Dependable systems are characterized by a number of attributes including: reliability, availability, safety and security. For some attributes (namely for reliability, availability, safety), there exist probability-based theoretic foundations, enabling the application of dependability analysis techniques. The goal of dependability analysis is to forecast the values of dependability attributes, b...

In this paper, the authors examine UK mobile users’ perceptions of m-commerce utilization. For this purpose, the authors devise a Mobile Network Utilization Model empirically tested in experimental settings. The empirical findings reveal strong support for the capability of the proposed utilization model in measuring the concept of Mobile Task-Technology Fit (MTTF) and explaining the utilizatio...

Fault observability based on the behavior of memory references is studied. Traditional studies view memory as one monolithic entity that must completely work to be considered reliable. The usage patterns of a particular program’s memory are emphasized here. This paper develops a new model for the successful execution of a program taking into account the usage of the data by extending a cache me...

This paper presents our analysis of the failure behavior of large scale systems using the failure logs collected by Los Alamos National Laboratory on 22 of their computing clusters.We note that not all nodes show similar failure behavior in the systems. Our objective, therefore, was to arrive at an ordering of nodes to be incrementally (one by one) selected for duplication so as to achieve a ta...

This paper turns the concept of input distributions on its head to exploit inverse input distributions Al though such distributions are not always true math ematical inverses they do capture an intuitive prop erty inputs that have high frequencies in the original distribution will have low frequencies in the inverse distribution and vice versa We can use the inverse distribution in several di e...

Some spans b are always very critical in any network. These spans may be; i) Most heavily loaded spans in the network, ii) Spans with small MTTF (mean time to failure), iii) Spans with high MTTR (mean time to repair), iv) Spans having large amount of premium traffic etc. In this paper a new scheme is proposed to provide protection to these critical spans using p-cycles. Fully distributed method...

The distributed system is a paradigm in which the components can communicate by means of the interface connected between them. The interaction between the components takes place in order to achieve a common goal. The reliability metrics is used to evaluate the performance of the components which is connected by the distributed systems. The Mean Time Between Failure (MTBF), Mean Time to Repair (...

A widely accepted equation for availability is Availability=MTTF/(MTTF+MTTR), where MTTF is the mean time to failure of a system or subsystem (i.e. the reciprocal of reliability), MTTR is its mean time to recovery, and A is a number between 0 and 1. The equation suggests that to improve availability, a 10x decrease in MTTR (for example) is just as valuable as a 10x increase in MTTF, a founding ...

Abstract -We estimate the availability, reliability, and mean transaction time (response time) for repairable database configurations, centralized or distributed, in which each service component is continuously available for repair. Reliability, the probability that the entire transaction can execute properly without failure, is computed as a function of mean time to failure (MTTF) and mean tim...

It is shown that under reasonable assumptions, conservation of angular momentum provides a strong constraint on gravity wave drag feedbacks to radiative perturbations in the middle atmosphere. In the time mean, radiatively induced temperature perturbations above a given altitude z cannot induce changes in zonal mean wind and temperature below z through feedbacks in gravity wave drag alone (assu...