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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.
21

Naujų riedėjimo guolių defektų diagnostiniai tyrimai / Defect diagnostic tests for new rolling bearings

Degutis, Aurimas 11 June 2014 (has links)
Šio tyrimo tikslas yra sukurti, realizuoti ir išbandyti metodą leidžiantį atlikti naujo riedėjimo guolio elementų neardoma diagnostiką ir įvertinti surinkimo kokybę. Norint įvertinti guolio kokybę jo neišardant, pasitelkti virpesių pagreičio signalo stebėsenos ir analizės metodai. Atlikti sekantys uždaviniai siekiant įgyvendinti tyrimo tikslą: • Apžvelgti pramonėje naudojami guolių kokybės įvertinimo metodai. • Sukurtas ir realizuotas metodas naujo guolio kokybei nustatyti. • Praktiškai patikrinta metodo teikiama nauda. • Išnagrinėta suteptų ir nesuteptų guolių įtaką kokybės nustatymui. Atliekant virpesių signalų tyrimą sukurtu ir realizuotu guolių elementų virpesių pagreičio vidutinės kvadratinės vertės metodu, galima nustatyti guolio surinkimo kokybę, jo elementų pažeidimus, neatliekant ardymo kas būna neišvengiama taikant kitus metodus. Metodo efektyvumas patvirtintas atliekant tiriamųjų guolių išsamius mechaninius tyrimus, kurių metu buvo išardyti tyrimuose naudoti riedėjimo guoliai ir nuodugniai ištirta jų riedėjimo elementų kokybė ir gauti rezultatai palyginti su realizuoto metodo teikiamais rezultatais. Realizuoti pagalbiniai metodai kaip virpesių pagreičio skirtumo radimas, vyraujančių dažnių paieška, kurie suteikia papildomos informacijos apie guolį ir/ar jo kokybę. Sukurtas ir realizuotas virpesių pagreičio signalo centravimo metodas, patikrinta jo teikiama praktinė nauda. / The purpose of this thesis is to create, implement and test a method which would allow to evaluate the quality of newly made bearing and its elements, without the need of disassembling the bearing. To evaluate the quality of the bearing without disassembling it, vibration signal monitoring and analysis methods were used. The following tasks were completed in order to accomplish the goal of the thesis: • Reviewed bearing quality evaluation and failure detection methods used in industry. • Created and implemented a method which could evaluate the quality of a bearing. • Experimentally tested the efficiency of the method. • Investigated the used oil influence on the quality detection. The quality of the bearing and its elements can be measured using bearing elements vibration acceleration root mean square method. This method does not require the disassembling of the bearing which might not be avoided when using other methods. The efficiency of the method was proven by performing extensive mechanical analysis on studied bearings, which required to disassemble the bearing and check in detail the quality of the bearing. The collected results were compared with the ones received from the implemented method. Some additional methods were created and implemented which would give more information about the bearing and its quality. The vibration acceleration signal centering method was implemented and its efficiency was checked experimentally.
22

Stavební průzkum a hodnocení stavu konstrukce / Building survey and evaluating the state construction

Suchánková, Zuzana January 2016 (has links)
The diploma thesis is focused on study of diagnostic methods used for reinforced concrete structure with a practical example of a survey on the subject of the original memorial Bata in Zlin, today's House of Art. The theoretical part of the thesis describes the general methodology of the survey with the distribution methods for testing materials and structures, and displays the evaluation according to ČSN ISO 1382 Also deals with the required properties and used by diagnostic methods for concrete and steel. In the practical part of the surveyed, which is supposed to show the methodology of the survey to the evaluation process involving the setting apart of strength and classification of concrete and chemical analysis, which should show whether the concrete is not based on aluminous cement.
23

Stavební průzkum a diagnostika konstrukce / Survey and Diagnostics of Building Construction

