No description available.

<p>In this project several tests were performed to evaluate the performance of an On-Board Imager® (OBI) mounted on a clinical linear accelerator. The measurements were divided into three parts; geometric accuracy, image registration and couch shift accuracy, and image quality. A cube phantom containing a radiation opaque marker was used to study the agreement with treatment isocenter for both kV-images and cone-beam CT (CBCT) images. The long term stability was investigated by acquiring frontal and lateral kV images twice a week over a 3 month period. Stability in vertical and longitudinal robotic arm motion as well as the stability of the center-of-rotation was evaluated. Further, the agreement of kV image and CBCT center with MV image center was examined.</p><p>A marker seed phantom was used to evaluate and compare the three applications in image registration; 2D/2D, 2D/3D and 3D/3D. Image registration using kV-kV image sets were compared with MV MV and MV-kV image sets. Further, the accuracy in 2D/2D matches with images acquired at non-orthogonal gantry angles was evaluated. The image quality in CBCT images was evaluated using a Catphan® phantom. Hounsfield unit (HU) uniformity and linearity was compared with planning CT. HU accuracy is crucial for dose verification using CBCT data.</p><p>The geometric measurements showed good long term stability and accurate position reproducibility after robotic arm motions. A systematic error of about 1 mm in lateral direction of the kV-image center was detected. A small difference between kV and CBCT center was observed and related to a lateral kV detector offset. The vector disagreement between kV- and MV-image centers was  2 mm at some gantry angles. Image registration with the different match applications worked sufficiently. 2D/3D match was seen to correct more accurately than 2D/2D match for large translational and rotational shifts. CBCT images acquired with full-fan mode showed good HU uniformity but half fan images were less uniform. In the soft tissue region the HU agreement with planning CT was reasonable while a larger disagreement was observed at higher densities. This work shows that the OBI is robust and stable in its performance. With regular QC and calibrations the geometric precision of the OBI can be maintained within 1 mm of treatment isocenter.</p>

In this project several tests were performed to evaluate the performance of an On-Board Imager® (OBI) mounted on a clinical linear accelerator. The measurements were divided into three parts; geometric accuracy, image registration and couch shift accuracy, and image quality. A cube phantom containing a radiation opaque marker was used to study the agreement with treatment isocenter for both kV-images and cone-beam CT (CBCT) images. The long term stability was investigated by acquiring frontal and lateral kV images twice a week over a 3 month period. Stability in vertical and longitudinal robotic arm motion as well as the stability of the center-of-rotation was evaluated. Further, the agreement of kV image and CBCT center with MV image center was examined. A marker seed phantom was used to evaluate and compare the three applications in image registration; 2D/2D, 2D/3D and 3D/3D. Image registration using kV-kV image sets were compared with MV MV and MV-kV image sets. Further, the accuracy in 2D/2D matches with images acquired at non-orthogonal gantry angles was evaluated. The image quality in CBCT images was evaluated using a Catphan® phantom. Hounsfield unit (HU) uniformity and linearity was compared with planning CT. HU accuracy is crucial for dose verification using CBCT data. The geometric measurements showed good long term stability and accurate position reproducibility after robotic arm motions. A systematic error of about 1 mm in lateral direction of the kV-image center was detected. A small difference between kV and CBCT center was observed and related to a lateral kV detector offset. The vector disagreement between kV- and MV-image centers was  2 mm at some gantry angles. Image registration with the different match applications worked sufficiently. 2D/3D match was seen to correct more accurately than 2D/2D match for large translational and rotational shifts. CBCT images acquired with full-fan mode showed good HU uniformity but half fan images were less uniform. In the soft tissue region the HU agreement with planning CT was reasonable while a larger disagreement was observed at higher densities. This work shows that the OBI is robust and stable in its performance. With regular QC and calibrations the geometric precision of the OBI can be maintained within 1 mm of treatment isocenter.

No description available.

<p>På bara ett par år har elektronisk handel potential att radikalt förändra de ekonomiska och sociala förhållanden i samhället. Internets snabba tillväxt kopplar samman individer och organisationer till ett stort globalt nätverk som representerar enorma möjligheter. Det talas om ett nätverkssamhälle och en nätverksekonomi.</p><p>Elektronisk handel driver företag mot att bedriva affärer på ett fundamentalt nytt sätt. Behovet av att dela information i realtid ökar tillsammans med förändringarna i värdekedjan.</p><p>Syftet med studien är att kartlägga elektronisk handel i allmänhet. Studien fokuseras på hur elektronisk handel används för att länka samman företag, stora som små, från råmaterial till konsumenten. Arbetet belyser hinder och krav i samband med elektronisk handel och det sätt de hanteras på.</p><p>Företagen i undersökningen visar ingen tydlig strävan mot att uppnå en totalt integrerad värdekedja. Grundliga affärsprocesser flyttas mot Internet för att utnyttja nätverkets fördelar. Främst används EDI och online-tjänster som Internetbutiker för elektronisk handel.</p>

