Sensores ���em movimento"

A dom��tica e a Internet das Coisas (Internet of Things ��� IoT) s��o dois conceitos que est��o a ter bastante impacto na sociedade e a mudar o seu quotidiano, pelo que o utilizador �� mais exigente na utiliza����o dos seus equipamentos, pretendendo, que sejam mais simples e eficazes. A IoT �� tamb��m muito utilizada na vertente da qualidade de vida (verifica����o da qualidade do ar, temperatura etc.) pelo que �� necess��rio a utiliza����o de uma rede de sensores de forma que toda a informa����o recolhida seja disponibilizada ao utilizador. Os sensores est��o ligados a n��s da rede de forma a recolherem informa����o. Essa rede pode ser constitu��da por diferentes topologias, sendo que a mais usual �� a rede em Malha, pois no caso de um dos n��s deixar de funcionar, a mensagem �� enviada atrav��s de outros n��s at�� chegar ao n�� principal. O passo seguinte consiste em enviar toda essa informa����o para a Cloud, sendo que, nas solu����es existentes, �� necess��rio que o utilizador tenha um ponto fixo (gateway) com acesso �� internet. Quando n��o �� poss��vel internet por cabo, a solu����o �� a utiliza����o de redes sem fios ou a utiliza����o de, por exemplo, um cart��o 3G/4G que implica o pagamento de taxas ��s operadoras m��veis. Estas solu����es implicam, na sua grande maioria uma instala����o el��trica para alimenta����o dos n��s dos sensores. O grande problema surge quando o utilizador n��o possui nenhum acesso �� Internet (no local onde s��o instalados os sensores), ou no caso de n��o exist��ncia de nenhuma instala����o el��trica para alimenta����o dos n��s dos sensores. A solu����o proposta nesta disserta����o consiste na utiliza����o de um telem��vel, de um utilizador aleat��rio, como gateway. Assim, um utilizador comum pode ligar os seus sensores onde for necess��rio. Esses sensores s��o configurados Over-The-Air atrav��s de uma camada de aplica����o do dispositivo de comunica����o, como por exemplo, o Synapse. Ap��s configura����o, os sensores est��o prontos a recolher toda a informa����o e envi��-la atrav��s da rede at�� ao n�� principal. O n�� principal �� constitu��do pelo dispositivo de comunica����o referido anteriormente, ligado a um microcontrolador (Arduino, por exemplo) que tem agregado um leitor de cart��es SD e um dispositivo Bluetooth (BLE). Toda a informa����o recolhida pelos sensores �� guardada no cart��o SD at�� que um utilizador, com um telem��vel (Smartphone Android com a aplica����o desenvolvida instalada) com o Bluetooth ligado, se aproxime do n�� principal. Assim que a liga����o �� aceite e estabelecida, a aplica����o envia a data mais recente de um sensor espec��fico presente na sua base de dados na Cloud para o Arduino, permitindo que este apague os dados mais antigos presentes no cart��o e envie, como resposta para o telem��vel, a informa����o mais antiga recolhida pelo sensor, atualizando assim a informa����o. A aplica����o deste conceito pode ser ��til quando n��o existe nenhuma liga����o �� internet ou quando um utilizador, por exemplo uma entidade respons��vel pelo meio ambiente e que seja necess��rio inserir sensores numa floresta, para preven����o de fogos. Assim os n��s v��o enviar toda a informa����o recolhida atrav��s da sua rede. Posteriormente, cabe ao utilizador escolher um s��tio estrat��gico, onde saiba que ir��o passar indiv��duos com alguma frequ��ncia, de modo a que estes recebam essa informa����o para o seu telem��vel.

