摘要:

Two new algorithms for identification and model reduction of stable linear continuous systems are proposed, based on the weighted impulse response gramians (Agathoklis and Sreeram 1988 b). In identification, the model parameters are obtained from the solution of a linear system of equations with coefficients obtained from the numerical evaluation of the weighted impulse response gramians. The reduction technique is based on retaining part of the original weighted impulse response gramians obtained as the solutions to the Lyapunov equation for the original system in controllability canonical form. This yields different stable models for different values of the weighting factor. The model corresponding to zero weighting factor matches the impulse response norm of the original system and its derivatives exactly. Finally, the method is illustrated by a numerical example and is compared with well-known balanced realization techniques.

ISSN:0020-7721    

DOI:10.1080/00207729008910475

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

This paper proposes a stable dual mode GMDH. In each layer, two types of functions are prepared and compared with each other. The output of the model is given by the superior function, which is automatically selected according to the criterion proposed in this paper. Two real social systems arc applied to check the effectiveness of this method. A modelling interval longer than the period of the real system suppresses large predictionsl errors.

ISSN:0020-7721    

DOI:10.1080/00207729008910476

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A multidisk computer system is considered. Various requests arrive at the system and a disk may serve the purpose of source and/or destination for information. The concept of priority queues is incorporated and different measures of system effectiveness are obtained, tn particular, a detailed analysis is carried out for preemptive resume discipline. A comparison of systems with and without priorities is illustrated numerically.

ISSN:0020-7721    

DOI:10.1080/00207729008910477

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

This paper deals with the profit function analysis of a single-server two-unit standby system with two modes of each unit normal (N) and total failure (F). Regarding the standby unit, an interconversion is made repeatedly after a random length of time from warm to cold and cold to warm. Upon failure of the operative unit, the standby unit, if it is warm, starts the operation instantaneously; otherwise the system goes down until the cold standby starts operation. System failure occurs when both units fail totally. Identifying the system at suitable regenerative instants, integral equations are set up and explicit expressions of interest to system designers are obtained to carry out the profit function analysis. The results of two particular cases are also derived.

ISSN:0020-7721    

DOI:10.1080/00207729008910478

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The basic principles of an algorithm for the folding of programmable logic arrays (PLAs) are presented in this paper. The algorithm is valid for both column and row folding, although it has been described considering only the simple column folding. The pairwise compatibility relations among all the pairs of the columns of the PLA are mapped into a square matrix, called the compatibility matrix of the PLA. A foldable compatibility matrix (FCM), is then derived from the compatibility matrix. The algorithm presented in this paper is based on the FCM concept and the folding theorem, which states that the existence of an n x m FCM is both necessary and sufficient to fold 2m columns of an M-column PLA (2m ≤ n). Once an FCM is obtained, the ordered pairs of foldable columns and the reordering of the rows are readily determined. It has been conjectured that the algorithm produces the maximum folding of the PLA in all cases.

ISSN:0020-7721    

DOI:10.1080/00207729008910479

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

It is shown by example that a closed-loop system eigenvalue may be made totally insensitive by making the corresponding left eigenmode insensitive, even though no closed-loop system right eigenmode may be made insensitive. This paper, therefore, formulates and solves a fundamental response insensitivity problem. It is established to what extent output feedback control can be used to render the closed-loop system left eigenstructure insensitive to possibly many, not necessarily small, parameter variations in the open-loop state-space model. It is explained that the results presented cannot be seen merely by transposing all the results in a previous paper on the corresponding issues for the right eigenstructure. A lemma is given that details the loss of design freedom that occurs when a closed-loop eigenvalue is assigned to a transmission zero. Sufficient conditions for the total insensitivity of a closed-loop dyad mode are given. It is shown by example that more closed-loop eigenvalues may be made insensitive by a mixture of parametric left and right eigenstructure insensitivity than by either alone. Multistage parametric eigenstructure-insensitive design is discussed.

ISSN:0020-7721    

DOI:10.1080/00207729008910480

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A differentiable dynamic complex is a generalized dynamical system. A differentiable dynamic complex is defined as an extension of the concept of an orientor equation and is a generalization of the constructive definition of a differential dynamic system, as discussed in this paper. The constructive definition of a differential dynamic system considered here has been obtained through generalization of the mathematical model of non-linear electrical network. Basic definitions are introduced and theorems on the problem of finding the space of motion and the dynamic equation of a differentiable dynamic complex are presented. The main conclusion is that the space of motion of the differentiable dynamic complex ℘ is the set union of all ℘-invariant submanifolds of the configuration space of ℘. Examples of differentiable dynamic complexes and differential dynamic systems are given.

ISSN:0020-7721    

DOI:10.1080/00207729008910481

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A recently developed method for explicitly evaluating the time-averaged performance measure of an impulse-forced dynamical system is used to evaluate the effect of periodic injections as a cancer chemotherapy regimen. Explicit formulae are derived for two time-averaged performance measures, thus avoiding the need for tedious repeated numerical integrations. The method is shown to give more accurate predictions than previous periodic optimization methods in the case of one performance measure, and is successfully applied to the other performance measure for which previous optimization methods are inapplicable.

ISSN:0020-7721    

DOI:10.1080/00207729008910482

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The on-line microprocessor based measurements of phase angles and magnitudes of voltages and currents at selected locations on a power system are proposed. These measurements can be used to assess the resolution of a transient trajectory, and, by considering the velocity and acceleration of machines in synchronous frames of reference, may be employed in determining the nature of a transient in order to take the necessary control action. This work addresses those systems which behave like two coherent systems of generators for the disturbances under consideration. Placement of phasor measurement systems, techniques of on-line transient assessment and the requisite control action will be considered. A realistic system where such a control problem exists in practice will be used to confirm the developed techniques.

ISSN:0020-7721    

DOI:10.1080/00207729008910483

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Determining the tuning coefficients of a classical three term digital controller for slow delay-time processes is a laborious task. The results obtained using the least squares method of determining the tuning coefficients of a classical three term controller, employed for adaptive control of a slow second-order process with delay-lime, are described. The method requires limited and possibly inaccurate information on the parameters of the process. The adaptability of the algorithm is also demonstrated.

ISSN:0020-7721    

DOI:10.1080/00207729008910484

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor