Дисертації з теми "Elemental imaging"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Elemental imaging".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
Lum, Tsz Shan. "Elemental imaging and speciation for bioanalysis." HKBU Institutional Repository, 2016. https://repository.hkbu.edu.hk/etd_oa/328.
Повний текст джерелаStedman, Jacqueline D. "Regional distribution of elemental concentrations in brain tissue of #normal' ageing and sporadic Alzheimer's disease subjects as determined by PIXE, RBS and INA analyses." Thesis, University of Surrey, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318698.
Повний текст джерелаAsogan, Dhinesh. "A non-contact laser ablation cell for mass spectrometry." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/11014.
Повний текст джерелаDickson, Hazel Rebecca. "Strategies for the identification of pharmaceutical compounds in thin tissue sections using lazer-based elemental and molecular mass spectrometric imaging techniques." Thesis, University of Sheffield, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.522450.
Повний текст джерелаBuchriegler, Josef [Verfasser], Jürgen [Gutachter] Faßbender, and Matjaz [Gutachter] Kavcic. "Full-field PIXE imaging using a Colour X-ray Camera : Advantages and drawbacks in elemental mapping of large areas with a poly-capillary optics / Josef Buchriegler ; Gutachter: Jürgen Faßbender, Matjaz Kavcic." Dresden : Technische Universität Dresden, 2021. http://d-nb.info/1235346390/34.
Повний текст джерелаChoi, Hyungryul. "Fabrication of anti-reflective and imaging nanostructured optical elements." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/106723.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references (p. 69-73).
Moth eyes minimize reflection over a broad band of angles and colors and lotus leaves minimize wetting over a broad range of breakthrough pressures by virtue of subwavelength structures patterned on their respective surfaces; similar examples of organisms exploiting geometry to attain properties unavailable in bulk materials are abundant in nature. These instances have inspired applications to man-made structures, collectively known as functional materials: for example, self-cleaning/anti-fogging surfaces, and solar cells with increased efficiency. I fabricated a functional surface where both wetting and reflectivity are controlled by geometry. Using a periodic array of subwavelength-sized high aspect ratio cones, patterned on glass and coated with optimized surfactants, I have experimentally shown that we can significantly enhance transmission from the surfaces of a glass slab, and at the same time make the surfaces either superhydrophobic or superhydrophilic, depending on the applications, such as antifogging and self-cleaning glass. Novel lithographic techniques result in high patterning accuracy over large surface areas, and is easily adaptable to nanoimprinting for future mass replication. In addition, an all-dielectric subwavelength-patterned Luneburg lens was fabricated for operation at free-space wavelength of A =1.55 um.
by Hyungryul Choi.
S.M.
Neugebohren, Jannis. "Implementing Ion Imaging to Probe Chemical Kinetics and Dynamics at Surfaces." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2018. http://hdl.handle.net/11858/00-1735-0000-002E-E43B-1.
Повний текст джерелаVianna, Graziela Valadares Gomes de Mello. "Imagens sonoras no ar: a sugestão de sentido na publicidade radiofônica." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/27/27153/tde-09092009-120319/.
Повний текст джерелаThe objective of this thesis is to comprehend the suggestions of sense that are constructed by the sound elements of radio language. So, we analysed the text, the performing of the voices, the music, the sound effects, the silence and the sound techniques (recording, mixing and post-recording effects, like reverberation, equalization) to understand how those suggestions are constructed. Elements that are associated to the cultural background of the listener to create multisensorial images. For this purpose, we defined radio advertising as the object of our analysis. We considered the fact that near the dates related to consuming Christmas, Summer vacation, Easter, Mother\'s Day, Valentine\'s Day, Father\'s Day and Children\'s Day advertising is intensified in the media. So we recorded the two more popular radio stations in each capital of south and south east brazilian regions one week before each date. Those regions had received 95,1 % of total investments in advertising in radio (2004/2005). After this recording, we selected two commercials for each date one jingle and one spot that utilizes drama as a technique to persuade the listener. The analysis of radio advertising allow us to identify the \"model-listener\" of the advertisings and the objectives of each commercial. And also permit us to verify the strategies to persuade the audience and point some possibilities to suggest sound images to this audience. The research establishes a typology of the sound elements of the radio language that are related to the potential of expression of this medium. We believe that this work can be a contribution for further researches about radio language, for the professionals of advertising and for those who works on radio stations to better comprehend such potential. So, radio could become more attractive for advertising investments and for the listeners.
Lima, Cícero Ribeiro de. "Estudo da obtenção de imagens de tomografia de impedância elétrica do pulmão pelo método de otimização topológica." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/3/3132/tde-15092006-162839/.
Повний текст джерелаThe Electrical Impedance Tomography (EIT) is a recent monitoring technique on biological tissues. The EIT allows us to obtain images representing a transversal plane of any section of human body (head, thorax, thigh, etc). Each image pixel is related to its corresponding value of electrical impedance (or resistivity). The images are generated from voltage values measured on electrodes positioned around the section of human body. These voltages are obtained by applying to the electrodes an alternated sequence of low intensity electrical currents in according to an excitation pattern (adjacent or diametral). The EIT is based on an inverse problem, where given the voltages measured outside of body, this technique tries to find the conductivity distribution inside of the body. In this work, the main objective is to apply Topology Optimization Method (TOM) to obtain images of body section in EIT. Topology Optimization seeks a material distribution inside of a design domain, determining which points of space should be solid and which points should be void, to minimize (or maximize) an objective function requirement, satisfying specified constraints. In this work, the MOT is an iterative method whose computational algorithm (implemented in C language) combines Finite Element Method (FEM) and an optimization algorithm called Sequential Linear Programming (SLP). The topology optimization problem applied to obtain images consists of finding the material (or conductivity) distribution in the body section that minimizes the difference between electric potential measured on electrodes and electric potential calculated by using a computational model. The main advantage of TOM applied to image reconstruction in EIT is to allow us to include several constraints in optimization problem, which reduces the solution space and avoids images without clinical meaning. In this work, the MOT uses a material model based on SIMP to makes relaxation of topology optimization problem and several regularization schemes are implemented to solve inverse problem of EIT, such as image tuning control, weighted distance interpolation based on average conductivity of domain, spatial filtering technique for gradient control, graduated changing in penalty factor of material model during the optimization process (continuity method), and continuous approximation of material distribution (CAMD). This work belongs to a thematic project whose aim is to study reconstruction image algorithms that could be used in an EIT device to monitor accurately mechanical ventilation of lung and to diagnose when any portion of lung is damaged (obstructed or collapsed) during mechanical ventilation process. To illustrate the implementation of the method, image reconstruction results obtained by using voltage numerical and experimental data of well-know 2D domains are shown.
Pleasants, Ian Blair. "Detector elements for hard X-ray and gamma-ray astronomy applications." Thesis, University of Southampton, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262152.
