• Title/Summary/Keyword: A-parameter

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Unified Estimates for Parameter Changes in a Pareto Model with an Exponential Outlier

  • Ryu, Se-Gi;Lee, Chang-Soo;Chang, Chu-Seock
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.2
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    • pp.507-514
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    • 2007
  • We shall propose several estimators for the scale parameter in the Pareto distribution with an unidentified exponential outlier when the scale parameter is functions of a known exposure level, and obtain expectations and variances for their proposed estimators. And we shall compare numerically efficiencies for proposed estimators of the scale and shape parameters in the small sample sizes.

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A. Study on Power System Stabilization by using Parameter Optimization (최적 파라미터를 이용한 전력계통 안정화에 관한 연구)

  • Moon, Young-Hyun;Kwak, No-Hong
    • Proceedings of the KIEE Conference
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    • 1989.07a
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    • pp.179-183
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    • 1989
  • This study presents a methodology to choose the optimal parameter of controller by using the performance index sensitivity. The pro-posed method is to select the controller parameter to have the minimum sensitivity. It is shown that the optimal parameter proves the effectiveness in the dynamic stability of power system.

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On the Study for the Simultaneous Test

  • Park, Hyo-Il
    • Communications for Statistical Applications and Methods
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    • v.20 no.4
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    • pp.241-246
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    • 2013
  • In this study, we propose a nonparametric simultaneous test procedure for the location translation and scale parameters. We consider the Wilcoxon rank sum test for the location translation parameter and the Mood test for the scale parameter with the quadratic and maximal types of combining functions. Then we derive the limiting null distributions of the combining functions. We illustrate our procedure with an example and compare efficiency by obtaining the empirical powers through a simulation study. Finally, we discuss some interesting features related to the nonparametric simultaneous tests.

An Alternative Optimization Procedure for Parameter Design

  • Kwon, Yong Man
    • Journal of Integrative Natural Science
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    • v.12 no.3
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    • pp.69-73
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    • 2019
  • Taguchi has used the signal-to-noise ratio (SN) to achieve the appropriate set of operating conditions where variability around target is low in the Taguchi parameter design. Taguchi has dealt with having constraints on both the mean and variability of a characteristic (the dual response problem) by combining information on both mean and variability into an SN. Many Statisticians criticize the Taguchi techniques of analysis, particularly those based on the SN. In this paper we propose a substantially simpler optimization procedure for parameter design to solve the dual response problems without resorting to SN.

RESEARCH ON NORMAL STRUCTURE IN A BANACH SPACE VIA SOME PARAMETERS IN ITS DUAL SPACE

  • Gao, Ji
    • Communications of the Korean Mathematical Society
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    • v.34 no.2
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    • pp.465-475
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    • 2019
  • Let X be a Banach space and $X^*$ be its dual. In this paper, we give relationships among some parameters in $X^*$: ${\varepsilon}$-nonsquareness parameter, $J({\varepsilon},X^*)$; ${\varepsilon}$-boundary parameter, $Q({\varepsilon},X^*)$; the modulus of smoothness, ${\rho}_{X^*}({\varepsilon})$; and ${\varepsilon}$-Pythagorean parameter, $E({\varepsilon},X^*)$, and weak orthogonality parameter, ${\omega}(X)$ in X that imply uniform norm structure in X. Some existing results are extended or approved.

Estimation of Probability Density Functions of Damage Parameter for Valve Leakage Detection in Reciprocating Pump Used in Nuclear Power Plants

  • Lee, Jong Kyeom;Kim, Tae Yun;Kim, Hyun Su;Chai, Jang-Bom;Lee, Jin Woo
    • Nuclear Engineering and Technology
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    • v.48 no.5
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    • pp.1280-1290
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    • 2016
  • This paper presents an advanced estimation method for obtaining the probability density functions of a damage parameter for valve leakage detection in a reciprocating pump. The estimation method is based on a comparison of model data which are simulated by using a mathematical model, and experimental data which are measured on the inside and outside of the reciprocating pump in operation. The mathematical model, which is simplified and extended on the basis of previous models, describes not only the normal state of the pump, but also its abnormal state caused by valve leakage. The pressure in the cylinder is expressed as a function of the crankshaft angle, and an additional volume flow rate due to the valve leakage is quantified by a damage parameter in the mathematical model. The change in the cylinder pressure profiles due to the suction valve leakage is noticeable in the compression and expansion modes of the pump. The damage parameter value over 300 cycles is calculated in two ways, considering advance or delay in the opening and closing angles of the discharge valves. The probability density functions of the damage parameter are compared for diagnosis and prognosis on the basis of the probabilistic features of valve leakage.

