Simulation methods are used when closed-form solutions do not exist. An interesting simulation method that has been widely used in many scientific fields is the Monte Carlo method. Not only it is a simple technique that enables to estimate the quantity of interest, but it can also provide relevant information about the value to be estimated through its confidence interval. However, the use of classical Monte Carlo method is not a reasonable choice when dealing with rare event probabilities. In fact, very small probabilities require a huge number of simulation runs, and thus, the computational time of the simulation increases significantly. This observation lies behind the main motivation of the present work. In this thesis, we propose efficient importance sampling estimators to evaluate rare events probabilities. In the first part of the thesis, we consider a variety of turbulence regimes, and we study the outage probability of free-space optics communication systems under a generalized pointing error model with both a nonzero boresight component and different horizontal and vertical jitter effects. More specifically, we use an importance sampling approach,based on the exponential twisting technique to offer fast and accurate results. We also show that our approach extends to the multihop scenario. In the second part of the thesis, we are interested in assessing the outage probability achieved by some diversity techniques over generalized fading channels. In many circumstances, this is related to the difficult question of analyzing the statistics of the sum of random variables. More specifically, we propose robust importance sampling schemes that efficiently evaluate the outage probability of diversity receivers over Gamma-Gamma, α − µ, κ − µ, and η − µ fading channels. The proposed estimators satisfy the well-known bounded relative error criterion for both maximum ratio combining and equal gain combining cases. We show the accuracy and the efficiency of our approach compared to naive Monte Carlo via some selected numerical simulations in both case studies. In the last part of this thesis, we propose efficient importance sampling estimators for the left tail of positive Gaussian quadratic forms in both real and complex settings. We show that these estimators possess the bounded relative error property. These estimators are then used to estimate the outage probability of maximum ratio combining diversity receivers over correlated Nakagami-m or correlated Rician fading channels

People for long term exposed to an air-conditioned but highly humid environment are vulnerable to hyper-sensitivity or asthma triggered by fungi or dust mites. This thesis aims to develop a high-linearity and low-hysteresis capacitive relative humidity (RH) microsensor to more precisely accommodate the humidity of living spaces. To reduce the hysteresis and enhance the linearity, this research uses not only one polyimide (PI) thin film as a humidity sensing layer but also utilizes another PI thin film as a protecting layer of the top electrodes. To improve further the RH sensitivity and responding speed, interlacing out-of-plane electrodes are designed in the RH microsensor. The main processing steps of the RH sensor developed in this study involve at least five photolithographic and four thin film deposition processes. The influences of sensing area, number of electrode pairs and testing temperature on the sensitivity and sensing linearity of humidity microsensors were investigated. Based on the measurement results, the sensitivity apparently increase as well as the sensing area (2 mm ¡Ñ 2 mm: 0.12 pF/%RH, 3 mm ¡Ñ 3 mm: 0.48 pF/%RH, 5 mm ¡Ñ 5 mm: 1.09 pF/%RH), and decrease with the number of electrode pairs (40 pairs: 0.51 pF/%RH, 20 pairs: 0.4 pF/%RH) and increase with the testing temperature. The thesis has demonstrated that the capacitance of the RH sensor vary from the relative humidity with a very linear relationship (linearity: 98.8%~99.99%) over the range of 30~70%RH. Finally, to increase effectively the surface area and to reduce further the hysteresis, three-dimensional (3D) moisture entrances and exits were designed and a very low hysteresis value (0.5%RH) can be achieved.

