Shape theory and mathematical design of a general geometric kernel through regular stratified objects

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This dissertation focuses on the mathematical design of a unified shape kernel for geometric computing, with possible applications to computer aided design (CAM) and manufacturing (CAM), solid geometric modelling, free-form modelling of curves and surfaces, feature-based modelling, finite element meshing, computer animation, etc. The generality of such a unified shape kernel grounds on a shape theory for objects in some Euclidean space. Shape does not mean herein only geometry as usual in geometric modelling, but has been extended to other contexts, e. g. topology, homotopy, convexity theory, etc. This shape theory has enabled to make a shape analysis of the current geometric kernels. Significant deficiencies have been then identified in how these geometric kernels represent shapes from different applications. This thesis concludes that it is possible to construct a general shape kernel capable of representing and manipulating general specifications of shape for objects even in higher-dimensional Euclidean spaces, regardless whether such objects are implicitly or parametrically defined, they have ‘incomplete boundaries’ or not, they are structured with more or less detail or subcomplexes, which design sequence has been followed in a modelling session, etc. For this end, the basic constituents of such a general geometric kernel, say a combinatorial data structure and respective Euler operators for n-dimensional regular stratified objects, have been introduced and discussed

Contour Enhancement Algorithm for Improving Visual Perception of Deutan and Protan Dichromats

A variety of recoloring methods has been proposed in the literature to remedy the problem of confusing red-green colors faced by dichromat people (as well by other color-blinded people). The common strategy to mitigate this problem is to remap colors to other colors. But, it is clear this does not guarantee neither the necessary contrast to distinguish the elements of an image, nor the naturalness of colors learnt from past experience of each individual. In other words, the individual’s perceptual learning may not hold under color remapping. With this in mind, we introduce the first algorithm primarily focused on the enhancement of object contours in still images, instead of recoloring the pixels of the regions bounded by such contours. This is particularly adequate to increase contrast in images where we find adjacent regions that are color-indistinguishable from the dichromacy’s point of view.info:eu-repo/semantics/publishedVersio

Contour Enhancement Algorithm for Improving Visual Perception of Deutan and Protan Dichromats

A variety of recoloring methods has been proposed in the literature to remedy the problem of confusing red-green colors faced by dichromat people (as well by other color-blinded people). The common strategy to mitigate this problem is to remap colors to other colors. But, it is clear this does not guarantee neither the necessary contrast to distinguish the elements of an image, nor the naturalness of colors learnt from past experience of each individual. In other words, the individual’s perceptual learning may not hold under color remapping. With this in mind, we introduce the first algorithm primarily focused on the enhancement of object contours in still images, instead of recoloring the pixels of the regions bounded by such contours. This is particularly adequate to increase contrast in images where we find adjacent regions that are color-indistinguishable from the dichromacy’s point of view

Polygonization of Multi-Component Non-Manifold Implicit Surfaces through A Symbolic-Numerical Continuation Algorithm

In computer graphics, most algorithms for sampling implicit surfaces use a 2-points numerical method. If the surface-describing function evaluates positive at the first point and negative at the second one, we can say that the surface is located somewhere between them. Surfaces detected this way are called sign-variant implicit surfaces. However, 2-points numerical methods may fail to detect and sample the surface because the functions of many implicit surfaces evaluate either positive or negative everywhere around them. These surfaces are here called sign-invariant implicit surfaces. In this paper, instead of using a 2-points numerical method, we use a 1-point numerical method to guarantee that our algorithm detects and samples both sign-variant and sign-invariant surface components or branches correctly. This algorithm follows a continuation approach to tessellate implicit surfaces, so that it applies symbolic factorization to decompose the function expression into symbolic components, sampling then each symbolic function component separately. This ensures that our algorithm detects, samples, and triangulates most components of implicit surfaces

Modelling the bending behaviour of plain-woven fabric using flat shell element and strain smoothing technique

This paper describes a new approach to improve on modelling the bending behaviour of plain-woven fabric. The four-node flat shell element is developed by incorporating a strain smoothing technique, six degrees of freedom at each node. The material laws for in-plane and out-of-plane behaviors are expressed in terms of orthotropic elastic material. The physical and mechanical parameters of fabric samples are measured using Kawabata Evaluating System for Fabric (KES-F). An improved numerical model with a strain smoothing operation for modelling the bending behaviour of plain-woven fabric is then carried out. The bending behavior of a rectangular plain-woven fabric sheet with clamped edges is simulated.Fundação para a Ciência e a Tecnologia (FCT

