Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains ix, 64 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 61-64).

Thesis (M.S.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains viii, 58 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 42-44).

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains ix, 92 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 89-92).

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains viii, 95 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 92-95).

M.Ing. (Electrical And Electronic Engineering) / Iris recognition systems have attracted much attention for their uniqueness, stability and reliability. This recognition system is composed of four main modules, namely, iris acquisition, iris segmentation, feature extraction and encoding and - nally iris matching. However, performance of this system is a ected by poor image quality. In this research, a novel iris image quality assessment method based on character component is presented. This method is composed of two steps, individual assessment of character quality parameters and fusion of estimated quality parameters using Principal Component Analysis (PCA). The de ned quality parameters considered in this research are entropy, sharpness, occlusion, dilation, area ratio, contrast and blur. The designed technique was tested on three databases: Chinese Academy of Science Institute of Automation (CASIA), University of Beira Interior (UBIRIS) and Internal Collection (IC). Individual assessment of quality parameters has shown that dilation, sharpness and blur have more in uence on the quality score than the other parameters. The images were classi ed into two categories (good and bad) by human visual inspection. The e ect of the individual parameters on each database is illustrated, with CASIA exhibiting higher quality scores than the UBIRIS and IC databases. Support Vector Machine (SVM) and Linear Discriminant Analysis (LDA) were used to evaluate the performance of the proposed quality assessment algorithm. A k-fold cross validation technique was employed to the classi ers to obtain unbiased results. Two performance measures were used to rate the proposed algorithm, namely, Correct Rate (CR) and Area Under the Curve (AUC). Both performance measures showed that SVM classi er outperforms LDA in correctly classifying the quality of the images in all three databases. The experimental results demonstrated that the proposed algorithm is capable of detecting poor quality images as it yields an e ciency of over 84% and 90% in CR and AUC respectively. The use of character component to assess quality has been found to be su cient, though there is a need to develop a better technique for standardization of quality. The results found using a SVM classi er a rms the proposed algorithm is well-suited for quality assessment.

No description available.

In recent years, computing power and biometric sensors have not only become more powerful, but also more affordable to the general public. In turn, there has been great interest in developing and deploying biometric personal ID systems. Unlike the conventional security systems that often require people to provide artificial identification for verification, i.e. password or algorithmic generated keys, biometric security systems use an individual's biometric measurements, including fingerprint, face, hand geometry, and iris. It is believed that these measurements are unique to the individual, making them much more reliable and less likely to be stolen, lost, forgotten, or forged. Among these biometric measurements, the iris is regarded as one of the most reliable and accurate security approaches because it is an internal organ protected by the body's own biological mechanisms. It is easy to access, and almost impossible to modify without the risk of damaging the iris. Although there have been significant advancements in developing iris-based identification processes during recent years, there remains significant room for improvement. This dissertation presents a novel approach to the iris localization and code matching. It uses a fixed diameter method and a parabolic curve fitting approach for locating the iris and eyelids as well as a k-d tree for iris matching. The iris recognition rate is improved by accurately locating the eyelids and eliminating the signal noise in an eye image. Furthermore, the overall system performance is increased significantly by using a partial iris image and taking the advantage of the k-d binary tree. We present the research results of four processing stages of iris recognition: localization, normalization, feature extraction, and code matching. The localization process is based on histogram analysis, morphological process, Canny edge detection, and parabolic curve fitting. The normalization process adopts Daugman's rubber-sheet approach and converts the iris image from Cartesian coordinators to polar coordinates. In the feature extraction process, the feature vectors are created and quantized using 1-D Log-Gabor wavelet. Finally, the iris code matching process is conducted using a k-dimensional binary tree and Hamming distance.

