2019
Autores
Ana Torres; Catarina Delgado; Eduardo Leite;
Publicação
Abstract
2019
Autores
Ana Torres; Catarina Delgado; Carolina Mustur;
Publicação
Abstract
2019
Autores
Cerqueira, V;
Publicação
Abstract
2019
Autores
Souto, T; Alves, H; Conde, AR; Pinto, L; Ribeiro, Ó;
Publicação
Journal of Psychology & Clinical Psychiatry
Abstract
2019
Autores
Enes, T; Lousada, J; Aranha, J; Cerveira, A; Alegria, C; Fonseca, T;
Publicação
FORESTS
Abstract
Research Highlights: This study bridges a gap of knowledge about the maximum size-density trajectory for juvenile stands of maritime pine. The continuity of the trajectory along the development stages to maturity is assured with a straightforward approach providing support to determine optimum density along all the revolution periods for the species. Background and Objectives: Forest fire is a significant threat to forests in the Mediterranean regions, but also a natural disturbance that plays a vital role in the perpetuation of forest stands. In recent decades, there has been an increase of burnt area in maritime forests in Portugal, followed by an increased interest in managing the natural and usually abundant regeneration occurring after the fires. The gap in the knowledge of growth dynamics for juvenile stages, for these forest systems, currently constrains their correct management, for forest planning, particularly in determining the optimal densities. The study aims to identify the maximum attainable density trajectory at the early stages of development of the species that could support a non-empirical definition of silvicultural prescriptions and thinning decisions, along the revolution. Materials and Methods: A representative data set collected in stands regenerated after fire supports the analysis of the maximum size-density trajectory for the species. Results: The maximum size-density trajectory for the juvenile stands deviates from the expected trajectory defined in the self-thinning line published for the species. Significant deviation occurs at the lower end of the line, indicating the need for a reevaluation of the existing self-thinning line. We propose a new self-thinning model for the species that explicitly considers the behavior of size-density for juvenile stands. The new model assures a logical continuity for the trajectory from the young stages of development to maturity. Conclusions: The proposed model based on the maximum attainable size-density trajectory provides ecological-based support to define silvicultural guidelines for management of the species.
2019
Autores
Agra, A; Cerveira, A; Requejo, C;
Publicação
Lecture Notes in Logistics
Abstract
A multi-item inventory distribution problem motivated by a practical case study occurring in the logistic operations of a hospital is considered. There, a single warehouse supplies several nursing wards. The distribution of medical products is done by two different teams of workers using a heterogeneous fleet, that is, the available vehicles have different capacities and different structures required to be used in specific nursing wards. The goal is to define a weekly distribution plan of medical products ensuring a balanced workload of both working teams and satisfying all the required constraints (inventory capacities, safety stock levels, vehicle capacities, etc.) that minimizes the total number of visits to locations. A mixed integer formulation is presented and several improvements are discussed. This is a NP-hard problem hardly solved to optimality within a reasonable amount of time, and more so for real size instances, with hundreds to few thousand of products. To circumvent this issue, a matheuristic is proposed to solve the problem. Finally, computational tests are reported and discussed. © 2019, Springer Nature Switzerland AG.
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