• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 121
  • 43
  • 30
  • 13
  • 11
  • 9
  • 8
  • 8
  • 7
  • 4
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 353
  • 104
  • 52
  • 52
  • 49
  • 47
  • 47
  • 43
  • 43
  • 42
  • 40
  • 37
  • 35
  • 32
  • 30
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
311

A field and laboratory study on the dynamic response of the Eddystone lighthouse to wave loading

Banfi, Davide January 2018 (has links)
Because little was known about how the masonry lighthouses constructed during the 19th century at exposed locations around the British Isles were responding to wave action, the dynamic response of the Eddystone lighthouse under wave impacts was investigated. Like other so called 'rock lighthouses', the Eddystone lighthouse was built on top of a steep reef at a site that is fully submerged at most states of the tide. Consequently, the structure is exposed to loading by unbroken, breaking and broken waves. When the breaking occurs, wave loading leads to complex phenomena that cannot be described theoretically due to the unknown mixture of air and water involved during the wave-structure interaction. In addition, breaking waves are generally distinguished from unbroken and broken wave due to the fact that they cause impulsive loads. As a consequence, the load effects on the structural response require a dynamic analysis. In this investigation the dynamic response of the Eddystone lighthouse is investigated both in the field and by means of a small-scale model mounted in a laboratory wave channel. In particular, field data obtained by the use of geophones, cameras and a wave buoy are presented together with wave loading information obtained during the laboratory tests under controlled conditions. More than 3000 structural events were recorded during the exceptional sequence of winter storms that hit the South-West of England in 2013/2014. The geophone signals, which provide the structural response in terms of velocity data, are differentiated and integrated in order to obtain accelerations and displacements respectively. Dynamic responses show different behaviours and higher structural frequencies, which are related to more impulsive loads, tend to exhibit a predominant sharp peak in velocity time histories. As a consequence, the structural responses have been classified into four types depending on differences of ratio peaks in the time histories and spectra. Field video images indicate that higher structural frequencies are usually associated with loads caused by plunging waves that break on or just in front of the structure. However, higher structural velocities and accelerations do not necessarily lead to the largest displacements of around a tenth of mm. Thus, while the impulsive nature of the structural response depends on the type of wave impact, the magnitude of the structural deflections is strongly affected by both elevation of the wave force on the structure and impact duration, as suggested by structural numerical simulations and laboratory tests respectively. The latter demonstrate how the limited water depth strongly affects the wave loading. In particular, only small plunging waves are able to break on or near the structure and larger waves that break further away can impose a greater overall impulse due to the longer duration of the load. As a consequence of the depth limited conditions, broken waves can generate significant deflections in the case of the Eddystone lighthouse. However, maximum accelerations of about 0.1g are related to larger plunging waves that are still able to hit the lighthouse with a plunging jet. When compared to the Iribarren number, the dimensionless irregular momentum flux proposed by Hughes is found to be a better indicator concerning the occurrence of the structural response types. This is explained by the fact that the Iribarren number does not to take into account the effects of the wide tidal range at the Eddystone reef, which has a strong influence on the location of the breaking point with respect to the lighthouse. Finally, maximum run up were not able to rise up to the top of the lighthouse model during the laboratory tests, despite this having been observed in the field. As a consequence, the particular configuration of the Eddystone reef and the wind could have a considerable bearing and exceptional values of the run up, greater than 40 m, cannot be excluded in the field.
312

Individual differences in eating behaviours and their relationship with motivation, cognition and weight control

