Journées de l'optimisation 2018

HEC Montréal, Québec, Canada, 7 — 9 mai 2018

Horaire Auteurs Mon horaire

MA2 OR/MS scientific writing activity – Best presentation competition

7 mai 2018 10h30 – 12h10

Salle: Banque Scotia (69)

Présidée par Marilène Cherkesly

4 présentations

  • 10h30 - 10h55

    A model strengthening for solving an off-road transportation problem under steep-slope terrains

    • Sattar Ezzati, prés., Postdoctoral
    • Ljusk Ola Eriksson, SLU, Sweden

    The planning of off-road transportation network to allow logging systems to harvested sites is a challenging task. To address this problem, a mixed-integer programming model is developed to handle these decisions at the operational level. The model solved by introduced a set of valid inequalities in to the original model.

  • 10h55 - 11h20

    A mathematical model for mobile clinic site evaluation in war zones

    • Rosemarie Santa González, prés., UQÀM

    When the United States withdraw its troops from Iraq, the Islamic State in Iraq and Levant, also
    known as ISIS or IS, took advantage of the debilitated position of Iraq’s government to seize and control
    civilians and territory (BBC News Website) turning Iraq into a war zone. One of the side effects of this is that
    citizens have limited access to healthcare; thus, various non-governmental organizations (NGOs) are
    providing humanitarian relief to the population affected by the war. Currently, the Première Urgence
    Internationale (PUI), an international French NGO foresees mobile clinics operations in Iraq. Mobile clinics
    are employed to serve as a temporary solution. These are vehicles in which healthcare practitioners and
    equipment travel to populations in need. These vehicles are often modified to provide health services from
    within them. Yet, before deploying a mobile clinic to a war zone, the potential locations must be evaluated to
    ensure that there is a need for the allocation of a mobile clinic and most importantly that the medical
    personnel and equipment are not exposed to extreme conditions that would hinder the services. This study
    seeks to provide a mathematical model to aid in the evaluation of potential sites for mobile clinics in Iraq. To
    identify common practices and guidelines of mobile clinic operations, official documentation from the
    International Federation of the Red Cross and Red Crescent Societies (IFRC) and World Health Organization
    (WHO) were studied. Additionally, a literature review is conducted to identify relevant studies that employed
    tools from operations management and operations research that could be applied to the problem at hand. In
    this study, mathematical model will be proposed to provide PUI a schedule of the visits to potential sites. The
    model will consider the estimated population in need, the war status of the zone, and the authorization to
    access the zones. The main objective of the mathematical model is to minimize the costs incurred during the
    visits of potential sites. As part of the collaboration between the researchers and PUI this model will be
    implemented and further improved for mobile clinic operations in Iraq. Furthermore, the researchers will
    continue to work with PUI to develop decision making tools for humanitarian operations in war zones.

  • 11h20 - 11h45

    A robust optimization model for tactical capacity planning in an outpatient setting

    • Nazanin Aslani, prés.,
    • Terekhov Daria, Concordia University

    Tactical capacity planning (TCP) is essential for addressing physician scarcity and long access times. TCP provides decisions for allocation of clinic’s resources to schedule appointments. We proposes an optimal robust TCP based on cardinality constrained method which deals with demand uncertainty, multiple appointment types and access time targets.

  • 11h45 - 12h10

    Optimization of railway transportation: Hazmat and regular commodities

    • Bahman Bornay, prés., Concordia University
    • Mingyuan Chen,
    • Satyaveer S. Chauhan, Concordia University

    Transportation of dangerous goods (TDG) has been receiving more attention in the realm of academic and scientific research during the last few decades as countries have been increasingly becoming industrialized throughout the world, thereby making Hazmats an integral part of our life style. Considering the low-probability-and-high-consequence (LPHC) essence of transportation of Hazmats, on the one hand, and immense volume of shipments accounting for more than hundred tons in North America and Europe, on the other, we can safely state that the number of scholarly articles and dissertations have not been proportional to the significance of the subject of interest. In consonance with the abovementioned motivation, we are focusing on railway transportation of both Hazmats and regular commodities. Yards and tracks are the constituents of our network. Orders are made at various nodes and shipped towards their destination yards. The interests of both carrier companies and authorities, which is the minimization of cost and risk, respectively, have been considered; hence, both transportation cost and population exposure terms have been incorporated into the objective function. We made use of a mathematical air dispersion model, vis à vis Gaussian Plume Model (GPM), to compute the radius of evacuation distance from potential incident spots, either on rail segments or yards of the underlying network. Since the incorporated risk evaluation measure which minimizes the population exposure, was a nonlinear concave down function, then the link-based multicommodity, multiorder multiobjective MINLP model was piecewise linearized, thereby reducing to a MILP model, variants of which are also included with bifurcated and nonbifurcated flows. Moreover, under various scenarios w.r.t. the risk adversity/proneness of decision maker, a set of nondominated Pareto-optimal paths for each traffic class have been found while experimenting on a network from literature.