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2016
Pereira, Rui, Marco Couto, João Saraiva, Jácome Cunha, and João P. Fernandes. "The Influence of the Java Collection Framework on Overall Energy Consumption." 5th International Workshop on Green and Sustainable Software (ICSE 2016). 2016. –. Abstractgreens.pdf

This paper presents a detailed study of the energy consumption of the different Java Collection Framework (JFC) implementations. For each method of an implementation in this framework, we present its energy consumption when handling different amounts of data. Knowing the greenest methods for each implementation, we present an energy optimization approach for Java programs: based on calls to JFC methods in the source code of a program, we select the greenest implementation. Finally, we present preliminary results of optimizing a set of Java programs where we obtained 6.2% energy savings.

Chastre, Carlos, Hugo Biscaia, Noel Franco, and António Monteiro. "Experimental Analysis of Reinforced Concrete Beams Strengthened with Innovative Techniques." 41th IAHS Word Congress of Housing. Sustainability and Innovation for the Future. Albufeira, Portugal 2016. 10. Abstract41_iahs_2016_-_carlos_chastre-ext-abstract.pdf

The strengthening of reinforced concrete structures with FRP materials has received a considerable increment in recent years due to their durability characteristics, high strength-weight and stiffness-weight ratios of FRP compared to other materials.An experimental program was conducted in order to analyse the behaviour of different structural solutions to strengthen reinforced concrete beams with carbon FRP composites: EBR (Externally-Bonded Reinforcement), NSM (Near Surface Mounted) reinforcement and an innovative technique externally-bonded using continuous reinforcement embedded at ends (CREatE). The RC beams had a 3m span by 0.3m height and were tested until rupture in a 4-point bending test system.The CREatE technique has proved to be the most effective of the three alternatives tested, with the full utilisation of the CFRP and the highest strength, combined with the highest ductility.

Biscaia, Hugo, Carlos Chastre, David Cruz, and Noel Franco. "A New Bonding Technique for the Rehabilitation of Old Timber Floors with CFRP Composites." 41th IAHS Word Congress of Housing. Sustainability and Innovation for the Future. Albufeira, Portugal 2016. 10. Abstract41_iahs_2016_-_hugo_biscaia_-_ext-abstract.pdf

Despite the number of applications with Carbon Fiber Reinforced Polymers (CFRP) have been grown in civil constructions, the studies available in the literature dedicated to the strengthening of old timber beams are very rare. This paper analyses the bending behaviour of old suspended timber floors flexurally-strengthened with CFRP laminates. A new bonding technique developed by the authors is presented which mainly consists on the embedding of both CFRP ends into the core of the timber beams. Differences between the traditional strengthening, i.e. Externally Bonded Reinforcement (EBR), and the new bonding technique are reported. A timber pavement without any CFRP laminate bonded to its soffit was also considered and the results were used as reference values for comparison with the strengthened specimens. The results revealed that the CFRP laminate used for the flexurally-strengthened of the specimen according to the EBR technique reached only 27.2% of the rupture strain of the CFRP laminate whereas the new bonding technique was capable to prevent the premature debonding of the CFRP from the timber substrate and the rupture of the CFRP laminate was observed. Furthermore, the strain distributions in the CFRP laminates and the bond stresses within the CFRP-to-timber interfaces were affected when the new technique was used. For the sake of better understanding the rupture modes observed, a numerical approach was developed which allowed us to conclude that, until the collapse of the beams, the timber never reached its yielding point and the collapse were mainly due to the poor quality of the timber (e.g. quantity of knot, cracks and irregular geometries) and the low shear capacity of the beams.

Chastre, Carlos, Hugo Biscaia, and Noel Franco. "Reforço de Vigas de Betão Armado com Armaduras Pós-Instaladas de Aço ou de FRP." 10º Congresso de Mecânica Experimental (CNME 2016). LNEC, Lisbon, Portugal 2016. 12. Abstractcnme2016_paper_45_chastre.pdf

Apresentam-se e analisam-se um conjunto de ensaios realizados em vigas de betão armado reforçadas com armaduras pós-instaladas de aço ou de FRP, incluindo os referentes a uma nova técnica (CREatE) desenvolvida na FCT NOVA, tendo-se concluído que a técnica CREatE possibilita aumentos de resistência e ductilidade consideráveis face às técnicas tradicionais.