Moravská, Veronika January 2016 (has links)
This thesis deal with survey and diagnostics of industrial building in Chropyne. The theoretical presents to the general issue of building technical surveys, diagnostics reinforced concrete structures and describes methods for diagnosis of reinforced concrete structures. Practical part deals with building survey and diagnostics of the object including static assessment.
24

Probabilistic Modelling of Hearing : Speech Recognition and Optimal Audiometry

Stadler, Svante January 2009 (has links)
Hearing loss afflicts as many as 10\% of our population.Fortunately, technologies designed to alleviate the effects ofhearing loss are improving rapidly, including cochlear implantsand the increasing computing power of digital hearing aids. Thisthesis focuses on theoretically sound methods for improvinghearing aid technology. The main contributions are documented inthree research articles, which treat two separate topics:modelling of human speech recognition (Papers A and B) andoptimization of diagnostic methods for hearing loss (Paper C).Papers A and B present a hidden Markov model-based framework forsimulating speech recognition in noisy conditions using auditorymodels and signal detection theory. In Paper A, a model of normaland impaired hearing is employed, in which a subject's pure-tonehearing thresholds are used to adapt the model to the individual.In Paper B, the framework is modified to simulate hearing with acochlear implant (CI). Two models of hearing with CI arepresented: a simple, functional model and a biologically inspiredmodel. The models are adapted to the individual CI user bysimulating a spectral discrimination test. The framework canestimate speech recognition ability for a given hearing impairmentor cochlear implant user. This estimate could potentially be usedto optimize hearing aid settings.Paper C presents a novel method for sequentially choosing thesound level and frequency for pure-tone audiometry. A Gaussianmixture model (GMM) is used to represent the probabilitydistribution of hearing thresholds at 8 frequencies. The GMM isfitted to over 100,000 hearing thresholds from a clinicaldatabase. After each response, the GMM is updated using Bayesianinference. The sound level and frequency are chosen so as tomaximize a predefined objective function, such as the entropy ofthe probability distribution. It is found through simulation thatan average of 48 tone presentations are needed to achieve the sameaccuracy as the standard method, which requires an average of 135presentations.
25

Dítě s diagnostikovaným syndromem poruchy pozornosti s hyperaktivitou ve vzdělávacím procesu základního školství / Child with diagnosed syndrome of Attention Deficit Hyperactivity Disorder in the learning process of basic education

Cupa, Dalimil January 2014 (has links)
The thesis deals with various approaches of primary school teachers to pupils with Attention deficit hyperactivity disorder (ADHD). The theoretical part describes in detail the etiology of ADHD, the problems of ADHD children experienced in the learning process of primary education, as well as individual needs of ADHD students and recommended approaches of teachers to these students. It deals with possibilities of treatments. The empirical part is based on a survey performed among parents of primary school students with ADHD focusing on parents' perceptions of teachers' attitude toward pupils. Teachers' point of view and perceptions were gained through interviews. The results are summared and suggestions for thinking about it have been made in the end of the thesis.
26

Modelos mistos lineares elípticos com erros de medição / Elliptical linear mixed models with measurement errors

Borssoi, Joelmir André 20 February 2014 (has links)
O objetivo principal deste trabalho é estudar modelos mistos lineares elípticos em que uma das variáveis explicativas ou covariáveis é medida com erros, sob a abordagem estrutural. O trabalho é apresentado numa notação longitudinal, todavia a covariável medida com erros pode ser observada temporalmente ou como medidas repetidas. Assumimos uma estrutura hierárquica apropriada com distribuição elíptica conjunta para os erros envolvidos, porém a inferência é desenvolvida sob uma abordagem marginal em que consideramos a distribuição marginal da resposta e da variável medida com erros. Procedimentos de influência local em que o esquema de perturbação é escolhido de forma apropriada são desenvolvidos. Um exemplo para motivação é apresentado e analisado através dos procedimentos apresentados neste trabalho. Detalhamos nos apêndices os principais procedimentos necessários para o desenvolvimento do modelo proposto. / The aim of this thesis is to study elliptical linear mixed models in which one of the explanatory variables is subject to measurement error under the structural assumption. The work is presented by assuming a longitudinal structure, however the explanatory variable may be observed along the time or as repeated measures. A joint hierarchical structure is assumed for the elliptical errors, but the inference is made under the marginal structure. The methodology of local influence is applied with the perturbation schemes being selected appropriately. A motivation example is presented and analysed by the procedures developed in this work. All the main derivations for the development of the proposed model are presented in the appendices.
27

