• 제목/요약/키워드: Wind climate

검색결과 610건 처리시간 0.025초

대구지역의 국지순환풍의 환기경로 및 대기오염수송에 관한 수치모의 (Numerical Simulation on the Wind Ventilation Lane and Air Pollutants Transport due to Local Circulation Winds in Daegu Districts)

  • 구현숙;김해동
    • 한국지구과학회지
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    • 제25권6호
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    • pp.418-427
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    • 2004
  • 최근 도시기후를 고려한 도시계획이 많은 나라에서 실용화되고 있다. 도시기후의 고려는 주로 도시의 바람 길 조성이라는 개념으로 구체화되고 있다. 도시의 바람 길 조성은 주로 하계에 도시지역의 열적 쾌적성을 개선하는 것을 목표로 한다. 아울러, 과학적 조사에 근거하여 도시의 단지계획을 합리적으로 함으로써 청정한 냉기류의 도심유입을 원활히 하여 도심의 대기오염을 저감하고자 하는 것도 목적으로 한다. 이 연구에서는, 수치실험을 통하여 전형적인 난후기일을 대상으로 대구지역의 국지순환풍이 지나는 바람의 길을 조사하였다. 그리고 이 바람에 의한 대기오염의 수송도 조사하였다. 수치실험에 사용한 모형은 RAMS(지역규모 대기모델)이다. 수치실험의 관심지역은 대구광역시 일대(약900$km^2$)이다. 수평규모는 약 30km이다. 수치실험은 일반풍이 약하고 쾌청한 일기조건을 갖는 늦봄의 기상조건 하에서 수행되었다. 수치실험의 결과 다음과 같은 3가지 결과를 얻었다: (1) 대구의 대표적 산지인 팔공산과 앞산에서 야간에 산정에서 복사냉각으로 생성된 국지풍이 지나는 길을 발견할 수 있었다. 그 바람은 대구의 동쪽 지역에서 중력류의 형태로 계곡을 따라서 흘러내렸다. (2) 평지에서는, 그 바람이 대구의 중심지를 지나 서쪽으로 흘러갔다. (3) 그 결과로, 대기오염물질은 야간에 국지풍에 의해 서쪽지역으로 수송되어졌다.

ACCURATE ESTIMATION OF GLOBAL LATENT HEAT FLUX USING MULTI-SATELLITE DATA

  • Tomita Hiroyuki;Kubota Masahisa
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.14-17
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    • 2005
  • Global latent heat flux data sets are crucial for many studies such as those related to air-sea interaction and climate variation. Currently, various global latent heat flux data sets are constructed using satellite data. Japanese Ocean Flux data sets with Use of Remote sensing Observations (J-OFURO) includes one of the satellite-derived global latent heat flux data (Kubota et aI., 2000). In this study, we review future development of J-OFURO global latent heat flux data set. In particular, we investigate usage of multi-satellite data for estimating accurate global latent heat flux. Accurate estimation of surface wind speeds over the global ocean is one of key factors for the improved estimation of global latent heat flux. First, we demonstrate improvement of daily wind speed estimation using multi-satellites data from microwave radiometers and scatterometers such as DMSP/SSMI, ERS/AMI, QuikSCAT/SeaWinds, AqualAMSR-E, ADEOS2/AMSR etc. Next, we demonstrate improvement of global latent heat flux estimation using the wind speed data derived from multi-satellite data.

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웹 기반 풍력발전 모니터링 시스템 개발에 관한 연구 (A Study on the Development of the Web-based Monitoring System for the Wind Turbine Powers)

  • 김인수;김성식;최영준
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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    • pp.1147-1148
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    • 2006
  • The increase of exhaust gas which is caused by with the industry activity which follows in the Industrial Revolution of the human being has had an influence on the globe climate system so that causes the problem of the greenhouse effect. As a comprehensive countermeasures, it has been prompted to save energy, build a structure environmentally friendly and use renewable energy sources that are continually replenished by nature-the sun, the wind, the Earth's heat, and plants. In addition, new technologies that turn these fuels into usable forms of energy-most often electricity, but also heat, chemicals or mechanical power have been applied actively to the social infrastructure. Therefore, there should be methods to manage forms of renewable energy effectively and securely. This paper proposes the web-based monitoring system for the wind power system of these methods and introduces the real web-based monitoring system installed in Daegwallyeong.

