To see the other types of publications on this topic, follow the link: Spectral content.
Dissertations / Theses on the topic 'Spectral content'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Spectral content.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Ajohani, Maha. "SPECTRAL PHASOR ANALYSIS ON ABSORBANCE SPECTRA FOR QUANTIFYING THE CONTENT OF DYE MIXTURES." Miami University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=miami1464191406.
Full text
2
Filiberti, Daniel Paul. "Combined Spatial-Spectral Processing of Multisource Data Using Thematic Content." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1066%5F1%5Fm.pdf&type=application/pdf.
Full text
3
Higgins, Neil Anthony. "Information content of ATSR-2 dual-view angle spectral data." Thesis, University of Salford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244821.
Full text
4
Adekristi, Armen. "Algorithm for Spectral Matching of Earthquake Ground Motions using Wavelets and Broyden Updating." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/22079.
Full textAbstract:
This study focuses on creating a spectral matching algorithm that modifies the real strong ground motions in the time domain by adding wavelets adjustment to the acceleration time series. The spectral matching procedure is at its core a nonlinear problem, thus a nonlinear solving method was employed in the proposed algorithm. The Broyden updating method was selected as the nonlinear solving method because it does not require a differentiation analysis. The Broyden updating also makes use the information of spectral misfit and wavelet magnitudes vector to approximate the Jacobian matrix which expected to give an efficient calculation.A parametric study was numerically conducted to obtain a set of gain factors that reduce the computational time and minimize the spectra misfit. The study was conducted using ten different ground motions, taken from FEMA P-695 (FEMA, 2009), which represent far field, near field-pulse and near field-no pulse earthquake ground motions.
A study of compatible wavelet functions was carried out to determine the appropriate wavelet function for the proposed method. The study include the baseline drift, the frequency and time resolution, and the cross correlation between wavelet adjustments during the spectra matching procedure. Based on this study, the corrected tapered cosine wavelet was selected to be used in the proposed algorithm.
The proposed algorithm has been tested and compared with other methods that are commonly used in spectral matching; the RSPMatch method and the frequency domain method. The comparing parameters were the computational time, the average misfit, the maximum misfit and error, the PGA, PGV, PGD, the Arias Intensity and the frequency content for both acceleration and displacement time histories. The result showed that the proposed method is able to match the target while preserving the energy development and the frequency content of the original time histories.
Master of Science
5
Lampart, Walter. "Spectroscopic diagnostic of laser-produced plasmas in the soft x-ray spectral range /." [S.l : s.n.], 1987. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
Full text
6
Bennett, James. "Hybrid Spectral Micro-CT: System Implementation, Exposure Reduction, K-edge Imaging Optimization, and Content Management." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/25525.
Full textAbstract:
Spectral computed tomography (CT) has proven an important development in biomedical imaging, yet there are several limitations to this nascent technology. Near-term implementation of spectral CT imaging can be enhanced using a hybrid architecture that integrates a narrow-beam spectral 'interior' imaging chain integrated with a traditional wide-beam 'global' imaging chain. The first study demonstrates the feasibility of hybrid spectral micro-CT architecture with a first-of-its-kind system implementation and preliminary results showing improved contrast resolution and spatial resolution. The second study seeks to characterize the hybrid spectral micro-CT scan protocol for reduction of radiation exposure. In the third study, the spectral 'interior' imaging chain was optimized for K-edge imaging of high-z elemental contrast agents. In the final study, an open-source, low-cost solution for managing digital content in an academic setting was demonstrated. The results of these studies confirm the merits of a hybrid architecture and warrant further consideration in future pre-clinical and clinical spectral micro-CT and CT scanner design and protocols.Ph. D.
7
Martin, Alexandre. "Théorie de Mourre et opérateurs de Schrödinger : De nouvelles classes d'opérateurs conjugués." Thesis, Cergy-Pontoise, 2018. http://www.theses.fr/2018CERG0978/document.
Full textAbstract:
Dans cette thèse, nous nous intéressons à l’étude du spectre essentiel d’opérateurs de Schrödinger et tout particulièrement à l’obtention d’un Principe d’Absorption Limite pour ces opérateurs. Ce Principe d’Absorption Limite consiste en l’existence d’une limite de l’opérateur résolvante lorsque le paramètre spectral se rapproche du spectre essentiel et permet de connaitre des informations sur le groupe engendré par l’Hamiltonien de Schrödinger. Une méthode pour montrer ce Principe d’Absorption Limite est d’utiliser la théorie de Mourre. Cette théorie nécessite l’utilisation d’un autre opérateur appellé opérateur conjugué. Lorsqu’on veut appliquer la théorie de Mourre aux opérateurs de Schrödinger, on utilise habituellement un opérateur conjugué nommé le générateur des dilatations. Cet opérateur implique que les dérivées du potentiel doivent avoir une certaine décroissance ce qui peut être gênant dans certains cas.Dans cette thèse, nous appliquerons le théorème de Mourre avec d’autres types d’opérateurs conjugués, dont certains n’impliquent pas de conditions de dérivabilité. Dans une première partie, nous nous intéresserons aux opérateurs de Schrödinger sur l’espace euclidienpour lesquels nous montrerons un Principe d’Absorption Limite à énergie strictement positive, un Principe d’Absorption Limite à énergie nulle et l’absence de valeurs propres plongées dans le spectre essentiel. Dans une seconde partie, nous nous intéresserons aux opérateurs de Schrödinger sur des guides d’ondes pour lesquels nous montrerons un Principe d’Absorption Limite loin des seuils et un Principe d’Absorption Limite près des seuilsIn this thesis, we are interested in the study of the essential spectrum of Schrödinger operators and more particulary in the obtention of a Limiting Absorption Principle for these operators. This Limiting Absorption Principle consists on the existence of a limit for the resolvent operator when the spectral parameter is near the essential spectrum and permits to know some properties about the group generated by the Schrödinger Hamiltonian we study. A technique to prove this Limiting Absorption Principle is to use the Mourre theory. This theory needs to use an other operator called the conjugate operator. When we want to apply the Mourre theory to Schrödinger operators, we usually used a conjugate operatornamed the generator of dilations. This operator implies some conditions of decay on the derivatives of the potentials which can be a problem in certain cases. In this thesis, we will apply the Mourre theory with other types of conjugate operators wich, for some of them, does not imply any conditions on the derivatives of the potential.In a first part, we will be interested in Schrödinger operators on the euclidian space. We will show a Limiting Absorption Principle at positive energy, a Limiting Absorption principle at zero energy and the absence of eigenvalue embedded in the essential spectrum. In a second part, we will be interested in Schrödinger operators on wave guides for which we will prove a Limiting Absorption Principle far thresholds and near thresholds
8
Irshad, Humayun. "Automated Mitosis Detection in Color and Multi-spectral High-Content Images in Histopathology : Application to Breast Cancer Grading in Digital Pathology." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENM007/document.
Full textAbstract:
La gradation de lames de biopsie fournit des informations pronostiques essentielles pour le diagnostic et le traitement. La détection et le comptage manuel des mitoses est un travail fastidieux, sujet à des variations inter-et intra- observateur considérables. L'objectif principal de cette thèse de doctorat est le développement d'un système capable de fournir une détection des mitoses sur des images provenant de différents types de scanners rapides automatiques, ainsi que d'un microscope multispectral. L'évaluation des différents systèmes proposés est effectuée dans le cadre du projet MICO (MIcroscopie COgnitive, projet ANR TecSan piloté par notre équipe). Dans ce contexte, les systèmes proposés ont été testés sur les données du benchmark MITOS. En ce qui concerne les images couleur, notre système s'est ainsi classé en deuxième position de ce concours international, selon la valeur du critère F-mesure. Par ailleurs, notre système de détection de mitoses sur images multispectrales surpasse largement les meilleurs résultats obtenus durant le concoursDigital pathology represents one of the major and challenging evolutions in modernmedicine. Pathological exams constitute not only the gold standard in most of medicalprotocols, but also play a critical and legal role in the diagnosis process. Diagnosing adisease after manually analyzing numerous biopsy slides represents a labor-intensive workfor pathologists. Thanks to the recent advances in digital histopathology, the recognitionof histological tissue patterns in a high-content Whole Slide Image (WSI) has the potentialto provide valuable assistance to the pathologist in his daily practice. Histopathologicalclassification and grading of biopsy samples provide valuable prognostic information thatcould be used for diagnosis and treatment support. Nottingham grading system is thestandard for breast cancer grading. It combines three criteria, namely tubule formation(also referenced as glandular architecture), nuclear atypia and mitosis count. Manualdetection and counting of mitosis is tedious and subject to considerable inter- and intrareadervariations. The main goal of this dissertation is the development of a framework ableto provide detection of mitosis on different types of scanners and multispectral microscope.The main contributions of this work are eight fold. First, we present a comprehensivereview on state-of-the-art methodologies in nuclei detection, segmentation and classificationrestricted to two widely available types of image modalities: H&E (HematoxylinEosin) and IHC (Immunohistochemical). Second, we analyse the statistical and morphologicalinformation concerning mitotic cells on different color channels of various colormodels that improve the mitosis detection in color datasets (Aperio and Hamamatsu scanners).Third, we study oversampling methods to increase the number of instances of theminority class (mitosis) by interpolating between several minority class examples that lietogether, which make classification more robust. Fourth, we propose three different methodsfor spectral bands selection including relative spectral absorption of different tissuecomponents, spectral absorption of H&E stains and mRMR (minimum Redundancy MaximumRelevance) technique. Fifth, we compute multispectral spatial features containingpixel, texture and morphological information on selected spectral bands, which leveragediscriminant information for mitosis classification on multispectral dataset. Sixth, we performa comprehensive study on region and patch based features for mitosis classification.Seven, we perform an extensive investigation of classifiers and inference of the best one formitosis classification. Eight, we propose an efficient and generic strategy to explore largeimages like WSI by combining computational geometry tools with a local signal measureof relevance in a dynamic sampling framework.The evaluation of these frameworks is done in MICO (COgnitive MIcroscopy, ANRTecSan project) platform prototyping initiative. We thus tested our proposed frameworks on MITOS international contest dataset initiated by this project. For the color framework,we manage to rank second during the contest. Furthermore, our multispectral frameworkoutperforms significantly the top methods presented during the contest. Finally, ourframeworks allow us reaching the same level of accuracy in mitosis detection on brightlightas multispectral datasets, a promising result on the way to clinical evaluation and routine
9
Suliman, Ahmed S., and Donald F. Post. "Relationship Between Soil Spectral Properties and Sand, Silt, and Clay Content of the Soils on the University of Arizona Maricopa Agricultural Center." Arizona-Nevada Academy of Science, 1988. http://hdl.handle.net/10150/296411.
