• Title/Summary/Keyword: Least squares method

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A Study of Broad-band Conformal Beam Forming using Moving Least Squares Method (Moving Least Squares 기법을 이용한 광대역 컨포멀 빔 형성 연구)

  • Jung, Sang-Hoon;Lee, Kang-In;Jung, Hyun-Kyo;Chung, Young-Seek
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.68 no.1
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    • pp.83-89
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    • 2019
  • In this paper, beam forming using moving least squares method (MLSM) is studied. In the previous research, the least squares method (LSM), one of the data interpolation methods, was used to determine the desired beam pattern and obtain a beam pattern that minimizes the square of the error with the desired beam pattern. However, LSM has a disadvantage in that the beam pattern can not be formed to satisfy the exact steering angle of the desired beam pattern and the peak sidelobe level (PSLL) condition. To overcome this drawback, MLSM is used for beam forming. In order to verify, the proposed method is applied in beam forming of Bezier platform array antenna which is one of conformal array antenna platform.

A Comparison Study on Total Least Squares and Least Squares (토털최소제곱법과 최소제곱법의 비교연구)

  • 이임평;최윤수;권재현
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2003.10a
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    • pp.15-19
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    • 2003
  • The Total Least Squares (TLS) method is introduced in comparison with the conventional Least Squares (LS) method. The principles and mathematical models for both methods are summarized and the comparison results from their applications to a simple geometric example, fitting a straight line to a set of 2D points are presented. As conceptually reasoned, the results clearly indicate that LS is more susceptible of producing wrong parameters with worse precision rather than TLS. For many applications in surveying, can adjustment computation and parameter estimation based on TLS provide better results.

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AN ITERATIVE ALGORITHM FOR SOLVING THE LEAST-SQUARES PROBLEM OF MATRIX EQUATION AXB+CYD=E

  • Shen, Kai-Juan;You, Chuan-Hua;Du, Yu-Xia
    • Journal of applied mathematics & informatics
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    • v.26 no.5_6
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    • pp.1233-1245
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    • 2008
  • In this paper, an iterative method is proposed to solve the least-squares problem of matrix equation AXB+CYD=E over unknown matrix pair [X, Y]. By this iterative method, for any initial matrix pair [$X_1,\;Y_1$], a solution pair or the least-norm least-squares solution pair of which can be obtained within finite iterative steps in the absence of roundoff errors. In addition, we also consider the optimal approximation problem for the given matrix pair [$X_0,\;Y_0$] in Frobenius norm. Given numerical examples show that the algorithm is efficient.

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A transductive least squares support vector machine with the difference convex algorithm

  • Shim, Jooyong;Seok, Kyungha
    • Journal of the Korean Data and Information Science Society
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    • v.25 no.2
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    • pp.455-464
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    • 2014
  • Unlabeled examples are easier and less expensive to obtain than labeled examples. Semisupervised approaches are used to utilize such examples in an eort to boost the predictive performance. This paper proposes a novel semisupervised classication method named transductive least squares support vector machine (TLS-SVM), which is based on the least squares support vector machine. The proposed method utilizes the dierence convex algorithm to derive nonconvex minimization solutions for the TLS-SVM. A generalized cross validation method is also developed to choose the hyperparameters that aect the performance of the TLS-SVM. The experimental results conrm the successful performance of the proposed TLS-SVM.

PSEUDO-SPECTRAL LEAST-SQUARES METHOD FOR ELLIPTIC INTERFACE PROBLEMS

  • Shin, Byeong-Chun
    • Journal of the Korean Mathematical Society
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    • v.50 no.6
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    • pp.1291-1310
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    • 2013
  • This paper develops least-squares pseudo-spectral collocation methods for elliptic boundary value problems having interface conditions given by discontinuous coefficients and singular source term. From the discontinuities of coefficients and singular source term, we derive the interface conditions and then we impose such interface conditions to solution spaces. We define two types of discrete least-squares functionals summing discontinuous spectral norms of the residual equations over two sub-domains. In this paper, we show that the homogeneous least-squares functionals are equivalent to appropriate product norms and the proposed methods have the spectral convergence. Finally, we present some numerical results to provide evidences for analysis and spectral convergence of the proposed methods.

FIR System Identification Method Using Collaboration Between RLS (Recursive Least Squares) and RTLS (Recursive Total Least Squares) (RLS (Recursive Least Squares)와 RTLS (Recursive Total Least Squares)의 결합을 이용한 새로운 FIR 시스템 인식 방법)

  • Lim, Jun-Seok;Pyeon, Yong-Gook
    • The Journal of the Acoustical Society of Korea
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    • v.29 no.6
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    • pp.374-380
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    • 2010
  • It is known that the problem of FIR filtering with noisy input and output data can be solved by a total least squares (TLS) estimation. It is also known that the performance of the TLS estimation is very sensitive to the ratio between the variances of the input and output noises. In this paper, we propose a convex combination algorithm between the ordinary recursive LS based TLS (RTLS) and the ordinary recursive LS (RLS). This combined algorithm is robust to the noise variance ratio and has almost the same complexity as the RTLS. Simulation results show that the proposed algorithm performs near TLS in noise variance ratio ${\gamma}{\approx}1$ and that it outperforms TLS and LS in the rage of 2 < $\gamma$ < 20. Consequently, the practical workability of the TLS method applied to noisy data has been significantly broadened.

BLOCK DIAGONAL PRECONDITIONERS FOR THE GALERKIN LEAST SQUARES METHOD IN LINEAR ELASTICITY

  • Yoo, Jae-Chil
    • Communications of the Korean Mathematical Society
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    • v.15 no.1
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    • pp.143-153
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    • 2000
  • In [8], Franca and Stenberg developed several Galerkin least squares methods for the solution of the problem of linear elasticity. That work concerned itself only with the error estimates of the method. It did not address the related problem of finding effective methods for the solution of the associated linear systems. In this work, we propose the block diagonal preconditioners. The preconditioned conjugate residual method is robust in that the convergence is uniform as the parameter, v, goes to $\sfrac{1}{2}$. Computational experiments are included.

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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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LEAST ABSOLUTE DEVIATION ESTIMATOR IN FUZZY REGRESSION

  • KIM KYUNG JOONG;KIM DONG HO;CHOI SEUNG HOE
    • Journal of applied mathematics & informatics
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    • v.18 no.1_2
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    • pp.649-656
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    • 2005
  • In this paper we consider a fuzzy least absolute deviation method in order to construct fuzzy linear regression model with fuzzy input and fuzzy output. We also consider two numerical examples to evaluate an effectiveness of the fuzzy least absolute deviation method and the fuzzy least squares method.