摘要:

A new way of formulating a multipoint Padé approximant of a linear system transfer function is given. It is seen to be very flexible and computationally efficient. The expansion points can be a mixture of real, complex, purely imaginary and multiple points with no complex arithmetic required. The underlying idea of the method is to convert the rational approximation problem into one of polynomial approximation. This results in simple matrix multiplications and the solution of a set of linear equations to derive the reduced model. Examples are given to demonstrate the application of the technique.

ISSN:0020-7721    

DOI:10.1080/00207729308949525

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A simulation technique called multi stage Monte Carlo optimization (MSMCO) is used to approximate the roots to a 300 degree polynomial. MSMCO consists of repeated random searches in an ever-narrowing focused region centred about the “best answer so far”. This process continues until a good approximate root is produced. Then it is factored out of the polynomial equation and the search for the next root begins in a similar fashion. Multi stage is a general purpose solution technique that can work on a wide variety of problems. Its best potential for application is for the approximate solutions to difficult problems.

ISSN:0020-7721    

DOI:10.1080/00207729308949526

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Most of the empirical studies modelling the association between slock returns and accounting earnings assume a homogeneous return-earnings relation across firms and over time. However, in recent years some studies have reported that this association significantly varies across firms and also over time. Whether macro-economic factors explain the intertemporal variation of earnings response coefficients (ERCs), i.e. the slope coefficients between stock returns and corporate earnings in the Finnish stock market is studied. In the theoretical part of the study it is shown that there exists a relationship between macroeconomic variables affecting future cash flows/dividends or pricing operator and the intertemporal variation of earnings response coefficients. The empirical analysis reveals some time-series variation of ERCs in the Finnish stock market. A significant proportion of this variation is observed to be due to the changes in the underlying macroeconomic characteristics.

ISSN:0020-7721    

DOI:10.1080/00207729308949527

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A dual redundant control system whose fault-tolerant policy is capable of removing the failed controller is proposed. The heuristics of detecting failures of a controller and changing the time weight take the form of a set of linguistic decision rules in fuzzy logic. This detection method based on performance measure enables the detection of a failed controller without relying on mathematical model and failure assumptions. It can handle gradually degrading failures as well as catastrophic failures by introducing the concept of failure measure and time weight. The failed controller is smoothly removed by reducing the time weight of the failed controller.

ISSN:0020-7721    

DOI:10.1080/00207729308949528

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A class of non-parametric methods based on the minimax solution is developed here for models of stochastic linear programming. These methods provide a measure of robustness through the adoption of a cautious policy. The usefulness of these methods is illustrated through data envelopment analysis which utilizes an optimizing method of efficiency measurement.

ISSN:0020-7721    

DOI:10.1080/00207729308949529

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

An algorithm for input-output decoupling of non-linear control systems using a simple precompensator is presented. The existence of functional relations between the inputs is examined. The algorithm has a simplified form. Accordingly, necessary and sufficient conditions are established which guarantee solvability of the problem. Significant reduction in computation time with respect to an existing algorithm is demonstrated.

ISSN:0020-7721    

DOI:10.1080/00207729308949530

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The recursive reduced order algorithm in the context of linear closed-loop Stackelberg strategies for singularly perturbed systems is presented. Motivated by previous results for the weakly coupled linear quadratic Nash games, it is shown that a similar algorithm can be produced for singularly perturbed linear quadratic Stackelberg games and the fixed point method is very effective in this case also. It is shown that the proposed recursive algorithm improves the accuracy of the sought solution, that is, the singularly perturbed recursive algorithm converges with the rate of convergence of accuracy O(ϵ). Since all results on linear closed-loop Stackelberg game problem for the singularly perturbed systems can be obtained as far with an accuracy O( ϵ) only, that represents a significant improvement. In order to demonstrate the effectiveness of the proposed algorithm and the failure of the O( ϵ) theory, a numerical example is shown.

ISSN:0020-7721    

DOI:10.1080/00207729308949531

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Various sufficient conditions of eigenvalue clustering for interval matrices are presented. The proposed sufficient conditions guarantee that all eigenvalues of the interval matrices lie inside various specified regions in the complex plane. The derived theorems can be applied to both continuous- and discrete-time dynamic interval systems. The dynamical characteristics of a linear system are influenced by the eigenvalue locations of the system. Therefore, by the analysis of eigenvalue clustering, we can understand more properties about interval dynamic systems such as stability margin, performance robustness and so on. Three examples are given to illustrate the applicability of the results.

ISSN:0020-7721    

DOI:10.1080/00207729308949532

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Dynamic coordinated control of two robot manipulators that rigidly grasp a common object is studied. A dynamic coordinated control model for the two manipulators is derived that is suitable for system analysis and design in state space. The model takes into account kinematic and dynamic constraints between the two manipulators, and is explicitly described by non-linear state equtions and non-linear output equations in the state space. Since coordinated control requires the control of forces applied to the object by manipulators, the output equations include both position components and force components. While robotic systems with position outputs can be linearized using a static state feedback, systems with force outputs, such as the present two robot system, require a dynamic non-linear state feedback for exact linearization. By using dynamic non-linear feedback, coordinated control of two robotic manipulators is converted into a control problem of linear systems.

ISSN:0020-7721    

DOI:10.1080/00207729308949533

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Interval systems arise when systems experience parameter variations. This paper derives frequency domain criteria for interval systems to be strictly aperiodic. The frequency domain criteria only requires one frequency domain plot to check for strict aperiodicity of linear interval systems. Furthermore, the largest allowable perturbation bounds can be graphically estimated from the same frequency domain plot.

ISSN:0020-7721    

DOI:10.1080/00207729308949534

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor