Uma técnica de linearização por realimentação para compensação de agarramento em válvulas de controle pneumáticas

In control loops valve stiction is a very common problem. Generally, it is one of main causes of poor performance of industrial systems. Its most commonly observed effect is oscillation in the process variables. To circumvent the undesirable effects, friction compensators have been proposed in order to reduce the variability in the output. This work analyzes the friction compensation in pneumatic control valves by using feedback linearization technique. The valve model includes both dead zone and jump. Simulations show that the use of this more complete model results in controllers with superior performance. The method is also compared through simulations with the method known as Constant Reinforcement (CR), widely used in this problem.

Uso didático do Facebook como estratégia de leitura para o gênero textual poesia

The poor performance of students in reading and writing activities, prompted the search for actions that would minimize this problem, noticeable mainly in public education. The lack of interest in reading of poetic texts seen in students from the 7th year in a public school in RN, has led us to question the reasons for the rejection of poetry. Thus, the idea to organize and develop new reading possibilities mediated by digital technologies, considering the preference of teenagers by virtual environments. Therefore, it was essential to observe how students used web resources in order to plan actions that aimed to improve their reading performance. We present to justify the need for reflection on the educational problems starting from our reality, in order to establish appropriate procedures to minimize them. To this end, we draw is to investigate how students appropriated the Facebook social network in order to elaborate reading strategies using this platform. The study is anchored in the reflections of the following theorists and researchers: language concepts and language: Bakhtin (2011 [1979] 2006 [1999]), Bronckart (2012 [1999]), Marcuschi (2008); reading strategies: Leffa (1996) Solé (1998), Antunes (2009), Kleiman (2013); genre: Bakhtin (2011 [1979] 2006 [1999]), Marcuschi (2008); didactic sequence: Dolz, Noverraz and Schneuwly (2013 [2004]); technologies: Moran (2008 [2000]), Kenski (2007), Bento (2012), Behrens (2013); literary literacy: Cosson (2007); other theoretical orientations: PCN (1998), PDE (2008), Perrenoud (1999), among others. The methodology followed action research guidelines, a qualitative approach perspective. The research instruments included questionnaires, interviews, observations and field notes. The results pointed to the interest of students in this social network, which favored the development of a didactic sequence whose activities converged on the didactic use of Facebook as a support for the presentation of textual poetry genre, drawing the attention of students for reading. Thus, we reiterate the need to include the pedagogical use of Information and Communication Digital Technologies educational activities to better meet the expectations of the generation of "digital natives", offering them a significant Portuguese-speaking school that fits your interests.

Uso didático do Facebook como estratégia de leitura para o gênero textual poesia

The poor performance of students in reading and writing activities, prompted the search for actions that would minimize this problem, noticeable mainly in public education. The lack of interest in reading of poetic texts seen in students from the 7th year in a public school in RN, has led us to question the reasons for the rejection of poetry. Thus, the idea to organize and develop new reading possibilities mediated by digital technologies, considering the preference of teenagers by virtual environments. Therefore, it was essential to observe how students used web resources in order to plan actions that aimed to improve their reading performance. We present to justify the need for reflection on the educational problems starting from our reality, in order to establish appropriate procedures to minimize them. To this end, we draw is to investigate how students appropriated the Facebook social network in order to elaborate reading strategies using this platform. The study is anchored in the reflections of the following theorists and researchers: language concepts and language: Bakhtin (2011 [1979] 2006 [1999]), Bronckart (2012 [1999]), Marcuschi (2008); reading strategies: Leffa (1996) Solé (1998), Antunes (2009), Kleiman (2013); genre: Bakhtin (2011 [1979] 2006 [1999]), Marcuschi (2008); didactic sequence: Dolz, Noverraz and Schneuwly (2013 [2004]); technologies: Moran (2008 [2000]), Kenski (2007), Bento (2012), Behrens (2013); literary literacy: Cosson (2007); other theoretical orientations: PCN (1998), PDE (2008), Perrenoud (1999), among others. The methodology followed action research guidelines, a qualitative approach perspective. The research instruments included questionnaires, interviews, observations and field notes. The results pointed to the interest of students in this social network, which favored the development of a didactic sequence whose activities converged on the didactic use of Facebook as a support for the presentation of textual poetry genre, drawing the attention of students for reading. Thus, we reiterate the need to include the pedagogical use of Information and Communication Digital Technologies educational activities to better meet the expectations of the generation of "digital natives", offering them a significant Portuguese-speaking school that fits your interests.

