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Numerical analysis of a tunnel behaviour considering the spatial variability of...

Miranda, Tiago F. S.; Viana, Ana; Martins, Francisco F.; Guo, Xiangfeng; Cristelo, Nuno; Dias, Daniel

This study applies random field theory to simulate the spatial variability of the ground where a tunnel was excavated in a granitic soil mass, in the city of Porto (Portugal). Numerical analyses are performed using finite element method combined with random field theory to simulate tunnel excavation. A parametric study to analyse the influence of the correlation coefficient is performed. The results are compare...


2-echelon lastmile delivery with lockers and occasional couriers

Santos, André Gustavo dos; Viana, Ana; Pedroso, João Pedro

We propose a new approach for the lastmile delivery problem where, besides serving as collecting points of orders for customers, parcel lockers are also used as transshipment nodes in a 2-echelon delivery system. Moreover, we consider that a customer (occasional courier) visiting a locker may accept a compensation to make a delivery to another customer on their regular traveling path. The proposed shared use of...


The probabilistic travelling salesman problem with crowdsourcing

Santini, Alberto; Viana, Ana; Klimentova, Xenia; Pedroso, João Pedro

We study a variant of the Probabilistic Travelling Salesman Problem arising when retailers crowdsource last-mile deliveries to their own customers, who can refuse or accept in exchange for a reward. A planner must identify which deliveries to offer, knowing that all deliveries need fulfilment, either via crowdsourcing or using the retailer’s own vehicle. We formalise the problem and position it in both the lite...


Influence of seasonality on the quality of oysters from the Sado and Mira rivers

Ferro Palma, Silvina; João Carvalho, Maria; Costa, Manuela; Floro, António; Viana, Ana; Gonçalves Fidalgo, Liliana; Rodrigues, C.; Mata, A.; Salgado, R.

There is a lack of knowledge about the influence of seasonality on the microbial and physicochemical quality of oysters in Sado and Mira rivers. Water, sediment, and oysters (Crassostrea angulata and Crassostrea gigas) were collected for microbiological, nutritional, and sensory analyses. The microbiological water quality and the oyster shell contamination were better during the warmer months. No seasonal effec...


Proof-of-Concept Study of Multifunctional Hybrid Nanoparticle System Combined w...

Lopes, Joana; Ferreira-Gonçalves, Tânia; Figueiredo, Isabel; Rodrigues, Cecília; Ferreira, Hugo; Ferreira, David; Viana, Ana; Faísca, Pedro

Abstract: The global impact of cancer emphasizes the importance of developing innovative, effective and minimally invasive therapies. In the context of superficial cancers, the development of a multifunctional nanoparticle-based system and its in vitro and in vivo safety and efficacy characterization are, herein, proposed as a proof-of-concept. This multifunctional system consists of gold nanoparticles coated w...


Probing for maximizing the expected number of transplants

Alvelos, Filipe Pereira e; Viana, Ana; Klimentova, Xenia

Kidney exchange programs rely on the exchange of donors between patients having an in compatible willing donor. In this paper, we address two problems of deciding which potential transplants to probe for maximizing the expected number of transplants. For both of them each potential transplant has a probability of failure and a set of crossmatch tests can be made (removing the uncertainty of the potential transp...


Maximizing the expected number of transplants in kidney exchange programs with ...

Alvelos, Filipe Pereira e; Klimentova, Xenia; Viana, Ana

In this paper, we propose a branch-and-price approach for solving the problem of maximizing the expected number of transplants in Kidney Exchange Programs (KEPs). In these programs, the decision on which transplants will be conducted is usually made with the support of optimization models with the assumption that all operations will take place. However, after a plan of transplants is defined, a pair may leave t...


Preface to the Special Issue on Improving Healthcare: New Challenges, New Appro...

Dias, Joana Maria Pina Cabral Matos; Rocha, Humberto; Viana, Ana


Co and (Co,Mo) doping effects on the properties of highly reduced TiO2 anatase ...

Silvestre, António Jorge; Rout, S.; Dalui, S.; Pereira, Laura; Viana, Ana; Conde, Olinda

This work reports on the structural, optical, electrical and magnetic properties of Co:TiO2 and (Co,Mo):TiO2 anatase thin films grown onto (0001) sapphire substrates by Pulsed Laser Deposition in highly reducing conditions and at a low temperature of 350 _C. Undoped TiO2_d as well as doped films with nominal compositions of Ti0.95Co0.05O2_d, Ti0.94Co0.05Mo0.01O2_d, and Ti0.92Co0.05Mo0.03O2_d were studied. They ...


Maximising expectation of the number of transplants in kidney exchange programmes

Klimentova, Xenia; Pedroso, João Pedro; Viana, Ana

This paper addresses the problem of maximising the expected number of transplants in kidney exchange programmes. New schemes for matching rearrangement in case of failure are presented, along with a new tree search algorithm used for the computation of optimal expected values. Extensive computa-tional experiments demonstrate the effectiveness of the algorithm and reveal a clear superiority of a newly proposed s...


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