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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

DEVELOPMENT AND COMMERCIALIZATION OF A FECAL DNA BASED MOLECULAR DIAGNOSTIC ASSAY FOR COLORECTAL CANCER SCREENING

Gokhale, Priyanka G. January 2010 (has links)
No description available.
22

Bio-BCA (Bio-Barcode Cascade Amplification) : development of a photosensitive, DNA-based exponential amplification platform technology for the detection of nucleic acid biomarkers

Lehnus, Massimiliano January 2018 (has links)
No description available.
23

A comparison of the subtests of the Gesell School Readiness Screening Test as predictors of reading achievement

Sapp, Dolores W. 01 January 1984 (has links) (PDF)
The major purpose of this study was to determine which subtests of the Gesell School Readiness Screening Test are the best predictors of reading achievement. The procedure used was a stepwise multiple regression to determine which subtests were the best predictors of achievement for each reading section of the Comprehensive Test of Basic Skills. Seventy-two students from four schools were evaluated for this study. Three testing instruments were administered to these students. They were the Gesell test, the Otis-Lennon test, and the reading subtests of the Comprehensive Test of Basic Skills. The Gesell test consisted of eight subtests: Cubes, Name, Copy Forms, Numbers, Incomplete Man, Interview, Animals, and Interests. The best single predictor subtest was Interview. Four separate regression analyses were computed, one for each of the subtests of the reading section of the Comprehensive Test of Basic Skills. In each case, the Gesell subtest Interview entered the stepwise regression at step one. After the information for Interview was entered into the regression equation, the remaining seven subtest scores added very little to the prediction. In summary, although there was some predictive ability in the Gesell test, the level of predictability was not strong. Post factum interpretation of the low predictability was presented as were recommendations for Volusia County in the use of the Gesell test for placement of students in the kindergarten-first grade transitional class.
24

Measurement of Self-Heating of Biomass Pellets using Isothermal Calorimetry

Larsson, Ida January 2017 (has links)
Self-heating in storage facilities of biomass pellet can lead to spontaneous combustion. This has resulted in many fires over the years, causing both financial and environmental losses. In order to assess the risk for spontaneous combustion of biomass pellets during storage, it is important to know how prone the fuel is to self-heating, i.e. to determine its reactivity. This thesis presents experimental work performed to develop a sensitive screening test procedure for biomass pellets, using isothermal calorimetry for direct measurement of the heat production rate. This method can be used to compare the reactivity of different biomass pellets. This could be useful for e.g. facility owners to gain better knowledge of their fuels propensity for self-heating and thereby facilitate safer storage. The screening test procedure can also be used for research purposes. Experiments have been performed with 31 different biomass pellet batches to investigate how the pellet composition, origin, etc. influence the reactivity of the pellets. The results from these experiments clearly show a significant difference in reactivity between different types of pellets. The results indicate that pine/spruce mix pellets are significantly more reactive than all other types of pellets tested, and that pellets consisting of 100 % pine are more reactive than pellets consisting of 100 % spruce. Pellets produced from winery wastes, straw, or eucalyptus, have low reactivity compared to pellets consisting of pine and/or spruce. The reactivity of the pellets was shown to be reduced by either introducing certain types of anti-oxidants into the pellets or by extracting lipids from the raw material of pellets. The screening test procedure is already being used today by some facility owners for assessing their fuels propensity for self-heating. The procedure is also one of the suggested test methods in “ISO/CD 20049 Solid biofuels — Determination of self-heating of pelletized biofuels”. / This thesis presents experimental work performed to develop a sensitive screening test procedure for biomass pellets, using isothermal calorimetry for direct measurement of the heat production rate. This method can be used to directly compare the reactivity, that is how prone the fuel is to self-heating, of different batches of biomass pellets. The results could be used for safety assessment by the industry or for research purposes to investigate how different factors influence the self-heating potential. Experiments were performed with 31 different biomass pellet batches to investigate how the pellet composition, origin, etc. influence the heat release rate. The results clearly show that there is a significant difference in reactivity between different types of pellets. Pine/spruce mix pellets are more reactive than the other types of pellets tested and pellets consisting of 100 % pine are more reactive than pellets consisting of 100 % spruce. Pellets produced from winery wastes, straw, or eucalyptus, have low reactivity compared to pellets consisting of pine and/or spruce. The results also show that the reactivity of the pellets can be reduced by either introducing certain types of anti-oxidants into the pellets or by extracting lipids from the raw material of pellets.
25

Acompanhamento do desenvolvimento infantil em creches. / Follow-up of the child development in day care centers.

