• 한국포장학회지
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• 제28권3호
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• pp.211-215
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• 2022

Air distribution occupies an important position in the smart unit load container design process for agricultural products. Inner air may be uncomfortable because of its temperature, speed, direction, and volume flow rate. It doesn't matter how efficient the ventilation equipment is if the air is not distributed well. The main aim of this study was to design the inlet and outlet fan locations of smart unit load container for agricultural products. A numerical study was performed on the effects of the location of inlet air and outlet air in relation to the container cooling sources on air distribution and thermal comfort. A concept of combining inner container cooling sources with the exhaust outlet was employed in this investigation. Also, in this research, the developed CFD (Computational Fluid Dynamics) models were thoroughly validated. This system was adopted for use in container spaces, where the exhaust outlet was located. In this study, the location of the inlet was derived through CFD for a container with a size of 1,100×1,100×1,700 mm, and it was derived that the inlet was located at the center of the lower part of the container for efficient air flow. It was efficient to position the outlet through the air inlet in the center of the lower part of the container at the top of the same side.

• 한국의류학회지
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• 제46권5호
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• pp.836-847
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• 2022

This study establishes basic data for the development of a new Chemical, Biological, and Radioactive (CBR) protective clothing by selecting the ventilation position to optimize thermal comfort on the basis of the opening and closing of each part. Participants were eight men in their 20s who had previously worn CBR protective clothing. After vigorous exercise and perspiration, the microclimate of the clothing and skin temperature was measured. Results revealed that when the ventilation zipper was opened after exercising, the skin and clothing microclimate temperatures, which had increased during the exercise, decreased in the chest and shoulder blade regions. The clothing microclimate humidity decreased in the chest area. The change was greatest in the chest region; the skin temperature decreased by 0.2℃, the clothing microclimate temperature by 2.7℃, and the clothing microclimate humidity by 3.2%RH through ventilation. Thus, the opening that allows the exchange of accumulated heat and moisture while wearing the CBR protective clothing is efficient.

• 한국의상디자인학회지
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• 제25권3호
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• pp.53-67
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• 2023

Blood circulation is one of the most important life support functions of our body. It is essential to maintain healthy blood circulation as problems with blood circulation can lead to numerous diseases and serious complications. This study developed women's leggings with gradual compression and soft surface heating functions to improve blood circulation, and evaluated their performance and wearability. A silicon print pattern was developed to provide gradual compression, and a flexible heating surface coated with MWCNT (multi-walled carbon nanotube) conductive ink was fabricated for comfort and thermal effect. For the design, incision lines and materials were applied in consideration of aesthetic aspects, and design lines and colors were altered using a 3D program. The developed leggings showed that blood circulation can be improved when gradual compression and heating functions are simultaneously applied. Results were confirmed through measurements of clothing pressure, blood flow, and surface temperature. In the subjective wearability evaluation, it was confirmed that wearers felt gradual pressure, and they showed high satisfaction with wearability and design.

• 설비공학논문집
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• 제12권12호
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• pp.1098-1125
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• 2000

