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Automatic and Adaptive Red Eye Detection and Removal : Investigation and ImplementationSamadzadegan, Sepideh January 2012 (has links)
Redeye artifact is the most prevalent problem in the flash photography, especially using compact cameras with built-in flash, which bothers both amateur and professional photographers. Hence, removing the affected redeye pixels has become an important skill. This thesis work presents a completely automatic approach for the purpose of redeye detection and removal and it consists of two modules: detection and correction of the redeye pixels in an individual eye, detection of two red eyes in an individual face.This approach is considered as a combination of some of the previous attempts in the area of redeye removal together with some minor and major modifications and novel ideas. The detection procedure is based on the redness histogram analysis followed by two adaptive methods, general and specific approaches, in order to find a threshold point. The correction procedure is a four step algorithm which does not solely rely on the detected redeye pixels. It also applies some more pixel checking, such as enlarging the search area and neighborhood checking, to improve the reliability of the whole procedure by reducing the image degradation risk. The second module is based on a skin-likelihood detection algorithm. A completely novel approach which is utilizing the Golden Ratio in order to segment the face area into some specific regions is implemented in the second module. The proposed method in this thesis work is applied on more than 40 sample images; by considering some requirements and constrains, the achieved results are satisfactory.
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What Do We Know About Joint Attention in Shared Book Reading? An Eye-tracking Intervention StudyGuo, Jia January 2011 (has links)
<p>Joint attention is critical for social learning activities such as parent-child shared book reading. However, there is a potential disassociation of attention when the adult reads texts while the child looks at pictures. I hypothesize that the lack of joint attention limits children's opportunity to learn print-related skills. The current study tests the hypothesis with interventions that enhance real-time joint attention. Eye movements of parents and children were simultaneously tracked when they read books together on computer screens. I also provided real-time feedback to the parent regarding where the child was looking, and vice versa. Changes of dyads' reading behaviors before and after the joint attention intervention were measured from both eye movements and video records. Baseline data showed little joint attention in parent-child shared book reading. The real-time attention feedback significantly increased the joint attention and children's print-related learning. These findings supported my hypothesis that engaging in effective joint attention is critical for children to acquire knowledge and skills during shared reading and other collaborative learning activities.</p> / Dissertation
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Ocular drug delivery using microneedlesJiang, Ninghao 21 November 2006 (has links)
Traditional methods of drug delivery to the eye include topical application, intraocular injection and systemic administration; however, each method has its limitation to efficiently delivery drugs to the back of the eye. In this study, microneedles were tested to provide targeted drug delivery into the eye in a minimally invasive way.
To better interpret subsequent microneedle studies, we first quantified lateral drug diffusion profile within the sclera, by carrying out a diffusion study of a model compound, sulforhodamine, through human cadaver sclera, and developing a theoretical model for prediction of drug delivery kinetics and distribution. The results showed that measurable amounts of sulforhodamine were detected at distances of 5 and 10 mm from the sulforhodamine donor reservoir at 4 h and 3 days, respectively. The effective lateral diffusivity of sulforhodamine was determined to be 3.82 x 10-6 cm2/s, which is similar in magnitude to the transverse diffusivity.
We next assessed the capability of using coated solid metal microneedles to deliver drugs into the ocular tissue in both in vitro and in vivo scenarios. The in vitro insertion tests showed that these microneedles were mechanically strong enough to penetrate into human cadaver sclera, and the coating solution rapidly dissolved off the needles after insertion and had been deposited within the tissue. In the in vivo experiments, microneedle delivery exhibited elevated fluorescein levels in the rabbit eye 60 times greater than that delivered by topical application of the equivalent dose. Similarly, microneedle delivery of pilocarpine caused rapid and extensive pupil constriction. Safety exams reported no inflammatory responses in the eye after microneedle administrations.
We also used hollow glass microneedles to infuse solutions into the sclera tissue in vitro and examined the physiological barriers for flow. On average, 18 microliters of sulforhodamine solution and a solution containing nanoparticles was delivered into the sclera upon retraction of the microneedle. Successful delivery of micron-sized particles into the sclera could be improved by breaking down tightly packed collagen and GAG fibers using either collagenase or hyaluronidase.
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The Role Of Familiarity On Change PerceptionKaracan, Hacer 01 July 2007 (has links) (PDF)
In this study the mechanisms that control attention in natural scenes was examined. It was explored whether familiarity with the environment makes participants more sensitive to changes or novel events in the scene. Previous investigation of this issue has been based on viewing 2D pictures/images of simple objects or of natural scenes, a situation which does not accurately reflect the challenges of natural vision. In order to examine this issue, as well as the differences between 2D and 3D environments, two experiments were designed in which the general task demands could be manipulated. The results revealed that familiarity with the environment significantly increased the time spent fixating regions in the scene where a change had occurred. The results support the hypothesis that we learn the structure of natural scenes over time, and that attention is attracted by deviations from the stored scene representation. Such a mechanism would allow attention to objects or events that were not explicitly on the current cognitive agenda.