Full textAbstract:
From the Proceedings of the 1988 Meetings of the Arizona Section - American Water Resources Association and the Hydrology Section - Arizona-Nevada Academy of Science - April 16, 1988, University of Arizona, Tucson, Arizona
10
Mistele, Bodo. "Tractor based spectral reflectance measurements using an oligo view optic to detect biomass, nitrogen content and nitrogen uptake of wheat and maize and the nitrogen nutrition index of wheat." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=980399661.
Full text
11
Frankman, David J. "Radiation and Convection Heat Transfer in Wildland Fire Environments." Diss., CLICK HERE for online access, 2009. http://contentdm.lib.byu.edu/ETD/image/etd3066.pdf.
Full text
12
Koch, Tim Verfasser], Michael [Akademischer Betreuer] Wicke, Kay [Akademischer Betreuer] Raum, and Claus-Peter [Akademischer Betreuer] [Czerny. "Predicting the intramuscular fat content in porcine M. longissimus via ultrasound spectral analysis with consideration of structural and compositional traits / Tim Koch. Gutachter: Michael Wicke ; Kay Raum ; Claus-Peter Czerny. Betreuer: Michael Wicke." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2011. http://d-nb.info/1043719369/34.
Full text
13
Bernard, Paolantoni Sandrine. "Analyse spectrale et simulation numérique de cavités contenant un matériau négatif." Electronic Thesis or Diss., Institut polytechnique de Paris, 2020. http://www.theses.fr/2020IPPAE005.
Full textAbstract:
Cette thèse réalise une étude théorique et numérique du spectre de cavités partiellement composées de matériau négatif, c'est-à-dire de matériau pour lequel la perméabilité magnétique et/ou la permittivité électrique (ou au moins leur partie réelle) deviennent négatives dans certaines plages de fréquences. Cette étude s'inscrit dans la continuité des travaux engagés dans notre laboratoire qui se concentrent sur la propagation des ondes électromagnétiques en présence de matériau négatif, à fréquence fixée. L'objectif de cette thèse est de prendre en compte la dispersion fréquentielle, autrement dit la dépendance en fréquence de la perméabilité et de la permittivité, en considérant la fréquence comme paramètre spectral. Nous mettons en évidence le spectre essentiel résultant de la présence de matériau négatif ainsi que les phénomènes de résonance qui en découlent, pour différents modèles décrivant ce matériau.L'étude théorique se concentre sur le cas de cavités bidimensionnelles polygonales pour les modèles de Drude et de Lorentz (avec et sans dissipation). L'étude théorique du modèle le plus simple (Drude non dissipatif) est étendue au cas d'une interface courbe (mais régulière).Ce modèle fait également l'objet d'une étude numérique, visant à explorer l'effet d'une discrétisation éléments finis du problème théorique, et ainsi mettre en avant les difficultés à observer numériquement certains des phénomènes de résonanceThis thesis achieves a theoretical and numerical studies of cavities partially filled with a negative material, that is a material for which the magnetic permeability and/or the electric permittivity (or at least their real part) become negative in some frequency ranges. This study is part of the main thrust of the work started in our team focusing on the electromagnetic wave propagation in presence of such negative materials, at a given fraquency. The purpose of this thesis is to take into account the frequency dispersion, that is the frequency dependence of the permeability and/or the permittivity, considering the frequency as the spectral parameter. We highlight the essential spectrum arising from the presence of negative material, as well as the resulting resonance phenomena, for different models describing this material. The theoretical study focuses on the case of polygonal bi-dimensional cavities for the Drude and the Lorentz models (with dissipation or not). The theoretical study of the simplest model (the non dissipative Drude model) is extended to the case of a curved (but regular) interface. This model is also the subject of a numerical study, aimed at exploring the effect of a finite element discretization of the theoretical problem, and thus highlight the difficulties to numerically notice some of the resonance phenomena
14
Khosravi, Peiman. "Spectral spatiality in the acousmatic listening context." Thesis, City University London, 2012. http://openaccess.city.ac.uk/2717/.
Full textAbstract:
Sounds are often experienced as being spatially higher or lower in congruence with their frequency ‘height’ (i.e. pitch register). The term ‘spectral spatiality’ refers to this impression of spatial height and vertical depth as evoked by the perceived occupancy of evolving sound-shapes (spectromorphologies) within the continuum of audible frequencies. Chapters One and Two draw upon a diverse body of literature to explore the cognitive and physiological processes involved in human spatial hearing in general, and spectral spatiality in particular. Thereafter the potential pertinence of a spectral space consciousness in the acousmatic listening experience is highlighted, particularly with regard to more abstract acousmatic contexts where sounds do not directly invoke familiar source identities. Chapters Three and Four further elaborate aspects of spectral space consciousness and propose a terminological framework for discussing musical contexts in terms of their spectral space design. Consequently, it is argued that in acousmatic music, spectral spatiality must be considered as an inseparable aspect of spatiality in general, although its pertinence only becomes directly highlighted in particular musical contexts. The recurring theme in this thesis is that, in acousmatic music, 'space' is not a parameter but a multifaceted quality that is inherent to all sounds. As well as providing an analytical framework for discussing spatiality in acousmatic music, this thesis highlights the compositional potentials offered by spectral spatiality, particularly in relation to the creation of perspectival image in multichannel works. For instance, the possibility of (re)distributing the spectral components of a sound around the listener (circumspectral image) is discussed in context, and a software tool is presented that enables an intuitive and experimental approach to the composition of circumspectral sounds for 6 and 8 channel loudspeaker configurations. This thesis is useful for both composers and analysts interested in aspects of spatiality in acousmatic music. It also offers some insight into spectral space consciousness in non-acousmatic music, and may therefore contribute towards a more general understanding of the nature of our spatial experience in music.
15
Roberson, Travis Leon. "Improving Soil Moisture Assessment of Turfgrass Systems Utilizing Field Radiometry." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/87391.
Full textAbstract:
The need for water conservation continues to increase as global freshwater resources dwindle. In response, many golf course superintendents are implementing new methods and tools to become more frugal with their water applications. For example, scheduling irrigation using time-domain reflectometer (TDR) soil moisture sensors can decrease water usage. Still, TDR measurements are time-consuming and only cover small scales, leading to many locations being unsampled. Remotely sensed data such as the normalized difference vegetation index (NDVI) offer the potential of estimating moisture stress across larger scales; however, NDVI measurements are influenced by numerous stressors beyond moisture availability, thus limiting its reliability for irrigation decisions. An alternative vegetation index, the water band index (WBI), is primarily influenced by water absorption within a narrow spectral range of near-infrared light. Previous research has established strong relationships between moisture stress of creeping bentgrass (CBG) grown on sand-based root zones, a typical scenario for golf course putting greens. However, this relationship characterizes only a small portion of total acreage across golf courses, which limits widespread adoption. In our research, �007� CBG and �Latitude 36� hybrid bermudagrass (HBG) were grown on three soil textures, USGA 90:10 sand (S), sand loam (SL) and clay (C), arranged in a 2 x 3 factorial design, randomized within six individual dry-down cycles serving as replications. Canopy reflectance and volumetric water content (VWC) data were collected hourly between 0700 and 1900 hr using a hyperspectral radiometer and an embedded soil moisture sensor, until complete turf necrosis. The WBI had the strongest relationship to VWC (r = 0.62) and visual estimations of wilt (r = -0.91) compared to the green-to-red ratio index (GRI) or NDVI. Parameters associated with non-linear regression were analyzed to compare grasses, soils, indices, and their interactions. The WBI and GRI compared favorably with each other and indicated significant moisture stress approximately 28 hr earlier than NDVI (P = 0.0010). WBI and GRI respectively predicted moisture stress 12 to 9 hr before visual estimation of 50% wilt, whereas NDVI provided 2 hr of prediction time (P = 0.0317). When considering the time to significant moisture stress, the HBG lasted 28 hr longer than CBG, while S lasted 42 hr longer than either SL and C (P �� 0.0011). Nonlinear regression analysis showed that WBI and GRI can be useful for predicting moisture stress of CBG and HBG grown on three diverse soils in a highly controlled environment. Our results provide substantial evidence and direction for future research investigating how WBI and GRI can expedite moisture stress assessment and prediction on a large-acreage basis.Master of Science in Life Sciences
Managed turfgrasses provide several benefits including filtering pollutants, cooling their surroundings, generating oxygen, preventing erosion, serving as recreational surfaces, and increasing landscape aesthetics. Intensively managed turfgrass systems, such as on golf courses and sports fields, require more inputs to maintain acceptable conditions. Freshwater use is often excessive on intensively managed turfgrasses to maintain proper plant growth. Drought conditions often limit water availability, especially in regions with limited rainfall. Turf managers tend to over-apply water across large acreage when few localized areas begin to show symptoms of drought. Additionally, turf managers sometimes wrongly identify stressed areas from other factors as ones being moisture-deprived. Advancements such as the use of soil moisture meters have simplified irrigation decisions as an aid to visual inspections for drought stress. While this method enhances detection accuracy, it still provides no solution to increase efficiency. Expanding our current knowledge of turfgrass canopy light reflectance for rapid moisture stress identification can potentially save both time and water resources. The objective of this research was to enhance our ability to identify and predict moisture stress of creeping bentgrass (CBG) and hybrid bermudagrass (HBG) canopies integrated into varying soil textures (USGA 90:10 sand (S), sand loam (SL) and Clay (C)) using light reflectance measurements. Dry-down cycles were conducted under greenhouses conditions collecting soil moisture and light reflectance data every hour from 7 am to 7 pm after saturating and withholding water from established plugs. Moisture stress was most accurately estimated over time using two vegetation indices, the water band index (WBI) and green-to-red ratio index (GRI), with approximately ninety percent accuracy to visible wilt stress. The WBI and GRI predicted moisture stress of CBG in all soil types and HBG in SL and C approximately 14 hours before the grasses reached 50% wilt. While light reflectance varies on exposed soils, our research shows that underlying soils do not interfere with measurements across typical turfgrass stands. This research provides a foundation for future research implementing rapid, aerial measurements of moisture stressed turfgrasses on a broad application of CBG and HBG on constructed or native soils.
