• Title/Summary/Keyword: Climate Characteristics

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Fatigue wind load spectrum construction based on integration of turbulent wind model and measured data for long-span metal roof

  • Liman Yang;Cong Ye;Xu Yang;Xueyao Yang;Jian-ge Kou
    • Wind and Structures
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    • v.36 no.2
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    • pp.121-131
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    • 2023
  • Aiming at the problem that fatigue characteristics of metal roof rely on local physical tests and lacks the cyclic load sequence matching with regional climate, this paper proposed a method of constructing the fatigue load spectrum based on integration of wind load model, measured data of long-span metal roof and climate statistical data. According to the turbulence characteristics of wind, the wind load model is established from the aspects of turbulence intensity, power spectral density and wind pressure coefficient. Considering the influence of roof configuration on wind pressure distribution, the parameters are modified through fusing the measured data with least squares method to approximate the actual wind pressure load of the roof system. Furthermore, with regards to the wind climate characteristics of building location, Weibull model is adopted to analyze the regional meteorological data to obtain the probability density distribution of wind velocity used for calculating wind load, so as to establish the cyclic wind load sequence with the attributes of regional climate and building configuration. Finally, taking a workshop's metal roof as an example, the wind load spectrum is constructed according to this method, and the fatigue simulation and residual life prediction are implemented based on the experimental data. The forecasting result is lightly higher than the design standards, consistent with general principles of its conservative safety design scale, which shows that the presented method is validated for the fatigue characteristics study and health assessment of metal roof.

Quantitative Study on the Effect of the Building Composition on the Urban Thermal Environment (건물군 조건이 도시 열환경에 미치는 영향에 관한 정량적 검토)

  • Yeo, In-Ae;Yoko, Kamata;Yee, Jurng-Jae;Yoon, Seong-Hwan
    • 한국태양에너지학회:학술대회논문집
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    • 2009.04a
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    • pp.180-183
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    • 2009
  • In this study, Urban Climate Simulation was performed by 3-Dimensional Urban Canopy Model. The characteristics of urban climate was 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. (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.

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Characteristics of Summer Tropospheric Ozone over East Asia in a Chemistry-climate Model Simulation

  • Park, Hyo-Jin;Moon, Byung-Kwon;Wie, Jieun
    • Journal of the Korean earth science society
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    • v.38 no.5
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    • pp.345-356
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    • 2017
  • It is important to understand the variability of tropospheric ozone since it is both a major pollutant affecting human health and a greenhouse gas influencing global climate. We analyze the characteristics of East Asia tropospheric ozone simulated in a chemistry-climate model. We use a global chemical transport model, driven by the prescribed meteorological fields from an air-sea coupled climate model simulation. Compared with observed data, the ozone simulation shows differences in distribution and concentration levels; in the vicinity of the Korean Peninsula, a large error occurred in summer. Our analysis reveals that this bias is mainly due to the difference in atmospheric circulation, as the anomalous southerly winds lead to the decrease in tropospheric ozone in this region. In addition, observational data have shown that the western North Pacific subtropical high (WNPSH) reduces tropospheric ozone across the southern China/Korean Peninsula/Japan region. In the model, the ozone changes associated with WNPSH are shifted westward relative to the observations. Our findings suggest that the variations in WNPSH should be considered in predicting tropospheric ozone concentrations.

Educational Climate of Childcare Centers, Professionalism of Teachers, and Quality of Childcare Curriculum Implementation (어린이집의 교육풍토, 보육교사의 전문성 인식과 보육과정 운영의 질)

  • Lee, Sung Hye;Kim, Yeon Ha
    • Korean Journal of Childcare and Education
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    • v.9 no.3
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    • pp.75-93
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    • 2013
  • The present study was to investigate if quality of childcare curriculum implementation could be predicted by educational climate, teachers' professionalism, and teacher/classroom characteristics. According to the results, strong positive associations existed between eudcational climate, professionalism, and implementation of childcare curriculum. The most powerful predictor of curriculum implementation quality was 'respect and acceptance' which was a sub-factor of educational climate. Also, 'public service', a sub-factor of professionalism, explained a significant amount of variances in quality of curriculum implementation. Among teacher/childcare characteristics, the type of centers was one of the strong predictors. These study results provide meaningful implications regarding the importance of socio-cultural contexts in childcare centers as well as teachers'professionalism.

