BABAR is a particle physics experiment at the Stanford Linear Accelerator Center (SLAC). The purpose of BABAR is to study matter-antimatter asymmetry in the bottom quark system. At SLAC, electons and positrons collide, which annihilate and decay into a variety of daughters. An Upsilon(4S) meson is one of the possible daughters. An Upsilon(4S) decays into a B meson and an anti-B meson more than 96% of the time. A B meson has an anti-bottom quark and an anti-B meson has a bottom quark. The purpose of this thesis is to measure how many Upsilon(1S) originated from Upsilon(4S) in the entire BABAR data set. This thesis compares on-peak data and off-peak data. On-peak data was taken at center of mass energy 10.58GeV. One of the possible interactions is e+e− -> Upsilon(4S) since the mass of Upsilon(4S) is 10.58GeV/c^2. On-peak data, taken at center of mass energy 10.54GeV, is not enough to have any BB pairs because 10.54GeV is less than the mass of an Upsilon(4S). This thesis can be useful for BABAR physicist because it helps set an upper limit on how many BB pairs there are in the entire BABAR data set. In other words, it sets an upper limit on how much more than 96% does Upsilon(4S) decay to BB. Measurement of the decay of Upsilon(4S) -> Upsilon(1S) + X give evidence for non-BB decays of the Upsilon(4S). The final results of this study show that there were (110 +- 3) × 10^5 Upsilon(1S) on-peak, of which (10 +- 9) × 10^5 originated from an Upsilon(4S). Increasing the centre of mass energy from 10.54GeV to 10.58GeV increases the Upsilon(1S) production by (10 +- 8)%.

London or dispersion interactions are weak van der Waals (vdW) interactions. They are important in determining the structure and properties of many chemical and biochemical systems. In this thesis, an optimizer using the nonempirical generalized gradient approximation (GGA) functional PW86+PBE+XDM, to capture van der Waals interactions, is presented. The work in this thesis covers the assessment of a variety of basis sets for their ability to reproduce accurate GGA repulsive and binding energies. Selected basis sets were then used to compute binding energies of 65 vdW complexes at equilibrium. This functional was also tested for binding energies of two sets of vdW complexes at distorted geometries. The last part deals with forces to investigate their accuracy using PW86+PBE+XDM in order to build an optimizer for vdW complexes using a nonempirical DFT method. Eventually, after confirming a high reproducibility of the optimizer on the geometries and binding energies, it was used in two biologically relevant applications. This optimizer is a unique tool to compute deformation energies with a nonempirical DFT method. The second part of this thesis covers a biologically relevant application where a conventional DFT is used. This application is related to the carrier of the genetic codes in living cells, DNA. DNA undergoes harmful mutations under external perturbations such as applied external electric fields. In this study, DNA base pairs were first mimicked by a simpler model, namely, the formic acid dimer. The effect of applied external electric fields on the geometries of the formic acid dimer is studied. The effect of these applied fields on the potential energy surface, the barrier height and the frequency of the double proton transfer in the formic acid dimer are also investigated. The study was then repeated on DNA base pairs to study the effect of an external applied electric field on the tunneling corrected rate constants of the double proton transfer reactions in AT and GC.

No description available.

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

By enlarging the spatial and temporal spectral problems within a certain Lie algebra, a hierarchy of integrable couplings of the Kaup-Newell soliton equations is constructed. The recursion operator of the resulting hierarchy of integrable couplings is explicitly computed. The integrability of the new coupling hierarchy is exhibited by showing the existence of infinitely many commuting symmetries.

Testing every possible combination of the input parameter values is often impractical, inefficient or too expensive. One common alternative is pairwise testing where every pairwise combination of the parameter values is tested. Although pairwise testing significantly reduces the number of test cases, the challenge remains in analyzing the test outputs to discern the precise characteristics of parameters causing the failures. This thesis proposes a novel approach to output analysis by identifying “bad pairs”: pairs that always result in failed test cases. A framework implementing the proposed approach is presented together with three case studies. Results from the case studies suggest there are positive relationships among the numbers of failed test cases, faults, and independent bad pairs. Also, filtering of test cases seems to have a significant impact on the bad pairs identified. We believe the proposed approach can facilitate the debugging process in software testing.

