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        검색결과 66

        41.
        2020.12 KCI 등재 서비스 종료(열람 제한)
        With global warming and the rapid increase in urbanization accompanied by a concentration of population, the urban heat island effects (UHI) have become an important environmental issue. In this study, rooftop greening and permeable asphalt pavement were selected as measures to reduce urban heat island and applied to a simple virtual urban environment to simulate temperature change using ENVI-met. A total of five measures were tested by dividing the partial and whole area application of each measure. The results showed that the temperature range of the base experiment is 33.11-37.11 ℃, with the UTCI comfort level described as strong heat and very strong heat stress. A case applied permeable asphalt has a greater temperature difference than a rooftop greening case, the larger the area where each condition was applied, the greater the temperature change was.
        42.
        2019.02 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to quantitatively analyze the effects of a restoration project on the decrease in the temperature in the surrounding areas. The thermal environment characteristics of the investigation area were analyzed using the meteorological data from the Busanjin Automatic Weather System which is closest to the target area. The terrain data of the modeling domain was constructed using a digital map and the urban spatial information data, and the numerical simulation of the meteorological changes before and after the restoration of the stream was performed using the Envi-met model. The average temperature of the target area in 2016 was 15.2℃ and was higher than that of the suburbs. The monthly mean temperature difference was the highest at 1.1℃ in November and the lowest in June, indicating that the temperatures in the urban areas were high in spring and winter. From the Envi-met modeling results, reductions in temperature due to stream restoration were up to 1.7℃ in winter, and decreased to 3.5℃ in summer. The effect of temperature reduction was seen in the entire region where streams are being restored.
        43.
        2018.09 KCI 등재 서비스 종료(열람 제한)
        Agricultural or rural landscape provides various ecosystem services. However, the ecosystem services function is declining due to various environmental problems such as climate change, land use change, stream intensification, non-point pollution and garbage. The A1B scenario predicts that the mean air temperature of South Korea will rise 3.8℃ degrees celsius in 2100. Agricultural sector is very vulnerable to climate change, so it must be thoroughly predicted and managed. In Korea, the facility horticulture complex is 54,051ha in 2016 and is the 3rd largest in the world(MAFRA, 2014). Facilities of horticultural complexes are reported to cause problems such as groundwater decrease, vegetation and insects diversity reduction, landscapes damage and garbage increase, compared with the existing land use paddy fields. Heat island phenomenon associated with climate change is also accelerated by the high heat absorption of horticultural sites. Therefore, we analyzed the heat island phenomenon occurring in the facility of horticultural complex in Korea. As an improvement measurement, I examined how much air temperature is reduced by putting the channel and the open space. In the case of the Buyeo area, the Computational Fluid Dynamics (CFD) simulation was analyzed for the average summer temperature distribution in the current land use mode at 38.9℃. As an improvement measurement, CFD simulation after 10% of 6m water channel was found to have an effect of lowering the summer temperature of about 2.7℃ compared with the present average of 36.2℃. In addition, CFD simulations after analyzing 10% of the open space were analyzed at 34.7℃, which is 4.2℃ lower than the present. For the Jinju area, CFD simulations were analyzed for the average temperature of summer at 37.8℃ in the present land use pattern. As an improvement measure, CFD simulations after 10% of 6m water channel were found to have an effect of lowering the summer temperature of about 2.6℃ compared to the current average of 35.2℃. In addition, CFD simulations after analyzing 10% of the open space were analyzed at 33.9℃, which is 3.9℃ lower than the present. It can be said that the effect of summer temperature drop in open space and waterway has been proven. The results of this study are expected to be reflected in sustainable agriculture land use and used as basic data for government - level policy in land use planning for climate change.
        44.
        2016.11 KCI 등재 서비스 종료(열람 제한)
        From December 2014 to November 2015, an automatic weather system (AWS) was installed over a wide road of Daegu to continuously measure meteorological factors and surface temperature. We investigated the effective operating period of the clean-road system using the daily maximum and minimum air and asphalt surface temperatures, with the aim of creating an optimum thermal environment. The clean-road system was installed over a part of the broad way of Dalgubul(Dalgubul-Daero) by Daegu Metropolitan City in 2011. Until now, the clean-road system has been operated from the middle of April to the end of September. We assumed that it was desirable that the clean-road system could be operated when the discomfort index was above 55. In conformity with the conditions, we concluded that the optimum operation period of the clean-road system is from the end of March to about the middle of October.
