Browsing by Subject "MILP"

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Access status: Open Access ,
A MILP model for the municipal solid waste selective collection routing problem
(AGH University of Science and Technology Press, 2019) Korcyl, Antoni; Książek, Roger; Gdowska, Katarzyna
Nowadays, selective solid waste management in the European Union belongs to important responsibilities of municipalities. In Solid Waste Management (SWM) the main operational task is to set a schedule for solid waste collection and to find optimal routes for garbage trucks, so that the total costs of the solid waste collection service can be minimized, subject to a series of constraints which not only guarantee the fulfillment of the SWM's obligations but also ensure the desirable quality level of that service. The optimization in garbage truck routing belongs to so called rich Vehicle Routing Problems as it aims to cover the following constraints: pickup nodes (clients) must be visited during their predefined time windows, the number and capacity of depots and specialized sorting units cannot be exceeded, each garbage truck can be assigned to at most one depot, each route should be dedicated to collecting one type of segregated solid waste, and the route must be served by a garbage truck which can collect that type of solid waste, the availability of garbage trucks and their drivers must be respected, each garbage truck must be drained at a specialized sorting unit before going back to the depot. This paper contributes a newly developed Mixed-Integer Programming (MIP) model for the Municipal Solid Waste Selective Collection Routing Problem (MSWSCRP) with time windows, limited heterogeneous fleet, and different types of segregated solid waste to be collected separately. Results obtained for solving small-sized instance of the MSWSCRP are reported.
Access status: Open Access ,
The effect of environmental criteria on locating a biorefinery: a green facility location problem
(AGH University of Science and Technology Press, 2017) Serrano-Hernández, Adrián; Faulin, Javier; Belloso, Javier; Sawik, Bartosz
Underestimating facility location decisions may penalize business performance over the time. These penalties have usually been studied from the economic point of view, analyzing its impact on profitability. Additionally, the concern about obtaining sustainability is gaining importance, leading to a search for renewable energy sources to reduce greenhouse gas emissions. However, little attention has been paid to choosing a location considering environmental criteria. Thus, this work aims at determining a biorefinery location considering its impacts on natural resources. Therefore, a mixed integer linear programming (MILP) model has been developed, taking into account crop location and biomass production seasonality to obtain a proper location that minimizes environmental impact. The initial version of this paper was presented at the ICIL Conference in 2016.