853 resultados para Faults detection and location


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Although the oral cavity is easily accessible to inspection, patients with oral cancer most often present at a late stage, leading to high morbidity and mortality. Autofluorescence imaging has emerged as a promising technology to aid clinicians in screening for oral neoplasia and as an aid to resection, but current approaches rely on subjective interpretation. We present a new method to objectively delineate neoplastic oral mucosa using autofluorescence imaging. Autofluorescence images were obtained from 56 patients with oral lesions and 11 normal volunteers. From these images, 276 measurements from 159 unique regions of interest (ROI) sites corresponding to normal and confirmed neoplastic areas were identified. Data from ROIs in the first 46 subjects were used to develop a simple classification algorithm based on the ratio of red-to-green fluorescence; performance of this algorithm was then validated using data from the ROIs in the last 21 subjects. This algorithm was applied to patient images to create visual disease probability maps across the field of view. Histologic sections of resected tissue were used to validate the disease probability maps. The best discrimination between neoplastic and nonneoplastic areas was obtained at 405 nm excitation; normal tissue could be discriminated from dysplasia and invasive cancer with a 95.9% sensitivity and 96.2% specificity in the training set, and with a 100% sensitivity and 91.4% specificity in the validation set. Disease probability maps qualitatively agreed with both clinical impression and histology. Autofluorescence imaging coupled with objective image analysis provided a sensitive and noninvasive tool for the detection of oral neoplasia.

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The recovery and stability of DNA for the detection and genotyping of HPV in UCM-containing specimens, after exposure to denaturing reagents and stored for up to 2 years were evaluated. Samples were collected from 60 women who had cervical cytology specimens harboring cervical intraepithelial neoplasia (CIN) 2 or 3. All samples were stored in UCM and had been frozen at -20 degrees C following the addition of the denaturing reagent (sodium hydroxide) and the removal of the aliquot required for Hybrid Capture 2 testing for the identification of HPV DNA. The samples had been stored for 6, 12 and 24 months (20 samples for each storage time). HPV DNA extraction was performed according to a protocol designed specifically and the presence and quality of DNA was confirmed by human P-globin detection using the consensus primers G73 and G74. HPV DNA was amplified using the consensus primers PGMY09 and PGMY11, and reverse line-blot hybridization was used to detect type-specific amplicons for 37 HPV types. The DNA extracted from the denatured specimen was recovered in 57/60 (95%) of the samples. HPV DNA was detected in 56/57 (98%) of the recovered samples. Twenty-six of the 56 samples recovered (48%) were genotyped successfully. (c) 2007 Elsevier B.V. All rights reserved.

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Oxidation of cholesterol (Ch) by a variety of reactive oxygen species gives rise mainly to hydroperoxides and aldehydes. Despite the growing interest in Ch-oxidized products, the detection and characterization of these products is still a matter of concern. In this work, the main Ch-oxidized products, namely, 3 beta-hydroxycholest-5-ene-7 alpha-hydroperoxide (7 alpha-OOH), 3 beta-5 alpha-cholest-6-ene-5-hydroperoxide (5 alpha-OOH), 3 beta-hydroxycholest-4-ene-6 alpha-hydroperoxide (6 alpha-OOH), 3 beta-hydroxycholest-4-ene-6 beta-hydroperoxide (6 beta-OOH), and 3 beta-hydroxy-5 beta-hydroxy-B-norcholestane-6 beta-carboxaldehyde (ChAld), were detected in the same analysis using high-performance liquid chromatography (HPLC) coupled to dopant assisted atmospheric pressure photoionization tandem mass spectrometry. The use of selected reaction monitoring mode (SRM) allowed a sensitive detection of each oxidized product, while the enhanced product ion mode (EPI) helped to improve the confidence of the analyses. Isotopic labeling experiments enabled one to elucidate mechanistic features during fragmentation processes. The characteristic fragmentation pattern of Ch-oxidized products is the consecutive loss of 1120 molecules, yielding cationic fragments at m/z 401, 383, and 365. Homolytic scissions of the peroxide bond are also seen. With (18)O-labeling approach, it was possible to establish a fragmentation order for each isomer. The SRM transitions ratio along with EPI and (18)O-labeled experiments give detailed information about differences for water elimination, allowing a proper discrimination between the isomers:Phis is of special interest considering the emerging role of Ch-oxidized products in the development of diseases.

