Digitally-implemented naturally sampled PWM suitable for multilevel converter control

For dynamic closed loop control of a multilevel converter with a low pulse number (ratio of switching frequency to synthesized fundamental), natural sampled pulse-width modulation (PWM) is the best form of modulation. Natural sampling does not introduce distortion or a delayed response to the modulating signal. However previous natural sampled PWM implementations have generally been analog. For a modular multilevel converter, a digital implementation has advantages of accuracy and flexibility. Re-sampled uniform PWM is a novel digital modulation technique which approaches the performance of natural PWM. Both hardware and software implementations for a five level multilevel converter phase are presented, demonstrating the improvement over uniform PWM.

Decision support system with incomplete and domain incoherent information management

Many of the most common human functions such as temporal and non-monotonic reasoning have not yet been fully mapped in developed systems, even though some theoretical breakthroughs have already been accomplished. This is mainly due to the inherent computational complexity of the theoretical approaches. In the particular area of fault diagnosis in power systems however, some systems which tried to solve the problem, have been deployed using methodologies such as production rule based expert systems, neural networks, recognition of chronicles, fuzzy expert systems, etc. SPARSE (from the Portuguese acronym, which means expert system for incident analysis and restoration support) was one of the developed systems and, in the sequence of its development, came the need to cope with incomplete and/or incorrect information as well as the traditional problems for power systems fault diagnosis based on SCADA (supervisory control and data acquisition) information retrieval, namely real-time operation, huge amounts of information, etc. This paper presents an architecture for a decision support system, which can solve the presented problems, using a symbiosis of the event calculus and the default reasoning rule based system paradigms, insuring soft real-time operation with incomplete, incorrect or domain incoherent information handling ability. A prototype implementation of this system is already at work in the control centre of the Portuguese Transmission Network.

Development and characterization of microsattelite Loci for the harvested limpets Patella Candei (D'orbigny, 1839) and Patella Aspera (Röding, 1798) using 454 sequencing

World Congress of Malacology, Ponta Delgada, July 22-28, 2013.

Plataforma de gestão de incidentes

Mestrado em Engenharia Electrotécnica e de Computadores. Área de Especialização de Telecomunicações.

Board-level prototype validation: a built-in controller and extended BST architecture

Prototype validation is a major concern in modern electronic product design and development. Simulation, structural test, functional and timing debug are all forming parts of the validation process, although very often addressed as dissociated tasks. In this paper we describe an integrated approach to board-level prototype validation, based on a set of mandatory/optional BST instructions and a built-in controller for debug and test, that addresses the late mentioned tasks as inherent parts of a whole process

Theory and phenomenology of two-higgs-doublet models

We discuss theoretical and phenomenological aspects of two-Higgs-doublet extensions of the Standard Model. In general, these extensions have scalar mediated flavour changing neutral currents which are strongly constrained by experiment. Various strategies are discussed to control these flavour changing scalar currents and their phenomenological consequences are analysed. In particular, scenarios with natural flavour conservation are investigated, including the so-called type I and type II models as well as lepton-specific and inert models. Type III models are then discussed, where scalar flavour changing neutral currents are present at tree level, but are suppressed by either a specific ansatz for the Yukawa couplings or by the introduction of family symmetries leading to a natural suppression mechanism. We also consider the phenomenology of charged scalars in these models. Next we turn to the role of symmetries in the scalar sector. We discuss the six symmetry-constrained scalar potentials and their extension into the fermion sector. The vacuum structure of the scalar potential is analysed, including a study of the vacuum stability conditions on the potential and the renormalization-group improvement of these conditions is also presented. The stability of the tree level minimum of the scalar potential in connection with electric charge conservation and its behaviour under CP is analysed. The question of CP violation is addressed in detail, including the cases of explicit CP violation and spontaneous CP violation. We present a detailed study of weak basis invariants which are odd under CP. These invariants allow for the possibility of studying the CP properties of any two-Higgs-doublet model in an arbitrary Higgs basis. A careful study of spontaneous CP violation is presented, including an analysis of the conditions which have to be satisfied in order for a vacuum to violate CP. We present minimal models of CP violation where the vacuum phase is sufficient to generate a complex CKM matrix, which is at present a requirement for any realistic model of spontaneous CP violation.

