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Socratext : busca aproximada de cadeias em imagens usando matrizes de substituição; Socratext : approximate string search in images using substitution matrix

Polastro, Mateus de Castro
Fonte: Universidade de Brasília Publicador: Universidade de Brasília
Tipo: Dissertação
Português
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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2011.; A facilidade de armazenamento e troca de documentos no formato digital, juntamente com a redução dos custos de equipamentos de impressão e digitalização de documentos, vem aumentando a necessidade de utilização na Informática Forense de programas para busca aproximada de palavras-chaves em textos originados por reconhecimento ótico de caracteres (OCR – Optical Character Recognition). Porém, as ferramentas que levam em conta os erros de OCR ainda não são totalmente satisfatórias, principalmente devido aos vários tipos de degradação comumente encontradas em documentos digitalizados. Neste trabalho, um algoritmo para busca de palavras-chaves em textos gerados a partir de OCR, baseado em programação dinâmica e na utilização de matrizes de substituição de aminoácidos, é descrito e implementado. Os resultados mostraram que o algoritmo proposto superou, principalmente em textos contendo maior número de erros, o algoritmo de distância de edição de Levenshtein, utilizado nas principais ferramentas para esse fim. Além disso, um estudo detalhado de como os erros de OCR afetam a recuperação da informação...

A Specific Subset of Transient Receptor Potential Vanilloid-Type Channel Subunits in Caenorhabditis elegans Endocrine Cells Function as Mixed Heteromers to Promote Neurotransmitter Release

Jose, Antony M.; Bany, I. Amy; Chase, Daniel L.; Koelle, Michael R.
Fonte: Copyright © 2007 by the Genetics Society of America Publicador: Copyright © 2007 by the Genetics Society of America
Tipo: Artigo de Revista Científica
Publicado em /01/2007 Português
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Transient receptor potential (TRP) channel subunits form homotetramers that function in sensory transduction. Heteromeric channels also form, but their physiological subunit compositions and functions are largely unknown. We found a dominant-negative mutant of the C. elegans TRPV (vanilloid-type) subunit OCR-2 that apparently incorporates into and inactivates OCR-2 homomers as well as heteromers with the TRPV subunits OCR-1 and -4, resulting in a premature egg-laying defect. This defect is reproduced by knocking out all three OCR genes, but not by any single knockout. Thus a mixture of redundant heteromeric channels prevents premature egg laying. These channels, as well as the G-protein Gαo, function in neuroendocrine cells to promote release of neurotransmitters that block egg laying until eggs filling the uterus deform the neuroendocrine cells. The TRPV channel OSM-9, previously suggested to be an obligate heteromeric partner of OCR-2 in sensory neurons, is expressed in the neuroendocrine cells but has no detectable role in egg laying. Our results identify a specific set of heteromeric TRPV channels that redundantly regulate neuroendocrine function and show that a subunit combination that functions in sensory neurons is also present in neuroendocrine cells but has no detectable function in these cells.

Islet Oxygen Consumption and Insulin Secretion Tightly Coupled to Calcium Derived from L-type Calcium Channels but Not from the Endoplasmic Reticulum*

