• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.11a
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• pp.475-481
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• 1999

This paper presents a recursive least square estimation algorithm to estimate parameters of the vector controlled induction machine based on measurements of the stator voltage, curents and slip frequency. Due to its recursive structure, this algorithm has the potential to be used for on-line estimation and adaptive control. The algorithm is designed using regression model derived from the motor electrical equation. This model is valid when there is a tittle-scale separation between vector control system and adaptive system. Vector control performed at fast stage and slow stage is in charge of parameters estimation. The performance of tile algorithm is illustrated by means of simulation results and experiment.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.25 no.4
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• pp.224-261
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• 2021

The interest in implicit-explicit (IMEX) integration methods has emerged as an alternative for dealing in a computationally cost-effective way with stiff ordinary differential equations arising from practical modeling problems. In this paper, we introduce implicit-explicit second derivative linear multi-step methods (IMEX SDLMM) with error control. The proposed IMEX SDLMM is based on second derivative backward differentiation formulas (SDBDF) and recursive SDBDF. The IMEX second derivative schemes are constructed with order p ranging from p = 1 to 8. The methods are numerically validated on well-known stiff equations.

• Journal of IKEEE
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• v.23 no.3
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• pp.817-825
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• 2019

Difference equation is useful for control algorithm in the microprocessor. To approximate a derivative values from sampled data, it is used the methods of forward, backward and central differences. The key of computing discrete derivative values is the finite difference coefficient. The focus of this paper is a new approach method of finite difference formula. And we apply the proposed method to the recursive least squares(RLS) algorithm.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.3
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• pp.399-406
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• 1996

This paper presents a method of hierarchical state estimation of the time-varying linear systems via Block-pulse function(BPF). When we estimate the state of the systems where noise is considered, it is very difficult to obtain the solutions because minimum error variance matrix having a form of matrix nonlinear differential equations is included in the filter gain calculation. Therefore, hierarchical approach is adapted to transpose matrix nonlinear differential equations to a sum of low order state space equation from and Block-pulse functions are used for solving each low order state space equation in the form of simple and recursive algebraic equation. We believe that presented methods are very attractive nd proper for state estimation of time-varying linear systems on account of its simplicity and computational convenience. (author). 13 refs., 10 figs.

• Journal of the Semiconductor & Display Technology
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• v.13 no.4
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• pp.7-13
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• 2014

In this paper, an area-efficient degree-computationless modified Euclidean (DCME) algorithm is presented and implemented for high-speed Reed-Solomon (RS) decoder. The DCME algorithm can be used to solve the key equation in Reed-Solomon decoder to get the error location polynomial and the error value polynomial. A pipelined recursive structure is adopted for reducing the area of key equation solver (KES) block with sacrifice of an amount of decoding latency. For comparisons, KES block for RS(255,239,8) decoder with the proposed architecture is implemented using Verilog HDL and synthesized using Synopsys design tool and 65nm CMOS technology. The synthesis results show that the proposed architecture can be implemented with less gate counts than other existing DCME architectures.

• Korean Journal of Social Welfare Studies
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• v.42 no.2
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• pp.179-203
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• 2011

The purpose of the study is 1) to investigate the reciprocal relationship between cognitive functioning and depressive symptoms and 2) to examine whether there is gender difference in this mutual relationship. The uniqueness of the current study is in its investigation on the simultaneous reciprocal relationship between cognitive functioning and depressive symptoms, which is different from previous studies examining unidirectional relationship. Subjects were 3,511 individuals aged 65 and over who participated in the first and second wave of Korean Longitudinal Study of Ageing. Non-recursive structural equation modeling identified the reciprocal relationship between cognitive functioning and depressive symptoms, with poorer cognitive functioning leading to higher depressive symptoms and higher depressive symptoms resulting in poorer cognitive functioning. Multi-group analysis showed the gender difference in the relationship between cognitive functioning and depressive symptoms. Specifically, cognitive functioning was the significant predictor of depressive symptoms for females, whereas the depressive symptoms was the significant predictor of cognitive functioning for males. These findings indicate that the reciprocal relationship and gender difference should be considered when we development practice implications for prevention and treatment related to depression and cognitive functioning. Based on these findings, implications for theory and practice were discussed.

• Journal of Korean Institute of Industrial Engineers
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• v.5 no.2
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• pp.2-7
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• 1979

The fundamental stochastic duel of Williams and Ancker is combined with the probabilistic linear, square and mixed laws of Brown and Smith when the battle time is limited and interfiring times are continuous. The Probability of a given side's winnig or a draw is derived in a recursive equation with Laplace transforms. Examples with negative exponential firing times are given. In linear law an exact closed form solution is obtained, whereas for square and mixed laws only square ($2{\times}2$) duels are considered.

• Journal of applied mathematics & informatics
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• v.34 no.1_2
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• pp.35-48
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• 2016

In this paper we deal with the expressions of solutions and the periodicity nature of some systems of nonlinear difference equations with order three with nonzero real numbers initial conditions.

• Journal of the Korean Data and Information Science Society
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• v.14 no.4
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• pp.1007-1012
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• 2003

A recursive procedure for finding the Cholesky root of the inverse of sample covariance matrix, leading to a direct solution for the inverse of a positive definite matrix, is developed using the likelihood equation for the maximum likelihood estimation of the Cholesky root under normality assumptions. An example of the Hilbert matrix is considered for an illustration of the procedure.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.203-207
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• 1992

In this paper, a new GPC(Generalized Predictive Control) algorithm which is robust to disturbances isproposed. This controller minimizes the LQ cost function when the disturbance maximizes this cost function. The solution is obtained from the min-max problem which can be solved by differential game theory and has the non-recursive form which does not use the Riccati equation. Its another solution for state space models is investigated.