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Urs, Raksha. "Investigation of Accommodation and Presbyopia using Ultrasound Imaging during Ex Vivo Simulated Accommodation." Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_dissertations/360.
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The goal of this project is to obtain quantitative images of the lens and the ciliary body to validate EVAS-II (Second generation Ex Vivo Accommodation Simulator). To accomplish this goal it was necessary to develop methods, instrumentation and image processing techniques to acquire 3D images in EVAS-II, using UBM (Ultrasound Bio Microscope), and to apply these techniques to non-human primate eyes. The lens studies included measurement of speed of sound in the lens to reconstruct accurate images of the lens, development of instrumentation to measure the un-distorted lens shape and development of a mathematical model to quantify the whole lens shape. Speed measurements showed that the speed of sound exhibits a gradient profile in the equatorial plane, similar to refractive index and protein distributions in the lens. Lens shape measurements showed that the UBM can be used to accurately measure thickness, diameter, cross-sectional area, volume and surface area of the lens. The ciliary body studies included development of instrumentation and algorithms to obtain 3-D images of tissue in EVAS-II and development of methodology to quantify ciliary body movement during stretching. Studies showed that the accommodation process in young baboon eyes in EVAS-II is comparable to the in vivo process in rhesus monkeys. The UBM can be used to obtain reliable quantitative information about the lens and the ciliary body. 3-D UBM enables monitoring of ciliary body motion of the entire accommodative apparatus.
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Rabie, E. P. "Biometry of the crystalline lens during accommodation." Thesis, University of Manchester, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378316.
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Otero, Molins Carles. "Lens-based technologies to study accommodation and refraction." Doctoral thesis, Universitat Politècnica de Catalunya, 2018. http://hdl.handle.net/10803/461452.
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A visual stimulus can be presented in free space or through lens-based systems. Interestingly, it has been reported many times in the past that some subjects have poorer accommodative responses when optically stimulated, with no aparent reason. However, this limitation has not precluded the use of lens-based systems in ophthalmic devices, virtual reality displays or research setups, probably because it is outweighed by some advantages such as the computer-control of the focal plane of the stimuli. Under this general context, the objective of this thesis is to apply lens-based technologies (from computer-controlled electró-optical lenses to Badal Systems) to study accommodation and refraction.
The methodology of this thesis is structured in 6 studies. The first three studies investigate the response of the accommodative system when optically-stimulated with a Badal optometer. The remaining 3 studies take advantage of electro-optical varifocal systems to investigate new methodologies related to the automated subjective refraction and the accommodative facility test. Concretely, the fourth study is a clinical validation of a new automated refraction algorithm and is the only study thatworks specifically on eye¿s refraction. The fifth and sixth studies use an electro-optical liquid lens to present a repeated step-like stimulus at different accommodative distances. The fifth study validates a new accommodative facility test that integrates both the far and near accommodative facility testwith random changes of accommodative stimulus and, the sixth study explores how the predictability of a stimulus affects the accommodation dynamics.
The results of the first three studies show that previously reported differences in accommodative response when using lens-based methods compared to free space viewing may be explained by the effect of other factors such as the refractive error or field of view rather than the method to stimulate accommodation. It is also shown that the most accurate accommodative responses are obtained for fields between 8º and 10º which suggests that there may be an optimum peripheral retinal image size for accommodation stimulation. Also, it is shown that the only factor that in isolation significantly affects the accuracy of the accommodative responses is the type of refractive error. And finally, it is also shown that the accuracy of the accommodation response generally improves with a 2-dimensional stimulus with apparent depth cues and simulated out-of-focus blur in a relatively large field of view. Even though these conditions may not be adequate for all individuals, they can be used to improve the overall visual comfort in those virtual reality systems that use a varifocal optical system to change the focal plane of a 2-dimensional surface or visual simulators.
The results of the study 4 show the first implementation of a potential novel method of performing non1cycloplegic subjective refraction in adults without clinician suport. Although this method has some limitations thatwarrant further research and it should be tested in a wider population in terms of age4 refraction and different ocular conditions4 it is precise and more accurate than objective refraction methods and it has the potential to be incorporated in novel lens1based technologies to improve primary eye care services in developing countries.
And finally, the last two studies showed also the first implementation of a new accommodative facility test that integrates both the far and near accommodative facility testwith random changes of accommodative stimulus. This new methodology is a faster test than performing both the near and far accommodative tests and it provides more information than conventional accommodative facility tests. Additionally these two studies showed that the prediction operator does not exist in accommodation and the unpredictability of the stimulus does not affect the accommodation dynamics.Un estímul visual es pot presentar a l'espai lliure o a través de sistemes basats en lents. Curiosament, en el passat s'ha reportat moltes vegades que alguns subjectes acomoden de forma més pobre quan aquesta és estimulada per mitjans òptics. Tanmateix, aquesta limitació no ha impedit l'ús de sistemes basats en lents en dispositius oftàlmics, sistemes de realitat virtual o muntatges òptics de recerca, probablement perquè es compensen les limitacions amb alguns avantatges com el control per ordinador del pla focal del estímul. En aquest context general, l'objectiu d'aquesta tesi és aplicar tecnologies basades en lents (des de lents electró-òptiques controlades per ordinador fins a sistemes Badal) per estudiar l'acomodació i refracció. La metodologia d'aquesta tesi està estructurada en 6 estudis. Els primers tres estudis investiguen la resposta del sistema acomodatiu quan està estimulat òpticament amb un optòmetre Badal. Els 3 estudis restants aprofiten els sistemes varifocals electró-òptics per investigar noves metodologies relacionades amb la refracció subjectiva automàtica i la prova de flexibilitat acomodativa. Concretament, el quart estudi és una validació clínica d'un nou algorisme de refracció automatitzat i és l'únic estudi que treballa específicament en la refracció ocular. Els estudis cinquè i sisè utilitzen una lent òptica electró-òptica per presentar un estímul repetit a diferents distàncies acomodatives. El cinquè estudi valida una nova prova híbrida acomodativa que integra la prova de flexibilitat acomodativa llunyana i propera amb canvis aleatoris d'estímul acomodatiu i, el sisè estudi explora com la predictibilitat d'un estímul afecta la dinàmica acomodativa. Els resultats dels tres primers estudis mostren que les diferències reportades anteriorment en la resposta acomodativa quan s'utilitzen mètodes basats en lents en comparació amb la visualització d'estímuls en l'espai lliure es pot explicar per l'efecte de factors com l'error refractiu o el camp de visió més que en el mètode d'estimulació d'acomodació. També es demostra que l'acomodació és més precisa per a camps visuals entre 8 i 10º, el que suggereix que hi pot haver una mida d'imatge retiniana òptima per a l'estimulació de l'acomodació. A més, es demostra que l'únic factor que afecta aïlladament l'exactitud de la resposta acomodativa és el tipus d'error refractiu. També, es demostra que la precisió de la resposta acomodativa generalment millora amb un estímul bidimensional amb pistes de profunditat perifèriques i desenfoc simulat per a un camp de visió relativament gran. Aquestes condicions es poden utilitzar per millorar el confort visual en aquells sistemes de realitat virtual o simuladors visuals que utilitzen un sistema òptic varifocal per canviar el pla focal d'una superfície bidimensional. Els resultats de l'estudi 4 mostren la primera implementació d'un nou mètode potencial per a la realització de refracció subjectiva no cicloplègica en adults sense suport clínic. Encara que aquest mètode requereix encara una investigació addicional en una població més àmplia en termes d'edat, refracció i condicions oculars diferents, és més precís que els mètodes de refracció objectius i té el potencial d'incorporar-se a noves tecnologies basades en lents per millorar els serveis d'atenció primària en països en vies de desenvolupament. Finalment, els dos últims estudis mostren la primera implementació d'una nova prova de flexibilitat acomodativa que integra tant la prova llunyana i propera, amb canvis aleatoris d'estímul acomodatiu. Aquesta nova metodologia és una prova més ràpida que l'execució de les proves d'acomodació pròxima i llunyana i proporciona més informació que les proves de flexibilitat acomodativa per separat. Addicionalment, aquests dos estudis mostren que la capacitat predictiva en l'acomodació es insignificant i que la imprevisibilitat de l'estímul no afecta la dinàmica acomodativa
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Nankivil, Derek. "A Second Generation Ex-Vivo Accommodation Simulator: Design and Calibration." Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_theses/161.
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Presbyopia is the progressive decrease in accommodative ability with age, and it implies a major loss of visual function. Presbyopia is the only condition of the eye which affects everyone who lives beyond 50 years of age. As part of a joint effort, the Ophthalmic Biophysics Center at the Bascom Palmer Eye Institute and the Vision Cooperative Research Centre at the University of New South Wales, developed two different ex-vivo accommodation simulators (EVAS) to examine the mechanisms of accommodation and presbyopia, and to test and validate new ophthalmic surgical procedures such as lens refilling. The purpose of this thesis is to mechanically and optically calibrate the second generation instrument (EVASII), and to compare it to the first generation design (EVASI). To validate the optical measurements of EVASII, an optical calibration has been performed, yielding a lens power measurement system with a mean accuracy of ±0.56D. To enhance the optical capabilities and tissue dissection options, the mechanics of mounting the tissue has been improved by using magnetic mounts, and the mechanical calibration of EVASII, yielded a force measurement system with a mean uncertainty of ±0.81g Also, a comparison of EVASII and EVASI has been performed, showing that the results of the two systems are significantly different; however, both systems successfully simulate accommodation. Thus, general trends concerning efficacy and optimization of surgical procedures as well as age related accommodative changes can be compared for each individual system.
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Heistand, Mark Richard. "Biomechanics of the lens capsule." Texas A&M University, 2004. http://hdl.handle.net/1969.1/2726.
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Knowledge of the mechanics of the lens capsule is crucial for improving cataract surgery as well as understanding better the physiological role of the lens capsule in the process of accommodation. Previous research on the mechanical properties of the lens capsule contains many gaps and contradictions due to experimental limitations and inappropriate assumptions. Thus, the goal of this work is to quantify fully the regional, multiaxial mechanical behavior of the lens capsule and to calculate the change in stress and strain fields as a result of cataract surgery.
Determining in situ the multiaxial mechanical behavior of the lens capsule required the design and construction of an experimental device capable of altering stresses in the capsule while measuring localized surface deformations. Tests performed on this device reveal that the meridional and circumferential strains align with the principal directions and are equivalent through most of the anterior lens capsule, except close to the equator where the meridional strain is greater. Furthermore, preconditioning effects were also found to be significant. Most importantly, however, these tests provide the data necessary for calculating material properties.
This experimental system is advantageous in that it allows reconstruction of 3D geometry of the lens capsule and thereby quantification of curvature changes, as well as measurement of surface deformations that result from various surgical interventions. For instance, a continuous circular capsulorhexis (CCC) is commonly used during cataract surgery to create a hole in the anterior lens capsule (typically with a diameter of 5 mm). After the introduction of a CCC, strain was found to redistribute evenly from the meridional direction (retractional strain) to the circumferential direction (extensional strain), where both directional components of strain reached magnitudes up to 20% near the edge of the CCC. Furthermore, the curvature was found to increase at the edge of the CCC and remain the same near the equator, indicating that the mere introduction of a hole in the lens capsule will alter the focal characteristics of the lens and must therefore be considered in the design of an accommodative intraocular lens.
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Cheng, Desmond. "Bifocal lens control of myopia progression in children." Queensland University of Technology, 2008. http://eprints.qut.edu.au/29688/.
