Deep learning for BER prediction in optical connections impaired by inter-core crosstalk

Four-level pulse amplitude modulation (PAM4) signals transmission in short-haul intensity modulation-direct detection datacenters connections supported by homogeneous weakly-coupled multicore fibers is seen as a promising technology to meet the future challenge of providing enough bandwidth and achieve high data capacity in datacenter links. However, in multicore fibers, inter-core crosstalk (ICXT) limits significantly the performance of such short-reach connections by causing large bit error rate (BER) fluctuations. In this work, a convolutional neural network (CNN) is proposed for eye-pattern analysis and BER prediction in PAM4 inter-datacenter optical connections impaired by ICXT, with the aim of optical performance monitoring. The performance of the CNN is assessed by estimation of the root mean square error (RMSE) using a synthetic dataset created with Monte Carlo simulation. Considering PAM4 interdatacenter connections with one interfering core and for different skew-symbol rate products, extinction ratios and crosstalk levels, the obtained results show that the implemented CNN is able to predict the BER without surpassing a RMSE limit of 0.1.info:eu-repo/semantics/acceptedVersio

Osteoma Osteóide Cervical - Radiofrequência ou a Clássica Curetagem?

Os Osteomas Osteóides são tumores benignos, osteoblásticos, cuja incidência ronda os 3% do total de todos os tumores. Ocorrem mais frequentemente no fémur e tíbia, e o esqueleto axial é afetado em apenas 10% dos casos, maioritariamente ao nível da coluna lombar (56,1%), sendo a coluna cervical afetada em apenas 26,8% dos casos. O clássico tratamento cirúrgico está a ser substituído por técnicas ablativas mini-invasivas, como a termoablação por radiofrequência por via percutânea. No entanto, na coluna cervical, torna-se difícil prever o efeito do calor quando aplicado na proximidade de estruturas nervosas e vasculares. Apresenta-se o caso clínico de uma doente do sexo feminino de 24 anos, observada por cervicalgia persistente, cuja tomografia computorizada realizada demonstrou um Osteoma Osteóide localizado a nível do pedículo esquerdo da 6ª vértebra cervical. A doente foi submetida a tratamento cirúrgico, através de curetagem transpedicular guiada por fluoroscopia, tendo sido obtida uma resolução imediata, completa e sustentada da dor

Formation of Shore-Normal Grooves (Gutters) in Sandstone by Wave Action.

Regularly spaced incised shore-normal grooves (gutters) on plane consolidated surfaces in littoral and sublittoral zones are widely observed in the marine geological record. Despite their common occurrence there are few investigations into their origins in contemporary marine environments. While their formation is often attributed to wave-induced currents related to wave swash and backwash on the beach-face, no conceptual model has been advanced to explain the presence of gutters, their morphology or their quasi-regular alongshore spacing. The paper examines gutters cut in soft sandstone at Medmerry near Selsey, UK and argues that their formation is related to wave breaking and swash zone processes during an unprecedented sequence of storms in the winter of 2013/14. During this period exceptionally high near-shore waves (Hs around 6m) were recorded for the south coast beaches and these storm conditions persisted periodically through to mid-February 2014. The consequence was extensive beach erosion and the exposure of underlying substrates. In this study gutter morphology was quantified using terrestrial lidar and a wave-resolving numerical model was used to defined the nearshore wave conditions and swash characteristics. Three of the largest storm events during the winter of 2013/14 were modelled: (a) moderate waves coincident with an exceptionally high tide; (b) exceptionally high waves occurring during neap tides; and (c) high waves occurring during spring tides. The model results showed swash zone shear stress is a dome-shaped function of distance across the beach-face thereby controlling gutter depth. Further, high-speed sheet flows characterised by periodic, shore-normal, high and low speed streaks alongshore are thought to be implicated in the mechanism controlling gutter spacing. However, in any situation, the specific spacing of gutters is moderated by both the local sheet flow characteristics and the larger-scale morphological forcing. Together these factors indicate that gutter spacing is an emergent property which makes spacing unpredictable

Lepton flavor violation in SUSY left-right symmetric theories

The seesaw mechanism is the most popular explanation for the smallness of neutrino masses. However, its high scale makes direct tests impossible and only indirect signals at low energies are reachable for collider experiments. One of these indirect links with the high scale is lepton flavor violation (LFV). We discuss LFV decays of sleptons in the context of a SUSY left-right symmetric model that naturally incorporates the seesaw mechanism. This non-minimal embedding of the seesaw leads to observable LFV effects in the right-handed sleptons sector, contrary to minimal models where these are found to be totally negligible. Therefore, LFV observables can be used as a powerful tool to study physics right below the GUT scale.Comment: To appear in the proceedings of PASCOS 2010, the 16th International Symposium on Particles, Strings and Cosmology, Valencia, Spai

Electromagnetic hybrid active-passive vehicle suspension system

The suspension systems currently in use can be classified as passive, semi-active and active. The passive suspension systems are the most commonly used due to their low price and high reliability. However, this system can not assure the desired performance from a modem suspension system An important improvement of the suspension performance is achieved by the active systems. Nevertheless, they are only used in a very reduced number of automobile models because they are expensive and complex. Another disadvantage of active systems is the relatively high energy consumption. The use of electromagnetic linear actuators is an alternative for the implementation of active suspensions. Moreover, this solution has the advantage of the suspension energy recovery. In spite of the materials development, the electromagnetic actuators are yet expensive to produce. In this paper it is proposed an hybrid suspension system which combines the simplicity of the passive dampers with the performance of an electromagnetic active suspension. Maintaining the passive damper, it is possible to keep the performance of the active suspension, but using a smaller electromagnetic actuator