Human and climatic change impact modelling on the habitat suitability for the chimpanzee (Pan troglodytes ellioti) – Case study: The proposed Mount Cameroon National Park

Dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Science in Geospatial Technologies

Historically accurate reconstructions and characterisation of chrome yellow pigments

Dissertation presented at the Faculty of Sciences and Technology of the New University of Lisbon in fulfillment of the requirements for the Master degree in Conservation Science

Morbidity and survival in advanced AIDS in Rio de Janeiro, Brazil

Opportunistic diseases (OD) are the most common cause of death in AIDS patients. To access the incidence of OD and survival in advanced immunodeficiency, we included 79 patients with AIDS treated at Hospital Evandro Chagas (FIOCRUZ) from September 1997 to December 1999 with at least one CD4 count <=100 cells/mm³. The incidence of OD was analyzed by Poisson's regression, and survival by Kaplan Meier and Cox analysis, considering a retrospective (before CD4 <=100 cells/mm³) and a prospective (after CD4 <=100 cells/mm³) period, and controlling for demographic, clinical and laboratory characteristics. The confidence interval estipulated was 95%. Mean follow-up period was 733 days (CI = 683-782). During the study 9 (11.4%) patients died. Survival from AIDS diagnosis was a mean of 2589 days (CI = 2363-2816) and from the date of the CD4 count CD4 <=100 cells/mm³ was a mean of 1376 (CI = 1181-1572) days. Incidence of OD was 0.51 pp/y before CD4 <= 100 cells/mm³ and 0.29 pp/y after CD4 <= 100 cells/mm³. A lower number of ODs before CD4 < 100 cells/mm³ was associated with lower incidence rates after CD4 <= 100 cells/mm³. AIDS diagnosis based on CD4+ counts <= 200 cells/mm³ was associated with lower incidence rates after CD4 <= 100 cells/mm³. Baseline CD4 counts above 50 cells/mm³ (HR = 0.13) and restoration of baseline CD4+ counts above 100 cells/mm³ (HR = 0.16) were associated with a lower risk of death. Controling both variables, only restoration of baseline counts was statistically significant (HR = 0.22, p = 0.04). We found a very low incidence of OD and long survival after CD4 < 100 cells/mm³. Survival was significantly associated with restoration of baseline CD4 counts above 100 cells/mm³.

Re-Use Assessment of Thermoset Composite Wastes as Aggregate and Filler Replacement for Concrete-Polymer Composite Materials: A case study regarding GFRP pultrusion wastes

Glass fibre-reinforced plastics (GFRP), nowadays commonly used in the construction, transportation and automobile sectors, have been considered inherently difficult to recycle due to both the cross-linked nature of thermoset resins, which cannot be remoulded, and the complex composition of the composite itself, which includes glass fibres, polymer matrix and different types of inorganic fillers. Hence, to date, most of the thermoset based GFRP waste is being incinerated or landfilled leading to negative environmental impacts and additional costs to producers and suppliers. With an increasing awareness of environmental matters and the subsequent desire to save resources, recycling would convert an expensive waste disposal into a profitable reusable material. In this study, the effect of the incorporation of mechanically recycled GFRP pultrusion wastes on flexural and compressive behaviour of polyester polymer mortars (PM) was assessed. For this purpose, different contents of GFRP recyclates (0%, 4%, 8% and 12%, w/w), with distinct size grades (coarse fibrous mixture and fine powdered mixture), were incorporated into polyester PM as sand aggregates and filler replacements. The effect of the incorporation of a silane coupling agent was also assessed. Experimental results revealed that GFRP waste filled polymer mortars show improved mechanical behaviour over unmodified polyester based mortars, thus indicating the feasibility of GFRP waste reuse as raw material in concrete-polymer composites.

