• Title/Summary/Keyword: Thermal Island

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Analysis on Urban Heat Island Effects for the Metropolitan Green Space Planning (광역적 녹지계획 수립을 위한 도시열섬효과 분석)

  • Park, Kyung-Hun;Jung, Sung-Kwan
    • Journal of the Korean Association of Geographic Information Studies
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    • v.2 no.3
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    • pp.35-45
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    • 1999
  • The research is to examine urban heat island effects which is resulted from urbanization using thermal infrared band of Landsat TM data and to demonstrate heat island alleviation effects of green spaces through correlation analysis of NDVI(Normalized Difference Vegetation Index) and surface temperature. According to the results, forests which are covered with natural vegetation have a high NDVI digital values, but surface temperature is very low, and urban areas which is composed of artificial paving materials have a low NDVI, surface temperature increases gradually. In summary, the analysis of relationship between NDVI and surface temperature, used in this study, is regarded as one of effective methodologies for proving heat island alleviation effects of vegetation.

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A Study on the Micro-climate of the City to Construct Wind Ways (바람길 조성을 위한 도시미기후 측정 분석)

  • Jeon, Ji-Hyeon;Park, Seok-Bong
    • Journal of the Korean Solar Energy Society
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    • v.25 no.4
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    • pp.111-118
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    • 2005
  • The purpose of this study is to address the progress of the heat island phenomenon and the scheme to decrease in heat island phenomenon through analysis of micro-climates according to land use and make a plan to construct wind ways. The result is: 1) Analysis of temperature and humidity at 6 spots for 24 hours showed that heat island phenomenon was considerably intense around center road of Gwangju and can be mild through making lakes and green zones. 2) Analysis of the direction and velocity of the wind at 2 spots for 24 hours showed that the direction of the wind at the center of Gwangju was SSW(South-South-West) and average velocity of the it was $1.2{\sim}1.5\;m/s$. To make the inflow of the low-temperature air current from Mt. Mudeung into the city through Gwangju river, efficient management of Gwangju riverside parks should be considered for Gwangju river itself to be wind way. 3) Analysis of mobile temperature measurement on 3 courses for 24 hours showed that the low-temperature air current of Mt. Mudeung and a micro-climate of Gwangju river can lighten thermal storage phenomena of the city in that the temperature was lowest at Gwangju riverside. These outcome is from a day term measurement. So, to figure out accurate condition of heat island phenomenon in Gwangju City, it is needed to have long term measurements and accumulation of those information.

VARIATIONS OF SEA SURFACE TEMPERATURE BETWEEN JEJU AND MOGPO AND BETWEEN JEJU AND WANDO (제주와 목포, 제주와 완도간의 표면수온 변화)

  • Rho, Hong Kil;Kim, Kuh
    • 한국해양학회지
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    • v.18 no.1
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    • pp.64-72
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    • 1983
  • A series of sheps-of-opportunity sea sryface temperature (SST) measurement beween Jeju and Wando during a period from December 1979 through June 1981 produced following results. 1. A sihnificantly warm water appeared south of Chuja Island and Cheongsan Island during Island. It is suggested that this water represents a current entering the Jeju Strait from the west. Direction of this currint in other seasons is not certain. 2. Coastal waters were found north of the Cheongsan Island and Bogil Islhnd throughout the measurement period. In February these waters sometimes reached as far as Chuja Island to south. 3. Frequently thermal fronts were observed near the Chuja Island and the Cheongsan Island. 4. In summer cold waters appeared north of the Chuja Island and Changsu Island. Intrusion of cold bottom water from offshore and its subsequent vertical mixing due to strong tidal current are probably reponsible for this appearance. 5. Cold waters also appeared locally around islands and in ghe Jeju Harbor in spring and summer. 6. North-south SST difference reached 8-9$^{\circ}C$ in winter which is the annual maximum. 7. Annual range of SST varies from 12-14$^{\circ}C$ in the central part of the Jeju Strait to 16-20$^{\circ}C$ in coastal waters to north. The highest SST appeared everywhere in September but the lowest one did not appesr in the same month of year.

