Browsing by resource type "preprint"
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- An Overview of Blockchain Integration with Robotics and Artificial IntelligencePublication . Lopes, Vasco; Alexandre, LuísBlockchain technology is growing everyday at a fast-passed rhythm and it's possible to integrate it with many systems, namely Robotics with AI services. However, this is still a recent field and there isn't yet a clear understanding of what it could potentially become. In this paper, we conduct an overview of many different methods and platforms that try to leverage the power of blockchain into robotic systems, to improve AI services or to solve problems that are present in the major blockchains, which can lead to the ability of creating robotic systems with increased capabilities and security. We present an overview, discuss the methods and conclude the paper with our view on the future of the integration of these technologies.
- A characterization theorem for semi-classical orthogonal polynomials on non-uniform latticesPublication . Rebocho, M. N.; Filipuk, Galina; Chen, Yang; Branquinho, A.It is proved a characterization theorem for semi-classical orthogonal polynomials on non- uniform lattices that states the equivalence between the Pearson equation for the weight and some systems involving the orthogonal polynomials as well as the functions of the second kind. As a consequence, it is deduced the analogue of the so-called compatibility conditions in the ladder operator scheme. The classical orthogonal polynomials on non- uniform lattices are then recovered under such compatibility conditions, through a closed formula for the recurrence relation coefficients.
- Characterizations of Laguerre-Hahn affne orthogonal polynomials on the unit circlePublication . Branquinho, A.; Rebocho, M. N.In this work we characterize a monic polynomial sequence, orthogonal with respect to a hermitian linear functional [...]
- Classification of Laguerre-Hahn orthogonal polynomials of class onePublication . Rebocho, M. N.; Filipuk, GalinaWe study orthogonal polynomials related to Stieltjes functions satisfying Riccati type differential equations with polynomial coefficients, AS0 = BS2 + CS + D, with max {deg(A); deg(B)} <= 3; deg(C) <= 2. We derive recurrences for the three-term recurrence relation coefficients of the orthogonal polynomials, including connections with some forms of discrete Painlevé equations.
- Coherent pairs of linear functionals on the unit circlePublication . Branquinho, A.; Foulquie-Moreno, Ana; Marcellan, Francisco; Rebocho, M. N.In this paper we extend the concept of coherent pairs of measures from the real line to Jordan arcs and curves. [...]
- Convergence of the Crank-Nicolson-Galerkin finite element method for a class of nonlocal parabolic systems with moving boundariesPublication . Almeida, Rui M.P.; Duque, José C. M.; Ferreira, Jorge; Robalo, Rui J.The aim of this paper is to establish the convergence and error bounds to the fully discrete solution for a class of nonlinear systems of reaction-diffusion nonlocal type with moving boundaries, using a linearized Crank-Nicolson-Galerkin finite element method with polynomial approximations of any degree. A coordinate transformation which fixes the boundaries is used. Some numerical tests to compare our Matlab code with some existing moving finite elements methods are investigated.
- Cost Benefit Analysis: Evaluation among the Millimetre Wavebands and Super High Frequency Bands of Small Cell 5G NetworksPublication . Teixeira, Emanuel; Ramos, Anderson; Lourenço, Marisa; Velez, Fernando J.; Peha, JonThis article discusses the benefit-cost analysis aspects of millimetre wavebands (mmWaves) and Super High Frequency (SHF). The devaluation along the distance of the carrier-to-noise-plus-interference ratio with the coverage distance is assessed by considering two different path loss models, the two-slope urban micro Line-of-Sight (UMiLoS) for the SHF band (from the ITU-R 2135 Report) and the modified Friis propagation model, for frequencies above 24 GHz. The equivalent supported throughput is estimated at the 5.62, 28, 38, 60, and 73 GHz frequency bands, and the influence of carrier-to-noise- plus-interference ratio in the radio and network optimization process is explored. Mostly owing to the lessening caused by the behaviour of the two-slope propagation model for SHF band, the supported throughput at this band is higher than at the millimetre wavebands only for the longest cell lengths. The benefit cost analysis of these pico-cellular networks was analysed for regular cellular topologies by considering unlicensed spectrum. For shortest distances, we can distinguish an optimal of the revenue in percentage terms for values of the cell length, R ≈ 10 m for the millimitre wavebands, and for longest distances, an optimal of the revenue can be observed at R ≈ 550 m for the 5.62 GHz. It is possible to observe that, for the 5.62 GHz band, the profit is slightly inferior than for millimetre wavebands, for the shortest Rs, and starts to increase for cell lengths approximately equal to the ratio between the break-point distance and the co-channel reuse factor, achieving a maximum for values of R approximately equal to 550 m.
- De Monachorum Aetate: Reflexão ternária na passagem para o 3.º MilénioPublication . Rosa, José Maria SilvaNa celebração do terceiro centenário do nascimento e do baptismo do Frei Casimiro, no limiar do Terceiro Milénio, e neste Santuário Mariano do Nordeste Transmontano, qual o sentido da reflexão que apresentamos sob o título «De monachorum aetate», isto é, Acerca da idade, ou da era, dos monges? Pois bem, a reflexão que aqui e agora propomos em três momentos continua de certo modo o tema desenvolvido no ano passado, nas II Jornadas Culturais de Balsamão, sobre a figura do Frei Casimiro. Ali defendemos a ideia de que o primeiro Mariano que chegou a este lugar era um homem que não olhava para trás; a sua visão do mundo e da vida era toda ela virada para o futuro.
- Deformed Laguerre-Hahn orthogonal polynomials on the real linePublication . Branquinho, A.; Rebocho, M. N.We study families of orthogonal polynomials on the real line whose Stieltjes functions satisfy a Riccati type differential equation with polynomial coefficients. We derive discrete dynamical systems, obtained as a result of deformations of the recurrence relation coefficients of the orthogonal polynomials related to the above referred Stieltjes functions.
- Deployment of Beyond 4G Wireless Communication Networks with Carrier AggregationPublication . Khan, Bahram; Velez, Fernando J.With the growing demand for new blend of applications, the user’s dependency on the Internet is increasing day by day. Mobile Internet users are giving more attention to their own experience, especially in terms of communication reliability, high data rate and service stability on the move. This increase in the demand is causing saturation of existing radio frequency bands. To address these challenges, many researchers are finding the best approach, Carrier Aggregation (CA) is one of the newest innovations which seems to fulfil the demands of future spectrum, CA is one the most important feature for Long Term Evolution - Advanced. In direction to get the upcoming International Mobile Telecommunication Advanced (IMT-Advanced) mobile requirements 1 Gb/s peak data rate, the CA scheme is presented by 3GPP to sustain high data rate using widespread frequency bandwidth up to 100 MHz. Technical issues containing the aggregation structure, its implementation, deployment scenarios, control signal technique and challenges for CA technique in LTE-Advanced, with consideration backward compatibility are highlighted. Performance evaluation in macrocellular scenarios through a simulation approach shows the benefits of applying CA and low-complexity multi-band schedulers in service quality and system capacity enhancement. The Enhanced multi-band scheduler is less complex than the General multi-band scheduler and performs better for cell radius longer than 1800 m (and a PLR threshold of 2%).