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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

Contributions à la modélisation, évaluation et conception de systèmes de recherche d'information en pair-à-pair

Sicard, Jérôme 23 November 2010 (has links) (PDF)
Cette thèse se base sur une vision originale des systèmes de Recherche d'Information en pair-à-pair (RI-P2P) ; pour proposer un ensemble d'outils pour mieux les évaluer et mieux les concevoir.Synthétiquement, la problématique d'évaluation consiste à comprendre quel système fonctionne bien dans quelles conditions ; comment les différents composants/aspects d'un système contribuent à ses performances ; comment des modifications du système peuvent faire évoluer ses performances. D'un point de vue conception, on voudrait savoir choisir une approche P2P en fonction du contexte de l'application à implémenter (jeu de données, propriétés du réseau...) ; comprendre comment mixer des systèmes ; mieux maîtriser l'impact d'une modification de l'implémentation sur le comportement et les performances d'un système.Nous pensons que ces deux problématiques d'évaluation et de conception sont fortement liées. Un même fondement est nécessaire pour progresser dans ces deux sens : mieux comprendre l'architecture des systèmes RI-P2P. À la base de notre réflexion, nous considérons qu'un système RI-P2P est l'implémentation en P2P d'un modèle RI, idée qui s'oppose au modèle traditionnel en deux couches. Nous nous appuyons sur cette idée pour donner un ensemble de définitions qui permettent de mieux appréhender les différents composants RI et composants P2P d'un même système et la façon dont ils s'organisent. Nous montrons ensuite comment on peut utiliser cette vision originale du domaine pour spécifier la démarche d'évaluation d'un système P2P et pour aider à la conception de nouveaux systèmes.
22

"Efeito tardio do ruído na audição e na qualidade do sono em indivíduos expostos a níveis elevados" / Delayed Effect of Elevated Noise Levels on Hearing and Sleep

