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Vieira, Ewerton Rocha 1987. "Transition matrix theory = Teoria da matriz de transição." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/307536.
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Orientador: Ketty Abaroa de RezendeTese (doutorado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Científica
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Resumo: Nessa tese, apresentamos uma unificação da teoria das matrizes de transição algébrica, singular, topológica e direcional ao introduzir a matriz de transição (generalizada), a qual engloba todas as quatros citadas anteriormente. Alguns resultados de existência são apresentados bem como a verificação de que cada matriz de transição supracitada são casos particulares da matriz de transição (generalizada). Além disso, nós abordamos como as aplicações das quatros matrizes de transiçao, na teoria do índice de Conley, se traduzem para a matriz de transição (generalizada). Quando a matriz de transição (generalizada) satisfizer o requerimento adicional de cobrir o isomorfismo do índice de Conley F definido pelo fluxo, pode-se provar propriedades de existência e de conexão de órbitas. Essa matriz de transição com a propriedade de cobrir o isomorfismo F é definida como matriz de transição topológica generalizada e a utilizamos para obter conexões de órbitas num fluxo Morse-Smale sem órbitas periódicas bem como para obter conexões de órbitas numa continuação associada à sequência espectral dinâmica
Abstract: In this thesis, we present a unification of the theory of algebraic, singular, topological and directional transition matrices by introducing the (generalized) transition matrix which encompasses each of the previous four. Some transition matrix existence results are presented as well as the verification that each of the previous transition matrices are cases of the (generalized) transition matrix. Furthermore, we address how applications of the previous transition matrices to the Conley Index theory carry over to the (generalized) transition matrix. When this more general transition matrix satisfies the additional requirement that it covers flow-defined Conley-index isomorphisms, one proves algebraic and connection-existence properties. These general transition matrices with this covering property are referred to as generalized topological transition matrices and are used to consider connecting orbits of Morse-Smale flows without periodic orbits, as well as those in a continuation associated to a dynamical spectral sequence
Doutorado
Matematica
Doutor em Matemática
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Messent, Anthea Jane. "Novel roles for matix metalloproteinases in cell-matrix interactions." Thesis, Open University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242514.
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Friberg, Adam. "Matrix Integrals : Calculating Matrix Integrals Using Feynman Diagrams." Thesis, Uppsala universitet, Teoretisk fysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-227928.
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In this project, we examine how integration over matrices is performed. We investigate and develop a method for calculating matrix integrals over the set of real square matrices. Matrix integrals are used for calculations in several different areas of physics and mathematics; for example quantum field theory, string theory, quantum chromodynamics, and random matrix theory. Our method consists of ways to apply perturbative Taylor expansions to the matrix integrals, reducing each term of the resulting Taylor series to a combinatorial problem using Wick's theorem, and representing the terms of the Wick sum graphically with the help of Feynman diagrams and fat graphs. We use the method in a few examples that aim to clearly demonstrate how to calculate the matrix integrals.I detta projekt undersöker vi hur integration över matriser genomförs. Vi undersöker och utvecklar en metod för beräkning av matrisintegraler över mängden av alla reell-värda kvadratiska matriser. Matrisintegraler används för beräkningar i ett flertal olika områden inom fysik och matematik, till exempel kvantfältteori, strängteori, kvantkromodynamik och slumpmatristeori. Vår metod består av sätt att applicera perturbativa Taylorutvecklingar på matrisintegralerna, reducera varje term i den resulterande Taylorserien till ett kombinatoriellt problem med hjälp av Wicks sats, och att representera termerna i Wicksumman grafiskt med hjälp av Feynmandiagram. Vi använder metoden i några exempel som syftar till att klart demonstrera hur beräkningen av matrisintegraler går till.
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Kunchum, Rakshith. "On Improving Sparse Matrix-Matrix Multiplication on GPUs." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1492694387445938.
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Munro, Christopher James. "Algorithms for matrix polynomials and structured matrix problems." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/algorithms-for-matrix-polynomials-and-structured-matrix-problems(9154f9f0-8b86-46f8-8066-40c5139fcc51).html.
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Rife, Susan A. "Matrix algebra." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA316035.
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McGinn, Bonnie Gay. "Creative Matrix." VCU Scholars Compass, 2007. http://hdl.handle.net/10156/1366.
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Delatorre, Anthony R., and William K. Cooke. "Matrix algebra." Thesis, Monterey, California. Naval Postgraduate School, 1998. http://hdl.handle.net/10945/8658.
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Approved for public release; Distribution is unlimitedThis thesis is designed to act as an instructor's supplement for refresher matrix algebra courses at the Naval Postgraduate School (NPS). The need for a beginning matrix algebra supplement is driven by the unique circumstances of most NPS students. Most military students attend XPS several years after receiving their undergraduate degrees. This supplement, unlike most college textbooks, bridges the gap between the student's educational lay-off and the rigors of mathematically oriented degrees such as applied math, operations research and engineering. By reviewing the fundamental concepts of vectors and matrices, and performing basic operations with them, the student quickly develops the background needed in NPS's demanding curriculums. This supplement focuses on matrix and vector operations, linear transformations, systems of linear equations, and computational techniques for solving systems of linear equations. The goal is to enhance current matrix algebra textbooks and help the beginning student build a foundation for higher level engineering and mathematics based courses.
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Johansson, Isak, and Eriksson Jonas Bederoff. "Matrix similarity." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-194214.
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This thesis will deal with similar matrices, also referred to as matrix conju- gation. The rst problem we will attack is whether or not two given matrices are similar over some eld. To solve this problem we will introduce the Ratio- nal Canonical Form, RCF. From this normal form, also called the Frobenius normal form, we can determine whether or not the given matrices are sim- ilar over any eld. We can also, given some eld F, see whether they are similar over F or not. To be able to understand and prove the existence and uniqueness of the RCF we will introduce some additional module theory. The theory in this part will build up to nally prove the theorems regarding the RCF that can be used to solve our problem. The next problem we will investigate is regarding simultaneous conjugation, i.e. conjugation by the same matrix on a pair of matrices. When are two pairs of similar matrices simultaneously conjugated? Can we nd any necessary or even sucient conditions on the matrices? We will address this more complicated issue with the theory assembled in the rst part. 2
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Schuler, Sabine. "Modelling consolidation of matrix-coated fibre metal matrix composites." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284419.
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Stanton, Heather. "The role of matrix metalloproteinases in cell-matrix interactions." Thesis, Open University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284376.
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Xie, Tailiang. "Positive definite matrix-valued functions and matrix variogram modeling." Diss., The University of Arizona, 1994. http://hdl.handle.net/10150/186727.
