Railway track condition assessment at network level by frequency domain analysis of GPR data

The railway track system is a crucial infrastructure for the transportation of people and goods in modern societies. With the increase in railway traffic, the availability of the track for monitoring and maintenance purposes is becoming significantly reduced. Therefore, continuous non-destructive monitoring tools for track diagnoses take on even greater importance. In this context, Ground Penetrating Radar (GPR) technique results yield valuable information on track condition, mainly in the identification of the degradation of its physical and mechanical characteristics caused by subsurface malfunctions. Nevertheless, the application of GPR to assess the ballast condition is a challenging task because the material electromagnetic properties are sensitive to both the ballast grading and water content. This work presents a novel approach, fast and practical for surveying and analysing long sections of transport infrastructure, based mainly on expedite frequency domain analysis of the GPR signal. Examples are presented with the identification of track events, ballast interventions and potential locations of malfunctions. The approach, developed to identify changes in the track infrastructure, allows for a user-friendly visualisation of the track condition, even for GPR non-professionals such as railways engineers, and may further be used to correlate with track geometric parameters. It aims to automatically detect sudden variations in the GPR signals, obtained with successive surveys over long stretches of railway lines, thus providing valuable information in asset management activities of infrastructure managers

Visualization of ontology evolution using OntoDiffGraph

Dissertação de mestrado em Ciências da ComputaçãoOntologies evolve with the passing of time due to improvements, corrections or changes in requirements that need to be made. It is hard to keep track of these changes made in an ontology without a tool built specifically for that purpose. The goal of this master’s work is the creation of a visualization technique with the objective of allowing the viewer to easily identify changes made in an ontology by comparing two versions of it. The proposed approach adapts the already existing VOWL (Visual Notation for OWL On tologies) specification so that it can also display the differences between two versions of an ontology through the use of a graph. This was implemented in an application, called On toDiffGraph, however this feature is not all that this application has implemented. In fact, to be able to detect the changes that were made, an algorithm was developed that allows the application to find the axioms that were added or removed in an ontology and display them in a graph. OntoDiffGraph also contains several other features that help with the identification of the changes that were made, such as displaying all axioms of the ontology in a list or filtering nodes and edges of the graph that are not relevant to the visualization of changes made in the ontology. OntoDiffGraph was used in an experiment to obtain user feedback and discover how it performed when compared to a similar application (OWLDiff). The participants gave a lot of important constructive feedback and they also displayed a preference of OntoDiffGraph over the other alternative.As ontologias evoluem com o passar do tempo devido a melhoramentos, correções ou mu danças nos requisitos que necessitam de ser feitas. É difícil observar estas mudanças feitas numa ontologia sem utilizar ferramentas especializadas para este fim. O objetivo deste trabalho de mestrado é a criação de uma técnica de visualização com a intenção de oferecer ao observador a capacidade de fácil identificação das mudanças feitas numa ontologia ao comparar duas versões distintas. A abordagem tomada adapta a especificação VOWL (Visual Notation for OWL Ontologies) de forma a que também seja possível visualizar as diferenças entre duas versões de uma ontologia através do uso de um grafo. Esta abordagem foi implementada numa aplicação, com o nome de OntoDiffGraph, no entanto esta funcionalidade não é tudo o que foi im plementado. Para que seja possível detetar as mudanças que foram feitas, um algoritmo foi desenvolvido que permite que a aplicação, além de identificar os conceitos/relações e propriedades que sofreram mudanças, encontre os axiomas que foram adicionados ou re movidos da ontologia e os apresente num grafo. OntoDiffGraph também tem diversas outras funcionalidades que ajudam na identificação de mudanças, tal como a apresentação de todos os axiomas da ontologia numa lista ou a filtração de nodos e arestas que não são relevantes para a visualização das mudanças feitas na ontologia. OntoDiffGraph foi também utilizado num experimento com o objetivo de obter críticas e comparar o seu desempenho com uma aplicação similar (OWLDiff). Os participantes no experimento ofereceram bastantes críticas construtivas e demonstraram uma preferência por OntoDiffGraph em vez de OWLDiff

Responsabilidade Social da Universidade: práticas da UFSC.