INFLUÊNCIA da Natureza do Contra Corpo, da Distribuição do Tamanho das Partículas Abrasivas e da Velocidade no Ensaio de Microabrasão

Foram realizados ensaios de microabrasão com intuito de observar a influência de dois parâmetros no coeficiente de desgaste: a distribuição do tamanho das partículas abrasivas empregando diferentes contra corpos e a velocidade de rotação da esfera. Para obter diferentes distribuições do tamanho foram misturados dois pós abrasivos com tamanho médio de partícula de 5,97 µm (0 G) e 14,39 µm (100 G). Os ensaios foram realizados utilizando amostras de aço AISI 1020 e contra corpos esféricos de aço martensítico AISI 52100, aço inoxidável austenítico AISI 304, borracha poliuretano e zircônia-alumina. A mudança na natureza da esfera resultou em diferentes comportamentos do coeficiente de desgaste com a variação da distribuição granulométrica. Ao utilizar esfera de aço martensítico AISI 52100, no geral, os menores coeficientes de desgaste foram obtidos em 50% em massa do pó com maior diâmetro médio de partículas, resultado que já havia sido encontrado por Gomez et al. (2015). Aplicando o contra corpo de aço inoxidável austenítico AISI 304, os menores coeficientes de desgaste foram obtidos em 20% em massa do pó com maior diâmetro médio de partículas. Empregando esfera de borracha poliuretano, altamente elástica, não houve variações dos coeficientes de desgaste para as diferentes distribuições granulométricas. Já com esferas de zircônia-alumina, foi observado uma relação linear entre o coeficiente de desgaste e o aumento da fração mássica do pó com maior tamanho de partícula abrasiva. Para o estudo da velocidade de rotação do contra corpo, foram realizados ensaios com 40, 80 e 150 rpm, empregando amostras de aço AISI 1020 e esferas de aço martensítico AISI 52100. Além disso, utilizou-se abrasivo de SiC, de 2,11 µm (A) e 6,57 µm (B), com concentração de solução abrasivas fixa (0,1 g/cm³) ou com uma concentração que diminuiu em função da velocidade de rotação, para manter constante a quantidade de abrasivo durante um único teste. A tendência geral das curvas foi de diminuição do coeficiente de desgaste com o aumento da velocidade. Por meio do microscópio eletrônico de varredura (MEV), foi possível observar que os micromecanismos de desgaste foram predominantemente riscamento nas superfícies de desgaste com microrolamento entre os sulcos, com exceção da borracha, que produziu calota apenas com riscamento. Em ensaios variando a velocidade, os micromecanismos foram riscamento com microrolamento

Estudos da patogenicidade do circovirus suíno tipo 2 (PCV2) em suínos e do papel do macho suíno na disseminação viral dentro do plantel.

Projeto/Plano de Ação: 03.03.230.01

Effects of manipulations of player numbers vs. field dimensions on inter-individual coordination during small-sided games in youth football

The relative space per player formulated in small-sided and conditioned games can be manipulated either by promoting variations in player numbers or by modifying field dimensions. In this study we analysed how the same relative spaces per player, obtained through manipulations of player numbers and field dimensions, influenced inter-individual coordination. The positional data (GPS, 10 Hz) of 24 U-15 yrs performing in three different relative spaces per player (118, 133 and 152m2) was used. Inter-individual behavioural measures included: (i) effective relative space per player, (ii) radius of free movement; (iii) numerical relations inside each player’s relative space per player; and (iv) players’ spatial distribution variability. Magnitude-based inferences were used to analyse the practical significance of the selected variables. Results showed that manipulations of player numbers elicited more free space in the vicinity of each player. However, more advantageous numerical relations adjacent to each individual player and broader individual spatial distributions on field were observed during manipulations of field dimensions. These findings highlight the complex nature of performance behaviours captured by the co-adaptation of players to surrounding spatial constraints. Sport pedagogists should carefully evaluate the use of player numbers and field dimensions as strategies to simulate constraints of specific game contexts

Evolutionary Insights into IL17A in Lagomorphs

In leporids, IL17A had been implicated in the host defense against extracellular pathogens, such as Francisella tularensis that infects hares and rabbits and causes the zoonotic disease tularemia. Here, we studied IL17A from five lagomorphs, European rabbit, pygmy rabbit, brush rabbit, European brown hare, and American pika. We observed that this protein is highly conserved between these species, with a similarity of 97-99% in leporids and ~88% between leporids and American pika. The exon/intron structure, N-glycosylation sites, and cysteine residues are conserved between lagomorphs. However, at codon 88, one of the interaction sites between IL17A and its receptor IL17RA, there is an Arg>Pro mutation that only occurs in European rabbit and European brown hare. This could induce critical alterations in the IL17A structure and conformation and consequently modify its function. The differences observed between leporids and humans or rodents might also represent important alterations in protein structure and function. In addition, as for other interleukins, IL17A sequences of human and European rabbit are more closely related than the sequences of human and mouse or European rabbit and mouse. This study gives further support to the hypothesis that European rabbit might be a more suitable animal model for studies on human IL17.FCT and North Portugal Regional Operational Programme 2007/2013 (ON.2) grants supported this work

Permanent-magnets linear actuators applicability in automobile active suspensions

Significant improvements in automobile suspension performance are achieved by active systems. However, current active suspension systems are too expensive and complex. Developments occurring in power electronics, permanent magnet materials, and microelectronic systems justifies analysis of the possibility of implementing electromagnetic actuators in order to improve the performance of automobile suspension systems without excessively increasing complexity and cost. In this paper, the layouts of hydraulic and electromagnetic active suspensions are compared. The actuator requirements are calculated, and some experimental results proving that electromagnetic suspension could become a reality in the future are shown