        45.
        2016.09 KCI 등재 서비스 종료(열람 제한)
        This study evaporative cooling system a heat wave climate change and reduction of the inside and outside thermal environment change research. Measurement items included micro meteorological phenomena and measured comfort indices. A micro meteorograph of temperature, relative humidity, surface temperature, and the comfort indices of WBGT, UTCI, and PMV were measured. The difference in inside and outside temperatures were compared for different land types, with the largest difference found in Type A (4.81℃), followed by Type B (4.40℃ ) and Type C (3.12℃). Relative humidity was about 10.43% higher inside due to water injection by the evaporative cooling system. Surface temperature was inside about 6.60℃ higher than the outside all types. WBGT were Type A (3.50℃) > Type B (2.71℃) > Type C (1.88℃). UTCI was low heat stress inside than outside all types. PMV was analysed Type C for inside predicted percentage of dissatisfied 75%, other types was percentage of dissatisfied 100% by inside and outside. Correlation analysis between land cover type and temperature, surface temperature, pmv, utci. T-test analysed inside and outside temperature difference was significant in all types of land.
        46.
        2016.02 KCI 등재 서비스 종료(열람 제한)
        This study reduced and built Street Canyons created by skyscrapers in order to verify effect of Street Canyons by green wall within the city centre and analysed influence factors on temperature reduction according to applicative types of green wall in the lab. Applicative types were divided into three types such as non- greening type(Case A), one-side greening type(Case B), both side greening type(Case C). The result of analysis of each types showed that average temperature of Case B and Case C is respectively 1.0℃ and 1.7℃ lower than Case A. The result of analysis of WBGT was that the highest temperature was given by Case A(40.2℃) and second one was from Case B(39.8℃) and third one was from (39.1℃) and in UTCI Case A records the highest temperature of 34.7℃ and Case B provided the second highest temperature of 33.9℃ and Case B gave the lowest temperature of 32.7℃. In PMV the highest temperature of 2.65 was from Case B and second one of 2.61 was from Case A and third one of 2.54 was from Case C. Duncan analysis of each types based on solar radiation and thermal comfort generated that there was analytical significance between Case A and Case B and Case B in terms of each types of average temperature reduction. The significance of thermal comfort in WBGT, MRT, PMV showed non-significance but, In UTCI it was analysed that there was significance between Case C and Case A.
        47.
        2015.10 KCI 등재 서비스 종료(열람 제한)
        To investigate the thermal environment over the summertime asphalt pavements, an automatic weather observation system was installed at a parking lot paved with asphalt to observe various meteorological parameters and surface temperature from July 1 to September 30, 2014. Since the number of rainy days in summer of 2014 particularly after the mid July is more than that of average data, a ratio of daily peak surface temperature above 45 ℃ was 28% which was lower than the average. The observational data about hourly average surface temperature and various heat balance factors at days where daily peak surface temperature is above 45 ℃ are as follows: An hour that had the daily maximum temperature was around 15 pm and the value was 49℃ approximately. Net shortwave radiation was the highest at 12pm as 800 W/m2 and much radiation of 500 W/m2 was absorbed at the ground between 11am and 17pm. Sensible heat that was delivered from the ground to the atmosphere was evaluated as 200 W/m2 between 10am and 19pm. underground transfer heat up to 100 W/m2 was measured as negative from 19pm to the next day 8am, which indicated the lower atmosphere was heated at night.
        48.
