• Title/Summary/Keyword: heat islands

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Virtual Machine Placement Algorithm for Saving Energy and Avoiding Heat Islands in High-Density Cloud Computing Environment (고밀도 클라우드 컴퓨팅 환경에서 에너지 절감 및 열섬 방지를 위한 가상 머신 배치 알고리즘)

  • Choi, JungYul
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.10
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    • pp.1233-1235
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    • 2016
  • It is desirable to place virtual machines for minimizing the number of operational servers in order to save energy in high-density cloud computing environment. However, the compacted servers can incur heat islands. This paper firstly finds out the relationship between the server utilization by the virtual machine placement and the energy consumption of servers and heat from servers. Then, this paper proposes a virtual machine placement algorithm to save energy consumed and avoid heat islands.

Urban Heat Islands in Seoul during the Summertime of 2003 (2003년 여름철 서울의 도시열섬)

  • Kim Yeon-Hui;Eom Hyang-Hui;O Seong-Nam;Kim Sang-Baek
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.503-503
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    • 2003
  • Urban heat islands related with Cheongyecheon restoration in Seoul metropolitan area for the summertime of 2003. To investigate the spatial and temporal structure of the urban heat island in Seoul, temperature data measured at 32 automatic weather stations (AWSs) in the Seoul metropolitan area and 12 additional stations operated by the portable device for the measurement of temperature and relative humidity in the Cheonggyecheon area. (omitted)

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Using ASTER TIR imagery to identify Heat Islands: A case study of New Jersey (ASTER 열적외선 이미지를 이용한 열섬 현상 탐지: 뉴저지를 사례로)

  • Park, Gwang yong;David W. Gwynn;David A. Robinson
    • Proceedings of the KGS Conference
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    • 2004.05a
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    • pp.56-56
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    • 2004
  • The ability to detect urban heat islands in satellite imagery is a function of spatial, spectral, and temporal resolutions. Imagery from the satellite-mounted Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor acquired since December 1999 allows us to view the Earth at a higher spectral resolution in the thermal infrared (TIR) portion of the electromagnetic spectrum than most other satellite systems (e.g., AVHRR, Landsat TM). (omitted)

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Spatial Distribution of Urban Heat and Pollution Islands using Remote Sensing and Private Automated Meteorological Observation System Data -Focused on Busan Metropolitan City, Korea- (위성영상과 민간자동관측시스템 자료를 활용한 도시열섬과 도시오염섬의 공간 분포 특성 - 부산광역시를 대상으로 -)

  • HWANG, Hee-Soo;KANG, Jung Eun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.23 no.3
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    • pp.100-119
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    • 2020
  • During recent years, the heat environment and particulate matter (PM10) have become serious environmental problems, as increases in heat waves due to rising global temperature interact with weakening atmospheric wind speeds. There exist urban heat islands and urban pollution islands with higher temperatures and air pollution concentrations than other areas. However, few studies have examined these issues together because of a lack of micro-scale data, which can be constructed from spatial data. Today, with the help of satellite images and big data collected by private telecommunication companies, detailed spatial distribution analyses are possible. Therefore, this study aimed to examine the spatial distribution patterns of urban heat islands and urban pollution islands within Busan Metropolitan City and to compare the distributions of the two phenomena. In this study, the land surface temperature of Landsat 8 satellite images, air temperature and particulate matter concentration data derived from a private automated meteorological observation system were gridded in 30m × 30m units, and spatial analysis was performed. Analysis showed that simultaneous zones of urban heat islands and urban pollution islands included some vulnerable residential areas and industrial areas. The political migration areas such as Seo-dong and Bansong-dong, representative vulnerable residential areas in Busan, were included in the co-occurring areas. The areas have a high density of buildings and poor ventilation, most of whose residents are vulnerable to heat waves and air pollution; thus, these areas must be considered first when establishing related policies. In the industrial areas included in the co-occurring areas, concrete or asphalt concrete-based impervious surfaces accounted for an absolute majority, and not only was the proportion of vegetation insufficient, there was also considerable vehicular traffic. A hot-spot analysis examining the reliability of the analysis confirmed that more than 99.96% of the regions corresponded to hot-spot areas at a 99% confidence level.

Dark-field Transmission Electron Microscopy Imaging Technique to Visualize the Local Structure of Two-dimensional Material; Graphene

  • Na, Min Young;Lee, Seung-Mo;Kim, Do Hyang;Chang, Hye Jung
    • Applied Microscopy
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    • v.45 no.1
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    • pp.23-31
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    • 2015
  • Dark field (DF) transmission electron microscopy image has become a popular characterization method for two-dimensional material, graphene, since it can visualize grain structure and multilayer islands, and further provide structural information such as crystal orientation relations, defects, etc. unlike other imaging tools. Here we present microstructure of graphene, particularly, using DF imaging. High-angle grain boundary formation wass observed in heat-treated chemical vapor deposition-grown graphene on the Si substrate using patch-quilted DF imaging processing, which is supposed to occur by strain around multilayer islands. Upon the crystal orientation between layers the multilayer islands were categorized into the oriented one and the twisted one, and their local structure were compared. In addition information from each diffraction spot in selected area diffraction pattern was summarized.