Повний текст джерелаLangridge, Mark T. "Manufacture of micro-optical elements for imaging and light-guidance." Thesis, University of Surrey, 2015. http://epubs.surrey.ac.uk/807979/.
Повний текст джерелаLi, Xiaobei. "Instrumentation and inverse problem solving for impedance imaging /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/5973.
Повний текст джерелаDominick, Colleen Elizabeth. "An investigation of array elements for enhanced single echo acquisition imaging." Thesis, Texas A&M University, 2005. http://hdl.handle.net/1969.1/4309.
Повний текст джерелаCravo, Anderson Gabriel Santiago. "Elastografia em imagens de ultrassom utilizando elementos de contorno." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/3/3142/tde-14062016-141801/.
Повний текст джерелаThis thesis presents a new methodology for computational elastography applied to simulated ultrasound images, using numerical methods and comptuter vision methods. The aim is to estimate the elastic moduli of diferent tissues using two diferent images of the same cross section acquired in diferent times and pressure conditions. The proposed methodology consists in evaluate the displacement field using optical flow techniques and then apply an inverse analysis using a numerical method. In order to evaluate the displacement field, two distinct formulations for optical flow are used: Lucas-Kanade and Brox. For the inverse analysis problem, the Finite Element Method and the Boundary Element Method are used, both implemented in general purpose graphic units, GpGPUs. Considering a number of materials that may be present in the images, the multiresgions boundary element method is used in order to couple diferent matrices for diferent materials. The optimization process is evaluated using complex variable method. The methodology is validated in three diferent steps: noiseless simulations; additive white gaussian noise simulations; and ultrasound mathematical phantom with speckle tracking. The results show that the Finite Element Method presents more accurate estimatives but a high computational cost, while the Boundary Element Method presents tolerable errors but a better processing time.
Bass, Mark James. "Velocity mapping of elementary bimolecular reactions." Thesis, University of Oxford, 2004. http://ora.ox.ac.uk/objects/uuid:ea381f05-6a68-435f-91d6-30d14a8c8dc4.
Повний текст джерелаRodriguez, Rivera Noemi Ines. "Imagem por dupla difração com luz branca sem elementos intermediários." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/278130.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin
Made available in DSpace on 2018-08-08T07:18:00Z (GMT). No. of bitstreams: 1 RodriguezRivera_NoemiInes_D.pdf: 6088514 bytes, checksum: c2c66dc6b71f900d00c6832f96aaf3eb (MD5) Previous issue date: 2007
Resumo: Apresentamos neste trabalho a análise da formação de imagens por elementos difrativos com luz branca fazendo o traçado de raios pelas direções principais. O primeiro sistema analisado é composto por duas redes de difração e uma fenda, o segundo por dois elementos bidimensionais de estrutura espiral e um orifício, que formam imagens ortoscópicas (relevo natural). A partir das análises mencionadas desenvolvemos um sistema de dois elementos difrativos sem elementos intermediários que forma uma imagem de luz branca que é pancromática, porque oferece as cores originais. Além disso, apresentamos um sistema formador de uma imagem por transmissão que consiste na projeção de objetos usando uma fonte linear (filamento extenso) e um elemento difrativo. Aproveitando as propriedades de uma fonte linear, desenvolvemos um sistema que permite que espelhos ou lentes imperfeitos gerem imagens nítidas. Mediante estes sistemas visamos conseguir um dia a formação de imagens convergentes, entretanto já oferecemos novas maneiras de se exibir imagens tridimensionais atrativas e amplas
Abstract: We present the analysis of the formation of images by diffractive elements using white light by performing ray-tracing through main directions. The first system we describe is composed of two diffraction gratings and a slit, the second by two bi-dimensional spiral elements and a hole aperture, generating ortoscopic (natural relief) images. From this we had found a system of two diffractive elements without any intermediating element that makes and image which is panchromatic because gives original colors. Furthermore, we present a transmission imaging system that projects objects by means of a linear source (extended filament) and a diffractive element. Profiting the imaging properties of that linear source we also developed a system for mirrors and lenses having no sharpness to generate sharp images. By studying these systems we seek to find a way to achieve the making of convergent images and we already offer new ways to exhibit attractive and large three-dimensional images
Doutorado
Física
Doutor em Ciências
Lerch, Terence. "Thermal evaluation of an integrated circuit chip using infrared imaging and finite element techniques /." Online version of thesis, 1991. http://hdl.handle.net/1850/11113.
Повний текст джерелаAkalin, Acar Zeynep. "Electro-magnetic Source Imaging Using Realistic Head Models." Phd thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12606173/index.pdf.
Повний текст джерелаs gyrus. In conclusion, this thesis presents a complete source localization framework for future brain research using the EMSI.
Magalhães, Daniel Souza Ferreira. "Estudo de imagens por dupla difração com seleção de luz branca e elementos definidos bidimensionalmente." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/278144.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin
Made available in DSpace on 2018-08-04T02:40:53Z (GMT). No. of bitstreams: 1 Magalhaes_DanielSouzaFerreira_M.pdf: 2786566 bytes, checksum: d02ed179060d33a6a269a495bcb6a2bb (MD5) Previous issue date: 2005
Resumo: Neste trabalho analisamos a formação de imagens por elementos difrativos com luz branca fazendo o traçado de raios pelas direções principais e explorando as possibilidades que a simetria de um conjunto de dois elementos definidos bidimensionalmente e intermediados por um pequeno orifício oferece. A mais interessante delas é a de termos uma imagem convergente, que pode ser vista projetando sobre uma tela, por exemplo
Abstract: We perform ray tracing analysis on the imaging of white light objects by diffractive elements by means of the main direction of the rays. We explore the possibilities that the symmetry of a set of two bidimensionally acting diffracting elements intermediated for a pinhole offers. The most interesting of them is that we have a convergent image, that can be seen projecting on a screen, for example
Mestrado
Ótica
Mestre em Física
Duarte, Peter. "Using computerized imaging to evaluate the visual preference effects of downtown streetscape elements." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/MQ51060.pdf.
Повний текст джерелаDobson, Andrew. "Seismic modelling for the sub-basalt imaging problem including an analysis and development of the boundary element method." Thesis, University of Edinburgh, 2005. http://hdl.handle.net/1842/765.
Повний текст джерелаQiu, Yan. "Three dimensional finite element model for lesion correspondence in breast imaging." [Tampa, Fla.] : University of South Florida, 2003. http://purl.fcla.edu/fcla/etd/SFE0000192.
Повний текст джерелаMiao, Cheng Hsi. "The design of phased synthetic aperture imaging systems using a minimum number of elements." Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185625.
