La recherche qui suit se veut une étude exploratoire utilisant l’étude de cas pour caractériser les rapports personnels que les futurs enseignants du primaire se construisent avec les notions de variation et covariation au cours de leur formation initiale. La notion de fonction y est abordée compte tenu, entre autres, de son importance dans les programmes d’enseignement au secondaire et des difficultés que rencontrent les élèves dans l’apprentissage de cette notion. Une conceptualisation, par les élèves, de la notion de fonction comme relation entre des quantités variables passe par une acquisition préalable des notions de variation et covariation. Un début d’acquisition de ces notions est possible dès l’école primaire à travers des activités pré-algébriques qui utilisent les régularités avec les suites de nombres ou les patterns. Pour cette raison, les enseignants du primaire doivent être en mesure de faire apprendre les activités sur les régularités aux élèves. C’est pourquoi la formation des enseignants est abordée dans cette recherche en regardant, les connaissances nécessaires pour l’enseignement des mathématiques au primaire et les lacunes qui affectent cette formation. La recherche s’appuie sur la théorie anthropologique du didactique (TAD) qui a développé des outils conceptuels sur la notion de rapport au savoir. La TAD est un moyen de comprendre les choix d'une institution pour organiser l'enseignement des objets mathématiques, ainsi que la signification assignée à ces objets et les conséquences qu'il en résulte sur l'apprentissage. Cette compréhension passe par l'analyse des pratiques qui mettent en jeu les objets de savoirs mathématiques au sein d’une institution. Outre les notions d’institution, d’objet de savoir et de sujet, c’est surtout à partir de l’éclairage des notions de rapport personnel et de rapport institutionnel que l’exploration des rapports personnels des futurs enseignants du primaire est conduite. Dans cette recherche, comme nous nous intéressons au programme de formation initiale des futurs enseignants du primaire, nous prenons comme institution de référence le programme de Baccalauréat en Éducation Préscolaire et Enseignement Primaire (BEPEP). Une analyse de contenu des documents de référence dans l’institution BEPEP permet d’abord d’examiner le rapport institutionnel de BEPEP avec les objets de variation et covariation en regardant notamment la place et le rôle de ces objets au sein de l’institution. Puis une enquête (questionnaire et entrevues) essaie de saisir les traits significatifs des rapports personnels des futurs enseignants avec les mêmes objets. Enfin la triangulation des informations du programme de formation et celles de l’enquête permet de déterminer si les rapports personnels des futurs enseignants du primaire sont la conséquence du rapport institutionnel de BEPEP. Les résultats semblent indiquer que les activités impliquant les suites de nombres, les patterns, les notions de variation et covariation ne sont pas suffisamment présentes dans le programme de formation de nos participants. Ce vide institutionnel semble affecter les rapports personnels des futurs enseignants qui sont, pour la plupart, incapables d’utiliser ces activités et notions. / The following research is an exploratory study using the case study to characterize the personal relationships that primary preservice teachers build with the notions of variation and covariation during their initial training program. The notion of function is discussed considering, among others, its importance in educational programs at the secondary and difficulties students face when learning functions. To make students conceptualise the notion of function as a relationship between varying quantities requires first to make them acquire the notions of variation and covariation. This acquisition is possible from primary school through pre-algebraic activities using the sequences of numbers or patterns. This work should be supported by primary school teachers. That is why teacher training is also addressed in this research by looking, for example, the knowledge needed to teach mathematics and the gaps that may affect that training program. The research leans on the anthropological theory of the didactic (ATD) which has developed conceptual tools of the notion of relationship to knowledge. The ATD is a way to understand the choices made by an institution to organise the teaching of mathematical objects, and the meaning assigned to those objects and the consequences that result in learning. This understanding requires the analysis of practices that involve the objects of mathematical knowledge within any institution. Beyond the notions of institution, object of knowledge, about, it is mostly from the lighting of the notions of personal relationship and institutional relationship that the exploration of the personal relationships of the primary preservice teachers is lead. A content analysis of initial training of future teachers allows first examine the institutional relationship with the objects of variation and covariation in particular looking at the place and the role of these objects in the BEPEP institution. Then, a survey (questionnaire and interviews) tries to capture significant features of preservice teachers’ personal relationships with the same objects. Finally, the triangulation of the data collected from the initial training and from the survey attempts to determine whether personal relationships are the result of the institutional relationship. iv Results seem to indicate that mathematical and pedagogical activities involving numerical sequences, growing patterns, the notions of variation and covariation are not sufficiently present in the training program of our participants and, consequently, most of them are unable to efficiently use these activities and notions. This institutional void seems to affect the primary preservice teachers’ personal relationships that most part of them are unable to use these activities and notions.

