• Transactions on Electrical and Electronic Materials
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• 제13권6호
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• pp.292-296
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• 2012

An optimum heat sink for a 30 W chip on board (COB) LED down-light is designed, fabricated, and characterized. By using the SolidWorks Flow simulator and thermal analysis software, the thermal characteristics of the optimum heat sink is analyzed. Four different types of heat sink are simulated and an optimum structure of the heat sink is found. The simulated temperature of the heat sink when operating the LED down-light is $55.9^{\circ}C$, which is only a difference of $2^{\circ}C$ from the measured temperature. In order to reduce the temperature further, a copper spreader is introduced to the heat sink. The temperature of the heat sink with the copper spreader is $3^{\circ}C$ lower than without the copper spreader.

• 한국가구학회지
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• 제19권4호
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• pp.229-234
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• 2008

In a previous study, it was revealed that three major softwoods, Japanese pine, Korean pine and Japanese larch, heat-treated at $220^{\circ}C$, could produce high quality dark-colored boards. It is known that heat treatment decreases the hygroscopicity of wood. The hygroscopicity of major domestic softwoods and hardwoods heat-treated at $220^{\circ}C$ was investigated by a saturated salt solution method and compared with that of black and white charcoals. Equilibrium moisture contents of wood decreased with the increase of heat treatment time. Isotherm shapes of wood species were different from those of charcoals. Heat treatment decreases the equilibrium moisture contents of black locust more than those of Korean pine and Japanese larch. It was found that surface hardness of wood is improved by heat treatment to a certain extent, but a longer heat treatment causes thermal degradation, resulting in the decrease of the surface hardness.

• 열처리공학회지
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• 제32권5호
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• pp.195-200
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• 2019

For expanding the applications and workability of TiAl alloy, elongation is very important property. Fine microstructure is needed for elongation and physical properties of TiAl alloys. In this study, The effects of cyclic heat treatment process for fine microstructure of Ti-46Al-Nb-W-Cr-Si-C alloy, which was made by VAR (vacuum arc remelting) and VIM(vacuum induction melting) centrifugal casting process, was investigated. Cycle heat treatment process was very effective for recrystallization of this TiAl system, which has microstructure size of $50{\sim}100{\mu}m$ through pre-heat treatment, cyclic heat treatment in ${\alpha}+{\gamma}$ phase region and solution heat treatment respectively. Refined grain size was finally confirmed by photos of optical microscope and scanning electron microscope.

• 한방안이비인후피부과학회지
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• 제7권1호
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• pp.35-51
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• 1994

This is the study on causes and remedies of hearing disturbance in chinese medical journals(1991-1993). The results were as follows. 1. The causes of sudden deafness(突發性耳聾) were usually fire in the liver(肝火).phlegmatic fire(痰火), deficiency of the vital function and essence of the kidney(腎虛), blood stasis or sludge due to stagnation of vital energy stagnation(氣滯血瘀). Remove endogenous heat or fire method(淸瀉火熱法). circulation of phlegm and dampness(運化痰濕). using tonics to cure disease due to deficiency of vital essence of both the liver and the kidney(滋補肝腎) were used for each treatment. 2.The causes of menieres disease were usually mental disturbance due to phlegmatit fire(痰化上搖). dampness-phlegm long standing(痰濕內停), water-dampness retention(水濕停滯), Method of remove heat and circulation phlegm(淸熱化痰法), method of remove water and dampness(利水渗濕法), invigorate function of the spleen and circulation of dampness method(健脾化濕法) were used for each treatment. 3. The causes of toxico-deafness(中毒性 耳聾) were usually heart, liver and kidney functional weakness(心肝腎虛), vital essence and blood weakness(氣血虛弱). Remove obstruction in the flow and circulation phlegm(通窮化痰), reinforce vital energy and tonify blood (補氣活血), using tonics to cure disease due to deficiency of vital essence of both the liver and the kidney(滋補肝腎) were used for each treatment. 4. The causes of deafness (耳聾), tinitus(耳鳴) were usually mental disturbance due to wind and heat(風熱上搖). flaming up of excessive heat of the liver(肝火上亢). exhaustion seat of reproductive essence in kidney(腎精虧虛). Remove endogenous heat and disperse wind(淸熱疏風). remove the fire of liver(淸肝瀉火), through nourish kidney check exuberance of yang(滋腎潛陽), nourish kidney yang(補腎陽). replenish vital energy and improve essential substance(益精血), blood activate for treatment of blood stasis(活血化瘀) were used for each treatment. 5. The effects of mainly used drugs were classified into method of water and dampness remove medicine(利水渗濕藥), nourishing liver and kidney medicine(補肝腎藥), improve blood and vital energy activate medicine(活血行氣藥), through nourish yan medicine check exuberance of yang(滋陰潛陽藥).

