• Title/Summary/Keyword: Thermal-Comfort

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Research on Actual Usage and Satisfaction of ROKAF Fighter Pilot's Flight Duty Uniform (공군 전투조종사 비행복 착용특성 및 만족도 조사)

  • Lee, Ah Lam;Nam, Yun Ja;Hong, Yu Hwa;Im, Sojung;Lim, Chae Keun
    • Journal of the Korean Society of Clothing and Textiles
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    • v.40 no.4
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    • pp.669-684
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    • 2016
  • This study investigates Korean fighter pilot's usage and satisfaction of a flight duty uniform (FDU). The survey was conducted from October 2014 to March 2015 using Focus Group Interview (FGI) and questionnaires. FGI collected qualitative data about duty and requirements; subsequently, surveys were performed to collect quantitative data about wearing conditions and satisfaction with FDU. The results of the FGI and the questionnaire were as follows. Type of pilot duty was divided into two parts, flight duty and ground duty. It is important to consider duties as well as factors related to survival when developing FDU. According to anthropometric data and wearing size, the basic size for apparel grading should be changed from actual size, 'M95XL' to 'M100L'. It is also necessary to improve the whole sizing system. Further studies about body form changes in pilot's movement are needed to improve mobility because the respondents perceived some restrictions at several body parts in movement with the coverall uniform. Summer FDU had a low satisfaction level in vent hole function and appearance. Furthermore, protection problems in the vent hole were also an issue. Making a seasonal classification of FDU fabric will be more effective than a vent hole to increase a pilot's thermal satisfaction. Respondents had a passive stance towards FDU reform (including pocket change); therefore, a new FDU design strategy should concentrate on improving current FDU functions like mobility (or comfort) rather than dramatic changes. Pilots complained about the quality stability of FDU; therefore, quality control by military administration as well as concrete and clear design instructions by the developer should be attained together. The results obtained in this study are expected to be used as an important basis for the further development of FDU.

Influence of Cold Floors on the Human Body Skin Temperatures and Thermal Comfort (- 찬바닥이 인체피부온도 및 온열적 쾌적감에 미치는 영향 -)

  • 김봉애
    • Journal of the Korean Home Economics Association
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    • v.31 no.1
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    • pp.211-223
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    • 1993
  • 바닥마감재료가 다른 여름철의 찬바닥이 인체피부온도 및 온열적 쾌적감에 미치는 영향을 검토하기 위하여, 주위벽 및 천장의 온도를 기온과 거의 같게 한 항온실을 이용해서 바닥에 앉은 자세, 의자에 앉은 자세, 서 있는 자세별로 검토했다. 그 결과를 요약하면 다음과 같다. (1) 평균피부온도는 기온이 낮고 수온이 낮을수록 낮았다. Carpet 마감재료는 서 있는 자세, 바닥에 앉은 자세의 평균피부온도가 낮고 의자에 앉은 자세가 높았다. Cork 마감재료가 Carpet, Flooring 마감재료에 비해 평균피부온도가 낮았다. (2) 온냉감평가는 흑구온도가 낮게 되면$\ulcorner$중성이다$\lrcorner$혹은$\ulcorner$서늘하다$\lrcorner$쪽으로 평가하고, Cork, Carpet, Flooring 마감재료의 순으로 $\ulcorner$서늘하다$\lrcorner$쪽으로 평가 하였다. (3) 쾌적감평가는 바닥에 앉은 자세와 서 있는 자세가 의자에 앉은 자세보다 쾌적한 것으로 평가하였다. 마감재료는 Cork, Flooring, Carpet 순으로 쾌적하다고 평가 하였다. (4) 바닥마감재료에 대한 평가는 바닥에 앉은 자세의 경우, Carpet 마감재료는$\ulcorner$차가운$\lrcorner$$\ulcorner$습기찬$\lrcorner$의 평가점수가 높고, Cork 마감재료는$\ulcorner$평활한$\lrcorner$$\ulcorner$차가운$\lrcorner$$\ulcorner$감촉이 좋은$\lrcorner$$\ulcorner$딱딱한$\lrcorner$의 평가점수가 높고, Flooring 마감재료는$\ulcorner$평활한$\lrcorner$$\ulcorner$탄력성이 없는$\lrcorner$$\ulcorner$딱딱한$\lrcorner$의 평가점수가 높았다.$\ulcorner$따듯한$\lrcorner$-$\ulcorner$차가운$\lrcorner$의 평가는 바닥온도의 영향을 받아서, Cork, Flooring 마감재료가 Carpet 마감재료보다$\ulcorner$차가운$\lrcorner$의 높은 점수평가를 하였다. (5) Carpet 마감재료는 평균피부온도가 34$^{\circ}C$를 넘어도$\ulcorner$약간 시원하다$\lrcorner$는 평가이고, 서 있는 자세와 의자에 앉은 자세가 바닥에 앉는 자세보다 쾌적하다고 평가한다. Cork 마감재료는 3자세 모두 평균피부온도 33~34$^{\circ}C$의 사이에서 가장 쾌적하다. Flooring 마감재료는 온열적중성, 쾌적감의 중성의 평가가 많다. 이상의결과를 종합하면, 찬바닥이 인체에 미치는 영향은 바닥마감재료로는 Cork, Flooring이 보다 좋은 평가를 하였음으로, 여름철 바닥마감재료로서는 Cork, Flooring 마감재료가 바람직하다고 생각된다. 자세별로는 서 있는 자세는 바닥에 앉은 자세와 거의 같은 경향을 보이고, 의자에 앉은 자세는 바닥에 앉은 자세와 서 있는 자세 만큼 영향을 받지 않았다. 이후 실험결과를 중심으로 찬바닥의 경우, 보다 쾌적한 온열환경범위를 제안하려고 한다.

