当前位置: X-MOL 学术J. Sched. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
An Efficient Filtering Algorithm for the Unary Resource Constraint with Transition Times and Optional Activities
Journal of Scheduling ( IF 2 ) Pub Date : 2020-02-15 , DOI: 10.1007/s10951-019-00632-8
Sascha Van Cauwelaert , Cyrille Dejemeppe , Pierre Schaus

This paper describes a unified global constraint to model scheduling problems with unary resources, i.e., each resource can process only a single activity at a time. In addition, the constraint enforces sequence-dependent transition times between activities. It often happens that activities are grouped into families with zero transition times within a family. Moreover, some of the activities might be optional from the resource viewpoint (typically in the case of alternative resources). The global constraint unifies reasoning with both optional activities and families of activities. The scalable filtering algorithms we discuss keep a low time complexity of $$\mathcal {O}(n \cdot \log (n) \cdot \log (f))$$ O ( n · log ( n ) · log ( f ) ) , where n is the number of tasks on the resource and f is the number of families. This results from the fact that we extend the $$\varTheta $$ Θ -tree data structure used for the Unary Resource constraint without transition times. Our experiments demonstrate that our global constraint strengthens the pruning of domains as compared with existing approaches, leading to important speedups. Moreover, our low time complexity allows maintaining a small overhead, even for large instances. These conclusions are particularly true when optional activities are present in the problem.

中文翻译:

具有转换时间和可选活动的一元资源约束的高效过滤算法

本文描述了一个统一的全局约束来模拟一元资源的调度问题,即每个资源一次只能处理一个活动。此外,该约束强制执行活动之间依赖于序列的转换时间。经常发生的情况是,活动被分组到家庭中,家庭内的过渡时间为零。此外,从资源的角度来看,某些活动可能是可选的(通常是在替代资源的情况下)。全局约束将推理与可选活动和活动系列统一起来。我们讨论的可扩展过滤算法保持低时间复杂度 $$\mathcal {O}(n \cdot \log (n) \cdot \log (f))$$ O ( n · log ( n ) · log ( f ) ) ,其中 n 是资源上的任务数,f 是族数。这是因为我们扩展了用于一元资源约束的 $$\varTheta $$ Θ -tree 数据结构而没有转换时间。我们的实验表明,与现有方法相比,我们的全局约束加强了域的修剪,从而带来了重要的加速。此外,我们的低时间复杂度允许维持较小的开销,即使对于大型实例也是如此。当问题中存在可选活动时,这些结论尤其正确。即使对于大型实例。当问题中存在可选活动时,这些结论尤其正确。即使对于大型实例。当问题中存在可选活动时,这些结论尤其正确。
更新日期:2020-02-15
down
wechat
bug