NCube/papyrus huggingface dataset:
Analyse de l'absorption circumstellaire de WD 1145+017

WD 1145+017 is a metal polluted white dwarf with an actively disintegrating asteroid orbiting around it. This system is the first to show the active decomposition phase of the accretion process. The different observed data show a complex system composed of many pieces of the rocky objets, a dust disk and a gaseous disk, all orbiting the polluted white dwarf. We present an eccentric precessing gas disk model designed to study the variable circumstellar absorption features detected for WD 1145+017. This model, inspired by one recently proposed by Cauley et al., calculates explicitly the gas opacity for any predetermined physical conditions in the disk, predicting the strength and shape of all absorption features, from the UV to the optical, at any given phase of the precession cycle. The successes and failures of this simple model provide valuable insight on the physical characteristics of the gas surrounding the star, notably its composition, temperature and density. This eccentric disk model also highlights the need for supplementary components, most likely circular rings, in order to explain the presence of zero velocity absorption as well as highly ionized Si lines. We find that a precession period of 4.6±0.3 yrs can successfully reproduce the shape of the velocity profile observed at most epochs from April 2015 to January 2018, although minor discrepancies at certain times indicate that the assumed geometric configuration may not be optimal yet. Finally, we show that our model can quantitatively explain the change in morphology of the circumstellar feature during transiting events.

Keyphrases: White dwarf star, Circumstellar disk, Physics, Astronomy and astrophysics
Analyse SAXS de traces ioniques causées par bombardements d’ions d’or dans des échantillons de silicium amorphe

The following thesis aims to verify whether the formation of latent traces by heavy and fast ions passes through a liquid phase. Given the fact that the process of trace formation is too fast to be directly studied, our experience aims to measure after the fact elements that would be indicative of a merger. In this context, we will study whether there has been a redistribution of gold ions (initially present by doping in amorphous silicon samples) following the irradiation of the samples. This redistribution of gold could be explained by the phenomenon of refining the melted zone, which would occur during a rise in temperature during the creation of latent ionic traces predicted by the theoretical model of the thermal peak.  The samples studied are amorphous silicon membranes of 2 µm in thickness, doped with gold at different percentages (pure, medium and high) and irradiated with fast heavy ions of gold at 1.1 GeV or silver at 75 MeV.  No SAXS image was able to reveal the presence of latent ionic traces for samples irradiated with silver ions at 75 MeV. Although the stopping power of the latter is low (9.5 keV/nm), it exceeds the threshold observed for several other phenomena associated with traces. [2] [3] We would therefore have found a regime where there are effects of heavy and fast ions, but without a visible signature in SAXS.  In contrast, irradiated samples of gold ions demonstrated the presence of latent ionic traces via SAXS images. These images demonstrate a diffusion pattern characteristic of core-shell type traces. However, these results do not show differences in gold segregation according to the initial doping level. All samples (pure, medium and high doping) have a core radius of (2.5 ± 0.1) nm and a total radius of (9.9 ± 0.5) nm, which are values similar to those obtained in the literature. [4] On the other hand, the absence of a difference according to the doping could be explained by the fact that the resolidification after the fusion would be too fast, to the point where the gold would undergo solute trapping which would prevent the segregation. Another possible explanation would be that there would be no fusion at all during the formation of the trace.  First of all, this thesis deals with all the steps necessary for the design of the samples, namely their amorphization, the implantation of gold impurities, then the irradiation. Two categories of samples are discussed: the validation samples, then the actual samples that were studied. Subsequently, this thesis addresses the detection of latent ion traces, first with an AFM (which proved to be insufficient), then with SAXS measurements. Finally, a theoretical code to reproduce the experimental measurements obtained was developed based on the literature. It generates promising numerical results compared to the experimental data obtained.

Keyphrases: HF, or, SAXS, form factor, gold, latent ion track, zone reﬁning, Amorphous silicon
Transmission spectroscopy of TRAPPIST-1d with the new Palomar/WIRC+Spec instrument : a Karhunen-Loève transform based approach to extracting spectrophotometry

The TRAPPIST-1 system provides an unprecedented opportunity to characterize the first potentially habitable planets outside our solar system. In this work we describe the development of a custom data reduction pipeline for the WIRC+Spec mode of the recently upgraded Wide Field Infrared Camera instrument on Palomar Observatory. We introduce a novel, Karhunen-Loève transform based approach to extract photometric and spectroscopic light curves from irregularly shaped sources, which we apply to observations of the TRAPPIST-1d exoplanet to measure the J band (1.1 to 1.4 µm) and Ks band (1.95 to 2.35 µm) transmission spectra. We also present a detailed guide into the implementation of a self-consistent, radiative-convective temperature structure calculation for efficient and accurate atmospheric modelling. Comparing a host of atmospheric scenarios to the observations of TRAPPIST-1d to date, we constrain its atmosphere, ruling out cloud-free atmospheres with metallicities lower than 300 times the solar value at 3σ confidence.

