Dissertations / Theses: 'Spectral Patterns'

1

Römer, Christoph [Verfasser]. "Identification of Relevant Patterns in Spectral Signatures / Christoph Römer." Bonn : Universitäts- und Landesbibliothek Bonn, 2016. http://d-nb.info/1095099116/34.

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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.

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Bennett, Leslie Leatham. "Associations Between Linguapalatal Contact Patterns and Spectral Moments for /s/." BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/1668.

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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.

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Nimmer, Max [Verfasser]. "Spectral Imaging Based on 2D Diffraction Patterns and Robust Principal Component Analysis / Max Nimmer." München : Verlag Dr. Hut, 2019. http://d-nb.info/119641436X/34.

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5

Traub, Janet. "Patterns in the Variation of CDOM Spectral Slopes in the Western Lake Erie Basin." University of Toledo / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1352917941.

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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.

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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.

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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.

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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.

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Zuurmond, Gideon Joubert. "Accurate camera position determination by means of moiré pattern analysis." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96862.

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Thesis (MSc)--Stellenbosch University, 2015.
English abstract: We introduce a method for determining the position of a camera with accuracy beyond that which is obtainable through conventional methods, using a single image of a specially constructed calibration object. This is achieved by analysing the moiré pattern that emerges when two high spatial frequency patterns are superimposed, such that one pattern on a plane is observed through another pattern on a second, semi-transparent parallel plane, with the geometry of both the patterns and the planes known. Such an object can be created by suspending printed glass over printed paper or by suspending printed glass over a high resolution video display such as an OLED display or LCD. We show how the camera’s coordinate along the axis perpendicular to the planes can be estimated directly from frequency analysis of the moiré pattern relative to a set of guide points in one of the planes. This method does not require any prior camera knowledge. We further show how the choice of the patterns allows, within limits, arbitrary accuracy of this coordinate estimate at the cost of a stricter limit on the span along that coordinate for which the technique is usable. This improved accuracy is illustrated in simulation. With a sufficiently accurate estimate of the camera’s full set of 3D coordinates, obtained by conventional methods, we show how phase analysis of the moiré pattern in relation to the guides allows calculation of a new estimate of position in the two axes parallel to the planes. This new estimate is shown in simulation to offer significant improvement in accuracy.
Afrikaanse opsoming: Ons stel ’n metode bekend om die posisie van ’n kamera te bepaal met akkuuraatheid bo dit wat verkrygbaar is uit konvensionele metodes, deur gebruik te maak van ’n spesiaal gekonstrueerde kalibrasievoorwerp. Die metode berus op analise van moiré patrone wat onstaan waneer twee hoë ruimtelike frekwensie patrone oor mekaar neergelê word deurdat een patroon op ’n plat vlak waargeneem word deur ’n tweede patroon op ’n parallelle, gedeeltelik deursigtige vlak, met die geometrie van beide patrone en vlakke bekend. So ’n voorwerp kan geskep word deur ’n spesiaal gedrukte glas vlak te monteer oor gedrukte papier of oor ’n hoë resolusie skerm, soos ’n OLED skermof LCD. Onswys hoe die kamera se koördinaat langs die as loodreg op die vlakke direk uit frekwensie analise van die moiré patroon relatief tot ’n stel gidspunte in een van die vlakke bepaal kan word. Hierdie metode vereis geen vooraf kennis oor die kamera nie. Ons wys verder hoe die keuse van patrone, binne perke, arbitrêre akkuuraatheid in die bepaling van hierdie koördinaat kan verkry ten koste van ’n nouer bruikbare verstek in hierdie koördinaat. Die verbeterde akkuuraatheid is geïllustreer in simulasie. Indien ’n benadering van die kamera se volle stel 3D koördinate met voldoende akkuuraatheid ook beskikbaar is, wys ons ook hoe fase analise van die moiré patroon relatief tot die gidspunte ons in staat stel om’n nuwe benadering te kanmaak vir die koördinate in die twee asse parallel aan die vlakke. Daar word in simulasie getoon hoe hierdie nuwe benadering beduidend beter akkuuraatheid kan bied in vergelyking met konvensionele metodes van benadering.

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Carrasco, Hernandez Roberto. "Calculation of patterns of solar radiation within urban geometries." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/calculation-of-patterns-of-solar-radiation-within-urban-geometries(5ac30e2c-0713-4217-8680-a2035d982710).html.

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The present work proposes methods to calculate street-level exposures to solar radiation. The methods comprise a combination of different software algorithms, online databases and real-time standard measurements of solar radiation. Firstly, the use of the free access image database “Google Street View” to reconstruct urban geometries is illustrated. Google Street View represents an enormous source of information readily available for its general use in the field of urban atmospheric studies. With the aid of existing software packages, it was possible to reconstruct urban geometries as projected fisheye images of the canyon upper-hemispheric view, and to model total-shortwave solar irradiance within an urban canyon. The models allowed the calculation of relative street-canyon irradiance as a fraction of that received under a full-sky view, depending on the visibility of the solar disc and the reduced sky view factor. The combined use of the ideal models with real-time data allows for the calculation of street-canyon irradiance under any cloud conditions. Validation of these techniques was obtained by comparing the calculations against in situ measurements of irradiance from a local street canyon. The existing software, however, does not allow the calculation of spectral irradiance, required for inferring, for example, the biological effects of solar radiation. The use of spectral radiative transfer software was explored to provide spectral irradiance, but commonly available models do not include the effects of horizon obstructions. The approach presented here followed the same general guidelines used to calculate total-shortwave irradiance. The spectral models required a spectral partitioning of global irradiance into direct and diffuse components, allowing the independent analysis of horizon obstruction effects on these components at each wavelength. To partition global irradiance, two equations were developed for the calculation of the diffuse-to-global irradiance ratio (DGR) under cloudless conditions: one based on simplified radiative transfer theory, and an empirical fit for local conditions. Afterwards, the effects of horizon obstructions were evaluated in combination with real-time measurements of unobstructed global spectral irradiance. A set of simulated obstructions were used to validate the models. Finally, it was observed that neglecting the anisotropic distribution of the diffuse component of solar radiation in these simple models could produce large uncertainties in some situations. A practical solution for including the anisotropy of diffuse radiation was proposed, requiring images from an unobstructed digital sky camera. The combination of tools described here will allow calculation of total and spectral global irradiance upon a flat horizontal surface whatever the local field of view. This is possible at any geographical location were the urban geometries can be described, either by manually obtaining digital photographs, or through the Google Street View database, and where there is a reasonably local standard measurement of radiation.

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Zheng, Feng. "Using spectral reflection and multi-dye layer pixel values to quantify soil patterns for assessing field fertility conditions." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26212.

