Three-dimensional modelling and inversion of controlled source electromagnetic data

The marine Controlled Source Electromagnetic (CSEM) method is an important and almost self-contained discipline in the toolkit of methods used by geophysicists for probing the earth. It has increasingly attracted attention from industry during the past decade due to its potential in detecting valuable natural resources such as oil and gas. A method for three-dimensional CSEM modelling in the frequency domain is presented. The electric field is decomposed in primary and secondary components, as this leads to a more stable solution near the source position. The primary field is computed using a resistivity model for which a closed form of solution exists, for example a homogeneous or layered resistivity model. The secondary electric field is computed by discretizing a second order partial differential equation for the electric field, also referred in the literature as the vector Helmholtz equation, using the edge finite element method. A range of methods for the solution of the linear system derived from the edge finite element discretization are investigated. The magnetic field is computed subsequently, from the solution for the electric field, using a local finite difference approximation of Faraday’s law and an interpolation method. Tests, that compare the solution obtained using the presented method with the solution computed using alternative codes for 1D and 3D synthetic models, show that the implemented approach is suitable for CSEM forward modelling and is an alternative to existing codes. An algorithm for 3D inversion of CSEM data in the frequency domain was developed and implemented. The inverse problem is solved using the L-BFGS method and is regularized with a smoothing constraint. The inversion algorithm uses the presented forward modelling scheme for the computation of the field responses and the adjoint field for the computation of the gradient of the misfit function. The presented algorithm was tested for a synthetic example, showing that it is capable of reconstructing a resistivity model which fits the synthetic data and is close to the original resistivity model in the least-squares sense. Inversion of CSEM data is known to lead to images with low spatial resolution. It is well known that integration with complementary data sets mitigates this problem. It is presented an algorithm for the integration of an acoustic velocity model, which is known a priori, in the inversion scheme. The algorithm was tested in a synthetic example and the results demonstrate that the presented methodology is promising for the improvement of resistivity models obtained from CSEM data

Learning roadmap studio : new approaches and strategies for efficient learning and training processes

Learning systems have emerged in a set of different information systems, oriented for different kinds of organizations and institutions, such as learning management systems, knowledge management systems and learning content management systems, which can be integrated or merged with others. From past experience, it has been denoted that strategies and pedagogical processes are tasks that can be created, enriched and boosted by actors who participate in learning and training processes: course managers, teachers and students. The challenge posed to the different actors involved also accelerates the changes that have been happening in education and training, empowering a society based on knowledge. Initiatives such as eLearning (EU Comission 2000), eLearningEurope, eTwinning and Education Observatories are an evidence of this challenge. Platforms, applications, tools and systems must respond to challenges that those actors face nowadays: heterogeneous target audiences, in terms of student profiles, number of participants, differentiated contents and schedules to achieve knowledge, outcomes and competences. Thus, a prototype application, named Learning Roadmap Studio (LRMS), has been developed and deployed at Aveiro Norte Polytechnic School of the University of Aveiro, in order to suppress gaps in learning processes and to power better learning and training. It represents a new challenge for the University of Aveiro for higher education and is already being tested. At its core is the concept of “learning roadmaps” that act upon two fundamental axes: education and learning. For the teachers, it aims at becoming a self-supporting tool that stimulates the organization and management of the course materials (lectures, presentations, multimedia content, and evaluation materials, amongst others). For the students, the learning roadmap aims at promoting self-study and supervised study, endowing the pupil with the capabilities to find the relevant information and to capture the concepts in the study materials. The outcome will be a stimulating learning process together with an organized management of those materials. It is not intended to create new learning management systems. Instead, it is presented as an application that enables the edition and creation of learning processes and strategies, giving primary relevance to teachers, instead of focusing on tools, features and contents

Determinants of bond’s mispricing

This paper attempts to analyse the existence of underpricing in bond offers Banco Carregosa participated between October 2014 and June 2018 and the factors affecting bond’s mispricing in two different time frames, 1st day and 1st month. It was found that, for a very short term, underpricing is mostly affected by credit risk factors and macroeconomic conditions and partially described by liquidity aspects and information asymmetries. For longer periods, liquidity aspects and macroeconomic context are the main determinants. Credit risk factors lose their influence and information asymmetries continue to partially affect bond’s mispricing, however, represented by a different factor

Automated image tagging through tag propagation

Trabalho apresentado no âmbito do Mestrado em Engenharia Informática, como requisito parcial Para obtenção do grau de Mestre em Engenharia InformáticaToday, more and more data is becoming available on the Web. In particular, we have recently witnessed an exponential increase of multimedia content within various content sharing websites. While this content is widely available, great challenges have arisen to effectively search and browse such vast amount of content. A solution to this problem is to annotate information, a task that without computer aid requires a large-scale human effort. The goal of this thesis is to automate the task of annotating multimedia information with machine learning algorithms. We propose the development of a machine learning framework capable of doing automated image annotation in large-scale consumer photos. To this extent a study on state of art algorithms was conducted, which concluded with a baseline implementation of a k-nearest neighbor algorithm. This baseline was used to implement a more advanced algorithm capable of annotating images in the situations with limited training images and a large set of test images – thus, a semi-supervised approach. Further studies were conducted on the feature spaces used to describe images towards a successful integration in the developed framework. We first analyzed the semantic gap between the visual feature spaces and concepts present in an image, and how to avoid or mitigate this gap. Moreover, we examined how users perceive images by performing a statistical analysis of the image tags inserted by users. A linguistic and statistical expansion of image tags was also implemented. The developed framework withstands uneven data distributions that occur in consumer datasets, and scales accordingly, requiring few previously annotated data. The principal mechanism that allows easier scaling is the propagation of information between the annotated data and un-annotated data

