• The KSFM Journal of Fluid Machinery
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• v.10 no.3 s.42
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• pp.33-38
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• 2007

Fan selection procedure and fan noise evaluation method are presented for the system electronic cooling by combining FNM(Flow Network Model) and fan noise correlation model. Internal flow paths and distribution in electronic system we analyzed by using the FNM with the flow resistances for flow elements of the system. Based on the fan operation point predicted from the FNM analysis results, the present fan noise model predicts overall sound power, pressure levels and spectrum. The predictions of the flow distribution, the fan operation and the noise level in electronic system by the present method are well agreed with 3-D CFD and actual test results.

• 전자공학회논문지 IE
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• v.49 no.2
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• pp.40-45
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• 2012

In this paper, cooling system of power transformers is proposed for temperature optimized control. We predict the peak temperature of power transformer coils using load factors and construct a cooling system using weighting function. For the optimized temperature control for power transformer, a correlation function based on the load factor of a load current and the each temperatures for winding coils, for air and for oil is presented to predict the winding-coil peak temperature. Also, the results controlled by applying the power transformer is presented.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.11
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• pp.1267-1273
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• 2009

Hot press forming can produce high-strength components by rapidly cooling between closed punch and die after hot forming using quenchable boron steel austenized in a furnace. In the hot press forming process, the cooling rate is influenced by the size, position and arrangement of the cooling channel and the file condition of cooling water in the die. Also, mechanical properties of the final components and operation time are related to cooling rate. Therefore, the design of optimized cooling channel is one of the most important works. In this paper, the effect of position and size of the cooling channel on the cooling rate was investigated by using design of experiment and FE analysis in hot press bending process. Therefore the optimum cooling channel ratio was presented in the HPB.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.4
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• pp.430-435
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• 2009

The cooling stage greatly affects the product quality in the injection molding process. The cooling system that minimizes temperature variance in the product surface will improve the quality and the productivity of products. The cooling circuit optimization problem that was once solved by a response surface method with 4 design variables. It took too much time for the optimization as an industrial design tool. It is desirable to reduce the optimization time. Therefore, we tried the back-propagation algorithm of artificial neural network(BPN) to find an optimum solution in the cooling circuit design in this research. We tried various ways to select training points for the BPN. The same optimum solution was obtained by applying the BPN with reduced number of training points by the fractional factorial design.

• Progress in Superconductivity and Cryogenics
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• v.4 no.2
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• pp.68-72
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• 2002

This work investigates the transient cooling characteristics of an Infrared (IR) detector cryochamber, which has a critical effect on the cooling load. The current thermal modeling considers the conduction heat transfer through a cold well. the gaseous conduction due to outgassing. and the radiation heat transfer. The transient cooling Performance. i.e. the penetration depth and cooling load, is determined using a finite difference method. It is found that the penetration depth increases as the bore conductivity increases. Gaseous conduction and radiation hardly affect the penetration depth. The transient cooling load increases as the bore conductivity increases. The effects of gaseous conduction and radiation on transient heat transfer are weak at initial stages of cooling. However, their effects become significant as the cooling Process Proceeds.

• Journal of the Korean Chemical Society
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• v.18 no.4
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• pp.297-303
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• 1974

An investigation has been performed to find an effective separation method of steriols and tocopherols from the deodorized condensates of vegetable oils. Simple heating of the starting mixture isolated the oil layer from water, and the former was collected. It was then methyl esterified followed by a distillation for the removal of fatty acid. The ensuing step was to saponify the residue. The unsaponifiable matter was extracted by both methanol and concentrated. The sterol was crystallized by cooling such concentrated solution. To obtain tocopherol, the mother liquor was first dissolved in methanol. Cooling this solution to $-20^{\circ}C$ trapped fatty acid which was filtered out. The filtrate was then treated with ion exchange resin.

