• 제목/요약/키워드: change problem

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학교 기후 변화 교육의 현황과 과제 (The Current State and Tasks of School Climate Change Education)

  • 윤순진
    • 한국환경교육학회지:환경교육
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    • 제22권2호
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    • pp.1-22
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    • 2009
  • Even though climate change is visibly proceeding and public concern about climate change is increasing both nationally and internationally, teenagers' and students' perception of climate change is relatively low in Korea. Since climate change is a problem with long-term effects, it is young people including children and juveniles of the current generation and future generations who are more affected by climate change. They are the most interested party who should know why climate change happens, what kind of impacts will be given, and how to respond to the problem. Based on the aforementioned concern, this study aims to explore the extent and contents of school education with regard to climate change in Korea as well as in other advanced countries and to provide policy suggestions. This study finds that school climate change education requires consideration of multiple aspects including reorganization of school curriculum, revitalization of related programs by school, expansion of teachers' training chances, in which multiple institutions such as the Ministry of Environment, the Ministry of Education, Science and Technology, Offices of Education are related and, consequently, the activation of climate change education program is by no means simple. Therefore, for effective climate change education in schools, cooperation and coordination of related institutions are essential, along with development of diverse school education curriculums and programs and training programs for teachers.

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정규확률변수 관측치열에 대한 베이지안 변화점 분석 : 서울지역 겨울철 평균기온 자료에의 적용 (Bayesian Change Point Analysis for a Sequence of Normal Observations: Application to the Winter Average Temperature in Seoul)

  • 김경숙;손영숙
    • 응용통계연구
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    • 제17권2호
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    • pp.281-301
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    • 2004
  • 본 논문에서는 일변량 정규분포를 따르는 확률변수의 관측치열에 대한 변화점 문제(change point problem)를 고찰한다. 변화점의 존재유무, 그리고 만일 변화점이 존재한다면 어떠한 유형으로 발생했는지 즉, 변화점 발생 이후로 평균만 변화, 분산만 변화, 또는 평균과 분산 모두가 변화했는지를 밝힌다. 가능한 여러 유형의 변화모형들 가운데 최적의 모형을 선택하기 위해 베이지안 모형선택 기법을 이용하고, 선택된 모형에 내재된 모수를 추정 하기 위해 메트로폴리스-혜스팅스 알고리 즘을 포함한 깁스샘플링 을 이용한다. 이러한 방법론은 모의실험을 통해 검토되고, 또한 서울지역의 겨울철 평균기온 자료에 적용된다.

Prediction of reservoir sedimentation: A case study of Pleikrong Reservoir

  • Thu Hien Nguyen;XuanKhanh Do
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2023년도 학술발표회
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    • pp.36-36
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    • 2023
  • Sedimentation is a natural process that occurs in all reservoirs. Sedimentation problem reduces the storage capacity of the reservoir and limits its ability to provide water for various uses, such as irrigation, hydropower generation, and flood control. Therefore, predicting reservoir sedimentation is important for ensuring the efficient operation and sedimentation management of a reservoir and . In this study, the HECRAS model was applied to predict longitudinal distribution of deposited sediment in the Pleikrong reservoir to 2050. Different scenarios was considered: (i) no climate change, (ii) climate change (under two emissions scenarios, RCP4.5 and RCP8.5), and (iii) climate change and land use change (followed land use planning of the watershed). The computation results with different scenarios were analyses and compared. The results show that the reservoir reduced storage volume's rate and sedimentation proceed toward to the dam in the case of climate change is faster than in the case of no climate change. Analyses also indicates that following the land used planning could also improve the long-term problem of the reservoir sedimentation. The outcomes of this study will be helpful for a sustainable plan of sediment management for the Pleikrong reservoir.

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최단 경로 갱신문제를 해결하는 분산알고리듬 (An Efficient Distributed Algoritm for the Weighted Shortest-path Updating Problem)

  • 박정호;이경오;강규철
    • 한국정보처리학회논문지
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    • 제7권6호
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    • pp.1778-1784
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    • 2000
  • We consider the weighted shortest path updating problem, that is, the problem to reconstruct the weighted shortest paths in response to topology change of the network. This appear proposes a distributed algorithms that reconstructs the weighted shortest paths after several processors and links are added and deleted. its message complexity and ideal-time complexity are O(p$^2$+q+n') and O(p$^2$+q+n') respectively, where n' is the number of processors in the network after the topology change, q is the number of added links, and p is the total number of processors in he biconnected components (of the network before the topology change) including the deleted links or added links.

