A comparison of risk aversion between markets

In this study we perform a comparison between the Dow Jones Industrial Average and the FTSE 100 indexes concerning their estimated risk aversions. Risk neutral densities are calculated for both indexes using a polynomial-lognormal, a GB2 and a mixture of two lognormal distributions; we show that the best fit to observed data is obtained using the latter. For the method of best fit, and assuming a power utility function, the risk aversion of investors is calculated using a maximum likelihood method and a likelihood ratio. The FTSE 100 presents the highest value of risk aversion of the two indexes, as well as the lowest volatility. A negative correlation is found between risk aversion estimates and the volatility of the underlying index

Natural resources for sustainability

Os alunos vencedores do Concurso Escolar “Recursos Naturais para a Sustentabilidade”, promovido pela AGA – Associação Geoparque Arouca e Unesco, participaram num seminário, decorrido em Arouca, no qual foram discutidas diversas questões ambientais e decorreu a entrega de prémios relativos a este concurso. Além de assistirem a várias comunicações sobre os recursos naturais, os alunos tiveram oportunidade de apresentarem à audiência o seu projeto

Desafios das Universidades Empreendedoras: Universidade Tradicional X Universidade Corporativa

Este artigo tem como objetivo analisar e fazer um paralelo entre a Universidade tradicional e a Universidade corporativa. Pretende ainda, colaborar na discussão do tema,Universidade empreendedora, apresentando novos desafios para as universidades brasileiras, com o intuito de estas instituições alcancem seus objetivos, diante de cenários cada vez mais instáveis. O estado da arte remete para constatações de que as universidades tradicionais necessitam de estratégias gerenciais empreendedoras e voltadas para atender as necessidades da sociedade. Que as diversas recessões políticas e financeiras, por que passam estas instituições, contribuem para que os gerentes públicos usem ferramentas gerenciais inovadores e necessárias, visando estratégias principalmente de parcerias entre universidades e empresas, interagindo para alavancar e desenvolver o mercado que as envolve, através da troca de experiências, de conhecimento e de tecnologias específicas

Multiple manipulators path planning using double A∗

Streamlining automated processes is currently undertaken by developing optimization methods and algorithms for robotic manipulators. This paper aims to present a new approach to improve streamlining of automatic processes. This new approach allows for multiple robotic manipulators commonly found in the industrial environment to handle different scenarios, thus providing a high-flexibility solution to automated processes. Design/methodology/approach - The developed system is based on a spatial discretization methodology capable of describing the surrounding environment of the robot, followed by a novel path-planning algorithm. Gazebo was the simulation engine chosen, and the robotic manipulator used was the Universal Robot 5 (UR5). The proposed system was tested using the premises of two robotic challenges: EuRoC and Amazon Picking Challenge. Findings - The developed system was able to identify and describe the influence of each joint in the Cartesian space, and it was possible to control multiple robotic manipulators safely regardless of any obstacles in a given scene. Practical implications - This new system was tested in both real and simulated environments, and data collected showed that this new system performed well in real-life scenarios, such as EuRoC and Amazon Picking Challenge. Originality/value - The new proposed approach can be valuable in the robotics field with applications in various industrial scenarios, as it provides a flexible solution for multiple robotic manipulator path and motion planning.The research leading to these results has received funding from the project "NORTE-01-0145-FEDER-000020" which is nanced by the North Portugal Re- gional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, and through the European Regional Development Fund (ERDF).info:eu-repo/semantics/publishedVersio

