• Title/Summary/Keyword: Climate Design

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Estimation of Design Wave Height for the Waters around the Korean Peninsula

  • Lee, Dong-Young;Jun, Ki-Cheon
    • Ocean Science Journal
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    • v.41 no.4
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    • pp.245-254
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    • 2006
  • Long term wave climate of both extreme wave and operational wave height is essential for planning and designing coastal structures. Since the field wave data for the waters around Korean peninsula is not enough to provide reliable wave statistics, the wave climate information has been generated by means of long-term wave hindcasting using available meteorological data. Basic data base of hindcasted wave parameters such as significant wave height, peak period and direction has been established continuously for the period of 25 years starting from 1979 and for major 106 typhoons for the past 53 years since 1951 for each grid point of the North East Asia Regional Seas with grid size of 18 km. Wind field reanalyzed by European Center for Midrange Weather Forecasts (ECMWF) was used for the simulation of waves for the extra-tropical storms, while wind field calculated by typhoon wind model with typhoon parameters carefully analyzed using most of the available data was used for the simulation of typhoon waves. Design wave heights for the return period of 10, 20, 30, 50 and 100 years for 16 directions at each grid point have been estimated by means of extreme wave analysis using the wave simulation data. As in conventional methodsi of design criteria estimation, it is assumed that the climate is stationary and the statistics and extreme analysis using the long-term hindcasting data are used in the statistical prediction for the future. The method of extreme statistical analysis in handling the extreme vents like typhoon Maemi in 2003 was evaluated for more stable results of design wave height estimation for the return periods of 30-50 years for the cost effective construction of coastal structures.

A Development of Nonstationary Frequency Analysis Model using a Bayesian Multiple Non-crossing Quantile Regression Approach (베이지안 다중 비교차 분위회귀 분석 기법을 이용한 비정상성 빈도해석 모형 개발)

  • Uranchimeg, Sumiya;Kim, Yong-Tak;Kwon, Young-Jun;Kwon, Hyun-Han
    • Journal of Coastal Disaster Prevention
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    • v.4 no.3
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    • pp.119-131
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    • 2017
  • Global warming under the influence of climate change and its direct impact on glacial and sea level are known issue. However, there is a lack of research on an indirect impact of climate change such as coastal structure design which is mainly based on a frequency analysis of water level under the stationary assumption, meaning that maximum sea level will not vary significantly over time. In general, stationary assumption does not hold and may not be valid under a changing climate. Therefore, this study aims to develop a novel approach to explore possible distributional changes in annual maximum sea levels (AMSLs) and provide the estimate of design water level for coastal structures using a multiple non-crossing quantile regression based nonstationary frequency analysis within a Bayesian framework. In this study, 20 tide gauge stations, where more than 30 years of hourly records are available, are considered. First, the possible distributional changes in the AMSLs are explored, focusing on the change in the scale and location parameter of the probability distributions. The most of the AMSLs are found to be upward-convergent/divergent pattern in the distribution, and the significance test on distributional changes is then performed. In this study, we confirm that a stationary assumption under the current climate characteristic may lead to underestimation of the design sea level, which results in increase in the failure risk in coastal structures. A detailed discussion on the role of the distribution changes for design water level is provided.

A Study at Investigating the Climate Change in East Asia with Changing Sea Surface Temperature

  • Park, Geun-Yeong;Lim, Yong-Jae
    • Journal of Integrative Natural Science
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    • v.13 no.1
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    • pp.27-33
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    • 2020
  • The unsustainable human activities like increased use of automobiles, heavy industrialization and the use of large volumes of fertilizers, chemicals and pesticides in the agricultural land cause climate change problems in one way or another. Under normal circumstances, the heat radiations from the sun will be reflected back. An excessive volume of GHGs in the atmosphere would prevent these radiations from reflecting back. East Asia is facing severe climate change issues in recent times. A lot of climate change problems such as hurricanes and floods have been reported from this region in the last couple of decades. The study aimed at investigating the climate change in East Asia with changing Sea Surface Temperature (SST). The study adopted a quantitative research method with a case study research design where a deliberate focus was made on the East Asia Region. Secondary data was gathered and analyzed to yield both descriptive and inferential statistics. The study concluded that the impact of East Asia Climate variability was significant mainly for some extreme events. Also, the study concluded that there was a significant link between the change of the East Asia climate variability and that of the sea surface temperature. Further, the study concluded that a linear relationship existed between the sea surface temperature and the climate of East Asia. Hence, a linear regression was a significant predictor of the East Asia Climate (EAC) based on changing sea surface temperature. The model revealed that 37.4% of the variations in the climate change index were explained by the changes in the sea surface temperature. The climate was expected to change with a value of 49.48 for a unit change in the sea surface temperature.

The Impact of Safety Climate and Fatigue on Safety Performance of Operating Room Nurses (수술실 간호사의 안전분위기와 피로 수준이 안전이행에 미치는 영향)

  • Choi, U-Eun;Kim, Hyun-Young
    • Journal of Korean Academy of Nursing Administration
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    • v.22 no.5
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    • pp.471-479
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    • 2016
  • Purpose: This study was conducted to evaluate the level of safety climate, fatigue, and safety performance and to identify the impact of safety climate and fatigue on the safety performance of operating room nurses. Methods: The study design was a descriptive survey. Participants were 174 operating room nurses from two general hospitals and two university hospitals in S and D cities. Three structurally designed questionnaires were used to evaluate their safety climate, fatigue, and safety performance. Collected data were analyzed using descriptive analysis, t-tests, ANOVAs, Pearson correlation coefficient, and stepwise multiple regression. Results: Safety performance of operating room nurses had a mean of 3.26 on a 5-point scale. 'Current department career'(${\beta}=.17$, p=.006) and 'safety climate (work-unit contribution) (${\beta}=.63$, p<.001) accounted for 39% of the variance in operating room nurses' safety performance. Conclusion: Findings indicate that work-unit contribution towards safety climate is an important factor in increasing operating room nurses' safety performance. Therefore, it is essential to find motivational properties consistent with the characteristics of the operating room environment.

