• Title/Summary/Keyword: Cool air

검색결과 280건 처리시간 0.028초

도시공원 및 주변환경의 특성이 도시공간의 온도저감에 미치는 영향 (Heat Mitigation Effects of Urban Space based on the Characteristics of Parks and their Surrounding Environment)

  • 서정은;오규식
    • 한국환경복원기술학회지
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    • 제23권5호
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    • pp.1-14
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    • 2020
  • In order to improve the urban thermal environment, efforts are being made to increase green areas in cities that include park construction, planting, and green roofing. Among these efforts, urban parks play an important role not only in improving the urban thermal environment, but also in terms of ecosystem services (serving as resting places for citizens, providing cleaner air quality, reducing noise, etc.). Therefore, the purpose of this study is to suggest planning and management guidelines for urban parks that are effective in improving the thermal environment, by analyzing the urban surface temperature reduction performance of urban parks. To do this, first, land surface temperature was calculated by using Landsat 8 images. Second, the PCI (Park Cool Island) index was calculated to identify the temperature reduction performance of urban parks. Third, the characteristics of parks (area, shape, vegetation) and the surrounding spatial characteristics (land cover, building-related variables, etc.) were identified. Finally, the relationship between the PCI indices (PCI scale, PCI effect, PCI intensity) and the characteristics of the parks and their surroundings were analyzed. The results revealed that the parks consisting of a larger area, simple shape, and higher tree coverage ratio had increased PCI performance, and were advantageous for improving the urban thermal environment. Meanwhile, PCI performance was found to have decreased in areas with a higher impermeable area ratio and building coverage ratio. The outcomes of this study can be used to identify priority areas for planning and management of urban parks and can also be utilized as planning and management guidelines for improving urban thermal environment.

연료전지 자동차용 이산화탄소 열펌프 시스템에서의 냉방 성능에 관한 실험적 연구 (An experimental study on the cooling performance of carbon dioxide heat pump system for fuel cell vehicles)

  • 김성철;박민수;김민수;황인철;노영우;박문수
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2005년도 춘계학술대회
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    • pp.378-383
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    • 2005
  • This experimental study presents the results of the cooling performance test of a $CO_2$ heat pump system for fuel cell vehicles. The experimental facility provides the cool ing and heating environment for cabin and heat releasing component. The test loop is designed to target the cooling capacity of 5kW and its coefficient of performance (COP) of 2.2. The cooling performance of the heat pump system is strongly dependent on the refrigerant charge and the degree of superheat. We carried out basic experiments to obtain optimum refrigerant charge and the degree of superheat level at the internal heat exchanger outlet. The heat pump system for fuel cell vehicles is different from that of engine-driven vehicles, where the former has an electricity-driven compressor and the latter has the belt-driven (engine-driven) compressor. In the fuel cell vehicle, the compressor speed is an independent operating parameter and it is controlled to meet the cooling/heating loads. Experiments were carried out at cooling mode with respect to the compressor speed and the incoming outdoor air speed. The results obtained in this study can provide the fundamental cool ing performance data using the $CO_2$ heat pump system for fuel cell vehicles.

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레인코트용 자카드 직물의 소비자 요구도 및 패턴 이미지 감성 평가 (Consumer Needs and Pattern Sensibility of Jacquard fabrics for Raincoat)

  • 김정화;이정순
    • 한국의류산업학회지
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    • 제16권4호
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    • pp.645-652
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    • 2014
  • This study identifies consumer needs and a pattern sensory evaluation of jacquard fabrics for raincoats using quick-drying-absorbing polyester. We investigate the consumer's consciousness and raincoat improvements. Twelve kinds of jacquard fabrics were developed for use in this study. Developed jacquard fabrics were assessed subjectively by 152 university students using a 7-point scale of 26 consumer needs and 31 pattern image sensory descriptors. Data were analyzed by SPSS. The major results were: There was a need for consumers to improve the front fastener type, cuff fastener, mesh patch position, and raincoat pocket position. The most important parameter to choose raincoat fabric was waterproof and the other parameters were vapor-porous/water repellent, design, color, fashionability, air-permeability and easy-put on/off. The pattern image sensibility of jacquard fabrics was explained by seven factors: gorgeous, simple, cute, futuristic, ethnic, feminine, and cool. A higher pattern preference was found in the jacquard fabrics of unique, sporty, natural, luxurious, and trendy images. The pattern preference was predicted at 45.3% with gorgeous, simple, pure, cute, futuristic factors. The correlation coefficient between the pattern image sensibility factor 1 (gorgeous) and pattern preference was 0.674 and with factor 3 (cute) was 0.416, and with factor 6 (cool) was 0.209. The 4 factors (gorgeous, simple, cute, futuristic) were selected as a significant pattern image sensibility that influenced preference.

