1014824 research outputs found
Sort by
Computationally intelligent visual servoing
No full textIn visual servoing methods, the pseudo-inverse of the coupled robot-image Jacobian plays important role which maps the error in image space to the joint velocity. This map is highly non-linear and computationally complex. The complexity increases in order of O(N2) where N is the number of robot-manipulator joint. Another problem with classical visual servoing methods or model based approaches is that the system instability may occur when a discrepancy between reference model and the real system exists. This thesis proposed visual servoing methods based on computationally intelligent techniques addressing problem in the model based visual servoing approaches. A model free image based visual servoing approach using a modified Broyden's method is proposed in this thesis, The robot-image Jacobian is approximated iteratively, in each instant, during servoing towards the desired position. In addition, a computationally simple robot-image Jacobian approximation is applied together with a weighted norm method for joint limit avoidance. A computationally efficient approach for image based visual servoing has also been developed using the Takagi-Sugeno (T-S) fuzzy model. In a distributed fashion, the proposed approach maps directly the error in the visual space to the joint velocity. The method can tune the controller's parameters online. The Lyapunov method is used to derive the online adaptation algorithm. Finally a position based visual servoing approach using the Kalman filter is proposed and evaluated for a visual tracking system. This proposed method uses both the position error and its derivative as the input variables to the controller. A Kinect camera is used to provide 2D and 3D information of the object. Using a Kinect camera, the controller design effort can be simplified, while the approach reduces the computational complexity of the position based visual servoing algorithm, since the complex 3D estimation algorithm is not required. The experiments reported in this thesis work use a 7 DOF PowerCube robot manipulator. A stability analysis for the proposed algorithms using the Lyapunov method is provided.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Educational homogamy, parenting practices and children’s early development
No full textThis thesis investigates the pattern of parental educational homogamy and its implications for parenting practices and children’s early development in contemporary Britain. At the heart of the thesis lies an interest in the mechanisms behind the intergenerational transmission of educational success and, more specifically, the consequences for children of new patterns of parental resemblance in education. The thesis is composed of three empirical chapters, each of which is concerned with a different outcome: 1) trends in educational attainment and educational assortative mating amongst parental couples; 2) parents’ childrearing values and stimulation-oriented interactions with children; and 3) children’s early cognitive and behavioural skills. The first chapter combines data from four birth cohort studies from 1958, 1970, 1990 and 2000-01 while the second and third chapters rely exclusively on the latter study. The empirical analyses use Log-linear and Diagonal Reference models. With regard to trends in educational assortative mating, the thesis finds that the strength of homogamy increased between 1958 and 1970 to decrease thereafter and remain stable, at its lowest level, throughout the 1990s. Moreover, amongst recent cohorts of parental couples the percentage of unions where mothers are more educated than their male partners equalled that of unions exhibiting the opposite pattern. The findings concerning the dynamics of parenting in heterogamous couples suggest a pattern of female dominance in the attitudinal domain as fathers align with the views that can be expected on the basis of the mother’s level of education rather than their own; however, no significant adjustments between partners are observed in parenting behaviours. Lastly, the thesis finds a positive gradient in the association between parental education and children’s early cognitive and socio-emotional development but little or no support for the hypotheses of differential effects for sons and daughters or gender biases in parental preferences for children. That is, no significant interactions are observed between the gender of children and the impact of parents’ absolute and relative levels of education. Taken together, the findings of the thesis qualify concerns about the increase of educational assortative mating in industrialised societies and its potential consequences for the intergenerational reproduction of inequalities in education.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Novel approaches towards the total syntheses of pinnaic acid and matrine
