empirical researches have shown that in highly volatile market, conditional correlation between returns is stronger, so diversification cannot reduce risk. to test this claim in iran’s financial market, quintiles of stock return distribution have been estimated by kernel density and garch models. then, average conditional correlation, error variance and conditional capm has been calculated to t...

The reliable change index (RCI) expresses change relative to its associated error, and is useful in the identification of postoperative cognitive dysfunction (POCD). This paper examines four common RCIs that each account for error in different ways. Three rules incorporate a constant correction for practice effects and are contrasted with the standard RCI that had no correction for practice. Th...

Background and Objectives: Patient safety (PS) is one of the most important and essential elements of quality in healthcare setting. A systematic review and meta-analysis was performed to assess the status of patient safety culture using the Hospital Survey on Patient Safety Culture (HSOPSC). Methods: In this systematic review and meta-analysis study, data were collected through searching dat...

This study examined the effects of different sample sizes and different levels of bias (systematic error) between replicated measurements on the accuracy of estimates of random error calculated using two common formulae: Dahlberg's and the 'method of moments' estimator (MME). Computer-based numerical simulations were used to generate clinically realistic measurements involving random errors wit...

Introduction: Radiation therapy is one of the methods of cancer treatment. In this method, it is necessary to avoid harming the healthy tissues of the patient which is in the vicinity of the target, as much as possible. Treatment verification is one of the most important steps of radiation therapy which has two usual methods, using Port film and EPID. The accuracy and precision of treatment in ...

Pretreatment dose verification with beam-by-beam analysis for intensity-modulated radiation therapy (IMRT) is commonly performed with a gantry angle of 0° using a 2D diode detector array. Any changes in multileaf collimator (MLC) position between the actual treatment gantry angle and 0° may result in deviations from the planned dose. We evaluated the effects of MLC positioning errors between th...

the output error of the globoidal cam mechanism can be considered as a relevant indicator ofmechanism performance, because it determines kinematic and dynamical behavior of mechanicaltransmission. based on the differential geometry and the rigid body transformations, themathematical model of surface geometry of the globoidal cam is established. then we present theanalytical expression of the ou...