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Photographic zoom fisheye lens design for DSLR camerasYan, Yufeng, Sasian, Jose 27 September 2017 (has links)
Photographic fisheye lenses with fixed focal length for cameras with different sensor formats have been well developed for decades. However, photographic fisheye lenses with variable focal length are rare on the market due in part to the greater design difficulty. This paper presents a large aperture zoom fisheye lens for DSLR cameras that produces both circular and diagonal fisheye imaging for 35-mm sensors and diagonal fisheye imaging for APS-C sensors. The history and optical characteristics of fisheye lenses are briefly reviewed. Then, a 9.2- to 16.1-mm F/2.8 to F/3.5 zoom fisheye lens design is presented, including the design approach and aberration control. Image quality and tolerance performance analysis for this lens are also presented. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)
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Dynamic Image Precompensation for Improving Visual Performance of Computer Users with Ocular AberrationsHuang, Jian 18 June 2013 (has links)
With the progress of computer technology, computers are expected to be more intelligent in the interaction with humans, presenting information according to the user's psychological and physiological characteristics. However, computer users with visual problems may encounter difficulties on the perception of icons, menus, and other graphical information displayed on the screen, limiting the efficiency of their interaction with computers.
In this dissertation, a personalized and dynamic image precompensation method was developed to improve the visual performance of the computer users with ocular aberrations. The precompensation was applied on the graphical targets before presenting them on the screen, aiming to counteract the visual blurring caused by the ocular aberration of the user's eye. A complete and systematic modeling approach to describe the retinal image formation of the computer user was presented, taking advantage of modeling tools, such as Zernike polynomials, wavefront aberration, Point Spread Function and Modulation Transfer Function. The ocular aberration of the computer user was originally measured by a wavefront aberrometer, as a reference for the precompensation model. The dynamic precompensation was generated based on the resized aberration, with the real-time pupil diameter monitored. The potential visual benefit of the dynamic precompensation method was explored through software simulation, with the aberration data from a real human subject.
An "artificial eye'' experiment was conducted by simulating the human eye with a high-definition camera, providing objective evaluation to the image quality after precompensation. In addition, an empirical evaluation with 20 human participants was also designed and implemented, involving image recognition tests performed under a more realistic viewing environment of computer use. The statistical analysis results of the empirical experiment confirmed the effectiveness of the dynamic precompensation method, by showing significant improvement on the recognition accuracy. The merit and necessity of the dynamic precompensation were also substantiated by comparing it with the static precompensation. The visual benefit of the dynamic precompensation was further confirmed by the subjective assessments collected from the evaluation participants.
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Sindrome de Turner : a perspectiva das pacientesSuzigan, Ligia Zuppi Conceição 17 February 2004 (has links)
Orientadores: Andrea Trevas Maciel Guerra, Roberto Benedito de Paiva e Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-04T01:13:43Z (GMT). No. of bitstreams: 1
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Previous issue date: 2004 / Resumo: Objetivo: Identificar a percepção das pacientes com Síndrome de Turner (ST) a respeito de sua condição. Casuística e Método: Entrevistas individuais com 36 pacientes com ST entre 15 e 25 anos e mais de 2 anos de acompanhamento, abordando temas referentes ao impacto no momento do diagnóstico, compreensão a respeito da ST, seu impacto sobre a vida atual e expectativas de futuro. Resultados: Apenas 1/3 compreendeu o diagnóstico de ST imediatamente, e o sentimento associado a esse momento foi freqüentemente neutro (17) ou de preocupação (12). Cerca de 1/3 não soube explicar a etiologia da ST, não relacionou a ela os sintomas que apresenta e(ou) acredita haver cura. Em sua vida atual, embora a grande maioria declare que a ST não interfere em sua vida (2/3) e se considere feliz (3/4), em mais da metade dos casos há evidências de dificuldades de interação social e de relacionamento amoroso, baixa auto-estima, insatisfação com a aparência física, em particular a baixa estatura e sofrimento com a questão da esterilidade. Suas expectativas de futuro estão predominantemente ligadas a trabalho e estudo; mesmo estando com 19 anos, em média, uma em cada duas ainda espera crescer. Conclusão: Além da abordagem médica da ST, é fundamental que o conhecimento das pacientes a respeito dessa síndrome e as questões referentes a esterilidade, baixa estatura, auto-imagem e interações sociais sejam alvo de atenção especial e contínua a partir do momento do diagnóstico; a situação ideal seria a de atuação de um psicólogo juntamente com a equipe médica / Abstract: Objective: To identify the perception of patients with Turner syndrome (TS) about their condition. Methodology: Thirty-six women with TS, aged between 15 and 25 years and with over two years of medical follow-up, were individually interviewed about: the impact of TS at the moment of the diagnosis, their understanding of the syndrome, its effect in their current lives and their expectations for the future. Results: Only one third of the patients understood the diagnosis immediately and their feelings associated to that moment were neutral (17) or concerned (12). About one third of the interviewed women were unable to explain the etiology of TS, they have not related their symptoms with TS and/or believe there might be a cure for it. Although most say that the syndrome has no interference in their current lives (2/3) and that they consider themselves happy persons (3/4), in more than half of the interviews there are evidences of difficulties with social interactions and love relationships, low self-esteem, dissatisfaction with their physical appearances, mainly short stature, and worries about infertility. Their hopes for the future refer mainly to study and have a job; growing up expectation was mentioned by one in two of the women, in spite of their mean age of 19 years. Conclusion: Besides medical treatment, it is important that the knowledge of the patients about the syndrome and some issues as infertility, short stature, self-image and social interactions receive proper and continuous attention from the moment of the diagnosis. The ideal situation should be a joint-action of the psychologist and the medical team / Mestrado / Saude da Criança e do Adolescente / Mestre em Saude da Criança e do Adolescente
