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  • 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

SOME DESIGN CONSIDERATIONS FOR PRISMATIC ANAMORPHS

Swindell, W. 30 September 1970 (has links)
QC 351 A7 no. 59 / The optical properties of two prisms combined as a single anamorphic element are discussed. There is a family of solutions for which the angular magnification versus field angle is U-shaped. Thus there are regions for which the angular magnification is almost constant. The distortions associated with these regions are explored. It is shown how distortion can be effectively eliminated over a restricted field by cascading a negative and a positive anamorphic element.
2

Anamorphic Preclinical SPECT Imaging with High-Resolution Silicon Double-Sided Strip Detectors

Durko, Heather Lynn January 2014 (has links)
Preclinical single-photon emission computed tomography (SPECT) is an essential tool for studying progression, response to treatment, and physiological changes in small animal models of human disease. The wide range of imaging applications is often limited by the static design of many preclinical SPECT systems. We have developed a prototype imaging system that replaces the standard static pinhole aperture with two sets of movable, keel-edged copper-tungsten blades configured as crossed (skewed) slits. These apertures can be positioned independently between the object and detector, producing an anamorphic image in which the axial and transaxial magnications are not constrained to be equal. We incorporated a 60 mm x 60 mm, millimeter-thick megapixel silicon double-sided strip detector that permits ultrahigh-resolution imaging. While the stopping power of silicon is low for many common clinical radioisotopes, its performance is sufficient in the range of 20-60 keV to allow practical imaging experiments. The low-energy emissions of ¹²⁵I fall within this energy window, and the 60-day half life provides an advantage for longitudinal studies. The flexible nature of this system allows the future application of adaptive imaging techniques. We have demonstrated ~225-μm axial and ~175-μm transaxial resolution across a 2.65 cm³ cylindrical field of view, as well as the capability for simultaneous multi-isotope acquisitions. We describe the key advancements that have made this system operational, including bringing up a new detector readout ASIC, development of detector control software and data-processing algorithms, and characterization of operating characteristics. We describe design and fabrication of the adjustable slit aperture platform, as well as the development of an accurate imaging forward model and its application in a novel geometric calibration technique and a GPU-based ultrahigh-resolution reconstruction code.
3

Aberrations of Anamorphic Optical Systems

Yuan, Sheng January 2008 (has links)
A detailed study of the aberrations of anamorphic optical systems is presented. This study has been developed with a theoretical structure similar to that of rotationally symmetric optical systems (RSOS) and can be considered a generalization.A general method of deriving the monochromatic primary aberration coefficient expressions for any anamorphic system types with double plane symmetry has been provided.The complete monochromatic primary aberration coefficient expressions for cylindrical anamorphic systems, toroidal anamorphic systems and general anamorphic systems with aspheric departure have been presented, in a form similar to the Seidel aberrations of RSOS.Some anamorphic image system design examples are provided that illustrate the use and value of the theory developed.
4

Regressão não linear quantílica para classificação de sítio em povoamentos de Eucalyptus sp. / Non-linear quatile regression for site classification in Eucalyptus sp Stands

Santos, Carlos Juliano 09 May 2017 (has links)
Submitted by Milena Rubi ( ri.bso@ufscar.br) on 2017-11-07T17:07:00Z No. of bitstreams: 1 SANTOS_Carlos_2017.pdf: 906783 bytes, checksum: bccefa4afd7b8ef5d98df40bff297122 (MD5) / Approved for entry into archive by Milena Rubi ( ri.bso@ufscar.br) on 2017-11-07T17:07:12Z (GMT) No. of bitstreams: 1 SANTOS_Carlos_2017.pdf: 906783 bytes, checksum: bccefa4afd7b8ef5d98df40bff297122 (MD5) / Approved for entry into archive by Milena Rubi ( ri.bso@ufscar.br) on 2017-11-07T17:07:22Z (GMT) No. of bitstreams: 1 SANTOS_Carlos_2017.pdf: 906783 bytes, checksum: bccefa4afd7b8ef5d98df40bff297122 (MD5) / Made available in DSpace on 2017-11-07T17:07:31Z (GMT). No. of bitstreams: 1 SANTOS_Carlos_2017.pdf: 906783 bytes, checksum: bccefa4afd7b8ef5d98df40bff297122 (MD5) Previous issue date: 2017-05-09 / Não recebi financiamento / The productive capacity is conventionally estimated by anamorphic or polymorphic calculated site curves; however, these curves have some limitations. Due to these limitations, the objective of this work was to evaluate the creation of growth curves for site classification by the nonlinear quantile regression method and to compare them with the curves generated by the algebraic difference method. The database was collected in two mesoregions of the state of São Paulo (Paulista and Bauru Metropolitan Macro), with 460 measurements in 98 plots with distinct periods in Eucalyptus sp. The site curves were adjusted according to the Chapman-Richards model using the algebraic difference method for anamorphic and polymorphic curves and nonlinear quantum regression (RNLQ). The results of this work allowed to conclude that the site curves adjusted by the RNLQ method are superior to the curves generated by the algebraic difference method by graphical analysis of the residuals with smaller ranged of the errors and greater homogeneity and residual standard error with lower values in the classes in general. / A capacidade produtiva é estimada convencionalmente por meio de curvas de sítio calculadas de forma anamórfica ou polimórfica, contudo, estas curvas possuem algumas limitações. Devido a estas limitações, o objetivo deste trabalho foi avaliar a criação de curvas de crescimento para classificação de sítio pelo método de regressão não linear quantílica e compará-las com as curvas geradas pelo método da diferença algébrica. A ba se de dados foi coletada em duas mesorregiões do estado de São Paulo (Macro Metropolitana Paulista e Bauru), com 460 medições em 98 parcelas com períodos distintos em Eucalyptus sp. As curvas de sítio foram ajustadas segundo modelo de Chapman-Richards pelo método da diferença algébrica para curvas anamórficas e polimórficas e regressão não linear quantílica (RNLQ). Os resultados deste trabalho permitiram concluir que as curvas de sítio ajustadas pelo método da RNLQ são superiores às curvas geradas pelo método da diferença algébrica pela análise gráfica dos resíduos com menor amplitude dos erros e maior homogeneidade e erro padrão residual com menores valores nas classes em geral.
5

