Dissertations / Theses on the topic 'Mapping in physics'
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Chess, Jordan J. "Mapping Topological Magnetization and Magnetic Skyrmions." Thesis, University of Oregon, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10684160.
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A 2014 study by the US Department of Energy conducted at Lawrence Berkeley National Laboratory estimated that U.S. data centers consumed 70 billion kWh of electricity. This represents about 1.8% of the total U.S. electricity consumption. Putting this in perspective 70 billion kWh of electricity is the equivalent of roughly 8 big nuclear reactors, or around double the nation's solar panel output. Developing new memory technologies capable of reducing this power consumption would be greatly beneficial as our demand for connectivity increases in the future. One newly emerging candidate for an information carrier in low power memory devices is the magnetic skyrmion. This magnetic texture is characterized by its specific non-trivial topology, giving it particle-like characteristics. Recent experimental work has shown that these skyrmions can be stabilized at room temperature and moved with extremely low electrical current densities. This rapidly developing field requires new measurement techniques capable of determining the topology of these textures at greater speed than previous approaches. In this dissertation, I give a brief introduction to the magnetic structures found in Fe/Gd multilayered systems. I then present newly developed techniques that streamline the analysis of Lorentz Transmission Electron Microscopy (LTEM) data. These techniques are then applied to further the understanding of the magnetic properties of these Fe/Gd based multilayered systems.
This dissertation includes previously published and unpublished co-authored material.
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Schwartz, Benjamin M. (Benjamin Matthew). "Mapping bulk electrical properties with non-contact RF measurements." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/36118.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2006.Includes bibliographical references (leaf 43).
The human body is composed primarily of dielectric tissue with spatially varying permittivity and conductivity. Traditional MRI does not measure these properties. Instead, the conductivity of the patient is a nuisance, causing unpredictable detuning of coils and field inhomogeneities. This thesis presents a method for mapping the electrodynamic properties of the patient's body with both MR and non-MR techniques. Such mapping has direct applications for medical imaging and SAR calculation.
by Benjamin M. Schwartz.
S.B.
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Snyman, Izak. "Analysis and applications of the generalised Dyson mapping." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/49829.
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Thesis (MSc)--Stellenbosch University, 2004.ENGLISH ABSTRACT: In this thesis, generalized Dyson boson-fermion mappings are considered. These are techniques used in the analysis of the quantum many-body problem, and are instances of so-called boson expansion methods. A generalized Dyson boson-fermion mapping, or a Dyson mapping for short, is a one-to-one linear but non-unitary operator that can be applied to vectors representing the states of a many-fermion system. A vector representing a fermion system maps onto a vector that is most naturally interpreted as representing a state of a many-body system that contains both bosons and fermions. The motivation for doing such a mapping is the hope that the mapping will reveal some property of the system that simplifies its analysis and that was hidden in the original form. The aims of this thesis are 1. to review the theory of generalized Dyson boson-fermion mappings, 2. by considering a tutorial example, to demonstrate that it is feasible to implement the theory and 3. to find a useful application for a generalized Dyson boson-fermion mapping, by considering a non-trivial model, namely the Richardson model for superconductivity. The realization of the first two aims mainly involve the collecting together of ideas that have already appeared in the literature, into one coherent text. Some subtle points that were treated only briefly due to space restrictions in the journal publications where the theory was first expounded, are elaborated on in the present work. On the other hand, the analysis of the Richardson Hamiltonian that uses a Dyson mapping, goes beyond what has already appeared in the literature. It is the first time that a boson expansion technique is implemented for a system where the roles of both collective and non-collective fermion pairs are important. (The Dyson mapping associates bosons with Cooper pairs, while the fermions not bound in Cooper pairs result in fermions being present in the mapped system as well.) What is found is that the Dyson mapping uncovers non-trivial properties of the system. These properties aid the construction of time-independent perturbation expansions for the stationary states of the system, as well as time-dependent expansions for transition amplitudes between states. The time-independent expansions agree with results that other authors obtained through methods other than boson expansions. The time-dependent expansions, that one would be hard-pressed to develop without a Dyson mapping, might in future prove useful in understanding aspects of the dynamics of ultracold fermi gases, when time-dependent magnetic fields are used to vary the atom-atom interaction strenght.
AFRIKAANSE OPSOMMING: In hierdie tesis word veralgemeende Dyson boson-fermion-afbeeldings ondersoek. Hierdie afbeeldings word gebruik in die analise van die kwantum veeldeeltjie probleem, en is voorbeelde van sogenaamde boson-uitbreidingstegnieke. 'n Veralgemeende Dyson bosonfermion- afbeelding, of kortweg 'n Dyson afbeelding, is 'n een-tot-een, lineêre maar nie-unitêre operator wat inwerk op vektore wat toestande verteenwoordig van 'n veel-fermion sisteem. 'n Vektor wat 'n fermionsisteem verteenwoordig word so afgebeeld op 'n vektor waarvoor die mees natuurlike interpretasie is dat dit 'n toestand verteenwoordig van 'n sisteem waarin beide bosone en fermione aanwesig is. So 'n afbeelding word gewoonlik gemaak in die hoop dat eienskappe van die sisteem, wat versteek was in die oorspronklike weergawe, voor-die-hand-liggend is na die afbeelding. Hierdie tesis het ten doel 1. om die teorie van veralgemeende Dyson boson-fermion-afbeeldings te hersien, 2. om 'n eenvoudige voorbeeld deur te werk, en so te demonstreer dat die teorie sonder moeite geïmplimenteer kan word en 3. om 'n nuttige toepassing te vind vir 'n veralgemeende Dyson boson-fermion-afbeelding deur 'n nie-triviale model, naamlik die Richardson model vir supergeleiding, te ondersoek. Die eerste twee van hierdie doelwitte behels hoofsaaklik dat idees wat reeds in die literatuur verskyn het, saamgevat word in een koherente teks. Sommige subtiele punte wat, vanwee beperkte ruimte, slegs kortliks bespreek is in die joernaalartikels waarin die teorie oorspronklik verskyn het, word in hierdie tesis meer breedvoering bespreek. Daarteenoor verteenwoordig die analise van die Richardson model met behulp van 'n Dyson afbeelding 'n nuwe bydra. Dit is naamlik die eerste keer dat 'n bosonuitbreiding ingespan word vir 'n sisteem waar sowel kollektiewe as nie-kollektiewe fermionpare 'n belangrike rol speel. (Die Dyson afbeelding assosieer bosone met die oorspronklike sisteem se Cooper pare, terwyl die fermione wat in die oorspronklike sisteem nie tot Cooper pare gebind is nie, sorg dat daar ook fermione teenwoordig is in die afgebeelde sisteem.) Ons vind dat die Dyson afbeelding nie-triviale eienskappe van die sisteem aan die lig bring. Hierdie eienskappe is nuttig vir die konstruksie van beide tyd-onafhanklike steuringsreekse vir die stasionêre toestande van die sisteem en vir tyd-afhanklike steuringsreekse vir oorgangsamplitudes tussen toestande. Die tyd-onafhanklike uitbreidings stem ooreen met resultate wat ander outeurs afgelei het sonder die gebruik van 'n Dyson afbeelding. Die tyd-afhanklike uitbreidings, wat kwalik afgelei kan word sonder 'n Dyson afbeelding, mag vorentoe nuttig wees om aspekte van die dinamika van baie koue Fermi gasse te verstaan, wanneer tydafhanklike magneetvelde gebruik word om die inter-atoomwisselwerking te manipuleer.