Beteli, Vivian Cesar 29 March 2006 (has links)
O período da vida em que as crianças freqüentam instituições de educação infantil (creches e pré-escolas) corresponde a uma fase crítica para o desenvolvimento. Dentre as áreas do desenvolvimento, a linguagem é uma das mais vulneráveis uma vez que necessita intensamente da intervenção de outrem. Devido à importância do desenvolvimento acredita-se que acompanhá-lo é uma ação básica de saúde, bem como um importante cuidado de enfermagem. Os objetivos desta pesquisa foram: descrever perfil de desenvolvimento, especialmente no que diz respeito às habilidades de linguagem, de crianças hígidas de 0 a 6 anos de idade incompletos que freqüentam instituição de educação infantil. Trata-se de um estudo quantitativo, descritivo e longitudinal (coorte) com amostra não probabilística. Utilizou-se o Teste de Triagem de Desenvolvimento de Denver II (TTDD II). No período de 2001 a 2004 foram realizadas 150 aplicações do TTDD II em crianças de 4 meses e 23 dias até 5 anos 7 meses e 11 dias. Tais crianças freqüentavam instituições de educação infantil consideradas de boa qualidade localizadas na cidade de São Paulo. Os critérios de inclusão foram: idade gestacional conhecida (para menores de 2 anos), ausência de mal formação congênita, não ser estrangeira (devido à área de linguagem), e nunca ter freqüentado outra creche. A condição sócio-econômica das famílias era homogênea, sendo a renda média de 7,60 salários mínimos, portanto, superior à renda média per capita na região metropolitana de São Paulo no mesmo período, que era 4,28 salários mínimos. Os resultados foram estatisticamente iguais nas 3 creches, tanto para o resultado global do TTDD II, quanto para a área de habilidades de linguagem isoladamente. Não houve associação estatística dos resultados em relação aos sexos. Em termos de resultado global houve melhora estatisticamente significante ao longo das 5 avaliações (1ª x 3ª p=0,015). O desempenho da linguagem se manteve estatisticamente igual ao longo dos 5 momentos. Assim, é possível ventilar as seguintes possibilidades: as 3 instituições em questão não estão conseguindo otimizar as condições de molde a propiciar às crianças o pleno desenvolvimento de suas habilidades de linguagem, e/ou, o TTDD II não possibilitou a triagem adequada nesta área. A favor da primeira possibilidade há o fato que as habilidades de linguagem parecem declinar quando as crianças alcançam 3 anos de idade, melhorando mais tarde. Exatamente neste período o módulo educadora/crianças está abaixo no nível recomendado. Quanto à segunda possibilidade, tem-se que o TTDD II ainda não está validado para a língua portuguesa empregada no Brasil. Conclui-se que: freqüentar as creches pode ter sido benéfico para o desenvolvimento das crianças no que tange ao desenvolvimento global. No caso da das habilidades de linguagem há necessidade de outras pesquisas. / The period of life in which children are enrolled in institutions of child education (pre-school and day care centers) is a critical phase for the child development. Among the developmental areas, the language is the most susceptible since it strongly needs someone else’s intervention. Due to the development importance child follow-up is a basic health care in nursing. The purpose of this study was to describe the development profile, specially regarding language abilities of healthy children with ages ranging from 0 to 6 incomplete years, who were enrolled in child day care centers. This is a quantitative, descriptive and longitudinal (cohort) study with a non-probabilistic sampling. The Denver II Developmental Screening Test (DDST II) was used. From 2001 to 2004, 150 DDST III were applied in children with ages varying from 4 months and 23 days up to 5 years, 7 months and 11 days. These children were enrolled in good quality Day Care Centers located in the city of São Paulo. The criteria of inclusion were as follows: identified gestational age (for those under the age of 2 years), lack of congenital malformation, born Brazilian (due to the language area) and never been enrolled in a day care center before. The socioeconomic condition of the families was homogeneous, average of 7.60 minimum wage, thus, above the mean income per capita in the metropolitan area of São Paulo, in the same period, which was 4.28 minimum wages. The results were statistically equal in three Day Care Centers, both for the global result of the DDST II and for the language ability areas alone. There was no statistical association of the results regarding gender. In terms of global results, a statistically significant improve was observed in the five evaluations performed (1a x 3a p=0.015). Language performance maintained statistically equal on these five moments. Consequently, it was possible to demonstrate the following likelihood features: the three institutions were not able to optimize the conditions needed to give the child full development of his/her language abilities and/or the DDST II did not allow an adequate screening in this area. In the first option, it seems that language abilities may decrease when the child reaches the age of three years and developing later. At this moment, the educator/child module is below the recommended level. Regarding the second option, the DDSTII is not yet validated for the Portuguese language in Brazil. It was concluded that to enroll children in day care centers seems to be effective for the global child development. Regarding language abilities further studies are still needed.
26

