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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.
101

Contribution à la modélisation du magnétisme statique et dynamique pour le génie électrique / Contribution of static and dynamic magnetism modelings for electrical engineering

Marion, Romain 13 December 2010 (has links)
De nos jours, la modélisation numérique constitue un outil indispensable pour le prototypage de convertisseurs électromagnétiques. Les matériaux magnétiques jouent un rôle essentiel dans la conversion de l’énergie, il est donc nécessaire de maîtriser leur comportement et leur représentation. L’objectif de ce travail s’inscrit dans ce cadre et s’attache à élaborer des lois réalistes de comportement de matériaux afin de les inclure dans des simulateurs de circuits. Concernant le comportement statique, le modèle de Jiles-Atherton a été implémenté puis adapté, simplifié et modifié afin d’en améliorer la précision et l’implémentation. La modélisation dynamique du matériau a été effectuée grâce au modèle DWM élaboré au laboratoire Ampère. Ce modèle intègre les effets dynamiques excédentaires grâce à une loi « dynamique de matériau » implémentée au sein de l’équation de diffusion magnétique. Ce modèle a été ensuite homogénéisé afin d’en améliorer son implémentation future dans un simulateur de circuit. Chacun des différents modèles a été testé et validé sur plusieurs échantillons. / Nowadays, numerical modeling is an indispensable tool for the prototyping of electromagnetic converters. Magnetic materials play an essential role into the energy conversion so it is necessary to control their behavior as well as their modeling. The objective of this work is to develop realistic laws of material behavior for circuit simulators use. Regarding the static behavior, the Jiles-Atherton model has been implemented and adapted, simplified and modified to improve accuracy and implementation. Dynamic modeling of the material was performed using the model DWM developed into the Ampere laboratory. This model incorporates the excedentary dynamic effects thanks to a "dynamical material law" implemented into the magnetic diffusion equation. Then this model was homogenized to improve its future implementation in a circuit simulator. Each of the different models has been tested and validated on several samples.
102

Dynamique morphosédimentaire de la baie d’Agadir : approche multi-méthodes et préconisations pour une gestion intégrée de la zone côtière / Sediment morpho dynamics of the bay of Agadir : multi-method approach and recommendations for an integrated management of the coastal zone

Aouiche, Ismail 20 May 2016 (has links)
Les systèmes côtiers, où le transport sédimentaire est perturbé par les aménagements côtiers sur la côte et l’avant côte, fournissent généralement d'excellents exemples permettant de mettre en lumière ces liens. Cela est faisable lorsque l’ensemble des données bathymétriques d’avant-côte, qui ne sont pas toujours disponibles, sont recueillies au fil du temps. La baie et la ville d'Agadir forment ensemble un des pôles de développement économique le plus important de la côte atlantique du Maroc. En utilisant une approche méthodologique basée sur la modélisation de la houle et des courants, le différentiel de levées topo-bathymétriques, la détermination de l’évolution du trait de côte et le suivi topographique de la zone intertidale, nous mettons en évidence les liens étroits entre les variations des petits fonds et la ligne du trait de côte. Ces liens impliquent à la fois les voies de transport cross-shore et longshore, les variations du budget sédimentaire et la détermination de cellules sédimentaires. Nous avons également suivi l’évolution morphologique de la zone intertidale de la baie en réponse à huit tempêtes qui ont lieu entre Janvier 2014 et Mars 2014. Les résultats obtenus par les simulations numériques montrent que les deux premières tempêtes sont responsables des changements morphologiques majeurs au niveau de la zone intertidale. / Coastal systems where sediment transport is perturbed by engineering interventions on the shoreline and shoreface commonly provide fine examples liable to throw light on these links. This is especially so where shoreface bathymetric datasets, which are generally lacking, are collected over time, enabling more or less fine resolution of the meso-scale coastal sediment budget. Agadir Bay and the city of Agadir together form one of the two most important economic development poles on the Atlantic coast of Morocco. Using a combined methodological approach based on wave–current modelling, bathymetric chart-differencing, determination of shoreline fluctuations, and beach topographic surveying, we highlight the close links between variations in the bed of the inner shoreface and the bay shoreline involving both cross-shore and longshore sand transport pathways, sediment budget variations and new sediment cell patterns. This work discusses also the morphological changes and evolution of Agadir Bay beach (Morocco) in response to eight storms between January 2014 and March 2014. A comparison is carried out of the evolution and variability of the beach in a sector of the bay protected by the commercial harbour of Agadir relative to a sector down drift of the harbour that is more exposed to waves, and changes affecting the beach following these storms are examined. Wave influence is evaluated using numerical simulations. The results show that despite being of relatively low intensity, the two first storm events, and especially storm 1, are responsible for major beach morphological changes.
103