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Perko, Ashley Nicole. "The Omniscope : mapping the Universe in 3D with neutral hydrogen." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/65534.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Physics, 2011.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 57-58).
21 cm tomography has the potential to become the most powerful cosmological probe yet. The Omniscope is a novel radio telescope being built to take advantage of this signal. This thesis describes my work on integrating, testing, and characterizing all modules of the Omniscope and identifying opportunities for further improving their sensitivity.
by Ashley Nicole Perko.
S.B.
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Menezes, Debora Peres. "Boson mapping techniques and the nuclear collective motion." Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329926.
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Mielke, Thomas Martin. "Mapping spaces, configuration spaces and gauge theory." Thesis, University of Warwick, 1995. http://wrap.warwick.ac.uk/109201/.
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The present thesis considers the space of connections modulo based gauge equivalence on a principal SU(2) bundle over a closed simply-connected smooth four-dimensional manifold M. Up to homotopy equivalence, this is the space of basepoint-preserving maps from M to BSU('2), the classifying space of SU(2). It depends only on the homotopy type of M which is characterized by the intersection form. The Z/pZ-homology of the mapping space for p a prime not equal to 3 is computed and given in terms of the data associated to the intersection form. For the prime 3, partial results are obtained. The main method is to consider a fibration associated to a CW decomposition of M and to show that the corresponding Eilenberg- Moore spectral sequence collapses. These results generalize from manifolds to spaces homotopy equivalent to a bouquet of 2-spheres with a single 4-cell attached. For the possible homotopy types the space of connections modulo gauge equivalence ran attain, a classification is obtained in the following sense. The homotopy type of this space is uniquely determined by the rank, type and signature modulo eight of the intersection form. On the other hand, the homotopy type determines the rank, type and signature modulo four of the intersection form. Both results together give a complete classification for the case of spin manifolds. The homotopy types of the spaces of connections modulo gauge equivalence over two spin manifolds agree if and only if the intersection forms are of the same rank. These results use a classification of unimodular bilinear forms over the ring Z/4Z. In a final part, a map is constructed from the labelled configuration spaces of points in the manifold to the mapping space. This map is shown to be asymptotically surjective in homology with Z/2Z-coefficients. For homology with general coefficients, classes are constructed which are not approximated by this map.
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Green, Gregory Maurice. "Mapping Milky Way Dust in 3D With Stellar Photometry." Thesis, Harvard University, 2016. http://nrs.harvard.edu/urn-3:HUL.InstRepos:33493261.
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I present a three-dimensional map of interstellar dust reddening, covering three-quarters of the sky out to a distance of several kiloparsecs, based on Pan-STARRS 1 and 2MASS photometry. The map reveals a wealth of detailed structure, from filaments to large cloud complexes. The map has a hybrid angular resolution, with most of the map at an angular resolution of 3.4′ to 13.7′ , and a maximum distance resolution of ∼25%. The three-dimensional distribution of dust is determined in a fully probabilistic framework, yielding the uncertainty in the reddening distribution along each line of sight, as well as stellar distances, reddenings and classifications for 800 million stars detected by Pan-STARRS 1. The method developed here compares observed stellar photometry with empirical stellar templates, incorporating prior knowledge about the structure of the Galaxy.
I validate the per-star reddening estimates by comparison with reddening estimates for stars with both SDSS photometry and SEGUE spectral classifications, finding per-star agreement to within ∼0.15 mag out to a stellar E(B−V) of 1 mag. I demonstrate the consistency of the resulting reddening estimates with those of two-dimensional emission-based maps of dust reddening. In particular, I find agreement with the Planck τ353 GHz-based reddening map to within 0.05 mag in E(B−V) to a depth of 0.5 mag, and explore systematics at reddenings less than E(B−V) ≈ 0.08 mag. I compare the 3D map developed here to two existing three-dimensional dust maps, by Marshall et al. (2006) and Lallement et al. (2013), exploring the strengths and weaknesses of the different 3D mapping methods. The map presented here has better angular resolution than both 3D maps compared, and it has better distance resolution than Marshall et al. (2006) within ∼3 kpc, but shows radial “finger-of-God” features not contained in Lallement et al. (2013).
The map can be queried or downloaded at http://argonaut.skymaps.info. I expect the three-dimensional reddening map presented here to find a wide range of uses, among them correcting for reddening and extinction for objects embedded in the plane of the Galaxy, studies of Galactic structure, calibration of future emission-based dust maps and determining distances to objects of known reddening. The method we present is not limited to the passbands of the Pan-STARRS 1 and 2MASS surveys, but may be extended to incorporate photometry from other optical and near-infrared surveys, such as WISE, Spitzer GLIMPSE, UKIDSS, SDSS (where available), and in the future, LSST and Gaia. The method can also be naturally extended to stellar kinematic data, such as that soon to be released by Gaia.Astronomy
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Praeger, Matthew. "Development and spatio-spectral mapping of a capillary high harmonic source." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/66192/.
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This work describes the development and operation of a capillary based High Harmonic Generation (HHG) system. Using this system a coherent beam of soft x-rays is generated, studied and applied. A series of experiments was then undertaken in order to deepen our knowledge of the HHG process and to optimise the performance of the source. Notable contributions made to the field are: A novel laser mode quality measuring device. (Laser mode quality strongly affects the efficiency of the capillary launch). A study of the spectral output of the system as a function of gas pressure, laser power, and laser spectral phase. An analysis technique for recovering spatially-resolved spectral information about a beam by studying the Fresnel diffraction pattern produced at an array of apertures. A study of pulse compression using cascaded quadratic nonlinearity for spectral broadening.
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Slaughter, Katherine Alice. "Mapping the transition : content and pedagogy from school through university." Thesis, University of Edinburgh, 2012. http://hdl.handle.net/1842/7618.
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A study has been carried out at the University of Edinburgh in order to examine how physics students’ abilities and attitudes towards study change during their time at university. This is a large topic with numerous possible avenues of research, as a result the field has been narrowed for this thesis in order to focus on three main subject areas; how students adapt during the transition from school to university, how students attitudes towards studying physics change during an undergraduate degree and, finally, student data handling skills in the undergraduate laboratory with links to whether student perceptions of their data handling skills are consistent with their ability. It has been found that students may face difficulties going from school to university study. Students potentially face gaps in their prior learning due to differences in school leaving qualification syllabi, which is compounded by instructors having expectations of student ability that are higher than student actual ability. It has been seen that students become less positive in their attitudes towards study over the course of their first year of instruction, potentially due to a drop in confidence. In the subject area of attitudes towards study, longitudinal studies have been carried out in order to examine the expert-like thinking of students. Results gathered are suggestive of a selection effect with the most expert-like thinkers possessing levels of expert thinking similar to those of physics instructors, even when initially entering the degree program. Investigation of student laboratory work has shown that there is a large gap between student estimations of their own ability and the reality of such skills. This has been demonstrated by contrasting the results of surveys examining student perceptions towards practical work with data gathered from a data handling diagnostic test that has been designed and implemented as part of this thesis.
