• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 48
  • 21
  • 8
  • 4
  • 1
  • 1
  • 1
  • Tagged with
  • 90
  • 90
  • 60
  • 45
  • 45
  • 35
  • 35
  • 18
  • 17
  • 14
  • 13
  • 13
  • 13
  • 12
  • 11
  • 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.
1

Predicting epileptic seizures from intracranial EEG

Laurent, François, January 1900 (has links)
Thesis (M.Eng.). / Written for the Dept. of Biomedical Engienering and Montreal Neurological Institute. Title from title page of PDF (viewed 2009/06/17). Includes bibliographical references.
2

Predictive value of group I oral lesions in detecting HIV infection amongst patients attending PHC facilities in Gauteng

Bhayat, Ahmed 15 May 2008 (has links)
Abstract The utilization of oral lesions as a screening tool for HIV is not well documented. Attendees at two primary health care facilities (Khutsong and Heidelberg) were assessed to determine the predictive value of group I oral lesions for HIV infection. The objectives were to investigate the: 1) HIV prevalence amongst attendees at PHC facilities, 2) Prevalence of HIV-related oral lesions and 3) Correlation between the oral lesions and the HIV status using the Likelihood Ratio test. Methods: All patients over 12 months of age presenting at the two facilities for a curative care consultation over a one-week period (in April 2005) were included. Consent was obtained by trained counselors who also conducted a brief interview and offered pre-test counseling to patients wishing to know their HIV status. Two calibrated dentists conducted a head, neck and oral examination and administered a rapid saliva HIV test (OraQuick HIV-1/2-Rapid HIV-1/2 Antibody Test). Results: A total of 654 attendees were surveyed in the 2 facilities. There was a 100% response. The mean age of the participants was 34 years (range: 1-94), and the majority (73%) were female. HIV prevalence rates were 34% at Khutsong and 36% at Heidelberg. The HIV prevalence peaked at 46% in the 16-45 age groups. Of the 228 who tested positive for HIV, 121 (53%) patients were diagnosed with 1 or more Group I oral lesion. Oral candidiasis (46%) and oral hairy leukoplakia (19%) were the two most common oral lesions diagnosed in the HIV positive cohort. The positive predictive values and specificity values for multiple lesions ranged between 96% and 100%. Most of the likelihood ratios for multiple lesions were greater than 10 which implied that the patients who presented with these lesions were extremely likely to test positive for HIV. The sensitivity values (1% to 37%) and negative predictive values (66% to 70%) remained relatively low. Conclusion: The HIV prevalence of patients attending PHC facilities was high (34%). Oral lesions are useful markers of HIV-infection and should alert clinicians to the presence of HIV infection. Multiple group I lesions were more predictive of HIV infection compared to single lesions.
3

FGAMP: um novo método para previsão de séries temporais financeiras usando parâmetros multifractais / FGAMP: a new method for forecasting financial time series using multifractal parameters