Ana Lúcia Rios 24 February 2003 (has links)
Nos últimos vinte anos, os estudos sobre os efeitos do ruído na audição e conseqüente qualidade de vida do ser humano ganharam grande impulso, evidenciando sua importância. O propósito do presente estudo foi verificar o efeito do ruído persistente, decorrente das condições de trabalho, sobre a qualidade de vida, relativamente às repercussões sobre a audição e a qualidade do sono. Neste sentido visou contribuir para a valorização dos prejuízos do ruído excessivo e sistemático sobre a saúde. Foram estudados 20 trabalhadores do sexo masculino, da Seção de Engenharia do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (HCFMRP-USP), com idade entre 33 e 50 anos, expostos a ruído ambiental maior ou igual a 85 dB, em jornada de oito horas de trabalho diário, há pelo menos oito anos; sem alterações anatômicas de orelha externa/média e de vias aéreas superiores. Outros 20 trabalhadores da Seção de Atividades Complementares do mesmo hospital na mesma faixa etária e mesmas características físicas, sócio-econômico-culturais, expostos ao ruído ambiental habitual inferior a 85 dB na jornada de trabalho de 8 horas diárias, compuseram um grupo controle. Os dados de audiometria tonal limiar e imitanciometria foram correlacionados com a qualidade do sono observada através da polissonografia e com parâmetros clínicos gerais de saúde. Com os resultados dos testes de comparação aplicados a idade, estatura, peso, índice de massa corporal, circunferência do pescoço, cintura e quadril e indicadores do estado sócio-econômico-cultural obtidos em entrevista, verificamos que as amostras foram semelhantes nestes aspectos. A análise estatística da audiometria e imitanciometria, nos dois grupos, feita pelo teste exato de Fischer revelou perda auditiva leve e moderada, do tipo PAIR, significante (p < 0,001) no G1. O sono dos indivíduos dos dois grupos apresentou anormalidades nas medidas de continuidade do sono revelando sono de má qualidade. Dos 40 indivíduos, treze (32,5 %) apresentaram distúrbio respiratório do sono, dez dos quais tinham sonolência pela Escala de Epworth; doze outros (30 %) tinham sonolência sem distúrbio respiratório do sono. Os indicadores da quantidade de sono revelaram-se normais. As comparações mostraram que o sono dos dois grupos é igual, quando analisado pelo teste de Mann – Whitney para dados independentes. Análise de contingência entre sono alterado e perda auditiva revelou ausência de interrelação (p = 0,4316). Concluimos que a permanência prolongada sob ruído ambiental superior aos níveis considerados seguros foi suficiente para produzir danos auditivos detectáveis laboratorialmente através dos testes usuais e que não há razão para crer que a má qualidade do sono do cidadão comum guarde relação com a convivência diurna em ambientes ruidosos. / In the last twenty years, the studies on the effect of noise in the hearing and consequently in the quality of life of the human have earned great impulse, evidencing its importance. The purpose of the present study was to verify the effect of persistent noise, occasioned by work conditions, on the quality of life, concerned to the repercussions on the hearing and on the quality of sleep. In this direction, this study aimed at contributing to the awareness of damages caused by extreme and systematic noise on health. Twenty male workers, from the Engineering Section of the Hospital of Clinics of the Faculty of Medicine of Ribeirão Preto (HCFMRP-USP), with ages between 33 and 50 years old, exposed to environmental noise louder or equal 85 dB, on a daily eight-hour working week, for at least eight years, with no anatomical alterations of the extern/medium ear and upper airways; were studied. Other twenty workers from the Complementary Activities Section of the same hospital, in the same age range and equal physical, social-economical-cultural characteristics, exposed to usual environmental noise (lower than 85 dB), on a daily eight-hour working week, composed a control group. The data from the pure tone audiometry and the impedance measurements were correlated with the quality of sleep observed through the polysomnography and with the general clinical health parameters. The results showed that two groups had similar physical social-economic and cultural aspects, when comparison tests where applied to age, height, weight, body mass index, size of the neck, wrist and hips and socio-economic and cultural markers obtained by clinical interview. Statistical analysis of audiometria e imitanciometria by Fischer’s test has shown significant (p = 0,001) mild and moderate hearing loss in G1. The majority of the subjects had bad sleep quality as shown by analysis of sleep disruption markers. The 40 subjects, thirteen (32,5 %) have had sleep disordered breathing ten of whom had day-time sleepiness as measured by Epworth scale; twelve other subjects (30 %) had day-time sleepiness without sleep disordered breathing. The sleep amount markers where normal. At statistical analysis by Mann-Whitney test the sleep of the two groups was equal. Analysis of contingency between altered sleep and hearing loss has shown no correlation (p = 0,4316). Conclusion long stay under noisy condition was enough to produce hearing loss detectable through usual laboratorial tests the there is no reason to believe that sleep of bad quality of ordinary people keep relation with diurnal stay under noisy condition.
23

The Effects of using Think-Pair-Share during Guided Reading Lessons

Carss, Wendy Diane January 2007 (has links)
The aim of this research was to describe the effects of Think-Pair-Share strategies, used during Guided Reading lessons, on reading achievement. Think-Pair-Share is a co-operative teaching strategy that includes three components; time for thinking, time for sharing with a partner and time for each pair to share back to a larger group. The use of Think-Pair-Share unites the cognitive and social aspects of learning, promoting the development of thinking and the construction of knowledge. The strategy lends itself to inclusion within Guided Reading lessons, where the focus is on meaningful discussion around text and promotion of the use of comprehension skills and strategies to foster comprehension. The literature review describes the effectiveness of explicit comprehension strategy instruction within the context of small group discussion. Strategies that foster cooperative learning have been successful in developing interpersonal skills, cognitive skills and metacognitive awareness. There is very little research documenting the effects of the use of the Think-Pair-Share strategy. The study took place in a Year 6 classroom with two intervention groups, each containing six children. One group was reading above their chronological age and the other below. Control groups reading at these levels were also used. Three variations of Think-Pair-Share were utilised during the eight week intervention period; Predict-Pair-Share, Image-Pair-Share and Summarise-Pair-Share, and the research centred on the effects of the intervention on reading comprehension. A quasi-experimental design was employed using a pre-test, post-test format and a mix of quantitative and qualitative measures to ascertain the effects. The results confirmed the positive effects of the strategy on reading achievement, especially for those students reading above their chronological age, although an extended period of intervention may have had more significant effects on those reading below. Positive effects on aspects of oral language use, thinking, metacognitive awareness, and the development of reading comprehension strategies were noted with both of the intervention groups. Results have significance for those concerned with implementing effective literacy practice. They demonstrate the versatility of the Think-Pair-Share strategy as a tool to foster conversation, and one that can be adapted to suit the learning focus and the needs of particular groups of students.
24

