Página 1 dos resultados de 353039 itens digitais encontrados em 0.097 segundos

Contracepção na adolescência: conhecimento sobre os métodos anticoncepcionais entre alunos de escolas públicas municipais de Ribeirão Preto - SP; Birth Control in Adolescence: Knowledge on Contraceptive Methods among Students in the Municipal School System of Ribeirão Preto- SP

Dib, Silvia Cristina Souza
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 13/12/2007 PT
Relevância na Pesquisa
35.87%
Este estudo teve como objetivo analisar o conhecimento sobre métodos anticoncepcionais (MAC) e identificar as variáveis associados ao conhecimento adequado sobre o tema, em adolescentes de escolas públicas municipais de Ribeirão Preto-SP. Consiste em um estudo do tipo transversal, desenvolvido segundo uma abordagem quantitativa. Foram escolhidas, intencionalmente, duas escolas municipais. A amostra foi constituída por cento e vinte (120) adolescentes, de ambos os sexos, com idade de 13 a 16 anos. A coleta de dados ocorreu no período de 05/03/2007 a 16/03/2007, sendo que o instrumento para a coleta foi um questionário semi-estruturado. Os resultados mostraram que os adolescentes deste estudo pertenciam ao grupo de idade entre 13 - 14 anos (81,7%), sendo que adolescen tes com 15-16 anos represen taram a menor parte (18,3%). O sexo masculino representou 51,6% da amostra e, o feminino, 48,4%. A iniciação sexual ocorreu com 13 anos para ambos ,no sexo feminino com (71,43%)e no sexo masculino (41,18%). Com relação ao uso da camisinha masculina 57,5% dos adolescentes entrevistados não utilizaram a camisinha e 28,3% a utilizaram em suas relações sexuais. Quanto ao uso de métodos anticoncepci onais, para a primeira relação...

Operação de carga-rápida (bulk-loading) em métodos de acesso métricos; Bulk-loading Dynamic Metric Acess Methods

Vespa, Thiago Galbiatti
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 10/12/2007 PT
Relevância na Pesquisa
35.86%
O grau de similaridade entre elementos de dados é o fator primordial para a recuperação de informações em Sistemas Gerenciadores de Bases de Dados que manipulam dados complexos, como seqüências genéticas, séries temporais e dados multimídia (imagens, áudios, vídeos, textos longos). Para responder a essas consultas em um tempo reduzido, faz-se necessário utilizar métodos que usam métricas para avaliar a similaridade entre os elementos. Esses métodos são conhecidos como Métodos de Acesso Métricos. Dentre os mais conhecidos na literatura estão a M-tree e a Slim-tree. Existem duas maneiras de executar as operações de construção de índices em qualquer método de acesso: inserindo elemento a elemento ou usando a operação de carga-rápida (bulk-loading). O primeiro tipo de construção é comum e necessário para todo tipo de método de indexação dinâmico. Já as operações de carga-rápida são utilizadas para conjuntos de dados maiores, como por exemplo, na recuperação de backups em bases de dados ou na criação posterior de índices. Nessas situações, a inserção individual tende a ser mais demorada. Realizar uma carga-rápida possibilita a construção de índices com melhor eficiência e em menor tempo...

Zeros de polinômios característicos e estabilidade de métodos numéricos; Zeros of characteristic polynomials and stability of numerical methods

