The evolution of systems is a growing field of interest stimulated by many possible applications. This work is devoted to semi-Markov random evolutions (SMRE). This class of evolutions is rich enough to describe the evolutionary systems changing their characteristics under the influence of random factors. At the same time there exist efficient mathematical tools for investigating the SMRE. The topics addressed in this book include classification, fundamental properties of the SMRE, averaging theorems, diffusion approximation and normal deviations theorems for SMRE in ergodic case and in the scheme of asymptotic phase lumping. Both analytic and stochastic methods for investigation of the limiting behaviour of SMRE are developed. This text includes many applications of rapidly changing semi-Markov random media, including storage and traffic processes, branching and switching processes, stochastic differential equations, motions on Lie groups, and harmonic oscillations. This volume should be of interest to statisticians whose work involves operator theory, functional analysis, systems theory and cybernetics.
1. Markov Renewal Processes.- 2. Phase Merging of Semi-Markov Processes.- 3. Semi-Markov Random Evolutions.- 4. Algorithms of Phase Averaging for Semi-Markov Random Evolutions.- 5. Compactness of Semi-Markov Random Evolutions in the Averaging Scheme.- 6. Limiting Representations for Semi-Markov Random Evolutions in the Averaging Scheme.- 7. Compactness of Semi-Markov Random Evolutions in the Diffusion Approximation.- 8. Stochastic Integral Limiting Representations of Semi-Markov Random Evolutions in the Diffusion Approximation.- 9. Application of the Limit Theorems to Semi-Markov Random Evolutions in the Averaging Scheme.- 10. Application of the Diffusion Approximation of Semi-Markov Random Evolutions to Stochastic Systems in Random Media.- 11. Double Approximation of Random Evolutions.- References.- Notation.