Risk Assessment of a Stochastic Service System

A stochastic service system of finite size M is comprised of identical service facilities,including or not a waiting queue,which simultaneously treats N customers,N∈{0,1,…,M}.Depending on the concepts of system information z.and system entropy S=£(f),we promote a risk assessment procedure.By definition,the system entropy is the uncertainty associated with the system,and the system expected loss is the risk associated with the system.Thus,accepting the system information as loss function,we can identify risk and uncertainty,associated with the system,using the entropy as risk function.Further,we differ risk of the system(i.e.,risk observed by an outside observer),risk observed by an arriving customer,and risk observed by a departing customer,giving a separate expression for each one.Then,these risks are compared with each other,when the system has the same average number E(N)of customers seen by any viewpoint.The three risk types(together with the three customer means)allow us to distinguish two systems obeying the same probability distribution.This approach enables system operators to choose suitable values for system utilization and size,in view of the three risks ratio.The developed procedure is applied to the information linear system,Erlang loss system,single-server queueing system with discouraged arrivals,Binomial system and Engset loss system.

OPTIMIZATION FOR COMBAT CONFIGURATION OF AIR DEFENSE WEAPON SYSTEMS

At evaluating the combat effectiveness of the defense system, target′s probability to penetrate the defended area is a primary care taking index. In this paper, stochastic model to compete the probability that target penetrates the defended area along any flight path is established by the state analysis and statistical equilibrium analysis of stochastic service system theory. The simulated annealing algorithm is an enlightening random search method based on Monte Carlo recursion, and it can find global optimal solution by simulating annealing process. Combining stochastic model to compete the probability and simulated annealing algorithm, this paper establishes the method to solve problem quantitatively about combat configuration optimization of weapon systems. The calculated result shows that the perfect configuration for fire cells of the weapon is fast found by using this method, and this quantificational method for combat configuration is faster and more scientific than previous one based on principle via map fire field.

On the Backlog and Delay Distributions of Primary and Secondary Users in a Cognitive Radio Network

In a cognitive radio network, the secondary users can use the spectrum holes when the primary users do not utilize the spectrum, but they must vacant the spectrum when the primary users need to transmit data on the spectrum. In other words, the primary users have higher priority over the secondary users. In this paper, backlog and delay distribution bounds for both primary users and secondary users are obtained. The analysis is based on stochastic network calculus, for which, stochastic service curves are t-n-st derived for both primary users and secondary users, and the network calculus independent case analysis approach is used to find the distribution bounds. Numerical results and simulation results are also presented and discussed.