The role of disorder on the AC and DC electrical conductivity of vapour grown carbon nanofibre/epoxy composites

Four dispersion methods were used for the preparation of vapour grown carbon nanofibre (VGCNF)/epoxy composites. It is shown that each method induces certain levels of VGCNF dispersion and distribution within the matrix, and that these have a strong influence on the composite electrical properties. A homogenous VGCNF dispersion does not necessarily imply higher electrical conductivity. In fact, it is concluded that the presence of well distributed clusters, rather than a fine dispersion, is more important for achieving larger conductivities for a given VGCNF concentration. It is also found that the conductivity can be described by a weak disorder regime.

LEARNING ENVIRONMENTS IN THE CONTEXT OF A MASTER DEGREE IN ANIMATION AND ILLUSTRATION

This paper aims to describe the processes of teaching illustration and animation, together, in the context of a masters degree program. In Portugal, until very recently, illustration and animation higher education courses, were very scarce and only provided by a few private universities, which offered separated programs - either illustration or animation. The MA in Illustration and Animation (MIA) based in the Instituto Politécnico do Cávado e Ave in Portugal, dared to join these two creative areas in a common learning model and is already starting it’s third edition with encouraging results and will be supported by the first international conference on illustration and animation (CONFIA). This masters program integrates several approaches and techniques (in illustration and animation) and integrates and encourages creative writing and critique writing. This paper describes the iterative process of construction, and implementation of the program as well as the results obtained on the initial years of existence in terms of pedagogic and learning conclusions. In summary, we aim to compare pedagogic models of animation or illustration teaching in higher education opposed to a more contemporary and multidisciplinary model approach that integrates the two - on an earlier stage - and allows them to be developed separately – on the second part of the program. This is based on the differences and specificities of animation (from classic techniques to 3D) and illustration (drawing the illustration) and the intersection area of these two subjects within the program structure focused on the students learning and competencies acquired to use in professional or authorial projects.

Teaching and learning production and operations management: the journey from identity crisis to a cross, disciplinary approach

Este artigo tem suas raízes em algumas questões relacionadas à "forma" e ao "conteúdo" do que nós, professores, ensinamos na área de Administração da Produção e Operações. Inicialmente, descrevo a evolução histórica desse campo no Brasil. Em seguida, discuto a crise de identidade que o campo está sofrendo. Com o objetivo de apresentar respostas para essa situação, apresento seis propostas para o desenvolvimento e consolidação do campo. Finalmente, descrevo uma iniciativa prática, envolvendo uma disciplina específica da área, ensinada para alunos de pós-graduação. Essa iniciativa enfatiza a "dimensão do conteúdo" (de uma abordagem técnico-operacional para uma abordagem estratégico-gerencial) como também a "dimensão da forma" (do foco no ensino para o foco no aprendizado). O sucesso dessa experiência em curso confirma a coerência da agenda proposta e induz futuros aperfeiçoamentos.

Estresse e desordem temporomandibular (DTM) : incidência e relação em docentes de nível

