• Title/Summary/Keyword: parameter sensitivity

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Robust control of nonlinear system by using pole sensitivity (극점감도를 고려한 비선형 시스팀의 강인한 제어)

  • 서병설;강진식;임동균
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.185-190
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    • 1991
  • In this paper, we present a method of analising a system with nonlinear parameter by pole sensitivity defined by the rate of pole movement with respect of non-linear parameter variation. Pole sensitivity give us not only the rate of pole movement but also the directional information. We present a method of design of a state feedback for a system with nonlinear system parameter by considering the pole sensitivity and show that the suggested method guarantee the stability robustness for a system with nonlinear parameter, parameter perturbation and urimodelled dynamics.

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Analysis of Flux Observers Using Parameter Sensitivity

  • Nam H.T.;Lee K.J.;Choi J.W.;Kim H.G.;Chun T.W.;Noh E.C.
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.418-422
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    • 2001
  • To achieve a high performance in direct vector control of induction motor, it is essential to correct estimation of rotor flux. The accuracy of flux observers for induction machines inherently depends on parameter sensitivity. This paper presents an analysis method for conventional flux observers using Parameter Sensitivity. The Parameter sensitivity is defined as the ratio of the percentage change in the system transfer function to the percentage change of the parameter variation. We define the ratio between real flux and estimated flux as the transfer function, and analyzed a parameter sensitivity of this transfer function by simulation.

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Analysis of Induction Motor Flux Observer using Parameter Sensitivity (파라메터 민감도를 이용한 유도전동기 자속 추정기 해석)

  • Nam, Hyun-Taek;Lee, Kyung-Joo;Kim, Jin-Kyu;Choi, Young-Tae;Choi, Jong-Woo;Kim, Heung-Geun
    • Proceedings of the KIEE Conference
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    • 2001.07b
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    • pp.1176-1178
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    • 2001
  • To obtain a high performance in a direct vector controlled induction machine, it is essential to correct estimation of rotor flux. The accuracy of flux observers for induction machines inherently depends on parameter sensitivity. This paper presents an analysis method for conventional flux observers using parameter Sensitivity. The Parameter sensitivity is defined as the ratio of the percentage change in the system transfer function to the percentage change of the parameter variation. We define the ratio between real flux and estimated flux as the transfer function, and analyzed a parameter sensitivity of this transfer function.

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Comparison of Rotor Flux Observer Characteristics in Induction Motor Using Parameter Sensitivity (파라미터 민감도를 이용한 유도전동기 회전자 자속관측기의 특성 비교)

  • 최종우;남현택;박용환;김흥근
    • The Transactions of the Korean Institute of Power Electronics
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    • v.7 no.4
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    • pp.377-383
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    • 2002
  • To obtain a high performance in a direct vector controlled induction machine, it is essential to obtain the current rotor flux. The accuracy of flux observers for induction machines inherently depends on parameter sensitivity. This paper proposes an analysis method for conventional flux observers using "parameter sensitivity". The "parameter sensitivity" is defined as the ratio of the percentage change in the system transfer function to the percentage change of the parameter variation. We define the ratio between real flux and estimated no as the transfer function, and analyze a parameter sensitivity of this transfer function. Practical verification is presented to conform the capabilities of the proposed analysis method.sed analysis method.

An Application of the Sensitivity Method for Parameter Estimation (파라미터 추정을 위한 민감도 기법의 응용에 관한 연구)

  • 백문열
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.2
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    • pp.112-118
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    • 2000
  • This paper deals with the application of sensitivity method to the parameter estimation for the dynamic analysis of gener-al mechanical system. In this procedure we take the derivatives of the given system with respect to a certain parameter and use this information to implement the steepest descent method. This paper will give two examples of this technique applied to simple vehicle models. This paper will give two examples of this technique applied to simple vehicle models. Simulation results show excellent convergence and accuracy of parameter estimates.

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Analysis of Induction Machine Flux Observer (유도전동기 자속추정기의 특성해석)

  • Nam Hyun-Taek;Lee Kyung-Joo;Choi Jong-Woo;Kim Heung-Geun
    • Proceedings of the KIPE Conference
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    • 2001.12a
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    • pp.7-10
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    • 2001
  • To obtain a high performance in a direct vector controlled induction machine, it is essential to correct estimation of rotor flux. The accuracy of flux observers for induction machines inherently depends on parameter sensitivity. This paper presents an analysis method for conventional flux observers using Parameter Sensitivity. The Parameter sensitivity is defined as the ratio of the percentage change in the system transfer function to the percentage change of the parameter variation. We define the ratio between real flux and estimated flux as the transfer function, and analyzed a parameter sensitivity of this transfer function.

