239 research outputs found

    Mathematical Modeling And Simulation of Photo-Voltaic Converter Operation when Varying Different Parameters

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    The paper presents a method of mathematical modelling of a solar converter using the results of full-scale testing. The advantages of analytical modelling method applied to photovoltaic systems are also presented; this is because the model parameters are directly measurable by data acquisition from the photovoltaic field consisting of photovoltaic cells type Z - (mono-crystalline photovoltaic). The model parameter also includes both the photovoltaic cell characteristics as a device (forming the photovoltaic field) and the temperature influence on the photovoltaic field performance. The results of the photovoltaic model numerical simulation (PV) to the major parameters conversion variation can also be used to design and assess the performance of low and medium - power photovoltaic systems operating in single regime (to supply the home appliances)

    THE IMPACT OF ACCESSION TO THE EUROPEAN UNION ON PERCEPTIONS RELATED TO BUSINESS RISKS IN CENTRAL AND EASTERN EUROPE. A DISTANCE-TYPE ANALYSIS

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    The purpose of this paper is to investigate the impact of 2004 accession to the European Union on perceptions related to business risks in Central and Eastern European countries. The investigation makes use of the data provided by the Regular Reports on Global Competitiveness published annually by the World Economic Forum. Methodologically, our analysis requires the estimation of an average for the core of 15 member states of the European Union (EU 15) for each individual pillar considered to describe properly the business environment. In doing so, it is possible to measure the convergence – in terms of a distance-type analysis – of the new member states with the average of EU 15, prior and after the accession, comparatively. In addition, based on a k-means clustering technique, we investigate similarities between the same countries, as well as the convergence of different groups of countries with the group which contains this average.business risk, convergence, clusters, Eastern European Enlargement

    Analysis Of Functional Stability Of The Triphased Asynchronous Generator Used In Conversion Systems Of A Eolian Energy Into Electric Energy

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    This paper presents a study of the influence of the main perturbation agent over the functional stability of the triphased asynchronous generator (for the two alternative: with coiled and short circuit rotor), used for the conversion systems from a eolian energy into electric energy

    COMPARATIVE ANALYSIS OF THE BEHAVIOR OF COAXIAL AND FRONTAL COUPLINGS – WITH PERMANENT MAGNETS – IN HIGH TEMPERATURE ENVIRONMENTS

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    This paper presents a comparative analysis of the behavior of coaxial and frontal couplings – with permanent magnets – in high temperature environments specific to iron and steel industry. The comparative analysis is made at the level of the specific forces developed in the most difficult environments. The maximum temperature was limited for reasons of thermal stability of the Nd-Fe-B permanent magnets. In this context it was studied, by the help of the PDE-ase soft that uses the finite element method, the way magnetic induction modifies, the specific forces developed and the distribution of temperature within the coaxial and frontal couplers with permanent magnets, for variations of the distance between the magnets (air gap) within the limits 2-20 mm

    Design and Implementation of a Physical Bitcoin Coin

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    [Abstract] One of the major factors hindering the adoption of crypto assets in general, and Bitcoin in particular, is the high level of complexity they present to the common user. Although physical coins are a possible solution, the need to place trust in the manufacturers (so that they throw away the private key) is a big drawback that has hampered their widespread use. The recent boom of the maker movement has brought in a significant number of users with access to 3D printing devices, as well as the supporting electronic and computing resources. We have taken advantage of these capabilities to develop an open source project that interested parties can use to easily print a physical model of a Bitcoin coin, along with the necessary software that allows the creation and validation of keys and addresses.Xunta de Galicia; ED431C 2018/4

    System for Automatic Assessment of Alzheimer’s Disease Diagnosis Based on Deep Learning Techniques

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    [Abstract] Automatic detection of Alzheimer’s disease is a very active area of research. This is due to its usefulness in starting the protocol to stop the inevitable progression of this neurodegenerative disease. This paper proposes a system for the detection of the disease by means of Deep Learning techniques in magnetic resonance imaging (MRI). As a solution, a model of neuronal networks (ANN) and two sets of reference data for training are proposed. Finally, the goodness of this system is verified within the domain of the application

    Obtendo informaciĂłn Ăştil para a mellora dunha materia a partir dos resultados dos exames de resposta mĂşltiple

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    [Resumo] Os procesos de avaliación, deben aplicarse ós docentes e mesmo á materia en si, non só ós alumnos. Con esta finalidade formúlase unha análise dos resultados acadados polo alumnado durante a proba de avaliación empregada na materia de Marcos de Desenvolvemento (Grao en Enxeñaría Informática – Facultade de Informática). O exame é de resposta múltiple (4 opcións por pregunta, só unha válida e restando puntos as respostas erróneas). Os exames analízanse en dúas ramas: por unha banda, estúdanse as taxas de acerto/fallo/en branco de cada unha das preguntas; por outra, a porcentaxe de opcións (a,b,c,d, branco) en cada pregunta. Este sinxelo estudo, automatizado mediante o emprego dunha folla de cálculo, permite, non obstante, obter interesantes conclusións: • Detecta ambigüidades ou erros na formulación das preguntas que, polo xeral, se derivan nunha elevada porcentaxe de respostas en branco. • Detecta lagoas de coñecemento nalgunha das áreas da materia, que orixinan preguntas cunha elevada taxa de erros. Cada pregunta está asociada a un bloque teórico, polo que se podes establecer en qué aspectos os alumnos presentan máis ou menos coñecementos. Ambos aspectos poden ser empregados para detectar erros na formulación da materia e/ou exame e facer posible así a definición de plans de mellora de cara ós vindeiros cursos académicos
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