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In many applications in the physical and earth sciences there are multiple variables of interest which are correlated. In these cases, the spatial random function becomes vector-valued, in which spatial correlation and component (inter-variable) correlation come out simultaneously. We denote by Z(x) = (z₁(x), …, z(m)(x)ᵀ the vector-valued random function. Similarly the covariance and variogram structure of Z(x) play a central role in any prediction scheme. But the covariance function and variogram of Z(x) are no longer scalar functions. They are matrix-valued functions when m > 1 and have a positive (negative) definiteness property in a generalized sense. Any prediction technique for vector-valued spatial functions relies heavily on this property. Therefore, characterizing and modeling the matrix-valued covariance or variogram structure of Z(x) is extremely important in spatial statistics and become more difficult than in scalar cases. For instance, (a) there is a lack of standard models for the covariance function and variogram (23); (b) there is no efficient graphic aid for fitting models since the covariance function and variogram are matrix-valued functions; (c) there are many parameters need to be estimated. Even the basic analytic properties of matrix-valued positive definite functions are not clear. In this dissertation, we generalize the concept of (scalar) positive definite functions to matrix-valued functions which are related to correlations and variograms of vector-valued random functions, to analytically study matrix-valued (conditionally) positive definite functions beyond basic definitions, to create matrix-valued variogram models, to provide techniques for systematic variogram modeling.
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Cheung, Caroline Tsui Yee. "Matrix metalloproteinases, inflammation, and matrix remodeling in coxsackievirus-induced myocarditis." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/30760.
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Myocarditis, or inflammation and injury of the heart muscle, induced by infection
with coxsackievirus B3 (CVB3) is believed to lead to longterm heart disorders. Under
pathological conditions, dysregulation of cardiac extracellular matrix (ECM) turnover results
in maladaptive remodeling, progression of disease, and depressed cardiac function. The
mechanisms by which this ECM alteration occurs are unclear, but inflammatory cells may be
involved as secretors of matrix metalloproteinases (MMPs), cytokines, and growth factors
that regulate ECM homeostasis.
I hypothesize that MMPs play important roles in viral myocarditis. These enzymes
degrade interstitial molecules, but they also regulate the immune system via modulation of
cytokines and growth factors.
To investigate the proposed hypothesis, I first examined the expression profile of
MMP-2, MMP-8, MMP-9, MMP-12, and the tissue inhibitor of metalloproteinases (TIMPs),
at key milestones in the evolution of myocarditis using a mouse model. To further explore
the mechanisms, I infected MMP-8, MMP-9, and MMP-12 knockout mice, and examined
how these deficiencies affected the immune response and matrix remodeling. Lastly, I
inhibited the 4-1BB pathway, a major T-lymphocyte co-stimulatory molecule, to examine the
synergy between the immune response and matrix remodeling.
Following CVB3 infection, increased MMP-2, MMP-9, and MMP-12 expression was
detected with corresponding decreases in TIMP expression, suggesting that an imbalance in
MMPs and their inhibitors may result in increased protease activity. To examine the roles of
the individual MMPs during CVB3 infection, I infected mice lacking MMP-8, MMP-9, or
MMP-12. Following viral infection, mice deficient in MMP-12 and MMP-9 experienced increased viral titers and tissue injury while MMP-8 knockout mice showed minimal
differences as compared to controls. The mechanisms by which the MMPs operate may be in
ECM remodeling, but also modulation of the immune response, notably T-cells. In order to
determine the effect of the immune response on matrix remodeling, I inhibited the 4-1BB
receptor, a major T-cell stimulatory pathway, and observed a decrease in inflammation and
matrix remodeling, while MMP-12 was decreased, in association with an improvement in
cardiac function.
My results suggest that MMPs may play crucial roles in CVB3 infection through their
immune modulation and matrix remodeling activities.Medicine, Faculty of
Pathology and Laboratory Medicine, Department of
Graduate
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Clark, Richard L. "Altering the fiber-matrix interphase in semicrystalline polymer matrix composites." Thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-12042009-020216/.
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Odelade, Mobolaji. "P300 Control Matrix| A Novel Approach to P300 Speller Matrix." Thesis, North Carolina Agricultural and Technical State University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10976563.
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Over the years, researchers have been able to prove Brain Computer Interface (BCI) -P300 Speller as an effective communication tool. The first P300 speller was developed by Farwell and Donchin (1988), using the oddball paradigm to evoke a P300 response from a speller matrix. This P300 speller matrix has been a strong basis for studies that aimed at using BCI-P300 protocol for spelling, cursor movement, internet navigation or even control and manipulation of devices. However, application of P300 based BCI to controlling and manipulation of devices often involves the user relating with multiple interfaces. These multiple interfaces could be a distraction or have negative effects on the user (Fazel-Rezai et al. 2012) and as a consequence hinders the evoking of P300 potential and causing inaccurate classification. For this research, a novel P300 control matrix is developed by replacing the alphabets in the traditional P300 speller matrix with arrow images. Then the novel P300 control matrix was investigated to compare the P300 latency and amplitude to that of the traditional P300 speller matrix. The elements in the novel P300 control matrix were in form of arrows facing upward, left, right and downward directions, while elements in the P300 speller matrix were alphabets U, L, R and D for the upward, left, right and downward directions respectively. The participants were presented with a set of randomly sequenced directions, and each participant decides which of the arrows or letters to focus on based on the direction presented to them. Electroencephalography (EEG) was used to record the brainwaves using the international 10-20 system of electrode placement. This research is potentially a more efficient approach for controlling devices using P300-based BCI systems by eradicating the need for multiple interfaces associated with BCI-robotic control systems that are based on P300 speller.
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Hu, Fenglin. "Web site matrix." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0021/MQ48271.pdf.
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Terkhova, Karina. "Capacitance matrix preconditioning." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244593.
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Solhjem, Sara Louise. "Sign Matrix Polytopes." Diss., North Dakota State University, 2018. https://hdl.handle.net/10365/28767.
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Motivated by the study of polytopes formed as the convex hull of permutation matrices and alternating sign matrices, several new families of polytopes are defined as convex hulls of sign matrices, which are certain {0,1,-1}--matrices in bijection with semistandard Young tableaux. This bijection is refined to include standard Young tableau of certain shapes. One such shape is counted by the Catalan numbers, and the convex hull of these standard Young tableaux form a Catalan polytope. This Catalan polytope is shown to be integrally equivalent to the order polytope of the triangular poset: therefore the Ehrhart polynomial and volume can be combinatorial interpreted. Various properties of all of these polytope families are investigated, including their inequality descriptions, vertices, facets, and face lattices, as well as connections to alternating sign matrix polytopes, and transportation polytopes.
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Choglay, Ashraf Ali. "Cell-matrix interactions." Thesis, University of Edinburgh, 1993. http://hdl.handle.net/1842/19624.
