System Reliability Assessment Of Component-Integrated Wireless Sensor Networks With Consideration Of Data Accuracy

The system reliability of wireless sensor networks (WSN) is an important issue to ensure robust data acquisition. Especially when sensor networks are directly integrated into components, for example inside the composite layup of composite parts, the non-repairability has to be considered for sensor placement. Since the quality of the acquired data is as important as the reliability of the network itself to fulfill the main function of data acquisition, a combined perspective on data and hardware is needed. Therefore, an algorithmic approach for data path-based reliability assessment is enhanced to the estimation of data accuracy regarding signal quality losses during transmission. This approach uses signal attenuation along data paths to estimate changes in the Signal-to-Noise ratio (SNR) and therefore in the accuracy of acquired data. To demonstrate the algorithmic effectiveness, a case study is presented that analyzes an exemplary WSN from both a data and a hardware perspective. Resulting from the demonstrated effectiveness and applicability, the approach presented in this paper aids engineers in designing WSNs for reliable data acquisition

Reliability modelling of complex systems. Part 2

Series-“m out of n” systems and “m out of n”-series systems are defined and exemplary theorems on their limit reliability functions are presented and applied to the reliability evaluation of a piping transportation system and a rope elevator. Applications of the asymptotic approach in large series systems reliability improvement are also presented. The paper is completed by showing the possibility of applying the asymptotic approach to the reliability analysis of large systems placed in their variable operation processes. In this scope, the asymptotic approach to reliability evaluation for a port grain transportation system related to its operation process is performed

Conclusions from the workshop on Baltic Sea region critical infrastructure networks and next steps in EU-CIRCLE project research

The report is devoted to the next steps in the Gdynia Maritime University team EU-CIRCLE project “A pan – European framework for strengthening Critical Infrastructure resilience to climate change” research activity after preliminary analysis of main static and dynamic industry critical infrastructures existing in the Baltic Sea Region performed to classify them as either a single critical infrastructure network or a network of critical infrastructure networks

Reliability and risk analysis of multi-state systems with degrading components

Applications of multi-state approach to the reliability evaluation of systems composed of independent components are considered. The main emphasis is on multi-state systems with degrading components because of the importance of such an approach in safety analysis, assessment and prediction, and analysing the effectiveness of operation processes of real technical systems. The results concerned with multi-state series systems are applied to the reliability evaluation and risk function determination of a homogeneous bus transportation system. Results on homogeneous multi-state “m out of n” systems are applied to durability evaluation of a steel rope. A nonhomogeneous series-parallel pipeline system composed of several lines of multi-state pipe segments is estimated as well. Moreover, the reliability evaluation of the model homogeneous multi-state parallel-series electrical energy distribution system is performed

Safety of critical infrastructures

The paper presents a general approach to safety analysis of critical infrastructures that aims to suggest new and to develop existing methods and tools capable of supporting intelligent modeling and decision making in controlling and optimizing the safety of those systems and their accidents consequences risk. Its main focus is on the suggestions of the creation and usage of new techniques, procedures and strategies to improve and to optimize safety of real complex infrastructure systems related to the inside dependencies – among their subsystems and components and the outside dependencies – coming from their operation environment and from other dangerous events and natural hazards. The approach tries to create an original and coherent methodology of safety of critical infrastructures useful in ensuring and improving safety of those systems in various industrial sectors by providing an integrated package of solutions consisting of various packages of theoretical and practical tools ready for direct use by safety theoreticians and practitioners dealing with safety of real critical infrastructures

On a class of limit reliability functions of some regular homogeneous series-parallel systems

.In the investigation of large-scale systems the problem of the complexity of their reliability functions arises. This problem may be solved approximately by assuming that the number of system components tends to infinity and finding the limit reliability function. In this paper a four-element class of limit reliability functions for a regular homogeneous series-parallel system is presented. The number of series components of the system has the order of the logarithm of the number of its parallel components. The result is obtained under the assumption that the lifetimes of the particular components are independent and identically distributed random variables. The class presented is different from the known class of limit distributions of minimax statistics of independent random variables with the same distribution. Moreover, some examples of the systems considered and their limit reliability functions are given. The results can be useful in the investigation of the reliability of large systems

Safety and reliability of a three-state system at variable

Safety and reliability of a three-state system at variable operation conditions K e y w o r d s Three-state system, operation, reliability, safety, risk, prediction. S ł o w a k l u c z o w e System trójstanowy, eksploatacja, niezawodność, bezpieczeństwo, ryzyko, predykcja. S u m m a r y There is proposed the method of reliability analysis of a three-state system at variable operations conditions. Introduced are the notions of the conditional and unconditional the threestate system reliability functions, the mean values of system lifetimes in the reliability state subsets and in the particular reliability states, the system risk function, and the moment when the system risk function exceeds its permitted level. These characteristics are determined for an exemplary three-state system operating at four operation states

Reliability modelling of complex systems. Part 1

The paper is concerned with the application of limit reliability functions to the reliability evaluation of large systems. Two-state large non-repaired 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, parallel and series-parallel systems are defined and their exact reliability functions are determined. The classes of limit reliability functions of these systems are presented. The results of the investigation concerned with domains of attraction for the limit reliability functions of the considered systems and the investigation concerned with the reliability of large hierarchical systems as well are discussed in the paper. The paper contains exemplary applications of the presented facts to the reliability evaluation of large technical systems

On a class of limit reliability functions of some regular homogeneous series-parallel systems

.In the investigation of large-scale systems the problem of the complexity of their reliability functions arises. This problem may be solved approximately by assuming that the number of system components tends to infinity and finding the limit reliability function. In this paper a four-element class of limit reliability functions for a regular homogeneous series-parallel system is presented. The number of series components of the system has the order of the logarithm of the number of its parallel components. The result is obtained under the assumption that the lifetimes of the particular components are independent and identically distributed random variables. The class presented is different from the known class of limit distributions of minimax statistics of independent random variables with the same distribution. Moreover, some examples of the systems considered and their limit reliability functions are given. The results can be useful in the investigation of the reliability of large systems