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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

On the variability of the fine structure constant /

Evans, Jason L. January 2004 (has links) (PDF)
Thesis (M.S.)--Brigham Young University. Dept. of Physics and Astronomy, 2004. / Includes bibliographical references (p. 87-88).
12

Variation of the fine structure constant in 5D Kaluza-klein theory

Ng, Sui-chung. January 2005 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.
13

Precision measurement of the n=2 phosphorus-3 intervals of atomic helium : a determination of the fine-structure constant /

George, Matthew Charles. January 2003 (has links)
Thesis (Ph.D.)--York University, 2003. Graduate Programme in Physics and Astronomy. / Typescript. Includes bibliographical references (leaves 124-126). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:NQ99172
14

EXAFS studies of carbon supported fuel cells electrocatalysts

Maniguet, Stéphanie January 2002 (has links)
No description available.
15

X-ray absorption fine structure Debye-Waller factors /

Poiarkova, Anna V., January 1999 (has links)
Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (p. [83]-91).
16

Spectroscopic studies of the human copper chaperone for superoxide dismutase : probing the active cluster with selenocysteine variants /

Barry, Amanda Nell. January 2007 (has links)
Thesis (Ph.D.) OGI School of Science & Engineering at OHSU, October 2007. / Includes bibliographical references (leaves 132-158).
17

Extraction de structures fines sur des images texturées : application à la détection automatique de fissures sur des images de surface de chaussées / Fine structure extraction in textured images : application on automatic road crack detection

Nguyen, Tien Sy 30 November 2010 (has links)
La dernière décennie a vu l'exploitation d’application d’inspection automatique dans plusieurs domaines grâce à l’avancé des capteurs de vision et des méthodes d’analyse de texture et de segmentation d’images. Cependant, la nature difficile des images de chaussées (fortement texturée), la petite taille des défauts (fissures) conduisent au constat que l’inspection dans ce domaine est réalisée manuellement. Chaque année, en France, des opérateurs doivent visualiser des milliers de kilomètres d'images de route pour y relever des dégradations. Cette façon de faire est couteuse, lente et a un résultat plutôt subjectif. L’objectif de ce travail de thèse est de développer une méthode permettant la détection et la classification des fissures automatiquement sur ces images de chaussées. Le coeur de la thèse est une nouvelle méthode de segmentation, la Free Form Anisotropy (FFA). D'une part, elle permet de prendre en compte simultanément les attributs concernant la forme et l’intensité des pixels d’une fissure pour la détection. D’autre part, une nouvelle modélisation est utilisée en recherchant des chemins minima dans des graphes (images) afin de trouver la forme de la fissure dès qu'elle est présente dans l’image. Après la segmentation, l’extraction et la classification de défauts sont réalisées par une transformée de Hough et par le calcul de l’orientation locale des pixels. Les résultats expérimentaux ont été obtenus à partir de plusieurs bases d’images et compares avec des méthodes existantes. / These last decades have seen application of automatic inspection in many fields thanks to advanced vision sensors and image analysis methods. However, the difficult nature of pavement images, the small size of defects (cracks) lead to the fact that inspection in this area is done mostly manually. Each year in France, operator must view images of thousands kilometers of roads to detect these degradations. This method is expensive, slow and has a rather subjective result. The objective of this thesis is to develop a method for the detection and the classification of cracks on these pavement images automatically. In this thesis, a new method of segmentation has been developed: the Free Form Anisotropy (FFA). On one hand, this method allows to take into account both the features concerning form and intensity of cracks, for the detection. On the other hand, a new model is used to search minimum paths in graphs (images). This minimum path follows crack form when crack is present. After segmentation, extraction and classification of defects are performed by the Standard Hough Transform and by calculating local orientation of pixels. Experimental results have been obtained from different image databases and compared with other existing methods.
18