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The variability of soil chemical properties exerts a great influence on the practice of fertilization and other soil management. Quantitative reliable measurements of the soil variability are vital to the accuracy of fertilizer recommendations and the effective uses of fertilizer. The aim of the thesis is to determine whether soil classifications and variability assessments can be facilitated by the use of quantitative remote sensing techniques. An agricultural field with very contrasting soils was selected for this study and field variability in total and organic C, exchangeable cations, CEC, major fertility elements N, P, and K, soil water content and coarse fragments was examined using three different sampling techniques and laboratory analysis. The remote sensing techniques evaluated in this study were: 1) laboratory spectral reflection measurements of soil samples in the green, red and two near IR bands using a multi-channel radiometer, and 2) multi-dye layer pixel value analysis of digitized color aerial photos taken at the time of sampling. Conventional, selective and stratified random sampling techniques were used to quantify the soils in the field and although the variability in K, Ca, and P was high no significant differences were obtained in the mean values among the three techniques. Three distinct soil types were identified in the field, which included type I - very dark soils, type II - gravelly, very light colored soils, and type III - average brown or dominant soils. All three categories could be separated by Munsell value and chroma data. Significant differences in C, N, K, CEC, moisture content and coarse fragment content were obtained among the three soil types. Once the chemical data were translated into fertilizer requirements it became evident that soil type II (gravelly light colored soils) needed a higher K fertilizer rate than either type I or type III, thus suggesting that a differential fertilizer rate application within the field should be beneficial to crop performance. Correlation and regression studies of soil parameters with spectral reflection and dye-layer pixel values revealed the nature of the relationships between soil spectral properties and physical and chemical conditions. Significant correlations were found between reflectance values and most of the chemical parameters, and between pixel values, soil chemistry and moisture content. In both cases, % organic C showed the highest correlation. The results from stepwise regression and discriminant analysis revealed that organic C, water content and color value were the most-dominant soil parameters to influence spectral or pixel value variations. The relationship between water content and pixel value was significant suggesting that the variation in water content mignt be quantified by an analysis of dye-layer pixel values. Soil organic matter and soil color proved to be best predicted by laboratory reflectance measurements. Multi-variate cluster and discriminant analysis revealed that the soil types could be quantified with both spectral and multi-dye layer pixel value analysis and that the remote sensing data were best related to organic matter, soil color and soil moisture content in the field. The pattern of soil types in the field was determined visually by planimetry and by quantitative dye-layer pixel value analysis. The two results were found to be in close agreement and provided quantitative values for the spatial extent of the three soil types. These values were used to determine the total amount of fertilizers required for the field and the quantified spatial pattern is an excellent medium to facilitate soil sampling for fertilizer assessment for future cultivation.
Land and Food Systems, Faculty of
Graduate

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11

Castillo, Guevara Ramon D. "Coordination of Local and Global Features: Fractal Patterns in a Categorization Task." University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1321372828.

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12

Dorai-Raj, Sundardas Samuel. "First- and Second-Order Properties of Spatiotemporal Point Patterns in the Space-Time and Frequency Domains." Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/28540.

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Point processes are common in many physical applications found in engineering and biology. These processes can be observed in one-dimension as a time series or two-dimensions as a spatial point pattern with extensive amounts of literature devoted to their analyses. However, if the observed process is a hybrid of spatial and temporal point process, very few practical methods exist. In such cases, practitioners often remove the temporal component and analyze the spatial dependencies. This marginal spatial analysis may lead to misleading results if time is an important factor in the process. In this dissertation we extend the current analysis of spatial point patterns to include a temporal dimension. First- and second-order intensity measures for analyzing spatiotemporal point patterns are explicitly defined. Estimation of first-order intensities are examined using 3-dimensional smoothing techniques. Conditions for weak stationarity are provided so that subsequent second-order analysis can be conducted. We consider second-order analysis of spatiotemporal point patterns first in the space-time domain through an extension of Ripley's $K$-function. An alternative analysis is given in the frequency domain though construction of a spatiotemporal periodogram. The methodology provided is tested through simulation of spatiotemporal point patterns and by analysis of a real data set. The biological application concerns the estimation of the homerange of groups of the endangered red-cockaded woodpecker in the Fort Bragg area of North Carolina. Monthly or bimonthly point patterns of the bird distribution are analyzed and integrated over a 23 month period.
Ph. D.

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13

Zhong, Shiyin. "Electricity Load Modeling in Frequency Domain." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/75109.

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In today's highly competitive and deregulated electricity market, companies in the generation, transmission and distribution sectors can all benefit from collecting, analyzing and deep-understanding their customers' load profiles. This strategic information is vital in load forecasting, demand-side management planning and long-term resource and capital planning. With the proliferation of Advanced Metering Infrastructure (AMI) in recent years, the amount of load profile data collected by utilities has grown exponentially. Such high-resolution datasets are difficult to model and analyze due to the large size, diverse usage patterns, and the embedded noisy or erroneous data points. In order to overcome these challenges and to make the load data useful in system analysis, this dissertation introduces a frequency domain load profile modeling framework. This framework can be used a complementary technology alongside of the conventional time domain load profile modeling techniques. There are three main components in this framework: 1) the frequency domain load profile descriptor, which is a compact, modular and extendable representation of the original load profile. A methodology was introduced to demonstrate the construction of the frequency domain load profile descriptor. 2) The load profile Characteristic Attributes in the Frequency Domain (CAFD). Which is developed for load profile characterization and classification. 3) The frequency domain load profile statistics and forecasting models. Two different models were introduced in this dissertation: the first one is the wavelet load forecast model and the other one is a stochastic model that incorporates local weather condition and frequency domain load profile statistics to perform medium term load profile forecast. 7 different utilities load profile data were used in this research to demonstrate the viability of modeling load in the frequency domain. The data comes from various customer classes and geographical regions. The results have shown that the proposed framework is capable to model the load efficiently and accurately.
Ph. D.

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Dodson, Zoey. "Linking glacial erosion and rock type via spectral roughness and spatial patterns of fractures on glaciated bedrock in the Teton Range, Wyoming, USA." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1539080658075619.

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15

Thorsen, Linda. "The clinical application of QEEG : A pilot study of spectral and ERP deviant patterns in children in a special psychiatric unit: An exploratory multiple case report." Thesis, Norges teknisk-naturvitenskapelige universitet, Psykologisk institutt, 2011. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-14740.

