• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 19
  • 10
  • 7
  • 6
  • 3
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 65
  • 10
  • 9
  • 8
  • 7
  • 7
  • 7
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 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.
31

Secretaries, statesmen and spies : the clerks of the Tudor Privy Council, c.1540 - c.1603

Vaughan, Jacqueline D. January 2007 (has links)
This dissertation studies the office of the clerk of the Privy Council, including discussions of the office itself, and the nineteen men who held that office between its creation, in 1540, and 1603. The dual focus on the office and officers aims to provide greater understanding of both. Areas of study include the personal and professional backgrounds of the clerks, their careers, writings both political and personal, additional offices held and both social and financial concerns. This covers areas as diverse as knighthoods, land grants, election to the House of Commons, political treatises and university education. Additionally, the duties of the office, both standard and extraordinary, are discussed, as well as details regarding the creation and handling of the clerk’s primary concern, the Privy Council register. This includes details regarding signatures, meetings with ambassadors, examination of prisoners, Council meetings, salaries and fees, and attendance rotation. Ties between the clerks and clerkship and the Privy Council and its members are discussed throughout, as well as the role of patronage, education, foreign experience and personal motives. This study aims to provide a greater understanding of the clerks of the Privy Council and their office, knowing that one cannot be fully understood without the other.
32

Spectres de diffusion Raman induits par les intéractions pour les bandes v2 et v3 de la molécule CO2 en gaz pur et en mélange avec de l'argon

Egorova, Natalia 30 October 2008 (has links) (PDF)
Dans cette thèse, nous avons étudié les mécanismes de diffusion Raman induite par les collisions dans le cas du CO2 comprimé et en mélange avec de 'argon, ceci pour les bandes v2 et v3. Nous avons analysé des mélanges de concentrations relatives différentes, dans l'intervalle de pressions 10-100 atm, et déterminé les sections efficaces, qui caractérisent les interactions CO2-CO2 et CO2-Ar, en unités absolues. Nous avons optimisé le seuil de détection du signal, ce qui nous a permis, pour la première fois, d'acquérir les deux moments principaux qui caractérisent les diffusions isotrope et anisotrope. Nous avons découvert un nouvel effet : une diffusion Raman qui change la parité de la molécule libre et qui est liée à l'émission dipolaire magnétique. Pour interpréter quantitativement les moments mesurés, nous avons élaboré une technique diagrammatique pour calculer les caractéristiques électro-optiques des couples déterminés par les interactions à longues distances. L'analyse diagrammatique de la polarisabilité induite a permis de révéler le nouveau mécanisme d'induction qui est lié à la polarisation non linéaire du partenaire de collision par le champ extérieur et par le champ du moment dipolaire transitoire de la molécule qui effectue la transition ( mécanisme NLD). Nous avons défini les formules des moments des bandes Raman induites par les interactions anisotropes des couples de molécules linéaires. Notre calcul a montré le rôle substantiel du mécanisme NLD dont la prise en compte permet d'obtenir un bon accord avec les résultats expérimentaux.
33

Available actors, appropriate action : theodramatic formation and performance

Vander Lugt, Wesley January 2013 (has links)
Situated within the theatrical turn in Christian theology, this project explores theatre as a model for theological ethics, looking particularly at the dynamic interplay between formation as disponibility (availability) and performance as fittingness (appropriateness). A primary goal is to demonstrate how disponible formation and fitting performance are multi-dimensional realities oriented simultaneously toward the triune God (as playwright-producer-protagonist), Scripture (as transcript and prescript), the church (as characters in company), tradition (as performance paradigms), unbelievers (as audience), and local context (as theatrical environment and place). As a result, this theodramatic approach seeks to integrate theology and ethics, describing and resourcing everyday Christian practice with reflection on the theodrama. In addition, focusing on the dynamic interplay between formation and performance represents an attempt to unify agent-oriented with action-oriented theological ethics within a holistic, theodramatic framework. Finally, through attentive interaction with theatrical theory and practice, this project contributes to a fruitful and growing dialogue between Christian theology and the arts, particularly how theatre provides imaginative, heuristic models for theological ethics pursued within the liberating constraints of confessional Christianity.
34

