Programming-level and redundancy-free method for enhancing software reliability against transient errors in hardware

Software play remarkable roles in different critical applications. On the other hand, due to the shrinking of transistor size and reduction in supply voltage, radiation-induced transient errors (soft errors) have become an important source of computer systems failure. As the rate of transient hardware faults increases, researchers have investigated software techniques to control these faults. Performance overhead is the main drawback of software-implemented methods like recovery blocks that use technical redundancy. Enhancing the software reliability against soft errors by utilizing inherently error masking (invulnerable) programming structures is the main goal of this study. During the programming phase and at the source code level, programmers can select different storage classes such as automatic, global, static and register for the data into their program without paying attention to their inherent reliability. In this study, the inherent effects of these storage classes on the program reliability are investigated. Extensive series of profiling and fault-injection experiments were performed on the set of benchmark programs implemented with different storage classes. Regarding the results of experiments, we find that the programs implemented with automatic storage classes have inherently higher reliability than the programs with static and register storage classes without performance overhead. This finding enables the programmers to develop highly reliable programs without technical redundancy and performance overhead.

Optimizations of Managerial Maintenance Policies

This paper takes up managerial maintenance policies during different phases for mission executions. When a mission execution is divided into two phases and three phases respectively, replacement, minimal repair and keeping failure status become alternatives for managerial maintenance policies. Further, we give approximations of the above managerial maintenance policies to make the computations simple. In this paper, keeping failure status is considered as the last choice for the last phase of mission executions. We aim to minimize the expected maintenance costs for the total mission executions. All of the discussions are made analytically and their numerical examples are given.

A Bayesian Inference Reliability Evaluation on the Corrosion-Affected Underground High-Voltage Power Grid

The underground high-voltage power transmission cables are high value engineering assets that suffer from multiple deteriorations through-out life cycles. Recent studies identified a new failure mode – the pitting corrosion deterioration on the layer of phosphor bronze reinforcing tape, which protects the oil-filled power transmission cables from oil leakage due to deterioration of the leads heath. Two models estimating the phosphor bronze tape life were established separately in this study. The first model, based on mathematical fitting, is generated using a replacement priority model from the power supply industry. This is considered as an empirical-based model. The second model, based on the corrosion fatigue mechanism, utilizes the information of the pit depth distribution and the concept of pit-to-crack transfer probability. The Bayesian inference approach is the conjunction algorithm to update the existing probability of failure (PoF) model with the newly identified failure modes. Through this algorithm, the integrated PoF model contains a more comprehensive background information while maintaining the empirical knowledge on the engineering assets’ performance.

Interval Estimation in Lifetime Distributions Using Progressively Type II Censored Data

In this paper, we developed a method for constructing confidence intervals for the parameters of lifetime distributions based on progressively type II censored data. The method produces closed form expressions for the bounds of the confidence intervals for several special cases of parameters and lifetime distributions. Closed form approximations are derived for the intervals for the parameters of the location or scale families of distributions. The method is illustrated with several examples and analyses of real data sets are included to illustrate the application of the method.

Reliability Evaluation and Cost Optimization of Solar Road Studs

Roads have always been the main source of transportation all over the world. Easy accessibility and more safety are the most important features of road transportation. Improvements in these areas are constantly required and invited. Solar road studs are one of the remarkable improvements in road safety. Solar road studs use solar energy, which is the most sustainable and pollution-free source of energy that provides reliable power supplies and fuel diversification. Solar road studs are flashing solar cell-powered LED lighting devices used in road construction to delineate road edges and centerlines. This research work is dedicated to evaluating the reliability measures which include availability, mean time to failure (MTTF), cost analysis, and sensitivity analysis with their graphical representation by using the Markov process. Along with reliability assessment, Particle Swarm Optimization (PSO) technique is applied to optimize the cost of the system.