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창의적 문제 해결이론(트리즈)을 이용한 자전거용 무단 변속장치의 개발 (A Study on the Development of a Continuously Variable Transmission for Bicycles by Theory of Inventive Problem Solving (TRIZ))

  • 이건상;최준호;유병철
    • 한국정밀공학회지
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    • 제24권7호
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    • pp.75-82
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    • 2007
  • This paper represents a study on the development of the conceptual design for the bicycle transmission by TRIZ. At first the problem of the transmission of commercial bicycles was analyzed. The problem was defined as "the variable sprocket pitch diameter with respect to the tension change of chain". The conceptual solutions were derived by Su-Field Model Analysis, IFR(Ideal Final Result), SLP(Smart Little People), and Contradiction Matrix. The here developed sprocket prototype shows the automatic change of sprocket pitch diameter with the tension change of chain.

대변형 탄소성 접촉문제에 관한 연구 (A Study on the Elastic-Plastic Contact Problem for Large Deformation)

  • 전병희;김동원
    • 대한기계학회논문집
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    • 제17권7호
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    • pp.1658-1667
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    • 1993
  • In this research, a numerical algorithm has been developed, which can be applied to the large deformation and large displacement contact problems between two deformable bodies. The contact conditions expressed in terms of the rate of angle change have been proposed considering the change in geometric shape and rate of contact force. A set of linear simultaneous equations is constructed by adding the geometric shape change and contact conditions to the original stiffness matrix. A new method to determine time increment has been proposed based on Euler method, in which the condition to prevent the contact bodies from penetrating and overrunning each other has been taken into consideration. Practical application to contact problem is extrusion in which bodies are sliding along the contact boundary.

퍼지-뉴럴 제어기를 이용한 유도전동기 속도 제어 (Speed Control of an Induction Moter using Fuzzy-Neural Controller)

  • 최성대;김낙교
    • 대한전기학회논문지:시스템및제어부문D
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    • 제55권10호
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    • pp.443-445
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    • 2006
  • Generally PI controller is used to control the speed of an induction motor. It has the good performance of speed control in case of adjusting the control parameters. But it occurred the problem to change the control parameters in the change of operation condition. In order to solve this problem, Fuzzy control or Artificial neural network is introduced in the speed control of an induction motor. However, Fuzzy control have the problems as the difficulties to change the membership function and fuzzy rule and the remaining error Also Neural network has the problem as the difficulties to analyze the behavior of inner part. Therefore, the study on the combination of two controller is proceeded. In this paper, Fuzzy-neural controller to make up these controllers in parallel is proposed and the speed control of an induction motor is performed using the proposed controller Through the experiment, the fast response and good stability of the proposed speed controller is proved.

기후변화와 대기환경의 통합적 관리에 대한 고찰 (A Review of the Integrated Strategy for Climate Change and Air Pollution Management)

  • 송창근;이석조;윤종수
    • 한국대기환경학회지
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    • 제27권6호
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    • pp.805-818
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    • 2011
  • The unequivocal risk of climate change, the weakness of energy security, and the problem of air quality will be possibly accelerated by the same reason, the enhanced fossil fuel dependancy in the future. It is obvious that greenhouse gases and air pollutants are mainly emitted from same sources. Moreover, greenhouse gases and air pollutants have their adversed impacts on same socio-economical, and environmental sectors. With these regards, several but limited studies have emphasized on the importance of the integrated management of climate change and air quality problem. In this study, we address the current trend of energy consumption and the change of air quality condition. Also the related policies are checked out in order to reduce emissions of greenhouse gases and air pollutants in Korea. By surveying previous studies, it is shown that the cost of climate change actions can be reduced by air quality co-benefits and vis-a-versa. Also the integrated strategy for climate change and air quality is introduced in term of cost-effectiveness and co-benefit.

Change Analysis with the Sample Fourier Coefficients

  • Jaehee Kim
    • Communications for Statistical Applications and Methods
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    • 제3권1호
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    • pp.207-217
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    • 1996
  • The problem of detecting change with independent data is considered. The asymptotic distribution of the sample change process with the sample Fourier coefficients is shown as a Brownian Bridge process. We suggest to use dynamic statistics such as a sample Brownian Bridge and graphs as statistical animation. Graphs including change PP plots are given by way of illustration with the simulated data.

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