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This thesis is divided in two parts: Part I provides an overview of the basic and clinical QEEG research fields, and is specifically aimed at addressing issues regarding the clinical application of QEEG in childhood disorders. Specific brain oscillations and event related potentials (ERP) have been found to reflect meaningful states, behaviors, and cognitive processes. Clinical studies on neuropsychiatric disorders have demonstrated differences in certain QEEG parameters in clinical populations compared to control groups, however, results have been inconsistent across studies. Studies searching for disorder-specific QEEG profiles in childhood disorders have demonstrated impressive classification accuracies in sorting patients from control groups. But the clinical application of QEEG metrics faces several issues, such as heterogeneity and comorbidity. Part II presents a multiple case study of 14 children referred to a neuropsychiatric unit for observation. QEEG analysis was conducted for each individual and provided a wide range of EEG measures that were compared to a normative database. All deviances were analyzed in relation to reported symptoms and problems, and performance measures. Results revealed significant deviances in two or more QEEG parameters for all of the participants, and furthermore, certain problem areas were found to correlate with spectral deviances in the alpha- and theta-bands. A discussion of the results particularly in relation to issues regarding clinical application of QEEG is provided, and suggests that the heterogeneity in childhood disorders are reflected in heterogeneity in the electrophysiological patterns associated with different symptom complexes, and interpretations of deviances faces similar biases as traditional diagnostics.

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El, Ghawalby Heyayda. "Spectral geometry for structural pattern recognition." Thesis, University of York, 2011. http://etheses.whiterose.ac.uk/1525/.

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Graphs are used pervasively in computer science as representations of data with a network or relational structure, where the graph structure provides a flexible representation such that there is no fixed dimensionality for objects. However, the analysis of data in this form has proved an elusive problem; for instance, it suffers from the robustness to structural noise. One way to circumvent this problem is to embed the nodes of a graph in a vector space and to study the properties of the point distribution that results from the embedding. This is a problem that arises in a number of areas including manifold learning theory and graph-drawing. In this thesis, our first contribution is to investigate the heat kernel embedding as a route to computing geometric characterisations of graphs. The reason for turning to the heat kernel is that it encapsulates information concerning the distribution of path lengths and hence node affinities on the graph. The heat kernel of the graph is found by exponentiating the Laplacian eigensystem over time. The matrix of embedding co-ordinates for the nodes of the graph is obtained by performing a Young-Householder decomposition on the heat kernel. Once the embedding of its nodes is to hand we proceed to characterise a graph in a geometric manner. With the embeddings to hand, we establish a graph characterization based on differential geometry by computing sets of curvatures associated with the graph nodes, edges and triangular faces. The second contribution comes from the need to solve the problem that arise in the processing of a noisy data over a graph. The Principal difficulty of this task, is how to preserve the geometrical structures existing in the initial data. Bringing together several, distinct concepts that have received some independent recent attention in machine learning; we propose a framework to regularize real-valued or vector-valued functions on weighted graphs of arbitrary topology. The first of these is deduced from the concepts of the spectral graph theory that have been applied to a wide range of clustering and classification tasks over the last decades taking in consideration the properties of the graph $p$-Laplacian as a nonlinear extension of the usual graph Laplacian. The second one is the geometric point of view comes from the heat kernel embedding of the graph into a manifold. In these techniques we use the geometry of the manifold by assuming that it has the geometric structure of a Riemannian manifold. The third important conceptual framework comes from the manifold regularization which extends the classical framework of regularization in the sense of reproducing Hilbert Spaces to exploit the geometry of the embedded set of points. The proposed framework, based on the $p$-Laplacian operators considering minimizing a weighted sum of two energy terms: a regularization one and an additional approximation term which helps to avoid the shrinkage effects obtained during the regularization process. The data are structured by functions depending on data features, the curvature attributes associated with the geometric embedding of the graph. The third contribution is inspired by the concepts and techniques of the graph calculus of partial differential functions. We propose a new approach for embedding graphs on pseudo-Riemannian manifolds based on the wave kernel which is the solution of the wave equation on the edges of a graph. The eigensystem of the wave-kernel is determined by the eigenvalues and the eigenfunctions of the normalized adjacency matrix and can be used to solve the edge-based wave equation. By factorising the Gram-matrix for the wave-kernel, we determine the embedding co-ordinates for nodes under the wave-kernel. The techniques proposed through this thesis are investigated as a means of gauging the similarity of graphs. We experiment on sets of graphs representing the proximity of image features in different views of different objects in three different datasets namely, the York model house, the COIL-20 and the TOY databases.

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Miti, Filippo. "Mathematical models for cellular aggregation: the chemotactic instability and clustering formation." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/12020/.

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In this thesis we present a mathematical formulation of the interaction between microorganisms such as bacteria or amoebae and chemicals, often produced by the organisms themselves. This interaction is called chemotaxis and leads to cellular aggregation. We derive some models to describe chemotaxis. The first is the pioneristic Keller-Segel parabolic-parabolic model and it is derived by two different frameworks: a macroscopic perspective and a microscopic perspective, in which we start with a stochastic differential equation and we perform a mean-field approximation. This parabolic model may be generalized by the introduction of a degenerate diffusion parameter, which depends on the density itself via a power law. Then we derive a model for chemotaxis based on Cattaneo's law of heat propagation with finite speed, which is a hyperbolic model. The last model proposed here is a hydrodynamic model, which takes into account the inertia of the system by a friction force. In the limit of strong friction, the model reduces to the parabolic model, whereas in the limit of weak friction, we recover a hyperbolic model. Finally, we analyze the instability condition, which is the condition that leads to aggregation, and we describe the different kinds of aggregates we may obtain: the parabolic models lead to clusters or peaks whereas the hyperbolic models lead to the formation of network patterns or filaments. Moreover, we discuss the analogy between bacterial colonies and self gravitating systems by comparing the chemotactic collapse and the gravitational collapse (Jeans instability).

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Yielding, Amy Ann. "Spectrally arbitrary zero-nonzero patterns." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Dissertations/Spring2009/a_yielding_043009.pdf.

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Aven, Matthew. "Daily Traffic Flow Pattern Recognition by Spectral Clustering." Scholarship @ Claremont, 2017. http://scholarship.claremont.edu/cmc_theses/1597.

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This paper explores the potential applications of existing spectral clustering algorithms to real life problems through experiments on existing road traffic data. The analysis begins with an overview of previous unsupervised machine learning techniques and constructs an effective spectral clustering algorithm that demonstrates the analytical power of the method. The paper focuses on the spectral embedding method’s ability to project non-linearly separable, high dimensional data into a more manageable space that allows for accurate clustering. The key step in this method involves solving a normalized eigenvector problem in order to construct an optimal representation of the original data. While this step greatly enhances our ability to analyze the relationships between data points and identify the natural clusters within the original dataset, it is difficult to comprehend the eigenvalue representation of the data in terms of the original input variables. The later sections of this paper will explore how the careful framing of questions with respect to available data can help researchers extract tangible decision driving results from real world data through spectral clustering analysis.