        2015.09 KCI 등재 서비스 종료(열람 제한)
        To investigate thermal environment and effect of clean-road system over a broad way, we conducted the filed meteorological observation during 12~13 August 2014. The clean-road system was employed over a part of the broad way of Dalgubul(Dalgubul-Daero) by Daegu Metropolitan city in 2011. The clean–road system in general is operated two times(4 am, 2 pm) during summertime. In case of scorching alert, the system is operated 3 times a day(4 am, 2 pm and 4 pm). To evaluate the present thermal condition and the improvement effects due to the system, we analyzed the time variation of discomfort index and WBGT(wet-bulb and globe temperature). WBGT was more than 25 during 8 a.m. ~ 9 p.m. And discomfort index was more than 75 during 8 a.m. ~ 11 p.m. The thermal improvement effect of the clean-road system was restrictive during daytime.
        49.
        2014.07 KCI 등재 서비스 종료(열람 제한)
          This study suggests plan of green space management based on the result of research apprehending the characteristic through sorting types of city thermal environment targeting summer which thermal pollution is the most serious. Considering anthropogenic heat, development level of wind road, thermal environment, as a result of types of thermal environment process, it is appeared 36 types, and 10 types is relevant of this research subject. Type Ⅰ-1, size of building is large, artificial covering area is wide, and thermal load of anthropogenic heat is high, typeⅡ-1, development condition of wind road is incomplete as Ⅱlevel, entering cold air is difficult and thermal management and improvement is needed area. Type Ⅲ-1, scale is large and it is area of origin of cold air, development level of wind road is mostly favorable, type Ⅲ-2 is revealed as smaller scale than Ⅲ-1, and small area of origin of cold air. Type Ⅳ, anthropogenic heat is 81~150 W/㎡, average, but development function of wind road is very favorable. Type Ⅴ, large area of thermal load and the origin of cold air are distributed as similar ratio, and level of development function of wind road is revealed as Ⅱ level. According to standard of type classification of thermal environment, as a result of suggesting plan of green space management and biotops area ratio, type Ⅰ-1 is buffer green space and waterway creation, goal biotops area ratio 35%, type Ⅱ-1 afforestation in site and goal biotops area ratio 40%, type Ⅲ-1, preservation plan to display the current function continuously is requested. Type Ⅳ suggests afforestation of stream current, and typeⅤ suggests quantitative increase of green space and goal biotops area ratio 45%.
        50.
        2014.02 서비스 종료(열람 제한)
        국내 공동주택은 내장재의 고급화, 가연물 증가, 초고층화 등으로 화재하중이 증가하고 있다. 이러한 화재하중의 증가는 화재시 열방출(heat release rate)을 증가하는 주요한 원인이 되며 화재위험성도 증가시킨다. 따라서 본 연구에서는 공동주택의 열 환경변화에 따른 화재안전대책을 마련하고자 한다. 1. 국내·외 모두 전체 화재 중 주거화재가 가장 큰 비율을 차지한다. 국내는 매년 전체 화재의 약 30%, 미국은 2008년 기준 전체 건물화재의 78.3%, 영국은 건물화재의 65%가 주거공간에서 발생하였다. 2. 공동주택의 열 환경에 영향을 미치는 중요한 인자에는 다양한 가전제품, 냉방 및 난방기기, 실내 장식물, 수납물, 불연성능이 떨어진 다양 종류의 마감재 등이 있다. 가전제품, 냉난방기기 등은 고에너지를 사용하는 기기로써 잠재화재위험성이 높으며 화재 시에 발열량 증가의 원인이 된다. 최근에는 열에너지가 많이 요구되는 제품으로 대형화되고 그 수요도 증가하고 있다. 또한 과거에 비해 더 많은 소비전력을 요구하여 열방출율이 높다. 또한 유류, 가스, 전기 등 열 공급의 방식에 따라 화재발생 mechanism이 달라지고 열방출율을 예측하기도 어렵다. 또한 각종 관련 제품에 따라 내재되어 있는 위험요소 및 열량의 차이로 화재하중이 달라질 수 있다. 공동주택의 마감재의 기준은 3층 이상이며 거실의 바닥면적 합계가 200 ㎡ 이상인 경우(5층 이상 시 500 ㎡) 거실부분 등의 마감재료로 불연재료 및 준불연재료를 사용하여야 한다. 불연재료는 불에 타지 않는 재료로 10분간 305℃에서 가열시 잔류 불꽃이 없으며 20분동안 750℃에서 가열 시, 열 발생이 적은 재료이다. 3. 화재안전대책 : 동일한 평형의 거주공간이라 할지라도 세대별 실내장식물 양, 마감재 물성, 가전제품의 내구연한의 차이 등으로 인해 잠재화재위험성이 달라 화재양상이나 규모를 예측하기 어렵다. 최근에는 고정 및 이동 하중 증가로 인하여 화재 시 다종, 다량의 연기 및 유해가스 등의 발생으로 가시도 확보가 곤란해져 인명피해도 증가하고 있다. 하지만, 주거공간에 가연물을 완전히 제거하는 것은 거의 불가능하므로 화재를 초기에 감지하여 진압하는 것이 매우 중요하다. 특히, 화재 초기에 화재 사실을 정확히 감지하여 통보하는 역할을 하는 감지기의 성능개선이 필요하다.
