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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

Osseous Lesions of the Hand and Foot in Diabetes Mellitus: Correlation between Magnification Roentgenographic Findings and Clinical Findings

ISHIGAKI, TAKEO, SAKUMA, SADAYUKI, SAKAI, MICHIKO 03 1900 (has links)
No description available.
2

EFFECTS OF ASYMMETRICAL LIVE LOADS ON SIDESWAYS AND MOMENT AMPLIFICATION FACTORS OF STEEL MOMENT FRAME CONSIDERING P-DELTA INTERACTION

Neupane, Bibek 01 May 2016 (has links)
The P-delta effect, which is a second order effect, is experienced by a structure mostly when the structure is subjected to lateral forces like earthquake and wind. In addition to earthquake and wind loads, when the structure is subjected to various live load patterns other than symmetrical loading, the structure experiences side sway or lateral translation. In this thesis, P-delta effects due to symmetrical and asymmetrical live loads is studied on a three-bay, two-story steel moment frame. The main objective of this research is to investigate P-delta effects on the column which is subjected to critical load case. The effect is analyzed based on the value of the moment magnification factor, B2. Besides, the story drift due to asymmetrical loading is also investigated. For the purpose of this study, “Approximate Second-Order Analysis” specified in “Appendix 8” of AISC Steel Construction Manual (AISC 2011) is used to amplify the first order effects to account for the second-order effects in the steel moment frame. Additionally, computer software is used to calculate the first order moments and axial forces.
3

Ergonomic Magnification Method for Reading With and Without Display Size Constraint

Wong, Natalie January 2021 (has links)
No description available.
4

Subjective Verticality Is Disrupted by Astigmatic Visual Distortion in Older People

Elliott, David B., Black, A.A., Wood, J.M. 25 April 2020 (has links)
Yes / PURPOSE: There is little research evidence to explain why older adults have more problems adapting to new spectacles incorporating astigmatic changes than younger adults. We tested the hypothesis that astigmatic lenses oriented obliquely would lead to errors in verticality perception that are greater for older than younger adults. METHODS: Participants included 12 young (mean ± SD age 25.1 ± 5.0 years) and 12 older (70.2 ± 6.3 years) adults with normal vision. Verticality perception was assessed using a computer-based subjective visual vertical (SVV) task, under static and dynamic (in the presence of a moving peripheral distractor) conditions and when viewing targets through the near refractive correction (control condition), and two forms of astigmatic lenses oriented in the vertical, horizontal, and oblique meridians. RESULTS: The older group demonstrated much greater dynamic SVV errors (e.g., 3.4° for the control condition) than the younger group (1.2°, P = 0.002), larger errors with vertical and horizontal astigmatic lenses (older group 4.1°and 5.2° for toric and magnifier lenses vs. younger group 1.2° and 1.4°, respectively, P < 0.001), and a larger influence of the oblique astigmatic lenses (older group 5.6° vs. younger group 2.1°, P<0.001). CONCLUSIONS: Astigmatic lenses produced little or no errors in SVV in young adults, but large static and dynamic SVV errors in older adults. This indicates a greater reliance on visual input with increased age for SVV, and helps explain why oblique astigmatic refractive corrections can cause dizziness in older patients and why they report greater difficulties adapting to new spectacles with astigmatic changes.
5

Optimal cosmology from gravitational lensing : utilising the magnification and shear signals