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Demir, Nilay Sezin. "Spectrally Arbitrary and Inertially Arbitrary Sign Pattern Matrices." Digital Archive @ GSU, 2007. http://digitalarchive.gsu.edu/math_theses/26.

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A sign pattern(matrix) is a matrix whose entries are from the set {+,-,0}. An n x n sign pattern matrix is a spectrally arbitrary pattern(SAP) if for every monic real polynomial p(x) of degree n, there exists a real matrix B whose entries agree in sign with A such that the characteristic polynomial of B is p(x). An n x n pattern A is an inertialy arbitrary pattern(IAP) if (r,s,t) belongs to the inertia set of A for every nonnegative triple (r,s,t) with r+s+t=n. Some elementary results on these two classes of patterns are first exhibited. Tree sign patterns are then investigated, with a special emphasis on 4 x 4 tridiagonal sign patterns. Connections between the SAP(IAP) classes and the classes of potentially nilpotent and potentially stable patterns are explored. Some interesting open questions are also provided.

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El-Helw, Amr M. "Pattern classification using spread spectrum." Thesis, Staffordshire University, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479162.

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Kaphle, Krishna. "Spectrally Arbitrary Tree Sign Pattern Matrices." Digital Archive @ GSU, 2006. http://digitalarchive.gsu.edu/math_theses/17.

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A sign pattern (matrix) is a matrix whose entries are from the set {+,–, 0}. A sign pattern matrix A is a spectrally arbitrary pattern if for every monic real polynomial p(x) of degree n there exists a real matrix B whose entries agree in sign with A such that the characteristic polynomial of B is p(x). All 3 × 3 SAP's, as well as tree sign patterns with star graphs that are SAP's, have already been characterized. We investigate tridiagonal sign patterns of order 4. All irreducible tridiagonal SAP's are identified. Necessary and sufficient conditions for an irreducible tridiagonal pattern to be an SAP are found. Some new techniques, such as innovative applications of Gröbner bases for demonstrating that a sign pattern is not potentially nilpotent, are introduced. Some properties of sign patterns that allow every possible inertia are established. Keywords: Sign pattern matrix, Spectrally arbitrary pattern (SAP), Inertially arbitrary pattern (IAP), Tree sign pattern (tsp), Potentially nilpotent pattern, Gröbner basis, Potentially stable pattern, Sign nonsingular, Sign singular

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Wood, Christiaan. "An investigation into multi-spectral tracking." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1319.

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Acar, Erman. "Classification Of Motor Imagery Tasks In Eeg Signal And Its Application To A Brain-computer Interface For Controlling Assistive Environmental Devices." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12612994/index.pdf.

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This study focuses on realization of a Brain Computer Interface (BCI)for the paralyzed to control assistive environmental devices. For this purpose, different motor imagery tasks are classified using different signal processing methods. Specifically, band-pass filtering, Laplacian filtering, and common average reference (CAR) filtering areused to enhance the EEG signal. For feature extraction
Common Spatial Pattern (CSP), Power Spectral Density (PSD), and Principal Component Analysis (PCA) are tested. Linear Feature Normalization (LFN), Gaussian Feature Normalization (GFN), and Unit-norm Feature Vector Normalization (UFVN) are studied in Support Vector Machine (SVM) and Artificial Neural Network (ANN) classification. In order to evaluate and compare the performance of the methodologies, classification accuracy, Cohen&rsquo
s kappa coefficient, and Nykopp&rsquo
s information transfer are utilized. The first experiments on classifying motor imagery tasks are realized on the 3-class dataset (V) provided for BCI Competition III. Also, a 4-class problem is studied using the dataset (IIa) provided for BCI Competition IV. Then, 5 different tasks are studied in the METU Brain Research Laboratory to find the optimum number and type of tasks to control a motor imagery based BCI. Thereafter, an interface is designed for the paralyzed to control assistive environmental devices. Finally, a test application is implemented and online performance of the design is evaluated.

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Eastwood, James Andrew. "The effect of canopy chlorosis distributions on vegetation spectral signatures." Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240296.

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Shao, Yuan. "Higher order spectra invariants for shape pattern recognition." Ohio : Ohio University, 2000. http://www.ohiolink.edu/etd/view.cgi?ohiou1179949998.

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Tate, Anne Rosemary. "Pattern recognition analysis of in vivo magnetic resonance spectra." Thesis, University of Sussex, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307732.

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Wu, Di. "A Global Spatial Model for Loop Pattern Fingerprints and Its Spectral Analysis." Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1538788/.

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The use of fingerprints for personal identification has been around for thousands of years (first established in ancient China and India). Fingerprint identification is based on two basic premises that the fingerprint is unique to an individual and the basic characteristics such as ridge pattern do not change over time. Despite extensive research, there are still mathematical challenges in characterization of fingerprints, matching and compression. We develop a new mathematical model in the spatial domain for globally modeling loop pattern fingerprints. Although it is based on the well-known AM-FM (amplitude modulation and frequency modulation) image representation, the model is constructed by a global mathematical function for the continuous phase and it provides a flexible parametric model for loop pattern fingerprints. In sharp contrast to the existing methods, we estimate spatial parameters from the spectral domain by combining the exact values of frequencies with their orientations perpendicular to the fingerprint ridge flow. In addition, to compress fingerprint images and test background Gaussian white noise, we propose a new method based on periodogram spacings. We obtain the joint pdf of these m-dependent random variables at Fourier frequencies and derive the asymptotic distribution of the test statistic.

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MEIJA, JURIS. "INTERPRETATION OF MASS SPECTRA FOR ELEMENTAL SPECIATION STUDIES." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1116247516.

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Fischer, Manfred M., and Petra Staufer-Steinnocher. "Spectral Pattern Recognition by a Two-Layer Perceptron: Effects of Training Set Size." WU Vienna University of Economics and Business, 1996. http://epub.wu.ac.at/4160/1/WSG_DP_5596.pdf.

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Pattern recognition in urban areas is one of the most challenging issues in classifying satellite remote sensing data. Parametric pixel-by-pixel classification algorithms tend to perform poorly in this context. This is because urban areas comprise a complex spatial assemblage of disparate land cover types - including built structures, numerous vegetation types, bare soil and water bodies. Thus, there is a need for more powerful spectral pattern recognition techniques, utilizing pixel-by-pixel spectral information as the basis for automated urban land cover detection. This paper adopts the multi-layer perceptron classifier suggested and implemented in [5]. The objective of this study is to analyse the performance and stability of this classifier - trained and tested for supervised classification (8 a priori given land use classes) of a Landsat-5 TM image (270 x 360 pixels) from the city of Vienna and its northern surroundings - along with varying the training data set in the single-training-site case. The performance is measured in terms of total classification, map user's and map producer's accuracies. In addition, the stability with initial parameter conditions, classification error matrices, and error curves are analysed in some detail. (authors' abstract)
Series: Discussion Papers of the Institute for Economic Geography and GIScience

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Hosseini-Yazdi, Ahmad Reza. "Spectral pattern analysis and modelling applied to the cardio-respiratory development of neonates." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/47112.