Modelos mistos lineares elípticos com erros de medição / Elliptical linear mixed models with measurement errors

Joelmir André Borssoi 20 February 2014 (has links)
O objetivo principal deste trabalho é estudar modelos mistos lineares elípticos em que uma das variáveis explicativas ou covariáveis é medida com erros, sob a abordagem estrutural. O trabalho é apresentado numa notação longitudinal, todavia a covariável medida com erros pode ser observada temporalmente ou como medidas repetidas. Assumimos uma estrutura hierárquica apropriada com distribuição elíptica conjunta para os erros envolvidos, porém a inferência é desenvolvida sob uma abordagem marginal em que consideramos a distribuição marginal da resposta e da variável medida com erros. Procedimentos de influência local em que o esquema de perturbação é escolhido de forma apropriada são desenvolvidos. Um exemplo para motivação é apresentado e analisado através dos procedimentos apresentados neste trabalho. Detalhamos nos apêndices os principais procedimentos necessários para o desenvolvimento do modelo proposto. / The aim of this thesis is to study elliptical linear mixed models in which one of the explanatory variables is subject to measurement error under the structural assumption. The work is presented by assuming a longitudinal structure, however the explanatory variable may be observed along the time or as repeated measures. A joint hierarchical structure is assumed for the elliptical errors, but the inference is made under the marginal structure. The methodology of local influence is applied with the perturbation schemes being selected appropriately. A motivation example is presented and analysed by the procedures developed in this work. All the main derivations for the development of the proposed model are presented in the appendices.
28

Vasculariza??o uterina atrav?s da ultrassonografia color doppler em ?guas com endometrite bacteriana induzida submetidas a tratamento / Characterization of uterine vascularization using color Doppler in equine endometritis