        51.
        2013.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        TRiplet Ionospheric Observatory-CubeSat for Ion, Neutron, Electron & MAgnetic fields (TRIO-CINEMA) is a CubeSat with 3.14 kg in weight and 3-U (10 × 10 × 30 cm) in size, jointly developed by Kyung Hee University and UC Berkeley to measure magnetic fields of near Earth space and detect plasma particles. When a satellite is launched into orbit, it encounters ultrahighvacuum and extreme temperature. To verify the operation and survivability of the satellite in such an extreme space environment, experimental tests are conducted on the ground using thermal vacuum chamber. This paper describes the temperature control device and monitoring system suitable for CubeSat test environment using the thermal vacuum chamber of the School of Space Research, Kyung Hee University. To build the chamber, we use a general purpose thermal analysis program and NX 6.0 TMG program. We carry out thermal vacuum tests on the two flight models developed by Kyung Hee University based on the thermal model of the TRIO-CINEMA satellite. It is expected from this experiment that proper operation of the satellite in the space environment will be achieved.
        52.
        2012.01 KCI 등재 서비스 종료(열람 제한)
        This study forecasts changes in thermal environment and microclimate change per new building construction and assignment of green space in urban area using Computational Fluid Dynamics(CFD) simulation. The analysis studies temperature, humidity and wind speed changes in 4 different given conditions that each reflects; 1) new building construction; 2) no new building construction; 3) green spaces; and 4) no green spaces. Daily average wind speed change is studied to be; Case 2(2.3 m/s) > Case 3. The result of daily average temperate change are; Case 3(26.5℃) > Case 4(24. 6℃) > Case 2(23.9℃). This result depicts average of 2.5℃ temperature rise post new building construction, and decrease of approximately 1.8℃ when green space is provided. Daily average absolute humidity change is analysed to be; Case 3(15.8 g/kg') > Case 4(14.1 g/kg') > Case 2(13.5 g/kg'). This also reveals that when no green spaces is provided, 2.3 g/kg' of humidity change occurs, and when green space is provided, 0.6 g/kg change occurnd 4(1.8 m/s), which leads to a conclusion that daily average wind velocity is reduced by 0.5 m/s per new building construction in a building complex.
        53.
        2011.09 KCI 등재 서비스 종료(열람 제한)
        In this study, thermal environment improvements throughout public design improvement project on the urban street space were compared and evaluated. Thermo-Render 3.0, 3D-CAD based thermal environment simulation program, had been used for thermal environment improvement evaluations. Followings are the results. First, clayey blocks which have low heat transfer rate and cool island effect by trees and roof gardens brought cooling effects for buildings and surface of streets. Seconds, MRT values showed low levels because of low radiant mulching materials. Thirds, roof gardens contributed to reduce heat island effect since HIP levels were affected by decreasing heat storage effect of buildings from roof gardens. As a result, reducing heat storage effect throughout selecting and arranging proper materials which would not increase heat island potentials should be performed to improve heat island effects.
        54.
