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2013
Mota, Pedro. "On a Continuous-Time Stock Price Model with Two Mean Reverting Regimes." Advances in Regression, Survival Analysis, Extreme Values, Markov Processes and Other Statistical Applications. Eds. João Lita da Silva, Frederico Caeiro, Isabel Natário, and Carlos A. Braumann. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. 297-305. Abstract

Motivated by the need to describe regime switching in stock prices, we introduce and study a stochastic process in continuous time with two regimes and one threshold driving the change in regimes. When the difference between the regimes is simply given by different sets of real-valued parameters for the drift and diffusion coefficients, we show that there are consistent estimators for the threshold as long as we know how to classify a given observation of the process as belonging to one of the two regimes.

d d Ruivo, C.R.a b, Ferreira Vaz P. M. d D. "On the error of calculation of heat gains through walls by methods using constant decrement factor and time lag values." Energy and Buildings. 60 (2013): 252-261. AbstractWebsite

A transient heat transfer model was developed to numerically predict the thermal behaviour of the external walls of a room under realistic outdoor conditions. The excitation is not simply sinusoidal even though it is considered to have daily periodicity. The numerical model is based on the finite difference method and handles one-dimensional heat conduction through multilayered walls. The boundary condition at the outer surface of the wall is described with the sol-air temperature concept. The temperatures of indoor air and of other internal surfaces in the room are assumed to be equal and constant. The numerical results were used to calculate values of the decrement factor and time lag of several walls. The calculation followed two methods found in literature, in which these parameters are assumed constant, distinguished by the temperature evolution used: the sol-air or the wall's outer surface. Additionally, the inner surface temperature is used in both methods. The walls investigated range from low to high mass construction, face towards various directions and have light or dark coloured sunlit outer surfaces. The heat fluxes at the inner surface of the walls predicted by numerical modelling and estimated by the simplified methods are compared in detail to conclude on the validity of these simplified methods. As a by-product it is also possible to conclude on the dependence of the decrement factor and of the time lag on the outer surface colour and on the orientation of different types of walls. The results show that both simplified methods have poor accuracy in a significant number of cases. Also, it was found that the wall's azimuth significantly affects the time lag.© 2013 Published by Elsevier B.V.

Elisa, M., B. A. Sava, I. C. Vasiliu, R. C. C. Monteiro, JP Veiga, L. Ghervase, I. Feraru, and R. Iordanescu. "Optical and structural characterization of samarium and europium-doped phosphate glasses." Journal of Non-Crystalline Solids. 369 (2013): 55-60. Abstract
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Elisa, M. a, B. A. a Sava, I. C. a Vasiliu, R. C. C. b Monteiro, J. P. B. Veiga, L. a Ghervase, I. a Feraru, and R. a Iordanescu. "Optical and structural characterization of samarium and europium-doped phosphate glasses." Journal of Non-Crystalline Solids. 369 (2013): 55-60. AbstractWebsite

The work deals with optical and structural properties of aluminophosphate glasses from Li2O-BaO-Al2O3-La 2O3-P2O5 system containing Sm 3 + and Eu3 + ions. X-ray fluorescence (XRF) has been used to establish the elemental composition of these materials. The influence of Sm3 + and Eu3 + ions on the optical properties of these glasses has been investigated in relation with their structural characteristics. The optical behavior of these materials has been studied by ultra-violet-visible (UV-Vis) spectroscopy, revealing absorption maxima specific to the doping ions. Structural information via vibration modes was provided by Fourier Transform Infrared (FTIR) absorption spectra evidenced as POP symmetrical and asymmetrical stretching vibration modes, POP bend, PO 2- symmetrical and asymmetrical stretching vibration modes, PO stretching vibration mode and POH water absorbance. Raman spectra acquired by 514.5 nm laser excitation disclosed peaks specific to metaphosphate network. Information about the elemental compositional homogeneity of Sm 3 + and Eu3 +-containing glasses as well as about the defects of the doped-glasses is revealed by scanning electron microscopy/energy dispersive spectrometry (SEM/EDS). Fluorescence spectroscopy measurements put in evidence important fluorescence peaks found at 596 nm and 643 nm for Sm 3 + ions in phosphate matrix and 611 nm and 700 nm in the case of Eu3 +-doped glass. © 2013 Elsevier B.V.

