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  • Project MELOGIC- Pilot Testing- Teruel Spain
    Snapshots from the MELOGIC exercise (evacuation of population and supply of goods) that was executed in Teruel, Spain on Thursday the 29th of September 2016. The Regional channel (TVE) covered also the MELOGIC  exercise with an extended video. 

    For further details on the MELOGIC project please visit the following website

    Post date: Tuesday, October 4, 2016 - 13:54
  • Project MELOGIC- The MELOGIC disaster relief exercise was presented in the local newspaper_Teruel Spain

    The MELOGIC disaster relief exercise (evacuation of population and supply of goods) was presented in the local newspaper "Diario de Teruel" on Friday the 30th of September. Various snapshots from the Command Center as well as from the Shelter for the evacuees are presented and described. For further details on the MELOGIC project please visit the following website 

    Post date: Tuesday, October 4, 2016 - 13:28
  • Solving the Bus Evacuation Problem and its Variants

    Dikas, G. and Minis, I.

    Computers and Operations Research, vol. 70, 2016, pp 75-86.


    In this paper we address the problem of transporting passengers from their origins to multiple gathering centers. We consider two interesting and related cases of this transportation problem: (a) the case of evacuation in anticipation of major natural threats, and (b) the case of transporting casualties after an emergency or terrorist incident, or from a battlefield. Both problem cases share common characteristics and restrictions, i.e. limited available vehicles and limited capacity of the collection/gathering centers, but differ in terms of objectives and the scale of demand. To address the evacuation problem and its variants we have proposed two-index, mixed integer, linear formulations, and we have developed a Hybrid Solution Framework. Extensive experimental results indicate that for both cases the proposed framework provides efficient solutions in reasonable computational times.

    Keywords: Hybrid solution framework. Column generation. Bus evacuation problem. Casualty Evacuation Problem.
    Post date: Thursday, June 9, 2016 - 08:42
  • The Team Orienteering Pick-Up and Delivery Problem with Time Windows and its applications in fleet sizing

    Baglagis, D.G., Dikas, G. and Minis, I. 

    RAIRO- Operations Research, v. 50, n.3, 2016, pp 503-517.


    In this paper we consider the problem of prioritized pick-up and delivery operations under resource constraints. Our proposed formulation combines the Team Orienteering Problem with the case of Pick-up and Delivery with Time Windows and Capacity Constraints. We solved this model to optimality using an exact Branch-and-Price method, which is based on previous work. To study the performance of the solution method and its refinements, we conducted extensive computational experiments. We also applied the proposed model and method to a relevant logistic system and investigated its performance under various conditions. Finally, we present a practical method to determine the most suitable fleet configuration for a pick-up and delivery system that delivers prioritized operations to a known client base.

    Key words: Pick-up and delivery problem / Team orienteering problem / Branch and Price / Vehicle Fleet Sizing

    Post date: Thursday, June 9, 2016 - 08:36
  • Single Vehicle Routing with Predefined Client Sequence and Multiple Warehouse Returns: The Case of Two Warehouses

    Dikas, G., Minis, I. and Mamassis, K.

    Central European Journal of Operations Research, 2015, pp 1-22.


    We examine three interesting cases of the single vehicle routing problem with a predefined client sequence and two load replenishment warehouses. Given the location and demand of the clients, we seek the minimal cost route, which includes optimal load replenishment visits to the warehouses in order to fully satisfy the client demand. The cases studied vary with respect to inventory availability at each warehouse and are of increasing complexity. We have developed solution algorithms that address this complexity, ranging from a standard dynamic programming algorithm for the simplest case, to labeling algorithms and a new partitioning heuristic. The efficiency of these algorithms has been studied by solving a wide range of problem instances, and by comparing the results with those obtained from a state-of-the-art MILP solver.

    Keywords: Single vehicle routing·Multiple warehouse routing problems·Dynamic programming for the VRP·Labeling algorithms for the VRP
    Post date: Thursday, June 9, 2016 - 08:31