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This research investigated underlying issues that were critical to the success of the bifocal trial and comprised of three studies. The first study evaluated if Chinese-Canadian children were suitable subjects for the bifocal trial. The high prevalence of myopia in Chinese children suggests that genetic input plays a role in myopia development, but the rapid increase in prevalence over the last few decades indicates environmental factors are also important. Since this bifocal trial was conducted in Canada, this work aimed to determine whether Chinese children who had migrated to Canada would still have high myopia prevalence and a high rate of myopia progression. The second study determined the optimal bifocal lens power for myopia treatment and the effect of incorporating base-in prism into the bifocal. In the majority of published myopia control studies, the power of the prescribed near addition was usually predetermined in the belief that the near addition would always help to improve the near focus. In fact, the effect of near addition on the accommodative error might be quite different even for individuals in which the same magnitude of accommodation lag had been measured. Therefore, this work was necessary to guide the selection of bifocal and prism powers most suitable for the subsequent bifocal trial. The third study, the ultimate goal of this research, was to conduct a longitudinal clinical trial to determine if bifocals and prismatic bifocals could control myopia progression in children.
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Ziebarth, Noel Marysa. "Atomic Force Microscopy Measurement of the Elastic Properties of the Lens." Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_dissertations/181.
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The goal of this project was to develop techniques and instrumentation to measure the elastic properties of the lens and lens capsule in situ and their changes with age using Atomic Force Microscopy (AFM). The studies include the construction, characterization, and calibration of laboratory-based Atomic Force Microscope (AFM) to measure mechanical properties of ophthalmic tissues. Atomic Force Microscopy is a nanoscale imaging technique that has been applied to mechanical property measurement through nanoindentation. Young's modulus of elasticity is determined by monitoring the cantilever deflections when it contacts the sample. The studies also include the development of tissue preparation techniques to enable measurement of the lens elasticity using AFM. This study found that lens capsule elasticity decreases with age, outer lens cortex elasticity remains constant with age, and the inner lens cortex is stiffer than the outer lens cortex. The effect of the changing biometry and mechanical properties with age was investigated by developing a mathematical model of accommodation. These changes will be the limiting factor to accommodative amplitude. Changes in lens capsule mechanical properties will affect the maximal accommodative amplitude in older eyes.
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Borja, David. "Dynamic Optical Model of the Primate Crystalline Lens and Implications for the Restoration of Accommodation." Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_dissertations/355.
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The human crystalline lens is a complex, inhomogeneous and dynamic optical element which enables the eye to adjust focus in a process known as accommodation. Age related changes in the optical and mechanical properties of the lens cause a loss in accommodative ability leading to a condition known as presbyopia. Several experimental surgical techniques are under development for the correction of presbyopia. The goal of this dissertation is to better understand the relationship between the crystalline lens shape, its non-uniform refractive index gradient and its optical power and their changes with age and accommodation. In this study direct lens power and shape measurements were acquired on isolated lenses, and on lenses mounted in a lens stretching system designed to simulate accommodation. Several lens shape and power measurement techniques were developed for this study including a Scheimpflug camera system optimized for imaging the crystalline lens. Direct measurements of lens shape and power were used to develop an age-dependent optical-mechanical model of the lens during accommodation. The study shows that the normal growth of the lens is a major contributor to the progressive loss of accommodation amplitude, independent of changes in the elastic properties of the lens. These findings suggest that accommodation can be restored by refilling the lens with a material having a uniform refractive index.
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Schultz, Kristin E. "Accommodative microfluctuations, crystalline lens tension, ciliary body thickness, and refractive error in children." Columbus, Ohio : Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1240445960.
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Ruggeri, Marco. "Extended Depth Optical Coherence Tomography for Anterior Segment and Accommodation Imaging in Real-Time." Scholarly Repository, 2011. http://scholarlyrepository.miami.edu/oa_dissertations/686.
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The changes in the human crystalline lens shape and its internal structure during accommodation and with aging are a fundamental component of the dynamic mechanism of accommodation and presbyopia, the loss of near vision with age. A better understanding of the crystalline lens changes during accommodation will help in developing new treatments to correct for presbyopia. The goal of this dissertation is to design and develop an imaging system to study the dynamic changes in lens shape during accommodative response. An imaging system based on spectral domain optical coherence tomography (SD-OCT) was developed with long axial range, high axial and lateral resolution and high speed for in vivo imaging the anterior segment along its entire length at video-rate. A slit-lamp mounted optical delivery scanning device for the extended depth SD-OCT system was developed. The delivery system was combined with a custom made unit that provides accommodation and disaccommodation step stimuli. A method to correct for the distortions of the OCT images was also developed that provides corrected two dimensional biometric data at different accommodative states.
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Jamali, Afsoon Jamali. "LARGE AREA TUNABLE LIQUID CRYSTAL LENS." Kent State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=kent1541671894328594.
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Ong, Chee Horng. "Efficacy of multifocal soft contact lens on asthenopic orthophoric and esophoric myopes with lag of accommodation." Thesis, Aston University, 2018. http://publications.aston.ac.uk/37815/.
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The primary aim of this study was to investigate the effectiveness of multifocal soft contact lenses (MFSCLs) in alleviating asthenopic symptoms in symptomatic, orthophoric and esophoric myopes with lag of accommodation by using clinical methods that are commonly used in general practice. Also, whether the amount of MFSCL addition differentially modifies symptoms of asthenopic individuals was assessed. This study found that Convergence Insufficiency Symptom Survey (CISS) score improved after wearing MFSCLs, when comparing to spectacle (SPECT) and single vision contact lenses (SVCLs). There was no significant difference between the symptom score of multifocal low add (LAMFCLs) and high add contact lenses (HAMFCLs), implying that varying the amount of near addition did not improve the symptom score. Accommodative lag was not significantly improved with MFSCLs. Distant esophoric shift was observed when changing from SPECT to SVCLs and HAMFCLs. Near esophoric shift was found to be lower for both MFSCLs when compared to SVCLs. Accommodation response changes with MFSCLs wear after a period of one month were also studied. Amplitude of accommodation (AoA) and near point of convergence (NPC) was improved while wearing MFSCLs. Increased positive relative accommodation (PRA) and decreased negative relative accommodation (NRA) was observed while wearing HAMFCLs. No adaptation effect was observed after one month of wearing MFSCLs. One hundred Singapore optometrists were surveyed, and it was found that 75% were seeing asthenopic patients, with the most common symptoms being tired eyes. Ophthalmic lenses were the most commonly prescribed treatment and had a high success rate. The majority (69%) of the surveyed optometrists have not considered the use of MFSCLs as a treatment option. In conclusion, this study presented novel findings showing that MFSCLs are effective in relieving asthenopic symptoms. The study finding also suggested that pre-presbyopic individuals do not use the near addition power provided by MFSCLs to replace their accommodative activity, and that MFSCLs do not create a significant change in the phoric status at near. Further work is required to determine whether the improvement in asthenopic symptoms with MFSCLs is contributed by negative SA.
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Richdale, Kathryn. "The Human Eye in Presbyopia: Changes in the Lens and Ciliary Body with Age and Accommodation." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1312396264.
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Theagarayan, Baskar. "MANIPULATION OF OCULAR ABERRATIONS IN MYOPES." Doctoral thesis, Linnéuniversitetet, Institutionen för naturvetenskap, NV, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-8314.
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Myopia is a major cause of vision loss throughout the world. High myopia is associated with severe eye diseases like maculopathy, retinal detachment and glaucoma. The prevalence of myopia is increasing, and varies by country and by ethnic group. In some Asian populations the prevalence is 70%-80%. This thesis includes five experiments. In experiment I we investigated the effects of added positive and negative spherical aberration on accommodative response accuracy. We found that the accommodative response can be altered by modulating the spherical aberration of the eye with soft contact lenses. There was an improvement in the accommodative response slopes and a decrease in the lag of accommodation with the negative spherical aberration lenses compared to positive spherical aberration lenses. In experiment II we investigated whether the negative spherical aberration in contact lenses could be tolerated visually in terms of wearability and comfort. We found that all the subjects were satisfied with the contact lens comfort, distance and near vision and the stability of the vision with the lenses. The accommodative response was stable through out the treatment period. In experiment III we investigated the efficacy of a novel dual treatment for the improvement of accommodative accuracy and dynamics in myopes. The spherical aberration of the eye was effectively altered to negative in the treatment group as predicted. In the control group as expected there was no significant change in the spherical aberration of the eye with and without contact lenses. The treatment lenses decreased the lag of accommodation and increased the accommodative response slope at 3 months. In the experiment IV we investigated the effect of the treatment lenses used in the previous experiment on high and low contrast visual acuities after a one year treatment period. The results showed a significant improvement in both high and low contrast visual acuities after the one year period in the treatment group compared to the control group, even though it was not clinically significant. In experiment V we investigated the intrasession repeatability of peripheral aberrations using COAS-HD VR aberrometer and also reported the distribution of higher order aberrations in a group of young emmetropes. There was no significant difference in the variance of total higher-order RMS between on- and off-axis measurements. There was a significant change in the horizontal coma, spherical aberration and higher-order RMS with off-axis angle along the horizontal visual field. We demonstrated that fast, repeatable and valid peripheral aberration measurements can be obtained with this instrument. This thesis contributes new results in this field of myopia, aberration and accommodation.
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Rueff, Erin M. "Contact Lens Discomfort, Vision Correction Preferences, and Accommodative Treatment in Presbyopic and Non-Presbyopic Contact Lens Wearers." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1529583462118691.
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Anselmo, Gustavo Trierveiler. "SIMULADOR DIDÁTICO DA ACOMODAÇÃO DO OLHO HUMANO." UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2016. http://tede2.uepg.br/jspui/handle/prefix/2147.
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The Simulator Didactics of Accommodation of the Human Eye is a set of activities that have as objective facilitate the teaching-learning process on optics and, especially, on the process of human accommodation. The educational product explores concepts of geometrical optics (light rays and refraction) in the paraxial approximation and its applications to spherical lenses. Didactic simulator was built with a flexible lens, produced with a latex-made male condom filled with water. Its spherical shape, with a diameter of approximately , was compared with the theoretical model of the “ball lens”. We have experimentally determined its focal length ( and compared it with the corresponding theoretical value, obtaining a accuracy. The flexibility feature of this lens gives the possibility to simulate the accommodation process of the eye in two different situations: for diverging and parallel light beams, corresponding to objects near and far from the observer, respectively. These concepts were addressed in the educational spirit of the meaningful learning of David Ausubel. It has been proposed 4 lesson plans from the previous organizers (taught in 8 lessons), 1 lesson plan for application of the didactic simulator (3 lessons) and 2 meetings for application and discussion of the questionnaires (2 lessons), summing up 13 classes. We have used several resources: lectures, computer simulators, construction of one darkroom, dissection of the bull's-eye and a experimental apparatus produced by students. Adding to other support materials, these instruments facilitated the learning of content offered and the better understanding of the students. This is proven by the results obtained in 42 questionnaires applied. Of these, 24 were before and 18 after the application of the project. There has been an increase of ~200% in the number of hits in the second stage. The proposal has been applied in a class of 39 students, where we had a meaningful learning of over of the class. One should stress also the impact on students, who were more willing to learn, requiring better quality lessons, both in content and evaluation of them.
