Recently, some authors proposed the use of symmetric weightsfor computing the elements of cross-efficiency matrix. In spite ofthe fact that the proposed method decreases the number of zeroweights, a large number of zero weights may still exist among inputand output symmetric weights. To decrease the number of input andoutput symmetric weights, this paper improves the proposed secondarygoal mode...

A number of results relative to the complexity of terminological logics have recently appeared in the literature. Unfortunately, most of these results are “negative”, as they show that, in the logics they refer to, deciding subsumption is intractable. In this paper we show that computing subsumption is O(n2) in B∇ac〈ma\∀4N−, a logic obtained by adding the two operators atleast and atmost, which...

The nature of input materials is changed as long as the product reaches the consumer in many types of manufacturing processes. In designing and improving multi-stage systems, the study of the steps separately may not lead to the greatest possible improvement in the whole system, therefore the study of inputs and outputs of each stage can be effective in improving the output quality characterist...

In this paper the real-world occurrence of the multiple-product multiple-constraint single period newsboy problem with two objectives, in which there is incremental discounts on the purchasing prices, is investigated. The constraints are the warehouse capacity and the batch forms of the order placements. The first objective of this problem is to find the order quantities such that the expected ...

This paper includes a simulation model built in order to predict the performance indicessuch aswaiting time by analyzing queue’s components in the real world under uncertain and subjective situation. The objective of this paper is to predict the waiting time of each customer in an M/M/C queuing model. In this regard, to enable decision makers to obtain useful results with enough knowledge on th...

Nowadays, application of high speed crafts with large tonnage is of our country's essences. In order to gain high speed, new multi hull crafts are traditional. A hull form having been used recently in frigates is the Trimaran. Trimaran hull form and motion have been extensively studied due to the development of numerical and analytical methods as well as the exploitation of experimental setup. ...

this paper submitting the computation of optimize point of ordering in inventory control systems and particularly for continuous review of ordering system (r,q) by fuzzy logic method which similarly can be used for other ordering systems. since in the ordering models we cannot forecast the parameters like cost exactly, we have ambiguity. in this case using precise parameters may cause wrong dec...