Export 2079 results:
Sort by: Author Title Type [ Year  (Desc)]
2015
Xing, Lida, Martin G. Lockley, Daniel Marty, Jianping Zhang, Yan Wang, Hendrik Klein, Richard T. McCrea, Lisa G. Buckley, Matteo Belvedere, Octávio Mateus, Gerard D. Gierliński, Laura Piñuela, Scott W. Persons, IV, Fengping Wang, Hao Ran, Hui Dai, and Xianming Xie. "An Ornithopod-Dominated Tracksite from the Lower Cretaceous Jiaguan Formation (Barremian–Albian) of Qijiang, South-Central China: New Discoveries, Ichnotaxonomy, Preservation and Palaeoecology." PLoS ONE. 10 (2015): e0141059. Abstractlida_et_al_2015_an_ornithopod-dominated_tracksite_from_the.pdfWebsite

The historically-famous Lotus Fortress site, a deep 1.5–3.0-meter-high, 200-meter-long horizonal notch high up in near-vertical sandstone cliffs comprising the Cretaceous Jiaguan Formation, has been known since the 13th Century as an impregnable defensive position. The site is also extraordinary for having multiple tetrapod track-bearing levels, of which the lower two form the floor of part of the notch, and yield very well preserved asseamblages of ornithopod, bird (avian theropod) and pterosaur tracks. Trackway counts indicate that ornithopods dominate (69%) accounting for at least 165 trackmakers, followed by bird (18%), sauropod (10%), and pterosaur (3%). Previous studies designated Lotus Fortress as the type locality of Caririchnium lotus and Wupus agilis both of which are recognized here as valid ichnotaxa. On the basis of multiple parallel trackways both are interpreted as representing the trackways of gregarious species. C. lotus is redescribed here in detail and interpreted to indicate two age cohorts representing subadults that were sometimes bipedal and larger quadrupedal adults. Two other previously described dinosaurian ichnospecies, are here reinterpreted as underprints and considered nomina dubia. Like a growing number of significant tetrapod tracksites in China the Lotus Fortress site reveals new information about the composition of tetrapod faunas from formations in which the skeletal record is sparse. In particular, the site shows the relatively high abundance of Caririchium in a region where saurischian ichnofaunas are often dominant. It is also the only site known to have yielded Wupus agilis. In combination with information from other tracksites from the Jiaguan formation and other Cretaceous formations in the region, the track record is proving increasingly impotant as a major source of information on the vertebrate faunas of the region. The Lotus Fortress site has been developed as a spectacular, geologically-, paleontologically- and a culturally-significant destination within Qijiang National Geological Park.

de Sousa, Borges P., D. Martins, I. Catarino, G. Bonfait, and et al 15 K liquid hydrogen thermal energy storage unit for future ESA science missions. Cryogenic Engineering Conference and the Cryogenic Materials Conference . Tucson, AZ, USA, 2015.
Martins, D., Borges P. de Sousa, I. Catarino, and G. Bonfait. "40 K Liquid Neon Energy Storage Unit." Physics Procedia. 67 (2015): 1193-1198. Abstract

n/a

Young, Mark T., Stéphane Hua, Lorna Steel, Davide Foffa, Stephen L. Brusatte, Silvan Thüring, Octávio Mateus, José Ignacio Ruiz-Omeñaca, Philipe Havlik, Yves Lepage, and Marco Brandalise de Andrade. "Addendum to ‘Revision of the Late Jurassic teleosaurid genus Machimosaurus (Crocodylomorpha, Thalattosuchia)’." Royal Society Open Science. 2 (2015). Abstractyoung_et_al_2015_addendum_to_revision_of_the_late_jurassic_teleosaurid_genus_machimosaurus_crocodylomorpha_thalattosuchia.pdfWebsite

n/a

Petrova, K. T., T. M. Potewar, P. Correia-da-Silva, M. T. Barros, R. C. Calhelha, A. Ciric, M. Sokovic, and I. C. F. R. Ferreira. "Antimicrobial and cytotoxic activities of 1,2,3-triazole-sucrose derivatives." Carbohydr. Res. 417 (2015): 66-71. DOI: 10.1016/j.carres.2015.09.003.
Botelho, M., and H. Rocha Aspectos da comunicação matemática na resolução de problemas. Atas do XXVI SIEM. Évora, Portugal: APM, 2015. Abstract