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Cellular involvement in collagen fibril organisation is a poorly understood phenomenon. The localisation of procollagen to the cell membrane coincident with secretion, the identification of cell surface receptors for collagen, and the assembly of collagen fibrils within extracellular compartments suggest a role for plasma membranes in the assembly and organisation of collagen fibrils. Cell-collagen interaction may be mediated by collagen receptors, cell surface proteoglycans and also membrane lipids. The interactions of type I collagen with phosphatidylcholine have been described and there have been several reports of lipid association with collagen. The interactions of [3H]procollagen I with various phospholipids were studied by density gradient centrifugation. At physiological conditions of pH, ionic strength and temperature, there was no evidence of procollagen binding to phosphatidylcholine phosphatidylethanolamine, phosphatidylinositol or phosphatidylserine liposomes. In contrast type I procollagen bound strongly to sphingomyelin lipsomes, in a reversible and saturable manner, with an apparent dissociation constant (Kd) of 2.6 nM. Binding occurred over a range of temperatures (4oC to 35oN) and was relatively unaffected by salt concentrations up to 1.2 M NcCl. Binding was observed in phosphate buffers but not in the presence of high concentrations of Tris or Hepes. Bovine serum albumin had no effect on procollagen binding to sphingomyelin, neither did unlabeled type I collagen, with or without the non-helical telopeptides. Type II procollagen and denatured type I procollagen also bound to sphingomyelin. Procollagen binding to sphingomyelin at 35oC was considerably reduced when small amounts of phosphatidylcholine were present, though binding was partially restored when the temperature was reduced below the corresponding phase transition temperature. Purified, unlabelled procollagen C-propeptides successfully competed for binding, and [125I]C-propeptides bound to sphingomyelin in the absence of procollagen. Weaker binding to sphingomyelin, mediated by the collagen triple helical region, was also observed, but this was dominated by the sphingomyelin C-propeptide interaction. The data suggest a novel mechanism for matrix vesicle mediated biomineralisation.
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Noble, Hannah. "Mueller Matrix Roots." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/204893.
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This dissertation is comprised of two separate topics within the domain of polarization optical engineering. The first topic is a Mueller matrix roots decomposition, and the second topic is polarization computer generated holography. The first four chapters of the dissertation are on the topic of the Mueller matrix roots decomposition. Recently, an order-independent Mueller matrix decomposition was proposed in an effort to organize the nine depolarization degrees of freedom. Chapter 1 discusses relevant Mueller matrix decomposition prior art and the motivation for this work. In chapter 2, the critical computational issues involved in applying this Mueller matrix roots decomposition are addressed, along with a review of the principal root and common methods for its calculation. The choice of the pth root is optimized at p = 10⁵, and computational techniques are proposed which allow singular Mueller matrices and Mueller matrices with a half-wave of retardance to be evaluated with the matrix roots decomposition. A matrix roots algorithm is provided which incorporates these computational results. In chapter 3, the Mueller matrix roots decomposition is reviewed and a set of Mueller matrix generators are discussed. The parameterization of depolarization into three families, each with three degrees of freedom is explained. Analysis of the matrix roots parameters in terms of degree of polarization maps demonstrates that depolarizers fall into two distinct classes: amplitude depolarization in one class, and phase and diagonal depolarization in another class. It is shown that each depolarization family and degree of freedom can be produced by averaging two non-depolarizing Mueller matrix generators. This is extended to provide further insight on two sample measurements, which are analyzed using the matrix roots decomposition. Chapter 4 discusses additional properties of the Mueller matrix roots generators and parameters, along with a pupil aberration application of the matrix roots decomposition. Appendix C, adapted from a conference proceedings paper, presents an application of the matrix roots depolarization parameters for estimating the orientation of a one-dimensionally textured object. The last two chapters are on the topic of polarization computer generated holography. In chapter 5, an interlaced polarization computer-generated hologram (PCGH) is designed to produce specific irradiance and polarization states in the image plane. The PCGH produces a tangentially polarized annular pattern with correlated speckle, which is achieved by a novel application of a diffuser optimization method. Alternating columns of orthogonal linear polarizations illuminate an interlaced PCGH, producing a ratio of polarization of 88% measured on a fabricated sample. In chapter 6, an etched calcite square-wave retarder is designed, fabricated, and demonstrated as an illuminator for an interlaced polarization computer generated hologram (PCGH). The calcite square-wave retarder enables alternating columns of orthogonal linear polarizations to illuminate the interlaced PCGH. Together, these components produce a speckled, tangentially polarized PCGH diffraction pattern with a measured ratio of polarization of 84% and a degree of linear polarization of 0.81. An experimental alignment tolerance analysis is also reported.
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De, Biasi Federico. "Matrix-Assisted NMR." Doctoral thesis, Università degli studi di Padova, 2019. http://hdl.handle.net/11577/3424861.
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During the last decades, the interest of chemistry toward increasingly sophisticated processes has grown exponentially. As a consequence, the evolution of the systems under investigation has been necessarily paired with the development of modern methodologies capable of handling the enormous amount of data stemming from samples of great complexity. Among the many examples in the literature, one of the biggest ongoing challenges is the analysis of mixtures, from reaction crude extracts to biological fluids like blood and urine. Indeed, chromatography has been - and still remains - one of the primary methods adopted to reduce the complexity of a multi-analyte system. Nonetheless, one intrinsic problem of the chromatographic approach is its inability to identify unknown molecules, and hyphenated techniques (mostly based on mass spectroscopy) have been developed just to overcome this stumbling block.
On the other hand, Nuclear Magnetic Resonance (NMR) spectroscopy is one of the most powerful techniques for the investigation of organic compounds. NMR exploits an intrinsic property exhibited by some atomic nuclei -- the spin -- to acquire chemical and structural information through well-established experimental protocols, known as pulse sequences. In particular, solution-state NMR can boast a vast ensemble of procedures aimed at collecting detailed data about through bond connectivities (COSY, TOCSY, HSQC,...) or through space proximities (NOESY, ROESY,...). All these information are nothing less than fundamental for the structure determination of unknown compounds.
Even tough this makes NMR spectroscopy largely appealing, the acquisition of such extensive information ultimately translates into detecting many signals at once, so that spectra interpretation can become a very challenging task. This is especially true when observing 1H resonances, which display a small dispersion in the frequency domain (about 12 ppm) and spectral crowding becomes consequently a serious problem.
Not surprisingly, the situation becomes almost unmanageable when NMR is applied to the assay of mixtures, where the superposition of signals stemming from different species is virtually assured. Certainly, multidimensional NMR techniques can be useful for the interpretation of crowded single-molecule spectra, but they rapidly loose all their advantages as the number of components in the sample increases. As for chromatography, the advent of hybrid techniques like LC-NMR, where LC stands for Liquid Chromatography, has partly circumvented the aforementioned difficulties, yet at the cost of an expensive and dedicated instrumentation.
In the context of mixture analysis, matrix-assisted NMR methodologies stand as an alternative to the various hyphenated techniques. They rely on the combination of NMR spectroscopy and an external agent added to the sample, which can be either a molecular or macromolecular species, or even a mesoscopic matrix. The aim of such matrices is to differentiate the signals of the various components, favouring their detection and characterisation.
The present work is divided into three independent parts. The first two are dedicated to different subjects of matrix-assisted NMR. In particular, Part I is aimed at the understanding of the physical phenomena underlying signal broadening when a solid, stationary phase is used in Matrix-Assisted Diffusometry (MAD) NMR measurements. Part II focuses on nanoparticle-assisted NMR chemosensing, a technique where monolayer-protected gold nanoparticles are exploited to transfer magnetization to selected classes of analytes by means of the Nuclear Overhauser Effect. In this second part, different nanoparticle-assisted methodologies are presented and analysed, alongside with some strategies aimed at the enhancement of the sensitivity.