S?, Marcus Andr? Ferreira 23 August 2017 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-08-28T19:02:05Z No. of bitstreams: 1 2017 - Marcus Andr? Ferreira S?.pdf: 1043888 bytes, checksum: 7a3d94bc8171597abb3f0dde51169347 (MD5) / Made available in DSpace on 2018-08-28T19:02:05Z (GMT). No. of bitstreams: 1 2017 - Marcus Andr? Ferreira S?.pdf: 1043888 bytes, checksum: 7a3d94bc8171597abb3f0dde51169347 (MD5) Previous issue date: 2017-08-23 / Objectives of this study were to characterize the endometrial vascular perfusion of mares with bacterial endometritis using color Doppler ultrasonography and submitted to phytotherapeutic treatment. 19 crossbred and Mangalarga Marchador mares without endometritis were used. ImageJ 1.46r? was applied to evaluate the images. Additionally, subjective vascular uterine perfusion was estimated analyzing the percentage of color Doppler signals present in the mesometrial, myometrium and endometrium, in longitudinal section of the uterine body and transverse section of the uterine horns. Step 1. The mares (n=20) were submitted to intrauterine inoculation with Escherichia coli cepa from the equine uterus. The color Doppler ultrasound sessions were performed in M0 (moment immediately prior to intrauterine inoculation) and M1 (24 hours after intrauterine inoculation). Step 2. The animals were divided into two groups: control group (n=10) and treated group (n=10) using phytotherapic solution Fitoclean? (Organnact Animal Health, Curitiba, Paran?, Brazil). Both groups, color Doppler ultrasonography was performed at time T1 (immediately before starting treatment), T2 (24h after treatment) and T3 (48h after treatment). Step 3. Mares in which pathogens were identified in the samples collected during stage 2 were submitted to antibiotic therapy by intrauterine infusion using Gentamicin. Seven days after the antibiotic therapy, a new color Doppler ultrasound examination was performed. For statistical analysis, the Tukey test, t Student and Anova test was applied to compare the means obtained in the different periods and Chi Square were apllied to evaluation of phytoterapic effect. Step 1. It was found that the mean values of vascularization were no moment (P<0.05). Bacterial growth was observed in all samples collected. Step 2. The mean value of vascularization at time T1 in both groups was significantly higher (P<0.05) than the obtained at moments 2 and 3. At the time T1, we observed a significant increase in portion 1, while T2 showed a significant decreasing in this portion. Step 3. According to the results obtained in the culture and antibiogram examinations performed during the step 2, 13 mares (65%, 13/20) were submitted to antibiotic therapy through intrauterine infusion with Gentamicin. After that treatment, the vascularization observed decreased related to M1. With these results, we can conclude that in these conditions is possible the use of color Doppler ultrasonography as a method for bacterial endometritis; It was not possible to correlate results obtained by color Doppler ultrasonography with the traditional findings for the diagnosis of endometritis. / Os objetivos do presente estudo foram caracterizar atrav?s da ultrassonografia color Doppler a perfus?o vascular endometrial de ?guas com endometrite bacteriana e submetidas a tratamento fitoter?pico. Para tanto, foram utilizadas 20 ?guas mesti?a e Mangalarga Marchador livres de endometrite. O programa ImageJ 1.46r? foi utilizado para avalia??o das imagens. Adicionalmente, a perfus?o vascular subjetiva do ?tero foi estimada levando-se em considera??o o percentual de sinais Doppler coloridos presentes no mesom?trio, miom?trio e endom?trio, em corte longitudinal do corpo uterino e transversal dos cornos uterinos. Etapa 1. Todas as ?guas (n=20) foram submetidas a inocula??o intrauterina com cepa de Escherichia coli proveniente de ?tero equino. As sess?es de ultrassonografia color Doppler foram realizadas em M0 (momento imediatamente anterior ? inocula??o intrauterina) e M1 (24 horas ap?s a inocula??o intrauterina). Etapa 2. Os animais foram divididos aleatoriamente em dois grupos: grupo experimental 1 (n=10) e grupo experimental 2 (n=10) com solu??o fitoter?pica Fitoclean? (Organnact Sa?de Animal, Curitiba, Paran?, Brasil). Em ambos os grupos, os exames de cultura uterina, antibiograma, citologia endometrial e ultrassonografia modo B e color Doppler foram realizados nos momentos T1 (imediatamente antes de iniciar o tratamento), T2 (24h ap?s o tratamento) e T3 (48h ap?s o tratamento). Etapa 3. As ?guas em que foram identificados agentes patog?nicos nas amostras coletadas durante a etapa 2, foram submetidas ? antibioticoterapia por infus?o intrauterina utilizando Gentamicina. Sete dias ap?s a realiza??o da antibioticoterapia, foi realizado novos exame de ultrassonografia color Doppler. Para an?lise estat?stica, foi aplicado o teste de Tukey, teste t de Student e Anova para compara??o das m?dias obtidas nos diferentes per?odos e Qui Quadrado para avalia??o do efeito do fitoter?pico. Etapa 1. Verificou-se que os valores m?dios de vasculariza??o no momento M1 foram significativamente superiores aos obtidos em M0 para as tr?s partes do ?tero (P<0,05). Houve crescimento bacteriano em todas as amostras coletadas. Etapa 2. O valor m?dio de vasculariza??o no momento T1 em ambos os grupos foi significativamente superior (P<0,05) aos obtidos nos momentos 2 e 3. No momento T1, observou-se aumento significativo no segmento 1, enquanto que em T2 observou-se uma redu??o significativa neste segmento. Etapa 3. De acordo com os resultados obtidos nos exames de cultura e antibiograma realizados ap?s o t?rmino da etapa 2, 13 ?guas (65%, 13/20) foram submetidas a antibioticoterapia atrav?s de infus?o intrauterina com Gentamicina. Ap?s este tratamento, a vasculariza??o observada apresentou grande redu??o em compara??o ao momento M1. Diante destes resultados, concluiu-se que nas condi??es deste estudo foi poss?vel utilizar a ultrassonografia modo Color Doppler como m?todo diagn?stico para a endometrite bacteriana; n?o foi poss?vel correlacionar resultados obtidos atrav?s da ultrassonografia color Doppler com os achado nos exames tradicionais para diagn?stico da endometrite.
29