Davies, Kirsty Mary January 2018 (has links)
A considerable percentage of the UK population are overweight (BMI≥25kg/m2) or obese (BMI≥30kg/m2). However, despite living in the same culture and exposed to a similar “obesogenic” environment, some individuals gain weight while others do not (French et al., 1995). This variability in weight control has been suggested to be associated with individual differences in eating behaviours (French et al., 2012). Certain factors, such as motivation (hedonic hunger and hunger status) as well as cognition (impulsivity and memory) may have an impact on eating behaviours and their relationship with weight control. Thus, the objective of this thesis was to explore individual differences in eating behaviours and investigate their relationship with motivation, cognition and weight control. The first experiment (Chapter 2) investigated the relationship between eating behaviours, motivation (hedonic hunger) and food consumption during an ad-libitum buffet. This study suggests that restrained eating behaviour was associated with higher overall energy intake, greater energy intake from unhealthy foods and greater energy intake from both high and low energy dense foods. However, no interactions between restraint and disinhibition or hedonic hunger was seen. Following this, the second experiment (Chapter 3) examined whether eating behaviours, such as disinhibition, restraint and hunger, change during a weight loss and weight maintenance period and whether they could predict changes in weight during these periods. Indeed, the results suggest that lower baseline restraint could predict greater weight loss during a low-energy liquid diet and interventions which increase restraint and decrease disinhibition may be beneficial for longer term weight maintenance. The third experiment (Chapter 4) was designed to investigate whether motivation and cognition influences eating behaviours. The results suggest that hedonic hunger, restraint and impulsivity may lead to higher levels of disinhibited eating behaviour. This study was also able to replicate the findings of previous literature suggesting that episodic memory is negatively associated with BMI (Cheke et al., 2016). Finally, following on from the previous study results, the fourth experiment (Chapter 5) included a more diverse sample of participants including dieters. The results provide evidence that individuals on a diet have poorer episodic memory ability than those currently not on a diet. This study also extended previous results suggesting that hedonic hunger (but also episodic memory and hunger) are important factors in disinhibited eating. Hedonic hunger was also shown to be important in levels of hunger.
313

Parental guidelines regarding the emotional needs of primary school children diagnosed with ADHD

Coetzee, Jacoba Martina 30 November 2006 (has links)
The aim of this study was to create awareness of the emotional needs of children diagnosed with ADHD. In order to reach the aim of this study, an initial literature study was executed to describe ADHD and the emotional needs of children. Semi-structured interviews and two projective techniques were used to conduct the empirical study. Valuable data was also collected from the biographical questionnaires completed by the parents. Based on the data collected and analysed, findings were made which were verified by means of a second literature study. This was followed by conclusions which served as the basis for recommendations that were made in the form of guidelines to the parents, with the aim to make the parents aware of the emotional needs of their children diagnosed with ADHD. These guidelines will be made available to the parents at a seminar that will be held on acceptance of this research. / Social Work / M.Diac. (Play Therapy)
314

De la sensibilité différentielle à la diathèse-stress dans la prédiction de la consommation de substances à l’adolescence : interactions entre l’environnement familial et le tempérament au cours du développement

Rioux, Charlie 02 1900 (has links)
No description available.
315

An investigation of behaviour management strategies on learners with Attention Deficit Hyperactivity Disorder in the classroom

Wulfsohn, Renee 12 1900 (has links)
Learners with Attention Deficit Hyperactivity Disorder (ADHD) traditionally display disruptive and other associated negative behaviour in the classroom setting. Behaviour management strategies utilised by the teacher in the school environment can assist in reducing this type of behaviour that impacts negatively upon their academic performance. This research study develops and investigates the effectiveness of a programme of practical behaviour management strategies designed to reduce disruptive behaviour of learners with ADHD in the classroom. / Educational Studies / M. Ed. (Educational Psychology)
316

An assessment battery for the diagnosis and evaluation of attention deficit hyperactivity disorder

Hotz, Trevor Leon 06 1900 (has links)
Psychology / M.A. (Psychology)
317

Metacognitive strategies for learning disabled adolescents in specialised education

Masureik-Berger, Arlene Roslyn 1 January 1994 (has links)
Learning disabilities are a life-long problem for many individuals. Besides the adjustments all adolescents experience in life, learning disabled adolescents must contend with academic problems at school which have a drastic effect on their selfesteem. This becomes particularly evident when these pupils face the demands of the secondary school syllabus where they have to be able to concentrate, read for information, memorise facts, answer questions and solve problems, and write assignments. By the time learning disabled adolescents reach secondary school they have already experienced so much failure that they become passive towards their studies. Teaching these pupils metacognitive learning strategies covering these skills helps them to become more independent learners. Through executive training procedures they are assisted to become more involved in their studies, the promotion of better self-regulation and self-monitoring is fostered, and as their scores improve, so does their motivation and selfconcept / Educational Studies / M.Ed. (Orthopedagogics)
318

