• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 4
  • 1
  • Tagged with
  • 10
  • 10
  • 5
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Optimal linear representations of images under diverse criteria

Rubinshtein, Evgenia. Srivastava, Anuj. January 2006 (has links)
Thesis (Ph. D.)--Florida State University, 2006. / Advisor: Anuj Srivastava, Florida State University, College of Arts and Sciences, Dept. of Statistics. Title and description from dissertation home page (viewed Sept. 22, 2006). Document formatted into pages; contains xiv, 123 pages. Includes bibliographical references.
2

Processamento e an?lise de imagens na caracteriza??o da superf?cie do tit?nio submetido a um ensaio de cultura de c?lulas

Ara?jo, Franci?ric Alves de 26 March 2009 (has links)
Made available in DSpace on 2014-12-17T14:06:51Z (GMT). No. of bitstreams: 1 FranciericAA.pdf: 3105945 bytes, checksum: 434348633df1dedcb6e622baefde201e (MD5) Previous issue date: 2009-03-26 / This work aims to develop a methodology for analysis of images using overlapping, which assists in identification of microstructural features in areas of titanium, which may be associated with its biological response. That way, surfaces of titanium heat treated for 08 (eight) different ways have been subjected to a test culture of cells. It was a relationship between the grain, texture and shape of grains of surface of titanium (attacked) trying to relate to the process of proliferation and adhesion. We used an open source software for cell counting adhered to the surface of titanium. The juxtaposition of images before and after cell culture was obtained with the aid of micro-hardness of impressions made on the surface of samples. From this image where there is overlap, it is possible to study a possible relationship between cell growth with microstructural characteristics of the surface of titanium. This methodology was efficient to describe a set of procedures that are useful in the analysis of surfaces of titanium subjected to a culture of cells / O presente trabalho tem como objetivo desenvolver uma metodologia de an?lise de imagens, utilizando sobreposi??es, que auxilie na identifica??o de caracter?sticas microestruturais, em superf?cies de tit?nio, que possam estar associadas com a sua resposta biol?gica. Desse modo, superf?cies de tit?nio tratadas termicamente de 08(oito) diferentes maneiras foram submetidas a um ensaio de cultura de c?lulas. Buscou-se uma rela??o entre os gr?os, textura e contornos de gr?os da superf?cie de tit?nio (atacada) procurando relacionar com o processo de prolifera??o e ades?o. Foi utilizado um software open source para a contagem das c?lulas aderidas ? superf?cie do tit?nio. A justaposi??o das imagens antes e ap?s a cultura de c?lulas foi obtida com o aux?lio de impress?es de micro-dureza feita sobre a superf?cie das amostras. A partir desta imagem onde h? a sobreposi??o, ? poss?vel o estudo de uma poss?vel rela??o entre o crescimento celular com as caracter?sticas microestruturais da superf?cie de tit?nio. Essa metodologia se mostrou eficiente ao descrever um conjunto de procedimentos que s?o ?teis na analise de superf?cies de tit?nio submetidos a uma cultura de c?lulas
3

Exploring the Restorative Effects of Nature: Testing A Proposed Visuospatial Theory

Valtchanov, Deltcho January 2013 (has links)
In this thesis, the restorative effects of exposure to nature are examined through the lens of existing restoration theories. Limitations of existing theories, such as Attention Restoration Theory and Psycho-evolutionary Restoration Theory, are highlighted. To address the limitations of existing theories, an expanded theoretical framework is proposed: The expanded framework introduces a newly proposed neural mechanism and theory of restoration that build on existing theories by proposing a link to recently discovered reward systems in the ventral visual pathway. Results from six experiments provide consistent evidence to suggest that positive and negative responses to visual scenes are related to the low-level visuospatial properties of the scenes. Specifically, a discovery is made to suggest that the power of a limited visual spatial frequency range can consistently predict responses to natural, urban, and abstract scenes on measures of restoration (blink-rates, number of fixations, self-reported stress and pleasantness). This provides the first evidence to suggest that low-level visual properties of scenes may play an important role in affective and physiological responses to scenes. Furthermore, this newly discovered relationship provides a new way to objectively predict the relative restorative value of any given scene.
4