Esta dissertação descreve um conjunto de atividades realizadas com o objetivo de facilitar o processo de ensino-aprendizagem sobre a óptica e, principalmente, da acomodação do cristalino humano. O produto educacional gerado, chamado de Simulador Didático da Acomodação do Cristalino do Olho Humano, explora conceitos de óptica geométrica (raio de luz e refração) dentro da aproximação paraxial e suas aplicações em lentes esféricas. Para isso foi construído um aparato com uma lente flexível, produzida com preservativo masculino feito de látex preenchido com água. O seu formato esférico, com diâmetro de aproximadamente , foi comparado com o modelo teórico das “ball lens”. Determinamos experimentalmente sua distância focal ( que, comparado com seu valor teórico, tem uma acurácia de . Por ser flexível, foi possível simular o processo de acomodação do cristalino em dois casos: para feixes de luz divergentes e paralelos, simulando situações com objetos próximos e distantes do observador, respectivamente. Estes conceitos foram abordados conforme a concepção educacional da aprendizagem significativa de David Ausubel. Foram propostos quatro planos de aulas de organizadores prévios (ministrado em oito aulas), um plano de aula de aplicação do simulador didático (três aulas) e dois momentos para aplicação e discussão dos questionários (duas aulas), totalizando 13 aulas. Utilizou-se variados recursos: aulas expositivas, simuladores computacionais, construção de câmara escura, dissecação do olho de boi e aparatos experimentais produzidos pelos alunos. Aliados a materiais de apoio, esses instrumentos facilitaram a aprendizagem dos conteúdos ministrados e o melhor entendimento dos alunos. Isso é comprovado pelos resultados obtidos em 42 questionários aplicados. Destes, 24 foram antes e 18 depois da aplicação do projeto. Houve um aumento de ~200% no número de acertos na segunda etapa. A proposta foi aplicada em uma turma de 39 alunos, onde obtivemos uma aprendizagem significativa de mais da classe. A ressaltar, também o impacto nos alunos, que se mostraram mais dispostos a aprenderem, exigindo aulas de melhor qualidade, tanto na exposição do conteúdo como na avaliação.
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Ego, Frédéric. "Accommodation de la convergence oblique dans une chaîne de type cordilleraine : les Andes d'Equateur." Paris 11, 1995. http://www.theses.fr/1995PA112522.
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Au nord de 4s de latitude, les andes equatoriennes constituent la partie meridionale des andes du nord. Le contexte geodynamique et la tectonique des andes equatoriennes, du neogene a l'actuel, s'inscrivent dans le cadre de la subduction de la plaque nazca sous la plaque sud americaine. La nature oblique de la convergence entre ces deux plaques est responsable de l'expulsion du bloc andin vers le nne. Entre 4s et 4n de latitude, l'obliquite de la convergence au niveau de la marge equato-colombienne n'est que partiellement decomposee a la fosse. En effet, les vecteurs glissement de la subduction superficielle ne sont ni paralleles au vecteur convergence, ni orthogonaux a la fosse ; la subduction est donc oblique. La majeure partie (75-90%) de la composante decrochante, parallele a la marge, est accommode a la fosse, la partie restante est accommodee dans la chaine par du decrochement dextre. Une faible partie ( 7%) de la composante compressive, parallele au vecteur de la subduction, est transmise a la plaque superieure et accommodee par des structures compressives. Les deformations de la plaque superieure resultent d'un champ de contrainte homogene compressif selon une direction e-w et sont principalement accommodees par le systeme transpressif dextre des hautes andes equatoriennes. La deformation est essentiellement compressive et largement distribuee sous forme de plis dans la vallee interandine et de chevauchements dans la zone subandine (s. L. ), qui definissent le relais compressif n-s. Une vitesse de raccourcissement de 4. 6 mm/a selon une direction n92e a ete calculee sur l'ensemble de la chaine. Au nord et au sud du relais compressif, la chaine est plus oblique (n30e a n35e) et la deformation y est essentiellement decrochante. Elle se localise sur deux failles dextres majeures qui sont au nord, la faille du rio chingual-la sofia (frc) (7 mm/a) dans la cordillere orientale, et au sud, la faille de pallatanga (fp) (4 mm/a) dans la cordillere occidentale. La difference de vitesse entre ces deux failles s'explique par la variation de l'obliquite de la convergence le long de la marge. Le systeme transpressif dextre est la source majeure de l'alea sismique. La frc peut engendrer un seisme de magnitude maximale previsible de 7-7. 5 tous les 400440 ans et la fp un de magnitude 6. 7-7. 2 tous les 380320 ans. Dans la vallee interandine, un seisme de magnitude 6. 6-7. 6 pourrait se produire tous les 470270 ans sur la faille de quito
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Daniel, François. "Dysfonctionnements de la synergie vergence et accommodation chez les jeunes adultes : impact sur les saccades, la lecture et la cognition." Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCB095/document.
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La qualité de la vision sensorielle, l’aspect oculomoteur et la cognition ont très souvent été abordés de façon individuelle. D’un côté, les désordres de la vergence, liés fréquemment à des désordres de l’accommodation, entraînent des symptômes tels que douleurs, diminution de la qualité de vision mais aussi problèmes d’attention et de concentration, pouvant avoir une incidence sur l’apprentissage. D’un autre côté, les désordres de la vergence sont aussi liés à des problèmes oculomoteurs dans la coordination et la précision des saccades, domaine sur lequel repose l’aptitude à la lecture. L’ambition de cette thèse est d’approfondir ces constats et d’introduire des moyens expérimentaux afin de mettre en évidence les liens entre accommodation/vergence (A/V), contrôle des saccades et leur interférence avec la cognition. Dans une première partie, nous avons étudié l’impact des dysfonctionnements A/V classique et l’impact d’un conflit A/V induit sur les performances au test de Stroop, reconnu pour évaluer certains types de fonctions cognitives, faisant appel aux capacités basiques de lecture et exigeant un déploiement attentionnel élevé. Pour une population d’étudiants, les résultats ont montré des performances diminuées en cas de désordres de la vergence existant et en cas de conflit A/V induit, attestant d’une incidence négative des dysfonctionnements et des déséquilibres A/V induits sur les fonctions exécutives et les processus attentionnels. Ici, l’hypothèse d’une interaction des processus visuels et cognitifs en parallèle apparait plus plausible que celle d’un model sériel, avec une performance cognitive retardée par un problème visuel. Dans un deuxième temps, une réhabilitation de la vergence chez les sujets en présentant des désordres a permis une restauration des capacités, a montré une amélioration de la coordination des saccades et a eu une incidence positive sur l’aspect cognitif pendant la lecture, venant confirmer la théorie d’interférence en parallèle. L’ensemble des travaux apportent des ouvertures de recherches (1) sur le plan théorique, en croisant des domaines comme la neurologie, la psychologie cognitive, l’oculomotricité, l’optométrie et l’orthoptie ; (2) sur le plan clinique, en proposant des tests caractéristiques de dépistage ainsi que des solutions d’amélioration ; (3) sur le plan éducatif, en proposant des pistes pour expliquer l’incidence que le système visuel peut avoir sur les performances académiquesQuality of sensory vision, eye movements and cognition have been broached one by one so far. However, recent studies suggest possible interactions between these fields without clarifying the link. On the one hand, vergence/accommodative (V/A) dysfunctions leads to visual symptoms like sore eyes, blurry or double vision but also problems of attention, concentration, and appear to have a negative impact on academic performances. On the other hand, people diagnosed with vergence disorders also show poor coordination of their saccades, which are essential in reading and cognitive demanding activities. The goal of this thesis is to go into this analysis in depth and to propose experimental ways to evidence the links between V/A disorders, control of the saccades and their influence on cognition. In a first part, we studied the impact of typical V/A disorders and the impact of an induced A/V conflict on the performances during the Stroop test, which is a neurological test known for evaluating cognitive executive functions like inhibition, demanding a high attentional deployment and stimulating basic reading skills. Results show that vergence dysfunctions and V/A inducted conflict have a negative influence on the Stroop performances in students, leading to a diminished control of cognitive functions. These results suggest a more parallel interaction between visual and attentional processes instead of a serial model where vision would be a prerequisite to cognition, slowing down the cognitive processes when disturbed. Secondly, we pursue this theory: vergence rehabilitation in subjects diagnosed with vergence disorders permitted an increase of the vergence capacities, showed an improvement on the coordination of the reading saccades and had a positive influence on the cognitive aspect during reading. This work gives new research possibilities at different level: (1) at a theoretical level, it permits to cross fields like neurology, cognitive psychology, eye movements and optometry; (2) at a clinical level, it suggests typical tests for a more efficient screening and opens new perspectives on solutions to rehabilitate people with V/A disorders; (3) at an educational level, it gives clues on how visual functions could affect academic performances
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Gharsallaoui, Hajer. "Reconfiguration de lois de commande et accommodation active des modes de fonctionnement pour les systèmes plats." Thesis, Ecole centrale de Lille, 2010. http://www.theses.fr/2010ECLI0022/document.
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Les travaux de recherche entrent dans le cadre de la reconfiguration de lois de commande des systèmes dynamiques présentant divers modes de fonctionnement afin d’assurer les performances désirées. Deux approches d’accommodation ont été proposées pour la commande de ces systèmes dynamiques : une approche passive qui présente un régulateur à paramètres fixes ne garantissant pas les mêmes performances pour différents modes de fonctionnement et une approche active dans laquelle les paramètres du système de commande peuvent être mis à jour selon le mode de fonctionnement détecté. C’est cette deuxième approche basée sur une représentation multi-modèles du système qui a été retenue dans nos travaux.Les erreurs de modélisation correspondant aux variations de conditions de fonctionnement, sont dans ce cas détectées par un algorithme de détection et de localisation de variations de modes de fonctionnement. Il s’en suit une reconfiguration d’une loi de commande par platitude en utilisant le principe de commutation. Cette approche garantit la régulation et la poursuite d’une trajectoire de référence. Pour sa mise en œuvre, un banc de régulateurs, conçu par platitude, a été élaboré pour les modèles discrets plats obtenus autour des divers points de fonctionnement.La détection des modes de fonctionnement est effectuée par une génération de résidus en utilisant un ensemble d’observateurs de type Luenberger dont les gains sont calculés en utilisant l’outil LMI.L'étude de la stabilité ainsi que l'introduction de dispositifs d'anti-emballement liés à la commutation entre les régulateurs, ont été considérés dans l'approche proposéeThe work presented in this memory concerns the control reconfiguration of dynamical systems with variation of operating modes in order to ensure the desired performances. For the control of dynamic systems, two approaches of accommodation have been proposed. The passive approach presents a controller with fixed parameters that doesn’t ensure the same performance for different operating modes and an active approach in which the controller settings can be updated according to the variation of the detected operating mode. Our work has therefore focused on this second approach based on multi-models system representation. The modelling errors corresponding to the variations of operating conditions are detected in this case by detection and localization algorithm, consequently, a reconfiguration strategy based on flatness-based switching control is proposed. This approach guarantees the control and the tracking of a reference trajectory. In fact, we have synthesised a discrete flatness-based multi-controllers associated for each operating model obtained from different operating points. Detection of operating modes is done by a residual generation by using Luenberger observers which gains are calculated using the LMI tool. Study of the stability as well as the use of anti-windup devices related to switching between controllers; have been considered in the proposed approach
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Xu, Shun. "Crystallographic analysis of twin variant selection and twin-twin junctions in commercially pure titanium." Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0125/document.