Klein, Hendrik, Jesper Milàn, Lars B. Clemmensen, Nicolaj Frobøse, Octávio Mateus, Nicole Klein, Jan S. Adolfssen, Eliza J. Estrup, and Oliver Wings. "Archosaur footprints (cf. Brachychirotherium) with unusual morphology from the Upper Triassic Fleming Fjord Formation (Norian–Rhaetian) of East Greenland." Geological Society, London, Special Publications. 434.1 (2016): 71-85. Abstractklein_et_al_2015_archosaur_footprints_cf._brachychirotherium_with_unusual.pdfWebsite

The Ørsted Dal Member of the Upper Triassic Fleming Fjord Formation in East Greenland is well known for its rich vertebrate fauna, represented by numerous specimens of both body and ichnofossils. In particular, the footprints of theropod dinosaurs have been described. Recently, an international expedition discovered several slabs with 100 small chirotheriid pes and manus imprints (pes length 4–4.5 cm) in siliciclastic deposits of this unit. They show strong similarities with Brachychirotherium, a characteristic Upper Triassic ichnogenus with a global distribution. A peculiar feature in the Fleming Fjord specimens is the lack of a fifth digit, even in more deeply impressed imprints. Therefore, the specimens are assigned here tentatively to cf. Brachychirotherium. Possibly, this characteristic is related to the extremely small size and early ontogenetic stage of the trackmaker. The record from Greenland is the first evidence of this morphotype from the Fleming Fjord Formation. Candidate trackmakers are crocodylian stem group archosaurs; however, a distinct correlation with known osteological taxa from this unit is not currently possible. While the occurrence of sauropodomorph plateosaurs in the bone record links the Greenland assemblage more closer to that from the Germanic Basin of central Europe, here the described footprints suggest a Pangaea-wide exchange.Supplementary material: Three-dimensional model of cf. Brachychirotherium pes–manus set (from MGUH 31233b) from the Upper Triassic Fleming Fjord Formation (Norian–Rhaetian) of East Greenland as pdf, ply and jpg files (3D model created by Oliver Wings; photographs taken by Jesper Milàn) is available at https://doi.org/10.6084/m9.figshare.c.2133546

Faias, Marta, Pedro Mota, Alberto Mulenga, and Joaquim P. Pina. "Asymmetry of ARCH effects and natural resources disease or virtue: Mozambique experience." AIP Conference Proceedings. 1738 (2016). AbstractWebsite

We study the exchange rate behavior, mainly as to the presence of asymmetry in the shocks to conditional variance. Particularly, we investigate if the presence of that asymmetric response is specific to a marked behavior of the currency, appreciation/Dutch disease/depreciation, and if it appears masked when taking long non-homogeneous periods. Taking Mozambique Metical bilateral exchange rate against South Africa Rand, a major trading partner, we identify specific movements in defined sub-periods, where the most recent has the Dutch disease under scrutiny. Our results point out that asymmetry emerges especially when the currency is depreciating, while it is masked when considering larger periods that combine differences in currency behavior.

Fernandes, M., Y. Vygranenko, M. Vieira, G. Lavareda, Nunes C. de Carvalho, and A. Amaral. "Automated rf-PERTE System for Room Temperature Deposition of TCO Coatings." Energy Procedia. 102 (2016): 96-101. Abstract

In this work we present a fully automated plasma-enhanced reactive thermal evaporation system (rf-PERTE) that can be used for the deposition of transparent metal oxide films without intentional heating of the substrate. The system and developed software enables the full control over critical deposition conditions such as mass flow of oxygen, process pressure, current flowing through crucible and rf-power. These parameters are automatically adjusted during the deposition thus keeping them in a narrow process window. This way, highly transparent and conductive coating can be deposited with a high degree of reproducibility of the optical and electrical characteristics. The resistivity of 9×10-4 Ω-cm and the peak transmittance of 90% in the visible spectral range were achieved for indium oxide films deposited on glass substrates. This technique is also suitable for the deposition of transparent conducting coatings in a wide range of plastic materials for flexible solar cells. In particular, we have successfully deposited indium oxide on PEN (polyethylene naphtalate) sheets with electrical and optical properties approaching the ones for films on glass.