Problém korespondence v úlohách geometrické morfometrie / Correspondence Problem in Geometrics Morphometric Tasks

Krajíček, Václav January 2015 (has links)
Title: Correspondence Problem in Geometric Morphometrics Tasks Author: Václav Krajíček Department / Institute: Department of Software and Computer Science Education Supervisor of the doctoral thesis: RNDr. Josef Pelikán Supervisor's e-mail address: pepca@cgg.mff.cuni.cz Abstract: Shape analysis in physical anthropology, biomedicine, and related disci- plines is mostly done using landmarks or by measuring distances. New techno- logical advancements allow the digitization of object's appearance in the form of triangular meshes or volume images. These digital images are especially beneficial in the cases when landmarks cannot be used to effectively describe the shape. In order to statistically analyze shape in a sample of observations, which are represented by these modalities, correspondence has to be found. Registration is a crucial tool in mapping the shape representations into a common space where correspondence is found by nearest neighbor principle in the case of triangular meshes or by overlaps in the case of volume images. B- spline based non-rigid registration is chosen because of its versatility, relative speed and ability to handle both meshes and volume images. Experiments were also performed with other alternatives - Thin-plate splines and Coherent point drift. The algorithm was modified to handle...
5

Banco de imagens: abordagem teórica conceitual de representação de fotografias para uso na publicidade

Souza, Jóice Cleide Cardoso Ennes de 15 March 2013 (has links)
Submitted by Priscilla Araujo (priscilla@ibict.br) on 2016-10-13T19:24:46Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese-JoiceCardoso.pdf: 3135800 bytes, checksum: 1d8708703eb3a010bf4bd6f4a6d0b57e (MD5) / Made available in DSpace on 2016-10-13T19:24:46Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese-JoiceCardoso.pdf: 3135800 bytes, checksum: 1d8708703eb3a010bf4bd6f4a6d0b57e (MD5) Previous issue date: 2013-03-15 / O trabalho aborda a indexação de imagens fotográficas em bancos de imagens para publicidade, justificada pela proliferação de fotografias na atual sociedade da informação e sua divulgação rápida e online. Os bancos de imagem se apresentam como recurso para os publicitários que demandam de tempo para a criação de anúncios, pois oferecem coleções fotográficas selecionadas, com tratamento documental direcionado ao usuário. Objetiva investigar procedimentos para a representação e recuperação de fotografias arquivadas em bancos de imagens, visando obter subsídios para reflexão e desenvolvimento de esquema teórico para indexação de fotografias em arquivos digitais. A análise qualitativa foi realizada a partir da identificação de elementos na literatura sobre publicidade direcionada ao público feminino, para definição de atributos visando atender demandas de conteúdo publicitário. Selecionou-se o banco de imagens Latinstock para o desenvolvimento da análise empírica por oferecer coleções para uso publicitário, ser em português e explicitar os princípios adotados na análise conceitual das fotografias. As amostras investigadas indicam que os atributos usados pelo banco de imagem são compatíveis com a representação de aspectos subjetivos/abstratos da fotografia, e que o uso de substantivos e adjetivos na indexação atendem aos elementos identificados na literatura de publicidade. Concluiu-se que a indexação de imagens para publicidade compreende atributos técnicos, figurativos e subjetivos. / The research approaches the indexing of images in images databank for advertising, justified by the proliferation of photographs in the information society and its rapid online dissemination. Image databank are presented as a resource for advertisers that demand time for creating ads because they offer selected photographic collections with the documentary directed the user. Work aims to investigate procedures for the representation and retrieval of archived photographs in image databanks, in order to obtain subsidies for reflection and development of theoretical scheme for indexing photos into digital files. Qualitative analysis was performed based on the identification of elements in the advertising literature targeted to a female audience, to define attributes to meet the demands of advertising content. Stock photos Latinstock was selected to the empirical analysis by offering collections for advertising use, in Portuguese and explains the principles adopted in the conceptual analysis of the photographs. The samples investigated indicate that the attributes used by the image databank are compatible with the photo representation of subjective and abstracts aspects, and the use of nouns and adjectives in indexing meet the elements identified in the advertising literature. It was concluded that indexing of images for advertising comprises technical, figurative and subjective attributes.
6

