• Title/Summary/Keyword: Climate Technology

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A copula based bias correction method of climate data

  • Gyamfi Kwame Adutwum;Eun-Sung Chung
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2023년도 학술발표회
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    • pp.160-160
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    • 2023
  • Generally, Global Climate Models (GCM) cannot be used directly due to their inherent error arising from over or under-estimation of climate variables compared to the observed data. Several bias correction methods have been devised to solve this problem. Most of the traditional bias correction methods are one dimensional as they bias correct the climate variables separately. One such method is the Quantile Mapping method which builds a transfer function based on the statistical differences between the GCM and observed variables. Laux et al. introduced a copula-based method that bias corrects simulated climate data by employing not one but two different climate variables simultaneously and essentially extends the traditional one dimensional method into two dimensions. but it has some limitations. This study uses objective functions to address specifically, the limitations of Laux's methods on the Quantile Mapping method. The objective functions used were the observed rank correlation function, the observed moment function and the observed likelihood function. To illustrate the performance of this method, it is applied to ten GCMs for 20 stations in South Korea. The marginal distributions used were the Weibull, Gamma, Lognormal, Logistic and the Gumbel distributions. The tested copula family include most Archimedean copula families. Five performance metrics are used to evaluate the efficiency of this method, the Mean Square Error, Root Mean Square Error, Kolmogorov-Smirnov test, Percent Bias, Nash-Sutcliffe Efficiency and the Kullback Leibler Divergence. The results showed a significant improvement of Laux's method especially when maximizing the observed rank correlation function and when maximizing a combination of the observed rank correlation and observed moments functions for all GCMs in the validation period.

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북서태평양 중기해양예측모형(OMIDAS) 해면수온 예측성능: 계절적인 차이 (Predictability of Sea Surface Temperature in the Northwestern Pacific simulated by an Ocean Mid-range Prediction System (OMIDAS): Seasonal Difference)

  • 정희석;김용선;신호정;장찬주
    • Ocean and Polar Research
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    • 제43권2호
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    • pp.53-63
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    • 2021
  • Changes in a marine environment have a broad socioeconomic implication on fisheries and their relevant industries so that there has been a growing demand for the medium-range (months to years) prediction of the marine environment Using a medium-range ocean prediction model (Ocean Mid-range prediction System, OMIDAS) for the northwest Pacific, this study attempted to assess seasonal difference in the mid-range predictability of the sea surface temperature (SST), focusing on the Korea seas characterized as a complex marine system. A three-month re-forecast experiment was conducted for each of the four seasons in 2016 starting from January, forced with Climate Forecast System version 2 (CFSv2) forecast data. The assessment using relative root-mean-square-error was taken for the last month SST of each experiment. Compared to the CFSv2, the OMIDAS revealed a better prediction skill for the Korea seas SST, particularly in the Yellow sea mainly due to a more realistic representation of the topography and current systems. Seasonally, the OMIDAS showed better predictability in the warm seasons (spring and summer) than in the cold seasons (fall and winter), suggesting seasonal dependency in predictability of the Korea seas. In addition, the mid-range predictability for the Korea seas significantly varies depending on regions: the predictability was higher in the East Sea than in the Yellow Sea. The improvement in the seasonal predictability for the Korea seas by OMIDAS highlights the importance of a regional ocean modeling system for a medium-range marine prediction.

Potential of regression models in projecting sea level variability due to climate change at Haldia Port, India

  • Roshni, Thendiyath;K., Md. Sajid;Samui, Pijush
    • Ocean Systems Engineering
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    • 제7권4호
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    • pp.319-328
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    • 2017
  • Higher prediction efficacy is a very challenging task in any field of engineering. Due to global warming, there is a considerable increase in the global sea level. Through this work, an attempt has been made to find the sea level variability due to climate change impact at Haldia Port, India. Different statistical downscaling techniques are available and through this paper authors are intending to compare and illustrate the performances of three regression models. The models: Wavelet Neural Network (WNN), Minimax Probability Machine Regression (MPMR), Feed-Forward Neural Network (FFNN) are used for projecting the sea level variability due to climate change at Haldia Port, India. Model performance indices like PI, RMSE, NSE, MAPE, RSR etc were evaluated to get a clear picture on the model accuracy. All the indices are pointing towards the outperformance of WNN in projecting the sea level variability. The findings suggest a strong recommendation for ensembled models especially wavelet decomposed neural network to improve projecting efficiency in any time series modeling.