Dítě s rizikem specifické poruchy učení / Child with risk for learning disabilities

WALDOVÁ, Petra January 2016 (has links)
This diploma thesis deals with the possibilities of prediction of specific learning disabilities among children of preschool age. The thesis is divided into two consequent parts a theoretical part and a practical part. In the theoretical part I focus mainly on the etiology and the diagnosis of specific learning disabilities. The thesis focuses mainly on given examples of a few predictive batteries from Czech and even foreign authors. The practical part contains results of a research survey where are the data I collected through predictive battery of British authors: Nicolson and Fawcett: The Dyslexia Early Screening Test. The main objective of the diploma thesis was to find out the possibility of using this test by pedagogical workers at pre-schools in order to avoid specific learning disabilities. For the research, the quantitative research method was used.
27

Avalia??o do desenvolvimento neuropsicomotor em crian?as na rede b?sica de sa?de utilizando o teste de Denver II: identifica??o de fatores de risco materno

Cunha, Hilton Luiz da 22 February 2008 (has links)
Made available in DSpace on 2014-12-17T14:13:22Z (GMT). No. of bitstreams: 1 HiltonLC.pdf: 613137 bytes, checksum: 5fb2db6e3e506a15970d49908b77bf14 (MD5) Previous issue date: 2008-02-22 / Alterations in the neuropsychomotor development of children are not rare and can manifest themselves with varying intensity at different stages of their development. In this context, maternal risk factors may contribute to the appearance of these alterations. A number of studies have reported that neuropsychomotor development diagnosis is not an easy task, especially in the basic public health network. Diagnosis requires effective, low-cost, and easy - to-apply procedures. The Denver Developmental Screening Test, first published in 1967, is currently used in several countries. It has been revised and renamed as the Denver II Test and meets the aforementioned criteria. Accordingly, the aim of this study was to apply the Denver II Test in order to verify the prevalence of suspected neuropsychomotor development delay in children between the ages of 0 and 12 months and correlate it with the following maternal risk factors: family income, schooling, age at pregnancy, drug use during pregnancy, gestational age, gestational problems, type of delivery and the desire to have children. For data collection, performed during the first 6 months of 2004, a clinical assessment was made of 398 children selected by pediatricians and the nursing team of each public health unit. Later, the parents or guardians were asked to complete a structured questionnaire to determine possible risk indicators of neuropsychomotor development delay. Finally the Denver II Developmental Screening Test (DDST) was applied. The data were analyzed together, using Statistical Package for Social Science (SPSS) software, version 6.1. The confidence interval was set at 95%. The Denver II Test yielded normal and questionable results. This suggests compromised neuropsychomotor development in the children examined and deserves further investigation. The correlation of the results with preestablished maternal risk variables (family income, mother s schooling, age at pregnancy, drug use during the pregnancy and gestational age) was strongly significant. The other maternal risk variables (gestational problems, type of delivery and desire to have children) were not significant. Using an adjusted logistic regression model, we obtained the estimate of the greater likelihood of a child having suspected neuropsychomotor development delay: a mother with _75 4 years of schooling, chronological age less than 20 years and a drug user during pregnancy. This study produced two manuscripts, one published in Acta Cir?rgica Brasileira , in which an analysis was performed of children with suspected neuropsychomotor development delay in the city of Natal, Brazil. The other paper (to be published) analyzed the magnitude of the independent variable maternal schooling associated to neuropsychomotor development delay, every 3 months during the first twelve months of life of the children selected.. The results of the present study reinforce the multifactorial characteristic of development and the cumulative effect of maternal risk factors, and show the need for a regional policy that promotes low-cost programs for the community, involving children at risk of