Duncan, Christopher Alexander James January 2015 (has links)
Gravitational lensing studies the distortions of a distant galaxy’s observed size, shape or flux due to the tidal bending of photons by matter between the source and observer. Such distortions can be used to infer knowledge on the mass distribution of the intervening matter, such as the dark matter halos in which clusters of individual galaxies may reside, or on cosmology through the statistics of the matter density of large scale structure and geometrical factors. In particular, gravitational lensing has the advantage that it is insensitive to the nature of the lensing matter. However, contamination of the signal by correlations between galaxy shape or size and local environment complicate a lensing analysis. Further, measurement of traditional lensing estimators is made more difficult by limitations on observations, in the form of atmospheric distortions or optical limits of the telescope itself. As a result, there has been a large effort within the lensing community to develop methods to either reduce or remove these contaminants, motivated largely by stringent science requirements for current and forthcoming surveys such as CFHTLenS, DES, LSST, HSC, Euclid and others. With the wealth of data from these wide-field surveys, it is more important than ever to understand the full range of independent probes of cosmology at our disposal. In particular, it is desirable to understand how each probe may be used, individually and in conjunction, to maximise the information of a lensing analysis and minimise or mitigate the systematics of each. With this in mind, I investigate the use of galaxy clustering measurements using photometric redshift information, including a contribution from flux magnification, as a probe of cosmology. I present cosmological forecasts when clustering data alone are used, and when clustering is combined with a cosmic shear analysis. I consider two types of clustering analysis: firstly, clustering with only redshift auto-correlations in tomographic redshift bins; secondly, clustering using all available redshift bin correlations. Finally, I consider how inferred cosmological parameters may be biased using each analysis when flux magnification is neglected. Results are presented for a Stage–III ground-based survey, and a Stage–IV space-based survey modelled with photometric redshift errors, and values for the slope of the luminosity function inferred from CFHTLenS catalogues. I find that combining clustering information with shear gives significant improvement on cosmological parameter constraints, with the largest improvement found when all redshift bins are included in the analysis. The addition of galaxy-galaxy lensing gives further improvement, with a full combined analysis improving constraints on dark energy parameters by a factor of > 3. The presence of flux magnification in a clustering analysis does not significantly affect the precision of cosmological constraints when combined with cosmic shear and galaxy-galaxy lensing. However if magnification is neglected, inferred cosmological parameter values are biased, with biases in some cosmological parameters found to be larger than statistical errors. We find that a combination of clustering, cosmic shear and galaxy-galaxy lensing can provide a significant reduction in statistical errors from each analysis individually, however care must be taken to measure and model flux magnification. Finally, I consider how measurements of galaxy size and flux may be used to constrain the dark matter profile of a foreground lens, such as galaxy- or galaxy-cluster-dark matter halos. I present a method of constructing probability distributions for halo profile free parameters using Bayes’ Theorem, provided the intrinsic size-magnitude distribution may be measured from data. I investigate the use of this method on mock clusters, with an aim of investigating the precision and accuracy of returned parameter constraints under certain conditions. As part of this analysis, I quantify the size and significance of inaccuracies in the dark matter reconstruction as a result of limitations in the data from which the sample and size-magnitude distribution is obtained. This method is applied to public data from the Space Telescope A901/902 Galaxy Evolution Survey (STAGES), and results are presented for the four STAGES clusters using measurements of source galaxy size and magnitude, and a combination of both. I find consistent results with existing shear measurements using measurements of galaxy magnitudes, but interesting inconsistent results when galaxy size measurements are used. The simplifying assumptions and limitations of the analysis are discussed, and extensions to the method presented.
6

Macro Self-Portraiture and the Feminine Grotesque

Wages, Emily C 01 January 2016 (has links)
According to the Mirriam-Webster online dictionary, “grotesque” is defined as “a style of decorative art characterized by fanciful or fantastic human and animal forms often interwoven with foliage or similar figures that may distort the natural into absurdity, ugliness, or caricature.” Originating from the Old Italian grottesca, cave painting, feminine of grottesco of a cave, from the time of its conception, the grotesque has been inexorably linked to art and the female. The work of other female artists that explore themes of the feminine grotesque are discussed, including Katheryn Wakeman, Jenny Saville, and Maria Lassnig. In my current work, I have been creating oil paintings of macro images of my own body to construct a fragmented and magnified, borderless, grotesque view of the body. The images focus on the mouth, due to its complicated nature as both internal and external, hidden and in plain sight, as well as due to connotations with speech, ingestion, and sexuality. The work walks a fine line between aesthetically pleasing while also commanding an uncomfortably visceral, fleshy quality. While the works are somewhat ambiguous and allow for various readings, they also allude to larger issues of sexism. The use of magnification and fragmentation references the insufficient representation of the female body both art historically —with the beautiful female nude painted by the male artist—as well as contemporarily in an overly-Photoshopped society. The visceral feeling of disgust should allow viewers to commune with their own bodies’ psychophysiological reactions and question the politics of how beauty standards are established as well as whether beauty is a valuable concept when judging the female form.
7

