931 resultados para Transformada wavelet discreta
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Dissertação (mestrado)— Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2015.
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Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2015.
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Tese (Doutorado em Tecnologia Nuclear)
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Dissertação (mestrado)—Universidade de Brasília, Faculdade UnB Gama, Faculdade de Tecnologia, Programa de Pós-graduação em Integridade de Materiais da Engenharia, 2016.
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Among the many types of noise observed in seismic land acquisition there is one produced by surface waves called Ground Roll that is a particular type of Rayleigh wave which characteristics are high amplitude, low frequency and low velocity (generating a cone with high dip). Ground roll contaminates the relevant signals and can mask the relevant information, carried by waves scattered in deeper regions of the geological layers. In this thesis, we will present a method that attenuates the ground roll. The technique consists in to decompose the seismogram in a basis of curvelet functions that are localized in time, in frequency, and also, incorporate an angular orientation. These characteristics allow to construct a curvelet filter that takes in consideration the localization of denoise in scales, times and angles in the seismogram. The method was tested with real data and the results were very good
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En el presente trabajo de fin de máster se realiza una investigación sobre las técnicas de preproceso del dataset de entrenamiento y la aplicación de un modelo de predicción que realice una clasificación de dı́gitos escritos a mano. El conjunto de dataset de train y test son proporcionado en la competencia de Kaggle: Digit Recognizer y provienen de la base de datos de dı́gitos manuscritos MNIST. Por tratarse de imágenes las técnicas de preproceso se concentran en obtener una imagen lo más nı́tida posible y la reducción de tamaño de la misma, objetivos que se logran con técnicas de umbralización por el método de Otsu, transformada de Wavelet de Haar y el análisis de sus componentes principales. Se utiliza Deep Learning como modelo predictivo por ajustarse a este tipo de datos, se emplean además librerı́as de código abierto implementadas en el lenguaje estádisto R. Por último se obtiene una predicción con las técnicas y herramientas mencio- nadas para ser evaluada en la competencia de Kaggle, midiendo y comparando los resultados obtenidos con el resto de participantes.
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Subtle structural differencescan be observed in the islets of Langer-hans region of microscopic image of pancreas cell of the rats having normal glucose tolerance and the rats having pre-diabetic(glucose intolerant)situa-tions. This paper proposes a way to automatically segment the islets of Langer-hans region fromthe histological image of rat's pancreas cell and on the basis of some morphological feature extracted from the segmented region the images are classified as normal and pre-diabetic.The experiment is done on a set of 134 images of which 56 are of normal type and the rests 78 are of pre-diabetictype. The work has two stages: primarily,segmentationof theregion of interest (roi)i.e. islets of Langerhansfrom the pancreatic cell and secondly, the extrac-tion of the morphological featuresfrom the region of interest for classification. Wavelet analysis and connected component analysis method have been used for automatic segmentationof the images. A few classifiers like OneRule, Naïve Bayes, MLP, J48 Tree, SVM etc.are used for evaluation among which MLP performed the best.
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In this work we compare Grapholita molesta Busck (Lepidoptera: Tortricidae) populations originated from Brazil, Chile, Spain, Italy and Greece using power spectral density and phylogenetic analysis to detect any similarities between the population macro- and the molecular micro-level. Log-transformed population data were normalized and AR(p) models were developed to generate for each case population time series of equal lengths. The time-frequency/scale properties of the population data were further analyzed using wavelet analysis to detect any population dynamics frequency changes and cluster the populations. Based on the power spectral of each population time series and the hierarchical clustering schemes, populations originated from Southern America (Brazil and Chile) exhibit similar rhythmic properties and are both closer related with populations originated from Greece. Populations from Spain and especially Italy, have higher distance by terms of periodic changes on their population dynamics. Moreover, the members within the same cluster share similar spectral information, therefore they are supposed to participate in the same temporally regulated population process. On the contrary, the phylogenetic approach revealed a less structured pattern that bears indications of panmixia, as the two clusters contain individuals from both Europe and South America. This preliminary outcome will be further assessed by incorporating more individuals and likely employed a second molecular marker.
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In questa tesi tratteremo una variante della fattorizzazione CUR di una matrice data, ottenuta attraverso l'algoritmo DEIM ("discrete empirical interpolation method") a confronto con un metodo ampiamente usato in letteratura, il metodo dei Leverage Score. A tal fine verrà anche trattato un metodo per ottenere la fattorizzazione QR di una matrice in maniera incrementale. Verrà illustrato il comportamento degli algoritmi sviluppati su due esempi applicativi.