The influence of mathematical communication over the students’ learning led to this research, whose main goal is to understand the impact on problem solving of the students’ communication difficulties. The study adopts a qualitative and interpretative methodology, undertaking two case studies of 10th grade students. The reached conclusions point to the students’ difficulties at the interpretation of the problem, namely at the interpretation of figures, and at the interpretation of the available data, especially when part of them is irrelevant to the problem. Some difficulties were also identified at the communication level, in relation to the arguments used by the students to support their ideas, where a clear preference to restrict them to mathematic calculations was identified.

Resumo
A importância da comunicação matemática sobre a aprendizagem dos alunos, levou à realização desta investigação que pretendeu compreender o impacto sobre a resolução de problemas das dificuldades de comunicação evidenciadas pelos alunos. Optou-se por uma metodologia de natureza qualitativa e interpretativa e pela realização de estudos de caso envolvendo dois alunos do 10.º ano. As conclusões alcançadas apontam para dificuldades na interpretação do enunciado, nomeadamente relativamente às figuras e a dados em quantidade superior ao necessário. Também ao nível da comunicação da resolução foram identificadas dificuldades em fundamentar ideias, evidenciando uma preferência pelo recurso ao cálculo.

Franco, J., B. Galinhas, Borges P. de Sousa, D. Martins, I. Catarino, and G. Bonfait. "Building a Thinner Gap in a Gas-Gap Heat Switch." Physics Procedia. 67 (2015): 1117-1122. Abstract

n/a

Botelho, M., and H. Rocha A comunicação matemática na avaliação da resolução de problemas. Atas do ProfMat 2015. Évora, Portugal: APM, 2015. Abstractpaper.pdf

A aprendizagem dos nossos alunos é fortemente influenciada pelas caraterísticas das tarefas que lhes propomos e a resolução de problemas é frequentemente apontada como uma das tarefas com mais potencial para promover aprendizagens ricas. Mas aprender implica ser capaz de desenvolver raciocínios, de comunicar as nossas ideias e de compreender as dos outros num processo argumentativo e reflexivo. A avaliação das aprendizagens num contexto de resolução de problemas envolve assim, necessariamente como parte importante do processo, uma análise da comunicação que se estabelece entre todos os envolvidos.
Nesta comunicação iremos focar-nos precisamente na comunicação que se estabelece durante a resolução de problemas, abordando as dificuldades dos alunos e dando atenção à interpretação que fazem do enunciado, à compreensão que manifestam das figuras apresentadas, à relação que conseguem estabelecer entre a situação em causa e a informação disponibilizada através de um gráfico, à forma como conseguem explicitar o seu raciocínio e à linguagem matemática que utilizam no decurso do processo de argumentação. Para tal vamos basear-nos num conjunto de problemas propostos a alunos do 10.º ano de escolaridade no decorrer do estudo de funções.

Mota, Bruna, Ana Carvalho, Maria Isabel Gomes, and Ana Paula Barbosa-povoa. "Design and planning of sustainable supply chains." Sustainability of Products, Processes and Supply Chains: Theory and Applications. Ed. Fengqi You. Amsterdam: Elsevier, 2015. 333-353.
Correia, Ana, Rodrigo Martins, Elvira Fortunato, Pedro Barquinha, and João Goes Design of a robust general-purpose low-offset comparator based on IGZO thin-film transistors. IEEE International Symposium on Circuits and Systems (ISCAS’15). Lisbon, Portugal: IEEE, 2015.
Vieira, P. F., Susana M. Vieira, J. M. C. Sousa, Maria Isabel Gomes, and Ana Paula Barbosa-póvoa. "Designing Closed-Loop Supply Chains with Nonlinear Dimensioning Factors Using Ant Colony Optimization." Soft Computing. 19.8 (2015): 2245-2264.2015_vieiravieiragomessousabpovoa_softcomp.pdfWebsite
Pereira, Fernando, Filipe Moutinho, João Paulo Barros, Anikó Costa, and Luís Gomes. "Executable models for Embedded Controllers Development - {A} Cloud Based Development Framework." Proceedings of the MoDELS 2015 Demo and Poster Session co-located with {ACM/IEEE} 18th International Conference on Model Driven Engineering Languages and Systems (MoDELS 2015), Ottawa, Canada, September 27, 2015. 2015. 40-43. Abstract

