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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.
11

Parent Perspectives of Adolescent Wisdom

Besecker, Zachary 22 April 2022 (has links)
No description available.
12

Explosionsschutz in Ethernet-basierten Feldbussystemen

Kwidzinski, M., Mahendrarajah, A., Stephan-Büldt, L., Große, N. 14 February 2024 (has links)
Die Leitsysteme der Prozessindustrie haben sich in den letzten Jahren kaum verändert. Mit Ethernet- APL gibt es nun eine Möglichkeit Ethernet bis ins Feld zu bekommen. Ethernet-APL liefert schnelle Kommunikation über lange Distanzen und das auch in explosionsgefährdeten Bereichen.
13

Benchmark d'un modèle layer wise de multicouches et implémentation du modèle dans Abaqus / Bending analysis a layer-wise model and implementation in Abaqus

Nguyen, Duc Thai 04 June 2012 (has links)
Dans ce travail de thèse, le comportement des composites stratifiés est étudié en utilisant des développements d'ordres élevés ou de type layer wise. Un modèle layer wise LS1 (et l'élément fini à huit nœuds qui lui est associé) a été développé en premier lieu pour l'analyse spécifique des contraintes entre les couches pour des problèmes de bords libres ou bien pour l'étude des liaisons entre les couches. Il est fondé sur un modèle de type layer wise qui considère le stratifié comme une superposition de plaques de Reissner couplées les unes aux autres par des efforts d'interfaces. Cet élément a 5n degrés de liberté par noeud (n étant le nombre de couches) et donne une prédiction des contraintes d'interface. Les travaux précédents se concentraient sur la précision et l'utilisation de l'estimation de ces contraintes d'interface. Mais le modèle permet aussi de calculer les déplacements et les déflexions ainsi que d'extraire les contraintes dans l'épaisseur avec ou sans post-traitement. Dans ce mémoire, la précision et la validité du calcul des déplacements et des contraintes ont été établies à partir d'un nombre important de benchmarks en flexion de composites et des plaques sandwich. Le but de cette étude est aussi de mieux positionner et de promouvoir cette approche en contraintes issue des travaux de Pagano peu utilisés et mal référencés. Ce modèle est ensuite développé et implémenté dans le code de calcul par éléments finis Abaqus via la routine utilisateur User-Element (UEL). Pour démontrer l'efficacité du modèle et du code de calcul, des exemples qui comprennent des plaques isotropes et anisotropes sont traités / In this document, the behaviour of laminated composite is investigated using several high order or layer wise finite element calculations. A layer wise model and its devoted finite element on C° eight-node layer wise finite element have been originally and specifically developed for an interlaminar stresses analysis in a free edge problem or for a bonding study. This model is the core of the present comparisons. It is based on a typical layer wise model that considers the laminate by a superposition of Reissner plates coupled by interfacial stresses. This element consists of 5n degrees of freedom per node (n is the layer number) and is able to predict interlaminar stresses. These out-of-plane stresses are deduced directly from constitutive equations without post-processing works. The previous papers dealt with the accuracy of these estimated interface stresses. However, the model not only permits to compute displacements and usual deflections but also to compute stresses through the layer thicknesses with or without postprocess. In the present paper, the accuracy and the validity of these computed displacements and stresses have also been established on a large number of important benchmarks of bending examples for composites and sandwich plates. The aim of this research is also to better positioning and promoting of this stress approach deriving from the works of Pagano, which was not generally studied in this way. This model has also been implemented into the ABAQUS finite-element program through a User-Element subroutine interface. To demonstrate the effectiveness of the model and the finite element code, examples which include isotropic and anisotropic plates, the problem of the perforated plate are calculated
14

An Evaluation of Eight Class B School Transportation Systems of Wise County, Texas

Braboy, John Robert January 1948 (has links)
The problem of this study is to determine the efficiency of the transportation systems of eight Class B schools of Wise County, Texas.
15

The History of Education of Wise County

Barker, Wiliam Franklin 08 1900 (has links)
The purpose of this study was to collect, organize, and present information pertaining to the development of the educational system of Wise County, Texas. While there has been much interest in the collecting of material and information that relates to the early history, as well as much knowledge of the historical development, data concerning the educational progress of the county have been neglected by historians. It is important that this neglect be remedied. Since the history of education is of a professional nature, the collection, the preservation, and the interpretation of the historical information may be considered the special duty of the persons who are in some way connected with the educational system
16

