No description available.

By using a special design of electrode pattern and the differential biased circuit, the gradient of the electric field distribution inside the liquid crystal sample cell can be achieved through the adjustment of driving voltage. The characteristics of positive or negative types of lens can be converted by changing the polarity of gradient within the sample cell which posses the homogeneous alignment. The liquid crystal lens with a variable focal length and the tunable types of focusing is demonstrated by utilizing the controllable distribution of electric field. This special design incorporating with the fabrication technology of TFT has a potential to develop a large scale of liquid crystal lens.

It is difficult to fabricate electrode, which have gradient electric field from edge to center by applying voltage. In this study, a gradient refractive index profile can be easily formed. We change the experimental parameter about exposure time of UV light, concentration of PVK film and the Cell gap to investigate the influence on focal length. As the exposure time increase, the differences in conductivity become large from edge to center, which create better index distribution. For high concentration of PVK films, UV light can not effectively improve the conductivity of transmittance zone, which case the worse index distribution. The increasing of cell gap resulting in poor distribution of the refractive index, which cause larger focal length.

There has been to date no attempt at a detailed examination of Aleksandr Grin’s philosophical views interpreted on the basis of his literary work. Whilst some critics have noted interesting links between the writer’s oeuvre and a few popular philosophers, this has usually been done in passing and on an ad hoc basis. This thesis aims to fill this gap by reconstructing Grin’s views in relation to the European philosophical tradition. The main body of the thesis consists of three parts built on and named after three essential themes in philosophy: External World, Happiness and Morality. Part One delineates Grin’s views on nature and civilisation: I argue first that his cult of nature makes it possible to conceive of Grin as a pantheistic thinker close to Rousseau and Bergson, and then I reconstruct the author’s criticism of urbanisation and industrialisation. In the second part I assess the place of happiness in Grin’s world-view, indicating its similarities to the philosophy of various thinkers from the Ancients to Schopenhauer and Nietzsche. After sketching a general picture of the concept of happiness in Grin’s works, I discuss the place of material and immaterial factors in the writer’s outlook. I also gather maxims expressed by the protagonists in his fiction that can be taken as recommendations concerning ways of achieving and defending happiness. Finally, I link happiness with the problem of morality in Grin’s oeuvre. In the final part I examine modes of moral behaviour as displayed by the author’s protagonists. Firstly, I argue that in Grin’s works we find numerous examples and themes that allow us to perceive him as an existentialist. Secondly, I indicate Grin’s adherence to rules of conduct commonly associated with chivalric literature. Thirdly, I emphasise the importance of Promethean-like characters in the moral hierarchy of Grin’s protagonists.

The purpose of this thesis is to describe the development of an anatomically based, young adult eye model, which includes a crystalline lens with a gradient refractive index (GRIN). This model will then be used to investigate the effect of laser refractive surgery. The first step in this process involved developing a symmetrical eye model that was found to be a better predictor of empirical longitudinal spherical aberration than any previous model. Myopia was simulated by either a purely axial or refractive technique. While these models were found to be good predictors of the spherical aberration measured in young adults, they did not predict the total amount of high-order aberrations. The techniques used to simulate a single type of myopia caused the myopic models to become anatomically inaccurate. To improve the eye models a biconic surface was used to quantify the anterior corneal shape as a function of myopia. A method to describe the refractive error and biconic shape parameters in Jackson Cross Cylinder terms was implemented to determine correlations. Results indicate that a biconic accurately models the average shape of the anterior corneal surface as a function of myopia. Adopting the biconic model for the anterior corneal surface and adding average misalignments of the ocular components transformed the models from symmetrical to asymmetrical. Refractive error was now simulated by the anatomically accurate changes in both the anterior corneal shape and axial length. The asymmetrical aberrations resulted from the misalignment of the ocular components and provided a good prediction of average empirical aberrations but underestimated the aberrations of individual subjects. Photorefractive keratectomy, a form of laser refractive surgery, was simulated by theoretically calculated and by empirically measured changes in the shape of the anterior corneal surface. Applying the change in anterior corneal shape to the asymmetrical models was used to develop postoperative models. Changes in corneal shape and model aberrations attributed to theoretical calculations do not match empirical observations. The prediction of increased high-order aberrations in postoperative models based on empirically measured changes in the anterior corneal topography was similar to clinical results. Average anatomically based, GRIN eye models have been developed that accurately predict the average aberrations of emmetropic and myopic young adults. These models underestimate the asymmetrical and total high-order aberrations that have been measured in individual subjects but are still useful for investigating the average effects of procedures like refractive surgery.