neuropsychomotor development delay. Moreover, they suggest the need for better qualified health professionals in terms of monitoring child development. This was an inter- and multidisciplinary study with the integrated participation of doctors, nurses, nursing assistants and professionals from other areas, such as statisticians and information technology professionals, who met all the requirements of the Postgraduate Program in Health Sciences of the Federal University of Rio Grande do Norte / As altera??es do desenvolvimento neuropsicomotor na crian?a n?o s?o raras e podem manifestar-se com intensidade vari?vel em diferentes etapas do seu desenvolvimento. Neste contexto, fatores de risco materno podem contribuir para o aparecimento daquelas altera??es. Alguns estudos t?m relatado que o diagn?stico neuropsicomotor n?o ? uma tarefa f?cil, sobretudo, na rede b?sica de sa?de. Isto requer procedimentos eficazes, de baixo custo e de f?cil aplicabilidade. O Teste de Triagem de Desenvolvimento de Denver, publicado pela primeira vez em 1967, hoje usado em diversos pa?ses, revisado e nominado atualmente como Teste de Denver II, preenche aqueles crit?rios. Dessa forma, o objetivo deste estudo foi aplicar o Teste de Denver II com a finalidade de verificar a preval?ncia de suspeita de atraso no desenvolvimento neuropsicomotor de crian?as de 0 a 12 meses de idade e correlacionar com fatores maternos de risco: renda familiar, escolaridade, idade ao engravidar, uso de drogas durante a gesta??o, idade gestacional, intercorr?ncias gestacionais, tipo de parto e o desejo de ter o filho. Para a coleta dos dados, realizada nos seis primeiros meses do ano de 2004, inicialmente foi feita a avalia??o cl?nica das 398 crian?as selecionadas com a participa??o de pediatras e equipe de enfermagem de cada posto de sa?de; posteriormente, os pais ou cuidadores responderam a um question?rio estruturado para determina??o de poss?veis indicadores de risco de desenvolvimento neuropsicomotor. Finalmente, aplicou-se o Teste de Triagem de Desenvolvimento de Denver II (Teste de Denver II). Os dados coletados foram analisados em conjunto, atrav?s do programa Statistical Package for Social Science SPSS, vers?o 6.1. Utilizou-se o intervalo de confian?a de 95%. Atrav?s da aplica??o do Teste de Denver II, obtivemos resultados Normais e Question?veis. Estes sugerem preju?zos no desenvolvimento neuropsicomotor da crian?a examinada e merece maior investiga??o. A correla??o dos resultados com as vari?veis de risco materno pr?-estabelecidas renda familiar, escolaridade da m?e, idade ao engravidar, uso de drogas durante a gesta??o e idade gestacional foi fortemente significativa. As outras vari?veis de risco materno - intercorr?ncias gestacionais, tipo de parto e desejo de ter filho - n?o foram significativas. Atrav?s da t?cnica multivariada de regress?o log?stica, chegamos ? estimativa de maior probabilidade de uma crian?a ser suspeita de atraso de desenvolvimento neuropsicomotor: m?e com instru??o escolar formal _ 4 anos, idade cronol?gica inferior a 20 anos e usu?ria de droga durante a gesta??o. Este estudo gerou dois manuscritos, um deles publicado na "Acta "Cir?rgica Brasileira , pela qual se faz uma an?lise de crian?as com suspeita de atraso no seu desenvolvimento neuropsicomotor na rede p?blica de sa?de, da cidade de Natal. O outro manuscrito, a ser publicado, analisa a magnitude da vari?vel independente escolaridade materna associada ? suspeita de atraso de desenvolvimento neuropsicomotor, trimestralmente, nos doze primeiros meses de vida das crian?as selecionadas. Os resultados apresentados neste estudo refor?am a caracter?stica multifatorial de neurodesenvolvimento e o efeito cumulativo dos fatores de risco ix materno; alertam para a necessidade de uma pol?tica regional que promovam programas de baixo custo e abordagem comunit?ria, envolvendo crian?as com riscos de atraso no seu desenvolvimento neuropsicomotor. Al?m disso, sugere um melhor preparo de todos os profissionais de sa?de em rela??o ? vigil?ncia do desenvolvimento da crian?a. Esta foi uma pesquisa inter e multidisciplinar pela participa??o integrada de profissionais da sa?de, como m?dicos, enfermeiros, auxiliares de enfermagem e profissionais de outras ?reas, como estat?sticos e profissionais de inform?tica, que preenchem todos os requisitos do Programa de P?sgradua??o em Ci?ncias da Sa?de da Universidade Federal do Rio Grande do Norte
28

Acompanhamento do desenvolvimento infantil em creches. / Follow-up of the child development in day care centers.