Gilbert, Merle; Jung, Seung-Ryoung; Reed, Benjamin J.; Sweet, Ian R.
Fonte: American Society for Biochemistry and Molecular Biology Publicador: American Society for Biochemistry and Molecular Biology
Tipo: Artigo de Revista Científica
Publicado em 05/09/2008 Português
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The aim of the study was to test whether the source of intracellular calcium (Ca2+) is a determinant of beta cell function. We hypothesized that elevations in cytosolic Ca2+ caused by the release of Ca2+ from the endoplasmic reticulum (ER) have little physiologic impact on oxygen consumption and insulin secretion. Ca2+ release from the ER was induced in isolated rat islets by acetylcholine and response of oxygen consumption rate (OCR), NAD(P)H, cytosolic Ca2+, and insulin secretory rate (ISR) were measured. Glucose increased all four parameters, and thereafter acetylcholine further increased cytosolic Ca2+, OCR, and ISR. To assess the contribution of Ca2+ release from the ER in mediating the effects of acetylcholine, ER Ca2+ stores were first emptied by inhibiting the sarcoendoplasmic reticulum Ca2+-ATPase, which subsequently reduced the effect of acetylcholine on cytosolic Ca2+ but not its effects on OCR or ISR. As predicted, OCR and ISR were acutely sensitive to changes in L-type Ca2+ channel activity; nimodipine completely inhibited glucose-stimulated ISR and suppressed OCR by 36%, despite only inhibiting cytosolic Ca2+ by 46%. Moreover, in the presence of nimodipine and high glucose, acetylcholine still elevated cytosolic Ca2+ levels above those observed in the presence of high glucose alone but did not significantly stimulate ISR. In conclusion...

Incorporation in Lipid Microparticles of the UVA Filter, Butyl Methoxydibenzoylmethane Combined with the UVB Filter, Octocrylene: Effect on Photostability

Scalia, Santo; Mezzena, Matteo
Fonte: Springer US Publicador: Springer US
Tipo: Artigo de Revista Científica
Publicado em 21/04/2009 Português
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The aim of this study was to reduce the photoinstability of butyl methoxydibenzoylmethane (BMDBM), the most widely used UVA filter, by incorporating it in lipid microparticles (LMs) alone or together with the UVB filter octocrylene (OCR), acting also as photostabilizer. Microparticles loaded with BMDBM or with combined BMDBM and OCR were produced by the hot emulsion technique, using glyceryl behenate as lipid material and poloxamer 188 as surfactant. The LMs were characterized by release studies, scanning electron microscopy, and powder X-ray diffractometry. The BMDBM and OCR loading was 15.2% and 10.6%, respectively. In order to reproduce the conditions prevalent in commercial sunscreen products, the photoprotective efficacy of the LMs was evaluated after their introduction in a model cream (oil-in-water emulsion) containing a mixture of UVA and UVB filters. A small but statistically significant decrease in BMDBM photodegradation was obtained when the UVA filter was encapsulated alone into the LMs (the extent of degradation was 28.6% ±2.4 for non-encapsulated BMDBM and 26.0% ±2.5 for BMDBM-loaded microparticles). On the other hand, the co-loading of OCR in the LMs produced a more marked reduction in the light-induced decomposition of microencapsulated BMDBM (the UVA filter loss was 21.5% ±2.2). Therefore...

A highly energetic process couples calcium influx through L-type calcium channels to insulin secretion in pancreatic β-cells

Jung, Seung-Ryoung; Reed, Benjamin J.; Sweet, Ian R.
Fonte: American Physiological Society Publicador: American Physiological Society
Tipo: Artigo de Revista Científica
Português
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Calcium (Ca2+) influx is required for the sustained secretion of insulin and is accompanied by a large rate of energy usage. We hypothesize that the energy usage reflects a process [Ca2+/metabolic coupling process (CMCP)] that couples Ca2+ to insulin secretion by pancreatic islets. The aim of the study was to test this hypothesis by testing the effect of inhibiting candidate Ca2+-sensitive proteins proposed to play a critical role in the CMCP. The effects of the inhibitors on oxygen consumption rate (OCR), a reflection of ATP usage, and insulin secretion rate (ISR) were compared with those seen when L-type Ca2+ channels were blocked with nimodipine. We reasoned that if a downstream Ca2+-regulated site was responsible for the OCR associated with the CMCP, then its inhibition should mimic the effect of nimodipine. Consistent with previous findings, nimodipine decreased glucose-stimulated OCR by 36% and cytosolic Ca2+ by 46% and completely suppressed ISR in rat pancreatic islets. Inhibitors of three calmodulin-sensitive proteins (myosin light-chain kinase, calcineurin, and Ca2+/calmodulin-dependent protein kinase II) did not meet the criteria. In contrast, KN-62 severed the connection between Ca2+ influx, OCR, and ISR without interfering with Ca2+ influx. In the presence of nimodipine or KN-62...