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McGinn, Christopher Francis. "Mapping the redistribution of jet energy in PbPb collisions at the LHC with CMS." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/127721.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Physics, 2019Cataloged from the official PDF of thesis.
Includes bibliographical references (pages 195-202).
Quenched jets produced in heavy ion collisions at the LHC and reconstructed with the CMS detector are studied to understand the nature of interactions between hardscattered partons and the simultaneously produced hot and dense medium, the Quark- Gluon Plasma (QGP). Jets are objects with color charge evolving through many energy scales, so are an excellent tool for scattering experiment in QGP, with potential to resolve quasiparticle structure and induce medium response. Redistribution of jet energy is quantified in two methods: measurement of transverse PT of final state particles projected onto dijet azimuthal axis, and measurement of jet production cross sections in PbPb and pp as function of jet radius. Missing momentum shows recovery of lost energy when moving beyond the jet cone for a fixed collection of jets, approaching full recovery at ... A jet radius scan of jet production cross sections shows consistent observed suppression in PbPb when compared to appropriately scaled pp at all radii. However, less suppression is observed with increasing jet resolution parameter R. In combination the results imply that while jet energy lost to medium interactions can be found when looking beyond the jet cone, the substantial changes to the jet population in pp at each studied R lead to sustained spectral suppression with even the largest cone size.
by Christopher Francis McGinn.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Physics
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Jones, Beryl Wyn. "Mapping unstructured mesh codes onto local memory parallel architectures." Thesis, University of Greenwich, 1994. http://gala.gre.ac.uk/6201/.
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Initial work on mapping CFD codes onto parallel systems focused upon software which employed structured meshes. Increasingly, many large scale CFD codes are being based upon unstructured meshes. One of the key problems when implementing such large scale unstructured problems on a distributed memory machine is the question of how to partition the underlying computational domain efficiently. It is important that all processors are kept busy for as large a proportion of the time as possible and that the amount, level and frequency of communication should be kept to a minimum. Proposed techniques for solving the mapping problem have separated out the solution into two distinct phases. The first phase is to partition the computational domain into cohesive sub-regions. The second phase consists of embedding these sub-regions onto the processors. However, it has been shown that performing these two operations in isolation can lead to poor mappings and much less optimal communication time. In this thesis we develop a technique which simultaneously takes account of the processor topology whilst identifying the cohesive sub-regions. Our approach is based on an unstructured mesh decomposition method that was originally developed by Sadayappan et al [SER90] for a hypercube. This technique forms a basis for a method which enables a decomposition to an arbitrary number of processors on a specified processor network topology. Whilst partitioning the mesh, the optimisation method takes into account the processor topology by minimising the total interprocessor communication. The problem with this technique is that it is not suitable for dealing with very large meshes since the calculations often require prodigious amounts of computing processing power.
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Toerien, René. "Mapping the learning trajectories of physical sciences teachers' topic specific knowledge for teaching chemical bonding." Doctoral thesis, University of Cape Town, 2017. http://hdl.handle.net/11427/25508.
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Education in South Africa is a national concern and the training and professional development of teachers, especially in science and mathematics, has consequently been prioritised by the National Government. More than 60 percent of the teachers in South Africa are older than 40 years of age, which means that within the next 10-15 years many experienced teachers will exit the system, leaving a younger and less experienced cohort of teachers behind. This study aims to make explicit the learning trajectories of physical sciences teachers, specifically with respect to their knowledge for teaching chemical bonding, in order to support other teachers and thereby accelerating the route to expertise. Learning can be viewed as change, and change has a trajectory. Mapping the learning trajectories, and the significant events that influenced teachers' learning over time, can give insight into how the change had taken place. This study used a mixed methods approach within the pragmatic research paradigm to map learning trajectories for a group of 60 South African physical sciences teachers. Pedagogical content knowledge (PCK), the unique knowledge held by teachers, was used for the theoretical framing of the study. An adapted version of the Model of Teacher Professional Knowledge and Skill, including PCK, was used as an analytical framework. A measuring instrument for topic specific knowledge for teaching chemical bonding was designed and validated using the Rasch measurement model. Quantitative and qualitative analysis of the teachers' responses to the instrument and a grounded analysis of story-line interview data from ten purposively selected teachers were used to identify the factors that played a role in the development of the teachers' knowledge. A further qualitative analysis of PCK episodes from the interview data revealed how the above factors influenced the teachers' knowledge. Findings revealed that teaching the same content multiple times and at multiple grade levels, embracing changes in the curriculum as opportunities for learning, and further studies at tertiary level, especially completing post-graduate studies in education, all played a role in the teachers' perceived shifts in their topic specific knowledge for teaching (TSKFT). Three learning trajectories were identified for the teachers in this study: teachers shifted towards deeper conceptual understanding of the content and used more sophisticated explanatory frameworks; teachers shifted towards more integrated topic specific knowledge for teaching; and teachers shifted from being text book bound and teacher-focussed towards becoming more student-focussed in their approach to teaching. The findings from this study provide guidelines for professional development programmes in terms of differentiated support to teachers according to their career stages and the inclusion of content specific training programmes which makes teaching for conceptual progression explicit. A further recommendation includes encouraging teachers to embark on post-graduate studies in education as this played a pivotal role in shifting teachers' topic specific knowledge for teaching chemical bonding.
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Lebois, Alice. "Brain microstructure mapping using quantitative and diffsusion MRI." Phd thesis, Université Paris Sud - Paris XI, 2014. http://tel.archives-ouvertes.fr/tel-01063198.