• Korean Journal of Poultry Science
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• v.41 no.3
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• pp.159-164
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• 2014

This study was conducted to investigate whether water chilling had effect on water retention, freshness or internal temperature of chicken carcasses during chilling or storage in two different chicken processing plants (designated as A and B). A total of 240 carcasses from chicken processing plants (n = 120 per chicken processing plant) was randomly sampled and evaluated the effect of water chilling on carcass characteristics (i.e., water retention, water loss or freshness during chilling or storage). Torrymeter value was used as an indicator of freshness in chicken carcasses. Water chilling did not affect carcass water retention between the processing plants. However, chicken carcasses processing in B plant exhibited significantly higher freshness (p<0.05) compared with those in A plant. This difference in freshness was mainly due to the longer transit time through the water chiller in A versus B plants. Water loss of carcasses during storage was not different between plants. It was found that carcass freshness can be affected by water chilling time as manifested in this study. Further study is warranted to see whether freshness or microbiological status of chicken carcasses may be affected depending on the chilling methods, i.e., air or water chilling.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.227-228
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• 2011

EV의 중요한 부품은 MCU(인버터), BMS(고전압), LCD(저전압 충전장치), OBC(완속충전장치), EWP(냉각장치), PTC(히터), A/C(에어컨) 등으로 구성되어 있으며, 특히 EV용 인버터의 경우 핵심 부품으로 신뢰성 및 보호기능에 대한 중요성이 인식되고 있다. EV 인버터는 온도(인버터, 모터), 단락과 단선, 인터락 및 최대출력제한 등에 대한 보호기능 구현이 되어 있으며, 고장발생시 고장을 진단할 수 있는 기능(DTC)이 구현되어 있다. 이러한 보호기능 중에 단락과 단선 시 인버터의 보호는 중요한 요소이며, 이를 구현하기 위한 회로설계 및 회로분석이 필요하다. 본 논문에서는 EV용 인버터에 사용되는 병렬 운전형 인버터의 단락 및 단선 시 시스템을 보호할 수 있는 드라이버 회로 설계 및 분석을 수행하며, 실험을 통해 그 결과를 검증한다.

• Journal of KIISE:Computer Systems and Theory
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• v.35 no.12
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• pp.540-551
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• 2008

Today's microprocessor designs are not free from temperature as well as power consumption. As processor technology scales down, an on-chip circuitry increases power density, which incurs excessive temperature (hotspot) problem. To tackle thermal problems cost-effectively, Dynamic Thermal Management (DTM) has been suggested: DTM techniques have benefits of thermal reliability and cooling cost. However, they require trade-off between thermal control and performance loss. This paper proposes a dual integer register file structure to minimize the performance degradation due to DTM invocations. In on-chip thermal control, the most important functional unit is an integer register file. It is the hotspot unit because of frequent read and write data accesses. The proposed dual integer register file migrates read data accesses by adding an extra register file, thus reduces per-unit dynamic power dissipation. As a result, the proposed structure completely eliminates localized hotspots in the integer register file, resulting in much less performance degradation by average 13.35% (maximum 18%) improvement compared to the conventional DTM architecture.

• Journal of the Korean Data and Information Science Society
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• v.25 no.4
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• pp.705-714
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• 2014

This study aimed at identifying the effect of vapocoolant spray and EMLA (eutectic mixture of local anesthetics) cream upon DPT (diphtheria-pertussis-tetanus)vaccineassociated injection pain in infants. A nonequivalent control group pretest-posttest design was used. The subjects were 49 infants, 19 of them for control group, 15 of them for vapocoolant group, and 15 infants for EMLA group. Pulse and oxygen saturation as pain indicators were measured before and after DPT vaccination. FLACC was also measured after vaccination. The data were collected between October 2009 and June 2010 and analyzed using SPSS WIN 20.0. EMLA group had significant a little changes in pulse (F=43.37, p <.001) and oxygen saturation (F=9.86, p=.003) compared to the control and vapocoolant group. But there was no difference in FLACC pain score among three groups. This results showed that EMLA cream is an effective agent for reducing DPT vaccination-associated pain. Therefore, EMLA cream can be used to reduce pain at public health centers and clinical settings.