• 제목/요약/키워드: Stability Limits

검색결과 356건 처리시간 0.034초

효과적(效果的)인 공정능력(工程能力)의 해석기법(解析技法)에 관한 연구(硏究) (An Effective Analyzing Method of Process Capability)

  • 송서일;황의철
    • 품질경영학회지
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    • 제15권1호
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    • pp.47-54
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    • 1987
  • It is common that the process capability fluctuates as time passes, but concentrates to the mean value. To keep up process capability with given limits is vital to stability of process. Various control charts, especially ${\sigma}-chart$, have been used for analyzing process capability, but It sometimes can not give distinct answer. So this paper introduces another analyzing method by ARMA (autoregressive moving average) which is originally developed for forecasting, and demonstrates the analyzing methodology through a case study.

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Contingency Constrained Optimal Power Flow에 관한 연구 (A Study on Contingency Constrained Optimal Power Flow Algorithm)

  • 정상헌;신영균;정구형;김발호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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    • pp.472-474
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    • 2003
  • This paper presents a contains contingency constrained Optimal Power Flow(CCOPF) algorithm. The proposed algorithm maintains the nodal voltage levels within the specified limits after contingency. A case study demonstrate the proposed algorithm with the IEEE-14RTS under N-1 contingency criterion.

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TOPOLOGICALLY STABLE POINTS AND UNIFORM LIMITS

  • Namjip Koo;Hyunhee Lee
    • 대한수학회지
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    • 제60권5호
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    • pp.1043-1055
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    • 2023
  • In this paper we study a pointwise version of Walters topological stability in the class of homeomorphisms on a compact metric space. We also show that if a sequence of homeomorphisms on a compact metric space is uniformly expansive with the uniform shadowing property, then the limit is expansive with the shadowing property and so topologically stable. Furthermore, we give examples to illustrate our results.

Reactive Reserve based Contingency Constrained Optimal Power Flow to Enhance Interface Flow Limits in Terms of voltage Stability

  • Hwachang Song;Lee, Byongjun
    • KIEE International Transactions on Power Engineering
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    • 제11A권4호
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    • pp.27-32
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    • 2001
  • This paper presents a concept of reactive reserve based contingency constrained optimal power flow (RCCOPF). RCCOPF for enhancement of interface flow limit is composed of two modules, which are the modified continuation power flow (MCPF) and reactive optimal power flow (ROPF). In RCCOPF, two modules are repeatedly performed to increase interface flow margins of selected contingent states until satisfying the required enhancement of interface flow limit. In numerical simulation, a simple example with New England 39-bus test system is shown.

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신뢰성해석을 이용한 호안제체의 안정성에 관한 연구 (A Study on Stability of Marine Embankment Using Reliability Analysis)

  • 박준모;장연수;오세웅
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2003년도 봄 학술발표회 논문집
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    • pp.789-796
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    • 2003
  • A reliability analysis is performed to investigate the influence of the uncertainty from the limited in-situ samples and the inherent heterogeneity of the ground on the probability of piping for the marine embankment near shore. The result are compared with those of the deterministic piping stability analysis performed using the fininte element flow analysis. The random variables used are hydraulic conductivity of the ground subsurface and embankment, and the water level of both internal and external side of the embankment. The probability of piping is most sensitive to the mean and standard deviation of internal water level of the embankment among the random variables included in the reliability analysis. It is found that the lower limits of internal water level which satisfies the allowable proability of piping failure for the embankment studied were E.L(-) 1.83m and E.L(-) 1.48m during and after the construction of the embankment, respectively.

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HPLC를 이용한 옥천산 중 갈근, 감초, 오미자 지표성분의 다성분 동시분석 (Quality Evaluation of Herbal Prescription, Oc Chun San, Employing Simultaneous Determination of the Marker Compounds by HPLC)

  • 유정림;장대식;김진숙
    • 한국한의학연구원논문집
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    • 제11권2호
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    • pp.167-178
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    • 2005
  • As a part of the quality control of herbal prescriptions which has been used for diabetes and related diseases, a reversed-phase liquid chromatographic method was developed for the simultaneous quantification of the three marker compounds, puerarin (Puerariae Radix), glycyrrhizin (Glycyrrhizae Radix), schizandrin (Schizandrae Fructus) in Oc Chun San. The HPLC analysis method was validated for parameters such as linearity, Limits of Detection(LOD), quantification(LOQ), repeatability, stability and recovery.

