• 제목/요약/키워드: Cold climate

검색결과 453건 처리시간 0.026초

Risk Analysis of Thaw Penetration Due to Global Climate Change in Cold Regions

  • Bae, Yoon-Shin
    • 한국방재학회 논문집
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    • 제9권2호
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    • pp.45-51
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    • 2009
  • 지구기후모델을 이용하여 예측된 (1) 물성치와 (2) 현재 및 미래의 표면 에너지 입력상수의 가변성을 고려한 동결 및 융해깊이를 예측하기 위하여 확률론적 접근법이 도입되었다. 확률론적 접근법을 예시하기 위하여 극지방에서의 융해깊이 예측을 고려해보았다. 특히 확률론적 융해깊이 예측을 위하여 몬테카를로 시뮬레이션과 함께 Stefan 공식이 사용되었다. 시뮬레이션 결과는 물성치의 가변성을 보여주었다. 표면 에너지 입력상수와 온도 데이터는 융해깊이를 예측하는데 상당한 불확실성을 야기시킬 수 있다.

혹한온도 조건에서의 양생방법 변화에 따른 벽체 콘크리트의 온도이력 특성 (Temperature History of Wall Concrete with Heat Insulating Curing Method Subjected to Severly Cold Climate)

  • 손호정;한상윤;정상현;안상구;한천구;한민철
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2011년도 추계 학술논문 발표대회
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    • pp.51-52
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    • 2011
  • This study is to propose a curing method for a concrete wall structure under severe cold climate. The curing methods of using heated cable, heated panel and insulated form were applied. Results showed that the concrete cured by the heated cable resulted in the highest temperature history and the highest strength development at 28 days. Further, it is believed that the curing methods of the heated panel and insulated form are also recommendable for the resistance of the early frost damage on the concrete in practice.

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비오톱 지도와 항공라이다 자료를 이용한 바람통로 분석 및 기후평가 (Wind Corridor Analysis and Climate Evaluation with Biotop Map and Airborne LiDAR Data)

  • 김연미;안승만;문수영;김현수;장대희
    • 한국조경학회지
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    • 제40권6호
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    • pp.148-160
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    • 2012
  • 본 연구는 비오톱 지도와 항공 라이다 자료만을 이용해 GIS 분석기법을 적용하여 개개의 비오톱에 대한 기후분석 및 평가정보를 제공함을 목적으로 하고 있다. 1차 분석단계에서 비오톱 지도로부터 면적, 경사, 경사길이, 표면특성, 바람통로 기능, 바람통로 폭, 바람통로 장애물 요소를 각각 구하여 냉기/신선기 생성 및 바람통로 기능을 평가하였으며 2차 분석단계에서는 이들 요소를 종합하여 기후평가를 수행하여 비오톱 단위 별로 기후평가 자료를 생성하였다. 항공라이다 자료는 비오톱을 이용한 바람통로 분석에 유효하였다. 평가인자와 평가 등급 간의 상관성을 그래프 및 상관계수를 통해 확인한 결과 냉기/신선기 생성 등급과 Surface_GRD 평균값과의 상관계수가 (-)0.967로 높게 나타났으며 바람통로 기능에서는 등급별 Function_GRD 평균값과의 상관계수가 (-)0.884, Obstacle_GRD 평균값과의 상관계수는 (-)0.834로 나타났다. 기후평가 등급과 WindCorridor_GRD 상관계수는 0.928, 기후평가 등급과 ColdAir_GRD 상관계수는 0.855로 나타나 비오톱의 WindCorridor_GRD가 ColdAir_GRD에 비해 상관성이 높게 나타났으며 항공사진 정사영상을 이용한 육안 검수에서도 기후평가 및 등급화 결과가 잘 반영된 것으로 나타났다. 결과적으로, 비오톱 지도와 항공라이다 자료를 이용해 기후 분석 및 평가 방법을 적용한 결과 광명-시흥시 보금자리 주택개발 예정지의 기후평가등급에 따른 면적분포 비율은 1등급 18.5%, 2등급 18.2%, 3등급 30.7%, 4등급 25.2%, 5등급 7.4% 순으로 나타났으며 본 연구방법을 통해 기후평가 정보를 각각의 비오톱 단위별로 통계적 정보와 함께 제시할 수 있었다.