Correlação da algometria, escala análogo visual, escala numérica de avaliação da dor em mulheres com dor pélvica crônica

Alfonsin, Mariane Meirelles January 2013 (has links)
Introdução: A Dor Pélvica Crônica (DPC) é um problema social, com alta prevalência, acometendo mulheres na idade reprodutiva. Cada vez mais salientamos a importância de investigar instrumentos apropriados para avaliação da dor, facilitando na prática clínica a escolha do melhor método que torne mais completa a avaliação de aspectos da intensidade na mensuração da dor crônica. Portanto, o objetivo deste estudo é correlacionar diferentes instrumentos de avaliação da intensidade dolorosa, a escala numérica (EN), escala visual analógica (EVA) e a algometria de pressão, nas mulheres com DPC, a fim de identificar o instrumento que melhor expressa o quadro doloroso. Métodos: foram avaliadas pelo ginecologista oitenta mulheres encaminhadas ao ambulatório do serviço de Ginecologia e Obstetrícia do Hospital de Clínicas de Porto Alegre (HCPA), trinta e três mulheres apresentaram algum aspecto dos nossos critérios de não inclusão. Selecionamos para participar do estudo quarenta e sete pacientes com DPC, sendo que vinte pacientes apresentavam endometriose diagnosticada por videolaparoscopia e vinte e sete pacientes apresentavam outras causas ginecológicas. Utilizamos no estudo um roteiro para anamnese cujos dados relacionados com a DPC foram coletados, tais como diagnóstico, tratamento, sintomatologia e locais da dor. Escores de dor foram classificados de acordo com a intensidade, através das escalas de dor (EN e EVA), instrumentos baseados no autorrelato do indivíduo e algometria de pressão, para verificar o limiar de dor à pressão das pacientes. Na análise dos dados, a concordância entre as escalas foi avaliada pelo coeficiente de correlação intraclasse (ICC) e a associação entre as escalas com o algômetro foi avaliada pelo coeficiente de correlação de Spearman, o nível de significância adotado foi de 5% (P<0,05). Resultados: As participantes do estudo tinham idade média de 38,3 ± 7,6 anos. Utilizamos o ICC para análise da correlação entre os instrumentos de relato da percepção dolorosa, ou seja, entre as EN e EVA, em relação à dor (0,992), na dismenorreia (1,00) e na dispareunia (0,996), e encontramos excelente concordância entre as escalas, com P<0,01. As associações da algometria com as escalas foram moderadas e inversas, apresentando diferenças estatisticamente significativas, quanto maior a pontuação nas escalas EN e EVA em relação à dispareunia, menores os valores no algômetro, exceto nos pontos LA1 e LA2 em ambos os lados. Também houve associação inversa das escalas EN e EVA na dismenorréia, no ponto LAB2 lado direito e associação inversa no ponto PS lado direito com a escala EVA de dor, com diferenças estatisticamente significativas. Conclusão: As escalas são instrumentos eficientes para avaliação da dor, podendo ser utilizada tanto a EN quanto a EVA na avaliação da intensidade dolorosa. Na avaliação das mulheres com DPC devemos utilizar a algometria de pressão associada à EN ou EVA, instrumentos inversamente proporcionais, confiáveis e sensíveis, tornando menos subjetiva a avaliação da dor para melhor expressar o quadro doloroso. / Introduction: The Chronic Pelvic Pain (CPP) is a social problem, with high prevalence, affecting women in reproductive age. Increasingly, has been emphasised the importance of investigating appropriate instruments for evaluation of pain in clinical practice, by facilitating the choice of the best method to make more complete the evaluation in measuring intensity aspects of chronic pain. Therefore, the objective of this study is to correlate different painful intensity assessment tools, the numeric scale (NS), visual analogue scale (VAS) and algometry pressure, in women with CPP, in order to identify the instrument that best expresses the pain. Methods: were evaluated by the gynecologist eighty women referred to the Gynecology and Obstetrics service, Clinical Hospital of Porto Alegre (HCPA), thirty three women had some aspect of our criteria for not inclusion. The study included forty seven patients, twenty patients had endometriosis diagnosed by laparoscopy and twenty seven patients had other gynecological causes. For the analyses in this study we used a road map for anamnesis whose data related to the CPP was collected, such as diagnosis, treatment, symptoms and pain locations. In addition, pain scores were classified according to intensity, through the pain scales (NS and VAS), based on self-report instruments of individual and algometry, to verify the pressure pain threshold of the patients. Statistically, the agreement between scales was assessed by intraclass correlation coefficient (ICC) and the association between the scales with the algometer were evaluated by Spearman's rank correlation coefficient, the level of significance adopted was 5% (P<0,05). Results: Study participants had an average age of 38.3 ± 7.6 years old. In the statistical analysis, we used ICC reporting instruments of perception painful I mean, between NS and VAS regarding pain (0,992), in dysmenorrhoea (1.00) and Dyspareunia (0.996), and we found excellent correlation between scales, with P<0,01. The associations of algometria with the scales were moderate and inverses, showing differences statistically significant, the higher the score NS and VAS in relation to Dyspareunia smaller values in algometer, except in points LA1 and LA2 on both sides. Indeed, there were also inverse association of scales NS and VAS on dysmenorrhea, in point LAB2 in the right side and inverse association in point PS in the right side with scale VAS of pain, with statistically significant differences. Conclusion: the scales are effective instruments for evaluation of pain, and may be used both in NS and VAS at painful intensity evaluation. In the evaluation of women with CPP should be used the algometry pressure associated with NS or VAS, instruments inversely proportional, reliable and sensitive, making less subjective pain assessment to better express the pain.
104

