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  • 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.
161

Visual Attentional Capture Resists Modulation in Singleton Search under Verbal Working Memory Load

Johansson, Martin January 2016 (has links)
Visual attentional capture is a form of visual attentional selection that is automatic and involuntary in nature, and is of high adaptive value as it allows visual attention to be oriented in a reflexive manner towards visual information without necessarily being guided by pre-existing knowledge, goals, and plans. According to the load-hypothesis (Lavie & De Fockert, 2005), attentional capture of salient stimuli increases under load on working memory due to disruption of stimulus-processing priorities. Moreover, it has been proposed that maintenance of task-irrelevant verbal information increases distractor interference in singleton search by increasing attentional capture of salient, but task-irrelevant, color singletons. This hypothesis was tested in the present study by having participants complete several succeeding trials of singleton search while simultaneously maintaining digits in working memory. The presence of task-irrelevant color singletons in the search array of a singleton search task led to increased response times, indicating attentional capture. However, the cost to response times associated with distractor presence did not increase under load on working memory, indicating that distractor interference may not be affected by load on working memory when task-irrelevant verbal information is maintained over an extended period of time. Individual differences in action video game playing and trait anxiety were considered and excluded as possible confounders.
162

The Quest for Maternal Survival in Rwanda : Paradoxes in Policy and Practice from the Perspective of Near-Miss Women, Recent Fathers and Healthcare Providers

Påfs, Jessica January 2016 (has links)
Rwanda has made significant progress in decreasing the number of maternal deaths and increasing the number of antenatal care visits and childbirths at health facilities. This thesis seeks to illuminate potential barriers for Rwanda’s goal for maternal survival. The studies explore the bottom-up perspective of policies and practices in regards to maternal care in Kigali. Semi-structured interviews were conducted between 2013 and 2016 with women who nearly died (‘near-miss’) during pregnancy, their partners, and with other recent fathers and community members, as well as healthcare providers who work within abortion care. The framework of naturalistic inquiry guided the study design and data collection. Analysis was conducted using framework analysis, thematic analysis and naturalistic inquiry. The findings identify paradoxical outcomes in the implementation of maternal care policies. Despite recent amendments of the abortion law, safe abortion was identified as being non-accessible. Abortion-related symptoms continue to carry a criminalized and stigmatized label, which encourages risk-taking and clandestine solutions to unwanted pregnancies, and causes care-seeking delays for women with obstetric complications in early pregnancy. Healthcare providers had limited awareness of the current abortion law, and described tensions in exercising their profession due to fear of litigation. The first antenatal care visit appeared to require the accompaniment of a male partner, which underpinned women’s reliance on men in their care-seeking. Men expressed interest in taking part in maternal care, but faced resistance for further engagement from healthcare providers. Giving birth at a health facility was identified as mandatory, yet care was experienced as suboptimal. Disrespect during counseling and care was identified, leading to repeated care-seeking and may underpin the uptake of traditional medicine. An enhanced implementation of the current abortion law is recommended. Reconsideration of policy is recommended to ensure equitable and complete access to antenatal care: women should be able to seek care accompanied by their person of choice. These findings further recommend action for improved policy to better address men’s preferred inclusion in maternal health matters. The findings of this thesis promote continued attention to implementing changes to strengthen quality, and trust, in public maternal care.
163

Stimulus-Free RT Level Power Model using Belief Propagation

Ponraj, Sathishkumar 25 October 2004 (has links)
Power consumption is one of the major bottlenecks in current and future VLSI design. Early microprocessors, which consumed a few tens of watts, are now replaced by millions of transistors and with the introduction of easy-to-design tools to explore at unbelievable minimum dimensions, increase in chip density is increasing at a alarming rate and necessitates faster power estimation methods. Gate level power estimation techniques are highly accurate methods but when time is the main constraint, power has to be estimated a lot higher in the abstraction level. Estimating power at higher levels also saves valuable time and cost involved in redesigning when design specifications are not met. We estimate power at every levels of abstraction for a breadth first design-space exploration. This work targets a stimulus-free pattern-insensitive RT level hierarchical probabilistic model, called Behavioral Induced Directed Acyclic Graph (BIDAG), that can freely traverse between the RT and logic level and we prove that such a model corresponds to a Bayesian Network to map all the dependencies and can be used to model the joint probability distribution of a set of variables. Each node or variable in this structure represents a gate level Directed Acyclic Graph structure, called the Logic Induced Directed Acyclic Graph (LIDAG). We employ Bayesian networks for the exact representation of underlying probabilistic framework at RT level, capturing the dependence exactly and again use the same probabilistic model for the logic level. Bayesian networks are graphical representations used to concisely represent the uncertain knowledge of the system. In order to get an posterior belief of a query node or variable, with or without preset nodes or variables called the evidence nodes, we use stochastic inference algorithm, based on importance sampling method, called the Evidence Pre-propagation Importance Sampling (EPIS) which is anytime and scales really well for RT and logic networks. Experimental results indicate that this method of estimation yields high accuracy and is qualitatively superior to macro-models under a wider range of input patterns. The main highlights of this work is that as it is a probabilistic model, it is input pattern independent and nonsimulative property implies less time for power modelling.
164

Addressing the contradiction between discourse and practice in health promotion.

