• Title/Summary/Keyword: least squares

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Parameter Estimation of Permanent Magnet Synchronous Motors using a Least Squares Method (최소자승법을 이용한 영구자석 동기전동기의 파라미터 추정)

  • Kwon, Ki-Hoon;Lee, Kyo-Beum
    • Proceedings of the KIPE Conference
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    • 2018.11a
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    • pp.175-176
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    • 2018
  • This paper presents a method to estimate the parameter of permanent magnet synchronous motor using a least squares method. The approximate solution of the linear simultaneous equations is obtained by the pseudoinverse least squares method of the input current and output voltage data of the current controller. It is possible to obtain the current response of the same bandwidth to the general control target by using the Pole-zero Cancellation technique. This paper verifies the performance of the proposed method by comparing the results of estimation of parameters of different motors by simulation.

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Another Look at Combined Intrablock and Interblock Estimation in Block Designs

  • Paik, U.B.
    • Journal of the Korean Statistical Society
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    • v.15 no.2
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    • pp.118-126
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    • 1986
  • The relationships between combined estimators and generalized least squares estimators in block designs are reviewed. Here combined estimators mean the best linear combination of intrablock and interblock estimaters. It is well known that only for balanced incomplete block designs the combined estimators of Yates and of the generalized least squares estimators give the same result. In this paper, a general form of the combined estimators for treatment effects is derived and it can be seen that such estimators are equivalent to the generalized least squares estimators.

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Type I projection sum of squares by weighted least squares (가중최소제곱법에 의한 제1종 사영제곱합)

  • Choi, Jaesung
    • Journal of the Korean Data and Information Science Society
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    • v.25 no.2
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    • pp.423-429
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    • 2014
  • This paper discusses a method for getting Type I sums of squares by projections under a two-way fixed-effects model when variances of errors are not equal. The method of weighted least squares is used to estimate the parameters of the assumed model. The model is fitted to the data in a sequential manner by using the model comparison technique. The vector space generated by the model matrix can be composed of orthogonal vector subspaces spanned by submatrices consisting of column vectors related to the parameters. It is discussed how to get the Type I sums of squares by using the projections into the orthogonal vector subspaces.

Robust Velocity Estimation of an Omnidirectional Mobile Robot Using a Polygonal Array of Optical Mice

  • Kim, Sung-Bok;Lee, Sang-Hyup
    • International Journal of Control, Automation, and Systems
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    • v.6 no.5
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    • pp.713-721
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    • 2008
  • This paper presents the robust velocity estimation of an omnidirectional mobile robot using a polygonal array of optical mice that are installed at the bottom of the mobile robot. First, the velocity kinematics from a mobile robot to an array of optical mice is derived as an overdetermined linear system. The least squares velocity estimate of a mobile robot is then obtained, which becomes the same as the simple average for a regular polygonal arrangement of optical mice. Next, several practical issues that need be addressed for the use of the least squares mobile robot velocity estimation using optical mice are investigated, which include measurement noises, partial malfunctions, and imperfect installation. Finally, experimental results with different number of optical mice and under different floor surface conditions are given to demonstrate the validity and performance of the proposed least squares mobile robot velocity estimation method.

The Generation of a Smooth C Extension Surface (부드러운 $C^2$확장 곡면 생성)

  • 김회섭
    • Korean Journal of Computational Design and Engineering
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    • v.9 no.2
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    • pp.143-147
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    • 2004
  • To design parts satisfying physical property in the continuous region, we do it in the discrete rectangular mesh points. Then we obtain points data from parts design and usually construct the surface using least squares method. In such case, that surface has an oscillation in the ineffective region which is inadequate for physical phenomena or NC machining. To solve both problems simultaneously, we extend the surface smoothly to have small curvature in the extended region. Up to now, we use the least squares method for the parts design in Color Picture Tube or Color Display Tube but in this paper, we use functions which is easily controllable. This surface has no error within the effective region compared to the least squares method.

Estimation of Seasonal Cointegration under Conditional Heteroskedasticity

  • Seong, Byeongchan
    • Communications for Statistical Applications and Methods
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    • v.22 no.6
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    • pp.615-624
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    • 2015
  • We consider the estimation of seasonal cointegration in the presence of conditional heteroskedasticity (CH) using a feasible generalized least squares method. We capture cointegrating relationships and time-varying volatility for long-run and short-run dynamics in the same model. This procedure can be easily implemented using common methods such as ordinary least squares and generalized least squares. The maximum likelihood (ML) estimation method is computationally difficult and may not be feasible for larger models. The simulation results indicate that the proposed method is superior to the ML method when CH exists. In order to illustrate the proposed method, an empirical example is presented to model a seasonally cointegrated times series under CH.

On the generalized truncated least squares adaptive algorithm and two-stage design method with application to adaptive control

  • Yamamoto, Yoshihiro;Nikiforuk, Peter-N.;Gupta, Madam-M.
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10b
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    • pp.7-12
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    • 1993
  • This paper presents a generalized truncated least, squares adaptive algorithm and a two-stage design method. The proposed algorithm is directly derived from the normal equation of the generalized truncated least squares method (GTLSM). The special case of the GTLSM, the truncated least squares (TLS) adaptive algorithm, has a distinct features which includes the case of minimum steps estimator. This algorithm seemed to be best in the deterministic case. For real applications in the presence of disturbances, the GTLS adaptive algorithm is more effective. The two-stage design method proposed here combines the adaptive control system design with a conventional control design method and each can be treated independently. Using this method, the validity of the presented algorithms are examined by the simulation studies of an indirect adaptive control.

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ANALYSIS OF VELOCITY-FLUX FIRST-ORDER SYSTEM LEAST-SQUARES PRINCIPLES FOR THE OPTIMAL CONTROL PROBLEMS FOR THE NAVIER-STOKES EQUATIONS

  • Choi, Young-Mi;Lee, Hyung-Chun
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.14 no.2
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    • pp.125-140
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    • 2010
  • This paper develops a least-squares approach to the solution of the optimal control problem for the Navier-Stokes equations. We recast the optimality system as a first-order system by introducing velocity-flux variables and associated curl and trace equations. We show that a least-squares principle based on $L^2$ norms applied to this system yields optimal discretization error estimates in the $H^1$ norm in each variable.

Parameter Estimation using a Modified least Squares method (수정된 최소자승법을 이용한 파라미터 추정)

  • Han, Young-Seong;Kim, Eung-Seok;Han, Hong-Seok;Yang, Hai-Won
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.691-694
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    • 1991
  • In a discrete parameter estimation system, the standard least squares method shows slow convergence. On the other hand, the weighted least squares method has relatively fast convergence. However, if the input is not sufficiently rich, then gain matrix grows unboundedly. In order to solve these problems, this paper proposes a modified least squares algorithm which prevents gain matrix from growing unboundedly and has fast convergence.

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An Efficient Recursive Total Least Squares Algorithm for Training Multilayer Feedforward Neural Networks

  • Choi Nakjin;Lim Jun-Seok;Sung Koeng-Mo
    • Proceedings of the Acoustical Society of Korea Conference
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    • autumn
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    • pp.527-530
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    • 2004
  • We present a recursive total least squares (RTLS) algorithm for multilayer feedforward neural networks. So far, recursive least squares (RLS) has been successfully applied to training multilayer feedforward neural networks. But, when input data contain additive noise, the results from RLS could be biased. Such biased results can be avoided by using the recursive total least squares (RTLS) algorithm. The RTLS algorithm described in this paper gives better performance than RLS algorithm over a wide range of SNRs and involves approximately the same computational complexity of $O(N^{2})$.

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