Calvet, Laura, Albert Ferrer, Isabel M. Gomes, Angel A. Juan, and David Masip. "Combining statistical learning with metaheuristics for the multi-depot vehicle routing problem with market." Computers & Industrial Engineering. 94 (2016): 93-104. Abstract2016_calvetferrergomesjuanmasip.pdfWebsite

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Faustino, Pedro, and Carlos Chastre. "Damage Effect on Concrete Columns Confined with Carbon Composites." ACI Structural Journal. 113 (2016). AbstractWebsite

Five experimental cyclic tests were carried out on reinforced concrete rectangular columns with rounded corners, different condition (new and damaged) and different strengthening systems: that included confinement through carbon fiber (CFRP) jackets, anchor dowels, high strength repair mortar and external longitudinal stainless steel bars. Lateral load - displacement relationship, energy dissipation, ductility and curvature results were analyzed together with two different damage assessment classifications. The overall evaluation concludes that the use of external confinement with CFRP on RC columns is viable and of effective performance enhancement alone and combined with other techniques. Damaged columns that were retrofitted showed an increased load capacity up to 20% along with good ductile behavior within the limits of the US, European, Canadian and Japanese codes, with minor/moderate degree of damage at 1% drift ratio and moderate degree of damage at 2% drift ratio.

Fernandes, Miguel D., Luis B. Oliveira, João Goes, and João P. Oliveira Design of a Low Phase Error Multiphase Clock Generator for Modern Wideband Receivers. IEEE 12th Conference on PhD Research in Microelectronics and Electronics (PRIME 2016). Lisbon, Portugal: IEEE, 2016.
Cunha, Jácome, João Paulo Fernandes, Jorge Mendes, Rui Pereira, João Alexandre Saraiva, and Pedro Martins. "Evaluating Refactorings for Spreadsheet Models." Journal of Systems and Software. 118 (2016): 234-250. Abstractmain.pdf

Software refactoring is a well-known technique that provides transformations on software artifacts with the aim of improving their overall quality.

In the past, we have proposed a catalog of refactoring for spreadsheet models expressed in the ClassSheets modeling language, which allows us to specify the business logic of a spreadsheet in an object-oriented fashion.

Reasoning about spreadsheets at the model level enhances a model-driven spreadsheet environment where a ClassSheet model and its conforming instance (the spreadsheet data) automatically co-evolves after a refactoring is applied at the model level. Our motivation for such research was to improve the model and its conforming instance: the spreadsheet data.

In this paper we define such refactorings using previously proposed evolution steps for models and instances.

We also present an empirical study we designed and conducted in order to confirm our original intuition that these refactorings have a positive impact on end-user productivity, both in terms of effectiveness and efficiency.

The results are presented not only in terms of productivity changes between refactored and non-refactored scenarios, but also in terms of overall user satisfaction, relevance, and experience.

In almost all cases the refactorings indeed improved end-users productivity. Moreover, in most cases users were more engaged with the refactored version of the spreadsheets they worked with.

Dias, J. P., M. FIgueira, and F. Oliveira. "Existence and linearized stability of solitary waves for a quasilinear Benney system." Proceedings of the Royal Society of Edinburgh. 146-03 (2016): 547-564.Website
Biscaia, Hugo, Carlos Chastre, David Cruz, and Noel Franco. "Flexural Strengthening of Old Timber Floors with Laminated Carbon Fiber Reinforced Polymers." Journal of Composites for Construction (2016): 04016073. AbstractWebsite

A set of three old suspended timber floors were flexurally-strengthened with Carbon Fiber Reinforced Polymers (CFRP) strips in order to investigate the effectiveness of externally bonding FRP to their soffits. The specimens were from an old building and 740 mm-wide bands were transferred to the laboratory in order to be tested in a 4-point bending test. One specimen was tested with no strengthening system and the results obtained were used as reference values for comparison with the specimens those were externally bonded and reinforced (EBR) with CFRP strips. Two similar EBR systems were studied: (i) keeping both ends of the CFRP strips free of any restriction (traditional technique); and (ii) embedding both ends of the CFRP strips into the timber, thus providing a bonding anchorage of the strips (new technique). The installation of the new strengthening system comprises the opening of holes in the timber and the creation of a transition curve between the holes and the timber surface. This transition curve allows a smooth transition of the CFRP laminate between the hole and the timber surface, thus avoiding stress concentrations in this area. After the opening of the holes, the resin is applied inside the hole and on the beam surface, and then the CFRP laminate is mounted. The load-carrying capacity of the specimens, the rupture modes, the strains and bond stress distributions within the CFRP-to-timber interface are presented. A nonlinear numerical simulation of the specimens based on the mid-span cross-sectional equilibrium is also presented. The results showed that the use of the new strengthening system enhances the performance of the specimens when compared with the traditional strengthening system.