Human Islet Oxygen Consumption Rate and DNA Measurements Predict Diabetes Reversal in Nude Mice

Papas, K. K.; Colton, C. K.; Nelson, R. A.; Rozak, P. R.; Avgoustiniatos, E. S.; Scott, W. E.; Wildey, G. M.; Pisania, A.; Weir, G. C.; Hering, B. J.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
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There is a need for simple, quantitative and prospective assays for islet quality assessment that are predictive of islet transplantation outcome. The current state-of-the-art athymic nude mouse bioassay is costly, technically challenging and retrospective. In this study, we report on the ability of 2 parameters characterizing human islet quality: (1) oxygen consumption rate (OCR), a measure of viable volume; and (2) OCR/DNA, a measure of fractional viability, to predict diabetes reversal in nude mice. Results demonstrate that the probability for diabetes reversal increases as the graft’s OCR/DNA and total OCR increase. For a given transplanted OCR dose, diabetes reversal is strongly dependent on OCR/DNA. The OCR and OCR/DNA (the ‘OCR test’) data exhibit 89% sensitivity and 77% specificity in predicting diabetes reversal in nude mice (n = 86). We conclude that the prospective OCR test can effectively replace the retrospective athymic nude mouse bioassay in assessing human islet quality prior to islet transplantation.

Short-term Calorie Restriction Reverses Vascular Endothelial Dysfunction in Old Mice by Increasing Nitric Oxide and Reducing Oxidative Stress

Rippe, Catarina; Lesniewski, Lisa; Connell, Melanie; LaRocca, Thomas; Donato, Anthony; Seals, Douglas
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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To determine if short-term calorie restriction reverses vascular endothelial dysfunction in old mice, old (O, n=30) and young (Y, n=10) male B6D2F1 mice were fed ad libitum (AL) or calorie restricted (CR, ∼30%) for 8 weeks. Ex vivo carotid artery endothelium-dependent dilation (EDD) was impaired in OAL vs. YAL (74±5 vs. 95±2% of maximum dilation, P<0.05), whereas OCR and YCR did not differ (96±1 vs. 94±3%). Impaired EDD in OAL was mediated by reduced nitric oxide (NO) bioavailability associated with decreased endothelial NO synthase expression (aorta) (P<0.05), both of which were restored in OCR. Nitrotyrosine, a cellular marker of oxidant modification, was markedly elevated in OAL (P<0.05), whereas OCR was similar to Y. Aortic superoxide production was 150% greater in OAL vs. YAL (P<0.05), but normalized in OCR, and TEMPOL, a superoxide dismutase (SOD) mimetic that restored EDD in OAL (to 97±2%), had no effect in Y or OCR. OAL had increased expression and activity of the oxidant enzyme, NADPH oxidase, and its inhibition (apocynin) improved EDD, whereas NADPH oxidase in OCR was similar to Y. Manganese SOD activity and sirtuin1 expression were reduced in OAL (P<0.05), but restored to Y in OCR. Inflammatory cytokines were greater in OAL vs. YAL (P<0.05)...

Aging per se Increases the Susceptibility to Free Fatty Acid–Induced Insulin Resistance