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Introdução: Atualmente, a deficiência de ferro com consequente anemia é considerado um grave problema de saúde pública no Brasil devido sua prevalência e suas implicações direta no desenvolvimento das crianças com baixo rendimento escolar e baixa produtividade quando adultos. Objetivo: Realizar uma intervenção para melhorar a adesão ao uso de sulfato ferroso profilático seguindo recomendações do Ministério da Saúde em uma população abrangente do Centro de Saúde Padre Libério, em Pará de Minas, Minas Gerais. Metodologia: Utilizando-se do método de estimativa rápida através de uma observação ativa, os profissionais do Centro de Saúde Padre Libério (CSPL) do município de Pará de Minas detectaram que poucas crianças estão em uso de sulfato ferroso profilático na idade preconizada pelo Ministério da Saúde. Resultados: Após um diagnóstico situacional quantitativo foram estabelecidos diferentes ações de intervenção para melhorar a adesão ao uso de sulfato ferroso profilático seguindo recomendações do Ministério da Saúde, em que se destacam: atividades teóricas educativas, busca ativa das crianças que não faziam uso do sulfato ferroso seguido de sua prescrição, maior controle das puericulturas. Considerações finais: Considerando a relevância da anemia por deficiência de ferro o uso de sulfato ferroso profilático se torna uma ferramenta fundamental para combatê-lo.
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Purpose: To evaluate the onset time and quality of peribulbar anesthesia with 1% ropivacaine associated or not with hyaluronidase 100 tru/ml for cataract extraction. Methods: Prospective, randomized, double-blind and controlled study including fifty-seven patients, scheduled to undergo peribulbar anesthesia for cataract extraction, allocated to two groups. Group C: 1% ropivacaine with addition of 100 tru/ml hyaluronidase, and Group S 1% ropivacaine, without hyaluronidase. The onset time for globe akinesia was studied at intervals of 2 minutes, using Nicoll's score. We evaluated pain by analogic score during the surgery and the necessity of complementing the anaesthesia. The peribulbar block was considered satisfactory when the Nicoll's score was less than 4. Results: The mean time of onset of block in group C was 4.07 minutes (± 3.24), and in group S 5.03 (± 3.28). There was no statistically significant difference between the groups. Both were similar regarding pain score, no pain was observed in 57.14% of group C, and in 68.97% of group S. The supplementary anesthetic was necessary in 2 cases of group C and in 3 cases of group S. Two cases of bradycardia (heart rate < 50 bpm) were observed during the surgery, and in one case administration of atropine IV was necessary. Conclusion: 1% ropivacaine provided a good quality of anesthesia for cataract extraction, with a faster onset of action in the group with hyaluronidase 100 iu/ml, although without significant difference.
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A case of central nervous system actinomycosis is reported. A 33-year-old male complained of headache, vomiting and blurred vision lasting for eight days prior to admission. On examination, a right hemiparesis, as well an intracranial hypertension were detected. The cerebrospinal fluid showed mild lymphomononuclear hypercytosis. Necropsy disclosed three abscess in the cerebral hemispheres, in addition to moderate cerebral edema on the left side but without purulent leptomeningitis. Actinomyces filaments and granules were demonstrated in the cerebral and lung abscesses. The Brazilian literature on actinomycosis is reviewed and six published cases with nervous system involvement were found. Relevant clinical and anatomical aspects of the cases and of the present one are discussed.
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The cerebral cysticercosis can produce intracranial hypertension by inflammatory obstruction of the basal cysterns or by expansive lesion in the cerebral parenchima or ventricular cavities. In the latter and in tumor cases the clinical picture is very similar and only after surgery can the etiology be determined. We present 11 operated cases of intracranial cysticercosis which presented the clinical picture of an expansive lesion. There were 7 females and 4 males with ages between 4 and 65 years. Nine patients were admitted because of headache, vomiting and visual disturbances suggestive of intracranial hypertension. One patient was admited with lymphocytic meningitis and another with focal seizures following hemiparesis. Five patients presented focal signs and six edema of the papilla. Epileptic manifestations were present in 45.5% of the cases. A plain X-ray films of the skull failed to reveal calcificatons, however signs of chronic hypertension were present in three cases. The electroencephalogram showed slow focal waves in 8 patients The spinal fluid examination revealed lymphocytosis in 4 cases, increased protein content in another 4 and complement fixation for cysticercosis was positive in 2 cases. The expansive lesions were localized by angiograph and ventriculography. In these the location was temporal in 4, frontal in 3, parietal in 2, in the third ventricle in one and in the fourth ventricle in another. At surgery we removed a large cyst from the cerebral parenchyma in six cases. Around the cyst a thick glial reaction was present. In the other cases the cyst was small but fixed to the ventricular trigone and produced dilatation of the inferior horn of the lateral ventricle. In two cases we removed a solitary intraventricular cyst from the third and fourth ventricles. In the two children operated upon there were several small hard cysts involving the cerebral parenchyma which displayed intense gliosis. There were no postoperative complications.
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Universidade Estadual de Campinas. Faculdade de Educação Física
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Universidade Estadual de Campinas . Faculdade de Educação Física