Informatica

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.

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.

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.

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.

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.

This work was stimulated by investigations on Markow Renewal Processes. For finding analytic solutions (to compute the probabilities of certain states of the system) multivariate Laplace transforms can be used. Tables with correspondences of function and their transforms very rarely help to solve such problems.