This study sought to assess the effects of pairing a neutral stimulus with a reprimand contingent on occurrences of two topographies of problem behavior. Using a multiple baseline withdrawal with a nested multi-element design, contingencies were first applied to eye poking and, subsequently, to a second behavior, skin picking. In each case, the participant wore wristbands (a previously neutral stimulus) during treatment sessions. Results indicated that the reprimands were effective in decreasing both behaviors. In addition, when skin picking resulted in reprimands, eye poking also decreased. However, when reprimands were contingent on eye-poking, the effects did not appear to generalize to skin-picking. Some possible accounts for this asymmetrical pattern of generalization are discussed.

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Dans cette thèse une nouvelle représentation spectrale des processus symétriques alpha-stables est introduite. Elle est basée sur une propriété de pseudo-additivité de la covariation et l'intégrale au sens de Morse-Transue par rapport à une bimesure que nous construisons en utilisant la pseudo-additivité. L'intérêt de cette représentation est qu'elle est semblable à celle de la covariance des processus du second ordre; elle généralise celle établie pour les intégrales stochastiques par rapport à un processus symétrique alpha-stable à accroissements indépendants. Une classification des processus harmonisables non stationnaires a été étudiée selon la structure de la bimesure qui les caractérise et les processus périodiquement covariés ont été définis. Pour pouvoir simuler cette inhabituelle classe de processus, une nouvelle décomposition en séries de type Lepage a été apportée. Finalement des techniques non paramétriques d'estimation spectrale sont discutées. En particulier un estimateur presque sûrement convergeant sous une condition de mélange fort, a été introduit pour les processus périodiquement covariés.

It was the purpose of this design study to explore the Geometer’s Sketchpad dynamic mathematics software as a tool to model the derivative in introductory calculus in a manner that would foster a deeper conceptual understanding of the concept – developing domain specific understanding. Sketchpad’s transformation capabilities have been proved useful in the exploration of mathematical concepts by younger learners, college students and professors. The prospect of an open-ended exploration of mathematical concepts motivated the author to pursue the possibility of representing the concept of derivative in dynamic forms. Contemporary CAS studies have predominantly dwelt on static algebraic, graphical and numeric representations and the connections that students are expected to make between them. The dynamic features of Sketchpad and such like software, have not been elaborately examined in so far as they have the potential to bridge the gap between actions, processes and concepts on the one hand and between representations on the other. In this study Sketchpad model-eliciting activities were designed, piloted and revised before a final implementation phase with undergraduate non-math major science students enrolled for an introductory calculus course. Although most of these students had some pre-calculus and calculus background, their performance in the introductory course remained dismal and their grasp of the derivative slippery. The dual meaning of the derivative as the instantaneous rate of change and as the rate of change function was modeled in Sketchpad’s multiple representational capabilities. Six forms of representation were identified: static symbolic, static graphic, static numeric, dynamic graphic, dynamic numeric and occasionally dynamic symbolic. The activities enabled students to establish conceptual links between these representations. Students were able to switch systematically from one form of (foreground or background) representation to another leading to a unique qualitative understanding of the derivative as the invariant concept across the representations. Experimental students scored significantly higher in the posttest than in the pretest. However, in comparison with control group students the experimental students performed significantly better than control students in non-routine problems. A cyclical model of developing a deeper concept image of the derivative is therefore proposed in this study. / Educational Studies / D. Ed. (Education)

