Browsing by Issue Date, starting with "2016-10"
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- Using clustering techniques to provide simulation scenarios for the smart gridPublication . Miguel, Pedro; Gonçalves, José; Pires Neves, Luís; Martins, A. GomestThe objective of this work is to obtain characteristic daily profiles of consumption, wind generationand electricity spot prices, needed to develop assessments of two different options commonly regardedunder the smart grid paradigm: residential demand response, and small scale distributed electric energystorage. The approach consists of applying clustering algorithms to historical data, namely using a hierar-chical method and a self-organizing neural network, in order to obtain clusters of diagrams representingcharacteristic daily diagrams of load, wind generation or electricity price. These diagrams are useful notonly to analyze different scenarios of combined existence, but also to understand their individual relativeimportance. This study enabled also the identification of a probable range of variation around an averageprofile, by defining boundary profiles with the maximum and minimum values of any cluster prototypes.
- Methodology for real impact assessment of the best location of distributed electric energy storagePublication . Gonçalves, José; Martins, António; Pires Neves, LuísThis paper presents a methodology to provide a decision maker, e.g. the distribution system operator,information on the associated impacts of the operation of distributed electric energy storage systems(ESS1) in an urban environment, in order to support the choice of the best locations of storage units. Thedeveloped methodology uses three types of profile prototypes based on actual data, obtained throughclustering techniques. These profiles, which include electricity demand, electricity prices and renewableelectricity production, are used to optimize the placement of electric energy storage units. The paper con-siders expected attitudes of the main stakeholders towards distributed electric ESS implementation, anddiscusses possible regulatory framework options to define the distributed electric ESS business model.The model was applied to a case study using the nanophosphate lithium-ion battery technology as anexample. Results show a significant influence of the charge/discharge profile of batteries on the choiceof their best locations.
- A multiresidue approach for the simultaneous quantification of antibiotics in macroalgae by ultra-high performance liquid chromatography–tandem mass spectrometryPublication . Leston, Sara; Freitas, Andreia; Rosa, João; Barbosa, Jorge; Lemos, Marco; Pardal, Miguel Ângelo; Ramos, FernandoTogether with fish, algae reared in aquaculture systems have gained importance in the last years, for many purposes. Besides their use as biofilters of effluents, macroalgae’s rich nutritional profiles have increased their inclusion in human diets but also in animal feeds as sources of fatty acids, especially important for the fish industry. Nonetheless, algae are continuously exposed to environmental contaminants including antibiotics and possess the ability for bioaccumulation of such compounds. Therefore, the present paper describes the development and validation of an ultra-high performance liquid chromatography with tandem mass spectrometry (UPLC–MS/MS) method for the simultaneous quantification of antibiotics in the green macroalgae Ulva lactuca. This multi-residue method enables the determination of 38 compounds distributed between seven classes and was fully validated according to EU Decision 2002/657/EC.
- Reconstruction of lost depth data in multiview video-plus-depth communications using geometric transformsPublication . Marcelino, Sylvain; Soares, Salviano; Faria, Sergio; Assunção, PedroThis paper addresses depth data recovery in multiview video-plus-depth communications affected by transmission errors and/or packet loss. The novel aspects of the proposed method rely on the use of geometric transforms and warping vectors, capable of capturing complex motion and view-dependent deformations, which are not efficiently handled by traditional motion and/or disparity compensation methods. By exploiting the geometric nature of depth information, a region matching approach combined with depth contour reconstruction is devised to achieve accurate interpolation of arbitrary shapes within lost regions of depth maps. The simulation results show that, for different packet loss rates, up to 20%, the depth maps recovered by the proposed method produce virtual views with better quality than existing methods based on motion information and spatial interpolation. An average PSNR gain of 1.48 dB is obtained in virtual views synthesised from depth maps using the proposed method.