우리나라 한중콘크리트 적용기간의 변화 (Variation of Application Period of Cold Weather Concrete in Korea)

  • 한민철
    • 콘크리트학회논문집
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    • 제17권2호
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    • pp.237-245
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    • 2005
  • 본 연구에서는 우리나라 기상청의 기온자료를 이용하여 시간변화에 따른 각 지역의 한중콘크리트 적용기간을 KCI, ACI 및 AIJ 방법에 따라 산정한 후 동방법의 기존연구결과와 비교 분석함으로써 시간변화에 따른 한중콘크리트 적용기간의 변화를 분석하고자 하였다. 연구결과에 따르면, KCI에 의한 적용기간은 평균 9.5순으로 나타났고, ACI에 의한 적용기간은 10.1순 그리고 AIJ에 의한 적용기간은 9.2순으로 산정되었다. 시간변화에 따른 적용기간으로서 KCI 및 ACI 규정에 의한 본연구의 적용기간은 10년전의 종전 연구보다 약 5${\~}$6일 정도 짧아진 것으로 확인되었으나, AIJ 규정에 의한 적용기간은 종전의 연구와 거의 차이가 없었고, 단, 김의 연구와 비교할 경우 약 3일 정도 짧아지는 것으로 나타났다. 한편, 지역별로는 남부지방의 경우 종전연구에 비하여 한중콘크리트 적용기간이 비교적 많이 단축되었는데,. 이는 지구의 온난화에 의한 평균기온의 상승으로 인한 것으로 사료된다.

낙동강 구미 보의 수면 열수지 계절 변화 (Seasonal Variation of the Surface Heat Budget in the Gumi Reservoir of Nakdong River)

  • 김학윤;서광수;조창범;김해동
    • 한국환경과학회지
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    • 제25권8호
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    • pp.1057-1063
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    • 2016
  • The heat budget is investigated in the Gumi Reservoir of the Nakdong river. In warm climate season, solar radiation effects play a important role in the change of water temperature. The features of the surface heat balance are almost derived by the latent heat flux and the solar radiation flux. On the other hand, in cold climate season, change of heat stored in the water is mainly dominated by latent and sensible heat transfer between water and air, since flux of solar radiation and loss of outgoing long wave radiation balance approximately. For the annual averages, net flux of radiation, evaporation(latent heat) loss are dominant in the Gumi reservoir. The evaporation losses are dominant from spring to early winter. This means that the Gumi reservoir rolls like a lake of thermal medium or deep depth.

An experimental performance analysis of a cold region stationary photovoltaic system

  • Choi, Wongyu;Warren, Ryan D.;Pate, Michael B.
    • Advances in Energy Research
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    • 제4권1호
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    • pp.1-28
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    • 2016
  • A grid-connected photovoltaic (PV) system comprised of multicrystalline silicon (mc-Si) modules was installed in a cold climate region in the U.S. This roof-mounted stationary PV system is a real-world application of PV for building energy generation in International Energy Conservation Code (IECC) Climate Zone 5 (and possibly similar climate zones such as 6, 7 and 8), and it served the purposes of research, demonstration, and education. The importance of this work is highlighted by the fact that there has been less emphasis on solar PV system in this region of the U.S. because of climate and latitude challenges. The system is equipped with an extensive data acquisition system capable of collecting performance and meteorological data while visually displaying real-time and historical data through an interactive online interface. Experimental data was collected and analyzed for the system over a one-year period with the focus of the study being on measurements of power production, energy generation, and efficiency. The annual average daily solar insolation incident upon the array was found to be $4.37kWh/m^2$. During the first year of operation, the PV system provided 5,801 kWh (1,264 kWh/kWp) of usable AC electrical energy, and it was found to operate at an annual average conversion efficiency and PR of 10.6 percent and 0.79, respectively. The annual average DC to AC conversion efficiency of the inverter was found to be 94 percent.

야간 냉각율을 이용한 우포늪의 기온변화 완화효과 평가 (Evaluation of Mitigation Effect of Upo-Swamp on the Air temperature Variation with Nighttime Cooling Rate)

  • 박명희;김해동
    • 한국환경과학회지
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    • 제20권3호
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    • pp.309-319
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    • 2011
  • In this study, we investigated the effects of Upo-swamp upon local thermal environment with nighttime cooling rate. To do this, we set up the AWS(Automatic Weather observation System) over the central part of Upo-swamp on the early October 2007. We conducted the study by comparing the AWS data with another weather data observed by several meteorological observations of the Korea Meteorological Administration located at the vicinity of Upo-swamp for one year. The air temperature of Upo-swamp was higher than that of the surrounding in cold-climate season. But it was opposite in warm-climate season. We confirmed that Upo-swamp roles to mitigate the daily and annual air temperature ranges. And the daily air temperature variation of Upo-swamp lagged behind the land one. This phenomenon represent that the heat reservoir capacity of Upo-swamp is much larger than that of the ground.

