this study tries to codify a proper mathematical model which can be predict the costs of repair and maintaining the tractors as precisely as possible for three common models of tractors in shahid beheshti cultivation firm in andimeshk-ahvaz road of dezfoul. studied tractors include: newhland tm155 tractor which is chosen from the most perfect file of 10 tractor machines and jandier tractor-3140...

A method of using the demand response mechanism power grid to promote consumption surplus wind is proposed for new energy generation. In method, replacement output gas turbine used as an important way consume power, and realized by replace part turbine. With objective function maximum consumable constraints replaceable turbine, cost balance supply grid, a model considering constructed. addition...

background: activity based costing (abc) is one of the new methods began appearing as a costing methodol­ogy in the 1990's. it calculates cost price by determining the usage of resources. in this study, abc method was used for calculating cost price of remedial services in hospitals. methods: to apply abc method, shahid faghihi hospital was selected. first, hospital units were divided into thre...

In this paper, the single machine replacement problem is being modeled into the frameworks of stochastic dynamic programming and control threshold policy, where some properties of the optimal values of the control thresholds are derived. Using these properties and by minimizing a cost function, the optimal values of two control thresholds for the time between productions of two successive nonco...