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This thesis is focused on the human brain microstructure mapping using quantitative and diffusion MRI. The T1/T2 quantitative imaging relies on sequences dedicated to the mapping of T1 and T2 relaxation times. Their variations within the tissue are linked to the presence of different water compartments defined by a specific organization of the tissue at the cell scale. Measuring these parameters can help, therefore, to better characterize the brain microstructure. The dMRI, on the other hand, explores the brownian motion of water molecules in the brain tissue, where the water molecules' movement is constrained by natural barriers, such as cell membranes. Thus, the information on their displacement carried by the dMRI signal gives access to the underlying cytoarchitecture. Combination of these two modalities is, therefore, a promising way to probe the brain tissue microstructure. The main goal of the present thesis is to set up the methodology to study the microstructure of the white matter of the human brain in vivo. The first part includes the acquisition of a unique MRI database of 79 healthy subjects (the Archi/CONNECT), which includes anatomical high resolution data, relaxometry data, diffusion-weighted data at high spatio-angular resolution and functional data. This database has allowed us to build the first atlas of the anatomical connectivity of the healthy brain through the automatic segmentation of the major white matter bundles, providing an appropriate anatomical reference for the white matter to study individually the quantitative parameters along each fascicle, characterizing its microstructure organization. Emphasis was placed on the construction of the first atlas of the T1/T2 profiles along the major white matter pathways. The profiles of the T1 and T2 relaxation times were then correlated to the quantitative profiles computed from the diffusion MRI data (fractional anisotropy, radial and longitudinal diffusivities, apparent diffusion coefficient), in order to better understand their relations and to explain the observed variability along the fascicles and the interhemispheric asymmetries. The second part was focused on the brain tissue modeling at the cell scale to extract the quantitative parameters characterizing the geometry of the cellular membranes, such as the axonal diameter and the axonal density. A diffusion MRI sequence was developed on the 3 Teslas and 7 Teslas Siemens clinical systems of NeuroSpin which is able to apply any kind of gradient waveforms to fall within an approach where the gradient waveform results from an optimization under the hypothesis of a geometrical tissue model, hardware and time constraints induced by clinical applications. This sequence was applied in the study of fourteen healthy subjects in order to build the first quantitative atlas of the axonal diameter and the local axonal density at 7T. We also proposed a new geometrical model to model the axon, dividing the axonal compartment, usually modelled using a simple cylinder, into two compartments: one being near the membranes with low diffusivity and one farer from the membranes, less restricted and with higher diffusivity. We conducted a theoretical study showing that under clinical conditions, this new model allows, in part, to overcome the bias induced by the simple cylindrical model leading to a systematic overestimation of the smallest diameters. Finally, in the aim of going further in the physiopathology of the autism, we added to the current 3T imaging protocol the dMRI sequence developed in the framework of this thesis in order to map the axonal diameter and density. This study is ongoing and should validate shortly the contribution of these new quantitative measures of the microstructure in the comprehension of the atrophies of the corpus callosum, initially observed using less specific diffusion parameters such as the generalized fractional anisotropy. There will be other clinical applications in the future.
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Caballero, Gaudes Cesar. "Paradigm free mapping : detection and characterization of single trial fMRI BOLD responses without prior stimulus information." Thesis, University of Nottingham, 2010. http://eprints.nottingham.ac.uk/11488/.
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The increased contrast to noise ratio available at Ultrahigh (7T) Magnetic Resonance Imaging (MRI) allows mapping in space and time the brain's response to single trial events with functional MRI (fMRI) based on the Blood Oxygenation Level Dependent (BOLD) contrast. This thesis primarily concerns with the development of techniques to detect and characterize single trial event-related BOLD responses without prior paradigm information, Paradigm Free Mapping, and assess variations in BOLD sensitivity across brain regions at high field fMRI. Based on a linear haemodynamic response model, Paradigm Free Mapping (PFM) techniques rely on the deconvolution of the neuronal-related signal driving the BOLD effect using regularized least squares estimators. The first approach, named PFM, builds on the ridge regression estimator and spatio-temporal t-statistics to detect statistically significant changes in the deconvolved fMRI signal. The second method, Sparse PFM, benefits from subset selection features of the LASSO and Dantzig Selector estimators that automatically detect the single trial BOLD responses by promoting a sparse deconvolution of the signal. The third technique, Multicomponent PFM, exploits further the benefits of sparse estimation to decompose the fMRI signal into a haemodynamical component and a baseline component using the morphological component analysis algorithm. These techniques were evaluated in simulations and experimental fMRI datasets, and the results were compared with well-established fMRI analysis methods. In particular, the methods developed here enabled the detection of single trial BOLD responses to visually-cued and self-paced finger tapping responses without prior information of the events. The potential application of Sparse PFM to identify interictal discharges in idiopathic generalized epilepsy was also investigated. Furthermore, Multicomponent PFM allowed us to extract cardiac and respiratory fluctuations of the signal without the need of physiological monitoring. To sum up, this work demonstrates the feasibility to do single trial fMRI analysis without prior stimulus or physiological information using PFM techniques.
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Nicoletti, Olivia. "Mapping surface plasmons of metal nanoparticles with electron energy-loss spectroscopy." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608025.
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Wang, Kangkang. "Atomic Imaging and Spin Mapping of Magnetic Nitride Surfaces." Ohio University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1313500678.
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callahan, lauren k. "Chain Reactions: Mapping the Iranian Nuclear Program from 2002 to 2009." Scholarship @ Claremont, 2014. http://scholarship.claremont.edu/cmc_theses/871.
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From the revelation of the extent of the Iranian nuclear program in 2002 through the end of President Mahmoud Ahmadinejad’s first term in 2009, the interplay between international and domestic actions came to define the progression of the nuclear program. This thesis delves into these into these interactions, examining the failures and successes of Iran’s relationships with various international entities to determine how external factors affected the evolution of Iran’s nuclear program. This thesis draws upon a scientific knowledge of nuclear technology, a theoretical view of international relations, and a historical and cultural understanding of the Arab World to analyze the political and scientific ramifications of Iran’s nuclear program and directly link international actions and domestic reactions to explain the program’s progression. This clear connection elucidates the key failings of negotiations during this era: an inability of one side to understand the other.
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BURCICA, CRISTINA IRINA. "MAPPING THERMAL GRADIENTS IN SCN USING A FAST FOURIER TRANSFORM ANALYSIS." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1053544547.
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Plaks, Irina. "Mapping the Early Galaxy: RR Lyrae Kinematics and Metallicities." Bowling Green State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1627059931940409.
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Lavayssiere, Maylis. "Electrical and chemical mapping of silicon pn junctions using energy-filtered X-ray PhotoElectron Emission Microscopy." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00765630.
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Ce mémoire de thèse traite de l'étude de jonctions pn silicium planaires, réalisées par épitaxie localisée, avec un nouveau type de microscopie à émission de photoélectrons (XPEEM) filtré en énergie. L'objectif est d'améliorer notre compréhension des facteurs influençant l'imagerie XPEEM de jonctions modèles avec une perspective à plus long terme d'application de cette technique aux cas réels. Sur les trois types de jonction réalisées présentant des champs électriques variables P+/P, N+/P, P+/N), nous avons d'abord mis en oeuvre un procédé de passivation en trois étapes afin de se rapprocher de conditions en bandes plates en surface. Ce procédé nous a permis d'étudier la position des niveaux électroniques de part et d'autre des jonctions grâce à une imagerie en XPEEM spectroscopique avec électrons secondaires (travail de sortie local), électrons de coeur Si 2p et bande de valence, avec à la fois avec des sources X de laboratoire et le rayonnement synchrotron. Un mécanisme de contraste des images en électrons de coeur dû à la toute première couche atomique de surface a été montré. Ensuite, nous avons mis en évidence le rôle du champ électrique au niveau de la zone de déplétion des jonctions qui décale la position apparente de cette dernière dans l'image XPEEM. Nous avons comparé les résultats expérimentaux avec des simulations (logiciel SIMION) afin d'estimer son influence sur les conditions d'imagerie. Enfin, nous avons étudié l'impact de la technique d'imagerie en champ sombre sur la localisation de la jonction réelle au niveau de la surface de l'échantillon.