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Study on Estimation of Urban Anthropogenic Heat Generation (도시의 인공열 산정에 관한 연구)

  • 손은하;김유근;홍정혜
    • Journal of Korean Society for Atmospheric Environment
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    • v.16 no.1
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    • pp.37-47
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    • 2000
  • The Urban thermal environment is influenced and modified in many ways. One modification is brought by the anthropogenic heat generation emitted from the combustion processes and the use of energy such as industrial, domestic and traffic procedure. The anthropogenic heat generation affect an the increase of urban temperature, the well-known urban heat islands. The study on the urban thermal environment needs a great deal of the statistic data about the inner-structure of urban, the contribution of different constructions and the traffic amount on urban thermal environment in finite region. In order to overtake a quantitative analysis of effect of the anthropogenic heat, a distribution map of the urban anthropogenic heat was made using hte data of the energy consumption used at the several constructions and traffic amount of vehicles in Pusan Metropolitan. Annual mean heat flux over the 4$\textrm{km}^2$ urbanized area in Pusan is 41.5W/$m^2$, ranging from 31.4W/$m^2$ in summertime to 59.5W/$m^2$ in wintertime and maximum diurnal anthropogenic heat generation is corresponding to 10% of irradiance during summertime.

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Thermal Stability Improvement of Nickel-Silicide using PAI in the N-type Substrate (N-type 기판에서 PAI에 의한 Nickel-Silicide의 열안정성 개선)

  • 윤장근;지희환;오순영;배미숙;황빈봉;박영호;왕진석;이희덕
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.675-678
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    • 2003
  • 본 논문에서는 N-type 기판에서 Nickel-Silicide를 적용하였을 경우에 나타나는 문제점과 PAI (Pre-amorphization Implant)의 효과에 대하여 알아보았다. N-type 기판에 RTP (Rapid Thermal Process)를 통하여 Nickel-Silicide 를 형성하게 되는데, 여기까지는 안정한 Nickel mono-Silicide (NiSi)가 형성됨을 확인하였다. 하지만 후속 열처리 공정 후 심한 응집 현상 (Agglomeration)과 이상 산화 현상 (Abnormal Oxidation Phenomenon), Silicide Island 등 열안정성 (Thermal Stability) 측면에서 여러 가지 많은 문제점들이 나타났다. 이 후속 열처리의 열안정성 취약점들을 극복하는 방안으로 Ge 및 N₂ PAI를 적용하였다. PAI를 적용하였을 경우에는 그렇지 않은 경우에 비하여 고온 열처리 후에도 면저항이 비교적 잘 유지되었으며, 두께가 얇고 안정한 Nickel-Silicide 특성을 확보할 수 있었다. 특히 Ge PAI 에 비하여 N₂ PAI 의 경우가 보다 특성 개선 효과가 크게 나타났다.

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The Research of Planning Method of Adaption for Old Residential Neighborhoods According to Heat wave and Urban Heat-island Phenomena - Focused on Gun-Ja Dong, Gwang-Jin Gu - (폭염 및 도시열섬현상에 따른 노후 주거지의 적응 계획기법에 관한 연구 - 광진구 군자동 중심으로 -)

  • Kim, Min-Young;Moon, Eun-Seol
    • KIEAE Journal
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    • v.16 no.4
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    • pp.31-39
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    • 2016
  • Purpose: Urban heat island and Heat wave raise urban temperature and create damage of human life. Growing up as quantitative supply to solve shortage of housing, Urban residential area in Korea have a low rate of nature surface and heavily population makes temperature rise. Most houses in the declined residential area are multi-family rental housing and have many factors congesting housing environment such as narrow in-between space, outdoor staircases, walls and semi-basement floor, which make thermal environment getting worse. Most of the residents in this area are small tenants vulnerable to climate change adaptation, This damage is expected to be even greater. This study focus on multiple dwelling in urban residential area prone to temperature rise and draw temperature adaption method that can apply to multiple dwelling.

Analyzing Change of Discomfort Index for Transpiration of Street Tree (도시 가로수의 증산 작용으로 인한 불쾌지수 변화 분석)

  • Yun, Seok-Hwan;Lee, Dong-Kun;Park, Chae-Yeon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.23 no.5
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    • pp.29-43
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    • 2020
  • Thermal environment of city is getting worse due to severe urban heat island caused by climate change and urbanization. The cooling effect of street tree is regarded as a effective way to ameliorate the urban heat environment. The effect is largely made up of shadow formation and transpiration. This study aims to identify how the transpiration affects the discomfort index by analyzing comprehensive impact of the transpiration on the air temperature and relative humidity. The changes in the amount of transpiration, air temperature, and relative humidity were estimated for Seogyo-dong area which has a lot of floating population in Seoul, at 2 p.m. in dry day in July and August. On average, the transpiration of the street tree decreased the temperature 0.3℃ and increased the relative humidity 2.6% in an hour. As a result of these changes in temperature and humidity, the discomfort index rose mostly(0.036 on average). It was always get rise especially on the day when the discomfort index was above 80(0.05 on average). However, compared with the significant change in temperature and humidity, the variation of the discomfort index itself was very slight(up to 0.107). Therefore, the effect of transpiration by the street trees might not be effective in the planning to improve the thermal environment(especially on the day when the discomfort index is high). It is necessary to select the species of trees and planting location considering the cooling effect of shade formation synthetically.