16
Strabeli, Taila Fernanda. "Resposta hiperespectral na determinação do conteúdo de água na folha em diferentes espécies de Eucalyptus spp." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/11/11152/tde-29112016-145434/.
Full textAbstract:
Avaliar o estado hídrico das plantas é essencial para o monitoramento das culturas agrícolas e florestais. A interação da radiação eletromagnética com as plantas é um processo estudado por sensoriamento remoto (SR). Através da técnica de SR é possível interpretar os fatores que influenciam na quantidade de energia absorvida, transmitida e refletida pela planta. Neste estudo, buscou-se estabelecer as relações existentes entre variações nos parâmetros da água com o comportamento espectral e gerar modelos matemáticos que sejam capazes de predizer o conteúdo relativo da água (CRA) e espessura equivalente da água (EEA) em 11 diferentes espécies de Eucalyptus, utilizando um sensor hiperespectral. Os dados foram obtidos por meio da pesagem e respectiva leitura espectral das folhas, sendo que estas passaram por uma metodologia de desidratação. Tal metodologia permitiu encontrar uma diferença de reflectância média de 26% entre o máximo e mínimo teor de água na folha, provando a influência do CRA no comportamento espectral, sendo a água um dos fatores de maior domínio na reflectância na região do infravermelho médio (1300nm - 2500nm). A partir das curvas espectrais foi possível avaliar que os comprimentos de onda próximo ao 1400 nm e 1900 nm foram os mais sensíveis ao conteúdo de água. A análise de componentes principais permitiu reforçar estes resultados, uma vez que as pontuações (scores) dos componentes que apresentaram correlações significativas com o CRA tiveram maiores pesos (loadings) nas regiões espectrais citadas anteriormente. A partir das respostas espectrais também foram realizados os cálculos dos índices espectrais já descritos em literatura, e estes submetidos a análise de regressão simples para predição do CRA e EEA. O índice espectral calculado com a combinação de bandas do infravermelho médio (1300nm e 1450nm) foi o que apresentou melhores resultados ao predizer os parâmetros da água, sendo que o SR1300,1450 teve um R2=0,72 para o CRA e R2=0,81 para o EEA. Os dados espectrais foram correlacionados com os parâmetros da água, e encontrou-se que para o CRA o comprimento de onda 1881 nm apresentou um coeficiente de correlação máximo negativo de r= -0,89, enquanto que o EEA apresentou um coeficiente de correlação máximo negativo de r= -0,79 no comprimento de onda 2165 nm. Foram testados três métodos de seleção das variáveis hiperespectrais para gerar um modelo matemático por meio de uma regressão linear. Para o parâmetro CRA, o método de seleção de variáveis stepwise foi o que gerou o maior (R2= 0,86) e um RMSE = 13,85%, sendo que neste método restaram apenas seis variáveis preditoras. Enquanto que o método de seleção de variáveis pelas regiões do espectro foi o mais preciso ao predizer o parâmetro EEA, com um R2= 0,87 e um RMSE = 0,00012 g/cm2, sendo necessárias apenas 5 variáveis espectrais.The hydric condition assessment of plants is essential for monitoring agricultural and forest cultures. The interaction of electromagnetic radiation with plants is a process studied by remote sensing. Through this technique it is possible to interpret the factors that plays influence on the quantity of energy absorbed, transmitted and reflected by the plant. In this study was sought the establishment of existing relations between variations on the water parameters and the spectral behavior and then to generate mathematical models capable of predictiong the relative water content (RWC) and equivalent water thickness (EWT) among 11 different Eucalyptus species using a hyperespectral sensor. The data was obtained through weighting followed by reflectance readings of leaves in which the leaves had gone through a dehydrating methodology. The dehydrating methodology allowed finding a average reflectance difference of 26% between the maximum and the minimum water content on the leaf, proving the influence of the RWC in the spectral behavior in which the water plays great influence in the medium infrared reflectance region (1300 nm - 2500 nm). From the spectral curves it was possible to conclude that the wavelengths near 1400 nm and 1900 nm were the most sensitive to the water content. The principal content analyses reinforced these results once the scores of the components that showed significant relations with the RWC had the bigger loadings in the mentioned spectral regions. Spectral indices already described in literature were calculated using the spectral responses and their results were submitted to a simple regression for predicting RWC and EWT. The spectral index calculated by the combination of medium infrared (1300 nm and 1450 nm) was the one which had better results when prediction water parameters in which SR... had an R2=0,72 for RWC and R2=0,81 for EWT The spectral data was correlated to the water parameters and it was observed that for the RWC at 1881 nm showed a maximum negative coefficient of correlation of r=-0,89 whereas the EWT showed a maximum negative coefficient of correlation of r=-0,79 at 2165 nm. Three selection methods were tested for the hyperespectral variables in order to generate a mathematical model through linear regression. For the RWC parameter, the selection method of stepwise variables was the one which generated and R2=0,86 and a RSMSE = 13,85%. For this method just 6 predicting variables were left. While the variables selection method by spectral regions was the most precise when predicting the EWTparameter with a R2 = 0,87 and a RMSE = 0,00012 g/cm2 being just 5 spectral variables necessary.
17
Salameh, Christelle. "Vibrations ambiantes, contenu spectral et dommages sismiques : nouvelle approche adaptée à l’échelle urbaine. Application à Beyrouth." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAU008/document.
Full textAbstract:
Il a été observé maintes fois dans les enquêtes post-sismiques que les structures ayant des fréquences similaires à celles du sol de fondation présentent des dommages beaucoup plus importants (Caracas 1967, Mexique 1985, Pujili, Equateur 1996; L'Aquila 2009). Cette observation de bon sens n'est cependant que très peu, ou de façon très indirecte, prise en compte d'une part dans les réglementations parasismiques (échelle du bâtiment), et d'autre part dans les études de risque et de scénario à l'échelle urbaine. On assiste ainsi souvent à un niveau de précision incohérent entre les études d'aléa, qui sont maintenant à même de cartographier de manière fiable les fréquences de sol, les possibilités actuelles en matière d'analyse du comportement dynamique des bâtiments, et les cartes de vulnérabilité et de risque finales. Une analyse numérique complète pour étudier l'effet de coïncidence entre les fréquences du sol et du bâtiment est effectuée. Un ensemble de 887 profils de sol réalistes est couplé avec un total de 141 oscillateurs élastoplastiques à un degré de liberté, et leurs réponses combinées (non linéaires) sont calculées à la fois pour un comportement de sol linéaire et non-linéaire, pour un grand nombre (60) de signaux d'entrée avec différents niveaux de PGA et contenu fréquentiel. Les dommages associés sont quantifiés sur la base du déplacement maximal comparé à la fois par rapport aux déplacements élastiques et ultimes, selon les recommandations du projet européen RISK-UE (Lagomarsino et Giovinazzi, 2006), et par rapports aux dommages obtenus dans le cas d’un bâtiment similaire situé sur le substratum rocheux. La corrélation entre les incréments de dommages entre sol et rocher et un certain nombre de paramètres simples mécaniques et de chargement est ensuite analysée en utilisant une approche de réseau neuronal. Les résultats soulignent le rôle clé joué par le rapport de fréquence bâtiment / sol, même lorsque le sol et la bâtiment se comportent de manière non linéaire; d'autres paramètres importants sont le niveau de PGA, le contraste d’impédance sol/rocher et la ductilité du bâtiment. Une enquête numérique spécifique basée sur la simulation du bruit ambiant pour l'ensemble des 887 profils indique également que l'impact du contraste d’impédance sol/rocher peut être cohéremment remplacée en utilisant l'amplitude du rapport H/V. Aussi l'effet de coïncidence apparaît comme une observation importante, non seulement dans la réponse de l'analyse des sites linéaires, mais aussi dans la réponse d'un site non-linéaire: en dépit d'un niveau important de non-linéarité atteint la coïncidence spectrale se produit, mais à un rapport de fréquence décalé vers des valeurs inférieures. La méthode élaborée permet une mise en œuvre très facile, en utilisant des mesures de vibrations ambiantes, tant au niveau du sol et à l'intérieur des bâtiments. Un exemple d'application très illustratif est représenté pour la ville de Beyrouth (Liban)It has been observed repeatedly in post-seismic investigations that structures having frequencies close to foundation soil frequencies exhibit significantly heavier damages (Caracas 1967, Mexico 1985, Pujili, Ecuador 1996; L’Aquila 2009). However, these observations are generally not taken directly into account neither in present-day seismic regulations (small scale), nor at large-scale seismic risk analysis. We thus encounter frequently an incoherent precision level between hazard studies that are capable of reliably mapping the ground frequency, the actual possibilities of analyzing the dynamic behavior of the building, and the final vulnerability and risk maps. A comprehensive numerical analysis to investigate the effect of coincidence between soil and building frequencies is performed. A total of 887 realistic soil profiles are coupled with a set of 141 elastoplastic oscillators with a single degree of freedom and their combined (non-linear) response are computed both for linear and non-linear soil behavior, for a large number (60) of input signals of various PGA levels and frequency contents. The associated damage is quantified on the basis of the maximum displacement as compared to both yield and ultimate post-elastic displacements, according to the RISK-UE European project recommendations (Lagomarsino and Giovinazzi, 2006), and compared with the damage obtained in the case of a similar building located on bedrock. The correlation between this soil/rock damage increment and a number of simplified mechanical and loading parameters is then analyzed using a neural network approach. The results emphasize the key role played by the building/soil frequency ratio even when both soil and building behave non-linearly; other important parameters are the PGA level, the soil/rock impedance contrast and the building ductility. A specific numerical investigation based on simulation of ambient noise for the whole set of 887 profiles also indicates that the impact of soil/rock impedance contrast may be satisfactory replaced using the amplitude of H/V ratio. Moreover the effect of coincidence appears to be an important observation not only in the linear site analysis response but also in the nonlinear site response: in spite of a large nonlinearity level reached spectral coincidence occurs, however at a shifted frequency ratio towards lower values. The elaborated method allows a very easy implementation, using ambient vibration measurements both at ground level and within buildings. A very illustrative example application is shown for the city of Beirut (Lebanon)
18
Gittins, Katie. "Heat content and spectrum of the Laplacian." Thesis, University of Bristol, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.701384.