The purpose of this thesis is to describe the development of an anatomically based, young adult eye model, which includes a crystalline lens with a gradient refractive index (GRIN). This model will then be used to investigate the effect of laser refractive surgery. The first step in this process involved developing a symmetrical eye model that was found to be a better predictor of empirical longitudinal spherical aberration than any previous model. Myopia was simulated by either a purely axial or refractive technique. While these models were found to be good predictors of the spherical aberration measured in young adults, they did not predict the total amount of high-order aberrations. The techniques used to simulate a single type of myopia caused the myopic models to become anatomically inaccurate. To improve the eye models a biconic surface was used to quantify the anterior corneal shape as a function of myopia. A method to describe the refractive error and biconic shape parameters in Jackson Cross Cylinder terms was implemented to determine correlations. Results indicate that a biconic accurately models the average shape of the anterior corneal surface as a function of myopia. Adopting the biconic model for the anterior corneal surface and adding average misalignments of the ocular components transformed the models from symmetrical to asymmetrical. Refractive error was now simulated by the anatomically accurate changes in both the anterior corneal shape and axial length. The asymmetrical aberrations resulted from the misalignment of the ocular components and provided a good prediction of average empirical aberrations but underestimated the aberrations of individual subjects. Photorefractive keratectomy, a form of laser refractive surgery, was simulated by theoretically calculated and by empirically measured changes in the shape of the anterior corneal surface. Applying the change in anterior corneal shape to the asymmetrical models was used to develop postoperative models. Changes in corneal shape and model aberrations attributed to theoretical calculations do not match empirical observations. The prediction of increased high-order aberrations in postoperative models based on empirically measured changes in the anterior corneal topography was similar to clinical results. Average anatomically based, GRIN eye models have been developed that accurately predict the average aberrations of emmetropic and myopic young adults. These models underestimate the asymmetrical and total high-order aberrations that have been measured in individual subjects but are still useful for investigating the average effects of procedures like refractive surgery.

The present thesis analyzes the cultural image of the Russian neo-Romantic writer Alexander Grin (1880-1932) as it has been constructed by Soviet ideology and received in Soviet popular culture since the late 1950s. The topic of the thesis is unique, and it has not yet been investigated before. The thesis explores three major aspects of Grin's representation in Soviet culture: critical, fictional and cinematic. The first part "Critical representation of Grin's works in the USSR" focuses upon the process of construction and development of ideological "myths about Grin" in the system of Soviet culture. It demonstrates and analyzes the transformation of the official and public attitude to Grin's works from the 1920s to the 1980s. The second part is entitled "Representation of Grin's image in Soviet fiction: Grin as a fictional character". Through the coherent analysis of three Soviet novels (introducing Alexander Grin as a protagonist), it explores the phenomenon of the transformation of both the personal and socio-cultural attitudes to Grin. The fictional works are viewed in chronological order: The Black Sea by Konstantin Paustovsky (Chernoe more, 1935), The Wizard from Gel'-Giu by Leonid Borisov (Volshebnik iz Gel'-Giu, 1944) and The Lord of Chances by Valentin Zorin (Povelitel' sluchaynostey, 1977-79). The third part concentrates entirely on the Cinematic representation of Grin's works on the Soviet screen, analyzing five major film-versions of Grin's works: Scarlet Sails (Alye parusa, dir. Ptushko, 1961), She Who Runs the Waves (Begushchaya po volnam, dir. Lubimov, 1967), Shining World (Blistayushchiy mir, dir. Mansurov, 1984), The Golden Chain (Zolotaya Tsep , dir. Muratov, 1986), Mister Designer (Gospodin oformitel', dir. Teptsov, 1986). The study of Grin's case offers a unique opportunity to investigate how the old ideological myths are occupying the minds of younger generations nowadays. Grin is still a "cult figure" for Russian society, but it remains to be investigated to what extent his contemporary image (and the image of his fiction) is influenced by the old models of the Soviet era.

No description available.

L'imagerie optique biomédicale est confrontée aux phénomènes d'absorption et de diffusion de la lumière par les tissus qui atténuent et brouillent le signal au cours de sa propagation. La Tomographie de Cohérence Optique (OCT) filtre les photons balistiques par interférométrie en lumière temporellement incohérente. En particulier, l'approche Plein Champ atteint une résolution de 1 µm, mais sa profondeur de pénétration ne dépasse pas 1 mm. Il est donc impossible d'imager les organes internes in vivo et in situ : il faut pour cela disposer d'un instrument doté d'un endoscope, ce qui n'avait pas été réalisé à ce jour. Nous proposons un système d'OCT Plein Champ avec endoscope flexible qui repose sur le couplage de deux interféromètres, l'un extérieur à la sonde et l'autre situé à l'extrémité de la sonde en contact avec le tissu. Ainsi la sonde est entièrement passive et le signal interférométrique qui la traverse n'est pas perturbé par l'environnement. Sa flexibilité lui permettrait d'imager des organes internes comme le colon. Cependant l'utilisation d'un faisceau de plusieurs milliers de fibres optiques fait apparaître un signal d'interférence parasite dû aux phénomènes de couplage inter-coeurs et inter-modes. Des solutions sont proposées pour s'en affranchir et permettre l'imagerie d'échantillons de tissus. En imagerie par endoscopie rigide deux systèmes sont comparés, avec un ou deux interféromètres, et une sonde composée de lentilles à gradient d'indice. Cette sonde peut imager directement au contact des zones comme la peau, ou en pénétrant l'organe à la manière d'une aiguille, par exemple dans le sein. Elle est assez performante pour être utilisée in vivo sur la peau.