Keyphrases: Planets and satellites: individual (TRAPPIST-1d), Planets and satellites: atmospheres, Transit spectroscopy, Numerical methods
La théorie de l’art pour l’art : étude généalogique d’un nouveau paradigme éthique de l’art

The aim of this study is to propose a genealogy of the theory of “l’art pour l’art”, elaborated in the historical context of Romanticism. Taking as a starting point the movement of autonomy of the Fine Arts and aesthetics of the 18th century, this research is an attempt to reconstruct the main lines of this new artistic doxa that appeared under the July Monarchy. Following the same approach of dissociation between the notions of Beauty and Good that characterized the birth of the aesthetic discipline in the Enlightenment, the theory of “l’art pour l’art” is generally recognized because of its radical rejection of all forms of morality. Yet, behind this aspect, it appears that some of its proponents have shown a very strong ethical rigour in the exercise of their art. Gustave Flaubert is definitely one of them. In his Correspondance, a complete program of a “moral of art” is deployed. Rebuilding the foundations of this program will occupy the second and final major part of this work when the first part will be largely devoted to the aesthetic thought of Karl Philipp Moritz, a character who is sometimes misunderstood. This philosophical writer undoubtedly deserves to be considered in the genesis of the ideas of the theory of “l’art pour l’art”. His autotelic conception of Beauty certainly offers one of the most radical versions of the independence of the fine arts from morality on the 18th century. Moreover, his concept of formative imitation of beauty announces the profound changes that will affect the romantic conception of the artist and the act of creation in the 19th century.

Keyphrases: L’art pour l’art, Karl Philipp Moritz, Gustave Flaubert, Ethics and aesthetic, History of philosophy, Enlightenment, 19th century, Romanticism, Autonomy of fine arts, Literature
De Marx à Lénine : étude sur les origines et l'évolution doctrinale du léninisme

The aim of this paper is to offer a new conceptual framework within which to study Marxism and, a fortiori, its Leninist interpretation. We retrace in the works of Karl Marx (1818-1883) two paradigms elaborated consecutively: anthropo-metaphysical paradigm, understood as both in continuity and in rupture with German classical philosophy, and economico-historical paradigm, which conveys the theory of historical materialism. We demonstrate how economico-historical paradigm consolidates itself on the basis of anthropo-metaphysical paradigm in order that the latter yield scientific systematicity. To grasp the foundations of Leninism, we restrain our investigation to three key notions from which to evaluate Lenin’s original contribution to the writings of Marx: (1) the alliance of the proletariat and the peasantry, (2) the vanguard role of the party, and (3) the dictatorship of the proletariat and political violence. We note that the Leninist interpretation of each of these notions rests on a certain amount of concepts or positions present in the Marxist corpus. From this ascertainment, our task is to establish from which paradigmatic framework Leninism has established itself as a doctrine.

Keyphrases: Bolchéviks, Marx, Historical materialism, Communism, Marxism, Leninism, Marxism-Leninism, Bolsheviks, Dictatorship of the proletariat, Russian Revolution, Soviet Union, Marx, Lenin
Quelle place pour l’utopie dans la philosophie politique ?

The purpose of this master’s is to analyze the role of utopian thinking within political philosophy. Utopia, being an ideal used to criticize and transform present society is a useful concept for political thought. However, using utopia in these terms is criticized. To justify reintroducing this concept within political philosophy, we analyze two criticisms against utopia before reconceptualizing our main concept. The first chapter deals with the inability of ideal thought to address real world issues. To respond to this criticism, we analyze the recent debate between ideal and non-ideal theory. This discussion provides us with a renewed understanding of the role of feasibility and action-guiding in ideal theory. The second chapter deals with the authoritarian character of utopian ideals. Within this perspective, utopia is a pursuit of social perfection which can only be enforced through violence. This criticism is partially responded with examples of utopia which do not conform with this definition. The third chapter proposes to rethink the concept of utopia. The first perspective to be analyzed is Rawls’s realist utopia, but it does not adequately reintroduce utopian thought within political philosophy. In turn, the theories of Böker and McKenna enable us to think of utopia in a more open and dynamic perspective. To finish this master’s, we return to our first inquiry. Not only does utopia has a role within political philosophy, it should be seen as an essential part.