Full text
19
Dickinson, Nathan James. "The metal content of hot DA white dwarf spectra." Thesis, University of Leicester, 2012. http://hdl.handle.net/2381/10919.
Full textAbstract:
In this thesis, a study of the high ionisation-stage metal absorption features in the spectra of hot DA white dwarfs is presented. Metals are present in the photospheres of such stars due to radiative levitation (Chayer et al. 1994, 1995; Chayer Fontaine & Wesemael 1995). However, studies of the patterns between metal abundance and Teff show that, though the broad patterns predicted are seen, individual abundance measurements often do not reflect the predictions of radiative levitation theory (e.g. Barstow et al. 2003b). In this thesis, an analysis of the nitrogen abundance in three stars is performed, where a highly abundant layer of nitrogen was thought to reside at the top of the photospheres of the stars. The nitrogen abundance and distribution in these DAs is found to be homogeneous and of an abundance in keeping with stars of higher Teff. The accretion of metals from circumstellar discs has been shown to be the source of photospheric metals in DAs with Teff < 25,000 K (e.g. Zuckerman et al. 2003), where gravitational diffusion dominates (Koester & Wilken, 2006). In some cases, gaseous components are seen at such discs (e.g. SDSS 122859.93+104032.9; Gänsicke et al. 2006). A survey is made of a sample of hot (19,000 K < Teff < 51,000 K) DAs, where similar accretion may explain the inability of radiative levitation theory alone to account for the detected photospheric metal abundances. No circumstellar gas discs are found, though accretion from as yet undetected circumstellar sources remains an attractive explanation of the photospheric abundances of the stars. Circumstellar absorption is seen in the UV spectra of some hot DA stars (Holberg et al. 1998; Bannister et al. 2003). Sources suggested for this material include circumstellar discs, the ionisation of the ISM, stellar mass loss and planetary nebulae. A re-analysis of this absorption is presented, using a technique that for the first time allows proper modelling of the circumstellar absorption features, and provides column densities for all components. The ionisation of circumstellar discs or planetesimals, the ionisation of the ISM and the ionisation of mass lost by binary companions are put forward as the origin for this circumstellar material.
20
Biarnés, Pérez Marc 1973. "Increased fundus autofluorescence, a biomarker of lipofuscin content, as a risk factor for the progression of geographic atrophy secondary to age-related macular degeneration." Doctoral thesis, Universitat Pompeu Fabra, 2014. http://hdl.handle.net/10803/318157.
Full textAbstract:
L’atròfia geogràfica (AG) és la variant avançada de la degeneració macular associada a l’edat seca i es caracteritza per la presència d’àrees d’atròfia de l’epiteli pigmentari de la retina (EPR) que creixen progressivament, amb pèrdua secundària dels fotorreceptors i la coriocapilar adjacents. Actualment és una condició sense tractament.
L’acumulació de lipofuscina a l’EPR, visualitzable clínicament mitjançant l’autofluorescència del fons d’ull (AFU) com a zones d’elevada autofluorescència, ha estat vinculada a la progressió de l’AG en alguns estudis. De fet, s’han descrit certs patrons (“fenotips”) en l’AFU basats en la distribució d’hiperautofluorescència que s’han associat amb taxes específiques de progressió de la malaltia.
En aquesta Tesi hem fet un estudi clínic prospectiu per simplificar la complexa classificació dels patrons d’AFU i avaluar el paper de la hiperautofluorescència, un biomarcador de la lipofuscina, en la progressió de l’AG.Geographic atrophy (GA) is the advanced form of dry age-related macular degeneration. It is characterized by large areas of retinal pigment epithelium (RPE) atrophy that grow progressively, with concomitant loss of photoreceptors and choriocapillaris. Currently, there is no treatment for this disorder. Lipofuscin build-up within the RPE, which is identifiable by fundus autofluorescence (FAF) as areas of increased autofluorescence, has been linked to GA progression in some studies. Actually, the distribution of hyperautofluorescence on FAF identified some patterns (“phenotypes”), which have been associated with specific rates of disease growth. We conducted a prospective clinical study to simplify the complex classification of FAF patterns and to determine the role of increased FAF, a biomarker of lipofuscin, in the progression of GA.
21
Howard, John Brooks. "Double point contact single molecule absorption spectroscopy." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31648.
Full textAbstract:
Thesis (Ph.D)--Physics, Georgia Institute of Technology, 2010.Committee Chair: Marchenkov, Alexei; Committee Member: Davidovic, Dragomir; Committee Member: Gole, James; Committee Member: Hunt, William; Committee Member: Reido, Elisa. Part of the SMARTech Electronic Thesis and Dissertation Collection.
22
Bennett, Leslie L. "Associations between linguapalatal contact patterns and spectral moments for /s/ /." Diss., CLICK HERE for online access, 2009. http://contentdm.lib.byu.edu/ETD/image/etd2793.pdf.
Full text
23
Bennett, Leslie Leatham. "Associations Between Linguapalatal Contact Patterns and Spectral Moments for /s/." BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/1668.
Full textAbstract:
Both acoustic and palatographic measures have proven to be useful in speech science research. However, it is not known how closely or consistently these two measures are associated with each other. Therefore, this study investigated the association between changes in tongue-to-palate contact patterns and simultaneous changes in acoustic spectral moments for the fricative /s/. Twenty adults were fitted with pseudopalates and repeated VCV nonsense syllables consisting of an initial schwa followed by the target consonant /s/ and ending with one of three corner vowels (/i, ɑ, u/). EPG (electropalatography) data were quantified using three custom numerical indices (s-narrow, s-wide, and asymmetry) derived from specified zones on the pseudopalate which loosely reflected dimensional differences in the fricative groove. These indices produced general details about changes in tongue contact over time, but index values were not unique to specific contact patterns. The EPG numerical index values were then compared with differences in spectral moments (spectral mean and variance) from the time-aligned acoustic signal. On the whole, all combinations of spectral mean and variance and EPG indices resulted in some weak but significant correlations across all vowel contexts and participant groupings. The majority of these correlations were negative, meaning that as EPG index values increased, spectral mean and variance decreased. Some of the strongest of these correlations were present between s-narrow and spectral mean and variance. Therefore, in order to give a clearer picture of the link between lingual physiology and spectral moments, these variables were correlated for each individual speaker. Stronger significant correlations between s-narrow and both spectral mean and variance were identified in some participants. The majority of these correlations were also negative, suggesting that as the s-narrow index increased, the spectral mean and the variance decreased. A few participants' results that showed interesting lingua-palatal contact patterns are discussed in more detail. Generalization based on specific correlations from this study must be undertaken with considerable caution due to desynchronization of EPG data and the acoustic signal found in several tokens.
24
Alotaibi, Faisal F. "CONTENT TRADING AND PRIVACY-AWARE PRICING FOR EFFICIENT SPECTRUM UTILIZATION." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1574698784641394.
Full text
25
Hajar, Mayssaa. "Contribution of random sampling in the context of rotating machinery diagnostic." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSES001/document.
Full textAbstract:
Récemment, le diagnostic des machines tournantes devient un des sujets de recherche les plus importants. Plusieurs axes sont développés dans ce domaine : traitement de signal, reconnaissance des formes et autres. En plus, les systèmes industriels peuvent être surveillés à distance en temps réel grâce à la disponibilité de l’internet. Cette surveillance se trouve exigeante au niveau de l’acquisition et le stockage des données. En 2004, le Compressive Sensing est introduit dans le but d’acquérir les données a une basse fréquence afin d’économiser l’énergie dans les réseaux de capteurs sans fils. Des résultats similaires peuvent être achevés par l’Echantillonnage Aléatoire qui procure une acquisition à basse fréquence grâce à sa propriété d’anti-repliement. Comme cette technique d’échantillonnage est jusqu’à l’instant de la rédaction de cette thèse n’est pas encore disponible au marché, le travail sur ce sujet se trouve promettant afin de présenter une implémentation pratique validée. D’où, la contribution de cette thèse est de présenter les différentes propriétés de l’échantillonnage aléatoire à travers une étude théorique détaillée dans le domaine temporel et fréquentiel suivie d’une simulation et d’une application pratique sur des signaux synthétisés simples puis sur des signaux de vibration extraits des principaux composants des machines : roulements et engrenages. Les résultats obtenus au niveau de la simulation et la pratique sont satisfaisants grâce à la diminution de la fréquence d’échantillonnage et la quantité de données à sauvegarder ce qui peut être considéré comme une résolution de la problématique de la surveillance à temps réelNowadays, machine monitoring and supervision became one of the most important domains of research. Many axes of exploration are involved in this domain: signal processing, machine learning and several others. Besides, industrial systems can now be remotely monitored because of the internet availability. In fact, as many other systems, machines can now be connected to any network by a specified address due to the Internet of Things (IOT) concept. However, this combination is challenging in data acquisition and storage. In 2004, the compressive sensing was introduced to provide data with low rate in order to save energy consumption within wireless sensor networks. This aspect can also be achieved using random sampling (RS). This approach is found to be advantageous in acquiring data randomly with low frequency (much lower than Nyquist rate) while guaranteeing an aliasing-free spectrum. However, this method of sampling is still not available by hardware means in markets. Thus, a comprehensive review on its concept, its impact on sampled signal and its implementation in hardware is conducted. In this thesis, a study of RS and its different modes is presented with their conditions and limitations in time domain. A detailed examination of the RS’s spectral analysis is then explained. From there, the RS features are concluded. Also, recommendations regarding the choice of the adequate mode with the convenient parameters are proposed. In addition, some spectral analysis techniques are proposed for RS signals in order to provide an enhanced spectral representation. In order to validate the properties of such sampling, simulations and practical studies are shown. The research is then concluded with an application on vibration signals acquired from bearing and gear. The obtained results are satisfying, which proves that RS is quite promising and can be taken as a solution for reducing sampling frequencies and decreasing the amount of stored data. As a conclusion, the RS is an advantageous sampling process due to its anti-aliasing property. Further studies can be done in the scope of reducing its added noise that was proven to be cyclostationary of order 1 or 2 according to the chosen parameters
26
Senchyna, Peter, Daniel P. Stark, Alba Vidal-García, Jacopo Chevallard, Stéphane Charlot, Ramesh Mainali, Tucker Jones, Aida Wofford, Anna Feltre, and Julia Gutkin. "Ultraviolet spectra of extreme nearby star-forming regions – approaching a local reference sample for JWST." OXFORD UNIV PRESS, 2017. http://hdl.handle.net/10150/625962.