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 1998 and 1999 has been done. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environment. The conclusions are as follows. 1) A review of the recent studies on fluid flow, turbomachinery and pipe-network shows that many experimental investigations are conducted in applications of impingement jets. Researches on turbulent flows, pipe flows, pipe-networks are focused on analyses of practical systems and prediction of system performance. The results of noise reduction in the turbomachinery are also reported. 2) A review of the recent studies on heat transfer analysis and heat exchanger shows that there were many papers on the channel flow with the application to the design of heat exchanger in the heat transfer analysis. Various experimental and numerical papers on heat exchanger were also published, however, there were few papers available for the analysis of whole system including heat exchanger. 3) A review of the recent studies on heat pump system have focused on the multi-type system and the heat pump cycle to utilize treated sewage as the heat source. The defrosting and the frosting behaviors in the fin-tube heat exchanger is experimentally examined by several authors. Several papers on the ice storage cooling system are presented to show the dynamic simulation program and optimal operation conditions. The study on the micro heat pipes for the cooling of high power electronic components is carried out to examine the characteristics of heat and mass transfer processed. In addition to these, new type of separate thermosyphon is studied experimentally. 4) The recent studies on refrigeration/air conditioning system have focused on the system performance and efficiency for new alternative refrigerants. New systems operating with natural refrigerants are drawing lots of attention. In addition to these, evaporation and condensation heat transfer characteristics of traditional and new refrigerants are investigated for plain tubes and also for microfin tubes. Capillary tubes and orifice are main topics of research as expansion devices and studies on thermophysical properties of new refrigerants and refrigerant/oil mixtures are widely carried out. 5) A review of the recent studies on absorption cooling system shows that numerous experimental and analytical studies on the improvement of absorber performance have been presented. Dynamic analysis of compressor have been performed to understand its vibration characteristics. However research works on tow-phase flow and heat transfer, which could be encountered in the refrigeration system and various phase-change heat exchanger, were seemed to be insufficient. 6) A review of recent studies on duct system shows that the methods for circuit analysis, and flow balancing have been presented. Researches on ventilation are focused on the measurement of ventilation efficiency, and variation of ventilation efficiency with ventilation methods by numerous experimental and numerical studies. Furthermore, many studies have been conducted in real building in order to estimate indoor thermal environments. Many research works to get some information for cooling tower design have been performed but are insufficient. 7) A review on the recent studies on architectural thermal environment and building mechanical systems design shows that thermal comfort analysis is sitting environment, thermal performance analysis of Korean traditional building structures., and evaluation of building environmental load have been performed. However research works to improve the performance of mechanical system design and construction technology were seemed to be insufficient.

• 환경영향평가
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• 제30권2호
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• pp.105-116
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• 2021

건물이 밀집되고 인구밀도가 높은 도시는 열섬현상이 가중되고 열쾌적성에 취약하다. 도심에서 방치되고 있는 공지는 주거환경과 도시미관을 저해하고 지역 전체의 경제적 활력이 낮아지며 도시를 쇠퇴하는 하나의 요인으로 다루어진다. 이에 본 연구에서는 서울 종로구 송현동의 공지를 대상으로 개발 시나리오에 따라 주변 미기후 영향을 비교하고자 하였다. 현 상태 유지, 녹지 중심, 건물 중심, 녹지-건물 절충 시나리오를 설정하고, ENVI-met을 사용하여 개별 시나리오별로 대상지와 대상지 주변 1 km 내 변화되는 풍속, 기온, 평균복사온도를 개발 시나리오별 내·외부 영향을 비교분석하였다. 연구 결과, 대상지 내·외부는 녹지 중심의 시나리오가 현 상태 유지 시나리오와 비교했을 때 계절별 평균 기온은 낮아졌고, 풍속이 빨라진 것으로 도출되었다. 여름철 최대 -0.73 ℃가 낮아지거나 1.5 ℃까지 상승될 것으로 예상되었고, 풍속은 시나리오에 따라 최대 210 m 범위까지 영향이 있었다. 또한, 녹지는 내·외부, 건물 배치 및 크기는 녹지보다 효과는 적으나 인접한 외부 공간에 영향을 주는 것을 확인하였다. 본 연구는 송현동 개발 방향에 대한 의사결정 지원 도구로써 도움을 줄 수 있고, 향후 환경영향평가 제도에 미기후에 대한 부분을 반영하는데 활용할 수 있을 것으로 예상된다.

• 한국의류학회지
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• 제30권3호
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• pp.407-411
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• 2006