ANALYSIS OF THE EARTH CONSTRUCTION’S THERMAL BEHAVIOR – IN SITU MEASUREMENT AND EVALUATION OF THERMAL PERFORMANCE OF THREE RAMMED EARTH CASE STUDIES

The emergence of the new paradigm of sustainable construction related to the concern of excessive energy consumption of our society, led to the investigation of techniques, materials and construction solutions that could causes less environmental impact. Consequently, the interest given to ancient techniques that dealt with earth constructive solutions aroused, which has captivated the interest of architects, builders and people in general. Although this type of material is associated to a less dignified and poor construction, the search for modern expression in new buildings’ design has shown the physical and plastic potential of the usage of earth in modern architecture. However, the regulation of the constructions’ minimum requirements related to materials’ mechanical strength and thermal performance (such as the Portuguese Thermal Building Regulation- RCCTE), has been one of the biggest obstacles in spreading and growing the application of this technique. This study intends to increase the knowledge of the thermal behavior of this type of construction. In this article, the results of in situ measurement campaigns, carried out during the summer and winter periods, are presented. They were performed on three different single-family dwellings located in Abrantes, Portugal. These dwellings were built using the rammed-earth technique, each one having walls with 50-55 cms of thickness. Several experimental measurements were conducted in order to evaluate the rammed-earth wall thermal behavior, such as: the incident global radiation on vertical plane of the facade; indoor and outdoor environment temperatures and moisture; indoor and outdoor surfaces wall temperatures; and heat flows. The experimental results revealed a large thermal inertia of the walls, which led to low indoor temperatures in both seasons. The results demonstrate the need to improve the thermal conductivity of the earth in order to meet the minimum requirements imposed by the Building Regulations

Análise reflexiva do ensino de língua portuguesa: um caminho para novas práticas pedagógicas