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천리안 위성 적외 영상 자료를 이용한 태풍의 최대풍속반경 산출 및 통계적 특성 (Estimation and Statistical Characteristics of the Radius of Maximum Wind of Tropical Cyclones using COMS IR Imagery)

  • 권민호
    • 대기
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    • 제22권4호
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    • pp.473-481
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    • 2012
  • The objective methods estimating the radius of maximum wind (RMW) of tropical cyclones (TCs) are discussed using infraed (IR) imagery of geostationary satellite, and an alternative method is suggested that can estimate RMW in the TCs having eyes using IR imagery. The RMW-estimating methods are based on the characteristic structure of the eyewall of a tropical cyclone. RMW is dependent upon the radius of the eye and the distance from the center to the top of the most developed convective cloud. In order to test these methods, blackbody brightness temperature of Korean geostationary satellite, COMS (Communication, Ocean, and Meteorological Satellite) IR imagery are utilized in this study. The estimated RMWs are compared with surface winds of ASCAT (Advanced Scatterometer) of a polar orbiting satellite.

Emerging Green Clusters in South Korea? The Case of the Wind Power Cluster in Jeonbuk Province

  • Berg, Su-Hyun;Hassink, Robert
    • STI Policy Review
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    • 제3권1호
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    • pp.63-79
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    • 2012
  • Regional innovation systems and clusters represent a fashionable conceptual basis for regional innovation policies in many industrialized countries (including South Korea). Due to questions related to climate change and environment-friendly energy production, the green industry has been increasingly discussed in relation to regional innovation systems and clusters. This explorative paper analyzes these discussions and critically examines the emergence of green clusters in South Korea based on the case of the wind power cluster in Jeonbuk Province. It tentatively concludes that the role of the central government is too powerful and the role of regional actors (policy-makers and entrepreneurs) is too weak for the successful emergence of green clusters.

인발 성형법을 이용한 C/GFRP 복합소재 신호등 부착대의 구조적 안정성에 관한 연구 (Structural Stability Study of C/GFRP Composite material Traffic Light Fixture and Wind Load)

  • 나경수;곽이구
    • 한국기계가공학회지
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    • 제20권11호
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    • pp.9-16
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    • 2021
  • As the climate changes rapidly due to warming, it is becoming very important to ensure the stability of environmental structures. It is necessary to choose a material that withstands repeated external forces (wind loads) and satisfies members and joints that have energy absorbing power. Even if the strength of the traffic light attachment is sufficient, if the rigidity is insufficient, there is a limit to the displacement during strong winds. Excessive deformation may cause damage and fall, resulting in a safety accident. The author intends to study mechanical properties and resistance to external environment as a structural material capable of withstanding wind load (50m/sec) by fabricating a C/GFRP composite traffic light attachment using the pultrusion method (Pultrusion).

도시의 건폐율 및 용적률이 도시기후에 미치는 영향 분석 (Analysis on the Effects of Building Coverage Ratio and Floor Space Index on Urban Climate)

  • 여인애;이정재;윤성환
    • 한국태양에너지학회 논문집
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    • 제29권3호
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    • pp.19-27
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    • 2009
  • In this study, Urban Climate Simulation was performed by 3-Dimensional Urban Canopy Model. The characteristics of urban climate were analyzed combining artificial land coverage, building size, heat production from the air conditioning and topographic conditions as physical variables which affects urban climate characteristics. The results are as follows. (1) The aspects of the urban climatal change is derived to be related to the combination of the building coverage ratio, building height and shading area. According to the building height, the highest temperature was increased by $2.1^{\circ}C$ from 2-story to 5-story building and the absolute humidity by 2.1g/kg maximum and the wind velocity by 1.0m/s was decreased from 2-story to 20-story building. (2) Whole heat generation was influenced by the convective sensible heat at the lower building height and by the artificial heat generation at the higher one over 20-story building influence to some extent of the building coverage ratio. The effect of the altitude is not more considerable than the other variables as below $1^{\circ}C$ of the air temperature. In the last, deriving the combination of building coverage and building height is needed to obtain effectiveness of the urban built environment planning at the point of the urban climate. These simulation results need to be constructed as DB which shows urban quantitative thermal characters by the urban physical structure. These can be quantitative base for suggesting combinations of the building and urban planning features at the point of the desirable urban thermal environment as well as analyzing urban climate phenomenon.

