In this paper, we investigate software fault detection and fault correction processes based on infinite server queuing model which incorporate testing effort functions. Some researches proposed in the literature to study fault detection and fault correction processes. However, most of them do not consider the amount of resources consumed during fault detection and fault correction processes. Th...

Analytical models of selected DiffServ network elements supporting Assured Forwarding (AF) service in a Differentiated Services (DiffServ) network are proposed in the dissertation. Simple analytical models for main network elements: meter/markers and droppers are provided. Models of the following meter/markers were proposed: Single Rate Three Color Marker (srTCM), Two Rate Three Color Marker (t...

Cloud computing is a recently developed new technology for complex systems with massivescale service sharing, which is different from the resource sharing of the grid computing systems. Cloud reliability analysis and modeling are not easy tasks because of the complexity and large scale of the system. This paper systematically analyzes cloud computing and models the reliability of the cloud serv...

Analytic models provide a simple but approximate method for predicting the performance of complex processing systems early in the design cycle. Over the years, extensive use has been made of various queuing models to analyze the memory hierarchies of multiprocessor systems in order to estimate the finite cache penalty and resulting system performance measured in cycles per instruction executed....

Distributed Software Systems (DSS) are used these days by many people in the real time operations and modern enterprise applications. One of the most important and essential attributes of measurements for the quality of service of distributed software is performance. Performance models can be employed at early stages of the software development cycle to characterize the quantitative behavior of...

This paper presents one of the features of DS (Differentiated Services) architecture, namely the queuing or congestion management. Packets can be placed into separate buffer queues, on the basis of the DS value. Several forwarding policies can be used to favor high priority packets in different ways. The major reason for queuing is that the router must hold the packet in its memory while the ou...

An actual problem is how to evaluate the quality of IP network. Differentiated Services is a promising architecture for the next generation Internet due to its highly flexible, scalable and interoperable design. In Differentiated Services, scheduling disciplines play an important role in achieving service differentiation. In this paper two queuing models are pending: M/G/WFQ and M/G/1/p3. Thus ...

This paper aims to find the optimal arrangement of consultation rooms in the specialist outpatient clinics of a hospital in Singapore to maximize the utilization factor. Doctors’ utilization and waiting time of the patients were also optimized in this research. This was done by building and validating queuing and simulation models to predict and model the real life variance and uncertainty in t...

We analyze the problem of the numerical solution of structured Markov chains encountered in queuing models: we describe the main computational problems and present the most advanced algorithms currently available for their solutions.