Made available in DSpace on 2014-06-11T19:22:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2002Bitstream added on 2014-06-13T19:47:17Z : No. of bitstreams: 1 pinto_ft_me_botfm.pdf: 958150 bytes, checksum: 843d0330e855d190281854ed5ea3461d (MD5) / O objetivo do presente estudo foi avaliar a presença de alterações morfológicas nos vasos irianos de ratos normais e diabéticos aloxânicos. Material e Método: Foram utilizados 16 ratos da raça Wistar, divididos em 2 grupos experimentais: grupo controle (GC) e grupo diabético (GD). A indução do diabete foi feita por injeção endovenosa de Aloxana. Os animais foram acompanhados com avaliação clínica e exames laboratoriais durante todo o período experimental, tendo sido sacrificados em 2 momentos: M1(1 mês) e M2 (12 meses) após o início do seguimento. Estudou-se os vasos irianos sob microscopia óptica e eletrônica de transmissão. Resultados: A avaliação morfológica do GC mostrou que os ratos apresentaram espessamento da membrana basal nas células endoteliais e pericitos assim como aumento dos corpos densos principalmente no M2. Os animais do GD apresentaram alterações nas células endoteliais, pericitos , células musculares e fibroblastos perivasculares . Os pericitos, assim como as células musculares, estiveram mais alteradas que as células endoteliais. Todas as alterações foram mais freqüentes no M2, sendo mais importantes nos animais do GD. Conclusões: Os vasos da íris de ratos apresentam alterações decorrentes da senilidade. Alterações semelhantes ocorrem nos ratos diabéticos, que as apresentam com maior intensidade, principalmente quando a descompensação metabólica ocorre por tempo prolongado. Descritores: diabetes experimental, rato, íris, vasos, microscopia eletrônica de transmissão. / The objective of this study was to assess the presence of morphological changes in iris vessels of both normal and diabetic alloxanic rats. Material and Method: 16 Wistar rats have been used, divided into 2 experimental groups: Control Group (GC) and Diabetic Group (GD). The diabetes induction was made by Alloxan intravenous injection. The animals had been observed by clinical assessments and laboratory tests throughout the experimental period, having been slaughtered at 2 experimental moments: M1 – the animals were slaughtered one month after the experiment beginning, and M2 – the animals were slaughtered 12 months after the experiment beginning. At both moments, the iris vessels had been studied under both optical and electronical transmission microscopes. Results: The morphological assessment of the GC animals showed that, at M2, the rats presented dense bodies increasing and basal membrane thickening in endothelial cells, pericytes and muscles cells. GD animals presented changes in endothelial cells, pericytes and muscles cells beyond basal membrane thickening. Pericytes, as well as muscles cells, had more changes than endothelial cells. All changes were more frequent at M2, being more important in GD animals. Conclusions: The iris vessels of rats present changes relating to senility. Similar changes occur to diabetic rats, within wider intensity, mainly when metabolic disorder continues for a longer time. Describers: experimental diabetes, rat, iris, vessels, electronical transmission microscopy.

Orientador: Silvana Artioli Schellini / Resumo: O objetivo do presente estudo foi avaliar a presença de alterações morfológicas nos vasos irianos de ratos normais e diabéticos aloxânicos. Material e Método: Foram utilizados 16 ratos da raça Wistar, divididos em 2 grupos experimentais: grupo controle (GC) e grupo diabético (GD). A indução do diabete foi feita por injeção endovenosa de Aloxana. Os animais foram acompanhados com avaliação clínica e exames laboratoriais durante todo o período experimental, tendo sido sacrificados em 2 momentos: M1(1 mês) e M2 (12 meses) após o início do seguimento. Estudou-se os vasos irianos sob microscopia óptica e eletrônica de transmissão. Resultados: A avaliação morfológica do GC mostrou que os ratos apresentaram espessamento da membrana basal nas células endoteliais e pericitos assim como aumento dos corpos densos principalmente no M2. Os animais do GD apresentaram alterações nas células endoteliais, pericitos , células musculares e fibroblastos perivasculares . Os pericitos, assim como as células musculares, estiveram mais alteradas que as células endoteliais. Todas as alterações foram mais freqüentes no M2, sendo mais importantes nos animais do GD. Conclusões: Os vasos da íris de ratos apresentam alterações decorrentes da senilidade. Alterações semelhantes ocorrem nos ratos diabéticos, que as apresentam com maior intensidade, principalmente quando a descompensação metabólica ocorre por tempo prolongado. Descritores: diabetes experimental, rato, íris, vasos, microscopia eletrônica de transmissão. / Abstract: The objective of this study was to assess the presence of morphological changes in iris vessels of both normal and diabetic alloxanic rats. Material and Method: 16 Wistar rats have been used, divided into 2 experimental groups: Control Group (GC) and Diabetic Group (GD). The diabetes induction was made by Alloxan intravenous injection. The animals had been observed by clinical assessments and laboratory tests throughout the experimental period, having been slaughtered at 2 experimental moments: M1 - the animals were slaughtered one month after the experiment beginning, and M2 - the animals were slaughtered 12 months after the experiment beginning. At both moments, the iris vessels had been studied under both optical and electronical transmission microscopes. Results: The morphological assessment of the GC animals showed that, at M2, the rats presented dense bodies increasing and basal membrane thickening in endothelial cells, pericytes and muscles cells. GD animals presented changes in endothelial cells, pericytes and muscles cells beyond basal membrane thickening. Pericytes, as well as muscles cells, had more changes than endothelial cells. All changes were more frequent at M2, being more important in GD animals. Conclusions: The iris vessels of rats present changes relating to senility. Similar changes occur to diabetic rats, within wider intensity, mainly when metabolic disorder continues for a longer time. Describers: experimental diabetes, rat, iris, vessels, electronical transmission microscopy. / Mestre

