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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

O estudo da acur?cia da resson?ncia magn?tica multiparam?trica no diagn?stico do c?ncer de pr?stata

Moraes, M?rcia Cristina Gon?alves de Oliveira 30 August 2017 (has links)
Submitted by PPG Medicina e Ci?ncias da Sa?de (medicina-pg@pucrs.br) on 2018-07-20T19:52:55Z No. of bitstreams: 1 M?RCIA_CRISTINA_GON?ALVES_DE_OLIVEIRA_MARAES.pdf: 3458644 bytes, checksum: 005c22fed45246220ed1f2e0de9490a9 (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-07-30T12:47:18Z (GMT) No. of bitstreams: 1 M?RCIA_CRISTINA_GON?ALVES_DE_OLIVEIRA_MARAES.pdf: 3458644 bytes, checksum: 005c22fed45246220ed1f2e0de9490a9 (MD5) / Made available in DSpace on 2018-07-30T12:58:07Z (GMT). No. of bitstreams: 1 M?RCIA_CRISTINA_GON?ALVES_DE_OLIVEIRA_MARAES.pdf: 3458644 bytes, checksum: 005c22fed45246220ed1f2e0de9490a9 (MD5) Previous issue date: 2017-08-30 / Abstract: Today, the incidence of prostate cancer is considered high, however, unlike other malignant tumours, there is an expressive number of cases in which prostate cancer does not progress to clinical disease. The management of patients with prostate cancer should be individually fitted due to the broad behaviour spectrum of this cancer, ranging from low grade tumours with low aggressive biological characteristics to high grade tumours with metastatic capacity. The possibility of predicting the future behavior of the disease allows the selection of the most appropriate conduct for each case. Studies have shown that mpMRI (multiparametric Magnetic Resonance Imaging) has a high negative predictive value for clinically significant prostate cancer, indicating that its application as a screening method and as assessment method of disease progression is promising. To standardize the protocols and reports of prostate mpMRI, the PI-RADS v2 (Prostate Imaging Reporting and Data System version 2) was launched in 2015. Multiparametric Magnetic Resonance Imaging standardized by PI-RADSv2 has been taking a prominent place in the management of prostate cancer, but the specificity and positive predictive value still need to be improved. Purpose: To assess whether the ADC (Apparent diffusion coefficient) value and tumour ADC ratio associated with PI-RADS v2 may increase accuracy in predicting clinically significant prostate cancer. Materials and methods: 91 individuals with suspected prostate cancer were retrospectively studied through mpMRI imaging standardized by PI-RADS v2, obtaining the ADC value from the tumour and the contralateral tissue. The findings were correlated to anatomopathological study (biopsy, prostatectomy or transurethral resection). Results: Accuracy, sensitivity, specificity, positive predictive value and negative predictive value for the consensus between the two reviewers using PI-RADS v2, category 3 associated with categories 4 and 5 for the detection of clinically significant cancer were 70.3%, 97.4%, 50.9%, 58.7% and 96.4% (p <0.001), respectively. The association of the ADC value (<0.795x10-3) to categories 3, 4 and 5 of the PI-RADSv2, in turn, demonstrated accuracy, specificity and positive predictive value of 78.9%, 84.9% and 76.5%; and the association with the tumour ADC ratio (<0.62) presented 77.5%, 86.5% and 77.4% of accuracy, specificity and positive predictive value, respectively. Conclusion: The association of the ADC value and the tumour ADC ratio to the PI-RADS v2 in mpMRI increases the accuracy, specificity and positive predictive value in the detection of aggressive prostate cancer, and may help in the screening of individuals who would undergo invasive procedures and radical therapy, or conservative management, as active surveillance or watchful waiting. / Introdu??o: ? considerada alta a incid?ncia de c?ncer de pr?stata na atualidade, contudo, diferentemente de outras neoplasias, existe um n?mero expressivo de casos em que o c?ncer de pr?stata n?o evolui para a doen?a cl?nica. Por este motivo, o manejo dos pacientes com neoplasia prost?tica deve ser moldado individualmente face ao amplo espectro que varia desde tumores de baixo grau, com caracter?sticas biol?gicas de baixa agressividade, a tumores de alto grau, com capacidade metast?tica. A possibilidade de prever o comportamento futuro da doen?a permite a sele??o da conduta mais adequada para cada caso. Estudos vem comprovando que a Resson?ncia Magn?tica multiparam?trica (RMmp) apresenta um alto valor preditivo negativo para o c?ncer de pr?stata com signific?ncia cl?nica, indicando que sua aplica??o como m?todo de triagem e na avalia??o da progress?o da doen?a ? promissora. Para padronizar os protocolos e os relat?rios da RMmp da pr?stata foi lan?ado em 2015 o PI-RADS v2 (?Prostate Imaging Reporting and Data System? vers?o 2). A RMmp padronizada pelo PI-RADS v2 vem assumindo um lugar de destaque no manejo do c?ncer de pr?stata, contudo, ainda s?o considerados baixos a Especificidade e o Valor Preditivo Positivo. Objetivos: Avaliar se o valor de ADC (?Apparent diffusion coefficient? = Coeficiente de Difus?o Aparente) e a raz?o tumoral do ADC associados ao PI-RADS v2 podem aumentar a acur?cia da RMmp na predi??o do c?ncer de pr?stata com signific?ncia clinica. Materiais e m?todos: Foram estudados retrospectivamente 91 indiv?duos com suspeita de c?ncer de pr?stata, submetidos a RMmp padronizada pelo PI-RADS v2, obtendo-se o ADC quantitativo da les?o e do tecido contralateral. Os achados foram correlacionados ao estudo anatomopatol?gico (bi?psia, prostatectomia ou ressec??o transuretral). Resultados: A acur?cia, sensibilidade, especificidade, valor preditivo positivo e valor preditivo negativo para o consenso entre os dois avaliadores utilizando a RMmp padronizada pelo PI-RADS v2, com a categoria 3 associada as categorias 4 e 5 para a detec??o do c?ncer com signific?ncia cl?nica foram 70,3%; 97,4%; 50,9%; 58,7% e 96,4% (p<0,001), respectivamente. A associa??o do valor do ADC (<0,795x10-3) ?s categorias 3, 4 e 5 do PI-RADS v2, por sua vez, demonstrou acur?cia, especificidade e valor preditivo positivo de 78,9%; 84,9% e 76,5%; e a associa??o com a raz?o tumoral do ADC (< 0,62), apresentou 77,5%; 86,5% e 77,4% de acur?cia, especificidade e valor preditivo positivo, respectivamente. Conclus?o: A associa??o do valor do ADC e da raz?o tumoral do ADC ao PI-RADS v2 na RMmp aumenta a acur?cia, especificidade e valor preditivo positivo na detec??o do c?ncer agressivo da pr?stata, podendo auxiliar na triagem dos indiv?duos e na decis?o entre a conduta agressiva, com procedimentos invasivos e terapia radical, ou a conduta conservadora, com vigil?ncia ativa ou observa??o.
52

