In recent years, the problem of selecting and evaluating the suppliers in supply chain management has aroused considerable interest in business firms. Owing to the development of information systems, reaching an appropriate decision for adopting discrete methods is a need. The researchers intend to present a new model in this paper as a contributing factor in the grey environment in which the r...

the problems of shortages and quality deterioration of water, have led to an increased interest in the reuse of treated grey water in many parts of the world. this study examined the suitability of locally available materials (beach sand, oyster shells, and charcoal) to treat grey water samples collected weekly from three halls of residence (unity hall, africa hall, and independence hall) on kw...

The production planning is an important problem in most of manufacturing systems in practice. Unlike many researches existing in literature, this problem encounters with great uncertainties in parameters and input data. In this paper, a single machine capacitated production planning problem is considered and a linear programming formulation is presented. The production costs are assumed to be u...

Nowadays, in order to reach minimum production cost in machining operations, various optimization methods have been proposed. Since turning operation has different parameters affecting the workpiece quality, it was selected as a complicated manufacturing method in this paper. To reach sufficient quality, all influencing parameters such as cutting speed, federate, depth of cut and tool rake angl...

abstract this author introduces the concept of stepwise strategy approach (ssa) for dealing with a number of problems arises in the current age of technology. this new idea is combined with the knowledge of grey theory for adding flexibility to decision making process. grey theory is useful for grasping the ambiguity exists in the utilized information and the fuzziness appears in the human judg...

nowadays, in order to reach minimum production cost in machining operations, various optimization methods have been proposed. since turning operation has different parameters affecting the workpiece quality, it was selected as a complicated manufacturing method in this paper. to reach sufficient quality, all influencing parameters such as cutting speed, federate, depth of cut and tool rake angl...

Purpose – The purpose of this paper is to advance new rules about operations of grey numbers. Design/methodology/approach – The paper first puts forward the definitions of basic element of grey number and general grey number. The operation axiom, operation rules of general grey numbers and a new algebraic system for general grey numbers are built based on the “kernel” and the degree of greyness...