recently, the economic crisis has resulted in instability in stock exchange market and this has caused high volatilities in stock value of exchanged firms. under these conditions, considering uncertainty for a favorite investment is more serious than before. multi-objective portfolio selection (return, liquidity, risk and initial cost of investment objectives) using minmax fuzzy goal programmin...

in this paper, a fuzzy hunter-saxton equation is solved by using the adomian'sdecomposition method (adm) and homotopy analysis method (ham). theapproximation solution of this equation is calculated in the form of series whichits components are computed by applying a recursive relation. the existenceand uniqueness of the solution and the convergence of the proposed methodsare proved. a nume...

In this paper, the problem of predicting times to failure of units censored in multiple stages of progressively hybrid censoring for the proportional hazards family is considered. We discuss different classical predictors. The best unbiased predictor ($BUP$), the maximum likelihood predictor ($MLP$) and conditional median predictor ($CMP$) are all derived. As an example, the obtained results ar...

The current study investigates performance in two-stage production systems through the measurement of capacity utilization (CU). In short-run, the degree of capacity utilization depends on the ability of decision making units to utilize fixed production factors. To develop this indicator in two-stage production processes, a modified SBM network DEA model is proposed. A numerical example is also...

this paper addresses a reliable facility location problem with considering facility capacity constraints. in reliable facility location problem some facilities may become unavailable from time to time. if a facility fails, its clients should refer to other facilities by paying the cost of retransfer to these facilities. hence, the fail of facilities leads to disruptions in facility location dec...

the aim of this work is to investigate the variational discretization and mixed finite element methods for optimal control problem governed by semi linear parabolic equations with integral constraint. the state and co-state are approximated by the lowest order raviart-thomas mixed finite element spaces and the control is not discreted. optimal error estimates in l2 are established for the state...

In this paper, we discuss the prediction problem based on censored coherent system lifetime data when the system structure is known and the component lifetime follows the proportional reversed hazard model. Different point and interval predictors based on classical and Bayesian approaches are derived. A numerical example is presented to illustrate the prediction methods used in this paper. Mont...