This paper aims to study the locomotive assignment problem which is very important for railway companies, in view of high cost of operating locomotives. This problem is to determine the minimum cost assignment of homogeneous locomotives located in some central depots to a set of pre-scheduled trains in order to provide sufficient power to pull the trains from their origins to their destinations...

This paper presents using policy tree and estimation of distribution algorithms (EDAs) to solve resource-constrained project scheduling problem (RCPSP) with considering rework with probability. Firstly, the algorithm adopts policy tree to model the project scheduling problem, which contains decision variables, stochastic variables and precedence relations, trying to make proactive scheduling an...

We define a language RS , a subclass of the scheduling language RSV (resource constrained project scheduling with variant processes). RS involves the determination of the starting times for ground activities of a project satisfying precedence and resource constraints, in order to minimize the total project duration. In RS ground activities and two structural symbols (operators) ‘seq’ and ‘pll’ ...

We present new results concerning the problem of nding a constrained pattern in a set of 2-intervals. Given a set of n 2-intervals D and a model R describing if two disjoint 2-intervals can be in precedence order (<), be allowed to nest (@) and/or be allowed to cross (G), the problem asks to nd a maximum cardinality subset D′ ⊆ D such that any two 2-intervals in D′ agree with R. We improve the ...

4. Weighted sum of completion times 1 Eugene L. Lawler, Maurice Queyranne, Andreas S. Schulz, David B. Shmoys 4.1. Smith’s ratio rule 2 4.2. Preference orders on jobs 5 4.3. Preference orders on sequences and series-parallel precedence constraints 8 4.4. NP-hardness of further constrained min-sum problems 14 4.5. The ratio rule via linear programming 18 4.6. Approximation algorithms for 1|prec|...

This paper reports on a new solution approach for the well-known multi-mode resource-constrained project scheduling problem (MMRCPSP). This problem type aims at the selection of a single activity mode from a set of available modes in order to construct a precedence and a (renewable and non-renewable) resource feasible project schedule with a minimal makespan. The problem type is known to be NPh...

We consider the scheduling problem of minimizing the average weighted job completion time on a single machine under precedence constraints. We show that this problem with arbitrary job weights, the special case of the problem where all job weights are one, and several other special cases of the problem all have the same approximability threshold with respect to polynomial time approximation alg...

The production of civil aircrafts is confronted with a significant demand for the interconnectivity resources among distributed factories, while complex coupling relationships various might restrict improvement efficiency. Therefore, researching scheduling methods aircraft necessary, but previous studies have not taken material inventory into account sufficiently. This article proposes method t...

This paper describes a specification-based regression testing technique that can be applied for revalidating concurrent programs after specification changes. This kind of regression testing technique requires sequencing constraints which specify the precedence relations among synchronization events. In our method, the sequencing constraints are extracted automatically from Message Sequence Char...

Local search techniques like simulated annealing and tabu search are based on a neighborhood structure defined on the set of feasible solutions of a discrete optimization problem. For the scheduling problems Pm )I C,,,,, 1 1 prec 1 1 Ui, and a large class of sequencing problems with precedence constraints having local interchange properties we replace a simple neighborhood by a neighborhood on ...