• 제목/요약/키워드: CHANGE OF TEMPERATURE

검색결과 10,052건 처리시간 0.039초

통합모델을 이용한 토지피복변화와 도시 모수화 방안에 따른 지상 기온 모의성능 민감도 분석 (Sensitivity Analysis of Near Surface Air Temperature to Land Cover Change and Urban Parameterization Scheme Using Unified Model)

  • 홍선옥;변재영;박향숙;이영곤;김백조;하종철
    • 대기
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    • 제28권4호
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    • pp.427-441
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    • 2018
  • This study examines the impact of the urban parameterization scheme and the land cover change on simulated near surface temperature using Unified Model (UM) over the Seoul metropolitan area. We perform four simulations by varying the land cover and the urban parameterization scheme, and then compare the model results with 46 AWS observation data from 2 to 9 August 2016. Four simulations were performed with different combination of two urban parameterization schemes and two land cover data. Two schemes are Best scheme and MORUSES (Met Office Reading Urban Surface Exchange Scheme) and two land cover data are IGBP (International Geosphere and Biosphere Programme) and EGIS (Environmental Geographic information service) land cover data. When land use data change from IGBP to EGIS, urban ratio over the study area increased by 15.9%. The results of the study showed that the higher change in urban fraction between IGBP and EGIS, the higher the improvement in temperature performance, and the higher the urban fraction, the higher the effect of improving temperature performance of the urban parameterization scheme. 1.5-m temperature increased rapidly during the early morning due to increase of sensible heat flux in EXP2 compared to CTL. The MORUSES with EGIS (EXP3) provided best agreement with observations and represents a reasonable option for simulating the near surface temperature of urban area.

제주계통의 기온변화 민감도를 반영한 주말 전력수요예측 (A Study on the Weekend Load Forecasting of Jeju System by using Temperature Changes Sensitivity)

  • 정희원;구본희;차준민
    • 전기학회논문지
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    • 제65권5호
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    • pp.718-723
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    • 2016
  • The temperature changes are very important in improving the accuracy of the load forecasting during the summer. It is because the cooling load in summer contribute to the increasing of the load. This paper proposes a weekend load forecasting algorithm using the temperature change characteristic in a summer of Jeju. The days before and after weekends in Jeju, when the load curves are quite different from those of normal weekdays. The temperature change characteristic are obtained by using weekends peak load and high temperature data. And load forecasted based on the sensitivity between unit temperature changes and load variations. Load forecast data with better accuracy are obtained by using the proposed temperature changes than by using the ordinary daily peak load forecasting. The method can be used to reduce the error rate of load forecast.

우유의 열처리가 우유품질과 영양가에 미치는 영향: III. 우유 열처리에 의한 병원균 사멸효과 (Effects of Heat Treatment on the Nutritional Quality of Milk III. Effect of Heat Treatment on Killing Pathogens in Milk)

  • 문용일;정지윤;오세종
    • Journal of Dairy Science and Biotechnology
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    • 제35권2호
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    • pp.121-133
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    • 2017
  • A small amount of milk is sold as 'untreated' or raw in the US; the two most commonly used heat-treatments for milk sold in retail markets are pasteurization (LTLT, low-temperature long time; HTST, high-temperature short time) and sterilization (UHT, ultra-high temperature). These treatments extend the shelf life of milk. The main purpose of heat treatment is to reduce pathogenic and perishable microbial populations, inactivate enzymes, and minimize chemical reactions and physical changes. Milk UHT processing combined with aseptic packaging has been introduced to produce shelf-stable products with less chemical damage than sterile milk in containers. Two basic principles of UHT treatment distinguish this method from in-container sterilization. First, for the same germicidal effect, HTST treatments (as in UHT) use less chemicals than cold-long treatment (as in in-container sterilization). This is because Q10, the relative change in the reaction rate with a temperature change of $10^{\circ}C$, is lower than the chemical change during bacterial killing. Based on Q10 values of 3 and 10, the chemical change at $145^{\circ}C$ for the same germicidal effect is only 2.7% at $115^{\circ}C$. The second principle is that the need to inactivate thermophilic bacterial spores (Bacillus cereus and Clostridium perfringens, etc.) determines the minimum time and temperature, while determining the maximum time and temperature at which undesirable chemical changes such as undesirable flavors, color changes, and vitamin breakdown should be minimized.

$\gamma$-알루미나/KCl 수용액의 전기 이중층에서 계면 물성 (Interfacial Properties of $\gamma-Alumina/KCI^{(ag)}$ Electrical Double Layer)

  • 홍영호;함영민;장윤호
    • 한국세라믹학회지
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    • 제31권6호
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    • pp.678-684
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    • 1994
  • The surface of alumina is capable of acquiring a change when it is in an aqueous solution. This surface change will have a strong influence on the surrounding ions, particularly those of opposite change known as the counter ions. A site-binding model of the {{{{ gamma }}-alumina/KCl(aq) interface was used to calculated theoretical surface ionization constants and P.Z.C.(Point of zero change) of {{{{ gamma }}-alumina. This paper was carried out to investigate the effect of calcination temperature on the acidic and electrical properties of pure {{{{ gamma }}-alumina prepared by the precipitation method from the Al(NO3)3.9H2O and NH4OH. From the experimental data it was shown that {{{{ gamma }}-alumina have a mainly Br nsted acid site. However, the acidity of {{{{ gamma }}-alumina decreased with increasing calcination temperature at strength Ho +9.3. The surface charge density of {{{{ gamma }}-alumina was increased with electrolyte ionic strength and calcination temperature.

