Journal:Informatica
Volume 4, Issues 1-2 (1993), pp. 217–226
Abstract
New computational rules of the simplex method are represented. They differ from classical rules in the sense that the column corresponding to the objective function is also transformed and first the pivot row and then the pivot column is determined. In this case the most negative element in pivot row can be chosen for pivot element. In evaluating procedure systems equivalent to systems appearing in classical simplex method are used and theoretically they determine the-same sequence of basic solutions. The calculations are more precise due to such choice of pivot element and it is assured also by the results of test-problems.
Journal:Informatica
Volume 4, Issues 1-2 (1993), pp. 199–216
Abstract
An analysis of an event driven local area network protocol for special purposes in industrial applications is represented. The analysis is performed using the specification language ESTELLE/Ag and protocol analysis tool PRANAS-2. Validation was focused on the correctness media access algorithm, initialization of the protocol and recovery from error situations. The obtained simulation results can be used for comparison of the effectiveness of this protocol with other protocols.
Journal:Informatica
Volume 4, Issues 1-2 (1993), pp. 188–198
Abstract
The article is dedicated to Newton's method for solving non-linear equation systems. The Kantorovich convergence theorem assumes that the derivative of the system function is Lipschitz continuous. Our purpose is to provide error estimates in the case of a Hölder continuous derivative.
Journal:Informatica
Volume 4, Issues 1-2 (1993), pp. 172–187
Abstract
It is well known that, in general, exact algorithms for the Quadratic Assignment Problem (QAP) cannot solve problems of size N>15. Therefore, it is necessary to use heuristic approaches for solving large-scale QAPs. In this paper, we consider a class of heuristic approaches based on local search criteria. In particular, we selected four algorithms; CRAFT, Simulated Annealing, TABU search and the Graph Partitioning (GP) approach and studied their relative performance in terms of the quality of solutions and CPU times. All of these algorithms performed roughly the same, based on the results of two sets of test problems executed on an IBM ES/3090-600S computer.
Journal:Informatica
Volume 4, Issues 1-2 (1993), pp. 163–171
Abstract
We consider finite population slotted ALOHA where each of n terminals may have its own transmission probability pi. Given the traffic load λ, throughput is maximized via a constrained optimization problem. The results of Abramson (1985) are obtained as special case.
Journal:Informatica
Volume 4, Issues 1-2 (1993), pp. 140–147
Abstract
A stochastic discrete neuronetwork is defined. In the investigation of discrete neuronetworks probability methods are applied – a weak convergence of probability measures. Limit theorems (the strong law of large number and normal law) are proved for the stream of signals, going out of neurons.
Journal:Informatica
Volume 4, Issues 1-2 (1993), pp. 126–139
Abstract
This paper is devoted to the investigation of the investigation of the convergence of iterative methods for solving boundary value problems with discontinuous coefficients. The dependence of the rate of convergence on the size of the discontinuity of coefficients is analyzed for three popular general iterative methods. A new criterion on the applicability of such methods is proposed and investigated. The efficiency of this criterion is demonstrated for a model problem.
Journal:Informatica
Volume 4, Issues 1-2 (1993), pp. 111–125
Abstract
The additive regression function is considered in the framework of the proportional hazard regression model for event-history data. The model is subjected to nonparametric estimation by the local likelihood procedure. Example illustrates the method, the hypotheses about the model are tested.
Journal:Informatica
Volume 4, Issues 1-2 (1993), pp. 94–110
Abstract
In the previous paper (Pupeikis, 1992) the problem of off-line estimation of dynamic systems parameters in the presence of outliers in observations have been considered, when the filter generating an additive noise has a very special form. The aim of the given paper is the development, in such a case, of classical generalized least squares method (GLSM) algorithms for off-line estimation of unknown parameters of dynamic systems. Two approaches using batch processing of the stored data are worked out. The first approach is based on the application of S-, H-, W- algorithms used for calculation of M-estimates, and the second one rests on the replacement of the corresponding values of the sample covariance and cross-covariance functions by their robust analogues in respective matrices of GLSM and on a further application of the least squares (LS) parameter estimation algorithms. The results of numerical simulation by IBM PC/AT (Table 1) are given.