• 제목/요약/키워드: Parameter estimate

검색결과 1,578건 처리시간 0.026초

A Mathematical model to estimate the wind power using three parameter Weibull distribution

  • Seshaiah, C.V.;Sukkiramathi, K.
    • Wind and Structures
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    • 제22권4호
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    • pp.393-408
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    • 2016
  • Weibull distribution is a suitable distribution to use in modeling the life time data. It has been found to be a exact fit for the empirical distribution of the wind speed measurement samples. In brief this paper consist of important properties and characters of Weibull distribution. Also we discuss the application of Weibull distribution to wind speed measurements and derive an expression for the probability distribution of the power produced by a wind turbine at a fixed location, so that the modeling problem reduces to collecting data to estimate the three parameters of the Weibull distribution using Maximum likelihood Method.

하저터널에서 상대내공변위 계측을 통한 지반정수 예측 (Geotechnical parameter estimation in underwater tunnel using relative convergence measurement)

  • 김도훈;장재혁;이인모
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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    • pp.792-802
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    • 2008
  • If a tunnel is constructed below the groundwater level, the groundwater flow will occur inducing the seepage force toward the tunnel and will result in the increase of tunnel convergence. The longitudinal deformation during tunnel excavation will also be increased due to seepage pressure. A back-analysis methodology in underwater tunnel was proposed in this study based on the relative longitudinal deformation measured in-situ. Geotechnical parameters can be estimated utilizing the proposed method where the prior estimate as well as the measured convergence can be reasonably combined by adopting the Extend Bayesian Method.

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확장 루엔버거 관측기를 이용한 저속영역에서의 전동기 관성 추정 (Inertia Identification of Electric Machine Using Extended Luenberger Observer at Low Speed Region)

  • 이교범;강호진;송중호;최익;유지윤
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2002년도 전력전자학술대회 논문집
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    • pp.142-145
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    • 2002
  • A new scheme to estimate machine inertia in low speed is proposed in this paper. It is necessary to consider the machine parameter of low speed instantaneous observer to precise control in servo system, which has frequent load variation and speed change. To estimate machine parameter, especially the moment of inertia, Reduced-Order Extended Luenberger Observer (ROELO) is applied. The effectiveness of the proposed ROELO is showed by simulation.

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Application of Weibull Distribution Function to Analysis of Breakthrough Curves from Push Pull Tracer Test

  • Hyun-Tae, Hwang;Lee, Kang-Kun
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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    • pp.217-220
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    • 2003
  • In the case of the remediation studies, push pull test is a more time and cost effective mettled than multi-well tracer test. It also gives Just as much or more information than the traditionally used methods. But the data analysis for the hydraulic parameters, there have been some defections such as underestimation of dispersivity, requirement for effective porosity, and calculation of recovery of center of mass to estimate linear velocity. In this research, Weibull distribution function is proposed to estimate the center of mass of breakthrough curve for Push pull test. The hydraulic parameter estimation using Weibull function showed more exact values of center of mass than those of exponential regression for field test data.

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Scaling-Translation Parameter Estimation using Genetic Hough Transform for Background Compensation

  • Nguyen, Thuy Tuong;Pham, Xuan Dai;Jeon, Jae-Wook
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제5권8호
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    • pp.1423-1443
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    • 2011
  • Background compensation plays an important role in detecting and isolating object motion in visual tracking. Here, we propose a Genetic Hough Transform, which combines the Hough Transform and Genetic Algorithm, as a method for eliminating background motion. Our method can handle cases in which the background may contain only a few, if any, feature points. These points can be used to estimate the motion between two successive frames. In addition to dealing with featureless backgrounds, our method can successfully handle motion blur. Experimental comparisons of the results obtained using the proposed method with other methods show that the proposed approach yields a satisfactory estimate of background motion.

산사태 위험도 추정을 위한 간극수압 예측에 관한 연구 (III)-모델 매개변수 분석- (Porewater Pressure Predictions on Hillside Slopes for Assessing Landslide Risks(III)-Model Parameter Identification-)

  • 이인모;박경호
    • 한국지반공학회지:지반
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    • 제8권4호
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    • pp.41-50
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    • 1992
  • In general, the conceptual lumped-parameter groundwater flow model to predict the groundwater fluctuations in hillside slopes has unknown model parameters to be estimated from the known input -output data. The purpose of this study is to estimate the optimal model parameters of the groundwater flow model developed by authors. The Mazilnum A Posteriori( MAP) estimation method is utilized for this purpose and it is applied to a site which shows the typical landslide in Korea. The result of application shows tllat the 반AP estimation method can estimate the unknown parameters properly well. The groundwater model developed along with estimation technique applied in this paper will be used for assessing risk of landslides.

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Penalized rank regression estimator with the smoothly clipped absolute deviation function

  • Park, Jong-Tae;Jung, Kang-Mo
    • Communications for Statistical Applications and Methods
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    • 제24권6호
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    • pp.673-683
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    • 2017
  • The least absolute shrinkage and selection operator (LASSO) has been a popular regression estimator with simultaneous variable selection. However, LASSO does not have the oracle property and its robust version is needed in the case of heavy-tailed errors or serious outliers. We propose a robust penalized regression estimator which provide a simultaneous variable selection and estimator. It is based on the rank regression and the non-convex penalty function, the smoothly clipped absolute deviation (SCAD) function which has the oracle property. The proposed method combines the robustness of the rank regression and the oracle property of the SCAD penalty. We develop an efficient algorithm to compute the proposed estimator that includes a SCAD estimate based on the local linear approximation and the tuning parameter of the penalty function. Our estimate can be obtained by the least absolute deviation method. We used an optimal tuning parameter based on the Bayesian information criterion and the cross validation method. Numerical simulation shows that the proposed estimator is robust and effective to analyze contaminated data.

계단 응답을 이용환 유도 전동기 파라미터 식별 (Induction Motor Parameter Identification using Step Response)

  • 전범호;노치원;류준형;이광원
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 B
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    • pp.723-725
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    • 2000
  • This paper presents a parameter identification method to estimate the stator resistance. stator inductance, rotor resistance and rotor inductance of the induction motor. A step voltage is applied across the stator terminals while the machine is in the standstill condition, and the resulting stator voltage and current response are measured. Observer/Kalman Filter Identification(OKID) algorithm is used to estimate induction motor parameters. Simulation results are presented to verify the identified model.

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비용을 고려한 계수치 2단계 샘플링 방법의 경제적 설계 (The Economic Design of Two-Stage Sampling Plan for Attributes)

  • 이경종;이상용
    • 품질경영학회지
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    • 제21권1호
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    • pp.35-43
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    • 1993
  • The principal objective of a sampling plan is to make efficient use of the budget allocated and to obtain as precise an estimate of a population parameter as possible. In order to estimate the proportion of defectives produced or to determine some measure of product Quality, it is necessary to select random samples which represent a population parameter of the process. In this case, the two stage sampling is more efficient and convenient than simple random sampling. Therefore this paper aims to propose the design procedures of two stage sampling plan to obtain a representative samples in considering the sampling precision under the restricted sampling unspection cost.

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Approximate Method in Estimating Sensitivity Responses to Variations in Delayed Neutron Energy Spectra

  • J. Yoo;H. S. Shin;T. Y. Song;Park, W. S.
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1997년도 추계학술발표회논문집(1)
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    • pp.85-90
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    • 1997
  • Previous our numerical results in computing point kinetics equations show a possibility in developing approximations to estimate sensitivity responses of nuclear reactor We recalculate sensitivity responses by maintaining the corrections with first order of sensitivity parameter. We present a method for computing sensitivity responses of nuclear reactor based on an approximation derived from point kinetics equations. Exploiting this approximation, we found that the first order approximation works to estimate variations in the time to reach peak power because of their linear dependence on a sensitivity parameter, and that there are errors in estimating the peak power in the first order approximation for larger sensitivity parameters. To confirm legitimacy of our approximation, these approximate results are compared with exact results obtained from our previous numerical study.

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