Повний текст джерелаBarreto, Janaina Lucene Mendonza. "Coco de roda novo quilombo: da roda ao centro, imagens e símbolos de uma tradição." Universidade Federal da Paraíba, 2017. http://tede.biblioteca.ufpb.br:8080/handle/tede/9773.
Повний текст джерелаMade available in DSpace on 2018-02-22T13:13:47Z (GMT). No. of bitstreams: 1 Arquivo Total.pdf: 3421973 bytes, checksum: db60176d1cf41839ed3a79cfeeb7ccca (MD5) Previous issue date: 2017-06-30
This research aims to identify and analyze, from a phenomenological approach as well as interviews, some visual elements of the Coco de Roda do Ipiranga New Quilombo, artistic and cultural manifestation that occurs in the municipality of Conde, Paraíba. The elements that we identify in the course of research and that will be approached are: the hype; The coconut wheel; The bow and the garments. It is important to consider that the Coco de Roda here studied and debated, in its visual elements, is a form of resistance and artistic and cultural expression of great relevance for the society of Paraiba and for the country, considering its tradition and musical richness, of dance , Of the visual elements, in short, of all living and latent culture. Thus, by emphasizing and discussing the visual elements, we intend to contribute, on the one hand, to the scientific knowledge and knowledge present in the University, particularly for the fields of visual arts, culture and anthropology and, on the other hand, to strengthen the idea And the conviction that it is a significant cultural manifestation for society and, for the moment, for cultural public policies at the local, regional and national levels.
Esta pesquisa objetiva identificar e analisar, a partir de uma abordagem fenomenológica bem como de entrevistas realizadas, alguns elementos visuais do Coco de Roda do Novo Quilombo do Ipiranga, manifestação artístico e cultural que ocorre no município do Conde, Paraíba. Os elementos que identificamos no percurso de pesquisa e que serão abordados são: o bombo; a roda de coco; a umbigada e as vestimentas. Importa considerar que o Coco de Roda aqui estudado e debatido, em seus elementos visuais, é uma forma de resistência e expressão artístico e cultural de grande relevância para a sociedade paraibana e para o país, tendo em vista sua tradição e riqueza musical, de dança, dos elementos visuais, enfim, de toda a cultura viva e em latência. Assim, ao ressaltar e discutir os elementos visuais pretende-se contribuir, por um lado, para os conhecimentos científicos e saberes presentes na Universidade, em particular para os campos das artes visuais, cultura e antropologia e, por outro, para o fortalecimento da ideia e convicção de que trata-se de uma manifestação cultural significativa para a sociedade e, desde logo, para as politicas publicas culturais em âmbito local, regional e nacional.
Qin, Shanlin. "Fractional order models: Numerical simulation and application to medical imaging." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/115108/1/115108_9066888_shanlin_qin_thesis.pdf.
Повний текст джерелаZhang, Wenlong. "Forward and Inverse Problems Under Uncertainty." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEE024/document.
Повний текст джерелаThis thesis contains two different subjects. In first part, two cases are considered. One is the thin plate spline smoother model and the other one is the elliptic boundary equations with uncertain boundary data. In this part, stochastic convergences of the finite element methods are proved for each problem.In second part, we provide a mathematical analysis of the linearized inverse problem in multifrequency electrical impedance tomography. We present a mathematical and numerical framework for a procedure of imaging anisotropic electrical conductivity tensor using a novel technique called Diffusion Tensor Magneto-acoustography and propose an optimal control approach for reconstructing the cross-property factor relating the diffusion tensor to the anisotropic electrical conductivity tensor. We prove convergence and Lipschitz type stability of the algorithm and present numerical examples to illustrate its accuracy. The cell model for Electropermeabilization is demonstrated. We study effective parameters in a homogenization model. We demonstrate numerically the sensitivity of these effective parameters to critical microscopic parameters governing electropermeabilization
Cavalcanti, Luiz Carlos Amaral Mendonça. "Detecção de elementos antrópicos em imagens aéreas da floresta amazônica." Universidade Federal do Amazonas, 2016. http://tede.ufam.edu.br/handle/tede/5301.
Повний текст джерелаApproved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-12-01T13:30:28Z (GMT) No. of bitstreams: 1 Dissertação - Luiz C. A. M. Cavalcanti.pdf: 12456865 bytes, checksum: 8cefb0785da034136e29212e34ef9290 (MD5)
Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-12-01T13:30:49Z (GMT) No. of bitstreams: 1 Dissertação - Luiz C. A. M. Cavalcanti.pdf: 12456865 bytes, checksum: 8cefb0785da034136e29212e34ef9290 (MD5)
Made available in DSpace on 2016-12-01T13:30:50Z (GMT). No. of bitstreams: 1 Dissertação - Luiz C. A. M. Cavalcanti.pdf: 12456865 bytes, checksum: 8cefb0785da034136e29212e34ef9290 (MD5) Previous issue date: 2016-07-01
Agência de Fomento não informada
During environmental crimes patrolling, the response time is a very important component for the success of the missions. Generally, infractions occur in remote and hard-access places, characteristics that hinder both the patrolling as well the action of environmental protection agents. To increase the approaches’ success rate and reduce the risk of human lives, unmanned aerial vehicles (UAVs) can be used to cover large areas of forest in a short time without being perceived by offenders, allowing the patrolling organs responsible for these areas to plan and act more efficiently in the repression of such crimes. The new problem generated by this approach is the huge amount of data generated during these missions, which often includes hours of video. The manual inspection of all this material in searching for anthropic elements is very tiring and error-prone. This work presents a evaluation of image segmentation techniques, inspections of features to be extracted, followed by a supervised classification of those segments for anthropic element detection in amazon’s rain forest aerial images. Besides making publicly available a dataset with more than 3,000 images and 10,000 segments labeled accordingly, this work investigates different strategies for anthropic elements classification. The experiments obtained a consistency error rate inferior to 8% in image segmentation and a precision above 94% on target objects classification through one-class classifiers ensemble, using One-class SVM and REPTree algorithms.
Durante o patrulhamento de crimes ambientais, o tempo de resposta é um componente muito importante no sucesso das missões. Geralmente as infrações ocorrem em lugares ermos e de difícil acesso, características que dificultam tanto o patrulhamento quanto a ação de agentes de preservação ambiental. Para aumentar a taxa de sucesso das abordagens e reduzir o risco de vidas humanas, veículos aéreos não-tripulados (VANTs) podem ser usados para cobrir grandes áreas de floresta em pouco tempo, sem que sejam percebidos por infratores, permitindo que os órgãos de patrulhamento dessas áreas possam planejar e agir com mais eficiência na repressão a esses crimes. O novo problema gerado por essa abordagem é a enorme quantidade de dados gerada durante essas missões, que muitas vezes compreendem horas de vídeo. A inspeção manual de todo esse material em busca de elementos antrópicos é muito cansativa e propensa a erros. Este trabalho apresenta uma avaliação de técnicas de segmentação de imagens, inspeção de características a serem extraídas, seguido da classificação supervisionada destes segmentos para detecção de elementos antrópicos em imagens aéreas da floresta amazônica. Além da publicação de uma base de dados com cerca de 3.000 imagens e 10.000 segmentos devidamente rotulados e investiga diferentes estratégias para classificação de elementos antrópicos. Os experimentos realizados obtiveram taxas de erro de consistência inferiores a 8% na segmentação das imagens utilizando o algoritmo SRM e precisão acima de 94% na classificação dos objetos de interesse através de conjuntos de classificadores unários, utilizando os algoritmos One-Class SVM e REPTree.
