摘要:

A multi-product multi-market segment optimal control model for coordinating marketing and production decisions in a firm is presented. On the marketing side, the model considers pricing and the rate of advertising expenditure for each product for each market segment as decision (i.e. control) variables. On the production side, the production rate for an individual product is considered as a decision variable. The model assumes that demand for a product in each market segment is subject to seasonal and other exogenous effects. The model includes the following two special cases: (a) single-product multiple-market segments, (b) multiple products having purely exogenous, time-varying demand. The production planning subproblem in the model represents a class of partially singular optimal control problems. A solution procedure using Pontryagin's maximum principle is designed to solve the partially singular control problem. A hierarchical approach is then used in designing the solution procedure for the overall model.

ISSN:0020-7721    

DOI:10.1080/00207728908910284

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A mixed method of model reduction for linear multivariable systems is proposed. The least common denominator of the elements in the reduced transfer matrix model is constructed by preserving the dynamic modes with dominant energy contributions, and the parameters of the numerators are found using the continued-fraction method. In addition, a reduced model with state-space form, having the same order as those of the reduced transfer matrix, is also found. The reduced model is always stable if the original system is stable. Moreover, the reduced model gives rather good approximations in both the transient and steady-slate responses of the original system.

ISSN:0020-7721    

DOI:10.1080/00207728908910285

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A pseudo-plant contains a nominal model of the controlled process and combines suitable signals to form a pseudo-output which equals the true output if the model is exact. Robustness against unstructured uncertainty is improved using a pseudo-plant, and in adaptive control the parameter estimates become less sensitive to the input frequency. By introducing an appropriate gain term in the pseudo-plant design, the norm of the effective unstructured uncertainty can be made arbitrarily small. It is shown that the approach can handle a larger unstructured uncertainty which satisfies the established robustness result in non-adaptive and adaptive pole-placement control. Simulation results are presented.

ISSN:0020-7721    

DOI:10.1080/00207728908910286

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A synthesis of real eigenvector matrices enabling real modal analysis for systems with complex conjugate eigenvalues, is extended to encompass general linear time-in variant systems An exclusively time-domain treatment introducing block matrix invariant operator faculates the modeling and analyzing of the system response.

ISSN:0020-7721    

DOI:10.1080/00207728908910287

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A method for finding an approximate solution of a linear two-point boundary value problem with time-varying coefficients is proposed. Properties of Taylor series are first briefly presented and the transformation matrix relating the back vector to the current time vector together with the operation matrix of integration for Taylor series are utilized to solve the linear two-point boundary value problems. The method is computationally very attractive and applications are demonstrated through illustrative examples.

ISSN:0020-7721    

DOI:10.1080/00207728908910288

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Maximizing the correlation between inputs and outputs in data envelopment analysis is analysed in three respects: (a) the minimization of the Lp-norm; (h) the standard regression approach; and (c) the case of composite outputs. The implications of canonical correlation are explored and their applications to efficiency studies of public sector enterprises discussed. This shows that the correlation measure may involve in some sense a basic and fundamental extension of the efficiency model analysed by data envelopment analysis.

ISSN:0020-7721    

DOI:10.1080/00207728908910289

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Unified stability robustness measure bounds are introduced for generalized dynamic output feedback controllers. Bounds are obtained for allowable non–linear time–varying perturbations such that the resulting closed–loop system remains stable. Bounds on a special, but important class of perturbations, in which the perturbation is linear, are also derived.

ISSN:0020-7721    

DOI:10.1080/00207728908910290

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A new approach for hierarchical system optimization and parameter estimation of a large-scale industrial process is described. This approach can be viewed as a hierarchical implementation of the approximate linear model approach with a three iterative loop structure. The internal double loop iteration where only model-based information is involved is a two-model approach. Augmentation is introduced to enforce and accelerate convergence in the internal double loop. The third iterative loop arises from the hierarchical implementation of the technique and involves coordination of price vectors to ensure balance between separable sub-optimization problems. The major advantages of this triple iterative loop configuration are that it significantly reduces the required on-line iterations in order to reach the optimum, especially when the process is linear or nearly linear and it has a balanced distribution of model–based computations in the internal double loop. Optimality and convergence conditions are examined. Computer simulations are provided to demonstrate the behaviour of the algorithm.

ISSN:0020-7721    

DOI:10.1080/00207728908910291

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A non-linear model for three competing social groups, each endeavouring to enlarge its size in a closed homogeneously mixing population is developed. Familiar examples of such a competition are provided by political parties, cults, sects etc. each trying to increase its area of influence in the society. The non-linearity of the model arises from the interactive processes involved in the process of conversion of members from one group to another. A special case dealing with the possibility of a mass-mediated external source for conversion is also considered. An interesting finding of the model is periodic variation in the size of each group with appropriately restricted values of the parameters of the model.

ISSN:0020-7721    

DOI:10.1080/00207728908910292

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A pre-programmed controller that works over a family of single-input single-output systems representing the diabetic subject was achieved, based on the recent practical fourth-order digital model of the experimentally validated glucoregulatory system. The controller was chosen such that it contains an integral action to ensure that the steady-state error vanishes. Its zeros are so selected as to match the undesired complex-conjugate poles of the unstable metabolism. The controller utilizes a nonlinear reference: ramp function succeeded by step input. The closed-loop gain and the coefficient of the ramp function are tuned successively such that desired dynamics are obtained using the root-locus portrait. Three sets of well-behaved responses and their corresponding internal states were obtained with variable peak undershoot. The robustness tracking property of the controller was tested using the bounding polynomials suggested by Kharitonov's stability criterion.

ISSN:0020-7721    

DOI:10.1080/00207728908910293

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor