task graph scheduling is a multi-objective optimization and np-hard problem. in this paper a new algorithm on homogeneous multiprocessors systems is proposed. basically, scheduling algorithms are targeted to balance the two parameters of time and energy consumption. these two parameters are up to a certain limit in contrast with each other and improvement of one causes reduction in the other on...

train energy saving problem investigates how to control train's velocity such that the quantity of energy consumption is minimized and some system constraints are satis ed. on the assumption that the train's weights on different links are estimated by fuzzy variables when making the train scheduling strategy, we study the fuzzy train energy saving problem. first, we propose a fuzzy energy ...

All practical real-time scheduling algorithms in multiprocessor systems present a trade-off between their computational complexity and performance. In real-time systems, tasks have to be performed correctly and timely. Finding minimal schedule in multiprocessor systems with real-time constraints is shown to be NP-hard. Although some optimal algorithms have been employed in uni-processor systems...

Highway construction projects are one of the most important construction projects in the world. Therefore predicting the time of these kinds of projects is important. Basically highway projects are including few activities which are repeating along the horizontal direction. One of the best methods for scheduling these types of projects is linear scheduling method. The repetitive nature of the h...

In a multiprocessor environment scheduling is very essentially done with greater challenges. Researchers are in the edge of finding solutions to these challenges. Scheduling is the art of allocating limited resources to competing tasks over time. A feasible schedule satisfies the constraints that are associated with any particular set of tasks and resources. So as to improve the performance of ...

An architecture and a procedure for communicating scheduling expert systems based on fuzzy set theory is proposed. Fuzzy sets are used to express and to exchange constraints and their potential relaxation with the cooperating scheduling system that can interpret these constraints. The procedure is intended to optimize the global evaluation among the communicating systems. An example from steel ...

mathematical modeling of supply chain operations has proven to be one of the most complex tasks in the field of operations management and operations research. despite the abundance of several modeling proposals in the literature; for vast majority of them, no effective universal application is conceived. this issue renders the proposed mathematical models inapplicable due largely to the fact th...

This paper addresses parallel machine scheduling with learning effects. The objective is to minimize the makespan. To satisfy reality, we consider the processing times as fuzzy numbers. To the best of our knowledge, scheduling with learning effects and fuzzy processing times on parallel machines has never been studied. The possibility measure will be used to rank the fuzzy numbers. Two heuristi...

|Jobshop scheduling problems are NP ?hard problems. The durations in the reality of manufacturing are often imprecise and the imprecision in data is very critical for the scheduling procedures. Therefore, the fuzzy approach, in the framework of the Dempster-Shafer theory, commands attention. The fuzzy numbers are considered as sets of possible probabilistic distributions. After a review of some...

This paper presents the fuzzy mixed-integer goal programming model for a single machine scheduling problem with bi-objectives consisting of the minimization of the total weighted flow time and total weighted tardiness. This model is solved by a fuzzy goal programming approach to verify and validate the proposed approach for the above problem. Two test problems in small and large sizes are gener...