감물염색을 활용한 전통 문화상품의 개발 (Development of Traditional Cultural Products Using Persimmon Dyeing)

  • 이은진;김선경;조효숙
    • 복식문화연구
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    • 제15권6호
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    • pp.1053-1062
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    • 2007
  • This study purposed to restructure representative traditional patterns formatively, manufacture actual cultural products with traditional dyeing technique using persimmon, and commercialize the results of the research. Traditionally in Korea, the dying of natural fiber such as cotton, flax and silk with persimmon was called Galmul dyeing, and clothes made through Galmul dyeing were called Galot. Galot was very useful because it is strong, does not pick up dirt easily, dries easily, and is cool in summer. In addition, cloth dyed with persimmon becomes stiff, so it does not need to be starched or ironed after washing. Moreover, it does not transmit heat under direct rays and is highly air-permeable, so it is cool and useful for standing the heat. In this study, we used traditional persimmon dyeing technique, printing traditional patterns fit for contemporary people's aesthetic sense not through dip-dying but through printing. When persimmon dyeing is used in expressing patterns, it produces not only visual effect but also embossing effect due to the characteristic of persimmon that makes printed patterns stiff, so we can obtain unique texture distinguished from other printing methods. We chose seven motive patterns, which were lotus pattern symbolizing eternal life, peony pattern symbolizing wealth and rank and prosperity, character Su(壽) pattern widely used as a symbol of health, bird and cloud pattern in the Goryeo Dynasty, Sahapyeoeuisohwa(四合如意小花) pattern printed on brocade in the Goryeo Dynasty, lattice pattern, cloth pattern on wall paintings from the Period of the Three Kingdoms. From each pattern chosen as a motive was extracted unit patterns and the original pattern was restored using Adobe Illustrator. Restored patterns were restructured to be applied to cultural products fit for contemporary formative sense. Fabrics used in dyeing were cotton, linen, ramie, silk, and polyester. Although the same persimmon dyeing was applied, we produced different feelings of patterns using various fabrics and in some cases gold and silver powder was added for the effect of gloss in addition to the embossing of patterns. Using printed fabrics we manufactured tea pads, place mats, cushions, wrapping cloth for gifts, wallet, lampshades.

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태열(胎熱)에 관한 문헌적(文獻的) 고찰(考察) (Literatural Study on Tae-yeul)

  • 구진숙;김장현
    • 대한한방소아과학회지
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    • 제15권1호
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    • pp.235-253
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    • 2001
  • Tae-yeul is the baby's disorder inheritted by its mother during fregnancy. This is due to its mother's overeating hot, fatty food and taking harmful medicine. So internal physical fever is accumulated in mother's body, and it heats up the placenta and the umbilical cord. Generally, this disorder means the skin disease that is occurred from $2{\sim}5$ months to 1 year after birth. It is specialized by the dirty oozing, a severe itching and the rash at its head and face. It is similar in its symptoms such as atopic dermatitis in western medicine. Recently, this disease has the increasing tendency of prevalence rate because of the bad atmosphere and the invironmental pollution. The results were summerised as follows; 1, 2, 3, 4 1. The causes of Tae-yeul are summarized by fragnat woman's contacting a cool air, overating a hot and toxic food and taking emotional shock. 2. The symptoms of Tae-yeul are the edema on upper eyelids, stifling convulsions, flush, the fever of one side body, the asthma of sputum increase, the yawing of the tired mind, the bowl complaint, the red urine and urination disturbance. 3. In the treatment method of Tae-yeul, its mother feed her milk after taking a madicine. So one must expect to be treated slowly. If one tries to treat it with a cool madicine quickly, it can cause vomitting or a serious disorder. 4. In the prescription of Tae-yeul, they used a Moktongsan, a Chiwhnagtang, an Yangyoubang, a Tojuksan, a Whangyunsan, a Juryungtang and a Kamdutang, etc.. For the method of cleaning face or bathing, they used Sasungsan, Whanbaekpijuntang. 5. Tae-yeul including Naesun, Taelyumchang, yousun, etc. is similar to the atopic dermatitis of western medicine in its symptoms.

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사기오미론(四氣五味論)의 구조적 해석 (Structural Interpretation of Properties and Flavors of Drugs)

  • 조용주;김진주
    • 한국한의학연구원논문집
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    • 제11권2호
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    • pp.23-33
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    • 2005
  • Four Properties and five Flavors of Drugs is interpreted by adaptation of human body to the environmental theory(天人相應). The Structural model of the body is compared with sky, earth, sun and moon (天, 地, 日, 月). The natural changes of the four seasons give rise to that of Four Properties and five Flavors of Drugs. On equal terms it is happened in our body. On this study we can draw an analogy between sky, earth, sun & moon (天, 地, 日, 月) and the body. The six bu(六腑) is related to the earth, the five ju(五主) to the sky, the five jang(五臟) to the sun, the meridians system (經絡) to the moon. When spring, the air is warm, the water element of the earth is ascending, and the earth gives birth to the sour flavor. Like this, the water element is absorbed by six bu and then is ascended to the meridian system. When summer, the air is hot and the water element of the earth is floated, the earth make the bitter flavor. In the same way, the six bu absorbed the hot air from the five ju and the water element is quickly absorbed by six bu and then the water element is ascended to the meridian system. When rainy season (長夏), the earth creates the sweet flavor The sweet flavor give warmer energy to the five jang and the six bu. When autumn, the earth change the sweet flavor into pungent. The earth gives warmer energy to the sky, because of cool weather According to same process, the pungent flavor give warmer energy to the five jang and the six bu, and the meridian system gets back the water element from the five ju. When winter, the air is cold and the water element of the earth is hidden. The sky and the earth are not interchangeable. At that time, the earth produce the salty flavor and the water element is keeping in the meridian system.