Polidorio, Airton Marco [UNESP]. "Detenção de elementos da paisagem urbana em imagens aéreas multiespectrais." Universidade Estadual Paulista (UNESP), 2007. http://hdl.handle.net/11449/100265.
Повний текст джерелаAtividades inerentes à Fotogrametria e ao Sensoriamento Remoto que utilizam dados extraídos de imagens aéreas estão em constante desenvolvimento, seja pela inserção de novas tecnologias relacionadas com a aquisição desses dados, seja pelo estabelecimento de novos conceitos e métodos que permitem computá-los, transformando-os em informação. Essa transformação, dados-informação, é feita por vários processos entre os quais, alguns foram automatizados e outros necessitam da supervisão e da interação com um operador humano para realizá-la. Um dos fatores que impede a completa automação desses processos é a falta de conhecimento contextual prévio sobre a natureza dos dados. A detecção e a discriminação de elementos específicos em dados de imageamento aéreo constituem uma forma de adquirir esse conhecimento contextual. Este trabalho aborda esse problema de detectar e discriminar elementos específicos em dados de imageamento aéreo de regiões urbanas, especificamente: sombras, vegetação verde, corpos d'água, rodovias pavimentadas e telhados de edificações, bem como discriminar a natureza da elevação desses elementos, de forma que seja possível inferir se determinado elemento tem elevação própria, ou se estáao nível da superfície do terreno.
Inherent activities to Photogrammetryand Remote Sensingthat use data acquired byaerial images are in constant development, due the useful of new hardware to acquire such data, or due the establishment of new concepts and methods that allow computing those data, transforming them in information. That transformation, data-to-information, is done by several processes. Some of these processes were automated and others still need the supervision and the interaction with a human operator to accomplish that transformation. A factor that obstruct the complete automation those processes is the lackof previous context-knowledge about the nature of those data. The detection and the discrimination of specific elements in aerial imagingdata constitute a wayto acquire that context-knowledge. This work approaches the problem related with the automatic detection and discrimination of specific elements in aerial imagingdata of urban areas, specifically: shadows; green vegetation; water bodies, paved-roads and roofs buildings, besides determiningthe nature of the elevation of those elements, in order to allow infer if a specific element has own elevation, or it is been at the level of the terrain surface. In order, to detect those elements, this workproposes new metrics, designed as enhancements indexes, to treat the elements of interest.
Polidorio, Airton Marco. "Detenção de elementos da paisagem urbana em imagens aéreas multiespectrais /." Presidente Prudente : [s.n.], 2007. http://hdl.handle.net/11449/100265.
Повний текст джерелаAbstract: Inherent activities to Photogrammetryand Remote Sensingthat use data acquired byaerial images are in constant development, due the useful of new hardware to acquire such data, or due the establishment of new concepts and methods that allow computing those data, transforming them in information. That transformation, data-to-information, is done by several processes. Some of these processes were automated and others still need the supervision and the interaction with a human operator to accomplish that transformation. A factor that obstruct the complete automation those processes is the lackof previous context-knowledge about the nature of those data. The detection and the discrimination of specific elements in aerial imagingdata constitute a wayto acquire that context-knowledge. This work approaches the problem related with the automatic detection and discrimination of specific elements in aerial imagingdata of urban areas, specifically: shadows; green vegetation; water bodies, paved-roads and roofs buildings, besides determiningthe nature of the elevation of those elements, in order to allow infer if a specific element has own elevation, or it is been at the level of the terrain surface. In order, to detect those elements, this workproposes new metrics, designed as enhancements indexes, to treat the elements of interest.
Orientador: Nilton Nobuhiro Imai
Coorientador: Antonio Garcia Tommaselli
Banca: José Alberto Quintanilha
Banca: Flávio Bortolozzi
Banca: Maria de Lourdes Bueno Trindade Galo
Banca: Júlio Hasegawa
Doutor
Zanjani-pour, Sahand. "Intervertebral disc stress and pressure in different daily postures : a finite element study." Thesis, University of Exeter, 2016. http://hdl.handle.net/10871/26682.
Повний текст джерелаChen, Cheng. "Finite element modeling of trabecular bone from multi-row detector CT imaging." Thesis, University of Iowa, 2014. https://ir.uiowa.edu/etd/1440.
Повний текст джерелаChean, Shen Lee. "Numerical study for acoustic micro-imaging of three dimensional microelectronic packages." Thesis, Liverpool John Moores University, 2014. http://researchonline.ljmu.ac.uk/4502/.
Повний текст джерелаQiu, Yan 1973. "Three dimensional finite element model for lesion correspondence in breast imaging [electronic resource] / by Yan Qiu." University of South Florida, 2003. http://purl.fcla.edu/fcla/etd/SFE0000192.
Повний текст джерелаDocument formatted into pages; contains 64 pages.
Thesis (M.S.C.S.)--University of South Florida, 2003.
Includes bibliographical references.
Text (Electronic thesis) in PDF format.
ABSTRACT: Predicting breast tissue deformation is of great significance in several medical applications such as surgery, biopsy and imaging. In breast surgery, surgeons are often concerned with a specific portion of the breast, e.g., tumor, which must be located accurately beforehand. Also clinically it is important for combining the information provided by images from several modalities or at different times, for the planning and guidance of interventions. Multi-modality imaging of the breast obtained by mammography, MRI and PET is thought to be best achieved through some form of data fusion technique. However, images taken by these various techniques are often obtained under entirely different tissue configurations, compression, orientation or body position. In these cases some form of spatial transformation of image data from one geometry to another is required such that the tissues are represented in an equivalent configuration.
ABSTRACT: We constructed the 3D biomechanical models for this purpose using Finite Element Methods (FEM). The models were based on phantom and patient MRIs and could be used to model the interrelation between different types of tissue by applying displacements of forces and to register multimodality medical images.
System requirements: World Wide Web browser and PDF reader.
Mode of access: World Wide Web.
César, de Miranda Loureiro Eduardo. "Construção de simuladores baseados em elementos de volume a partir de imagens tomográficas coloridas." Universidade Federal de Pernambuco, 2002. https://repositorio.ufpe.br/handle/123456789/9491.