Full textAbstract:
Nearby dwarf galaxies provide a unique laboratory in which to test stellar population models below Z(circle dot)/2. Such tests are particularly important for interpreting the surprising high-ionization ultraviolet (UV) line emission detected at z > 6 in recent years. We present HST/COS UV spectra of 10 nearby metal-poor star-forming galaxies selected to show He II emission in SDSS optical spectra. The targets span nearly a dex in gas-phase oxygen abundance (7.8 < 12 + logO/H < 8.5) and present uniformly large specific star formation rates (sSFR similar to 10(2) Gyr(-1)). The UV spectra confirm that metal-poor stellar populations can power extreme nebular emission in high-ionization UV lines, reaching CIII] equivalent widths comparable to those seen in systems at z similar to 6-7. Our data reveal a marked transition in UV spectral properties with decreasing metallicity, with systems below 12 + logO/H less than or similar to 8.0 (Z/Z(circle dot) less than or similar to 1/5) presenting minimal stellar wind features and prominent nebular emission in He II and C IV. This is consistent with nearly an order of magnitude increase in ionizing photon production beyond the He+-ionizing edge relative to H-ionizing flux as metallicity decreases below a fifth solar, well in excess of standard stellar population synthesis predictions. Our results suggest that often-neglected sources of energetic radiation such as stripped binary products and very massive O-stars produce a sharper change in the ionizing spectrum with decreasing metallicity than expected. Consequently, nebular emission in C IV and He II powered by these stars may provide useful metallicity constraints in the reionization era.
27
Almeida, Patricio. "Couplage thermomécanique et vibratoire d'un compresseur centrifuge lors d'un contact aube-carter." Thesis, Ecully, Ecole centrale de Lyon, 2014. http://www.theses.fr/2014ECDL0043/document.
Full textAbstract:
Pour les compresseurs axiaux et centrifuges, la minimisation du jeu, entre l’extrémité des aubes et le carter qui les entoure, augmente l’efficacité aérodynamique des turbomachines mais favorise également l’apparition de contacts structuraux. En présence du contact, les deux structures échangent de l’énergie et le système peut devenir instable lorsque ses fréquences propres, exprimées dans le même repère, sont égales. Nous verrons qu’il existe également la possibilité de créer des réponses forcées lorsque les harmoniques de la vitesse de rotation coïncident avec les fréquences propres de la structure fixe ou tournante. Dans les deux cas, les structures peuvent subir des endommagements assez importants. La maitrise de l’interaction aube-carter est donc logiquement un phénomène que les constructeurs de turbomachines doivent intégrer lors de la définition d’un moteur. Ainsi, dans l’étape de conception des compresseurs, il faut prévoir le comportement vibratoire du système en prenant en compte les phénomènes physiques les plus influents. Dans ce contexte, ce travail de recherche est focalise sur l’étude du comportement mécanique et thermomécanique résultant de l’interaction aube-carter entre un compresseur centrifuge (ou rouet) expérimental du premier étage de compression d’un moteur d’hélicoptère et son couvercle qui est recouvert d’un matériau abradable afin de réduire la sévérité du contact. L’objectif majeur des travaux présentes dans ce manuscrit est d’établir un scénario plausible pour expliquer les divers phénomènes présents lors du contact et de créer une base de données expérimentales, dans un environnement de laboratoire au travers d’un essai réaliste et maitrisé. Puis, il s’agit de confronter et valider les interprétations expérimentales sur un modèle numérique. Pour atteindre nos objectifs, nous avons utilisé un dispositif d’essai adapté afin de fournir des données fiables sur le comportement dynamique et thermomécanique en situation de contact aube-carter. L’analyse des résultats expérimentaux et numériques montre des évènements transitoires concomitants entre la structure fixe et tournante. Le contenu spectral des réponses est caractérise par la présence d’harmoniques de la vitesse de rotation et de sidebands, qui influencent le comportement dynamique du système lorsqu’ils coïncident avec les fréquences propres des structuresIn axial and centrifugal compressors, minimizing the clearance between the blade tips of the impeller and its surrounding casing increases the aerodynamic efficiency, but also the probability of contacts. An energy exchange is then produced between the two structures, leading to forced excitation of the natural modes and potentially to dynamical instabilities, such as interaction phenomena. In both cases, the structures suffer subsequent structural damages. Mastering blade-to-casing interactions is thus a phenomenon that turbomachinery manufacturers must incorporate into the design process of an engine. Compressor designers must predict the vibration behavior of the system, taking into account the predominant physical phenomena. In this context, this work focuses on the study of the dynamic and thermomecanichal behavior resulting from blade-to-casing interactions between a low-pressure centrifugal compressor (or impeller) and a casing lined with abradable coating. The main purpose of this work is to build a likely scenario to explain the various phenomena present when contact occurs, and the creation of a database for subsequent comparisons with numerical simulations. To achieve this, a test rig heavily instrumented has been used in order to better understand the influence of various physical phenomena (dynamic, wearing, heating). Analysis of experimental and numerical results shows transient events, characterized by a simultaneous increase in amplitude on both the rotating and stationary structures. The spectral content of the response highlights the presence of harmonics of the rotating speed and some sidebands aside from the main excited frequencies, which may cause the system to become unstable when they coincide with the natural frequencies of structures
28
Ma, Bojiang. "Cognitive spectrum access, multimedia content delivery, and full-duplex relaying in wireless networks." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/60167.
Full textAbstract:
Due to the growing number of wireless communication devices and emerging bandwidth-intensive applications, the demand of data usage is increasing rapidly. Utilizing various radio access technologies and multiple frequency bands in wireless networks can provide efficient solutions to meet the growing demand of data. These techniques are promising for the fifth generation (5G) wireless communication systems. However, to fully exploit their benefits, spectrum and spatial reuse, power saving, throughput and utility enhancement are crucial issues. In this thesis, we propose different resource allocation algorithms to address the aforementioned issues in wireless communication networks. First, we study the resource allocation problem for a hybrid overlay/underlay cognitive cellular network. We propose a hybrid overlay/underlay spectrum access mechanism to improve the spectrum and spatial reuse. We formulate the resource allocation problem as a coalition formation game among femtocell users, and analyze the stability of the coalition structure. We propose an efficient algorithm based on the solution concept of recursive core. The proposed algorithm achieves a stable and efficient spectrum allocation. Next, we study the resource allocation problem for multimedia content delivery in millimeter wave (mmWave) based home networks. We characterize different usage scenarios of multimedia content delivery. We formulate a joint power and channel allocation problem, which captures the spectrum and spatial reuse of mmWave communications, based on a network utility maximization framework. The problem is a non-convex mixed integer programming (MIP) problem. We reformulate the non-convex MIP problem into a convex MIP problem and propose a resource allocation algorithm based on the outer approximation method. We also develop an efficient heuristic algorithm which has a substantially lower complexity than the outer approximation based algorithm. Finally, we study full-duplex relay-assisted device-to-device (D2D) communication in mmWave based wireless networks. To design an efficient relay selection and power allocation scheme, we formulate a multi-objective combinatorial optimization problem, which balances the trade-off between power consumption and system throughput. The problem is transformed into a weighted bipartite matching problem. We then propose a joint relay selection and power allocation algorithm, which can achieve a Pareto optimal solution in polynomial time.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
29
Nicodeme, Claire. "Evaluation de l'adhérence au contact roue-rail par analyse d'images spectrales." Thesis, Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLEM024/document.
Full textAbstract:
L’avantage du train depuis sa création est sa faible résistance à l’avancement du fait du contact fer-fer de la roue sur le rail conduisant à une adhérence réduite. Cependant cette adhérence faible est aussi un inconvénient majeur : étant dépendante des conditions environnementales, elle est facilement altérée lors d’une pollution du rail (végétaux, corps gras, eau, etc.). Aujourd’hui, les mesures prises face à des situations d'adhérence dégradée impactent directement les performances du système et conduisent notamment à une perte de capacité de transport. L’objectif du projet est d’utiliser les nouvelles technologies d’imagerie spectrale pour identifier sur les rails les zones à adhérence réduite et leur cause afin d’alerter et d’adapter rapidement les comportements. La stratégie d’étude a pris en compte les trois points suivants : • Le système de détection, installé à bord de trains commerciaux, doit être indépendant du train. • La détection et l’identification ne doivent pas interagir avec la pollution pour ne pas rendre la mesure obsolète. Pour ce faire le principe d’un Contrôle Non Destructif est retenu. • La technologie d’imagerie spectrale permet de travailler à la fois dans le domaine spatial (mesure de distance, détection d’objet) et dans le domaine fréquentiel (détection et reconnaissance de matériaux par analyse de signatures spectrales). Dans le temps imparti des trois ans de thèse, nous nous sommes focalisés sur la validation du concept par des études et analyses en laboratoire, réalisables dans les locaux de SNCF Ingénierie & Projets. Les étapes clés ont été la réalisation d’un banc d’évaluation et le choix du système de vision, la création d'une bibliothèque de signatures spectrales de référence et le développement d'algorithmes classification supervisées et non supervisées des pixels. Ces travaux ont été valorisés par le dépôt d'un brevet et la publication d'articles dans des conférences IEEEThe advantage of the train since its creation is in its low resistance to the motion, due to the contact iron-iron of the wheel on the rail leading to low adherence. However this low adherence is also a major drawback : being dependent on the environmental conditions, it is easily deteriorated when the rail is polluted (vegetation, grease, water, etc). Nowadays, strategies to face a deteriorated adherence impact the performance of the system and lead to a loss of transport capacity. The objective of the project is to use a new spectral imaging technology to identify on the rails areas with reduced adherence and their cause in order to quickly alert and adapt the train's behaviour. The study’s strategy took into account the three following points : -The detection system, installed on board of commercial trains, must be independent of the train. - The detection and identification process should not interact with pollution in order to keep the measurements unbiased. To do so, we chose a Non Destructive Control method. - Spectral imaging technology makes it possible to work with both spatial information (distance’s measurement, target detection) and spectral information (material detection and recognition by analysis of spectral signatures). In the assigned time, we focused on the validation of the concept by studies and analyses in laboratory, workable in the office at SNCF Ingénierie & Projets. The key steps were the creation of the concept's evaluation bench and the choice of a Vision system, the creation of a library containing reference spectral signatures and the development of supervised and unsupervised pixels classification. A patent describing the method and process has been filed and published
30
Marshall, Benjamin James. "The Correlation between Spectral Moment Measures and Electropalatographic Contact Patterns for /s/ and /ʃ/." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3231.
