• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.8
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• pp.469-476
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• 2004

In this paper, a 3D shape optimization algorithm which guarantees a smooth optimal shape is presented using parameterized sensitivity analysis. The design surface is parameterized using Bezier spline and B-spline, and the control points of the spline are taken as the design variables. The parameterized sensitivity for the control points are found from that for nodal points. The design sensitivity and adjoint variable formulae are also derived for the 3D non-linear problems. Through an application to the shape optimization of 3D electromagnet to get a uniform magnetic field, the effectiveness of the proposed algorithm is shown.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.2
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• pp.273-282
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• 1996

This work is conceded with the estimation of output derivatives and their use for the design of robust controller for linear systems with system uncertainties due to modeling errors and disturbances. It is assumed that a nominal transfer function model and quantitative bounds for system uncertainties and known. The developed control schemes are shown to achieve regulation of the system output and ensures boundedness of the system states without imposing any structural conditions on system uncertainties and disturbances. Output derivative estimation is first conducted through restructuring of the plant in a specific parameterization. They are utilized for constructing robust nonlinear high-gain feedback controller of a SMC(Sliding Mode Control)type. The performances of the developed controller are evaluated and shown to be effective and useful through simulation study.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.10
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• pp.26-32
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• 2010

This paper proposes a new load torque observer based on the Takagi-Sugeno fuzzy method for a permanent magnet synchronous motor(PMSM). A Linear Matrix Inequality(LMI) parameterization of the fuzzy observer gain is given, and the LMI conditions are derived for the existence of the fuzzy load torque observer guaranteeing $\alpha$-stability and linear quadratic performance. In this paper, a nonlinear speed controller is employed to validate the performance of the proposed fuzzy load torque observer, and various simulation results are presented under motor parameter and load torque variations.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.406-408
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• 2005

실행 환경 및 상황에 맞게 스스로 소프트웨어의 구성과 서비스를 변경시키기 위한 적응형 소프트웨어의 개발을 위해서는 변경 대상 및 변경 기법의 정의가 중요하다. 본 논문에서는 소프트웨어의 구성요소 및 기능을 실시간에 변경하기 위해 제품계열 방법에서 주로 사용되는 Information Hiding 기반의 가변성 관리 기법과 Parameterization 기반의 가변성 관리기법을 사용한다. 두 방법을 사용하면 실행 과정에 영향을 주지 않으면서 소프트웨어의 구성요소를 변경하거나 특성을 customizing할 수 있다.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.936-938
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• 1996

The $H_{\infty}$ robust controller is designed for on-line adaptive control application by using polynomial approach. The $H_{\infty}$ robust controllers for adaptive system were designed first by Grimble. But they have a problem that two minimum costs can exist and did not minimize the conventional $H_{\infty}$ cost function which is the $H_{\infty}$ sum of weighted sensitivity and complementary sensitivity terms. In this paper, the two minimum costs problem can be avoided and the conventional $H_{\infty}$ cost function is minimized by employing the Youla parameterization and polynomial approach at the same time. In addition pole placement is possible without any relation with weighting function.

• Journal of Electrical Engineering and Technology
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• v.13 no.3
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• pp.1147-1155
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• 2018

This paper presents an improved method to determine the internal parameters for improving accuracy of a lithium ion battery equivalent circuit model. Conventional methods for the parameter estimation directly using the curve fitting results generate the phenomenon to be incorrect due to the influence of the internal capacitive impedance. To solve this phenomenon, simple correction procedure with transient state analysis is proposed and added to the parameter estimation method. Furthermore, conventional dynamic equation for correction is enhanced with advanced RC impedance dynamic equation so that the proposed modeling results describe the battery dynamic characteristics more exactly. The improved accuracy of the battery model by the proposed modeling method is verified by single cell experiments compared to the other type of models.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.570-571
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• 2012

본 논문에서는 PV Simulator의 운전시 기존 방식에 비해 성능이 우수한 PV Cell Modeling 알고리즘을 제안한다. PV Simulator가 PV Cell의 비선형적인 I-V 특성을 구현하기 위해서는 제조사가 제공하는 3가지 운전점(단락회로운전, 개방회로운전 및 최대전력운전)에서의 전압, 전류 데이터를 이용하여 빠르고 정확하게 PV Cell 등가회로의 파라메터 값을 추출하여야 한다. 본 논문에서는 방정식 근을 비교하는 방식을 이용하여 기존 방식에 비해 실리콘-결정형 및 박막형 셀을 포괄하는 빠르고 정확한 등가회로 파라메터 추출방법을 제시하고, 제안한 모델링 방법에 대한 유효성을 시뮬레이션을 통해 검증하였다.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2019.08a
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• pp.260-261
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• 2019

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.230-230
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• 2016

Hydrological modeling is a very complex task dealing with multi-source of data, but it can be potentially benefited from recent improvements and developments in remote sensing. The estimation of actual land surface evapotranspiration (ET), an important variable in water management, has become possible based entirely on satellite data. This study adopted a Surface Energy Balance Algorithm for Land (SEBAL) with the use of MODerate Resolution Imaging Spectrometer (MODIS) satellite products. The SEBAL model is one of the commonly used approach for the ET estimation. A primary advantage of the SEBAL model is rather its minimum requirement for ground-based weather data. The MODIS provides ET (MOD16) product that is based on the Penman-Monteith equation. This study aims to further develop the SEBAL model by employing a more rigorous parameterization scheme including the estimation of uncertainty associated with parameter and model selection in regression model. Finally, the proposed model is compared with the existing approaches and comprehensive discussion is then provided.

• Communications for Statistical Applications and Methods
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• v.31 no.3
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• pp.263-277
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• 2024

This paper proposes new parameterizations of the tilted beta binomial distribution, obtained from the combination of the binomial distribution and the tilted beta distribution, where the beta component of the mixture is parameterized as a function of their mean and variance. These new parameterized distributions include as particular cases the beta rectangular binomial and the beta binomial distributions. After that, we propose new linear regression models to deal with overdispersed binomial datasets. These new models are defined from the proposed new parameterization of the tilted beta binomial distribution, and assume regression structures for the mean and variance parameters. These new linear regression models are fitted by applying Bayesian methods and using the OpenBUGS software. The proposed regression models are fitted to a school absenteeism dataset and to the seeds germination rate according to the type seed and root.