Повний текст джерелаEste trabalho apresenta uma nova metodologia aplicada na construção de simuladores baseados em elementos de volume. O processo de segmentação dos modelos resume-se à tarefa de colorir as imagens tomográficas atribuindo uma cor diferente para cada órgão segmentado. Um modelo de cabeça e pescoço foi construído utilizando esta nova técnica. Além de simplificar o procedimento permitindo a construção dos modelos em um menor período de tempo, as informações são armazenadas de forma otimizada aumentando a performance do programa que calcula o transporte de radiação. A execução de comandos gráficos pelo mesmo programa que calcula o transporte de radiação permite também que imagens sejam reconstruídas a partir dos dados do modelo mostrando regiões de isodose, sob diversos pontos de vista, aumentando o nível da informação passada ao usuário. Radiografias virtuais do modelo construído também podem ser obtidas. Esta capacidade permite que estudos sejam realizados visando a otimização das técnicas radiográficas avaliando ao mesmo tempo as doses nos órgãos e tecidos. O programa aqui apresentado, denominado MCvoxEL, que implementa esta nova metodologia, foi validado comparando-se os seus resultados com os de programas já consolidados no meio científico. Coeficientes de conversão para doses provenientes de exposições a feixes de fótons paralelos também foram obtidos
Diarra, Bakary. "Study and optimization of 2D matrix arrays for 3D ultrasound imaging." Thesis, Lyon 1, 2013. http://www.theses.fr/2013LYO10165/document.
Повний текст джерела3D Ultrasound imaging is a fast-growing medical imaging modality. In addition to its numerous advantages (low cost, non-ionizing beam, portability) it allows to represent the anatomical structures in their natural form that is always three-dimensional. The relativelyslow mechanical scanning probes tend to be replaced by two-dimensional matrix arrays that are an extension in both lateral and elevation directions of the conventional 1D probe. This2D positioning of the elements allows the ultrasonic beam steering in the whole space. Usually, the piezoelectric elements of a 2D array probe are aligned on a regular grid and spaced out of a distance (the pitch) subject to the space sampling law (inter-element distancemust be shorter than a mid-wavelength) to limit the impact of grating lobes. This physical constraint leads to a multitude of small elements. The equivalent in 2D of a 1D probe of 128elements contains 128x128 = 16,384 elements. Connecting such a high number of elements is a real technical challenge as the number of channels in current ultrasound scanners rarely exceeds 256. The proposed solutions to control this type of probe implement multiplexing or elements number reduction techniques, generally using random selection approaches (« spars earray »). These methods suffer from low signal to noise ratio due to the energy loss linked to the small number of active elements. In order to limit the loss of performance, optimization remains the best solution. The first contribution of this thesis is an extension of the « sparse array » technique combined with an optimization method based on the simulated annealing algorithm. The proposed optimization reduces the required active element number according to the expected characteristics of the ultrasound beam and permits limiting the energy loss compared to the initial dense array probe.The second contribution is a completely new approach adopting a non-grid positioningof the elements to remove the grating lobes and to overstep the spatial sampling constraint. This new strategy allows the use of larger elements leading to a small number of necessaryelements for the same probe surface. The active surface of the array is maximized, whichresults in a greater output energy and thus a higher sensitivity. It also allows a greater scansector as the grating lobes are very small relative to the main lobe. The random choice of the position of the elements and their apodization (or weighting coefficient) is optimized by the simulated annealing.The proposed methods are systematically compared to the dense array by performing simulations under realistic conditions. These simulations show a real potential of the developed techniques for 3D imaging.A 2D probe of 8x24 = 192 elements was manufactured by Vermon (Vermon SA, Tours,France) to test the proposed methods in an experimental setting. The comparison between simulation and experimental results validate the proposed methods and prove their feasibility
L'ecografia 3D è una modalità di imaging medicale in rapida crescita. Oltre ai vantaggiin termini di prezzo basso, fascio non ionizzante, portabilità, essa permette di rappresentare le strutture anatomiche nella loro forma naturale, che è sempre tridimensionale. Le sonde ascansione meccanica, relativamente lente, tendono ad essere sostituite da quelle bidimensionali che sono una estensione in entrambe le direzioni laterale ed azimutale dellasonda convenzionale 1D. Questo posizionamento 2D degli elementi permette l'orientamentodel fascio ultrasonico in tutto lo spazio. Solitamente, gli elementi piezoelettrici di una sondamatriciale 2D sono allineati su una griglia regolare e separati da una distanza (detta “pitch”) sottoposta alla legge del campionamento spaziale (la distanza inter-elemento deve esseremeno della metà della lunghezza d'onda) per limitare l'impatto dei lobi di rete. Questo vincolo fisico porta ad una moltitudine di piccoli elementi. L'equivalente di una sonda 1D di128 elementi contiene 128x128 = 16.384 elementi in 2D. Il collegamento di un così grandenumero di elementi è una vera sfida tecnica, considerando che il numero di canali negliecografi attuali supera raramente 256. Le soluzioni proposte per controllare questo tipo disonda implementano le tecniche di multiplazione o la riduzione del numero di elementi, utilizzando un metodo di selezione casuale (« sparse array »). Questi metodi soffrono di unbasso rapporto segnale-rumore dovuto alla perdita di energia. Per limitare la perdita di prestazioni, l’ottimizzazione rimane la soluzione migliore. Il primo contributo di questa tesi è un’estensione del metodo dello « sparse array » combinato con un metodo di ottimizzazione basato sull'algoritmo del simulated annealing. Questa ottimizzazione riduce il numero degli elementi attivi richiesto secondo le caratteristiche attese del fascio di ultrasuoni e permette di limitare la perdita di energia.Il secondo contributo è un approccio completamente nuovo, che propone di adottare un posizionamento fuori-griglia degli elementi per rimuovere i lobi secondari e per scavalcare il vincolo del campionamento spaziale. Questa nuova strategia permette l'uso di elementi piùgrandi, riducendo così il numero di elementi necessari per la stessa superficie della sonda. La superficie attiva della sonda è massimizzata, questo si traduce in una maggiore energia equindi una maggiore sensibilità. Questo permette inoltre la scansione di un più grande settore,in quanto i lobi secondari sono molto piccoli rispetto al lobo principale. La scelta casualedella posizione degli elementi e la loro apodizzazione viene ottimizzata dal simulate dannealing. I metodi proposti sono stati sistematicamente confrontati con la sonda completaeseguendo simulazioni in condizioni realistiche. Le simulazioni mostrano un reale potenzialedelle tecniche sviluppate per l'imaging 3D.Una sonda 2D di 8x24 = 192 elementi è stata fabbricata da Vermon (Vermon SA, ToursFrance) per testare i metodi proposti in un ambiente sperimentale. Il confronto tra lesimulazioni e i risultati sperimentali ha permesso di convalidare i metodi proposti edimostrare la loro fattibilità
Watson, Francis Maurice. "Better imaging for landmine detection : an exploration of 3D full-wave inversion for ground-penetrating radar." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/better-imaging-for-landmine-detection-an-exploration-of-3d-fullwave-inversion-for-groundpenetrating-radar(720bab5f-03a7-4531-9a56-7121609b3ef0).html.