Mapeamento e estimativa de área de cana-de-açúcar no estado do Paraná / Mapping and estimate of the sugarcane area in Paraná state, Brazil

Cechim Júnior, Clóvis 04 February 2016 (has links)
Made available in DSpace on 2017-07-10T19:24:19Z (GMT). No. of bitstreams: 1 Clovis_Cechim_MC.pdf: 6987482 bytes, checksum: c33db297dd7ec8aaf8bfde9e1e56c2cc (MD5) Previous issue date: 2016-02-04 / Sugarcane has been cropped and produced in Brazil for a long time, so, it deserves mention because it makes the country as the largest producer, with also representativeness in sugar and ethanol production. The knowledge of reliable estimates concerning their cropped areas is essential for Brazilian agribusiness, as they help in determining prices to producers by power plants as well as allow establishing logistics flow of production. The cropped areas estimates are made by official agencies. Therefore, in order to reduce this subjectivity, geotechnology use comes as an alternative since it has been widely used in mappings agricultural crops. Thus, this study aimed at developing a methodology for mapping sugarcane crop in Paraná State with satellite images as LANDSAT, IRS and spectrum-temporal series of vegetation indexes from MODIS sensor, for 2010/2011 to 2014/2015 harvesting season. The carried out mappings indicated a strong positive correlation concerning Canasat and official IBGE. The developed method was based on Fuzzy ARTMAP classification and was efficient to map and estimate the sugarcane cropped area using vegetation index in Paraná State. / A cana-de-açúcar como cultura cultivada e produzida no Brasil merece destaque, pois torna o País o maior produtor mundial, com representatividade também na produção de açúcar e etanol. O conhecimento de estimativas confiáveis de suas áreas cultivadas é imprescindível para o agronegócio brasileiro, por auxiliar na determinação dos preços aos produtores pelas usinas e permitir estabelecer a logística de escoamento da produção. As estimativas de área cultivada são realizadas de forma subjetiva pelos órgãos oficiais. Com a finalidade de diminuir tal subjetividade, surge como alternativa o uso de geotecnologias, as quais têm sido muito utilizadas em mapeamentos de culturas agrícolas. Diante disto, o objetivo deste trabalho foi o desenvolvimento de uma metodologia para o mapeamento da cultura de cana-de-açúcar para o Estado do Paraná usando imagens dos satélites LANDSAT, IRS e de séries espectro-temporais de índices de vegetação, provenientes do sensor MODIS, para as safras de 2010/2011 a 2014/2015. O mapeamento da cultura foi realizado a partir do modelo de classificação supervisionada Fuzzy ARTMAP, tendo como variáveis de entrada, termos harmônicos de amplitude e fase e as métricas fenológicas da cultura. Os mapeamentos realizados indicaram forte correlação positiva com relação aos dados do Canasat e oficiais IBGE. O método desenvolvido com base na classificação Fuzzy ARTMAP demonstrou ser eficiente para mapear e estimar a área cultivada da cultura de cana-de-açúcar utilizando índices de vegetação no Estado do Paraná.
7

Mapeamento e estimativa de área de cana-de-açúcar no estado do Paraná / Mapping and estimate of the sugarcane area in Paraná state, Brazil