This dissertation analysed the interactions between instructors and students in a language classroom in Russia. Using video-recorded data, instructor interviews, and student assessments from English classes at a private language school for children in the Urals region of Russia, a Conversation Analytic [CA] framework was employed to determine: how the talk (specifically turn-taking, adjacency pairs, and repairs) was sequentially organised; if and how the institutional setting constrained the talk; and if previously determined 'universal' structures of talk applied to this Russian academic discourse. This research also tested the hypotheses that the 'universal' structures of talk would apply regardless of gender, but would be used differently by the boys and girls, and by the instructors interacting with them. The relevance of the participants' institutional identities or gender to the interaction was also examined. The analysis showed that the participants did orient to their institutional identities of instructor or student, and the institutional setting did constrain the organisation of talk. The instructors' responses to the interviews and 'student assessment' questionnaires showed that they generally had positive attitudes toward girls and mixed attitudes toward boys. While the underlying sequences, the universal 'rules' of interaction, applied to interactions with both boys and girls, how (and how frequently) the sequences were used did vary by gender (i.e., typically 'male' and 'female' speech styles). Also, some of the organisation of talk showed that the instructors did orient to the students' genders in the classroom. This research is significant as the first CA study of the sequential organisation of talk in an institutional setting in Russia. In general, this research contributes to the CA findings on the organisation of talk in different languages, cultures, and settings; specifically, it provides the first point of comparison of Russian classroom interactions, from a CA perspective, with the large corpus of data already collected in classrooms in the Western tradition of education. Finally, this research is significant as it provides a thorough microanalysis of the relativity of gender-specific verbal behaviour; the analysis also shows how the instructors behave verbally, and in this way produce gender-specific communication styles. / Slavic Linguistics

Thèse (Ph. D.)--Université Laval, 2003. / Bibliogr.

Cette thèse part du postulat que, pour infléchir les consommations de drogues, il est nécessaire d'analyser finement les déterminants de l'entrée dans ces consommations lors de l'adolescence. Les outils fournis par la science économique permettent d'apporter un éclairage nouveau quant à ces déterminants. Après avoir présenté un panorama des politiques publiques de lutte contre le tabac et l'alcool en France, nous articulons notre réflexion autour de quatre grands thèmes. Nous nous intéressons tout d'abord aux ressources monétaires dont disposent les adolescents et nous montrons que le montant et l'origine de ces ressources sont des facteurs clefs des consommations adolescentes de drogues. Nous étudions ensuite les relations de complémentarité ou de substitution qui lient les consommations de tabac et d'alcool. Nous mettons en évidence qu'une politique de taxation des spiritueux permet de réduire les consommations de spiritueux et de tabac des adolescents européens, mais que les résultats diffèrent selon le groupe de pays européens. Ensuite, nous examinons l'influence du groupe de pairs. Nous soulignons que la probabilité qu'un adolescent consomme de la drogue croît avec le nombre de pairs perçus comme étant consommateurs de drogues et décroît avec la taille du groupe de pairs, la volonté d'acquérir un statut social supérieur et la qualité des relations avec les pairs. Nous concluons par une analyse théorique mettant en évidence qu'au-delà des politiques traditionnelles reposant sur l'augmentation des coûts de la drogue, considérer les bénéfices de la consommation de drogues offre de nouvelles pistes de réflexion pour les politiques publiques de prévention primaire. / This thesis starts with the recognition that, in order to curb drugs use (alcohol, tobacco, cannabis), it is necessary to precisely analyze the determinants of entry into these consumptions, especially during adolescence. The tools provided by the economic analysis allow us to shed new light on these determinants. After presenting an overview of public policies fighting against tobacco and alcohol in France, we articulate our thinking around four main themes. First, we analyze the monetary resources available to the adolescents, and we show that the amount and the origin (pocket money, illegal activity, etc.) of these resources are key determinants of adolescent drugs use. Second, we examine the issue of complementarity and substitution between tobacco and alcohol use. We highlight that a taxation policy on spirits helps reduce both the use of spirits and tobacco for European adolescents, but the results are heterogeneous according to the group of European countries considered. Third, we examine the influence of peer group structure on adolescent's consumption of drugs. We emphasize that adolescent's drugs use positively depends on the number of peers perceived as drug users, and negatively on the size of the peer group, the desire to acquire a higher social status or good relationship with peers. Fourth, we provide a theoretical analysis highlighting that traditional policies based on costs' increase (taxation, consumption restrictions, etc.) face decreasing returns. As a result, considering the benefits of drug use (via pleasure) offers new avenues for reflection for public policies.

