جستجوی مقالات مرتبط با کلیدواژه « integer non-linear programming » در نشریات گروه « برق »

This paper presents an economic order quantity model (EOQ) for growing items. In this inventory system, a buyer orders those items such as livestock and poultry, after a period of time grow and reach their ideal weight. Then, the company slaughters and sells items to customers. Shortage is not allowed and the order number must be integer values. Due to this, we have an integer non-linear programming problem and assumed that the items with a linear approximation grow and after reaching to the ideal weight become ready for consumption. We proved that the proposed model is a convex programming problem to obtain an optimal solution regardless of the integer of the order. Then, according to the value obtained, a solution algorithm for integer optimal solution is developed. At the end, we use a hypothetical numerical example to explain and express the proposed model and solution method. Also, we've done a sensitivity analysis showing the impact of each parameter on the objective function and order quantity values.

In water distribution networks, a significant amount of electricity is used to pump the water into the tanks. Planning and pump schedule could have an important role in energy consumption management and reducing the related cost. The aim of this study is to determine the optimal pump schedule on a 24-hour basis in which aims to minimize the cost of electrical energy, whilst meeting the required time varying consumer with regard to restrictions relating to the minimization of maintenance pumps. For this purpose, the pump schedule optimization problem with pumping water from the wells to the tank is formulated in the form of an Integer Non-Linear Programming model (INLP) and solved by the branch and bound method. In addition to the minimizing the energy consumption cost, the model includes a constraint to limit the number of pumps that are switched to reduce the pumps maintenance costs. To illustrate the effectiveness of the model, the water network of Noosh-Abad city in the outskirts of Kashan city is used as a case study. The results show that the formulated model in this study can meet the both mentioned objectives, so that the outputs of the model compared to the historical operation, both in terms of energy costs and the depreciation of the pumps is in much better situation. In particular, in the case of strict maintenance control, the energy cost is about 15% lower than that of the historical operation.