• 대한한의학원전학회지
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• 제19권2호통권33호
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• pp.248-265
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• 2006

Impulse of ki refers to palpitation around the navel, it is mostly caused by impairment of yang due to erroneous sweating, deficiency of the spleen yang. Behcet's syndrome caused by prolonged damp-heat and pathogenic germs. Its symptoms are characterized by conjunctival congestion, blue canthus and ulceration of the oral cavity, restlessness all the time, etc. It is advisable to follow the therapeutic principles of clearing away heat and drying damp, detoxicating and sterilizing. Lily disease is one of the emotional disease. It caused by yin deficiency of the heart and lung, found in mental depression or convalescence after a critical disease. Its symptoms are characterized by restlessness, reticence, insomnia, failure to walk, poor appetite, a subjective hot or cold, bitter taste and dark urine. It is advisable to follow the therapeutic principle of nourishing yin to clear away heat. Cholera refers to the disease marked by sudden severe vomiting and diarrhea, and colic of the heart and the abdomen. It is mostly caused by deficiency of the ki in the middle-energizer, emotional stress, etc. It is characterized by such symptoms as sudden severe vomiting and diarrhea, restlessness, etc. It is advisable to follow the therapeutic principles of warming yang and removing toxic substances, and strengthening the spleen and stomach. Heat invasion of blood chamber due to affection of the exterior pathogens, pathogenic heat invading the blood in deficiency and fighting with the blood. Its symptoms are marked by fever, feeling of the fullness, etc. There are deficiency of blood, hot blood and stasis of blood. The different therapeutic treatment should be taken according to different types thereof.

• 한방안이비인후피부과학회지
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• 제5권1호
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• pp.27-44
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• 1992

The cause and mechanism of eye diseases are follow in biblography. The etiological factor of eye diseases are nearly caused by heat. It is important to distinguish deficiency and substance. In external etiologic factors wind-fever is most of all in six exogenous factors. In internal etiologic factors xu(deficiency) of kidney, blood and fire of seven emotions are lots. In factors other than the internal and external, eating greasy food and hyper-caloric food are a lot of case. In relation with the yin-yang andxu-shi, ther are a lot of eye diseases symptom as dark-dizziness due to the yin-xu of hepatic-kidney. According to eight principles of differentiation of syndromes, syndromes of exterior, heat, shi, almost fall into the category of yang and syndromes of interior, cold, xu, nearly fall into the category of yin. In interior treatment, inducing wind and clearing heat, using Qi and tonifying blood, tonifying and suing of hepatic-kid ney are useful and often used treatment.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.353-358
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• 2000

This paper presents the experimental investigation about miniature heat pipe for notebook PC. The focus of analysis is the operating temperature not to exceed $65^{\circ}C$ maximum allowable CPU surface temperature. Copper is used to heat pipe material and brass is wick material, and working fluid is selected to water. This cooling system is heat spreader method using a aluminum plate, since this method is most commonly used. According to the present study, heat for 3mm heat pipe, 8W, and for 4mm heat pipe, 10W, is found to power dissipation limit respectively, Soon after this investigation, sufficient long term life test should be followed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1364-1369
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• 2004

New method for the design, fabrication, and calibration of micro-machined heat flux sensor has been developed. Two types of micro-machined heat flux sensor having different thicknesses of the thermal-resistance layer are fabricated using the MEMS technique. Photo-resist patterning using a chrome mask, bulk-etching and copper-nickel sputtering using a shadow mask are applied to make heat flux sensors, which are calibrated in the convection-type heat flux calibration facility. The sensitivity of the device varies with thermal-resistance layer, and hence can be used to measure the heat flux in heat-transfer phenomena.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1358-1363
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• 2004

The objective of this work is to propose calibration facility in which a thin film type heat flux sensor can be calibrated under convective flow condition by using a small wind tunnel with the constant temperature plate condition. A small wind tunnel has been built to produce a boundary layer shear flow above a constant temperature copper plate. 12-independent copper blocks, thin film heaters, insulators and temperature controllers were used to keep the temperature of flat plate constant at a specified temperature. Three commercial thin film-type heat flux sensors were tested. Convective calibrations of these gages were performed over the available heat flux range of $1.4{\sim}2.5kW/m^2$. The uncertainty in the heat flux measurements in the convective-type heat flux calibration facility was ${\pm}2.07%$. Non-dimensional sensitivity is proposed to compare the sensitivity calibrated by manufacturer and that of experiment conducted in this study.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.701-704
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• 2006

Recently, the attention is paid to the problem of thermal crack by hydration heat according to the increase of high strength and mass concrete structures. At this point, various research has been carried out for the control of hydration heat in high strength and mass concrete. As a part of the research, the application of Low Heat Technology (LHT) for the control of thermal crack by hydration heat was investigated in this study. To investigate the application, it was selected LHT which can reduce hydration heat of concrete with effect in series I and II. Also, it was investigated the characteristics of hydration heat generation of low heat concrete using LHT with binder types in seriesIII.