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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.
181

Ledarskap, syskonposition och locus of control

Hasselblad, Emelie January 2008 (has links)
En majoritet bland ledare i olika organisationer har en bakgrund som storasyskon eller ensambarn (Hudson, 1990). Denna studie genomfördes för att få svar på om personer med ledaransvar skiljer sig åt gällande syskonplats och locus of control jämfört med de personer som inte har ledaransvar. Ledare och medarbetare på en statlig myndighet svarade på en enkät gällande plats i syskonskara, erfarenhet av ledarskap och locus of control. Resultatet visade att sistfödda i detta urval hade en högre grad av intern locus of control än förstfödda vilket kan tyda på en annan typ av sistfödd på denna myndighet. Urvalet var dock bristfälligt (N = 48) och slutsats kunde inte dras utan att riskera ett felaktigt resultat.
182

Socioekonomisk position och hälsa : ett välfärdsperspektiv på hälsoskillnader bland de äldsta i Sverige

Ringmar, Edith January 2009 (has links)
No description available.
183

The effects of casting position and bar shape on the lap length of plain bars in concrete

2013 March 1900 (has links)
Eighteen splice specimens were tested under four-point loading as part of a larger experimental investigation to study the behaviour of lap spliced plain steel bars in reinforced concrete specimens. Three of the specimens were instrumented with strain gauges adhered to the reinforcement and the concrete side face. Three lap splice lengths, two bar sizes for square bars, and one bar size for round bars were investigated. The principal reinforcement was either cast in the bottom or top position. The results of maximum loads, crack patterns, load versus deflection behaviour, and deflected profiles are presented for all specimens. The analysis of specimens with strain gauge instrumentation is also presented, and includes results of strain compatibility, bond stress distribution, and flexural section analysis. All specimens failed by bond, caused by a sudden pullout of the reinforcement within the splice region. An equivalent round diameter based upon the cross-section area of the square bars allowed for a single predictive equation between the maximum normalized load as a function of splice length, casting position and bar size. A top cast factor of 0.4 and 0.6 captures the reduction in the maximum normalized load for specimens cast with round and square bars, respectively, in the top position. The CEB-FIP Model Code (1993) predictive equations are reasonably conservative in capturing the behaviour of specimens reinforced with round bars cast in the bottom position, and square bars with side dimension of 25 mm cast in the bottom position. However, the CEB-FIP Model Code (1993) predictive equation is unconservative when predicting the behaviour of specimens reinforced with either square or round bars cast in the top position. On the other hand, the draft CEB-FIP Model Code (2010) provisions showed an overly conservative prediction for all specimens reinforced with either round or square bars cast in the top or bottom position. Instrumented specimens showed that strain compatibility between the longitudinal reinforcement and the surrounding concrete did not exist for much of the loading range due to bond loss. The evaluation of the neutral axis location within the shear span showed that shear is first transferred by beam action, followed by arch action. The use of three strain gauges adhered to the concrete side face provided flexural moments similar to that predicted theoretically.
184

Plasma position control in the STOR-M tokamak : a fuzzy logic approach

Morelli, Jordan Edwin 04 February 2003
Adequate control of the position of the plasma column within the STOR-M tokamak is a chief requirement in order for experimental quality discharges to be obtained. Optimal control over tokamak discharge parameters, including the plasma position, is very difficult to achieve. This is due in large part to the difficulty in modelling the tokamak discharge parameters, as they are highly nonlinear and time varying in nature. The difficulty of modelling the tokamak discharge parameters suggests that a control system, such as a fuzzy logic based controller, which does not require a system model may be well suited to the control of fusion plasma. In order to improve the quality of control over the plasma position within the STOR-M tokamak, the existing analog PID controller was modified. These modifications facilitate the application of a digital controller by a personal computer via the Advantech PCL-711B data acquisition card. The performance of the modified plasma position controller and an Arbitrary Signal Generator developed by the author was evaluated. This modified plasma position controller was applied successfully to the STOR-M tokamak during both normal mode and A.C. mode operation. In both cases, the modified controller provided adequate control over the position of the plasma column within the discharge chamber. Furthermore, the modified controller was more convenient to optimize than the original, existing analog PID controller. By taking advantage of the modifications that were made to the plasma position controller, a fuzzy logic controller was developed by the author. The fuzzy logic based plasma position controller was also successfully applied to the STOR-M tokamak during both normal mode and A.C. operation. The fuzzy controller was demonstrated to reliably provide a higher degree of control over the position of the plasma column within the STOR-M tokamak than the modified PID controller.
185

Motion Control of Rigid Bodies in SE(3)

Roza, Ashton 26 November 2012 (has links)
This thesis investigates the control of motion for a general class of vehicles that rotate and translate in three-space, and are propelled by a thrust vector which has fixed direction in body frame. The thesis addresses the problems of path following and position control. For path following, a feedback linearization controller is presented that makes the vehicle follow an arbitrary closed curve while simultaneously allowing the designer to specify the velocity profile of the vehicle on the path and its heading. For position control, a two-stage approach is presented that decouples position control from attitude control, allowing for a modular design and yielding almost global asymptotic stability of any desired hovering equilibrium. The effectiveness of the proposed method is verified both in simulation and experimentally by means of a hardware-in-the-loop setup emulating a co-axial helicopter.
186

