Reliability analysis is an important issue in wireless sensor networks (WSNs). This paper aims to study the reliability of a data flow in event-driven wireless sensor networks with multiple sending transmission approach without acknowledgments. Initially, an event-driven wireless sensor network model is described in terms of limited node battery energy and shadowed fading channels. Then, in ord...

Computers freezing to work is a common problem and can cause unexpected damages if the work is important but not saved yet. This kind of problems is often caused by software failures which are hard to predict. This paper focuses on the reliability analysis of laptop computers experiencing multiple occurrences of failures in operation. The failure has been defined as the event that the computer ...

Diagnostics of the 1.5 GeV Taiwan Light Source (TLS) have been continuously upgraded since its operation started in 1993. The BPM electronics of the Taiwan Light Source (TLS) have been upgraded to Libera Brilliance in August 2008 to improve performance and functionality. Orbit feedback has also been migrated to a fast orbit feedback system to enhance orbit stability. Commercial photon BPM elect...

In this paper, we examine the problem of predicting machine availability in desktop and enterprise computing environments. Predicting the duration that a machine will run until it restarts (availability duration) is critically useful to application scheduling and resource characterization in federated systems. We describe one parametric model fitting technique and two non-parametric prediction ...

Abstract This paper deals with the availability analysis of a complex system that consists of two subsystems namely subsystem 1 and subsystem 2.Subsystem 1 is working under k-out of –n good policy and subsystem 2 has two identical units in parallel configuration. Controller for proper functioning controls the subsystems 1. All failure rates are constant and follow exponential distribution but r...

As systems scale up, their mean-time-to-failure reduces drastically. We consider parallel servers subject to permanent failures but such that only one needs to survive in order to execute a given task. This kind of failure-model is appropriate in at least two types of systems: systems in which repair cannot take place (e.g. spacecraft) and systems that have strict deadlines (e.g. navigation sys...

A heterogeneous computing system provides a variety of different machines, orchestrated to perform an application whose subtasks have diverse execution requirements. The subtasks must be assigned to machines (matching) and ordered for execution (scheduling) such that the overall application execution time is minimized. A new dynamic mapping (matching and scheduling) heuristic called the hybrid ...

Increasing MTTF requires increasing reliability. In previous lectures we saw a variety of ways to do so: testing, static analysis, formal methods, etc. A highly reliable system is a highly available system. Reducing MTTR requires reducing the (mean) time it takes for the system to come back up once a failure has occurred. Once a failure occurs, we must detect it, diagnose it, and the recover th...

Designing highly dependable systems requires a good understanding of failure characteristics. Unfortunately, little raw data on failures in large IT installations is publicly available. This paper analyzes failure data recently made publicy available by one of the largest high-performance computing sites. The data has been collected over the past 9 years at Los Alamos National Laboratory and in...

The reliability of software is one of the most important software metrics. In the course of time, systems have become more and more complex and that is why software has become more complex, too. It is an undeniable fact that this will lead to an increasing number of software faults. Models of software reliability are used to track down software faults. The aim is to make sure that an improvemen...