Atenção e comportamento inibitório em adolescentes com diabetes tipo 1

Shinosaki, Jullyanna Sabrysna Morais 24 August 2016 (has links)
Introdução: o Diabetes Mellitus é uma epidemia mundial de incidência crescente e alta morbi-mortalidade. Apesar de a neuropatia diabética ser a complicação neurológica mais comum, é crescente o conhecimento de que existe um acometimento do sistema nervoso central, notadamente no que concerne às alterações cognitivas. Objetivos: investigar, por meio de duas tarefas cognitivas objetivas, simples, rápidas, de baixo custo e de fácil aplicação, diferenças entre pacientes com Diabetes Mellitus Tipo 1 (DM1) e controles quanto a medidas de atenção e impulsividade, componentes-chave das funções executivas tradicionalmente avaliados por questionários subjetivos, longos, de difícil reprodutibilidade e que exigem psicólogos treinados; correlacionar as diferenças encontradas com características clínicas; explorar as correlações entre as duas tarefas. Métodos: Foram comparados os desempenhos de 20 pacientes com DM1 e 20 controles, de ambos os sexos, com idades entre 12 e 15 anos, utilizando a tarefa Agir-Não Agir e uma tarefa de Labirintos, e verificadas correlações entre eles. Resultados: o grupo DM1 teve mais respostas antecipatórias (RA) na tarefa Agir-Não Agir (p<0,05) e fez mais mudanças de trajetória nos Labirintos (p <0,01). Houve correlação entre hipoglicemias não-graves e RA (p=0,01), e entre hipoglicemias graves e número de toques nas paredes dos labirintos (p <0,05). HbA1c> 9% correlacionou-se com um maior número de becos sem saída nos labirintos (p <0,05). Os parâmetros mostraram-se coerentes dentro de cada tarefa e entre elas. Conclusões: Encontramos indicadores de desatenção e impulsividade coexistindo no DM1, o primeiro estando mais relacionado à hiperglicemia, e o último à hipoglicemia. Investigações adicionais são necessárias para estudar o declínio cognitivo associado ao diabetes por meio de avaliações mais objetivas, e avaliar a confiabilidade e as propriedades psicométricas das tarefas aqui propostas. / Background : Diabetes Mellitus is a worldwide epidemic of increasing incidence and high morbidity and mortality. Although diabetic neuropathy is the most common neurological complication, the knowledge that there is an involvement of the central nervous system is increasing, especially in relation to cognitive changes. Aims: To investigate with two simple, inexpensive, rapid, objective and easy-to-apply tasks, differences between patients with Type 1 Diabetes Mellitus (T1DM) and controls in outcome measures of attention and impulsivity, key-executive function components traditionally assessed by subjective and long questionnaires of difficult reproducibility that require trained psychologists; to correlate the alterations with clinical characteristics; to explore correlations between the tasks. Methods: We compared the scores of 20 T1DM to 20 controls, both sexes, aged 12 to 15 years, using a Go-NoGo and a Maze task, and verified correlations between them. Results: T1DM group had more anticipatory answers (AA) in Go-NoGo task (p<0,05) and made more direction changes in Mazes (p<0,01). There was correlation between non-severe hypoglycaemias and AA (p=0,01), and between severe hypoglycaemias and number of touches in Mazes’ walls (p<0,05). HbA1c>9% correlated to a greater number of alleys in Mazes (p<0,05). The tasks’ parameters were coherent among each task and between them. Conclusions: We found indicators of inattention and impulsivity coexisting in T1DM, the first more related to hyperglycaemia and the later to hypoglycemia. Further research is needed to study diabetes-associated cognitive decline with more objective parameters and evaluate the reliability and psychometric properties of the tasks herein proposed. / Dissertação (Mestrado)
319

Cognitive Depletion and Its Effect on Decision Making / Vliv kognitivního vyčerpání na rozhodování

Farská, Kateřina January 2012 (has links)
One of the factors significantly influencing our daily decisions is the so-called cognitive depletion.The theory of cognitive depletion postulates the existence of a limited mental resource that is necessary for self-regulation. If the resource is diminished by a task involving self-control, achievement in subsequent self-control task will be impaired. This project examines the effect of cognitive depletion on decisions in the Iowa Gambling Task designed to simulate real-life decision making involving gains and losses. Further, a possible effect of moderating factors that could be affected by cognitive depletion and consequently influence decisions in the Iowa Gambling Task -- risk preference and impulsivity -- is investigated. Dual-process theories postulate there are two systems involved in decision-making: faster, intuitive, emotional System 1 and slower, deliberative, rational System 2. It was found that cognitive depletion leads to enhancement of System 1. As advantageous decisions in the Iowa Gambling Task are closely related to emotional reactions -- domain of System 1 -- it was hypothesized that cognitive depletion will lead to not worse, or possibly even better results in depleted subjects. A controlled laboratory experiment was conducted involving 39 subjects in total. No difference was found in average desicions of depleted and non-depleted subjects in the Iowa Gambling Task, supporting the hypothesis. Further, short-term increase in impulsivity caused by cognitive depletion was very probably moderating choices in the IGT, leading to worse overall performance. Regarding risk preferences, we found that non-depleted subjects were generally more risk seeking in losses context, while depleted subjects exhibited rather loss aversion. This change in risk behaviors due to cognitive depletion very probably did not mediate choices in the Iowa Gambling Task.
320