Maganini, Natalia Diniz 08 May 2017 (has links)
Este trabalho fornece informações sobre uma questão importante que é a previsão de preços e apresenta um novo método para fazer previsão para o comportamento de séries temporais financeiras, que foi nomeado de FGAMP (Forecasting with a general average of the multifractal parameters). O novo método utiliza os parâmetros extraídos do momento 5 do método MFDFA (Multifractal Detrended Fluctuation Analysis) como marcador para reconhecer um padrão e realizar uma previsão. As séries temporais utilizadas para verificar a viabilidade do método consistiram de 6 cotações de preços de ativos de alta frequência - minuto a minuto - em um período de um ano, perfazendo aproximadamente 110.000 observações para cada ativo. Um deles é o índice Ibovespa e os outros 5 são ações de alta negociabilidade no mercado, que representam, aproximadamente 32% do próprio índice que é a principal carteira teórica de ações do mercado brasileiro. Um dos diferenciais deste método é que a previsão é realizada para um horizonte de tempo - chamado de janela posterior - aqui testada para 1 dia, 5 dias ou 10 dias. Procurou-se verificar se, em algum ou em alguns momentos, o preço do ativo irá subir - igual ou mais do que um percentual definido - em relação ao último ponto de um intervalo adjacente, chamado de janela anterior. A este percentual foi dado o nome de limiar. Os medidores de qualidade geralmente utilizados em finanças, como por exemplo, MAPE, MASE e RMSE, não são adequados para medir a qualidade deste tipo de previsão, pois verificam a dispersão do previsto em relação ao realizado, observando apenas um ponto. O medidor de qualidade aqui utilizado é o Valor Preditivo Positivo, amplamente difundido na área da saúde em tabelas de validação de diagnóstico e demonstra o grau de acerto do previsto acontecer em um horizonte de tempo determinado. O critério para a tomada de decisão foi baseado nos valores dos parâmetros numa primeira metade da série, aqui denominada de série de treinamento, sendo que os testes foram feitos na segunda metade da série, aqui denominada de série de teste. Os resultados encontrados apresentam 7 parâmetros que são bons marcadores para previsão: Hq(9), Hq(10), Hq(11), tq(11), hq(7), hq(8) e Dq(7), de acordo com a nomenclatura aqui adotada. Um tamanho de janela anterior - utilizada para o cálculo dos parâmetros - bastante eficiente é o de 540 pontos, sendo que são melhores para prever um horizonte de tempo de 10 dias (um tamanho também razoável encontrado para a janela posterior). O objetivo principal da pesquisa era o de estudar a viabilidade do uso destes parâmetros como marcadores do estado do sistema e verificar se conseguiam indicar o comportamento futuro com alguma eficiência. O resultado foi que o modelo FGAMP apresenta-se bastante viável, chegando a acertar até 97,54% das vezes quando afirma que o preço do ativo irá subir igual ou mais do que 1%, até 91,94% das vezes para uma subida de 2% ou mais e até 88,70% das vezes quando afirma uma subida de 3% ou mais. Foi definido como comparador de eficiência o percentual de acerto de quando é afirmado que o preço do ativo irá subir mais ou igual ao limiar em um ou alguns pontos para todas as janelas testadas (que seria uma solução trivial), sendo que aqui este percentual foi denominado de porcentagem real. Percebe-se que quanto maior o percentual que se quer prever (aqui testados 1%, 2% e 3%) maior é a eficiência do modelo FGAMP em relação à porcentagem real: o novo método chega a ser 128,65% mais eficiente. Isto demonstra a viabilidade do método e os resultados evidenciam que ele pode ser útil para investidores e analistas de mercado, no mínimo como uma nova ferramenta em Análise Técnica / This paper provides information about an important issue that is price forecasting and presents a new method to forecast financial time series behaviour, which was named FGAMP (Forecasting with a general average of the multifractal parameters). The new method uses the parameters extracted from moment 5 of the MFDFA (Multifractal Detrended Fluctuation Analysis) method as a marker to recognize a pattern and perform a prediction. The time series used to verify the viability of the method consisted of 6 quotes of prices of high frequency assets - minute by minute - in a period of one year, making approximately 110,000 observations for each asset. One of them is the Ibovespa index and the other 5 are highly tradable shares in the market, representing approximately 32% of the index itself, which is the main theoretical portfolio of shares in the Brazilian market. One of the differentials of this method is that the forecast is performed for a time horizon - called a posterior window - here tested for 1 day, 5 days or 10 days. We sought to verify whether the asset price will rise at any or in some moments - equal to or more than a defined percentage - in relation to the last point of an adjacent interval, called the previous window. This percentage was given the name of threshold. Quality meters generally used in finance, such as MAPE, MASE and RMSE, are not adequate to measure the quality of this type of forecast, as they verify the dispersion of the predicted relative to the realized, observing only one point. The quality measure used here is the Positive Predictive Value, widely diffused in the health area in diagnostic validation tables and demonstrates the degree of accuracy of what is expected to happen in a given time horizon. The criterion for decision making was based on the values of the parameters in the first half of the series, here called the training series, and the tests were done in the second half of the series, here called the test series. The results show 7 parameters that are good predictor markers: Hq (9), Hq (10), Hq (11), tq (11), hq (7), hq (8) and Dq (7), according to the nomenclature adopted here. A previous window size - used for the calculation of the parameters - very efficient is 540 points, and these windows are better to predict a time horizon of 10 days (a reasonable size also found for the posterior window). The main goal of the research was to study the feasibility of using these parameters as markers of the state of the system and to verify if they were able to indicate future behavior with some efficiency. The result was that the FGAMP model is quite feasible, reaching up to 97.54% accuracy when it affirms that the price of the asset will rise equal to or greater than 1%, up to 91.94% of the time for a rise Of 2% or more and up to 88.70% of the time when it affirms an increase of 3% or more. It was defined as efficiency comparator the percentage of correctness when it is stated that the price of the asset will rise more or equal to the threshold in one or some points for all the windows tested (which would be a trivial solution). That percentage was denominated, here, real percentage. It is noticed that the greater the percentage that is predicted (here tested 1%, 2% and 3%) the greater the efficiency of the FGAMP model in relation to the real percentage: the new method reaches more efficiency (till 128.65% more efficient). This demonstrates the feasibility of the method and the results evidence that it can be useful to investors and market analysts, at least as a new tool in Technical Analysis
4