Vivian Cesar Beteli 29 March 2006 (has links)
O período da vida em que as crianças freqüentam instituições de educação infantil (creches e pré-escolas) corresponde a uma fase crítica para o desenvolvimento. Dentre as áreas do desenvolvimento, a linguagem é uma das mais vulneráveis uma vez que necessita intensamente da intervenção de outrem. Devido à importância do desenvolvimento acredita-se que acompanhá-lo é uma ação básica de saúde, bem como um importante cuidado de enfermagem. Os objetivos desta pesquisa foram: descrever perfil de desenvolvimento, especialmente no que diz respeito às habilidades de linguagem, de crianças hígidas de 0 a 6 anos de idade incompletos que freqüentam instituição de educação infantil. Trata-se de um estudo quantitativo, descritivo e longitudinal (coorte) com amostra não probabilística. Utilizou-se o Teste de Triagem de Desenvolvimento de Denver II (TTDD II). No período de 2001 a 2004 foram realizadas 150 aplicações do TTDD II em crianças de 4 meses e 23 dias até 5 anos 7 meses e 11 dias. Tais crianças freqüentavam instituições de educação infantil consideradas de boa qualidade localizadas na cidade de São Paulo. Os critérios de inclusão foram: idade gestacional conhecida (para menores de 2 anos), ausência de mal formação congênita, não ser estrangeira (devido à área de linguagem), e nunca ter freqüentado outra creche. A condição sócio-econômica das famílias era homogênea, sendo a renda média de 7,60 salários mínimos, portanto, superior à renda média per capita na região metropolitana de São Paulo no mesmo período, que era 4,28 salários mínimos. Os resultados foram estatisticamente iguais nas 3 creches, tanto para o resultado global do TTDD II, quanto para a área de habilidades de linguagem isoladamente. Não houve associação estatística dos resultados em relação aos sexos. Em termos de resultado global houve melhora estatisticamente significante ao longo das 5 avaliações (1ª x 3ª p=0,015). O desempenho da linguagem se manteve estatisticamente igual ao longo dos 5 momentos. Assim, é possível ventilar as seguintes possibilidades: as 3 instituições em questão não estão conseguindo otimizar as condições de molde a propiciar às crianças o pleno desenvolvimento de suas habilidades de linguagem, e/ou, o TTDD II não possibilitou a triagem adequada nesta área. A favor da primeira possibilidade há o fato que as habilidades de linguagem parecem declinar quando as crianças alcançam 3 anos de idade, melhorando mais tarde. Exatamente neste período o módulo educadora/crianças está abaixo no nível recomendado. Quanto à segunda possibilidade, tem-se que o TTDD II ainda não está validado para a língua portuguesa empregada no Brasil. Conclui-se que: freqüentar as creches pode ter sido benéfico para o desenvolvimento das crianças no que tange ao desenvolvimento global. No caso da das habilidades de linguagem há necessidade de outras pesquisas. / The period of life in which children are enrolled in institutions of child education (pre-school and day care centers) is a critical phase for the child development. Among the developmental areas, the language is the most susceptible since it strongly needs someone else’s intervention. Due to the development importance child follow-up is a basic health care in nursing. The purpose of this study was to describe the development profile, specially regarding language abilities of healthy children with ages ranging from 0 to 6 incomplete years, who were enrolled in child day care centers. This is a quantitative, descriptive and longitudinal (cohort) study with a non-probabilistic sampling. The Denver II Developmental Screening Test (DDST II) was used. From 2001 to 2004, 150 DDST III were applied in children with ages varying from 4 months and 23 days up to 5 years, 7 months and 11 days. These children were enrolled in good quality Day Care Centers located in the city of São Paulo. The criteria of inclusion were as follows: identified gestational age (for those under the age of 2 years), lack of congenital malformation, born Brazilian (due to the language area) and never been enrolled in a day care center before. The socioeconomic condition of the families was homogeneous, average of 7.60 minimum wage, thus, above the mean income per capita in the metropolitan area of São Paulo, in the same period, which was 4.28 minimum wages. The results were statistically equal in three Day Care Centers, both for the global result of the DDST II and for the language ability areas alone. There was no statistical association of the results regarding gender. In terms of global results, a statistically significant improve was observed in the five evaluations performed (1a x 3a p=0.015). Language performance maintained statistically equal on these five moments. Consequently, it was possible to demonstrate the following likelihood features: the three institutions were not able to optimize the conditions needed to give the child full development of his/her language abilities and/or the DDST II did not allow an adequate screening in this area. In the first option, it seems that language abilities may decrease when the child reaches the age of three years and developing later. At this moment, the educator/child module is below the recommended level. Regarding the second option, the DDSTII is not yet validated for the Portuguese language in Brazil. It was concluded that to enroll children in day care centers seems to be effective for the global child development. Regarding language abilities further studies are still needed.
29