Estudo das propriedades mecânicas de laminados com cortiça micro-aglomerada

Mestrado em Engenharia MecânicaEsta tese desenvolveu-se a partir de uma proposta de uma conceituada empresa portuguesa especializada em kayaks e consistiu em desenvolver um laminado de base natural e com núcleo de cortiça, capaz de se assemelhar em termos mecanicos aos de fibra de vidro e resina epóxi já utilizados. Após uma alargada pesquisa de materiais e fornecedores, procedeu-se ao fabrico de várias placas diferentes. Os materiais de base foram o núcleo de cortiça, peles em fibra de linho e bio-resina epóxi. De modo a avaliar as respostas mecânicas em regime estático e dinamico, foram realizados ensaios de flexão e impacto. As conclusões obtidas após exaustiva análise dos resultados permitem concluir que os laminados naturais podem oferecer propriedades mecânicas interessantes e quiça rivalizar com os seus concorrentes sintéticos, mantendo as óbvias vantagens em termos de responsabilidade ambiental. Ficam também directrizes para o caso de se pretender o fabrico de um protótipo utilizando estes materiais.This work started from the demand of a renowed portuguese company specialized in kayaks. It focused the development of a fully natural composite material based on natural fibers and cork acting as a core, that showed similar mechanical properties when compared to synthetic materials based on fiberglass and epoxy resin. After a thorough search for materials, the choices relyed on flax fibers and epoxy bio-resin, besides the agglomerated cork core. Several laminates were produced and then subjected to static and dynamic mechanical testing, carried out via bending and impacts tests respectively. After a careful analysis of the obtained results, it was possible to conclude that the proposed materials show compatible mechanical properties and can even rivalize against synthetic materials. On top of that, natural materials keep the obvious advantage of eco-friendliness. In the end, guidelines are given in case a prototype may be constructed using the proposed composites

Land use and land cover dynamics in Leiria City: relation between peri-urbanization processes and hydro-geomorphologic disasters

The objective of the present study is to evaluate the relation between the spatial and temporal dynamics of Land Use and Land Cover (LULC) and the hydro-geomorphological processes and their impacts. The study area is the city of Leiria, in central Portugal, within the period 1958–2018 based on the historical record of floods and landslides disasters. The LULC analysis shows an accentuated increase in the artificial areas and a continuous decrease in the agricultural areas. With regard to hydro-geomorphologic disaster occurrences, a total of 124 occurrences were identified, having caused a set of impacts. The obtained results allow one to characterize the artificialization process, its intensity and territorial dispersion, as a consequence of urban sprawl and peri-urbanization, along with its consequences in exposure to hydro-geomorphological processes. The analysis concludes that changing the risk drivers resulted in an increase in frequency and spatial dispersion of hydro-geomorphologic disasters over the analysed period.N/

Melhoria do processo produtivo na Simoldes aços, SA

O trabalho presente nesta dissertação incidiu sobre a aplicação das metodologias Lean no âmbito do processo produtivo de uma empresa metalomecânica de moldes – SIMOLDES AÇOS, SA. No atual enquadramento, com os mercados nacionais e internacionais debaixo de feroz competição, as empresas são obrigadas a estudar métodos e técnicas que permitam eliminar desperdícios, reduzir custos e tempos de produção, ao mesmo tempo que são exigidos maiores níveis de qualidade dos produtos fabricados com vista ao aumento da competitividade. No decorrer do trabalho desta dissertação de mestrado foi realizada uma análise abrangente do estado atual do sector de atividade do processo produtivo na empresa SIMOLDES AÇOS SA, o que permitiu identificar as áreas e os pontos a intervir e desenhar as soluções de melhoria na atividade do processo produtivo. Na fase concludente do trabalho foram implementadas algumas dessas propostas de melhoria, ao passo que outras ficaram programadas para futura implementação. Na base do trabalho desenvolvido esteve a metodologia Lean, que apresenta um papel relevante na implementação de uma abordagem integrada da função do processo produtivo na aquisição dos objetivos da produção. O presente projeto baseou a sua estratégia de implementação na aplicação da ferramenta do 5S. Esta ferramenta visa a redução de desperdícios, da melhoria do desempenho dos processos e da plena integração de todos os colaboradores no processo de fabrico. Com a implementação das melhorias propostas, foram observadas melhorias significativas no fluxo das atividades do processo produtivo.The present work in this dissertation focused on the application of Lean methodologies in the production process of an engineering company moulds – SIMOLDES AÇOS, SA. In the current environment, with the domestic and international markets under fierce competition, companies are forced to study methods and techniques to eliminate waste, reduce costs and production times while that required higher levels of quality of manufactured products with order to increase competitiveness. During the work of this dissertation was carried out a comprehensive analysis of the current state of the sector of activity of the production process in the company SIMOLDES AÇOS SA, which allowed us to identify the areas and points to act and design solutions to improve the activity of the production process. In the concluding phase of the work were implemented some of these proposed improvements, while others were scheduled for future implementation. On the basis of the work was to Lean methodology, which has an important role in the implementation of an integrated function of the production process in the acquisition of production goals. This project based its implementation strategy in applying the tool of 5S. This tool is aimed at waste reduction, performance improvement processes and full integration of all employees in the manufacturing process. With the implementation of the proposed improvements, significant improvements were observed in the flow of activities in the production process