Botta, Vanessa Avansini
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 07/04/2008 PT
Relevância na Pesquisa
35.88%
A Teoria das equações diferenciais faz parte de uma área da Matemática muito rica em aplicações. Os métodos numéricos para a solução de equações diferenciais ordinárias são, da mesma forma que as próprias equações, fontes importantes de problemas a serem pesquisados. Como destaque tem-se os métodos multiderivadas de passo múltiplo, que são importantes na solução de problemas stiff. Os métodos numéricos mais conhecidos para a solução desses problemas são os BDF, que compõem, para L = 1, a família dos métodos (K, L) de Brown. Algumas questões relacionadas à estabilidade dos métodos (K, L) ainda não foram solucionadas como, por exemplo, uma conjectura de Jeltsch. Para analisá-la, é necessário estudar o comportamento dos zeros dos polinômios característicos associados aos métodos (K, L). Neste trabalho é apresentado um estudo sobre zeros de polinômios com o objetivo de demonstrar a validade da conjectura de Jeltsch para K '< OU =' 'K IND; L' . As regiões de estabilidade para alguns valores de K e L fixos são apresentadas e também é utilizada a teoria das order stars para mostrar algumas propriedades dos métodos (K, L). Portanto, este trabalho apresenta um estudo sobre os métodos (K, L) de Brown e usa uma ferramenta pouco utilizada na literatura...

Adolescência e anticoncepção: iniciação sexual e uso de métodos anticoncepcionais em adolescentes da Ilha de Santiago, Cabo Verde - África Ocidental; Adolescence and Contraception: the onset of sexual life and use of contraceptive methods among adolescents of Santiago Island, Cape Verde - West Africa

Tavares, Carlos Mendes
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 08/04/2009 PT
Relevância na Pesquisa
35.87%
Objetivo: Descrever a iniciação sexual e o uso de métodos anticoncepcionais e estimar fatores associados a estas condutas, em adolescentes de 13 a 17 anos de idade, de escolas da rede pública de ensino secundário da Ilha de Santiago, Cabo Verde. Métodos: Estudo transversal realizado com amostra probabilística e representativa de 768 adolescentes com idade entre 13 e 17 anos, de escolas secundárias públicas da Ilha de Santiago em 2007. A associação foi testada pelo teste de proporção, qui-quadrado de Pearson ou Fisher e regressão logística. Para estimar os fatores associados ao uso de métodos anticoncepcionais e preservativo, foi analisada a sub-amostra de 368 adolescentes sexualmente ativos. O início da vida sexual, o uso de métodos anticoncepcionais e o uso de preservativo foram analisados como desfechos. Foram consideradas variáveis independentes: características sociodemográficas, afetivo-sexuais e comportamentais. Foi utilizada regressão logística para análise simultânea dos fatores, considerando-se nível de significância de 5%. Resultados: Entre os adolescentes do sexo masculino, os fatores associados ao início da vida sexual foram: idade maior que 14 anos, ser católico e consumir bebidas alcoólicas. Entre as adolescentes do sexo feminino...

Aplicação de metodologias de preservação e caracterização de fungos na coleção de culturas do Instituto de Medicina Tropical de São Paulo; Application of preservation methods and characterization of fungal isolates from the Instituto de Medicina Tropical de São Paulo culture collection

Cavalcanti, Sarah Desirée Barbosa
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 11/02/2011 PT
Relevância na Pesquisa
35.86%
A coleção de fungos do Instituto de Medicina Tropical de São Paulo/USP compreende 1047 isolados de fungos, algas e actinomicetos de interesse médico e veterinário, que até o início deste estudo eram mantidos sob repiques sucessivos a cada três meses. Criada em 1925 pelo Prof. Dr. Floriano Paulo de Almeida e, a partir de 1953, mantida pelo Prof. Dr. Carlos da Silva Lacaz, a coleção necessitava de adequação de seu espaço físico e atualização nos métodos de preservação dos isolados. A reforma física foi realizada de acordo com as normas de biossegurança recomendadas pelo manual de procedimentos para manipulação de patógenos. Diversos estudos têm demonstrado que repiques sucessivos propiciam alterações nas características morfológicas, antigênicas, genéticas e de virulência de isolados fúngicos. Deste modo, foram aplicadas metodologias de preservação de longo prazo, como: liofilização, água destilada esterilizada, congelamento a -80ºC e em nitrogênio líquido (-196ºC). Foram selecionados 386 isolados, entre fungos dimórficos (213), filamentosos (hialinos e melanizados - 106) e leveduras (67), relacionados às infecções fúngicas mais prevalentes em nosso meio. Foram utilizados dois métodos de preservação para cada grupo de fungos: as leveduras foram submetidas à liofilização e congelamento em freezer -80ºC; e os fungos dimórficos e filamentosos preservados em água destilada esterilizada e no vapor de nitrogênio líquido. Esses isolados foram inicialmente avaliados quanto à caracterização morfológica e...