Rehabilitation of renders of old buildings in Portugal: survey, supporting methodology proposal and case study

The main purpose of the research is to present a proposal for a methodology to support the rehabilitation project of renders of old buildings in Portugal. To achieve the objective it was considered essential to define the main types of participants and aspects to integrate the proposal. The research methodology consists in an inquiry presented to professional participants in rehabilitation, a market study of materials and products available in Portugal, the design of a methodology proposal and its application to a case study. The inquiry sample totals 24 answers from the targeted professionals. A sequence of relevant supporting procedures consists in the proposal, which aims to provide a supporting methodology to decide and project in this context and also to be tested with its application to the building. This proposal was applied to an old building with load-bearing stone masonry walls and air-lime based renders. It was concluded that the assessment of the building and external renderings’ condition, its diagnosis and of the supporting walls, the definition of intervention, the specification of materials to be used and performance requirements to comply, and also plans for conservation and periodic maintenance, are crucial. From the inquiry, compatibility between materials and complementary roles and points of view of different types of participants in rehabilitation must be highlighted. A proposal for a methodology to support the project could provide useful guidance particularly for architects and construction engineers, and improve the understanding of direct participants on site, therefore contributing for the correct implementation of intervention.

Rehabilitation of renders of old buildings in Portugal: survey, supporting methodology proposal and case studies

The main purpose of the research is to present a proposal for a methodology to support the rehabilitation project of renders of old buildings. To achieve the objective it was considered essential to define the main types of participants and aspects to integrate the proposal. The research methodology consists in an inquiry presented to several professional participants in rehabilitation, a market study of materials and products available in Portugal, the design of a methodology proposal and its application to a case study. The inquiry sample totals 24 answers from the targeted professionals. A sequence of relevant supporting procedures consists in the proposal, which aims to provide a supporting methodology to decide and project in this context and also to be tested with its application to the building. This proposal was applied to an old building with load-bearing stone masonry walls and air-lime based renders. It was concluded that the assessment of the building and external renderings’ condition, its diagnosis and of the supporting walls, the definition of intervention, the specification of materials to be used and performance requirements to comply, and also plans for conservation and periodic maintenance, are crucial. From the inquiry, compatibility between materials and complementary roles and points of view of different types of participants in rehabilitation must be highlighted. A proposal for a methodology to support the project could provide useful guidance particularly for architects and construction engineers, and improve the understanding of direct participants on site, therefore contributing for the correct implementation of the intervention.

Aquatic and semiaquatic Heteroptera (Insecta) from Pitinga, Amazonas, Brazil

A list of aquatic and semiaquatic Heteroptera from a collecting trip to Pitinga, a village in a mining area in the County of Presidente Figueiredo in the Central Amazon is presented. Identified were fifty five species of Heteroptera, distributed in 13 families. Among the insects collected, some are new records for this Amazonian region and in addition 3 apparently undescribed species of Microvelia and one of Paravelia remain for further study.

Otra visión del patrimonio geológico: la puesta en valor de los depósitos cuaternários de la costa galega (NW España)

En la última década se ha desarrollado una base de conocimiento sólido relacionado con la geodiversidad, caracterización, conservación y gestión del patrimonio geológico, que lleva implícito una legislación al respecto. Sin embargo, el escaso conocimiento a nivel científico por parte de la Administración sobre “lugares de interés geológico” hace complicado conseguir una normativa adecuada, a fin de proteger algo que no está contemplado. A esto se suma, un desconocimiento parcial de la sociedad sobre procesos geológicos, su relación con la biodiversidad y su valor como patrimonio natural. Este trabajo tiene como objetivo mostrar el valor de los depósitos sedimentarios antiguos localizados en la costa de Galicia como archivos paleoambientales y geoformas con entidad propia. Estos valores son ejemplificados con depósitos localizados en la “Costa Sur”, así definida en el Plan de Ordenación Litoral (POL) de Galicia.