På bara ett par år har elektronisk handel potential att radikalt förändra de ekonomiska och sociala förhållanden i samhället. Internets snabba tillväxt kopplar samman individer och organisationer till ett stort globalt nätverk som representerar enorma möjligheter. Det talas om ett nätverkssamhälle och en nätverksekonomi. Elektronisk handel driver företag mot att bedriva affärer på ett fundamentalt nytt sätt. Behovet av att dela information i realtid ökar tillsammans med förändringarna i värdekedjan. Syftet med studien är att kartlägga elektronisk handel i allmänhet. Studien fokuseras på hur elektronisk handel används för att länka samman företag, stora som små, från råmaterial till konsumenten. Arbetet belyser hinder och krav i samband med elektronisk handel och det sätt de hanteras på. Företagen i undersökningen visar ingen tydlig strävan mot att uppnå en totalt integrerad värdekedja. Grundliga affärsprocesser flyttas mot Internet för att utnyttja nätverkets fördelar. Främst används EDI och online-tjänster som Internetbutiker för elektronisk handel.

This thesis demonstrates how two early nineteenth century British novels, William Earle’s Obi, or The History of Three-Fingered Jack (1800) and the anonymously-written The Woman of Colour; A Tale (1808), feature prominent women of colour that move beyond the silenced, enslaved, minor representations of black and mixed race women made popular in previously published texts throughout the seventeenth and eighteenth centuries. The progression of Amri and Olivia’s positions through the use of literary strategies, such as Homi K. Bhabha’s mimicry, Paul Gilroy’s double consciousness, and gender-reversals reveal the inherent ambivalence of the women’s positions in each narrative and the importance of these representations against the hegemonic female position. Although I argue that neither author succeeds in overturning traditional limitations of representing women of colour in literature of the period, investigating these texts is crucial to understanding the autonomous, influential women of colour in later nineteenth century literary works.

L'objet de ma recherche porte sur l'obeah à Ste-Lucie, compris comme un ensemble de pratiques de gestion thérapeutique, spirituelle, magique et sorcellaire de la maladie et de l'infortune. Ces pratiques, nommées de façon similaire dans d'autres îles anglophones de la Caraïbe, sont souvent associées à la sorcellerie. Toutefois, il est possible de constater à Ste-Lucie que leur désignation suppose l'énonciation de valeurs morales, attribuées aux infortunes, à leur étiologie, aux pratiques de guérison ou aux personnes qui y sont associées. Cette thèse démontre la possibilité d'envisager l'obeah comme une pratique morale et éthique - au moins autant qu'une pratique thérapeutique ou religieuse - car elle implique la production et l'utilisation de valeurs morales au quotidien. L'obeah peut être considéré comme telle dans la mesure où ces pratiques sont définies moralement, où elles sont le reflet de discours moraux (discours de/sur l'obeah) en même temps qu'elles sont l'objet de processus de moralisation (altérisation, contagion morale), où elles donnent lieu au développement d'un travail éthique chez les praticiens de/associés à l'obeah. En ce sens, les pratiques de/associées à l'obeah sont façonnées par les discours moraux et les justifications éthiques. La démonstration se base sur le concept d'économie morale pour rendre compte du contexte de production des enjeux moraux entourant ces pratiques, de la répartition des évaluations morales chez les acteurs concernés par l'obeah et produisant un discours à l'égard de ces pratiques (discours coloniaux, historiques, publics, médiatiques, biomédicaux et religieux). Ce concept permet d'envisager la circulation et l'utilisation de valeurs morales entourant l'obeah telles qu'elles sont élaborées par les institutions (légales, religieuses et médicales), mais aussi par la population st-lucienne et par les praticiens concernés par de tels jugements moraux. À travers les évaluations morales portant sur l'obeah, ce sont les valeurs et idiomes moraux des membres de la société st-lucienne qui transparaissent, mais ce sont peut-être surtout les moralités telles qu'elles sont incarnées par les gens qui sont mises de l'avant, c'est-à-dire leur travail éthique, lequel met au premier plan les enjeux entourant la moralité individuelle. Les accusations morales et sorcellaires témoignent des représentations sociales plus larges à l'égard du Bien et du Mal, mais aussi des enjeux socio-politiques actuels, selon la perspective d'une économie politique de la sorcellerie. Principalement étudiées en termes religieux, magiques, thérapeutiques et culturels, les pratiques de l'obeah sont ici analysées à partir d'une anthropologie des moralités et de l'éthique, afin de saisir les processus de moralisation qu'elles génèrent et qui en sont constitutifs.

No description available.