"Análise crítica e estimativa dos valores preditivos positivos das calcificações de aspecto mamográfico não benigno" / Critical analysis and estimative of predictive positive value of non benign mammographic aspect calcifications

Campos, Marilia Chaves Vieira de 18 July 2006 (has links)
Foram avaliados 507 casos de calcificações quanto as suas características (densidade, morfologia, distribuição, extensão e número) e associação com o câncer de mama.De acordo com os valores preditivos positivos de cada tipo de calcificação elas foram categorizadas pelo sistema BI-RADS em subcategorias 4A (2 a 10%), 4B (10,1 a 30%) e 4C (30,1 a 70,0%) e categoria 5 (acima de 70%). Todas as características se mostraram importantes na diferenciação das calcificações em benignas e malignas, em menor grau a densidade e em maior grau a morfologia e a distribuição. A distribuição linear ou segmentar, e a morfologia pleomorfa ou linear apresentaram as mais altas taxas de malignidade / Five hundred and seven cases of calcificações had been evaluated about its characteristics (density, morphology, distribution, extension and number) and association with the breast cancer. Using the VPP of each type of calcifications they had been categorized by the BI-RADS system in categories 4Â (2 to10%), 4B (10,1 to 30%) and 4C (30,1 to 70.0%) and category 5 (above 70%). All the characteristics had shown importance in the differentiation of the calcificações in benign and malignant, in lesser degree the density and bigger degree the morphology and distribuition. A linear or segmentary distribuition, and the pleomorfic or linear morphology had presented the highest taxes of malignidade
5

AVALIAÇÃO DE CARACTERÍSTICAS CLÍNICAS E LABORATORIAIS COMO FATORES PREDITIVOS NO PERÍODO DE INDUÇÃO DO TRATAMENTO DE PACIENTES COM LEUCEMIAS AGUDAS / ASSESSMENT OF CLINICAL AND LABORATORY CHARACTERISTICS AS FACTORS IN PREDICTIVE IN THE PERIOD OF INDUCTION OF THE TREATMENT OF PATIENTS WITH ACUTE LEUKEMIA