Cechim Júnior, Clóvis 04 February 2016 (has links)
Made available in DSpace on 2017-05-12T14:47:35Z (GMT). No. of bitstreams: 1 Clovis_Cechim_MC.pdf: 6987482 bytes, checksum: c33db297dd7ec8aaf8bfde9e1e56c2cc (MD5) Previous issue date: 2016-02-04 / Sugarcane has been cropped and produced in Brazil for a long time, so, it deserves mention because it makes the country as the largest producer, with also representativeness in sugar and ethanol production. The knowledge of reliable estimates concerning their cropped areas is essential for Brazilian agribusiness, as they help in determining prices to producers by power plants as well as allow establishing logistics flow of production. The cropped areas estimates are made by official agencies. Therefore, in order to reduce this subjectivity, geotechnology use comes as an alternative since it has been widely used in mappings agricultural crops. Thus, this study aimed at developing a methodology for mapping sugarcane crop in Paraná State with satellite images as LANDSAT, IRS and spectrum-temporal series of vegetation indexes from MODIS sensor, for 2010/2011 to 2014/2015 harvesting season. The carried out mappings indicated a strong positive correlation concerning Canasat and official IBGE. The developed method was based on Fuzzy ARTMAP classification and was efficient to map and estimate the sugarcane cropped area using vegetation index in Paraná State. / A cana-de-açúcar como cultura cultivada e produzida no Brasil merece destaque, pois torna o País o maior produtor mundial, com representatividade também na produção de açúcar e etanol. O conhecimento de estimativas confiáveis de suas áreas cultivadas é imprescindível para o agronegócio brasileiro, por auxiliar na determinação dos preços aos produtores pelas usinas e permitir estabelecer a logística de escoamento da produção. As estimativas de área cultivada são realizadas de forma subjetiva pelos órgãos oficiais. Com a finalidade de diminuir tal subjetividade, surge como alternativa o uso de geotecnologias, as quais têm sido muito utilizadas em mapeamentos de culturas agrícolas. Diante disto, o objetivo deste trabalho foi o desenvolvimento de uma metodologia para o mapeamento da cultura de cana-de-açúcar para o Estado do Paraná usando imagens dos satélites LANDSAT, IRS e de séries espectro-temporais de índices de vegetação, provenientes do sensor MODIS, para as safras de 2010/2011 a 2014/2015. O mapeamento da cultura foi realizado a partir do modelo de classificação supervisionada Fuzzy ARTMAP, tendo como variáveis de entrada, termos harmônicos de amplitude e fase e as métricas fenológicas da cultura. Os mapeamentos realizados indicaram forte correlação positiva com relação aos dados do Canasat e oficiais IBGE. O método desenvolvido com base na classificação Fuzzy ARTMAP demonstrou ser eficiente para mapear e estimar a área cultivada da cultura de cana-de-açúcar utilizando índices de vegetação no Estado do Paraná.
8

Анализ структуры люминесцентных керамик оксида алюминия допированных различными металлами : магистерская диссертация / Analysis of the structure of luminescent ceramics of aluminum oxide doped with various metals

Рябинина, М. В., Ryabinina, M. V. January 2017 (has links)
The method of introduction of metals to nanopowder, and made on their basis of compacts - impregnation in solution which contains necessary impurity is studied. This method is simple and effective, and also allows to vary the maintenance of a dopant in material. Microphotos of a surface of the studied samples are received on the scanning electronic microscope of Zeiss Sigma VP. The analysis of fragments of structure of solid bodies is made on the specialized software of SIAMS 700 (SIAMS Photolab complex). The average size of particles ceramics aluminum oxide with the entered metals was measured in work and distribution by the sizes is constructed. / Изучен метод допирования нанопорошков и изготовленных на их основе компактов - пропитка в растворе, который содержит необходимую примесь. Данный метод прост и эффективен, а так же позволяет варьировать содержание допанта в материале. Микрофотографии поверхности исследуемых образцов получены на сканирующем электронном микроскопе Zeiss Sigma VP. Анализ фрагментов структуры твердых тел выполнен на специализированном программном обеспечении SIAMS 700 (комплекс SIAMS Photolab). В работе был измерен средний размер частиц керамик оксида алюминия допиированных металлами и построено распределение по размерам.
9

Unsupervised 3D image clustering and extension to joint color and depth segmentation / Classification non supervisée d’images 3D et extension à la segmentation exploitant les informations de couleur et de profondeur