- Fatigue behaviour of selective laser melting steel componentsPublication . Santos, L.M.S.; Ferreira, J.A.M.; Jesus, J.S.; Costa, J.M.; C. CapelaSelective laser melting (SLM) is a laser based rapid manufacturing technology that builds metal parts layer-by-layer using metal powders and a computer controlled laser. Various important aspects strongly affect the mechanical properties of sintered metal components, such as: porosity, surface roughness, scan speed, layer thickness, and residual stresses. Therefore, properties of SLM manufactured parts must be carefully analysed, particularly under fatigue conditions. The purpose of this work was to study the effect of scan speed, porosity and microstructure on the mechanical properties and fatigue strength of sintered laser samples. Sintered laser parts were manufactured in maraging steel AISI 18Ni300. Fatigue behaviour is related to process parameters, such as: surface residual stresses, microstructure and porosity. The results showed that a very high scan speed (400 or 600 mm/s) causes the appearance of high percentages of porosity and a consequent drastic reduction of tensile strength and stiffness. Fatigue behaviour was assessed in terms of the traditional S-N curves and of the da/dN–DK crack propagation curves. Fatigue life predictions based on Hartman and Schijve’s equation underestimated significantly fatigue lives, particularly for low stress levels. The results of the tests performed at variable amplitude loading were well fitted by Miner’s law.
- Marca da União Europeia: recentes alterações legislativasPublication . Lucas, EugénioNo processo de construção da União Europeia, que teve início em 1952, o tema da propriedade industrial, em concreto as marcas, não foi uma prioridade como o foram outras políticas comuns. Só em 1994 surge o primeiro normativo relativo à marca comunitária, que foi sucessivamente alterado, sendo a mais recente alteração legislativa de 2015, em resultado da qual a marca comunitária se passou a denominar marca da União Europeia.
- Estimation of mirror shape and extrinsic parameters in axial non-central catadioptric systemsPublication . Perdigoto, Luis; Araujo, HelderWe propose a method to estimate the mirror shape and position, and the extrinsic parameters in axial noncentral catadioptric systems (i.e. systems with an axial symmetrical mirror and a pinhole camera with its optical center located at the mirror axis). Our method requires one or more images of a planar calibration pattern consisting of points and lines with known position (e.g. a checkerboard), and that the camera be internally calibrated. We also present an alternative algorithm for the particular case of catadioptric systems with spherical mirror, were the estimation is achieved by fitting quartic curves to the images of lines of the calibration pattern. An analytical solution is presented for every method. Each analytical solution is then refined by a non-linear optimization procedure. We present experimental results, on simulated and real images, that demonstrate the validity of our work.
- A importância da liderança transformacional no grupo CALZEDONIA, em PortugalPublication . Silva, Salomé Rodrigues da; Marcelino, Neuza Manuel Pereira RibeiroO presente estudo analisa a relação entre Liderança Transformacional e o Empenhamento Afetivo dos subordinados e o seu Desempenho Individual, e, ainda analisa a relação entre o Empenhamento Afetivo dos subordinados e o seu Desempenho Individual. A Liderança Transformacional é agradavelmente diferente de todas as teorias de liderança anteriores na medida em que é capaz de modificar comportamentos e formar profissionais e pessoas melhores, através de exemplos e atitudes. O líder transformacional é uma referência positiva, um modelo a seguir, é uma fonte e inspiração para todos. Os líderes transformacionais promovem um alto nível de empenhamento dos subordinados, e conseguem que estes exerçam mais esforço, e que alcancem elevados níveis de desempenho, bem como elevados níveis morais e éticos. Este estudo inclui uma amostra de 149 colaboradores do grupo CALZEDONIA, que desempenham a função de Assistente de Vendas e de Gerente de Loja (ou Store Manager) em Portugal. Para a análise dos dados foi usado o software IBM SPSS Statistics, versão 22. Os resultados indicaram que a Liderança Transformacional explica cerca de 12 % do Empenhamento Afetivo e 19% do Desempenho Individual, e que o Empenhamento Afetivo explica cerca de 14% do Desempenho Individual, naturalmente existem outros fatores que também explicam estas variáveis em estudo. Deste estudo é possível concluir que a Liderança Transformacional tem um papel importante na promoção do empenhamento dos subordinados e na produção de grandes mudanças e elevados desempenhos dos colaboradores, portanto contribui para o crescimento sustentável da organização.