Documentação automatizada de APIs com tutoriais gerados a partir do Stack Overflow

One of the most common forms of reuse is through API usage. However, one of the main challenges to effective usage is an accessible and easy to understand documentation. Several papers have proposed alternatives to make more understandable API documentation, or even more detailed. However, these studies have not taken into account the complexity of understanding of the examples to make these documentations adaptable to different levels of experience of developers. In this work we developed and evaluated four different methodologies to generate tutorials for APIs from the contents of Stack Overflow and organizing them according to the complexity of understanding. The methodologies were evaluated through tutorials generated for the Swing API. A survey was conducted to evaluate eight different features of the generated tutorials. The overall outcome of the tutorials was positive on several characteristics, showing the feasibility of the use of tutorials generated automatically. In addition, the use of criteria for presentation of tutorial elements in order of complexity, the separation of the tutorial in basic and advanced parts, the nature of tutorial to the selected posts and existence of didactic source had significantly different results regarding a chosen generation methodology. A second study compared the official documentation of the Android API and tutorial generated by the best methodology of the previous study. A controlled experiment was conducted with students who had a first contact with the Android development. In the experiment these students developed two tasks, one using the official documentation of Android and using the generated tutorial. The results of this experiment showed that in most cases, the students had the best performance in tasks when they used the tutorial proposed in this work. The main reasons for the poor performance of students in tasks using the official API documentation were due to lack of usage examples, as well as its difficult use.

Le sommeil comme marqueur du déclin cognitif dans la maladie de Parkinson

La maladie de Parkinson (MP) est une maladie neurodégénérative qui se caractérise principalement par la présence de symptômes moteurs. Cependant, d’autres symptômes, dits non moteurs, sont fréquents dans la MP et assombrissent le pronostic; ceux ci incluent notamment les désordres du sommeil et les troubles cognitifs. De fait, sur une période de plus de 10 ans, jusqu’à 90 % des patients avec la MP développeraient une démence. L’identification de marqueurs de la démence dans la MP est donc primordiale pour permettre le diagnostic précoce et favoriser le développement d’approches thérapeutiques préventives. Plusieurs études ont mis en évidence la contribution du sommeil dans les processus de plasticité cérébrale, d’apprentissage et de consolidation mnésique, notamment l’importance des ondes lentes (OL) et des fuseaux de sommeil (FS). Très peu de travaux se sont intéressés aux liens entre les modifications de la microarchitecture du sommeil et le déclin cognitif dans la MP. L’objectif de cette thèse est de déterminer, sur le plan longitudinal, si certains marqueurs électroencéphalographiques (EEG) en sommeil peuvent prédire la progression vers la démence chez des patients atteints de la MP. La première étude a évalué les caractéristiques des OL et des FS durant le sommeil lent chez les patients avec la MP selon qu’ils ont développé ou non une démence (MP démence vs MP sans démence) lors du suivi longitudinal, ainsi que chez des sujets contrôles en santé. Comparativement aux patients MP sans démence et aux sujets contrôles, les patients MP démence présentaient au temps de base une diminution de la densité, de l’amplitude et de la fréquence des FS. La diminution de l’amplitude des FS dans les régions postérieures était associée à de moins bonnes performances aux tâches visuospatiales chez les patients MP démence. Bien que l’amplitude des OL soit diminuée chez les deux groupes de patients avec la MP, celle ci n’était pas associée au statut cognitif lors du suivi. La deuxième étude a évalué les marqueurs spectraux du développement de la démence dans la MP à l’aide de l’analyse quantifiée de l’EEG en sommeil lent, en sommeil paradoxal et à l’éveil. Les patients MP démence présentaient une diminution de la puissance spectrale sigma durant le sommeil lent dans les régions pariétales comparativement aux patients MP sans démence et aux contrôles. Durant le sommeil paradoxal, l’augmentation de la puissance spectrale en delta et en thêta, de même qu’un plus grand ratio de ralentissement de l’EEG, caractérisé par un rapport plus élevé des basses fréquences sur les hautes fréquences, était associée au développement de la démence chez les patients avec la MP. D’ailleurs, dans la cohorte de patients, un plus grand ralentissement de l’EEG en sommeil paradoxal dans les régions temporo occipitales était associé à des performances cognitives moindres aux épreuves visuospatiales. Enfin, durant l’éveil, les patients MP démence présentaient au temps de base une augmentation de la puissance spectrale delta, un plus grand ratio de ralentissement de l’EEG ainsi qu’une diminution de la fréquence dominante occipitale alpha comparativement aux patients MP sans démence et aux contrôles. Cette thèse suggère que des anomalies EEG spécifiques durant le sommeil et l’éveil peuvent identifier les patients avec la MP qui vont développer une démence quelques années plus tard. L’activité des FS, ainsi que le ralentissement de l’EEG en sommeil paradoxal et à l’éveil, pourraient donc servir de marqueurs potentiels du développement de la démence dans la MP.