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COMMISSIONING RESULT OF THE KSTAR HELIUM REFRIGERATION SYSTEM

  • Park, Dong-Seong;Chang, Hyun-Sik;Joo, Jae-Joon;Moon, Kyung-Mo;Cho, Kwang-Woon;Kim, Yang-Soo;Bak, Joo-Shik;Cho, Myeon-Chul;Kwon, Il-Keun;Andrieu, Frederic;Beauvisage, Jerome;Desambrois, Stephane;Fauve, Eric
    • Nuclear Engineering and Technology
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    • 제40권6호
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    • pp.467-476
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    • 2008
  • To keep the superconducting (SC) magnet coils of KSTAR at proper operating conditions, not only the coils but also other cold components, such as thermal shields (TS), magnet structures, SC bus-lines (BL), and current leads (CL) must be maintained at their respective cryogenic temperatures. A helium refrigeration system (RRS) with an exergetic equivalent cooling power of 9 kW at 4.5 K without liquid nitrogen ($LN_2$) pre-cooling has been manufactured and installed. The main components of the KST AR helium refrigeration system (HRS) can be classified into the warm compression system (WCS) and the cryogenic devices according to the operating temperature levels. The process helium is compressed from 1 bar to 22 bar passing through the WCS and is supplied to cryogenic devices. The main components of cryogenic devices are consist of cold box (C/B) and distribution box (D/B). The C/B cool-down and make the various cryogenic helium for the KSTAR Tokamak and the various cryogenic helium is distributed by the D/B as per the KSTAR requirement. In this proceeding, we will present the commissioning results of the KSTAR HRS. Circuits which can simulate the thermal loads and pressure drops corresponding to the cooling channels of each cold component of KSTAR have been integrated into the helium distribution system of the HRS. Using those circuits, the performance and the capability of the HRS, to fulfill the mission of establishing the appropriate operating condition for the KSTAR SC magnet coils, have been successfully demonstrated.

차량 도장 건조 성능 향상을 위한 수치해석 연구 (A NUMERICAL STUDY FOR IMPROVING PERFORMANCE ON PAINT DRYING SYSTEM OF A VEHICLE)

  • 이승재;최종락;허남건;김희수
    • 한국전산유체공학회지
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    • 제16권2호
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    • pp.75-80
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    • 2011
  • In this study, three-dimensional transient numerical simulations were carried out for a paint drying system of vehicle. The vehicle on assembly line passes through the drying system consisting of hot and cool air blow region. For the moving motion of the vehicle, moving of inlet boundary condition and MRF technique are used. The transient distribution of temperature and velocity in the drying system were predicted numerically. In order to validate the numerical results, transient distribution of the vehicle surface temperature was compared with experimental data, showing a good agreement. As a result of present study, optimal operating condition of the drying system are to be suggested.

Hot and cool temperature control of the car-seat utilizing the thermoelectric device

  • Choi, Hyung-Sik;Kim, You-Shin;Woo, Jung-Jae;Jeon, Chang-Hoon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.1816-1821
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    • 2003
  • The thermoelectric device was applied to a car-seat to control the hot temperature in summer and cold temperature in the winter. The characteristics of the device used to a car-seat were analyzed. The air conditioning structure was designed to regulate the hot side of the thermoelectric device. To control the temperature of the car-seat, a robust control algorithm based on the sliding mode control was applied, and a controller using one-chip microprocessor was developed. The performance of the proposed controller through experiments was shown.

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이산화탄소를 이용한 가스터빈 블레이드 막냉각 특성 연구 (A Numerical Study on the Film-Cooling Characteristics of Gas Turbine Blade using CO2)

  • 김상권;이종철;김윤제
    • 한국유체기계학회 논문집
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    • 제15권2호
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    • pp.41-44
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    • 2012
  • In order to cool the turbine blade under high temperature operating conditions, the film-cooling method is generally applied. In this study, $CO_2$ was used as working fluid and it helped the operating system to prevent the loss of compressed air. The trapezoidal diffuser shape was adopted at the cross section of hole and the characteristics of heat flow with various working fluids were numerically studied. In particular, the different mixture ratios of $CO_2$, such as various density ratios of 0.2, 0.8, and 1.0, respectively, were considered. Numerical results are graphically depicted with various conditions.