining the contents of the Problems and discussed about it.