Undersökning av flexibel implementation för hantering av multipla rösttjänster

Brandt, Viktor, Olofsson, Jesper January 2020 (has links)
Att välja vilken eller vilka röststyrningstjänster man som företag vill stödja kan i dagens läge vara ett svårt val att göra. Det kan även var så att man inte har resurser att göra två olika implementationer. I den här undersökningen tittar vi på om det finns ett bra sätt att göra en implementation som kan hantera fler än en röststyrningstjänst. Tjänsterna vi har fokuserat på i undersökningen är Amazon Alexa och Google Assistant.
35

Prevalencia y factores asociados a la intención de vacunarse contra la COVID-19 en el Perú / Prevalence and factors associated with the intention to vaccinate against COVID-19 in Peru

Herrera-Añazco, Percy, Uyen-Cateriano, Ángela, Urrunaga-Pastor, Diego, Bendezu-Quispe, Guido, Toro-Huamanchumo, Carlos J., RodrÍguez-Morales, Alfonso J., Hernández, Adrian V., Benites-Zapata, Vicente A. 27 August 2021 (has links)
Objetivos: Estimar la prevalencia y los factores asociados a la intención de vacunación (IDV) contra la COVID-19 en el Perú. Materiales y métodos: Estudio transversal analítico utilizando una encuesta realizada por la Universidad de Maryland, EUA, en Facebook. La variable dependiente fue la IDV. Se calcularon razones de prevalencia (RP) crudas y ajustadas, con sus intervalos de confianza al 95% (IC95%), mediante modelos lineales generalizados de la familia Poisson para evaluar la asociación de variables sociodemográficas, el cumplimiento de estrategias comunitarias de mitigación, los síntomas de la COVID-19, la salud mental y la aceptación de la vacunación ante la recomendación (AVR) por diversos actores y autoridades sanitarias. Resultados: Se analizaron los datos de 17 162 adultos. La prevalencia general de la IDV fue del 74,9%. Se asociaron a una menor prevalencia de la IDV ser de sexo femenino (RP = 0,95; IC95%: 0,94-0,97), vivir en un pueblo (RP = 0,95; IC95%: 0,91-0,99) o en una aldea u otra área rural (RP = 0,90; IC95%: 0,86-0,93) y la AVR de políticos (RP = 0,89; IC95%: 0,87-0,92). Contrariamente, tener síntomas de COVID-19 (RP = 1,06; IC95%: 1,03-1,09), inseguridad económica (RP = 1,04; IC95%: 1,01-1,06), miedo a enfermar o que un familiar enferme de COVID-19 (RP = 1,49; IC95%: 1,36-1,64) y la AVR de familiares y amigos (RP = 1,10; IC95%: 1,08-1,12), trabajadores de la salud (RP = 1,29; IC95%: 1,26- 1,32), la Organización Mundial de la Salud (RP = 1,34; IC95%: 1,29-1,40) y funcionarios del gobierno (RP = 1,18; IC95%: 1,15-1,22) se asociaron con mayor prevalencia de IDV. Conclusiones: Tres cuartas partes de los encuestados manifiestan IDV. Existen factores potencialmente modificables que podrían mejorar la aceptación de la vacuna. / Objectives: To estimate the prevalence and factors associated with COVID-19 vaccination intention (VI) in Peru. Materials and methods: Analytical cross-sectional study using the survey conducted by the University of Maryland, USA, on Facebook. The dependent variable is VI. Crude and adjusted prevalence ratios (PR) were calculated, with their 95% confidence intervals (95%CI) using generalized linear models of the Poisson family, to evaluate the association of sociodemographic variables, com- pliance with community mitigation strategies, symptoms of COVID-19, mental health and acceptance of vaccination before the recommendation (AVR) by various actors and health authorities, with the ITV. Results: Data from 17,162 adults were analyzed. The overall prevalence of VI was 74.9%. A lower prevalence of VI was associated with the female sex (PR=0.95; 95%CI:0.94-0.97), living in a town (PR=0.95; 95%CI:0.91-0.99) or village or other rural area (PR=0.90; 95%CI:0.86-0.93) and the AVR of politicians (PR=0.89; 95%CI:0.87-0.92). Conversely, having COVID-19 symptoms (PR=1.06; 95%CI:1.03-1.09), economic insecurity (PR=1.04; 95%CI:1.01-1.06), fears of becoming seriously ill or that a family member becomes seriously ill from COVID-19 (PR=1.49; 95%CI:1.36-1.64) and the AVR of family and friends (PR=1.10; 95%CI: 1.08-1.12), healthca- re workers (PR=1.29; 95%CI: 1.26-1.32), World Health Organization (PR=1.34; 95%CI: 1.29-1.40) and government officials (PR=1.18; 95%CI: 1.15-1.22) was associated with a higher prevalence of VI. Conclusio of the respondents had VI. There are potentially modifiable factors that could improve vaccine acceptance.
36