Novel Approaches for Application of Principal Component Analysis on Dynamic PET Images for Improvement of Image Quality and Clinical Diagnosis

Razifar, Pasha January 2005 (has links)
<p>Positron Emission Tomography, PET, can be used for dynamic studies in humans. In such studies a selected part of the body, often the whole brain, is imaged repeatedly after administration of a radiolabelled tracer. Such studies are performed to provide sequences of images reflecting the tracer’s kinetic behaviour, which may be related to physiological, biochemical and functional properties of tissues. This information can be obtained by analyzing the distribution and kinetic behaviour of the administered tracers in different regions, tissues and organs. Each image in the sequence thus contains part of the kinetic information about the administered tracer. </p><p>Several factors make analysis of PET images difficult, such as a high noise magnitude and correlation between image elements in conjunction with a high level of non-specific binding to the target and a sometimes small difference in target expression between pathological and healthy regions. It is therefore important to understand how these factors affect the derived quantitative measurements when using different methods such as kinetic modelling and multivariate image analysis.</p><p>In this thesis, a new method to explore the properties of the noise in dynamic PET images was introduced and implemented. The method is based on an analysis of the autocorrelation function of the images. This was followed by proposing and implementing three novel approaches for application of Principal Component Analysis, PCA, on dynamic human PET studies. The common underlying idea of these approaches was that the images need to be normalized before application of PCA to ensure that the PCA is signal driven, not noise driven. Different ways to estimate and correct for the noise variance were investigated. Normalizations were carried out Slice-Wise (SW), for the whole volume at once, and in both image domain and sinogram domain respectively. We also investigated the value of masking out and removing the area outside the brain for the analysis. </p><p>The results were very encouraging. We could demonstrate that for phantoms as well as for real image data, the applied normalizations allow PCA to reveal the signal much more clearly than what can be seen in the original image data sets. Using our normalizations, PCA can thus be used as a multivariate analysis technique that without any modelling assumptions can separate important kinetic information into different component images. Furthermore, these images contained optimized signal to noise ratio (SNR), low levels of noise and thus showed improved quality and contrast. This should allow more accurate visualization and better precision in the discrimination between pathological and healthy regions. Hopefully this can in turn lead to improved clinical diagnosis. </p>
17

Novel Approaches for Application of Principal Component Analysis on Dynamic PET Images for Improvement of Image Quality and Clinical Diagnosis

Razifar, Pasha January 2005 (has links)
Positron Emission Tomography, PET, can be used for dynamic studies in humans. In such studies a selected part of the body, often the whole brain, is imaged repeatedly after administration of a radiolabelled tracer. Such studies are performed to provide sequences of images reflecting the tracer’s kinetic behaviour, which may be related to physiological, biochemical and functional properties of tissues. This information can be obtained by analyzing the distribution and kinetic behaviour of the administered tracers in different regions, tissues and organs. Each image in the sequence thus contains part of the kinetic information about the administered tracer. Several factors make analysis of PET images difficult, such as a high noise magnitude and correlation between image elements in conjunction with a high level of non-specific binding to the target and a sometimes small difference in target expression between pathological and healthy regions. It is therefore important to understand how these factors affect the derived quantitative measurements when using different methods such as kinetic modelling and multivariate image analysis. In this thesis, a new method to explore the properties of the noise in dynamic PET images was introduced and implemented. The method is based on an analysis of the autocorrelation function of the images. This was followed by proposing and implementing three novel approaches for application of Principal Component Analysis, PCA, on dynamic human PET studies. The common underlying idea of these approaches was that the images need to be normalized before application of PCA to ensure that the PCA is signal driven, not noise driven. Different ways to estimate and correct for the noise variance were investigated. Normalizations were carried out Slice-Wise (SW), for the whole volume at once, and in both image domain and sinogram domain respectively. We also investigated the value of masking out and removing the area outside the brain for the analysis. The results were very encouraging. We could demonstrate that for phantoms as well as for real image data, the applied normalizations allow PCA to reveal the signal much more clearly than what can be seen in the original image data sets. Using our normalizations, PCA can thus be used as a multivariate analysis technique that without any modelling assumptions can separate important kinetic information into different component images. Furthermore, these images contained optimized signal to noise ratio (SNR), low levels of noise and thus showed improved quality and contrast. This should allow more accurate visualization and better precision in the discrimination between pathological and healthy regions. Hopefully this can in turn lead to improved clinical diagnosis.
18

