background: to measure suspected abuse of the methamphetamine (ma) among methadone maintenance treatment (mmt) patients in tehran, we studied all 206 patients who were admitted to mmt program from 2009 to 2015 to andishe-no addiction treatment clinic.  methods: ma presence was screened in one of the random urine samples routinely taken for tests of other drugs.  results: 70 (34.3%) patients wer...

a b s t r a c tintroduction: although decision-making processes have become a principal target of study among addiction researchers, few researches are published according to effects of different treatment methods on the cognitive processes underlying decision making up to now. utilizing cognitive modeling method, in this paper we examine the effects of methadone maintenance treatment (mmt) on ...

since lean concept has appeared many works have been done on decreasing or even eliminating of wastes such as extra inventory. although these studies have not taken into account expected availability seriously. so in this paper, a multiple objective decision making (modm) model has been developed by viewpoint of these subjects. they are decreasing wastes and increasing system availability. wast...

this paper presents a new bi-objective mathematical model for a permutation flowshop scheduling problem with availability constraint in case of preventive maintenance operations on machines. in this paper, preventive maintenance is flexible and there is not a certain time for the maintenance operation; however, time between two consecutive maintenance operations for each machine should not be g...

In this paper, a single-product, single-machine system under Markovian deterioration of machine condition and demand uncertainty is studied.  The objective is to find the optimal intervals for inspection and preventive maintenance activities in a condition-based maintenance planning with discrete monitoring framework. At first, a stochastic dynamic programming model whose state variable is the ...