Full textAbstract:
Spectral Moment Analysis has helped further our understanding of the spectral properties of obstruent speech production; however, the physiologic correlates of these spectral measures are not well understood. The aim of the present study was to examine the possible correlations between the linguapalatal contact patterns used to produce the fricatives /s/ and /ʃ/ and the resulting spectral characteristics. Using spectral moment analysis and electropalatography (EPG), the real-word productions of eight speakers of American English were investigated. The spectral measures for the fricative tokens in the present study were found to be similar to data reported in previous research with adult speakers. Although the majority of the correlations examined in this study were found to be statistically significant, none of the correlations accounted for a large proportion of the variance in the data. Generally the strongest correlations were found between the spectral mean and the symmetry of the contact pattern in the anterior region of the hard palate and the width of the contact pattern in the medial region of the palate. These findings may indicate that although the width and symmetry of linguapalatal contact contributes to the spectral signature /s/ and /ʃ/ fricatives, they are likely only part of a much more complex process that may involve other mechanisms such as lip rounding, tongue groove depth and shape, aerodynamic factors, and the shape of the vocal tract in other regions.
31
Barrett, Janelle. "The Correlation Between Spectral Moment Measures and Electropalatometric Contact Patterns for /t/ and /k/." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3304.
Full textAbstract:
Spectral moment analysis has helped further our understanding of the spectral properties of obstruent speech production; however, the physiologic correlates of these spectral measures are not well understood. The aim of the present study was to examine the possible correlations between the linguapalatal contact patterns used to produce the stops /t/ and /k/ and the resulting spectral characteristics. Using spectral moment analysis and electropalatography, the real-word productions of eight speakers of American English were investigated. The spectral measures for the stop consonant tokens in the present study were found to be similar to data reported in previous research with adult speakers. The majority of the correlations examined in this study were found to be statistically insignificant, although significant correlations were found between the anterior vertical and posterior vertical indices with spectral variance and spectral skewness, respectively. Despite the significance of these correlations, this did not account for a large proportion of variance in the data. Further analysis using curve estimates revealed significant curvilinear relationships among the data. These findings may indicate that although the anterior-posterior tongue placement and symmetry of linguapalatal contact contribute to the spectral signature of /t/ and /k/ stop consonants, this articulatory movement is only part of a more complex process that may involve aerodynamic factors and the overall shape of the vocal tract.
32
Amaduzzi, Alberto. "Enzymes' characterization via spectral analysis of the Laplacian associated to their relative contact maps." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/23899/.
Full textAbstract:
The main motivation for my thesis is the believe that global properties of enzymes areessential for a complete understanding of their behaviors. In my thesis, in particular,I investigate qualitative properties of enzymes via spectral techniques associated to thegraph Laplacian. I try to apply visualization techniques to understand similarities anddissimilarities among different enzymes’ structures, encoded in adjacency matrices re-trieved from coordinate data in online available datasets. The purpose is to make anexploration of features and see whether these techniques, that are used extensively inliterature for visual discrimination tasks, are also useful for these biological entities.I have tried to design a size-independent analysis that would be able to differentiateamong different taxonomies, different catalytic properties and different environmentsassociated to enzymes. This attempt provided useful hints for the analysis of enzymeproperties, even if as a final remark the dependence from enzyme size is still found inthe Laplacian eigenvalue spectrum.
33
Sorgato, Casares Verónica. "Novel multi-spectral imaging technique for the spatial quantification of optical properties." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066284/document.
Full textAbstract:
La nouvelle technique 'Dual-Step' d'Imagerie Multispectrale qui a été développée a comme objectif de contribuer au diagnostic clinique des lésions superficielles, en procurant des cartes grand champ quantitatives des propriétés optiques endogènes telles que l'absorption et la diffusion. L'approche repose sur la combinaison d'une technique sans-contact de Spectroscopie de Réflectance Diffuse spatialement résolue (DRSsr) pour estimer la diffusion utilisée ensuite par une autre technique d'Imagerie Multispectrale (MSI) pour estimer l'absorption. Les bancs d'essai de chaque technique ont \'et\'e construits et caractérisés dans le cadre de ce travail. La quantification optimale des propriétés optiques s'appuie sur un nouvel algorithme de calibration ('ACA-Pro' ) qui atteint des erreurs d'estimation minimales et inférieures à 3.3% pour la diffusion et 5.3% pour l'absorption. La technique 'Dual-Step' a été validée sur des fantômes d'intralipide mais aussi sur des échantillons ex-vivo de peau humaine et des modèles in-vivo d'inflammation de peau de rats. Les résultats montrent la faisabilité de la technique 'Dual-Step' et son potentiel en diagnostic clinique grâce à son approche quantitative, grand champ et non-invasiveThe Novel 'Dual-Step' Multispectral Imaging Technique that has been developed intends to contribute to the clinical diagnosis of superficial lesions by providing non-invasively quantitative spatial wide field maps of absorption and scattering endogenous optical properties. The approach relies on the combination of a Non-Contact Spatially-resolved Diffuse Reflectance Spectroscopy (DRSsr) technique with a Multispectral Imaging (MSI) technique. Absolute quantification is based on the scattering estimation with Non-Contact DRSsr which is subsequently used by MSI to estimate wide field absorption. The instrumental setups of each technique are built and thoroughly characterized in this work. The optimal quantification of optical properties relies on a newly established calibration algorithm 'ACA-Pro' that achieves minimal estimation errors inferior to 3.3% for scattering and 5.3% for absorption. The developed 'Dual-Step' technique has been validated not only with an extensive intralipid phantom study but also with ex-vivo biological human skin samples and in-vivo inflammation skin models on rats. The results show the potential of the 'Dual-Step' technique as a valid quantitative, wide-field, and non-invasive clinical diagnosis approach
34
Mukherjee, Baishali Banerjee. "Musical interaction with children with autistic spectrum disorder in an Indian context." Thesis, University of Strathclyde, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488840.
Full textAbstract:
Autism is a developmental disorder affecting normal stages of communication and social and interpersonal development and learning. Educational interventions to help children with autism to improve their communicative functioning are considered to be of utmost importance for the life of the child and their family. Adapting the basic principles of music therapy, the research reported in this thesis aimed to enhance communication skills in children with autism in India by using Indian music in an improvised, interactive way in individual session.
35
Mehdawi, Meftah A. "Spectrum measurement, sensing, analysis and simulation in the context of cognitive radio." Thesis, University of Hull, 2015. http://hydra.hull.ac.uk/resources/hull:16072.
Full textAbstract:
The radio frequency (RF) spectrum is a scarce natural resource, currently regulated locally by national agencies. Spectrum has been assigned to different services and it is very difficult for emerging wireless technologies to gain access due to rigid spectmm policy and heavy opportunity cost. Current spectrum management by licensing causes artificial spectrum scarcity. Spectrum monitoring shows that many frequencies and times are unused. Dynamic spectrum access (DSA) is a potential solution to low spectrum efficiency. In DSA, an unlicensed user opportunistically uses vacant licensed spectrum with the help of cognitive radio. Cognitive radio is a key enabling technology for DSA. In a cognitive radio system, an unlicensed Secondary User (SU) identifies vacant licensed spectrum allocated to a Primary User (PU) and uses it without harmful interference to the PU. Cognitive radio increases spectrum usage efficiency while protecting legacy-licensed systems. The purpose of this thesis is to bring together a group of CR concepts and explore how we can make the transition from conventional radio to cognitive radio. Specific goals of the thesis are firstly the measurement of the radio spectrum to understand the current spectrum usage in the Humber region, UK in the context of cognitive radio. Secondly, to characterise the performance of cyclostationary feature detectors through theoretical analysis, hardware implementation, and real-time performance measurements. Thirdly, to mitigate the effect of degradation due to multipath fading and shadowing, the use of -wideband cooperative sensing techniques using adaptive sensing technique and multi-bit soft decision is proposed, which it is believed will introduce more spectral opportunities over wider frequency ranges and achieve higher opportunistic aggregate throughput. Understanding spectrum usage is the first step toward the future deployment of cognitive radio systems. Several spectrum usage measurement campaigns have been performed, mainly in the USA and Europe. These studies show locality and time dependence. In the first part of this thesis a spectrum usage measurement campaign in the Humber region, is reported. Spectrum usage patterns are identified and noise is characterised. A significant amount of spectrum was shown to be underutilized and available for the secondary use. The second part addresses the question: how can you tell if a spectrum channel is being used? Two spectrum sensing techniques are evaluated: Energy Detection and Cyclostationary Feature Detection. The performance of these techniques is compared using the measurements performed in the second part of the thesis. Cyclostationary feature detection is shown to be more robust to noise. The final part of the thesis considers the identification of vacant channels by combining spectrum measurements from multiple locations, known as cooperative sensing. Wideband cooperative sensing is proposed using multi resolution spectrum sensing (MRSS) with a multi-bit decision technique. Next, a two-stage adaptive system with cooperative wideband sensing is proposed based on the combination of energy detection and cyclostationary feature detection. Simulations using the system above indicate that the two-stage adaptive sensing cooperative wideband outperforms single site detection in terms of detection success and mean detection time in the context of wideband cooperative sensing.
36
Hardy-Baranski, Bertrand. "Façonnage du contenu spectral d'un OPO doublement résonant par maîtrise de la phase relative, applications pour la spectroscopie." Phd thesis, Ecole Polytechnique X, 2011. http://pastel.archives-ouvertes.fr/pastel-00702290.