Einstein, Francine H.; Huffman, Derek M.; Fishman, Sigal; Jerschow, Elina; Heo, Hye J.; Atzmon, Gil; Schechter, Clyde; Barzilai, Nir; Muzumdar, Radhika H.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
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Elevations in systemic free fatty acids (FFA) contribute to insulin resistance. To determine the effects of an acute elevation in FFA on insulin action with aging, we infused saline or intralipid (IL) during a hyperinsulinemic–euglycemic clamp in three groups of rats: young ad libitum–fed (YAL), old ad libitum–fed (OAL), and old on lifelong calorie restriction (OCR). The OCR group was included to distinguish between aging per se and age-related changes in body fat distribution. IL induced marked insulin resistance in both YAL and OCR, but the onset of insulin resistance was approximately two to three times more rapid in OCR as compared with YAL. In response to IL infusion, plasminogen-activating inhibitor-1 (PAI-1) expression was increased in subcutaneous fat from OAL animals. In visceral fat, a marked increase in PAI-1 and interleukin-6 expression was observed in OAL and OCR rats, but not YAL, in response to IL treatment. Thus, aging per se increases the inflammatory response to excess nutrients and vulnerability to FFA-induced insulin resistance with aging.

Bioenergetic characterization of mouse podocytes

Abe, Yoshifusa; Sakairi, Toru; Kajiyama, Hiroshi; Shrivastav, Shashi; Beeson, Craig; Kopp, Jeffrey B.
Fonte: American Physiological Society Publicador: American Physiological Society
Tipo: Artigo de Revista Científica
Português
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Mitochondrial dysfunction contributes to podocyte injury, but normal podocyte bioenergetics have not been characterized. We measured oxygen consumption rates (OCR) and extracellular acidification rates (ECAR), using a transformed mouse podocyte cell line and the Seahorse Bioscience XF24 Extracellular Flux Analyzer. Basal OCR and ECAR were 55.2 ± 9.9 pmol/min and 3.1 ± 1.9 milli-pH units/min, respectively. The complex V inhibitor oligomycin reduced OCR to ∼45% of baseline rates, indicating that ∼55% of cellular oxygen consumption was coupled to ATP synthesis. Rotenone, a complex I inhibitor, reduced OCR to ∼25% of the baseline rates, suggesting that mitochondrial respiration accounted for ∼75% of the total cellular respiration. Thus ∼75% of mitochondrial respiration was coupled to ATP synthesis and ∼25% was accounted for by proton leak. Carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP), which uncouples electron transport from ATP generation, increased OCR and ECAR to ∼360% and 840% of control levels. FCCP plus rotenone reduced ATP content by 60%, the glycolysis inhibitor 2-deoxyglucose reduced ATP by 35%, and 2-deoxyglucose in combination with FCCP or rotenone reduced ATP by >85%. The lactate dehydrogenase inhibitor oxamate and 2-deoxyglucose did not reduce ECAR...

Sexual Dysfunction before and after Cardiac Rehabilitation

Schumann, Jörg; Zellweger, Michael J.; Di Valentino, Marcello; Piazzalonga, Simone; Hoffmann, Andreas
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Português
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Background. The aim of this study was to assess sexual function before and after cardiac rehabilitation in relation to medical variables. Methods. Analysis of patients participating in a 12-week exercise-based outpatient cardiac rehabilitation program (OCR) between April 1999 and December 2007. Exercise capacity (ExC) and quality of life including sexual function were assessed before and after OCR. Results. Complete data were available in 896 male patients. No sexual activity at all was indicated by 23.1% at baseline and 21.8% after OCR, no problems with sexual activity by 40.8% at baseline and 38.6% after OCR. Patients showed an increase in specific problems (erectile dysfunction and lack of orgasm) from 18% to 23% (P < .0001) during OCR. We found the following independent positive and negative predictors of sexual problems after OCR: hyperlipidemia, age, CABG, baseline ExC and improvement of ExC, subjective physical and mental capacity, and sense of affiliation. Conclusions. Sexual dysfunction is present in over half of the patients undergoing OCR with no overall improvement during OCR. Age, CABG, low exercise capacity are independent predictors of sexual dysfunction after OCR.

