Explosion of smoothness from a point to everywhere for conjugacies between Markov families

For uniformly asymptotically affine (uaa) Markov maps on train tracks, we prove the following type of rigidity result: if a topological conjugacy between them is (uaa) at a point in the train track then the conjugacy is (uaa) everywhere. In particular, our methods apply to the case in which the domains of the Markov maps are Canter sets. We also present similar statements for (uaa:) and C-r Markov families. These results generalize the similar ones of Sullivan and de Faria for C-r expanding circle maps with r > 1 and have useful applications to hyperbolic dynamics on surfaces and laminations.

Explosion of smoothness from a point to everywhere for conjugacies between diffeomorphisms on surfaces

For diffeomorphisms on surfaces with basic sets, we show the following type of rigidity result: if a topological conjugacy between them is differentiable at a point in the basic set then the conjugacy has a smooth extension to the surface. These results generalize the similar ones of D. Sullivan, E. de Faria and ours for one-dimensional expanding dynamics.

Convergence of Smart Grid ICT architectures for the last mile

The evolution of the electrical grid into a smart grid, allowing user production, storage and exchange of energy, remote control of appliances, and in general optimizations over how the energy is managed and consumed, is also an evolution into a complex Information and Communication Technology (ICT) system. With the goal of promoting an integrated and interoperable smart grid, a number of organizations all over the world started uncoordinated standardization activities, which caused the emergence of a large number of incompatible architectures and standards. There are now new standardization activities which have the goal of organizing existing standards and produce best practices to choose the right approach(es) to be employed in specific smart grid designs. This paper follows the lead of NIST and ETSI/CEN/CENELEC approaches in trying to provide taxonomy of existing solutions; our contribution reviews and relates current ICT state-of-the-art, with the objective of forecasting future trends based on the orientation of current efforts and on relationships between them. The resulting taxonomy provides guidelines for further studies of the architectures, and highlights how the standards in the last mile of the smart grid are converging to common solutions to improve ICT infrastructure interoperability.

Distributed Linear Precoding and User Selection in Coordinated Multicell Systems

In this manuscript we tackle the problem of semidistributed user selection with distributed linear precoding for sum rate maximization in multiuser multicell systems. A set of adjacent base stations (BS) form a cluster in order to perform coordinated transmission to cell-edge users, and coordination is carried out through a central processing unit (CU). However, the message exchange between BSs and the CU is limited to scheduling control signaling and no user data or channel state information (CSI) exchange is allowed. In the considered multicell coordinated approach, each BS has its own set of cell-edge users and transmits only to one intended user while interference to non-intended users at other BSs is suppressed by signal steering (precoding). We use two distributed linear precoding schemes, Distributed Zero Forcing (DZF) and Distributed Virtual Signalto-Interference-plus-Noise Ratio (DVSINR). Considering multiple users per cell and the backhaul limitations, the BSs rely on local CSI to solve the user selection problem. First we investigate how the signal-to-noise-ratio (SNR) regime and the number of antennas at the BSs impact the effective channel gain (the magnitude of the channels after precoding) and its relationship with multiuser diversity. Considering that user selection must be based on the type of implemented precoding, we develop metrics of compatibility (estimations of the effective channel gains) that can be computed from local CSI at each BS and reported to the CU for scheduling decisions. Based on such metrics, we design user selection algorithms that can find a set of users that potentially maximizes the sum rate. Numerical results show the effectiveness of the proposed metrics and algorithms for different configurations of users and antennas at the base stations.

A biomimetic sensor for monitoring oxidative stress biomarker in point-of-care

1st ASPIC International Congress

Protein-responsive polymers for point-of-care detection of cardiac biomarker

This work describes a novel use for the polymeric film, poly(o-aminophenol) (PAP) that was made responsive to a specific protein. This was achieved through templated electropolymerization of aminophenol (AP) in the presence of protein. The procedure involved adsorbing protein on the electrode surface and thereafter electroploymerizing the aminophenol. Proteins embedded at the outer surface of the polymeric film were digested by proteinase K and then washed away thereby creating vacant sites. The capacity of the template film to specifically rebind protein was tested with myoglobin (Myo), a cardiac biomarker for ischemia. The films acted as biomimetic artificial antibodies and were produced on a gold (Au) screen printed electrode (SPE), as a step towards disposable sensors to enable point-of-care applications. Raman spectroscopy was used to follow the surface modification of the Au-SPE. The ability of the material to rebind Myo was measured by electrochemical techniques, namely electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV). The devices displayed linear responses to Myo in EIS and SWV assays down to 4.0 and 3.5 μg/mL, respectively, with detection limits of 1.5 and 0.8 μg/mL. Good selectivity was observed in the presence of troponin T (TnT) and creatine kinase (CKMB) in SWV assays, and accurate results were obtained in applications to spiked serum. The sensor described in this work is a potential tool for screening Myo in point-of-care due to the simplicity of fabrication, disposability, short time response, low cost, good sensitivity and selectivity.