Design of an Evaluation Platform for multimodal 3D Data

Xu, Chengjie 11 September 2018 (has links)
Sensor Fusion for 3D data is a popular topic. Multisensor data combination enhance the qualities of each other while single sensor lacks accuracy. In this thesis, an evaluation platform for Multimodal 3D data from Kinect v2 and Microphone Array is designed and implemented by using ReactJS. In automotive industry and computer vision area, 3D detection and localization are widely used. Solutions of 3D detection and localization using different measurement systems are discussed in a large number of papers. Data Fusion systems are normally using ultrasound based, radio waves based, Time-of-Flight, structured light, stereo cameras and sound based sensors. All of these measurement systems might provide different 3D data models. And each system works fine separately. However, in some cases, multiple measurement systems need to work together. Their 3D data sets are different and could not be compared and combined directly. In order to simplify the design process of multiple measurement systems, this web based evaluation platform is focused on comparison and combination of 3D data sets from different coordinate systems. It provides a quick and easy development method between multiple measurement systems. In this thesis, an evaluation platform which based on Kinect v2 body detection and microphone array sound detection systems will be discussed. First an introduction about project overview is given. The second section of this paper deals with several project related technologies. The third section provides the concept of this project. The forth section describes development and implement detail. The next section is about data visualization and statistical analysis. Further the final results, evaluation and discussion are given.
37

Single-Shot, Ultrafast, Multi-Frame X-Ray Imaging of Defect-Bearing Ablator Materials in Extreme Conditions

Hodge, Daniel S. 12 December 2022 (has links)
Characterization of the dynamic behavior of defect-bearing ablator materials subjected to extreme conditions is essential in advancing fusion energy as an reliable and abundant energy source. By understanding how materials evolve spatially and temporally we can minimize hydrodynamic instabilities, which are major contributing factors to energy yield degradation in inertial confinement fusion (ICF) experiments. In this thesis we demonstrate the capabilities of an ultrafast x-ray imaging (UXI) detector, the Icarus V2, where we capture multiple frames of single void-bearing sample compressed by a high-intensity laser shockwave. Using the Matter in Extreme Conditions (MEC) instrument at the Linac Coherent Light Source (LCLS), we conducted two experiments with the x-ray free electron laser (XFEL) multi-pulse mode, delivering four nanosecond-separated pulses to a sample impacted by a laser shockwave, obtaining multiframe images of a single sample in the holographic and direct imaging regime with the UXI detector. In contrast to the low temporal resolution provided by current cameras, the Icarus V2 can capture images with high temporal resolution, which can be used to determine the mechanisms that prevent thermonuclear ignition in ICF experiments. For images captured in the holographic regime at our XFEL energy of 8.23 keV, we realized that the shock front was obscured by strong phase-contrast effects. We recognized that by increasing the XFEL energy while in the holographic regime, more distinguishable features could be revealed behind and along the shock front. Alternatively, in the direct-imaging configuration we discovered that the evolution of microstructural features were directly recognizable in comparison to the holographic regime at lower XFEL energies. Overall, the images captured by the UXI in both regimes demonstrated our ability to obtain multiframe images of processes that occur over several nanoseconds for single samples, which has never been done before. Moreover, the capabilities of the UXI enable extraction of quantitative information over multiple frames, which can help with uncovering the underlying physics involved in high energy density (HED) physics experiments and other experiments involving non-repeatable ultrafast phenomena. Specifically, insight into the behavior of the void can be gained by performing phase retrieval on the images and obtaining the areal density of the materials during laser-shock ablation. Generally, the UXI improves data acquisition speed and operational efficiency, which extends this camera's functionality to experiments that occur at various time scales or experiments that require multiple images to be captured.
38