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The Feminine Factor of the Therapeutic Landscape by Water from a Perspective of the Japanese Hot Spring (일본 온천을 중심으로 본 물을 매개로 하는 치유의 경관에서의 여성적 요소)

  • Park, Sookyung
    • Journal of the Korean association of regional geographers
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    • v.22 no.3
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    • pp.529-552
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    • 2016
  • The purpose of this study is to examine the matter as to how the meaning of the physical therapeutic landscape by water, which is associated with physical, cultural, spatial, and economical aspects, appears in the space centering on women and is to look into the feminine factors in term of a rest area, consideration, and imagery for women. From a perspective of a rest area for women, the meaning of a physical aspect is remarkable and is materialized in thermal waters and bathing, atmosphere, subsidiary facilities and safe nightlife. According to these phenomena, female visitors are able to feel freedom, power, which can return themselves to the best condition by thermal waters, therapeutic equipments provided in a watering place continuously, safe protection and exchange with strangers with an open mind. And the cultural aspect of the therapeutic landscape by water is discovered in consideration for women. It is the fact that joins the Japanese culture based on consideration towards others to the traditional culture of hot springs by itself. For example, women can feel various pleasure, experience the protection or the support by someone and pursuit not only physical beauty but also mental or spiritual one through welcome bus, service of Okami san and Nakai san, decorations, funny installments and secure of private space. Lastly, the imagery of women can be identified in cultural, spatial, and economical aspects extensively somewhat and is embodied by advertising mediums, signs of hot springs, shrines, objets and products variously. It is made into healthiness, relaxation, comfort, familiarity and image that are realized to love or are connected to a happy marriage life. To sum up the results, the healing or therapeutic elements for women appearing in hot springs are gathered to some abstraction such as freedom, safe, effect beyond the body, pleasure, durability of healing or therapy, beauty and hope; furthermore, if these abstraction are combined each other closely, the effect of healing or therapy, which transforms anxiety into a stable condition, can be exposed externally.

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The Influence of the Landscaping Shade Membrane's Brightness on the Mean Radiant Temperature(MRT) of Summer Outdoor (조경용 차양막 재료의 명도가 하절기 옥외공간의 평균복사온도에 미치는 영향)

  • Lee, Chun-Seok;Ryu, Nam-Hyung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.43 no.5
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    • pp.65-73
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    • 2015
  • The purpose of this study was to compare the Mean Radiant Temperature(MRT) under two landscaping shade membranes, white and black, with those of natural outdoor spaces at summer midday. An additional perforated black shading net was applied and compared for the consideration of the practical application. The average MRT at the height of 2.4m, 10cm below the membranes of black, white, and perforated black were $49.1^{\circ}C$, $41.6^{\circ}C$ and $36.8^{\circ}C$ respectively, while that of open sky was $41.8^{\circ}C$. This indicates that a closer position to the darker membrane caused a higher MRT. At the height of 1.1m and 1.7m, the difference of MRT between the black and the white membranes was slight, while the value of white was unexpectedly higher than the black. The MRT of black perforated net showed the lowest value at every height. The black membrane absorbed more solar radiation than the white, which caused the greater release of long wave radiation and higher temperature near the membrane itself. In spite of the higher albedo of the white membrane, the higher solar radiation transmittance rate of which seemed to cause the slightly higher MRT than the black at the hight of 1.1m and 1.7m. In summary, the performance of the black membrane was slightly better than the white in terms of the air conditioning of the human related space around the height of 1.1m and 1.7m, when the shading membranes were at 2.5m height.