Camelo, Nivânia Lisboa 30 July 2012 (has links)
Made available in DSpace on 2016-08-19T18:16:04Z (GMT). No. of bitstreams: 1 Dissertacao Nivania.pdf: 1096637 bytes, checksum: 1906816bc4fae34d973336171b5bd415 (MD5) Previous issue date: 2012-07-30 / Background: The recent WHO classification incorporates immunophenotypic and cytogenetic characteristics that have prognostic impact. Several studies have attempted to identify clinical, biological and laboratory findings that correlate with prognosis, in order to incorporate them within the risk classification system used to define the therapeutic strategy. This work was done since there is no study in our state correlating the clinical and laboratory variables to specific immunological as predictive factors in the treatment of patients with acute leukemia. Objective: To evaluate the predictive value of different markers in PB (peripheral blood) and BM (bone marrow) in the induction period of treatment and disease-free survival in patients with acute leukemia. Methods: We evaluated 110 patients diagnosed with acute leukemia by immunophenotyping. In PB were analyzed: the percentage of blasts, leukocyte count and platelets and hemoglobin, and percentage of blasts in BM, all at diagnosis and after treatment in order to evaluate the therapeutic response. Results: Of 110 patients 61.82% were male. Most (80.9%) was framed in the age group of children and adolescents. As for the subgroups of acute leukemias 61.82% of ALL patients had type B, 12.73% of ALL type T and 25.45% of AML. The percentage of blasts in BM and PB for each of the sub groups of leukemia during induction treatment showed no significant difference on the other hand, in a comparative study between the subgroups of leukemia, there was a difference in their standard of presentation to diagnosis. For T-ALL platelet count on the initial induction period (D0) showed significant difference for patients who relapsed after the induction period. Regarding AML, patients with lower hemoglobin on D0 showed a significant tendency to relapse after the induction period. The recovery of platelet count to LLA B at the last day of the induction period of the treatment to values above 100,000/mm³ is not pointed to the recurrence of the disease follow-up period. Conclusion: The percentage of blasts in BM and PB not shown to have predictive value in respect of reference of each of these groups of leukemia in the induction phase of treatment. Platelet counts below 100.000/mm3 in T-ALL seem to D0 have predictive value for recurrence of disease after the induction period of treatment. For AML, patients with lower Hb determination on D0 were more likely to relapse after the induction period. The CD10 antigen expression at diagnosis of the disease should be a marker of good prognosis for remission induction phase of treatment. For ALL B, platelet counts above 100.000/mm3 in the D29 demonstrated predictive value for maintenance of non-recurrence of disease after D29. / Introdução: Seguindo os conceitos da classificação da OMS para as leucemias agudas, vários estudos tentam identificar características clínicas, biológicas e laboratoriais que se correlacionam com o prognóstico, objetivando incorporá-las dentro do sistema de classificação de risco usado para definir a estratégia terapêutica. Este trabalho foi realizado posto não haver nenhum estudo em nosso estado correlacionando as características clínicas e laboratoriais específicas às variáveis imunológicas como fatores preditivos no tratamento de pacientes com leucemias agudas. Objetivo: Avaliar o valor preditivo de diferentes marcadores em SP (sangue periférico) e MO (medula óssea) no período de indução do tratamento e sobrevida livre de doença em pacientes com leucemias agudas. Metodologia: Foram avaliados 110 pacientes com diagnóstico de leucemia aguda por imunofenotipagem. Em SP foram analisados: o percentual de blastos, a contagem de leucócitos e plaquetas e dosagem de hemoglobina; e o percentual de blastos em MO, todos ao diagnóstico e após o tratamento, a fim de avaliar a resposta terapêutica. Resultados: Dos 110 pacientes 61,82% eram do sexo masculino. A maioria (80,9%) estava enquadrada na faixa etária infanto-juvenil. Quanto aos subgrupos de leucemias agudas 61,82% dos pacientes eram portadores de LLA tipo B, 12,73% de LLA tipo T e 25,45% de LMA. O percentual de blastos em MO e SP para cada um dos sub grupos de leucemia, no período de indução do tratamento não demonstrou diferença significativa, por outro lado, em estudo comparativo entre os sub grupos de leucemia, houve diferença no seu padrão de apresentação ao diagnóstico. Para as LLA -T a contagem de plaquetas no dia inicial do período de indução (D0) demonstrou diferença significativa para os pacientes que apresentaram recidiva após o período de indução. Em relação às LMA, os pacientes com menor dosagem de hemoglobina no D0 apresentaram significativa tendência à recidiva após o período de indução. A recuperação da contagem de plaqueta para LLA B no último dia do período de indução do tratamento a valores acima de 100.000/mm³ apontou para a não recidiva da doença no período de acompanhamento. Conclusão: O percentual de blastos em SP ou MO não demonstraram ter valor preditivo em relação à remissão de cada um destes grupos de leucemias na fase de indução do tratamento. A contagem de plaquetas abaixo de 100.000/mm3 nas LLA - T ao D0 parecem ter valor preditivo para recidiva da doença após o período de indução do tratamento. Para as LMA, os pacientes com menor dosagem de Hb no D0 apresentaram maior tendência à recidiva após o período de indução. A expressão do antígeno CD10 ao diagnóstico da doença deva ser um marcador de bom prognóstico para remissão da doença na fase de indução do tratamento. Para as LLA B, contagens de plaquetas acima de 100.000/mm3 ao D29 demonstraram valor preditivo para manutenção de não recidiva da doença após D29.
6

