Tsitsiashvili G., Losev A., Osipova M., Kharchenko Yu.

ANALYSIS OF HUBS LOADS IN BIOLOGICAL NETWORKS

Numerical experiments with biological networks are made and hubs loads are analysed. These experiments are based on algorithms of oriented graphs factorization. Numerical results allow to find narrow places in the networks.

Pereguda A.

MATHEMATICAL MODEL OF THE RELIABILITY OF INFORMATION PROTECTION WITH LAYERED SECURITY SYSTEM. INTRODUCTION

The article describes a mathematical model of reliability of the information system security systems consisting of object information protection and security of the two systems. The functioning process of the studied information security system is described as a superposition of alternating renewal processes. Upper and lower bounds for the expectation of time before unauthorized access to information.

Farhadzadeh E., Farzaliyev Y., Muradaliyev A.

METHOD AND ALGORITHM OF THE CHOICE OPTIMUM NUMBER ATTRIBUTES DESCRIBING RELIABILITY OF THE EQUIPMENT OF ELECTRO INSTALLATIONS

Estimation of parameters of individual reliability demands to estimate expediency of classification of all population of statistical data on the set versions of attributes. The method and algorithm optimum number of attributes classification of data is developed. Application allows calculate optimum on accuracy of an estimation of parameters of individual reliability, to reveal significant versions of attributes, to pass at the account of reliability of the concrete equipment with qualitative to a quantitative level.

Konorev B., Sergiienko V., Kharchenko V., Zholtkevych G.

ESTIMATING OF CRITICAL SOFTWARE LATENT FAULTS PRESENCE WITH REQUIRED TRUSTWORTHINESS

The estimation of latent faults probability is a key indicator for quantitative assessment of critical systems reliability and safety. The article presents the method of latent faults probability estimating for critical software with a required (controlled) trustworthiness. Compositional set-theoretical model of residual and latent faults is proposed for framework assessment of latent faults. The procedure of the experimental calibration of faults sensitivity and diversity degree of inspection methods of source software faultlessness is presented. The "dotted" injections method using faults profile for the level of programming languages is proposed.

Bochkov A., Zhigirev N.

THE ANALYTIC HIERARCHY PROCESS MODIFICATION FOR DECISION MAKING UNDER UNCERTAINTY

The AHP-method proved its efficiency in different situations of decision making under conditions when experts can perform pairwise comparisons of ​​compared objects under study. But, our real life consists of uncertainties. How can we compare the objects if information about them is not available or extremely uncertain? Pairwise comparisons are impossible. In this case, we propose to use the approach of minimizing the functional «errors» in the evaluation of comparable objects (F-ratio test). Through successive iterations initially given equal weight values ​​compared objects are close to the true value (within the stated error). This method does not require the consistency of the pairwise comparisons matrix and, moreover, can be applied to AHP incomplete matrix. The iterations are repeated as long as the new changes do not result in improved objects estimates. The practical example of the method use is considered.

Tsitsiashvili G., Osipova M.

ALGORITHMS OF ISOMETRIC SURFACES CONSTRUCTIONS

In this paper a problem of a construction of isometric surfaces is considered. It is important in different technical applications.  This problem usually is solved for surfaces with constant Gauss curvature using so called “gold” Gauss theorem. But in practical applications it is interesting to consider more wide class of surfaces. Here this problem is solved for surfaces of cylinder, conical and spherical types and their generalizations using a criterion of isometric based on equalities of coefficients of first quadratic forms.

Golub I., Voitov O., Boloev E.

FEASIBILITY OF OPERATING CONDITIONS AND THE LOCATION OF SENSOR VARIABLES IN THE ELECTRIC POWER SYSTEM

In the paper the methods of probabilistic load flow, including linear method of generalized disturbance, are used to detect sensor variables in an electric power system, identify their probabilistic characteristics, detect critical variables, for which the probability that they lie in the feasible range is lower than the required one, and select the control actions to increase this probability. The controls are selected by the method similar to the method of deterministic equivalent by subsequently and iteratively solving deterministic and probabilistic problems. The method of contribution factors makes it possible to choose from a set of possible controls a vector of control that contains the minimum number of components. The presented numerical results on the example of test and real networks demonstrate the efficiency of the proposed approaches to the electric power system operation control.

Guliyev H.

REACTIVE CAPACITY COMPENSATION AND VOLTAGE REGULATION MULTI-PURPOSE OPTIMIZATION METHOD IN POWER DISTRIBUTION NETWORKS

Using the most effective method of usefulness theory in multi-purpose optimization, algorithms and effective methods of reactive capacity compensations inside given technical restrictions of power network of electricity have been worked out.

González-Prida V., Viveros P., Crespo A., Martin C.

MULTI-CRITERIA DECISION TOOL APPLIED TO A SYSTEM RELIABILITY FOR THE PRIORIZATION OF SPARE PARTS

This paper proposes a method for spare part priorization based on the system reliability behavior. The method considers the values taken by the reliability distribution parameters, as the result of a multi-criteria decision process. The range of values is divided into possible alternatives, which depend on the importance of different criteria. The presented exercise provides a quick view about how different spare part policies can be selected by the effect, not only of the design, installation quality or performed maintenance, but also due to factors that sometimes come from subjective assessments. Hence, the Analytic Hierarchy Process (AHP) includes both qualitative and quantitative criteria in the priorization scheme. The presented method is intended to be a starting point for the analysis of external factors that make an important influence on the decision–making of complex industrial assets, with high amounts of data, system configurations, and maintenance inputs, which will be analyzed in future researches with the support of a tailored software application.