The Vaccine Adverse Event Reporting System (VAERS) received thousands of reports of adverse events that occurred after vaccine administrations from the post-marketing vaccine safety surveillance. However, the causality between vaccines and reported adverse events cannot be taken for granted. In this report several data mining methods were applied to VAERS database that is coded in MedDRA terms to discover possible associations between vaccines and adverse events. Efforts were devoted to identify events that are reported more frequently after administering one vaccine than other vaccines using the following data mining techniques: relative ratio (RR), statistical significance (LogP), proportional reporting ratio (PRR), and screened PRR (SPRR). The vaccine-event combinations that ranked top in each method varied substantially among the methods. RR and PRR gave excessive weight to small counts of vaccine-event pairs, but SPRR was able to correct this weakness. There are only 33 vaccine-event pairs that were shared among the top 1,000 ranked in each method. Evaluating the properties of these data mining methods and exploring other methods will help improve vaccine safety surveillance. / text

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Relative Debugging is a paradigm that assists users to locate errors in programs that have been corrected or enhanced. In particular, the contents of key data structures in the development version are compared with the contents of the corresponding data structures, in an existing version, as the two programs execute. If the values of two corresponding data structures differ at points where they should not, an error may exist and the user is notified. Relative Debugging requires users to identify the corresponding data structures within the two programs, and the locations at which the comparisons should be performed. To quickly and effectively identify useful data structures and comparison points requires that users have a detailed knowledge of the two programs under consideration. Without a detailed knowledge of the two programs, the task of locating useful data structures and comparison points can quickly become a difficult and time consuming process. Prior to the research detailed in this thesis, the Relative Debugging paradigm did not provide any assistance that allowed users to quickly and effectively identify suitable data structures and program points that will help discover the source of an error. Our research efforts have been directed at enhancing the Relative Debugging paradigm. The outcome of this research is the discovery of techniques that empower Relative Debugging users to become more productive and allow the Relative Debugging paradigm to be significantly enhanced. Specifically, the research has resulted in the following three contributions: 1. A Systematic Approach to Relative Debugging. 2. Data Flow Browsing for Relative Debugging. 3. Automatic Relative Debugging. These contributions have enhanced the Relative Debugging paradigm and allow errors to be localized with little human interaction. Minimizing the user's involvement reduces the cost of debugging programs that have been corrected or enhanced, and has a significant impact on current debugging practices.