Partial Discharges Studied with Variable Frequency of the Applied Voltage

Edin, Hans January 2001 (has links)
This thesis concerns partial discharge (PD) diagnostics withvariable frequency of applied voltage in the frequency range 1mHz - 400 Hz. The exploration of a new type of spectroscopythat combines partial discharge analysis and dielectricresponse is demonstrated. A question addressed is if and howthe PD activity varies with the frequency of the appliedvoltage. The nature of an existing frequency dependence couldbe useful in the classification of different defects and tojudge the degree of progressive ageing. A Variable-Frequency Phase Resolved Partial DischargeAnalysis (VF-PRPDA) technique is developed for the appliedvoltage frequency range 1 mHz - 400 Hz. The VF-PRPDA techniqueis combined with a system for high voltage dielectricspectroscopy that allows simultaneous measurements. TheVF-PRPDA technique is used for studying the frequencydependence of PD. The PD activity is for example measured byintegrated measures like total charge per cycle and totalnumber of discharges per cycle. Statistical measures like mean,standard deviation, skewness, kurtosis etc. are applied tomeasure the frequency dependence of the phasedistributions. High voltage dielectric spectroscopy is supplemented withharmonic analysis for studying non-linear dielectric responsecurrents. The VF-PRPDA technique is demonstrated on defined objectslike point-plane gaps and artificial voids, but also on aninsulated stator bar and a paper insulated cable. Surfacedischarges on insulating surfaces are studied in an environmentwith a controlled relative humidity and temperature. Theadsorption of moisture on the insulating surface alters thesurface conductivity of the surface and the frequencydependence of the PD activity. The influence of temperature upon the PD activity is studiedfor a oil paper insulated cable. The results of the measurements show that the partialdischarge activity in general is frequency dependent over thefrequency range 1 mHz - 400 Hz. The reasons behind thefrequency dependence are linked to surface- and bulk-conducting mechanisms, frequency dependent field distributionsand statistical effects of the supply of start electrons. An algorithm is developed that relates the phase resolved PDcurrent measured with the PRPDA technique to the non-linearcurrent measured with dielectric spectroscopy. The algorithm isexperimentally verified by simultaneous measurements of PRPDAand dielectric spectroscopy on defined objects. The resultsexplain the contribution of PD to the apparent capacitance andloss. Moreover, the harmonics of the fundamental currentcomponent yield information about, for example, polaritydependent discharge sources. Keywords:diagnostic methods, partial discharges, phaseresolved, variable frequency, dielectric spectroscopy,dielectric response, harmonics, insulation / QC 20100527
30

A importância do teste de captura hibrida 2 no acompanhamento de pacientes tratadas por lesão intraeptelial cervical de auto grau