Distorção de imagens em radiografias panoramicas com relação a distancia intergoniaca / Distortion of images in panoramic radiographs in relation to the intergoniac distance

Ladeira, Daniela Brait Silva 12 August 2018 (has links)
Orientador: Solange Maria de Almeida / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-12T22:00:11Z (GMT). No. of bitstreams: 1 Ladeira_DanielaBraitSilva_M.pdf: 1017119 bytes, checksum: 322eb3926821425fc8da5596828faa73 (MD5) Previous issue date: 2009 / Resumo: A realização de medidas precisas em radiografias panorâmicas é duvidosa, devido à distorção por ampliação de imagens. Por ser um método tomográfico, somente a porção do objeto localizada na camada de imagem do aparelho estará livre de distorção. O objetivo nesse trabalho foi determinar a camada de imagem do aparelho panorâmico Orthopantomograph OP 100 e avaliar a relação entre distâncias intergoníacas e medidas lineares em radiografias panorâmicas. Para a determinação da camada de imagem foi construído um phantom constituído por uma placa acrílica de 14cm², com sua superfície contendo perfurações a cada 0,5cm. O phantom foi posicionado no local do apoio de mento do aparelho panorâmico, com sua superfície paralela ao plano horizontal. Esferas metálicas de 0,315cm foram inseridas nas perfurações, e executadas radiografias panorâmicas. Cada coluna de cada quadrante foi individualmente preenchida pelas esferas para a execução das radiografias, em três planos horizontais diferentes: alturas orbital, oclusal e mentual. As imagens radiográficas obtidas foram analisadas e a camada de imagem localizada. Mostrou-se curva no plano horizontal, e mais estreita na região anterior; no plano vertical, apresentou discreta assimetria da cavidadeorbitária em direção ao mento, e entre os lados direito e esquerdo. Na etapa seguinte, mandíbulas maceradas foram separadas em três grupos de dez mandíbulas cada, de acordo com as distâncias intergoníacas: G1(8,2cm), G2(9,0cm) e G3(9,6cm). As mandíbulas receberam em sua superfície, triângulos retângulos isósceles confeccionados com esferas metálicas de 0,198cm, fixados nas regiões de incisivos, caninos/pré-molares, molares, ângulo e ramo da mandíbula. As mandíbulas foram individualmente radiografadas sobre o phantom, nos limites da camada de imagem, primeiramente com os triângulos fixados na superfície externa, e em uma segunda etapa, na superfície interna. As imagens radiográficas dos triângulos foram medidas, e obtiveram-se duas medidas para cada triângulo, uma vertical e outra horizontal, e calculadas as medianas entre as medidas internas e externas. Após análise estatística utilizando-se o teste de Tukey (a=0,05), observou-se que não houve diferenças estatisticamente significativas nas medidas verticais e horizontais entre os grupos G1, G2 e G3. Concluiu-se não haver relação entre a distância intergoníaca e medidas lineares horizontais e verticais. Porém, as medidas variaram entre as diferentes regiões de um mesmo grupo. Essa variação foi maior para as medidas horizontais em relação às verticais. / Abstract: Precise measures in panoramic radiographs are questionable due to the image distortion. As a tomographic method, only the structures located on the image layer is free of distortion. The aim in this work was to determine the image layer of the panoramic Orthopantomograph OP 100 unit and to evaluate the relationship between intergoniac distances and linear measures in panoramic radiographies. To determine the image layer it was idealized a phantom produced by a 14cm² acrylic plate with holes every 0,5cm. The phantom was placed on the panoramic device mental support, with the surface parallel to the horizontal plan. 0,315cm metal spheres were inserted in the holes and then, panoramic radiographies were taken. A column of each quadrant was filled by the spheres to radiographic exposure in three horizontal plains: orbital, occlusal and symphysis levels. The radiographic images were examined and the image layer was located. It showed curve in the horizontal plane with narrowing in the anterior region; in the vertical plan, it showed slight asymmetry of the orbital cavity toward the symphysis, and between the right and left sides. After that, dry mandibles were separated in three different groups with ten mandibles per group according the intergoniac distances: G1(8,2cm), G2(9,0cm) e G3(9,6cm). Isosceles rectangular triangles confectioned with 0,198cm metal spheres were set in the regions of incisors, canines/ bicuspid, molars, angle and mandibular ramus. Each mandible was radiographed separately on the phantom in the image layer limits. At first the triangles were set on the external surface and, in a second step, they were set on the internal surface. After all the radiographic images taken, the triangles were measured resulting in two measures for each triangle, one vertical and another one horizontal. The median values between the internal and external measures were calculated and the data were submitted to Tukey Test (a=0,05). There were no statistically significant differences in vertical and horizontal measures among the groups G1, G2 and G3. Thus, it was possible to conclude that there is not relationship between the intergoniac distance and horizontal and vertical linear measures. However, the measures ranged between the different regions of one same group and this variation was greater for horizontal measures in relation to vertical. / Mestrado / Radiologia Odontologica / Mestre em Radiologia Odontológica
8