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The objective of this thesis work, is to propose an algorithm to detect the faces in a digital image with complex background. A lot of work has already been done in the area of face detection, but drawback of some face detection algorithms is the lack of ability to detect faces with closed eyes and open mouth. Thus facial features form an important basis for detection. The current thesis work focuses on detection of faces based on facial objects. The procedure is composed of three different phases: segmentation phase, filtering phase and localization phase. In segmentation phase, the algorithm utilizes color segmentation to isolate human skin color based on its chrominance properties. In filtering phase, Minkowski addition based object removal (Morphological operations) has been used to remove the non-skin regions. In the last phase, Image Processing and Computer Vision methods have been used to find the existence of facial components in the skin regions.This method is effective on detecting a face region with closed eyes, open mouth and a half profile face. The experiment’s results demonstrated that the detection accuracy is around 85.4% and the detection speed is faster when compared to neural network method and other techniques.

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This paper aims to present three new methods for color detection and segmentation of road signs. The images are taken by a digital camera mounted in a car. The RGB images are converted into IHLS color space, and new methods are applied to extract the colors of the road signs under consideration. The methods are tested on hundreds of outdoor images in different light conditions, and they show high robustness. This project is part of the research taking place in Dalarna University / Sweden in the field of the ITS.

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http://digitalcommons.colby.edu/atlasofmaine2005/1018/thumbnail.jpg

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Moose (Alces alces) are a keystone herbivore in Maine. Because of the large number of rural roads in Maine, there is a high rate of moose-vehicle collisions (MVCs), which is increasing. On-road encounters with animals resulted in 231 fatalities in the United States in 1999. Because of the fatality of MVCs, it is important to know where they are most likely to occur. I used GIS analysis to estimate where future MVCs would occur, factoring in the variables of land cover suitability for moose, distance from water bodies, locations of past MVCs, and speed limits on the roads. I ran four different analyses, each one weighting the variables equally. I also ran a regression to determine if increasing road speed was associated with the increase in the number of MVCs per length of road. There was not a strong positive relationship between the number of MVCs per length of road and the speed limit, but it was interesting to note that there were more MVCs per length of road on 35mph and 40mph roads than on 45, 50, 55 or 65mph roads. Future research on MVCs would benefit from the inclusion of include moose population density and road traffic data.

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When an accurate hydraulic network model is available, direct modeling techniques are very straightforward and reliable for on-line leakage detection and localization applied to large class of water distribution networks. In general, this type of techniques based on analytical models can be seen as an application of the well-known fault detection and isolation theory for complex industrial systems. Nonetheless, the assumption of single leak scenarios is usually made considering a certain leak size pattern which may not hold in real applications. Upgrading a leak detection and localization method based on a direct modeling approach to handle multiple-leak scenarios can be, on one hand, quite straightforward but, on the other hand, highly computational demanding for large class of water distribution networks given the huge number of potential water loss hotspots. This paper presents a leakage detection and localization method suitable for multiple-leak scenarios and large class of water distribution networks. This method can be seen as an upgrade of the above mentioned method based on a direct modeling approach in which a global search method based on genetic algorithms has been integrated in order to estimate those network water loss hotspots and the size of the leaks. This is an inverse / direct modeling method which tries to take benefit from both approaches: on one hand, the exploration capability of genetic algorithms to estimate network water loss hotspots and the size of the leaks and on the other hand, the straightforwardness and reliability offered by the availability of an accurate hydraulic model to assess those close network areas around the estimated hotspots. The application of the resulting method in a DMA of the Barcelona water distribution network is provided and discussed. The obtained results show that leakage detection and localization under multiple-leak scenarios may be performed efficiently following an easy procedure.

