• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.304-310
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• 2001

A numerical model which simulates the heat and mass transfer processes within a counter-current plate type generator for ammonia/water absorption refrigerators was developed. Ammonia/water solution flows downward under gravity and ammonia/water vapor generated by flow boiling flows upward. The flow pattern within the generator was assumed to be a bubbly flow, and the liquid and vapor phase were assumed to be saturated. It was shown that the boiling of ammonia occurred mainly in the upper part of the generator. The effects of the generator length, the wall temperature and the mass flow rate of ammonia/water solution into the generator on the generation of ammonia/water vapor were investigated.

• 한국해안해양공학회:학술대회논문집
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• 한국해안해양공학회 2004년도 학술발표논문집 Proceedings of Coastal and Ocean Engineering in Korea
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• pp.150-159
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• 2004

In the present paper, the hydrodynamics properties of a Rahmen type flexible porous breakwater with dual fixed-pontoon system interacting with obliquely or normally incident small amplitude waves are numerically investigated. This system is composed of dual vertical porous membranes hinged a the side edges of dual fixed pontoons, and a submerged horizontal membrane that both ends are hinged at the steel frames mounted pontoons. The dual vertical membranes are extended downward and hinged at bottom steal frame fixed into seabed. The wave blocking and dissipation mechanism and its effects of permeability, Rahmen type membrane and pontoon geometry, pre-tensions on membranes, relative dimensionless wave number, and incident wave headings are thoroughly examined.

• 한국해양공학회지
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• 제16권5호
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• pp.7-14
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• 2002

in the present paper, the hydrodynamics properties of a Rahmen type flexible porous breakwater interacting with obliquely or normally incident small amplitude waves are numerically investigated. This system is composed of dual vertical porous membranes hinged at th side edges of a submerged horizontal membrane. The dual vertical membranes are extended downward and hinged at seabed. The effects of permeability, Rahmen type membrane breakwater geometry pre-tensions on membranes, relative dimensionless wave number, and incident Wave headings are thoroughly examined.

• 태양에너지
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• 제19권4호
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• pp.11-20
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• 1999

The study on ice thermal storage system is to improve total system performance and increase the economical efficiency in actual air-conditioning facilities. To obtain the high charging and discharging efficiencies in ice thermal storage system, the improvement of thermal stratification is essential, therefore the process flow must be piston flow in the cylindrical type. In the influence of the inlet port type, the inflowing water in the distributor type diffuses through the whole storage tank more than in the slot type. In case of the flow process in the ice storage tank, the upward flow type in the charging process and the downward flow type in the discharging process make the stratification well, thereby the loss of energy wored be smaller. The influence of the inlet temperature difference and the change of the inlet flow rate is intensive when the temperature difference is larger, the flow rate is smaller in case of charging and the results are opposite in case of discharging with the reason that the good coduction condition. The total effeciency of the ice thermal storge system is 73% on condition that the porosity in the thermal storage tank is 0.55. This result shows that cylinderical ice storage tank has better storage capacity than rectangular type in case of the same porosity.

• 한국해양환경ㆍ에너지학회지
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• 제20권2호
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• pp.84-90
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• 2017

본 연구는 3차원 CFD(Computational Fluid Dynamics)이용하여 모노파일 기초 주변의 환형 세굴방지공에 의한 세굴방지 효과를 파악하였다. Torsethaugen(1975)의 수리모형 실험결과를 바탕으로 FLOW-3D의 해석결과를 검증하였다. 검증결과를 바탕으로 유속변화에 따른 세굴을 연구한 결과, 유속이 증가할수록 최대 세굴심과 세굴폭 또한 증가하는 경향을 확인하였다. 모노파일 기초 주변에 세굴방지 효과 연구를 위해 바닥면에 환형 세굴방지공을 부착하여 수치실험을 수행하였으며, 약 68.5%의 세굴 감소 효과를 확인했다. 또한 하강 유속과 구조물 주변 저층 유속이 감소한 것을 확인하였고, 이는 세굴방지공이 세굴에 영향을 미치는 하강류의 저감 효과를 보이는 것으로 판단된다.

• 한국전산유체공학회지
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• 제21권3호
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• pp.98-109
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• 2016

The flow and heat transfer characteristics of a heat exchanger having rectangular pin-fin in the flow direction have been investigated numerically. On the bottom plate, the convective boundary conditions for the hot side was given, and the fins were arranged in a channel-type geometric model using the periodic boundary condition in the span-wise direction. Three-dimensional numerical calculations for the flow and conjugate heat transfer problem were conducted using SIMPLE algorithm and $k-{\varepsilon}$ turbulence model. For the slanted pin-fin models, it was found that the downward cooling flow is generated due to the downward pressure gradient component, which can enhance the heat transfer performance near the bottom surface and the fin stem region. Four different inclined angles were considered in the Reynolds number range of 13,500-55,000. The aero-thermal performance of the slanted pin-fin heat exchangers, such as the volume and area goodness factors, were summarized and compared with the baseline plate-fin type heat exchanger quantitatively.