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3D 프린팅을 활용한 재료조합에 따른 온습도 변화 분석 (Analysis of Changes in Temperature and Humidity by Material Combination Using 3D Printing)

  • 이희란;김소영;이예진;이옥경
    • 한국의류산업학회지
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    • 제24권1호
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    • pp.127-137
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    • 2022
  • Recently, various clothing items are being developed using 3D printing technology, but comfort has become an issue while wearing them for a long time. Therefore, this study researched on how the temperature and humidity of the devices developed by 3D printing change depending on the material combination. Five types of material combinations (EVA foam, TPU density 10%, TPU density 30%, EVA foam+TPU density 10%, and EVA foam+TPU density 30%) were selected as variables, and the experiment was conducted for two different cases with and without a cover. All the ten types of samples were placed on the hot plate set at 36℃, and the surface temperature and humidity were measured at three different points for 10 minutes. As a result, the case with only TPU showed the greatest temperature change while the case with 100% EVA foam showed the least temperature change. The humidity of the surface layer gradually decreased with time for 100% EVA foam. For the case with TPU materials, the moisture was transferred to the surface layer at first, thereby increasing the humidity but then dropped significantly. Meanwhile, the cases with the cover on showed similar tendencies of change in both temperature and humidity where the overall temperature and humidity delivery were slow.

CFRP로 보강된 콘크리트 보의 온도 변화에 따른 영향 분석 (Analysis of Effects on Concrete Beam Strengthened with CFRP Plate according to Temperature Change)

  • 조홍동;한상훈;이승수;신진환
    • 한국안전학회지
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    • 제18권2호
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    • pp.79-85
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    • 2003
  • In this study, the behavior characteristics of specimen strengthened with CFRP plate were analyzed according to the change of temperature. CFRP plate itself has a good resistance at the high temperature, but epoxy used as a adhesive is lost its bonding strength at the relatively low temperature. Therefore, this study carries out experiment on the beams slot-bonded with CFRP plates in order to maintain the successful bonding strength of epoxy at high temperature. It is presented that the range of glass transition temperature is 60-8$0^{\circ}C$ and RC beams slot-bonded with CFRP plate shows more increasing resistance and failure load than that of interface bonded at the high temperature.

Estimation of Sea Surface Temperature Change by Tide Embankment Construction

  • Shin Dong-hoon;Lee Kyoo-seock
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.146-148
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    • 2005
  • This study investigates to detect sea surface temperature (SST) and land cover change after tide embankment construction using Landsat Thematic Mapper (TM) thermal infrared (TIR) band data at Shihwa Lake and surrounding area. SST measurement is important for studies of both the structure of the ocean and as the thermal boundary between the ocean and the atmosphere. The TIR band of TM images can be used to detect SST change whose shoreline is complicated and narrow like the study site. The purpose of this study is to estimate SST and land cover change at Shihwa Lake and surrounding area.

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Analyzing the correlation between urban forestry and surface temperature using Landsat TM data

  • Jo, Myung-Hee;Kim, Sung-Jae;Lee, Kwang-Jae
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.905-907
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    • 2003
  • In this study, the correlation between the heat island effect and the vegetation in Deagu Korea was performed through using Landsat TM data. the island effect, presents high temperature on air like island, is connected with correlation between the surface temperature and the temperature on the air. In this study, surface temperature was analyzed by detecting the change of urban forestry with remote sensing using the vegetation vitality statistics reference (ratio change of the Park greens in Daegu) the heat island effect not only brings the environment pollution but also brings serious problem such as the destruction of ecosystem to city as a whole. Jeff Luvall has studied to restrain the heat island effect by making urban forestry. Even though Daegu had been the serious high temperature urban area the current temperature of Daegu has been dropped. The correlation between the heat island effect and the vegetation index was analyzed by using satellite images.

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첨가제를 포함한 TMA포접화합물의 열물성에 관한 기초적 연구 (A Basic Study on Thermal Properties of TMA Clathrate with Additives)

  • 고광옥;정낙규;김진홍
    • 설비공학논문집
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    • 제13권11호
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    • pp.1097-1105
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    • 2001
  • The purpose of this study is to investigate the propriety of TMA clathrate as a cold storage medium. Particularly, this is to examine the extent of subcooling improvement when the additives are added to the TMA clathrate, because water used cold storage material has low phase change temperature and subcooling. This study has been analysed and compared with TMA 30 wt% clathrate how phase change temperature, subcooling and specific heat in the various concentrations are changed. This results view to be improved phase change temperature and subcooling of TMA 30 wt% as a cold storage medium, when it had some additive. Additional1y, it is found that the additive must be controlled under available solution limit and study for new additive must be lasted to know its effect.

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온도보정계수를 고려한 태양광발전 운전특성연구 (A Study on Drive Characteristic of Photovoltaic to consider temperature compensation account.)

  • 이정일;윤정필;유희옥;윤형상;차인수
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2001년도 전력전자학술대회 논문집
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    • pp.63-66
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    • 2001
  • Photovoltaic System does military exploit that use heliometer light and is clearness source of energy. Photovoltatic System is no noise, shock among is several Substitute energy and after establishment maintenance having simple special quality, is applied in many fields. However, while Photovoltatic System is having these advantage, but react sensitively in effect of Photovoltaic scanning Quantity, temperature change etc.. surrounding environment, when did not satisfy condition, express indefinite output price. Consider voltage$\cdot$current output measurement value and temperature revision calculation by temperature change of existing photovoltaic system and change of output price of when did Simulation analyzed comparison.

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