In this paper we compare the relative performance of two fault tolerant mechanisms dealing with repairable and non-repairable components that have failed. The relative improvement in the reliability and safety of a system with repairable components is calculated with respect to the corresponding system where the components are not repairable. The fault tolerant systems under study correspond to...

Assessing the quality of service of a computer system is a difficult task. A lot of work has been conducted on evaluating quality of service attributes like performance, robustness, and dependability. Two approaches used for evaluating performance and robustness are modeling and benchmarking. For evaluating dependability, modeling can be used either alone or combined with fault injection [Sie92...

The dependability of a system is particularly important when dealingwith autonomous or semiautonomous systems. With an increasing degree of autonomy and safety requirements, the requirements for dependability increase. Hence, being able to measure and compare the dependability of a system is more and more inevitable. Since autonomous mobile systems are usually described by their behavior it is ...

Multiple-Phased Systems, whose operational life can be partitioned in a set of disjoint periods, called “phases”, include several classes of systems such as Phased Mission Systems and Scheduled Maintenance Systems. Because of their deployment in critical applications, the dependability modeling and analysis of Multiple-Phased Systems is a task of primary relevance. However, the phased behavior ...

Cesium is an object-oriented environment for testing that implementations of real-time, fault-tolerant protocols satisfy the safety and timeliness properties prescribed by their speciications. Protocol implementations are tested under conngurable workloads and failure scenarios. A centralized simulator executes all tasks in a single address space while providing the appearance of truly distribu...

In this paper, performance evaluation of different schemes for location of fault in series compensated transmission lines are presented. A fault location algorithm using two end measurements and another fault location algorithm using one end measurements for transmission lines with series compensator at midpoint are simulated and results are obtained. Both the schemes are compared on the basis ...

Enclosed CD-ROM contains source code and downloaded references. Synopsis: Performing experimental evaluation of wireless networking is prone to large differences between experiments as the non-deterministic nature of the environment may influence the results differently between tests. This fact has motivated the work described in this report, which constitutes the development and deployment of ...

The operation of wireless ad hoc networks is intrinsically tied to the ability of nodes to coordinate their actions in a dependable and efficient manner. The failure of some nodes and momentary breakdown of communications, either of accidental or malicious nature, should not result in the failure of the entire system. This paper presents Turquois an intrusion-tolerant consensus protocol specifi...

Transmission Control Protocol (TCP) has been profusely used by most of internet applications. Since 1970s, several TCP variants have been developed in order to cope with the fast increasing of network capacities especially in high Bandwidth Delay Product (high-BDP) networks. In these TCP variants, several approaches have been used, some of these approaches have the ability to estimate available...

Computer controlled systems are used in many application fields, with different levels of criticality requirements. A common characteristic of such systems is the increasing complexity in internal structure (redundancy, layering of functionality) and operational issues (performance constraints, criticality of the controlled applications, etc.). The increasing need for effective design has contr...