Lima, Catiele, José Barata, Pedro Fernandes, and Tiago Cardoso. "A Importância da Atuação do Arquiteto-Urbanista no Planejamento das Smart Cities." Pluris. Brasil 2016. Abstract

A importância do papel do Arquiteto-urbanista na caracterização dos conceitos e no planejamento das Smart Cities é um tema com muito por estudar e desenvolver. Este artigo faz uma aproximação a esta questão através de análise crítica com a seguinte abordagem: 1 - é feita uma descrição mais detalhada do porquê deste trabalho de investigação; 2 – apresenta-se uma contextualização da transição dos cenários; 3 - é levantada a problematização e a identificação de alguns motivos do “desenquadramento” da atuação do arquiteto-urbanista na cena; 4 – são discutidos aspectos e elencadas algumas características para “(re)enquadramento” dentro do cenário ideal, 5 – são analisados alguns casos de estudo; 6 - são tecidas conclusões. Este artigo mostra, portanto, o resultado deste estudo comparativo entre panorama atual e desejado, considerando este último como o cenário conceitual. É inicialmente caracterizada a situação atual através de levantamento da crítica especializada, depois é descrita a situação desejada tendo como base a análise de quatro casos de estudo; sendo dois de Smart Cities construídas a partir do zero e dois de cidade existentes que estão sendo transformadas em Smart Cities. Por fim, são identificados elementos que contribuem, na opinião dos autores, para o reassumir do papel do arquiteto-urbanista. Com este trabalho, foi possível, de uma forma sistematizada, estudar e suscitar ações deficitárias na atuação dos arquitetos-urbanistas, como também descortinar potenciais ações que podem induzir e reverter a transformação do cenário atual. Ficou claro que as necessidades intrínsecas ao novo modelo de cidade exigem ainda mais proposições criativas. O delinear das futuras cenas seria então ideal se os arquitetos-urbanistas retomassem posicionamento crítico propositivo e o utilizassem na solução que imagina novas e condizentes maneiras de habitar o espaço. O prelúdio já delineado convida então, os protagonistas na produção do espaço a alforriar-se da inércia, saindo da condição de espectadores e passando a condição de entendedores antecipados do cenário.

Mota, Bruna, Maria Isabel Gomes, Ana Carvalho, and Ana Paula Barbosa-povoa. "The influence of Corporate Social Responsibility on economic performance within supply chain planning." Computational Management Science: State of the Art 2014. Eds. Raquel J. Fonseca, Gerhard-Wilhelm Weber, and Joan Telhada. Springer, 2016. 151-156.2016_motagomescarvalhobpovoa_cms.pdf
Seco, João Costa, Paulo Ferreira, and Hugo Lourenço Nested Data Manipulation in Distributed and Heterogeneous Environments -- extended version. Universidade Nova de Lisboa, 2016.tech-report.pdf
Fernandes, Vítor H., and Teresa M. Quinteiro. "A note on bilateral semidirect product decompositions of some monoids of order-preserving partial permutations." Bull. Korean Math. Soc.. 53.2 (2016): 495-506. AbstractWebsite

In this note we consider the monoid $PODI_n$ of all monotone partial permutations on $\{1,\ldots,n\}$ and its submonoids $DP_n$, $POI_n$ and $ODP_n$ of all partial isometries, of all order-preserving partial permutations and of all order-preserving partial isometries, respectively. We prove that both the monoids $POI_n$ and $ODP_n$ are quotients of bilateral semidirect products of two of their remarkable submonoids, namely of extensive and of co-extensive transformations. Moreover, we show that $PODI_n$ is a quotient of a semidirect product of $POI_n$ and the group $\mathcal{C}_2$ of order two and, analogously, $DP_n$ is a quotient of a semidirect product of $ODP_n$ and $\mathcal{C}_2$.

