Ce travail de thèse porte sur l’étude expérimentale des polaritons de microcavité dans des microstructures de semiconducteurs III-V. Il présente un volet fondamental sur les propriétés de cohérence et de polarisation des lasers à polaritons, et un volet plus applicatif dédié à la démonstration de principe de nouveaux dispositifs tout optique à polaritons.Dans la première partie, nous utilisons une caméra streak en mode « single shot » pour mesurer des corrélations de photons du second ordre avec une résolution à la picoseconde. Cette technique nous permet de mesurer la statistique d’émission de lasers à polaritons. Nous analysons ainsi la dynamique à l’échelle picoseconde de l’établissement de la cohérence spontanée et de la polarisation du mode, à l’allumage du laser. Nous mettons en évidence une initialisation stochastique de la polarisation, suivie d’une précession autour d’un champ magnétique effectif présent dans la cavité. Le rôle de la dimensionnalité de la cavité est discuté, et un modèle théorique permet une meilleure compréhension de ces mesures. La deuxième partie est dédiée à la réalisation de dispositifs à polaritons, dont le contrôle est tout optique. Ces dispositifs sont essentiellement constitués d’un résonateur 0D couplés à des guides 1D d’entrée et de sortie. Nous démontrons le fonctionnement d’un « router » à polaritons, et observons une bistabilité optique du résonateur 0D pilotée à distance. Ce dernier effet est l’ingrédient de base d’une mémoire optique, et nous montrons des résultats préliminaires concernant l’implémentation de portes logiques tout optiques AND, OR et XOR. / This PhD thesis is dedicated to the experimental study of microcavity polaritons in III-V semiconductor microstructures. It consists in a fundamental part focusing on the coherence and polarization properties of polariton lasers, and in a more applied second part which concerns the proof of principle of new all-optical polariton devices.In the first part, we use a streak camera in the single shot regime to measure second order photon correlations with a picosecond resolution. This technique allows measuring the emission statistics of polariton lasers and analyzing at the picosecond scale the dynamics of the establishment of the spontaneous coherence and polarization of the mode during the laser initialization. We show a stochastic initialization of the polarization followed by a precession around an effective magnetic field inside the cavity. The influence of the system dimension is discussed and a theoretical model allows us to better understand these measurements. The second part is dedicated to the realization of polariton devices with an all-optical control. These devices are constituted of a 0D resonator coupled to 1D input and output waveguides. We demonstrate the operation of a polariton router and a remotely controlled optical bistability. This last effect is the core ingredient of an optical memory and we show preliminary results on the implementation of all-optical AND, OR and XOR logic gates.

Les automates distribués sont des machines à états finis qui opèrent sur des graphes orientés finis. Fonctionnant comme des algorithmes distribués synchrones, ils utilisent leur graphe d'entrée comme un réseau dans lequel des processeurs identiques communiquent entre eux pendant un certain nombre (éventuellement infini) de rondes synchrones. Pour la variante locale de ces automates, où le nombre de rondes est borné par une constante, Hella et al. (2012, 2015) ont établi une caractérisation logique par des formules de la logique modale de base. Dans le cadre de cette thèse, nous présentons des caractérisations logiques similaires pour deux classes d'automates distribués plus expressives.La première classe étend les automates locaux avec une condition d'acceptation globale et la capacité d'alterner entre des modes de calcul non-déterministes et parallèles. Nous montrons qu'elle est équivalente à la logique monadique du second ordre sur les graphes.En nous restreignant à des transitions non-déterministes ou déterministes, nous obtenons également deux variantes d'automates strictement plus faibles pour lesquelles le problème du vide est décidable.Notre seconde classe adapte la notion standard d'algorithme asynchrone au cadre des automates distribués non-locaux. Les machines résultantes sont prouvées équivalentes à un petit fragment de la logique de point fixe, et plus précisément, à une variante restreinte du μ-calcul modal qui autorise les plus petits points fixes mais interdit les plus grands points fixes. Profitant du lien avec la logique, nous montrons aussi que la puissance expressive de ces automates asynchrones est indépendante du fait que des messages puissent être perdus ou non.Nous étudions ensuite la décidabilité du problème du vide pour plusieurs classes d'automates non-locaux. Nous montrons que le problème est indécidable en général, en simulant une machine de Turing par un automate distribué qui échange les rôles de l'espace et du temps. En revanche, le problème s'avère décidable en LOGSPACE pour une classe d'automates oublieux, où les nœuds voient les messages reçus de leurs voisins, mais ne se souviennent pas de leur propre état. Finalement, à titre de contribution mineure, nous donnons également de nouvelles preuves de séparation pour plusieurs hiérarchies d'alternance de quantificateurs basées sur la logique modale. / Distributed automata are finite-state machines that operate on finitedirected graphs. Acting as synchronous distributed algorithms, they use their input graph as a network in which identical processors communicate for a possibly infinite number of synchronous rounds. For the local variant of those automata, where the number of rounds is bounded by a constant, Hella et al. (2012, 2015) have established a logical characterization in terms of basic modal logic. In this thesis, we provide similar logical characterizations for two more expressive classes of distributed automata.The first class extends local automata with a global acceptance condition and the ability to alternate between non deterministic and parallel computations. We show that it is equivalent to monadic second-order logic on graphs. By restricting transitions to be non deterministic or deterministic, we also obtain two strictly weaker variants for which the emptiness problem is decidable.Our second class transfers the standard notion of asynchronous algorithm to the setting of non local distributed automata. There sulting machines are shown to be equivalent to a small fragment of least fixpoint logic, and more specifically, to a restricted variantof the modal μ -calculus that allows least fixpoints but forbids greatest fixpoints. Exploiting the connection with logic, we additionally prove that the expressive power of those asynchronous automata is independent of whether or not messages can be lost.We then investigate the decidability of the emptiness problem forseveral classes of nonlocal automata. We show that the problem isundecidable in general, by simulating a Turing machine with adistributed automaton that exchanges the roles of space and time. Onthe other hand, the problem is found to be decidable in logspace for a class of forgetful automata, where the nodes see the messages received from their neighbors but cannot remember their own state. As a minor contribution, we also give new proofs of the strictness of several set quantifier alternation hierarchies that are based on modallogic.