The Impact of Organizational Information Security Climate on Employees' Information Security Participation Behavior (조직의 정보보안 분위기가 조직 구성원의 정보보안 참여 행동에 미치는 영향)

  • Park, Jaeyoung;Kim, Beomsoo
    • The Journal of Information Systems
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    • v.29 no.4
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    • pp.57-76
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    • 2020
  • Purpose Although examining the antecedents of employees' extra-role behavior (i.e. information security participation behavior) in the information security context is significant for researchers and practitioners, most behavioral security studies have focused on employees' in-role behavior (i.e. information security policy compliance). Thus, this research addresses this gap by investigating how organizational information security climate influences information security participation behavior based on social information processing theory and Griffin and Neal's safety model. Design/methodology/approach We developed a research model by applying Griffin and Neal's safety model to the information security context and then tested our research model by conducting an online survey for employees of organizations with information security policies. Structural equation modeling (SEM) with SmartPLS 3.3.2 is used to test the corresponding hypothesis. Findings Our results show that organizational information security climate, information security knowledge, information security motivation are effective in motivating information security participation behavior. Also, we find that organizational information security climate positively influences both information security knowledge and information security motivation. Our findings emphasize the importance of organizational information security climate because it is capable of affecting employees on information security participation behavior. Our study contributes to the literature on information security by exploring the role of organizational information security climate in enhancing employees' information security participation behavior.

Analysis of the effect of climate change on IDF curves using scale-invariance technique: focus on RCP 8.5 (Scale-Invariance 기법을 이용한 IDF 곡선의 기후변화 영향 분석: RCP 8.5를 중심으로)

  • Choi, Jeonghyeon;Lee, Okjeong;Kim, Sangdan
    • Journal of Korea Water Resources Association
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    • v.49 no.12
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    • pp.995-1006
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    • 2016
  • According to 5th IPCC Climate Change Report, there is a very high likelihood that the frequency and intensity of extreme rainfall events will increase. In reality, flood damage has increased, and it is necessary to estimate the future probabilistic design rainfall amount that climate change is reflected. In this study, the future probabilistic design precipitation amount is estimated by analyzing trends of future annual maximum daily rainfall derived by RCP 8.5 scenarios and using the scale-invariance technique. In the first step, after reviewing the time-scale characteristics of annual maximum rainfall amounts for each duration observed from 60 sites operating in Korea Meterological Administration, the feasibility of the scale-invariance technique are examined using annual daily maximum rainfall time series simulated under the present climate condition. Then future probabilistic design rainfall amounts for several durations reflecting the effects of climate change are estimated by applying future annual maximum daily rainfall time series in the IDF curve equation derived by scale-invariance properties. It is shown that the increasing trend on the probabilistic design rainfall amount has resulted on most sites, but the decreasing trend in some regions has been projected.

Toward Net-Zero Energy Retrofitting: Building-Integrated Photovoltaic Curtainwalls

  • Kim, Kyoung Hee;Im, Ok-Kyun
    • International Journal of High-Rise Buildings
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    • v.10 no.1
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    • pp.35-43
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    • 2021
  • With the rapid urbanization and growing energy use intensity in the built environment, the glazed curtainwall has become ever more important in the architectural practice and environmental stewardship. Besides its energy efficiency roles, window has been an important transparent component for daylight penetration and a view-out for occupant satisfaction. In response to the climate crisis caused by the built environment, this research focuses on the study of net-zero energy retrofitting by using a new building integrated photovoltaic (BIPV) curtainwall as a sustainable alternative to conventional window systems. Design variables such as building orientations, climate zones, energy attributes of BIPV curtainwalls, and glazed area were studied, to minimize energy consumption and discomfort hours for three cities representing hot (Miami, FL), mixed (Charlotte, NC), and cold (Minneapolis, MN). Parametric analysis and Pareto solutions are presented to provide a comprehensive explanation of the correlation between design variables and performance objectives for net-zero energy retrofitting applications.

Hydrologic Performance Change of Small Scale Hydro Power Plant with Rainfall Condition Change (강우형태변화에 의한 소수력발전소 수문학적 성능의 변화)

  • Park, Wan-Soon;Lee, Chul-Hyung
    • Journal of the Korean Solar Energy Society
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    • v.29 no.6
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    • pp.56-61
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    • 2009
  • The effects of design parameters for small scale hydro power(SSHP) plants due to climate change have been studied. The model to predict hydrologic performance for SSHP plants is used in this study. The results from analysis far rainfall conditions based on KIER model show that the capacity and load factor of SSHP site had large difference between the period. Especially, the hydrologic performance of SSHP site due to rainfall condition of recent period varied in design flowrate sensitively. However climate change gave small effect in load factor of existing SSHP plant. And also, the methodology represented in this study can be used to decide the primary design specifications of SSHP sites.

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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