Métodos intervalares para a resolução de sistemas de equações lineares; Interval methods for resolution of linear equation systems

Holbig, Carlos Amaral
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
35.92%
O estudo dos métodos intervalares é importante para a resolução de sistemas de equações lineares, pois os métodos intervalares produzem resultados dentro de limites confiáveis (do intervalo solução) e provam a existência ou não existência de soluções, portanto produzem resultados confiáveis, o que os métodos pontuais podem não proporcionar. Outro aspecto a destacar é o campo de utilizando de sistemas de equações lineares em problemas das engenharias e outras ciências, o que mostra a aplicabilidade desses métodos e por conseguinte a necessidade de elaboração de ferramentas que possibilitem a implementação desses métodos intervalares. O objetivo deste trabalho não é a elaboração de novos métodos intervalares, mas sim o de realizar uma descrição e implementação de alguns dos métodos intervalares encontrados na bibliografia pesquisada. A versão intervalar dos métodos pontuais não é simples e o calculo por métodos intervalares pode ser dispendioso, uma vez que se está tratando com vetores e matrizes de intervalos. A implementação dos métodos intervalares são foi possível graças a existência de ferramentas, como o compilador Pascal-XSC, que incorpora as suas características aspectos importantes como a aritmética intervalar...

Evaluation of three methods for hemoglobin measurement in a blood donor setting

Rosenblit,Jacob; Abreu,Cláudia Regina; Szterling,Leonel Nulman; Kutner,José Mauro; Hamerschlak,Nelson; Frutuoso,Paula; Paiva,Thelma Regina Silva Stracieri de; Ferreira Júnior,Orlando da Costa
Fonte: Associação Paulista de Medicina - APM Publicador: Associação Paulista de Medicina - APM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/1999 EN
Relevância na Pesquisa
35.87%
CONTEXT: The hemoglobin (Hb) level is the most-used parameter for screening blood donors for the presence of anemia, one of the most-used methods for measuring Hb levels is based on photometric detection of cyanmetahemoglobin, as an alternative to this technology, HemoCue has developed a photometric method based on the determination of azide metahemoglobin. OBJECTIVE: To evaluate the performance of three methods for hemoglobin (Hb) determination in a blood bank setting. DESIGN: Prospective study utilizing blood samples to compare methods for Hb determination. SETTING: Hemotherapy Service of the Hospital Israelita Albert Einstein, a private institution in the tertiary health care system. SAMPLE: Serial blood samples were collected from 259 individuals during the period from March to June 1996. MAIN MEASUREMENTS: Test performances and their comparisons were assessed by the analysis of coefficients of variation (CV), linear regression and mean differences. RESULTS: The CV for the three methods were: Coulter 0.68%, Cobas 0.82% and HemoCue 0.69%. There was no difference between the mean Hb determination for the three methods (p>0.05). The Coulter and Cobas methods showed the best agreement and the HemoCue method gave a lower Hb determination when compared to both the Coulter and Cobas methods. However...

Evaluation of invasive and non-invasive methods for the diagnosis of Helicobacter pylori infection in symptomatic children and adolescents