        2011.07 KCI 등재 서비스 종료(열람 제한)
        In this study, thermal environment changes for a marathon course of IAAF World Championship, Daegu 2011 were modeled to provide improvements of thermal environment, so that runners could have the maximum condition and citizens pleasant streets. The three biggest size of intersections were selected for the study. Envi-met, 3G microclimate model, were used for a thermal environment analysis and three different cases - present status, planting roadside tree scenario, and roof-garden scenario - were compared. The followings are the results of the study. 1. The highest thermal distribution were shown at 1 p.m., but there was no significant difference between a thermal distribution at 1 p.m. and that at 5 p.m. since a heat flux from buildings affects thermal distributions rather than insolation does. 2. Tree planting or adding environmental friendly factors might lead a temperature drop effect, but the effect was not significant for areas covered with impermeability packing materials such as concrete or asphalt (especally, for Site case 2) 3. The combination of tree planting and adding environmental friendly factors also brought a temperature drop effect (Site 1 and 2) and this case showed even better result if green spaces (especially, parks) were closed.
        55.
        2010.10 KCI 등재 서비스 종료(열람 제한)
        In this study the AWS was installed in three areas to analyze creation and characteristics of local wind circulation through observation. According to the result, in night time when mountain wind is well developed showed temperature in A area located in Dalbigol valley and B area adjacent with the valley was lower than C area located in the lowland of the center of city by 1.5∼4℃. The wind speed was also shown two times stronger than C area. In addition, in terms of wind direction, A and B areas showed east wind consistently according to topographic shapes of Dalbigol valley with high altitude and residential sites of lowland with low altitude. Although the C area didn’t show big changes in wind direction due to the effects of city structures, east wind is often seen so mountain wind from Dalbigol valley is found to have an effect at least. Through the analysis of temperature, wind speed, and wind direction, nigh time showed relatively cold mountain wind blew following Dalbigol valley, throughout residential sites and to the center of city with lowland. During the daytime, the temperature in the city with lowland and residential sites is constantly higher than A area located in Dalbigol valley, and strong wind speed following Dalbigol valley, and three areas have 200∼300° of main wind direction, so west valley wind throughout the city with lowland and following Dalbigol is clearly formed.
        56.
        2010.09 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to be used as basic data of environmental friendly construction planning by comparing and analyzing thermal environment, find particles and biotope area rate according to land cover types of outside space of schools located in Chung-ju. When meteorological factors were analyzed according to land cover types, for temperature planting area and paved area showed low-and high-temperature ranges, respectively, and relative humidity was negatively related with temperature as low-and high-temperature ranges corresponded to high-and low-humidity ranges, respectively. For Wet Bulb Globe Temperature Index (WBGT) by land cover types, it was observed to be artificial grass> bare land> natural grass. Find particles were different according to land cover types of playground with being bare land> artificial grass> natural grass in the order. Bare land playground, where there were artificial factors and no absorption of fine particles through stomata of leaves as a function of natural circulation, recorded the highest level of 39.8 ㎍/㎥ and the level was relatively higher compared to the levels by season in Chung-ju. Biotope area rate showed the order of M elementary school> K elementary school> C commercial high school. That was considered to be caused by the difference of land cover type of school playground accounting for a large part of a school.
        57.
        2010.03 KCI 등재 서비스 종료(열람 제한)
        The present study explores time and spatial thermal environment for Daegu, which is a city built on a basin area, according to varying land cover conditions of the earth's surface by analyzing data derived from meteorological observation and satellite images. The study has classified land use by utilizing MODIS satellite images and analyzed land surface temperature. Also, by using data acquired from automatic weather system, the study has evaluated the effects of atmospheric heating caused by city pavements by analyzing the sensible heat flux between the city's land surface and the atmosphere.The results are as follows. 1) Classification of land use in the Daegu area shows 46.64% of urban and built-up area, 1.39% of watersides, 35.19% of forest, 11.43% of crops, and 5.37% grasslands. 2) During the weekdays throughout the year, the land surface temperature was high for Dalseogu, Bukgu, and Seogu regions where industrial complexes could be found. Comparatively, lower temperature could be observed in the woodlands. 3) While the land surface temperature displayed the effects of pushing air upwards during the weekdays in urban areas, the reverse was true for forest regions. During the night, the temperature did not exert any significant influence on air movement.