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Lavidas, George. "Wave energy resource modelling and energy pattern identification using a spectral wave model." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/25506.

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The benefits of the Oceans and Seas have been exploited by societies for many centuries; the marine offshore and naval sectors have been the predominant users of the waters. It has been overlooked until recently, that significant amounts of energy can be harnessed by waves, providing an additional abundant resource for renewable energy generation. The increasing energy needs of current societies have led to the consideration of waves as an exploitable renewable resource. During the past decades, advancements have been made towards commercialising wave energy converters (WECs), though significant knowledge gap exists on the accurate estimation of the potential energy that can be harnessed. In order, to enhance our understanding of opportunities within wave energy highly resolved long-term resource assessment of potential sites are necessary, which will allow for not only a detailed energy estimation methodology but also information on extreme waves that are expected to affect the survivability and reliability of future wave energy converters. This research work aims to contribute the necessary knowledge to the estimation of wave energy resources from both highly energetic and milder sea environment, exhibiting the opportunities that lay within these environments. A numerical model SWAN (Simulating WAves Nearshore), based on spectral wave formulation has been utilised for wave hindcasting which was driven by high resolution temporal and spatially varying wind data. The capabilities of the model, allow a detailed representation of several coastal areas, which are not usually accurately resolved by larger ocean models. The outcome of this research provides long-term data and characterisation of the wave environment and its extremes for the Scottish region. Moreover, investigation on the applicability of wave energy in the Mediterranean Sea, an area which was often overlooked, showed that wave energy is more versatile than expected. The outcomes provide robust estimations of extreme wave values for coastal waters, alongside valuable information about the usage of numerical modelling and WECs to establish energy pattern production. Several key tuning factors and inputs such as boundary wind conditions and computational domain parameters are tested. This was done in a systematic way in order to establish a customized solution and detect parameters that may hinder the process and lead to erroneous results. The uncertainty of power production by WECs is reduced by the introduction of utilization rates based on the long-term data, which include annual and seasonal variability. This will assist to minimize assumptions for energy estimates and financial returns in business plans. Finally, the importance of continuous improvements in resource assessment is stressed in order to enhance our understanding of the wave environment.

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So, Wai-on Ann, and 蘇惠安. "Patterns of cognitive functioning in young children with autism spectrum disorders." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/209529.

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Previous research demonstrates an uneven pattern of cognitive abilities in children diagnosed with autism spectrum disorders (ASD). This study examined whether this uneven pattern exists in preschool children. Participants include 24 children with high-functioning ASD and 28 typically developing (TD) children aged 4 to 6 with comparable average age and development level. No significant group difference in cognitive abilities was found between the ASD and TD group on the MANOVA. Patterns of cognitive functioning found include better performance on memory, weaker performance on language comprehension and expression, fine motor and speed of processing. Nonverbal and visual motor abilities were comparable between groups. Language expression was less impaired than language comprehension, and fine motor abilities were correlated with more cognitive abilities.
published_or_final_version
Educational Psychology
Master
Master of Social Sciences

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Fischer, Manfred M., and Sucharita Gopal. "Spectral Pattern Recognition and Fuzzy ARTMAP Classification: Design Features, System Dynamics and Real World Simulations." WU Vienna University of Economics and Business, 1996. http://epub.wu.ac.at/4163/1/WSG_DP_5296.pdf.

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Classification of terrain cover from satellite radar imagery represents an area of considerable current interest and research. Most satellite sensors used for land applications are of the imaging type. They record data in a variety of spectral channels and at a variety of ground resolutions. Spectral pattern recognition refers to classification procedures utilizing pixel-by-pixel spectral information as the basis for automated land cover classification. A number of methods have been developed in the past to classify pixels [resolution cells] from multispectral imagery to a priori given land cover categories. Their ability to provide land cover information with high classification accuracies is significant for work where accurate and reliable thematic information is needed. The current trend towards the use of more spectral bands on satellite instruments, such as visible and infrared imaging spectrometers, and finer pixel and grey level resolutions will offer more precise possibilities for accurate identification. But as the complexity of the data grows, so too does the need for more powerful tools to analyse them. It is the major objective of this study to analyse the capabilities and applicability of the neural pattern recognition system, called fuzzy ARTMAP, to generate high quality classifications of urban land cover using remotely sensed images. Fuzzy ARTMAP synthesizes fuzzy logic and Adaptive Resonance Theory (ART) by exploiting the formal similarity between the computations of fuzzy subsethood and the dynamics of category choice, search and learning. The paper describes design features, system dynamics and simulation algorithms of this learning system, which is trained and tested for classification (8 a priori given classes) of a multispectral image of a Landsat-5 Thematic Mapper scene (270 x 360 pixels) from the City of Vienna on a pixel-by-pixel basis. Fuzzy ARTMAP performance is compared with that of an error-based learning system based upon the multi-layer perceptron, and the Gaussian maximum likelihood classifier as conventional statistical benchmark on the same database. Both neural classifiers outperform the conventional classifier in terms of classification accuracy. Fuzzy ARTMAP leads to out-of-sample classification accuracies, very close to maximum performance, while the multi-layer perceptron - like the conventional classifier - shows difficulties to distinguish between some land use categories. (authors' abstract)
Series: Discussion Papers of the Institute for Economic Geography and GIScience

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Clarke, Paula Joanne. "Patterns of memory asset and deficit in children with autism spectrum disorders." Thesis, University of York, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423751.

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Lee, Yuen Yue Barbara. "A robust pattern recognition methodology for differential discrimination of magnetic resonance spectra." Thesis, Liverpool John Moores University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394229.

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Staufer-Steinnocher, Petra, and Manfred M. Fischer. "A Neural Network Classifier for Spectral Pattern Recognition. On-Line versus Off-Line Backpropagation Training." WU Vienna University of Economics and Business, 1997. http://epub.wu.ac.at/4152/1/WSG_DP_6097.pdf.