Front end x-ray beam position monitors at the Canadian Light Source

Smith, Sheldon James 04 October 2006
The development of X-ray Beam Position Monitors (XBPM) used on the Canadian Light Source front ends is described in this thesis, from the design concepts to the practical implementation and commissioning. Surveyed into position to provide a fiducialized point of origin for incoming synchrotron radiation, the primary purpose of the XBPM is to provide a measure of synchrotron beam motion. Currently XBPMs have been installed on three beamlines at the Canadian Light Source, a 2.9 GeV third generation synchrotron radiation source. Two of the XBPMs are comprised of chemical vapour deposition synthetic diamond blades coated with gold and installed on insertion device beamlines, while the third makes use of molybdenum blades for a dipole beamline. By incrementally scanning the blades of the XBPM through the synchrotron beam it is possible to determine the monitors� spatial resolution to beam motion. For the commissioned XBPM a typical spatial resolution of +/- 1 micron of beam motion was achieved; and the thermal power loading capacity has been tested to the 2/5 of maximum value. An independent white beam profiler, comprised of a converter crystal and image acquisition software, was constructed to corroborate the functionality of the XBPM.
187

Plasma position control in the STOR-M tokamak : a fuzzy logic approach

Morelli, Jordan Edwin 04 February 2003 (has links)
Adequate control of the position of the plasma column within the STOR-M tokamak is a chief requirement in order for experimental quality discharges to be obtained. Optimal control over tokamak discharge parameters, including the plasma position, is very difficult to achieve. This is due in large part to the difficulty in modelling the tokamak discharge parameters, as they are highly nonlinear and time varying in nature. The difficulty of modelling the tokamak discharge parameters suggests that a control system, such as a fuzzy logic based controller, which does not require a system model may be well suited to the control of fusion plasma. In order to improve the quality of control over the plasma position within the STOR-M tokamak, the existing analog PID controller was modified. These modifications facilitate the application of a digital controller by a personal computer via the Advantech PCL-711B data acquisition card. The performance of the modified plasma position controller and an Arbitrary Signal Generator developed by the author was evaluated. This modified plasma position controller was applied successfully to the STOR-M tokamak during both normal mode and A.C. mode operation. In both cases, the modified controller provided adequate control over the position of the plasma column within the discharge chamber. Furthermore, the modified controller was more convenient to optimize than the original, existing analog PID controller. By taking advantage of the modifications that were made to the plasma position controller, a fuzzy logic controller was developed by the author. The fuzzy logic based plasma position controller was also successfully applied to the STOR-M tokamak during both normal mode and A.C. operation. The fuzzy controller was demonstrated to reliably provide a higher degree of control over the position of the plasma column within the STOR-M tokamak than the modified PID controller.
188

It’s complex: exploring the associations between socioeconomic position, work complexity and psychological distress in old age. : A population based study with more than 20-years follow-up.

Darin Mattsson, Alexander January 2013 (has links)
Self-reported psychological distress is quite common in the Swedish elderly population. Feelings of psychological distress may have devastating consequences. The overall aim of this study was to explore associations between socioeconomic position and work complexity during midlife with psychological distress in old age. Ordered logistic regression was used to investigate the associations between, (I) socioeconomic position during midlife and psychological distress in old age, (II) work complexity during midlife and psychological distress in old age, (III) the association between socioeconomic position and psychological distress independent of work complexity, and (IV) the association between work complexity and psychological distress independent of socioeconomic position. The results show that (I) higher socioeconomic position during midlife is associated with less psychological distress in old age (II) higher work complexity during midlife is associated with less psychological distress in old age, and that (III) higher work complexity is associated to less psychological distress independent of socioeconomic position, (IV) but the association between socioeconomic position and psychological distress diminishes adjusting for work complexity. The main conclusion from this study is that individuals with high socioeconomic position benefits from both their position in society and from their working conditions while individuals of lower socioeconomic position are more likely to also suffer the drawbacks of disadvantageous working conditions in relation to late life psychological distress.
189

Design management i produktutvecklingsföretag : Samarbetet mellan en design manager och en designkonsult

Celik Ercan, Ebru, Åkesson, Caroline January 2013 (has links)
Design management är ett arbetssätt som har börjat tillämpas av allt fler företag de senaste åren, men det kan fortfarande vara svårt att förstå betydelsen av design management. I uppsatsen undersöks det vilken betydelse en design managers kompetens och position har för samarbetet mellan det designköpande företaget och en designkonsult under ett designinköp. Genom ett flertal intervjuer, utifrån både design managers och designkonsulters perspektiv, undersöks det hur samarbetet fungerar mellan dessa parter. En analys av intervjumaterial med hjälp av en teoretisk referensram bestående av design management-teori, design som en integrerad process och beslutsrollsteori har lett fram till ett antal slutsatser om design management. Några av slutsatserna är att design management, enligt teorierna, som arbetssätt inte är så vanligt och att det finns en viss samarbetsbrist enligt de intervjuade designkonsulterna, som i viss mån underlättas om design managern har kunskap om vad design innebär.
190