Novel biosensing device for point-of-care applications with plastic antibodies grown on Au-Screen Printed Electrodes

A gold screen printed electrode (Au-SPE) was modified by merging Molecular Imprinting and Self-Assembly Monolayer techniques for fast screening cardiac biomarkers in point-of-care (POC). For this purpose, Myoglobin (Myo) was selected as target analyte and its plastic antibody imprinted over a glutaraldehyde (Glu)/cysteamine (Cys) layer on the gold-surface. The imprinting effect was produced by growing a reticulated polymer of acrylamide (AAM) and N,N′-methylenebisacrylamide (NNMBA) around the Myo template, covalently attached to the biosensing surface. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) studies were carried out in all chemical modification steps to confirm the surface changes in the Au-SPE. The analytical features of the resulting biosensor were studied by different electrochemical techniques, including EIS, square wave voltammetry (SWV) and potentiometry. The limits of detection ranged from 0.13 to 8 μg/mL. Only potentiometry assays showed limits of detection including the cut-off Myo levels. Quantitative information was also produced for Myo concentrations ≥0.2 μg/mL. The linear response of the biosensing device showed an anionic slope of ~70 mV per decade molar concentration up to 0.3 μg/mL. The interference of coexisting species was tested and good selectivity was observed. The biosensor was successfully applied to biological fluids.

Distributed Sensing of Fluid Dynamic Phenomena with the XDense Sensor Grid Network

IEEE International Conference on Cyber Physical Systems, Networks and Applications (CPSNA'15), Hong Kong, China.

XDense: A Dense Grid Sensor Network for Distributed Feature Extraction

XXXIII Simpósio Brasileiro de Redes de Computadores e Sistemas Distribuídos (SBRC 2015). 15 to 19, May, 2015, III Workshop de Comunicação em Sistemas Embarcados Críticos. Vitória, Brasil.

XDense: A Dense Grid Sensor Network for Distributed Feature Extraction

XXXIII Simpósio Brasileiro de Redes de Computadores e Sistemas Distribuídos (SBRC 2015), III Workshop de Comunicação em Sistemas Embarcados Críticos. Vitória, Brasil.

Gait Selection for Quadruped Legged Robots

This paper studies periodic gaits of quadruped locomotion systems. The purpose is to determine the best set of gait and locomotion variables for different robot velocities based on the system dynamics during walking. In this perspective, several performance measures are formulated and a set of experiments reveals the influence of the gait and locomotion variables upon those proposed indices. The results show that the locomotion parameters (β, LS and HB) should be adapted to the walking velocity in order to optimize the robot performance. Furthermore, for the case of a quadruped robot, we concluded that the gait should be adapted to VF .

Desenvolvimento de sequenciador para um Problema de Roteamento de Veículos

Este projecto tem como objectivo a optimização das rotas dos técnicos de serviço após venda da Schmitt+Sohn Elevadores, associadas à realização das manutenções preventivas a cada elemento contratado à empresa (elevadores, escadas rolantes, etc). Como tal, é necessário fazer uma distribuição dos equipamentos que se encontram em carteira, por um dos técnicos que assegura a manutenção, pelos vários dias úteis de cada mês, e pelas horas de trabalho de cada dia. Apesar do técnico ter disponíveis, por dia, 8h de trabalho, apenas 6h podem ser preenchidas com manutenções preventivas. As 2h restantes são essencialmente para possíveis manutenções correctivas para as quais o técnico seja solicitado. Caso o técnico não seja contactado para resolver nenhuma avaria, essas horas podem ser utilizadas pelo mesmo para adiantar trabalho do dia seguinte, isto é, visitar já alguns dos próximos pontos de manutenção preventiva do dia seguinte, ou para compensar trabalho que esteja atrasado. De salientar que, para cada dia, as deslocações do técnico de qualquer local ao primeiro ponto de uma rota ou de regresso do último ponto de uma rota não são contabilizadas. O trabalho desenvolvido nesta dissertação pretende dar resposta ao problema apresentado pela Schmitt+Sohn Elevadores. Para isso foi desenvolvida uma heurística para a optimização das rotas dos técnicos. Esta é baseada no conceito de “vizinho mais próximo” que procura sempre o ponto que se apresenta mais perto do último ponto que foi adicionado à rota. Com base nesta metodologia, nos processos de escolha dos pontos que formam clusters, e na selecção dos pontos iniciais de cada uma das rotas diárias, a ferramenta de optimização resultante define as rotas diárias para que o percurso efectuado por cada técnico num mês seja o menor possível. São feitas alterações às rotas definidas inicialmente quando encontrados pontos de uma mesma entrada a serem visitados em dias diferentes. Isto obrigaria o técnico a fazer duas viagens ao mesmo local. Por fim, o resultado é apresentado num documento Word a ser utilizado pelo técnico como guia diário das suas deslocações aos equipamentos que necessitam de verificações periódicas. Os resultados obtidos foram comparados com as rotas que estavam a ser usadas pela empresa, tendo apresentado resultados de melhor qualidade, constatando-se a eficiência da solução criada pelo algoritmo proposto neste trabalho.