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In this contributon we evaluate on-line and off-line techniques to train a single hidden layer neural network classifier with logistic hidden and softmax output transfer functions on a multispectral pixel-by-pixel classification problem. In contrast to current practice a multiple class cross-entropy error function has been chosen as the function to be minimized. The non-linear diffierential equations cannot be solved in closed form. To solve for a set of locally minimizing parameters we use the gradient descent technique for parameter updating based upon the backpropagation technique for evaluating the partial derivatives of the error function with respect to the parameter weights. Empirical evidence shows that on-line and epoch-based gradient descent backpropagation fail to converge within 100,000 iterations, due to the fixed step size. Batch gradient descent backpropagation training is superior in terms of learning speed and convergence behaviour. Stochastic epoch-based training tends to be slightly more effective than on-line and batch training in terms of generalization performance, especially when the number of training examples is larger. Moreover, it is less prone to fall into local minima than on-line and batch modes of operation. (authors' abstract)
Series: Discussion Papers of the Institute for Economic Geography and GIScience

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Barbier, Nicolas Serge. "Interactions spatiales et auto-organisation des végétations semi-arides." Doctoral thesis, Universite Libre de Bruxelles, 2006. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210779.

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Les recherches récapitulées dans cette thèse de doctorat ont porté sur les causes de l’organisation spatiale des végétations périodiques. Ces structures paysagères aux motifs réguliers, tachetés, tigrés ou labyrinthiques, d’échelle décamétrique à hectométrique, couvrant des étendues considérables sur au moins trois continents, constituent un cas d’école dans l’étude des processus endogènes présidant à l’hétérogénéité du couvert végétal. Ces structures prennent place sur un substrat homogène, mis à part la rétroaction du couvert lui-même, et sont marquées par des écotones abrupts et la persistance d’une proportion considérable de sol nu. Plusieurs modèles ont mis en avant l’existence possible d’un phénomène d’auto-organisation du couvert, qui verrait une structure d’ensemble émerger des interactions locales entre individus. Ces modèles se basent sur le jeu simultané de la consommation de la ressource (compétition) et de l’amélioration de l’un ou l’autre des éléments du bilan de la même ressource par le couvert (facilitation). La condition à l’existence d’une structure d’ensemble spatialement périodique et stable réside dans une différence entre la portée de la compétition (plus grande) et celle de la facilitation. L’apparition de ces structures est modulée par le taux de croissance biologique, qui est le reflet des contraintes extérieures telles que l’aridité, le pâturage ou la coupe de bois. Le modus operandi des interactions spatiales supposées entre individus reste largement à préciser.

Nos recherches ont été menées au sud-ouest de la République du Niger, à l’intérieur et dans les environs du parc Régional du W. Trois axes ont été explorés :(i) Une étude de la dépendance spatiale entre la structure de la végétation (biovolumes cartographiés) et les paramètres du milieu abiotique (relief, sol), sur base d’analyses spectrales et cross-spectrales par transformée de Fourier (1D et 2D). (ii) Une étude diachronique (1956, 1975 et 1996) à large échelle (3000 km²) de l’influence de l’aridité et des pressions d’origine anthropique sur l’auto-organisation des végétations périodiques, basée sur la caractérisation de la structure spatiale des paysages sur photos aériennes via la transformée de Fourier en 2D. (iii) Trois études portant sur les interactions spatiales entre individus :En premier lieu, via l’excavation des systèmes racinaires (air pulsé) ;Ensuite, par un suivi spatio-temporel du bilan hydrique du sol (blocs de gypse) ;Enfin, via le marquage de la ressource par du deutérium.

Nous avons ainsi pu établir que les végétations périodiques constituent bien un mode d’auto-organisation pouvant survenir sur substrat homogène et modulé par les contraintes climatiques et anthropiques. Un ajustement rapide entre l’organisation des végétations périodiques et le climat a pu être montrée en zone protégée. La superficie et l’organisation des végétations périodiques y ont tour à tour progressé et régressé en fonction d’épisodes secs ou humides. Par contre, en dehors de l’aire protégée, la possibilité d’une restauration du couvert semble fortement liée au taux d’exploitation des ressources végétales. Ces résultats ont d’importantes implications quant à la compréhension des interactions entre climat et écosystèmes et à l’évaluation de leurs capacités de charge. La caractérisation de la structure spatiale des végétations arides, notamment par la transformée de Fourier d’images HR, devrait être généralisée comme outil de monitoring de l’état de ces écosystèmes. Nos études portant sur les modes d’interactions spatiales ont permis de confirmer l’existence d’une facilitation à courte portée du couvert végétal sur la ressource. Cependant, cette facilitation ne semble pas s’exercer sur le terme du bilan hydrique traditionnellement avancé, à savoir l’infiltration, mais plutôt sur le taux d’évaporation (deux fois moindre à l’ombre des canopées). Ce mécanisme exclut l’existence de transferts diffusifs souterrains entre sols nu et fourrés. Des transferts inverses semblent d’ailleurs montrés par le marquage isotopique. L’étude du bilan hydrique et la cartographie du micro-relief, ainsi que la profondeur fortement réduite de la zone d’exploitation racinaire, jettent de sérieux doutes quant au rôle communément admis des transferts d’eau par ruissellement/diffusion de surface en tant que processus clé dans la compétition à distance entre les plantes. L’alternative réside dans l’existence d’une compétition racinaire de portée supérieure aux canopées. Cette hypothèse trouve une confirmation tant par les rhizosphères excavées, superficielles et étendues, que dans le marquage isotopique, montrant des contaminations d’arbustes situés à plus de 15 m de la zone d’apport. De même, l’étude du bilan hydrique met en évidence les influences simultanées et contradictoires (facilitation/compétition) des ligneux sur l’évapotranspiration.

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This PhD thesis gathers results of a research dealing with the causes of the spatial organisation of periodic vegetations. These landscape structures, featuring regular spotted, labyrinthine or banded patterns of decametric to hectometric scale, and extending over considerable areas on at least three continents, constitute a perfect study case to approach endogenous processes leading to vegetation heterogeneities. These patterns occur over homogeneous substratum, except for vegetation’s own feedbacks, and are marked by sharp ecotones and the persistence of a considerable amount of bare soil. A number of models suggested a possible case of self-organized patterning, in which the general structure would emerge from local interactions between individuals. Those models rest on the interplay of competitive and facilitative effects, relating to soil water consumption and to soil water budget enhancement by vegetation. A general necessary condition for pattern formation to occur is that negative interactions (competition) have a larger range than positive interactions (facilitation). Moreover, all models agree with the idea that patterning occurs when vegetation growth decreases, for instance as a result of reduced water availability, domestic grazing or wood cutting, therefore viewing patterns as a self-organised response to environmental constraints. However the modus operandi of the spatial interactions between individual plants remains largely to be specified.