Part III concerns the complete 1H-NMR characterisation of the atomically precise Au38(SBut)24 gold nanocluster, which can be considered as a prototypical nanoparticle. The Au38 core features four different symmetry-unique and equally populated binding sites for the grafting of the ligands that constitute the coating monolayer. Each binding site shows a distinct pattern of resonances, so that the overall 1H-NMR spectrum of the cluster is the result of the superposition of four independent subspectra. In this case, the full characterisation of the spectrum has been achieved through a combined NMR-MD (Molecular Dynamics) analysis.
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Planello, Aline Cristiane 1980. "Analise de polimorfismos no promotor dos genes MMP1, MMP3 e MMP9 na desordem da articulação temporomandibular." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288534.
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Orientador: Ana Paula de Souza PardoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: Objetivo: As Metaloproteinases da Matriz ( MMPs) são enzimas que degradam a matriz extracelular (MEC) e tem sido associadas às desordens temporomandibulares (DTM). Nós investigamos a freqüência dos -1607 1G/2G MMP1 polimorfismo (rs1799750), -1171 6A/5A MMP3 polimorfismo (rs3025058) e -1562 C/T MMP9 polimorfismo (rs3918242) em indivíduos com sinais de degeneração da ATM, diagnosticados por exame de imagem, a fim de analisar a associação desses polimorfismos e a DTM. Métodos: A população estudada foi composta por 115 indivíduos diagnosticados por exame de imagem (grupo DTM) e 117 controles. Os polimorfismos genéticos foram determinados por PCR/RFLP. Resultados: A freqüência do genótipo 2G/2G no gene MMP1 foi significantemente mais alta no grupo DTM do que no grupo Controle (p = 0.008). O genótipo 2G/2G no grupo DTM mostrou um risco aumentado para a DTM com um OR = 2.25 ( 95% IC = 1.26 - 3.99) quando comparado com os genótipo 1G/2G e 1G/1G. A freqüência dos alelos do gene MMP1 não mostrou diferença significativa entre os grupos (p > 0.05). A distribuição dos genótipos e alelos dos genes MMP3 e MMP9 não mostrou diferença significativa (p > 0.05). Conclusão: Nossos resultados mostram a associação entre o polimorfismo -1607 MMP1 e a suscetibilidade à DTM
Abstract: Objective. Matrix metalloproteinases (MMPs) degrade extracellular matrix components and have been implicated to play an important role in temporomandibular joint disorder (TMD). We investigated the frequency of -1607 1G/2G MMP1 polymorphism (rs1799750), -1171 6A/5A MMP3 polymorphism (rs3025058) and -1562 C/T MMP9 polymorphism (rs3918242) in individuals with TMJ degeneration diagnosed by image exam in order to analyze the association of these MMPs polymorphisms and TMD. Methods. The studied population comprised 115 TMD individuals diagnosed by image exam and 117 healthy controls. Genotypes were determined using polymerase chain reaction/Restriction fragment length polymorphism PCR/RFLP. Results. The MMP1 2G/2G genotype was significantly higher in the TMD group than in the Control group (p = 0.008). The genotype 2G/2G in the TMD group showed an increased risk to TMD with an OR = 2.25 (95% CI = 1.26 - 3.99) when compared with 1G/2G and 1G/1G genotypes. Analysis of MMP1 allele frequencies showed no significant difference (p > 0.05). The MMP3 and MMP9 genotypes distribution and alleles frequency did not differ between the groups (p > 0.05). Conclusion. Our results report the association of -1607 MMP1 gene polymorphism and increased risk to TMD
Mestrado
Histologia e Embriologia
Mestre em Biologia Buco-Dental
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Taylor, Matthew. "On upper triangular tropical matrix semigroups, tropical matrix identities and T-modules." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/on-upper-triangular-tropical-matrix-semigroups-tropical-matrix-identities-and-tmodules(d470a4a1-4eca-46c8-b9b8-4377affcc6fe).html.
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Gregory, Jeremy R. (Jeremy Ryan) 1976. "The role of precipitates on fiber/matrix interfaces in metal matrix composites." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/89301.
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Bear, Harriet Mary. "The role of tyrosine rich acidic matrix protein in the extracellular matrix." Thesis, University of Edinburgh, 1997. http://hdl.handle.net/1842/21534.
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A number of purification strategies were performed in an attempt to produce highly purified, active TRAMP free from lysyl oxidase for fibrillogenesis and enzymatic studies. TRAMP was eventually purified by DEAE anion exchange followed by Superdex-75 size exclusion (in the presence of urea) and Mono Q FPLC anion exchange chromatography. Yields of 10μg of TRAMP per g wet weight starting material were obtained. TRAMP purified as above was active in fibrillogenesis assays using the 'warm start' technique, in buffers containing 30mM TES, 30mM Na2HPO4, 135mM NaCl pH 7.4. The acceleratory effect of TRAMP on collagen I fibril formation was also observed when the phosphate concentration was lowered to 10mM and when TES was removed. TRAMP has previously been shown to bind to in vitro reconstituted collagen fibrils if present during their formation. Reducing the phosphate concentration decreased the amount of TRAMP associated with collagen I fibrils in co-sedimentation assays, whilst subsequent removal of TES had no effect on TRAMP binding to collagen I fibrils. Preliminary observations also suggested that treatment of TRAMP with sulphatase had no effect on the ability of TRAMP to accelerate collagen I fibril formation. A solid phase assay showed TRAMP to bind collagen I monomers with a higher affinity than fibrils, suggesting a role for TRAMP in the early, nucleation phase of fibril formation. TRAMP was unable to reverse the inhibitory effect of decorin on fibril formation. The presence of decorin had no effect on TRAMP binding to collagen monomers in solid phase assays but led to an increase in the amount of TRAMP associated with collagen fibrils in co-sedimentation assays. Attempts to identify specific binding sites for TRAMP on in vitro reconstituted collagen I fibrils by immunogold labelling and electron microscopy were unsuccessful. Western blot analysis of murine tissues confirmed previous reports that TRAMP was present in lung and skeletal muscle and absent in brain and spleen.
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Rodríguez, Escribà Marta. "Role of tRNA modifications in the synthesis of the extracellular matrix." Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/668499.
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Transfer RNAs (tRNAs) are key adaptor molecules that mediate decoding of messenger RNAs (mRNAs) into proteins by complementary pairing of their anticodons with mRNA codons. tRNAs that undergo adenosine to inosine editing at the wobble base, or position 34, display expanded codon decoding capacity as inosine enables pairing not only with uridine, but also with cytosine and adenosine. The essential heterodimeric enzyme Adenosine Deaminase Acting on Transfer RNA (ADAT) catalyzes this post-transcriptional modification in eukaryotes and is comprised of subunits ADAT2 and ADAT3. Emergence of heterodimeric ADAT has been proposed to have shaped both tRNA gene content and codon composition of eukaryotic genomes in such a way that these two features became mirrored. Although the exact contribution of wobble inosine (I34) to translation elongation has not been established, previous reports have suggested that it might play a role in improving translational efficiency and accuracy of genes enriched in codons recognized by I34-modified tRNAs.