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The Sensitivity Analysis of Parameters of Urban Runoff Models due to Variations of Basin Characteristics (I) - Development of Sensitivity Analysis Method - (유역특성 변화에 따른 도시유출모형의 매개변수 민감도분석(I) -민감도분석방법의 개발-)

  • Seo, Gyu-U;Jo, Won-Cheol
    • Journal of Korea Water Resources Association
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    • v.31 no.3
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    • pp.243-252
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    • 1998
  • In this study, the new dimensionless values were defined and proposed to determine the parameters of urban runoff models based on the relative sensitivity analysis. Also, the sensitivity characteristics of each parameter were investigate. In order to analyze the parameter sensitivities of each model, total runoff ratio, peak runoff ratio, runoff sensitivity ratio, sensitivity ratio of total runoff, and sensitivity ratio of peak runoff were defined. $$Total\;runoff\;ratio(Q_{TR})\;=\;\frac{Total\;runoff\;of\;corresponding\;step}{Maximum\;total\;runoff}$$$$Peak\;runoff\;ratio(Q_{PR})\;=\;\frac{Peak\;runoff\;of\;corresponding\;step}{Maximum\;peak\;runoff}$$$$Runoff\;sensitivity\;ratio(Q_{SR})\;=\;\frac{Q_{TR}}{Q_{PR}}$$ And for estimation of sensitivity ratios based on the scale of basin area, rainfall distributions and rainfall durations in ILLUDAS & SWMM, the reasonable ranges of parameters were proposed.

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Model Updating Using the Closed-loop Natural Frequency (폐루프 공진 주파수를 이용한 모델 개선법)

  • Jung Hunsang;Park Youngjin
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.9 s.90
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    • pp.801-810
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    • 2004
  • Parameter modification of a linear finite element model(FEM) based on modal sensitivity matrix is usually performed through an effort to match FEM modal data to experimental ones. However, there are cases where this method can't be applied successfully; lack of reliable modal data and ill-conditioning of the modal sensitivity matrix constitute such cases. In this research, a novel concept of introducing feedback loops to the conventional modal test setup is proposed. This method uses closed-loop natural frequency data for parameter modification to overcome the problems associated with the conventional method based on modal sensitivity matrix. We proposed the whole procedure of parameter modification using the closed-loop natural frequency data including the modal sensitivity modification and controller design method. Proposed controller design method is efficient in changing modes. Numerical simulation of parameter estimation based on time-domain input/output data is provided to demonstrate the estimation performance of the proposed method.

Evaluation of Multi-criteria Performances of the TOPMODEL Simulations in a Small Forest Catchment based on the Concept of Equifinality of the Multiple Parameter Sets

  • Choi, Hyung Tae;Kim, Kyongha;Jun, Jae-Hong;Yoo, Jae-Yun;Jeong, Yong-Ho
    • Journal of Korean Society of Forest Science
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    • v.95 no.5
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    • pp.569-579
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    • 2006
  • This study focuses on the application of multi-criteria performance measures based on the concept of equifinality to the calibration of the rainfall-runoff model TOPMODEL in a small deciduous forest catchment. The performance of each parameter set was evaluated by six performance measures, individually, and each set was identified as a behavioral or non-behavioral parameter set by a given behavioral acceptance threshold. Many behavioral parameter sets were scattered throughout the parameter space, and the range of model behavior and the sensitivity for each parameter varied considerably between the different performance measures. Sensitivity was very high in some parameters, and varied depending on the kind of performance measure as well. Compatibilities of behavioral parameter sets between different performance measures also varied, and very few parameter sets were selected to be used in making god predictions for all performance measures. Since different behavioral parameter sets with different likelihood weights were obtained for each performance measure, the decision on which performance measure to be used may be very important to achieve the goal of study. Therefore, one or more suitable performance measures should be selected depending on the environment and the goal of a study, and this may lead to decrease model uncertainty.

Effectiveness of Sensitivity Analysis for Parameter Selection in CLIMEX Modeling of Metcalfa pruinosa Distribution

  • Byeon, Dae-hyeon;Jung, Sunghoon;Mo, Changyeun;Lee, Wang-Hee
    • Journal of Biosystems Engineering
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    • v.43 no.4
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    • pp.410-419
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    • 2018
  • Purpose: CLIMEX, a species distribution modeling tool, includes various types of parameters representing climatic conditions; the estimation of these parameters directly determines the model accuracy. In this study, we investigated the sensitivity of parameters for the climatic suitability calculated by CLIMEX for Metcalfa pruinosa in South Korea. Methods: We first changed 12 parameters and identified the three significant parameters that considerably affected the CLIMEX simulation response. Results: The result indicated that the simulation was highly sensitive to changes in lower optimal temperatures, lower soil moisture thresholds, and cold stress accumulation rate based on the sensitivity index, suggesting that these were the fundamental parameters to be used for fitting the simulation into the actual distribution. Conclusion: Sensitivity analysis is effective for estimating parameter values, and selecting the most important parameters for improving model accuracy.