With advances in high-throughput techniques, the availability of large-scale omics data has revolutionized the fields of medicine and biology, and has offered a better understanding of the underlying biological mechanisms. However, the high-dimensionality and the unknown association structure between different data types make statistical integration analyses challenging. In this dissertation, we develop three dimensionality reduction methods to detect nonlinear association structure using omics data. First, we propose a method for variable selection in a nonparametric additive quantile regression framework. We enforce a network regularization to incorporate information encoded by known networks. To account for nonlinear associations, we approximate the additive functional effect of each predictor with the expansion of a B-spline basis. We implement the group Lasso penalty to achieve sparsity. We define the network-constrained penalty by regulating the difference between the effect functions of any two linked genes (predictors) in the network. Simulation studies show that our proposed method performs well in identifying truly associated genes with fewer falsely associated genes than alternative approaches. Second, we develop a canonical correlation analysis (CCA)-based method, canonical distance correlation analysis (CDCA), and leverage the distance correlation to capture the overall association between two sets of variables. The CDCA allows untangling linear and nonlinear dependence structures. Third, we develop the sparse CDCA (sCDCA) method to achieve sparsity and improve result interpretability by adding penalties on the loadings from the CDCA. The sCDCA method can be applied to data with large dimensionality and small sample size. We develop iterative majorization-minimization-based coordinate descent algorithms to compute the loadings in the CDCA and sCDCA methods. Simulation studies show that the proposed CDCA and sCDCA approaches have better performance than classical CCA and sparse CCA (sCCA) in nonlinear settings and have similar performance in linear association settings. We apply the proposed methods to the Framingham Heart Study (FHS) to identify body mass index associated genes, the association structure between metabolic disorders and metabolite profiles, and a subset of metabolites and their associated type 2 diabetes (T2D)-related genes. / 2023-11-05T00:00:00Z

This paper deals with the thermodynamic cycle of Striling engine. Analysis of the ideal cycle, Schmidt analysis and second-order method with loss correction by PROSA 2.4 software is applied. The results are compared with experimental data of two model engines.

In this thesis, our research focus on a weak second order stochastic Runge–Kutta method applied to a system of stochastic differential equations known as the Gatheral Model. We approximate numerical solutions to this system and investigate the rate of convergence of our method. Both call and put options are priced using Monte-Carlo simulation to investigate the order of convergence. The numerical results show that our method is consistent with the theoretical order of convergence of the Monte-Carlo simulation. However, in terms of the Runge-Kutta method, we cannot accept the consistency of our method with the theoretical order of convergence without further research.

Diploma thesis "Aplication of Second order election theory on European election in Visegrad states" examines a theory of second-order election and aplicates it on European elections in the Visegrad states. Since this theory was build on election results in founding states of the EU and this theory was many times proved in western Europe, the main goal is to find out whether the election results of the Visegrad states concur with the theory of second- order election or not. In that case goal of this thesis will be to find out where and why there is differences. The thesis is divided into three parts. First theoretical part deals with all theories which were tried to explain different outcomes from different types of elections. Second part introduces our hypotheses and methodology by which we examine these hypotheses. Third part analyses the results of elections from selected countries. First four chapters of the third part deal with selected countries separately. Fifth chapter compares our results from the Visegrad states among them and then it compares these results with results from the countries of EU-15.