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Le titane et ses alliages sont très largement étudiés en raison de leur grande utilisation dans l'industrie chimique, les implants médicaux et les industries aérospatiales. Vu le rôle important dans la déformation plastique, le maclage a été largement étudié dans les métaux hexagonaux L'état de contrainte locale peut être modifié par maclage, ce qui influence les modes séquentiels de déformation tels que le glissement, le maclage et le maclage secondaire Ainsi, il existe une demande urgente pour comprendre le mécanisme associé à la déformation induite par maclage, utile pour le développement de modèles prédictifs qui peuvent décrire les événements ultérieurs induits par maclage, ainsi que leurs corrélations avec les microstructures. Dans ce travail, l'analyse cristallographique de la sélection de variantes de macles et des jonctions macle-macle (TTJ= twin-twin junction) est appliquée sur du titane commercialement pur. Un nouveau mécanisme de maclage séquentiel, où les macles {101̅2} sont stimulées par des jonctions macle {112̅1}-macle, est observée par EBSD quasi in situ. Un autre mécanisme de maclage séquentiel a été trouvé lorsque le maclage de compression {112̅2} contient une macle d'extension {101̅2} près des joints de grain à forte désorientation. L'accommodation est utilisée pour déterminer le variant de macle séquentiel lorsque le facteur de Schmid classique (SF) n'est pas suffisant. En outre, une analyse détaillée des 425 macles secondaires {101̅2} détectées dans les macles {11 2̅ 2} primaires révèle que les deux variants de macles qui présentent une désorientation spécifique par rapport aux grains parents sont les plus fréquentes. Il est possible de justifier la prévalence des macles secondaires avec un mécanisme de nucléation aidée par les dislocations prismatiques. Lorsqu'il est complété par une analyse SF généralisée, le critère peut prédire avec précision la sélection entre deux variants dans le groupe des macles secondaires les plus fréquentes. Lorsque plusieurs variants de macles sont actifs dans le même grain, des interactions macle-macle peuvent se produire. Les jonctions macle {112̅2}-macle peuvent être divisés en trois types selon la cristallographie des macles {112̅2}. Une analyse statistique de ces interfaces révèle qu'un seul type est le plus fréquent tandis que les autres types sont rarement activés. La fréquence des TTJ peut être évaluée en utilisant une analyse SF généralisée. Il en ressort que les interfaces macle-macle (TTB= twin-twin boundary) ne se forment que d’un côté de la macle. Concernant la formation de TTBs basée sur les interactions des dislocations de macle, les dislocations d'interface dans les TTBs observées ont une énergie de ligne inférieure à celles des TTB non observées. Une opération similaire est appliquée à l'analyse de {112̅1} TTJsTitanium and its alloys have been extensively investigated due to their wide application in chemical industry, medical implants and aerospace industries. As a significant role in plastic deformation, twinning has been widely studied in hexagonal metals. The local stress state may be modified by twinning, which influences sequential plastic deformation modes such as slips, twinning and secondary twinning. Thus, there is also an urgent demand for understanding the mechanism associated with the twinning-induced deformation, which is useful for the development of predictive capabilities that can describe twinning and twinning-induced sequential events, and their correlations with microstructures. In this work, crystallographic analysis of twin variant selection and twin-twin junctions is applied in commercially pure titanium. A new sequential twinning mechanism that {101̅2} twins are stimulated by the {112̅1} twin-twin junctions (TTJs) is observed by quasi in-situ EBSD. Another sequential twinning mechanism that a {112̅2} compression twin adjoins a {10 1̅ 2} extension twin is found at high angle grain boundaries. Displacement gradient accommodation is used to determine the sequential twin variant while the classical Schmid factor (SF) is not sufficient. Besides, a detailed analysis of the detected 425 {101̅2} double twins inside primary {112̅2} twins reveals that the double twin variants that exhibit specific misorientation with respect to the parent grains are the most frequent. The prevalence of double twins is possible to justify with the prismatic-dislocation mediated nucleation mechanism. When complemented with an apparent SF analysis, the criterion can accurately predict the selection between two variants within the group of the popular double twins. When multiple twin variants are active in the same grain, twin-twin interactions may happen. {112̅2} TTJs can be divided into three types according to the crystallography of {112̅2} twins. A statistical analysis of {112̅2} TTJs reveals that one type is the most popular while other types are rarely activated. The frequency of TTJs can be evaluated by using an apparent SF analysis. The interesting finding is that twin-twin boundaries (TTBs) form in one side of the incoming twin as a TTJ forms. Corresponding to the formation of TTBs based on the interactions of twinning dislocations, interface dislocations in the observed TTBs have lower line energy than those in the un-observed TTBs. Similar operation is applied to the analysis of {112̅1} TTJs
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Berntsen, David A. "Accommodative lag, peripheral aberrations, and myopia in children." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1243829481.
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An, Chloe. "An Assessment of the Sharing Economy and Its Policy Solutions Through the Lens of Sustainability." Scholarship @ Claremont, 2018. http://scholarship.claremont.edu/pomona_theses/189.
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This senior thesis in environmental analysis explores the promise of sustainability of the sharing economy, its shortcomings from this positive potential, and possible policy solutions to help it reach its fullest, positive potential. At its core, the sharing economy enables shared access to goods and services that would otherwise sit in idle or underutilized capacity – popular platforms such as Uber, Lyft, Airbnb, and craigslist all fall within the sharing economy. By enabling affordable and convenient access to goods that would otherwise sit idle, the sharing economy encourages maximal use of a good that already exists rather than seeking out the production of new goods to meet demand. Unfortunately, as it grows, the sharing economy moves away from this key environmental promise because of two central challenges: first, a shift away from maximal resource use, the central pillar of its promise of sustainability, and second, negative side effects that arise from a lack of regulation of the decentralized economy. Therefore, appropriate public policy is needed to both regulate the decentralized economy to minimize negative behaviors and to encourage the positive behaviors of the sharing economy.
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Neveu, Pascaline. "L'impact des dispositifs de visualisation en relief sur les composantes oculomotrices d’accommodation et de vergence." Paris 8, 2012. http://octaviana.fr/document/181522632#?c=0&m=0&s=0&cv=0.
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L’émergence des dispositifs de visualisation en relief fait naître une problématique oculomotrice nouvelle. Le comportement oculomoteur, durant l’exposition à ces dispositifs, diffère de celui ayant cours en vision naturelle. L’accommodation (A), permettant d’ajuster la netteté, devient en conflit avec la vergence, permettant d’aligner le regard sur l’objet virtuel. L’implication de l’Homme et la manière dont son système oculomoteur est capable de faire face à ce conflit sont sous-exploitées et peu connues. Cette thèse étudie l’impact d’un conflit A/V sur le système oculomoteur au travers de trois études. Une première étude méthodologique détermine l’impact de différents types de mesures sur l’évaluation des paramètres oculomoteurs. Plusieurs paramètres oculomoteurs ont été évalués suivant une méthode de laboratoire et une méthode clinique. Les résultats montrent que la répétabilité des tests et la concordance entre les divers types de mesures sont très variables d’un paramètre oculomoteur à l’autre. Deux études ont ensuite été menées afin d’analyser les modifications engendrées par des conflits A/V. Le paradigme utilisé était du type pré-post exposition et portait sur plusieurs paramètres oculomoteurs critiques lors d’un conflit A/V. L’étude menée sur l’hyper relief, créant un conflit partiel entre A et V, montre que le système oculomoteur est capable de s’adapter de manière globale. L’étude menée sur la visualisation stéréoscopique, créant une dissociation totale entre les composantes A et V, pointe l’existence d’une adaptation oculomotrice très dépendante de la stimulation et encourage la poursuite de la compréhension de ce processus. Les travaux réalisés clarifient les connaissances sur le système oculomoteur dans le cadre spécifique du conflit A/V et amorcent la compréhension de l’impact des dispositifs de visualisations en relief sur le système oculomoteurDevelopment of the stereoscopic devices gives rise to new oculomotor problems. During exposure to these devices, oculomotor's behaviour differs from that during natural vision. Accommodation (A), allowing to obtain a clear image of the object looked at, becomes in conflict with vergence, allowing to align the eyes on the virtual object. The involvement of Human and how the oculomotor system is able to deal with this oculomotor conflict are under-exploited and little known. This thesis examines the impact of the A/V conflict on the oculomotor system through three studies. A first methodological study determines the impact of different types of measurements on the evaluation of oculomotor parameters. Several oculomotor parameters were assessed using various a laboratory and clinical method. The results show that the repeatability of the tests and the agreement between methods greatly vary. Two studies were then conducted to identify and understand the changes caused by A/V conflict generated by stereoscopy and hyper relief. The paradigm used was a pre-post exposure paradigm on several oculomotor parameters especially involved in stereoscopic viewing. The study on hyper relief, creating a partial conflict between the A and V components, shows that the oculomotor system is able to globally adapt. The study on the stereoscopic viewing, creating a total dissociation between the A and V components, shows the existence of an oculomotor adaptation highly dependent on the stimulation and encourages further understanding of this process. The work helps to clarify the knowledge of the oculomotor system in the specific context of A/V conflict and begins the understanding of the impact of stereoscopic displays on the oculomotor system
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BAZALGETTE, LOIC. "Relations plissement/fracturation multi échelle dans les multicouches sédimentaires du domaine élastique/fragile :Accommodation discontinue de la courbure par la fracturation de petite échelle et par les articulations. Possibles implications dynamiques dans les écoulements des réservoirs." Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2004. http://tel.archives-ouvertes.fr/tel-00007923.
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Ce travail de thèse est dédié à l'étude des liens génétiques existant entre les plis et les fractures formés dans la croûte terrestre superficielle, i.e., dans le domaine élastique/fragile. Ce problème est abordé à la fois d'un point de vue académique et dans la perspective d'une amélioration de l'exploration et de la production des réservoirs naturels (eau et hydrocarbures). Les principaux résultats de ce travail sont les suivants :
- Une classification originale des relations entre plis et fractures est établie sur la base d'études comparatives de terrain. La cinématique et les origines mécaniques des différentes associations observées sont discutées, ainsi que de possibles implications au niveau de la dynamique dans les réservoirs plissés fracturés sont proposées.
- Le rôle prédominant de zones de fractures appelées articulations sur l'accommodation de la courbure des plis est démontré par de nombreuses études de terrain. Une typologie de ces zones de fractures est proposée sur la base d'exemples naturels et leur origine mécanique est discutée. L'origine mécanique de ces articulations est précisée dans une étude expérimentale. On utilise des multicouches de paraffine cassante, sollicités dans un dispositif de chargement original. Ce dispositif permet une étude paramétrique des conditions de chargement et de la structure du multicouche, tout en autorisant l'observation en continu de la déformation. Les paramètres les plus importants contrôlant la distribution des articulations et leur évolution géométrique sont la pression de confinement et la friction interfaciale dans le multicouche.
- On présente en outre une étude de cas intégrant l'ensemble des résultats et des concepts. Il s'agit de l'anticlinal de la Montagna della Majella (Italie), qui représente un analogue de réservoir plissé/fracturé.
- Des implications des résultats précédents aux problèmes des écoulements dans les réservoirs sont discutées.
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Bazalgette, Loïc. "Relations plissement/fracturation multi échelle dans les multicouches sédimentaires du domaine élastique/fragile accommodation discontinue de la courbure par la fracturation de petite échelle et par les articulations : possibles implications dynamiques dans les écoulements des réservoirs /." Montpellier : Institut des sciences de la terre, de l'environnement et de l'espace de Montpellier, 2004. http://catalogue.bnf.fr/ark:/12148/cb40062728h.
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Bazalgette, Loïc. "Relations plissement / fracturation multi échelle dans les multicouches sédimentaires du domaine élastique / fragile : accommodation discontinue de la courbure par la fracturation de petite échelle et par les articulations : Possibles implications dynamiques dans les écoulements des réservoirs." Montpellier 2, 2004. http://www.theses.fr/2004MON20142.
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Hart, Linda Louise. "Accommodation : a novel." Thesis, University of Canterbury. Humanities, 2009. http://hdl.handle.net/10092/2550.
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Winn, Barry. "Studies in binocular accommodation." Thesis, Glasgow Caledonian University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378073.