The Effect of Educational Requirement of Magnification Loupes on Musculoskeletal Pain Among Ohio Registered Dental Hygienists

McLaughlin, MELISSA 28 August 2019 (has links)
No description available.
9

Super-Resolution via Image Recapture and Bayesian Effect Modeling

Toronto, Neil B. 11 March 2009 (has links) (PDF)
The goal of super-resolution is to increase not only the size of an image, but also its apparent resolution, making the result more plausible to human viewers. Many super-resolution methods do well at modest magnification factors, but even the best suffer from boundary and gradient artifacts at high magnification factors. This thesis presents Bayesian edge inference (BEI), a novel method grounded in Bayesian inference that does not suffer from these artifacts and remains competitive in published objective quality measures. BEI works by modeling the image capture process explicitly, including any downsampling, and modeling a fictional recapture process, which together allow principled control over blur. Scene modeling requires noncausal modeling within a causal framework, and an intuitive technique for that is given. Finally, BEI with trivial changes is shown to perform well on two tasks outside of its original domain—CCD demosaicing and inpainting—suggesting that the model generalizes well.
10

Adaptive gait changes due to spectacle magnification and dioptric blur in older people

Elliott, David B., Chapman, Graham J. 02 1900 (has links)
Yes / Purpose. A recent study suggested that updated spectacles could increase falls rate in older people. We hypothesized that this may be due to changes in spectacle magnification and this study assessed the effects of spectacle magnification on adaptive gait. Methods. Adaptive gait and visual function was measured in 10 older adults (mean age 77.1 ¿ 4.3 years) with the participants¿ optimal refractive correction and when blurred with +1.00DS, +2.00DS, -1.00DS and -2.00DS lenses. Adaptive gait measurements for the lead and trail foot included foot position before the step, toe clearance of the step edge and foot position on the step. Vision measurements included visual acuity, contrast sensitivity and stereoacuity. Results. The blur lenses led to equal decrements in visual acuity and stereoacuity for the +1.00DS and -1.00DS and the +2.00DS and -2.00DS lenses. However, they had very different effects on adaptive gait compared to the optimal correction: Positive blur lenses led to an increased distance of the feet from the step, increased vertical toe clearance and reduced distance of the lead heel position on the step. Negative lenses led to the opposite of these changes. Conclusion. The adaptive gait changes did not mirror the effects of blur on vision, but were driven by the magnification changes of the lenses. Steps appear closer and larger with positive lenses and further away and smaller with negative ones. Magnification likely explains the mobility problems some older adults have with updated spectacles and after cataract surgery. / Federation of Ophthalmic and Dispensing Opticians

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