Elisa, M., B. A. Sava, I. C. Vasiliu, R. C. C. Monteiro, JP Veiga, L. Ghervase, I. Feraru, and R. Iordanescu. "Optical and structural characterization of samarium and europium-doped phosphate glasses." Journal of Non-Crystalline Solids. 369 (2013): 55-60. Abstract
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Silva, Tiago A. N., and António A. Roque Optimização do Processo de Equilibragem Dinâmica – Metodologia Multiponto. Eds. APMI. Actas do 17.º Congresso Ibero-americano de Manutenção, 12.º Congresso Nacional de Manutenção e 1.º Encontro de Manutenção dos Países de Língua Oficial Portuguesa. Cascais, 2013. Abstract
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Mannion, PD, P. Upchurch, RN Barnes, and O. Mateus. "Osteology of the Late Jurassic Portuguese sauropod dinosaur Lusotitan atalaiensis (Macronaria) and the evolutionary history of basal titanosauriforms." Zoological Journal of the Linnean Society. 168 (2013): 98-206. Abstract
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Lopes, A. R., K. Trübenbach, T. Teixeira, V. M. Lopes, V. Pires, M. Baptista, T. Repolho, R. Calado, M. Diniz, and R. Rosa. "Oxidative stress in deep scattering layers: Heat shock response and antioxidant enzymes activities of myctophid fishes thriving in oxygen minimum zones." Deep-Sea Research Part I: Oceanographic Research Papers. 82 (2013): 10-16. AbstractWebsite
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2012
Fortunato, E., P. Barquinha, and R. Martins. "Oxide Semiconductor Thin-Film Transistors: A Review of Recent Advances." Advanced Materials. 24 (2012): 2945-2986. AbstractWebsite
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J, Beirlant, Caeiro F, and Gomes MI. "An Overview And Open Research Topics In Statistics Of Univariate Extremes." 10 (2012): 1-31. Abstract
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Mateus, Octávio. "Ontogenetical changes in the quadrate of basal tetanurans." Fundamental! 2012. 101-104. Abstract

Although nonavian theropod have received considerable interest in the last years, their ontogeny still remains poorly understood, especially the ontogenetical changes affecting their skull (Rauhutand Fechner, 2005). The quadrate, for instance, is preserved in several embryos and juvenile specimens belonging to many clades of theropods such as the Tyrannosauridae (Carr, 1999), Compsognathidae (Dal Sasso and Maganuco, 2011), Therizinosauroidea (Kúndrat et al., 2007), Oviraptoridae (Norell et al., 1994; Norell et al., 2001; Weishampel et al., 2008) and Troodontidae (Varrichio et al., 2002) but very little is usually said about the anatomy of this bone and no one has ever investigated ontogenetical variation in the nonavian theropod quadrate. The discovery of two quadrates belonging to embryos of the sinraptorid Lourinhanosaurus antunesi from Portugal and five isolated quadrates pertaining to juvenile, subadult and adult specimens of Spinosauridae from Morocco fills this gap and allows some ontogenetic information to be drawn for this bone in these two specific clades of Theropoda.

Rocha, H. O recurso a diferentes representações no ensino das funções com o apoio da tecnologia. Actas do XXIII SIEM – Seminário de Investigação em Educação Matemática. Coimbra, Portugal: APM, 2012.
Rodríguez-Martínez, E. V., A. D. Egídio dos Reis, and R. M. R. Cardoso. "On the Erlang(n) dual risk model and dividends problems." STIN Colloquium 2012. Mexico City 2012.
Hendrickx, C., and O. Mateus. "Ontogenetical changes in the quadrate of basal tetanurans." 10 th Annual Meeting of the European Association of Vertebrate Paleontologist ¡Fundamental! . 20 (2012): 101-104. Abstracthendrickx__mateus_2012_ontogenetical_changes_in_the_quadrate.pdf

Although nonavian theropod have received considerable interest in the last years, their ontogeny still remains poorly understood, especially the ontogenetical changes affecting their skull (Rauhut
and Fechner, 2005). The quadrate, for instance, is preserved in several embryos and juvenile specimens belonging to many clades of theropods such as the Tyrannosauridae (Carr, 1999), Compsognathidae (Dal Sasso and Maganuco, 2011), Therizinosauroidea (Kúndrat et al., 2007), Oviraptoridae (Norell et al., 1994; Norell et al., 2001; Weishampel et al., 2008) and Troodontidae (Varrichio et al., 2002) but very little is usually said about the anatomy of this bone and no one has ever investigated ontogenetical variation in the nonavian theropod quadrate. The discovery of two quadrates belonging to embryos of the sinraptorid Lourinhanosaurus antunesi from Portugal and five isolated quadrates pertaining to juvenile, subadult and adult specimens of Spinosauridae from Morocco fills this gap and allows some ontogenetic information to be drawn for this bone in these two specific clades of Theropoda.
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Pereira, Pedro, Helena Fino, Fernando Coito, and M. Ventim-Neves. "Optimization-Based Design of Nano-CMOS LC-VCOs." Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2012. Eds. Luis Camarinha-Matos, Ehsan Shahamatnia, and Gonçalo Nunes. Vol. 372. IFIP Advances in Information and Communication Technology, 372. Costa de Caparica - Portugal: Springer Boston, 2012. 453-464. Abstract