No full textThis thesis describes synthetic efforts towards two natural products matrine and pinnaic acid. The strategy towards matrine focused on effecting an overall, but not necessarily concerted [4+2] cycloaddition in which a 1,4-dihydropyridine supplies the dienophile and aN-vinyl pyrldone is activated to act as the diene component. Attempts to progress an expedient route to pinnaic acid that starts with a chiral pyrrolidine cata lysed conjugate addit ion between propionaldehyde and I - nitrocyclopentene is discussed. Chapter 1 is an introduction to previous syntheses of matrine and introduces background literature examples of azadienes or dihydropyridines being used in [4+2] cycloadditions, as well as methods for constructing enamides required for the target. Chapter 2 describes our progress towards the synthesis of matrine. Significant contributions include the use of organotrifluoroborates as air and moisturestable alternatives to boronic acids in the synthesis of N-vinyl pyridones. Zincke reaction and subsequent dithionite reduction gave a high-yield ing route to install the l ,4-dihydropyridines required for the target precursors. Several studies to initiate intramolecular bond formation between these functional groups are reported. Chapter 3 provides an introduction to previous syntheses of pinnaic acid. Examples of transformations required for our proposed route are introduced including organocatalysed 1,4-addit ions of carbon nucieophiles to nitroolefins, an important stereochemistry generating step, and the vinylogous aldol reaction, which are both important components of the planned route. Chapter 4 highlights progress towards the synthesis of pinnaic acid. Significant contributions include the improvement of the diastereoselectivity of our key conjugate addition step via reduction of the in situ generated aldehyde. A panel of organocatalysts was screened for this conjugate addition step, with chiral HPLC studies confirming modest gains in e.e. when trans-4-hydroxy- L-proline was employed. This route was used to gain step-efficient access to an intermediate in Heathcock's synthesis of pinnaic acid. Further studies toward a step efficient route to pinnaic acid are described including a Friedel-Crafts acylation between a protected butynol species and chloroacetyl chloride that was demonstrated on a large scale, albeit with a slight preference for the undesired (E)-isomer. Conversion of this material to phosphonate and sulphone species, as well as its use in a model Wittig reaction, was also demonstrated.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Interventionist sport as mediatized utopia : a practice informed critique of Football 4 Peace
No full textFootball 4 Peace (F4P) is a sports-based coexistence initiative that operates between divided communities in Israel. The project has nurtured a number of high-profile partnerships with various local, national and international agencies and organisations. The F4P programme utilises an innovative methodology that foregrounds a 'values-based' approach to coaching. Like many sports interventions, the project is highly mediatized and has been the subject of a number of documentary film projects. The originality of the approach to this study is primarily through an appropriation of Ernst Bloch's long neglected 'sociology of hope' into the specific socio-cultural milieu of Sport, Development and Peace interventions. Bloch's work provides an interpretive framework for a critique of Football 4 Peace and its utopian potential. The primary methods of research are a range of visual research methodologies. These practice-informed methodologies are supported by a range of text-based analytical approaches to the critique of the documentary artefacts of F4P. The originality of this approach is extended by the synthesis of Bloch's interpretative framework with visual research practices to provide a practice-informed exploration of the utopian interventionism of Football 4 Peace. The thesis reviews sports interventions through the lens of the utopian Marxism of Ernst Bloch, focusing on the sports cultures of Israel and Football 4 Peace in particular. It also tracks the reach of mediatization into sports initiatives such F4P and interrogates the codes, conventions and culture of sports documentary interventions. These themes build towards a critical analysis of Football 4 Peace and a research film that provide an interpretation of the utopianism of F4P that draws on Bloch's philosophy. The researcher's field experiences are also assessed in a critical reflection on visual research practice. The thesis concludes with an assessment of the anticipatory elements of the F4P project, discusses how the media representations of the project can be situated as utopian and reflects on the continuing relevance of Bloch's utopianism for visual research.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Semantic based content search and content summarization
No full textDocument summarization has been an intriguing task of Computational linguistics. A number of definitions have been proposed in References, all of which consider document summarization as a problem of text compression. One of the most complete definitions by Sparck-Jones states that " ... a summary is a reductive transformation of source text to summary text through content condensation by selection and/or generalisation on what is important in the source ... ". The importance of document summarization does not lie only in presenting information in a shortened form, but also in selecting the most appropriate content to present. Moreover, a main feature in summarization is the number of sources from which a summary may be produced; thus, single-document and multi -document have been proposed, denoting the number of sources from which the summary will be produced. In addition, another categorization that may be extracted from this definition refers to the importance of the source, and what the potential user thinks is important. This leads to the definition of generic and query-based or task focused summarization, where generic implies that the summarizer should