• Title/Summary/Keyword: conservation law

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Direct Energy Method of Power System Stability Analysis and its Application by using Energy Conservation Law (에너지보존법칙을 이용한 전력계통 안정도 직접 해석법에서의 응용)

  • Lee, Yong-Hoon;Cho, Byoung-Hoon;Ryu, Heon-Su;Moon, Young-Hyun
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.10
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    • pp.1207-1214
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    • 1999
  • Many papers have recently been presented to develop energy functions for power systems. However, earlier studies adopted case-by-case approaches, which failed to give a general approach to deal with various kinds of generator models. In this paper, two useful theorems are developed regarding the integral relationships of the generator power versus its phasor current and voltage. By using the proposed theorems, an exact energy conservation law can be derived from the complex integral. The proposed energy conservation law, which is free of the generator model, can be utilized to develop energy functions for various kinds of generator models including the speed governors and exciters. An illustrative example is given for a multimachine system with the Eq' model of generator. This thesis also shows a possibility of more accurate and fast stability analysis by using the proposed Energy Conservation Law.

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Energy Conservation Law and its application for Direct Energy method of Power System Stability (에너지 보존법칙과 전력계통 안정도 직접 해석법에서의 응용)

  • Moon, Young-Hyun;Lee, Yong-Hoon;Cho, Byoung-Hoon;Ryu, Heon-Su;Choi, Byoung-Kon
    • Proceedings of the KIEE Conference
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    • 1998.11a
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    • pp.263-268
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    • 1998
  • Many papers have recently been presented to develop energy functions for power systems. However, earlier studies adopted case-by-case approaches, which failed to give a general approach to deal with various kinds of generator models. In this paper, two useful theorems are developed regarding the integral relationships of the generator power versus its phasor current and voltage. By using the proposed theorems, an exact energy conservation law can be derived from the complex integral. The proposed energy conservation law, which is free of the generator model, can be utilized to develop energy functions for various kinds of generator models including the speed governors, and exciters. An illustrative example is given for a multimachine system with the Eq' model of generator. This thesis also shows a possibility of more accurate and fast stability analysis by using the proposed Energy Conservation Law.

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A Study on Improving the Regulations for Conservation and Wise use in Rice Fields (논습지 보전과 현명한 이용을 위한 법제 정비방안)

  • KONG, Ra-kyoung
    • Journal of Fisheries and Marine Sciences Education
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    • v.29 no.1
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    • pp.51-63
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    • 2017
  • Rice Fields have provided large areas of open water for centuries in regions with a variety of rice-growing cultures, and, in addition to producing rice also provide other animal and/or plant food sources and medicinal plants, thus acting as wetland systems and helping to sustain livelihoods and human well-being in these regions. Also rice fields in many parts of the world support important wetland biodiversity, such as reptiles, amphibians, fish, crustacean, insects and mollusca, and play a significant ole in water-bird flyways and the conservation of water-bird populations. The purpose of this study is to find a way conservation of rice fields in connection with paddies's laws, for example, amend the Conservation of Wetlands Law or legislate for the conservation of paddies.

A Qualitative Method to Find Out the Impact Direction in Traffic Accident (충돌방향 해석을 위한 정성적 추론이론 개발 및 적용)

  • Lee, Dae Hee;Park, Jin Soo
    • Journal of the Korean Society of Safety
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    • v.32 no.3
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    • pp.136-140
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    • 2017
  • The physical tool for analyzing collision accidents narrows down to the conservation law of momentum. The conservation law of momentum which is also utilized to investigate or to analyze a traffic accident is essential to Newton mechanics. This paper suggests an alternative analytical tool based on the conservation law of momentum. Simply put, the tool is a alternative qualitative method of analyzing a car's direction to find out whether it is driving over the centerline This paper proposes a deduction theory that use qualitative information to make a qualitative analysis of which car drove over the center line.

THE DELTA STANDING WAVE SOLUTION FOR THE LINEAR SCALAR CONSERVATION LAW WITH DISCONTINUOUS COEFFICIENTS USING A SELF-SIMILAR VISCOUS REGULARIZATION

  • LI, XIUMEI;SHEN, CHUN
    • Bulletin of the Korean Mathematical Society
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    • v.52 no.6
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    • pp.1945-1962
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    • 2015
  • This paper is mainly concerned with the formation of delta standing wave for the scalar conservation law with a linear flux function involving discontinuous coefficients by using the self-similar viscosity vanishing method. More precisely, we use the self-similar viscosity to smooth out the discontinuous coefficient such that the existence of approximate viscous solutions to the delta standing wave for the Riemann problem is established and then the convergence to the delta standing wave solution is also obtained when the viscosity parameter tends to zero. In addition, the Riemann problem is also solved with the standard method and the instability of Riemann solutions with respect to the specific small perturbation of initial data is pointed out in some particular situations.