To further understand the role of the inosine modification in translation, we generated cell lines depleted in the catalytic subunit ADAT2. Silencing of ADAT2 lead to impaired cellular proliferation and had a variable impact on the expression of genes coding for extracellular matrix (ECM) proteins such as mucins. Notably, ADAT2 deficiency did not have major effects on the post-translational glycosylation of mucins, neither did it trigger the unfolded protein response. Supported by the absence of clear defects in decoding rates in ADAT2 depleted cells, as measured by ribosome profiling, our findings suggest that a reduced pool of I34-modified tRNAs might suffice to carry out cellular functions in steady-state conditions. However, we found that, under circumstances involving a high demand for these tRNAs such as airway remodeling, ADAT2 is required for the proper translation of an ECM gene enriched in stretches of codons read by I34-tRNAs. Taken together, our results suggest that the inosine modification is particularly relevant for the synthesis of ECM proteins during specialized processes including neural development and airway remodeling.
The importance of the inosine modification has been recently underscored by the identification of pathogenic mutations in the gene encoding ADAT3, all of which share common neurodevelopmental phenotypes. The most prevalent mutation identified to date is a valine to methionine (V144M) substitution that is linked to intellectual disability and strabismus. In the present study we characterized human ADAT in terms of activity and quaternary structure, and investigated the effect of the ADAT3 V144M mutation on the enzyme. We showed that the V144M substitution leads to decreased enzymatic activity of ADAT, which might result from alterations in the tertiary structure and subcellular localization of ADAT3 that were found to be associated to the mutation.Els ARNs de transferència (ARNt) són molècules que tenen un paper clau en el procés de traducció dels ARN missatgers (ARNm) en proteïnes mitjançant la interacció del seu anticodó amb codons d’ARNm. Els ARNt que passen per un procés d’edició d’adenosina a inosina a la base wobble, o posició 34, són capaços de llegir més d’un codó d’ARNm gràcies a la capacitat de la inosina de reconèixer els tres nucleòtids uridina, citidina i adenosina. L’enzim responsable d’aquesta modificació post-transcripcional en eucariotes s’anomena Adenosina Deaminasa específica per l’ARNt (ADAT), es tracta d’un complex heterodimèric format per les subunitats ADAT2 i ADAT3 que és essencial per a la viabilitat de l’organisme. Estudis previs han proposat que l’aparició d’ADAT va determinar el nombre de còpies gèniques de cada ARNt així com la composició de codons presents als genomes eucariòtics de tal manera que aquests dos factors estiguessin mútuament balancejats. Tot i que la contribució precisa de la inosina 34 (I34) a la traducció de proteïnes durant la fase d’elongació encara s’ha determinat experimentalment, algunes investigacions han suggerit que podria jugar un rol en l’eficiència i fidelitat de traducció de gens enriquits en codons reconeguts per ARNt modificats amb I34. Amb l’objectiu d’investigar el rol de la inosina en la traducció, hem generat línies cel·lulars on el gen codificant per ADAT2 ha estat silenciat. La depleció d’ADAT2 comporta un retard en el creixement cel·lular i té un efecte variable en l’expressió gènica de proteïnes de la matriu extracel·lular. El patró de modificacions post-traduccionals de glicosilació d’aquestes proteïnes no resulta alterat per la deficiència d’ADAT2, que tampoc activa la resposta a proteïnes desplegades. Juntament amb l’absència de defectes en la velocitat d’elongació analitzada per ribosome profiling, aquestes observacions suggereixen que la cèl·lula és capaç de dur a terme les seves funcions amb un nombre reduït d’ARNt modificats amb inosina. Hem vist, però, que en condicions que requereixen majors quantitats d’ARNt inosinats, la depleció d’ADAT2 dóna lloc a la traducció ineficient d’un gen de matriu extracel·lular altament enriquit en codons sensibles llegits per ARNt modificats. Així doncs, els nostres resultats indiquen que la inosina pot exercir un rol important en la síntesi de proteïnes de la matriu extracel·lular, particularment durant processos de desenvolupament neuronal i de remodelat de les vies respiratòries. La rellevància de la modificació I34 s’ha vist reforçada recentment per la identificació de mutacions de caire patogènic localitzades al gen que codifica ADAT3. Totes elles tenen en comú la presència de fenotips relacionats amb el desenvolupament neurològic. La mutació d’ADAT3 més comuna consisteix en la substitució d’un residu valina per un metionina (V144M) i està associada a la manifestació de discapacitat intel·lectual i estrabisme. En el present estudi hem caracteritzat l’activitat enzimàtica i l’estructura quaternària de l’ADAT humà, així com l’impacte de la mutació V144M d’ADAT3 en el complex heterdimèric. Els nostres revelen que la substitució V144M dóna lloc a una menor activitat enzimàtica d’ADAT. És possible que aquesta reducció es vegi influïda per les alteracions en l’estructura terciària i en la localització cel·lular d’ADAT3 que indueix la mutació.
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Schafmeister, Frank. "Indirekte Sparse-Matrix Konverter /." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17428.
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Malek, Fadi. "Polynomial zerofinding matrix algorithms." Thesis, University of Ottawa (Canada), 1995. http://hdl.handle.net/10393/9980.
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In linear algebra, the eigenvalues of a matrix are equivalently defined as the zeros of its characteristic polynomial. Determining the zeros of polynomials by the computation of the eigenvalues of a corresponding companion matrix turns the table on the usual definition. In this dissertation, the work of Newbery has been expanded and a (complex) symmetric or nonsymmetric companion matrix associated with a given characteristic polynomial has been constructed. Schmeisser's technique for the construction of a tridiagonal companion matrix associated with a polynomial with real zeros has been generalized to polynomials with complex zeros. New matrix algorithms based on Schmeisser's and Fiedler's companion matrices are developed. The matrix algorithm which is based on Schmeisser's matrix uses no initial values and computes the simple and multiple zeros with high accuracy. The algorithms based on Fielder's matrices are applied recursively, and require initial values as approximations to the true zeros of the polynomial. A few techniques concerning the choice of the required initial values are also presented. An important part of this thesis is the design of a new composite three-stage matrix algorithm for finding the real and complex zeros of polynomials. The composite algorithm reduces a polynomial with multiple zeros to another polynomial with simple zeros which are then computed with high accuracy. The exact multiplicities of these zeros are then calculated by means of Lagouanelle's limiting formula. The QR algorithm has been used in all the algorithms to find the eigenvalues of the companion matrices. The effectiveness of these algorithms is illustrated by presenting numerical results based on polynomials taken from the literature and considered to be ill-conditioned, as well as random polynomials with randomly generated zeros in small and large clusters. Polynomials are represented and evaluated in quadruple precision; but it suffices to use a double precision QR algorithm in order to obtain almost double precision in the zeros of polynomials.
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Brenner, Barbara, Bodo B. Schlegelmilch, and Björn Ambos. "Inside the NIKE matrix." WU Vienna University of Economics and Business, 2013. http://epub.wu.ac.at/3791/1/Nike__WU%2DCaseSeries.pdf.