Changing Transmission Pattern of Plasmodium vivax Malaria in the Republic of Korea: Relationship with Climate Change

  • Park, Jae-Won
    • Environmental Analysis Health and Toxicology
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    • v.26
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    • pp.1.1-1.6
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    • 2011
  • Plasmodium vivax malaria has occurred annually in the Republic of Korea (ROK) since its re-emergence in 1993. P. vivax malaria in ROK has been strongly influenced by infected mosquitoes originating from the Democratic People's Republic of Korea. Korean P. vivax malaria has shown typical characteristics of unstable malaria transmitted only during the summer season, and displays short and long incubation periods. The changing pattern of the transmission period can be predicted by analyzing the seasonal characteristics of early primary attack cases with a short incubation period. Such cases began to gradually occur earlier in the 1990s after the re-emergence. Most of the malaria cases after mid-August are presumed to be early primary attack, short incubation period cases. Only primary transmission was possible until the early 2000s, whereas up to fourth or fifth transmission occurred in the mid-2000s. The results indicate that the length of transmission period has been gradually extending, which may be ascribed to a climate change-mediated temperature rise. Malaria and climate data should be integrated to analyze and predict the influence of climate change on malaria occurrence in ROK.

Thermal Sensation in Winter Classroom and Cold Climate Adaptability of Junior High School Students (남녀 중학생의 겨울철 교실 내 한서감과 기후적응성)

  • Cho, Areum;Shim, Huensup
    • Fashion & Textile Research Journal
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    • v.20 no.6
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    • pp.744-751
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    • 2018
  • This study aimed to provide the information on the thermal sensation and the amount of clothing worn of junior high school students in winter classroom the relation with their climate adaptability. Total usable questionnaires were obtained from 467 male and female students. The questionnaire included general characteristics, physical characteristics, self awareness of body shape, climate adaptability and subjective thermal sensation in winter classroom. The data were analyzed using SPSS Statistics 18.0 for frequency analysis, factor analysis, chi-square analysis, t-test and correlation analysis. The results were as follows. The average body type based on BMI was normal($20.1kg/m^2$ ). Females perceived their body type as thinner than males. They wore more (8.67 garment items compared to 8.14 for males). Only about 25% of students voted the thermal sensation to neutral(47% cool~very cold, 28% warm~very hot). Females were more sensitive to the cold, perceived less healthy, and wore more garments in the cold. Students felt colder in winter classroom when their cold adaptability was lower and they actively adjusted thermal insulation against the cold. It is recommended to suggest the guidelines for the proper indoor temperature and for the wear behavior in classroom in the perspectives of increasing the learning efficiency and improving the students' climate adaptability.

The Effect of Team Members' Psychological Characteristics and Knowledge Network Characteristics among Team Members on Team Performance (팀 구성원의 심리적 다양성과 구성원 간 지식네트워크 특성이 팀 성과에 미치는 효과: 학습 분위기의 조절효과를 중심으로)

  • Moon, Yun-Ji;Kang, So-Ra
    • The Journal of Information Systems
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    • v.20 no.1
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    • pp.1-20
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    • 2011
  • This study investigated the factors that facilitate knowledge creation of team with the aspect of knowledge management. We considered two characteristics which are team members' psychological characteristics (achievement needs and conflict emotion) and knowledge network characteristics among team members (internal cohesion and external bridging) and verified the relationship between these characteristics and team performance. Furthermore, we examined whether these characteristics have a different effect on team performance according to the mastery climate. This study performed a survey targeting team members in knowledge based firms and 376 final surveys to be used as a sample in this study. The result showed that team members' psychological characteristics and knowledge network characteristics among Team members have an influence on team performance significantly. In addition, the master climate moderated the relationship between team members' psychological characteristics and team performance.