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McManus, Kevin. "A strategy for mapping unstructured mesh computational mechanics programs onto distributed memory parallel architectures." Thesis, University of Greenwich, 1996. http://gala.gre.ac.uk/6249/.
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The motivation of this thesis was to develop strategies that would enable unstructured mesh based computational mechanics codes to exploit the computational advantages offered by distributed memory parallel processors. Strategies that successfully map structured mesh codes onto parallel machines have been developed over the previous decade and used to build a toolkit for automation of the parallelisation process. Extension of the capabilities of this toolkit to include unstructured mesh codes requires new strategies to be developed. This thesis examines the method of parallelisation by geometric domain decomposition using the single program multi data programming paradigm with explicit message passing. This technique involves splitting (decomposing) the problem definition into P parts that may be distributed over P processors in a parallel machine. Each processor runs the same program and operates only on its part of the problem. Messages passed between the processors allow data exchange to maintain consistency with the original algorithm. The strategies developed to parallelise unstructured mesh codes should meet a number of requirements: The algorithms are faithfully reproduced in parallel. The code is largely unaltered in the parallel version. The parallel efficiency is maximised. The techniques should scale to highly parallel systems. The parallelisation process should become automated. Techniques and strategies that meet these requirements are developed and tested in this dissertation using a state of the art integrated computational fluid dynamics and solid mechanics code. The results presented demonstrate the importance of the problem partition in the definition of inter-processor communication and hence parallel performance. The classical measure of partition quality based on the number of cut edges in the mesh partition can be inadequate for real parallel machines. Consideration of the topology of the parallel machine in the mesh partition is demonstrated to be a more significant factor than the number of cut edges in the achieved parallel efficiency. It is shown to be advantageous to allow an increase in the volume of communication in order to achieve an efficient mapping dominated by localised communications. The limitation to parallel performance resulting from communication startup latency is clearly revealed together with strategies to minimise the effect. The generic application of the techniques to other unstructured mesh codes is discussed in the context of automation of the parallelisation process. Automation of parallelisation based on the developed strategies is presented as possible through the use of run time inspector loops to accurately determine the dependencies that define the necessary inter-processor communication.
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Doyle, Jacqueline. "Describing and Mapping the Interactions between Student Affective Factors Related to Persistence in Science, Physics, and Engineering." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3353.
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This dissertation explores how students’ beliefs and attitudes interact with their identities as physics people, motivated by calls to increase participation in science, technology, engineering, and mathematics (STEM) careers. This work combines several theoretical frameworks, including Identity theory, Future Time Perspective theory, and other personality traits to investigate associations between these factors. An enriched understanding of how these attitudinal factors are associated with each other extends prior models of identity and link theoretical frameworks used in psychological and educational research. The research uses a series of quantitative and qualitative methodologies, including linear and logistic regression analysis, thematic interview analysis, and an innovative analytic technique adapted for use with student educational data for the first time: topological data analysis via the Mapper algorithm.
Engineering students were surveyed in their introductory engineering courses. Several factors are found to be associated with physics identity, including student interest in particular engineering majors. The distributions of student scores on these affective constructs are simultaneously represented in a map of beliefs, from which the existence of a large “normative group” of students (according to their beliefs) is identified, defined by the data as a large concentration of similarly minded students. Significant differences exist in the demographic representation of this normative group compared to other students, which has implications for recruitment efforts that seek to increase diversity in STEM fields. Select students from both the normative group and outside the normative group were selected for subsequent interviews investigating their associations between physics and engineering, and how their physics identities evolve during their engineering careers.
Further analyses suggest a more complex model of physics and engineering identity which is not necessarily uniform for all engineering students, including discipline-specific differences that should be further investigated. Further, the use of physics identity as a model to describe engineering student choices may be limited in applicability to early college. Interview analysis shows that physics recognition beliefs become contextualized in engineering as students begin to view physics as an increasingly distinct domain from engineering.
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Carroll, Carla June. "A Feasibility Study of Photometric Reverberation Mapping with Meter-Class Telescopes." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/5469.
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For the past several decades, mass estimates for supermassive black holes hosted by active galactic nuclei (AGN) have been made with the reverberation mapping (RM) technique. This methodology has produced consistent results and has been used to establish several relations that link the characteristics of the host galaxy to the mass of the central black hole. Despite this success, there are less than 50 AGN with black hole masses derived from RM. This low number is generally attributed to the difficulties in coordinating large blocks of telescope time for making simultaneous photometric and spectroscopic observations. Spectroscopic observations also generally require several months of nightly observations with moderate to large size telescopes as the signal-to-noise ratio is too low for smaller telescopes. We have made photometric observations of NGC 5548 in four filters (a custom-made Hα10 filter, the Strömgren y filter, the Johnson/Cousins V filter and the Johnson/Cousins R filter) in order to evaluate a photometric methodology for determining the lag time between the variations observed in the continuum and the Hα emission from the broad-line region (BLR) gas. This time delay represents the mean light travel time to the BLR and is therefore a measurement of the mean BLR radius. Multiple JAVELIN analyses of the three continuum light curves (y, V, and R), relative to the light curve from the Hα10 filter yields a value for τ = 3.3 ± 0.1 days. Adopting a value of f = 5.5, along with a single-epoch spectroscopic measurement from Park et of Δv = 4354±25 km/s, enables us to estimate a black hole mass of M_BH = 67.2±2.2x10^6 M_sun.
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Bentz, Misty C. "Black hole scaling relationships new results from reverberation mapping and Hubble Space Telescope imaging /." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1180453426.
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Ma, Donglin. "Exploration of Ray Mapping Methodology in Freeform Optics Design for Non-Imaging Applications." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/594394.
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This dissertation investigates various design metrologies on designing freeform surfaces for LED illumination applications. The major goal of this dissertation is to study designing freeform optical surfaces to redistribute the radiance (which can be simplified as intensity distribution for point source) of LED sources for various applications. Nowadays many applications, such as road lighting systems, automotive headlights, projection displays and medical illuminators, require an accurate control of the intensity distribution. Freeform optical lens is commonly used in illumination system because there are more freedoms in controlling the ray direction. Design methods for systems with rotational and translational symmetry were well discussed in the 1930's. However, designing freeform optical lenses or reflectors required to illuminate targets without such symmetries have been proved to be much more challenging. For the simplest case when the source is an ideal point source, the determination of the freeform surface in a rigorous manner usually leads to the tedious Monge-Ampère second order nonlinear partial different equation, which cannot be solved with standard numerical integration techniques. Instead of solving the differential equation, ray mapping is an easier and more efficient method in controlling one or more freeform surfaces for prescribed irradiance patterns. In this dissertation, we investigate the ray mapping metrologies in different coordinate systems to meet the integrability condition for generating smooth and continuous freeform surfaces. To improve the illumination efficiency and uniformity, we propose a composite ray mapping method for designing the total internal reflective (TIR) freeform lens for non-rotational illumination. Another method called "double pole" ray mapping method is also proposed to improve system performance. The ray mapping designs developed for the point source do not work well for extended sources, we have investigated different design methodologies including optimization method, deconvolution method and feedback modification method to design freeform optical surfaces for extended sources.