Biocorrosão marinha:a comunidade macroincrustante e seu efeito na corrosão de aços inoxidáveis especiais de alta liga (AISI 316, AISI 904l e Zeron 100)/Luciana Vicente Resende de Messano.

Messano, Luciana Vicente Resende de January 2007 (has links) (PDF)
Tese (Doutorado) - Universidade Federal do Rio de Janeiro, Coordenação dos Programas de Pós-Graduação de Engenharia, Programa de Engenharia Metalúrgica e de Materiais 2007. / Os materiais metálicos quando expostos ao ambiente marinho são susceptíveis à fixação de organismos incrustantes sobre as superfícies mersas. O objetivo principal deste trabalho foi verificar os efeitos da incrustação dos organismos, e em especial de bala / Made available in DSpace on 2018-02-14T17:42:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2007. Added 1 bitstream(s) on 2019-02-13T19:02:26Z : No. of bitstreams: 1 00000ee5.pdf: 1958420 bytes, checksum: 1b88dff6b144d49d66ef0f0ee8bfe48f (MD5)
53

Analysis, Implementation and Enhancement of Vendor dependent and independent Layer-2 Network Topology Discovery / Analyse, Implementierung und Verbesserung von Hersteller abhängigem und unabhängigem Layer-2 Netzwerk Topologie Erkennung

Barthel, Alexander 26 May 2005 (has links) (PDF)
This work shows and implements possibilities of OSI Layer-2 Network Topology Discovery based on information from Cisco Discovery Protocol, Spanning Tree Protocol and Switches' Filtering Databases. / Diese Arbeit zeigt und implementiert Möglichkeiten zur OSI Layer-2 Netzwerk Topologie Erkennung basierend auf Informationen des Cisco Discovery Protocol, Spanning Tree Protocol und Switch Filter Datenbanken.
54