Evaluating outdoor asbestos abatement activities in an idled petroleum refinery /

Tutt, Robert Dean, January 2001 (has links) (PDF)
Thesis--University of Oklahoma. / Includes bibliographical references (leaves 49-50).
7

Folate, Hormones and Infertility : Different factors affecting IVF pregnancy outcome

Murto, Tiina January 2014 (has links)
Various hormones have been studied as regards prediction of pregnancy outcome after infertility treatment, but no ideal candidate has been found. Folate and genetic variations in folate metabolism have also been associated with infertility, but it remains unclear how these factors affect IVF pregnancy outcome. It is known that infertility is associated with active folic acid supplement use, but the effect of socioeconomic and lifestyle factors on folic acid supplement use in infertile women has not been well investigated. The overall aim of this work was to obtain information on the prediction of live birth, and to study factors affecting the role of folate and folic acid intake in relation to IVF pregnancy outcome. Infertile women with various infertility diagnoses were studied. Healthy, fertile non-pregnant women were used as controls in three of the studies. Blood samples were taken for assay of eight different hormones, folate and homocysteine, and for genomic DNA extraction. A questionnaire was used to assess background data and use of folic acid supplements. Twenty-four-hour recall interviews were performed for validation of the questionnaire. The studied hormones were not good predictors of live birth. The best predictor was age of the women, together with ovulatory menstrual cycles, and thyroid-stimulating hormone and anti-Müllerian hormone (AMH) status. Well-educated women, high-status employed women, and married and infertile women used the most folic acid supplements. Infertile women had better folate status than fertile women. However, pregnancy outcome after infertility treatment was not dependent on folic acid intake, folate status, genetic variation of 5,10-methylenetetrahydrofolate reductase or socioeconomic status. In conclusion, AMH levels vary less than those of other hormones during the menstrual cycle, and AMH could be used as a predictive marker of live birth together with age and ovulation. Folate might play a minor role in IVF pregnancy outcome, but the importance of folate as regards other health perspectives should not be forgotten.
8

Radiologic diagnosis of appendicitis in children /

Kaiser, Sylvie, January 2004 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.
9

Variability of two sampling methods in plaque samples

Hsu, Kuei-Ling C. January 2008 (has links) (PDF)
Thesis (M.S.)--University of Alabama at Birmingham, 2008. / Title from first page of PDF file (viewed Feb. 16, 2009). Includes bibliographical references.
10

Prediction of clinical events in elderly using sensor data a case study on pulse pressure /

Florea, Elena V. January 2009 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2009. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. "May 2009" Includes bibliographical references.

Page generated in 0.0423 seconds