Leading with purpose: how leaders perceive and channel purpose im management

The growing importance of employees’ mentality towards organizations raises the question of what management methods would be better to be applied by leaders. Recently academics and psychologists have found strong positive results from the appliance of purpose inside organizations. These studies have proven that there is a lack of purpose inside organizations and more precisely inside the leader’s visions. This paper aims at outlining what purpose is to academics and how leaders perceive it. Then the goal is to understand how leaders try to channel their view of purpose to employees’ and what are the difficulties facing this process. Results obtained from a group of international leaders in different organizations and industries are compared to the theoretical perspective of academics extracted from a review of the existing literature. The findings suggest that leaders often do not understand the terminology of purpose and do not apply it in their day-to-day activities. It is further highlighted that they use different methods to motivate and direct employees in their teams and organizations

Experimental creative practice at the piano: a case study

This document focuses on the development of an artistic practice-based research project focused on active experimentation and the development of creativity at the piano. The experimentation process relies on the exploration of extended and prepared piano techniques, which are described throughout the text, as well as on the use of electronics. The creative process involves the composition of a musical piece (Become One) inspired mainly by Music for 18 Musicians, by Steve Reich, its structure, instrumentation and compositional processes. The purpose of this project is to reflect on the work of authors such as Dewey (1934), Shockley (2018), Vaes (2009) and Mayas (2019), and relate it to the documentation of these processes, hence fostering future creative and experimental practices in other performers; Prática criativa experimental ao piano: um estudo de caso Resumo: O presente documento foca-se no desenvolvimento de um projecto de investigação artística baseado na experimentação e no desenvolvimento da criatividade ao piano. O processo de experimentação está centrado na exploração de técnicas expandidas e de piano preparado, descritas ao longo do texto, assim como na utilização de electrónica. O processo criativo envolve a composição de uma obra musical (Become One), inspirada maioriatiamente em Música para 18 Músicos de Steve Reich, a sua estrutura, instrumentação e processos de composição. O propósito deste projecto centra-se na reflexão do trabalho de autores como Dewey (1934), Shockley (2018), Vaes (2019) e Mayas (2019), relacionando-a com a documentação dos processos criativo e de experimentação, promovendo a replicação de práticas idênticas por parte de outros instrumentistas

Projeto Europeu INTACT: a educação em ciências torna-se móvel

A par de outras cinco instituições de ensino superior europeias, o Instituto Politécnico de Bragança integra o projeto INTACT (Interactive Teaching Across Culture and Technology) em que está em foco o planeamento, a criação e a implementação de uma plataforma com recursos educativos adaptáveis a diferentes níveis de ensino com o pressuposto de o processo de ensino/aprendizagem ser bilingue e colaborativo (http://www.intact-comenius.eu). A entrevista desta edição foi feita à coordenadora do projeto, Professora Christine Bescherer da Universidade de Educação de Ludwigsburgo na Alemanha e ela explica o fundamental do projeto.Apart from other five European Higher Education Institutions, the Polytechnic Institute of Bragança is part of the INTACT Project (Interactive Teaching Across Culture and Technology) which focuses on the planning, development and implementation of a platform containing teaching resources which can be adaptable to different teaching levels. The resources are based on the idea that the teaching and learning process must be both bilingual and collaborative (http://www.intact-comenius.eu). This time we interviewed the coordinator of the project, Professor Christine Bescherer, from the University of Education Ludwigsburg, in Germany where she explains the fundamentals of the project

A sátira política na televisão: o caso do "Governo Sombra"

Dissertação apresentada à Escola Superior de Comunicação Social como parte dos requisitos para obtenção de grau de mestre em Jornalismo.No contexto televisivo, a sátira e o humor em conteúdos políticos tem tido um crescimento significativo nas últimas décadas, principalmente a nível internacional. Partindo da hipótese que a sátira é um recurso comunicacional que procura inverter a ordem social e discursiva dominante, analisamos o Governo Sombra, programa televisivo emitido no canal TVI 24. Este conteúdo detém características ímpares quanto ao formato, à independência dos intervenientes e, ainda, quanto à conjugação entre o sério e o cómico, entre a comunicação de temas políticos e a sátira. Esta investigação procura analisar e compreender quais são os conteúdos dominantes no programa, identificar quais os protagonistas, quem são os intervenientes e qual é o papel que eles possuem na mensagem disseminada. Dentro do universo do Governo Sombra parte-se de uma caracterização exaustiva do programa, para em seguida, analisar o discurso proferido relativamente a dois casos específicos: o de José Sócrates e o ataque ao jornal satírico Charlie Hebdo. Este exercício permitiu compreender a forma como são transmitidas as mensagens satíricas e humorísticas no programa, bem como de que forma o humor subverte a construção social estabelecida, tornando-se num olhar diferente sobre a realidade social e política.ABSTRACT: In the television context both satire and humor applied to political contents have been experiencing an exponential growth over the last few decades specially on an international level. Assuming that satire is a communication resource that seeks to reverse the social and discursive order, we analyze the TV show Governo Sombra that goes on air on TVI 24. The show has a series of unequal characteristics as its format, the independence of the intervenients, the conjugation between what is serious and what is comic and also between the political issues and satire. This paper seeks to analyse and understand the major contents in the tv show, to enlighten its protagonists, who are the intervenients, which roles they play in the message to target their audience. Inside the universe of Governo Sombra, we've started with an exhaustive characterization of the program that led this paper until two specific cases: José Sócrates and the strike at the satirical newspaper Charlie Hebdo. This exercise allowed us to understand the way that satire and humorist messages are sent on the TV show as well as the way that humor twists the social construction turning itself in a different perspective over the social and political reality