Odhad hloubky pomocí konvolučních neuronových sítí / Depth Estimation by Convolutional Neural Networks

Ivanecký, Ján January 2016 (has links)
This thesis deals with depth estimation using convolutional neural networks. I propose a three-part model as a solution to this problem. The model contains a global context network which estimates coarse depth structure of the scene, a gradient network which estimates depth gradients and a refining network which utilizes the outputs of previous two networks to produce the final depth map. Additionally, I present a normalized loss function for training neural networks. Applying normalized loss function results in better estimates of the scene's relative depth structure, however it results in a loss of information about the absolute scale of the scene.
55

Analysis, Implementation and Enhancement of Vendor dependent and independent Layer-2 Network Topology Discovery

Barthel, Alexander 15 April 2005 (has links)
This work shows and implements possibilities of OSI Layer-2 Network Topology Discovery based on information from Cisco Discovery Protocol, Spanning Tree Protocol and Switches' Filtering Databases. / Diese Arbeit zeigt und implementiert Möglichkeiten zur OSI Layer-2 Netzwerk Topologie Erkennung basierend auf Informationen des Cisco Discovery Protocol, Spanning Tree Protocol und Switch Filter Datenbanken.
56

Zapojení vybraných svalů horní části těla při oboustranném bruslení jednodobém, soupažném běhu prostém a při napodobivém cvičení na běžkařském trenažeru Concept 2 / Involvement of the muscles of the upper body collected at time of cross-country skiing and during simulating exercises

Horyna, Roman January 2018 (has links)
Title: Upper body muscles activity in V2 skating technique, double poling and on a skiing machine Concept 2 Objectives: Comparison of involvement upper body muscles during V2 skating technique, double poling and on a skiing machine Concept 2. Methods: Comparative analysis: the dates were measured by surface electromyography and 2-D video-analysis. Results: We found statistically significant coordination similarity by comparisons muscle preactivation and activation during V2 skating technique and double poling. Trunk flexors musculus obliquus abdominis externus and musculus rectus abdominis showed unlike the main propulsion muscles, musculus pectoralis major, musculus triceps brachii and musculus latissimus dorsi, significantly higher preactivation during V2 skating technique and double poling in comparison to skiing machine Concept 2. Activation of the main propulsion muscles on a skiing machine Concept 2 is significantly higher than during V2 skating technique and double poling. Skiing machine Concept 2 cannot be considered as a specific training method for cross-country skiing. Long-term application may cause disruption of double poling technique. Key words: Cross country skiing, V2 skating technique, double poling, skiing machine Concept 2 (SkiErg), kinesiology, surface electromyography
57

Transfer learning between domains : Evaluating the usefulness of transfer learning between object classification and audio classification

Frenger, Tobias, Häggmark, Johan January 2020 (has links)
Convolutional neural networks have been successfully applied to both object classification and audio classification. The aim of this thesis is to evaluate the degree of how well transfer learning of convolutional neural networks, trained in the object classification domain on large datasets (such as CIFAR-10, and ImageNet), can be applied to the audio classification domain when only a small dataset is available. In this work, four different convolutional neural networks are tested with three configurations of transfer learning against a configuration without transfer learning. This allows for testing how transfer learning and the architectural complexity of the networks affects the performance. Two of the models developed by Google (Inception-V3, Inception-ResNet-V2), are used. These models are implemented using the Keras API where they are pre-trained on the ImageNet dataset. This paper also introduces two new architectures which are developed by the authors of this thesis. These are Mini-Inception, and Mini-Inception-ResNet, and are inspired by Inception-V3 and Inception-ResNet-V2, but with a significantly lower complexity. The audio classification dataset consists of audio from RC-boats which are transformed into mel-spectrogram images. For transfer learning to be possible, Mini-Inception, and Mini-Inception-ResNet are pre-trained on the dataset CIFAR-10. The results show that transfer learning is not able to increase the performance. However, transfer learning does in some cases enable models to obtain higher performance in the earlier stages of training.
58

Real-time Head Motion Tracking for Brain Positron Emission Tomography using Microsoft Kinect V2