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A study of the binocular accommodation response is presented for normal and amblyopic observers to selected stimulus conditions using a binocular infra-red optometer and a commercially-available autorefractor. The work reviews the neural control of the near triad and discusses the historical development of models of mutual interaction between accommodation and convergence, presenting experimental evidence to support or refute each proposition. The basic characteristics of the accommodation response are reviewed along with the influencing factors. A central feature of this work is the evaluation of the correlation present between the eyes for both step-wise changes in target vergence and steady-state viewing. Reaction times for visually normal subjects were found to be similar to those found by previous workers and were independent of both size and direction of the step change. Response times for a mean step size of approximately 2.5D exhibited a marked degree of intersubject variability, particularly for the decreasing response and were step-size dependent. Eye dominancy was not found to be a significant factor in the overall response time. The binocular accommodation responses were found to have a high level of correlation to step-wise changes in target vergence. This in, itself, is perhaps not surprising in view of the anatomical similarities between the eyes and the relatively large dioptric changes induced. To obtain a clearer picture of the control of accommodation assessment of the microfluctuations was necessary. A high degree of correlation between amblyopic eyes and their fellow normal eyes is reported for both reaction and response times, although response times are longer than those for normal eyes. Reaction times for four subjects were not significantly different to those of the dominant eye. The subject presenting with the deepest amblyopia did have a significantly increased reaction time and a relationship with minimum angle of resolution is considered. Steady-state viewing shows the microfluctuations to have a high level of coherence, suggesting the control of accommodation to be at or above the point at which the IIIrd nerves are conjoint. Increasing target vergence causes an increase in the rms amplitude of the microfluctuations, binocular viewing not influencing the response characteristics. As target luminance decreased, rms values and low frequency drifts increased. Amblyopic eyes show an increase in the magnitude of the low frequency components of the microfluctuations for moderate to high stimulus vergences. The presence of different behaviour to that observed in normals supports a role for the microfluctuations. The response of amblyopic eyes to coloured stimuli results in an increase of the low frequency component to targets at the extremities of the visual spectrum, furthering the argument for a positive role for the fluctuations. The steady-state response to coloured stimuli differed from that found in normal eyes in that the appropriate response to overcome the chromatic interval was not observed for moderate to high stimulus vergences. The overall anomalous response could not use the additional information provided by coloured targets. Finally the detectibility of defocus was tested with sine waves and using signals derived from the microfluctuations. The threshold of detection for the microfluctuations is similar to that for sine waves, but is thought to be due to the presence of discontinuities and abrupt shifts in the response level. This adds support to Crane's(1966) hypothesis of 'accommodative saccades'.
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Rai, Gurjeet Kaur. "Accommodation and intraocular pressure." Thesis, Aston University, 2007. http://publications.aston.ac.uk/14645/.
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The relationship between accommodation and intraocular pressure (IOP) has not been addressed as a research question for over 20 years, when measurement of both of these parameters was less advanced than today. Hence the central aim of this thesis was to evaluate the effects of accommodation on lOP. The instrument of choice throughout this thesis was the Pulsair EasyEye non-contact tonometer (NCT) due principally to its slim-line design which allowed the measurement of lOP in one eye and simultaneous stimulation of accommodation in the other eye. A second reason for using the Pulsair EasyEye NCT was that through collaboration with the manufacturers (Keeler, UK) the instrument's operational technology was made accessible. Hence, the principle components underpinning non-contact lOP measures of 0.1mmHg resolution (an order of magnitude greater than other methods) were made available. The relationship between the pressure-output and corneal response has been termed the pressure-response relationship, aspects of which have been shown to be related to ocular biometric parameters. Further, analysis of the components of the pressure-response relationship together with high-speed photography of the cornea during tonometry has enhanced our understanding of the derivation of an IOP measure with the Pulsair EasyEye NCT. The NCT samples the corneal response to the pressure pulse over a 19 ms cycle photoelectronically, but computes the subject's lOP using the data collected in the first 2.34 ms. The relatively instantaneous nature of the lOP measurement renders the measures susceptible to variations in the steady-state lOP caused by the respiratory and cardiac cycles. As such, the variance associated with these cycles was minimised by synchronising the lOP measures with the cardiac trace and maintaining a constant pace respiratory cycle at 15 breathes/minute. It is apparent that synchronising the lOP measures with the peak, middle or trough of the cardiac trace significantly reduced the spread of consecutive measures. Of the 3 locations investigated, synchronisation with the middle location demonstrated the least variance (coeflicient of variation = 9.1%) and a strong correlation (r = 0.90, p = <0.001) with lOP values obtained with Goldmann contact tonometry (n = 50). Accordingly IOP measures synchronised with the middle location of the cardiac cycle were taken in the RE while the LE fixated low (L; zero D), intermediate (I; 1.50 D) and high (H; 4 D) accommodation targets, Quasi-continuous measures of accommodation responses were obtained during the lOP measurement period using the portable infrared Grand Seiko FR-5000 autorefractor. The lOP reduced between L and I accommodative levels by approximately 0.61 mmHg (p <0.00 I). No significant reduction in IOP between L and H accommodation levels was elicited (p = 0.65) (n = 40). The relationship between accommodation and lOP was characterised by substantial inter-subject variations. Myopes demonstrated a tendency to show a reduction in IOP with accommodation which was significant only with I accommodation levels when measured with the NCT (r = 0.50, p = 0.01). However, the relationship between myopia and lOP change with accommodation reached significance for both I (r = 0.61, p= 0.003) and H (r = 0.531, p= 0.0 1) accommodation levels when measured with the Ocular blood Flow Analyser (OBFA). Investigation of the effects of accommodation on the parameters measured by the OBFA demonstrated that with H accommodation levels the pulse amplitude (PA) and pulse rate (PR) responses differed between myopes and emmetropes (PA: p = 0.03; PR: p = 0.004). As thc axial length increased there was a tendency for the pulsatile ocular blood flow (POBF) to reduce with accommodation, which was significant only with H accommodation levels (r = 0.38, p = 0.02). It is proposed that emmetropes arc able to regulate the POBF responses to changes in ocular perfusion pressure caused by changes in lOP with I (r = 0.77, p <0.001) and H (r = 0.73, p = 0.001) accommodation levels. However, thc relationship between lOP and POBF changes in the myopes was not correlated for both I (r = 0.33, p = 0.20) and H (r = 0.05, p = 0.85) accommodation levels. The thesis presents new data on the relationships between accommodation, lOP and parameters of the OBFA,: and provides evidence for possible lOP and choroidal blood flow regulatory mechanisms. Further the data highlight possible deficits in the vascular regulation of the myopic eye during accommodation, which may play a putative role in the aetiology of myopia development.
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Dettner, Alexander. "Accommodation Of Religion : Arguments For The Permissibility And Desirability Of Accommodation Of Religion." Thesis, Uppsala universitet, Juridiska institutionen, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-192500.
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Caulet, Charles. "Les plages sableuses en environnement macro-tidal : de l'influence de la pente sur les processus morphodynamiques." Thesis, Brest, 2018. http://www.theses.fr/2018BRES0079/document.
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Ces travaux de thèse concernent la morpho-dynamique d'une plage de poche sableuse, située en environnement macrotidal. L'étude est menée sur la plage de Porsmilin, une plage de type intermédiaire avec une terrasse de basse mer. Cette étude s’appuie sur des observations in situ acquises lors de campagnes de mesures, organisées au cours de cette thèse. Le principal objectif est de caractériser le rôle de la pente, dans l'équilibre dynamique existant entre les processus hydrodynamiques et la morphologie de la plage. La dynamique des niveaux d’eau, de la propagation des ondes infragravitaires et de la turbulence sont examinés et mis en regard des variations morphologiques de la plage, en particulier de la pente locale de la plage. Les niveaux d’eau sont globalement sous-estimés par les formulations empiriques proposées dans la littérature. Des formules adaptées au site de Porsmilin sont présentées. L’impact de la brisure de pente observée le long du profil de plage sur la dynamique de la plage, est étudié. La variabilité de la position de la brisure de pente est impliquée dans les processus d’accommodation à court terme de la plage. Cela se traduit par un retrait vers le haut de plage de la brisure de pente, permettant une dissipation plus efficace de l’énergie incidente par la terrasse de basse mer. En revanche, ce retrait peut conduire, à une concentration d’énergie importante en haut de plage, lors de conditions particulièrement énergétiques, associées à un marnage important. La position de la brisure de pente pourrait être un bon indicateur de l'état de vulnérabilité de la plage face à des évènements énergétiques, ce qui constitue une information primordiale dans le contexte actuel d’érosion généralisée des littoraux sableuxThis PhD work is focused on the morphodynamic of a pocket beach, located in a macrotidal environment. The beach type is intermediate, with a low tide terrace. The study is based on in situ observations, collected during field campaigns organized during the PhD. The objective is to characterize the beach slope impact on hydrodynamics processes and beach morphology. The water levels dynamic, infragravity waves propagation and turbulence generation in the swash zone, are examined and linked to the beach slope variability.The empirical formulations proposed in the literature show large under-estimations of water levels in the site. Empirical formulations adapted to the beach are proposed.The characteristic break slope presents along the cross-shore profile of low tide terrace beaches is studied. The variability of the break slope location is relevant to explain the short term accommodation of the beach. Under incident wave energy, the location of the beach slope moves shoreward, allowing higher wave dissipation by the low tide terrace. Nevertheless, the reflective part is reduced, which leads to a vulnerable state of the upper beach under strong forcing associated with high tide. The location of the beach slope is found to be a good indicator of the beach vulnerability under a given wave forcing. It provides valuable information in the globalized beach erosion context
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Ouamba-Patas, Joseph-Nestor. "Les minorités religieuses, la neutralité de l'État et les accommodements raisonnables en France et au Royaume-Uni." Thesis, Strasbourg, 2013. http://www.theses.fr/2013STRAA026/document.
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Le pluralisme religieux est une réalité objective au Royaume-Uni et en France. Les minorités religieuses, demeurent un sujet récurrent qui suscite d’intarissables réflexions, d’études, de débats scientifiques et politiques. Elles sont une véritable préoccupation pour le politique, l’Europe et l’Etat ; à telle enseigne qu’il faille s’interroger sur ce que l’Etat peut leur proposer comme meilleure protection au XXIème siècle. La France et le Royaume-Uni sont confrontés à ce défi. Outre, la neutralité de l’Etat au regard de la religion rend complexes les rapports de ces minorités religieuses avec l’Etat en France où le concept de minorités religieuses n’est pas connu du droit français en vertu du caractère laïque de l’Etat français proclamé par l’article 1er de sa Constitution et la loi du 9 Décembre 1905 de la Séparation de l’Etat et de l’Eglise. Les minorités religieuses sont un non-sujet en droit français. Mais au Royaume-Uni, les minorités qualifiées de confessions religieuses sont reconnues quand bien même l’Eglise Anglicane est l’Eglise établie et officielle, avec à sa tête la Reine Elizabeth II. Il n’y a pas de séparation entre l’Eglise et l’Etat. En Ecosse, l’Eglise Presbytérienne fait figure d’Eglise établie, mais séparée de l’Etat. Aussi, toujours liée aux minorités religieuses, la question de l’application du principe d’ajustement raisonnable pour écarter des cas de discrimination en matière religieuse. L’ordre juridique britannique connaît ce principe et l’applique. Alors qu’en France, ce principe est ignoré et fait l’objet d’une application purement informelle. Certes, la globalisation apporte des faits positifs en Europe et notamment dans ces deux Etats, mais elle contient aussi des risques auxquels il faut prêter attention au XXIème siècle. Ainsi, les minorités nationales, les communautés linguistiques et les différentes unités constitutives de l’Etat demandent, en faisant appel au principe de la diversité, la reconnaissance de leurs droits collectifs, une multiplication des structures régionales et le perfectionnement de leurs prérogatives. L’apparition des « nouvelles minorités », celles des immigrants posent de nouvelles difficultés. En pratique, la religion historique du pays est privilégiée. Les religions pratiquées par les immigrés – Islam, Bouddhisme, Hindouisme, etc – sont alors l’objet d’une discrimination plus ou moins forte. Le besoin de visibilité de ces religions – et de l’Islam en occurrence – remet en cause le cadre fixé à la fin du XIXème siècle qui régit le fonctionnement des religions dans les divers Etats. Cette évolution touche plus durement les Etats laïcs de tradition catholique comme la France que les pays de tradition protestante où la place du religieux dans l’espace public est par tradition plus facilement acceptée comme le Royaume-Uni. Il faut aussi considérer que les religions importées par les populations migrantes sont souvent des « ethno-religions ». L’enjeu identitaire y est considérable, et il tend même à se substituer à celui de la liberté de croyance. Le Royaume-Uni et la France s’inscrivent dans ce registre à propos de leurs minorités religieusesReligious pluralism is an objective reality in France and Great-Britain. The religious minorities remain a recurring subject which inexhaustible reflections, studies, scientific and political debates. They show real concern to policymakers, Europe and State; so much so that it is necessary to wonder about what the State can propose them as better protection in the XXIst century. France and Great-Britain are confronted with this challenge. Besides the neutrality of the State with regard to the religion, makes complex relationships of these religious minorities with the State in France; where the concept of religious minorities is not known of French Law by virtue of the secularity – laic – character of the French State proclaimed by the 1st article of its Constitution and the Law of December 9th, 1905 of the Separation of the State and the Church. The religious minorities are no-subject in French Law. But in Great-Britain, the qualified religious, minorities of religious confessions are recognized when well even the Church of England is established and official Church with at its head Queen Elizabeth II. There is no separation between the Church and the State. In Scotland, the Kirk as considered as established Church and separated from the State. Also, always related to religious minorities, the question of application of reasonable principle of accommodation to draw aside from the cases of discrimination out of religious matter. The British legal order knows this principle and applies. Whereas in France this principle is ignored and is the object of purely abstract application. Admittedly, the globalization brings positive facts to Europe and in particular in these two States, but it contains also risks for which it is necessary to pay attention to the XXIst century. Thus, the national minorities, the speech communities and the various constitutional units of the State require, by calling on the principle of diversity, recognition of their collective rights, a multiplication of regional structures and improvement of their prerogative. The appearance of the “new minorities”, those of immigrants raises new difficulties. In practice, the historical religion of the country is often privileged. The religions practiced by immigrants – Islam, Buddhism, Hinduism, etc – are then the object of more or less strong discrimination. The need for the visibility of these religions – Islam I occurrence – calls into question the framework fixed at the end of XIXth century which governs the operation of religions in the various States. This evolution touches hardly the secular States of Catholic tradition like France, than the countries of Protestant tradition where the place of religious in public space is by tradition more easily accepted like Great-Britain. It as should be considered as the religions imported by migrant populations are often “ethno-religions”. The identity challenge is considerable there, and it even tends to replace that of freedom of belief. Great-Britain and France fall under this register in connection with their religious minorities
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Flitcroft, Daniel Ian. "Sensory control of ocular accommodation." Thesis, University of Oxford, 1988. http://ora.ox.ac.uk/objects/uuid:9533e285-150f-4bc9-90d8-4a4a870a7f0e.