Повний текст джерелаAtaseven, Yoldas. "Parallel Implementation Of The Boundary Element Method For Electromagnetic Source Imaging Of The Human Brain." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606548/index.pdf.
Повний текст джерелаYang, Jing. "The role of phonological working memory in Chinese reading development behavioral and fMRI evidence /." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B42664640.
Повний текст джерелаBrook, Nicholas H. "The flavour dependence of charged hadron production at large transverse momenta using high energy photon and hadron beams at the OMEGA spectrometer : equipped with a ring imaging Cherenkov detector." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328282.
Повний текст джерелаFerreira, Manoel Dênis Costa. "Análise inversa utilizando o método dos elementos de contorno e correlação de imagens digitais." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/18/18134/tde-25092012-084832/.
Повний текст джерелаThe identification of physical and geometrical parameters utilizing experimental measurements is a common procedure in treating many problems of science and engineering. In this context, the inverse analysis is an important tool in treating these problems. This work presents formulations that associate the use of boundary element method (BEM) and the technique of digital image correlation (DIC) (for obtaining the displacement fields) in solving some inverse problems of interest to Structure Engineering. A computer code based on the BEM, on regularization techniques and genetic algorithm has been implemented for the treatment of problems such as Identification of material properties, recovery of boundary conditions and identification of cohesive model parameters. Examples with data from a previous direct analysis (simulating experimental data) are presented to demonstrate the effectiveness of the proposed formulations. Three point flexural tests with notch were performed and images were acquired to obtain the displacement fields on one lateral surface of the samples, via DIC. These displacement fields were used to feed the inverse model proposed. The DIC technique resulted in quantitative and accurate data for the purposes of this study. The use of the BEM proved to be simple and efficient in solving the inverse problems treated.
Santos, Marina Vieira. "Imagens e Ciências no Ensino Fundamental II: um estudo à luz da semiótica peirceana." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/81/81132/tde-30032017-153653/.
Повний текст джерелаWhereas in the elementary school that chemical nature phenomena are treated for the first time and the images can assist the learning process and enable the construction of meanings for knowledge, this paper explores the actions and behaviors of a science teacher for their classes to the 9th grade of elementary school II, in order to explore the use of pictorial resources proposed for it. So, were part of this assessment questions such as what types of images were used in the development of the discipline? What the teacher aspired to use them? In what context are inserted? How was the communication process about the image? This research is characterized as a case study and was developed in a municipal school in the city of Salto - SP, where classes were monitored and recorded in a period of six months, a period in which they worked the chemical content. Each image used by the teacher in the classroom was considered a sign and explored from the theory of Charles Sanders Peirce semiotics. Consider it as a sign is to attribute it a load of materialization, in the other words, the object is materialized in the representation, enabling the transition between immaterial domain and the visual and understanding of how may or may not contribute to the construction of the chemical content considering also the speech of the teacher about the sign. The images were classified according to modes of relationship in which the sign is constituted (about its nature) and about its object. These relationships belong to called trichotomies established by Peirce, resulting in several classes, as qualisign iconic, sinsign iconic, sinsign indicial, legisign iconic, legisign indicial and legisign symbolic. These reviews and ratings added to teacher\'s arguments and buildings presented during the research showed a strongly realistic posture while reading the images.
LAURENT, DANIEL. "Monde imaginal et auto-education elements pour une hermeneutique de l'imaginal educatif." Lille 3, 1995. http://www.theses.fr/1995LIL30010.
Повний текст джерелаThe origin of the thesis stands on a two-fold questioning : an interrogation on the place and role of elected images (the 'imaginal') in the construction of the private and professional identity of the teacher and an attempt to define the esthetic experience which characterizes this process. The core of the problem inscribes itself between four notions : that of a narrative identity which, through esthetic experiences, enables the individual to draw into his stockpile of fictional "imaginal" in order to build a meaningful vision of his life, along with a hermeneutic of the self, conceived as aself-education, from his narrative identity, of the character. Hence the necessity of considering the relationships between a hermeneutic of the self and a hermeneutic of the 'imaginal', necessity which leads to a three-fold questioning : how, through a contact with artistic and fictional works, is it possible to validate a personal praxis by refering to a fictional 'imaginal' ? and what links the individual have to establish between his cultural praxis (the personal task of constructing one self) and the civilisational requirements of the overwhelming contemporary world. Through theoretical references to montaigne, nietzsche and freud and through 'imaginal' references to francois truffaut's films, the aim of the work is to re-establish self-reflexion as an aufklarung of the self by re-introducing personal experiences, the fundemental basis of subjectivity. It is also related to the philosophical conception which emphasizes the need for an individual to draw from his own biographical experience and from self reflexion to be in the habit of finding, in his own ressources, the means to exploit them for the leitmotives of his life. Centered upon the relation to the otherness (for in the imaginal, what narcisse maybe is looking for is not his image, but the approbation of the other), we are confronted to a task of self-education, that everybody is following, and where everybody meditates with his own means-including the 'imaginal' ones
McGuinness, Brigitt Angelica. "Teacher Perceptions of the Implementation Processes of the Imagine Learning Program in Title I Elementary Schools." W&M ScholarWorks, 2018. https://scholarworks.wm.edu/etd/1530192587.
