Krzysztof Kołowrocki

Bio: Krzysztof Kołowrocki is an academic researcher from California Maritime Academy. The author has contributed to research in topics: Critical infrastructure & Reliability (statistics). The author has an hindex of 15, co-authored 161 publications receiving 1158 citations. Previous affiliations of Krzysztof Kołowrocki include United States Merchant Marine Academy.

Reliability and Safety of Complex Technical Systems and Processes: Modeling - Identification - Prediction - Optimization

Abstract: Reliability and Safety of Complex Technical Systems and Processes offers a comprehensive approach to the analysis, identification, evaluation, prediction and optimization of complex technical systems operation, reliability and safety. Its main emphasis is on multistate systems with ageing components, changes to their structure, and their components reliability and safety parameters during the operation processes. Reliability and Safety of Complex Technical Systems and Processes presents integrated models for the reliability, availability and safety of complex non-repairable and repairable multistate technical systems, with reference to their operation processes and their practical applications to real industrial systems. The authors consider variables in different operation states, reliability and safety structures, and the reliability and safety parameters of components, as well as suggesting a cost analysis for complex technical systems.Researchers and industry practitioners will find information on a wide range of complex technical systems in Reliability and Safety of Complex Technical Systems and Processes. It may prove an easy-to-use guide to reliability and safety evaluations of real complex technical systems, both during their operation and at the design stages.

Reliability of large systems

Abstract: This article is concerned with the application of limit reliability functions to the reliability evaluation of large systems. Two-state large nonrepaired systems composed of independent components are considered. The asymptotic approach to the system reliability investigation and the system limit reliability function are defined. Two-state homogeneous series and parallel systems are defined and their exact reliability functions are determined. The classes of limit reliability functions of these systems are presented. This article contains an exemplary application of the presented facts to the reliability evaluation of large technical systems. The accuracy of this evaluation is illustrated. Brief review and the latest references on limit reliability functions of two-state and multistate homogeneous and nonhomogeneous series, parallel, and other systems are presented as well. Keywords: reliability; large system; asymptotic approach; limit reliability function

Reliability and Availability Analysis of Complex Port Transportation Systems

Abstract: A semi-Markov model of a system operation process is proposed and its selected parameters are determined. A series–parallel multi-state system is considered and its reliability and risk characteristics are found. Next, the joint model of the system operation process and the system multi-state reliability and risk is constructed. Finally, the asymptotic approach to reliability, availability and risk evaluation of the multi-state series–parallel system in its operation process is applied to the port grain transportation system. Copyright © 2006 John Wiley & Sons, Ltd.

A new approach to solving problems of multi-state system reliability optimization

Abstract: Usually engineers try to achieve the required reliability level with minimal cost. The problem of total investment cost minimization, subject to reliability constraints, is well known as the reliability optimization problem. When applied to multi-state systems (MSS), the system has many performance levels, and reliability is considered as a measure of the ability of the system to meet the demand (required performance). In this case, the outage effect will be essentially different for units with different performance rate. Therefore, the performance of system components, as well as the demand, should be taken into account. In this paper, we present a technique for solving a family of MSS reliability optimization problems, such as structure optimization, optimal expansion, maintenance optimization and optimal multistage modernization. This technique combines a universal generating function (UGF) method used for fast reliability estimation of MSS and a genetic algorithm (GA) used as an optimization engine. The UGF method provides the ability to estimate relatively quickly different MSS reliability indices for series-parallel and bridge structures. It can be applied to MSS with different physical nature of system performance measure. The GA is a robust, universal optimization tool that uses only estimates of solution quality to determine the direction of search. Copyright © 2001 John Wiley & Sons, Ltd.

Reliability and Availability Engineering: Modeling, Analysis, and Applications

Abstract: Do you need to know what technique to use to evaluate the reliability of an engineered system? This self-contained guide provides comprehensive coverage of all the analytical and modeling techniques currently in use, from classical non-state and state space approaches, to newer and more advanced methods such as binary decision diagrams, dynamic fault trees, Bayesian belief networks, stochastic Petri nets, non-homogeneous Markov chains, semi-Markov processes, and phase type expansions. Readers will quickly understand the relative pros and cons of each technique, as well as how to combine different models together to address complex, real-world modeling scenarios. Numerous examples, case studies and problems provided throughout help readers put knowledge into practice, and a solutions manual and Powerpoint slides for instructors accompany the book online. This is the ideal self-study guide for students, researchers and practitioners in engineering and computer science.

An analytical methodology for reliability assessment and failure analysis in distributed power system

Abstract: Minimizing total system failure could improve the reliability of power network in order to optimize power system operation. In this way, reliability analysis has been proposed by researchers to tackle the mentioned problem. This paper investigates an analytical methodology for reliability assessment and failure analysis techniques in an actual distributed power system. We use reliability analysis to evaluate system design and gathering outage data in this paper. Modelling and simulation of our assumed system are implemented in electrical transient analyzer program (ETAP) software. The results of theoretical/practical reliability and failure analysis including mean time between failure, mean time to repair, availability, system average interruption frequency index, system average interruption duration index, consumer average interruption duration index, average service availability index, average service unavailability index, expected energy not supplied, expected interruption costs, and interrupted energy assessment rate are compared with the summary of reliability assessment simulation. The capability and effectiveness of reliability evaluation are demonstrated according to the simulation results through ETAP which obtained by applying it to this power system.