La croissance importante du nombre d'étudiants et le changement de profils des apprenants constatés durant les deux dernières décennies ont bouleversé l'enseignement supérieur. Le besoin d'adapter les enseignements a émergé brutalement. Les cours en face à face s'adressant à un grand nombre d'étudiants offrent un cadre soutenable pour la recherche et la mise en oeuvre de nouvelles pratiques pédagogiques. Dans ce contexte, différentes études montrent que l'utilisation de systèmes de votes interactifs (SVI) est un moyen de proposer des évaluations formatives aux étudiants durant le cours en les engageant massivement. Cependant ces systèmes n'intègrent pas toutes les dimensions caractérisant l'évaluation formative, ils ne tirent pas parti des apports des systèmes d'échanges et de partage de textes (SEPT) ayant fait leur apparition avec Internet et offrent donc des modalités d'interactions limitées. Ainsi nos travaux adressent les deux questions de recherche suivantes : - comment enrichir la mise en oeuvre d'évaluations formatives dans le contexte d'un cours en face à face dispensé à un grand nombre d'étudiants ? - comment susciter l'engagement du plus grand nombre d'étudiants dans les activités relatives à ces évaluations formatives ? Pour répondre à ces questions, nous proposons en premier lieu un cadre de travail pour la conception de systèmes d'évaluation formative dans le contexte des cours en face à face adressés à une large audience. Nous introduisons ainsi le concept d'évaluation d'audience et décrivons les processus qui lui sont associés en utilisant un langage standard de modélisation. De plus, afin d'enrichir la mise en oeuvre de l'évaluation formative dans les amphithéâtres, nous proposons un nouveau processus baptisé "processus en N phases" intégrant des activités et stratégies caractéristiques de l'évaluation formative telles que l'évaluation par les pairs ou l'utilisation des étudiants comme ressources pour les autres. Ce processus supporte également des modalités d'interaction plus riches qui incluent la saisie de texte libre ou la fourniture de feedback sous forme textuelle. La deuxième partie de nos travaux porte sur la conception et la mise en oeuvre du système d'évaluation d'audience Tsaap-Notes qui combine les atouts des SVI et des SEPT pour implanter le processus en N phases. Ce système d'évaluation d'audience enrichi a fait l'objet d'une série d'expérimentations montrant des résultats probant sur la capacité du système à maintenir l'engagement de la très grande majorité des étudiants dans le processus d'évaluation formative. / The significant growth in student numbers and changing learner profiles observed during the last two decades have shaken higher education. The need to adapt teaching strongly appeared. Face to face lectures for a large audience are a sustainable frame for research and implementation of new pedagogical practices. In this context, different studies show that the use of audience response system (ARS) is an efficient way to provide students with formative assessments during lectures and that they engage a large numbers of attendees. However, these systems do not integrate all dimensions of formative assessments, they do not take advantages of sharing text systems (STS) who appeared with Internet and therefore provide only limited types of interaction. Thus, our work addresses the following research questions : - how to enhance implementation of formative assessments in the context of face to face lectures adressed to a large number of students ? - how to maintain engagement of the majority of students in activities related to these formative assessments ? In order to answer these questions, we first propose a framework for the design of formative assessment systems to be used during face to face lectures addressed to a large audience. Thus, we introduce the concept of Audience Assessment and describe its related processes using a standard language. Then, in order to enhance implementation of formative assessments addressed to a large audience, we propose a new process called "N phases process" which introduces characteristic activities and strategies of formative assessments such as peer assessment or use of students as resources of instruction for others. This process supports also richer types of interaction such as answer given as free text entry or feedback provided as text. The second part of our work focuses on the design and the implementation of the audience assessment system called " Tsaap-Notes ". Tsaap-Notes combines the strengths of SVI and STS to implement the N phases process. A series of experimentations has been conducted on Tsaap-Notes showing good results on the capacity of the N phases process to engage the large majority of students.