On Not-First/Not-Last conditions in disjunctive scheduling

On the Disjunctive Graph for Project Scheduling

An extension of the Disjunctive Model, eeciently representing Jobshop Scheduling (JS) problem, to more general Resource-Constrained Project Scheduling (RCPS) problem is proposed. The extension considers diierent groups of resources used by activities in diierent amounts limited to a constant value in every moment of the project duration. A solution to the problem is represented by a project res...

MDD Propagation for Disjunctive Scheduling

Disjunctive scheduling is the problem of scheduling activities that must not overlap in time. Constraint-based techniques, such as edge finding and not-first/not-last rules, have been a key element in successfully tackling large and complex disjunctive scheduling problems in recent years. In this work we investigate new propagation methods based on limited-width Multivalued Decision Diagrams (M...

Job Shop Scheduling via Disjunctive Boolean Formulas

Two Clause Learning Approaches for Disjunctive Scheduling

We revisit the standard hybrid CP/SAT approach for solving disjunctive scheduling problems. Previous methods entail the creation of redundant clauses when lazily generating atoms standing for bounds modifications. We first describe an alternative method for handling lazily generated atoms without computational overhead. Next, we propose a novel conflict analysis scheme tailored for disjunctive ...

Last but not least

Our eyes move in a continual stream of very rapid saccadic rotations, punctuated by brief periods of stationary fixation that typically last for about one third of a second. We are usually unaware of these movements, and indeed we cannot observe our own saccadic eye movements however hard we try. Here we employ a familiar principle to allow us to catch a glimpse for the first time of our own ey...