The present work, entitled “Reflective Analysis of Portuguese Language Teaching: A Path to New Pedagogical Practices”, was linked to the research project “Professional Portuguese teacher: his formation and his acting in contemporary”, coordinated by Prof. Dr. Thaís Fernandes Sampaio was required for approval at the Professional Master in Letters (PROFLETRAS) of the Federal University of Juiz de Fora (UFJF). Among the objectives of this research is the promotion of reflective analysis of our teaching practice anchored in the movements of critical reflection (LIBERALI, 2012). This is due to the interest in checking the means to resort to promoting change (FULLAN, 2009) in our pedagogical action. To this end, we sought guidance from some of the leading theorists (ANTUNES, 2003; BAGNO, 2000; DOLZ; NOVERRAZ; SCHNEUWLY, 2004; KOCH, 2005; MARCUSCHI, 2008; TRAVAGLIA, 1998) as well as official documents. (BRASIL, 1998; BRASIL, 2018; MINAS GERAIS, 2004) that guide Portuguese language teaching in the country. It was also worked on the elaboration and development of an intervention proposal, based on reflective teaching practices (ALARCÃO, 2000; 2005; GADOTTI, 2000; GHEDIN, 2002; GIROUX, 1997; KLEIMAN, 2008; LIBERALI, 2012; NÓVOA, 2008; SAMPAIO; SANTOS, 2018, ZEICHNER, 1993), in a ninth grade class at a network school state school in the state of Minas Gerais. Our proposal came from a situation that occurred unexpectedly within our classroom involving a gypsy student. This event and the invisibility of the residents of the Gypsy camps near the school inspired us to work on the life and culture of the people living in the Roma communities. This project was didactically divided into five stages, however the actions were intrinsically articulated and took place to make the work more meaningful to the participants. Thus, we sought answers and positions about the collaborative learning, the teacher as a mediator, the student protagonism, the place of the text in the LP class; concerns that guided our research. As a product of this theoretical-methodological study, a theoretical text (dissertation) and a pedagogical notebook were defended before the newsstand in which the development of this interventionist proposal was demonstrated step by step.O presente trabalho, intitulado “Análise reflexiva do ensino de língua portuguesa: um caminho para novas práticas pedagógicas” vinculou-se ao projeto de pesquisa “O profissional professor de Português: sua formação e sua atuação na contemporaneidade”, coordenado pela Prof. Dra. Thaís Fernandes Sampaio foi requisito para aprovação no Mestrado Profissional em Letras (PROFLETRAS) da Universidade Federal de Juiz de Fora (UFJF). Entre os objetivos desta pesquisa está a promoção de análise reflexiva de nossa prática docente ancorados nos movimentos da reflexão crítica (LIBERALI, 2012). Isso devido ao interesse na verificação dos meios aos quais recorrer para a promoção de mudanças (FULLAN, 2009) em nossa ação pedagógica. Para tanto, buscou-se orientações em alguns dos principais teóricos, (ANTUNES, 2003; BAGNO, 2000; DOLZ, NOVERRAZ, SCHNEUWLY, 2004; KOCH, 2005; MARCUSCHI, 2008; TRAVAGLIA, 1998;) bem como em documentos oficiais (BRASIL, 1998; BRASIL, 2018; MINAS GERAIS, 2004) que orientam o ensino de Língua Portuguesa no País. Trabalhou-se, ainda, na elaboração e desenvolvimento de uma proposta interventiva, com base em práticas reflexivas de ensino (ALARCÃO, 2000; 2005; GADOTTI, 2000; GHEDIN, 2002; GIROUX, 1997; KLEIMAN, 2008; LIBERALI, 2012; NÓVOA, 2008; SAMPAIO; SANTOS, 2018, ZEICHNER,1993), em uma turma de nono ano de escolaridade em uma escola da rede estadual de ensino no estado de Minas Gerais. Nossa proposta partiu de uma situação ocorrida inesperadamente dentro de nossa sala de aula envolvendo uma aluna cigana. O referido acontecimento e a invisibilidade dos moradores dos acampamentos ciganos nas proximidades da escola nos inspiraram a trabalhar sobre a vida e cultura dos povos que vivem nas comunidades ciganas. Este projeto foi didaticamente dividido em cinco etapas, entretanto as ações estiveram intrinsecamente articuladas e se deram de forma a tornar o trabalho mais significativo para os participantes. Dessa forma procurou-se buscar respostas e posicionamentos acerca da aprendizagem colaborativa, do professor como mediador, do protagonismo discente, do lugar do texto na aula de LP; inquietações que nortearam nossa pesquisa. Como produto deste estudo teórico-metodológico foi defendido perante a banca um texto teórico (dissertação) e um caderno pedagógico no qual demonstrou-se passo a passo o desenvolvimento desta proposta de natureza interventiva.CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

Sensitivity analysis of vertically loaded pile reliability

AbstractThe purpose of this paper is to examine the influence of geotechnical uncertainties on the reliability of vertically loaded pile foundations and the use of this information in decision-making support, especially when gathering the information necessary for reliability analyses. Two case studies of single pile foundations were selected, and each uncertainty source was investigated to identify which are the most important and influential in the evaluation of vertical pile resistance under axial loading. Reliability sensitivity analyses were conducted using FORM (the first-order reliability method) and MCS (Monte Carlo simulations). The characterisation of uncertainties is not an easy task in geotechnical engineering. The aim of the analyses described in this paper is to optimise resources and investments in the investigation of the variables in pile reliability. The physical uncertainties of actions, the inherent variability of soil and model error were assessed by experimental in situ standard penetration tests (SPT) or from information available in the literature. For the cases studied, the sensitivity analysis results show that, in spite of the high variability of the soils involved, model error also plays a very important role in geotechnical pile reliability and was considerably more important than soil variability in both case studies. From a comparison of the two reliability methods (FORM and MCS), it was concluded that FORM is applicable in simple cases and as a first approach because it is an approximate method and sometimes does not have the capability to incorporate every detail of the problem, namely a specific probability density function or more specific limit conditions

A ameaça terrorista em soft targets: a proteção do eixo turístico da zona de Belém