Modelação, Controlo e Simulação de uma Estação Marítima Autónoma

A exploração dos oceanos através de plataformas do tipo Autonomous Underwater Vehicle (AUV) e Autonomous Surface Vehicle (ASV) constitui uma forma segura e eficiente de caracterizar, mapear, monitorizar e, consequentemente, proteger estas vastas áreas remotas do planeta. O objetivo desta dissertação, realizada no Laboratório de Sistemas Autónomos (LSA) do Instituto Superior de Engenharia do Porto (ISEP), foi conceber e avaliar, recorrendo a simulação, uma estação autónoma marítima para a realização de mis sões de duração variável em áreas restritas. A estação autónoma deve ser capaz de permanecer num local de interesse por um período de tempo configurável sem estar ancorada (station keeping) e ser energeticamente eficiente. Em primeiro lugar, efetuou-se um levantamento exaustivo dos Autonomous Sur face Vehicles com diferentes tipos de propulsão existentes, seguido de um estudo dos princípios físicos da navegação à vela. Decidiu-se então conceber um ASV pro pulsionado pelo vento, equipado com um conjunto vela-cauda de asas rígidas. Esta solução, que permite controlar o ângulo de ataque da vela asa com o vento através da cauda, tem um baixo consumo energético. A plataforma idealizada foi modelada no SolidWorks e, posteriormente, contro lada e simulada através do Robot Operating System (ROS) e do ambiente de simu lação Gazebo. A correta simulação do comportamento do ASV no Gazebo envolveu a reutilização, alteração e criação de plugins. O sistema de controlo do ângulo de ataque da vela asa e da direção do veleiro recorreu a dois controladores do tipo Proporcional Derivativo (PD), um para atuar na cauda e outro no leme. O ASV simulado realiza missões definidas através de waypoints, incluindo station keeping. Por fim, foram realizados testes para caracterizar e validar o comportamento físico e o controlo do veleiro. Os resultados obtidos são promissores: a estação marí tima autónoma é capaz de navegar à vela até aos waypoints definidos e permanecer na área de interesse estabelecida.The exploration of the oceans with Autonomous Underwater Vehicle (AUV) and Autonomous Surface Vehicle (ASV) platforms is a safe and efficient way of charac terising, mapping, monitoring and, consequently, protecting these vast remote areas of the planet. The aim of this dissertation, carried out at the Laboratório de Sistemas Autónomos (LSA) of the Instituto Superior de Engenharia do Porto (ISEP), was to design and evaluate, using simulation, an autonomous maritime station for carrying out mis sions of varying duration in restricted areas. The autonomous station must be able to remain in a place of interest for a configurable period of time without being anchored (station keeping) and be energy efficient. Firstly, an exhaustive survey was carried out of ASV with different types of propulsion, followed by a study of the physical principles of sailing. Subsequently, the decision was to design a wind-propelled ASV, equipped with a rigid wing sail-tail assembly. This solution, which makes it possible to control the angle of attack of the wing sail with the wind through the tail, has low energy consumption. The idealised platform was modelled in SolidWorks and then controlled and simulated using the Robot Operating System (ROS) and the Gazebo environment. In order to correctly simulate the behaviour of the ASV in the Gazebo, it was necessary to reuse, modify and create plugins. The system for controlling the angle of attack of the wing sail and the sailboat’s direction used two Proportional Derivative (PD) controllers, one for the tail and the other for the rudder. The simulated ASV carries out missions defined through waypoints, including station keeping. Finally, tests were carried out to characterise and validate the physical behaviour and control of the sailboat. The results obtained are promising: the autonomous maritime station is able to sail towards the defined waypoints and remain within the given area of interest

Fire risk assessment in old urban areas: Coimbra old town

The fire risk assessment in old urban areas is a matter of concern both for those responsible for civil protection, and also for all inhabitants. These concerns range from the degradation of the old structures, bad electrical facilities, absence of detection systems and fire-fighting systems, lack of access for fire fighters’ vehicles, amongst others. Another major concern is that these urban centers present great heritage and cultural values. This study is based on a fire risk analysis on the historic old town of Coimbra, which was recently classified as World Heritage by UNESCO. In this study, fire risk assessment methods as GRETENER and ARICA were used with the purpose of obtaining values of the level of fire safety of buildings. After this analysis and knowing the results of methods, this study also aimed to point out measures to be implemented to improve the fire safety in the studied area.info:eu-repo/semantics/publishedVersio