Hasnat, Md Abul 01 October 2014 (has links)
L'accès aux séquences d'images 3D s'est aujourd'hui démocratisé, grâce aux récentes avancées dans le développement des capteurs de profondeur ainsi que des méthodes permettant de manipuler des informations 3D à partir d'images 2D. De ce fait, il y a une attente importante de la part de la communauté scientifique de la vision par ordinateur dans l'intégration de l'information 3D. En effet, des travaux de recherche ont montré que les performances de certaines applications pouvaient être améliorées en intégrant l'information 3D. Cependant, il reste des problèmes à résoudre pour l'analyse et la segmentation de scènes intérieures comme (a) comment l'information 3D peut-elle être exploitée au mieux ? et (b) quelle est la meilleure manière de prendre en compte de manière conjointe les informations couleur et 3D ? Nous abordons ces deux questions dans cette thèse et nous proposons de nouvelles méthodes non supervisées pour la classification d'images 3D et la segmentation prenant en compte de manière conjointe les informations de couleur et de profondeur. A cet effet, nous formulons l'hypothèse que les normales aux surfaces dans les images 3D sont des éléments à prendre en compte pour leur analyse, et leurs distributions sont modélisables à l'aide de lois de mélange. Nous utilisons la méthode dite « Bregman Soft Clustering » afin d'être efficace d'un point de vue calculatoire. De plus, nous étudions plusieurs lois de probabilités permettant de modéliser les distributions de directions : la loi de von Mises-Fisher et la loi de Watson. Les méthodes de classification « basées modèles » proposées sont ensuite validées en utilisant des données de synthèse puis nous montrons leur intérêt pour l'analyse des images 3D (ou de profondeur). Une nouvelle méthode de segmentation d'images couleur et profondeur, appelées aussi images RGB-D, exploitant conjointement la couleur, la position 3D, et la normale locale est alors développée par extension des précédentes méthodes et en introduisant une méthode statistique de fusion de régions « planes » à l'aide d'un graphe. Les résultats montrent que la méthode proposée donne des résultats au moins comparables aux méthodes de l'état de l'art tout en demandant moins de temps de calcul. De plus, elle ouvre des perspectives nouvelles pour la fusion non supervisée des informations de couleur et de géométrie. Nous sommes convaincus que les méthodes proposées dans cette thèse pourront être utilisées pour la classification d'autres types de données comme la parole, les données d'expression en génétique, etc. Elles devraient aussi permettre la réalisation de tâches complexes comme l'analyse conjointe de données contenant des images et de la parole / Access to the 3D images at a reasonable frame rate is widespread now, thanks to the recent advances in low cost depth sensors as well as the efficient methods to compute 3D from 2D images. As a consequence, it is highly demanding to enhance the capability of existing computer vision applications by incorporating 3D information. Indeed, it has been demonstrated in numerous researches that the accuracy of different tasks increases by including 3D information as an additional feature. However, for the task of indoor scene analysis and segmentation, it remains several important issues, such as: (a) how the 3D information itself can be exploited? and (b) what is the best way to fuse color and 3D in an unsupervised manner? In this thesis, we address these issues and propose novel unsupervised methods for 3D image clustering and joint color and depth image segmentation. To this aim, we consider image normals as the prominent feature from 3D image and cluster them with methods based on finite statistical mixture models. We consider Bregman Soft Clustering method to ensure computationally efficient clustering. Moreover, we exploit several probability distributions from directional statistics, such as the von Mises-Fisher distribution and the Watson distribution. By combining these, we propose novel Model Based Clustering methods. We empirically validate these methods using synthetic data and then demonstrate their application for 3D/depth image analysis. Afterward, we extend these methods to segment synchronized 3D and color image, also called RGB-D image. To this aim, first we propose a statistical image generation model for RGB-D image. Then, we propose novel RGB-D segmentation method using a joint color-spatial-axial clustering and a statistical planar region merging method. Results show that, the proposed method is comparable with the state of the art methods and requires less computation time. Moreover, it opens interesting perspectives to fuse color and geometry in an unsupervised manner. We believe that the methods proposed in this thesis are equally applicable and extendable for clustering different types of data, such as speech, gene expressions, etc. Moreover, they can be used for complex tasks, such as joint image-speech data analysis
10