The Influence of the Landscaping Shade Materials' Porosity on the Mean Radiant Temperature(MRT) of Summer Outdoors (조경용 차양 재료의 공극률이 하절기 옥외공간 평균복사온도에 미치는 영향)

  • Lee, Chun-Seok;Ryu, Nam-Hyung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.45 no.2
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    • pp.60-67
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    • 2017
  • The purpose of this study was to evaluate the influence of landscaping shade materials' porosity on the Mean Radiant Temperature (MRT) of summer outdoors. The MRTs were measured under seven different types of black membranes with holes of 8mm diameter at different intervals applied on the top of wooden boxes, and compared with those of four additional control plots with or without shade and lateral boxes. The applied porosities were 0.5, 1, 2, 4, 8, 16%, and 32%, and three groups of three shades were compared sequentially from August 13 to September 8, 2016. The MRTs under the shade without lateral block, no shade with lateral block, and shade with lateral block were $33.08^{\circ}C$, $45.80^{\circ}C$, and $42.3^{\circ}C$, respectively, while that of no-shaded no-lateral screen was $44.26^{\circ}C$, based on records from 11:00 AM to 3:00 PM on the days with a peak globe temperature higher than $30^{\circ}C$. An ANCOVA analysis showed that the MRTs under the shades with 0.5, 1, 2, 4, 8, 16%, and 32% porosities were calculated as 43.40, 43.10, 41.49, 40.43, 39.61, $37.91^{\circ}C$, and $38.12^{\circ}C$, respectively, while that in the no shaded control box was $45.8^{\circ}C$. The curve fitted between MRTs and the porosity showed a U-shaped quadratic function with the minimum MRT at 16% practically or 22.5% statistically.

Recent Progress in Air Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2006 (공기조화, 냉동 분야의 최근 연구 동향: 2006년 학회지 논문에 대한 종합적 고찰)

  • Han, Hwa-Taik;Shin, Dong-Sin;Choi, Chang-Ho;Lee, Dae-Young;Kim, Seo-Young;Kwon, Yong-Il
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.6
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    • pp.427-446
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    • 2008
  • A review on the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2006 has been accomplished. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro heat exchanger and siphon cooling device using nano-fluid. Traditional CFD and flow visualization methods were still popular and widely used in research and development. Studies about diffusers and compressors were performed in fluid machinery. Characteristics of flow and heat transfer and piping optimization were studied in piping systems. (2) The papers on heat transfer have been categorized into heat transfer characteristics, heat exchangers, heat pipes, and two-phase heat transfer. The topics on heat transfer characteristics in general include thermal transport in a cryo-chamber, a LCD panel, a dryer, and heat generating electronics. Heat exchangers investigated include pin-tube type, plate type, ventilation air-to-air type, and heat transfer enhancing tubes. The research on a reversible loop heat pipe, the influence of NCG charging mass on heat transport capacity, and the chilling start-up characteristics in a heat pipe were reported. In two-phase heat transfer area, the studies on frost growth, ice slurry formation and liquid spray cooling were presented. The studies on the boiling of R-290 and the application of carbon nanotubes to enhance boiling were noticeable in this research area. (3) Many studies on refrigeration and air conditioning systems were presented on the practical issues of the performance and reliability enhancement. The air conditioning system with multi indoor units caught attention in several research works. The issues on the refrigerant charge and the control algorithm were treated. The systems with alternative refrigerants were also studied. Carbon dioxide, hydrocarbons and their mixtures were considered and the heat transfer correlations were proposed. (4) Due to high oil prices, energy consumption have been attentioned in mechanical building systems. Research works have been reviewed in this field by grouping into the research on heat and cold sources, air conditioning and cleaning research, ventilation and fire research including tunnel ventilation, and piping system research. The papers involve the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies on indoor air quality took a great portion in the field of building environments. Various other subjects such as indoor thermal comfort were also investigated through computer simulation, case study, and field experiment. Studies on energy include not only optimization study and economic analysis of building equipments but also usability of renewable energy in geothermal and solar systems.