Made available in DSpace on 2014-06-11T19:30:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-02-27Bitstream added on 2014-06-13T19:00:26Z : No. of bitstreams: 1 almeida_cam_dr_botfm.pdf: 7230437 bytes, checksum: 147348523712c50c6dd9a2ac3c8f3cb5 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo do estudo foi avaliar a influência do diabetes sobre os vasos da íris, corpo ciliar e retina. Para isto, foi realizado estudo experimental, utilizando 20 ratos da raça Wistar, divididos em dois grupos: Grupo Controle (GC) e Grupo Diabético (GD). A indução do diabetes foi feita por injeção de aloxana, 42 mg/Kg de peso. Os animais foram observados em 3 momentos experimentais: M1-15 dias após a indução do diabetes, M2 -1 mês após M1 e M3 -12 meses após M1. Foram considerados para o estudo os animais do GD que em M1 apresentavam diabetes grave. Realizou-se acompanhamento diário de parâmetros clínicos (peso, diurese, ingestão hídrica e ingestão alimentar) e avaliação mensal de glicemia e glicose urinária. Nos momentos experimentais M2 e M3 foram realizadas enucleação e preparo dos olhos para avaliação sob microscopia eletrônica de transmissão. Os resultados obtidos mostraram que os animais diabéticos tiveram importante redução de peso, aumento de ingestão hídrica, aumento de ingestão alimentar e aumento de diurese, em relação aos animais controle. Na avaliação morfológica os três grupos de vasos tiveram alterações similares, com espessamento da membrana basal nas células endoteliais e pericitos, maior número de corpos densos, lisossomos, vesículas, vacúolos e figuras de mielina, que estavam presentes em GCM2 e foram mais acentuadas nos grupos diabéticos. Não foram observados microaneurismas na parede vascular. A análise morfométrica mostrou aumento significativo na espessura da membrana basal de vasos irianos nos animais diabéticos. Concluí-se que os vasos da íris, corpo ciliar e retina sofrem a influência do estado diabético. As alterações são progressivas, afetando tanto as células endoteliais, como as pericíticas. / The purpose of this study was to evaluate the influence of diabetes on vessels of iris, ciliary’s body and retina. For this, prospective experiment was accomplished, using 20 Wistar rats, divided in two groups: Control Group (CG) and Diabetic Group (DG). The diabetes induction was made by aloxana injection, 42 mg/Kg of weight. The animals had been observed at 3 experimental moments: M1-15 days after the diabetes induction, M2 - 1 month M1 and M3 -12 months after M1. They were considered for the study the animals of the DG that presented serious diabetes in M1. Clinical parameters had daily been followed (weight, diuresis, water ingestion and alimentary ingestion) and monthly evaluation of glycemia and urinary glucose. At the experimental moments M2 and M3 it was realized enucleation and preparation of the eyes for optic microscopy and electronic transmission microscopy evaluation. The gotten results had shown that the diabetic animals had had important weight reduction, water ingestion increase, alimentary ingestion increase and diuresis increase, compared to the animals of the CG. In the morphologic evaluation it has been observed that the three groups of vessels have had similar alterations, with thickening of the basal membrane in the endothelial cells and pericytes, greater number of dense bodies, lysosomes, vesicles, vacuoles and myelin figures” that they were in GCM2 and had been accentuated in diabetic groups. Microaneurysms in the vascular wall had not been observed. The morphometric analysis showed significant increase in the thickness of the basal membrane of iris vessels in diabetic animals. We conclude that iris, ciliary’s body and retina vessels suffer the influence from the diabetic state. The alterations are gradual, affecting in such a way the endothelial cells, as the pericytes.