• Title/Summary/Keyword: cool environment

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Comparative Evaluation of Cool Surface Ratio in University Campus: A Case Study of KNU and UC Davis (대학 캠퍼스의 쿨표면 비율 비교평가: 경북대학교와 UC Davis를 사례로)

  • Hwang, Young-Seok;Um, Jung-Sup
    • KIEAE Journal
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    • v.15 no.1
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    • pp.117-127
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    • 2015
  • The cool surface ratio could be used as a proxy of the overall thermal environment contributing to heat islands in urban area. This research proposes a comparative evaluation framework in an objective and quantitative way for measuring cool surface ratios. Two university campuses (Kyungpook National University: KNU, South Korea and UC Davis: University of California, Davis, USA) were selected as case study sites in order to monitor cool surface condition. Google Earth combined with digital maps realistically identified the major type of cool surfaces such as cool roofs and water bodies in the study area. Cool surfaces were sparsely identified over the KNU campus while the UC Davis campus was heavily covered by cool surfaces such as cool roofs and water bodies, resulting in almost four times more first-grade cool surfaces, as compared to KNU. It is confirmed that standard remote sensing technology can offer the viable method of measuring and comparing the campus-wide cool surface condition. It is anticipated that this research output could be used as a valuable reference to initiate a nation-wide cool surface strategy since objective evidence has been provided based on area-wide measurement for the cool surface in the two university context.

Effects of Wearing Support Panty Stocking on Thermoregulatory Responses When Exposed to the Cool Environment (서늘한 환경 노출시 고탄력 팬티스타킹 착용의 온열생리적 효과)

  • 이종민
    • Journal of the Korean Society of Clothing and Textiles
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    • v.24 no.5
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    • pp.696-701
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    • 2000
  • Stockings are considered to be excellent in retention of heat in cool weather. This study was to investigate the physiological effects of wearing support panty stocking when exposed to the cool environment from mild environment. Five healthy female college students wearing(ST) or not wearing(NST) support panty stocking, rested at 25$\pm$1$^{\circ}C$, 50$\pm$5% R.H. and were exposed to 18$\pm$1$^{\circ}C$, 50$\pm$5% R.H. for 90 minutes. The results obtained were as follows: Rectal Temperatures were lower in ST than in NST at both environments. Skin temperatures in ST were revealed higher at $25^{\circ}C$, but lower at 18$^{\circ}C$ than in NST. Heat production and total weight loss didn't show significant difference between ST and NST. Total thermal conductance from the body to the environment was higher in ST than in NST at 18$^{\circ}C$. It was suggested that wearing support panty stocking would keep the body warm in mild environment, but facilitate heat loss from the body in cool environment.

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Cool Island Intensity in a Large Urban Green in Downtown Daegu: Seasonal Variation and Relationship to Atmospheric Condition (대구 도심에 위치한 대규모 녹지공간의 냉섬 강도: 계절변화와 기상조건에의 관련성)

  • Park, Myong-Hee;Kim, Hae-Dong
    • Journal of Environmental Science International
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    • v.19 no.1
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    • pp.81-87
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    • 2010
  • Cool island intensity urban green space was investigated based in Dalsung Park, that is one of the largest parks in Daegu. Cool island intensity(CII), which is defined as the temperature difference between the green space and its surrounding built-up areas, shows time variations. A through-year measurement(2008-2009) of ground level air temperature revealed seasonal variation and relationship to the atmospheric condition of CII. The temperature variation in the park and the reference downtown Daegu was as same order as CII. The noontime CII is larger in summer than that in winter due to the leaf fall of the park trees. On the other hand, seasonal variation of nighttime CII is not so clear. The nighttime CII was larger under the stable atmosphere.

Reduction in Indoor and Outdoor Temperature of Office Building with Cool Roof (쿨루프 적용에 따른 업무용 건물의 내·외부 온도 저감 효과)

  • Song, Bong-Geun;Kim, Gyeong-Ah;Park, Kyung-Hun
    • KIEAE Journal
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    • v.16 no.6
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    • pp.95-101
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    • 2016
  • Purpose: This study aims to identify the effect of temperature reduction by the application of cool roof coatings to Changwon City Hall in South Gyeongsang Province. The indoor and outdoor temperatures of the cool roofing building were analyzed and compared to that of an existing building with green-colored roof coated with waterproof polyurethane. Method: The surface temperatures and reflectivity of rooftops, surface temperatures of ceilings and the interior, and outdoor temperature and humidity of the two aforementioned buildings were measured from June to September in 2014. The measurements were taken every 10 min. Result: The surface temperature of the building with the cool roof was lower by a maximum of $9^{\circ}C$ with the reflectivity of the rooftop at an average of 0.55, which is higher than that of the building with green polyurethane by approximately 0.3. The temperature of the ceiling inside the building with the cool roof was about $1{\sim}2^{\circ}C$ lower than that of the ordinary building. Also, the indoor temperature of the office with cool roof coatings was about $0.5{\sim}1.0^{\circ}C$ lower than that of the office with green-colored roofing building. The results show that cool roof coatings can lower the temperature of buildings. In the next research, the reduction in consumption of energy for air conditioning will be investigated by utilizing building energy simulation tools.