Control and Modeling of High-Frequency Voltage Regulator Modules for Microprocessor Application

Li, Virginia 11 June 2021 (has links)
The future voltage regulator module (VRM) challenges of high bandwidth control with fast transient response, high current output, simple implementation, and efficient 48V solution are tackled in this dissertation. With the push for control bandwidth to meet design specifications for microprocessor VRM with larger and faster load transients, control can be saturated and lost for a significant period of time during transient. During this time, undesirable transient responses such as large undershoot and ringback occurs. Due to the loss of control, the existing tools to study the dynamic behavior of the system, such as small signal model, are insufficient to analyze the behavior of the system during this time. In order to have a better understanding of the system dynamic performance, the operation the VRM is analyzed in the state-plane for a clear visual understanding of the steady-state and transient behaviors. Using the state-plane, a simplified state-plane trajectory control is proposed for constant on-time (COT) control to achieve the best transient possible for applications with adaptive voltage positioning (AVP). When the COT control is lost during a load step-up transient, the state-plane trajectory control will extend on-time to provide the a near optimal transient response. By observing the COT control law in the state-plane, a simplified state-plane trajectory control with analog implementation is proposed to achieve the best transient possible with smooth transitions in and out of the steady-state COT control. The concept of the simplified state-plane trajectory control is then extended to multiphase COT. For multiphase operation, additional operating behavior, such as phase overlapping during transient and interleaving during steady-state, need to be taken into consideration to design the desired state-plane trajectory control. A simple state-plane trajectory control with improved Ton extension is proposed and verified using multiphase COT control. After tackling the state-plane trajectory control for current mode COT, the idea is then extended to V2 COT. V2 COT is a more advanced current mode control which requires a more advanced state-plane trajectory control to COT. By calculating the intersection of the extended on-stage trajectory during transient and the ideal off trajectory in the form of a current limiting wall, a near optimal transient response can be achieved. For V2 COT with state-plane trajectory control, implementations using inductor vs. capacitor current, effect of component tolerance, and effect of IC delay are studied. The proposed state-plane trajectory control is then extended to enhanced V2 COT. Aside from tackling existing VRM challenges, the future datacenter 48V VRM challenge of a high efficiency, high power density solution to meet the VRM specifications is studied. The sigma converter is proposed for the 48V VRM solution due to exhibition of high efficiency and high-power density from hardware evaluation. An accurate model for the sigma converter is derived using the new modeling approach of modularizing the small signal components. Using the proposed model, the sigma converter is shown to naturally have very low output impedance, making the sigma converter suitable for microprocessor applications. The sigma converter is designed and optimized to achieve AVP and very fast transient response using both voltage-mode and current-mode controls. / Doctor of Philosophy / Microprocessors, such as central processing unit (CPU) and graphics processing unit (GPU) are the basis of today's electronics. In the recent decades, the demand for more powerful and faster data processing lead to a significant increase in power consumption by these microprocessors. Even with the introduction of multi-core processors and adaptive voltage positioning (AVP) to reduce the average power provided by the power supplies, the microprocessor can still draw a large amount of instantaneous power in a short period of time. With the microprocessors demanding high amount of current at fast slew-rate, the challenges for the next generation of microprocessor power supply, or voltage regulator modules (VRM), are fast response speed to ensure proper operation of the microprocessors, and high efficiency VRM to minimize the overall system power consumption. The challenge of a VRM with fast response speed is tackled first. To meet the AVP and transient requirements of microprocessor, the VR need to utilize high-bandwidth control methods. Of the control methods used by the industry, high control bandwidth can be easily achieved using constant on-time (COT) control. With the ever-increasing output current level and transient slew-rate requirements, COT control can saturate and lose its steady-state control for a period of time during load step-up transient. During this time, the system will operate with a fixed frequency control until COT control is recovered. Although the method is widely used in the industry, the method is too slow to meet the transient requirements. Many state-of-art methods have been proposed to resolve the load step-up transient issue of COT. However, of the methods proposed, it is difficult to optimize the transient improvement while having a simple analog implementation to ensure a fast response for the wide operating range and aggressive transient conditions observed in microprocessor VRM application. In this dissertation, COT control is studied using the state-plane to provide a clear visual understanding of the transient behavior of the control. Using the state-plane, a state-plane trajectory control is proposed to achieve near optimal load step-up transient response. The concept is then extended to multiphase VRM, which is typically used for high current applications. The state-plane trajectory control concept is then further extended to V2 COT control for VRM without AVP, such as those used by GPU and smartphone CPU. For the proposed state-plane trajectory controls, hardware implementation, evaluation, and experimental results are provided. After tackling the challenge of a VRM with fast response speed, the challenge of an efficient VRM is then tackled. In recent years, a significant amount of research has been put into studying VRM for a power delivery architecture which uses a 48V bus instead of the 12V bus. By using the 48V bus, less redundancy in the power delivery path can greatly increase the overall system efficiency if the VRM stage retains its efficiency. However, the increase in input voltage for the VRM provides an additional challenge to maintain high efficiency for the VRM stage itself. To maintain good efficiency, it is difficult to increase converter switching frequency beyond 300kHz. This limitation on switching frequency will limit the ability to achieve high bandwidth design and fast transient requirements. A 48V VRM using a different topology, the sigma converter, has demonstrated high-efficiency and high-power density, but the converter behavior and control methodology for VRM application is unclear. In this dissertation, the modeling and control of the sigma converter are studied using the proposed small-signal model. By evaluating the proposed small-signal model, the sigma converter can naturally have very low output impedance, making it an ideal candidate for 48V VRM. Then, the design guideline of the sigma converter with current-mode control is provided. With the work discussed in this dissertation, further study of the sigma converter with COT and state-plane trajectory control can be conducted in the future.
39