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Chemishkian, Sergey Y. 1962. "Computational methods for the optimization of the mapping of actuators and sensors in the control of flexible structures." Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/282656.
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In this work the problem of actuator and sensor mapping and controller design for the flexible structure control is approached as minimization of the residual deformations index (Hinfinity norm of the closed-loop disturbance - deformation path) over the set of non-destabilizing feedback controllers and over the set of possible actuator and sensor mappings. Computational load associated with this approach is reduced by restricting the search to the mapping areas where an inexpensive lower estimate of residual deformations index (derived as a part of this study) is less than the desired value of this index. Further improvement is achieved by including statistical description of the difference between the actual and the estimated performance index over the set of mappings, in order to adjust the level of the mapping acceptance/rejection in such a way that the number of rejected mappings is increased. Serial and parallel optimization procedures based on exhaustive search and genetic algorithms are discussed. These concepts and algorithms are applied to test cases of simply supported beam, the UCLA Large Space Structure, and a telescope mirror model: a hinged round plate.
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Marshall, Jennifer L. "Mapping the Local Galactic Halo and An Image Motion Compensation System for the Multi-Object Double Spectrograph." The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1155646690.
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Spode, Lennart. "Mapping the binding energy of H inside amorphous and crystalline transition metals using the effective medium theory." Thesis, Uppsala universitet, Materialfysik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-413982.
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Pezouvanis, Antonios. "Engine modelling for virtual mapping : development of a physics based cycle-by-cycle virtual engine that can be used for cyclic engine mapping applications, engine flow modelling, ECU calibration, real-time engine control or vehicle simulation studies." Thesis, University of Bradford, 2009. http://hdl.handle.net/10454/4419.
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After undergoing a study about current engine modelling and mapping approaches as well as the engine modelling requirements for different applications, a major problem found to be present is the extensive and time consuming mapping procedure that every engine has to go through so that all control parameters can be derived from experimental data. To improve this, a cycle-by-cycle modelling approach has been chosen to mathematically represent reciprocating engines starting by a complete dynamics crankshaft mechanism model which forms the base of the complete engine model. This system is modelled taking into account the possibility of a piston pin offset on the mechanism. The derived Valvetrain model is capable of representing a variable valve lift and phasing Valvetrain which can be used while modelling most modern engines. A butterfly type throttle area model is derived as well as its rate of change which is believed to be a key variable for transient engine control. In addition, an approximation throttle model is formulated aiming at real-time applications. Furthermore, the engine inertia is presented as a mathematical model able to be used for any engine. A spark ignition engine simulation (SIES) framework was developed in MATLAB SIMULINK to form the base of a complete high fidelity cycle-by-cycle simulation model with its major target to provide an environment for virtual engine mapping procedures. Some experimental measurements from an actual engine are still required to parameterise the model, which is the reason an engine mapping (EngMap) framework has been developed in LabVIEW, It is shown that all the moving engine components can be represented by a single cyclic variable which can be used for flow model development.
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Potter, Harrison D. P. "On Conformal Mappings and Vector Fields." Marietta College Honors Theses / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=marhonors1210888378.
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Aryal, Puruswottam. "Optical and Photovoltaic Properties of Copper Indium-Gallium Diselenide Materials and Solar Cells." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1404679981.
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Bernat, P. "Recherche du boson de Higgs dans le canal de désintégration en deux photons avec le détecteur ATLAS au LHC." Phd thesis, Université Paris Sud - Paris XI, 2010. http://tel.archives-ouvertes.fr/tel-00525583.
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Cette thèse a traité trois différents aspects ayant trait à la recherche du boson de Higgs dans le canal de désintégration en deux photons avec le détecteur ATLAS. Le premier est une étude sur l'uniformité intrinsèque du calorimètre électromagnétique (EM) d'ATLAS en utilisant la mesure du temps de dérive des électrons d'ionisation. Environs 500 000 signaux provenant de rayons cosmiques sont enregistrés et sont comparés à la forme du signal prédite en utilisant la méthode FPM (pour First Principle Method). L'ajustement de la forme prédite à celle mesurée permet de mesurer le temps de dérive des électrons d'ionisation de l'argon liquide. L'uniformité du temps de dérive dans le compartiment Middle calculée par blocs de taille 0.1 x 0.1 dans le plan (η,φ) est estimée à 1.27 ± 0.03%. L'impact de la variation du temps de dérive sur l'uniformité de la réponse du calorimètre est estimée à 0.29 ± 0.01%. En tenant compte de la variation de l'épaisseur des plaques de plomb qui constituent le milieu passif et qui ont été mesurées par ailleurs, l'uniformité intrinsèque du calorimètre est estimée à 0.34%. La vitesse de dérive des électrons mesurée dans les différents compartiments du calorimètre est en moyenne V_{D(E = 1 kV/mm) = 4.58 ± 0.07 mm.μ s^-1 en bon accord avec des mesures antérieures de la vitesse de dérive des électrons dans l'argon liquide à la température de 88.5K. Le second aborde la question de l'estimation de la matière en amont du calorimètre, utilisant une cartographie du détecteur interne. Cette mesure est faite relativement au nombre de conversions dans le tube à vide (beam pipe) de manière à être indépendante du flux initial de photons. Une connaissance précise de la matière en amont du calorimètre est essentielle à la calibration en énergie des électrons et photons reconstruits dans le calorimètre. Puisqu'une large fraction des photons proviennent de mésons π^0, le flux initial de photons qui intervient dans le taux de conversions dans le beam pipe est normalisé aux désintégrations Dalitz du π^0. L'observable qui permet de comparer les données aux simulations Monte-Carlo (MC) est le rapport du nombre de conversions reconstruites dans le beam pipe et du nombre de Dalitz reconstruits. Ce rapport estimé avec les données de collision à une énergie de 7 TeV dans le centre de masse donne un bon accord sur la mesure de la matière dans le beam pipe avec la prédiction du MC : X/X_0 = 0.669 ± 0.033(stat) ^+0.013_-0.080(syst)%, X/X_0 = 0.709 ± 0.028(syst) %, et X/X_0 = 0.709 ± 0.028(syst) %respectivement. Le dernier est l'étude de la normalisation du signal et du bruit de fond ainsi que l'analyse du potentiel discriminant dans l'analyse inclusive du canal H → γγ. Différentes simulations MC sont utilisées pour estimer une normalisation à l'ordre NLO du signal et du bruit de fond irréductible (γγ) ainsi que les erreurs systématiques associées. Celles-ci représentent respectivement 16% et 26% de la section efficace totale. Le pouvoir discriminant de l'impulsion transverse du système diphoton et du cosθ* est aussi étudié. En particulier, une forte corrélation entre le cosθ* et la masse invariante diphoton est observée. Le bruit de fond semi-réductible (γ-jet) est normalisé à NLO avec 27% d'erreurs systématiques. Une nouvelle normalisation qui s'applique après l'identification des photons est proposée. Elle prend en compte la différente réjection des jets provenant de quark ou de gluon et est estimée à 1.9 ± 0.6. Les perspectives d'exclusion du boson de Higgs dans le canal diphoton à 10 TeV et l'extrapolation à 7 TeV pour un luminosité intégrée de 1 f b^−1 sont présentées. Dans le dernier scénario, environ 5 fois le Modèle Standard est exclu à 95% de niveau de confiance pour une masse du boson de Higgs autour de 120 GeV/c^2 .