Precision Speed Control of PMSM Using Neural Network Disturbance Observer and Parameter Compensator (신경망 외란관측기와 파라미터 보상기를 이용한 PMSM의 정밀속도제어)

  • Go, Jong-Seon;Lee, Yong-Jae
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.51 no.10
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    • pp.573-580
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    • 2002
  • This paper presents neural load disturbance observer that used to deadbeat load torque observer and regulation of the compensation gain by parameter estimator As a result, the response of PMSM follows that of the nominal plant. The load torque compensation method is compose of a neural deadbeat observer. To reduce of the noise effect, the post-filter, which is implemented by MA process, is proposed. The parameter compensator with RLSM(recursive least square method) parameter estimator is suggested to increase the performance of the load torque observer and main controller. The proposed estimator is combined with a high performance neural torque observer to resolve the problems. As a result, the proposed control system becomes a robust and precise system against the load torque and the parameter variation. A stability and usefulness, through the verified computer simulation and experiment, are shown in this paper.

An Analysis of Bias-Dependent S11-Parameter in Multi-Finger MOSFETs (Multi-Finger MOSFET의 바이어스 종속 S11-파라미터 분석)

  • Ahn, Jahyun;Lee, Seonghearn
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.12
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    • pp.15-19
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    • 2016
  • The gate bias dependence of kink phenomenon with a large deviation from the resistance circle in Smith chart is observed in the frequency response of $S_{11}$-parameter for large multi-finger RF MOSFETs. For the first time, this bias dependence is analyzed by measuring magnitude and phase of $S_{11}$-parameter, input resistance and input capacitance. As a result, $V_{gs}$ dependent $S_{11}$-parameter is largely changed by the magnitude of input capacitance as well as dominant pole and zero frequencies of input resistance. At $V_{gs}=0V$, the kink phenomenon occurs in the high frequency region because of very small phase difference of $S_{11}$-parameter and high pole frequency of input resistance. However, the kink phenomenon at higher $V_{gs}$ is generated in the low frequency region owing to large phase difference and low pole frequency.

Calculation of the Peak-delay Force Reduction Parameter of Multi-Directional Random Waves Acting on a Long Caisson Breakwater (장대 케이슨 방파제에 작용하는 다방향 불규칙파랑의 파력감소계수 산정)

  • Jung, Jae-Sang;Kim, Bum-Hyung;Kim, Hyung-Jun;Cho, Yong-Sik
    • Journal of Korea Water Resources Association
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    • v.43 no.10
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    • pp.843-850
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    • 2010
  • By employing multi-directional random waves, a parameter controlling the force acting on a long caisson breakwater is investigated in detail. Both JONSWAP (Joint North Sea Wave Project) and asymmetric directional spectra are adopted for frequency and directional spectra. It is found that the parameter decreases as the length of caisson and the angle of main direction of incident waves increase. Furthermore, the parameter is much similar to that of regular waves as the maximum spreading parameter $s_{max}$ increases. The parameter, however, decreases as asymmetry parameter ${\mu}$ increases when the main direction of incident waves is oblique to the breakwater.

Extended Quasi-likelihood Estimation in Overdispersed Models

  • Kim, Choong-Rak;Lee, Kee-Won;Chung, Youn-Shik;Park, Kook-Lyeol
    • Journal of the Korean Statistical Society
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    • v.21 no.2
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    • pp.187-200
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    • 1992
  • Samples are often found to be too heterogeneous to be explained by a one-parameter family of models in the sense that the implicit mean-variance relationship in such a family is violated by the data. This phenomenon is often called over-dispersion. The most frequently used method in dealing with over-dispersion is to mix a one-parameter family creating a two parameter marginal mixture family for the data. In this paper, we investigate performance of estimators such as maximum likelihood estimator, method of moment estimator, and maximum quasi-likelihood estimator in negative binomial and beta-binomial distribution. Simulations are done for various mean parameter and dispersion parameter in both distributions, and we conclude that the moment estimators are very superior in the sense of bias and asymptotic relative efficiency.

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