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LOPES-DOS-SANTOS, V. , CONDE-OCAZIONEZ, S. ; NICOLELIS, M. A. L. , RIBEIRO, S. T. , TORT, A. B. L. . Neuronal assembly detection and cell membership specification by principal component analysis. Plos One, v. 6, p. e20996, 2011.

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A semi-nested reverse transcription-polymerase chain reaction (Semi-N-RT-PCR) was developed and used to detect the S glycoprotein gene of infectious bronchitis virus (IBV) strains and to discriminate H120 vaccine strain from other strains. Viral RNA was extracted from the allantoic fluid of chicken embryos and from tissues of chickens experimentally infected with different strains of IBV. Amplification and identification of the viral RNA was performed using two sets of primers complementary to a region of the S glycoprotein gene in the Semi-N-RT-PCR assay. The pair of primers used in the first PCR consisted of universal oligonucleotides flanking a more variable region of S1-S2 gene. The second primer pair was used in the Semi-N-RT-PCR and was comprised of one of the primers from the first universal pair together with either another universal internal oligolucleotide or a oligonucleotide sequence specific for the H120 strain of IBV. The universal primers detected all reference IBV strains and field isolates tested herein. The Semi-N-RT-PCR had high sensitivity and specificity, and was able to differentiate the H120 vaccine strain from other reference IBV strains; including M41 strain. All tissue samples collected from chickens experimentally infected with H120 or M41 strains were positive in the semi-nested RT-PCR using universal primers, while only the H120-infected tissue samples were amplified by the set of primers containing the H120-oligonucleotide. In conclusion, the ability of Semi-N-RT-PCR to detect distinct IBV strains and preliminarily discriminate the vaccine strain (H120) closes a diagnostic gap and offers the opportunity to use comprehensive PCR procedures for the IBV diagnosis.

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The purpose of this study was to evaluate the effect of the season of the year (summer vs winter), type of truck (A: single decker vs B : double-decker) and pig location on the truck (front, middle, rear) on the incidence of skin bruising and pork quality variation. For this purpose, 2660 gilts of an average weight of 126.7 (+/- 6.6) kg originating from 19 different farms were used. No interaction between season of the year, type of truck and location on truck was observed. A higher number of bruises on the body at unloading and slaughter (P < 0.0001) and a higher number of bruises on the carcass (P < 0.01) were observed in winter. At unloading a higher number of bruises on the body and on the carcass after slaughter was observed in pigs transported on Truck A (P=0.004 and P=0.05). A higher, although not significant, number of bruises was found on the body of pigs transported in the rear compartment of both trucks. Higher paleness value was found in the longissimus and semimembranosus muscles in summer (P=0.0001) than in winter. Cold and heat stress have a negative influence on skin bruises and meat quality, respectively. Poor vehicle design increases the incidence of bruised carcasses without detracting from pork quality regardless of the climate conditions tested and location of the animal it] the truck. (c) 2006 Elsevier B.V. All rights reserved.

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Sintomas do cancro bacteriano da videira na variedade Red Globe foram observados em agosto de 2009 em pomar de Tupi Paulista, Estado de São Paulo, Brasil, e o agente causal Xanthomonas campestris pv. viticola foi identificado por meio de testes patológicos e moleculares. O procedimento de erradicação foi adotado e aproximadamente 4.700 plantas foram destruídas. Um levantamento realizado nas regiões produtoras do Estado de São Paulo não encontrou nenhum outro pomar contaminado, e essa espécie bacteriana é considerada ausente neste estado.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This work presents a study on the generation of digital masks aiming at edge detection with previously known directions. This solution is important when edge direction is available either from a direction histogram or from a prediction based on camera and object models. A modification in the non-maximum suppression method of thinning is also presented enabling the comparison of local maxima for any edge directions. Results with a synthetic image and with crops of a CBERS satellite images are presented showing an example with its application in road detection, provided that directions are previously known.