# Computer Sciences

## A Model for Forecasting Characteristics of Floods Affecting the Value of the Caused Damage

According to GOST (State Standard) characteristics of floods are selected that have influence on the extent of damage. Forecasting of such characteristics will improve the efficiency of liquidation of floods effects. On the basis of formal apparatus of system dynamics that takes into account the casual relationships between modeled variables a mathematical model is developed to forecast characteristics of floods. A graph of cause-effect relations that exist between modeled characteristics is constructed.

## Analysis of the Ways of Occurrence and Prevention of Critical Combinations of Events in Man-machine Systems

Models, methods and algorithms are proposed for analyzing the processes of development and preventing critical combinations of events of various kinds that lead to accidents and catastrophes in man-machine and organizational systems. Critical combinations are combinations of events that are individually relatively harmless, but in combination lead to an accident. In technogenic systems, such events are individual operator errors, equipment failures and adverse environmental effects.

## The Dynamical Cause-effect Links’ Presentation in Human-machine Systems

A method of presentation variable cause-effect links for modeling processes in dynamic systems is proposed. Such a representation corresponds to the changing conditions that are associated with the action of many diverse factors that accompany the functioning of complex human-machine systems. The presence or absence of a causal relationship between the individual events in the proposed model is defined as a result of a set of stochastic or deterministic functions.

## Method for Analysis of Closed Queueing Networks with Discrete Time, Batch Movements of Customers and Dynamic Control of Service Rates

The closed queueing networks with single class of customers, discrete time and batch movements of customers are considered. Queues include multiple identical servers with geometric distribution of service times. A method for dynamic control of service rates in queues is proposed. The control is realized by use of different service rates during fixed time intervals in process of networks operation. When this method is used in queueing networks of considered type, close to given customer allocation among queueing systems is provided.

## The Algorithm for Checking Transitivity of Mappings Associated with the Finite State Machines from the Groups ASp

The paper deals with a question of determining the property of transitivity for mappings defined by finite automata. A criterion of transitivity for mappings defined by finite automata on the words of finite length in terms of finite automata and trees of deterministic functions is presented. It is shown that for finite automata from groups ASp an algorithm can be constructed for checking transitivity. To prove this fact some properties of Abelian groups of permutations are used.

## Indices of States in Dynamical System of Binary Vectors Associated with Palms Orientations

Dynamical system of binary vectors associated with palms orientations is considered. A tree is called a palm with s + c edges if it is a union of c + 1 paths with common end vertex and all of these paths except perhaps one (with s edges) have a length 1. The system splits into finite subsystems according to the dimension of states. States of a finite dynamical system (B s+c ,γ) are all possible orientations of a given palm with s + c edges.

## Adaptive Algorithm of Parametric Synthesis of Hybrid Dynamical Systems

Hybrid dynamical systems (HDS) are connected by means of the boundary conditions and the constraint’s conditions systems of ordinary differential equations and partial differential equations with the corresponding initial conditions. Under the parametric synthesis we understand the algorithm for selecting parameters of feedbacks of controlled HDS, providing the required quality of transients.

## On the Directional Movement of a Collective of Automata without a Compass on a One-dimensional Integer Lattice

A collective of finite automata has to preserve unidirectional movement on one-dimensional integer lattice whose elements (vertices) are unlabelled. The automata does not distinguish between equally labelled vertices by their coordinates of direction (that means each automaton has no compass). We considered collectives consisting of an automaton and some pebbles, i.e. automata of the simplest form, whose positions are completely determined by automaton.

## Morphismes Based on Compatible Tolerances of Finite Automata

It is suggested a method of a construction with the help of some triple of tolerances deﬁned on the sets of states, input and output symbols of an ﬁnite deﬁnite automaton an another automaton which is connected with the original automaton by a certain morphism.

Considered construction generalizes the known method of ﬁnding of the homomorphic images of an automaton with the help of a triple of equivalences, which satisﬁes to the certain conditions.

## Hash Functions for Diagnostic Information Reduction

In this paper we present a new approach for the solution of problem of the diagnostic information reduction. This approach is based on use of hash functions delivering a compact signature for records in a fault dictionary. The experimental results show a considerable decrease in the storage requirement of diagnostic information reduced with the help of such functions.