Vlastnosti pěnokeramických filtrů potřebné pro využití v numerických simulacích / Properties of ceramics foam filters needed for numerical simulation software

Boček, Vítězslav January 2017 (has links)
Final thesis, elaborated within the master study field of Foundry technology, deals with determination of some parameters of ceramic foam filters that are necessary for using numerical simulation during foundry practice. Thesis foccuses on defining methodology, manufacturing messuring device and measuring pressure drop on several type sof ceramic foam filters in dependence on flow rate of measuring medium. Measuring medium selected is water, mening this thesis deals also with water simulation in foundry technology.
105

Hardwarová realizace numerického integrátoru s metodou vyššího řádu / Hardware Realization of Higher Order Numerical Integrator

Matečný, František January 2018 (has links)
This work describes numerical integration and solution for ordinary differential equations by the Taylor series by different types of integrators. The next part is a description of floating point and fixed point arithmetic. Subsequently, we are presenting designs and calculation methods for parallels multiplication and division integrators in floating point and fixed point arithmetic. The designs were realized in VHDL and implemented on FPGA. Finally we summarizes the proposed solution and compare time complexity with another numerical methods.
106

Numerická klávesnice / Numeric keyboard

Hladký, Pavel January 2020 (has links)
This thesis deals with design of numeric keyboard, which can be connected to personal computer or laptop through USB interface. This numeric keyboard can be also configured using application for operating system Windows. Backlight pattern generator is also part of this application. Theoretic part deals with various types of keyboards, switches and closer description of USB interface. Practical part deals with sole design of circuit that detects keystrokes and sends information about active switches through USB, description of used components, description of microcontroller service routine and description of the application for backlight pattern generating. At the end of this thesis are described results of measurements which were made to choose mechanical switches with shortest debounce time and keyboard response to key press.
107

Studie šíření elektromagnetické vlny v heterogenních strukturách / Electroamgnetic wave propagation study in heterogeneous structures

Nešpor, Dušan January 2010 (has links)
The sight of work is study form high frequency electromagnetic wave in inhomogeneous materials. The main are refractions and reflection on boundary of materials with different properties and form electromagnetic wave in periodic structure. The work contain analytic and numeric solution. The numeric solution was realized in program COMSOL.
108

Měření parametrů optických spojů / Measurement of optical connections

Kučera, Zdeněk January 2014 (has links)
Communication via fiber optical cable (links) is the latest advancement of the transmission media currently used for data transmission. Despite initial problems, using of this medium in recent years has greatly expanded due to their indisputable advantages. Optical cable is a great combination of reliability and security of data transfer. Its constantly improving transmission parameters contribute to the high speeds in the long-distance transmission of data. In the theoretical part of this work some kinds of optical cables are mentioned, also the most important parameters and the most widely used methods of measurement of these cables. Apart from that other methods of joining optical cables and the most used types of optical cables are also mentioned. The values of the decline and reflection, which are led into the device after connecting these parts into the optical lines. The device using the measuring method of the reverse reflection is also described in this thesis altogether with its most important parts and the way of the display of the measured track on the graphic image of the device. The problematics of identification and decline dead zone and the factors influencing the lenght of dead zone – the ability to identify two independent events on the link patchcord of the variable lenght, is also described in details in this thesis. In the practical part a series of measurements and evaluation (numerical and graphical) of the measured values of decline lenghts and identificating dead zones of the OTDR device will be carried out.
109