Zhodnocení využití GUSS testu u pacientů s poruchou polykání po cévní mozkové příhodě / Assessing the use GUSS test in patients with dysphagia after stroke

Šmídová, Michaela January 2017 (has links)
(v AJ) Nursing care for patients with dysphagia after stroke is nowadays a very serious problem. This disease is particularly dangerous for patients because of the risk of imminent aspiration pneumonia. In 2015, Czech Republic has developed a standard treatment plan for patients with dysphagia after stroke and following this plan a new screening method was put into practice, which would prevent aspiration pneumonia (Salt, 2015). This method is called THE GUGGING SWALLOWING SCREEN - GUSS test. After a positive GUSS test result a standardized nursing care should follow, which would involve the whole medical team (doctors, health nurses, speech therapists, physiotherapists and orderly). The aim of this work is to verify whether the GUSS test and subsequently the determined process of the standard treatment together with the nursing care meets and the needs of the nurses. Another objective is to verify whether the nurses would want to add, innovate or make necessary updates based on the already acquired experiences. Furthermore, taking into consideration the frequent collaboration of nurses with the speech therapists, this study also aims to evaluate and asses the cooperation between nurses and the speech therapists. The work also evaluates the effectiveness of the use of GUSS test in providing nursing...
30

Elimination dynamique : accélération des algorithmes d'optimisation convexe pour les régressions parcimonieuses / Dynamic screening : accelerating convex optimization algorithms for sparse regressions

Bonnefoy, Antoine 15 April 2016 (has links)
Les algorithmes convexes de résolution pour les régressions linéaires parcimonieuses possèdent de bonnes performances pratiques et théoriques. Cependant, ils souffrent tous des dimensions du problème qui dictent la complexité de chacune de leur itération. Nous proposons une approche pour réduire ce coût calculatoire au niveau de l'itération. Des stratégies récentes s'appuyant sur des tests d'élimination de variables ont été proposées pour accélérer la résolution des problèmes de régressions parcimonieuse pénalisées tels que le LASSO. Ces approches reposent sur l'idée qu'il est profitable de dédier un petit effort de calcul pour localiser des atomes inactifs afin de les retirer du dictionnaire dans une étape de prétraitement. L'algorithme de résolution utilisant le dictionnaire ainsi réduit convergera alors plus rapidement vers la solution du problème initial. Nous pensons qu'il existe un moyen plus efficace pour réduire le dictionnaire et donc obtenir une meilleure accélération : à l'intérieur de chaque itération de l'algorithme, il est possible de valoriser les calculs originalement dédiés à l'algorithme pour obtenir à moindre coût un nouveau test d'élimination dont l'effet d'élimination augmente progressivement le long des itérations. Le dictionnaire est alors réduit de façon dynamique au lieu d'être réduit de façon statique, une fois pour toutes, avant la première itération. Nous formalisons ce principe d'élimination dynamique à travers une formulation algorithmique générique, et l'appliquons en intégrant des tests d'élimination existants, à l'intérieur de plusieurs algorithmes du premier ordre pour résoudre les problèmes du LASSO et Group-LASSO. / Applications in signal processing and machine learning make frequent use of sparse regressions. Resulting convex problems, such as the LASSO, can be efficiently solved thanks to first-order algorithms, which are general, and have good convergence properties. However those algorithms suffer from the dimension of the problem, which impose the complexity of their iterations. In this thesis we study approaches, based on screening tests, aimed at reducing the computational cost at the iteration level. Such approaches build upon the idea that it is worth dedicating some small computational effort to locate inactive atoms and remove them from the dictionary in a preprocessing stage so that the regression algorithm working with a smaller dictionary will then converge faster to the solution of the initial problem. We believe that there is an even more efficient way to screen the dictionary and obtain a greater acceleration: inside each iteration of the regression algorithm, one may take advantage of the algorithm computations to obtain a new screening test for free with increasing screening effects along the iterations. The dictionary is henceforth dynamically screened instead of being screened statically, once and for all, before the first iteration. Our first contribution is the formalisation of this principle and its application to first-order algorithms, for the resolution of the LASSO and Group-LASSO. In a second contribution, this general principle is combined to active-set methods, whose goal is also to accelerate the resolution of sparse regressions. Applying the two complementary methods on first-order algorithms, leads to great acceleration performances.

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