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This case describes how Nike, a consumer goods company with an ever expanding portfolio and a tremendous brand value, manages the tradeoff between local responsiveness and global integration. In particular, the case highlights Nike's organizational structure that consists of a global matrix organization that is replicated at a regional level for the European market. While this organizational structure allows Nike to respond to local consumer tastes it also ensures that the company benefits from integration advantages such as global marketing and sourcing. Supported by rich quotes from Nike managers on various organizational levels, this case draws a colorful picture of all the challenges involved that come with matrix and regional structures. Will Nike be able to better exploit its competitive advantage by introducing more regional structures in the future? What is the logic behind the Nike's regional structure?Series: WU Case Series
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Brown, Scott. "Finite reducible matrix algebras." University of Western Australia. School of Mathematics and Statistics, 2006. http://theses.library.uwa.edu.au/adt-WU2006.0079.
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[Truncated abstract] A matrix is said to be cyclic if its characteristic polynomial is equal to its minimal polynomial. Cyclic matrices play an important role in some algorithms for matrix group computation, such as the Cyclic Meataxe of Neumann and Praeger. In 1999, Wall and Fulman independently proved that the proportion of cyclic matrices in general linear groups over a finite field of fixed order q has limit [formula] as the dimension approaches infinity. First we study cyclic matrices in maximal reducible matrix groups, that is, the stabilisers in general linear groups of proper nontrivial subspaces. We modify Wall’s generating function approach to determine the limiting proportion of cyclic matrices in maximal reducible matrix groups, as the dimension of the underlying vector space increases while that of the invariant subspace remains fixed. This proportion is found to be [formula] note the change of the exponent of q in the leading term of the expansion. Moreover, we exhibit in each maximal reducible matrix group a family of noncyclic matrices whose proportion is [formula]. Maximal completely reducible matrix groups are the stabilisers in a general linear group of a nontrivial decomposition U1⊕U2 of the underlying vector space. We take a similar approach to determine the limiting proportion of cyclic matrices in maximal completely reducible matrix groups, as the dimension of the underlying vector space increases while the dimension of U1 remains fixed. This limiting proportion is [formula]. ... We prove that this proportion is[formula] provided the dimension of the fixed subspace is at least two and the size q of the field is at least three. This is also the limiting proportion as the dimension increases for separable matrices in maximal completely reducible matrix groups. We focus on algorithmic applications towards the end of the thesis. We develop modifications of the Cyclic Irreducibility Test - a Las Vegas algorithm designed to find the invariant subspace for a given maximal reducible matrix algebra, and a Monte Carlo algorithm which is given an arbitrary matrix algebra as input and returns an invariant subspace if one exists, a statement saying the algebra is irreducible, or a statement saying that the algebra is neither irreducible nor maximal reducible. The last response has an upper bound on the probability of incorrectness.
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Surovy, Martin. "Matrix Kundt-Newman sequences." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0013/MQ35001.pdf.
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Wiegers, Yvonne. "Matrix, aspects of identity." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0018/MQ57643.pdf.
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Austing, Peter. "Yang-Mills matrix theory." Thesis, University of Oxford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365336.
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Edrees, Hamza J. "Sialon ceramic matrix composites." Thesis, University of Strathclyde, 1990. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21383.
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The present study has been performed on β'-sialon matrix reinforced with either carbon fiber, metals or TiN components. The study describes the optimum methods of fabrication of these composites and also investigates their mechanical and electrical properties. In carbon fiber/sialon system, reaction between the fiber and the matrix has been identified and overcomed by applying high densification rate and low temperature sintering. Samples containing 10-20V% fiber was hot pressed to almost theoretical density at temperatures 1500-1550°C. In metal reinforced sialon matrix composites there is always a reaction between the metal and the sialon to form metal silicide liquid at relatively low temperatures, which is found to be helpfull in decreasing the maximum densification temperature. Sialon reinforced by 15V% Ni powder is pressureless sintered to over 95 % of the theoretical density at temperature of 1450°C. Reaction in such composites can be controlled by increasing the sintering heating rate and the amount of silicon metal dissolveed into the metal particles (which strongly influences the composites mechanical properties) can be controlled by a two stage heat treatment sintering particularly in the stainless steel/sialon system. The addition of TiN to sialon matrix resulted in processing with no troubles of chemical incompatibility and composites with attractive mechanical properties. Density of almost theoretical was achieved in the addition of 10-30V%TiN to sialon. The crack type investigations on sialon and sialon matrix composites shows that the cracks are of Palmqvist type. The indentation fracture toughness of the composites mentioned above is dependant on the reinforced phase type, volume fraction and sintering temperature. In fiber/sialon composites fracture toughness of 4 7.9 MNm⁻³/² was achived by hot pressing 15V% carbon fiber/sialon composites. In metal/sialon composites, however, fracture toughness of 13 MNm⁻³/² is achieved, whilst the indentation fracture toughness of 30V%TiN reinforced sialon composites is 8.9 MNm⁻³/². The electrical conductivity of these composites is strongly dependant on the reinforced phase volume fraction and most importantly on the particles size of the conductive phase. However, resistivity of 0.5 Ω. cm is achieved in the addition of 20V% carbon to the sialon matrix. In metal/sialon systems resistivity of 3.37 Ω. cm is achieved in 20V% Ni/sialon composite whilst 30V%TiN is required to create a resistivity of 443 Ω. cm in such composites.
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Soley-Beltran, Patricia. "Transsexualism and hetrosexual matrix." Thesis, University of Edinburgh, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492685.
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Sangsari, Rahman Bahmani. "Matrix type of rings." Thesis, University of Exeter, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272978.
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Heggarty, Jonathan W. "Parallel R-matrix computation." Thesis, Queen's University Belfast, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287468.
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Empringham, Lee. "Matrix converter current commutation." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342443.
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Zhou, Hanson M. (Hanson Mi) 1977. "Clustering via matrix exponentiation." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/17671.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2004.Includes bibliographical references (leaves 26-27).
Given a set of n points with a matrix of pairwise similarity measures, one would like to partition the points into clusters so that similar points are together and different ones apart. We present an algorithm requiring only matrix exponentiation that performs well in practice and bears an elegant interpretation in terms of random walks on a graph. Under a certain mixture model involving planting a partition via randomized rounding of tailored matrix entries, the algorithm can be proven effective for only a single squaring. It is shown that the clustering performance of the algorithm degrades with larger values of the exponent, thus revealing that a single squaring is optimal.
by Hanson M. Zhou.
S.M.
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Xin, Yu Ph D. Massachusetts Institute of Technology. "Algorithms for matrix completion." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/71500.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 69-72).
We consider collaborative filtering methods for matrix completion. A typical approach is to find a low rank matrix that matches the observed ratings. However, the corresponding problem has local optima. In this thesis, we study two approaches to remedy this issue: reference vector method and trace norm regularization. The reference vector method explicitly constructs user and item features based on similarities to reference sets of users and items. Then the learning task reduces to a convex regression problem for which the global optimum can be obtained. Second, we develop and analyze a new algorithm for the trace-norm regularization approach. To facilitate smooth primal optimization, we introduce a soft variational trace-norm and analyze a class of alternating optimization algorithms. We introduce a scalable primal-dual block coordinate descent algorithm for large sparse matrix completion. The algorithm explicitly maintains a sparse dual and the corresponding low rank primal solution at the same time. Preliminary empirical results illustrate both the scalability and the accuracy of the algorithm.
by Yu Xin.