none

ku, yi-chin 31 July 2007 (has links)
The purpose of the thesis aims to investigate pair trading strategies which are frequently used by hedge funds adopting non-directional strategies. It is also our intention to develop a set of streamlined operational guidelines for pair trading strategy to be implemented in the Taiwan securities markets. Daily closing prices of listed stocks are used. The database is compiled by Taiwan Economic Journal, covering companies listed on the Taiwan Stock Exchange and the GreiTai Market in Taiwan. The company-pairs are selected from firms listed on the same market, conducting business in the same product field, and with sample correlation coefficient higher than 0.7. We choose 10 sample company-pairs covering 20 listed companies. The trading strategies mix both divergence and convergence rules. For the former, when the price ratio of the pair exceeds the moving average price ratio plus (minus) 0.3 standard deviation, we buy the strong and short the weak to anticipate the price ratio trend continues. For the latter, when the price ratio goes beyond the moving average price ratio plus (minus) 1.7 standard deviations, we buy the weak and short the strong, anticipating the price ratio to go back to normal. The exit rules are based on absolute dollar profit, absolute dollar loss, and prolonged position period. The research results show that the pair trading strategies are not risk-free. Risk arises when the price ratio trend runs adversely than as expected. To control the risk, our challenges lie in fine tuning the entry and exit rules. With larger sample size and more in-depth investigation, we expect that the profit/loss ratio of the stragtegy can be improved. Then the pair trading strategy will become a good alternative for conservative individual investors seeking low risk investment opportunities to participate in the securities markets in Taiwan.
25

Some distributional solutions of the CH, DP and CH2 equations and the Lax pair formalism

Mohajer, Keivan 18 September 2008
This dissertation deals with a class of nonlinear wave equations of the type discovered by R. Camassa and D. D. Holm which includes the Camassa-Holm, the Degasperis-Procesi, and the two component Camassa-Holm equations. All these equations admit certain non-smooth soliton-like solutions, called peakons as well as other non-smooth solutions like cuspons. We apply the techniques of the theory of distributions of L. Schwartz to study these solutions. In particular, every non-smooth traveling wave which is a distributional solution of the two component Camassa-Holm equation is a distributional solution of the Camassa-Holm equation if the set of points where the height of the wave equals its speed, is of measure zero. This includes peakon or cuspon traveling wave solutions.<p>We also develop a suitable modification of the classical Lax pair formalism to deal with singular solutions. We show that the Lax pair formalism can be extended to a distributional weak Lax pair which is appropriate for dealing with the peakon solutions of the Camassa-Holm equation.
26

Some distributional solutions of the CH, DP and CH2 equations and the Lax pair formalism

Mohajer, Keivan 18 September 2008 (has links)
This dissertation deals with a class of nonlinear wave equations of the type discovered by R. Camassa and D. D. Holm which includes the Camassa-Holm, the Degasperis-Procesi, and the two component Camassa-Holm equations. All these equations admit certain non-smooth soliton-like solutions, called peakons as well as other non-smooth solutions like cuspons. We apply the techniques of the theory of distributions of L. Schwartz to study these solutions. In particular, every non-smooth traveling wave which is a distributional solution of the two component Camassa-Holm equation is a distributional solution of the Camassa-Holm equation if the set of points where the height of the wave equals its speed, is of measure zero. This includes peakon or cuspon traveling wave solutions.<p>We also develop a suitable modification of the classical Lax pair formalism to deal with singular solutions. We show that the Lax pair formalism can be extended to a distributional weak Lax pair which is appropriate for dealing with the peakon solutions of the Camassa-Holm equation.
27

