Impact- and Cost-Oriented Propagator Scheduling for Faster Constraint Propagation
نویسندگان
چکیده
Constraint Propagation can be speeded up significantly by choosing a good execution order for propagators. A propagator is an implicit representation of a constraint which is widely used in todays powerful constraint solvers. In this paper we evaluate different ways to find good execution orders automatically during runtime. We extend previous work in this area by two new techniques: fair-scheduling and impact-oriented prioritization of propagators.
منابع مشابه
Multi-objective scheduling and assembly line balancing with resource constraint and cost uncertainty: A “box” set robust optimization
Assembly lines are flow-oriented production systems that are of great importance in the industrial production of standard, high-volume products and even more recently, they have become commonplace in producing low-volume custom products. The main goal of designers of these lines is to increase the efficiency of the system and therefore, the assembly line balancing to achieve an optimal system i...
متن کاملExplaining Time-Table-Edge-Finding Propagation for the Cumulative Resource Constraint
Cumulative resource constraints can model scarce resources in scheduling problems or a dimension in packing and cutting problems. In order to efficiently solve such problems with a constraint programming solver, it is important to have strong and fast propagators for cumulative resource constraints. Time-table-edge-finding propagators are a recent development in cumulative propagators, that com...
متن کاملThe AllDifferent Constraint with Precedences
We propose ALLDIFFPREC, a new global constraint that combines together an ALLDIFFERENT constraint with precedence constraints that strictly order given pairs of variables. We identify a number of applications for this global constraint including instruction scheduling and symmetry breaking. We give an efficient propagation algorithm that enforces bounds consistency on this global constraint. We...
متن کاملAdvisors for Incremental Propagation
While incremental propagation for global constraints is recognized to be important, little research has been devoted to how propagator-centered constraint programming systems should support incremental propagation. This paper introduces advisors as a simple and efficient, yet widely applicable method for supporting incremental propagation in a propagator-centered setting. The paper presents how...
متن کاملA Domain Consistency Algorithm for the Stretch Constraint
The stretch constraint occurs in many rostering problems that arise in the industrial and public service sectors. In this paper we present an efficient algorithm for domain consistency propagation of the stretch constraint. Using benchmark and random instances, we show that this stronger consistency sometimes enables our propagator to solve more difficult problems than a previously proposed pro...
متن کامل