• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
• /
• pp.20-22
• /
• 2005

In this paper, we propose a novel stability criterion for switched linear systems. The proposed method employs the results on the upper bound of the solution of LME(Lyapunov Matrix Equation) and on the stability of hybrid system. The former guarantees the existence of Lyapunov-like energy functions and the latter shows that the stability of switched linear systems by using these energy functions. The proposed criterion releases the restriction on the stability of switched linear systems comparing with the existing methods and provides us with easy implementation way for pole assignment.

• 전기의세계
• /
• 제20권4호
• /
• pp.12-16
• /
• 1971

The electrical detector and computer systems for traffic flow and speed measurement are demonstrated in this paper. For the best traffic control optimization, linear and non-linear equations in the transition state are dealing with the perturbation of the linear car-following. In the conclusions, we construct a realizable system for the central automatic traffic control with a computer. Furthermore, fixed periodic switching system by manual with the automatic traffic control system is recommended for emergency perturbation.

• 전력전자학회논문지
• /
• 제4권6호
• /
• pp.554-560
• /
• 1999

리니어 스텝핑 모터(Linear Stepping Motor : 이하 LSM이라 칭함)는 운동 변환기구 없이 입력신호에 따라 선형적인 변위를 발생시키는 다이렉트 드라이브(Direct Drive)방식의 전동기이다. 따라서 LSM은 자동반송장치, 의료기기, OA,FA 응용 등에 다양하게 사용되고 있다. 그러나 LSM은 구동시 구조적으로 큰 진동이 발생됨으로서 추력이 급격히 떨어질 때가 있으며, 최악의 경우에는 역전이나 탈조현상이 발생하고, 또한 소음의 원인이 되기 때문에 응용에 있어서 많은 제약을 받고 있는 실정이다. 여기에 대응하기 위해, 본 논문에서는 권선 인덕턴스에 저장된 에너지와 LSM의 유도전압을 이용한 새로운 1상 여자방식에 의한 진동억제 방법을 보여주며, 또한 LSM의 구조를 기초로 자기등가회로를 구성하였으며, 또한 자기등가회로에 대한 방정식을 이용하여 LSM의 전기적인 등기회로를 유도하였다. 그리고, LSM의 새로운 1상 여자방식에 의한 진동특성을 전압방정식과 추력방정식 및 운동방정식을 사용하여 ACSL에 의하여 시뮬레이션 하였으며, 레이저 실측 시스템에 의한 실측결과와 비교·검토하였다.

• 대한수학회보
• /
• 제60권5호
• /
• pp.1181-1199
• /
• 2023

For solving complex symmetric positive definite linear systems, we propose a single step real-valued (SSR) iterative method, which does not involve the complex arithmetic. The upper bound on the spectral radius of the iteration matrix of the SSR method is given and its convergence properties are analyzed. In addition, the quasi-optimal parameter which minimizes the upper bound for the spectral radius of the proposed method is computed. Finally, numerical experiments are given to demonstrate the effectiveness and robustness of the propose methods.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
• /
• pp.432-435
• /
• 1995

In this paper a new approach to obtain the solution of the linear-quadratic Gaussian control problem for singularly perturbed discrete-time stochastic systems is proposed. The alogorithm proposed is based on exploring the previous results that the exact solution of the global discrete algebraic Riccati equations is found in terms of the reduced-order pure-slow and pure-fast nonsymmetric continuous-time algebraic Riccati equations and, in addition, the optimal global Kalman filter is decomposed into pure-slow and pure-fast local optimal filters both driven by the system measurements and the system optimal control input. It is shown that the optimal linear-quadratic Gaussian control problem for singularly perturbed linear discrete systems takes the complete decomposition and parallelism between pure-slow and pure-fast filters and controllers.

• Wind and Structures
• /
• 제28권2호
• /
• pp.89-97
• /
• 2019

The non-linear equations governing wind-induced internal pressures for a two-compartment building with background leakage are linearized based on some reasonable assumptions. The explicit admittance functions for both building compartments are derived, and the equivalent damping coefficients of the coupling internal pressure system are iteratively obtained. The RMS values of the internal pressure coefficients calculated from the non-linear equations and linearized equations are compared. Results indicate that the linearized equations generally have good calculation precision when the porosity ratio is less than 20%. Parameters are analyzed on the explicit admittance functions. Results show that the peaks of the internal pressure in the compartment without an external opening (Compartment 2) are higher than that in the compartment with an external opening (Compartment 1) at lower Helmholtz frequency. By contrast, the resonance peak of the internal pressure in compartment 2 is lower than that in compartment 1 at higher Helmholtz frequencies.

• 전자공학회논문지 IE
• /
• 제44권4호
• /
• pp.26-29
• /
• 2007

본 논문에서는 섭동 시스템 행렬을 가지는 선형 시스템에 대하여 Lyapunov 방정식과 함수를 고려하여 섭동 유계를 유도한다. 그리고 Lyapunov 함수의 도함수가 음의 정의로 보장되는 가장 큰 섭동 구간을 허락하는 Lyapunov 함수의 선택에 대하여 고려한다. 행렬 계수를 가지는 행렬 리카티 방정식의 해 존재에 대하여 살펴보며, 예를 통하여 검증한다.

• Journal of applied mathematics & informatics
• /
• 제31권5_6호
• /
• pp.661-667
• /
• 2013

In this paper we propose the iterated projection method for the approximate solution of an integro-differential equations with Cauchy kernel in $L^2([-1,1],\mathbb{C})$ using Legendre polynomials. We prove the convergence of the method. A system of linear equations is to be solved. Numerical examples illustrate the theoretical results.

• Journal of Mechanical Science and Technology
• /
• 제17권11호
• /
• pp.1608-1615
• /
• 2003

This paper studies on the linearization of a looper system in hot strip mills, that plays an important role in regulating a strip tension or a strip width. Nonlinear dynamic equations of the looper system are analytically linearized by a static feedback linearization algorithm with a compensator. The proposed linear model of the looper is validated by a comparison with a linear model using Taylor's series. It is shown that the linear model by static feedback well describes nonlinearities of the looper system than one using Taylor's series. Furthermore, it is shown from the design of an ILQ controller that the linear model by static feedback is very useful in designing a linear controller of the looper system.

• Structural Engineering and Mechanics
• /
• 제3권2호
• /
• pp.135-144
• /
• 1995

Since structural systems may fail in any one of several failure modes, computation of system reliability is always difficult. A method using numerical quadrature for computing structural system reliability with either one or more than one failure mode is presented in this paper. Statistically correlated safety margin equations are transformed into a group of uncorrelated variables and the joint density function of these uncorrelated variables can be generated by using the Maximum Entropy Method. Structural system reliability is then obtained by integrating the joint density function with the transformed safety domain enclosed within a set of linear equations. The Gaussian numerical integration method is introduced in order to improve computational accuracy. This method can be used to evaluate structural system reliability for Gaussian or non-Gaussian variables with either linear or nonlinear safety boundaries. It is also valid for implicit safety margins such as computer programs. Both the theory and the examples show that this method is simple in concept and easy to implement.