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DIST Department of information sciences and technologies

A seminar titled "Variable neighborhood search for a vehicle scheduling problem in agriculture" will be presented by Zorica Stanimirović on Monday, 11 April 2018 at 16.00 at the Faculty of Mathematics, Natural Sciences and Information Technologies of the University of Primorska.


TIME/PLACE: April 11th at 16:00 in FAMNIT-1-VP

LECTURER: Zorica Stanimirović, izredna profesorica z
          Oddelka za numerično matematiko in optimizacijo na
          Fakulteti za matematiko Univerze v Beogradu.

TITLE: Variable neighborhood search for a vehicle scheduling problem in agriculture

A Vehicle Scheduling Problem (VSP) that arises from sugar beet transportation within minimum working time under the set of constrains reflecting a real-life situation is considered. The problem is first modelled as Mixed Integer Quadratically Constrained Program (MIQCP) and then reformulated to Mixed Integer Linear Program (MILP). MILP formulation was used within the framework of Lingo 17 solver, producing optimal solutions only for small-size problem instances. Two variants of Variable Neighborhood Search metaheuristic - Basic VNS (BVNS) and Skewed VNS (SVNS) are designed to efficiently deal with large size problem instances. The proposed VNS approaches are evaluated and compared against Lingo 17 and each other on the set of real-life and generated problem instances. Both BVNS and SVNS reach all known optimal solutions on small-size instances and show similar performance on medium and large size instances regarding solution quality. In general, SVNS significantly outperforms BVNS in the sense of running times.

The content presented on the seminar is joint work with Ana ANOKIĆ, Tatjana DAVIDOVIĆ and Đorđe STAKIĆ.