한반도 동남권역에 영향을 미친 태풍 관측 연구 (A Study on the Observation of the Typhoons that Affected Southeastern Region of the Korean Peninsula)

  • 정우식;박종길;김은별
    • 한국환경과학회지
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    • 제20권9호
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    • pp.1191-1203
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    • 2011
  • In case of Typhoon Dianmu, the temperature, wind speed, wind direction and the rainfall per hour changed dramatically when the center of the typhoon passed through Gimhae. Such a change was commonly found in the regions where the center of the typhoon passed through but almost not in the regions far away from it. For example, in the case of Typhoon Malou where the center of the typhoon was far away from the observation site, such a phenomenon was not observed. The analysis of the vertical observation data showed that there was a little change in the wind speed and wind direction in the vertical direction in the case of Typhoon Dianmu of which center passed through Gimhae. There was a great change in the wind speed according to the height in the lower atmosphere just before the center of the typhoon approached the region. When the center of the typhoon was passing through the region, the vertical wind speed was decreased. However, the wind speed was rapidly increased again after the center of the typhoon had passed through the region. Unlike the Dianmu, the difference in the wind speed and wind direction between the upper layer and lower layer of the atmosphere was relatively great in the case of Malou.

Investigation of stiffening scheme effectiveness towards buckling stability enhancement in tubular steel wind turbine towers

  • Stavridou, Nafsika;Efthymiou, Evangelos;Gerasimidis, Simos;Baniotopoulos, Charalampos C.
    • Steel and Composite Structures
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    • 제19권5호
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    • pp.1115-1144
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    • 2015
  • Current climate conditions along with advances in technology make further design and verification methods for structural strength and reliability of wind turbine towers imperative. Along with the growing interest for "green" energy, the wind energy sector has been developed tremendously the past decades. To this end, the improvement of wind turbine towers in terms of structural detailing and performance result in more efficient, durable and robust structures that facilitate their wider application, thus leading to energy harvesting increase. The wind tower industry is set to expand to greater heights than before and tapered steel towers with a circular cross-section are widely used as more capable of carrying heavier loads. The present study focuses on the improvement of the structural response of steel wind turbine towers, by means of internal stiffening. A thorough investigation of the contribution of stiffening rings to the overall structural behavior of the tower is being carried out. These stiffening rings are placed along the tower height to reduce local buckling phenomena, thus increasing the buckling strength of steel wind energy towers and leading the structure to a behavior closer to the one provided by the beam theory. Additionally to ring stiffeners, vertical stiffening schemes are studied to eliminate the presence of short wavelength buckles due to bending. For the purposes of this research, finite element analysis is applied in order to describe and predict in an accurate way the structural response of a model tower stiffened by internal stiffeners. Moreover, a parametric study is being performed in order to investigate the effect of the stiffeners' number to the functionality of the aforementioned stiffening systems and the improved structural behavior of the overall wind converter.

Influences of Climate Factors and Water Temperature in Squid Spawning Grounds on Japanese Common Squid (Todarodes pacificus) Catches in the East (Japan) Sea

  • Lee, Chung-Il
    • Fisheries and Aquatic Sciences
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    • 제10권3호
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    • pp.150-158
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    • 2007
  • Data on squid catches, water temperature, and climatic factors collected for the Northwest and subtropical North Pacific were analyzed to examine the influence of oceanic and climatic conditions in spawning grounds on catches of Japanese common squid, Todarodes pacificus, in the East (Japan) Sea. The main spawning ground was divided into four sub-areas: the South Sea of Korea (R1), the southern waters off Jeju, Korea (R2), the southwestern part of Kyushu, Japan (R3), and the northern part of Okinawa, Japan (R4). Interannual and decadal fluctuations in water temperatures correlated well with squid catches in the East/Japan Sea. In particular, water temperatures at a depth of 50 to 100 m in sub-areas R3 and R4 showed higher correlation coefficients (0.54 to 0.59, p<0.01) in relation to squid catches in the East/Japan Sea than for R1 and R2, which had correlation coefficients of 0.40 or less (p>0.05). Air temperature and wind velocity fluctuations in each sub-area are correlated with water temperature fluctuations and were closely connected with variations in the surface mixed layers. Water, air temperatures and wind velocities at the main spawning grounds are linked to the Southern Oscillation Index (SOI) with higher signals in the ca. 2-4-year band. Strong changes in a specific band and phase occurred around 1976/77 and 1986/87, coincident with changes in squid catches.