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임의로 움직이는 물체 주위의 유동 해석을 위한 피드백 강제 외력을 이용한 가상경계방법 (AN IMMERSED BOUNDARY METHOD WITH FEEDBACK FORCING FOR SIMULATION OF FLOW AROUND AN ARBITRARILY MOVING BODY)

  • 신수재;황위희;성형진
    • 한국전산유체공학회지
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    • 제12권2호
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    • pp.14-20
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    • 2007
  • We present an improved immersed boundary method for computing incompressible viscous flow around an arbitrarily moving body on a fixed computational grid. The main idea is to incorporate feedback forcing scheme of virtual boundary method with Peskin's regularized delta function approach in order to use large CFL number and transfer quantities between Eulerian and Lagrangian domain effectively. From the analysis of stability limits and effects of feedback forcing gains, optimum regions of the feedback forcing are suggested.

과도에너지 함수를 이용하여 연계계통의 총송전용량 평가를 위한 최적화기법 응용 (Optimization Application for Assessment of Total Transfer Capability Using Transient Energy Function in Interconnection Systems)

  • 김규호;김수남;이상봉;이상근;송경빈
    • 전기학회논문지
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    • 제58권12호
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    • pp.2311-2315
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    • 2009
  • This paper presents a method to apply energy margin for assesment of total transfer capability (TTC). In order to calculate energy margin, two values of the transient energy function have to be computed. The first value is transient energy that is the sum of kinetic and potential energy at the end of fault. The second is critical energy that is potential energy at controlling UEP(Unstable Equilibrium Point). It is seen that TTC level is determined by not only bus voltage magnitudes and line thermal limits but also transient stability. TTC assessment is compared by the repeated power flow(RPF) method and optimization method.

THE STABILITY OF CERTAIN SETS OF ATTACHED PRIME IDEALS RELATED TO COSEQUENCE IN DIMENSION > k

  • Khanh, Pham Huu
    • 대한수학회보
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    • 제53권5호
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    • pp.1385-1394
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    • 2016
  • Let (R, m) be a Noetherian local ring, I, J two ideals of R, and A an Artinian R-module. Let $k{\geq}0$ be an integer and $r=Width_{>k}(I,A)$ the supremum of lengths of A-cosequences in dimension > k in I defined by Nhan-Hoang [9]. It is first shown that for each $t{\leq}r$ and each sequence $x_1,{\cdots},x_t$ which is an A-cosequence in dimension > k, the set $$\Large(\bigcup^{t}_{i=0}Att_R(0:_A(x_1^{n_1},{\ldots},x_i^{n_i})))_{{\geq}k}$$ is independent of the choice of $n_1,{\ldots},n_t$. Let r be the eventual value of $Width_{>k}(0:_AJ^n)$. Then our second result says that for each $t{\leq}r$ the set $\large(\bigcup\limits_{i=0}^{t}Att_R(Tor_i^R(R/I,\;(0:_AJ^n))))_{{\geq}k}$ is stable for large n.

GAUSSIAN QUADRATURE FORMULAS AND LAGUERRE-PERRON@S EQUATION

  • HAJJI S. EL;TOUIJRAT L.
    • Journal of applied mathematics & informatics
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    • 제18권1_2호
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    • pp.205-228
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    • 2005
  • Let I(f) be the integral defined by : $I(f) = \int\limits_{a}^{b} f(x)w(x)dx$ with f a given function, w a nonclassical weight function and [a, b] an interval of IR (of finite or infinite length). We propose to calculate the approximate value of I(f) by using a new scheme for deriving a non-linear system, satisfied by the three-term recurrence coefficients of semi-classical orthogonal polynomials. Finally we studies the Stability and complexity of this scheme.