• Title/Summary/Keyword: Wind climate

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Technology Competitiveness Analysis of New & Renewable Energy in Major Countries (주요국의 신재생에너지 분야 기술경쟁력 분석 연구)

  • Ha, Su-Jin;Choi, Ji-Hyeok;Oh, Sang Jin
    • New & Renewable Energy
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    • v.18 no.3
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    • pp.72-84
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    • 2022
  • As the threat of climate change escalates, 'net-zero' has become a priority for the international community, and the use of new and renewable energy sources is expected to play a significant role in reaching international carbon neutrality. Here, we evaluate technological competitiveness in terms of implementation and technology by analyzing scientific literature and patents in the new and renewable energy fields of five major countries. For the past 10 years (2009-2019), the most active areas of new and renewable energy research and development have been solar power, wind power, waste, and fuel cells. China is the forerunner in implementation, whereas the United States has the most advanced technology. Portfolio analysis revealed that Korea's fuel cell, the United States' bioenergy, China's waste, Japan's solar and fuel cell, and the European Union's wind power have shown to be in Star Field respectively. Technological competitiveness analysis found that Korea is lagging behind other countries in the new and renewable energy sector, and needs to set a new direction for future carbon-neutral research and development, investment, and policy.

A Study of the Correlation between Stroke Incidence by Climate of Day and Stems and Branches (기후(氣候) 및 간지(干支)와 중풍(中風) 發病日(발병일)에 관(關)한 상관성(相關性) 연구(硏究))

  • Choi, Hyo-Jae;Hwang, Min-Young;Baik, Yun-Seon;Ju, Dae-Hwan;Han, Chang-Ho;Shin, Gil-Cho;Lee, Won-Chul
    • The Journal of Internal Korean Medicine
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    • v.30 no.2
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    • pp.317-326
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    • 2009
  • Objectives : This study investigated the correlation between the incidence by the climate of the day and the Stems and Branches(干支) of stroke patients. Methods : From January in 2000 to March in 2008, we studied 370 stroke patients hospitalized at Dongguk University Bundang Hospital. Each participant was investigated for the day's average temperature, the day's average air humidity, the day's average wind speed, and the day's Stems and Branches (干支) in oriental medical theory. Results: Concerning the day's average temperature, the group at a temperature under 18 $^{\circ}C$ had the highest risk. For the day's average air humidity, the group at over 60 % humidity showed a higher ratio of stroke. In respect of the day's average wind speed, the group at speeds under 2.26 $^m/s^2$ (the last 5 years average wind speed in Gyeonggi-do) had a higher risk. In the aspect of Stems and Branches (干支), stroke occurred more in Yin day(陰日) than in Yang day(陽日). In the view of the Five Circuits (五運), the Wood (木) was most common followed by Fire(火). Using the relation between Stems and Branches (干支), the mutuality cooperate pattern was more common than the mutuality control group and same characteristic group. Using the Theory of Five Circuits (五運) and Six Qi (六氣), the Fire group (火) showed the highest risk. The Wood group (木) came next. Conclusions : We could suggest that stroke attack might have some significant relationship with climate, stems, and branches in oriental medical theory.

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Relationships between Intensity of Extreme Climate Events and Magnitude of Damages for Different Typhoon Tracks in the Republic of Korea (우리나라 태풍 내습 유형별 극한기후현상 강도와 피해 규모의 관련성)

  • Lee, Seung-Wook;Ahn, Suk-Hee;Lim, Byunghwan;Choi, Gwangyong
    • Journal of the Korean association of regional geographers
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    • v.22 no.2
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    • pp.450-465
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    • 2016
  • The purpose of this study is to examine the spatial characteristics of relationships between the intensity of extreme climate events driven by typhoons and the magnitude of economic damages at local municipality scales across the Republic of Korea for the recent 15-year period (2000~2014). As results, it is observed that the intensity of extreme temperature events such as heavy rainfall and gusty wind accounts for 50% of the damages magnitude across Korea, while the correlation between the two at the Si-Gun municipality level regionally varies. Positive correlations between the intensity of heavy rainfall events and typhoon damages are observed in the southeastern regions of Taebaek-Sobaek mountain ridges, while such statistically-significant patterns are not detected in the northwestern region. In contrast, statistically-significant positive correlations between the strength of gusty winds and damages are found in most of regions except for some interior regions and northeastern mountainous regions. Classification maps of major extreme climate event types (heavy rainfall-prevailing type, gusty wind-prevailing type, and their combined type) leading to typhoon damages at the Si-Gun municipality scales provided in this study may help local administrations to make the optimized policies for typhoon damage mitigation.

