objective: water scarcity is a growing global problem and increasing population pressures, living standards and the growing demand for environmental quality have evoked all the governments to represent better solutions about water resources management. in addition, there are growing political ties for reducing water use in agriculture that follow enough environmental benefits and increase the w...

climate change phenomenon is an important environmental challenge of the world. increasing extension of greenhouse gases and remote relationship phenomena accelerate the speed f climate change. changes in precipitation level, drought occurrence and changes in the level of surface and groundwater resources are the recognized consequences of climate change. in order to study consequences of clima...

In this paper we introduce the optimal solution for a simple and yet practical inventory policy with the important characteristic which eliminates the uncertainty in demand for suppliers. In this new policy which is different from the classical inventory policies, the time interval between any two consecutive orders is fixed and the quantity of each order is one. Assuming the fixed ordering cos...

climate change phenomenon is an important environmental challenge of the world that has increased its speed with the increasing extension of greenhouse gases and remote relationship phenomena. changes in precipitation level, drought occurrence and in the level of surface and groundwater resources are the recognized consequences of climate change. in order to study climate change phenomenon cons...

as an industrial crop, sugar beet plays an important role in meeting domestic demand for sugar. given the higher level of imported sugar iniran, the application of protectionist policies is an approach for supplying required sugar. one of these policies is technological improvement. in order to study the effect of this policy, sugar beet supply and demand equations in 1971-2008 were fitted by t...