A Study of Implicit Leadership Theories Among Business & Management Undergraduate Students

This qualitative study explores the subjective experience of being led by investigating the impact of their Implicit Leadership Theories (ILTs) on followers’ cognitive processes, affective responses and behavioural intentions towards leadership-claimants. The study explores how such responses influence the quality of hierarchical work-place relationships using a framework based on Leader-Member Exchange (LMX) Theory. The research uses focus groups to elicit descriptions of ILTs held by forty final year undergraduate Business and Management students. The data was then analysed using an abductive process permitting an interpretative understanding of the meanings participants attach to their past experiences and future expectations. This research addresses a perceived gap by making a theoretical contribution to knowledge and understanding in this field, focusing on how emotional responses affect their behaviour, how this impacts on organisational outcomes, and what the implications are for HRD practitioners. The findings support previous research into the content and structure of ILTs but extend these by examining the impact of affect on workplace behaviour. Findings demonstrate that where follower ILT needs are met then positive outcomes ensued for participants, their superiors, and their organisations. Conversely, where follower ILT needs are not matched, various negative effects emerged ranging from poor performance and impaired well-being, to withdrawal behaviour and outright rebellion. The research findings suggest dynamic reciprocal links amongst outcomes, behaviours, and LMX, and demonstrate an alignment of cognitive, emotional and behavioural responses that correspond to either high-LMX or low-LMX relationships, with major impacts on job satisfaction, commitment and well-being. Copyright

Efeito do cronótipo e da hora do dia no desempenho numa tarefa de emparelhamento de faces

Os ritmos circadianos têm vindo a despertar interesse há largos anos, sabendo-se que cada indivíduo tem a sua preferência pessoal por estar ativo a diferentes horas do dia. A noção de cronótipo traduz esta preferência, classificando-nos em matutinos, intermédios, ou vespertinos. Encontra-se já definida uma relação entre o cronótipo de um indivíduo e a hora do dia a que realiza determinadas tarefas, fator que influencia o desempenho em muitos processos cognitivos, observando-se o designado efeito de sincronia: o desempenho atinge o seu pico quando a tarefa se realiza na hora ótima, aquela que se coaduna com a hora preferencial da pessoa. Desse modo, sujeitos matutinos têm frequentemente um melhor desempenho em diversas tarefas durante a manhã, e sujeitos vespertinos ao final do dia. O presente estudo pretendeu verificar se este efeito influencia o processo de emparelhamento de faces não familiares, tarefa em que o desempenho é por norma pobre. Nesse sentido, 33 participantes (17 matutinos e 16 vespertinos) avaliaram os 168 pares de faces (84 em cada sessão) que compõem o Glasgow Face Matching Test, e decidiram se as duas pertenciam à mesma pessoa, ou a pessoas diferentes. A tarefa foi realizada em duas sessões, uma às 9h e outra às 19h, para avaliar o efeito de sincronia. Verificou-se um efeito de interação significativo entre o cronótipo e a hora ótima no tempo de reação dos participantes, quando acertavam a sua resposta. Parte dos nossos resultados foram de encontro ao esperado, com os participantes vespertinos a serem mais rápidos na sua hora ótima. É sugerida então a existência de alguma influência do cronótipo e da hora do dia na rapidez de processamento e emparelhamento de faces não familiares.