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Correlation Analysis of UA Using Wind Data of AWS/ASOS and SST in Summer in the East Sea (AWS/ASOS 바람자료를 이용한 여름철 동해 연안역의 용승지수와 수온과의 상관성)

  • Kim, Ju-Yeon;Han, In-Seong;Ahn, Ji-Suk
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.6
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    • pp.773-784
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    • 2018
  • In this study, we examined the UA (upwelling age) using wind data of AWS/ASOS in the East Sea coast and the correlation between UA and SST (sea surface temperature) from May to August in 1995 to 2016. The data used the 6 observations of the wind data of AWS/ASOS and the SST data of the COD/RISA provided by the National Institute and Fisheries Science near the East Sea coast. The UA was calculated quantitatively low but it rose when the actual cold water mass occurred. Correlation analysis between UA and SST showed the negative (-) r (correlation coefficient) predominately. At the time of cold-water mass in June to August 2013, the r had a very high negative value of -0.65 to -0.89 in the 6 observations. It proved that as the UA increases, the SST is lower. By knowing the UA, we were able to evaluate the trend of upwelling in the cold-water mass of the East Sea coast in the long term and it will contribute to minimizing the damage to aquatic organisms according to the size and intensity of the upwelling.

The study on substructure design and analysis for 5MW offshore wind turbine (5MW급 해상풍력 하부구조물 설계 및 해석에 관한 연구)

  • Sun, Min-Young;Lee, Sung-Bum;Lee, Ki-Yeol;Moon, Byung-Young
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.9
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    • pp.1075-1080
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    • 2014
  • This study aims at dedicating to relevant technology fields by suggesting design methods of structures and estimating their safety in relation to substructure for offshore wind power requiring high safety to various environment conditions. Especially, with respect to 5MW Offshore Wind Power System, this study will provide information about major wind directions and duration in combination with the developing wave climate at the test field. Therefore, connections between wind fields and approaching wave trains will be estimated and their intensity, direction and time shift will be pointed out. Furthermore, the local pressure distribution of breaking waves will be investigated by physical and numerical modeling. The currently applied structural and fatigue assessment of support structures for offshore wind energy converters is based on common design rules. Normally, constructions in structural engineering are treated as limited, single structures. This means that varying aspects of manufacturing are considered by high safety factors.

A Basic Study on the Effect of the Wind Pressure according to Form on the Flat Roof mounted PV System (평지붕 PV거치 시스템의 형태에 따른 풍압영향에 관한 기초연구)

  • Yun, Doo-Young;Lee, Eung-Jik
    • Journal of the Korean Solar Energy Society
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    • v.33 no.5
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    • pp.105-112
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    • 2013
  • The new renewable energy became popular as a clean and sustainable alternative energy under the circumstances that the entire world is facing severe abnormal climate due to the use of fossil fuel, and among which, solar energy can be obtained anywhere and is not difficult to apply it into the existing buildings, which makes it possible to be widely distributed. However, as PV module is installed into a single plate system, it shows structural weaknesses which are vulnerable to wind load and give loss to design elements in external appearance. Accordingly, this study planned one-step parallel system to complement the problems occurring from a single plate system and used STAR-CCM+ V.8 made by CD-Adapco, a computational fluid dynamics(CFD) simulation tool to measure wind load stability and support based on the design standards for a single plate system and one-step parallel system. Building height was limited to less than 10m and wind speed was given when increasing from 35m/s to 50m/s by 5m/s on PV system installed into the flat roof. In this case, our analysis suggested that step-one parallel system was in class 7-9 according to Beaufort's wind power classification, which did not have an impact on the fixed PV system, and the single plate system is considered to cause risks in designing wind speed in central districts because it is more than wind power class 12.