Análise de textura em imagens cerebrais : aplicações em acidente vascular cerebral isquêmico, epilepsia mioclônica juvenil, doença de Machado-Joseph, déficit cognitivo leve e doença de Alzheimer / Texture analysis in brain images : applications in ischemic brain stroke, juvenile myoclonic epilepsy, Machado-Joseph disease, mild cognitive impairment and Alzheimer¿s disease

Oliveira, Márcia Silva de 15 August 2018 (has links)
Orientador: Gabriela Castellano / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-08-15T22:34:24Z (GMT). No. of bitstreams: 1 Oliveira_MarciaSilvade_D.pdf: 17533323 bytes, checksum: 32a83eb4815b68f061baa91a4b0ab2e4 (MD5) Previous issue date: 2010 / Resumo: Análise de textura em imagens digitais é um termo que se refere a um grupo de técnicas de processamento de imagens que objetivam a extração de descritores da imagem ou de regiões de interesse (ROIs) de forma a simplificar a caracterização das mesmas. A textura pode ser entendida como características intrínsecas da imagem (por exemplo: brilho, cor e distribuição de formas) que remetem à ideia de regularidade, rugosidade, suavidade, entre outras, por isso o nome 'textura'. Um tipo particular de análise de textura, bastante utilizado em imagens médicas, se baseia em medidas estatítsticas relativas à distribuição de níveis de cinza da imagem (matriz de coocorrência). Os descritores de textura, baseados na matriz de coocorrência, são conhecidos como descritores de Haralick. Este trabalho consistiu na aplicação de vídeo deste tipo de análise em imagens de Tomografia Computadorizada (TC) de vítimas de Acidente Vascular Cerebral Isquêmico e em imagens de Ressonância Magnetica (RM) de portadores de Epilepsia Mioclônica Juvenil, Doença de Machado-Joseph, Déficit Cognitivo Leve e Doença de Alzheimer, visando o desenvolvimento de uma ferramenta computacional que auxilie o neurologista na identificação de areas atingidas por estas doenças e que não sejam distinguíveis em uma análise visual. Neste trabalho foram selecionadas regiões de interesse (ROIs) e calculados os parâmetros de textura para cada grupo de imagens. Após o cálculo dos descritores de textura foi realizada uma análise estatística para verificar se havia diferenciação entre os vários tipos de tecidos. Os resultados obtidos mostraram que a análise de textura pode, de fato, ser utilizada para a extração de características discriminantes, tanto nas imagens de TC quanto nas imagens de RM para as cinco patologias analisadas / Abstract: Texture analysis in digital images is a term that refers to a group of image processing techniques that aim to extract descriptors of the image or regions of interest (ROIs) in order to simplify their characterization. Texture may be understood as intrinsic characteristics of the image (such as brightness, color and distribution of forms) that refer to the idea of regularity, roughness and smoothness, hence the name 'texture'. A particular type of texture analysis, widely used in medical imaging, is based on statistical measurements related to the image gray level distribution (coocurrence matrix). The texture descriptors based on the coocurrence matrix are known as Haralick descriptors. This work consisted on applying this type of analysis to computed tomography (CT) images of victims of Ischemic Stroke and magnetic resonance images (MRI) of patients with Juvenile Myoclonic Epilepsy, Machado-Joseph disease, mild cognitive impairment and Alzheimer's disease, in order to develop a computational tool to assist neurologists in the identification of areas affected by these diseases and which are not perceived in a visual analysis. In this work we selected regions of interest (ROIs) and calculated the texture parameters for each group of images. After the calculation of the texture descriptors, a statistical analysis was performed to determine whether there was differentiation between the various types of tissues. The results showed that texture analysis can indeed be used for the extraction of discriminant features in both the CT an the MR images for the five studied pathologies / Doutorado / Física / Doutora em Ciências

Page generated in 0.1155 seconds