Dynamic load balancing of distributed memory parallel computational mechanics using unstructured meshes for multi-physical modelling

As the complexity of parallel applications increase, the performance limitations resulting from computational load imbalance become dominant. Mapping the problem space to the processors in a parallel machine in a manner that balances the workload of each processors will typically reduce the run-time. In many cases the computation time required for a given calculation cannot be predetermined even at run-time and so static partition of the problem returns poor performance. For problems in which the computational load across the discretisation is dynamic and inhomogeneous, for example multi-physics problems involving fluid and solid mechanics with phase changes, the workload for a static subdomain will change over the course of a computation and cannot be estimated beforehand. For such applications the mapping of loads to process is required to change dynamically, at run-time in order to maintain reasonable efficiency. The issue of dynamic load balancing are examined in the context of PHYSICA, a three dimensional unstructured mesh multi-physics continuum mechanics computational modelling code.

Diseño de un modelo de situación problema, con la unidad facilitadora solidaria llamada Belisol, para fortalecer el pensamiento numérico y variacional, en los estudiantes de la Institución Educativa Rural Benigno Mena González

Al analizar los resultados deficientes de las Pruebas Saber, del PTA ( Programa Todos a Aprender del MEN), y la participación en las Olimpiadas del Conocimiento, de los estudiantes de la Institución Educativa Rural Benigno Mena González del municipio de San Jerónimo, se consideró implementar un proyecto pedagógico, como plan de mejoramiento para la enseñanza y aprendizaje de las matemáticas, que sirviera como una iniciativa para fortalecer los pensamientos numérico y variacional en los estudiantes de secundaria de la Institución; se buscaba, con la implementación de esta propuesta, desarrollar habilidades en dominio, comprensión y solución de situaciones problemas cotidianas dentro del contexto escolar y desde la innovación de nuevas prácticas metodológicas en los procesos educativos. Desde esta perspectiva, nace el interrogante: ¿Cómo modelar una situación problema, teniendo como motivo la unidad facilitadora solidaria denominada Belisol, para fortalecer el pensamiento numérico y variacional, en los estudiantes de la Institución Educativa Rural Benigno Mena González del municipio de San Jerónimo?, para dar tránsito a una propuesta de investigación innovadora. Ahora bien, para intervenir y reflexionar sobre este interrogante, se propuso el método de Investigación Acción Participación (IAP), el cual se aplica a estudios que se interesan sobre realidades humanas y problemáticas cotidianas o sociales, que además, sean reales, de la acción, y de constante participación de los sujetos, entidades o comunidades involucradas; aquí cabe la posibilidad de un aprendizaje cooperativo, colectivo, y por supuesto, colaborativo donde se ha planteado como motivo de la situación problema planteada la unidad financiera llamada Belisol con el fin de exteriorizar los fundamentos de una acción formativa, orientada a la incursión en el ámbito de la educación matemática económica financiera, a través del ejercicio del ahorro escolar y el trueque, promoviendo de esta manera el espíritu solidario en la comunidad Benigniana.