A responsabilidade social tem sido amplamente debatida nos últimos anos, principalmente devido às transformações ocorridas no planeta. Assim a universidade, por ser uma instituição social, tem o dever de exercê-la. Desta forma o presente artigo objetiva definir o papel social da universidade, bem como verificar de que forma a mesma pratica a responsabilidade social através de um estudo de caso. Este trabalho é uma pesquisa descritiva, e as fontes de obtenção de dados foram: a pesquisa bibliográfica, pesquisa documental e pesquisa na internet. Verifica-se que a instituição alvo do estudo exerce atividades de caráter social e desta forma tem executado de maneira satisfatória a responsabilidade social

Space of memory and representation: Bouça da Cova da Moura (Ardegães, Maia, Northwest of Portugal): a case study

Bouça da Cova da Moura is the local place-name attributed to a stretch of a plateau overlooking the Leça valley. Here, Neolithic burial mounds share their landscape setting with scatters of archaeological materials that include Bell Beaker fragments, idols and metalwork. Since these are mostly surface findings, their contexts have not yet been accurately determined. Another significant feature is the presence of prehistoric rock carvings. The plateau may thus be considered a public space, conceptually and physically built over time. Its significance and meanings were certainly created and transmitted through practices of memory construction which are representative of cultural identity and social cohesion.Le site de Bouça da Cova da Moura se trouve sur un plateau faisant face au Rio Leça. On y a identifié des tertres funéraires du Néolithique, auxquels sont associés des zones de concentration d’artefacts, incluant céramiques campaniformes, idoles et mobilier métallique. S’agissant de mobilier de surface, le contexte de ces différentes concentrations n’a pas été déterminé avec attention. Un autre fait significatif est l’apparition de gravures rupestres préhistoriques. On peut considérer le plateau comme un espace publique, qui s’est bâti physiquement et conceptuellement au cours des temps. Son importance et sa signification ont certainement été créées et transmises à travers un certain nombre de pratiques de construction mémorielle, représentatives de l’identité culturelle et de la cohésion sociale.info:eu-repo/semantics/publishedVersio

Acting as a molecular tailor : dye structural modifications for improved sensitivity towards lysophosphatidic acids sensing

Lysophosphatidic acids (LPA) are key biomarkers for several physiological processes, the monitoring of which can provide insights into the host’s health. Common lab-based techniques for their detection are cumbersome, expensive and necessitate specialized personnel to operate. LPA-sensitive fluorescent probes have been described, albeit for non-aqueous conditions, which impedes their use in biological matrices. In this paper, we explore in detail the influence of structure on the extent of aggregation-induced fluorescence quenching using specially synthesized styrylpyridinium dyes bearing structural adaptations to bestow them enhanced affinity towards LPA in aqueous media. Spectroscopic investigations supported by time-resolved fluorimetry revealed the contribution of excimer formation to the fluorescence quenching mechanism displayed by the fluorescent probes. Experimental observations of the influence of structure on detection sensitivity were supported by DFT calculations

Visualization of ontology evolution using ontodi graph

Ontologies evolve with the passing of time due to improvements, corrections or changes in requirements that need to be made. In this paper we describe a thesis work aiming at the creation of a visualization technique with the objective of allowing the viewer to easily identify changes made in an ontology. With the use of a specification based on the already existing Visual Notation for OWL Ontologies (VOWL) it is possible to display the differences that exist between two versions of an ontology. The proposed approach will be implemented in an application, that is also discussed in the paper.This work has been supported by COMPETE: POCI-01-0145-FEDER-007043 and FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/ 00319/2013

Incompatibilidade distributiva e inflação estrutural

Este trabalho apresenta uma teoria de Inflação, de acordo com a percepção dos processos inflacionários como expressão de um impasse social

Cordon pricing in the Monocentric city model: Theory and application to Ile-de- France

International audienceWe propose a method to compute an equilibrium solution for the monocentric city model with traffic congestion, and to quantify the im- pact of cordon tolls on social surplus. The focus of this paper is on the comparison of road pricing of one and two cordons, with the no toll and first-best situations as benchmarks. We find that a one-cordon toll yields a social efficiency of 63% with respect to first-best, and that an optimal two-cordon toll increases the efficiency to 73%. Both policies have a pos- itive impact on CO2 emissions because they reduce the average length of trips and reduce the road size