We carried out a field research in South-West Niger, within and around the W Regional Park. Three research lines were explored: (i) The study of the spatial dependency between the vegetation pattern (mapped biovolumes) and the factors of the abiotic environment (soil, relief), on the basis of spectral and cross-spectral analyses with Fourier transform (1D and 2D). (ii) A broad scale diachronic study (1956, 1975, 1996) of the influence of aridity and human induced pressures on the vegetation self-patterning, based on the characterisation of patterns on high resolution remote sensing data via 2D Fourier transform. (iii) Three different approaches of the spatial interactions between individuals: via root systems excavation with pulsed air; via the monitoring in space and time of the soil water budget (gypsum blocks method); and via water resource labelling with deuterated water.

We could establish that periodic vegetations are indeed the result of a self-organisation process, occurring in homogeneous substratum conditions and modulated by climate and human constraints. A rapid adjustment between vegetation patterning and climate could be observed in protected zones. The area and patterning of the periodic vegetations successively progressed and regressed, following drier or wetter climate conditions. On the other hand, outside protected areas, the restoration ability of vegetation appeared to depend on the degree of vegetation resource exploitation. These results have important implications regarding the study of vegetation-climate interactions and the evaluation of ecosystems’ carrying capacities. Spatial pattern characterisation in arid vegetations using Fourier transform of HR remote sensing data should be generalised for the monitoring of those ecosystems. Our studies dealing with spatial interaction mechanisms confirmed the existence of a short range facilitation of the cover on water resource. However, this facilitation does not seem to act through the commonly accepted infiltration component, but rather on the evaporative rate (twice less within thickets). This mechanism excludes underground diffusive transfers between bare ground and vegetation. Inverse transfers were even shown by deuterium labelling. Water budget study and micro-elevation mapping, along with consistent soil shallowness, together cast serious doubts on the traditional mechanism of run-off/diffusion of surface water as a key process of the long range competition between plants. An alternative explanation lies in long range root competition. This hypothesis find support as well in the excavated root systems, shallow and wide, as in isotopic labelling, showing contaminations of shrubs located up to 15 m of the irrigated area. Water budget study also evidenced simultaneous contradictory effects (facilitation/competition) of shrubs on evapotranspiration.

Doctorat en sciences agronomiques et ingénierie biologique
info:eu-repo/semantics/nonPublished

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Ladroue, Christophe Ludovic Claude. "Pattern recognition techniques for the study of magnetic resonance spectra of brain tumours." Thesis, St George's, University of London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415201.

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Kirchner, William Thomas. "Ultrasonic acoustic health monitoring of ball bearings using neural network pattern classification of power spectral density." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/36130.

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This thesis presents a generic passive non-contact based acoustic health monitoring approach using ultrasonic acoustic emissions (UAE) to facilitate classification of bearing health via neural networks. This generic approach is applied to classifying the operating condition of conventional ball bearings. The acoustic emission signals used in this study are in the ultrasonic range (20-120 kHz), which is significantly higher than the majority of the research in this area thus far. A direct benefit of working in this frequency range is the inherent directionality of the microphones capable of measurement in this range, which becomes particularly useful when operating in environments with low signal-to-noise ratios. Using the UAE power spectrum signature, it is possible to pose the health monitoring problem as a multi-class classification problem, and make use of a multi-layer artificial neural network (ANN) to classify the UAE signature. One major problem limiting the usefulness of ANN's for failure classification is the need for large quantities of training data. Artificial training data, based on statistical properties of a significantly smaller experimental data set is created using the combination of a normal distribution and a coordinate transformation. The artificial training data provides a sufficient sized data set to train the neural network, as well as overcome the curse of dimensionality. The combination of the artificial training methods and ultrasonic frequency range being used results in an approach generic enough to suggest that this particular method is applicable to a variety of systems and components where persistent UAE exist.
Master of Science

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El-Deredy, Wael. "Artificial neural networks in pattern recognition : classification and analysis of proton NMR spectra of human brain tumours." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300151.

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Baccherini, Simona. "Pattern recognition methods for EMG prosthetic control." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/12033/.

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In this work we focus on pattern recognition methods related to EMG upper-limb prosthetic control. After giving a detailed review of the most widely used classification methods, we propose a new classification approach. It comes as a result of comparison in the Fourier analysis between able-bodied and trans-radial amputee subjects. We thus suggest a different classification method which considers each surface electrodes contribute separately, together with five time domain features, obtaining an average classification accuracy equals to 75% on a sample of trans-radial amputees. We propose an automatic feature selection procedure as a minimization problem in order to improve the method and its robustness.

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Danylov, A. B. "Reflection Spectra Simulation for Flat and Patterned Surfaces of CdTe Solar Elements." Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/42713.

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The paper comprises the simulation of light total reflection from solar element multilayered structure. For CdTe solar cell the analysis of optical losses in two different types of solar cells with indium tin oxide and zinc oxide as transparent upper contact (with glass superstrate and without it) is performed. The effect of glass superstrate in the elements is discussed and spectral dependences for reflectance in plain layer structure are built. For textured surfaces of solar element layer the comparison of influence of different types of texture on total light reflection is carried out.

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Stoyanova, Radka. "Development and application of methods for enhancing features in NMR spectra for pattern recognition." Thesis, Imperial College London, 2005. http://hdl.handle.net/10044/1/8269.

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Huang, Yingying. "DATA MINING OF PEPTIDE MS/MS SPECTRA TO ELUCIDATE GAS-PHASE PEPTIDE DISSOCIATION MECHANISMS AND IMPROVE PROTEIN IDENTIFICATION." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1133%5F1%5Fm.pdf&type=application/pdf.

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Oduwole, Elizabeth O. "Generation of a database of mass spectra patterns of selected Mycobacterium species using MALDI-ToF mass spectrometry." Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/2838.