This paper introduces a variability-aware methodology for the design of LC-VCOs in Nano-CMOS technologies. The complexity of the design as well as the necessity for having an environment offering the possibility for exploring design trade-offs has led to the development of design methodologies based multi-objective optimization procedures yielding the generation of Pareto-optimal surfaces. The efficiency of the process is granted by using analytical models for both passive and active devices. Although physics-based analytical expressions have been proposed for the evaluation of the lumped elements, the variability of the process parameters is usually ignored due to the difficulty to formalize it into an optimization performance index. The usually adopted methodology of considering only optimum solutions for the Pareto surface, may lead to pruning quasi-optimal solutions that may prove to be better, should their sensitivity to process parameter variation be accounted for. In this work we propose starting by generating an extended Pareto surface where both optimum and quasi-optimum solutions are considered. Finally information on the sensitivity to process parameter variations, is used for electing the best design solution.

Pereira, Pedro, Helena Fino, Fernando Coito, and Fernando Ventin-Neves Optimization-Based Design of Nano-CMOS LC-VCOs. Doceis 2012. Caparica, Pt: Springer, 2012.
Zeballos, L. J., M. I. Gomes, A. P. Barbosa-Povoa, and A. Q. Novais. "Optimum Design and Planning of Resilient and Uncertain Closed-Loop Supply Chains." 22nd European Symposium on Computer Aided Process Engineering. Eds. Ian David Lockhart Bogle, and Michael Fairweather. Vol. 30. Computer Aided Chemical Engineering, 30. London: Elsevier, 2012. 407-411. Abstract

The design and planning of efficient supply chains (SC) is a major challenge that increases when the return of products has to be accounted for, the so-called closed-loop supply chains (CLSC). In the present work the effect of disruptions and modifications in the operating conditions of CLSCs are investigated on the basis of a 2-stage scenario based model previously developed by the authors. Metrics derived from graph theory are used, along with more conventional economic and operational indices. A discussion on the results obtained is presented to assess how the design and planning of the CLSC respond to these challenges and how these metrics may contribute to this objective.

Mateus, O., M. T. Carrano, and P. Taquet Osteology of the embryonic theropods from the Late Jurassic of Paimogo, Portugal. Journal of Vertebrate Paleontology, Program and Abstracts, 2012, p.137. ISSN 1937-2809., 2012.mateus_et_al_2012_embryos_paimogo_portugal_svp_2012_abstract_book_meeting_abstracts.pdf.pdf
Rosa, R., M. S. Pimentel, J. Boavida-Portugal, T. Teixeira, K. Trübenbach, and M. Diniz. "Ocean warming enhances malformations, premature hatching, metabolic suppression and oxidative stress in the early life stages of a keystone squid." PLoS ONE. 7 (2012). AbstractWebsite
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Marques, Filipe J. On the product of independent Generalized Gamma random variables. Discussion Paper 19–2012, CMA-FCT-Universidade Nova de Lisboa, 2012. Abstract
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Pereira, P., H. Fino, F. Coito, and M. Ventim-Neves. "Optimization-Based Design of Nano-CMOS LC-VCOs." Technological Innovation for Value Creation (2012): 453-464. Abstract
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Fortunato, E., Barquinha Martins P. R. "Oxide semiconductor thin-film transistors: A review of recent advances." Advanced Materials. 24 (2012): 2945-2986. AbstractWebsite

Transparent electronics is today one of the most advanced topics for a wide range of device applications. The key components are wide bandgap semiconductors, where oxides of different origins play an important role, not only as passive component but also as active component, similar to what is observed in conventional semiconductors like silicon. Transparent electronics has gained special attention during the last few years and is today established as one of the most promising technologies for leading the next generation of flat panel display due to its excellent electronic performance. In this paper the recent progress in n- and p-type oxide based thin-film transistors (TFT) is reviewed, with special emphasis on solution-processed and p-type, and the major milestones already achieved with this emerging and very promising technology are summarizeed. After a short introduction where the main advantages of these semiconductors are presented, as well as the industry expectations, the beautiful history of TFTs is revisited, including the main landmarks in the last 80 years, finishing by referring to some papers that have played an important role in shaping transparent electronics. Then, an overview is presented of state of the art n-type TFTs processed by physical vapour deposition methods, and finally one of the most exciting, promising, and low cost but powerful technologies is discussed: solution-processed oxide TFTs. Moreover, a more detailed focus analysis will be given concerning p-type oxide TFTs, mainly centred on two of the most promising semiconductor candidates: copper oxide and tin oxide. The most recent data related to the production of complementary metal oxide semiconductor (CMOS) devices based on n- and p-type oxide TFT is also be presented. The last topic of this review is devoted to some emerging applications, finalizing with the main conclusions. Related work that originated at CENIMAT|I3N during the last six years is included in more detail, which has led to the fabrication of high performance n- and p-type oxide transistors as well as the fabrication of CMOS devices with and on paper. Transparent electronics is one of the most advanced science topics for a broad range of device applications. In this article an overview is presented of state-of-the-art n- and p-type oxides for TFTs and their integration, processed by physical vapor deposition and by solution processing techniques. Some of the most relevant emerging applications are also presented, including CMOS devices based on oxide TFTs fabricated on glass and even on paper. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

