The Gale-Hoffman inequalities characterize feasible external flow in a (capacitated) network. Among these inequalities, those that are redundant can be identified through a simple arc-connectedness criterion.

This paper proposes a variable neighborhood descent for solving a capacitated arc routing problem with time-dependent service costs. The problem is motivated by winter gritting applications where the timing of each intervention is crucial. The variable neighborhood descent is based on neighborhood structures that manipulate arcs or sequences of arcs. Computational results are reported on proble...

I this paper we extend forecast band evolution and capacitated production modelling to the multiperiod demand case. In this model, forecasts of discrete demand for any period are modelled as bands and defined by lower and upper bounds on demand, such that future forecasts lie within the current band. We develop heuristics that utilize knowledge of demand forecast evolution to make production de...

Facility-location problems have several applications in telecommunications, industrial transportation and distribution, etc. One of the most well-known facility-location problems is the p-median problem. This work addresses an application of the capacitated p-median problem to a real-world problem. We propose a genetic algorithm (GA) to solve the capacitated pmedian problem. The proposed GA use...

Multi-item capacitated lot-sizing problems are reformulated using a class of valid inequalities, which are facets for the single-item uncapacitated problem. Computational results using this reformulation are reported, and problems vnth up to 20 items and 13 periods have been solved to optimality using a commercial mixed integer code. We also show how the valid inequalities can easily be generat...

Tubulin is a protein constituent of cytoskeletal microtubules, closely related to sperm motility. However, the changes in tubulin distribution following capacitation and acrosome reaction are poorly understood. This study immunolocalized and quantified the expression of α-tubulin in fresh, capacitated and acrosome-reacted samples. Immunocytochemical data showed that in capacitated and acrosome-...

This abstract describes a branch, cut, and price (BCP) algorithm for the solution of a class of network design problems with routing and packing constraints that can all be seen as special cases of a general model we will call the Capacitated Node Routing Problem (CNRP). We present several alternative integer programming formulation of the CNRP that can be shown to generalize a number of other ...

We give a polynomial time approximation scheme (PTAS) for the unit demand capacitated vehicle routing problem (CVRP) on trees, entire range of tour capacity. The result extends to splittable CVRP.

Corrected Miller–Tucker–Zemlin type subtour elimination constraints for the capacitated vehicle routing problem are presented. 2003 Elsevier B.V. All rights reserved.

Delay management is an important issue in the daily operations of any railway company. The task is to update the planned timetable to a disposition timetable in such a way that the inconvenience for the passengers is as small as possible. The two main decisions that have to be made in this respect are the wait-depart decisions to decide which connections should be maintained in case of delays a...