• 제목/요약/키워드: stability measure

검색결과 855건 처리시간 0.026초

A DOMINATED CONVERGENCE THEOREM FOR THE OPERATOR-VALUED FEYNMAN INTEGRAL

  • Ahn, Byung-Moo
    • Journal of applied mathematics & informatics
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    • 제7권3호
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    • pp.959-968
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    • 2000
  • The existence of the operator-valued Feynman integral was established when a Wiener functional is given by a Fourier transform of complex Borel measure [1]. In this paper, I investigate a stability of the Feynman integral with respect to the potentials.

Preventive and Emergency Control of Power System for Transient Stability Enhancement

  • Siddiqui, Shahbaz A.;Verma, Kusum;Niazi, K.R.;Fozdar, Manoj
    • Journal of Electrical Engineering and Technology
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    • 제10권1호
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    • pp.83-91
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    • 2015
  • This paper presents preventive and emergency control measures for on line transient stability (security) enhancement. For insecure operating state, generation rescheduling based on a real power generation shift factor (RPGSF) is proposed as a preventive control measure to bring the system back to secure operating state. For emergency operating state, two emergency control strategies namely generator shedding and load shedding have been developed. The proposed emergency control strategies are based on voltage magnitudes and rotor trajectories data available through Phasor Measurement Units (PMUs) installed in the systems. The effectiveness of the proposed approach has been investigated on IEEE-39 bus test system under different contingency and fault conditions and application results are presented.

Information Security and Organizational Performance: Empirical Study of Korean Securities Industry

  • Kong, Heekyung;Jung, Suhyun;Lee, Insung;Yeon, Seung-Jun
    • ETRI Journal
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    • 제37권2호
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    • pp.428-437
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    • 2015
  • This study was conducted to analyze the effect of information security activities on organizational performance. With this in mind and with the aim of resolving transaction stability in the securities industry, using an organization's security activities as a tool for carrying out information security activities, the effect of security activities on organizational performance was analyzed. Under the assumption that the effectiveness of information security activities can be bolstered to enhance organizational performance, such effects were analyzed based on Herzberg's motivation theory, which is one of the motivation theories that may influence information protection activities. To measure the actual attributes of the theoretical model, an empirical survey of the securities industry was conducted. In this explorative study, the proposed model was verified using partial least squares as a structural equation model consisting of IT service, information security, information sharing, transaction stability, and organizational performance.

Study on redundancy resolution algorithm of humanoid

  • Yoo, Dong-Su;So, Byung-Rok;Choi, Jae-Yeon;Yi, Byung-Ju;Kim, Whee-Kuk
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.2759-2764
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    • 2003
  • Humans usually employ more joints than they actually need, and thus they can be categorized as a kinematically redundant system. Therefore, the behavior of the human body can be analyzed by several redundancy resolution algorithms. Different from typical industrial robots that are fixed to the ground, the COG/ZMP condition should be taken into account in the human body motion in order not to fall down. Thus a COG/ZMP stability index is employed as a measure of stability. Kinematic redundancy inherent in the human body can be exploited to satisfy the COG/ZMP condition. Simulation result shows that the COG/ZMP condition can be satisfied by exploiting the null space motion of the kinematically redundant human body model.

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Robust model matching design using normalized left coprime factorization approach

  • Hanajima, Naohiko;Eisaka, Toshio;Yanagita, Yoshiho;Tsuchiya, Takeshi;Tagawa, Ryozaburo
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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    • pp.360-365
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    • 1993
  • In this paper, we propose a new design procedure of the Robust Model Matching(RM) using the Normalized Left Coprime Factorization (NLCF) approach. The RMM aims at reducing the sensitivity of a given control system, but standard design procedures are not for robust stability. Therefore we try applying the robust stability condition based on NLCF to RMM procedure. We first formulate the RMM using the robust stability condition of NLCF approach, then we propose the new procedure of the RMM. The point is that the condition includes the measure of sensitivity of the RMM. In the proposed procedure, a cost function is determined through the condition and solved by H$_{\infty}$ contro technique. Finally we show a design example and check the performance..

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폴리올에스테르의 합성 및 열안정성 (Synthesis and Thermal Stability of Polyol Esters)

  • 백진욱;정근우;김영운;서인옥;한정식
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2002년도 제35회 춘계학술대회
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    • pp.130-134
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    • 2002
  • Polyol esters were synthesized by condensation reaction of polyols (PE and DIPE) and linear acids such as valeric acid, caproic acid, heptylic acid and caprylic acid. The structures of polyol esters were confirmed by gas chromatography. Hot tube test was used to measure thermal stability of polyol esters and its thermal properties depended on the structure of acid moiety contained in polyol esters.

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플랜트 매개 변수 공간상의 강인 안정화 제어기 설계 (Robust Controller Design in Parameter Space)

  • 황유모
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1992년도 하계학술대회 논문집 A
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    • pp.285-287
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    • 1992
  • This paper considers the design of robust stabilizing controller of a linear time-invariant digital system subject to variations of parameter vector. For a given controller the radius of the largest stability hypersphere in this parameter space is calculated. This radius is a measure of the stability Margin of the closed-loop system. Based on this calculation a design procedure is proposed to robustify a given stabilizing controller. This algorithm iteratively enlarges the stability hypersphere in parameter space and can be used to design a controller to stabilize a plant subject to given ranges of parameter perturbations. These results are illustrated by an example.

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Radial Basis Function Neural Network for Power System Transient Energy Margin Estimation

  • Karami, Ali
    • Journal of Electrical Engineering and Technology
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    • 제3권4호
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    • pp.468-475
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    • 2008
  • This paper presents a method for estimating the transient stability status of the power system using radial basis function(RBF) neural network with a fast hybrid training approach. A normalized transient energy margin(${\Delta}V_n$) has been obtained by the potential energy boundary surface(PEBS) method along with a time-domain simulation technique, and is used as an output of the RBF neural network. The RBF neural network is then trained to map the operating conditions of the power system to the ${\Delta}V_n$, which provides a measure of the transient stability of the power system. The proposed approach has been successfully applied to the 10-machine 39-bus New England test system, and the results are given.

제체의 사면안정 해석(I) (The Analysis of the Slope Stability in Embankment(I))

  • 최기봉
    • 한국안전학회지
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    • 제12권4호
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    • pp.134-142
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    • 1997
  • The stability of an embankment Impounding a water reservoir is highly depend upon the location of seepage line with the embankment. To evaluate the accurate safety factor of an embankment, it is important to illustrate the seepage phenomenon. Of particular interest is the stability following a rapid change (drawdown) of reservoir level Seepage forces in embankments are easily determined if frictional forces are expressed in relation to hydraulic gradient Ⅰ. If a piezometer is inserted into a body of embankment, the level to which free water rises is a measure of the energy at that point. From model test result, it is possible to calculate safety factors of earth embankment. To assure the validity of this research, tests were conducted with numerical experimental models. And the experiment models were constructed with slopes of 1:1.0, 1:1.5, 1:2.0, 1:2.5. Analysis of experimental results, seepage force was analyzed according to downstream time, internal friction angle and cohesion, respectively.

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