기후모델에 나타난 미래기후에서 쓰시마난류의 변화와 그 영향 (Changes in the Tsushima Warm Current and the Impact under a Global Warming Scenario in Coupled Climate Models)

  • 최아라;박영규;최희진
    • Ocean and Polar Research
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    • 제35권2호
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    • pp.127-134
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    • 2013
  • In this study we investigated changes in the Tsushima Warm Current (TWC) under the global warming scenario RCP 4.5 by analysing the results from the World Climate Research Program's (WCRP) Coupled Model Intercomparison Project Phase 5 (CMIP5). Among the four models that had been employed to analyse the Tsushima Warm Current during the 20th Century, in the CSIRO-Mk3.6.0 and HadGEM2-CC models the transports of the Tsushima Warm Current were 2.8 Sv and 2.1 Sv, respectively, and comparable to observed transport, which is between 2.4 and 2.77 Sv. In the other two models the transports were much greater or smaller than the observed estimates. Using the two models that properly reproduced the transport of the Tsushima Warm Current we investigated the response of the current under the global warming scenario. In both models the volume transports and the temperature were greater in the future climate scenario. Warm advection into the East Sea was intensified to raise the temperature and consequently the heat loss to the air.

윤리풍토가 일부 임상치과위생사 직무만족에 미치는 영향 (Effects of Ethical Climate on Job Satisfaction of Clinical Dental Hygienists)

  • 천석연;황창주
    • 한국치위생학회지
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    • 제18권4호
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    • pp.515-524
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    • 2018
  • Objectives: The purpose of this study is to investigate whether the ethical climate affects the job satisfaction of the clinical dental hygienists. Methods: A self-reported questionnaire was filled out by 207 dental hygienists. The data were analyzed by t-test or one-way ANOVA, multiple regression analysis, and Pearson's correlation analysis using IBM SPSS Statistics 19.0 program. Results: The factors affecting the job satisfaction of the general and ethical climate were the work experiences, the completion of vocational ethics education, the self interest type, the friendship type, the rule and the procedure type. When working experience and vocational ethics education are completed, self interest type and friend type have improved job satisfaction as the score increases, while job satisfaction is lowered as the rule and procedure type are increased. Conclusions: Since healthy ethical climate correlates with job satisfaction, it is necessary to establish an ethical climate in order to improve the job satisfaction of clinical dental hygienists. Efficient and stable management of ethical climate within dental clinics can be achieved when mutual interests are emphasized and respected rather than obedience is empathized to hospital regulations, procedures and policies.

The Impact of Organizational Climate on Organizational Reputation - The Mediating Role of Organizational Health: An Empirical Study from Jordan

  • AL HARAISA, Yazan Emnawer;AL-HARAIZAH, Ahed
    • The Journal of Asian Finance, Economics and Business
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    • 제8권10호
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    • pp.29-35
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    • 2021
  • The current study's objective isto determine the impact of organizational climate on organizational reputation in the context of organizational health as a mediating variable, in a case study of textile enterprises in Jordan that are listed on the Industrial Qualified zones. The study population contains (12) companies, according to the industrial qualified zones, with 317 employees who are working at CEO, deputy CEO, and supervisor positions chosen through convenience sampling. While the final sample of the current study consists of 174. Furthermore, to test the current study's hypotheses, the Smart Partial Least Square (PLS) technique was applied. Additionally, the current study concludes that there is a positive impact of organizational climate on organizational reputation. The current study shows that organizational climate has a positive impact on organizational health and organizational health has a positive impact on organizational reputation. Moreover, there is the mediation impact of organizational health on the relationship between organizational climate and organizational reputation. Based on the results of the current study, the study proposes that the level of organizational climate, organizational health, and organizational reputation in the examined companies be enhanced and increased.