This study aims to investigate how history teachers talk about the historical thinking concepts change and continuity. In this study, four teachers from three different secondary schools in Sweden were interviewed. The theoretical perspectives are Seixas and Morton’s guidelines for teaching change and continuity, and these have been used as a tool to categorize and analyze the teachers’ responses and reflections. From this, five categories or topics that the teachers’ discussions covered were formulated. The most common method that the teachers talked about was to use a timeline or some other form of chronological illustration to provide a solid foundation for the students. The teachers could then use this to consolidate higher levels of understanding of the concepts. The chronological understanding enabled the teachers to address the process of change in terms of variation in paces, patterns and turning points, which the teachers emphasized had a relation to where we look and who it affects. Concerning the discussion of how teachers instruct students about historical progress and decline, it became clear that this is strongly related to language comprehension. It was also evident that students view history as a constant process of improvement. When it comes to historical periodization, all teachers agreed that critical reflection on why and on what premises these divisions has been made is important to consider. However, this was primarily applied to the concept of change, and continuity was most commonly referred to when the historical content was discussed in relation to the history of attitudes or mentalities. The teachers explained different didactical methods while discussing these topics, and they also used different ways to exemplify these with historical content and metaphors. What also became clear was the relationship between the teachers’ educational background and their variation of teaching.

After decades of development, optical fiber technology has reached a high degree of sophistication and maturity, and currently serves as the backbone of today''s internet. Despite its technical versatility and capability, current silica fiber technology still has a significant flaw: since silica fibers only possess very weak second order nonlinearity, it has been impossible to develop a large number of important nonlinear optical devices and instruments, such as optical parametric amplifiers (OPA) and optical parametric oscillators (OPO). In this thesis,we show how to overcome this intrinsic limitation, and introduce second order nonlinearity into silica fiber devices. / Master of Science

In two experiments, second-order conditioned taste aversion techniques were employed to develop aversions in rats, with a geotactic-excitation procedure as the independent variable. Periodic tilting of an experimental apparatus resulted in angular orientation changes of all subjects located within compartments of the chamber. The effect was excitation of geotactic behaviors, expressed as locomotor activity within the confines of these compartments. In the first experiment, two groups of rats (n = 6) were exposed to experimental protocols which were identical with the exception of the independent variable. Three conditioning trials were presented, separated by five to seven days, within which strychnine injections preceded LiCl injections by 15 minutes. A treatment trial was presented five days following the last drug pairing, in which a novel flavor was available in lieu of tap water. Immediately following the 10-min water-access period, an injection of the CS-drug was administered. Testing for evidence of second-order CTA was conducted via presentation of the flavored solution on the fifth day following treatment. statistically significant results were obtained in terms of Learned Aversion Ratios and CTA Suppression Ratios. A second experiment was conducted in an attempt to isolate the influence of the excitation procedures with other drug-pairings. Five groups of rats (n = 6 in each group) were run in which hypertonic saline was paired with LiCl, strychnine, or hypertonic saline. Combinations of saline and the US-drugs were tested with and without the excitation procedures. A no-injection group (n = 6) received exposure to the flavor stimulus followed only by the excitation procedure. Results obtained on the Learned Aversion Ratios were statistically significant and in the predicted direction. The excitation group in which saline had been paired with LiCl showed a significant aversion ratio compared to the appropriate control groups, the Saline-Saline Group and the No-Injection Group. The Saline-Strychnine Excitation Group also showed a significant Learned Aversion Ratio compared to its respective control group and to the No-Injection Excitation Group. The implications of these results for such issues as stimulus equipotentiality, avfail, and research methodology and CTA research in general may provide additional foundations for future research in this experimental area.

Spatiotemporal dynamics of resource availability can produce markedly different patterns of landscape utilization which necessitates studying habitat selection across biologically relevant extents. Feral pigs (Sus scrofa) are a prolifically expanding, generalist species and researchers have yet to understand fundamental drivers of space use in agricultural landscapes within the United States. To study multi-scale habitat selection patterns, I deployed 13 GPS collars on feral pigs within the Mississippi Alluvial Valley. I estimated resource selection using mixed-effects models to determine how feral pigs responded to changes in forage availability and incorporated those results with autocorrelated kernel density home range estimates. My results indicated season-specific habitat functional responses to changes in agricultural phenology and illustrated the interdependencies of landscape composition, hierarchical habitat selection, and habitat functional responses. These results indicate fundamental drivers of feral pig spatial distributions in an agricultural landscape which I used to predict habitat use to direct feral pig management.