RESUMO: O trabalho docente exige dedicação em sala de aula e fora dela, pois o professor vê-se na missão de educador, formador de opiniões e de futuros profissionais no mercado de trabalho. Uma das patologias que pode ocorrer devido ao estresse gerado pela docência é o desenvolvimento de Desordens Temporomandibulares, que acarretará cefaleias, dores musculares na região cervical e facial e alterações posturais. Tivemos a pretensão de conduzir nossas reflexões sobre o estresse do docente para procurar responder às nossas inquietações. Para isso, formulamos o seguinte questionamento: qual a incidência e a relação entre o estresse e o desenvolvimento de Desordens Temporomandibulares no docente de nível superior? O objetivo geral desta investigação foi descrever e analisar a relação entre o estresse e a incidência de Desordem Temporomandibular (DTM) em docentes de nível superior da cidade de Palmas – Tocantins – Brasil. Para contemplar o objetivo geral, buscamos verificar a presença ou não de estresse e os principais sintomas de estresse nos docentes de Ensino Superior, identificando a fase do estresse em que os professores se encontravam e verificar a presença ou não de DTM e seus graus. Procuramos, ainda, avaliar a relação entre sexo e presença de estresse, estado civil e presença de estresse, o tempo de docência e a presença de estresse e a relação entre a carga horária em sala de aula e a carga horária total de trabalho e a presença de estresse, entre sexo e presença de DTM, estado civil e presença de DTM, o tempo de docência e a presença de DTM e a relação entre a carga horária em sala de aula e carga horária total de trabalho e a presença de DTM. A metodologia utilizada, para a realização deste trabalho, foi de caráter exploratório e descritivo com uma abordagem quantitativa dos dados obtidos. A pesquisa caracterizou-se num estudo de campo, fundamentada em um instrumento denominado “Inventário de Sintomas de Stress Lipp – ISSL” da autora Marilda Lipp (2005), versão para adulto, ao qual acrescentamos dados sociodemográficos (estado civil, tempo de docência, carga horária de sala de aula e de trabalho total). Recorremos, ainda, ao Questionário Índice de Helkimo para identificar a ocorrência de DTMs. A coleta dos dados foi realizada a partir de uma amostra de duzentos e trinta e três (233) docentes de Ensino Superior, com idade entre 23 e 74 anos. Com base na análise realizada, os resultados revelaram que a presença de sintomas de estresse se encontra em 106 (45,49%) docentes, com predomínio da fase de resistência. Verificamos que 127 (54,5%) docentes não apresentam estresse. A sintomatologia predominante são sintomas psicológicos. Vimos que o tempo de docência e a jornada de trabalho não contribuem como um valor preditivo da presença de estresse, bem como o estado civil, e verificamos que o sexo feminino apresentou mais sintomas de estresse. Ao analisarmos a presença ou não de DTM, vimos que os docentes apresentam sintomas de DTM em sua maioria, encontrada em 187 docentes (80,25%), com predomínio do grau de DTM leve. Vimos que o tempo de docência e a jornada de trabalho não contribuem como um valor significativo para a presença de DTM, mas que o sexo feminino apresentou mais sintomas de DTM, bem como os casados. Buscando responder ao problema norteador desta 6 investigação, vimos que, mesmo nos docentes sem presença de estresse, havia sintomas de DTM. Esses dados indicam que a profissão docente pode causar sobrecargas e gerar a DTM. Diante dessa amostra de docentes pesquisados, concluímos que os dados aqui apresentados sugerem uma ampliação do estudo. Considerando a relevância do papel desempenhado pelos docentes das Instituições de Ensino Superior na formação dos acadêmicos e em sua efetiva transformação em futuros profissionais, nossa contribuição para o conhecimento do processo de estresse e os graus de DTM na atividade docente proporcionará oportunidade aos profissionais das diversas áreas do conhecimento e, principalmente, aos docentes para despertarem para a elaboração de programas de combate, controle e prevenção do estresse e do desenvolvimento de DTMs, resultando, dessa forma, na conquista de uma vida mais saudável, tanto na área física quanto na área psicológica. ABSTRACT: Abstract The teacher’s job requires dedication in and out of the classroom for a teacher is in a education mission, he/she is an opinion maker and responsible for future professionals in the market. One of the pathologies that may take place due to the stress caused by this job is the Temporomandibular Joint Disorder (TMD) that will trigger cephaleas, muscle pain in the cervical and facial area and posture changes. The purpose of this paper is to conduct reflections about teachers’ stress trying to answer the following question: What is the incidence rate and correlation between stress and the occurrence of Temporomandibular Joint Disorder (DTM) in teachers of institutions of higher learning in the city of Palmas – Tocantis – Brazil. To fulfill the general purpose we tried to verify the presence or not of stress and the principal symptoms in teachers in universities and colleges, identifying the levels of stress that they were, and verifying the presence or not of TMD and its levels. We tried to evaluate the correlation between gender and the occurrence of stress, marital status and the presence of stress, career time and the presence of stress, and time working in classroom and the total time of work and the presence of stress. The methodology used to perform this was an exploratory and descriptive study with a quantitative approach of the data gathered. The research was characterized by a field study, fundamented by a tool called “Lipp Stress Symptom Inventory – ISSL” from the author Marilda Lipp (2005), adult version, which we also added social-demographic data (marital status, time teaching, hours working in the classroom, and total time of work). We also used the Helkimo Index Questionnaire to identify the occurrence of TMD’s. The data was collected from a sample of two hundred three (233) teachers of universities and colleges between 23 to 74 years of age. Based on the analysis performed, the results showed the presence of stress among 106 (45.49%) of the teachers, with the predominance of the resistance level. We observed that some 127 teachers (54.5%) did not show stress. The predominant symptomology were psychological ones. We observed that time of experience and the schedule do not influence as a predictive value for the stress presence, neither does the marital status and we also observed that the female gender showed more stress symptoms. When we analyzed the presence or not of TMD, we observed that most of the teachers showed symptoms of TMD, some 187 teachers (80.25%), with the predominance of first level TMD. We observed that the time as teacher and the schedule do not influence with an important value for the TMD presence, however the feminine gender as well as married teachers showed more symptoms of TMD. Trying to answer the most important issue of this study, we saw that even without the occurrence of stress the TMD was present showing that the profession can cause overwork and consequently TMD. With this sample of teachers studied we conclude that the found data suggest a wider research. Considering the role performed by teachers of universities and colleges in the development of students and future professionals, our contribution for the understanding of the stress development and TMD levels in the teaching activity will enable the opportunity for professionals of different areas of knowledge, and 8 principally for teachers, to awaken to the need to develop programs to fight, control, and prevent stress and the development of TMD, therefore resulting in a healthier life, both a physical as well as a psychological one.

