Background & Aims of the Study: Due to one-way flow of water in rivers Guilan, pollution trade theory and the system of Ratio-Trade (TRS) and Streeter - Phelps equation has been used. This system, with a view of the river self- purification and how the distribution and transport of pollutants, determined Ratio-Trade system (TRS) between the units and using this method offers optimal pat...

critical path method (cpm) is one of the most popular techniques used by construction practitioners for construction project scheduling since the 1950s. despite its popularity, cpm has a major shortcoming, as it is schedule based on two impractical acceptance that the project deadline is not bounded and that resources are unlimited. the analytical competency and computing capability of cpm thus...

this paper explores the capabilities of multi-objective particle swarm optimization algorithmin a simulation-optimization model for solving waste load allocation problems. the main goals are totaltreatment costs, violation of the water quality standards and equity. in this research, the water qualitysimulation model is coupled with a multi-objective optimization model, mopso. in order to derive...

Abstract How do trade costs affect international trade? This paper offers a new approach. We rely on flexible gravity equation that predicts variable cost elasticities, both across and within country pairs. apply this framework to popular variables such as currency unions, agreements World Trade Organization membership. While we estimate these are associated with increased bilateral average, fi...

In a supplier-retailer-buyer supply chain, the supplier frequently offers the retailer a trade credit of  periods, and the retailer in turn provides a trade credit of  periods to her/his buyer to stimulate sales and reduce inventory. From the seller’s perspective, granting trade credit increases sales and revenue but also increases opportunity cost (i.e., the capital opportunity loss during cre...

t his paper investigates the gain of bilateral trade between china and u.s. in manufacturing sectors when both countries play a role in asymmetric (biased) growth of  international trade. our model includes a special case of biased growth theory in international trade. we collected labor productivity, export and import data by using classification of manufacturing industries, for u.s. and china...