Cette thèse est consacrée à l’étude de théorèmes limites : grandes déviations et déviations modérées pour des estimateurs liés à des modèles financiers. Dans une première partie, nous nous sommes intéressés à l’étude des déviations grandes et modérées des estimateurs de la covariation et de la (co)volatilité réalisée issus des fonctionnelles associées à deux processus de diffusion couplés de manière synchronisée. Les techniques utilisées dans ces travaux sont basées d’une part sur celles utilisées dans Djellout-Guillin-Wu et sur la sous additivité et sur la notion d’approximation exponentielle inspirées des travaux de J. Najim d’autre part. Dans une deuxième partie, on considère que les deux processus de diffusion sont observés de manière non synchronisée et on établit des déviations modérées pour l’estimateur de la variation généralisée et pour celui de Hayashi-Yoshida. Les résultats sont obtenus par l’utilisation d’une nouvelle approche sur les déviations modérées des variables aléatoires m−dépendantes vérifiant des conditions de type "Chen-Ledoux". Dans la troisième et dernière partie, on s’intéresse à l’étude processus autorégressif d’ordre p dont le bruit est un processus autorégressif d’ordre q. On montre des déviations modérées pour certains estimateurs associés à notre modèle dont la statistique de Durbin-Watson. Les résultats sont donnés dans le cas où le bruit est gaussien puis dans le cas de condition de type "Chen-Ledoux" portant sur le bruit. / This thesis is devoted to the study of the limits theorem : large and moderate déviations for some financial mathematicals estimators. In the first part, we studied the large and moderate deviations of the estimators of covariation and the realized (co)volatility obtained from the functional associated to two diffusion processes coupled in synchronous manner. The techniques used in this work are based, on the one hand, on those used in Djellout-Guillin-Wu and the subadditivity and the exponential approximation notion inspired by J. Najim results on the other hand. In the second part, we consider that ours two diffusion processes are observed in a nonsynchronized manner and on the establish the moderate deviations for the generalised bipower variation estimator and the Hayashi-Yoshida estimator. The results are obtained by using a new approach on the moderate deviations of the m−dependent random variables based on the Chen-Ledoux type condition. In the third and last part, we study the stable autoregressive process of order p where the driven noise is also given by a q-order autoregressive process. We prove the moderate deviations for some estimators associated with our model such as the Durbin-Watson statistic. The results are given in the case where the driven noise is the normally distributed then in the case where the driven noise satisfy a Chen-Ledoux type condition.

Afin de mieux cerner les enjeux de la transition entre le secondaire et le postsecondaire, nous proposons un examen du passage de la notion de fonction à celle de dérivée. À la lumière de plusieurs travaux mettant en évidence des difficultés inhérentes à ce passage, et nous basant sur les recherches de Carlson et ses collègues (Carlson, 2002; Carlson, Jacobs, Coe, Larsen et Hsu, 2002; Carlson, Larsen et Jacobs, 2001; Oehrtman, Carlson et Thompson, 2008) sur le raisonnement covariationnel, nous présentons une analyse de la dynamique du développement de ce raisonnement chez des petits groupes d’élèves de la fin du secondaire et du début du collégial dans quatre situations-problèmes différentes. L’analyse des raisonnements de ces groupes d’élèves nous a permis, d’une part, de raffiner la grille proposée par Carlson en mettant en évidence, non seulement des unités de processus de modélisation (ou unités de raisonnement) mises en action par ces élèves lors des activités proposées, mais aussi leurs rôles au sein de la dynamique du raisonnement. D’autre part, cette analyse révèle l’influence de certaines caractéristiques des situations sur les interactions non linéaires entre ces unités. / To better understand the transitional challenges between high-school and post-secondary education, we propose a study of the passage from the notion of function to the notion of derivative. Based on numerous studies on the difficulties related to this passage and, more specifically, on the work of Carlson and colleague’s (Carlson, 2002; Carlson, Jacobs, Coe, Larsen & Hsu, 2002; Carlson, Larsen & Jacobs, 2001; Oehrtman, Carlson & Thompson, 2008) on covariational reasoning, we present an analysis of the dynamics of the development of covariational reasoning. By submitting four different problem-situations to small groups of students ending secondary school and beginning college (15-18 years old), we were able to examine that development. On one hand, the analysis of the reasoning of those students allowed us to refine the grid proposed by Carlson, bringing out, not only the reasoning units used by those students during the proposed activities, but also their role in the dynamic of the reasoning. On the other hand, this analysis reveals the influence of certain characteristics of the situations on the non-linear interactions between those units.

