• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 8
  • 7
  • 3
  • 3
  • 2
  • Tagged with
  • 27
  • 7
  • 6
  • 6
  • 6
  • 6
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 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.
1

Utvärdering av BD Vacutainer® Rapid Serum Tube vid analys av S-Paracetamol och S-Etanol

Bild, Filippa January 2014 (has links)
Avdelningen för klinisk kemi vid Länssjukhuset i Kalmar analyserar läkemedel och alkoholer med BD Vacutainer® Plus Plastic Serum Tube (Serum Tube), som kräver en koagulationstid i upp till 60 minuter. BD Vacutainer® Rapid Serum Tube (RST™) innehåller trombin och kräver en koagulationstid på endast 5 minuter. Syftet med studien var att undersöka möjligheten att förkorta den preanalytiska väntetiden före centrifugering vid intoxikationsanalyser i serumrör från akutmottagningen. Studien utfördes genom att jämföra RST™ med Serum Tube vid analys av S-Paracetamol och S-Etanol. Totalt analyserades 70 prover för S-Paracetamol, varav 35 RST™ och 35 Serum Tube från 35 patienter. Analys av S-Etanol utfördes på 60 prover, varav 30 RST™ och 30 Serum Tube från 30 patienter. RST™ centrifugerades efter 5 minuter och Serum Tube efter 50 minuter, före kolorimetrisk analys på analysinstrumentet VITROS® 5,1 FS. Resultaten för S-Paracetamol var inom intervallet 74,9 – 198,7 µmol/L för RST™ och inom 76,6 – 195,3 µmol/L för Serum Tube. Resultaten för S-Etanol var inom intervallet 7,5 – 74,5 mmol/L för RST™ och inom 7,5 – 74,8 mmol/L för Serum Tube. Pearsons korrelationskoefficient var 0,9977 för S-Paracetamol och 0,9980 för S-Etanol och det fanns en liten positiv bias vid analys med RST™ för båda analyterna, men ingen signifikant skillnad (p>0,05) mellan provrören påvisades. Användning av RST™ på akutmottagningen medför en förkortad preanalytisk väntetid och en snabbare turnaround time (TAT). Hypotesen att S-Paracetamol och S-Etanol kan analyseras med RST™ på VITROS® 5,1 FS stämmer, med undantag för höga koncentrationer av S-Paracetamol som inte kunde utvärderas. För att RST™ ska kunna användas rutinmässigt bör därför ytterligare studier utföras.
2

Modeling and Position Control of Piezoelectric Motors / Modélisation et contrôle en position des moteurs piezoélectriques

Brahim, Mouhanned 06 October 2017 (has links)
Pour des applications depositionnement, les moteurs piézoélectriquesprésentent aujourd’hui une alternativeintéressante aux moteurs électromagnétiquesclassiques en raison de leur forte précision del’ordre de quelques nanomètres ainsi que de leurfaible niveau de bruit électromagnétique. Dansce contexte, les travaux de cette thèse portent surla modélisation, la conception, et l’implantationen temps réel de contrôleurs en position pour desmoteurs piézoélectriques. L’objectif est deproposer un système de contrôle en positionrobuste pour des applications robotiques avecun cahier des charges prédéfini. Trois moteurspiézoélectriques avec des principes defonctionnement différents (USR60, PAD7220,N-310.13) ont été choisis. Leurs modèlesélectromécaniques ont été développés afin devalider leurs principes de fonctionnement etd’analyser leurs comportements dynamiquesface à des perturbations (variation de couple decharge, de température, etc…). Ensuite, cesmodèles sont utilisés pour simuler et valider lesperformances des algorithmes de contrôle enboucle fermée notamment en termes deprécision, de robustesse et de stabilité. Desbancs de test expérimentaux ont été mis enœuvre pour les trois moteurs, et des modèlesréduits reliant les positions des moteurs auxsignaux de commande correspondants ont étéidentifiés expérimentalement. Deux contrôleursde position de type H-infini (H∞) et RST sontensuite synthétisés et simulés. Ces contrôleurssont implantés en temps réel sur les bancs detests expérimentaux via un système dSPACE.Les performances de chaque moteur associé à sacommande sont évaluées. Une étudecomparative entre les résultats expérimentauxde ces deux contrôleurs et ceux d’un contrôleurPID classique est aussi présentée. / The Piezoelectric motors present aninteresting alternative to electromagneticsmotors for precise positioning systems. This ismainly due to their high accuracy in thenanometer scale, and to their very lowelectromagnetic noise levels. In this context, thework presented in this thesis deals with themodeling, design, and real time implementationof position controllers for piezoelectric motors.The objective is to propose robust closed loopposition controller of piezoelectric motors forrobotic applications. Based on the applicationspecification requirements, three motors withdifferent topologies (USR60, PAD7220, N-310.10) are selected. Their electro mechanicmodels are developed in order to validate theiroperating principle and to analyze theirdynamics.These models are also used to simulate thecontroller algorithms in closed loop.Experimental platforms based on the threemotors are designed, and the reduced modelslinking the motor positions to the correspondingcontrol signals are experimentally identified.Afterwards, two position controllers of type Hinfinity(H∞) and RST are synthesized andsimulated. These controllers are implemented inreal time via the experimental platformsequipped by dSPACE boards. The performancesof each motor in closed loop associated to theposition controllers are evaluated using theexperimental results. Comparative studybetween the experimental results of twoproposed controllers and conventional PIDcontroller is also presented.Université Paris-
3

