Suchergebnisse

Unmanned aerial vehicles (UAV's), initially used for military applications, have become increasingly attractive for civilian purposes. The use of this type of aircraft has grown exponentially in recent years, both for professional and recreational purposes, due to the numerous advantages they present. The increasingly demand of UAV led to an increase in investment, namely in the development of solar powered UAVs. Nowadays, with the arising of this type of UAV's, the mission planners have to start to be updated with new features considering UAV's with photovoltaic solar panels. This way, the present work describes the development and validation of a mission planner for solar powered UAV's, capable of planning and optimizing a mission given a initial guess of waypoints parameters (latitude, longitude, altitude and airspeed), considering real weather forecast and terrain elevation data. For this, the mission planner considers several mathematical models, required for the calculation of the mission performance, and a sequential quadratic programming algorithm to optimize the initial mission. After it describes the theoretical models, a practical application of the mission planner is done in order to verify its performance. Regarding its validation, several results divided by topics of interest are presented and discussed, concluding that the mission planner works efficiently, regarding the mission planning, even though, it has some aspects to be improved. ; Os veículos aéreos não tripulados (UAV's), inicialmente utilizados para aplicações militares, tornaram-se cada vez mais atraentes para fins civis. A utilização deste tipo de aeronave tem crescido exponencialmente nos últimos anos, tanto para fins profissionais como recreativos, devido às inúmeras vantagens que apresentam. Este aumento da procura levou a um crescente investimento no setor, nomeadamente nos UAVs movidos a energia solar, que hoje em dia já ocupam uma pequena fatia do mercado. No entanto, com o aparecimento deste tipo de UAV's, os softwares de planeamento de missões precisam de ser atualizados de forma a terem em conta a energia fornecida pelo sol. Desta forma, o presente trabalho descreve o desenvolvimento e validação de um planeador de missões para UAV's movidos a energia solar, capaz de planear e otimizar uma missão, considerando uma estimativa inicial dos parâmetros de cada waypoint (latitude, longitude, altitude e velocidade), e ainda considerando dados reais de previsão meteorologica e elevação de terreno. Para isso, o planeador de missões considera vários modelos matemáticos, necessários para o cálculo do desempenho da missão, e um algoritmo quadrático sequencial de forma a otimizar a missão inicial. Depois de descrever os modelos teóricos, uma aplicação prática do planeador de missão é feita com o objetivo de verificar o seu desempenho. Em relação à validação, vários resultados divididos por tópicos de interesse são apresentados e discutidos, concluindo: é eficiente em relação ao planeamento de missões, ainda assim, tendo alguns aspetos a serem melhorados.

Focalizo aqui brevemente a relação entre músicos indígenas – com ênfase no universo guarani – e o mercado da música, apontando para elementos específicos das demandas aí envolvidas. Se o lado indígena mostra sistemas estético-musicais abertos e flexíveis, ao lado da busca por caminhos de articulação política junto à sociedade envolvente, do lado do mercado a demanda se caracteriza em grande parte pela busca de um "índio" estereotipado ao qual seria negada a possibilidade de "mudar". Na parte final, alguns dos pontos levantados são considerados no exame de duas produções fonográficas recentes envolvendo músicas indígenas – guarani num caso e mehináku no outro. Indigenous music in the market: about demands, messages and noises in inter-musical (dis)encounters Abstract The article focuses the relation between indian musicians – with emphasis in the guarani universe - and the music market, pointing to specific elements of the demands involved. If the indian side shows open and flexible aesthetic-musical systems, coupled with the search for politic articulations with the more encompassing society, the markets´ demand characterizes itself to a large extent in the search of a stereotyped "indian" to whom it would be denied the possibility of "change". In the final part, some of the points raised are considered in the examination of two recent phonographic productions involving traditional musicians – Guarani in one case and Mehináku on the other.

The questions of how Entrepreneurship Education (EE) initiatives can be successfully spread and what political structures can help with their implementation during compulsory school remain open. We will add to the literature by proposing that the scale of the NUTS III and its governance model/characteristics are ideal for carrying out initiatives related to EE in the EU and, thus, developing local entrepreneurship ecosystems. We will do so based on the evidence gathered from the case study of the Intermunicipal Community of Viseu Dão-Lafões. To underpin our main argument, we will explain the successful case of how the Intermunicipal Community of Viseu Dão-Lafões (a NUTS III) managed to become an exception in the Portuguese scenario when it comes to the funding, administrative articulation, and implementation of EE programmes for youths in the region. ; info:eu-repo/semantics/publishedVersion

Having identified the need to conduct research on the intersection between entrepreneurship education (EE) and public policies, we carried out a systematic literature review on decision-making processes regarding the implementation of education for entrepreneurship programs in schools and the introduction of this topic in the policy-making process. This SLR followed every process inherent to its well-established protocol. The research undertaken confirmed that the understanding of decision processes associated with the implementation of EE programs is not only a "missing link" in the discussions about the way in which countries manage situations related to EE, but also a gap in academic knowledge. Indeed, the SLR process included only nine articles in the final review (obtained through a methodology based on an algorithm)—which is a clear sign that further scientific research around this specific topic is needed. The articles included in the final review suggest that: (i) entrepreneurship is fundamental to the progress and evolution of countries and their regions, (ii) there is evidence that EE is central to a more entrepreneurial youth, and (iii) the successful implementation of recommendations from regulatory institutions is based on political commitment and implementation capacities. ; info:eu-repo/semantics/publishedVersion

Purpose
– The purpose of this paper is to assess to what extent the loss of the ISO 9001 certification affects the decertified firms' financial performance.


Design/methodology/approach
– Using standard event study methods, this paper matches a sample of 143 Portuguese companies that lost their ISO 9001 certification with similar non-event counterpart firms (according to return-on-assets (ROA) and size) and compares the performance of these two groups of firms using financial data collected from the AMADEUS database.


Findings
– Results show no statistical significant differences in the financial performance (as measured by ROA, return-on-sales (ROS) and sales growth) between companies that lost their ISO 9001 certification and their matched firms. Although the literature suggests that certification improves firms' performance and that the benefits of certification may last over long periods of time, this paper's results suggest that, after decertification, companies do not exhibit over or underperformance in their operations vis-à-vis comparable firms that do not undergo the same event.


Originality/value
– As far as the authors are aware, this is the first study assessing the impact of ISO 9001 certificate withdrawal on the decertified firms' financial performance.

In the last few years, the number of systems and devices that use voice based interaction has grown significantly. For a continued use of these systems, the interface must be reliable and pleasant in order to provide an optimal user experience. However there are currently very few studies that try to evaluate how pleasant is a voice from a perceptual point of view when the final application is a speech based interface. In this paper we present an objective definition for voice pleasantness based on the composition of a representative feature subset and a new automatic voice pleasantness classification and intensity estimation system. Our study is based on a database composed by European Portuguese female voices but the methodology can be extended to male voices or to other languages. In the objective performance evaluation the system achieved a 9.1% error rate for voice pleasantness classification and a 15.7% error rate for voice pleasantness intensity estimation. ; Work partially supported by ERDF funds, the Spanish Government (TEC2009-14094-C04-04), and Xunta de Galicia (CN2011/019, 2009/062)