Fine Structure in Thermal Neutron (n,α) Reactions

Oakey, Neil Stanley 09 1900 (has links)
<p> Fine structure in thermal neutron (n, α) reactions has been studied for 149Sm, 147Sm, and 143Nd by means of an instrument called an electrostatic particle guide. This device, which was designed to eliminate the problems of background and low energy tailing in (n,α) spectroscopy, is described in detail. Alpha decay has been observed from thermal neutron capture states to levels in the daughter nucleus to greater than 2 MeV excitation. Cross sections and alpha energies are presented for each transition and as well, the alpha decay schemes for 146Nd, 144Nd, 140Ce. Experimental reduced widths have been calculated and are discussed in terms of Mang's theory of alpha decay. Evidence is presented for the (n, γα) process in the 143Nd (n,α) 140Ce reaction. </p> / Thesis / Doctor of Philosophy (PhD)
19

Predicting Speech Intelligibility and Quality from Model Auditory Nerve Fiber Mean-rate and Spike-timing Activity

Wirtzfeld, Michael Roy January 2017 (has links)
This dissertation examines the prediction of speech intelligibility and quality using simulated auditory nerve fiber activity. The relationship of neural mean-rate and spike-timing activity to the perceptual salience of the envelope (ENV) and temporal fine-structure (TFS) of speech is indistinct. TFS affects neural temporal coding in two ways. TFS produces phase-locked spike-timing responses and narrowband cochlear filtering of TFS generates recovered ENV. These processes, with direct encoding of ENV to mean-rate responses, are the established transduction processes. We postulate that models based on mean-rate (over a time-window of approx. 6 to 16 ms) and spike-timing cues should produce accurate predictions of subjectively graded speech. Two studies are presented. The first study examined the contribution of mean-rate and spike-timing cues to predicting intelligibility. The relative level of mean-rate and spike-timing cues were manipulated using chimaerically vocoded speech. The Spectro-Temporal Modulation Index (STMI) and Neurogram SIMilarity (NSIM) were used to quantify the mean-rate and spike-timing activity. Linear regression models were developed using the STMI and NSIM. An interpretable model combining the STMI and the fine-timing NSIM demonstrated the most accurate predictions of the graded speech. The second study examined the contribution of mean-rate and spike-timing cues for predicting the quality of enhanced wideband speech. The mean-rate and fine-timing NSIM were used to quantify the mean-rate and spike-timing activity. Linear regression models were developed using the NSIM measures and optimization of the NSIM was investigated. A quality-optimized model with intermediate temporal resolution had the best predictive performance. The modelling approach used here allows for the study of normal and impaired hearing. It supports the design of hearing-aid processing algorithms and furthers the understanding how TFS cues might be applied in cochlear implant stimulation schemes. / Thesis / Doctor of Philosophy (PhD) / This dissertation examines how auditory nerve fiber activity can be used to predict speech intelligibility and quality. A model of the cochlea is used to generate simulated auditory nerve fiber responses to speech stimuli and the information conveyed by the corresponding spike-events is quantified using different measures of neural activity. A set of predictive models are constructed in a systematic manner using these neural measures and used to estimate the perceptual scoring of intelligibility and quality of normal-hearing listeners for two speech datasets. The results indicate that a model combining a measure of average neural discharge activity with a measure of instantaneous activity provides the best prediction accuracy. This work contributes to the knowledge of neural coding in the cochlea and higher centers of the brain and facilitates the development of hearing-aid and cochlear implant processing strategies.
20

Development of x-ray spectroscopy coupling with resonant scattering -toward applications of practical materials- / 共鳴散乱を組み合わせたX線分光法の開発 -実用材料への応用に向けて-

Kawaguchi, Tomoya 23 March 2015 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18981号 / 工博第4023号 / 新制||工||1619(附属図書館) / 31932 / 京都大学大学院工学研究科材料工学専攻 / (主査)教授 松原 英一郎, 教授 邑瀬 邦明, 教授 宇田 哲也 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

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