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Kazemeini, Sayed Hesammoddin. "Seismic Investigations at the Ketzin CO2 Injection Site, Germany: Applications to Subsurface Feature Mapping and CO2 Seismic Response Modeling." Doctoral thesis, Uppsala universitet, Geofysik, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-105032.
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3D seismic data are widely used for many different purposes. Despite different objectives, a common goal in almost all 3D seismic programs is to attain better understanding of the subsurface features. In gas injection projects, which are mainly for Enhanced Oil Recovery (EOR) and recently for environmental purposes, seismic data have an important role in the gas monitoring phase. This thesis deals with a 3D seismic investigation at the CO2 injection site at Ketzin, Germany. I focus on two critical aspects of the project: the internal architecture of the heterogeneous Stuttgart reservoir and the detectability of the CO2 response from surface seismic data. Conventional seismic methods are not able to conclusively map the internal reservoir architecture due to their limited seismic resolution. In order to overcome this limitation, I use the Continuous Wavelet Transform (CWT) decomposition technique, which provides frequency spectra with high temporal resolution without the disadvantages of the windowing process associated with the other techniques. Results from applying this technique reveal more of the details of sand bodies within the Stuttgart Formation. The CWT technique also helps to detect and map remnant gas on the top of the structure. In addition to this method, I also show that the pre-stack spectral blueing method, which is presented for the first time in this research, has an ability to enhance seismic resolution with fewer artifacts in comparison with the post-stack spectral blueing method. The second objective of this research is to evaluate the CO2 response on surface seismic data as a feasibility study for CO2 monitoring. I build a rock physics model to estimate changes in elastic properties and seismic velocities caused by injected CO2. Based on this model, I study the seismic responses for different CO2 injection geometries and saturations using one dimensional (1D) elastic modeling and two dimensional (2D) acoustic finite-difference modeling. Results show that, in spite of random and coherent noises and reservoir heterogeneity, the CO2 seismic response should be strong enough to be detectable on surface seismic data. I use a similarity-based image registration method to isolate amplitude changes due to the reservoir from amplitude changes caused by time shifts below the reservoir. In support of seismic monitoring using surface seismic data, I also show that acoustic impedance versus Poisson’s ratio cross-plot is a suitable attribute for distinguishing gas-bearing sands from brine-bearing sands.CO2SINK Project
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Costa, Rosilaine Gomes de Santana. "Um estudo bibliográfico sobre a utilização de mapas conceituais como ferramenta de avaliação da aprendizagem: algumas considerações no ensino de física." Pós-Graduação em Ensino de Ciências e Matemática, 2013. https://ri.ufs.br/handle/riufs/5146.
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This work is a bibliographical research, which is a systematic review without meta-analysis, performed in various national and international journals and proceedings in the International Conferences on Concept Maps (CM) aiming to analyze how the researches which make use of CM are being developed as an
assessment tool to of student learning and it also establishes criteria to evaluatethem. The goal in using CM is to check students learning process regarding to the contents learned in the classroom, getting information about the concepts learned significantly, as well as those who have not been learned or learned incorrectly, making sure that these same students were able to establish connections between
the new concepts and the already existing knowledge in their cognitive structure. It was observed through the analysis of the methodology of the researched articles, that there is a significant number of works, from a universe of 105, making use of CM as an assessment tool in different areas, including Physics, and with different methodologies. It was also noticeable a certain concern from the authors in
establishing criteria to check/assess whether CM prepared by students achieved the desired goals. It is hoped that this research can guide teachers/researchers who intend to work with such an tool of learning assessment, which, although greatly important to education, is not widely used in the educational environmentEste trabalho é uma pesquisa bibliográfica, do tipo revisão sistemática sem metanálise, realizada em diversos periódicos nacionais e internacionais e nas atas das Conferências Internacionais sobre Mapas Conceituais (MC) com o objetivo de analisar como vêm sendo desenvolvidas as pesquisas que utilizam MC como ferramenta de avaliação da aprendizagem dos estudantes e que estabelecem critérios para avaliá-los. O objetivo de utilizar MC é verificar a aprendizagem dos alunos em relação aos conteúdos trabalhados em sala de aula, obtendo informações sobre os conceitos aprendidos de forma significativa, aqueles que não foram aprendidos e os aprendidos de forma incorreta, verificando se esses alunos conseguiram estabelecer as relações dos novos conceitos com os conhecimentos já existentes na sua estrutura cognitiva. Foi possível observar, por meio da análise da metodologia dos artigos, que há um número significativo de trabalhos, de um universo de 105, que utilizam MC como ferramenta de avaliação em diferentes áreas, dentre elas a Física, e com diversas metodologias. Foi perceptível ainda a preocupação dos autores em estabelecer critérios para verificar/avaliar se os MC elaborados pelos alunos atingiram os objetivos desejados. Espera-se que essa pesquisa possa orientar professores/pesquisadores que pretendam trabalhar com tal ferramenta de avaliação da aprendizagem, que, embora tenha grande importância para o ensino, ainda é pouco utilizada no meio educacional
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Hage, Hassan Maya. "Méthodologies de conception optimale de systèmes de conversion électromécanique." Phd thesis, Université Paris Sud - Paris XI, 2014. http://tel.archives-ouvertes.fr/tel-01002008.
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Cette thèse traite de la conception de systèmes électromécaniques, en particulier des machines électriques dédiées à des applications de traction. La démarche adoptée allie précision des résultats et réduction du temps de calcul du processus. A cet égard, deux thèmes ont été abordés dans cette thèse. Le premier thème concerne la modélisation de machines électriques et l'utilisation de méthodes semi-numériques. Une architecture de réseau de réluctances est proposée pour analyser les performances de machines à flux axial. Elle permet la prise en compte de l'aspect temporel et la caractéristique non-linéaire des matériaux ferromagnétiques. Des modèles basés sur la méthode des éléments finis ont été établis pour valider les résultats de modélisation. Le faible écart entre modèles numériques et semi-numériques montre le bien fondé des méthodes proposées. Des dimensionnements offrant un compromis entre précision de la solution finale et temps de calcul font l'objet du second thème de la thèse. La technique du Space Mapping est connue pour son efficacité, elle permet d'exploiter à moindre coût un modèle précis. Deux techniques qui en dérivent sont proposées en associant la modélisation par réseau de réluctances et des techniques d'optimisation. La première repose sur la modélisation de l'erreur entre des modèles de précisions différentes par une fonction à bases radiales. La deuxième intègre la correction de l'erreur dans la résolution des réseaux de réluctances en couplant les modèles linéaire et non-linéaire d'une machine électrique.