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Thesis (MScMedSc (Pathology. Medical Microbiology))--Stellenbosch University, 2008.
The genus Mycobacterium is a group of acid–fast, aerobic, slow- growing organisms which include more than 90 different species. A member of this genus, Mycobacterium tuberculosis, belonging to the Mycobacterium tuberculosis complex (MTB), is the causative agent of tuberculosis (TB). This disease is currently considered a global emergency, with more than 2 million deaths and over 8 million new cases annually. TB is the world’s second most common cause of death after HIV/AIDS. About one-third of the world’s population is estimated to be infected with TB. This catastrophic situation is further compounded by the emergence of Multi Drug Resistant tuberculosis (MDR-TB) and in more recent times, Extensive Drug Resistant tuberculosis (XDR-TB). Early diagnosis is critical to the successful management of patients as it allows informed use of chemotherapy. Also, early diagnosis is also of great importance if the menace of MDR-TB and XDR-TB is to be curbed and controlled. As MTB is highly infectious for humans, it is of paramount importance that TB be diagnosed as early as possible to stop the spread of the disease. Traditional conventional laboratory procedures involving microscopy, culture and sensitivity tests may require turnaround times of 3-4 weeks or longer. Tremendous technological advancement over the years such as the advent of automated liquid culture systems like the BACTEC® 960 and the MGITTM Tube system, and the development of a myriad of molecular techniques most of which involves nucleic acid amplification (NAA) for the rapid identification of mycobacterial isolates from cultures or even directly from clinical specimens have contributed immensely to the early diagnosis of tuberculosis. Most of these NAA tests are nevertheless fraught with various limitations, thus the search for a rapid, sensitive and specific way of diagnosing tuberculosis is still an active area of research. The search has expanded to areas that would otherwise not have been considered ‘conventional’ in diagnostic mycobacteriology. One of such areas is mass spectrometry. This study joins the relatively few studies of its kind encountered in available literature to establish the ground work for the application of mass spectrometry, specifically Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-ToF MS) in the field of diagnostic mycobacteriology. This is an area which is in need of the speed, sensitivity and specificity that MALDI-ToF technique promises to offer. Since this technology is still in its infancy, the use of utmost care in the preparation of reagents, and the handling and storage of the organisms used to generate reference mass spectra for the database cannot be overemphasized. Similarly, the optimization of certain crucial experimental factors such as inactivating method and choice of matrix is of paramount importance. The main aim of this thesis was to generate a database of reference mass spectra fingerprints of selected (repository) Mycobacterium species. This necessitated the standardization of an experimental protocol which ensured that experimental factors and the various instrument parameters were optimized for maximum spectra generation and reproducibility. A standard operating procedure (SOP) for generating the database of reference mass spectra finger print of selected Mycobacterium species was developed and used to investigate the ability of the database to differentiate between species belonging to the same clinical disease complex as well as the nontuberculosis complex. The findings of this study imply that if the defined protocol is followed, the database generated has the potential to routinely identify and differentiate (under experimental conditions) more species of Mycobacterium than is currently practical using PCR and its related techniques. It is therefore a realistic expectation that when the database is clinically validated and tested in the next phase of the study, it will contribute immensely to the diagnosis of tuberculosis and other mycobacterioses. It will also aid in the identification of emerging pathogens particularly amongst the non-tuberculous mycobacteria.

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Ward, Jessica. "Evaluating patterns of spared and enhanced processing within the music domain in autism spectrum disorders." Thesis, Goldsmiths College (University of London), 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.514390.

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Crabtree, Lisa. "Social participation patterns and preferences : a mixed methods study of children on the autism spectrum." Diss., NSUWorks, 2009. https://nsuworks.nova.edu/hpd_ot_student_dissertations/14.

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May 2009. "Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Occupational Therapy Department, College of Allied Health and Nursing, Nova Southeastern University."

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Condette, Nicolas. "Pattern formation in magnetic thin films." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2011. http://dx.doi.org/10.18452/16336.

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Die vorliegende Arbeit beschäftigt sich mit einer Klasse von Variationsproblemen, die im Kontext des Ferromagnetismus entstehen. Es soll hierbei ein numerischer und analytischer Hintergrund zur Behandlung von harten magnetischen dünnen Filmen mit senkrechter Anisotropie gegeben werden. Bei magnetischen dünnen Filmen handelt es sich um Schichten von magnetischen Materialien mit Dicken von wenigen Mikrometern bis hin zu einigen Nanometern. Ausgangspunkt der Betrachtungen ist ein Modell von Landau und Lifshitz, das die Grundzustände der Magnetisierung in einem dreidimensionalen Körpers mit den Minimierer eines nichtkonvexen und nichtlokalen Energiefunktionals, der sogenannten mikromagnetischen Energie, verbindet. Unter der Annahme sehr kleiner Filmdicken wird aus dem betrachteten Modell ein zwei-dimensionales Modell hergeleitet. Anschließend wird mit Hilfe der Gamma-Konvergenz die Konvergenz zu einem Sharp-Interface-Modell gezeigt. Das resultierende Energiefunktional besteht aus konkurrierenden Interface- und Dipolenergieanteilen. Der zweite Teil der Arbeit beschäftigt sich mit der Analyse einer numerischen Methode, die die Lösungen des vorher hergeleiteten Modells approximiert. Hierbei stützen sich die Betrachtungen auf ein relaxiertes Modell, in dem der Interfaceenergiebeitrag durch seine Modica-Mortola Approximation ersetzt und dann der entsprechende L^2 Gradientenfluß betrachtet wird. Die daraus resultierende nichtlineare und nichtlokale parabolische Gleichung wird anschließend durch ein Crank-Nicolson-Verfahren in der Zeitvariablen und einem Fourieransatz für die Raumvariablen diskretisiert. Wir beweisen die Existenz und Eindeutigkeit von Lösungen des numerischen Verfahrens, sowie deren Konvergenz zu Lösungen des anfänglich betrachteten stetigen Modells. Ferner werden auch a priori Fehlerabschätzungen für die numerische Methode hergeleitet. Abschließend werden die analytischen Resultate anhand numerischer Experimente illustriert.
This thesis is concerned with the study of a class of variational problems arising in the context of ferromagnetism. More precisely, it aims at providing a numerical and analytical background to the study of hard magnetic thin films with perpendicular anisotropy. Magnetic thin films are sheets of magnetic materials with thicknesses of a few micrometers down to a few nanometers used mainly in electronic industry, for example as magnetic data storage media for computers. Our initial considerations are based on a model of Landau and Lifshitz that associates the ground states of the magnetization within a three-dimensional body to the minimizers of a nonconvex and nonlocal energy functional, the so-called micromagnetic energy. Under film thickness considerations (thin film regime), we first reduce the aforementioned model to two dimensions and then carry out a Gamma-limit for a sharp-interface model. The resulting energy functional features a competition between an interfacial and a dipolar energy contribution. The second part of the thesis is concerned with the analysis of a numerical method to approximate solutions of the previously derived sharp-interface model. We base our considerations on a relaxed model in which we replace the interfacial energy contribution by its Modica-Mortola approximation, and then study the associated L^2 gradient flow. The resulting evolution equation, a nonlinear and nonlocal parabolic equation, is discretized by a Crank-Nicolson approximation for the time variable and a Fourier collocation method for the space variable. We prove the existence and uniqueness of the solutions of the numerical scheme, the convergence of these solutions towards solutions of the initial continuous model and also derive a-priori error estimates for the numerical method. Finally, we illustrate the analytical results by a series of numerical experiments.

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Opstad, Kirstie Suzanne. "Quantification and pattern recognition of Â¹H magnetic resonance brain tumour spectra for automated classification." Thesis, St George's, University of London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413702.

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Dissertations / Theses on the topic 'Spectral Patterns'

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