Systems thinking: learning or driving?

The ability to foresee how behaviour of a system arises from the interaction of its components over time - i.e. its dynamic complexity – is seen an important ability to take effective decisions in our turbulent world. Dynamic complexity emerges frequently from interrelated simple structures, such as stocks and flows, feedbacks and delays (Forrester, 1961). Common sense assumes an intuitive understanding of their dynamic behaviour. However, recent researches have pointed to a persistent and systematic error in people understanding of those building blocks of complex systems. This paper describes an empirical study concerning the native ability to understand systems thinking concepts. Two different groups - one, academic, the other, professional – submitted to four tasks, proposed by Sweeney and Sterman (2000) and Sterman (2002). The results confirm a poor intuitive understanding of the basic systems concepts, even when subjects have background in mathematics and sciences.

A Feedback Learning and Mental Models Perspective on Strategic Decision Making

This study aims to be a contribution to a theoretical model that explains the effectiveness of the learning and decision-making processes by means of a feedback and mental models perspective. With appropriate mental models, managers should be able to improve their capacity to deal with dynamically complex contexts, in order to achieve long-term success. We present a set of hypotheses about the influence of feedback information and systems thinking facilitation on mental models and management performance. We explore, under controlled conditions, the role of mental models in terms of structure and behaviour. A test based on a simulation experiment with a system dynamics model was performed. Three out of the four hypotheses were confirmed. Causal diagramming positively influences mental model structure similarity, mental model structure similarity positively influences mental model behaviour similarity, and mental model behaviour similarity positively influences the quality of the decision.

Systems thinking: learning or driving?

The ability to foresee how behaviour of a system arises from the interaction of its components over time - i.e. its dynamic complexity – is seen an important ability to take effective decisions in our turbulent world. Dynamic complexity emerges frequently from interrelated simple structures, such as stocks and flows, feedbacks and delays (Forrester, 1961). Common sense assumes an intuitive understanding of their dynamic behaviour. However, recent researches have pointed to a persistent and systematic error in people understanding of those building blocks of complex systems. This paper describes an empirical study concerning the native ability to understand systems thinking concepts. Two different groups - one, academic, the other, professional – submitted to four tasks, proposed by Sweeney and Sterman (2000) and Sterman (2002). The results confirm a poor intuitive understanding of the basic systems concepts, even when subjects have background in mathematics and sciences.