Estudo baseado na interpolação 3D dos valores de RQD: barragem de Itaipu / Study based on 3D interpolation of the RQD values: Itaipu Dam (PR), Brazil

Canello, Vivian Athaydes 13 January 2012 (has links)
Este trabalho foi baseado na realização de simulações computacionais 3D de parâmetros de RQD obtidos de classificação geomecânica de sondagens rotativas realizadas nas fases de investigação geológico-geotécnica e construção da barragem de Itaipu (PR), Brasil. Tais simulações foram desenvolvidas em duas áreas dispostas no entorno da barragem principal da usina, utilizando como ferramenta o programa GRASS, que executa interpolações tridimensionais pelo método numérico Spline Regularizado com Tensão (RST). Os resultados obtidos foram comparados com dados previamente interpretados e obtidos por outros métodos como os geoestatísticos e apresentaram resultados razoáveis devido as dimensões dos voxels adotados, diferenças dos métodos e distribuição espacial dos dados. / This work was based on three-dimensional computer simulations of the parameters RQD of the boreholes on geological and geotechnical research phases and construction of the Itaipu dam (PR), Brazil. These simulations were carried out in two areas arranged around the plant the main dam, using as tool the GRASS program, which performs three-dimensional interpolation by mathematical method Regularized Spline with Tension (RST) . The results were compared with data previously obtained and interpreted by other methods such as geostatistical and had reasonable results because the dimensions of the voxels adopted, differences in methods and spatial distribution of the data.
4

Estudo baseado na interpolação 3D dos valores de RQD: barragem de Itaipu / Study based on 3D interpolation of the RQD values: Itaipu Dam (PR), Brazil

Vivian Athaydes Canello 13 January 2012 (has links)
Este trabalho foi baseado na realização de simulações computacionais 3D de parâmetros de RQD obtidos de classificação geomecânica de sondagens rotativas realizadas nas fases de investigação geológico-geotécnica e construção da barragem de Itaipu (PR), Brasil. Tais simulações foram desenvolvidas em duas áreas dispostas no entorno da barragem principal da usina, utilizando como ferramenta o programa GRASS, que executa interpolações tridimensionais pelo método numérico Spline Regularizado com Tensão (RST). Os resultados obtidos foram comparados com dados previamente interpretados e obtidos por outros métodos como os geoestatísticos e apresentaram resultados razoáveis devido as dimensões dos voxels adotados, diferenças dos métodos e distribuição espacial dos dados. / This work was based on three-dimensional computer simulations of the parameters RQD of the boreholes on geological and geotechnical research phases and construction of the Itaipu dam (PR), Brazil. These simulations were carried out in two areas arranged around the plant the main dam, using as tool the GRASS program, which performs three-dimensional interpolation by mathematical method Regularized Spline with Tension (RST) . The results were compared with data previously obtained and interpreted by other methods such as geostatistical and had reasonable results because the dimensions of the voxels adopted, differences in methods and spatial distribution of the data.
5

Design, Simulation and Implementation of High Precision Control Algorithms for a Galvanometer Laser Scanner

Torres Bonet, Tomas 26 August 2014 (has links)
This thesis focuses on the theory, design, simulation and implementation of several digital controllers for periodic signals on a laser scanning galvanometer. A model for the galvanometer was obtained and veri ed using closed loop identi cation techniques. Using this model, controllers were designed and simulated using MATLAB and then implemented on a custom FPGA control processor with a focus on tracking performance. The types of controllers used were: an Iterative Learning Controller, an RST pole placement controller, an Adaptive Feed-forward cancellation controller, a combined Iterative Learning and Adaptive Feed-forward cancellation controller and a simple PID controller. The simulated results were better than the experimental results because of system noise and modelling uncertainties but the relative performance between each of the controllers was similar for both the simulation and experimental setup. The experimental results achieved were very good with one controller reaching errors under 50 rad. / Graduate / 0537 / t_Torres_bonet@hotmail.com
6