n/a

Baptista, Susana, Maria Isabel Gomes, Laureano Escudero, Pedro Medeiros, and Filipe Cabrita. "A Fix-and-Relax Algorithm for Solving Parallel and Sequential Versions of a Multi-period Multi-product Closed Loop Supply Chain Design and Operation Planning Model." Operations Research and Big Data: IO2015-XVII Congress of Portuguese Association of Operational Research (APDIO). Eds. Barbosa Ana Paula Ferreira Dias Póvoa, and Luis Joao de Miranda. Springer International Publishing, 2015. 9-14. Abstract2015_baptistagomesescuderomedeiroscabrita_io2015.pdf

n/a

Petrova, K. T., S. S. Dey, and M. T. Barros. "Formation of spherical and core-shell polymeric microparticles from glycopolymers." Carbohydr. Polym. 125 (2015): 281-287. DOI: 10.1016/j.carbpol.2015.02.052.
Barreto, J., D. Martins, Borges P. de Sousa, S. Kar, G. Bonfait, and I. Catarino Gas gap heat switch for a Cryogen-free magnet system., 2015.
Teixeira, João, Nuno Neuparth, Amalia Botelho, Ana Papoila, Pedro Martins, Paulo Paixão, Iolanda Caires, Daniel Aelenei, João Viegas, Manuela Cano, and Ana Mendes GERIA - Geria Study in Portugal on Health Effects of Air Quality in Elderly Care Centers. Eds. Jo Teixeira, Nuno Neuparth, Am Botelho, Ana Papoila, Pedro Martins, Paix, Iolanda Caires, Daniel Aelenei, Jo Viegas, Manuela Cano, and Ana Mendes. Published by Instituto de Sa: ISPUP - Instituto de Saúde Pública da Universidade do Porto, 2015. AbstractWebsite

As people have become increasingly aware, the age of the European population is rising and the percentage of adults aged 65 years and older is expected to increase. In addition, older people spend about 20 hours per day indoors, and many of them spend essentially their time in elderly care centers (ECC). In this sense, the study of indoor environments and how elder people may be particularly at risk of adverse health effects from pollutants, even at low exposures, due to multiple underlying chronic diseases is becoming an important issue to be addressed by research. Such conditions are highly prevalent, multifactorial, and associated with multiple comorbidities and poor outcomes, such as increased disability and decreased quality of life. The importance of this topic was heightened in 2012 by the World Health Day in 2012 Ageing and health with the theme "Good health adds life to years" and also the ?European Year for Active Ageing and Solidarity between Generations?. Accordingly, this project is suitable to integrate these initiatives and to ensure greater recognition of what older people bring to society and create more supportive conditions for them. To our knowledge, this is the first study in Portugal to assess effects of indoor air contaminants on health status and quality of life in older persons living in ECC. The aim of GERIA project is to carry out a risk assessment, often difficult for older people, involving the identification of multiple factors potentially affecting health and quality of life, the quantification of human exposure to pollutants, and the evaluation of the individual?s response to these stimuli. The results of this project contribute to the understanding of health effects due to indoor environment variables and to provide health benefits to ECC residents with relatively simple measures.

Mota, Bruna, Ana Carvalho, Maria Isabel Gomes, and Ana Paula Barbosa-povoa Green Supply Chain Design and Planning. Eds. J. M. Framinan, P. Perez Gonzalez, and A. Artiba. Proceedings of 2015 International Conference on Industrial Engineering and Systems Management (IESM),. I4 e2 - M. Goudalier, 2015. Abstract2015_motacarvalhogomesbpovoa_iesm2015.pdf