2011
Karlovich, Alexei Yu, and Ilya M. Spitkovsky. "On singular integral operators with semi-almost periodic coefficients on variable Lebesgue spaces." Journal of Mathematical Analysis and Appliactions. 384.2 (2011): 706-725. AbstractWebsite

Let \(a\) be a semi-almost periodic matrix function with the almost periodic representatives \(a_l\) and \(a_r\) at \(-\infty\) and \(+\infty\), respectively. Suppose \(p:\mathbb{R}\to(1,\infty)\) is a slowly oscillating exponent such that the Cauchy singular integral operator \(S\) is bounded on the variable Lebesgue space \(L^{p(\cdot)}(\mathbb{R})\). We prove that if the operator \(aP+Q\) with \(P=(I+S)/2\) and \(Q=(I-S)/2\) is Fredholm on the variable Lebesgue space \(L_N^{p(\cdot)}(\mathbb{R})\), then the operators \(a_lP+Q\) and \(a_rP+Q\) are invertible on standard Lebesgue spaces \(L_N^{q_l}(\mathbb{R})\) and \(L_N^{q_r}(\mathbb{R})\) with some exponents \(q_l\) and \(q_r\) lying in the segments between the lower and the upper limits of \(p\) at \(-\infty\) and \(+\infty\), respectively.

Marinheiro, J., and O. Mateus Occurrence of the marine turtle Thalassemys in the Kimmeridgian of Oker, Germany. 71st Annual Meeting of the Society of Vertebrate Paleontology. Abstracts of the 71st Annual Meeting of the Society of Vertebrate Paleontology, 2011. Abstractmarinheiro__mateus_2011_turtle_thalassemys_oker_germany_svp11abstracts.pdf

A partial chelonian was collected from the Langenberg Formation quarry of Oker (near Goslar, Lower Saxony, Germany). The amniotes from this formation include other chelonians (possible Plesiochelyidae), the sauropod Europasaurus holgeri, theropods (Velociraptorinae), crocodylomorphs (Atoposauridae, Theriosuchus pusillus, Goniopholis simus, Machimosaurus hugii, Steneosaurus brevirostris) and pterosaurs (Dsungapteridae, ?Ornithocheiroidea, ?Ctenochasmatidae).

The reported specimen, DFMMh/FV 296, includes a skull part (articulated quadrate, squamosal, basisphenoid, and pterygoid), a disarticulated 40 cm long partial carapace, plastron, and one cervical vertebra.

The carapace bears fontanelles, trapezoidal suprapygal with straight edges, small last neurals

[....]
a plicated longitudinal pattern in the proximal end of the costals originating on the posterior side of the scute sulci and dissipating posteriorly, wide central opening in the plastron, xiphiplastra with little or no contact between each other, and both the hyo- and hypoplastron have digit-form buttress projections.

The specimen has a central plastra fontanelle, which is regarded as a feature of the clade including [....], Santanachelys, and Thalassemys. DFMMh/FV 296 differs from
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edges and xiphiplastron participation in the central fontanelle is autapomorphic for the Thalassemys genus. A large central fontanelle with hyo and hypoplastron polygonal medial
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contact between xiphiplastra and reduced size of the two last neural plates is shared between T. hugii and the Oker specimen. DFMMh/FV 296 differs from this species due to the presence of plastral projections. The different shape of the plastron (no polygonal-like margins or hyo- and hypoplastron projections) suggests that T. moseri [....]
ent genus. Therefore, we can assign this specimen to Thalassemys sp.

Correia, VG, V. D. Bonifácio, V. P. Raje, T. Casimiro, G. Moutinho, C. L. da Silva, M. G. Pinho, and A. Aguiar-Ricardo. "Oxazoline-Based Antimicrobial Oligomers: Synthesis by CROP Using Supercritical CO 2." Macromolecular Bioscience. 11.8 (2011): 1128-1137. AbstractWebsite
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