Comparative Evaluation of Surface Temperature among Rooftop Colors of Flat Roof Building Models : Towards Performance Evaluation of Cool Roof (평지붕 건물 축소모형의 지붕색에 대한 표면 온도의 비교평가: 쿨루프 성능평가 차원에서)

  • Ryu, Taek Hyoung;Um, Jung-Sup
    • KIEAE Journal
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    • v.13 no.6
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    • pp.83-91
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    • 2013
  • Cool roofs are currently being emerged as one of important mechanism to save energy in relation to the building. It is specifically proposed that the changing trends of rooftop surface temperature in the flat roof building model could be used effectively as an indicator to reduced cooling load reduced by cool roof since it can present stable temperature record, that is not influenced according to the nearby physical as well as human variables. The temperature of cool roof in summer was lower around $20^{\circ}C$, compared to the general roofs. Such a seasonal or daily comparative study for rooftop temperature in the building model will highlight that the cool roof efficiency could be calculated in much area-wide context according to rooftop color distribution in urban residential area. It is anticipated that this research output could be used as a valuable reference in identifying energy saving by cool roof since an objective monitoring has been proposed based on the rooftop temperature in the building model, fully quantitative performance of thermal infrared image.

A Research on Cool URI based on Internationalized Resource Identifier for Web 2.0 (웹 2.0을 위한 다국어 식별자 기반의 Cool URI에 대한 연구)

  • Jung, Eui-Hyun;Kim, Weon;Song, Kwan-Ho;Park, Chan-Ki
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.5 s.43
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    • pp.223-230
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    • 2006
  • Web 2.0 and Semantic Web technology will be merged to be a next generation Web that leads presentation-oriented Web to data-centric Web. In the next generation Web, semantic processing, Web platform, and data fusion are most important technology factors. Among them, Cool URI used for data fusion can provide permanent and human readable URI and it has been already used in Blog system. However, Cool URI is not suitable to I18N environment such as Hangul and it is difficult to be adopted because several encodings are mingled in Korea Web society. In this paper, we discussed technology issues and Cool URI Web component to use Cool URI with Internationalized Resource Identifier (IRI). A proposed approach provides same function regardless of encoding type and supports both file system based and CGI based methods to be easily used from other applications. Results from several test environments show the implemented Web component satisfy the design purpose.

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The Relationship between Increased Cold Tolerance Resulting from Cool Clothing on Heat Tolerance (의복을 이용한 내한성 향상 훈련이 내열성에 미치는 영향)

  • 이종민
    • Journal of the Korean Society of Clothing and Textiles
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    • v.21 no.4
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    • pp.669-676
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    • 1997
  • The purpose of this study is to examine the effect of the improved cold tolerance resulting from cool clothing in winter on heat tolerance in summer. Ten healthy women were divided into two groups, cold group(C group) (n=5) and warm group(W group) (n=5) . In the previous study, C group was proved that their cold acclimatization was achieved through wearing cool clothing from September to February of the following year, while Wgroup was not proved because of wearing warm clothing during same period. After February, no more clothing training was continued in two groups. To determine the heat tolerance, both groups were exposed from a thermoneutral environment(25$\pm$1$^{\circ}C$, 50$\pm$5% R.H.) to a hot environment (35$\pm$1$^{\circ}C$, 50$\pm$5% R.H.) before and after clothing training, respectively September in 1994 and truly in 1995. Rectal temperature, skin temperatures, thermal sensation and comfort were measured every 10 min., and Os uptake was measured at 10, 45, 85 min. after entering the chamber for 5 min. Body weight was measured before and after the experiment and amount of local sweat was measured during the 90 min long experiment. The results are as follows: Rectal temperatures in 35'c environment of C group were increased after training when compared with before clothing, while those of W group were not changed. But the changes of rectal temperature and heat production during 90 min in hot environment were almost the same in two groups after training. And mean skin temperatures, the changes of mean skin temperatures during 90 min in hot environment, total sweat amount and local sweat amount after training were also the same in two groups. From these results, it might be supposed that the heat loss of two groups were the same but the heat production, especially heat production during rest in C group was higher than in Wgroup. This fact suggests that the increase of rest heat production from cold acclimatization in winter is maintained to summer of the following year. And mild cold acclimatization coming from westing cool clothing does not have a negative effect on heat tolerance.

