Dans ces travaux de thèse, nous avons étudié les propriétés dynamiques et spectrales d’une diode laser puissante à 980 nm qui est soumise à un retour optique provenant d’un réseau de Bragg fibré (FBG). Dans cette configuration, le FBG est un élément clé de la thèse d’une part il permet de former une cavité externe par réflexion comme un miroir et d’autre part il est un filtre qui fournit un retour optique sélectif en fréquence (FOF : Filtered Optical Feedback) aux alentours de 980 nm. Nous nous sommes intéressé à étudier cette configuration FOF dans le cadre d’un projet de collaboration entre la société 3S Photonics Group et le Laboratoire de Physique des Lasers. Il s’agit plus particulièrement d’étudier expérimentalement les séries temporelles par un oscilloscope, les spectres RF par un analyseur de spectre RF et les spectres optiques par un analyseur de spectre optique et par un interféromètre Fabry-Perot, afin d’observer, identifier et comprendre ses comportements dynamiques, notamment fluctuations basses fréquences (LFF). Ce système laser FOF est très peu étudié et ces travaux de thèse permettront de nouvelles connaissances techniques ou scientifiques dans un domaine d’application relativement récent, notamment pour l’application dans les systèmes EDFA (Erbium Doped Fiber Amplifier). / In this thesis, we have studied spectrums and the dynamics properties of a high-powerlaser diode emitting at 980 subject to optical feedback via a fibre Bragg grating (FBG). In such a configuration, FBG is a key element of this work because it establishes an ex-ternal cavity with a reflection like a mirror on one hand and it is a filter which provides frequency selective optical feedback (FOF : Filtered Optical Feedback) at around 980 nm on the other hand. We are interested in investigating this FOF configuration for a project in a collaboration between 3S Photonics Group and the Laboratoire de Physique des Lasers.In order to observe, identify and understand its dynamical behaviours, especially low frequency fluctuations (LFF), the experimental studies have been undertaken particularly with time series from an oscilloscope, RF spectra from an RF spectrum analyser and optical spectra from an optical spectrum analyser and Fabry-Perot interferometer. Onlyfew studies have been done with this FOF laser system and our thesis work may allow new technical and scientific understanding for recent application, particularly application to Erbium-doped fibre amplifier.

abstract: 近年来，中国内地FOF业务发展迅速，但在业务发展初期的实践中，FOF管理人在遴选基金资产和预测其未来收益等方面遇到诸多困难，传统的FOF组合构建技术往往不理想。本文借鉴海外因子配置相关理论，尝试通过归因分析基金的收益来源，寻找能深度刻画基金经理管理能力的特质因子，创新性地提出了基于权益类基金的特质因子构建FOF组合的新方法。本文选择100家权益类私募基金，通过因子拆解剥离了市场、行业、风格等共同影响因素，遴选出特质因子表现更优的基金经理，而不是仅仅选择过往业绩好的基金经理，并基于特质因子构建一组FOF组合，与此同时，运用传统方法构建基于基金资产的另一组FOF组合，对比两种组合方法的组合绩效，实证结果显示基于特质因子的FOF组合绩效更优。本文进一步运用转移概率矩阵和相关性分析，找到了基于特质因子的FOF组合绩效更优的证据，即特质因子延续性更好和相关性更低。与基于基金资产的FOF组合配置传统方法相比，由于基金的特质因子延续性更好，运用历史数据预测未来收益的确定性相对更好；基金的特质因子之间的相关性低，大幅增强了FOF组合配置的稳定性和分散性。总体来讲，基于特质因子的FOF组合配置方法为FOF管理人提供了一个更量化、更有效、更稳健的组合配置新路径，能有效提升FOF组合配置的绩效。 关键词: FOF、因子投资、组合配置、特质因子 / Dissertation/Thesis / Doctoral Dissertation Business Administration 2020

Sequential pattern mining constitutes a basis for solution of problems in various domains like bio-informatics and web usage mining. Research on this field continues seeking faster algorithms. WAP-Tree based algorithms that emerged from web usage mining literature have shown a remarkable performance on single-item sequence databases. In this study, we investigated application of WAP-Tree based mining to multi-item sequential pattern mining and we designed an extension of WAP-Tree data structure for multi-item sequence databases, the MULTI-WAP-Tree. In addition, we propose a new mining strategy on WAP-Tree which involves a hybrid traversal strategy in possible sequences search space and a new early prunning idea called Sibling Principle on Pattern Tree. Two algorithms, FOF-PT and MULTI-FOF-PT, applying this strategy on WAP-Tree and MULTI-WAP-Tree respectively, are developed. Experiments showed that FOF-PT outperforms both other WAP-Tree based algorithms and PrefixSpan in terms of execution time. Moreover, experimental results revealed MULTI-FOF-PT finds patterns faster than PrefixSpan on dense multi-item sequence databases with small alphabets.

Grammar is an essential part of language learning. Thus, it is important that teachers know how to efficiently teach grammar to students, and with what approach - explicitly orimplicitly as well as through Focus on Forms (FoFs), Focus on Form (FoF) or Focus onMeaning (FoM). Furthermore, the common use of textbooks in English education in Sweden makes it essential to explore how these present grammar. Therefore, to make teachers aware of what grammar teaching approach a textbook has, this degree project intends to examine how and to what degree English textbooks used in Swedish upper secondary schools can be seen to exhibit an overall explicit or implicit approach to grammar teaching. The aim is to analyze three English 5 textbooks that are currently used in classrooms in Sweden, through the use of relevant research regarding grammar teaching as well as the steering documents for English 5 in Swedish upper secondary school. The analysis was carried out with the help of a framework developed by means of research on explicit and implicit grammar teaching as well as the three grammar teaching approaches FoFs, FoF and FoM. Thus, through the textbook analysis, we set out to investigate whether the textbooks present grammar instruction explicitly or implicitly and through FoFs, FoF or FoM. After having collected research on the topic of how to teach grammar, it became apparent that researchers on grammar teaching agree that FoF is the most beneficial out of the three above mentioned approaches, and thus, we decided to take a stand for this approach throughout the project. The results of this study showed that two out of three textbooks used overall implicit grammar teaching through FoM. Moreover, one out of the three textbooks used overall explicit grammar teaching through an FoF approach.

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

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

This essay aims to investigate theoretically how two currently used coursebooks, What’s Up 9 and Solid Gold 1, in a local area of Southern Sweden, present (introduces and covers) grammar. The overall aim is to investigate how grammar is presented, using the present simple and the present continuous as examples. The findings are also mapped to teaching approaches, as well as SLA (Second Language Acquisition) research, to see what approaches are favoured for teaching grammar in the first decades of the 21st century. In order to investigate the course- books, a qualitative content analysis and conceptual analysis was chosen with the presentation of grammar mapped into different categories, by using concepts for teaching and approaches used in SLA. The results show that the two proposed coursebooks favoured a FoFs (Focus on Forms) approach for presenting grammar. Furthermore, the results show that grammar is pre- sented explicitly and, if the teachers use the structures proposed in the coursebook rigidly, they automatically follow a deductive teaching procedure. When using a FoFs, explicit instructions and taking a deductive teaching approach, it may be regarded as the coursebooks suggest a grammar-translation approach as well. However, when observing other exercises connected to the reading texts in the coursebooks, it was detected that both coursebooks favoured a text- based approach for teaching, where the learners are supposed to learn the structure of different texts. In doing so, the grammatical structures are learned subconsciously and implicitly, which indicates that grammar is, in general, taught implicitly in the coursebooks, but presented (intro- duced and covered) explicitly.