Quantifying Climate Regulation of Terrestrial Ecosystems Using a Land-Atmosphere Interaction Model Over East Asia for the Last Half Century

  • Hong, Seungbum;Jang, Inyoung;Jeong, Heon-Mo
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.1 no.1
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    • pp.58-67
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    • 2020
  • Terrestrial ecosystems influence climate change via their climate regulation function, which is manifested within the carbon, water, and energy circulation between the atmosphere and surface. However, it has been challenging to quantify the climate regulation of terrestrial ecosystems and identify its regional distribution, which provides useful information for establishing regional climate-mitigation plans as well as facilitates better understanding of the interactions between the climate and land processes. In this study, a land surface model (LSM) that represents the land-atmosphere interactions and plant phenological variations was introduced to assess the contributions of terrestrial ecosystems to atmospheric warming or cooling effects over East Asia over the last half century. Three main climate-regulating components were simulated: net radiation flux, carbon exchange, and moisture flux at the surface. Then, the contribution of each component to the atmospheric warming or cooling (negative or positive feedback to the atmosphere, respectively) was investigated. The results showed that the terrestrial ecosystem over the Siberian region has shown a relatively large increase in positive feedback due to the enhancement of biogeochemical processes, indicating an offset effect to delay global warming. Meanwhile, the Gobi Desert shows different regional variations: increase in positive feedback in its southern part but increase in negative one in its eastern part, which implies the eastward movements of desert areas. As such, even though the LSM has limitations, this model approach to quantify the climate regulation is useful to extract the relevant characteristics in its spatio-temporal variations.

Application of the Large-scale Climate Ensemble Simulations to Analysis on Changes of Precipitation Trend Caused by Global Climate Change (기후변화에 따른 강수 특성 변화 분석을 위한 대규모 기후 앙상블 모의자료 적용)

  • Kim, Youngkyu;Son, Minwoo
    • Atmosphere
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    • v.32 no.1
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    • pp.1-15
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    • 2022
  • Recently, Japan's Meteorological Research Institute presented the d4PDF database (Database for Policy Decision-Making for Future Climate Change, d4PDF) through large-scale climate ensemble simulations to overcome uncertainty arising from variability when the general circulation model represents extreme-scale precipitation. In this study, the change of precipitation characteristics between the historical and future climate conditions in the Yongdam-dam basin was analyzed using the d4PDF data. The result shows that annual mean precipitation and seasonal mean precipitation increased by more than 10% in future climate conditions. This study also performed an analysis on the change of the return period rainfall. The annual maximum daily rainfall was extracted for each climatic condition, and the rainfall with each return period was estimated. In this process, we represent the extreme-scale rainfall corresponding to a very long return period without any statistical model and method as the d4PDF provides rainfall data during 3,000 years for historical climate conditions and during 5,400 years for future climate conditions. The rainfall with a 50-year return period under future climate conditions exceeded the rainfall with a 100-year return period under historical climate conditions. Consequently, in future climate conditions, the magnitude of rainfall increased at the same return period and, the return period decreased at the same magnitude of rainfall. In this study, by using the d4PDF data, it was possible to analyze the change in extreme magnitude of rainfall.

A Study on Vulnerability Assessment to Climate Change in Regional Fisheries of Korea (국내 수산 부문의 지역별 기후변화 취약성 평가 연구)

  • Lee, Beo-Dul;Kim, Bong-Tae;Cho, Yong-Sung
    • The Journal of Fisheries Business Administration
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    • v.42 no.1
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    • pp.57-70
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    • 2011
  • Fisheries are subject to unexpected weather condition. While some change of it may be positive for some fisheries, the current state suggests that the effects will be undesirable for many fisheries. The aim of this study is to assess the vulnerability to climate change in 11 regional fisheries of Korea using the framework of IPCC. The vulnerability assessment depends upon the interrelation of three key elements; exposure, sensitivity and adaptive capacity, which were derived from Analytical Hierarchy Process method in this study. These elements would contribute to comprehend relative importance at the regional characteristics of fisheries. We compared the vulnerability index of 11 regional fisheries so as to look for strategies and adaptation methods to the impacts of potential climate change. Jeoun-Nam, Kyeong-Nam, and Jeju are identified as the most vulnerable provinces to climate change on their fisheries because they have high level of sensitivity to predicted climate change and relatively low adaptive capacity. The relatively low vulnerability of Ulsan, Gyeonggi reflects high financial independence, well-equipped infrastructure, social capital in these regions. Understanding of vulnerability to climate change suggests future research directions. This paper will provide a guide to local policy makers and fisheries managers about vulnerability and adaptation planning to climate change.