Microresonators for organic semiconductor and fluidic lasers

Vasdekis, Andreas E. January 2007 (has links)
This thesis describes a number of studies of microstructured optical resonators, designed with the aim of enhancing the performance of organic semiconductor lasers and exploring potential applications. The methodology involves the micro-engineering of the photonic environment in order to modify the pathways of the emitted light and control the feedback mechanism. The research focuses on designing new organic microstructures using established semi-analytical and numerical methods, developing fabrication techniques using electron-beam lithography, and optically characterising the resulting structures. Control of the feedback mechanism in conjugated polymer lasers is first investigated by studying Distributed Feedback or photonic crystal resonators based on a square feedback lattice. This study identified the diffraction to free space radiation as a major source of loss in current microstructured resonator designs. By cancelling the coupling to free space through the use of different feedback symmetries and diffraction orders, a threshold reduction by almost an order of magnitude is demonstrated. The introduction of mid-gap defect photonic states in an otherwise uniformly periodic structure was studied in Distributed Bragg Reflector (DBR) resonators. This enabled GaN diode pumped polymer lasers to be demonstrated, indicating that the transition from complex excitation sources to more compact systems is possible. Devices for potential applications in the field of optical communications are also explored by demonstrating a polymer DBR laser based on silicon. In this way, the potential for integrating conjugated polymers with silicon photonics is confirmed. Photonic crystal fibres, which have a periodic microstructure in the transverse direction, are explored as an alternative means for controlling the optical properties of organic lasers. Fluidic fibre organic lasers were demonstrated as efficient sources with good spectral purity. In these devices, mechanisms to tune the emission wavelength were explored and the origin of the frequency selection mechanism was investigated.
40

Des chaperons pharmacologiques agissant sur les récepteurs V2 de la vasopressine offrent un traitement potentiel pour le diabète insipide néphrogénique

Bernier, Virginie January 2004 (has links)
Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Page generated in 0.0347 seconds