objective: the study aimed to design and evaluate the content and face validity, and reliability of knowledge, attitude, and behavior questionnaire on preventive behaviors among vulnerable women concerning sexually transmitted diseases (stds). materials and methods: this cross-sectional study was carried out in two phases of an action research. in the first phase, to explain stds preventive dom...

The paper considers reliability analysis for aging multi-state system where the system and its components can have different performance levels ranging from perfect functioning to complete failure. Aging is treated as failure rate increasing during system lifetime. Reliability measures for multi-state system such as mean accumulated performance deficiency, mean number of failures, average avail...

This paper presents mathematical models and a solution approach to determine the optimal preventive maintenance schedules for a repairable and maintainable series system of components with an increasing rate of occurrence of failure (ROCOF). The maintenance planning horizon has been divided into discrete and equally-sized periods and in each period, three possible actions for each component (ma...

Bayesian approach using nonhomogeneous Poisson process is considered for modeling software reliability problems. A generalized gamma and lognormal order statistics models are considered to model epochs of the failures of software. Metropolis algorithms along with Gibbs steps are proposed to perform the Bayesian inference of such models. Some Bayesian model diagnostics are developed and incorpor...

Akademisk avhandling som med tillstånd av Kungl Tekniska Högskolan framlägges till offentlig granskning för avläggande av teknologie doktorsexamen, fredagen den 18:e april, Abstract Maximum asset performance is one of the major goals for electric power distribution system operators (DSOs). To reach this goal minimal life cycle cost and maintenance optimization become crucial while meeting deman...

this paper studies a maintenance policy for a system composed of two components, which are subject to continuous deterioration and consequently stochastic failure. the failure of each component results in the failure of the system. the components are inspected periodically and their deterioration degrees are monitored. the components can be maintained using different maintenance actions (repair...

This paper explores a reliability based heuristic mathematical model for basic and classical age replacement policy. Using new model, optimal preventive age replacement policy is determined to maximize system reliability. For special systems having exponential density function with constant hazard function, a different simple decision-making model is proposed. A case study of two industrial mac...

The paper proposes a preventive maintenance (PM) planning model for the performance improvement of cellular manufacturing systems (CMS) in terms of machine reliability, and resource utilization. In a CMS, parts are processed by a group of interdependent machines, where machine reliability plays an important role in the performance improvement of the cell. Assuming that machine failure times fol...

One of the most important goal of the diagnostic system is to provide the high reliability. This article describes the concept and the proposal for a diagnostics for the Low Level Radio Frequency system for EUXFEL. It enables immediate location of faults and understanding of their causes, tests the functionality of LLRF system, tests each of the electronic boards and connections. The diagnostic...