in this paper, a new approach to overlapping operations in job shop scheduling is presented. in many job shops, a customer demand can be met in more than one way for each job, where demand determines the quantity of each finished job ordered by a customer. in each job, embedded operations can be performed due to overlapping considerations in which each operation may be overlapped with the other...

We consider in this paper the uplink slot assignment problem in a multi-spot geostationary satellite. Radio interference impose constraints on the slots that can simultaneously be assigned in different cells that have the same frequency. The problem is shown to be an NP-complete one, which motivates us to search for a heuristic solution approach. We describe here a heuristic solution based on s...

this study aims to deal with a more realistic combined problem of project scheduling and material ordering. the goal is to minimize the total material holding and ordering costs by determining the starting time of activities along with material ordering schedules subject to some constraints. the problem is first mathematically modelled. then a hybrid simulated annealing and genetic algorithm is...

earth dam is a structure as homogeneous or non-homogeneous forms for raising water level or water supply. earth dam consist of different parts that one of the main parts is clay core. choosing an optimal non permeable core which causes reduction of seepage through dam body and also being stable is necessary. the objective of this research is to optimize the geometry of earth dam clay core such ...

Metaheuristics are general problem solving algorithms which abstract from the actual problem description. Therefore they can be easily applied to many optimization problems. Simulated annealing is a simple and fast metaheuristic with an analogy to metal processing. As metal particles generate a solid and regular structure when cooling slowing simulated annealing seeks a low-energy solution avoi...

Simulated annealing is a well-studied local search metaheuristic used to address discrete and, to a lesser extent, continuous optimization problems. The key feature of simulated annealing is that it provides a mechanism to escape local optima by allowing hill-climbing moves (i.e., moves which worsen the objective function value) in hopes of finding a global optimum. A brief history of simulated...

This paper deals with a multi-period fixed charge production-distribution problem associated with backorder and inventories. The objective is to determine the size of the shipments from each supplier and backorder and inventories at each period, so that the total cost incurred during the entire period towards production, transportation, backorder and inventories is minimised. A 0-1 mixed intege...

The paper deals with the problem of high-school time-tabling that is important in applications, but hard for solving. The algorithm is presented for timetabling based on Multi-start and Simulated Annealing with parameters adapted using the Bayes approach. The algorithm proposed is compared with other timetabling algorithms using the web-based software. A multi-start algorithm is a simple way to...

fuzzy clustering methods are conveniently employed in constructing a fuzzy model of a system, but they need to tune some parameters. in this research, fcm is chosen for fuzzy clustering. parameters such as the number of clusters and the value of fuzzifier significantly influence the extent of generalization of the fuzzy model. these two parameters require tuning to reduce the overfitting in the...