Abstract Formal methods such as CSP (Communicating Sequential Processes) are widely used for reasoning about concurrency, communication, safety and liveness issues. Some of these models have been extended to permit reasoning about real-time constraints. Yet, the research in formal specification and verification of complex systems has often ignored the specification of stochastic properties of t...

This paper seeks to identify some of the technology challenges and research opportunities in assessing, optimising and assuring performance and dependability on the grid. Grid computing offers many scientific and commercial benefits, but also many technical and organisational challenges. Amongst the challenges for grid computing is the need to provide reliable quality of service to end users, w...

Performance modeling of recent computer and communication system development has become more complicated as the size and complexity of the system has increased, (see [7] and [4]). Finite source queueing models are efficiently used for performance evaluation of computer systems (see [1], [3], [4] and [9]). Realistic consideration of certain stochastic systems, however, often requires the introdu...

We construct for the first time a fractional-order hyperchaotic system via original integer-order system. The dynamical behavior of this is investigated in detail using approximation method and Lyapunov exponents. Next, an adaptive control strategy univariate controlled has been proposed. Also, tracking performance fully taken into account numerous applications, instance, sinusoidal periodic si...

Stochastic Petri nets (SPNs) have emerged over the years as a favored approach for performance and dependability modeling and evaluation. Their usual utilization assumes that systems specification and design do not evolve, in opposition to real-life. This paper is aimed at a preliminary exploration of how to take advantage of the existing body of results on SPNs for modeling the evolution of co...

The use of PKI in large scale environments suffers some inherent problems concerning the options to adopt for the optimal cost-centered operation of the system. In this paper a Markov based probability model has been applied and a performability indicator has been introduced for assisting the evaluation of the operational cost of the system in a decision support process. Considering the unavail...

The authors present a new approach for the automated generation of test cases to be used for demonstrating the reliability of large industrial mission-critical systems. In this study they extend earlier work by using a performability model to track resource usage and resource failures. Results from the transient Markov chain analysis are used to estimate the software reliability at a given syst...