Probabilistic Model of Technical Queuing Systems with Subsystems for Detection and Recovery of Failures

The given article presents an analytical model developed for a multichannel technical queuing system with time redundancy for operability management, subsystems of reliable periodical control of sudden and gradual failure detection and a subsystem for system recovery after failure. It is assumed in the model that the failures are governed by the Poisson probability distribution law and the times of reliable control and system recovery after failures are governed by an arbitrary law of probability distribution, in the general case depending on the number of servicers. The paper defines probabilities of accomplishment of certain task volumes by the system within a priori defined time intervals, taking into consideration its reliability characteristics.

On One Model of Complex Technical Queuing System with Unreliable Devices and with Time Redundancy

The given article deals with the development of analytical model of request service process by multichannel technical system with unreliable, repaired and reconfigured service facilities. It is assumed that the system is functioning in service mode of random length random request flows. The system considers the existence of time redundancy for afterservice of calls, the service of which is interrupted with refusal, non-depreciating the performed part of the task. Special probability functions are introduced which on the basis of probability reasoning allow to make the systems of integral equations describing the dynamics of request service process.

Development of the Software Application with Graphical User Interface for One Model Cyber Security

The article is dedicated to the development of software application with graphical user interface for analyzing of the operation of Integrated System of Data Defense from cyber-threats (ISDD) which includes subsystems of detection and elimination of vulnerabilities existing in the system, as well as Requests of Unauthorized Access (RUA). In the subsystems of eliminations of vulnerabilities and queues of unauthorized access considered as multichannel queueing systems with corresponding servers and queues, at random times there come requests to fix threats detected by the system. It is supposed that flows of requests demanding to eliminate threats coming to the mentioned subsystems of queueing systems are described with the Poisson distribution of probabilities, but processes of their elimination obey exponential law. For the system described above, there has been developed software realization of graphical interface which allows easily to change input parameters and observe graphical reflection of changes of the output indicators of the system.

On One Analytical Model of a Probability Estimation of Quality and Efficiency of Functioning of Complex Technical Queuing Systems

The work is dedicated to the development of analytical model of probability estimation of reliability, productivity, quality and efficiency of functioning of the complex technical queuing system consisting of the arbitrary number of marked groups of the service devises (channels, facilities, servers) differing with reliable characteristics (parameters of refusals and restorations) of forming their composition (also of arbitrary number) marked, identical, unreliable and restorable serving channels in which for serving come in requirements with intensities depending on marking of channels. In the considered system it is supposed that the currents of refusals of serving devices and currents of coming requirements are subdued to Poisson, and the currents of restorations of refused devices and the currents of services of coming requirements—exponential laws of distribution of probabilities. A stochastic process of transfers of a system by that is Markovian process with continuous time and discrete states. Correlations linking the basic parameters and exit characteristics of the systems of the pointed out type are obtained in a view of probabilities of the system location in the given moment of time in one of the possible states.

On One Model of Multichannel Queuing System with Unreliable Repairable Servers and Input Memory

The work deals with the development of analytical model of multichannel technical queuing system with unreliable servers and input memory where server failure flows and incoming request flows comply with Poissonian laws, while the flows of failed facilities repairs and flows of incoming requests comply with exponential laws of probability distribution. Random process of system change-over is a Markovian process with continuous time and discrete states. Relations binding basic parameters and output characteristics of the system indicated are obtained as probabilities of system staying in the given moment in one of the possible states. The proposed model is the most generalized compared to some models known in literature which could be considered as special cases of the considered model.

Development and Investigation of the Program Model of Multichannel Queueing System with Unreliable Recoverable Servers in Matlab Environment

In real life, in different industries, we often deal with systems designed for multiple use for performing single-type tasks. Processes taking place at this time are called service of requirements, and the systems themselves—Queueing Systems. This article is dedicated to computer software modelling of processes taking place in the systems in question, Markov processes in particular. In this article, by means of Matlab environment, software realization of one of the typical models of queueing service theory-multichannel QS with unreliable recoverable servers and limited number of requirements in the system, is fulfilled. The results of this research are important because it gives the possibility to use received results to determine optimality degree of some real queueing systems that possess Markov property.

Development of an Analytical Model of the Process of Cybersecurity Protection of Distributed Information Systems of Critical Infrastructure

This article is dedicated to the creation of the analytical model of quantitative estimation of cybersecurity of Information Systems of Critical Infrastructure (ISCI). The model takes into consideration the existence, in the discussed ISCI, of both the intelligent tools of detection, analysis and identification of threats and vulnerabilities and means for restauration and elimination of their consequences. The development of the model also takes into consideration probabilistic nature of flow of events happening in ISCI and transferring the system between different states of cybersecurity. Among such probabilistic events we mean any operational perturbations (that can cause extreme situations) happening in ISCI under the influence of cyber-threats, as well as events concerning restoration and elimination of consequences of such cyber-threats. In this work, as methods of modelling, there have been used methods of system-oriented analysis based on theory of probability, theory of reliability and theory of queues. These methods enabled to describe analytically dependence of effectiveness indices of ISCI operation on abovementioned probabilistic processes.