Influence of one selected Tisochrysis lutea strain rich in lipids on Crassostrea gigas larval development and biochemical composition

Effects of a remarkably high overall lipid Tisochrysis lutea strain (T+) upon gross biochemical composition, fatty acid (FA), sterol and lipid class composition of Crassostrea gigas larvae were evaluated and compared with a normal strain of Tisochrysis lutea (T) and the diatom Chaetoceros neogracile (Cg). In a first experiment, the influence of different single diets (T, T+ and Cg) and a bispecific diet (TCg) was studied, whereas, effects of monospecific diets (T and T+) and bispecific diets (TCg and T+Cg) were evaluated in a second experiment. The strain T+ was very rich in triglycerides (TAG: 93–95% of total neutral lipids), saturated FA (45%), monounsaturated FA (31–33%) and total fatty acids (4.0–4.7 pg cell−1). Larval oyster survival and growth rate were positively correlated with 18:1n-7 and 20:1n-7, in storage lipids (SL), and negatively related to 14:0, 18:1n-9, 20:1n-9, 20:4n-6 and trans-22-dehydrocholesterol in membrane lipids (ML). Surprisingly, only the essential fatty acid 20:5n-3 in SL was correlated positively with larval survival. Correlations suggest that physiological disruption by overabundance of TAG, FFA and certain fatty acids in larvae fed T+ was largely responsible for the poor performance of these larvae. ‘High-lipid’ strains of microalgae, without regard to qualitative lipid composition, do not always improve bivalve larval performance.

Non-invasive monitoring of changes in exhaled markers of airway inflammation in Thoroughbred racehorses

Exhaled breath (EB) and exhaled breath condensate (EBC) contain numerous volatile gases and a wide-array of non-volatile compounds, several of which have been investigated as markers of lower airway inflammation in human and veterinary medicine and have been used to diagnose and monitor diseases associated with pulmonary inflammation. The identification of reliable biomarkers within EB and EBC is an active research focus with the common goal of establishing non-invasive and repeatable assessment of respiratory health and disease in mammals. The application of EB and EBC analysis holds considerable appeal in the investigation of respiratory disease in Thoroughbred racehorses, as inflammatory airway disease (IAD) is a common cause for poor performance in this population of animals. This study documented that EB and EBC samples can be safely collected from Thoroughbred racehorses in their own environment, without adverse effect or interference with the horse’s training regimen. The use of off-line collection and analysis of exhaled gases via chemiluminescence is suitable for the measurement of exhaled carbon monoxide, but is not appropriate for analyzing exhaled nitric oxide in horses. Significant changes in the concentration of exhaled CO and the pH of EBC occurred in response to strenuous exercise and when exercising in different environmental temperatures. Exhaled CO was associated with tracheal mucus score (and the number of neutrophils in the mucus) and EBC pH was significantly different in horses with evidence of neutrophilic IAD compared to horses without IAD. Numerous physiological and environmental variables were identified as confounding factors in the assessment of both exhaled CO and EBC pH, with respiratory rate prior to EB collection, and during EBC collection, consistently identified as an explanatory variable influencing the concentration of exhaled biomarkers. Further studies in EB and EBC analysis in horses need to focus on objectively accounting for key respiratory dynamics during sample collection.