        58.
        2009.04 KCI 등재 서비스 종료(열람 제한)
        In recent years, the urban thermal environment has become worse, such as days on which the temperature goes above 30℃, sultry nights and heat stroke increase, due to the changes in terrestrial cover such as concrete and asphalt and increased anthropogenic heat emission accompanied by artificial structure. The land use type is an important determinant to near-surface air temperature. Due to these reasons we need to understand and improve the urban thermal environment. In this study, the fifth-generation Pennsylvania State University- National Center for Atmospheric Research Mesoscale Model(MM5) was applied to the metropolitan of Daegu area in order to investigate the influence of land cover changes and urban modifications increase of Albedo to the surface energy budget on the simulated near-surface air temperature and wind speed. The single urban category in existing 24-category U.S. Geological survey land cover classification used in MM5 was divided into 6 classes to account for heterogeneity of urban land cover. As a result of the numerical simulation intended for the metropolitan of Daegu assumed the increase of Albedo of roofs, buildings, or roads, the increase of Albedo (Cool scenario)can make decrease radiation effect of surface, so that it caused drops in ambient air temperature from 0.2 to 0.3 on the average during the daylight hours and smaller (or near-zero) decrease during the night. The Sensible heat flux and Wind velocity is decreased. Modeling studies suggest that increased surface albedo in urban area can reduce surface and air temperatures near the ground and affect related meteorological parameters such as winds, surface air temperature and sensible heat flux.
        59.
        2006.12 KCI 등재 서비스 종료(열람 제한)
        난분 함수량에 따른 생육반응에서 건중에 비해 생체중의 변화가 현저하였다. 특히 난분 함수량이 0%± 5인 C point는 100%± 5인 A point에 비해 16.1g에서 4.7g으로 지하부의 생체중 감소가 매우 격감하였으나, 지상부의 생체중에서는 3.5g에서 2.1g으로 다소 감소하는 경향을 볼 수 있었다. 건중에서는 현저한 차이를 볼 수 없었다. 또한 엽록소와 총수용성 탄수화물(Total soluble carbohydrate)에서 용토 내의 함수량에 따른 현저한 차이를 볼 수 있었으나, 지상부와 지하부에 따른 다른 현상을 볼 수 있었다. 체내 총수용성 탄수화물량의 변화를 살펴보면, 지상부는 난분 내의 함수량이 0%± 5의 C point시점에서 0.2mg/g DW로 다소 감소함을 알 수 있었으나, 근권부에서는 100%± 5인 A point에서 0.14mg/g DW에 비해 50%± 5(B point) 그리고 0%± 5(C point)의 시점에서 0.22mg/g DW로 보다 증가함을 알 수 있었다. 난분 함수량에 따른 proline 축적량 변화는 100%± 5인 A point에 0.05mg/g FW 비해 0%± 5인 C point의 시점에서 0.6mg/g FW로 큰 변화를 볼 수 없었다. 한편, glycinebetaine에서는 지상부에서는 변화가 없었으나, 근권부인 뿌리에서 함수량이 100%± 5(A point)의 0.11mg/g DW에서 0%± 5인 C point의 시점에서 0.26mg/g DW로 2배의 증가를 불 수 있었다.
        60.
        2005.02 KCI 등재 서비스 종료(열람 제한)
        Thermal neutrality is not enough to achieve thermal comfort. The temperature level can be the optimal, and still people may complain. This situation is often explained by the problem of local discomfort. Local discomfort can be caused by radiant asymmetry, local air velocities, too warm and too cold floor temperature and vertical temperature difference. This temperature difference may generate thermal discomfort due to different thermal sensation in different body parts. Therefore, thermal comfort can not be correctly evaluated without considering these differences. This study investigates thermal discomfort sensations of different body parts and its effect on overall thermal sensation and comfort in air-heating room. Experimental results of evaluating thermal discomfort at different body parts in an air-heating room showed that thermal sensation on the shoulder was significantly related to the overall thermal sensation and discomfort. Although it is known that cool-head, warm-foot condition is good for comfort living, cool temperature around the head generated discomfort
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