FABIO JOSE AYRES
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Artigo Científico Detection of the Optic Nerve Head in Fundus Images of the Retina with Gabor Filters and Phase Portrait Analysis(2010) Rangayyan, Rangaraj M.; Zhu, Xiaolu; FABIO JOSE AYRES; Ells, Anna L.We propose a method using Gabor filters and phase portraits to automatically locate the optic nerve head (ONH) in fundus images of the retina. Because the center of the ONH is at or near the focal point of convergence of the retinal vessels, the method includes detection of the vessels using Gabor filters, detection of peaks in the node map obtained via phase portrait analysis, and an intensity-based condition. The method was tested on 40 images from the Digital Retinal Images for Vessel Extraction (DRIVE) database and 81 images from the Structured Analysis of the Retina (STARE) database. An ophthalmologist independently marked the center of the ONH for evaluation of the results. The evaluation of the results includes free-response receiver operating characteristics (FROC) and a measure of distance between the manually marked and detected centers. With the DRIVE database, the centers of the ONH were detected with an average distance of 0.36 mm (18 pixels) to the corresponding centers marked by the ophthalmologist. FROC analysis indicated a sensitivity of 100% at 2.7 false positives per image. With the STARE database, FROC analysis indicated a sensitivity of 88.9% at 4.6 false positives per image.Relatório de pesquisa A judicialização de benefícios previdenciários e assistenciais(2020) NATALIA PIRES DE VASCONCELOS; Arguelles, Diego Werneck; Lima, Rafael Scavone Bellem de; FABIO JOSE AYRES; HEDIBERT FREITAS LOPES; Carlotti, Danilo; Wang, Henrique Yu Jiunn; Funari, Helena; PAULO FURQUIM DE AZEVEDO; Queirós, Danielly; Colares, Elisa; Stemler, Igor; Mota, Isabely; Monteiro, Alexander; Bittencourt, Cristianna; Amorim, Pedro; Marques, Ricardo; Rosa, Thatiane; Ferreira, Carlos Vinicius Ribeiro; Pereira, Filipe; Borges, Davi; Amorim, Pedro; Barbão, Jaqueline; VANESSA BOARATIDecisões administrativas na área de previdência social são objeto frequente de demandas judiciais. A magnitude dessa judicialização é grande o suficiente para afetar não só a política previdenciária, mas o funcionamento do próprio Judiciário, visto que se trata de um dos tipos de demanda que mais congestiona as cortes brasileiras. Esta pesquisa se dedica a esse tema, tendo como principal objetivo o de (i) investigar as causas da revisão judicial de decisões administrativas do Instituto Nacional do Seguro Social (INSS) referentes à concessão ou revisão de benefícios previdenciários ou assistenciais, bem como (ii) apontar propostas de políticas para mitigar os custos associados ao elevado nível de litigância nessa área. Sendo um fenômeno de representatividade nacional, esta pesquisa também investiga as heterogeneidades regionais e os diferentes padrões de concessão administrativa e judicial de benefícios previdenciários e assistenciais.Artigo Científico Well-Connected Communities in Real-World and Synthetic Networks(2023) Park, Minhyuk; Tabatabaee, Yasamin; Ramavarapu, Vikram; Liu, Baqiao; Pailodi, Vidya Kamath; Ramachandran, Rajiv; Korobskiy, Dmitriy; FABIO JOSE AYRES; Chacko, George; Warnow, TandyIntegral to the problem of detecting communities through graph clustering is the expectation that they are "well connected". In this respect, we examine five different community detection approaches optimizing different criteria: the Leiden algorithm optimizing the Constant Potts Model, the Leiden algorithm optimizing modularity, Iterative K-Core Clustering (IKC), Infomap, and Markov Clustering (MCL). Surprisingly, all these methods produce, to varying extents, communities that fail even a mild requirement for well connectedness. To remediate clusters that are not well connected, we have developed the "Connectivity Modifier" (CM), which, at the cost of coverage, iteratively removes small edge cuts and re-clusters until all communities produced are well connected. Results from real-world and synthetic networks illustrate a tradeoff users make between well connected clusters and coverage, and raise questions about the "clusterability" of networks and models of community structure.Trabalho de Evento Unsupervised Improvement of Audio-Text Cross-Modal Representations(2023) Wang, Zhepei; Subakan, Cem; Subramani, Krishna; Wu, Junkai; TIAGO FERNANDES TAVARES; FABIO JOSE AYRES; Smaragdis, ParisRecent advances in using language models to obtain cross-modal audio-text representations have overcome the limitations of conventional training approaches that use predefined labels. This has allowed the community to make progress in tasks like zero-shot classification, which would otherwise not be possible. However, learning such representations requires a large amount of human-annotated audio-text pairs. In this paper, we study unsupervised approaches to improve the learning framework of such representations with unpaired text and audio. We explore domain-unspecific and domain-specific curation methods to create audio-text pairs that we use to further improve the model. We also show that when domain-specific curation is used in conjunction with a soft-labeled contrastive loss, we are able to obtain significant improvement in terms of zero-shot classification performance on downstream sound event classification or acoustic scene classification tasks.Artigo Científico Effect of Pixel Resolution on Texture Features of Breast Masses in Mammograms(2010) Rangayyan, Rangaraj M.; Nguyen, Thanh M.; FABIO JOSE AYRES; Nandi, Asoke K.The effect of pixel resolution on texture features computed using the gray-level co-occurrence matrix (GLCM) was analyzed in the task of discriminating mammographic breast lesions as benign masses or malignant tumors. Regions in mammograms related to 111 breast masses, including 65 benign masses and 46 malignant tumors, were analyzed at pixel sizes of 50, 100, 200, 400, 600, 800, and 1,000 μm. Classification experiments using each texture feature individually provided accuracy, in terms of the area under the receiver operating characteristics curve (AUC), of up to 0.72. Using the Bayesian classifier and the leave-one-out method, the AUC obtained was in the range 0.73 to 0.75 for the pixel resolutions of 200 to 800 μm, with 14 GLCM-based texture features using adaptive ribbons of pixels around the boundaries of the masses. Texture features computed using the ribbons resulted in higher classification accuracy than the same features computed using the corresponding regions within the mass boundaries. The t test was applied to AUC values obtained using 100 repetitions of random splitting of the texture features from the ribbons of masses into the training and testing sets. The texture features computed with the pixel size of 200 μm provided the highest average AUC with statistically highly significant differences as compared to all of the other pixel sizes tested, except 100 μm.