Association between Participation in Outpatient Cardiac Rehabilitation and Self-Reported Receipt of Lifestyle Advice from a Healthcare Provider: Results of a Population-Based Cross-Sectional Survey

Johnson, Natalie A.; Inder, Kerry J.; Ewald, Ben D.; James, Erica L.; Bowe, Steven J.
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Português
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We test the hypothesis that the odds of self-reported receipt of lifestyle advice from a health care provider will be lower among outpatient cardiac rehabilitation (OCR) nonattendees and nonreferred patients compared to OCR attendees. Logistic regression was used to analyse cross-sectional data provided by 65% (4971/7678) of patients aged 20 to 84 years discharged from public hospitals with a diagnosis indicating eligibility for OCR between 2002 and 2007. Among respondents, 71% (3518) and 55% (2724) recalled advice regarding physical activity and diet, respectively, while 88% (592/674) of smokers recalled quit advice. OCR attendance was low: 36% (1764) of respondents reported attending OCR, 11% (552) did not attend following referral, and 45% (2217) did not recall being invited. The odds of recalling advice regarding physical activity and diet were significantly lower among OCR nonattendees compared to attendees (OR 0.34, 95% CI 0.21, 0.56 and OR 0.33, 95% CI 0.25, 0.44, resp.) and among nonreferred respondents compared to OCR attendees (OR 0.10, 95% CI 0.07, 0.15 and OR 0.17, 95% CI 0.14, 0.22, resp.). Patients hospitalised for coronary heart disease should be referred to OCR or a suitable alternative to improve recall of lifestyle advice that will reduce the risk of further coronary events.

Prediction of Marginal Mass Required for Successful Islet Transplantation

Papas, Klearchos K.; Colton, Clark K.; Qipo, Andi; Wu, Haiyan; Nelson, Rebecca A.; Hering, Bernhard J.; Weir, Gordon C.; Koulmanda, Maria
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/2010 Português
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Islet quality assessment methods for predicting diabetes reversal (DR) following transplantation are needed. We investigated two islet parameters, oxygen consumption rate (OCR) and OCR per DNA content, to predict transplantation outcome and explored the impact of islet quality on marginal islet mass for DR. Outcomes in immunosuppressed diabetic mice were evaluated by transplanting mixtures of healthy and purposely damaged rat islets for systematic variation of OCR/DNA over a wide range. The probability of DR increased with increasing transplanted OCR and OCR/DNA. On coordinates of OCR versus OCR/DNA, data fell into regions in which DR occurred in all, some, or none of the animals with a sharp threshold of around 150-nmol/min mg DNA. A model incorporating both parameters predicted transplantation outcome with sensitivity and specificity of 93% and 94%, respectively. Marginal mass was not constant, depended on OCR/DNA, and increased from 2,800 to over 100,000 islet equivalents/kg body weight as OCR/DNA decreased. We conclude that measurements of OCR and OCR/DNA are useful for predicting transplantation outcome in this model system, and OCR/DNA can be used to estimate the marginal mass required for reversing diabetes. Because human clinical islet preparations in a previous study had OCR/DNA values in the range of 100–150-nmol/min mg DNA...

TGF-β1 stimulates mitochondrial oxidative phosphorylation and generation of reactive oxygen species in cultured mouse podocytes, mediated in part by the mTOR pathway

Abe, Yoshifusa; Sakairi, Toru; Beeson, Craig; Kopp, Jeffrey B.
Fonte: American Physiological Society Publicador: American Physiological Society
Tipo: Artigo de Revista Científica
Português
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Transforming growth factor (TGF)-β has been associated with podocyte injury; we have examined its effect on podocyte bioenergetics. We studied transformed mouse podocytes, exposed to TGF-β1, using a label-free assay system, Seahorse XF24, which measures oxygen consumption rates (OCR) and extracellular acidification rates (ECAR). Both basal OCR and ATP generation-coupled OCR were significantly higher in podocytes exposed to 0.3–10 ng/ml of TGF-β1 for 24, 48, and 72 h. TGF-β1 (3 ng/ml) increased oxidative capacity 75%, and 96% relative to control after 48 and 72 h, respectively. ATP content was increased 19% and 30% relative to control after a 48- and 72-h exposure, respectively. Under conditions of maximal mitochondrial function, TGF-β1 increased palmitate-driven OCR by 49%. Thus, TGF-β1 increases mitochondrial oxygen consumption and ATP generation in the presence of diverse energy substrates. TGF-β1 did not increase cell number or mitochondrial DNA copy number but did increase mitochondrial membrane potential (MMP), which could explain the OCR increase. Reactive oxygen species (ROS) increased by 32% after TGF-β1 exposure for 48 h. TGF-β activated the mammalian target of rapamycin (mTOR) pathway, and rapamycin reduced the TGF-β1-stimulated increases in OCR...

