• Title, Summary, Keyword: linear system

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New Fuzzy Inference System Using a Kernel-based Method

  • Kim, Jong-Cheol;Won, Sang-Chul;Suga, Yasuo
    • 제어로봇시스템학회:학술대회논문집
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    • pp.2393-2398
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    • 2003
  • In this paper, we proposes a new fuzzy inference system for modeling nonlinear systems given input and output data. In the suggested fuzzy inference system, the number of fuzzy rules and parameter values of membership functions are automatically decided by using the kernel-based method. The kernel-based method individually performs linear transformation and kernel mapping. Linear transformation projects input space into linearly transformed input space. Kernel mapping projects linearly transformed input space into high dimensional feature space. The structure of the proposed fuzzy inference system is equal to a Takagi-Sugeno fuzzy model whose input variables are weighted linear combinations of input variables. In addition, the number of fuzzy rules can be reduced under the condition of optimizing a given criterion by adjusting linear transformation matrix and parameter values of kernel functions using the gradient descent method. Once a structure is selected, coefficients in consequent part are determined by the least square method. Simulated result illustrates the effectiveness of the proposed technique.

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A note on a method for estimating the linear expenditure system with one restriction

  • Lee, Seok-Koo
    • Journal of the Korean Statistical Society
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    • v.4 no.1
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    • pp.67-78
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    • 1975
  • Over twenty-five years ago, Professor Klein and Rubin presented the linear expenditure system. That system was first estimated by Stone. Subsequently many investigators have estimated that system. In this paper, many points of the error structure shown by Pollak and Wales are referred to. Barten presented an estimation theorem on a singular covariance matrix. In order to estimate parameters, we place an emphasis on the maximum likihood method which we believe to be most appropriate. As we have one linear restriction on parameters to be estimated, we maximized the associated likelihood function subject to that linear restriction through the well-known lagrange multiplier method. This paper is organized in the following fashion : (1) a brief description on classical consumer theory, (2) a linear expenditure system and its constraint, (3) dyanmic specification and stochastic specification, (4) estimation method, and (5) conclusion.

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Static equilibrium and linear vibration analysis of a high speed electric train system (고속전철 시스템의 정적평형 및 선형진동 해석)

  • 김종인;유홍희;황요하
    • Journal of the Korean Society for Railway
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    • v.2 no.4
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    • pp.1-8
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    • 1999
  • A formulation to perform static equilibrium and linear vibration analysis is presented in this paper. The formulation employs minimum number of equations of motion which are derived by using a partial velocity matrix. The static equilibrium analysis is performed first, then the linear vibration analysis is performed at the static equilibrium position. By using the formulation presented in this paper, static equilibrium and linear vibration analysis of a high speed electric train system are performed. A single bogie system, a power car vehicle, and a train system which consists of five vehicles are analyzed, respectively. Natural frequencies and a few lowest mode shapes of the two are identified in this paper.

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A NOTE ON PARTIAL SIGN-SOLVABILITY

  • Hwang, Suk-Geun;Park, Jin-Woo
    • Bulletin of the Korean Mathematical Society
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    • v.43 no.3
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    • pp.471-478
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    • 2006
  • In this paper we prove that if AX=b is a partial sign-solvable linear system with A being sign non-singular matrix and if ${\alpha}=\{j:\;x_j\;is\;sign-determined\;by\; Ax=b\}, then $A_{\alpha}X_{\alpha}=b_{\alpha}$ is a sign-solvable linear system, where $A_{\alpha}$ denotes the submatrix of A occupying rows and columns in o and xo and be are subvectors of x and b whose components lie in ${\alpha}$. For a sign non-singular matrix A, let $A_l,\;...,A_{\kappa}$ be the fully indecomposable components of A and let ${\alpha}_i$ denote the set of row numbers of $A_r,\;r=1,\;...,\;k$. We also show that if $A_x=b$ is a partial sign-solvable linear system, then, for $r=1,\;...,\;k$, if one of the components of xor is a fixed zero solution of Ax=b, then so are all the components of x_{{\alpha}r}$.