Odd solutions to perturbed conservation laws

  • Jerome A. Goldstein;Park, Mi-Ai
    • Bulletin of the Korean Mathematical Society
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    • v.33 no.4
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    • pp.521-530
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    • 1996
  • This paper treats the existence of odd solutions of the Cauchy problem for a perturbation of a conservation law.

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Study on Comparison of Korean and Japanese National Park Systems from the Conservation Perspective (보전적 측면에서 바라본 한국과 일본의 국립공원제도 비교)

  • Jo Tae-Dong
    • Journal of Environmental Science International
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    • v.13 no.10
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    • pp.871-882
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    • 2004
  • Korea's national park system resembles that of Japan in many ways. In this study, National park Systems of the two countries are compared from a standpoint of their historical backgrounds to be formed and in aspect of its conservation by the main revision of national park laws in perspective. In conclusion it was found out that Korea's toleration-based regulations on building park amenities have gradually neglected the park conservation effort, whereas Japan's authorization-oriented regulations have streng thened their emphasis on park conservation. From the comparison as above, the polices to be modified for Korean national park are proposed as follows: 1. National park system, which values diversity of species, is to be proposed. For this, the Article 8 which allows a development of National parks, Enforcement Ordinance Article 4, The Article 18 of Law, Enforcement Regulation Article 6 & 7 of National Park Law should be reviewed for deletion and revision. 2. On the basis of the laws, zoning system should be readjusted by discriminated conservation policy. Also, the readjustment of zoning system should be enforced after thorough analysis and research on the value of natural resources in the national park. 3. Korea should closely review the recently revised Japanese laws on the national parks and nature revitalization promotion for applying them to conservation policy of Korean national parks.

Policy of Soil Environment and Restoration Technology-Status and Recent Changes (토양환경 정책 및 복원 기술-현황과 최근변화)

  • Jang, Yeon-Su
    • Journal of the Korean Professional Engineers Association
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    • v.41 no.3
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    • pp.30-34
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    • 2008
  • Recently problems of soil and groundwater contamination occur in major construction sites of highway, dam and railways. Contaminants of oil fuels are also detected in the former fuel storage facilities of railroad station and army troops of transportation, etc. These facilities are planned as the sites of commercial infrastructures after restoration from pollutants by the law of soil environment conservation of Korea. In this manuscript, the contents of soil environment conservation law including soil assessment and restoration technology are introduced. Recent changes of soil environment area are also analyzed.

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The Characteristic Analysis of E.M.F. Induced by Moving Normal Spot in a Cylindrical Superconducting Foil

  • Kim, Ho-Min;Bae, Joon-Han;Yoon, Yong-Soo;Chu, Yong;Ko, Tae-Kuk;Han, Tae-Su
    • Progress in Superconductivity
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    • v.1 no.2
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    • pp.99-104
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    • 2000
  • The e.m.f. induced by a normal spot moving in a superconducting foil has been investigated by using the simulation and the experiment of a simple superconducting Power Supply. The induced e.m.f. has been derived theoretically from the magnetic field distribution within the spot. It is the sum of a DC component induced constantly by the Faraday's law during the spot's movement and a pulse component induced periodically by the flux conservation law at every electrical degrees 2$\pi$ radians. The DC component of the output voltage appears slightly nonlinear to the rotating speed, having values greater than the linear approximation values. The theoretical interpretation has been verified through experiment.

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Conservation of Rivers and National Reimbursement Responsibility (하천관리와 국가배상책임)

  • Kim, Dong-Bok
    • Proceedings of the Korea Contents Association Conference
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    • 2006.05a
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    • pp.322-326
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    • 2006
  • There are the road of the artificial government property and rivers of the natural government property in representative Public Facilities applied National Reimbursement Law. Art.5. Doctrine on Responsibility of Public Facilities. Recently damage of a people has frequently been occurring caused by the flood of rivers and the flood disaster, and a people tends to request national reimbursement regarded it not as a natural disaster but as a man-made disaster. Especially the flood repeatedly occurred by the flood of rivers and destructive of the embankment of rivers, and it is also occurring in repairing rivers. Therefore a nation have to take responsibility of compensation for damage because of defect of conservation of rivers, and pay attention to improving the facilities of conservation and at the same time expand the range of responsibility. Thus the range of this study limits the national reimbursement of conservation of rivers among National Reimbursement Law. Art.5. Compensation for Damages on Defect about an Establishment and Management of public Facilities. Within this range, the objection of this study is to seek controversial issues and solutions, which belong with national reimbursement responsibility about conservation of rivers, as every principle of law and precedent coming under natural government property about compensation for damages caused by defect of conservation of rivers is analyzed and examined.

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