Le sommeil comme marqueur du déclin cognitif dans la maladie de Parkinson

La maladie de Parkinson (MP) est une maladie neurodégénérative qui se caractérise principalement par la présence de symptômes moteurs. Cependant, d’autres symptômes, dits non moteurs, sont fréquents dans la MP et assombrissent le pronostic; ceux ci incluent notamment les désordres du sommeil et les troubles cognitifs. De fait, sur une période de plus de 10 ans, jusqu’à 90 % des patients avec la MP développeraient une démence. L’identification de marqueurs de la démence dans la MP est donc primordiale pour permettre le diagnostic précoce et favoriser le développement d’approches thérapeutiques préventives. Plusieurs études ont mis en évidence la contribution du sommeil dans les processus de plasticité cérébrale, d’apprentissage et de consolidation mnésique, notamment l’importance des ondes lentes (OL) et des fuseaux de sommeil (FS). Très peu de travaux se sont intéressés aux liens entre les modifications de la microarchitecture du sommeil et le déclin cognitif dans la MP. L’objectif de cette thèse est de déterminer, sur le plan longitudinal, si certains marqueurs électroencéphalographiques (EEG) en sommeil peuvent prédire la progression vers la démence chez des patients atteints de la MP. La première étude a évalué les caractéristiques des OL et des FS durant le sommeil lent chez les patients avec la MP selon qu’ils ont développé ou non une démence (MP démence vs MP sans démence) lors du suivi longitudinal, ainsi que chez des sujets contrôles en santé. Comparativement aux patients MP sans démence et aux sujets contrôles, les patients MP démence présentaient au temps de base une diminution de la densité, de l’amplitude et de la fréquence des FS. La diminution de l’amplitude des FS dans les régions postérieures était associée à de moins bonnes performances aux tâches visuospatiales chez les patients MP démence. Bien que l’amplitude des OL soit diminuée chez les deux groupes de patients avec la MP, celle ci n’était pas associée au statut cognitif lors du suivi. La deuxième étude a évalué les marqueurs spectraux du développement de la démence dans la MP à l’aide de l’analyse quantifiée de l’EEG en sommeil lent, en sommeil paradoxal et à l’éveil. Les patients MP démence présentaient une diminution de la puissance spectrale sigma durant le sommeil lent dans les régions pariétales comparativement aux patients MP sans démence et aux contrôles. Durant le sommeil paradoxal, l’augmentation de la puissance spectrale en delta et en thêta, de même qu’un plus grand ratio de ralentissement de l’EEG, caractérisé par un rapport plus élevé des basses fréquences sur les hautes fréquences, était associée au développement de la démence chez les patients avec la MP. D’ailleurs, dans la cohorte de patients, un plus grand ralentissement de l’EEG en sommeil paradoxal dans les régions temporo occipitales était associé à des performances cognitives moindres aux épreuves visuospatiales. Enfin, durant l’éveil, les patients MP démence présentaient au temps de base une augmentation de la puissance spectrale delta, un plus grand ratio de ralentissement de l’EEG ainsi qu’une diminution de la fréquence dominante occipitale alpha comparativement aux patients MP sans démence et aux contrôles. Cette thèse suggère que des anomalies EEG spécifiques durant le sommeil et l’éveil peuvent identifier les patients avec la MP qui vont développer une démence quelques années plus tard. L’activité des FS, ainsi que le ralentissement de l’EEG en sommeil paradoxal et à l’éveil, pourraient donc servir de marqueurs potentiels du développement de la démence dans la MP.

Equine exercise electrocardiogram : standardized lungeing test

Dissertação de Mestrado Integrado em Medicina Veterinária

A importância das academias no futebol de formação

Atualmente, as academias de futebol designam-se como uma estrutura de excelência com o objetivo de formar jogadores profissionais para a equipa principal, baseando-se não só na vertente desportiva, como também na vertente humana. As academias são um local de prática desportiva de qualidade, onde agentes especializados como professores, psicólogos e nutricionistas, estão presentes para que a evolução dos atletas seja exemplar. A criação de academias minimiza os gastos em atletas, pois estes são produzidos nestas instalações, moldando-os consoante as suas ambições, fazendo com que não haja uma necessidade na busca de jogadores de outros clubes, diminuindo assim o risco na compra de atletas que possam não conseguir adaptar-se ao clube ou demonstrem fraco rendimento no mesmo. O principal objetivo desta dissertação é compreender todo este funcionamento na academia e procurar perceber se todos estes fatores se sucedem. Posto isto, foi desenvolvido um inquérito respondido por 14 treinadores de academias de futebol existentes em clubes, tanto a nível nacional, como a nível internacional. Com este estudo foi possível concluir que muitas academias desenvolvem um trabalho notável e que muitas aproveitam todo este trabalho a longo prazo, usufruindo assim de benefícios financeiros para o clube.

Algoritmos construtivos para treino de redes neuronais b-spline

Dissertação de mest. em Engenharia de Sistemas e Computação - Área de Sistemas de Controlo, Faculdade de Ciências e Tecnologia, Univ.do Algarve, 2001