Full textAbstract:
Actuellement, un besoin croissant de techniques de détection et de quantification des gaz se manifeste, que ce soit pour la caractérisation de polluants atmosphériques, pour le contrôle de la qualité de l'air intérieur ou encore pour des aspects de sécurité en milieu industriel. Pour répondre à cette problématique, nous avons développé et caractérisé une source optique compacte, nanoseconde, constituée d'une architecture innovante d'oscillateur paramétrique optique doublement résonant (Dropo). La compréhension du rôle de la phase relative des ondes en interaction a été primordiale pour maîtriser le contenu spectral émis par ce type de sources paramétriques. Au cours de ce travail nous avons abouti à la maîtrise de cette phase, et réalisé une nouvelle architecture, dite nested-cavity OPO (NesCOPO). Avec cette cavité originale, un contrôle achromatique de la phase relative est réalisé pour toute la bande de gain paramétrique, permettant de démontrer le façonnage de cette dernière. Nous avons ainsi mis en évidence deux modes de fonctionnement suivant que la bande de gain présente un lobe unique ou deux lobes séparés d'environ un térahertz. Dans la dernière configuration, une émission bifréquence de l'OPO a été démontrée. Dans la première configuration, une émission monofréquence a été obtenue de manière contrôlée. Cette nouvelle architecture d'OPO - NesCOPO - a ouvert la voie à de nouveaux types d'accord en fréquence, particulièrement intéressants pour des expériences de spectroscopie. En tirant parti de l'imbrication de deux cavités optiques, nous avons ainsi été en mesure de réaliser des balayages fréquentiels automatisés sur toute la bande de gain avec une résolution ajustable. Une autre technique de balayage, promettant des balayages sur plusieurs dizaines de cm-1, a conduit à une évolution de l'architecture du NesCOPO et a été brevetée. Afin de valider son potentiel pour des applications de spectroscopie, et tirant parti du seuil d'oscillation très bas (1 µJ), nous avons pu implanter le NesCOPO, pompé par microlaser, dans des instruments compacts de mesure de gaz locale (technique photoacoustique) et à distance.
37
Hardy-Baransky, Bertrand. "Façonnage du contenu spectral d'un OPO doublement résonnat par maîtrise de la phase relative, applications pour la spectroscopie." Palaiseau, Ecole polytechnique, 2011. http://www.theses.fr/2011EPXX0100.
Full text
38
Bongard, Sébastien. "Radiation transfer and type Іa [ia] supernovae spectra analysis in the context of supernovae factory." Lyon 1, 2005. http://tel.archives-ouvertes.fr/docs/00/05/85/56/PDF/dissertation.pdf.
Full textAbstract:
Dans cette thèse, effectuée en cotutelle avec l'Université d'Oklahoma City, nous avons étudié le transfert radiatif dans les enveloppes en expansion rapide des supernovae de type Ia (SNeIa) dans le cadre de la collaboration SupernovaeFactory. Ces étoiles qui explosent avec une luminositée comparable à celle d'une galaxie sont utilisées comme chandelles standard permettant d'étudier le comportement à grande échelle de l'univers. Nous avons utilisé le code de transfert radiatif PHOENIX développé par P. Hauschildt, F. Allard et E. Baron, pour simuler des spectres de SNeIa à différentes dates et luminosités afin d'étudier le processus de formation spectrale. Nous avons parallèlement élaboré un module de grille adaptative qui augmente sa robustesse de convergence. Nous avons montré que la formation des spectres de SNeIa n'était pas aussi localisée que dans le modèle photospherique standard mais qu'elle mettait en relation des régions allant de 5000 km/s à 20000 km/s pour des époques proches du maximum de luminosité. Nous avons de plus développé des indicateurs spectraux permettant de mesurer la luminosité des SNeIa avec une précision égale à celle des méthodes basées sur l'analyse des courbes de lumière. Il devient ainsi possible de contraindre de façon indépendante l'évolution des SNeIa avec le redshift, ce qui place ce travail à l'interface entre l'étude des supernovae en tant qu'objets stellaires et leur utilisation en cosmologie
39
Fritsche, Tobias. "Parasite spectrum and seasonal epidemiology of gastrointestinal nematodes of small ruminants in The Gambia /." [S.l.] : [s.n.], 1992. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
Full text
40
Greub, Christoph Greub Christoph. "Regularization schemes for infrared and collinear singularities ; Calculation of lepton spectra from W production at the Sppp-sS collider /." Bern, 1989. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
Full text
41
Kourkoulou, Anastasia. "Implicit learning of spatial context in adolescents and adults with autism spectrum disorder." Thesis, Durham University, 2010. http://etheses.dur.ac.uk/325/.
Full textAbstract:
The aim of the current thesis was to investigate whether individuals with Autism Spectrum Disorders (ASDs) who show good visuospatial abilities, such as superior processing of local structures (Happé & Frith, 2006; Mottron, Dawson, Soulières, Hubert, & Burack, 2006), may also show intact or even superior learning of visuospatial information. In a series of experiments, with adolescents and adults with ASD and a comparison group of Typically Developing (TD) individuals, learning of spatial context was investigated using a visual search task, known as contextual cueing (Chun & Jiang, 1998). Contextual cueing refers to faster target detection in a visual search task with repeated exposure to a visual configuration (context), compared to configurations presented only once. Experiments 1 to 3 indicated that implicit learning may be reduced in ASD, however explicit learning was found to be preserved in ASD. In Experiments 4 to 6 implicit learning was re-examined. Results showed that when attention was oriented to the local parts of the display, individuals with ASD showed superior but atypical implicit learning of context relative to TDs (Experiment 4). However, when attention was directed to spatially distant, non-local contexts, performance was no different than for TD individuals (Experiment 5). Experiment 6 revealed superior implicit learning of local context in ASD and superior implicit learning of global context in TD individuals. Finally, Experiment 6 supported the view that contextual cueing is a local processing task, since both groups attended to local cues for longer periods of time. It is concluded that individuals with ASD show preserved or even superior implicit learning under conditions that involve attention to the local patterns.
42
Page, Teneille. "Effortful Control, Attention and Executive Functioning in the Context of Autism Spectrum Disorder." Master's thesis, Faculty of Humanities, 2019. http://hdl.handle.net/11427/30545.
Full textAbstract:
Autism Spectrum Disorder (ASD) involves a broad presentation of symptoms classified along continuum of severity, with core deficits in Social Affect and Restricted, Repetitive Behaviours required for formal diagnosis (American Psychiatric Association, 2013; Lauritsen, 2013). The development of particular cognitive, behavioural and interpersonal difficulties seen in ASD is of great interest. Temperament offers particular value given that it influences the development of social behaviours, emotionality and self-regulation (Shiner et al., 2012). The self-regulatory temperament factor, effortful control, is known to be diminished in ASD (Garon et al., 2009, 2016) and is theorised to be related to attention and executive functioning (Rothbart & Rueda, 2005). This link is of particular interest, given that attention and executive function deficits are prominent in ASD (Craig et al., 2016; Lai et al., 2017; Sanders, Johnson, Garavan, Gill, & Gallagher, 2008). To date, however, a thorough literature search failed to yield a study which has investigated whether effortful control,attention and executive functioning are concurrently associated with ASD symptomatology.Moreover, the relationship between effortful control, attention and executive functioning is not as unambiguous as previously theorised in typical development, with little investigation into these relationships in ASD. To elucidate the association effortful control, attention and executive functioning have with ASD symptomatology, the relationship between effortful control and these cognitive variable needs to be better established empirically. Therefore the current investigation’s aims were twofold. Study One investigated the relationship of effortful control with attention and executive functions in neurotypical and ASD samples. Study Two explored the association between effortful control, attention, executive functions and core ASD deficits (i.e. Social Affect and Restricted, Repetitive Behaviours). A sample of 38 ASD and 38 neurotypical boys (aggregate-matched on key demographic factors), aged 6 - 15, and their primary caregivers were recruited. Study One considered both groups (n=76) and featured both quasi-experimental and relational investigations. Study Two focused only on the ASD sample (n=38) and used a purely relational design. Neurocognitive measures were used to assess two attention domains (i.e. attention span and sustained attention), and three executive functions (i.e. working memory, inhibition and switching). Effortful control was measured using a parent-report questionnaire and ASD core deficits were examined using the Autism Diagnostic Observation Schedule, Second edition (ADOS-2; Lord, Luyster, Gotham, & Guthrie, 2012). Results of Study One revealed effortful control was a significant predictor of attention span, working memory and inhibition, with ASD participants performing significantly more poorly on these cognitive domains and rated significantly more poorly on effortful control. Study Two’s results indicated that Social Affect was significantly correlated with inhibition and the interaction effect between effortful control and working memory. Furthermore, only effortful control, attention span and their interaction effect were significantly associated with Restricted Repetitive Behaviours. Specifically, effortful control was found to moderate this relationship. At high levels of effortful control, increased attention span was associated with less Restricted, Repetitive Behaviours. These findings may aid efforts to establish a predictive model for ASD core deficits on the basis of temperament and cognitive difficulties. Keywords: Autism Spectrum Disorder (ASD), Effortful Control, Attention, Executive Functions, Social Affect, Restricted Repetitive Behaviours
43
Prickett, Megan M. "Success Indicators of College Students with Autism Spectrum Disorder." TopSCHOLAR®, 2015. http://digitalcommons.wku.edu/theses/1524.
Full textAbstract:
This study examined the executive functioning skills as students with Autism Spectrum Disorder (ASD) entered college. The participants consisted of 95 college students with ASD who attended the Kelly Autism Program (KAP) on Western Kentucky University’s campus in Bowling Green, Kentucky. The individuals in the sample were categorized three groups: individuals who graduated from college, individuals who were still attending college, and individuals who dropped out of college. The results indicated that the executive functioning skills of inhibiting and initiation were statistically significantly different between the three groups and additional skills were significantly different when comparing only the group that graduated from college with the group that dropped out of college.
44
Lovisa, Stephane. "Propriétés optiques de puits quantiques de CdTe contenant un gaz d'électrons bidimensionnel." Université Joseph Fourier (Grenoble ; 1971-2015), 1998. http://www.theses.fr/1998GRE10099.