A Feedback Learning and Mental Models Perspective on Strategic Decision Making

This study aims to be a contribution to a theoretical model that explains the effectiveness of the learning and decision-making processes by means of a feedback and mental models perspective. With appropriate mental models, managers should be able to improve their capacity to deal with dynamically complex contexts, in order to achieve long-term success. We present a set of hypotheses about the influence of feedback information and systems thinking facilitation on mental models and management performance. We explore, under controlled conditions, the role of mental models in terms of structure and behaviour. A test based on a simulation experiment with a system dynamics model was performed. Three out of the four hypotheses were confirmed. Causal diagramming positively influences mental model structure similarity, mental model structure similarity positively influences mental model behaviour similarity, and mental model behaviour similarity positively influences the quality of the decision

Mortality problems in Brazil and in Germany: past-present-future. Learning from each other?

This article was written by a Swiss-German historical demographer after having visited different Brazilian Universities in 1984 as a guest-professor. It aims at promoting a real dialog between developed and developing countries, commencing the discussion with the question: Can we learn from each other? An affirmative answer is given, but not in the superficial manner in which the discussion partners simply want to give each other some "good advice" or in which the one declares his country's own development to be the solely valid standard. Three points are emphasized: 1. Using infant mortality in S. Paulo from 1908 to 1983 as an example, it is shown that Brazil has at its disposal excellent, highly varied research literature that is unjustifiably unknown to us (in Europe) for the most part. Brazil by no means needs our tutoring lessons as regards the causal relationships; rather, we could learn two things from Brazil about this. For one, it becomes clear that our almost exclusively medical-biological view is inappropriate for passing a judgment on the present-day problems in Brazil and that any conclusions so derived are thus only transferable to a limited extent. For another, we need to reinterpret the history of infant mortality in our own countries up to the past few decades in a much more encompassing "Brazilian" sense. 2. A fruitful dialog can only take place if both partners frankly present their problems. For this reason, the article refers with much emprasis to our present problems in dealing with death and dying - problems arising near the end of the demographic and epidemiologic transitions: the superanuation of the population, chronic-incurable illnesses as the main causes of death, the manifold dependencies of more and more elderly and really old people at the end of a long life. Brazil seems to be catching up to us in this and will be confronted with these problems sooner or later. A far-sighted discussion already at this time seems thus to be useful. 3. The article, however, does not want to conclude with the rather depressing state of affairs of problems alternatingly superseding each other. Despite the caution which definitely has a place when prognoses are being made on the basis of extrapolations from historical findings, the foreseeable development especially of the epidemiologic transition in the direction of a rectangular survival curve does nevertheless provide good reason for being rather optimistic towards the future: first in regards to the development in our own countries, but then - assuming that the present similar tendencies of development are stuck to - also in regard to Brazil.

A bot spooler architecture to integrate virtual worlds with e-learning management systems for corporate training

Joining efforts of academic and corporate teams, we developed an integration architecture - MULTIS - that enables corporate e-learning managers to use a Learning Management System (LMS) for management of educational activities in virtual worlds. This architecture was then implemented for the Formare LMS. In this paper we present this architecture and concretizations of its implementation for the Second Life Grid/OpenSimulator virtual world platforms. Current systems are focused on activities managed by individual trainers, rather than groups of trainers and large numbers of trainees: they focus on providing the LMS with information about educational activities taking place in a virtual world and/or being able to access within the virtual world some of the information stored in the LMS, and disregard the streamlining of activity setup and data collection in multi-trainer contexts, among other administrative issues. This architecture aims to overcome the limitations of existing systems for organizational management of corporate e-learning activities.

Learning and Knowledge in the Context of Absorptive Capacity

Develop a new model of Absorptive Capacity taking into account two variables namely Learning and knowledge to explain how companies transform information into knowledge

Learning dependent sources using mixtures of Dirichlet: applications on hyperspectral unmixing

This paper is an elaboration of the DECA algorithm [1] to blindly unmix hyperspectral data. The underlying mixing model is linear, meaning that each pixel is a linear mixture of the endmembers signatures weighted by the correspondent abundance fractions. The proposed method, as DECA, is tailored to highly mixed mixtures in which the geometric based approaches fail to identify the simplex of minimum volume enclosing the observed spectral vectors. We resort then to a statitistical framework, where the abundance fractions are modeled as mixtures of Dirichlet densities, thus enforcing the constraints on abundance fractions imposed by the acquisition process, namely non-negativity and constant sum. With respect to DECA, we introduce two improvements: 1) the number of Dirichlet modes are inferred based on the minimum description length (MDL) principle; 2) The generalized expectation maximization (GEM) algorithm we adopt to infer the model parameters is improved by using alternating minimization and augmented Lagrangian methods to compute the mixing matrix. The effectiveness of the proposed algorithm is illustrated with simulated and read data.

