the robust coloring problem (rcp) is a generalization of the well-known graph coloring problem where we seek for a solution that remains valid when extra edges are added. the rcp is used in scheduling of events with possible last-minute changes and study frequency assignments of the electromagnetic spectrum. this problem has been proved as np-hard and in instances larger than 30 vertices, meta-...

the advent of e-commerce has prompted many manufacturers to redesign their traditional channel structure by engaging in direct sales. in this paper, we present a dual channel inventory model based on queuing theory in a manufacturer-retailer supply chain, consisting of a traditional retail channel and a direct channel which stocks are kept in both upper and lower echelon. the system receives st...

‎this paper proposes a multi-supplier multi-product inventory model in which the suppliers have unlimited production capacity, allow delayed payment, and offer either an all-unit or incremental discount. the retailer can delay payment until after they have sold all the units of the purchased product. the retailer’s warehouse is limited, but the surplus can be stored in a rented warehouse at a...

this paper is an attempt to numerical modeling and experimental study of air flow in the yazdi wind-towers. wind towers has been known as one of the most effective climatic elements in iranian traditional architecture. this paper is an attempt to evaluating yazdi wind-tower to discussion the two main questions: 1. what is the role of orientation of wind-towers span, regarding to climate and hei...

vibration generated by vehicles during road transport has an important effect on the agricultural products damage process, particularly vegetable and fruit. modulus of elasticity is one of the most important mechanical properties of fruits and its variation can be described as one of the damage criteria during transportation. this research was conducted to evaluate the effects of vibration para...

microencapsulation as one of the most modern methods has remarkable effects on probiotic survival. in this study lactobacillus casei (atcc 39392) and bifidobacterium bifidum (atcc 29521) were encapsulated using calcium alginate-gelatinized starch, chitosan coating and inulin via emulsion technique, and were incubated in simulated gastric juice (along with pepsin, ph=1.5) and simulated intestina...