S.M.
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Srebro, Nathan 1974. "Learning with matrix factorizations." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28743.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004.Includes bibliographical references (p. 157-164).
Matrices that can be factored into a product of two simpler matrices can serve as a useful and often natural model in the analysis of tabulated or high-dimensional data. Models based on matrix factorization (Factor Analysis, PCA) have been extensively used in statistical analysis and machine learning for over a century, with many new formulations and models suggested in recent years (Latent Semantic Indexing, Aspect Models, Probabilistic PCA, Exponential PCA, Non-Negative Matrix Factorization and others). In this thesis we address several issues related to learning with matrix factorizations: we study the asymptotic behavior and generalization ability of existing methods, suggest new optimization methods, and present a novel maximum-margin high-dimensional matrix factorization formulation.
by Nathan Srebro.
Ph.D.
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Nan, Feng S. M. Massachusetts Institute of Technology. "Low rank matrix completion." Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/55077.
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Thesis (S.M.)--Massachusetts Institute of Technology, Computation for Design and Optimization Program, 2009.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 75-76).
We consider the problem of recovering a low rank matrix given a sampling of its entries. Such problems are of considerable interest in a diverse set of fields including control, system identification, statistics and signal processing. Although the general low rank matrix completion problem is NP-hard, there exist several heuristic methods that solve the problem approximately by solving the convex relaxation of the original problem. One particularly popular method is to use nuclear norm (sum of singular values) to approximate the rank of the matrix and formulate the problem as a semidefinite program that can be solved efficiently. In this thesis, we propose a local completion algorithm that searches for possible completion in the neighborhood of each unspecified entry given the rank of the matrix. Unlike existing methods, this algorithm requires only local information of the matrix if the rank is known. Critical in all low rank matrix completion algorithms is the sampling density. The denser the matrix is sampled, the more likely it can be recovered accurately. We then propose a condensation process that increases the sampling density in a specific part of the matrix through elementary row and column re-ordering. Hence we can solve a sub-problem of the original low rank matrix completion problem and gain information on the rank of the matrix. Then the local algorithm is readily applicable to recover the entire matrix. We also explore the effect of additional sampling structures on the completion rate of the low rank matrix completion problems. In particular, we show that imposing regularity in the sampling process leads to slightly better completion rates.
(cont.) We also provide a new semidefinite formulation for a particular block sampling structure that reduces the size of the constraint matrix sizes by a factor of 1.5.
by Feng Nan.
S.M.
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Kwizera, Petero. "Matrix Singular Value Decomposition." UNF Digital Commons, 2010. http://digitalcommons.unf.edu/etd/381.
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This thesis starts with the fundamentals of matrix theory and ends with applications of the matrix singular value decomposition (SVD). The background matrix theory coverage includes unitary and Hermitian matrices, and matrix norms and how they relate to matrix SVD. The matrix condition number is discussed in relationship to the solution of linear equations. Some inequalities based on the trace of a matrix, polar matrix decomposition, unitaries and partial isometies are discussed. Among the SVD applications discussed are the method of least squares and image compression. Expansion of a matrix as a linear combination of rank one partial isometries is applied to image compression by using reduced rank matrix approximations to represent greyscale images. MATLAB results for approximations of JPEG and .bmp images are presented. The results indicate that images can be represented with reasonable resolution using low rank matrix SVD approximations.
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Chamberlain, A. "Novel silicate matrix composites." Thesis, University of Warwick, 1994. http://wrap.warwick.ac.uk/107576/.
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Within this study, a novel matrix selection principle, within the MAS glass ceramic system, has been developed with emphasis placed on the use of this matrix in a ceramic fibre reinforced composite. Matrix selection was applied in order to develop a diphasic microstructure to allow tailoring of the matrix thermal expansion coefficient via a phase mixture. The phases selected were a-cordierite and enstatite, with a Nicalon fibre reinforcement. Initial studies centred on the use of chopped fibre systems in order to develop a processing methodology giving the correct phase structure, microstructure and interface development between the matrix and the fibre. It was found that variations in process route including the use of window I and window II pressing regimes (below and above the maximum crystallisation rate) caused large differences in the matrix microstructure. During this part of the study the effects of added nucleants were investigated (P2O5 at 2wt%, and Ti02 at 10wt%), the results indicating that, with the use of glass frit, the added nucleant was not necessary. Initial studies upon composite fabrication indicated the criticality of pressure application during processing indicated by a fall in the elastic modulus of the composite from the rule of mixtures calculation. A pre-preg methodology was developed to produce high quality green state composite, including a T-piece traverse head arrangement for the fibre tow infill, 'walls' on the winding cage and rollering the pre-preg sheets. Following this, a refined process route for hot pressing was developed with application of pressure during heating in a 'process-window' identified using DTA. Composites were fabricated using the NL-607 fibre type with optimised properties reaching a matrix microcracking stress of cmm = 665±75MPa, ultimate flexure strength of oUBS = 1168±41MPa and E = 157±12GPa (within the rule of mixtures calculation). TEM analysis indicated an interface width of 25-70nm. with carbon enrichment occurring. Measurement of the micromechanical properties of the interface used an indentation technique giving the interfacial debond energy 2T = 12.4±5.4Jnv2, and shear sliding resistance T = 48±15MPa. Tensile studies indicated that two regions could be identified associated with microcracking in the 90° and 0° plies by a modulus drop and acoustic emission. Thermal aging in air (lOOhrs) indicated that channelled oxidation via fibre / matrix interfaces was occurring at intermediate temperatures (450° - 700°C) and partial silica bridging of the interface at higher temperatures in this interval. Micromechanical property measurements indicated that for 450°C aging 2T = 13.6±4.4Jnr2 with T = 108±54 MPa, whereas for 700°C aging 2T = 35.6±29.2Jnr2 with T = 248±120MPa. At higher temperatures (1000°C), rapid silica bridging of the interface caused plugging to occur and the retention of as-fabricated mechanical properties for the bulk material. Fibres in the bulk of the composite had micromechanical properties similar to as fabricated materials, whereas fibres ~ 30pm from the edge of the sample had very high micromechanical properties indicative of fully silica bridged interfaces. Above 1000°C microstructural degradation was observed with the formation of a surface layer on the composites (60-80pm at 1000°C, 80- 140pm at 1200°C). Tensile creep studies indicated, for the conditions utilised within this work ( 1000°-1150°C and 50-90MPa), that fibre creep properties dominated, with the observed creep rate being - 1.6 x 10 8-s1. For all the creep studies conducted, nonsteady state creep was observed, with a continuously decreasing creep rate with time.
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Bixler, Reid Morris. "Sparse Matrix Belief Propagation." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/83228.