The Influence of Revised Reinforcement Sensitivity Theory Subsystems on Social Interaction and Social Observation Anxiety

Kramer, Samuel Louis 01 May 2014 (has links)
Evidence suggests that both the BIS and the BAS play a role in the individual differences seen in social anxiety disorder; however, findings concerning the role of the BAS have been mixed. To date, the role of RST subsystems underlying social anxiety has been measured with outdated scales. This study addressed this issue by using a measure purpose-built for the revised RST. The current study was able to replicate past findings that the BAS is differentially related to social interaction anxiety and social observation anxiety (Kimbrel et al., 2010; Kimbrel et al., 2012). While using a newer measure based on the revised RST; however, results indicated that BAS sensitivity related to both subdimensions of social anxiety. In addition, findings indicate that the RST systems remain good predictors of social anxiety symptoms even after accounting for the influence of levels of positive and negative affect. Implications and future directions are discussed.
7

Families in the Sky: Investigating the Population Structure of Pinus longaeva

Decker, Samuel Arnold 11 April 2022 (has links)
In the Western United States, the Great Basin is a geographic feature that is home to a variety of unique species, including Great Basin bristlecone pine (Pinus longaeva, PILO). P. longaeva is well known for the age of some of the trees, some of which are over 4000 years old. In this study 17 microsatellite markers (simple sequence repeat, SSR) are identified and used to genotype a selection of 480 individuals spread across 24 PILO populations and 60 individuals divided equally between 2 outgroup species, Pinus aristata and Pinus flexilis. One population of PILO, HMW, shows more genetic similarity with P. aristata, and is included with outgroup species in the analysis. The population structure of PILO is examined and found to be weakly related to the geographic distance between populations. The population statistics Fst, Gst, Rst, Dest and an AMOVA analysis suggest that there is a substantial amount of admixture at the individual level, similar to some other species of pines. Phylogenetic trees computed using the neighbor-joining method based on the average population genetic distance and based on individual genetic distance support the population structure results and show further evidence that most of the species variation is concentrated at the individual level, rather than inside of or between species. It is possible that gene flow is still occurring, or that gene flow has occurred recently enough that the separated populations have not yet diverged from each other in a measurable way.
8

Topics of galactic structure and stellar and chemical evolution

Chaname, Julio 13 September 2005 (has links)
No description available.
9

Modélisation et commande d’une chaine de conversion pour véhicule électrique intégrant la fonction de charge des batteries / Modeling and control of a power converter for electric vehicle integrating battery charging function

Lacroix, Samantha 29 May 2013 (has links)
Le développement des véhicules hybrides et électriques s’est intensifié ces dernières années, face aux problématiques environnementales et économiques. Afin que les performances de ces derniers soient comparables à celle d’un véhicule à moteur thermique, de nombreuses avancées technologiques sont indispensables. Le déploiement de véhicule entièrement à traction électrique, ne serait être réalisable, sans des infrastructures de recharge adaptées. Cette thèse constitue une contribution à l’étude d’un chargeur de batteries intégré au véhicule électrique, dans le cadre du projet SOFRACI.L'architecture de ce chargeur entièrement réversible sert également pour la traction du véhicule. L’utilisation de tous les éléments y compris le moteur de traction pour les deux fonctions, réduit l’encombrement et le coût de la structure. L’objectif principal consiste à modéliser le système de conversion alternatif-continu du chargeur et à établir les lois de commandes.Lors de la première phase de l’étude, une attention particulière a été portée à l’utilisation des enroulements de la machine en tant qu’inductance de filtrage du convertisseur. Un modèle correspondant à ce fonctionnement a été obtenu et a permis de mettre en évidence un couplage magnétique existant entre les diverses phases.En s’appuyant sur les modèles obtenues, la seconde étape a consisté à définir les stratégies de commande. Deux méthodes ont été employées. La première, par le biais d’une transformation a permis de se ramener dans un repère, où la majorité des termes de couplage ont été éliminés. Pour l’autre méthode, tous les éléments du couplage ont été considérés. Pour chacune de ces stratégies, des correcteurs PI et RST fondés sur le placement de pôles robustes ont été dimensionnés pour garantir la stabilité du système.Une part importante du travail a été consacrée à la réalisation d’un banc d’essai expérimental reconstituant la conversion alternative-continue. Compte tenu des différences de dynamiques des grandeurs asservies, une carte FPGA et un processeur ont été utilisés. L’exploitation de ce moyen d’essai a permis de comparer et de valider les lois de commande développées. / Environmental constraints and reduction of fossil fuels resources have led industrials and laboratories to search for alternative solutions in the transportation domain. For the last few years, several vehicles or planes functions have been gradually electrified, up to their complete electrification. This thesis presents an AC/DC converter integrated in an Electric Vehicle (EV) for the charger application. The conversion is realized by using the electric traction powertrain, in order to reduce the global cost and increase compactness where a specific motor has been design.During the first phase of the study, a model of the motor used as filtering inductances has been obtained and allowed to highlight an existing magnetic coupling between the motor’s phases.The second step was to define control strategies. Two methods were used. The first one, by a transformation allowed eliminating the majority of the coupling term. In the other method, all coupling elements have been considered. For each strategies, IP and RST controllers based on robust pole placement were designed to ensure system stability.An important part of the work was devoted to the realization of an experimental test bench for AC-DC conversion. A FPGA and a processor were used for control implementation. The control laws has been compared and validated thanks to the experimental platform.
10