개화기(1876~1910) 서양인이 본 한반도 기후 해석 (The Perception about the Climate of the Korean Peninsula by Westerners Visited in Enlightenment Period (1876~1910))

  • 신지은;전영신;권원태
    • 한국기후변화학회지
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    • 제3권3호
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    • pp.161-181
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    • 2012
  • 개화기(1876~1910) 조선은 서양의 과학기술이 활발하게 소개되었다는 점에서 격동의 시기였다. 이러한 서양 근대과학과 동양과학의 상호작용은 당시 조선을 방문하였던 서양인의 기록에서 일면 엿볼 수 있다. 본 연구는 개화기에 조선을 방문하였던 서양인의 문헌 중 날씨와 기후에 대한 기록에 초점을 맞추어 그 특징을 파악하는 데에 목적이 있다. 연구 결과는 수치를 이용한 정량적 기록, 근대과학 체계에서 기후 파악, 그리고 강우에 대한 기록이라는 세 가지 특징으로 정리할 수 있다. 이와 같은 특징은 개화기 조선을 방문한 서양인들이 한반도의 기후에 대해 객관적이고 체계적으로 이해하고 있었음을 보여준다.

Impacts of Climate Change and Financial Support on Household Livelihoods: Evidence from the Northwest Sub-Region of Vietnam

  • DO, Thi Thu Hien;NGUYEN, Thi Lan Anh;NGUYEN, Thi Hoai Phuong
    • The Journal of Asian Finance, Economics and Business
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    • 제9권6호
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    • pp.115-126
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    • 2022
  • The study's goal is to determine the amount of climate change's impact on ethnic minority (EM) households' livelihoods, as well as their adaptability to climate change and long-term viability. The research was conducted in Vietnam's Northwestern Sub-region, where ethnic minorities account for more than half of the overall population. The study uses a combination of qualitative and quantitative methods based on a survey of 480 households in 04 provinces severely affected by climate change in the Northwest sub-region of Vietnam. The results show that: climate change (extreme weather events) occurs with increasing frequency, mainly affecting the life expectancy, health, and capital of households; Vulnerable groups (women, ethnic minorities) have a poor adaptive capacity and mainly suffer the consequences of shocks, are afraid to change their livelihoods; Microfinance plays an important role in enhancing the sustainability of livelihoods through increasing capital and financial assets and reducing the vulnerability of ethnic minority households. Finally, research has some solutions for microfinance - special credit specifically for ethnic minority households in the Northwest Sub-region: support for microfinance advice, home credit with transition orientations to adapt to climate change response and relieves its impact on the social lives.

AR콘텐츠를 활용한 기후위기그림책 패키지의 개발 사례 (A Case Study of the Development of Climate Crisis Picture Book Package Using AR Contents )

  • 한유미;박성원;최예정
    • Journal of Information Technology Applications and Management
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    • 제29권6호
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    • pp.145-157
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    • 2022
  • Climate crisis is one of the most urgent and serious threats to the right to life. As AR picture books are particularly effective for safety education, this study aimed to produce an AR picture book featuring animals that are endangered due to the climate crisis. In order to increase the educational effect and enhance the climate sensitivity, this study developed a children's activity workbook (with follow-up activities) and a teacher's guide (with lesson plans) as a package. To this end, market research and surveys were first conducted. Next, through the management and support of the Korea Institute of Startup & Entrepreneurship Development, this research team produced a climate crisis themed AR picture book package through expert advice, help from outsourcing companies, and field application. The package was promoted through publicity in various forms of media. The contents of the AR-using picture book package of this case study were introduced and then advantages and disadvantages were discussed.