Historic and potential technology transition paths of grid battery storage: Co-evolution of energy grid, electric mobility and batteries

Scarcity of fuels, changes in environmental policy and in society increased the interest in generating electric energy from renewable energy sources (RES) for a sustainable energy supply in the future. The main problem of RES as solar and wind energy, which represent a main pillar of this transition, is that they cannot supply constant power output. This results inter alia in an increased demand of backup technologies as batteries to assure electricity system safety. The diffusion of energy storage technologies is highly dependent on the energy system and transport transition pathways which might lead to a replacement or reconfiguration of embedded socio-technical practices and regimes (by creating new standards or dominant designs, changing regulations, infrastructure and user patterns). The success of this technology is dependent on hardly predictable future technical advances, actor preferences, development of competing technologies and designs, diverging interests of actors, future cost efficiencies, environmental performance, the evolution of market demand and design and evolution of our society.

Analysis of a controversial decision process: the case of the pumped hydro storage power plant Atdorf in Germany

Based on the report for the unit ���M��todos Interactivos de Participa����o e Decis��o A��� (Interactive methods of participation and decision A), coordinated by Prof. Lia Maldonado Teles de Vasconcelos and Prof. Nuno Miguel Ribeiro Videira Costa. This unit was provided for the PhD Program in Technology Assessment in 2015/2016.

Econet wireless Zimbawe Limited: Building the future

In February 2015, when Econet Wireless Zimbabwe Limited, EWZL, the market leader of the telecommunications sector in Zimbabwe, published the financial results, the management team was worried about the shareholders��� reaction. With over 60% market share in its core business (the voice and SMS market), it has achieved remarkable results due to the great diversification strategy. However, the share price was continuously falling due to exogenous factors that were pressuring margins and threatening future sustainability of the company. EWZL was highly exposed to Zimbabwe���s specific risks and regulatory policies. This case explores both the business environment surrounding the company and the strategic decisions necessary to fight against the economic and political challenges. Students will step into Econet���s obstacles by analyzing the strategies and diagnosing the multiple risk factors affecting the profitability of the firm. Furthermore, they will have to compute the valuation of the firm, facing several challenges of a developing country.

On-board electric vehicle battery charger with enhanced V2H operation mode

This paper proposes an on-board Electric Vehicle (EV) battery charger with enhanced Vehicle-to-Home (V2H) operation mode. For such purpose was adapted an on-board bidirectional battery charger prototype to allow the Grid-to-Vehicle (G2V), Vehicle-to-Grid (V2G) and V2H operation modes. Along the paper are presented the hardware topology and the control algorithms of this battery charger. The idea underlying to this paper is the operation of the on-board bidirectional battery charger as an energy backup system when occurs a power outages. For detecting the power outage were compared two strategies, one based on the half-cycle rms calculation of the power grid voltage, and another in the determination of the rms value based in a Kalman filter. The experimental results were obtained considering the on-board EV battery charger under the G2V, V2G, and V2H operation modes. The results show that the power outage detection is faster using a Kalman filter, up to 90% than the other strategy. This also enables a faster transition between operation modes when a power outage occurs.

An evolutionary multi-objective optimization system for earthworks

Earthworks involve the levelling or shaping of a target area through the moving or processing of the ground surface. Most construction projects require earthworks, which are heavily dependent on mechanical equipment (e.g., excavators, trucks and compactors). Often, earthworks are the most costly and time-consuming component of infrastructure constructions (e.g., road, railway and airports) and current pressure for higher productivity and safety highlights the need to optimize earthworks, which is a nontrivial task. Most previous attempts at tackling this problem focus on single-objective optimization of partial processes or aspects of earthworks, overlooking the advantages of a multi-objective and global optimization. This work describes a novel optimization system based on an evolutionary multi-objective approach, capable of globally optimizing several objectives simultaneously and dynamically. The proposed system views an earthwork construction as a production line, where the goal is to optimize resources under two crucial criteria (costs and duration) and focus the evolutionary search (non-dominated sorting genetic algorithm-II) on compaction allocation, using linear programming to distribute the remaining equipment (e.g., excavators). Several experiments were held using real-world data from a Portuguese construction site, showing that the proposed system is quite competitive when compared with current manual earthwork equipment allocation.

