Controlo de Sistemas Pneumáticos

Neste artigo apresenta-se várias abordagens aos problemas de controlo de sistemas industriais tendo como base de atuação a pneumática. São apresentadas as metodologias de controlo de sistemas pneumáticos mais correntes como sejam o método de Cascata, de Memórias e dos Mapas de Karnaugh quer ao nível do controlo pneumático quer elétrico. Apresentam-se diversas abordagens de controlo destes mesmos sistemas recorrendo a autómatos programáveis (PLC)

Icnofósseis de invertebrados e raízes fósseis da formação Marília (membro echaporã), Grupo Bauru, Cretáceo superior, Brasil

Dissertação (mestrado)—Universidade de Brasília, Instituto de Geociências, Programa de Pós-Graduação em Geologia Regional. 2014.A Formação Marília (Grupo Bauru, Cretáceo Superior, Brasil) já rendeu uma grande quantidade de fósseis de vertebrados. Entretanto, seu conteúdo icnológico e botânico é pouco conhecido. Neste trabalho são reportados descobertas de icnofósseis (Beaconites isp., Skolithos isp., Taenidium barretti), rizólitos associados à micorrizas e outros icnofósseis associados no Membro Echaporã da Formação Marília na região sudoeste do Estado de São Paulo. A associação de icnofósseis e vertebrados permitiu sua classificação como Icnofácies Scoyenia. Os rizólitos indicam que pelo menos dois tipos de plantas herbáceas/arbustivas estavam presentes na região. As análises sedimentológicas sugerem que o afloramento estudado representa sedimentos fluviais com predominância de barras arenosas sujeitas a períodos de exposição subaérea relativamente longos. _________________________________________________________________________________ ABSTRACTThe Marília Formation (Bauru Group, Upper Cretaceous, Brazil) has furnished a large array of vertebrate fossils. However, its ichnological and botanical contents are poorly known. Here we report the findings of trace fossils (Beaconites isp., Skolithos isp., Taenidium barretti), rhizoliths associated with mycorrhizae, and other unidentified trace fossils for the Echaporã Member of the Marília Formation in the southwest region of the State of Sao Paulo. The association of trace fossils and vertebrates suggests they can be regarded to the Scoyenia Ichnofacies. The rhizoliths indicate that at least two herbaceous/arbustive plants were commonly present. Sedimentological analysis shows the studied outcrop comprises fluvial deposits, with a predominance of sand bars that underwent relatively long periods of subaerial exposure

BOAS ADMINISTRAÇÕES ELEGEM CANDIDATOS? UMA ANÁLISE DO COMPORTAMENTO DOS ELEITORES EM SETE CAPITAIS BRASILEIRAS NAS ELEIÇÕES DE 2008

Are well evaluated mayors reelected or elect their peers? This article aims at testing the following hypothesis considering the Brazilian 2008 elections, presented by Almeida (2008): is a good government reelected or elects its supporters? The article presents the results of seven Brazilian capitals in 2008. At first I verify if there is a relationship between a well evaluated mayor administration and election success. I consider good administration as the causal variable that explains the victory of the candidate. However, when we analyze the election results from the seven capitals, other variable come up to explain the victory of the candidates in the elections. This means that the variable good administration when considered alone is not enough to explain the success of a political candidate. Using qualitative and quantitative research and developing a detailed analysis of election in Recife in 2008, this article concludes that the good administration variable affects the electoral success of a candidate. And that other variables also matter to explain the electoral victory of the candidate

Topological spatial relations between a spatially extended point and a line for predicting movement in space

Location is an important dimension of contextual information for mobile systems, playing a key role in the development of context-aware and location-based applications. The identification of a specific location is well addressed by several existing technologies such as, for example, GPS (Global Positioning System). Moreover, the prediction of the next position of a mobile user is a valuable enabler for the development of pro-active location-based applications. Based on this knowledge, those applications become able to provide useful services for the users before they explicitly ask for them. As a step towards the prediction of the next position of a mobile user, this paper presents the identification of the topological spatial relations that can exist between a spatially extended point (representing the uncertainty on the position of a mobile user) and a line (representing objects in which movement in space is possible). Using a 4x3 intersection matrix we identified 38 topological spatial relations that can exist between the objects in analysis (spatially extended points and lines). The geometric realization of the 38 topological spatial relations was done through the analysis of each one of the identified valid matrices. The validation of the existence of the identified topological relations was verified from their geometric realization

Topological relationships between a circular spatially extended point and a line : spatial relations and their conceptual neighborhoods

This paper presents the topological spatial relations that can exist in the geographical space between a Circular Spatially Extended Point and a Line and describes the use of those spatial relations in the identification of the conceptual neighbourhood graphs that state the transitions occurring among relations. The conceptual neighbourhood graphs were identified using the snapshot model and the smooth-transition model. In the snapshot model, the identification of neighbourhood relations is achieved looking at the topological distance existing between pairs of spatial relations. In the smooth-transition model, conceptual neighbours are identified analysing the topological deformations that may change a topological spatial relation. The graphs obtained were analysed as an alternative to map matching techniques in the prediction of the future positions of a mobile user in a road network.(undefined

From GPS tracks to context: Inference of high-level context information through spatial clustering

Location-aware applications use the location of users to adapt their behaviour and to select the relevant information for users in a particular situation. This location information is obtained through a set of location sensors, or from network-based location services, and is often used directly, without any further processing, as a parameter in a selection process. In this paper we propose a method to infer high-level context information from a series of position records obtained from a GPS receiver. This method, based on a spatial clustering algorithm, automatically estimates the location of the places where a user lives and works. The achieved results show that the proposed approach rapidly converges to the real locations, and that the proposed algorithm can be used to simultaneously estimate both the home and workplace, while adapting to a wide range of spatio-temporal human behaviours.This work was developed as part of the LOCAL project (http://get.dsi.uminho.pt/local) funded by the Fundação para a Ciência e Tecnologia through grant POSI/CHS/44971/2002, with support from the POSI program

Concave hull: a k-nearest neighbours approach for the computation of the region occupied by a set of points

There is an on-line version of the Concave Hull algorithm at: http://local.dsi.uminho.ptThis paper describes an algorithm to compute the envelope of a set of points in a plane, which generates convex or non-convex hulls that represent the area occupied by the given points. The proposed algorithm is based on a k-nearest neighbours approach, where the value of k, the only algorithm parameter, is used to control the “smoothness” of the final solution. The obtained results show that this algorithm is able to deal with arbitrary sets of points, and that the time to compute the polygons increases approximately linearly with the number of points.Fundação para a Ciência e a Tecnologia (FCT) - POSI/CHS/44971/2002

Automatic classification of location contexts with decision trees

Location contexts are geographic regions, with well defined boundaries, that can be used to characterize the context of the persons lying inside them. In this paper we describe a process that exploits the increasing availability of geographic data to automatically create and classify location contexts. The pro-posed process generates new geographic regions from a database of Points Of Interest through the use of spatial clustering techniques, and classifies them automatically using a decision tree based method. Some preliminary results demonstrate the validity of this approach, while suggesting that a richer geographic database could produce location contexts of higher quality.Fundação para a Ciência e a Tecnologia (FCT)