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Browsing by Issue Date, starting with "2022-06-18"

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  • Sectorization of a Parcel Delivery Service
    Publication . Mostardinha, Mafalda; Escobar Hernández, Pablo; Lopes, Isabel Cristina; Rodrigues, Ana Maria
    This paper explores the problem of sectorization of a parcel delivery service that wants to assign an action region to each of its teams, regarding the number of deliveries scheduled for each zone, so that there is a balanced service amongst sectors, covering contiguous zones, and considering limited capacities for the teams. Besides being relatively easy to model, the available optimization tools and software provide poor results when dimension increases in these types of problems, with computational capacity exceeding. In this paper an integer programming model, combined with an heuristic to return a faster solution, was implemented to solve a sectorization problem in two different situations. The main advantage of the strategy proposed, compared to previous ones, is its simplicity and easy implementation while still returning an optimal solution.
    2022-06-18Journal article Restricted access Show more
  • Beneficiaries of Social Disability Pension in Small Municipalities in the Northern Region of Portugal: Application of Cluster Analysis in the Identification of Potential Causes
    Publication . Torres, Cristina; Vieira, Isabel; Lopes, Isabel Cristina; Monteiro, Rui; Ferreira, Carla; Bem-Haja, Inês
    This study is focused on the northern region of Portugal and addresses the number of road accidents with casualties and the number of beneficiaries of the social disability pension. Municipalities with low population density are mostly located in the hinterland. The phenomenon of population aging entails the problem of people who are unable to work and become beneficiaries of the social disability pension. The hierarchical clustering method applied in this paper characterizes 46 municipalities in northern Portugal with a population of less than 20,000 inhabitants – designated small – according to economic activity, rate of road accidents with casualties and disability pensioners. These municipalities were divided into two homogeneous groups or clusters. It was possible to identify that Cluster 1 comprises the innermost municipalities featuring few road accidents with casualties, not many disability pensioners, and a small number of companies compared to Cluster 2. This study can contribute to helping local governments’ decision-making process to improve the economic activity, reduce the region’s human desertification, and improve municipal road conditions.
    2022-06-18Journal article Restricted access Show more