본 연구에서는 비만아동의 온도적응능력을 향상시키기 위해 초등학교 4학년$\∼$6학년에 재학 중인 비만아동 13명(남자 6명, 여자 7명)을 대상으로 하여, 10주간의 단기 의복착용훈련 프로그램을 시행한 후 프로그램의 효과를 알아보았다. 프로그램 시행기간 중 아동이 매일 직접 측정한 주택 내 실내온도는 평균 25.1$^{circ}C$였고, 아동이 착용한 체표면적당 의복의 무게(착의량)는 평균 300g/$m^{2}$였으며, 실내온도와 착의량 간에는 유의한 상관이 있었다(p < .01). 프로그램의 시행효과를 구체적으로 알아보기 위해, 23.0$\pm$0.5$^{circ}C$, 50$\pm$5$\%$RH로 조절된 인공기후실에서 실험을 실시하여, 반소매 면 티셔츠(0.13clo)와 T/C 반바지(0.09c1o)를 착용하고 안정상태에 있는 아동의 체온, 피부온, 혈압 및 맥박 등의 생리반응과 쾌적감 및 온랭감의 주관적 감각반응을 프로그램 시행 전후에 측정한 후 얻은 주요 결과는 다음과 같다. 평균피부온은 프로그램 시행전후에 유의한 차이가 없었으나, 전반적으로 체온과 평균혈압은 프로그램 시행 후에 내려갔다(p < .01). 주관적 감각반응에서는 프로그램 시행 후에 여아가 남아에 비해 약간 더 따뜻하게 느꼈고(p < .05), 이에 따라 아동자신이 선택한 쾌적온도는 더 낮은 경향을 나타내었다(p < .1). 이와 같은 연구결과는 비만아동의 행동성 및 자율성 체온조절연구에 유익할 것이나, 보다 명확한 자료를 얻기 위해서는 종합적이고 장기적인 훈련프로그램의 시행이 요구된다.

• 한국조경학회지
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• 제44권1호
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• pp.93-106
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• 2016

이 연구는 제안한 평균복사온도의 차감비교기법을 통해 도시림이 여름철 옥외 환경에 미치는 온열완화를 정량적으로 추정하고 평가는 것을 목적으로 한다. 항공 라이다 측량시스템 기반 3차원 점군자료로부터 도시림이 있는 모의 대상지와 도시림이 없는 모의 대상지 두 사례를 구축하여 SOLWEIG 기반에서 평균복사온도를 산출하고 두 값들을 비교 및 분석하였다. 연구를 통해 도시림 캐노피가 연구지역 전체 일평균 $T_{mrt}$를 약 $5^{\circ}C$ 정도 저감하며 태양의 위치와 지면 조건에 따라 시간평균 $T_{mrt}$가 $33^{\circ}C$까지 저감될 수 있음을 확인하였다. 결과들은 도시미기후 지표(풍속, 습도, 대기 온도 등) 및 생명기상(인지온도 등) 연구들을 향상시키고 더불어 삼림 기반 공공 녹색정책 개발에 활용될 수 있을 것이다.

• 한국환경복원기술학회지
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• 제24권6호
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• pp.121-132
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• 2021

Green facade has a significant impact on building's energy performance by controlling the absorption of solar radiation and improving outdoor thermal comfort through shading and evapotranspiration. In particular, since high-density building does not enough green space, green facade, and rooftop greening using artificial ground plants are highly utilized. However, the level of cooling effect according to plant traits and irrigation control is different. Therefore, in this study, the cooling effect analyzed for a total of 4 cases by controlling the irrigation condition based on hedera and spurge. Although hedera under sufficient water had the highest cooling effect(-2℃~-4℃), had the lowest cooling effect under non-irrigation(+1.1℃~+4.4℃). In addition, hedera under sufficient water had cooling effect than hedera under non-irrigation(-1℃~-8.1℃) and in the case of spurge, it had cooling effect(-0.3℃~-7.8℃) more than non-irrigation. As a result of measuring the amount of transpiration according to the light intensity (PAR) and carbon dioxide concentration conditions, transpiration of hedera was higher than the spurge (respectively 0.63204mmolm^-2s^-1, 0.674367mmolm^-2s^-1). The difference in the cooling effect of the green facade under irrigation condition was significant. But the potential cooling effect of green facade according to plants species was different. Therefore, in order to maximize and continuously provide the cooling effect of green facade in urban areas, it is necessary to consider the characteristics of plants and the control of water supply through the irrigation system.