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Cognitive Analysis Of Experts' / And Novices' / Cocnept Mapping ProcessesDogusoy, Berrin 01 July 2012 (has links) (PDF)
In this study, Concept map (CM) development processes of the experts and novices were explored. This studyaimed to investigate the similarities and differences among novices and experts&rsquo / CM development process regarding their cognitive processes. Two experiments were designed / eye-tracking, written and verbal data were collected from 29 pre-service teachers and 6 subject matter experts.Data were analyzed by using qualitative and quantitative data analysis methods. The results indicated that eventhough some of the strategies were similar, there were different patterns followed by the experts and novices during the CM development process. Both experts and novices embraced &lsquo / deductive reasoning&rsquo / , and preferred &lsquo / hierarchical&rsquo / type of CMs. The other patterns recognized during the process were&lsquo / filling information in an order&rsquo / , &lsquo / branch construction pattern&rsquo / ,&lsquo / content richness&rsquo / and &lsquo / progress pattern&rsquo / . Novices and experts were distinguished in their content richness measures which used to determine the quality of the maps. Regarding the progress pattern, novices and experts differed in terms of the frequency and duration for specific acts invarious phases of their progress in CM development process. Furthermore, expert participants differed from novices in their fixation count numbers, fixation durations, visit duration periods for specific actions. Fixation count numbers of the novices were higher than the experts during the entire process and in specific dimensions of the CM development process. As a conclusion, these pattern differences affect the CM development process directly and the instructors need to give emphasis to these critical points while using CM during the instruction, and with the help of these pattern differences, instructors could guide the learner effectively and acquire content rich CMs.
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Eye Tracking SystemLin, Jar-Way 21 July 2003 (has links)
¡@¡@It has been for a long time to develop systems of eye control, which are related to a variety of techniques, such as signal/image processing, characteristics of face identifying/tracking, action-mappings, etc. In terms of implementations, the acquisition of data can be done by either special instruments or by general devices. Such systems can be applied to many fields, for instance, military, medicine, entertainments, and other tasks that are fitted. And for the similar system, the performance differs due to the disparity of distinct situations and the way to use it.
¡@¡@In this thesis, we present a system that takes a sequence of images of a user as inputs, and then integrates methods of elliptical model of head, dual states of eyes, deformable templates, and the most yield filter to track the user¡¦s eyes. A coarse-to-fine strategy is used to rapidly locate the region of eyes and to get the information of eyes in order to translate into corresponding operations on machines. The experiment shows that our system is quite robust and fast so that it can help people who are unable to use physical body well.
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The effect of L-dopa on contrast sensitivity in normal subjects using functional magnetic resonance imagingSharma, Saloni. January 2003 (has links)
Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xi, 101 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 95-99).
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Prevalence of ocular abnormalities and correlation with functional status in adults with Down syndrome in Hong KongFong, Hon-chi, Angie., 方瀚芝. January 2010 (has links)
published_or_final_version / Public Health / Master / Master of Public Health
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Molecular mechanisms of choroid fissure closure and ventral retina formation in the zebrafish eyeLee, Jiwoon 10 February 2011 (has links)
During optic cup morphogenesis, the neuroectodermal layers of the optic vesicle (OV) invaginate ventrally, and fuse at the choroid fissure (CF) along the proximo-distal axis such that the retina and retinal pigment epithelium (RPE) are confined within the cup. Failure of CF closure results in colobomas, which are characterized by the persistence of a cleft or hole at the back of the eye. While CF closure is a critical aspect of ocular development, the molecular and cellular mechanisms underlying this process are poorly understood. My research examined CF closure and colobomas using zebrafish as a model system. In the first study, I determined that early cell fate changes within the eye field could cause colobomas using the zebrafish mutant blowout. Colobomas in blowout resulted from defects in optic stalk morphogenesis whereby the optic stalk extended into the retina and impeded the edges of the CF from meeting and fusing. Positional cloning of blowout identified a nonsense mutation in patched1, a negative regulator of the Hedgehog pathway. Up-regulation of Hedgehog pathway activity causes disruption in the patterning of the OV into proximal and distal territories, revealing that cell fate determination, mediated by Hedgehog signaling, is intimately involved in regulating CF closure. In the second study, I examined Bcl6 function and regulation during zebrafish eye development. bcl6 encodes a transcriptional repressor expressed in the ventral retina during zebrafish eye development. Loss of Bcl6 function leads to colobomas along with up-regulation of p53, a previously known Bcl6 target, and an increase in the number of apoptotic cells in the retina, demonstrating that Bcl6 plays a critical role in preventing apoptosis in the retina during early eye development. I also showed that Vax1 and Vax2 act upstream of bcl6 in the ventral retina. Furthermore, I identified functional interactions between Bcl6, Bcor and Hdac1 during eye development, demonstrating that Bcl6 functions along with Bcor and Hdac1 to mediate cell survival by regulating p53 expression. Together my studies expand the gene regulatory network involved in cell fate determination and cell survival during CF closure and ventral retina formation, and provide mechanistic insight into coloboma formation. / text
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Effects of Computer Usage on Ocular HealthMoy, Alexa J 01 January 2014 (has links)
The 2010 National Education Technology Plan steadily replaces paper textbooks with study materials on computers. One risk of increased computer usage is increased Computer Vision Syndrome (CVS) symptoms. I researched multiple studies to analyze the effects of computer use on dry eye and eye strain and how these symptoms can progress to musculoskeletal pain, headaches, decreased quality of life, loss of confidence and even anxiety and depression. Currently, there is not much data on tablet use so I propose two future experiments to determine if tablets can also cause CVS ocular symptoms.
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