Diretrizes para sinalização de trânsito anamórfica: uma proposta no redesenho da sinalização horizontal. / Guidelines for anamorphic traffic signaling: a proposal in the redesign of horizontal signaling.

Santos, Claudemilson dos 14 March 2018 (has links)
Submitted by Claudemilson dos Santos (claudemilson.unesp@gmail.com) on 2018-05-04T19:29:04Z No. of bitstreams: 1 TESE CLAUDEMILSON 2018 PUBLICADA.pdf: 5622961 bytes, checksum: 79c0398762c5c1699e1955254be82faf (MD5) / Approved for entry into archive by Lucilene Cordeiro da Silva Messias null (lubiblio@bauru.unesp.br) on 2018-05-07T17:46:48Z (GMT) No. of bitstreams: 1 santos_ c_ dr_bauru.pdf: 5611478 bytes, checksum: 24a4edf7aac9b1a4496e22587ac9e2e3 (MD5) / Made available in DSpace on 2018-05-07T17:46:48Z (GMT). No. of bitstreams: 1 santos_ c_ dr_bauru.pdf: 5611478 bytes, checksum: 24a4edf7aac9b1a4496e22587ac9e2e3 (MD5) Previous issue date: 2018-03-14 / Esta tese consiste num estudo que visou avaliar o impacto da aplicação da anamorfose no redesenho da sinalização de trânsito horizontal, cuja hipótese supõe que pode melhorar a percepção dos motoristas para essa categoria de sinalização de trânsito. Anamorfose é o nome que se dá para o desenho em perspectiva cônica cujo plano de projeção não é perpendicular à linha de visada. O plano de projeção pode se dividir em várias superfícies e formas, a imagem projetada se distorce até ficar irreconhecível; mas quando observado do ponto de vista pré-determinado, a imagem se forma novamente. Na sinalização de trânsito horizontal a anamorfose é utilizada para simular uma aparência tridimensional aos sinais de trânsito horizontais, denominada como Sinalização Horizontal Anamórfica (SHA). A base teórica, que se fundamentou nos princípios do design ergonômico e nas teorias da percepção e do comportamento humano; está expressa numa revisão que buscou compilar e discutir a relação entre as diversas áreas do conhecimento humano e o sistema de percepção visual no trânsito, e analisando-se o problema de pesquisa de diversos pontos de vista, buscando-se concordâncias, discordâncias e avanços nas ciências que estudam o comportamento humano. Para encontrar evidências que pudessem comprovar ou refutar a hipótese, foi realizado um experimento de desenvolvimento e aplicação de uma SHA em um trecho urbano simulado e comparou-se a taxa de percepção dos motoristas que por ela passaram com os que passaram por uma sinalização convencional. A sinalização horizontal utilizada para a pesquisa foi a legenda DEVAGAR, pois há estudos anteriores que detectaram índices de percepção muito baixos. Os resultados do teste revelou haver diferença significativa na taxa de percepção dos dois grupos. A discrepância entre os dois grupos pode significar que a SHA exerce algum efeito sobre a percepção visual do motorista. Os resultados revelaram que os motoristas que utilizarem o trecho contendo a SHA terão possibiidade maior de perceberem a sinalização do que os grupos que não continham a SHA, pois os testes estatísticos realizados comprovaram o aumento significativo de motoristas que perceberam a sinalização horizontal anamórfica em relação à sinalização convencional. / This thesis consists of a study that aimed to evaluate the impact of the application of anamorphosis on the redesign of horizontal traffic signs, whose hypothesis supposes that it can improve the perception of the drivers for this category of traffic signaling. Anamorphosis is the name given to the conical perspective drawing whose projection plane is not perpendicular to the line of sight. The projection plane can divide into several surfaces and shapes, the projected image distorts until it is unrecognizable; but when viewed from the predetermined point of view, the image is formed again. In horizontal traffic signaling the anamorphosis is used to simulate a three-dimensional appearance to the horizontal traffic signals, denominated Horizontal Anamorphic Signaling (SHA - from potuguese "Sinalização Horizontal Anamórfica). The theoretical basis, which was based on the principles of ergonomic design and theories of human perception and behavior; is expressed in a review that sought to compile and discuss the relationship between the various areas of human knowledge and the system of visual perception in traffic, and analyzing the research problem from different points of view, seeking concordances, disagreements and advances in sciences that study human behavior. To find evidence that could prove or disprove the hypothesis, an experiment was carried out to develop and apply an SHA in a simulated urban stretch, comparing the perception rate of the drivers that passed with those who passed through a conventional signaling. The horizontal signaling used for the research was the legend DEVAGAR, since there have been previous studies that detected very low indices of perception. The results of the test revealed that there was a significant difference in the perception rate of the two groups. The discrepancy between the two groups may mean that SHA has some effect on the driver's visual perception. The results showed that drivers using the SHA stretch will have a greater possibility of perceiving the signaling than the groups that did not contain SHA, since the statistical tests performed showed a significant increase in drivers who perceived the anamorphic horizontal signaling in relation to the conventional signaling.
6