• 감성과학
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• 제13권2호
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• pp.359-370
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• 2010

여름철 에너지 절약, 온실가스 줄이기, 직장인의 건강증진 등을 위한 쿨맵시 캠페인에 대하여 범국민 인식 및 실천의 필요를 바탕으로, 본 연구는 착의실험을 통해 클맵시 권장복장 착용시의 생리적 반응 및 주관적 감각에 대해 분석하였다. 1차 실험은 두 복장, 즉 일반복장, 쿨맵시 권장복장에 대한 생리적 반응의 측정으로서, 두 환경기온 $25^{\circ}C$와 $27^{\circ}C$, 상대습도 50%R.H.에서 20대 성인남성 4명을 대상으로 실험을 행하였다. 일반복장은 긴팔 셔츠 정장바지 차림이었고 쿨맵시 권장복장은 넥타이 없이 반팔셔츠에 정장바지 차림이었다. 피험자는 30분간의 안정기를 가진 후 60분 동안 실험을 실시하였는데 사무실 작업과 유사한 컴퓨터 워드작업을 행하였고, 피부온, 직장온, 의복하 습도, 발한량, 온열감, 습윤감, 쾌적감 등을 측정하였다. 대부분의 반응에서 $25^{\circ}C$ 일반복장의 경우와 $27^{\circ}C$ 쿨맵시복장의 경우가 유사한 결과를 나타내고 우수한 것으로 나타났다. $25^{\circ}C$ 쿨맵시복장의 경우에는 저강도 작업이 지속되면 직장온의 저하가 우려되었으며 $27^{\circ}C$ 일반복장에서는 고 평균 피부온, 고 발한량, 높은 온열감 등을 보였다. 2차 실험은 일반복장을 착용한 채 환경온도를 점진적으로 하강시키면서 권장 여름철 냉방온인 $27^{\circ}C$에서 쿨맵시 권장복장을 착용한 경우의 피부온도를 발현시키는 실내 환경온도를 찾는 것이었다. 그 결과 권장복장 경우의 피부온을 나타내려면 일반복장의 경우에는 환경온을 $2^{\circ}C$를 더 낮추어야만 하였다. 여름철 실내 환경온을 $27^{\circ}C$로 높이고 쿨맵시 권장복장을 착용하는 것이 사무실의 장시간 저강도 작업 하에서는 피부온, 주관적 온열감이 우수하였다.

• 설비공학논문집
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• 제22권7호
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• pp.492-507
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• 2010

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2009. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of general thermal and fluid flow, fluid machinery and piping, and new and renewable energy. Various topics were covered in the field of general thermal and fluid flow such as an expander, a capillary tube, the flow of micro-channel water blocks, the friction and anti-wear characteristics of nano oils with mixtures of refrigerant oils, etc. Research issues mainly focused on the design of micro-pumps and fans, the heat resistance reliability of axial smoke exhaust fans, and hood systems in the field of fluid machinery and piping. Studies on ground water sources were executed concerning two well type geothermal heat pumps and multi-heat pumps in the field of new and renewable energy. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included the heat transfer in thermoelectric cooling systems, refrigerants, evaporators, dryers, desiccant rotors. In the area of industrial heat exchangers, researches on high temperature ceramic heat exchangers, plate heat exchangers, frosting on fins of heat exchangers were performed. (3) In the field of refrigeration, papers were presented on alternative refrigerants, system improvements, and the utilization of various energy sources. Refrigeration systems with alternative refrigerants such as hydrocarbons, mixed refrigerants, and $CO_2$ were studied. Efforts to improve the performance of refrigeration systems were made applying various ideas of suction line heat exchangers, subcooling bypass lines and gas injection systems. Studies on heat pump systems using unutilized energy sources such as river water, underground water, and waste heat were also reported. (4) Research trend in the field of mechanical building facilities has been found to be mainly focused on field applications rather than performance improvements. In the area of cogeneration systems, papers on energy and economic analysis, LCC analysis and cost estimating were reported. Studies on ventilation and heat recovery systems introduced the effect on fire and smoke control, and energy reduction. Papers on district cooling and heating systems dealt with design capacity evaluation, application plan and field application. Also, the maintenance and management of building service equipments were presented for HVAC systems. (5) In the field of architectural environment, various studies were carried to improve indoor air quality and to analyze the heat load characteristics of buildings by energy simulation. These studies helped to understand the physics related to building load characteristics and to improve the quality of architectural environment where human beings reside in.