• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1995년도 봄 학술발표회 논문집
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• pp.263-267
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• 1995

The usual methods for the temperature control of mass-concrete structures include the use of low-heat cement, pre-cooling, post-cooling, or sheet curing. In order to control the heat of hydration during the construction of mass-concrete structures, the combination of the above methods is commonly employed. For the construction of mass-concrete structures such as massive pier or anchor, it is necessary to control the curing temperature with pipe cooling. In this study, the method of analysis on the effect of pipe of was proposed to prevent the thermal cracking due to heat of hydration In addition the effect of covering the concrete surface with blanket insulation was investigated. The results of the present study may be useful for the prediction of curing temperature of mass-concrete structures and the reasonable construction management.

• Journal of Biosystems Engineering
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• 제20권4호
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• pp.360-367
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• 1995

The effect of air vent holes, stacking methods of boxes and clearance between boxes on static pressure drop, were measured to design of pressure cooling system. Static pressure drops in air vent hole of carton box were measured for different hole opening ratio from 1% to 5%. Static pressure drop was expressed as a function of superficial velocity as second-degree polynomial. At given static pressure in plenum chamber, static pressure drop in boxes was shown as second-degree polynomial of the number of carton box in series stacking method, as first-degree polynomial in height and parallel stacking method. In pressure cooling of 24 boxes of Tsugaru apple, air flow rates through clearance between the boxes were shown 1.27 and 1.65 times than those of through the inside of boxes at the plenum pressure of 10mmAq and 20mmAq, respectively.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.962-967
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• 2003

Recently, environmental pollution has become a serious problem in industry, and many researches have been done in order to preserve the environment. The coolant, which promotes lubrication, cooling and penetration, contains chlorine, sulfur and phosphorus to improve the machining efficiency. These additives, which move around into the air during machining, pollute working. Therefore, many researches on how to reduce the amount of coolant during machining have been carried out. However, to reduce even small amount of coolant causes high temperature of a workpiece and it brings thermal defects. In this study, the experiments of wet & dry grinding using cooling methods (using coolant only, mist and compressed cold air only) are performed to solve the problem of environmental contamination and to get a better surface integrity of a workpiece by comparing surface roughness, roundness and residual stress.

• 한국컴퓨터정보학회논문지
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• 제16권7호
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• pp.1-11
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• 2011

사용자들의 높은 요구 사항을 만족시키는 컴퓨팅 시스템을 개발하기 위해 프로세서의 성능을 향상시키기 위한 연구는 지속적으로 진행되어 왔다. 공정 기술 발달을 비롯한 다양한 기술 발전을 통하여 프로세서의 성능은 비약적으로 발전하였으나 그 이면에는 새로운 문제들이 발생하게 되었다. 그 중에서, 최근 들어 주된 문제점 중 하나로 인식되고 있는 열섬 현상은 칩의 신뢰성에 심각한 영향을 미치기 때문에 프로세서 설계 시 성능, 전력 효율성과 함께 반드시 고려되어야 한다. 과거에는 기계적인 냉각 기법으로 프로세서의 온도를 효과적으로 제어할 수 있었지만, 최근에는 프로세서의 성능이 높아져 발생되는 온도가 높아 냉각 비용이 급속히 증가하고 있다. 이로 인해, 최근의 온도 제어 연구는 기계적인 냉각 기법보다는 구조적 기법을 통한 온도 제어에 더욱 집중되는 추세를 보이고 있다. 하지만, 구조적 기법을 통해 온도를 제어하는 방안은 프로세서의 온도를 낮추는 데에는 효율적이지만 이를 위해 성능을 희생한다는 단점이 존재한다. 따라서, 기계적 냉각 기법을 통해 프로세서의 온도를 효율적으로 제어할 수 있다면, 성능 저하가 발생되는 구조적 기법을 통한 온도 제어기법의 사용 빈도가 줄어 그 만큼 성능이 향상될 수 있을 것으로 기대된다. 본 논문에서는 고성능 멀티코어 프로세서에서 발생하는 온도를 기계적인 냉각 기법이 얼마나 효율적으로 제어할 수 있는지를 상세하게 분석해 보고자 한다. 공랭식 냉각기와 수랭식 냉각기를 이용하여 다양한 실험을 수행한 결과, 공랭식 냉각기와 비교하여 수랭식 냉각기가 온도를 효과적으로 제어하는 반면에 전력 소모가 더 많음을 확인할 수 있다. 특히, 1W의 전력을 통해 낮출 수 있는 온도를 분석해 보면 공랭식에 비해서 수랭식이 더 효율적임을 알 수 있으며, 수랭식 냉각기의 경우에는 냉각 단계가 냉각 효율은 오히려 감소하게 됨을 확인할 수 있다. 실험 결과를 바탕으로 온도에 따라 적절하게 기계적 냉각 기법을 활용한다면 프로세서의 온도를 더욱 효과적으로 제어할 수 있을 것으로 기대된다.

• Journal of Trauma and Injury
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• 제22권2호
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• pp.227-232
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• 2009

Purpose: Numerous experimental studies have shown the benefits of treating thermal burns by cooling. Nevertheless, few studies have shown the clinical effect of cooling therapy on thermal burns. This study aimed to identify the clinical effect of immediate cooling therapy. Methods: The research was conducted as a retrospective, case-control study. All patients had thermal injuries characterized as a superficial second-degree burn. In the cooling group, 14 patients had first-aid cooling therapy delivered by either parents, caregivers, general practitioners, local hospitals, and/or Myongji hospital. Included in the study were 22 control patients who were not treated with any cooling therapies. Other clinical factors, such as age, sex, cause of burn injury, and burn area (Total Body Surface Area %), were taken into consideration. The duration of treatment was defined as the time from the occurrence of the injury to the presence of complete re-epithelialization, as confirmed by two surgeons. Results: The duration of treatment in the cooling group was significantly less than that the control group (p<0.05). Conclusion: Cooling therapy as an initial emergent treatment is clinically effective for superficial second-degree burn injuries.