Ogata,Silvio Kazuo; Kawakami,Elisabete; Patrício,Francy Reis Silva; Pedroso,Margareth Zabeu; Santos,Antonio Mario
Fonte: Associação Paulista de Medicina - APM Publicador: Associação Paulista de Medicina - APM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2001 EN
Relevância na Pesquisa
35.87%
CONTEXT: Multiple diagnostic methods are available for the detection of Helicobacter pylori infection, but at present no single one can be used as the gold standard. OBJECTIVE: The aim of this study was to evaluate the diagnostic accuracy of 3 invasive and 2 non-invasive methods for detection of Helicobacter pylori infection in symptomatic children and adolescents. DESIGN: Prospective cohort study SETTING: Peptic Disease outpatients service, Discipline of Pediatric Gastroenterology, Universidade Federal de São Paulo / Escola Paulista de Medicina. PATIENTS: Forty-seven patients who underwent endoscopy because of dyspeptic symptoms. DIAGNOSTIC METHODS: Endoscopy with gastric biopsies for 3 invasive (rapid urease test, histology and culture) and 2 non-invasive methods (a commercial ELISA serology and 13carbon urea breath test - isotope ratio mass spectrometry) for detection of Helicobacter pylori infection. MAIN MEASUREMENTS: Sensitivity, specificity, positive and negative predictive values of each method and agreement and disagreement rates between the methods. RESULTS: Forty-seven patients [mean age, 11y9mo (SD 2y10mo), 27 female and 20 male]; 62% of them were Helicobacter pylori-positive. All methods agreed in 61%, and were negative in 21% and positive in 40%. The greatest concordance between 2 methods occurred between the invasive methods: histology and rapid urease test (89.6%) and histology and culture (87.5%). The greatest sensitivity...

Relative efficiency of anuran sampling methods in a restinga habitat (Jurubatiba, Rio de Janeiro, Brazil)

Rocha,C. F. D.; Van Sluys,M.; Hatano,F. H.; Boquimpani-Freitas,L.; Marra,R. V.; Marques,R. V.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/11/2004 EN
Relevância na Pesquisa
35.87%
Studies on anurans in restinga habitats are few and, as a result, there is little information on which methods are more efficient for sampling them in this environment. Ten methods are usually used for sampling anuran communities in tropical and sub-tropical areas. In this study we evaluate which methods are more appropriate for this purpose in the restinga environment of Parque Nacional da Restinga de Jurubatiba. We analyzed six methods among those usually used for anuran samplings. For each method, we recorded the total amount of time spent (in min.), the number of researchers involved, and the number of species captured. We calculated a capture efficiency index (time necessary for a researcher to capture an individual frog) in order to make comparable the data obtained. Of the methods analyzed, the species inventory (9.7 min/searcher /ind.- MSI; richness = 6; abundance = 23) and the breeding site survey (9.5 MSI; richness = 4; abundance = 22) were the most efficient. The visual encounter inventory (45.0 MSI) and patch sampling (65.0 MSI) methods were of comparatively lower efficiency restinga, whereas the plot sampling and the pit-fall traps with drift-fence methods resulted in no frog capture. We conclude that there is a considerable difference in efficiency of methods used in the restinga environment and that the complete species inventory method is highly efficient for sampling frogs in the restinga studied and may be so in other restinga environments. Methods that are usually efficient in forested areas seem to be of little value in open restinga habitats.

Handbook on Impact Evaluation : Quantitative Methods and Practices

Khandker, Shahidur R.; Koolwal, Gayatri B.; Samad, Hussain A.
Fonte: World Bank Publicador: World Bank
Relevância na Pesquisa
35.89%
This book reviews quantitative methods and models of impact evaluation. The formal literature on impact evaluation methods and practices is large, with a few useful overviews. Yet there is a need to put the theory into practice in a hands-on fashion for practitioners. This book also details challenges and goals in other realms of evaluation, including monitoring and evaluation (M&E), operational evaluation, and mixed-methods approaches combining quantitative and qualitative analyses. This book is organized as follows. Chapter two reviews the basic issues pertaining to an evaluation of an intervention to reach certain targets and goals. It distinguishes impact evaluation from related concepts such as M&E, operational evaluation, qualitative versus quantitative evaluation, and ex-ante versus ex post impact evaluation. Chapter three focuses on the experimental design of an impact evaluation, discussing its strengths and shortcomings. Various non-experimental methods exist as well, each of which are discussed in turn through chapters four to seven. Chapter four examines matching methods...