extract information according to the main topics discussed in the document, while query-based summarization focuses on extracting information according to simple or more complex questions on the document. Moreover, importance of content can be extracted through knowledge-rich (supervised and semi- supervised summarization) and knowledge lean approaches (unsupervised or shallow summarization). The last categorization refers to the type generation of the summary, the two main categories being: extractive summarization, where sentences are maintained in the summarization process unaltered; and abstraction, where the sentences are either semantically altered or compressed. The research depicted in this thesis, presents novel document summarization approaches based on the theories of Machine Learning (ML) and Natural Language Processing (NLP) for generic single-document extractive summarization. The motivation to target on Greek langaguage came from the lack of a Greek summarization system. Most notably, only one system for Greek Summarization system exists in the literature (GreekSum). The research undertaken resulted in: the development of a stemming algorithm used for noun and adjective identification, based on grammatical analysis on Greek language; the development of a novel statistical classification scheme, initially aimed to document summarization, that is proven to outperform other statistical summarizers as Narve Bayes Classifier (NBC) and Language Models (LM); the development of a supervised statistical summarization algorithm based on document classification techniques (Text Classification Assisted Summarization for Greek Language-TCASGL); and the development of a knowledge-lean summarization algorithm (Generic Unsupervised Text Summarization - GUTS), using shallow semantic document analysis and statistics. The results demonstrate that the classification algorithm significantly outperforms widely available statistical algorithms, while the ML approach yielded comparable results to other supervised systems. In addition to that, GUTS was shown to perform equally well with knowledge rich approaches.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Effets de l'interprète professionnel sur la pratique du médecine généraliste (entretiens semi-dirigés menés auprès de médecins généralistes utilisateurs de l'interprétariat professionnel)
No full textSTRASBOURG-Medecine (674822101) / SudocSudocFranceF
Taux plasmatique de neuro-hormones au cours de la syncope vaso-vagale (quel rôle pour la vasopressine ?)
No full textSTRASBOURG-Medecine (674822101) / SudocSudocFranceF
Place de la psychothérapie de soutien après une bouffée délirante aiguë ? (Etude à partir d'un cas clinique)
No full textCe travail présente le cas d'un adolescent de dix-sept ans hospitalisé dans un service de psychiatrie adulte suite à un premier épisode délirant aigu. Nous retraçons le déroulement de son hospitalisation et nous rendons compte de manière systématique des échanges lors des consultations qui ont suivi l'hospitalisation pendant presque deux ans. Nous interrogeons ensuite la notion de psychothérapie de soutien et nous proposons une revue de la littérature sur la psychothérapie de soutien. Nous abordons les spécificités de la psychothérapie de soutien dans le cadre de la schizophrénie, de la psychose naissante et des états limites. Enfin, nous revenons sur le cas de cet adolescent pout tenter de répondre aux principales questions et problématiques rencontrées au cours de ce suivi. Pour terminer, nous proposons quelques axes de travail pour une psychothérapie de soutien après une première bouffée délirante aiguë.AMIENS-BU Santé (800212102) / SudocSudocFranceF
Comment améliorer la prescription médicamenteuse chez le patient âgé en psychiatrie (étude réalisée au centre hospitalier Le Vinatier)
No full textAu cours des années à venir le nombre de personnes âgées tend à augmenter. Or le vieillissement physiologique de l'organisme est à l'origine de nombreuses modifications pharmacocinétiques et pharmacodynamiques qui font que cette population est fragile d'où l'importance de pratiques cliniques adaptées. Au cours de cette étude nous avons collaboré à l'élaboration d'un guide de prévention de l iatrogénie chez les patients âgés. Grâce à un travail pluridisciplinaire, cet ouvrage sert au personnel soignant du Vinatier dans leur pratique quotidienne. Puis selon les recommandations de la HAS (Haute Autorité de Santé) dans le cadre de la certification des établissements de santé, il a été mis en place le suivi d'un indicateur: la prescription de benzodiazépines à demi-vie longue chez les patients âgés du Vinatier. Les premiers résultats obtenus ont permis de définir les limites dans lesquelles la valeur du taux de l'indicateur doit se trouver. Le taux moyen au Centre Hospitalier le Vinatier est d'environ 19 %. Par la suite des relevés seront faits régulièrement. Dans le cas où une valeur serait hors limites, des mesures seront entreprises afin d'adapter les pratiques de chacun. L'objectif de ce travail est de mettre en place des éléments qui permettent à l'ensemble des prescripteurs de pouvoir faire évoluer leur pratique, afin de permettre une prise en charge des personnes âgées qui soit la meilleure possibleLYON1-BU Santé (693882101) / SudocSudocFranceF
Potentiel thérapeutique et mécanismes d'action du resvératrol dans les déficits héréditaires de la chaîne respiratoire
No full textPas de résumé en françaisPas de résumé en anglaisPARIS5-Bibliotheque electronique (751069902) / SudocSudocFranceF