• 한국군사과학기술학회지
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• 제24권6호
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• pp.629-637
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• 2021

For the stabilization of laser output power and wavelength of the high power fiber laser, the cooling plate must be properly taken into account. In this study, three analyzing methods which are heat transfer theory, CFD and experiment are used to analyze cooling plate performance by measuring pump Laser Diode(LD) temperature. Under limited operating conditions of a cooling plate, the internal flow of cooling plate is transitional flow so that the internal flow is assumed to be laminar and turbulence flow and conducted theoretical calculation. Through CFD, temperature of pump LD and characteristics of the internal flow were analyzed. By the experiment, temperature of pump LD was measured in real conditions and the performance of the cooling plate was verified. The results of this study indicate that three analyzing methods are practically useful to design the cooling plate for the high power fiber laser or similar things.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.385-388
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• 1997

As the environmental regulations become stricter, new machining technologies are being developed which takes envi ronmenta 1 aspects into account . Since cut t ing oi I has some impact on environment. many researches are being carried out to minimize the use of cutting oi I. The methods for minimizing cutting oil usage includes the following techniques: I ) Cooling of tools and work piece. 2) Useage of compressed cooling air for the removal of chip. 3) Minimal useage of environment-friendly vegetable cutt:ngoiI for lubrication between chip and tools. Since the turning machine is continuous, tools are under constant thermal load and tool wear increases as the lubricative performance degrades. Also surface roughnesses have a direct influence on turning. In order to examine the characteristics of turningmachining, this work investigates experimentally the degree of tool wear and characteristics of surface roughness in relation to machining conditions, supply methods, and cooling methods.

• Safety and Health at Work
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• 제10권2호
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• pp.219-223
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• 2019

Background: Ice cooling vests can cause tissue damage and have no flexibility. Therefore, these two undesirable properties of ice cooling vest were optimized, and the present study was aimed to compare the impact of the optimized ice cooling vest and a commercial paraffin cooling vest on physiological and perceptual strain under controlled conditions. Methods: For optimizing, hydrogel was used to increase the flexibility and a layer of the ethylene vinyl acetate foam was placed into the inside layer of packs to prevent tissue damage. Then, 15 men with an optimized ice cooling vest, with a commercial paraffin cooling vest, and without a cooling vest performed tests including exercise on a treadmill (speed of 2.8 km/hr and slope of %0) under hot ($40^{\circ}C$) and dry (40 %) condition for 60 min. The physiological strain index and skin temperature were measured every 5 and 15 minutes, respectively. The heat strain score index and perceptual strain index were also assessed every 15 minutes. Results: The mean values of the physiological and perceptual indices differed significantly between exercise with and without cooling vests (P < 0.05). However, the difference of the mean values of the indices except the value of the skin temperature during the exercises with the commercial paraffin cooling vest and the optimized ice cooling vest was not significant (P > 0.05). Conclusions: The optimized ice cooling vest was as effective as the commercial paraffin cooling vest to control the thermal strain. However, ice has a greater latent heat and less production cost.

• 마이크로전자및패키징학회지
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• 제20권3호
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• pp.1-6
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• 2013

TSV는 그동안 3D IC 적층을 하는데 핵심 기술로 많이 연구되어 왔고, RC delay를 줄여 소자의 성능을 향상시키고, 전체 시스템 사이즈를 줄일 수 있는 기술로 각광을 받아왔다. 최근에는 TSV를 전기적 연결이 아닌 소자의 열관리를 위한 구조로 연구되고 있다. TSV를 이용한 liquid cooling 시스템 개발은 TSV 제조, TSV 디자인 (aspect ratio, size, distribution), 배선 밀도, microchannel 제조, sealing, 그리고 micropump 제조까지 풀어야 할 과제가 아직 많이 남아있다. 그러나 TSV를 이용한 liquid cooling 시스템은 열관리뿐 아니라 신호 대기시간(latency), 대역폭(bandwidth), 전력 소비(power consumption), 등에 크게 영향을 미치기 때문에 3D IC 적층 기술의 장점을 최대로 이용한 차세대 cooling 시스템으로 지속적인 개발이 필요하다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.918-921
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• 2001

In grinding process, the heat of $1200^{\circ}$~$1500^{\circ}$ on the grinding area between grinding wheel and workpiece is generated. It decreases the surface integrity of workpiece and causes the thermal damages such as the deformed layer, residual stress and grinding burn. Generally coolant is widely used for preventing the heat generation on the grinding area, but it deteriorates the working condition by polluting the atmosphere of workplace and in the end pollutes the environment. The grinding methods using the compressed cold air and mist are the cooling methods to substitute conventional coolant. They can decrease the environmental pollution through not using coolant any more or minimizing it. In this study, the cooling effects of grinding methods using the compressed cold air and mist have been investigated. The grinding system equipped with the water bathe and mist spray nozzle was developed. The energy partition to workpiece through measuring the temperature on the workpiece surface was calculated. The surface integrity of workpiece and thermal damage like the deformed layer were analyzed.