Approximate Response of a Non-linear Vibration Isolation System Using the Harmonic Balance Method (하모닉 밸런스법을 이용한 비선형 진동절연 시스템의 근사적 응답)

  • Lee, Gun-Myung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.6
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    • pp.124-129
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    • 2018
  • A non-linear vibration isolation system which is composed of a non-linear spring and a linear damper was proposed in past research. When the support of the isolation system is excited harmonically, the response component of the isolation system mass at the excitation frequency has been calculated approximately using the harmonic balance method. The response was approximated by a single mode, and the result was compared with a numerical result which is assumed as an accurate one. Next, the response was approximated by two modes, and the result was compared with the former one.

Design of Linear Recursive Target State Estimator for Collision Avoidance System (차량 충돌 방지 시스템을 위한 선형 순환 표적 추정기 설계)

  • Han, Seul-Ki;Ra, Won-Sang;Whang, Ick-Ho;Park, Jin-Bae
    • Proceedings of the KIEE Conference
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    • pp.1740-1741
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    • 2011
  • This paper proposes a new linear recursive target state estimator for automotive collision warning system. The target motion is modeled in Cartesian coordinate system while the radar measurements such as range, line-of-sight angle and range rate are obtained in polar coordinate system. To solve the problem by nonlinear relation between these two coordinate system, a practical linear filter design scheme employing the predicted line-of-sight Cartesian coordinate system (PLCCS) is proposed. Especially, PLCCS can effectively incorporate range rate measurements into target tracking system. It is known that the utilization of range rate measurements enables the improvement of target tracking performance. Moreover, PLCCS based target tracking system is implemented by linear recursive filter structure and hence is more suitable scheme for the development of reliable collision warning system. The performance of the proposed method is demonstrated by computer simulations.

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Use of Higher Order Frequency Response Functions for Non-Linear Parameter Estimation (고차 주파수응답함수를 이용한 비선형시스템의 매개변수 추정)

  • 이건명
    • Journal of KSNVE
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    • v.7 no.2
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    • pp.223-229
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    • 1997
  • Presented is a method to estimate system parameters of a system with polynomial non-linerities from the measured higher order frequency response functions. Higher order FRFs can be measured on some restricted regions by sinusoidally exciting a non-linear system with various input amplitudes and measuring the response component at the excitation frequency. These higher order FRFs can be expressed in terms of system parameter, and the system parameters can be estimated from the measured FRFs. Since the expressions for higher order FRFs are complicated, system parameters can be estimated from them using an optimization technique. The present method has been applied to a simulated single degree of freedom system with non-linear stiffness and damping, and has estimated accurate system parameters.

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An improved linear sampled-data output regulators (개선된 선형 샘플치 출력 조절기)

  • 정선태
    • 제어로봇시스템학회:학술대회논문집
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    • pp.1726-1729
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    • 1997
  • In general, the solvability of linear robust output regulation problem are not preserved under time-sampling. Thus, it is found that the digital regulator implemented by itme-sampling of anlog output regulator designed based on the continuous-time linear system model is nothing but a 1st order approximation with respect to time-sampling. By the way, one can design an improved sampled-data regulator with respect to sampling time by utilizing the intrinsic structure of the system. In this paper, we study the system structures which it is possible to design an improved sampled-data regulator with respect to sampling time.

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Non-linear Chirp UWB Ranging System with Narrowband Interference Suppression Abilities

  • Shen, Hanbing;Zhang, Weihua;Kwak, Kyung-Sup
    • ETRI Journal
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    • v.29 no.4
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    • pp.521-523
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    • 2007
  • In this letter, we analyze an ultra-wideband ranging system based on non-linear chirp waveforms with the ability of narrowband interference suppression. A number of non-linear chirp waveforms are proposed and evaluated by simulation. The results verify that the proposed schemes can suppress the Narrowband interference to a certain degree.

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Robust suboptimal regulator design for linear multivariable system

  • Lee, Jae-Hyeok;Bien, Zeungnam
    • 제어로봇시스템학회:학술대회논문집
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    • pp.841-846
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    • 1990
  • In this study, a design method to obtain a robust suboptimal regulator for linear multivariable system is presented. This new design method is based on the optimal regulator design method using eigen-structure assignment and it uses additional cost function which represent robustness of the closed loop system. When we design the regulator using pole assignment method for linear multivariable system we have extra degree-of-freedom after assigning desired eigenvalues of the closed loop system in determining the feedback gain. So we assign additional robust suboptimal regulator. In this study we also feedback the system output for more practical applications.

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