Transient oxygen consumption rate measurements with the BDT̳M̳ oxygen biosensor system

Low, Clarke Alan
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 111 p.
Português
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Oxygen consumption rate (OCR) is a reliable indicator of tissue health. Recently, the OCR of isolated human islets has been shown to predict transplant outcome in diabetic mice. The Oxygen Biosensor System (OBS) is a high-throughput, convenient assay that indirectly measures oxygen consumption by measuring oxygen partial pressure, pO2, adjacent to tissue loaded into the OBS multiwell plate. Solving the general species transport equations for a steady-state solution has not accurately converted pO₂ measurements to OCR. Furthermore, the time to reach steady-state is prohibitively long (at least 5 hr). Transient OBS experiments have been conducted and the rate of p02 change has been shown to correlate with the amount of viable tissue, however, no direct relation with OCR has been established. The overall objective of this thesis was to accurately measure OCR using transient OBS measurements. I fabricated flat OBS plates to simplify the geometry for theoretical models, but theoretical simulations did not match well with experimental data. Furthermore, fabricated flat OBS plates did not behave experimentally as would be expected from I-D, slab geometry. Simplified theoretical models were developed to qualitatively understand the effects of silicone rubber thickness...

Rapid Method for Assessing Oxygen Consumption Rate of Cells from Transient-state Measurements of Pericellular Dissolved Oxygen Concentration

Dike, Laura E.; Xia, Haiyan; Guarino, Richard D.; Presnell, Sharon C.; Timmins, Mark R.
Fonte: Kluwer Academic Publishers Publicador: Kluwer Academic Publishers
Tipo: Artigo de Revista Científica
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Recently we described a method for estimating the oxygen consumption rate (OCR) of cells in static culture from equilibrium measurements of dissolved oxygen concentration (dO2), using an oxygen-sensing microplate and the steady-state solution to Fick's Law (Guarino et al. 2004). Here we describe a complementary method for estimating OCR from the transient-state rate of change of measured dO2. Although the system is open to the atmosphere and subject to a significant lag in sensor response, the rate of change of the measured dO2 immediately after seeding correlated directly with both cell number and steady-state OCR. This transient-state method is linear with cell number to a much higher density than is possible with the steady-state method because it derives from measurements made before diffusion limitations can be established. For a given sensor thickness, the same correlation line between the transient and non-diffusion-limited steady-state estimates of OCR was found to apply for various preparations of rat hepatocytes. The correlation slope varied predictably with sensor thickness. Thus, despite the non-idealities of this system, the initial rate measurement offers a rapid method to obtain an estimate of absolute OCR. To demonstrate the utility of this method...

Telugu OCR Framework using Deep Learning

Achanta, Rakesh; Hastie, Trevor
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 19/09/2015 Português
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In this paper, we address the task of Optical Character Recognition(OCR) for the Telugu script. We present an end-to-end framework that segments the text image, classifies the characters and extracts lines using a language model. The segmentation is based on mathematical morphology. The classification module, which is the most challenging task of the three, is a deep convolutional neural network. The language is modelled as a third degree markov chain at the glyph level. Telugu script is a complex abugida and the language is agglutinative, making the problem hard. In this paper we apply the latest advances in neural networks to achieve acceptable error rates.