A problemática dos soft targets, tem ganho uma enorme relevância nos últimos anos pela vulnerabilidade destes espaços à atividade terrorista na perpetração de ataques, que são cada vez mais imprevisíveis e variados. As zonas turísticas são consideradas alvos vulneráveis, pela elevada atratividade de pessoas e por não reunirem medidas de segurança robustas, sobretudo no espaço público. Na presente dissertação foi considerado o eixo turístico de Belém, por ser uma das zonas turísticas mais importantes e com mais impacto mediático em Portugal. O objetivo deste estudo centra-se em perceber o nível de preparação desta zona turística para responder a um ataque terrorista, ao nível de medidas de prevenção e das principais vulnerabilidades desta zona. Foi desenvolvido um estudo exploratório que envolveu a realização de 14 entrevistas, feitas em quatro atrações turísticas, a Diretores, Diretores de segurança, Adjuntos de segurança e, também, a polícias que exercem funções na zona de Belém ou são especialistas na área do terrorismo. O estudo revelou um consenso dos entrevistados, quanto ao nível de preparação de segurança da zona turística, abordando a existência de medidas de segurança, no entanto, insuficientes para fazer face a um ataque terrorista perpetrado por um active shooter. São ainda identificadas algumas vulnerabilidades pelos participantes, onde se destaca a débil formação antiterrorista ministrada aos funcionários das atrações, que não tem nenhuma alínea prevista nos seus planos de segurança. Bem como, soluções preventivas, nomeadamente, a implementação de mudanças legislativas, sobretudo na vertente safety, para uma melhor proteção desta zona turística a incidentes.The problem of soft targets has gained enormous relevance in recent years due to the vulnerability of these spaces to terrorist activity in the perpetration of attacks, which are increasingly unpredictable and varied. Tourist areas are considered soft targets, due to the high attraction of people and for not having robust security measures, especially in the public space. In this dissertation the tourist area of Belém was considered, for being one of the most important tourist areas and with more media impact in Portugal. The objective of this study focuses on understanding the level of preparedness of this tourist area to respond to a terrorist attack, in terms of prevention measures and the main vulnerabilities of this area. An exploratory study was developed, involving 14 interviews, conducted in four tourist attractions, with Directors, Security Directors, Security Deputies, and also with police officers who work in the Belem area or are specialists in the area of terrorism. The study revealed a consensus among the interviewees, as to the level of security preparedness of the tourist area, addressing the existence of security measures, however, insufficient to face a terrorist attack perpetrated by an active shooter. Some vulnerabilities are also identified by the participants, where the weak anti-terrorist training given to the attractions' employees, which has no items foreseen in their security plans, stands out. As well as, preventive solutions, namely, the implementation of legislative changes, especially in the area of safety, for a better protection of this tourist area to incidents

GIS-Based Assessment of the Chestnut Expansion Potential: A Case-Study on the Marvão Productive Area, Portugal

Sweet chestnut is a relevant species in Europe for the production of timber and fruit, alongside environmental effects such as biodiversity of protection against soil erosion. In Portugal, chestnut is cultivated mainly for fruit production, in two areas, in the North and the South of the country, with moderate water deficit and low slope and at altitudes higher than 500 m. The current area (845 ha) of the southern so-called Marvão Protected Designation of Origin, of a fortyfold lower order of magnitude by comparison with the Northern productive area, has a significant expansion potential, given its similarity with contiguous areas in the same region. In this context, the main objective of the present work was the evaluation through geographic information analysis of that expansive potential, by comparison of physiographic profiling of the current production area with contiguous areas. A GIS-based characterization of current and potential chestnut areas in Marvão is presented. The methodology involved (i) digital profiling of the main classes/values of the geographical spatial ecological fingerprint considering topography, soil and microclimate variables in the areas currently occupied with sweet chestnut stands and (ii) the evaluation of the distribution of that environmental fingerprint in the whole Marvão productive area, for extending the cultivation to contiguous areas with a similar ecological fingerprint. An enlarged 9889 ha chestnut area was proposed, allocated for high forest stands aiming at agroforestry fruit production and coppiced stands for timber production and environmental protection, corresponding to 4590 ha and 5299 ha, respectively. Fruit production was proposed to field slopes of 0–4% and 4–8%, and altitudes between 400 m and 500 m. Presumable high-quality sites allocated to temporary dry/irrigated cultivations were also proposed for fruit production, in the same slope classes and altitudes higher than 500 m. Timber production and environmental protection were proposed for slopes within 812% and >12% ranges. This selection took into account the logistical feasibility facilitated in lower slopes for intensive mechanized management operations. This methodology permits a future field evaluation of site indexes, productivity, and correlations between environmental variables and stand biometryinfo:eu-repo/semantics/publishedVersio