780 resultados para Electrical engineering Study and teaching.
Resumo:
Economic backwardness often influences the growth of firms in developing countries. In this paper, we investigate the growth conditions and paths available for latecomers competing with first movers. Employing the concepts of boundaries of the firm and the disadvantage of backwardness, we present a case study of China's mobile handset industry and proceed to develop a simple model. We find that although significant disadvantage does not allow latecomers to grow, there are possibilities for changing the conditions of growth if latecomers can utilize outside resources and/or indigenous advantages.
Resumo:
A historical study and a construction pathology survey were conducted prior to proposing a solution for restoring the upper windows on the south side of Old San Carlos College at Saragossa (16th-17th centuries), wich had been forteited to add a third storey to the cloister. Althought initially designed to a simple large hall format, the church is a harmonius blend of Aragonese Gothic architecture and typical Jesuit scheme, consisting in a central nave flanket by chapel-confessional and raised galleries for the community. A subsequent enlargement of the roof, wich rests on the original framing over the central nave, reduced the mechanical strength of the principal rafters on the opposite side, prompting a concomitant imbalance of forces that has affected the entire structure. In view of the foregoing, in addition to restituting the upper window, the proposal solution envisages restoring the roof over the central nave to its original design, and with the interior lighting in the church.
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In the last decade, a large number of software repositories have been created for different purposes. In this paper we present a survey of the publicly available repositories and classify the most common ones as well as discussing the problems faced by researchers when applying machine learning or statistical techniques to them.
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The use of modular or ‘micro’ maximum power point tracking (MPPT) converters at module level in series association, commercially known as “power optimizers”, allows the individual adaptation of each panel to the load, solving part of the problems related to partial shadows and different tilt and/or orientation angles of the photovoltaic (PV) modules. This is particularly relevant in building integrated PV systems. This paper presents useful behavioural analytical studies of cascade MPPT converters and evaluation test results of a prototype developed under a Spanish national research project. On the one hand, this work focuses on the development of new useful expressions which can be used to identify the behaviour of individual MPPT converters applied to each module and connected in series, in a typical grid-connected PV system. On the other hand, a novel characterization method of MPPT converters is developed, and experimental results of the prototype are obtained: when individual partial shading is applied, and they are connected in a typical grid connected PV array
Resumo:
Around ten years ago investigation of technical and material construction in Ancient Roma has advanced in favour to obtain positive results. This process has been directed to obtaining some dates based in chemical composition, also action and reaction of materials against meteorological assaults or post depositional displacements. Plenty of these dates should be interpreted as a result of deterioration and damage in concrete material made in one landscape with some kind of meteorological characteristics. Concrete mixture like calcium and gypsum mortars should be analysed in laboratory test programs, and not only with descriptions based in reference books of Strabo, Pliny the Elder or Vitruvius. Roman manufacture was determined by weather condition, landscape, natural resources and of course, economic situation of the owner. In any case we must research the work in every facts of construction. On the one hand, thanks to chemical techniques like X-ray diffraction and Optical microscopy, we could know the granular disposition of mixture. On the other hand if we develop physical and mechanical techniques like compressive strength, capillary absorption on contact or water behaviour, we could know the reactions in binder and aggregates against weather effects. However we must be capable of interpret these results. Last year many analyses developed in archaeological sites in Spain has contributed to obtain different point of view, so has provide new dates to manage one method to continue the investigation of roman mortars. If we developed chemical and physical analysis in roman mortars at the same time, and we are capable to interpret the construction and the resources used, we achieve to understand the process of construction, the date and also the way of restoration in future.
Resumo:
En el presente trabajo se ha intentado obtener una visión, lo más exacta posible, de cuál ha sido el currículo académico seguido por los miembros de algunas de las universidades más prestigiosas en todo el mundo. Para ello se han tomado 36 centros, todos ellos impartiendo la misma titulación de "Electrical Engineering", situados entre los 50 más importantes del mundo.
Resumo:
This study constitutes an establishment of the main guidelines for the restoration of modern architecture, considering the E.1027 Maison en Bord de Meras a prototype for theortical and technical features. E.1027 Maison en Bord de Mer is a small villa built by Eileen Gray and Jean Badovici between 1926 and 1929 in Roquebrune Cap-Martin, France. Later on, the original project was modified because of successive interventions, altering the spatial qualities until being eventually abandoned in 2008. As a consequence of these variations, a meticulous documentation of the building turns essential in order to undertake its restoration. For that purpose, a description of the house and its historical evolution has been made, comparing plans of its different transformations and ending with a detailed survey of the current state. After presenting the particular pathologies of Cray's villa, the research concludes with the restoration proposal for E.1027 itself