A Study on the Classification Criteria of Climatic Zones in Korean Building Code Based on Heating Degree-Days (난방도일 기반 대한민국 행정구역별 기후존 구분 기준 정립에 관한 연구)

  • Noh, Byeong Il;Choi, Jaewan;Seo, Donghyun
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.11
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    • pp.574-580
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    • 2015
  • Climatic zone in building code is an administrative district classification reflecting regional climatic characteristics. Use of Degree-Days is a fundamental method that can be used in various building design codes, analysis of building energy performance, and establishment of minimum thermal transmittance of building envelopes. Many foreign countries, such as the USA, the EU, Australia, Italy, India, China, etc., have already adapted climatic zone classification with degree-days, precipitation or amount of water vapor based on the characteristics of their own country's climate. In Korea, however, the minimum requirements for regional thermal transmittance are classified separately for the Jungbu area, Nambu area and Jeju Island with no definite criterion. In this study, degree-days of 255 Korean cities were used for climatic zone classification. Outdoor dry-bulb temperature data from the Korea Meteorological Administration for 1981~2010 was used to calculate degree-days. ArcGIS and the calculated degree-days were utilized to analyze and visualize climatic zone classification. As a result, depending on the distribution and distinctive differences in degree-days, four climatic zones were derived : 1) Central area, 2) Mountain area of Gyeonggi and Gangwon provinces, 3) Southern area, and 4) Jeju Island. The climatic zones were suggested per administrative district for easy public understanding and utilization.

Analysis of Temperature Change by Forest Growth for Mitigation of the Urban Heat Island (도시열섬 완화를 위한 녹지증가에 따른 온도변화 분석)

  • Yun, Hee Cheon;Kim, Min Gyu;Jung, Kap Yong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.31 no.2
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    • pp.143-150
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    • 2013
  • Recently, environmental issues such as climate warming, ozone layer depletion, reduction of tropical forests and desertification are emerging as global environmental problems beyond national problems. And international attention and effort have been carried out in many ways to solve these problems. In this study, the growth of green was calculated quantitatively using the technique of remote sensing and temperature change was figured out through temperature extraction in the city. The land-cover changes and thermal changes for research areas were analyzed using Landsat TM images on May 2002 and May 2009. Surface temperature distribution was calculated using spectral degree of brightness of Band 6 that was Landsat TM thermal infrared sensor to extract the ground surface temperature in the city. As a result of research, the area of urban green belt was increased by $2.87km^2$ and the ground surface temperature decreased by $0.6^{\circ}C{\sim}0.8^{\circ}C$ before and after tree planting projects. Henceforth, if the additional study about temperature of downtown is performed based on remote sensing and measurement data, it will contribute to solve the problems about the urban environment.

Study on Field Observations of the Thermal Environment in the Downtown Location and the Outskirt Site (하절기 도심과 외곽지의 열특성 비교 관측)

  • Jung, Im-Soo;Choi, Dong-Ho;Lee, Bu-Yong
    • 한국태양에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.21-25
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    • 2009
  • This study is about heat island as one of the urban climate variation factors in urbanized modern society, which compared and observed the thermal characteristics both the downtown location and the outskirt site in summer. The diurnal air temperature range at each point is $12.6^{\circ}C$ in the downtown location and $14.3^{\circ}C$ in the outskirt site, so, it was found that the diurnal air temperature range in the outskirt site was $1.7^{\circ}C$ higher than in the downtown location. There was 20 minutes difference to reach the highest temperature between globe temperature and air temperature in the downtown location, however, the time spent to reach the highest temperature between globe temperature and air temperature in the outskirt site was the same. When we compared the globe temperature between the downtown location and outskirt site, we found that the temperature in the outskirt site was lower than in the downtown location after sunset due to the sudden temperature drops, although the exposed time to insolation in the outskirt site is longer. The average of globe temperature difference on the sample days was $1.1^{\circ}C$, the average of surface temperature difference on the sample days was $1.0^{\circ}C$, and the average of air temperature difference on the sample days was $2.0^{\circ}C$ Thus, it was found that the average of air temperature difference was higher than the average of globe temperature and the average of surface temperature. The result of this study is that the urban environment factors have more effect on the air temperature difference than globe temperature and surface temperature.

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