Using Mixed Methods in Monitoring and Evaluation : Experiences from International Development

Bamberger, Michael; Rao, Vijayendra; Woolcock, Michael
Fonte: Banco Mundial Publicador: Banco Mundial
Relevância na Pesquisa
35.89%
This paper provides an overview of the various ways in which mixing qualitative and quantitative methods could add value to monitoring and evaluating development projects. In particular it examines how qualitative methods could address some of the limitations of randomized trials and other quantitative impact evaluation methods; it also explores the importance of examining "process" in addition to "impact", distinguishing design from implementation failures, and the value of mixed methods in the real-time monitoring of projects. It concludes by suggesting topics for future research -- including the use of mixed methods in constructing counterfactuals, and in conducting reasonable evaluations within severe time and budget constraints.

Integrating Qualitative Methods into Investment Climate Impact Evaluations

Mendoza Alcantara, Alejandra; Woolcock, Michael
Fonte: World Bank Group, Washington, DC Publicador: World Bank Group, Washington, DC
EN_US
Relevância na Pesquisa
35.89%
Incorporating qualitative methods into the evaluation of development programs has become increasingly popular in recent years, both for the distinctive insights such approaches can bring in their own right and because of their capacity to complement the strengths -- and where necessary correct some of the weaknesses -- of quantitative approaches. Some initial work deploying mixed methods has been undertaken in the assessment of investment climate reforms, but considerable room for expansion exists. This paper summarizes some of the key principles and practices underpinning mixed methods evaluations in development, highlight some notable examples of how such work has been conducted (and the particular contributions it has made), and offers some guidelines for those seeking to increase the sophistication and utility of qualitative methods in the evaluation of investment climate reforms.

Families of two-step fourth order P-stable methods for second order differential equations

Chawla, M.M.; Neta, Beny
Fonte: Escola de Pós-Graduação Naval Publicador: Escola de Pós-Graduação Naval
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
35.88%
This paper deals with a class of symmetric (hybrid) two-step fourth order P-stable methods for the numerical solution of special second order initial value problems. Such methods were proposed independently by Cash and Chawla and normally require three function evaluations per step. The purpose of this paper is to point out that there are some values of the (free) parameters available in the methods proposed which can reduce this work; we study two classes of such methods. This first is the class of 'economical' methods (see Definition 3.1) which reduce this work to two function evaluations per step, and the second is the class of 'efficient' methods (see Definition 3.2) which reduce this work with respect to implementation for nonlinear problems. We report numerical experiments to illustrate the order, acuracy and implementational aspects of these two classes of methods.

Methods for two-party privacy-preserving linear programming.

Bednarz, Alice
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2012
Relevância na Pesquisa
35.9%
Imagine two companies who each manage part of a delivery network. Suppose these companies are considering the benefits of cooperation | would they be able to deliver packages faster and more cheaply if they could share each other's networks? Answering this question would usually mean sharing private company information with each other, such as network topologies, internal capacities and budgets. Companies are reluctant to share such information, for fear of losing their competitive advantage, fear of revealing sensitive company information, or fear of breaching anti-trust laws. However, collaboration could bring mutual gain. What if it were possible to collaborate without sharing sensitive information? Fortunately, a methodology called secure multiparty computation can alleviate these privacy concerns. Developed in the 1980s, it allows parties who don't trust each other to compute functions involving their private data amongst themselves, whilst keeping their private information hidden. This method eliminates the need to find a trusted third party. Linear programs are one of the most common types of optimisation problems, occurring widely in industry. For example, supply chain planning problems, delivery problems and scheduling problems can all be modelled as linear programs. Recently...