Vegetational and lepidopteran conservation in rehabilitated ecosystems

Holl, Karen D. 24 October 2005 (has links)
Coal surface mining and associated reclamation practices have had an immense impact on the landscape of the Appalachian region of the United States. However, their effect on floral and faunal conservation has been poorly documented. Lepidopteran communities, vegetation, and nectar resources were studied on 19 mine sites reclaimed 0-30 years previously and five sites in the surrounding hardwoods in southwestern Virginia. The goals of this work were to characterize vegetational and lepidopteran communities of these sites; to understand the relationships between the two; and to assess the role of mine reclamation in regional conservation efforts. Vegetational community composition of the reclaimed sites appeared to be approaching that of the hardwood sites as time since reclamation increased. However, it will take a number of years, if ever, before the vegetational community composition and structure approximate that of the hardwoods. Between-site variation in vegetational communities was greater in the hardwoods, than the reclaimed sites. Recently reclaimed mined sites hosted a large number of both individuals and species of diurnal lepidoptera, comprising mostly widespread, generalist species. Multivariate analysis suggested that lepidopteran community composition of reclaimed sites was approaching that of the hardwoods and that lepidopteran communities of later successional reclaimed sites were fairly similar to those of the surrounding hardwoods. Moth community composition closely reflected vegetational community composition and species richness, while butterflies were poor indicators of vegetational communities. Reclaimed sites provided much more abundant and diverse nectar resources than hardwood forests. Results of nectar studies and butterfly behavioral observations suggested that adult butterfly community composition was strongly influenced by nectar abundance, but that nectar was not a limiting resource. While reclaimed sites hosted a number of the more common plant and lepidopteran species, it remains questionable whether reclaimed areas will ever host the entire complement of the biota present prior to disturbance. In order to further conservation efforts, rehabilitation projects must be designed and monitored over larger spatial and longer temporal scales. / Ph. D.
19

Discrete Image Registration : a Hybrid Paradigm

Sotiras, Aristeidis 04 November 2011 (has links) (PDF)
This thesis is devoted to dense deformable image registration/fusion using discrete methods. The main contribution of the thesis is a principled registration framework coupling iconic/geometric information through graph-based techniques. Such a formulation is derived from a pair-wise MRF view-point and solves both problems simultaneously while imposing consistency on their respective solutions. The proposed framework was used to cope with pair-wise image fusion (symmetric and asymmetric variants are proposed) as well as group-wise registration for population modeling. The main qualities of our framework lie in its computational efficiency and versatility. The discrete nature of the formulation renders the framework modular in terms of iconic similarity measures as well as landmark extraction and association techniques. Promising results using a standard benchmark database in optical flow estimation and 3D medical data demonstrate the potentials of our methods.
20

MAPS OF EVOLVING CLOUD STRUCTURES IN LUHMAN 16AB FROM HST TIME-RESOLVED SPECTROSCOPY

Karalidi, Theodora, Apai, Dániel, Marley, Mark S., Buenzli, Esther 06 July 2016 (has links)
WISE J104915.57-531906.1 is the nearest brown dwarf binary to our solar system, consisting of two brown dwarfs in the L/T transition: Luhman 16A and B. In this paper, we present the first map of Luhman 16A, and maps of Luhman 16B for two epochs. Our maps were created by applying Aeolus, a Markov-Chain Monte Carlo code that maps the top-of-the-atmosphere (TOA) structure of brown dwarf and other ultracool atmospheres, to light curves of Luhman 16A and B using the Hubble Space Telescope's G141 and G102 grisms. Aeolus retrieved three or four spots in the TOA of Luhman 16A and B, with a surface coverage of 19%-32% (depending on an assumed rotational period of 5 hr or 8 hr) or 21%-38.5% (depending on the observational epoch), respectively. The brightness temperature of the spots of the best-fit models was similar to 200 K hotter than the background TOA. We compared our Luhman 16B map with the only previously published map. Interestingly, our map contained a large TOA spot that was cooler (Delta T similar to 51 K) than the background, which lay at low latitudes, in agreement with the previous Luhman 16B map. Finally, we report the detection of a feature reappearing in Luhman 16B light curves that are separated by tens of hundreds of rotations from each other. We speculate that this feature is related to TOA structures of Luhman 16B.

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