A multi-objective optimization of the active and reactive resource scheduling at a distribution level in a smart grid context

In the traditional paradigm, the large power plants supply the reactive power required at a transmission level and the capacitors and transformer tap changer were also used at a distribution level. However, in a near future will be necessary to schedule both active and reactive power at a distribution level, due to the high number of resources connected in distribution levels. This paper proposes a new multi-objective methodology to deal with the optimal resource scheduling considering the distributed generation, electric vehicles and capacitor banks for the joint active and reactive power scheduling. The proposed methodology considers the minimization of the cost (economic perspective) of all distributed resources, and the minimization of the voltage magnitude difference (technical perspective) in all buses. The Pareto front is determined and a fuzzy-based mechanism is applied to present the best compromise solution. The proposed methodology has been tested in the 33-bus distribution network. The case study shows the results of three different scenarios for the economic, technical, and multi-objective perspectives, and the results demonstrated the importance of incorporating the reactive scheduling in the distribution network using the multi-objective perspective to obtain the best compromise solution for the economic and technical perspectives.

Adhesive selection for single lap bonded joints: Experimentation and advanced techniques for strength prediction

The integrity of multi-component structures is usually determined by their unions. Adhesive-bonding is often used over traditional methods because of the reduction of stress concentrations, reduced weight penalty, and easy manufacturing. Commercial adhesives range from strong and brittle (e.g., Araldite® AV138) to less strong and ductile (e.g., Araldite® 2015). A new family of polyurethane adhesives combines high strength and ductility (e.g., Sikaforce® 7888). In this work, the performance of the three above-mentioned adhesives was tested in single lap joints with varying values of overlap length (LO). The experimental work carried out is accompanied by a detailed numerical analysis by finite elements, either based on cohesive zone models (CZM) or the extended finite element method (XFEM). This procedure enabled detailing the performance of these predictive techniques applied to bonded joints. Moreover, it was possible to evaluate which family of adhesives is more suited for each joint geometry. CZM revealed to be highly accurate, except for largely ductile adhesives, although this could be circumvented with a different cohesive law. XFEM is not the most suited technique for mixed-mode damage growth, but a rough prediction was achieved.

Viabilidade Técnica e Económica das Diferentes Tecnologias de Microprodução

Sabendo que as energias de origem fóssil não são inesgotáveis e que afetam a qualidade do ambiente, nos últimos anos, o interesse pelas energias renováveis mereceu a atenção de ambientalistas e de governantes. Para diminuir a importação de energia, o próprio governo de Portugal incentivou, através de medidas legislativas diversas, a instalação de sistemas alternativos de produção elétrica. Face à pertinência desta matéria, a dissertação, Viabilidade Técnica e Económica das Diferentes Tecnologias de Microprodução, aborda o aproveitamento de energias renováveis através de tecnologias de Microprodução ligadas à rede elétrica. Nesta dissertação, numa primeira fase, apresentam-se os sistemas de microprodução existentes no mercado, descrevem-se os componentes que os constituem e destacam-se os aspetos legislativos aplicáveis. Numa segunda fase, com o objetivo de suportar a elaboração de uma ferramenta informática para apoio na escolha de equipamentos de microprodução, procede-se à análise financeira de tecnologias de microprodução, indicando os modelos matemáticos necessários. Um dos objetivos da dissertação, consiste na construção de uma ferramenta informática de cálculo e na sua aplicação a dois estudos de caso. Esse programa informático foi elaborado em Excel e é capaz de fornecer uma estimativa da produção de energia anual e da avaliação da viabilidade técnico-económica de cada tecnologia e pretende apoiar a decisão do investidor em tecnologias de microprodução. Tendo sido realizados dois estudos de caso - um edifício habitacional unifamiliar e um edifício Industrial – foi possível verificar o funcionamento da aplicação e a sua utilidade na determinação da solução mais vantajosa na escolha de uma tecnologia de microprodução, uma vez que, introduzidos os dados adequados, são gerados os cálculos que permitem fornecer uma visão de conjunto, possibilitando a comparação das diferentes propostas.