Associations prospectives entre l’engagement dans les jeux vidéo et le bien-être psychosocial des jeunes

Jalbert, Mégane 08 1900 (has links)
Contexte. La croissance du temps d'écran dans notre société, plus spécifiquement l’attrait grandissant à l’endroit des jeux vidéo est fulgurant. Ce passe-temps peut-il avoir des conséquences négatives sur l’ajustement psychosocial des enfants un an plus tard ?Objectif. Identifier les associations prospectives entre l’engagement dans les jeux vidéo à 12 anset le bien-être psychosocial à l’âge de 13 ans.Méthode. Cette étude comprend 1344 sujets dont 702 filles et 642 garçons provenant de l’ÉtudeLongitudinale du Développement des Enfants du Québec (ÉLDEQ). À 12 ans, l’enfant a rapporté le nombre d’heures par semaine durant lesquelles il s’engageait dans les jeux vidéo. Puis, à l’aide d’échelles fidèles et valides, celui-ci a rapporté ses comportements d’agressivité réactive, d’inattention et d’impulsivité ainsi que sa détresse émotionnelle à 13 ans. Pour mesurer les associations prospectives entre les jeux vidéo et le bien-être à 13 ans, des régressions multiples ont été effectuées tout en contrôlant les variables confondantes et concurrentes pertinentes.Résultats. L’engagement dans les jeux vidéo à 12 ans est associé à une augmentation des comportements d’agressivité réactive (β= 0,13), des symptômes de détresse émotionnelle (β = 0,10) ainsi que des comportements d’inattention et d’impulsivité (β = 0,15) à 13 ans chez les garçons. Quant aux filles, l’engagement dans les jeux vidéo à 12 ans est associé à une augmentation des comportements d’agressivité réactive (β= 0,16) ainsi que des comportements d’inattention et d’impulsivité (β = 0,09) à 13 ans. Aucune association entre les jeux vidéo et la détresse émotionnelle ne fut avérée pour cette population.Conclusion. Les jeux vidéo peuvent présenter un facteur de risque quant au développement ultérieur de difficultés, soit plus de comportements d’agression réactive, d’inattention et d’impulsivité, ainsi que davantage de détresse émotionnelle. Il est important d’agir de manière préventive quant à la quantité de temps alloué à ce passe-temps. / Context. The growth of screen time in our society, as well as the growing appeal for video games is dazzling. However, can this hobby have negative consequences on the psychosocial adjustment of children a year later? Objective. Identify the prospective associations between engagement in video games at age 12 and psychosocial well-being at age 13. Method. This study includes 1344 subjects including 702 girls and 642 boys from the Longitudinal Study of the Development of Children in Quebec (ÉLDEQ). At 12 years old, the child selfreported the number of hours he engaged in video games per week. Then, using loyal and valid scales, he reported reactive aggression, inattention and impulsivity and emotional distress at 13 years of age. To measure the prospective associations between video games and well-being at 13, multiple regressions were studied while controlling for the relevant confounding and competing variables. Results. Engaging in video games at 12 is associated with an increase in reactive aggression (β=0.13), symptoms of emotional distress (β = 0.10), and inattentiveness and impulsivity (β = 0.15) at 13 for boys. Engaging in video games at 12 is associated with an increase in reactive aggression (β=0.16) and inattentiveness and impulsivity (β = 0.09) at 13 for girls. They were no association between video games and emotional distress for this population. Conclusion. Video games can be a risk factor for developing difficulties later, more reactive aggression, more attention and impulsiveness, and more emotional distress. In this sense, it is important to act in prevention as to the number of times allocated to this hobby.

Page generated in 0.1242 seconds