Mudanças na taxa de acumulação e na natureza da matéria orgânica sedimentar, e suas relações com as variações climáticas e flutuações do nível relativo do mar durante os últimos 8.500 anos cal. A.P. foram investigadas em dois testemunhos provenientes do Saco de Ribeira, Enseada do Flamengo, e junto à praia do Lázaro, Enseada da Fortaleza, na região de Ubatuba, litoral norte do Estado de São Paulo. Para o estudo as amostras coletadas foram submetidas a diversas análises - granulometria, teor de CaCO3, teores de Carbono orgânico, Nitrogênio e Enxofre totais, e razões isotópicas de carbono. Datações 14C, calibradas para a idade calendário, permitiram estabelecer um modelo de idades para as variações sedimentares detectadas. Intervalos de clima mais quente, 8.000-6.000 anos cal. A.P., foram acompanhados de um aumento na taxa de acumulação de carbono T.A.C. (10-13 g m-2 ano-1), seguida de diminuição após 5.000 anos cal. A.P., para valores inferiores a 2 g m-2 ano-1. Variações climáticas regionais, possivelmente relacionadas a chuvas torrenciais, próximos ao máximo transgressivo, de 5.100 anos 14C A.P., foram detectadas pelo aumento nos valores de T.A.C. (10-12 g. m- 2 ano-1), aumento nas taxas de acumulação de massa (T.A.M.) e deposição de sedimentos mais grossos, acompanhados de aumento na tendência continental da natureza da matéria orgânica. As maiores tendências continentais da matéria orgânica sedimentar, registradas aproximadamente entre 1.500-1.200 anos cal. A.P., podem ser decorrentes de uma oscilação negativa do nível do mar. No geral, todos os resultados estão de acordo com as curvas de variação do nível relativo do mar, já descritas na literatura. As análises sedimentares da região estudada revelaram um evento regressivo-trangressivo, que ainda não havia sido referido para o Estado de São Paulo. A partir de ~2.000 anos cal. A.P., o mar teria atingido um nível mais baixo que o atual, com o mínimo provavelmente entre 1.500-1.200 anos cal. A.P., e encontra-se em ascensão até os dias atuais. As características anóxicas e a matéria orgânica sedimentar de origem planctônica registradas junto à praia do Lázaro, em meio a condições de energia relativamente mais alta, em ~900 anos cal. A.P., foram consideradas como resultado de condições óxicas das águas, acompanhadas de altas taxas de produtividade, e subseqüente degradação da matéria orgânica, existentes no período anterior. / Changes in the organic carbon accumulation rates (Corg A.R.) and organic matter source characteristics and their relation to climate and relative sea level changes during the last 8.500 cal. yr. B.P. were investigated in two sediment cores from 2 embayments - Flamengo and Fortaleza inlets - northern coast of São Paulo State. Sediment samples were analysed for grain size, organic Carbon, total Nitrogen and Sulphur contents, and ?13C ratio. Radiocarbon datings provided a model age to the sedimentary deposits. The warm climate interval 8.000-6.000 cal. yr. B.P. was accompanied by an increase in the Corg A.R. (10-13 g.m.-2 yr -1) and a decrease (~2 g.m.-2 yr -1) in the last ~5.000 cal. yr. B.P. Regional climate changes, as stormy weather, that may have ocurred near the maximum transgressive period called Santos Transgression at 5.100 yr. B.P., were recorded in the sedimentary profiles by relatively hight T.A.C. and T.A.M. values, coaser grain size sediment delivery, and enhanced terrestrial organic matter source characteristics. Improvement of terrestrial origin of the sedimentary organic matter recorded between 1.500-1.200 cal. yr. B.P in the studied area was mainly related to a negative sea-level oscillation. All the results are in general agreement with the existing sea level change curves. The sedimentary profiles suggest a negative sea-level fall event, that had\'nt been described yet for São Paulo State. It\'s proposed that the negative oscillation would have begun at ~2.000 cal. yr. B.P.and reached a minimum probably between 1.500-1200 cal. yr. B.P. The relative sea level has been rising since then. Anoxic conditions accompanied by algal origins of sedimentary organic matter, observed in the sedimentary profile from Fortaleza inlet at 900 cal. yr. B.P, during a more oxidizing environment are considered as a result of a previous well oxygencontaining water column and high productivity rates.

In this paper, relative clauses in King Alfred’s Old English translation of Gregory the Great’s Pastoral Care were examined using relative frequency as a tool to determine whether or not certain factors influenced the choice of relativization strategy. These factors include antecedent case, antecedent gender, antecedent number, distance, animacy, noun phrase type, case of relativized NP, and syntactic function. The method involved gathering together all the occurrences of relative clauses using the Old English corpus and a Modern English translation. This process was not unproblematic as the correct translation from Old English to modern English sometimes was left to the discretion of the translator. Some clauses that were initially thought to be relative clauses were, in fact, not relative clauses. The components of each of the clauses were then examined and categorized after any problematic examples were discarded. Relative frequencies for each of the categories were calculated and chi-square tests were performed to check the reliability of the results. The results of this paper were compared to another paper which did somewhat similar research to determine if the findings were consistent although that paper did not look at as many factors as this paper.