A peripheral model for [xi]āssociated production

James, Philip Benjamin, January 1966 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1966. / Typescript. On t.p. xi is represented by the Greek letter. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
28

Male adaptations to sperm competition in the sand martin Riparia riparia

Nicholls, E. Henry January 2000 (has links)
No description available.
29

Student performance prediction based on course grade correlation

Lei, Cheng 15 March 2019 (has links)
This research explored the relationship between an earlier-year technical course and one later year technical course, for students who graduated between 2010 and 2015 with the degree of bachelor of engineering. The research only focuses on the courses in the program of Electrical Engineering at the University of Victoria. Three approaches based on the two major factors, coefficient and enrolment, were established to select the course grade predictor including Max(Pearson Coefficient), Max(Enrolment), and Max(Pi) which is a combination of the two factors. The prediction algorithm used is linear regression and the prediction results were evaluated by Mean Absolute Error and prediction precision. The results show that the predictions of most course pairs could not be reliably used for the student performance in one course based on another one. However, the fourth-year courses are specialization-related and have relatively small enrolments in general, some of the course pairs with fourth-year CourseYs and having acceptable MAE and prediction precision could be used as early references and advices for the students to select the specialization direction while they are in their first or second academic year. / Graduate
30

Loss of chromosome 6q is frequently seen in gastric carcinoma of all stages.