Laverack, Glenn, kimg@deakin.edu.au,jillj@deakin.edu.au,mikewood@deakin.edu.au,wildol@deakin.edu.au January 1999 (has links)
The main theme of this thesis is the contradiction between discourse and practice in health promotion. Many health promoters continue to exert power-over the community through top-down programming whilst at the same time using an emancipatory discourse. The thesis has addressed this contradiction in three parts. The first part determines how the emancipatroty discourse has evolved and eplores the role of social movements in the development of contemporary health discourses and their influence on the legitimisation of empowerment. Central to this discourse is the empowerment of communities. To understand the role of this concept the thesis provides an interpretation of the different meanings of power and community, and the different levels of analysis of empowerment in the context of health promotion programming. The second part identifies the nature of health programming and the dominance of top-down, and to a much lesser extent, bottom-up approaches. The thesis argues that these two approaches are not, and do not have to be, mutually exclusive. To address this issue the thesis presents a new methodology is situated within a framework developed for the accomodation of empowerment goals within health promotion programmes. The study also identifies the organisational areas of influence on the processs of community empowerment and it is these which are used for the assessment of this concept. Both the framework and the methodology address the contradiction in health promotion by making community empowerment operational within a programme context. The third part of the thesis supports the rationale for the design of the methodology with field work in rural Fijian communities. The findings are presented as a composite case study to highlight the experiences of implementing the methodolgy and the main themes that emerged during the field work. the final chapter of the thesis brings together the central themes of the study and draws from these and 'emergent agenda' as a way forward for health promotion research and practice.
165

Gestion optimale des consommations d'énergie dans les bâtiments

Le, Ky 10 July 2008 (has links) (PDF)
L'objectif de la thèse est de fournir les méthodes qui permettent de gérer au mieux l'énergie en assurant le confort souhaité. Les modèles de charges sont développés et validés par des mesures. La prévision à court-terme de la consommation correspondant aux multi bâtiments (région) et au secteur résidentiel est proposée par réseaux de neurones et la méthode ascendante. Trois méthodes originales de la gestion optimale prédictive des chauffages et des climatisations sont développées: optimisation du confort thermique, minimisation des pics et minimisation des coûts de consommation. Deux méthodes originales de la gestion des charges en temps réel sont proposées: méthode basée sur un système de régulation adaptative des chauffages et des climatisations et méthode basée sur le délestage en fonction de la courbe de protection. Les méthodes proposées sont validées par simulation pour une maison (secteur résidentiel) et un hôtel (secteur tertiaire) avec les résultats satisfaisants.
166

Changement technique et double dividende d'écotaxes. Un essai sur la confluence des prospectives énergétique et macro-économique

GHERSI, Frédéric 01 April 2003 (has links) (PDF)
Les travaux présentés dans cette thèse portent sur l'évaluation des coûts macro-économiques de politiques climatiques nationales et mondiales.<br />Ils reposent sur une mise en relation innovante des prospectives énergétique et macroéconomique, dont l'objectif est d'assurer la représentation fidèle, dans la modélisation macroéconomique, des élasticités du système énergétique mises en lumière par l'analyse technico-économique.<br />Ils opèrent aussi un questionnement critique des études analytiques ayant conclu à l'improbabilité d'un dividende économique net de réformes fiscales environnementales, en démontrant que le signe ultime de l'effet prix général d'une réforme « écofiscale » est dépendant des structures de production et de consommation préexistant à la réforme, ainsi que de leur réactivité au signal-prix.<br />Ils soulignent enfin le rôle prépondérant du changement technique induit et de ses modalités—éviction de l'investissement de productivité générale éventuellement corrigée par une diffusion du progrès technique spécifique—sur l'obtention d'un second dividende.
167

Composites nanotubes de carbone - nanoparticules de platine enrobées pour électrodes de pile à combustible