Full textAbstract:
Les proprietes optiques et magneto-optiques de puits quantiques de cdte contenant un gaz d'electrons bidimensionnel ont ete etudiees par spectroscopie d'absorption et d'emission, en fonction de la concentration des electrons. Une premiere etude par spectroscopie d'emission, effectuee sur une serie d'echantillons a densite electronique fixe, a montre que la masse effective des electrons depend fortement de leur concentration. Des calculs tenant compte des effets a n corps expliquent bien cette renormalisation de masse. Par ailleurs, des dispositifs schottky ont ete realises qui permettent de varier continument la densite du gaz d'electrons dans un puits quantique de cdte a l'aide d'une tension inverse appliquee. L'etude des proprietes de magneto-absorption en fonction de la densite a mene a une modelisation de la force d'oscillateur de l'exciton charge negativement ou trion. Les spectres d'absorption obtenus en champ nul sur des echantillons possedant des desordres electrostatiques differents ont montre l'apparition de zones isolantes pour une valeur du rapport de la densite d'electrons et du parametre de desordre exactement egale a celle prevue par la theorie recente d'efros. La transition optique temoignant de l'apparition de ces zones est attribuee a un trion a n corps.
45
Thompson, Amber A. "ROMANTIC RELATIONSHIPS IN THE CONTEXT OF PARENTING CHILDREN WITH AUTISM." UKnowledge, 2014. http://uknowledge.uky.edu/hes_etds/13.
Full textAbstract:
This study examines the impact of raising a child with an autism spectrum disorder on relationship quality using the double ABCX model of adjustment and adaptation. Respondents (N = 126) recruited through Autism Society listervs completed online surveys designed to measure three factors of relationship quality: satisfaction, positive perceptions, and negative perceptions. Results from hierarchical multiple regression models indicate that the double ABCX model accounted for 47% of variance in satisfaction, 72% in positive perceptions, and 50% in negative perceptions, for predicting the quality of couple relationships. Implications for clinicians working with couples are discussed, such as the need for treatment that focuses on stress management and increasing support through affectionate, emotional, tangible, and social interactions.
46
Jordan, Jorge J. "UNDERSTANDING THE NON-CONTACT TEMPERATURE MEASUREMENT TECHNOLOGY." International Foundation for Telemetering, 2005. http://hdl.handle.net/10150/605042.
Full textAbstract:
ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, NevadaThe ability to accurately measure the temperature of different materials has always been a challenge for the Instrumentation Engineer. The use the classic contact type temperature detector such as thermocouples or RTD’s (Resistance Temperature Detectors) has not always shown to be the best approach to obtain the expected measurement. When not used carefully in closed environments, thermocouples and RTD’s could report the environmental temperature rather than the temperature from the product under examination. They are also temperature limited and when needed for applications above those limits, very expensive and low reliable materials are necessary to do the job. The use of non-contact thermometers has become the preferred choice for such applications. They have also come as a solution for the difficulties involved in the temperature measurements of moving targets. The industry has used portable and spot type infrared thermometers for some time, but the demand for better and more precise measurements has brought an incredible number of new products to the market. By means of advanced electronics and new software developments these products are used to cope with the difficulties of acquiring challenging measurements. Some of the same demands have made necessary the use of non-contact temperature measurement devices on aircraft instrumentation applications. The use of these capabilities has allowed the data acquisition community to get valuable data that was very difficult if not impossible to obtain before. In spite of all these facts, this promising emerging technology demands very careful attention before it is put to good use. The many products and solutions available do not accurately address every problem and the selection of the wrong technology for a specific task can prove to be fatal. The use of non-contact temperature devices is not an easy “off the shelf” pick but rather an option that demands knowledge of the infrared measurement theory as well as a complete understanding of the material under observation. The intention of this paper is to provide a practical understanding on the non-contact temperature measurement methods to the Aircraft Instrumentation Engineer who has not benefited from the use of this exiting technology.
47
Conceição, Maria Manuela Ferreira da. "As perceções dos professores face à inclusão de alunos com perturbações do espetro do autismo nas turmas de ensino regular e em unidades de ensino estruturado." Master's thesis, [s.n.], 2015. http://hdl.handle.net/10284/4791.
Full textAbstract:
Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências da Educação: Educação Especial, área de especialização em Domínio Cognitivo e MotorA presente dissertação tem como tema de estudo e objetivo essencial conhecer e refletir sobre a perceção dos professores face à inclusão de alunos com perturbações do espetro do autismo (PEA)1 nas turmas do ensino regular e em unidades de ensino estruturado. Como tal, incide numa primeira parte, de caráter teórico, sobre a escola inclusiva direcionada por excelência para alunos com PEA, com referência especial para a intervenção pedagógica utilizada para os mesmos. Numa segunda parte apresenta-se o trabalho empírico, de caráter exploratório (descritivo), assente numa metodologia quantitativa, com recurso a um inquérito por questionário dirigido a uma amostra de docentes de educação especial e do ensino regular de um agrupamento de escolas, com experiência docente com esta tipologia de alunos. Neste espírito, pretendeu-se conhecer as suas opiniões sobre diversificada temática, caso da aprendizagem, comportamento e inclusão dos alunos com PEA no contexto educativo, bem como a promoção da inclusão por parte do agrupamento para com estes alunos, nomeadamente quanto à organização, gestão dos recursos humanos/pedagógicos e processo de inclusão dos alunos na sala de aula do ensino regular, bem como nas unidades de ensino estruturado. Como resultados finais, há a relevar uma generalizada perceção positiva dos docentes inquiridos quanto à maior parte dos itens questionados nas diversas temáticas abordadas, testemunho de uma escola inclusiva e integração destes alunos nas turmas do ensino regular em unidades de ensino estruturado, conforme objetivo central de reflexão da presente dissertação.
This dissertation has a essential subject of study to know and reflect on teachers perception towards the inclusion of students with autism spectrum disorders in the regular classes and objective structured teaching units. As such, focuses in the first part, the theoretical nature of inclusive school guided by excellence for student with autism spectrum disorders, with special reference to the pedagogical intervention used to them. The second part presents the empirical work, which has exploraty and descriptive nature, based on a quantitative methodology using a survey questionnaire to a sample of special education and regular education teachers of a school group. These teachers have experience faculty with this typology of students. In this spirit, we intended to Know their opinions on divers themes, namely learning, behavior and inclusion of students with autism spectrum disorders in the educational context, as well as inclusion promotion of these students done by the grouping, particulary regarding the organization, management of human/ learning resources and inclusion process of students in the class or regular education room as well as in units of structured teaching. As final results, there is to reveal widespread positive perception of teachers as respondents for most items asked in the various addressed topics, testifying and inclusive school able to integrate these students in regular classes and units of structured teaching according to the central objective reflection of this dissertation.
48
Vaidya, Nikhilesh Avanish. "NOISE SPECTRUM OF A QUANTUM POINT CONTACT COUPLED TO A NANO-MECHANICAL OSCILLATOR." Diss., Temple University Libraries, 2017. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/447885.
Full textAbstract:
PhysicsPh.D.
With the advance in nanotechnology, we are more interested in the "smaller worlds". One of the practical applications of this is to measure a very small displacement or the mass of a nano-mechanical object. To measure such properties, one needs a very sensitive detector. A quantum point contact (QPC) is one of the most sensitive detectors. In a QPC, electrons tunnel one by one through a tunnel junction (a "hole"). The tunnel junction in a QPC consists of a narrow constriction (nm-wide) between two conductors. To measure the properties of a nano-mechanical object (which acts as a harmonic oscillator), we couple it to a QPC. This coupling effects the electrons tunneling through the QPC junction. By measuring the transport properties of the tunneling electrons, we can infer the properties of the oscillator (i.e. the nano-mechanical object). However, this coupling introduces noise, which reduces the measurement precision. Thus, it is very important to understand this source of noise and to study how it effects the measurement process. We theoretically study the transport properties of electrons through a QPC junction, weakly coupled to a vibration mode of a nano-mechanical oscillator via both the position and the momentum of the oscillator. %We study both the position and momentum based coupling. The transport properties that we study consist of the average flow of current through the junction, given by the one-time correlation of the electron tunneling event, and the current noise given by the two-time correlation of the average current, i.e, the variance. The first comprehensive experimental study of the noise spectrum of a detector coupled to a QPC was performed by the group of Stettenheim et al. Their observed spectral features had two pronounced peaks which depict the noise produced due to the coupling of the QPC with the oscillator and in turn provide evidence of the induced feedback loop (back-action). Benatov and Blencowe theoretically studied these spectral features using the Born approximation and the Markovian approximation. In this case the Born approximation refers to second order perturbation of the interaction Hamiltonian. In this approximation, the electrons tunnel independently, i.e., one by one only, and co-tunneling is disregarded. The Markovian approximation does not take into account the past behavior of the system under time evolution. These two approximations also enable one to study the system analytically, and the noise is calculated using the MacDonald formula. Our main aim for this thesis is to find a suitable theoretical model that would replicate the experimental plots from the work of Stettenheim et al. Our work does not use the Markovian approximation. However, we do use the Born approximation. This is justified as long as the coupling between the oscillator and QPC is weak. We first obtain the non-Markovian unconditional master equation for the reduced density matrix of the system. Non-Markovian dynamics enables us to study, in principle, the full memory effects of the system. From the master equation, we then derive analytical results for the current and the current noise. Due to the non-Markovian nature of our system, the electron tunneling parameters are time-dependent. Therefore, we cannot study the system analytically. We thus numerically solve the current noise expression to obtain the noise spectrum. We then compare our noise spectrum with the experimental noise spectrum. We show that our spectral noise results agree better with the experimental evidence compared to the results obtained using the Markovian approximation. We thus conclude that one needs non-Markovian dynamics to understand the experimental noise spectrum of a QPC coupled to a nano-mechanical oscillator.
Temple University--Theses
49
Saklayen, Sanjida Shoma. "Effects of Propranolol on Cognition and Eye Contact in Autism Spectrum Disorder (ASD)." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1269564876.
Full text
50
Bowers, Annika. "Imitation of adults and peers in a music-play context by children with autism spectrum disorders." Tallahassee, Fla. : Florida State University, 2010. http://purl.fcla.edu/fsu/lib/digcoll/undergraduate/honors-theses/2181952.
Full textAbstract:
Thesis (Honors paper)--Florida State University, 2010.Advisor: Dr. Michael B. Bakan, Florida State University, College of Communication & Information, Dept. of Communication Science and Disorders. Includes bibliographical references.