• 제목/요약/키워드: power law

검색결과 1,986건 처리시간 0.036초

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

  • 문영훈;이용훈;조병훈;류헌수;최병곤
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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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 the Legal Consciousness of Female University Students through Information Analysis

  • Park, Jong-Ryeol;Jeon, Myung-Gil
    • 한국컴퓨터정보학회논문지
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    • 제22권5호
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    • pp.111-118
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    • 2017
  • The Legal Consciousness is a feeling or attitude toward the law from the people. Most Korean had a traditional consciousness that did not consider the law so friendly, also, the perception of law is also very negative is the common result of various investigations so far. This is caused by a distrust of the political power that operates the law than just distrust of law. Moreover, it is a serious problem that these negative attitudes are getting stronger over time. Especially when looking at the situation of the monopoly of government affairs in Park Geun-hye administration, the law was not a means of realizing social justice on the side of the socially weak, it has come to the fact that the law has been recognized as a tool of oppression by the ruling group, which seizes power in a fraudulent manner and accumulates economic wealth. It was a really ridiculous incident. In addition, not all citizens need to be experts in law, but the law is a bowl for society, and filling the bowl is a moral form or value of society in general. And since society has a peculiar law, and the modern state has the rule of law as its basic principle, most human acts have a direct relationship with law. In particular, it is true that the problem of the legal consciousness of college students is frequently mentioned today. Therefore, in this study, through the examine the contents of the legal consciousness of the K university female students in Gwangju and will consider the cause of this.

신뢰성 스트레스 스크리닝 및 성장 모델 (Reliability Stress Screening and Growth Model)

  • 최성운
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2007년도 춘계학술대회
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    • pp.335-346
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    • 2007
  • This paper introduces reliability stress screening(RSS) for electronic hardware and components. This study also shows reliability centered maintenance(RCM), and reliability growth models. Moreover, this paper presents goodness-of-fit tests and estimation methods of power law model.

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제조물책임법 시행에 따른 중소기업 품질경영시스템에 관한 연구 (A study on the Quality Management System of Medium and Small-sized Enterprises under Product Liability Law)

  • 배성아;김복만
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 2001년도 추계학술대회 논문집
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    • pp.362-365
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    • 2001
  • Human, physical damage is happened frequently to consumer's safety accident by product defect on modern industrial society. Accordingly, advanced nation including the United States of America enforce product liability law and is protecting consumer more actively from danger of product defect. Our country(Korea) may enforce product liability law since July, 2002, and if business does not grope effective confrontation way about PL, capital strength weak smaller enterprise and venture business corporation's competitive power may affect much corporation's competitive power enfeeblement and survival. This research supplement based on induction and operating QMS in smaller enterprise essential factor that corporations must equip according to product liability law enforcement. And we present integration quality management system model of Product liability to do so that smaller enterprises may can cope effectively at force of Product liability law.

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Asymmetric transient thermal stress of a functionally graded hollow cylinder with piecewise power law

  • Ootao, Yoshihiro;Ishihara, Masayuki
    • Structural Engineering and Mechanics
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    • 제47권3호
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    • pp.421-442
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    • 2013
  • This paper is concerned with the theoretical treatment of transient thermoelastic problems involving a functionally graded hollow cylinder with piecewise power law due to asymmetrical heating from its surfaces. The thermal and thermoelastic constants of each layer are expressed as power functions of the radial coordinate, and their values continue on the interfaces. The exact solution for the two-dimensional temperature change in a transient state, and thermoelastic response of a hollow cylinder under the state of plane strain is obtained herein. Some numerical results for the temperature change and the stress distributions are shown in figures. Furthermore, the influence of the functional grading on the thermal stresses is investigated.

A Study on the Measurement of Whole-Body Vibration in Some Coal-fired Power Plant Workers

  • Heo, Seung-Moo;Lee, Yun Keun;Park, Hee Sok
    • 대한인간공학회지
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    • 제32권4호
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    • pp.341-344
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    • 2013
  • Objective: This study measured and evaluated the characteristics of the whole body vibration experienced in some coal-fired power plant in Korea. Background: Few studies have been carried out in Korea about the effects of whole body vibration of power plants on humans. Method: The evaluation scheme suggested by the Law of Noise and Vibration Control was applied. Results: It was found that 28.9% of total measurement points were above the limit suggested by the law. Conclusion: Many workers are exposed to whole body vibration during their job completion, and more efforts should be applied to prevention and control of the plat vibration.

고속 전철구간에서의 전력유도 환경 영향 분석 (Environmental Effect Analysis of Electromagnetic Induction in Express Electric Railway)

  • 이상무;최문환;조평동
    • 정보통신설비학회논문지
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    • 제9권1호
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    • pp.19-23
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    • 2010
  • The Electromagnetic Interference could occur due to power line on the telecommunication service. The Countermeasure is practised by legal law. Various affecting factors are described in the law. In this paper, an effect by pipeline especially in the ground, power feeding plant, and curved railway sector is analyzed as environmental factors which are not included in the law. By the practical measurement, it appears that the measured voltages on the spots with underground pipeline are grouped into lower voltage level, induced voltage tends to be high near power feeding plant, and also in the curved railway line. These analytical results can be meaningly considered in the application of countermeasure.

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역승법칙을 이용한 터픈드 Epoxy/Rubber 계면의 V-t 특성에 관한 연구 (A study on the v-t characteristics of interfaces between Toughened Epoxy and Rubber with Inverse Power Law)

  • 박정규;이동규;오현석;신철기;박건호;박우현;이기식;이준웅
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.437-440
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    • 2000
  • In this study, the interfacial dielectric breakdown phenomenon of interface between Epoxy and Rubber was discussed, which affects the stability of insulation system of power delivery devices. The breakdown strength of specimens are observed by applying high AC voltage at the room temperature. The breakdown times under the constant voltage below the breakdown voltage were gained. As constant voltage is applied, the breakdown time is proportion to the breakdown strength. The life exponent n is gained by inverse power law and the long time breakdown life time can be evaluated.

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Vibration of SWCNTs: Consistency and behavior of polynomial law index with Galerkin's model

  • Khadimallah, Mohamed A.;Hussain, Muzamal;Khedher, Khaled Mohamed;Bouzgarrou, Souhail Mohamed;Al Naim, Abdullah F.;Naeem, Muhammad Nawaz;Taj, Muhammad;Iqbal, Zafar;Tounsi, Abdelouahed
    • Advances in nano research
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    • 제9권4호
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    • pp.251-261
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    • 2020
  • In this article, vibration attributes of single walled carbon nanotubes based on Galerkin's method have been investigated. The influence of power law index subjected to different end supports has been overtly examined. Application of the Hamilton's variational principal leads to the formation of partial differential equations. The effects of different physical and material parameters on the fundamental frequencies are investigated for armchair and zigzag carbon nanotubes with clamped-clamped, simply supported and clamped-free boundary conditions. By using volume fraction for power law index, the fundamental natural frequency spectra for two forms of Single-Walled Carbon Nanotubes (SWCNTs) are calculated. The influence of frequencies against length-to-diameter ratios with varying power law index are investigated in detail for these tubes. MATLAB software package has been utilized for extracting tube frequency spectra. The obtained results are confirmed by comparing with available literature.