Phytohormnes producing Preussia sp. BSL-10 induce phytohormonal changes in tomato (Solanum lycopersium cv.) under divers temperature.

  • Al-Hosni, Khdija;Shahzad, Raheem;Kang, Sang-Mo;Lee, In-Jung
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.202-202
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    • 2017
  • Global climate change resulted in unwarranted change in global temperature and caused heat and cold stress, which are consider major threat to agriculture productivity around the world. The use of plant growth-promoting microbes is an eco-friendly strategy to counteract such stresses and confer tolerance to the plants. In current study, previously isolated endophytic fungi Preussia sp. BSL-10 has been found to produce phytohormones such as IAA and GA and as such, endophyte Preussia sp. BSL-10 found to induced tolerance against heat and cold stress. The results showed that under both heat and cold stress the plant growth parameter such as shoot, root length, shoot fresh weight and root fresh weight is higher in Preussia sp. BSL-10 treated plants as compare to free Preussia sp. BSL-10 control plants. In addition, the stress-sensitive endogenous ABA levels were significantly increased in Preussia sp. BSL-10 host plant. The current result suggest that the phytohormone-producing endophyte Preussia sp. BSL-10 can increase plant resistance toheat and cold stress, in turn improving agricultural productivity.

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경기북부지역 정밀 수치기후도 제작 및 활용 - I. 수치기후도 제작 (Development and Use of Digital Climate Models in Northern Gyunggi Province - I. Derivation of DCMs from Historical Climate Data and Local Land Surface Features)

  • 김성기;박중수;이은섭;장정희;정유란;윤진일
    • 한국농림기상학회지
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    • 제6권1호
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    • pp.49-60
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    • 2004
  • Northern Gyeonggi Province(NGP), consisting of 3 counties, is the northernmost region in South Korea adjacent to the de-militarized zone with North Korea. To supplement insufficient spatial coverage of official climate data and climate atlases based on those data, high-resolution digital climate models(DCM) were prepared to support weather- related activities of residents in NGP Monthly climate data from 51 synoptic stations across both North and South Korea were collected for 1981-2000. A digital elevation model(DEM) for this region with 30m cell spacing was used with the climate data for spatially interpolating daily maximum and minimum temperatures, solar irradiance, and precipitation based on relevant topoclimatological models. For daily minimum temperature, a spatial interpolation scheme accommodating the potential influences of cold air accumulation and the temperature inversion was used. For daily maximum temperature estimation, a spatial interpolation model loaded with the overheating index was used. Daily solar irradiances over sloping surfaces were estimated from nearby synoptic station data weighted by potential relative radiation, which is the hourly sum of relative solar intensity. Precipitation was assumed to increase with the difference between virtual terrain elevation and the DEM multiplied by an observed rate. Validations were carried out by installing an observation network specifically for making comparisons with the spatially estimated temperature pattern. Freezing risk in January was estimated for major fruit tree species based on the DCMs under the recurrence intervals of 10, 30, and 100 years, respectively. Frost risks at bud-burst and blossom of tree flowers were also estimated for the same resolution as the DCMs.

Long-term pattern changes of sea surface temperature during summer and winter due to climate change in the Korea Waters

  • In-Seong Han;Joon-Soo Lee;Hae-Kun Jung
    • Fisheries and Aquatic Sciences
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    • 제26권11호
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    • pp.639-648
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    • 2023
  • The sea surface temperature (SST) and ocean heat content in the Korea Waters are gradually increased. Especially the increasing trend of annual mean SST in the Korea Water is higher about 2.6 times than the global mean during past 55 years (1968-2022). Before 2010s, the increasing trend of SST was led by winter season in the Korea Waters. However, this pattern was clearly changed after 2010s. The increasing trend of SST during summer is higher about 3.9 times than during winter after 2010s. We examine the long-term variations of several ocean and climate factors to understand the reasons for the long-term pattern changes of SST between summer and winter in recent. Tsushima warm current was significantly strengthened in summer compare to winter during past 33 years (1986-2018). The long-term patterns of Siberian High and East Asian Winter Monsoon were definitely changed before and after early- or mid-2000s. The intensities of those two climate factors was changed to the increasing trend or weakened decreasing trend from the distinctive decreasing trend. In addition, the extreme weather condition like the heatwave days and cold spell days in the Korea significantly increased since mid- or late-2000s. From these results, we can consider that the occurrences of frequent and intensified marine heatwaves during summer and marine cold spells during winter in the Korea Waters might be related with the long-term pattern change of SST, which should be caused by the long-term change of climate factors and advection heat, in a few decade.