Statistical motion learning for improved transform domain Wyner-Ziv video coding

Wyner - Ziv (WZ) video coding is a particular case of distributed video coding (DVC), the recent video coding paradigm based on the Slepian - Wolf and Wyner - Ziv theorems which exploits the source temporal correlation at the decoder and not at the encoder as in predictive video coding. Although some progress has been made in the last years, WZ video coding is still far from the compression performance of predictive video coding, especially for high and complex motion contents. The WZ video codec adopted in this study is based on a transform domain WZ video coding architecture with feedback channel-driven rate control, whose modules have been improved with some recent coding tools. This study proposes a novel motion learning approach to successively improve the rate-distortion (RD) performance of the WZ video codec as the decoding proceeds, making use of the already decoded transform bands to improve the decoding process for the remaining transform bands. The results obtained reveal gains up to 2.3 dB in the RD curves against the performance for the same codec without the proposed motion learning approach for high motion sequences and long group of pictures (GOP) sizes.

Learning techniques for automatic email message tagging

A organização automática de mensagens de correio electrónico é um desafio actual na área da aprendizagem automática. O número excessivo de mensagens afecta cada vez mais utilizadores, especialmente os que usam o correio electrónico como ferramenta de comunicação e trabalho. Esta tese aborda o problema da organização automática de mensagens de correio electrónico propondo uma solução que tem como objectivo a etiquetagem automática de mensagens. A etiquetagem automática é feita com recurso às pastas de correio electrónico anteriormente criadas pelos utilizadores, tratando-as como etiquetas, e à sugestão de múltiplas etiquetas para cada mensagem (top-N). São estudadas várias técnicas de aprendizagem e os vários campos que compõe uma mensagem de correio electrónico são analisados de forma a determinar a sua adequação como elementos de classificação. O foco deste trabalho recai sobre os campos textuais (o assunto e o corpo das mensagens), estudando-se diferentes formas de representação, selecção de características e algoritmos de classificação. É ainda efectuada a avaliação dos campos de participantes através de algoritmos de classificação que os representam usando o modelo vectorial ou como um grafo. Os vários campos são combinados para classificação utilizando a técnica de combinação de classificadores Votação por Maioria. Os testes são efectuados com um subconjunto de mensagens de correio electrónico da Enron e um conjunto de dados privados disponibilizados pelo Institute for Systems and Technologies of Information, Control and Communication (INSTICC). Estes conjuntos são analisados de forma a perceber as características dos dados. A avaliação do sistema é realizada através da percentagem de acerto dos classificadores. Os resultados obtidos apresentam melhorias significativas em comparação com os trabalhos relacionados.

Dynamic equilibrium through reinforcement learning

Reinforcement Learning is an area of Machine Learning that deals with how an agent should take actions in an environment such as to maximize the notion of accumulated reward. This type of learning is inspired by the way humans learn and has led to the creation of various algorithms for reinforcement learning. These algorithms focus on the way in which an agent’s behaviour can be improved, assuming independence as to their surroundings. The current work studies the application of reinforcement learning methods to solve the inverted pendulum problem. The importance of the variability of the environment (factors that are external to the agent) on the execution of reinforcement learning agents is studied by using a model that seeks to obtain equilibrium (stability) through dynamism – a Cart-Pole system or inverted pendulum. We sought to improve the behaviour of the autonomous agents by changing the information passed to them, while maintaining the agent’s internal parameters constant (learning rate, discount factors, decay rate, etc.), instead of the classical approach of tuning the agent’s internal parameters. The influence of changes on the state set and the action set on an agent’s capability to solve the Cart-pole problem was studied. We have studied typical behaviour of reinforcement learning agents applied to the classic BOXES model and a new form of characterizing the environment was proposed using the notion of convergence towards a reference value. We demonstrate the gain in performance of this new method applied to a Q-Learning agent.