it is assumed in most of the existing models that the items can be stored for an unlimited time to meet the future’s demand and their quality and quantity does not change during that period. nevertheless there are special kinds of products which deteriorate or become unusable (such as food products, alcohol, medicines, etc.). therefore if the rate of deterioration is significantly high, the imp...

Hodnotenie a charakterizácia vybraných škodlivín v prípade zdrojov povrchovej vody High quantities of organic matter can reduce the chemical and biological quality of river water. The key indicator of the oxygenation status of water bodies is the biological oxygen demand (BOD) and ammonium. These are main indicators for the water quality classification. Although countries have different river c...

We consider a quantity-setting duopoly model, and we study the decision to move first or second, by assuming that the firms produce homogeneous goods and that there is some demand uncertainty. The competitive phase consists of two periods, and in either period, the firms can make a production decision that is irreversible. As far as the firms are allowed to choose (non-cooperatively) the period...

in this research two models for pricing and inventory decisions of complementary products with and without deterioration assumption are developed. in both of them, we assumed that the demand function of each product is dependent on own price and the price of another one. the aim of this paper is to optimize the total profit of integrated system such that the optimal values for the price of each...

water is the most essential component for sustaining lives of humans and other living creatures. supplying potable water with adequate residual pressure is a fundamental responsibility of city administration, which they do during normal conditions. but sometimes, abnormal conditions are formed resulting pressure deficient conditions during the daily operations of water distribution networks. th...

Inspired by prescription drug affordability practices, we study how a buyer may achieve cost reduction by combining a procurement process with quantity-dependent pricing contracts and exclusion clauses, the latter of which has been commonly adopted in contracting but rarely executed. We analyze the equilibrium outcomes when the buyer simultaneously or sequentially negotiates with imperfectly su...

The classical Economic Order Quantity (EPQ) models consider that the production rate is fixed and constant. But in many manufacturing and production processes the production rate is a function of stock on hand. For this sort of situations we develop and analyze an EPQ model with the assumption that the production rate is a function of the on-hand inventory and demand is a function of selling pr...

This paper develops an economic lot-sizing production model for deteriorating items with time dependent quadratic demand and delay in payments under two levels of trade credit policy. The trade credit policy adopted here is a two-level trade credit policy in which the supplier offers the retailer a permissible delay period M, and the retailer in turn provides customers a permissible delay perio...