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Apostolou, Sinoula. "Physical mapping of human chromosome 16." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09pha645.pdf.
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Khorasani, Maryam Zadeh. "Physical mapping of medaka (Oryzias latipes) genome." [S.l.] : [s.n.], 2006. http://www.diss.fu-berlin.de/2006/630/index.html.
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Kaufman, Alan P. (Alan Philip). "Data and algorithms for genomic physical mapping." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/36508.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.Includes bibliographical references (leaves 116-122).
by Alan P. Kaufman.
M.S.
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George, Sisilamma. "Physical mapping of the murine casein locus." Thesis, University of Edinburgh, 1996. http://hdl.handle.net/1842/13892.
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The murine casein locus has been characterised by long range restriction mapping and the analysis of long fragment genomic clones. Cloned sequences from five mouse casein genes (α, β, γ, ?, κ) were used to screen a murine (strain 129) genomic library in a bacterial artificial chromosome vector (BAC). Of the nine clones isolated, two contained 3 casein genes α, β, γ and γ, ?, κ respectively. The following combinations were found in other clones - α + β; β + γ; γ + ?. Thus, I deduced that the gene order in the locus is α- β- γ- ?-κ. I have confirmed this order by restriction analysis of the clones. Expression studies of casein genes at various time points during pregnancy and lactation revealed a co-ordinate expression pattern for the three (α, β and γ) calcium sensitive genes from mid pregnancy to parturition. The genetic variation in the casein loci of Mus musculus (eight different strains) and Mus spretus was also examined as restriction fragment length variations (RFLV) using five restriction enzymes, BamHI, SfiI, HindIII, EcoRI and XbaI. The information obtained from the present mapping study and the clones isolated (129 strain) can be used to manipulate the casein locus in embryonic stem (ES) cells as most gene targeting experiments are carried out in ES cells isolated from 129 mice. Gene targeting is more effective if the targeting DNA is prepared from isogenic DNA. It is also advantageous to use isogenic DNA derived maps in targeting experiments. Thus, the results of this study could not only contribute to basic studies on genome structure and function but also in the longer term underpin applications in biotechnology and agriculture/industry.
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Jain, Mudita 1968. "Algorithms for physical mapping using unique probes." Diss., The University of Arizona, 1996. http://hdl.handle.net/10150/290622.
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DNA molecules are sequences of characters over a four letter alphabet. Determining the text of the DNA sequence contained in human cells is the goal of the Human Genome Project. The structure of a DNA sequence is reconstructed from a set of shorter fragments sampled from it at unknown locations, as it is usually too long to be determined directly. We consider the problem when the the fragments are very long, and each fragment has a fingerprint consisting of the presence of two or three pre-selected, smaller sequences called probes within it. These probes have a unique location along the original DNA sequence. The fingerprints contain false negative and false positive errors, and the fragments may be chimeric. A physical map of a DNA sequence is a reconstruction of the order of the probes and fragments along it. In short, given a collection of fragments, with fingerprints for each fragment taken from a collection of probes, and parameters that bound the rates of false negatives, false positives, and chimeras in the input data, the problem is to find the most likely probe ordering. Physical mapping is NP-complete when the input data contains errors. To construct physical maps we first determine neighbourhoods of probes and clones that are highly likely to be adjacent on the original DNA sequence. We then use a new, versatile integer linear programming formulation of the problem, to derive heuristics for ordering probes within neighbourhoods. This formulation provides a single, uniform representation for diverse data such as end-clone probes and in-situ hybridization, and provides a natural medium for the integration of previously constructed maps with newer data. We also present an ordering heuristic based upon end-clone data. Finally, we connect these local permutations into a larger, more global probe permutation. For this we use heuristics that have at their core previously mapped data. All heuristics are implemented and evaluated by comparing the computed probe orderings to the original probe orderings for simulated data.
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Wang, Luping. "Physical Mapping of Human Transfer RNA Gene Clusters." Thesis, University of North Texas, 1989. https://digital.library.unt.edu/ark:/67531/metadc500957/.
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Two plaque-pure phage lambda clones designated as λhtX-l and λhtX-2 that hybridized to unfractionated bovine liver tRNA were isolated from a human X chromosome-specific library. The λDNAs were characterized by restriction mapping and Southern blot hybridization techniques. The human DNA segment in λhtX-l contains five or more presumptive tRNA genes and at least one Alu family member. The 19-kilobase human DNA insert in λhtX-2 contains two or more presumptive tRNA genes and at least three Alu family members. Another human genomic clone designated λhVKV7 hybridized to mammalian valine tRNA IAC. The clone was characterized by physical mapping and Southern blot hybridization techniques. The 18.5-kilobase human DNA fragment in λhVKV7 contains a cluster of three tRNA genes and at least nine Alu family members.
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Maccormick, Marion. "The ALICE Project at the IPN, OrsayR&D and software developments 1996-2003." Habilitation à diriger des recherches, Université Paris Sud - Paris XI, 2007. http://tel.archives-ouvertes.fr/tel-00159807.
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Ce document décrit en détail les étapes importantes de R&D dans la conception et mise au point de la chambre proportionnelle à lecture cathodique hautement segmentée de la station1 du Spectromètre Bras Dimuons de l'expérience ALICE, récemment implantée au LHC. Plusieurs aspects expérimentaux sont résumés - comprenant l'électronique, la construction mécanique, la modélisation du détecteur, les simulations de la physique et les faisceaux tests, les méthodes de cartographie en langue Orientée Objet et les résultats des prototypes en faisceaux test. Ce document est écrit à destination des jeunes expérimentateurs.
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Wang, Xiao Yu. "Genetic and physical mapping of Arabidopsis and Brassica." Thesis, University of Birmingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433979.
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Zimmer, Régis. "Micromanipulation and physical mapping of the chicken Z chromosome." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq24435.pdf.
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Liu, Zhiyong Michael. "Mapping physical topology with logical topology using genetic algorithm." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ62245.pdf.
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Törnsten, Anna. "Physical mapping of important trait loci in the pig /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 2000. http://epsilon.slu.se/avh/2000/91-576-5913-3.pdf.
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Hodges, Matthew David. "Physical mapping of chromosal rearrangements in Beckwith-Wieddemann syndrome." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.313712.
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Wixon, Joanne. "Physical and transcriptional mapping in human chromosome band 6p23." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363758.
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Craig, Nicola Jane. "Genetic and physical mapping of the rat agu locus." Thesis, University of Glasgow, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341722.
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Malas, Stavros. "Genetic and physical mapping studies on mouse chromosome 2." Thesis, University College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283659.
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