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Ransdell, Amanda OD. "Ciliary Muscle and Sustained Accommodation." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1427279533.
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Larsson, Magdalena. "Beliefs regarding accommodation of dialects." Thesis, Linnéuniversitetet, Institutionen för språk och litteratur, SOL, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-16867.
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The aim of this paper is to investigate non-linguists' ideas about dialect accommodation. That is to say, the research questions concern people's beliefs about whether they accommodate their dialects to their interlocutors. In addition, one research question concerns people's suggestions as to why they adjust their speech and if differences between native and foreign languages can be found. The investigation was carried out as an informant survey and a total of 26 participants, between the ages 20 and 30, answered the questions. The data were analysed and discussed from a sociolinguistic and a sociopsychological perspective, with the theory CAT as a foundation for the interpretations. The results show that people believed they change their speech depending on conversation partner. This was thought of as subconscious behaviour and was mainly reflected upon afterwards. Furthermore, comments from the questionnaire concern changes in speech when talking to friends, when the interlocutor's dialect is distinct and when the informants visit a different geographical area. In addition, the informants have ideas about efficient communication when it comes to comprehensibility between the conversation partners' vocabularies as well as being on the same communicative level. The results from a native language accommodation situation and a foreign language accommodation situation showed similar ideas. That is to say, people's perceptions about accommodation did not differ much depending on what language they used.
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Coetzee, Anrike. "The future of student accommodation : the development potential of accommodation in the Hatfield Student Village." Diss., University of Pretoria, 2019. http://hdl.handle.net/2263/73329.
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Over the past decade, the demand for student housing in the Hatfield Student Village, situated between the Hatfield and Hillcrest campuses of the University of Pretoria, has grown to a point, where the demand greatly overshadows the supply. Local developers, who recognised the need for housing among students, have made great progress in filling this gap. It has come to a point, where the University of Pretoria has the second largest supply of student housing in South Africa, after the University of Cape Town.
This study has sought to determine whether there is still development potential for student housing in the Hatfield area, and also to develop a 10-year masterplan for the future development of accommodation in the Hatfield and Hillcrest areas.
Prominent development companies in the student-housing industry were contacted; and interviews were conducted with 8 high-ranking individuals in 8 different companies. The interviews determined the developers’ appetites for the further development of student accommodation in an area, which is already highly competitive. Interviews were also conducted with various role-players in Hatfield, such as the CEO of Hatfield CID, as well as prominent Estate Agents working in the area. Further data were collected on the various occupancy levels in the existing student accommodation, in order to determine the need for future development.
The results showed that developers have developed the area to supply about 11 315 beds to the market. With 4 178 beds in line to enter the market within the next 5 to 10 years, the supply will be much larger than the demand. Opportunity must be given to the economy to recover; and thereafter, further development of student accommodation must concentrate on providing units for low-income students.
A 10-year masterplan, divided into short-, medium- and long-term time periods, provides a potential road-map to follow, for the future of student accommodation in the Hatfield Student Village. The plan elaborates on future development and the type of development, which would ensure a successful student community for the University of Pretoria.Dissertation (MSc)--University of Pretoria, 2019.
Construction Economics
MSc (Real Estate)
Unrestricted
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Mucke, Sven. "Visual suppression during dynamic ocular accommodation." Thesis, Glasgow Caledonian University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.547426.
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Carlin, Paul. "Modelling vergence, accommodation and their interaction." Thesis, Glasgow Caledonian University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241881.
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The vergence and accommodation systems, which are examples of physiological control systems, enable us to acquire and maintain clear single images of objects at a variety of distances in our visual world. Vergence and accommodation systems are interact with one each other and have both visual and non-visual components thus adding to their complexity. This thesis reviews the evolution of control theory models of vergence and accommodation from the 1960's to the present day and has outlined several properties of the systems which require further study. The thesis introduces the concept of Fuzzy Logic Control (FLC) to models of oculomotor control. FLC offers a new approach to modelling natural control systems and produces more realistic models than those obtained using conventional control theory techniques. Several characteristics of the vergence and accommodation systems were investigated with the aim of incorporating experimental data into control theory models using conventional techniques and FLC. The accommodation response to anisometropic stimuli was measured objectively. No evidence of a non-consensual response was found, from which it can be concluded that accommodation is consensual. A control theory model of binocular accommodation was simulated to illustrate the control strategies adopted by the accommodation during anisometropic stimulation. A Virtual Reality (VR) stimulus was used to investigate the possibility of adaptation of the crosslink components of vergence and accommodation by placing different demands on the vergence and accommodation systems. Crosslink behaviour was altered as a result of the VR stimulus which suggests that the links between vergence and accommodation (accommodative vergence and vergence accommodation) are amenable to adaptation. Control theory models were used to illustrate the effects of the VR stimulus on vergence and accommodation. The effect of proximity was investigated by measuring accommodation responses in the presence and absence of proximal cues. The effect of proximal cues under closed loop conditions was found to be minimal which suggests that proximal cues are only effective when visual cues are reduced. The results were extended to include the vergence system and a FLC model of proximal vergence and accommodation was implemented. Simulation of the model produced similar findings to a previous study which supports the use of FLC in models of oculomotor control. Voluntary vergence and accommodation were measured objectively under open loop conditions in a group of naive subjects. All subjects were able to produce voluntary responses corresponding to near and far. The ability of subjects to distinguish intermediate distances was more varied. The results show that voluntary responses can be produced without training and it is suggested that voluntary vergence and accommodation may be an important mode of response. The results were included in a control model of voluntary vergence and accommodation using FLC. The work presented provides support for the use of Fuzzy Logic in models of oculomotor control which can be used to improve models and complement existing models using conventional techniques.
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Hudon, Tamara. "Bilingual Infants' Accommodation of Accented Speech." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/26163.
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Infant word recognition is sometimes hindered by variability in the speech input. Previous research has shown that, at 9 months, monolinguals do not generalize wordforms across native- and accented-speakers (Schmale & Seidl, 2009). In the current study however, it was predicted that bilingual infants would be advantaged in accommodating for accented speech due to experience with phonetic variability across their two phonological systems. It was also predicted that this hypothesized ability would be restricted to accommodating for an accent derived from a familiar language (e.g., French-English bilinguals would accommodate for French-accented English but not Mandarin-accented English), since this type of variability would be consistent with the language sounds to which infants were regularly exposed.
Study 1 set the experimental stage by identifying native and non-native speakers with similar voices, as perceived by a group of adults. This was done in order to restrict variability across speakers to differences in accent, rather than biological differences in voice (e.g., a higher or lower pitched voice). Following speaker selection, acoustic measurements of vowels and word stress placement were taken to compare native and non-native speakers and confirmed several expected deviations between native and accented speech. Study 2 tested the hypothesis that bilingual infants would be advantaged in accommodating for these deviations when the accent is derived from a familiar phonology. Using a headturn preference procedure (HPP), 9- and 13-month-old English-learning monolinguals and French-English learning bilingual infants were tested on their ability to recognize familiarized English wordforms across a native- and French-accented speaker. Bilinguals in both age groups succeeded in generalizing wordforms across speakers, however monolingual infants failed regardless of age. Study 3 tested whether bilinguals’ success would persist when the accented speaker’s first language was unfamiliar. Infants in this study failed as a group to generalize across native- and Mandarin-accented productions of English wordforms. However, bilinguals who received balanced exposure to their two languages performed better in accommodating for Mandarin accented speech than unbalanced bilinguals. This hints at a general ability to ignore irrelevant phonetic information, perhaps due to an advantage in cognitive control.
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Szostek, Nicola. "Assessment of ocular accommodation in humans." Thesis, University of Plymouth, 2017. http://hdl.handle.net/10026.1/9883.
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Accommodation is the change in the dioptric power of the eye altering the focus from distance to near. Presbyopia is the loss of accommodative function that occurs with age. There are many techniques used to measure accommodation, however, there is little consensus as to how clinical data should be collected and analysed. The overarching theme of this thesis is the in vivo examination of accommodation and how lifestyle can affect the onset of presbyopia. An open-field autorefractor with badal adaption was used to examine accommodative dynamic profiles under varying demands of vergence. From this data a new metric for assessing the time for accommodative change was derived. Furthermore this thesis describes a bespoke automated accommodative facility instrument that was developed to provide further assessment of accommodative speeds. Defocus curves are used for assessing accommodation and depth-of-focus; the work presented explores the use of non-linear regression models to define the most appropriate method of assessing defocus curves in phakic subjects, and pseudophakic subjects implanted with an extended depth-of-focus intraocular lens. Using an absolute cut-off criteria of +0.30logMAR improved the repeatability and reliability of the depth-of-focus metrics over a cut-off criteria relative to the best corrected visual acuity. A swept-source anterior segment optical coherence tomographer (AS-OCT) was used to image the morphology of the ciliary muscle during accommodation. The accuracy of ciliary muscle measurements was improved when using reference points on the sclera to align the AS-OCT scan. The use of a ciliary muscle area metric demonstrated poor repeatability and reliability when compared to the traditional assessment of muscle morphology via thickness measurements. Physiological ageing in the crystalline lens occurs in line with ageing in other structures in the body. The methods for assessing accommodative function examined in previous chapters, were used to examine whether lifestyle factors which affect the rate of systemic ageing, such as smoking, also affect accommodative function. Although being a current smoker and having greater central adiposity was associated with a slower time for accommodative change, further research is required before these findings can be applied to the target population.