Introducing agile methods in a large software development organisation: a case study

Giblin, Mary
Fonte: University of Limerick Publicador: University of Limerick
Tipo: info:eu-repo/semantics/doctoralThesis; all_ul_research; ul_published_reviewed; ul_theses_dissertations
ENG
Relevância na Pesquisa
35.87%
peer-reviewed; The adoption of agile methods of software development has gained momentum within the software industry. NW Soft Solutions Ltd. (a pseudonym) is a large software development unit that develops large-scale network centric software solutions. NW Soft Solutions Ltd decided to adopt an agile development methodology. Martin Fowler in his article “The New Methodology”, states that in his opinion “Since agile methods are so fundamentally people-oriented, it's essential that you start with a team that wants to try and work in an agile way”. Using NW Soft Solutions as a case study, this thesis sets out to show how the developer’s attitudes towards agile methods change during the course of a transition from a more traditional waterfall methodology to agile methods. We see a shift in focus from agile practices at a superficial level towards the core values that underpin agile methods. Object-oriented metrics are used to evaluate and characterise the source code produced by teams using agile methods. The results obtained from the source code produced using agile methods are compared with the results for source code produced using a more traditional methodology. The contrast is stark. This case study shows that agile methods have guided the developers to produce code that manifests better quality and maintainability characteristics. Correlations between the degree of agility in a team and the characteristics of the code produced by that team are also explored.

Literacy methods, teaching methods and contents of literacy: historical perspectives and current challenges; Métodos de alfabetização, métodos de ensino e conteúdos da alfabetização: perspectivas históricas e desafios atuais

Frade, Isabel Cristina Alves da Silva
Fonte: Universidade Federal de Santa Maria Publicador: Universidade Federal de Santa Maria
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em 04/11/2007 POR
Relevância na Pesquisa
35.87%
The discussion about methods is recurrent in Pedagogy of literacy, and discuss it again means to think about the own schooling of the contents of the language. Its opacity and transparency as a theme, in some moments, may be described by the way the methods’ issue is taken: sometimes as a central question, others as a secondary problem; sometimes as something to be denied and, surprisingly, due to its reappearance in contemporary polemics, as a “solution” to the problems of literacy in many countries. Taking into account the researches about the history of literacy, as well as some practices revealed in books and manuals to the beginning of its process, this article aims at recovering the place of the methods of literacy from a historical and current point of view. The basis to this study considers that when methods are not in evidence in the theoretical field and in the field of politics, the forms of materializing new theories and challenges in actions are part of the nature of Pedagogy. To reflect about the different ways of intervention/methods and methodologies allows us to learn some lessons. Aiming at recovering principles, solutions and problems that methods present, this text is organized around the following objectives: a) to discuss the literacy methods...

Imputation of truncated p-values for meta-analysis methods and its genomic application

Tang, Shaowu; Ding, Ying; Sibille, Etienne; Mogil, Jeffrey S.; Lariviere, William R.; Tseng, George C.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 19/01/2015
Relevância na Pesquisa
35.88%
Microarray analysis to monitor expression activities in thousands of genes simultaneously has become routine in biomedical research during the past decade. A tremendous amount of expression profiles are generated and stored in the public domain and information integration by meta-analysis to detect differentially expressed (DE) genes has become popular to obtain increased statistical power and validated findings. Methods that aggregate transformed $p$-value evidence have been widely used in genomic settings, among which Fisher's and Stouffer's methods are the most popular ones. In practice, raw data and $p$-values of DE evidence are often not available in genomic studies that are to be combined. Instead, only the detected DE gene lists under a certain $p$-value threshold (e.g., DE genes with $p$-value${}<0.001$) are reported in journal publications. The truncated $p$-value information makes the aforementioned meta-analysis methods inapplicable and researchers are forced to apply a less efficient vote counting method or na\"{i}vely drop the studies with incomplete information. The purpose of this paper is to develop effective meta-analysis methods for such situations with partially censored $p$-values. We developed and compared three imputation methods - mean imputation...