Cette étude a pour objectif d’examiner la structure des relatives en arabe classique, en arabe standard moderne et en arabe égyptien. Nous avons tenté de montrer les caractéristiques des relatives dans chacune de ces variantes d’arabe et de les comparer à celles du français.La première partie expose l’analyse des relatives chez les grammairiens français, ainsi que notre point de vue sur celle-ci. La deuxième partie présente une étude de la structure de la phrase en arabe classique et en arabe moderne. Nous y exposons également l’analyse menée par les grammairiens arabes des unités que nous apparentons à des relatifs. Dans la troisième et la quatrième partie, nous analysons ce que nous avons appelé les relatives marquées et les relatives non marquées en arabe moderne et en arabe égyptien. Enfin, nous décrivons les ressemblances et les différences, qui sont ressorties de ces comparaisons, entre le système des relatives dans les trois variantes d’arabe étudiées et celui du français. / This study aims to examine the structure of relative pronouns between Classical Arabic, Modern Standard Arabic and Egyptian Arabic. We try to show the characteristics of relative pronouns for each of these three Arabic language variants and compare them with those of the French language.The first section presents an analysis of the relative pronouns by French grammarians, as well as our perspective on it. The second section presents a study of sentence structure in Classical Arabic and Modern Standard Arabic. In this section, we also present an overview of the analysis conducted by Arab grammarians of the units that we consider as relative pronouns. In the third and the fourth section, we analyze what we have called the marked relatives and unmarked relatives in Modern Standard Arabic and Egyptian Arabic. Finally, we describe the similarities and differences that emerge from these comparisons between the system of relative pronouns for each of these three Arabic language variants and the French language.

L’objectif de ce travail est de présenter une description grammaticale aussi complète que possible de la langue mano (près de 400 000 locuteurs en Guinée et au Libéria) tout en la plaçant dans un contexte typologique, en comparant le mano avec d’autres langues mandé, mais aussi en distinguant des particularités typologiques à un niveau plus large. Le texte de la thèse est divisé en six chapitres: Phonologie et phonétique; Morphologie; Groupe nominal; Groupe verbal; Système prédicatif; Syntaxe de l'énoncé. Justifiant l'orientation typologique de la thèse, chaque chapitre se conclut par une section présentant des caractéristiques typologiques. Les thèmes suivants ont été examinés en détail: étude quantitative de phonotactique, étude de la catégorie du nombre, y compris l’expression du nombre et l’accord en nombre ; le système des quantificateurs ; la structure argumentale ; l’étude de corpus de distribution des marqueurs prédicatifs ; la syntaxe de l’énoncé, notamment la syntaxe de l’énoncé relatif. Les annexes à la fin de la thèse représentent des compléments d'information importants, notamment les paradigmes verbaux complets. Deux de ces annexes sont des textes glosés. / This work aims to present a grammatical description – as complete as possible – of a South Mande language, Mano (400,000 speakers in Guinea and Liberia), placing it into a typological context, comparing the language with other Mande languages and distinguishing general typological particularities. The text of the thesis is divided into six chapters: Phonology and phonetics; Morphology; Noun phrase; Verb phrase; Predicative system; Syntax of the clause. Justifying the typological orientation of the thesis, each chapter is concluded by a section providing typological particularities of the data presented in it. A detailed analysis was given, among others, on the following themes: quantitative study of phonotactics; study of the category of number, including its expression and alignment by number; the system of quantification markers; argument structure, corpus study of predicative markers’ distribution; syntax of the clause, especially syntax of the relative clause.The appendices at the end of the thesis contain some important complementary information, including, for instance, complete verbal paradigms. Two of these appendices comprise of glossed texts.

Binomial group testing has been long recognized as an efficient method of estimating proportion of subjects with a specific characteristic. The method is superior to the classic maximum likelihood estimator (MLE), particularly when the proportion is small. Under the group testing model, we assume the testing is conducted without error. In the present research, a new Bayes estimator will be proposed that utilizes an additional piece of information, the proportion to be estimated is small and within a given range. It is observed that with the appropriate choice of the hyper-parameter our new Bayes estimator has smaller mean squared error (MSE) than the classic MLE, Burrows estimator, and the existing Bayes estimator. Furthermore, on the basis of heavy Monte Carlo simulation we have determined the best hyper-parameters in the sense that the corresponding new Bayes estimator has the smallest MSE. A table of these best hyper-parameters is made for proportions within the considered range.