Ramos, Elenice January 2013 (has links)
Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2013-10-14T14:20:36Z No. of bitstreams: 1 Elenice Ramos. A importancia do teste...2013.pdf: 1607959 bytes, checksum: 14657c8b98e28da00d115766bc7fa1a2 (MD5) / Made available in DSpace on 2013-10-14T14:20:36Z (GMT). No. of bitstreams: 1 Elenice Ramos. A importancia do teste...2013.pdf: 1607959 bytes, checksum: 14657c8b98e28da00d115766bc7fa1a2 (MD5) Previous issue date: 2013 / Universidade Federal da Bahia. Faculdade de Medicina. Salvador, BA, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil / O cancer do colo do útero é o segundo tipo de cancer mais frequente, nas mulheres, em nosso meio. O Papiloma Vírus Humano (HPV) é a principal causa da carcinogênese cervical. O carcinoma de células escamosas é o tipo mais comum de câncer cervical e é precedido de lesões pré-cancerosas, conhecidas como lesão intraepitelial de baixo grau (LIEBG) ou NIC 1 e lesão intraepitelial de alto grau (LIEAG) ou NIC 2 e 3. A detecção do HPV e das LIEs é feita através da colposcopia, citologia, histopatologia e biologia molecular. As LIEAG são as que podem progredir para câncer mais rapidamente, logo seu diagnóstico, tratamento e acompanhamento são de grande importância. O tratamento indicado é a Cirurgia de Alta Frequência (CAF). Objetivo: Avaliar a importância do teste de Captura Hibrida 2 (CH2), que é um método de hibridização molecular utilizado em vários centros para detectar DNA de HPV oncogênico em casos de alteração de células escamosas de significado indeterminado (ASC-US) e, mais recentemente, no acompanhamento das LIEAG tratadas. Metodologia: Foram estudados 44 prontuários de pacientes submetidas a esse tratamento em um centro de referência em Patologia Cervical, na cidade de Salvador – Bahia, que tiveram o resultado dos exames colposcópicos, citológicos, histopatológicos e CH2 pré e pós-tratamento, assim como o resultado histopatológico das peças cirúrgicas. Foi analisada a correlação dos resultados dos métodos de diagnóstico com o resultado histopatológico das peças da CAF antes e depois do procedimento, para avaliar a acurácia de cada método em detectar LIEAG e sua possível recidiva. Resultados: A sensibilidade para detectar lesão residual em pacientes cujas peças da CAF estavam com margens livres foi da CH2 52,38%, da colposcopia 33,33% e da citologia 28,57%. Conclusão a CH2 foi o método mais sensível para detectar LIEAG tanto no rastreamento como no seguimento de pacientes tratadas pela CAF, seguida pela colposcopia e citologia. / Cancer of the cervix is the second most common type of cancer in women in our midst. The Human Papilloma Virus (HPV) is the main cause of cervical carcinogenesis. Squamous cell carcinoma is the most common type of cervical cancer and is preceded by precancerous lesions, known as low-grade squamous intraepithelial lesion (LSIL) or CIN 1 and high-grade squamous intraepithelial lesion (HSIL) or CIN 2 and 3. HPV detection and IELs is done through colposcopy, cytology, histopathology and molecular biology. The HSIL are those that can progress to cancer more quickly, so your diagnosis, treatment and follow-up are of great importance. The recommended treatment is Loop Electrosurgical excisional procedure (LEEP). Objective: To evaluate the importance of testing Hybrid Capture 2 (CH2), which is a molecular hybridization used in many centers to detect oncogenic HPV DNA in cases of change in squamous cells of undetermined significance (ASC-US) and more recently, monitoring of treated HSIL. Methodology: A total of 44 records of patients undergoing this treatment at a referral center for Cervical Pathology in the city of Salvador - Bahia, which had the result of colposcopy, cytological, histopathological and CH2 pre-and post-treatment, as well as the Histopathological examination of the surgical specimens. We analyzed the correlation of the results of diagnostic histopathology with parts of LEEP before and after the procedure to evaluate the accuracy of each method in detecting HSIL and its possible recurrence. Results: The sensitivity for detecting residual lesions in patients whose pieces CAF margins were free of CH2 was 52.38%, 33.33% of colposcopy and cytology 28.57%. Conclusion CH2 was the most sensitive method to detect HSIL in both the tracking and the monitoring of patients treated by CAF, followed by colposcopy and cytology.

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