Mixed methods en la investigación de la actividad física y el deporte

Anguera Argilaga, María Teresa; Camerino i Foguet, Oleguer; Castañer Balcells, Marta; Sánchez Algarra, Pedro
Fonte: Universidade Autônoma de Barcelona Publicador: Universidade Autônoma de Barcelona
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em //2014 SPA
Relevância na Pesquisa
35.9%
La lógica del procedimiento científico se ha desarrollado tradicionalmente desde planteamientos dicotómicos, y uno de los más influyentes fue la radical oposición entre paradigma cuantitativo vs. paradigma cualitativo. A finales del siglo XX irrumpe con fuerza la corriente de mixed methods, que ya no podemos considerar emergente, a pesar de que sigue creciendo con fuerza, porque está ya estabilizada. Su avance ha sido desigual en función de los ámbitos de conocimiento, y en el de actividad física y deporte ha sido relativamente tardía, pero últimamente está dando magníficos frutos. En este articulo se presenta la panorámica actual relativa a las etapas del proceso de investigación, relativa a diseños, como planificación empírica estratégica del problema de estudio, recogida de datos, que abarca un arco de diferentes posibilidades que hasta hace poco se hallaban en liza, y de análisis de datos, que nos conducte a planteamientos no esperables hace pocos años. Nos hallamos en un momento de especial potencial de desarrollo metodológico en el marco de los mixed methods, y este articulo trata de impulsar las iniciativas en este sentido.; Scientific methods have traditionally been based on dichotomous approaches, one of the most influential being radical opposition between quantitative and qualitative paradigms. However...

Numerical methods for systems of highly oscillatory ordinary differential equations

Khanamiryan, Marianna
Fonte: University of Cambridge; Department of Applied Mathematics and Theoretical Physics Publicador: University of Cambridge; Department of Applied Mathematics and Theoretical Physics
Tipo: Thesis; doctoral; PhD
EN
Relevância na Pesquisa
35.89%
Current research made contribution to the numerical analysis of highly oscillatory ordinary differential equations. Highly oscillatory functions appear to be at the forefront of the research in numerical analysis. In this work we developed efficient numerical algorithms for solving highly oscillatory differential equations. The main important achievements are: to the contrary of classical methods, our numerical methods share the feature that asymptotically the approximation to the exact solution improves as the frequency of oscillation grows; also our methods are computationally feasible and as such do not require fine partition of the integration interval. In this work we show that our methods introduce better accuracy of approximation as compared with the state of the art solvers in Matlab and Maple.; This thesis presents methods for efficient numerical approximation of linear and non-linear systems of highly oscillatory ordinary differential equations. Phenomena of high oscillation is considered a major computational problem occurring in Fourier analysis, computational harmonic analysis, quantum mechanics, electrodynamics and fluid dynamics. Classical methods based on Gaussian quadrature fail to approximate oscillatory integrals. In this work we introduce numerical methods which share the remarkable feature that the accuracy of approximation improves as the frequency of oscillation increases. Asymptotically...

The "movement" of mixed methods research and the role of educators

Creswell,John W.; Garrett,Amanda L.
Fonte: South African Journal of Education Publicador: South African Journal of Education
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2008 EN
Relevância na Pesquisa
35.88%
The landscape of research is continually evolving, enabling researchers to study increasingly complex phenomena. Educational researchers have propelled much of this forward progress and have developed novel methodologies to provide increasingly sound and complete evidence. Mixed methods research has emerged alongside quantitative and qualitative approaches as an important tool for researchers. In this article our overall aim is to better acquaint educational scholars with the mixed methods field by articulating the development of the mixed methods field and by citing current trends and issues. The role of educational researchers in the evolution of mixed methods research is high-lighted. The early and ongoing dialogue of mixed methods research is multi-disciplinary in nature with current writings across fields. The current debate over key aspects of mixed methods research is now in progress and is ripe for future contributions. Even the very nature of what constitutes mixed methods research is being discussed among scholars. Understanding and advancing the mixed methods field is an important goal for methodologists and researchers. With the increased interest and enthusiasm for mixed methods research, it is likely that the dialogue surrounding mixed methods approaches will thrive...