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Farmer, Henry Keith. "Managing maintenance of multiple domestic accommodation." Thesis, Loughborough University, 2003. https://dspace.lboro.ac.uk/2134/34238.
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Buildings rarely fail within a short time of commissioning; most become unsatisfactory gradually, over a period of many years, as the design becomes obsolete and/or inadequate maintenance and improvements fail to keep pace with demand. Maintenance work is thus necessary to keep a building in an acceptable minimum condition. The industrialised building methods much used in the 1960s were frequently innovative and, at that time, unproven methods of construction. When these are added to the list of 'traditional build' failure contributors, the need for additional and regular maintenance is increased. Various factors contribute to domestic accommodation buildings ceasing to be Satisfactory—to fail in their purpose of providing a safe, warm and dry environment for the occupants. To the layperson, bad workmanship by the builders, poor quality materials, poor design and inadequate maintenance are common causes for complaint. This research investigated the cost of maintenance for buildings of multiple domestic accommodation, methods used to organise maintenance planning and budgeting, and considered whether the use of industrialised building methods had affected that cost. The current and anticipated future use of Planned Preventative Maintenance, together with other management methods, as tools for minimising maintenance cost is also examined. A method for introducing a system of planned preventative maintenance that is specifically tailored to individual buildings from a common pattern was developed as an output of this research. 'Designing out' the need for maintenance requires an understanding of maintenance activity cost centres (i.e. where does the money go and what elements of maintenance account for the greatest expenditure?). The way that building professionals perceive potential maintenance cost requirements is therefore investigated and comparison made with actual costs for the same elements of maintenance.
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Suryawardani, I. Gusti Ayu Oka. "Tourism leakage of accommodation in Bali." Thesis, Paris 1, 2015. http://www.theses.fr/2015PA010071/document.
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Le tourisme est le fer de lance de l'économie balinaise. Mais, les fruits de cette économie du tourisme ne bénéficient pas à toutes les classes de la société balinaise. Cela est dû, entre autres, au manque à gagner lorsque cette industrie importe par exemple des produits ou des services pour répondre aux besoins des touristes (alimentation pour la restauration par exemple). Le calcul du manque à gagner pour l'économie balinaise n’a jamais été fait auparavant. Pour cela, cette recherche est nécessaire. Les objectifs de la recherche étaient : de calculer le manque à gagner pour l'économie balinaise dans le secteur du logement pour les touristes en micro-économie (niveau industriel) ; d'estimer le manque à gagner pour le tourisme balinais dans le secteur de l'hébergement touristique en macroéconomie (au niveau provincial) ; d'évaluer l'impact de la subvention gouvernementale et la réduction des importations dans l' industrie du tourisme, les opportunités d'emploi et la distribution des revenus ; d'évaluer la perception et le choix des touristes internationaux face aux offres de produits importés et locaux, et aussi d'évaluer l'opinion des touristes sur le constat : est-ce que les dépenses des touristes pendant leur voyage à Bali bénéficient à la société balinaise ? ; et d'évaluer les opinions des gestionnaires des hôtels sur l'utilisation des produits importés et des produit locaux pour la consommation des touristes ; de créer une stratégie afin de minimiser le manque à gagner dans le secteur du tourisme pour l'économie balinaise. La recherche est basée sur les approches quantitatives et qualitatives. Les données primaires ont été recueillies par la méthode du sondage sur quatre destinations touristiques, à savoir : Kuta, Nusa Dua, Sanur et Ubud, auprès d'un échantillon de 79 hôtels selon la méthode de probabilité proportionnelle à la taille qui est divisée en trois échantillons en grappes : hôtels classés 1, 2 et 3 étoiles ; hôtels classés 4 & 5 étoiles et hôtels privés (non-chain) ou appartenant à une chaine hôtelière (chain) ; hôtels non-classés. Nombre de répondants 600 touristes internationaux qui étaient en vacances à ce moment-là. Le calcul du manque à gagner dans l'analyse micro a été mené selon la méthode d'Unluonen et. al. (2011), tandis que l'analyse macro a été faite selon la méthode de Thorbecke (1988) en utilisant l'approche de la matrice de comptabilité sociale (MCS) de la province de Bali de l'année 2010. La perception et le choix des touristes internationaux vis-à-vis des produits importés et locaux ont été analysé selon le logiciel JMP tandis que les stratégies de la minimisation du manque à gagner dans l'économie touristique balinaise ont été créées selon la méthode de l'ISM (interpretive Structural Modelling). [...] Les touristes internationaux choisissent de façon significative les produits locaux et ils sont prêts à dépenser leur argent au bénéfice des populations locales. Les gestionnaires des hôtels sont prêts à utiliser les produits locaux tant que l’offre est suffisante pour remplacer les produits importés. Les stratégies pour minimiser le manque à gagner pour le tourisme à Bali : optimiser les potentiels des produits locaux ; développer l'agriculture et l' élevage, réduire les produits importés pour la consommation des touristes, augmenter l'exportation des produits locaux, augmenter la qualité des produits locaux ainsi que la qualité des ressources humaines locales, renforcer la société locale, inciter le gouvernement à mettre en œuvre une politique de minimisation du manque à gagner dans l'économie touristique, limiter les investissements étrangers dans le secteur du logement touristique, stabiliser les fluctuations des taux de change, augmenter le rôle du Ministère des affaires étrangères, du ministère de l'industrie, du Ministère du commerce ainsi que le rôle du Ministère du tourisme et de l'économie créative afin de réduire ledit manque à gagnerTourism has become the leading economic sector in Bali Province of Indonesia. However, the economic impacts of tourism have not been convinced to be full y beneficial for Balinese community. One of the reasons is tourism leakage that occurs when the industry imports both products and services to support tourism industry in Bali. So far, the amount of tourism leakage in Bali has not been calculated yet. Therefore, there is a need to ascertain the current amount of leakage in Bali tourism. The objectives of the study are: (i) to calculate the amount of tourism leakage from accommodation sector in Bali at micro (industrial) level; (ii) to calculate the amount of tourism leakage from accommodation sector in Bali at macro (regional) level; (iii) to evaluate the impacts of government subsidies and import reduction by accommodation sector on tourism leakage, job opportunity and income distribution; (iv) to evaluate the perception and preference of foreign tourists on imported and local products as well as the willingness of foreign tourists to spend their money to benefit of Balinese people; (v) to evaluate the points of view of hotel managers related to imported and local products as well as their willingness in reducing the use of imported product and (vi) to develop strategies in minimizing tourism leakage in accommodation in Bali. Research was designed through quantitative and qualitative approaches. Data was collected by using survey method at four main tourist destinations in Bali, namely: Kuta, Nusa Dua, Sanur and Ubud. There were 79 hotels selected based upon probability proportional to size sampling method which consists of three clusters namely 1,2,3 Star-rated, 4&5 Star-rated either chain and non-chain and Non Star-rated hotels. The number of respondents was 600 foreign tourists were selected as respondents. Calculation of tourism leakage on micro analysis was undertaken by using a method developed by Unluonen, et. al. (2011), meanwhile, on macro analysis was carried out by using a method proposed by Thorbecke ( 1988) which was based on the Social Accounting Matrix (SAM) of Bali 2010. Perception and preference of foreign tourists on imported and local products were analyzed by using JMP program, meanwhile, Interpretative Structural Modelling (ISM) was undertaken to develop strategies. The results show that based on the micro analysis, the highest tourism leakage of accommodation sector in Bali is at 4&5 Star-rated chain hotels (51.0 %), followed by 4&5 Star-rated non-chain hotels (22.7 %), 1,2&3 Star-rated hotels (12.0 %), Non-star rated hotels (8.8 %), and with the average leakage of 18.8 %. Based on macro analysis, tourism leakage of accommodation sector in Bali are as follow: (i) Leakage of Non Star-rated hotels is 2.0 %; (ii) Leakage of 1,2&3 Star-rated hotels is 15.7 %; (iii) Leakage of 4&5 Star-rated non-chain hotels is 7.1 %, (iv) Leakage of 4&5 Star-rated chain hotels is 55.3%; and (v) Average leakage of all types of accommodation is 19.5%. Foreign tourists significantly look for local products and are willing to spend their money for Balinese people. Hotel managers are willing to use local product as long as local products are available to substitute the imported products. Strategies for minimization tourism leakage are optimizing the potential of local products, develop agriculture and livestock; reduce the use of imported products for tourists, improve quality of local products and human resources, empower community, urge government to develop and implement supporting policies in minimizing tourism leakage, establish policy on restriction of foreign investment on accommodation in Bali, improve the role of Ministry of Foreign Affairs, Ministry of Industry, Ministry of Trade and Ministry of Tourism and Creative Economy. 7 Ps of marketing mix on service: product, price, place, promotion, people, process and physical evidence need to be implemented in order to support sustainable tourism in Bali
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Arey, Dale Simon. "Accommodation for the peri-parturient sow." Thesis, University of Aberdeen, 1990. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU032002.
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Prior to giving birth, sows are normally confined in crates. One of the current aims in pig production is to develop an alternative farrowing system in which the sows are unconfined and grouped together. The aim of the new system is to improve the welfare of the sow and litter whilst maintaining high levels of productivity. Four studies were conducted to document the nest building and social behaviour of sows so that the system can be designed to suit their needs. The fifth study compared the productivity of unconfined individual and grouped sows with confined sows. Study 1. Six sows were housed in a pen which contained a sand floor and straw dispenser. Nine and a half hours before farrowing the sows displayed rooting, pawing and straw carrying and removed 23 kg straw to build a nest with hollow, straw lining and nest rim. Six sows were presented with similar nests. Nest building behaviour was affected by feeding behaviour. Study 2. Sixteen sows were presented with a hollow (H), a mattress (M), a nest box (B) which represented the 3 nest features and a control (C). Farrowing site preference was (H) 6, (M) 6, (B) 4 and (C) 0. In trial 2, (C) was replaced by a straw area (S), all 16 sows farrowed in (S) when it contained 4.5-18 kg straw. At 2.25 kg preference was (H) 1, (M) 3, (B) 1, (S) 3. Nest building behaviour was not affected by the amount of straw in (S).Study 3. Four previously confined and 3 unconfined sows were housed in a pen which included a straw (S), a central food (F) and a control (C) area. Entry into (S) and (C) was contingent on 10 panel presses. Food was delivered into (F) every 2 hours. The sows pressed the panel for (S) more than (C). Nest builidng behaviour was affected by feeding behaviour. Confined sows tended to show more behaviour associated with the straw. In trial 2, 5 sows were housed in pen which included a straw (S), a central (C) and a food (F) area. Cost of entry into (S) and (F) was gradually increased. Food was delivered into (F) every 45 mins. The fall in work rates for straw and food were similar as the cost was increased. The work rate for straw was increased 24 hours before farrowing. Study 4. Twenty-two sows were paired with an unfamiliar conspecific in pens which contained 2 strawed lying areas. As farrowing approached, the sows spent less time lying together and the aggressive behaviour of 12 dominant prepartal sows increased significantly. The level of aggression was significantly reduced in 11 dominant prepartal sows paired with unfamiliar conspecifics in modified pens and between 9 pairs of pre-partal sows which were familiar with each other. Sows were observed to lie together at farrowing and to farrow in more than one lying area. Study 5. Appetite and piglet mortality was compared for 43 sows in straw pens, 51 sows housed with pen-mates in straw pens and 50 sows in farrowing crates. Appetite was not reduced during the periparturient period or affected by pen type. There was no difference in the number of piglets which died during the first 24 hours after farrowing in the 3 pen types. Sows in farrowing crates tended to have more stillborn piglets.
