in the conventional design and analysis methods affecting parameters (loads, materials'strength, etc) are not set as probable variables. safety factors in the current codes andstandards are usually obtained on the basis of judgment and experience, which may beimproper or uneconomical. in technical literature, a method based on nonlinear static analysisis suggested to set reliability index on st...

abstract drought is a natural creeping event that starts due to lower moisture compared to normal condition. this phenomenon impacts all aspects of human activities. however there is neither any detailed definition nor a general and proper index for drought monitoring. in this study, fuzzy logic has been applied to deal with inherent uncertainties of the real world data. we presented a fuzzy mo...

In the present paper, we analyze the vague reliability of k-out-of-n : G system (particularly, series and parallel system) with independent and non-identically distributed components, where the reliability of the components are unknown. The reliability of each component has been estimated using statistical confidence interval approach. Then we converted these statistical confidence interval int...

Abstract: In conventional reliability analysis, the failure probabilities of the components of a system are treated as exact values. It is often difficult to obtain data for failure probabilities under changing environmental conditions. Hence fuzzy sets are used to analyze the fuzzy system reliability, where a fuzzy number represents the reliability of each component. Chen [14] analyzed the fuz...

Reliability analysis is one of the significant applications of statistics. Many parametric and non-parametric techniques are available for reliability estimation based on precise life time observations, without considering the uncertainty of individual observations. But life time observations are not precise measurements but more or less fuzzy. Therefore by considering life time measurements as...

background: the motricity index was used to measure strength in upper and lower extremities after stroke. the weighted score based on the ordinal 6 point scale of medical research council was used to measure maximal isometric muscle strength. there is dearth of articles dealing with the reliability of this method. therefore, the aim of this study was to determine the test retest reliability of ...

aim and background: the aim of current study was to investigate the factor structure, reliability, and validity of parenting stress index-short form (psi-sf) among tehran city's mothers with 7-12 year-old children. methods and materials: after translation, back translation and adaptation of instrument, due to normalization this instrument by applied survey design, 468 mothers from those which s...

With the increase in environmental pressure and rapid development of renewable energy technologies, an integrated system has been recognized as effective approach to accommodate large-scale renewables achieve sustainability. While significantly improves efficiency, interaction between different systems may also bring multiple operational risks its reliability, which necessitates reliability ass...

Reliability modeling is the most important discipline of reliable engineering. A new method for analyzing fuzzy system reliability using vague set theory is demonstrated, where the reliabilities of the components of a system are represented by vague sets defined in the universe of discourse [0, 1]. The proposed method can model and analyze the fuzzy system reliability in a more flexible and mor...