Desenvolvimento de sistema de alarmes para incontinentes

Disserta����o de mestrado em redes e servi��os telem��ticos

Sensorimotor synchronization when walking side by side with a point light walker

[Excerpt] Synchronization of periodic movements like side-by-side walking [7] is frequently modeled by coupled oscillators [5] and the coupling strength is defined quantitatively [3]. In contrast, in most studies on sensorimotor synchronization (SMS), simple movements like finger taps are synchronized with simple stimuli like metronomes [4]. While the latter paradigm simplifies matters and allows for the assessment of the relative weights of sensory modalities through systematic variation of the stimuli [1], it might lack ecological validity. Conversely, using more complex movements and stimuli might complicate the specification of mechanisms underlying coupling. We merged the positive aspects of both approaches to study the contribution of auditory and visual information on synchronization during side-by-side walking. As stimuli, we used Point Light Walkers (PLWs) and auralized steps sound; both were constructed from previously captured walking individuals [2][6]. PLWs were retro-projected on a screen and matched according to gender, hip height, and velocity. The participant walked for 7.20m side by side with 1) a PLW, 2) steps sound, or 3) both displayed in temporal congruence. Instruction to participants was to synchronize with the available stimuli. [...]

Thermal characterization of polyhydroxyalkanoates and poly(lactic acid) blends obtained by injection molding

In this work we present the thermal characterization of the full scope of polyhydroxyalcanoate and poly(lactic acid) blends obtain by injection molding. Blends of polyhydroxyalcanoate and poly(lactic acid) (PHA/PLA) were prepared in different compositions ranging from 0���100% in steps of 10%. The blends were injection molded and then characterized by differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and wide angle X-ray diffraction (WAXD). The increment of PHA fraction increased the degree of crystallinity of the blend and the miscibility of the base polymers as veri���ed by the Fox model. The WAXD analysis indicates that the presence of PHA hindered the PLA crystallization. The crystallization evolution trough PHA weight fraction (wf) shows a phase inversion around 50-60%. SEM analyses con���rmed that the miscibility of PHA/PLA blends increased with the incorporation of PHA and became total for values of PHA higher that 50%.

BeSmart2: A multicriteria decision aid application

This paper presents an improved version of an application whose goal is to provide a simple and intuitive way to use multicriteria decision methods in day-to-day decision problems. The application allows comparisons between several alternatives with several criteria, always keeping a permanent backup of both model and results, and provides a framework to incorporate new methods in the future. Developed in C#, the application implements the AHP, SMART and Value Functions methods.

OnBoard reconfigurable battery charger for electric vehicles with traction-to-auxiliary mode

This paper proposes a single-phase reconfigurable battery charger for Electric Vehicle (EV) that operates in three different modes: Grid-to-Vehicle (G2V) mode, in which the traction batteries are charged from the power grid; Vehicle-to-Grid (V2G) mode, in which the traction batteries deliver part of the stored energy back to the power grid; and in Traction-to-Auxiliary (T2A) mode, in which the auxiliary battery is charged from the traction batteries. When connected to the power grid, the battery charger works with sinusoidal current in the AC side, for both G2V and V2G modes, and also regulates the reactive power. When the EV is disconnected from the power grid, the control algorithms are modified and the full-bridge AC-DC bidirectional converter works as a full-bridge isolated DC-DC converter that is used to charge the auxiliary battery of the EV, avoiding the use of an additional charger to accomplish this task. To assess the behavior of the proposed reconfigurable battery charger under different operation scenarios, a 3.6 kW laboratory prototype has been developed and experimental results are presented.

Reconfigura����o e novas funcionalidades para um servidor REST ONVIF: servi��o de IO e configura����o de descoberta

Disserta����o de mestrado em Engenharia de Telecomunica����es e Inform��tica

Sistema de apoio a rondas de seguran��a

Disserta����o de mestrado integrado em Engenharia Eletr��nica Industrial e Computadores

Cria����o de um sistema de apoio para o suporte avan��ado de vida

Disserta����o de mestrado integrado em Engenharia Biom��dica (��rea de especializa����o em Eletr��nica M��dica)

Gest��o e instala����o de redes de sensores sem fios (dom��tica)

Disserta����o de mestrado integrado em Engenharia Eletr��nica Industrial e Computadores