Повний текст джерелаSato, Marcel. "Modelagem de problemas da mecanica da fratura e propagação de trincas em fadiga." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263144.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
Made available in DSpace on 2018-08-14T01:32:47Z (GMT). No. of bitstreams: 1 Sato_Marcel_M.pdf: 15643379 bytes, checksum: 9ad3608b9de1e264891ac44ce87bbb5a (MD5) Previous issue date: 2009
Resumo: Este trabalho apresenta uma ferramenta para modelar a propagação de múltiplas trincas por fadiga em modo misto para materiais isotrópicos, utilizando o Método dos Elementos de Contorno Dual. Este método é utilizado para realizar uma análise de tensões e deformações no sólido, de modo a proporcionar resultados confiáveis para o campo elástico na região ao redor da trinca. À partir destes resultados, os fatores de intensidade de tensão são obtidos utilizando-se a técnica da Integral J, realizando-se o desacoplamento dos modos através da decomposição do campo elástico em seus componentes simétricos e anti-simétricos. Os fatores de intensidade de tensão são utilizados para calcular o ângulo de propagação e tamanho de incremento pelo método da Mínima Densidade de Energia de Deformação. A vida em fadiga é obtida pela integração direta da expressão da Lei de Paris, modificada pelo modelo de fechamento de trinca. O algoritmo é validado com resultados experimentais para dois problemas envolvendo fratura em modo misto e fadiga. Em ambos os testes, foi utilizada a técnica de Correlação de Imagens Digitais para monitorar a propagação das trincas por fadiga e técnicas de processamento de imagens foram empregadas para analisar os resultados
Abstract: This work presents a tool to model problems of multiple site fatigue crack propagation in isotropic materials under mixed mode conditions, using the dual boundary element method. This method is used to make an analysis of tensions and deformations in the solid, providing reliable results for the elastic field in the region near the crack tip. The stress intensity factors are obtained using the J-integral technique and they are decoupled with a procedure based on the decomposition of the elastic field into its symmetric and anti-symmetric components. The crack propagation angle and the increment size are calculated through the minimum strain energy density criterion. The fatigue life is obtained through the integration of the Paris law expression modified by the crack closure model. The validation of the algorithm is made with experimental results for two mixed mode fracture problems with fatigue. In both cases, the digital image correlation technique was used to monitor the fatigue crack propagation during the tests and digital image processing techniques were used to analyze the result
Mestrado
Mecanica dos Sólidos e Projeto Mecanico
Mestre em Engenharia Mecânica
Oberg, Matheus Barbosa Andrade Moser. "Termoelasticidade : um estudo via método dos elementos de contorno, termografia e correlação digital de imagens." reponame:Repositório Institucional da UnB, 2016. http://repositorio.unb.br/handle/10482/20114.
Повний текст джерелаSubmitted by Fernanda Percia França (fernandafranca@bce.unb.br) on 2016-04-27T17:34:14Z No. of bitstreams: 1 2016_MatheusBarbosaAndradeMoserOberg.pdf: 3328409 bytes, checksum: 801212901d39931f4667cbcc8b950c35 (MD5)
Approved for entry into archive by Marília Freitas(marilia@bce.unb.br) on 2016-05-04T14:38:33Z (GMT) No. of bitstreams: 1 2016_MatheusBarbosaAndradeMoserOberg.pdf: 3328409 bytes, checksum: 801212901d39931f4667cbcc8b950c35 (MD5)
Made available in DSpace on 2016-05-04T14:38:33Z (GMT). No. of bitstreams: 1 2016_MatheusBarbosaAndradeMoserOberg.pdf: 3328409 bytes, checksum: 801212901d39931f4667cbcc8b950c35 (MD5)
Este trabalho apresenta um estudo numérico e experimental sobre termoelasticidade em regime permanente utilizando o método dos elementos de contorno (MEC) e técnicas de metrologia óptica. Na formulação termoelástica do MEC, o efeito das contribuições decorrentes do fenômeno termoelástico surge, naturalmente, na forma de uma integral de domínio. Visando preservar a característica principal do MEC, esta integral de domínio foi convertida a uma integral equivalente sobre o contorno utilizando o método da integração radial (MIR). Esta técnica de conversão, que consiste em uma abordagem puramente matemática, tem como requisito que o campo de temperaturas seja definido por meio de uma função matemática. Em grande parte dos problemas de engenharia, entretanto, esta informação é adquirida por meio de uma distribuição de valores pontuais de temperaturas. Desta forma, para aplicação do MIR, faz-se necessária a utilização de uma técnica de regressão para aproximação deste campo de temperaturas por uma função matemática que o descreva. Com o objetivo de avaliar a influência do tipo de regressão utilizada, foram elaborados uma montagem e um procedimento experimental para aquisição simultânea dos campos de temperaturas e de deslocamentos consequente. O campo de temperaturas é avaliado por meio de imagens térmicas, enquanto o campo de deslocamentos resultante é adquirido por correlação digital de imagens (CDI). Para assegurar a qualidade da análise por CDI, foi desenvolvido um equipamento de marcação CNC capaz de reproduzir de pontos, de distribuição gerada computacionalmente, sobre a superfície dos corpos de prova via impressão. A partir disto, foi construído um modelo numérico, reproduzindo as condições observadas experimentalmente, para análise via MEC com MIR. O campo de temperaturas foi aproximado por funções polinomiais de ordens bi quadrática, bi cúbica e bi quártica a fim de avaliar-se a sensibilidade do problema ao tipo de aproximação realizada. Por fim, comparando-se os campos de deslocamentos obtidos numericamente aos resultados experimentais observou-se uma boa concordância entre os resultados, independente do grau do polinômio utilizado na regressão. ______________________________________________________________________________________________ ABSTRACT
This work presents a numerical and experimental study on steady-state thermoelasticity using the boundary elements method (BEM), digital image correlation (DIC) and thermal images. In the BEM formulation for thermoelasticity, the effect of the thermoelastic loads, naturally, rises as a domain integral. In order to preserve BEM’s boundary only main characteristic this domain integral is converted into a boundary integral equivalent by the radial integration method (RIM). This technique, which consists in a purely mathematical approach, requires the temperature fields to be described as a function. However, in many engineering situations, this information is provided as a distribution of individual temperature values. In such situations, to successfully apply the MIR, it is necessary to use a regression technique to approach the temperature field by a mathematical function. In pursuance of evaluating the influence of the kind of regression applied, an experimental assembly was developed to acquire, simultaneously, the temperature field and the consequent displacement field field. The acquisition is performed by thermal images, while the resultant displacement field is obtained through DIC. To assure the quality of the DIC analysis, a CNC marking equipment was designed specifically to mark computer generated speckle patterns on the surfaces to be measured. After that, a numerical model was developed to reproduce the experimentally observed conditions for the BEM with RIM analysis. The experimental temperature field was approximated by three different kind of polynomial expressions: bi quadratic, bi cubic and bi quartic. In the end, the comparison between the numerical and the experimental displacement results showed good agreement regardless the type of polynomial regression used.
Nguyen, Van Dang. "A finite elements method to solve the Bloch-Torrey equation applied to diffusion magnetic resonance imaging of biological tissues." Palaiseau, Ecole polytechnique, 2014. http://pastel.archives-ouvertes.fr/docs/00/95/77/50/PDF/thesis_Dang.pdf.