<p>Sustained attention, the ability to direct and maintain attentional focus on tasks and stimuli, emerges during infancy and undergoes rapid development throughout early childhood. Abnormal patterns of sustained attention are implicated in several childhood psychological disorders. Improving our measurement of infant sustained attention may clarify how child psychopathology develops and inform targeted prevention and early intervention efforts. While several behavioral and psychophysiological measures index infant sustained attention, previous studies have employed these measures in isolation, focused on analyses at short timescales of milliseconds to a few seconds, and examined synchronous associations among these measures. Therefore, the associations and temporal relationships across multiple, concurrent behavioral and psychophysiological measures of infant sustained attention remain unclear, particularly at long timescales. The present study assessed sustained attention in 12-month-old infants using behavioral (looking), cardiac (heart rate), and neural (theta and alpha oscillations) measures to investigate two temporal aspects of infant sustained attention. First, we examined whether associations among infant sustained attention measures were similar or different across short (1-second) and long (10-second) timescales. Covariation analyses indicated largely similar association patterns among these measures across the two timescales. Second, we evaluated whether specific infant sustained attention measures temporally preceded other measures. Cross-correlation analyses broadly revealed that short-timescale measures exhibited asynchronous temporal relationships, such that looking behaviors preceded neural oscillations that in turn preceded cardiac responses. Our findings highlight the value of considering the temporal dimension when studying and measuring infant sustained attention. Additional multimodal research may yield greater insights into dynamic biobehavioral processes that underlie infant sustained attention and enhance clinical interventions aimed at promoting optimal outcomes for young children with abnormalities in sustained attention.</p>

This thesis comprises three original papers about learning rate of change in school mathematics. The overall aim of the thesis is to contribute with knowledge in this particular area of research. Within this aim, each of the original papers contribute with its own perspective. The theoretical framework used in the thesis is variation theory of learning (Marton &amp; Booth, 1997; Marton, 2015), by which learning is seen as experiencing a phenomenon in a new way. This theoretical point of departure is reflected in the research question of the thesis: What is critical to discern to use and express rate as a measure of the relation of changes in two quantities? The empirical study was conducted as a learning study (Pang &amp; Marton, 2003). A learning study is an iterative, interventional research arrangement in which teachers and researchers collaboratively explore a specific ability, the object of learning, worthwhile for the students to learn. The object of learning related to this thesis, ‘to express the quantitative rate of change of a linear relation’, was explored in a series of three research lessons at a secondary school. Data consists of students’ responses to written pre- and post-tests, and lesson videos. Some data have been analysed during the on-going empirical study and some data have been analysed after it was concluded. Principles from variation theory have been used as tools for analysis throughout the study. Main results of Paper I demonstrate how two critical aspects are identified and revised through the process of learning study. In Paper II the results indicate that qualitatively different questions in a task may affect students’ ways to relate changes in two quantities. The results of Paper III suggest how different perspectives of slope may promote homogeneity as an aspect of rate. Results also comprise six critical aspects of the object of learning, four of which was identified by revisiting the results of Paper II. In summary, the critical aspects also specify the meaning of a covariational perspective of rate. Results are discussed in relation to previous educational research about rate of change, covariation of quantities and students’ conceptions of rate and slope. Further research directions are suggested. / Den här sammanläggningsuppsatsen omfattar tre artiklar om förändringstakt i matematik. Uppsatsens övergripande syfte är att bidra med kunskap till detta specifika forskningsfält. Inom ramen för detta syfte bidrar var och en av de tre artiklarna med sitt eget perspektiv. Det teoretiska ramverket i uppsatsen är variationsteori (Marton &amp; Booth, 1997; Marton, 2015). Ur detta teoretiska perspektiv ses lärande som ett erfarande av ett fenomen på ett nytt sätt. Denna teoretiska utgångspunkt har färgat uppsatsens övergripande forskningsfråga: Vad är kritiskt att urskilja för att använda och uttrycka förändringstakt somett mått på relationen mellan förändringar i två storheter? Den empiriska studien genomfördes som en learning study (Pang et al., 2003). Learning study är en iterativ, intervenerande forskningsansats där lärare och forskare i samarbete utforskar en specifik förmåga, lärandeobjektet, något som är värdefullt för elever att lära sig. Lärandeobjektet som behandlas i denna uppsats, ’att uttrycka förändringstakten i en linjär relation kvantitativt’, utforskades i en serie av tre lektioner på en högstadieskola. Data består av elevers svar till skriftliga uppgifter i för- och eftertest, samt videoinspelade lektioner. Data har analyserats både under den pågående empiriska studien, och efter att den avslutades. Principer från variationsteori har använts som analysverktyg genom studiens gång. Huvudresultaten av Artikel I visar hur två kritiska aspekter identifieras, revideras och förfinas genom learning study som process. I Artikel II tyder resultaten på att kvalitativt olika frågor i en uppgift påverkade elevernas sätt att relatera förändringar i två storheter. Resultaten i Artikel III visar hur olika perspektiv på lutningen hos en graf kan föra fram homogenitet som en aspekt av förändringstakt. Uppsatsens resultat omfattar framför allt sex aspekter som är kritiska att urskilja för att utveckla förmågan att använda och uttrycka förändringstakt som ett mått på relationen mellan förändringar i två storheter. Fyra av dem identifierades då resultaten av Artikel II tolkades utifrån ett variationsteoretiskt perspektiv. Som helhet specificerar också de kritiska aspekterna innebörden av ett samvarierande perspektiv på förändringstakt. Resultaten diskuteras i förhållande till tidigare forskning om lärande om förändringstakt, samvariation mellan storheter och elevers uppfattningar av lutning. Några vidare forskningsriktningar pekas ut.