Study of the Effects of Ambient Temperature and Car Heater Power on the Train Cabin Temperature (외기 온도와 난방 출력의 철도차량 객실 온도에 대한 영향 연구)

  • Cho, Youngmin;Park, Duck-Shin;Kwon, Soon-Bark;Jung, Woo-Sung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.9
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    • pp.5877-5884
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    • 2014
  • Recently, abnormally cold weather has been reported more frequently in winter due to the climate change and abnormal weather changes. On the other hand, the heating capacity of a railcar may be not enough to warm the cabin under severe cold climatic conditions, which is one of the reasons for the passengers' complaints about heating. In this study, the effects of ambient temperature and heater power on the cabin temperature was investigated to obtain the minimum ambient temperature for the tested railcar. The test railcar was placed in a large-climatic chamber, and various ambient temperature conditions were simulated. The effects of the heater output were investigated by monitoring the cabin temperature under a range of heater output conditions. The mean cabin temperature was $14.0^{\circ}C$, which was far lower than the required minimum temperature of $18^{\circ}C$, under a $-10^{\circ}C$ ambient temperature condition with the maximum heat power. When the ambient temperature was set to $0^{\circ}C$ and $10^{\circ}C$, the maximum achievable cabin temperature was $26.1^{\circ}C$ and $34.0^{\circ}C$. Through calculations using the interpolation method, the minimum ambient temperature to maintain an $18^{\circ}C$ cabin temperature was $-6.7^{\circ}C$ for this car. The vertical temperature difference was higher with a higher power output and higher ambient temperature. The maximum vertical temperature difference was higher than $10^{\circ}C$ in some cases. However, the horizontal temperature difference vs. low temperature (< $2^{\circ}C$) was independent of the power output and ambient temperature. As a result, it is very important to reduce the vertical temperature difference to achieve good heating performance.

Review of Production, Husbandry and Sustainability of Free-range Pig Production Systems

  • Miao, Z.H.;Glatz, P.C.;Ru, Y.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.11
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    • pp.1615-1634
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    • 2004
  • A review was undertaken to obtain information on the sustainability of pig free-range production systems including the management, performance and health of pigs in the system. Modern outdoor rearing systems requires simple portable and flexible housing with low cost fencing. Local pig breeds and outdoor-adapted breeds for certain environment are generally more suitable for free-range systems. Free-range farms should be located in a low rainfall area and paddocks should be relatively flat, with light topsoil overlying free-draining subsoil with the absence of sharp stones that can cause foot damage. Huts or shelters are crucial for protecting pigs from direct sun burn and heat stress, especially when shade from trees and other facilities is not available. Pigs commonly graze on strip pastures and are rotated between paddocks. The zones of thermal comfort for the sow and piglet differ markedly; between 12-22$^{\circ}C$ for the sow and 30-37$^{\circ}C$ for piglets. Offering wallows for free-range pigs meets their behavioural requirements, and also overcomes the effects of high ambient temperatures on feed intake. Pigs can increase their evaporative heat loss via an increase in the proportion of wet skin by using a wallow, or through water drips and spray. Mud from wallows can also coat the skin of pigs, preventing sunburn. Under grazing conditions, it is difficult to control the fibre intake of pigs although a high energy, low fibre diet can be used. In some countries outdoor sows are fitted with nose rings to prevent them from uprooting the grass. This reduces nutrient leaching of the land due to less rooting. In general, free-range pigs have a higher mortality compared to intensively housed pigs. Many factors can contribute to the death of the piglet including crushing, disease, heat stress and poor nutrition. With successful management, free-range pigs can have similar production to door pigs, although the growth rate of the litters is affected by season. Piglets grow quicker indoors during the cold season compared to outdoor systems. Pigs reared outdoors show calmer behaviour. Aggressive interactions during feeding are lower compared to indoor pigs while outdoor sows are more active than indoor sows. Outdoor pigs have a higher parasite burden, which increases the nutrient requirement for maintenance and reduces their feed utilization efficiency. Parasite infections in free-range pigs also risks the image of free-range pork as a clean and safe product. Diseases can be controlled to a certain degree by grazing management. Frequent rotation is required although most farmers are keeping their pigs for a longer period before rotating. The concept of using pasture species to minimise nematode infections in grazing pigs looks promising. Plants that can be grown locally and used as part of the normal feeding regime are most likely to be acceptable to farmers, particularly organic farmers. However, one of the key concerns from the public for free-range pig production system is the impact on the environment. In the past, the pigs were held in the same paddock at a high stocking rate, which resulted in damage to the vegetation, nutrient loading in the soil, nitrate leaching and gas emission. To avoid this, outdoor pigs should be integrated in the cropping pasture system, the stock should be mobile and stocking rate related to the amount of feed given to the animals.