The Last Two Years of David Brachman: The Case for Slow Cinema as a Microbudget Production Model

Casilli, Marcos 01 January 2011 (has links)
The Last Two Years of David Brachman is a feature-length digital film directed, written and produced by Marcos Casilli in pursuit of the Master of Fine Arts in Film & Digital Media from the University of Central Florida. This is a very personal film that presents a sometimes-humorous approach to the following question: what makes life worth living? The film was made on what is categorized as a microbudget, but following the studio production model for the most part. This thesis presents a critique of that combination, advocating for a "slow cinema" model instead.
7

Inference generation in the reading of expository texts by university students

Pretorius, Elizabeth Josephine 02 1900 (has links)
The continued underperformance of many L2 students at primary, secondary and tertiary level is a cause for grave concern in South Africa. In an attempt to better understand the cognitivelinguistic conditions and processes that underlie academic performance and underperformance, this study looks at the problem of differential academic performance by focussing on the inferential ability of undergraduate L2 students during the reading of expository texts. The study works within a constructivist theory of reading, where the successful understanding of a text is seen to involve the construction of a mental representation of what the text is about. Inferencing plays an important role in constructing meaning during reading because it enables the reader to link incoming information with already given information, and it enables the reader to construct a mental representation of the meaning of a text by converting the linear input into a hierarchical mental representation of interrelated information. The main finding showed that the ability to make inferences during the reading of expository texts was strongly related to academic performance: the more inferences students made during the reading of expository texts, the better they performed academically. This relationship held across the making of various inferences, such as anaphoric inferences, vocabulary inferences, inferences about various semantic relations, and thematic inferences. In particular, the ability to make anaphoric, contrastive and causal inferences emerged as the strongest predictors of academic performance. The study provides strong empirical evidence that the ability to make inferences during reading enables a reader to construct meaning and thereby also to acquire new knowledge. Reading is not only a tool for independently accessing information in an information-driven society, it is fundamentally a tool for constructing meaning. Reading and inferencing are not additional tools that students need to master in the learning context- they constitute the very process whereby learning occurs. / Linguistics and Modern Languages / D.Litt. et Phil. (Linguistics)
8

Inference generation in the reading of expository texts by university students

Pretorius, Elizabeth Josephine 02 1900 (has links)
The continued underperformance of many L2 students at primary, secondary and tertiary level is a cause for grave concern in South Africa. In an attempt to better understand the cognitivelinguistic conditions and processes that underlie academic performance and underperformance, this study looks at the problem of differential academic performance by focussing on the inferential ability of undergraduate L2 students during the reading of expository texts. The study works within a constructivist theory of reading, where the successful understanding of a text is seen to involve the construction of a mental representation of what the text is about. Inferencing plays an important role in constructing meaning during reading because it enables the reader to link incoming information with already given information, and it enables the reader to construct a mental representation of the meaning of a text by converting the linear input into a hierarchical mental representation of interrelated information. The main finding showed that the ability to make inferences during the reading of expository texts was strongly related to academic performance: the more inferences students made during the reading of expository texts, the better they performed academically. This relationship held across the making of various inferences, such as anaphoric inferences, vocabulary inferences, inferences about various semantic relations, and thematic inferences. In particular, the ability to make anaphoric, contrastive and causal inferences emerged as the strongest predictors of academic performance. The study provides strong empirical evidence that the ability to make inferences during reading enables a reader to construct meaning and thereby also to acquire new knowledge. Reading is not only a tool for independently accessing information in an information-driven society, it is fundamentally a tool for constructing meaning. Reading and inferencing are not additional tools that students need to master in the learning context- they constitute the very process whereby learning occurs. / Linguistics and Modern Languages / D.Litt. et Phil. (Linguistics)

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