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Genetic features of multicentric/multifocal intramucosal gastric carcinoma / 多中心性/多発性粘膜内胃癌の遺伝学的特徴Takahashi(Mizuguchi), Aya 23 July 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21990号 / 医博第4504号 / 新制||医||1037(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 武藤 学, 教授 松田 文彦, 教授 小川 誠司 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
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Analysis And Design Of Wide-angle Foveated Optical SystemsCuratu, George 01 January 2009 (has links)
The development of compact imaging systems capable of transmitting high-resolution images in real-time while covering a wide field-of-view (FOV) is critical in a variety of military and civilian applications: surveillance, threat detection, target acquisition, tracking, remote operation of unmanned vehicles, etc. Recently, optical foveated imaging using liquid crystal (LC) spatial light modulators (SLM) has received considerable attention as a potential approach to reducing size and complexity in fast wide-angle lenses. The fundamental concept behind optical foveated imaging is reducing the number of elements in a fast wide-angle lens by placing a phase SLM at the pupil stop to dynamically compensate aberrations left uncorrected by the optical design. In the recent years, considerable research and development has been conducted in the field of optical foveated imaging based on the LC SLM technology, and several foveated optical systems (FOS) prototypes have been built. However, most research has been focused so far on the experimental demonstration of the basic concept using off the shelf components, without much concern for the practicality or the optical performance of the systems. Published results quantify only the aberration correction capabilities of the FOS, often claiming diffraction limited performance at the region of interest (ROI). However, these results have continually overlooked diffraction effects on the zero-order efficiency and the image quality. The research work presented in this dissertation covers the methods and results of a detailed theoretical research study on the diffraction analysis, image quality, design, and optimization of fast wide-angle FOSs based on the current transmissive LC SLM technology. The amplitude and phase diffraction effects caused by the pixelated aperture of the SLM are explained and quantified, revealing fundamental limitations imposed by the current transmissive LC SLM technology. As a part of this study, five different fast wide-angle lens designs that can be used to build practical FOSs were developed, revealing additional challenges specific to the optical design of fast wide-angle systems, such as controlling the relative illumination, distortion, and distribution of aberrations across a wide FOV. One of the lens design examples was chosen as a study case to demonstrate the design, analysis, and optimization of a practical wide-angle FOS based on the current state-of-the-art transmissive LC SLM technology. The effects of fabrication and assembly tolerances on the image quality of fast wide-angle FOSs were also investigated, revealing the sensitivity of these fast well-corrected optical systems to manufacturing errors. The theoretical study presented in this dissertation sets fundamental analysis, design, and optimization guidelines for future developments in fast wide-angle FOSs based on transmissive SLM devices.
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FUNDAMENTAL AND APPLIED RESEARCH ENABLED BY POLYMER NANOLAYER COEXTRUSION TECHNOLOGYJin, Yi 09 January 2007 (has links)
No description available.
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The Influence of Schizotypal Traits on Active Display RecognitionRohde, Lucinda V. 21 April 2015 (has links)
No description available.
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Achromatic Liquid Crystal Electro-Optical Devices Based On a Twisted Vertical Alignment ConfigurationChang, Kai-Han 18 April 2018 (has links)
No description available.
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A Study of Limited-Diffraction Array Beam and Steered Plane Wave ImagingWang, Jing 20 June 2006 (has links)
No description available.
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Correcting ocular spherical aberration with soft contact lenses.Cox, Michael J., Dietze, Holger H. January 2004 (has links)
No / Following aberroscopy, aspheric front surface soft contact lenses (SCLs) were custom-made to correct spherical
refractive error and ocular spherical aberration (SA) of 18 myopic and five hypermetropic subjects (age, 20.5
. 5 yr). On-eye residual aberrations, logMAR visual acuity, and contrast sensitivity were compared with the
best-correcting spectacle lens, an equally powered standard SCL, and an SCL designed to be aberration free in
air. Custom-made and spherical SCLs reduced SA ( p . 0.001; p . 0.05) but did not change total root-meansquare (rms) wave-front aberration (WFA). Aberration-free SCLs increased SA ( p . 0.05), coma ( p
. 0.05), and total rms WFA. Visual acuity remained unchanged with any of the SCL types compared with
the spectacle lens correction. Contrast sensitivity at 6 cycles/degree improved with the custom-made SCLs
( p . 0.05). Increased coma with aspheric lens designs and uncorrected astigmatism limit the small possible
visual benefit from correcting ocular SA with SCLs.
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