A Mixed Integer Linear Programming model for the design and planning of green supply chains is developed. Strategic and tactical decisions are taken, namely on facility location and capacity installation, supplier selection, technology selection, transportation network definition, supply planning, and product recovery. The aim of this work is to study the use of environmental indicators in these decisions while accounting for profit objectives. Different objective functions concerning environmental aspects are implemented. ReCiPe quantifies the environmental performance of the supply chain and combinations of ReCiPe’s midpoint categories allow a deeper analysis of the impact of these categories in strategic and tactical decisions. The goal is to understand if focusing on selected categories affects supply chain decisions and overall supply chain environmental impact. Net Present Value quantifies the economic performance and is used for lexicographic optimization. The model is applied to a case-study and important managerial insights are obtained. From a holistic point of view, it answers the question: how should supply chain environmental impact be assessed? From a case-study perspective, insights are obtained regarding what type of improvements should be implemented to reduce the environmental impact and how this would affect supply chain strategic and tactical decisions, along with economic performance.

Cardoso, Tiago, João Delgado, and José Barata. "Hand gesture recognition towards enhancing accessibility." Procedia Computer Science. 67 (2015): 419-429. Abstract

Human-Computer-Interaction (HCI) is a key topic on the Accessibility area, namely in what concerns a Smart-City environment, where humans have to interact with artefacts spread all around one particular city. In the last decade HCI has experienced a significant evolution towards a desired fully natural user interface, for example in what concerns the ability to recognize a wide range of hand gestures in real-time. Some efforts have lately been made in the hardware sector in order to deploy sensors that may gather information about the human body movements, as detailed as possible. One example of this effort is the Kinect Sensor from Microsoft. Nevertheless, although these solutions provide a solution for the body movement, they lack on the details, namely the hands, given their small dimension compared to the body as a whole. In other words, the SDKs provided by the vendors of these devices usually lack on the needed details concerning hand movements that would be needed for an accurate hand gesture recognition implementation. This paper presents an extension to the Kinect SDK based on a contour analysis for the estimation of the hand position. This algorithms are then used to provide the creation of a gesture library that might be used afterwards.

Tolstogouzov, A. B., S. F. Belykh, V. S. Gurov, A. A. Lozovan, A. I. Taganov, O. M. N. D. Teodoro, A. A. Trubitsyn, and S. P. Chenakin. "Ion Beam Sources Based on Room Temperature Ionic Liquids for Aerospace Applications , Nanotechnology , and Microprobe Analysis ( Review )." Instruments and Experimental Techniques. 58.1 (2015): 1-14.2014_review_ion_beam_sources.pdf
Pereira, Bruno Claro, Michael J. Benton, Marcello Ruta, and Octávio Mateus. "Mesozoic echinoid diversity in Portugal: Investigating fossil record quality and environmental constraints on a regional scale." Palaeogeography, Palaeoclimatology, Palaeoecology. 424 (2015): 132-146. Abstractpereira_e_al_2015_mesozoic_echinoids_portugal.pdfWebsite

Abstract Several analyses of diversity through geological time use global, synoptic databases, and this practice often makes it difficult to distinguish true signals in changing diversity from regional-scale sampling and/or geological artefacts. Here we investigate how echinoid diversity changed through the Mesozoic of the Lusitanian basin in Portugal based on a comprehensive, revised database, and seek to distinguish biological signal from geological or environmental constraints. The observed diversity pattern is far from having a defined trend, showing many fluctuations that appear to be linked with gaps in the geological record. This study revealed that, independently of the method used, whether correlation tests or model fitting, the diversity signal is not completely explained by the studied sampling proxies. Among the different proxies, marine facies variation in combination with outcrop area best explains the palaeodiversity curve.

Baptista, Susana, Ana Paula Barbosa-povoa, Laureano Escudero, Maria Isabel Gomes, and Celeste Pizarro. "A Metaheuristic for Solving Large-Scale Two-Stage Stochastic Mixed 0-1 Programs with the Time Stochas- tic Dominance Risk Averse Strategy." 12th International Symposium on Process Systems Engineering and 25th European Symposium on Computer Aided Process Engineering. Copenhagen, Denmark : Elsevier, 2015. 857-862. Abstractescape25.pdf

Supply Chain Design problems often result into multiperiod stochastic mixed integer problems that are hard to solve. In this paper we propose a metaheuristic algorithm as a specialization for two- stage problems of the so-named Fix-and-Relax Algorithm presented previously for solving large- scale multiperiod stochastic mixed 0-1 optimization problems under a time stochastic dominance risk averse strategy, so-named TSD. Some computational experience is presented.