Development of a multi-user handwriting recognition system using Tesseract open source OCR engine

Rakshit, Sandip; Basu, Subhadip
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 30/03/2010 Português
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The objective of the paper is to recognize handwritten samples of lower case Roman script using Tesseract open source Optical Character Recognition (OCR) engine under Apache License 2.0. Handwritten data samples containing isolated and free-flow text were collected from different users. Tesseract is trained with user-specific data samples of both the categories of document pages to generate separate user-models representing a unique language-set. Each such language-set recognizes isolated and free-flow handwritten test samples collected from the designated user. On a three user model, the system is trained with 1844, 1535 and 1113 isolated handwritten character samples collected from three different users and the performance is tested on 1133, 1186 and 1204 character samples, collected form the test sets of the three users respectively. The user specific character level accuracies were obtained as 87.92%, 81.53% and 65.71% respectively. The overall character-level accuracy of the system is observed as 78.39%. The system fails to segment 10.96% characters and erroneously classifies 10.65% characters on the overall dataset.; Comment: Proc. International Conference on C3IT (2009) 240-247

Recognition of Handwritten Roman Script Using Tesseract Open source OCR Engine

Rakshit, Sandip; Basu, Subhadip
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 30/03/2010 Português
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In the present work, we have used Tesseract 2.01 open source Optical Character Recognition (OCR) Engine under Apache License 2.0 for recognition of handwriting samples of lower case Roman script. Handwritten isolated and free-flow text samples were collected from multiple users. Tesseract is trained to recognize user-specific handwriting samples of both the categories of document pages. On a single user model, the system is trained with 1844 isolated handwritten characters and the performance is tested on 1133 characters, taken form the test set. The overall character-level accuracy of the system is observed as 83.5%. The system fails to segment 5.56% characters and erroneously classifies 10.94% characters.; Comment: Proc. National Conference on NAQC (2008) 141-145

Recognition of handwritten Roman Numerals using Tesseract open source OCR engine

Rakshit, Sandip; Kundu, Amitava; Maity, Mrinmoy; Mandal, Subhajit; Sarkar, Satwika; Basu, Subhadip
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 30/03/2010 Português
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The objective of the paper is to recognize handwritten samples of Roman numerals using Tesseract open source Optical Character Recognition (OCR) engine. Tesseract is trained with data samples of different persons to generate one user-independent language model, representing the handwritten Roman digit-set. The system is trained with 1226 digit samples collected form the different users. The performance is tested on two different datasets, one consisting of samples collected from the known users (those who prepared the training data samples) and the other consisting of handwritten data samples of unknown users. The overall recognition accuracy is obtained as 92.1% and 86.59% on these test datasets respectively.; Comment: Proc. Int. Conf. on Advances in Computer Vision and Information Technology (2009) 572-577

Discrimination of English to other Indian languages (Kannada and Hindi) for OCR system

Kumar, Ankit; Patnaik, Tushar; Verma, Vivek Kr
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 10/05/2012 Português
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India is a multilingual multi-script country. In every state of India there are two languages one is state local language and the other is English. For example in Andhra Pradesh, a state in India, the document may contain text words in English and Telugu script. For Optical Character Recognition (OCR) of such a bilingual document, it is necessary to identify the script before feeding the text words to the OCRs of individual scripts. In this paper, we are introducing a simple and efficient technique of script identification for Kannada, English and Hindi text words of a printed document. The proposed approach is based on the horizontal and vertical projection profile for the discrimination of the three scripts. The feature extraction is done based on the horizontal projection profile of each text words. We analysed 700 different words of Kannada, English and Hindi in order to extract the discrimination features and for the development of knowledge base. We use the horizontal projection profile of each text word and based on the horizontal projection profile we extract the appropriate features. The proposed system is tested on 100 different document images containing more than 1000 text words of each script and a classification rate of 98.25%...