Studium procesů v dohasínajícím plazmatu / Study of Post-Discharge Processes

Soural, Ivo January 2011 (has links)
The decaying plasma was studied by the optical emission spectroscopy. DC discharge created at 45 – 200 mA in Pyrex and Quartz tubes in flowing regime was used. The emission of three nitrogen spectral systems (1st and 2nd positive and 1st negative) were studied in time evolution for pressures of 500 – 5 000 Pa at two wall temperatures – ambient and liquid nitrogen (150 K inside the decaying plasma). Results showed that all three nitrogen systems (respectively N2(B, v), N2(C, v) and N2+(B, v) states as their origins) had their population maxima called pink-afterglow in the afterglow part. These maxima decreased with the increase of pressure for all systems, and moved to the later decay time. Maxima increased with discharge current (respectively power) and moved to shorter time. Populations at temperature of 150 K were measured due to the experimental arrangement from 17 ms, only, and thus pink aftergow maximum wasn’t observed (only at 5 000 Pa some maximum was recognized). Populations were smaller at 150 K that populations measured at laboratory temperature at the middle decay time (50-100 ms). At the late time, the populations were higher at lower temperature at lower pressure. Higher shifts (in intensity and decaytime) of pink afterglow maxima were observed in Quartz tube in comparison with their values in Pyrex tube. Besides the populations, rotational temperatures of selected bands of three observed spetral systems (for 1st negative 0-0 band, 1st positive 2-0 band and for 2nd positive 0-2 band) were measured. Rotational temperatures were monitored from presumption that this kind of temperature is equal to temperature of neutral gas (at local thermodynamic equilibrium). Results from 1st negative and 1st positive system showed strong decreasing of rotational temperatures up to about 10 ms at post-discharge begin, then temperatures were constant up to 20 ms of decay time and after that they grew up. Temperatures increased with the increase of current. The part with decreased temperature correlated with pink-afterglow part of post-discharge. Unfortunately, rotational temperatures of 2nd positive system had bad reproducibility and the time profile shape was opposite. Experimental results were compared with numerical kinetic model created by group of prof. Vasco Guerra at Instituto Supetior Técnico in Portugal. Several sets of conditions for simulation at 500 and 1 000 K in active discharge were applicable for the calculation corresponding to the experiment. Comparison of numerical simulation and experimental data done for N2(B) state demonstrated that maxima populations in pink afterglow are depended on the temperature difference between active discharge and post discharge. Maxima populations were supposed in pink afterglow disappeared if the same temperatures in active and post discharges were supposed. Temperature in active discharge is higher at higher apllied power, as it was showed from rotational temperatures observation. The results clearly showed that real temperature profile must be included into the kinetic model.
110

Riziko hybridizace ohrožené třešně křovité (Prunus fruticosa) s pěstovanými zástupci rodu Prunus / Assessing the threat of hybridization between Prunus fruticosa and cultivated Prunus species

Musilová, Lenka January 2013 (has links)
Presented thesis evaluates the risk of ongoing hybridization (antropohybridization) in highly endangered Prunus fruticosa in the Czech Republic and selected adjacent countries. Absolute genome size analysis (estimated by flow cytometry) combined with both numeric and geometric morphometrics were used for evaluation of hybridization. Prunus fruticosa frequently hybridize with naturalized Prunus cerasus (emerging tetraploid hybrid Prunus ×eminens) and native Prunus avium (forming triploid hybrid Prunus ×mohacsyana). Discrimination between P. ×eminens and P. ×mohacsyana is difficult, when using leaf morphology characters only, so the occurrence of triploid hybrids was strongly underestimated in the Czech Republic (only tetraploid hybrids were reported). Both hybrids are surely differentiated using flow cytometry analysis (based on different ploidy level). The majority of analyzed populations is formed by either individuals of pure P. fruticosa or one of the mentioned hybrids. Only four populations were mixed. Continuous variability in absolute genome size was found in two of them, which may indicate hybrid swarm forming (incl. primary hybrids and backcrosses). Our findings can be considered only as indirect evidence for introgression, which needs to be confirmed by molecular markers (for example...

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