Moura, JJG, PV Bernhardt, L. B. Maia, and P. J. Gonzalez. "Molybdenum and tungsten enzymes: from Biology to chemistry and back." Journal of Biological Inorganic Chemistry. 20 (2015): 181-182. AbstractWebsite
Böhle, Knud, and António Brandão Moniz. "No Countries for Old Technology Assessment? Sketching the Efforts and Opportunities to Establish Parliamentary TA in Spain and Portugal." EconStor Open Access Articles (2015): 29-44. AbstractWebsite

If the question is whether there is a parliamentary technology assessment (PTA) unit in Portugal or Spain, the clear answer is that there is still no such unit at the central state level at the present time, neither in Portugal nor in Spain. The question then has to be modified addressing previous and current efforts to establish PTA and the current framework conditions and opportunities. Practices of PTA are framed here as a democratic innovation in the context of changes in representative democracies. Against this backdrop, the efforts and opportunities to establish PTA in Spain and Portugal are studied. By sketching these developments and outlining the opportunities in these countries, our aim is to contribute to the debate about the likelihood of a new wave of PTA in Europe (Hennen/Nierling 2014).

Biscaia, Hugo C., Carlos Chastre, André Viegas, and Noel Franco. "Numerical modelling of the effects of elevated service temperatures on the debonding process of frp-to-concrete bonded joints." Composites Part B: Engineering. 70 (2015): 64-79. AbstractWebsite

There are many issues concerning the performance behaviour of FRP-to-concrete interfaces at elevated service temperatures (EST). At EST, i.e. slightly above the glass transition temperature (Tg), some properties associated with the FRP composites, such as the stiffness, strength or the bond characteristics, degrade. This is a crucial issue and there are only a few studies that take into account such effects on FRP-to-concrete interfaces at EST. This paper examines, through a numerical analysis, the performance of FRP-to-concrete bonded joints at EST using a new discrete model based on truss elements and shear springs. The External Bonded Reinforcement (EBR) systems subjected to EST are analyzed. The numerical discrete model was implemented in a MATLAB routine and the bond-slip curves of the interfaces at EST were obtained from a model found in literature. The numerical results revealed that the interface at EST behaves similarly to one with two equal mechanical loads applied at both ends of the FRP plate. The load-slip curves or bond stresses, strains or slippages along the bonded length obtained from several bond-slip curves at different temperatures were obtained. Two different single-lap shear tests were simulated at steady-state (steady temperature followed by load increase) and transient state (steady load followed by temperature increase). Regarding the influence of the temperature on the adhesion between the FRP and concrete, the results showed that an increase in the temperature at an earlier situation, i.e. during a period where temperature had no influence in the concrete deformations, leads to an increase in the effective bond length of the interface affecting the initial strength of the interface.

Brás, C. P., M. Fukushima, A. N. Iusem, and J. J. Júdice. "On the Quadratic Eigenvalue Complementarity Problem over a General Convex Cone." Applied Mathematics and Computation. 271 (2015): 594-608. AbstractWebsite

The solution of the Conic Quadratic Eigenvalue Complementarity Problem (CQEiCP) is first investigated without assuming symmetry on the matrices defining the problem. A new sufficient condition for existence of solutions of CQEiCP is presented, extending to arbitrary pointed, closed and convex cones a condition known to hold when the cone is the nonnegative orthant. We also address the symmetric CQEiCP where all its defining matrices are symmetric. We show that, assuming that two of its defining matrices are positive definite, this symmetric CQEiCP reduces to the computation of a stationary point of an appropriate merit function on a convex set. Furthermore, we discuss the use of the so called Spectral Projected Gradient (SPG) algorithm for solving CQEiCP when the cone of interest is the second-order cone (SOCQEiCP). A new algorithm is designed for the computation of the projections required by the SPG method to deal with SOCQEiCP. Numerical results are included to illustrate the efficiency of the SPG method and the new projection technique in practice.