Повний текст джерелаDiffusion magnetic resonance imaging (dMRI) is a non-invasive imaging technique that gives a measure of the diffusion characteristics of water in biological tissues, notably, in the brain. The hindrances that the microscopic cellular structure poses to water diffusion are statistically aggregated into the measurable macroscopic dMRI signal. Inferring the microscopic structure of the tissue from the dMRI signal allows one to detect pathological regions and to monitor functional properties of the brain. For this purpose, one needs a clearer understanding of the relation between the tissue microstructure and the dMRI signal. This requires novel numerical tools capable of simulating the dMRI signal arising from complex microscopic geometrical models of tissues. We propose such a numerical method based on linear finite elements that allows for a more accurate description of complex geometries. The finite elements discretization is coupled to the adaptive Runge-Kutta Chebyshev time stepping method. This method, which leads to the second order convergence in both time and space, is implemented on FeniCS C++ platform. We also use the mesh generator Salome to work efficiently with multiple-compartment and periodic geometries. Four applications of the method for studying the dMRI signal inside multi-compartment models are considered. In the first application, we investigate the long-time asymptotic behavior of the dMRI signal and show the convergence of the apparent diffusion coefficient to the effective diffusion tensor computed by homogenization. The second application aims to numerically verify that a two-compartment model of cells accurately approximates the three-compartment model, in which the interior cellular compartment and the extracellular space are separated by a finite thickness membrane compartment. The third application consists in validating the macroscopic Karger model of dMRI signals that takes into account compartmental exchange. The last application focuses on the dMRI signal arising from isolated neurons. We propose an efficient one-dimensional model for accurately computing the dMRI signal inside neurite networks in which the neurites may have different radii. We also test the validity of a semi-analytical expression for the dMRI signal arising from neurite networks
Gao, Guochao. "Contribution to seismic modeling and imaging in the presence of reflector roughness." Thesis, Ecole centrale de Marseille, 2020. http://www.theses.fr/2020ECDM0010.
Повний текст джерелаDue to various geological processes and crustal movements, rough interfaces widely exist within the Earth. The rough interface can strongly affect seismic wave propagation, manifested as changes in the amplitude, phase, scattering angle, frequency content, and even the wave-type conversion. Inevitably, the quality of seismic imaging or inversion is also greatly influenced. Despite the numerous works devoted to the interaction of waves with rough interfaces, this interaction remains to be better understood, as it is still quite challenging to model the seismic wave propagation and to properly reconstruct the subsurface. The thesis investigates the effect of rough interfaces on seismic wave modeling and imaging, and explores the potential of an electromagnetic method to remove this effect and to better image the subsurface.We use a spectral-element method, and more specifically the code SPECFEM2D, for modeling acoustic wave propagation in the time domain. First, we consider a sinusoidal grating and illustrate numerically the consequences of the grating equation on the temporal signals. Then, using f-k analysis, we show the location of the different diffraction orders in the frequency-wavenumber domain. After a sensitivity analysis, we select an appropriate configuration that allows for the separation of diffraction orders from a shot gather. Last, both roughness height and correlation length are shown to obviously influence the appearance of the diffracted wavefield. However, the correlation length has less effect on the energy of the diffracted waves than the interface roughness.We adopt a full-waveform inversion (FWI) scheme based on the software package DENISE to study the influence of different roughness heights and correlation lengths on seismic imaging results. When the roughness height increases up to the dominant wavelength or is greater, the random noise dominates in the seismic data, and the FWI results significantly deteriorate, especially for the reconstruction of a horizontal reflector located below the rough interface. In contrast, the correlation length has a much smaller effect on both random noise and quality of the inverted results than the roughness height. As shown here, the interface roughness has a major impact on both seismic wave propagation and imaging. When a rough interface is expected to be present in the subsurface, its effect should be critically considered in FWI, in order to properly reconstruct reflectors possibly located below, and then to properly interpret images of the subsurface. In this context, we perform some preliminary tests on the use of a selective extinction method to remove the impact of the roughness on the wavefields. The results are promising and show the potential of the method for better imaging. In addition, the standard deviation of the amplitude of the processed data may be used to evaluate the characteristics of the rough interface, which is also of interest for geophysicists and geologists
Coggin, Linda L. "Creating discourses of possibility| Storying between the real and the imagined to negotiate rural lives in two elementary classrooms." Thesis, Indiana University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3665263.
Повний текст джерелаIn an age of standardization of learning and the learner, literacy is narrowly defined to view young people from a deficit rather than a strength perspective. Empowering learners to draw on knowledges and experiences that they have access to in their everyday lives broadens the view of literacy learning. Research on literacy as a sociocultural practice, rural literacies, and performance theory frame this inquiry that seeks to understand how students are positioned as capable users of multiple literacy practices. This work examines: How do students living in rural contexts bring personal stories and interests into classrooms to make sense of literacy learning? What pedagogical practices make visible students' personal stories and interests as resources for literacy? How do students negotiate lived and imagined experience in classroom literacy engagements?
Using ethnographic methodologies and a practice centered performance approach, this research foregrounds the complexities of literacy learning that are responsive to this midwestern rural school community. Over the course of one academic year, I observed and participated in the everyday literacy events in a sixth grade and a second grade classroom. This work focuses on how rurality is imagined and experienced in these focal classrooms and the pedagogical practices that establish an ethos of sharing personal stories and experiences. An analysis of student created multimedia videos demonstrates how these literacy events were a location to 1) enact cultural ways of knowing, 2) negotiate multiple discourses that were significant in students' worlds, and 3) create new possibilities for using literacies and participating in classrooms. In the midst of tensions that place students as objects of instructional and political policies, discourses of possibility are created when young people are positioned as capable subjects who contribute and create knowing.
Diedrich, Tiago Josué. "Um método baseado em ontologias para interpretação e catalogação de elementos pouco evidentes em imagens." Instituto Tecnológico de Aeronáutica, 2014. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=3136.
Повний текст джерелаCueto, Rojas María José. "Incidencia de los elementos visuales sobre el posicionamiento de marca dentro de un proceso de rebranding." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2018. http://hdl.handle.net/10757/625251.
Повний текст джерелаAs indicated by Berry (1993) (Quoted in Arthur, 1995) and Pereira (2015), brands are not static, they are active constructions and in recurrent evolution and influenced by internal and external agents. Kapferer (2004) points out that a brand that does not change over time may lose its relevance. Since the brand may feel stagnant, outdated or inferior to its competitors; the renewal and updating is a process to be considered, that is, to carry out a Rebranding (Romero, 2015). This is taken as a renewal, a refreshing, a reinvention, a reputation and/or a repositioning (Merrilees and Miller, 2008). This process may lead to the creation of a new logo, term, symbol, design or combination of these for an established brand with the intention of developing a different or new position in the minds of all stakeholders and competitors (Muzellec and Lambkin, 2005). The following research focuses on the redesign of the logo in the positioning of a brand, analyzing the attributes of this that are exposed in the logo and that arise in the expected positioning of it within a rebranding strategy. It is so that you get that this visual element is an ideal tool to reinforce attributes of the brand in the positioning. This is analyzed in the millennial generation, an attractive segment for companies and to which the brand aims to currently go. A descriptive research was used based on a quantitative methodology using the survey method in the public to which the brand is directed, which led to the power of the logo redesign to reinforce certain shortcomings that the positioning of the brand could not possess.
Tesis