background pittsburgh sleep quality index (psqi) is one of the most important instruments frequently used to assess sleep quality. this questionnaire is used to assess sleep styles and quality in adults through seven dimensions. objectives the study aims to investigate the reliability, validity and factor structure of the persian version of psqi. materials and methods a survey method with quant...

the computation of structural failure probability is vital importance in the reliability analysis and may be carried out on the basis of the first-order reliability method using various mathematical iterative approaches such as hasofer-lind and rackwitz-fiessler (hl-rf). this method may not converge in complicated problems and nonlinear limit state functions, which usually shows itself in the f...