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We propose sparse-matrix belief propagation, which executes loopy belief propagation in Markov random fields by replacing indexing over graph neighborhoods with sparse-matrix operations. This abstraction allows for seamless integration with optimized sparse linear algebra libraries, including those that perform matrix and tensor operations on modern hardware such as graphical processing units (GPUs). The sparse-matrix abstraction allows the implementation of belief propagation in a high-level language (e.g., Python) that is also able to leverage the power of GPU parallelization. We demonstrate sparse-matrix belief propagation by implementing it in a modern deep learning framework (PyTorch), measuring the resulting massive improvement in running time, and facilitating future integration into deep learning models.Master of Science
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Milanovic, Zoran. "Solid matrix Christiansen filters." Diss., The University of Arizona, 1992. http://hdl.handle.net/10150/185764.
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Christiansen filters are scattering filters composed of two materials with dispersion curves (for refractive index) that intersect at one wavelength. These filters transmit unscattered light at the intersection wavelength and incoherently scatter light of other wavelengths. Unlike filters based on optical interference, the transmitted wavelength does not depend on the angle of light incidence on the filter. These filters have been fabricated with solid host matrices by mixing finely ground optical glass powders with pellets of optical grade resins and injection molding the combination into planar filters of various sizes. This method of fabrication can produce filters of any shape or size, limited only by the skill of the mold designer and the size of the molding machine. This dissertation discusses the fabrication, characterization and modeling of solid matrix Christiansen filters. After a brief proposal of our research objectives to motivate this study, the concepts behind and history of these filters are reviewed. A multiple scattering theory of Christiansen filters is discussed and a computer-based search for compatible materials is summarized. After verifying the refractive index dispersions of the selected polymer matrices, a detailed description of the technology and fabrication of these filters follows. Spectral transmission and other measurements are employed to characterize the optical performance of the filters and to compare the filters to theoretical models. We have produced blue, bandpass filters with transmittances ranging from 0.25 to 0.40 at 392 nm; green, bandpass filters with transmittances of 0.20 centered at 510 nm; and near-infrared, edge filters which begin at 700 nm and reach maximum transmittances ranging from 0.30 to 0.50 at 800 nm. The dissertation concludes with recommendations for future improvements and suggestions for possible applications. The results from the computer-based material search and tables of fabrication parameters are included in two appendices.
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Schatz, Sandra Regina. "From frankenstein to matrix." Florianópolis, SC, 2002. http://repositorio.ufsc.br/xmlui/handle/123456789/83728.
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Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de comunicação e Expressão, Programa de Pós-Graduação em Letras/Inglês e Literatura Correspondente.Made available in DSpace on 2012-10-20T02:49:28Z (GMT). No. of bitstreams: 0Bitstream added on 2014-09-26T01:01:56Z : No. of bitstreams: 1 182188.pdf: 2777855 bytes, checksum: 7b4d6a42680bc77daf11ab9ee93f46bd (MD5)
Este trabalho lida com o gênero literário de ficção científica. Combinando os princípios da "Cultural Criticism" e "Reader-Response Criticism," ele discute e interpreta duas narrativas ocidentais: Frankenstein de Mary Shelley e Matrix dos irmãos Wachowski. O trabalho se preocupa com dois aspectos relevantes: (1) a cultura Ocidental esmagando dependência na ciência e tecnologia e (2) o papel das narrativas como um instrumento de ambos apoio e mudança em relação aos valores e verdades propostas pelo discurso dominante ou cultura paradigmática.
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Jungnick, Nadine. "Influenza matrix protein M1." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2011. http://dx.doi.org/10.18452/16438.
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Die Aufklärung der Prozesse, die zur Zusammensetzung des Influenza A Virus führen, ist Bestandteil für die Bekämpfung dieser Infektionskrankheit. Der Viruspartikel setzt sich aus einer Hülle, der darunter liegenden Matrix und dem Genom zusammen. Das Genom ist als Bündel aus acht Ribunucleoproteinkomplexen organisiert. Die Hülle besteht aus einer Membran, die mit Sphingomyelin und Cholesterol angereichert ist und den darin eingebetteten Membranproteinen Hämagglutinin, Neuraminidase und dem Protonenkanal M2. Die unter der Hülle liegende Matrix wird von einem einzigen Influenzaprotein formiert: Dem Matrixprotein M1. Es spielt eine Schlüsselrolle im Replikationszyklus des Virus in der Zelle. Es interagiert mit dem genetischen Material, mit den Membranproteinen und der Lipidmembran der Hülle. Die vorliegende Arbeit gibt Auskunft, welche Lipide eine Rolle in der M1-MembranWechselwirkung spielen. Die Liste der identifizierten Lipide umfasst neben dem bereits bekannten Phosphatidylserin auch Phosphatidylglycerol und Phosphatidsäure. Verschiedene Phosphatidylinositole konnten ebenfalls identifiziert werden. Als stärkster M1 Bindungspartner trat dabei Phosphatidylinositol-4-Phosphat zutage. Weitere auf Mutanten basierende Untersuchungen zeigten, dass der membranbindende Bereich nicht auf eine einzelne Domäne in M1 festgelegt werden kann. Die N-terminale M1-Domäne mit ihrem Oberflächen-exponierten, positiv geladenen Areal und die C-terminale Domäne interagierten mit Modellmembranen. Das Resultat dieser Interaktionen konnte mittels mikroskopischer Untersuchungen an gigantischen unilamellaren Vesikeln dokumentiert werden. Für M1 und für eine Mutante, die nur aus der N-terminalen M1-Domäne besteht, konnte eine von anderen viralen Proteinen unabhängige homooligomere Organisation auf der Membran gezeigt werden. Diese M1-Cluster könnten während der Zusammensetzung des Viruspartikels als Fundament für die Eingliederung aller weiteren viralen Komponenten dienen.about the assembly process of the influenza A virus particle is essential for the development of effective approaches for prevention and treatment of this virus infection. The virus particle consists of an envelope, an underlying matrix, and the encapsulated genome. The genetic material is organized as bundle of eight ribonucleoprotein complexes that encode for eleven proteins. The envelope consists of a lipid bilayer that is enriched in sphingomyelin and cholesterol. The viral spike proteins, hemagglutinin and neuraminidase, as well as the proton channel M2 are embedded into this membrane. The matrix can be found below the envelope. It is formed by one single protein, the matrix protein M1. M1 plays a crucial role during the replication of the virus in the cell. It interacts with the genetic material, with the envelope proteins and with the lipid bilayer of the envelope. The results of this study reveal in detail which lipids are targeted by M1. The set of identified lipids contains phosphatylglycerol and phosphatidic acids as new binding partners, beside the known phophatidylserine. Additionally, several phosphatidylinositols were identified. Phosphatidylinositol-4-phosphate was the strongest binding partner from this group. Mutant-based analysis revealed that M1 owns more than one membrane binding site. The positively charged area in the N-terminal and the C-terminal domain mediated membrane association of the respective mutant protein. The final constitution of M1 on the membrane was characterized by confocal fluorescence microscopy on giant unilamellar vesicles. Full length M1 and a mutant that consisted only of the N-terminal part of M1 showed lateral clustering of homooligomers on the vesicle surface. The clusters formed independently of any other viral component. A function as fundament for the incorporation of the other viral components can be assumed for these clusters.
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Zarri, Luca <1972>. "Control of matrix converters." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/412/1/PhdTesisZarri.pdf.
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Zarri, Luca <1972>. "Control of matrix converters." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/412/.
Full text