An Application of Satellite Image Analysis to Visualize the Effects of Urban Green Areas on Temperature (위성영상을 이용한 도시녹지의 기온저감 효과 분석)

  • Yoon, Min-Ho;Ahn, Tong-Mahn
    • Journal of the Korean Institute of Landscape Architecture
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    • v.37 no.3
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    • pp.46-53
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    • 2009
  • Urbanization brings several changes to the natural environment. Its consequences can have a direct effect on climatic features, as in the Urban Heat Island Effect. One factor that directly affects the urban climate is the green area. In urban areas, vegetation is suppressed in order to accommodate manmade buildings and streets. In this paper we analyze the effect of green areas on the urban temperature in Seoul. The period selected for analysis was July 30th, 2007. The ground temperature was measured using Landsat TM satellite imagery. Land cover was calculated in terms of city area, water, bare soil, wet lands, grass lands, forest, and farmland. We extracted the surface temperature using the Linear Regression Model. Then, we did a regression analysis between air temperature at the Automatic Weather Station and surface temperature. Finally, we calculated the temperature decrease area and the population benefits from the green areas. Consequently, we determined that a green area with a radius of 500m will have a temperature reduction area of $67.33km^2$, in terms of urban area. This is 11.12% of Seoul's metropolitan area and 18.09% of the Seoul urban area. We can assume that about 1,892,000 people would be affected by this green area's temperature reduction. Also, we randomly chose 50 places to analysis a cross section of temperature reduction area. Temperature differences between the boundaries of green and urban areas are an average of $0.78^{\circ}C$. The highest temperature difference is $1.7^{\circ}C$, and the lowest temperature difference is $0.3^{\circ}C$. This study has demonstrated that we can understand how green areas truly affect air temperature.

The Comparison of the Solar Radiation and the Mean Radiant Temperature (MRT) under the Shade of Landscaping Trees in Summertime (하절기 조경용 녹음수 수관 하부의 일사와 평균복사온도 비교)

  • Lee, Chun-Seok;Ryu, Nam-Hyung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.42 no.5
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    • pp.22-30
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    • 2014
  • The purpose of this study was to compare the Solar Radiation(SR) and the Mean Radiant Temperature(MRT) under the shades of the three landscaping trees in clear summer daytimes. The trees were Lagerstroemia indica, Quercus palustris and Ulmus parvifolia. The solar radiation, the globe temperature and the air temperature were recorded every minute from the $1^{st}$ of April to the $30^{th}$ of September 2013 at a height of 1.1m above on the four monitoring stations, with four same measuring system consisting of a solar radiation sensor, two resistance temperature detectors(Pt-100), a black brass globe (${\phi}50mm$) and data acquisition systems. At the same time, the sky view photos were taken automatically hourly by three scouting cameras(lens angle: $60^{\circ}$) fixed at each monitoring station. Based on the 258 daily sky view photos and 6,640 records of middays(10 A.M.~2 P.M.) from the $1^{st}$ of June to the $30^{th}$ of August, the time serial differences of SR and MRT under the trees were analysed and compared with those of open sky, The major findings were as follows; 1. The average ratio of sky views screened by the canopies of Quercus palustris, Lagerstroemia indica and Ulmus parvifolia were 99%, 98% and 97%, and the SR were $106W/m^2$, $163W/m^2$ and $202W/m^2$ respectively, while the SR of open sky was $823W/m^2$. Which shows the canopies blocked at least 70% of natural SR. 2. The average MRT under the canopies of Quercus palustris, Lagerstroemia indica and Ulmus parvifolia were $30.34^{\circ}C$, $33.34^{\circ}C$ and $34.77^{\circ}C$ respectively, while that of open sky was $46.0^{\circ}C$. Therefore, it can be said that the tree canopies can reduce the MRT around $10{\sim}16^{\circ}C$. 3. The regression test showed significant linear relationship between the SR and MRT. In summary, the performances of the landscaping shade trees were very good at screening the SR and reducing the MRT at the outdoor of summer middays. Therefore, it can be apparently said that the more shade trees or forest at the outdoor, the more effective in conditioning the outdoor space reducing the MRT and the useless SR for human activities in summertime.