Morgado, M. L., M. Rebelo, L. L. Ferrás, and N. Ford. "Numerical solution for diffusion equations with distributed order in time using a Chebyshev collocation method." Applied Numerical Mathematics . 114 (2016): 108-123.
Biscaia, Hugo, Noel Franco, Ricardo Nunes, and Carlos Chastre. "Old suspended timber floors flexurally-strengthened with different structural materials." Key Engineering Materials. 713 (2016): 78-81. Abstract

The design of timber beams has strict limits when it comes to the Serviceability Limit States (SLS) either in short-term or in long-term deflections. In order to face this aspect efficiently, the increase of the cross section of the beams might be considered as a solution. However, the prohibitive increase of the costs associated to this solution or the change of the initial architecturedesign of the building, opens the opportunity to find new and more efficient solutions. In that way, the use of additional reinforcements to the timber beams may be seen as a promising solution because either new or old structures would keep always their original aesthetical aspect with no significant self-weight increase and improving their behaviour to short and long-term actions.Therefore, the current study is dedicated to the analysis of composite timber beams where Fiber Reinforcement Polymers (FRP), steel or stainless steel are used to improve the stiffness, strength and deflection behaviour of old suspended timber floors. An experimental program was conducted where old suspended timber floors reinforced with CFRP strips were subjected to 4-point bending tests. A simplify nonlinear numerical model was developed to simulate the bending behaviour of the specimens and several other cases with other reinforcement configurations and different structural materials were assumed. The numerical analysis herein presented also takes into account both Ultimate and Serviceability Limit States of the reinforced specimens.

Fernandes, Vítor H., Preeyanuch Honyam, Teresa M. Quinteiro, and Boorapa Singha. "On semigroups of orientation-preserving transformations with restricted range." Communications in Algebra (DOI:10.1080/00927872.2014.975345). 44.1 (2016): 253-264. Abstractauthorsfinalversion.pdfWebsite

Let $X_n$ be a chain with n elements ($n\in\N$) and let $\OP_n$ be the monoid of all orientation-preserving transformations of $X_n$. In this paper, for any nonempty subset $Y$ of $X_n$, we consider the subsemigroup $\OP_n(Y)$ of $\OP_n$ of all transformations with range contained in $Y$: we describe the largest regular subsemigroup of $\OP_n(Y)$, which actually coincides with its subset of all regular elements, and Green's relations on $\OP_n(Y)$. Also, we determine when two semigroups of the type $\OP_n(Y)$ are isomorphic and calculate their ranks. Moreover, a parallel study is presented for the correspondent subsemigroups of the monoid $\OR_n$ of all either orientation-preserving or orientation-reversing transformations of $X_n$.

Fernandes, Vítor H., and Teresa M. Quinteiro. "Presentations for monoids of finite partial isometries." Semigroup Forum (DOI: 10.1007/s00233-015-9759-4). 93.1 (2016): 97-110. AbstractWebsite

In this paper we give presentations for the monoid $\DP_n$ of all partial isometries on $\{1,\ldots,n\}$ and for its submonoid $\ODP_n$ of all order-preserving partial isometries.

Fernandes, Hugo, Lúcio Válter, and António Pinho Ramos. "Reforço ao punçoamento de lajes fungiformes com lâmina complementar de betão." Encontro Nacional Betão Estrutural 2016. Ed. GPBE. Coimbra: GPBE, 2016. 1-10. Abstract

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Kchaou, Bellaaj O., A. Garbaya, M. Kotti, P. Pereira, M. Fakhfakh, and Helena M. Fino. "Sensitivity aware NSGA-II based Pareto front generation for the optimal sizing of analog circuits." Integration, the \{VLSI\} Journal. 55 (2016): 220-226. AbstractWebsite

Abstract This paper deals with multiobjective analog circuit optimization taking into consideration performance sensitivity vis-a-vis parameters' variations. It mainly considers improving computation time of the inloop optimization approaches by including sensitivity considerations in the Pareto front generation process, not as a constraint, but by involving it within the used metaheuristic evolution process. Different approaches are proposed and compared. NSGA-II metaheuristic is considered. The proposed sensitivity aware approaches are showcased via two analog circuits, namely, a second generation \{CMOS\} current conveyor and a \{CMOS\} voltage follower. We show that the proposed ideas considerably alleviate the long computation time of the process and improve the quality of the generated front, as well.

Gonçalves, A., J. Resende, A. C. Marques, JV Pinto, D. Nunes, A. Marie, R. Gonçalves, L. Pereira, R. Martins, and E. Fortunato. "Smart optically active VO nanostructured layers applied in roof-type ceramic tiles for energy efficiency." Solar Energy Materials & Solar Cells. 150 (2016): 1-9.