January 2001 (has links)
Li Chung Yi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 110-123). / Abstracts in English and Chinese. / ABSTRACT --- p.i / ACKNOWLEDGEMENTS --- p.iv / TABLE OF CONTENTS --- p.v / LIST OF FIGURES --- p.ix / LIST OF TABLES --- p.xi / Chapter I. --- INTRODUCTION --- p.1 / Chapter I.1 --- Gastric Carcinoma --- p.1 / Chapter I.2 --- Etiology of Gastric Carcinoma --- p.2 / Chapter I.2.1 --- Environmental Factors: --- p.2 / Chapter I.2.2 --- Helicobacter Pylori Infection: --- p.2 / Chapter I.2.3 --- Genetic Factors: --- p.3 / Chapter I.2.4 --- Other Factors: --- p.4 / Chapter I.3 --- The Lauren Classification of Gastric carcinoma --- p.5 / Chapter I.3.1 --- Histolopathology of Intestinal Type of Gastric Carcinoma --- p.5 / Chapter I.3.2 --- Histopathology of Diffuse Type of Gastric Carcinoma --- p.8 / Chapter I.4 --- Cytogenetics Studies in Gastric Carcinoma --- p.10 / Chapter I.4.1 --- Cytogenetic Studies of Gastric carcinoma --- p.10 / Chapter I.5 --- Molecular Studies of Gastric Carcinoma --- p.14 / Chapter I.5.1 --- Genetic Instability --- p.14 / Chapter I.5.2 --- Amplification/ Mutation of Oncogenes --- p.15 / Chapter I.5.3 --- Alterations of Tumor Suppressor Genes --- p.20 / Chapter I.5.4 --- Cell Adhesion Molecules --- p.23 / Chapter I.5.5 --- Molecular Studies on Intestinal Metaplasia --- p.27 / Chapter II. --- LONG ARM OF CHROMOSOME 6 --- p.28 / Chapter III. --- BRIEF REVIEWS OF THE TECHNIQUES USED IN THIS STUDY --- p.34 / Chapter III.1 --- Comparative Genomic Hybridization (CGH) --- p.34 / Chapter III.2 --- Loss of Heterozygosity (LOH) --- p.37 / Chapter III.3 --- Methylation-Specific PCR (MSP) --- p.38 / Chapter IV. --- OBJECTIVES OF STUDY --- p.40 / Chapter V. --- MATERIALS AND METHODS --- p.41 / Chapter V.l --- Sample Collections --- p.41 / Chapter V.1.1 --- Patients Information for CGH Studies --- p.42 / Chapter V. 1.2 --- Patients Information for LOH Studies --- p.42 / Chapter V.2 --- Extraction of Genomic DNA for Tumor and Normal Tissues --- p.47 / Chapter V.2.1 --- Extraction of Genomic DNA from Frozen Tissues or Paraffin Embedded Sections --- p.47 / Chapter V.2.2 --- Extraction of Genomic DNA from Blood --- p.48 / Chapter V.3 --- Comparative Genomic Hybridization (CGH) of Gastric Carcinoma --- p.49 / Chapter V.3.1 --- Preparation of Normal Metaphase Slides --- p.49 / Chapter V.3.2 --- Metaphase Slide Denaturation --- p.49 / Chapter V.3.3 --- Nick Translation for DNA Labeling --- p.50 / Chapter V.3.4 --- Dot Blot Assay for Biotin and Digoxigenin-Labeled DNA --- p.51 / Chapter V.3.5 --- "Probe Preparation, Denaturation and Hybridization" --- p.51 / Chapter V.3.6 --- Post hybridization Washing and Detection --- p.52 / Chapter V.3.7 --- Image Acquisition and Analysis of CGH Images --- p.53 / Chapter V.4 --- Loss of Heterozygosity (LOH) Analysis on Chromosome 6q --- p.55 / Chapter V.4.1 --- Microsatellite Markers --- p.55 / Chapter V.4.2 --- Polymerase Chain Reaction (PCR) --- p.57 / Chapter V.4.3 --- Denaturing Polyacrylamide Gel Electrophoresis --- p.58 / Chapter V.4.4 --- SYBR Gold Nucleic Acid Gel Staining and Image Viewing --- p.58 / Chapter V.4.5 --- Assessment of Loss of Heterozygosity (LOH) --- p.59 / Chapter V.4.6 --- Statistical Analysis --- p.61 / Chapter V.5 --- Methylation Specific Polymerase Chain Reaction (MSP) --- p.62 / Chapter V.5.1 --- Bisulfite Modification of DNA --- p.62 / Chapter V.5.2 --- Mehtylation Specific PCR --- p.63 / Chapter VI. --- RESULTS --- p.66 / Chapter VI.1 --- Results of CGH --- p.66 / Chapter VI. 1.1 --- Chromosomal Copy Number Aberrations in Gastric Carcinoma --- p.66 / Chapter VI. 1.2 --- Comparison of CGH Results with Intestinal and Diffuse Type of Gastric Carcinoma --- p.67 / Chapter VI.2 --- LOH Analysis of Chromosome 6q --- p.73 / Chapter VII. --- DISCUSSIONS --- p.83 / Chapter VII.l --- Discussions on CGH --- p.83 / Chapter VII.2 --- Discussions on LOH Study --- p.89 / Chapter VII.2.1 --- Two Distinct Deletion Regions --- p.89 / Chapter VII.2.2 --- Possible Candidate Suppressor Genes in Two Deletion Regions --- p.93 / Chapter VII.2.3 --- Infrequent Loss of IGF2R Gene --- p.95 / Chapter VII.3 --- Relationship Between Intestinal Metaplasia and Gastric Carcinoma --- p.99 / Chapter VII.4 --- Microsatellite Instability --- p.100 / Chapter VII.5 --- Correlations --- p.103 / Chapter VII.6 --- Comparison Between CGH and LOH Results on Chromosome 6 --- p.104 / Chapter VII.7 --- Conclusions --- p.106 / Chapter VII.8 --- Limitations of the Study --- p.107 / Chapter VII.8.1 --- Limitation of CGH --- p.107 / Chapter VII.8.2 --- Limited Information Supply by LOH Analysis --- p.107 / Chapter VII.8.3 --- Small Sample Size --- p.107 / Chapter VII.9 --- Future Studies --- p.108 / Chapter VIII. --- REFERENCES --- p.110

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