Fragmented Urban Heat Islands in Seoul, Korea (분절화된 서울의 도시 열섬 현상)

  • Park, Gwangyong;Kwon, Won-Tae;David A. Robinson
    • Proceedings of the KGS Conference
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    • 2004.05a
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    • pp.48-48
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    • 2004
  • A fragmented urban heat island is observed over the Seoul metropolitan area. Long-term (1996-2003) hourly temperature, wind speed and direction, and precipitation data observed at 26 (51) automatic weather stations (AWS) in Seoul (Gyeonggi prevince) makes it possible to reveal more dynamic spatial and temporal patterns of the urban heat island in this area than previously revealed. (omitted)

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Influence of New Town Development on the Urban Heat Islands - ln the Case of Pan-Gyo Area and Bun-Dang New Town - (신도시 개발이 도시열섬 형성에 미치는 영향 - 분당신도시와 판교지역을 중심으로 -)

  • 송영배
    • Journal of the Korean Institute of Landscape Architecture
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    • v.30 no.4
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    • pp.37-46
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    • 2002
  • The main purpose of this research is to discuss the urban heat island which will be caused by urbanization, especially by the construction of new town on a wide green zone. Over the last ten years, five new towns have been developed around the Seoul metropolitan area. However these new towns become bedroom communities and create traffic problems between Seoul and its surrounding areas because of an increase in population and a lack of roads and other infrastructures. The construction of another such new town is under consideration in the Pan-gyo area. But it is important that Pan-gyo remains a wide green zone. Many studies show that green space can play an important role in improving urban eco-meteorological, ameliorative capability and air hygiene. The objective of this study is to analyze the urban heat islands of Bund-Dang Si which was constructed in 1996 and of the Pan-Gyo area planned as new town. To investigate the local thermal environment and its negative effects caused by change of the land use type and urbanization we used LANDSAT TM images for extraction of urban surface temperature according to change of land use over 15 years. These data were analyzed together with digital land use and topographic data. As a study result, we found that the thermal island of this area from 1985 to 1999 rapidly increased with a difference of mean temperature of more than 12'E. Before construction of Bun-Dang Si the temperature of this area was the same as the forest, but during the new town construction in 1991, an urban heat island developed. The temperature of forest with a size of over 50% of the investigation area was lowest, which leads us to conclude that the forest cools the urban and its surroundings. The mean temperature of the residential and commercial area is more than +4.5$^{\circ}C$ higher then forest, so this method of land use is the main factor increasing the urban heat island. Urban heat islands and green space play an important role in urban wind systems, i.e. Thermal Induced Air Exchange and Structural Wind Circulation, because of their special properties with regard to energy balance between constructed urban and land. The skill to allocate land use types in urban areas is a very important planning device to reduce air pollution and induce the fresh cold air from green space. An urban climatic experiment featuring a numerical wind simulation study to show the air corridor will be published in a following research paper.

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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Study on Energy Saving Properties by using City- Water as a Heat Source for Dwellings

  • Chung, Yong-Hyun;Mizuno, Minoro;Simoda, Yoshiyuki;Kum, Jong-Soo;Choi, Kwang-Hwan
    • International Journal of Air-Conditioning and Refrigeration
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    • v.6
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    • pp.168-176
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    • 1998
  • A simulation study was conducted to use city-water which is thermally regulated by unused energy as a heat source for urban dwellings. This study utilized multiple heat pump system using the city-water as a heat source and suggested a method of reducing the heat load of hot water supply. The simulation was done to calculate the energy savings at a dwelling for a year. The relation between the controlled temperature of city-water. and electric energy in all seasons was also investigated. Furthermore, it has been found that the controlled water system can lead to considerable energy savings and decrease environmental load such as sensible waste heat which otherwise would form heat islands.

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Recruitment characteristics of jack mackerel, Trachurus japonicus, in the waters around the Geumo Islands by using both sides fyke nets (각망을 이용한 금오열도 주변해역 전갱이의 연안가입특성 연구)

  • Kim, Hee-Yong;Choi, Mun-Seong;Seo, Young-Il;Lee, Sun-Kil;Cha, Hyung-Kee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.4
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    • pp.356-368
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    • 2011
  • Species composition of fishes and the recruitment properties of jack mackerel, Trachurus japonicus, in the waters around the Geumo Islands in the mid-South Sea were investigated by using both sides fyke nets every month from February to December 2010. During study period, a total of 30,503 fishes (1,380.4 kg) were collected and classified into 2 classes, 16 orders, 61 families and 121 species. The dominant species was jack mackerel occupying 80.5% of total individuals and 44.4% of total biomass. The fork length range of jack mackerel was 5.5-26.8 cm and individuals about 6 cm was appeared only in the middle and southern area of the Geumo Islands in May. The new recruitment of jack mackerel appeared from May in the waters around the Geumo Islands is probably caused by the warm water intrusion associated with the development of stratification due to the extinction of seasonal coastal cold waters by the increase of solar radiation heat. Furthermore, the jack mackerels less than 6 cm recruiting in the mid-South Sea in spring were considered as mixed ones by individuals spawned in the East China Sea and in the waters around the Jeju Island considering the collected time, migration period and spawning time of them.