- The organisation of physiotherapy for people with multiple sclerosis across Europe: a multicentre questionnaire surveyPublication . Rasova, Kamila; Freeman, Jenny; Martinkova, Patricia; Pavlikova, Marketa; Cattaneo, Davide; Jonsdottir, Johanna; Henze, Thomas; Baert, Ilse; Van Asch, Paul; Santoyo, Carme; Smedal, Tori; Beiske, Antonie Giæver; Stachowiak, Małgorzata; Kovalewski, Mariusz; Nedeljkovic, Una; Bakalidou, Daphne; Alves-Guerreiro, José; Nilsagård, Ylva; Dimitrova, Erieta Nikolikj; Habek, Mario; Armutlu, Kadriye; Donzé, Cécile; Ross, Elaine; Ilie, Ana Maria; Martić, Andrej; Romberg, Anders; Feys, PeterBackground: Understanding the organisational set-up of physiotherapy services across different countries is increasingly important as clinicians around the world use evidence to improve their practice. This also has to be taken into consideration when multi-centre international clinical trials are conducted. This survey aimed to systematically describe organisational aspects of physiotherapy services for people with multiple sclerosis (MS) across Europe. Methods: Representatives from 72 rehabilitation facilities within 23 European countries completed an online web-based questionnaire survey between 2013 and 2014. Countries were categorised according to four European regions (defined by United Nations Statistics). Similarities and differences between regions were examined. Results: Most participating centres specialized in rehabilitation (82 %) and neurology (60 %), with only 38 % specialising in MS. Of these, the Western based Specialist MS centres were predominately based on outpatient services (median MS inpatient ratio 0.14), whilst the Eastern based European services were mostly inpatient in nature (median MS inpatient ratio 0.5). In almost all participating countries, medical doctors - specialists in neurology (60 %) and in rehabilitation (64 %) - were responsible for referral to/prescription of physiotherapy. The most frequent reason for referral to/prescription of physiotherapy was the worsening of symptoms (78 % of centres). Physiotherapists were the most common members of the rehabilitation team; comprising 49 % of the team in Eastern countries compared to approximately 30 % in the rest of Europe. Teamwork was commonly adopted; 86 % of centres based in Western countries utilised the interdisciplinary model, whilst the multidisciplinary model was utilised in Eastern based countries (p = 0.046). Conclusion: This survey is the first to provide data about organisational aspects of physiotherapy for people with MS across Europe. Overall, care in key organisational aspects of service provision is broadly similar across regions, although some variations, for example the models of teamwork utilised, are apparent. Organisational framework specifics should be considered anytime a multi-centre study is conducted and results from such studies are applied.
- Prototype and proof of concept for a display system in retail storesPublication . Matos, David Emanuel Ruivo; Rabadão, Carlos Manuel da SilvaSelling devices on retail stores comes with the big challenge of grabbing the customer’s attention. Nowadays people have a lot of offers at their disposal and new marketing techniques must emerge to differentiate the products. When it comes to smartphones and tablets, those devices can make the difference by themselves, if we use their computing power and capabilities to create something unique and interactive. With that in mind, three prototypes were developed during an internship: a face recognition based Customer Detection, a face tracking solution with an Avatar and interactive cross-app Guides. All three revealed to have potential to be differentiating solutions in a retail store, not only raising the chance of a customer taking notice of the device but also of interacting with them to learn more about their features. The results were meant to be only proof of concepts and therefore were not tested in the real world.