a generalized heckman model is used for the joint modeling of longitudinal continuousresponses and dropout in order to see the influence of a small perturbation of the elements of thecovariance structure on displacement of the likelihood. the perturbation from random dropout in thedirection of informative dropout is considered for mastitis data.

fluorescent monitoring of dna amplification is the basis of real-time pcr. absolute quantification can be achieved using a standard curve method. the standard curve is constructed by amplifying known amounts of standards under identical conditions to that of the samples.the objective of the current study is to propose a mathematical model to assess the acceptability of pcr resulys.four commerci...

the problem of utilizing undesirable (bad) outputs in dea models often need replacing the assumption of free disposability of outputs by weak disposability of outputs. the kuosmanen technology is the only correct representation of the fully convex technology exhibiting weak disposability of bad and good outputs. also, there are some specific features of non-radial data envelopment analysis (dea...

a methodology is presented in this paper to find optimal location and dosage of chlorine injection in water distribution networks. the objective is to minimize the chlorine consumption while keeping the residual chlorine at each node within the standard range. unfortunately because of wrong water quality management in water distribution networks in many parts of the world, many problems such as...

introduction: hospital portals, as the first virtual entry, play an important role in connecting people with hospital and also presenting hospital virtual services. the main purpose of this article was to suggest a conceptual model to improve tehran private hospital portals. the suggested model can be used by all the health portals that are in the same circumstances and all the health portals w...

the objective of this research was to study the drying characteristics of powderedagricultural residues. drying experiments of wheat straw (triticum aestivum) wereconducted at four temperatures of 50, 60, 70, and 80°c by a thermogravimetric analyzer.drying temperature had a significant effect on the moisture change and drying time.there was no constant drying rate period, but a short rising rat...

abstract background: some studies have shown significant changes in quality of life due to menopausal status. a large number of factors, including psycho-social factors, have been found to be associated with quality of life. the aim of this study was to investigate factors affecting quality of life among postmenopausal women in isfahan based on behavioral analysis phase of precede model. method...