• Title/Summary/Keyword: Scaling factor (SF)

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Development of Poisson cluster generation model considering the climate change effects (기후변화 영향을 고려한 포아송 클러스터 가상강우생성모형 개발 및 검증)

  • Park, Hyunjin;Han, Jaemoon;Kim, Jongho;Kim, Dongkyun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.189-189
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    • 2015
  • 본 연구는 기후변화의 영향을 고려한 포아송 강우생성모형의 일종인 MBLRP(Modified Bartlett-Lewis Rectangular Pulse)를 개발하고, 대한민국 주요 도시에 대해 향후 100년간 강우의 변화를 살펴보았다. 기존 MBLRP 모형에서 기후변화에 따른 강우량 변화를 고려할 수 있도록 GCM 모형의 강우 자료를 활용하였고, GCM 모형으로부터 발생하는 불확실성을 고려하기 위해 IPCC의 RCP(Representative Concentration Pathways) 시나리오를 모의한 16개의 GCM 모형을 사용하였다. 2007년부터 2099년까지의 미래기간을 3개의 시 구간으로 구분하고, 16개 GCM 앙상블을 사용하여 미래기간 동안 대한민국 16개 도시에 대해 1000개의 샘플을 BWA 방법을 이용하여 생성하였다. 제어기간(1973-2005) 대비 미래기간(2007-2099)의 변화율을 나타내는 FOC(factor of change)와 온도의 연별 변화율을 나타내는 SF(scaling factor)의 개념을 결합하여 미래기간에 대한 CF(correction factor)를 산정하였다. 이때 CF는 16개 도시의 연 단위 강우량 변화 비율을 월별로 나타내며, 제어기간의 월 강우 관측치와 CF를 몬테카를로 모의를 실시하여 미래기간의 강우 시나리오를 산정한다. 이를 통해 월 평균 강우량 통계치를 연 단위로 얻을 수 있으며, 월 평균 강우량이 월 평균 분산, 무강우확률, 자기상관계수와 가지는 선형 관계를 통해 강우 통계치를 산출한다. 이와 같은 강우 통계치는 가상강우생성모형인 MBLRP 모형에 입력 자료로 활용되어 월 강우량을 시 단위의 강우 시계열 자료로 생성해낸다. 최종적으로 MBLRP 모형으로 산정된 시 단위 강우 시계열은 기후변화 영향을 고려한 GCMs 앙상블로 생성된 강우 시나리오를 기반으로 산출되기 때문에 향후 수자원 분석에 활용 가능할 것이라 기대된다.

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Self-Tuning Fuzzy Logic Controller for a Dual Star Induction Machine

  • Merabet, Elkheir;Amimeur, Hocine;Hamoudi, Farid;Abdessemed, Rachid
    • Journal of Electrical Engineering and Technology
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    • v.6 no.1
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    • pp.133-138
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    • 2011
  • This paper proposes a simple but robust self-tuning fuzzy logic controller for the speed regulation of a dual star induction machine based on indirect field oriented control. For feed the two star of this machine, two voltage source inverters based on sinus-triangular pulse-width modulation techniques are introduced. The simulation results show the robustness and good performance of the proposed controller.

Development and Psychometric Evaluation of a Quality of Life Scale for Korean Patients with Cancer(C-QOL) (한국 암 특이형 삶의 질 측정도구(C-QOL) 개발 및 평가)

  • Lee, Eun-Hyun
    • Journal of Korean Academy of Nursing
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    • v.37 no.3
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    • pp.324-333
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    • 2007
  • Purpose: The purpose of this study was to develop and evaluate a quality of life scale for Korean patients with cancer (C-QOL). Methods: The C-QOL was developed and validated as follows, item generation, pilot study, and psychometric tests. A total of 337 patients diagnosed with stomach, liver, lung, colon, breast, or cervix cancer were recruited. The patients were asked to complete the preliminary questionnaire comprising the content-validated items, the SF-36, and the ECOG performance status. The obtained data was analyzed using descriptive statistics, factor analysis, multidimensional scaling (MDS), multitrait/multi-item matrix, ANOVA, t-test, and Cronbach's alpha. Results: Preliminarily twenty-six items were generated through content validity and a pilot study. Factor analysis and MDS extracted a total of 21 items with a 5-point Likert-type scale (C-QOL). The C-QOL included five subscales: physical status (6 items), emotional status (6 items), social function (3 items), concern status (2 items), and coping function (4 items). The C-QOL established content validity, construct validity, item convergent and discriminant validity, known-groups validity, reliability, and sensitivity. Conclusion: The Newly developed C-QOL is an easily applicable instrument which established psychometric properties and reflected Korean culture. It is recommended for further study to examine the responsiveness of the C-QOL using a longitudinal research design.

Estimation and Mapping of Methane Emissions from Rice Paddies in Korea: Analysis of Regional Differences and Characteristics (전국 논에서 발생하는 메탄 배출량의 산정 및 지도화: 지역 격차 및 특성 분석)

  • Choi, Sung-Won;Kim, Joon;Kang, Minseok;Lee, Seung Hoon;Kang, Namgoo;Shim, Kyo-Moon
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.20 no.1
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    • pp.88-100
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    • 2018
  • Methane emissions from rice paddies are the largest source of greenhouse gases in the agricultural sector, but there are significant regional differences depending on the surrounding conditions and cultivation practices. To visualize these differences and to analyze their causes and characteristics, the methane emissions from each administrative district in South Korea were calculated according to the IPCC guidelines using the data from the 2010 Agriculture, Forestry and Fisheries Census, and then the results were mapped by using the ArcGIS. The nationwide average of methane emissions per unit area was $380{\pm}74kg\;CH_4\;ha^{-1}\;yr^{-1}$. The western region showed a trend toward higher values than the eastern region. One of the major causes resulting in such regional differences was the $SF_o$ (scaling factor associated with the application of organic matter), where the number of cultivation days played an important role to either offset or deepen the differences. Comparison of our results against the actual methane emissions data observed by eddy covariance flux measurement in the three KoFlux rice paddy sites in Gimje, Haenam and Cheorwon showed some differences but encouraging results with a difference of 10 % or less depending on the sites and years. Using the updated GWP (global warming potential) value of 28, the national total methane emission in 2010 was estimated to be $8,742,000tons\;CO_2eq$ - 13% lower than that of the National Greenhouse Gas Inventory Report (i.e., $10,048,000tons\;CO_2eq$). The administrative districts-based map of methane emissions developed in this study can help identify the regional differences, and the analysis of their key controlling factors will provide important scientific basis for the practical policy makings for methane mitigation.