För investerare vars portföljer utgörs av internationella investeringar är det i synnerhet viktigt att begrunda beroendestrukturen mellan internationella investeringar och valutakurser. Detta på grund av den valutarisk som investeraren exponerar sig mot utöver de internationella tillgångarnas inneboende risk. I denna studie undersöks hur svenska investerare med investeringar i den amerikanska aktie- och företagsobligationsmarknaden påverkas av valutakursförändringar i USD:SEK. De amerikanska investeringarna är i denna studie denominerade i amerikanska dollar men portföljen och dess risk är denominerad i svenska kronor, portföljen påverkas därmed av valutaeffekten.Vidare undersöks samvariationen mellan dessa tillgångar och en optimal valutahedge upprättas för att reducera svansrisk i en sådan portfölj.  För att bestämma en optimal valutahedge optimeras CVaR för nio olika portföljer med olika viktning av S&amp;P 500, investment grade- företagsobligationer och high yield-företagsobligationer. Två metoder för att ta fram scenariopriser till optimeringen används: historisk simulering samt Monte Carlo-simulering från en vine-copula. Resultaten i denna studie antyder att svenska investerare bör hedga bort viss exponering mot USD. På den amerikanska aktiemarknaden bör större andel av valutarisken bibehållas än på den amerikanska high yield-obligationsmarknaden. Detta antyder att viss valutarisk bidrar med en hedgande effekt. På den amerikanska investment grade-obligationsmarknaden bör endast en mycket liten exponering mot USD bibehållas och ingen tydlig hedgande effekt kunde påvisas. Analys av samvariation mellan amerikansk aktiemarknad, företagsobligationsmarknad och valutakursen USD:SEK antyder att USD:SEK uppvisar förhöjt negativt beroende vid svansutfall i både den amerikanska aktiemarknaden och high yield-obligationsmarknaden. Detta antyder att USD uppvisar så kallade safe haven-egenskaper för svenska investerare i dessa marknader. / For investors whose portfolios consist of international investments, it is of particular importance to consider the dependence structure between international investments and foreign exchange rates. This is due to the currency risk that the investor is exposed to in addition to the inherent risk of the international assets. This study examines how Swedish investors with investments in the US equity and corporate bond market are affected by exchange rate fluctuations in the currency pair USD:SEK. In this study, US investments are denominated in US dollars, but the portfolio and its risk are denominated in Swedish Kronor, the portfolio is thus affected by the foreign currency effect. Furthermore, the covariation between these assets is examined and an optimal hedge is established in order to reduce tail risk in such a portfolio. To determine the optimal currency hedge, CVaR is optimized for nine different portfolios with different weightings of S&amp;P 500, investment grade corporate bonds and high yield corporate bonds. Two methods for producing scenario prices for the optimization are used: historical simulation and Monte Carlo simulation from a vine copula. The results of this study suggest that Swedish investors should hedge some of the exposure against USD. In the US stock market, a larger share of currency risk should be maintained than in the US high yield bond market. This suggests that some currency risk contributes to a hedging effect. In the US investment grade bond market little exposure against USD should be maintained and no clear hedging effect could be demonstrated. Analysis of covariation between the US stock market, corporate bond market and the exchange rate USD:SEK indicates that USD:SEK displays increased negative dependence in tail events in boththe US stock market and the high yield bond market. This indicates that USD displays so-called safe haven properties for Swedish investors in these markets.