Why is Seogwipo Warm in Winter? The wind from Jeju City to Seogwipo-The Wind from Seogwipo to Jeju City (서귀포는 겨울철에 왜 따뜻할까? 제귀지풍과 귀제지풍)

  • Sung kook Lee;Moon Ho Lee;Jeong Su Kim
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.4
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    • pp.121-125
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    • 2023
  • In winter, Jeju's Seogwipo and Jungmun areas are 2~3℃ warmer than Jeju City. The reason is that when the north wind over Halla Mountain crosses Baengnokdam of Halla Mountain and passes the 300m long and 260m vertical rock face of Donnaeko at an altitude of 1600m above sea level, the cold air turns into warm air through adiabatic compression, and the warmth rides on Donnaeko and flies to Seogwipo and Jungmun. Conversely, the south wind that rises over the sea in Seogwipo in the summer passes over Hallasan Mountain and passes 99 valleys before turning into a muggy, humid climate, making Jeju hot. In other words, it is because of The wind from Jeju City to Seogwipo-The Wind from Seogwipo to Jeju City.

Dynamics of alpine treelines: positive feedbacks and global, regional and local controls

  • Kim, Jong-Wook;Lee, Jeom-Sook
    • Journal of Ecology and Environment
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    • v.38 no.1
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    • pp.1-14
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    • 2015
  • Whilst it is clear that increasing temperatures from global environmental change will impact the positions of alpine treelines, it is likely that a range of regional and local scaled factors will mediate the overall impact of global scale climate drivers. We summarized 12 categories of abiotic and biotic factors as 4 groups determining treeline positions. First, there are global factors related to climate-induced growth limitation and carbon limitation. Second, there are seven regional and local factors related to treeline dynamics including frost stress, topography, water stress, snow, wind, fire and non-fire disturbance. Third, species-specific factors can control treeline dynamics through their influence on reproduction and life history traits. Fourth, there are positive feedbacks in structuring the dynamics of treelines. Globally, the commonly accepted growth limitation hypothesis is that growth at a treeline is limited by temperature. Meanwhile, positive feedbacks between canopy cover and tree establishment are likely to control the spatial pattern and temporal dynamics of many treelines. The presence of non-linear dynamics at treelines has implications for the use of treelines as barometers of climate change because the lagged responses and abrupt shifts inherent in non-equilibrium systems may combine to mask the overall climate trend.

A study on Applicability through Comparison of Weather Data based on Micro-climate with existing Weather Data for Building Performative Design (건물 성능디자인을 위한 미기후 기반 기상데이터의 기존 기상데이터와 비교를 통한 활용 가능성 연구)

  • Kim, Eon-Yong;Jun, Han-Jong
    • KIEAE Journal
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    • v.11 no.6
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    • pp.101-108
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    • 2011
  • The weather data has important role for performative building design. If the data location is close to building site, the result of performative design can be accurate. The data which have used nowadays in Korea are from U.S. Department of Energy (DOE) and Korea Solar Energy Society (KSES) but they cover only several locations in Korea which are 4 in DOE and 11 in KSES and there are opinions which it could be served building design efficiently even if the data are not enough. However the weather data for micro-climate are exist which are Green Building Studio Virtual Weather Station (GBS VWS) and Meteonorm weather data. Each weather data has different generation methods which are TMY2, TRY, MM5, and extrapolation. In this research, the weather date for climate are compared with DOE and KSES to check correlation. The result shows the value of correlation in Dry Bulb Temp. and Dew Point Temp. is around 0.9 so they have high correlation in both but in Wind Speed case the correlation(around 0.2) is not exist. In overall result, the data has correlation with DOE and KSES as the value of correlation 0.648 of GBS VW and 0.656 of Meteonorm. Even if the correlation value is not high enough, the patterns of difference in each weather element are similar in scatter plot.

Performance Comparison of Automotive Air conditioning System by using R134a and R152a (R134a와 R152a 냉매를 이용한 자동차용 에어컨 시스템의 성능 비교)

  • Kim, Jeong-Su;Nam, Su-Byung;Lee, Dae-Woong;Yoo, Seong-Yeon;Kim, Jin-Hyuck
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.9-14
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    • 2006
  • This study presented the feasibility of R152a refrigerant as an alternative of R134a which is used in the current automobile air conditioning system. The performance of air conditioning system installed in the actual vehicle was tested using the climate wind tunnel. The experiments were conducted at various refrigerant charge quantities and various driving conditions such as city traffic, highway traffic and parking. Same components and lubricant were used for both R134a and R152a system. The effects of air set values of thermal expansion valve on the performance were also investigated. In case of the R152a system, refrigerant charge quantity can be reduced about 20%, better performance and superior compressor durability is expected due to the lower discharge pressure compared to the R134a system.

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