• 태양에너지
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• 제19권1호
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• pp.19-27
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• 1999

In this study, basic design data which were required for development of highly efficient ice storage system with low temperature latent heat were experimentally obtained. The ice storage system considered in this study was the one that has been widely used in the developed country and called the ice-on-coil type. Using the system, the ice storage performance for various design parameters which were the flow direction and the inlet temperature of the secondary fluid was tested. In addition, the clockwise variation of the heat transfer characteristics of the PCM in the ice storage tank were investigated. During the melting processes in the ice storage tank with several vertical tubes, decrease of the solid-liquid interface area, which was the heat transfer area, between the floating ice and the water made the decreasing rate of IPF less. Also, the total melting energy for the upward flow of the secondary fluid was higher than that for the downward flow during the melting process, but this trend did not appear if the initial temperature of the PCM was $4^{\circ}C$. The average ice recovery efficiency for the upward flow of the secondary fluid was higher than that for the downward flow.

• 산업융합연구
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• 제20권11호
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• pp.105-112
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• 2022

본 연구의 목적은 경영자의 능력과 경영자 성과-보상 민감도 간의 관련성에 보고이익전략이 미치는 조절효과를 살펴보는 것이다. 경영자의 보고이익전략에 따른 경영성과의 조정 방향은 상향조정과 하향조정 모두 발생할 수 있으며, 상향 조정과 하향 조정에 따라 경영자 보상에 미치는 영향이 차별적일 것으로 예상되어 분석한 결과, 과대보고를 위한 보고이익전략은 기대와 동일하게 상향조정 된 경영성과에 따라 보상을 지급하였으므로 성과에 근거한 차별적인 보상이 지급되지 않는 것으로 확인되었다. 반면에 과소보고를 위한 전략은 성과에 근거한 성과-보상 민감도를 감소시키는 것으로 나타났다. 과소보고전략은 경영자의 능력에 따른 보고전략의 수행에 대하여 추가적인 보상이 지급되어 보상의 수준은 증가하지만, 이러한 유형의 보상이 경영자의 실제 성과와는 무관하므로 성과-보상 민감도를 감소시킬 것이라는 가설을 지지하며, 보고이익전략에 따른 경영성과의 상향 및 하향 조정에 대해 차별적인 보상이 이루어진다는 것을 간접적으로 확인한 결과이다.

• 한국의류학회지
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• 제16권4호
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• pp.357-369
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• 1992

The purpose of this study was to clarify the relationship between the Ideal Beauty of Body and the Form of Dress, and to analyze its historical perspectives. First of all, the concept of the Ideal Beauty of Body, the definition of Dress Form, and the method and system to clarify Dress Form were depicted. Based on this frame work, the Form of Dress related to the Ideal Beauty of Body was described historically. For this purpose, documentary research were conducted and representative photography and paintings were used. The analysis was limited to the female one-Piece dress from Ancient Egypt, Greece, Rome, Byzantine, Gothic, Renaissance, Baroque, Rococo, Naoclassicism, and to Romanticism. The results were as follows: 1. The Ideal Beauty of Body was found to be different throughout history and to be intimate- ly linked with fashionable dress. 2. The Form of Dress consisted of four basic components: The form of body itself, the form of clothing itself, the method of wearing, and the relationship between body and clothing. 3. The standards for classification of body form were body structure, body type, body proportion, posture, and movement. Clothing form was generally classified into flat type (unstructured type) and three dementional type (structured type); flat type was subclassified into draped type and tunic type. The method of wearing was classified into attached type, tying-up type, wrap·around type, pull-over type, open type and plastistic type. The relationship between body and clothing after wearing was generally classified into body priority type and clothing priority type. The clothing priority type was further divided into body exaggeration type and body concealment type; Body exaggeration type was further divided into upward type, downward type, forward type, backward type, right type and constriction type. 4. The pursuit of venus coelestis, metaphysical body part, ectomorphic body type, flat type clothing, body priority type; the pursuit of Venus Naturalis, physical body part, endomorphic body type, three dementional type clothing, clothing priority type proved to be closely related respectively by the historical study on the Ideal Beauty of Body and the Form of Dress.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.209-212
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• 2005

Recently, since structures have become extremely airtight with the development of high-rise apartments, mixed use residential and commercial buildings and offices, large capacity range hoods have become commonly implemented. However, the high noise level caused by this range hood system made of thin plate is the cause of increased complaints among users. In this study, the level of noise emitted from this type of range hood was measured by height at the user's location in the kitchen. It was confirmed that a great deal of noise was emitted in the downward direction of the hood. In order to minimize the noise emitted from this type of range hood, a new type of fan was manufactured. This was done by changing only the material and shape of the fan, since it was determined to be the primary source of noise emission. Then a comparison and evaluation were carried out regarding the noise characteristics between the new type of fan and the existing type of fan. As a result, it was confirmed that the noise from the new fan was reduced by more than 2 dB compared to the existing fan without noise interference at the discharge end.