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Taylor, John. "Accommodation, refractive surgery and ocular aberrations." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/accommodation-refractive-surgery-and-ocular-aberrations(e457724c-b681-4957-ae7d-6ccdb2f0765d).html.
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The principal work in this thesis describes the investigation of the impact that alterations to ocular aberrations following refractive surgery have on the accommodative mechanism. A series of prospective studies were conducted with healthy adults (n=36) that had chosen to undergo refractive surgery at Manchester Royal Eye Hospital. A variety of monocular accommodative functions were assessed prior to surgery and then at one and three months following surgery on the same cohort of patients. Accommodative functions included amplitude of accommodation, accommodative facility (at 6m and 0.4m) including positive and negative response times, and accommodative stimulus-response functions. Dynamic accommodation responses were examined in a subgroup (n=10) at three months following refractive surgery and compared to an age-matched emmetropic control group (n=10) to evaluate differences in latency, amplitude, time constant and peak velocity of accommodation and disaccommodation. During the studies, ocular aberrations were concurrently measured to determine whether alterations to aberrations could help explain any observed changes in accommodative functions. Evaluation of visual, refractive and questionnaire outcome measures indicated that the patient cohort underwent successful surgery. Following surgery, significant alterations to a number of accommodative functions were discovered. Mean subjective ocular amplitude of accommodation increased by approximately 0.50D (p<0.05), mean stimulus-response function gradient decreased by approximately 10% (p<0.05) and distance facility rate increased by approximately 2-3 cycles/minute (p<0.05). Significant correlation was found between the change in accommodative stimulus-response function gradient, and the change in spherical aberration following surgery (p<0.05). Significant differences were also found in the parameters of accommodative dynamics, although some of these factors may be explained by refractive error differences between the refractive surgery patients (pre-operative myopes) and the emmetropic control group. The results suggest that alterations to aberrations following refractive surgery may be capable of influencing elements of the accommodation response. Additional studies were conducted to investigate the changes in aberrations during accommodation (n=31 subjects), and explore the contribution of the tear film (n=19 subjects) to higher order aberrations in eyes that have undergone refractive surgery. The results suggested that the rate of change in aberrations during accommodation is not affected by refractive surgery, but that the pattern of aberrations induced by post-blink tear film changes may differ in patients that have undergone refractive surgery. A further study is presented which investigated the form of the accommodative stimulus-response function to grating target of different spatial frequencies in groups of myopic (n=10) and emmetropic (n=10) participants recruited from among the staff and students at The University of Manchester. Both refractive groups appeared to show similar accommodative behavior, however the dominant feature of the data in both groups was between subject variation.
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Eloy, Pierre. "Héberger les vulnérables, éloigner les indésirables : trajectoires de prise en charge des familles immigrées sans abri à Paris." Thesis, Paris 1, 2019. http://www.theses.fr/2019PA01H052.
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Cette thèse a pour objet la prise en charge des familles immigrées en situation de sans-abrisme, qu’elles aient ou non recours aux dispositifs de l’urgence sociale parisiens. Cette recherche répond à plusieurs objectifs. Premièrement, elle propose une analyse des expériences de sans-abrisme des familles immigrées à Paris, objectivées à partir d’enquêtes quantitatives et d’entretiens avec des familles. La thèse éclaire les processus de disqualification sociale dont ces familles font l’objet. En effet, les familles immigrées ne disposent pas des mêmes ressources que les autres familles sans abri, et s’inscrivent dans des trajectoires différenciées, à la fois du fait de leurs dispositions constituées dans le pays d’origine et de leur traitement institutionnel. C’est tout particulièrement le cas des familles étiquetées comme Roms, dont les conditions d’existence, associées à un fort stigmate ethnoracial, réduisent considérablement les probabilités d’obtenir un hébergement pour échapper à la rue. Les difficultés à trouver une place en hébergement sont fortement conditionnées par le contexte institutionnel qui les singularise. Deuxièmement, cette recherche analyse l’évolution des politiques sociales à destination des populations sans abri, et notamment des familles immigrées. La segmentation des dispositifs d’hébergement s’inscrit dans des politiques de gestion de la pauvreté, qui ont longtemps oscillé entre aide sociale et répression. L’embolie chronique des dispositifs de prise en charge pour sans-domicile affaiblit le principe d’inconditionnalité d’accès à l’hébergement et condamne son application. Face au manque de place, les logiques de tri et de hiérarchisation des familles reposent sur une évaluation de la vulnérabilité dans laquelle le stigmate culturaliste a un effet négatif dans la prise en charge. Enfin, ce travail analyse les rapports sociaux et les tensions qui se nouent autour de la prise en charge de ces populations dites vulnérables. Les familles sans abri, considérées comme des acteurs sociaux, se débrouillent avec les compétences acquises au cours de leurs trajectoires. En effet, les marges d’autonomie dont elles disposent face à l’absence de logement et leurs moyens de négociation avec les institutions dépendent en partie des capitaux économiques, sociaux et culturels détenus, ainsi que du temps passé dans la carrière de survie. Entre volonté d’insertion et renoncement, les familles, notamment roms, n’adhèrent pas de la même façon aux dispositifsThe main purpose of this thesis is to study the care for the homeless immigrant families, within or outside the social emergency accommodation devices in Paris. This research meets several objectives. In the first place, it proposes an objective analysis of the homeless immigrant families in Paris, on the basis of quantitative surveys and interviews with the families. This thesis enlightens the process of social disqualification that the families are confronted with. In fact, the immigrant families do not have the same resources compared to other homeless families. They follow different trajectories regarding both their habitus formed in their countries of origin and the way that they are treated by the institutions. In the particular case of families labelled as the ‘Roma’, the living conditions of these families and their strong ethno-racial stigmatisation, decrease considerably their chances of obtaining a shelter to avoid being out streets. The difficulty of finding a shelter is strongly shaped and differentiated by the institutional context. In the second place, this research analyses the evolution of social policies towards the homeless populations, in particular concerning the immigrant families. The segmentation of accommodation devices falls within the poverty reduction policies, which have been wavering for a long time between social aid and repression. The chronic embolism of accommodation facilities undermines the principle of unconditional access to shelter and prevents its application. Due to the lack of accommodation places, the logic of selection and prioritization of families is based on an evaluation of vulnerability through which the cultural stigma has a negative effect in the sheltering process. Finally, this study analyses the social relations and tensions around the sheltering of these populations qualified as vulnerable. Considered as social actors, homeless families try to manage with the skills they acquired through their trajectories. In other words, the margin of the autonomy of the immigrant families facing the absence of accommodation and their ways of negotiation with the institutions depend partly on the economic, social and cultural capitals that they dispose, and on the time, they spent in their survival career. Between willingness for insertion and renouncement, in particular the ‘Roma’ families do not adhere to the accommodation devices in the same way
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DePianto, Daryle Joseph. "Studies on lens fiber cell gene expression & lens differentiation /." Connect to Digital dissertations. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.
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Gao, Weichuan, and Jose Sasian. "Air lens vs aspheric surface: a lens design case study." SPIE-INT SOC OPTICAL ENGINEERING, 2017. http://hdl.handle.net/10150/627181.
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We discuss the behavior of air lenses in lens design. The structural aberration coefficients of a thin air lens are derived and compared with their glass thin lens counterpart. Examples are provided for a telephoto lens and the Monochromatic Quartet where air lenses or aspheric surfaces are used.
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Wu, Monica S. "Family Accommodation in Adults with Obsessive-Compulsive Disorder: Psychometric Properties of the Family Accommodation Scale - Patient Version." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5407.
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Family accommodation is a salient construct within the context of obsessive-compulsive disorder (OCD) and occurs in a large majority of affected individuals and their families. Accommodating behaviors can manifest in various ways, including participation in the patient's rituals, modifying everyday routines, facilitating compulsive behaviors, or providing reassurance. It has been repeatedly linked to negative outcomes, such as attenuated treatment response, increased obsessive-compulsive symptom severity, higher levels of family distress, and lower levels of functioning. As such, it is of significant clinical importance to have a standardized measure that is able to be used in research and clinical practice.
The Family Accommodation Scale for Obsessive-Compulsive Disorder (FAS) was the initial attempt at a measure to systematically assess for family accommodation in patients with OCD, with different clinician-rated and self-reported versions completed by the relative arising thereafter. However, to date, there is not a patient-reported version of the instrument. Existing measures focus on reports from the relative (e.g., the patient's significant other, parent), overlooking information from the patient themselves. Additionally, adult patients with OCD often present to clinical services alone, frequently making it impractical to obtain information from their relative. As such, it is important to have a standardized patient-reported measure to examine the accommodating behaviors.
The present study sought to evaluate the psychometric properties of the Family Accommodation Scale for Obsessive-Compulsive Disorder - Patient Version (FAS-PV). A large majority of the participants (88.5%) endorsed at least one type of accommodating behavior in the previous week. Provision of reassurance and waiting for completion of compulsions were the most frequently reported behaviors, while helping with personal tasks and making excuses/lying due to OCD-related impairment were the least frequently endorsed. The FAS-PV demonstrated good internal consistency and test-retest reliability, as well as good convergent/divergent validity. The FAS-PV did not significantly differ from the relative-reported measure of family accommodation in terms of internal consistency or mean scores. Ultimately, the FAS-PV demonstrated sound psychometric properties and utility in assessing family accommodation from the patient's perspective.
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Yang, Dingjie. "The Network Lens." Thesis, Linnaeus University, School of Computer Science, Physics and Mathematics, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-6626.
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A complex network graphics may be composed of hundreds and thousands of objects, such as nodes and edges. Each object may hold a large number of attributes that might be difficult to explore in the network visualization. Therefore, many visualization tools and approaches have been developed to gain more information from the network graphics. In this paper, we introduce the concept of the Network Lens, a new widget that assists the users to deal with a complex network. The Network Lens is an interactive tool that combines data visualization to a magic lens. With the help of the Network Lens, users can display hidden information of the elements in the network graphics based on their interest. Moreover, the Network Lens supports a series of interactive functions that give the users flexible options to define their own lenses.
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Shepard, III Ralph Hamilton. "Metamaterial Lens Design." Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/194734.
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Developments in nanotechnology and material science have produced optical materials with astonishing properties. Theory and experimentation have demonstrated that, among other properties, the law of refraction is reversed at an interface between a naturally occurring material and these so-called metamaterials. As the technology advances metamaterials have the potential to vastly impact the field of optical science.In this study we provide a foundation for future work in the area of geometric optics and lens design with metamaterials. The concept of negative refraction is extended to derive a comprehensive set of first-order imaging principles as well as an exhaustive aberration theory to 4th order. Results demonstrate congruence with the classical theory; however, negative refraction introduces a host of novel properties. In terms of aberration theory, metamaterials present the lens designer with increased flexibility. A singlet can be bent to produce either positive or negative spherical aberration (regardless of its focal length), its contribution to coma can become independent of its conjugate factor, and its field curvature takes on the opposite sign of its focal power. This is shown to be advantageous in some designs such as a finite conjugate relay lens; however, in a wider field of view landscape lens we demonstrate a metamaterial's aberration properties may be detrimental.This study presents the first comprehensive investigation of metamaterial lenses using industry standard lens design software. A formal design study evaluates the performance of doublet and triplet lenses operating at F/5 with a 100 mm focal length, a 20° half field of view, and specific geometric constraints. Computer aided optimization and performance evaluation provide experimental controls to remove designer-induced bias from the results. Positive-index lenses provide benchmarks for comparison to metamaterial systems subjected to identical design constraints. We find that idiosyncrasies in a metamaterial lens' aberration content can be exploited to produce imaging systems that are superior to their conventional counterparts. However, in some circumstances the reduced low-order aberration content in a metamaterial lens reduces the effectiveness of aberration balancing and stop shifting. Through a series of design experiments the relative advantages and challenges of using metamaterials in lens design are revealed.