Redocumentation des traces d’utilisation d’un environnement informatique / The redocumentation of traces of using a computer system

Yahiaoui, Leila 17 September 2012 (has links)
Cette thèse d'ingénierie des connaissances a pour objet la redocumentation de l'activité médiée informatiquement à base de fichiers traces. Au cours d’un tel processus, un utilisateur interprète et réécrit les traces dans un nouveau document, qui correspond à un genre particulier et décrit l'activité dans toute sa richesse ; il a notamment la possibilité de reformuler le contenu des traces, de l'enrichir avec d'autres informations (justification ou informations sur le contexte), de supprimer des parties, etc. Il s’agit ainsi de renforcer le statut documentaire des traces selon les trois dimensions de la lisibilité, de l’intelligibilité et de l’échange. Nous proposons une approche générique semi-automatique qui combine le contenu de traces de l’activité et les connaissances des utilisateurs dans des formes narratives, facilement échangeables, décrivant l’activité de façon personnalisée pour les utilisateurs. Celle-ci utilise des modèles formels pour les traces et les documents produits, ainsi que les principes de la théorie de la structure rhétorique (RST). Elle soutient la redocumentation à travers deux phases : une phase automatique pour générer un document initial fragmenté à partir de la trace d'activité comme une première description pour celle-ci et une phase interactive pour personnaliser cette description selon les besoins et les choix d'un utilisateur afin de produire un document. Nous proposons également la spécification de cette approche pour le cas particulier de la redocumentation par le texte et nous présentons ActRedoc, un outil auteur que nous avons développé pour implémenter cette approche spécifique en utilisant différentes technologies du Web Sémantique. Les résultats de notre travail ont été testés dans un environnement réel qui est celui de la redocumentation des traces de navigation dans un site d’archives de journaux du XIXème développé par la bibliothèque municipale de Lyon. Nous présentons ainsi les résultats d'une première évaluation de l'approche de redocumentation en texte et de l'outil ActRedoc auprès d'un groupe d'utilisateurs / This thesis is situated within the framework of knowledge engineering; it is particularly interested in the redocumentation of the computermediated activity from traces files. We suppose that during such a process, a user interprets and rewrites traces in a new document that corresponds to a particular genre and describes the traced activity in détails ; all this via the possibility to rewrite traces content, to enrich this content with other information (justifications or information on the context), to delete parts from it, etc. Therefore, we strengthen the documentary status of traces according to the three dimensions of legibility, comprehensibility and exchange. For implementing such a process, we propose a generic semi-automatic approach which combines the content of activity traces with users knowledge in narrative forms, easily exchangeable, to describe the traced activity in a personalized way for users. This Approach uses formal models for traces and documents (produced), as well as principles of the rhetorical structure theory (RST). It supports the redocumentation process through two phases: an automatic phase to generate an initial fragmented document from traces as a first description of the activity and an interactive phase to personalize this description according to the user needs and choices so that to produce an easily exchangeable document. We also propose a specification of this approach for the particular case of redocumentation by text and we present ActRedoc, an authoring tool that we developed by using different technologies of the Semantic Web in order to implement this specific approach. The results of our work were tested in a real environment which concerns redocumenting the activity of browsing a site of archives of newspapers of the XIXth century developed by the municipal library of Lyon. Thus, we present a first evaluation of the approach of redocumentation by text and of the authoring tool ActRedoc by a group of users

Page generated in 0.0515 seconds