OBJECTIVES Despite the great contribution made by chemical substances to the development of modern civilization, their indiscriminate use has caused various kinds of damage to the global environment and human beings. Accordingly, the major developed countries and international society have tried to ensure the safe use of chemicals and a reduction in the use of hazardous chemicals through the es...

Introduction The research reported in this paper relates to an empirical study of business start-ups and their survival and growth or, conversely, their failure (exit) in the early years following start-up. A cohort of new start small or micro businesses which were set up with the support of a Training & Enterprise Council (TEC) in the West Yorkshire area are investigated. TECs are a government...

In this paper, a step fixed charge transportation problem is developed where the products are sent from the sources to the destinations in existence of both unit and step fixed-charges. The proposed model determines the amount of products in the existing routes with the aim of minimizing the total cost (sum of unit and step fixed-charges) to satisfy the demand of each customer. As the problem i...

in this paper, we consider a flow shop scheduling problem with availability constraints (fsspac) for the objective of minimizing the makespan. in such a problem, machines are not continuously available for processing jobs due to preventive maintenance activities. we proposed a mixed-integer linear programming (milp) model for this problem which can generate non-permutation schedules. furthermor...

a significant portion of gross domestic production (gdp) in any country belongs to the transportation system. transportation equipment, in the other hand, is supposed to be great consumer of oil products. many attempts have been assigned to the vehicles to cut down greenhouse gas (ghg). in this paper a novel heuristic algorithm based on clark and wright algorithm called green clark and wright (...

Linda Gel85, CG89] is a coordination language providing generative communication via tuple spaces. Each tuple space is a global associative memory consisting of a bag (or multi-set) of tuples, where the tuples are variable-sized objects. Repeated insertions and removals of variable-sized tuples are liable to result in the memory containing several small areas of free memory to which larger, var...

This paper presents a novel, integer-linear programming (ILP) model for an identical parallel-machine scheduling problem with family setup times that minimizes the total weighted flow time (TWFT). Some researchers have addressed parallel-machine scheduling problems in the literature over the last three decades. However, the existing studies have been limited to the research of independent jobs,...

Key British scientists were invited to a 'power' breakfast last month to discuss with no less than five ministers their views on how science policy can be developed. And in the chancellor's later annual budget statement, the government underlined its wish to see investment in science as a key to future prosperity. But future money will not all be coming from the government: there are growing ef...