Baret, Bertrand 12 January 2009 (has links) (PDF)
Ce travail porte sur la réalisation et la caractérisation d'électrodes pour piles à combustible (PAC). L'approche bottom-up adoptée associe par voie liquide des nanoparticules de platine enrobées par des molécules (NP) et des nanotubes de carbone (NT) préformés afin d'obtenir une dispersion liquide de nanocomposite. Ce procédé permet de contrôler dans une large gamme la couverture des nanotubes de carbone par les nanoparticules de platine. Puis, par filtration sur feutre de carbone nous obtenons des électrodes de PAC avec des couches actives de compositions très diverses (1 à 300 g Pt/cm², épaisseurs de 10 à 80 µm). Nous avons ensuite qualifié ex situ ces électrodes à l'aide de paramètres pertinents dont l'un est directement associé à la réduction de l'oxygène. Nous avons utilisé la voltampérométrie cyclique dans les conditions où les électrodes sont imprégnées d'électrolyte et calculé ces paramètres pour chaque électrode. Des différences observées dans ces paramètres entre deux méthodes d'imprégnation des électrodes ont révélé l'importance des modulations de mouillabilité des couches actives avec le rapport massique NP/NT et la nature de l'enrobage des nanoparticules. Cela débouche sur la possibilité de réaliser des électrodes modèles permettant à terme d'optimiser la gestion des points triples et donc l'utilisation du catalyseur dans les électrodes de PAC. Des tests en pile avec nos électrodes illustrent ainsi la possibilité de diminuer à l'avenir de manière très significative les densités de platine dans les PAC.
168

Age differences in arousal, perception of affective pictures, and emotional memory enhancement : Appraisal, Electrodermal activity, and Imaging data

Gavazzeni, Joachim January 2008 (has links)
<p>In contrast to effortful cognitive functions, emotional functioning may remain stable or even be enhanced in older adults. It is unclear how affective functions in aging correspond to subjective experiences and physiological changes. In <b>Study I</b>, ratings of emotional intensity and neural activity to facial expressions using functional magnetic resonance imaging (fMRI) were analyzed in younger and older adults. Negative expressions resulted in increased neural activity in the right amygdala and hippocampus in younger adults, and increased activation in the right insular cortex in older adults. There were no age differences in subjective ratings. In <b>Study II</b>, subjective ratings of, and skin conductance response (SCR) to, neutral and negative pictures were studied. The ratings of negative pictures were higher for older adults compared to younger adults. SCRs increased in both age groups for the negative pictures, but magnitude of SCRs was significantly larger in younger adults. Finally, in <b>Study III</b>, emotional memory after a one-year retention interval was tested. The memory performance of both age groups was higher in response to negative pictures compared to neutral ones, although the performance was generally higher for younger adults. SCR at encoding was the better arousal predictor for memory, but only in younger adults. The results indicate age-related changes in affective processing. Age differences may involve a gradual shift from bottom-up processes, to more top-down processes. The results are discussed in a wider lifespan perspective taking into consideration the accumulated life experience of older adults.</p>
169

Formalisation of edit operations for structure editors

Holmquist, Johan January 2005 (has links)
<p>Although several systems with structure editors have been built, no model exist to formally describe the edit operations used in such editors. This thesis introduces such a model --- a formalism to describe general structure edit operations for text oriented documents. The model allows free bottom-up editing for any tree-based structural document with a textual content. It can also handle attribute and erroneous structures. Some classes of common structures have been identified and structure editor specifications constructed for them, which can be used and combined in the creation of other structure editors.</p>
170

Age differences in arousal, perception of affective pictures, and emotional memory enhancement : Appraisal, Electrodermal activity, and Imaging data

Gavazzeni, Joachim January 2008 (has links)
In contrast to effortful cognitive functions, emotional functioning may remain stable or even be enhanced in older adults. It is unclear how affective functions in aging correspond to subjective experiences and physiological changes. In Study I, ratings of emotional intensity and neural activity to facial expressions using functional magnetic resonance imaging (fMRI) were analyzed in younger and older adults. Negative expressions resulted in increased neural activity in the right amygdala and hippocampus in younger adults, and increased activation in the right insular cortex in older adults. There were no age differences in subjective ratings. In Study II, subjective ratings of, and skin conductance response (SCR) to, neutral and negative pictures were studied. The ratings of negative pictures were higher for older adults compared to younger adults. SCRs increased in both age groups for the negative pictures, but magnitude of SCRs was significantly larger in younger adults. Finally, in Study III, emotional memory after a one-year retention interval was tested. The memory performance of both age groups was higher in response to negative pictures compared to neutral ones, although the performance was generally higher for younger adults. SCR at encoding was the better arousal predictor for memory, but only in younger adults. The results indicate age-related changes in affective processing. Age differences may involve a gradual shift from bottom-up processes, to more top-down processes. The results are discussed in a wider lifespan perspective taking into consideration the accumulated life experience of older adults.

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