Tsakiraki, Eleni January 2016 (has links)
The scope of the current research work was to evaluate the potential of the latest version of Microsoft Kinect sensor (Kinect v2) as an external tracking device for head motion during brain imaging with brain Positron Emission Tomography (PET). Head movements constitute a serious degradation factor in the acquired PET images. Although there are algorithms implementing motion correction using known motion data, the lack of effective and reliable motion tracking hardware has prevented their widespread adoption. Thus, the development of effective external tracking instrumentation is a necessity. Kinect was tested both for Siemens High-Resolution Research Tomograph (HRRT) and for Siemens ECAT HR PET system. The face Application Programming Interface (API) ’HD face’ released by Microsoft in June 2015 was modified and used in Matlab environment. Multiple experimental sessions took place examining the head tracking accuracy of kinect both in translational and rotational movements of the head. The results were analyzed statistically using one-sample Ttests with the significance level set to 5%. It was found that kinect v2 can track the head with a mean spatial accuracy of µ0 &lt; 1 mm (SD = 0,8 mm) in the y-direction of the tomograph’s camera, µ0 &lt; 3 mm (SD = 1,5 mm) in the z-direction of the tomograph’s camera and µ0 &lt; 1 ◦ (SD &lt; 1 ◦ ) for all the angles. However, further validation needs to take place. Modifications are needed in order for kinect to be used when acquiring PET data with the HRRT system. The small size of HRRT’s gantry (over 30 cm in diameter) makes kinect’s tracking unstable when the whole head is inside the gantry. On the other hand, Kinect could be used to track the motion of the head inside the gantry of the HR system.
59

Struktura a únavové vlastnosti vybrané titanové slitiny / Structure and fatigue properties of selected titanium alloy

Prudíková, Alena January 2014 (has links)
Main topic of the thesis was to evaluate fatigue properties of the titanium alloy Ti-A13-V2,5, labelled by ASTM as Grade 9. Most attention was focused on fatigue behaviour of the alloy in the range of high cycle fatigue. Fatigue testing was realised to detect the fatigue properties and consequently to generate the Wöhler curve and the Haigh diagram. In addition to this, tension and bending tests were performed. Metallographic and fractographic analyses of fatigue fracture form part of the overview about material properties, which was accomplished by use of REM. Experimental part of the thesis was backed by the literature research. The first half of it contains a short summary of basic information about the titanium and its alloys, so as some chapters about the history and properties of titanium, the way of its production, classification of titanium alloys and its thermic treatment. The fatigue is thoroughly scrutinised in the second half of the background research. Here can also be found the information about the fatigue process, its stages, the fatigue life and the most significant attributes of the fatigue fracture. The last chapters of the thesis are dedicated to the alloy Ti-A13-V2,5 - being examined in the experimental part - so as to its fatigue properties. The main benefit of this thesis is the completion of the missing information concerning the fatigue behaviour of the alloy, which is – according to the literature research - generally not available.
60

Zapojení vybraných svalů horní části těla při oboustranném bruslení jednodobém, soupažném běhu prostém a při napodobivém cvičení na běžkařském trenažeru Concept 2 / Involvement of the muscles of the upper body collected at time of cross-country skiing and during simulating exercises

Horyna, Roman January 2018 (has links)
Title: Upper body muscles activity in V2 skating technique, double poling and on a skiing machine Concept 2 Objectives: Comparison of involvement upper body muscles during V2 skating technique, double poling and on a skiing machine Concept 2. Methods: Comparative analysis: the dates were measured by surface electromyography and 2-D video-analysis. Results: We found statistically significant coordination similarity by comparisons muscle preactivation and activation during V2 skating technique and double poling. Trunk flexors musculus obliquus abdominis externus and musculus rectus abdominis showed unlike the main propulsion muscles, musculus pectoralis major, musculus triceps brachii and musculus latissimus dorsi, significantly higher preactivation during V2 skating technique and double poling in comparison to skiing machine Concept 2. Activation of the main propulsion muscles on a skiing machine Concept 2 is significantly higher than during V2 skating technique and double poling. Skiing machine Concept 2 cannot be considered as a specific training method for cross-country skiing. Long-term application may cause disruption of double poling technique. Key words: Cross country skiing, V2 skating technique, double poling, skiing machine Concept 2 (SkiErg), kinesiology, surface electromyography

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