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The milli-arcsecond scale radio properties of central AGNs in cool-core and non cool-core clusters

  • Baek, Junhyun;Chung, Aeree;Tremou, Evangelia;Sohn, Bongwon;Jung, Taehyun;Ro, Hyunwook
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.1
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    • pp.68.4-69
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    • 2016
  • We report preliminary results of KaVA observations of central galaxies in cool-core and non cool-core clusters. The main goal is to study how cooling environments of galaxy clusters affect the central AGN activities especially at its innermost region. For KaVA observations, 7 radio bright AGNs have been selected from the extended Highest Flux Galaxy Cluster Sample (eHIFLUGCS; the X-ray flux limited & all sky galaxy cluster catalog) with various cooling timescales. In our previous KVN study, we have found that most AGNs in the cool-core clusters show the hint of pc-scale jet-like features while the ones in the non cool-core clusters do not. Using the KaVA 22/43 GHz data of a much higher resolution than the KVN resolution, we have investigated detailed pc-scale jet properties such as physical size, morphology, and radiative age. Based on the KaVA data, we discuss the effect of cluster cooling environment on the evolution of AGNs in the cluster center.

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A Study on the Korean Ondol-System Application in Apartment Houses (공동주택의 한국형 온돌시스템 적용에 관한 연구)

  • Ahn, Min-Hee;Choi, Chang-Ho;Yu, Ki-Hyung;Cho, Dong-Woo
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.860-865
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    • 2006
  • The traditional Korean Ondol System that is a radiant floor heating system was made as warm floor and cool indoor temperature. Nowaday, Ondol is developed as the hydronic floor heating system. But unbalance of floor temperature and indoor temperature is occurred bocause strengthen thermal insulation and airtightness in building changes thermal performance. To solve these problems, we examine actual indoor environment of heating system methods in existing apartments and present the new method of floor heating system. The existing heating system made definite indoor temperatures but floor temperatures that is $22^{\circ}C-26^{\circ}C$ was maintained. To solve these problems, we adopted the differential heating system which made warm area and cool area. A differential heating system was made different pitches of heating pipe in single zone and ratio of warm area to cool area is 1 to 2. As a result of experiments, warm area temperature is $40.7^{\circ}C$, cool area temperature is $36.1^{\circ}C$. A difference of temperature between both area is 4K. A distribution of indoor vertical temperature is similar to both warm area and cool area.

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A Study on the Relationship between Structural Characteristics of Cotton Fabrics and their Cool-and-Warm Felling (I) - at $65\%$ Relative Humidity- (면직물의 구성특성과 냉온감과의 상관성에 관한 연구( I ) -상대습도 $65\%$하에서-)

  • Chang Jee Hye
    • Journal of the Korean Society of Clothing and Textiles
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    • v.14 no.2
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    • pp.152-163
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    • 1990
  • The purpose of this study is to experimentally analyze the relationship between structural characteristics of cotton fabrics and their cool-and-warm felling in order to develop more comfortable fabrics. Comfort in textile products has been emphasized as consumers preferred performance to fashion of clothing. Thermal comfort of clothing is a basic parameter of the comfort sensation which is usually represented by the cool-and-warm feeling felt by human skin. Cloo-and-warm feeling is perceived by the heat flux which transfers heat energy stored in an object to skin. We feel warm (cool) if the temperature of nerve extremity in skin ascends (descends). As cool-and-warm feeling determines the comfort sensation of clothing, it is important to develop new comfort fabrics. Although considerable works have been made on the body, clothing, and environment, there has been no research study on the structural characteristics of fabrics and their cool and warm feeling. Cool-and-warm feeling is closely related to the transient heat transfer property. This research study used the cotton fabrics manufactured in Korea as sample and measured $q_{max}$ value with thermal property measuring instrument (Thermo-Labo II type). $q_{max}$ values estimated by polynomial regression equation were compared with those observed in this study. This study also identified the structural parameters of cotton fabrics for a specific range of $q_{max}$ values. The findings of this study can be summarized as follows: 1) As the thickness, porosity and air permeability of cotton fabrics increase, $q_{max}$ value decreases. 2) As the fabric count and over factor of cotton fabrics increase, $q_{max}$ value also increases. 3) $q_{max}$ values have been estimated by simple and polynomial regression equations developed in this study. Regression curves which have been plotted by polynomial regression equations also provided with the range of structural parameters for a specific range of $q_{max}$ values of cotton fabrics. This study would be significant in that it has identified the structural Parameters for the cool-and-warm feeling of cotton fabric at $65\%$ relative humidity.

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