Graph matching using position coordinates and local features for image analysis

Sanromà Güell, Gerard 14 February 2012 (has links)
Encontrar las correspondencias entre dos imágenes es un problema crucial en el campo de la visión por ordenador i el reconocimiento de patrones. Es relevante para un amplio rango de propósitos des de aplicaciones de reconocimiento de objetos en las áreas de biometría, análisis de documentos i análisis de formas hasta aplicaciones relacionadas con la geometría desde múltiples puntos de vista tales cómo la recuperación de la pose, estructura desde el movimiento y localización y mapeo. La mayoría de las técnicas existentes enfocan este problema o bien usando características locales en la imagen o bien usando métodos de registro de conjuntos de puntos (o bien una mezcla de ambos). En las primeras, un conjunto disperso de características es primeramente extraído de las imágenes y luego caracterizado en la forma de vectores descriptores usando evidencias locales de la imagen. Las características son asociadas según la similitud entre sus descriptores. En las segundas, los conjuntos de características son considerados cómo conjuntos de puntos los cuales son asociados usando técnicas de optimización no lineal. Estos son procedimientos iterativos que estiman los parámetros de correspondencia y de alineamiento en pasos alternados. Los grafos son representaciones que contemplan relaciones binarias entre las características. Tener en cuenta relaciones binarias al problema de la correspondencia a menudo lleva al llamado problema del emparejamiento de grafos. Existe cierta cantidad de métodos en la literatura destinados a encontrar soluciones aproximadas a diferentes instancias del problema de emparejamiento de grafos, que en la mayoría de casos es del tipo "NP-hard". El cuerpo de trabajo principal de esta tesis está dedicado a formular ambos problemas de asociación de características de imagen y registro de conjunto de puntos como instancias del problema de emparejamiento de grafos. En todos los casos proponemos algoritmos aproximados para solucionar estos problemas y nos comparamos con un número de métodos existentes pertenecientes a diferentes áreas como eliminadores de "outliers", métodos de registro de conjuntos de puntos y otros métodos de emparejamiento de grafos. Los experimentos muestran que en la mayoría de casos los métodos propuestos superan al resto. En ocasiones los métodos propuestos o bien comparten el mejor rendimiento con algún método competidor o bien obtienen resultados ligeramente peores. En estos casos, los métodos propuestos normalmente presentan tiempos computacionales inferiores. / Trobar les correspondències entre dues imatges és un problema crucial en el camp de la visió per ordinador i el reconeixement de patrons. És rellevant per un ampli ventall de propòsits des d’aplicacions de reconeixement d’objectes en les àrees de biometria, anàlisi de documents i anàlisi de formes fins aplicacions relacionades amb geometria des de múltiples punts de vista tals com recuperació de pose, estructura des del moviment i localització i mapeig. La majoria de les tècniques existents enfoquen aquest problema o bé usant característiques locals a la imatge o bé usant mètodes de registre de conjunts de punts (o bé una mescla d’ambdós). En les primeres, un conjunt dispers de característiques és primerament extret de les imatges i després caracteritzat en la forma de vectors descriptors usant evidències locals de la imatge. Les característiques son associades segons la similitud entre els seus descriptors. En les segones, els conjunts de característiques son considerats com conjunts de punts els quals son associats usant tècniques d’optimització no lineal. Aquests son procediments iteratius que estimen els paràmetres de correspondència i d’alineament en passos alternats. Els grafs son representacions que contemplen relacions binaries entre les característiques. Tenir en compte relacions binàries al problema de la correspondència sovint porta a l’anomenat problema de l’emparellament de grafs. Existeix certa quantitat de mètodes a la literatura destinats a trobar solucions aproximades a diferents instàncies del problema d’emparellament de grafs, el qual en la majoria de casos és del tipus “NP-hard”. Una part del nostre treball està dedicat a investigar els beneficis de les mesures de ``bins'' creuats per a la comparació de característiques locals de les imatges. La resta està dedicat a formular ambdós problemes d’associació de característiques d’imatge i registre de conjunt de punts com a instàncies del problema d’emparellament de grafs. En tots els casos proposem algoritmes aproximats per solucionar aquests problemes i ens comparem amb un nombre de mètodes existents pertanyents a diferents àrees com eliminadors d’“outliers”, mètodes de registre de conjunts de punts i altres mètodes d’emparellament de grafs. Els experiments mostren que en la majoria de casos els mètodes proposats superen a la resta. En ocasions els mètodes proposats o bé comparteixen el millor rendiment amb algun mètode competidor o bé obtenen resultats lleugerament pitjors. En aquests casos, els mètodes proposats normalment presenten temps computacionals inferiors.

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