Keyphrases: Philosophy, Utopia, Ideal theory, Non-ideal theory, Authoritarianism, Political philosophy
Étude d’algorithmes de simulation par chaînes de Markov non réversibles

Markov chain Monte Carlo (MCMC) methods commonly use chains that respect the detailed balance condition. These chains are called reversible. Most of the theory developed for MCMC evolves around those particular chains. Peskun (1973) and Tierney (1998) provided useful theorems on the ordering of the asymptotic variances for two estimators produced by two different reversible chains. In this thesis, we are interested in non-reversible chains, which are chains that don’t respect the detailed balance condition. We present algorithms that simulate non-reversible chains, mainly the Guided Random Walk (GRW) by Gustafson (1998) and the Discrete Bouncy Particle Sampler (DBPS) by Sherlock and Thiery (2017). For both algorithms, we compare the asymptotic variance of estimators with the ones produced by the Metropolis- Hastings algorithm. We present a recent theoretical framework introduced by Andrieu and Livingstone (2019) and their analysis of the GRW. We then show that the DBPS is part of this framework and present an analysis on the asymptotic variance of estimators. Their main theorem can provide an ordering of the asymptotic variances of two estimators resulting from nonreversible chains. We show that an estimator could have a lower asymptotic variance by adding propositions to the DBPS. We then present empirical results of a modified DBPS. Through the thesis we will mostly be interested in chains that are produced by deterministic proposals. We show a general construction of the delayed rejection algorithm using deterministic proposals and one possible equivalent for non-reversible chains.

Keyphrases: MCMC, Markov chain, Peskun, Peskun ordering, PDMP, Piecewise deterministic Markov process, DBPS, Guided walk, Asymptotic variance, Non-reversible, Monte Carlo, Delayed rejection
Liens entre les habiletés rythmiques et les compétences de décodage en lecture : associer les périodicités oculaires au chunking perceptif en parole lue

Numerous studies have documented links between abilities in tasks involving rhythm and some basic reading skills. For instance, significant correlations are observed between children or adolescent’s reading skills and their performance on tasks on motor synchronization to an auditory cadence or rhythmic sequence. Moreover, it is known that dyslexia is often accompanied by difficulties at the rhythmic level, and recent studies in electroencephalography (EEG) and magnetoencephalography (MEG) have suggested that these deficits may result from atypical patterns of activity in low-frequency neuronal oscillations of the central nervous system. How can these developmental links between rhythm and reading be explained? In some studies, phonological awareness is used to understand this association, hence proposing an indirect explanation relying on a third variable to make sense of the phenomenon. Unlike these theories, the present work proposes a more direct explanation of the link between rhythm and reading, where the emphasis is put on the intrinsic role of rhythm for the perceptual chunking of verbal information in oral or silent reading. To test this hypothesis, an experiment is presented in which 43 participants had to read sentences orally while their voice and eye-movements were recorded by an eye-tracking system. Results show that the implicit rhythm of the text is strictly followed in the participants’ oral reading, independently of a rhythmic priming that was presented before the text. In addition, probabilistic measures of eye fixations resemble the voice’s rhythmic chunks, highlighting possible rhythmic properties of visual sampling for text reading. We conclude by discussing the implications of these results for theories of reading.

Keyphrases: chunking, oscillations, rhythm, reading, eye-tracking
A game theoretical model for a collaborative e-learning platform on privacy awareness

Nowadays, with the increasing use of digital technologies, especially for teenagers, privacy education plays an important role in their lives. While several e-learning platforms for privacy awareness training have been implemented, they are typically based on traditional learning techniques. In particular, these platforms do not allow students to cooperate and share knowledge with each other in order to achieve mutual benefits and improve learning outcomes.  In other words, they lack student-student interaction. Recent research on learning methods shows that the collaboration among students can result in better learning outcomes compared to other learning approaches.  Motivated by the above-mentioned facts, and since privacy domain is strongly linked to the social lives of teens, there is a pressing need for providing a collaborative learning platform for teaching privacy, and at the same time, allows students to share knowledge, interact with each other, solve quizzes collaboratively, and discuss privacy issues and situations.  For this purpose, this work proposes “Teens-online”, a collaborative e-learning platform for privacy awareness. The curriculum provided in this platform is based on the Personal Data Protection Competency Framework for School Students.  Moreover, the proposed platform is equipped with a partner-matching mechanism based on matching game theory. This mechanism guarantees a stable student-student matching according to a student's need (behavior and/or knowledge). Thus, mutual benefits will be attained by minimizing the chances of cooperating with incompatible students.  Experimental results show that the average learning-related utility obtained by applying the proposed partner-matching algorithm is much higher than the average utility obtained using other matching mechanisms. The results also suggest that by adopting the proposed approach, each student can be paired with their optimal partners, which in turn helps them reach their highest learning outcomes.

Keyphrases: Collaborative learning, Game theory, Privacy education, E-learning, Stable matching problem
Emerging communication between competitive agents

We investigate the fundamental question of how agents in competition learn communication protocols in order to share information and coordinate with each other. This work aims to overturn current literature in machine learning which holds that unaligned, self-interested agents do not learn to communicate effectively. To study emergent communication for the spectrum of cooperative-competitive games, we introduce a carefully constructed sender-receiver game and put special care into evaluation. We find that communication can indeed emerge in partially-competitive scenarios, and we discover three things that are tied to improving it. First, that selfish communication is proportional to cooperation, and it naturally occurs for situations that are more cooperative than competitive. Second, that stability and performance are improved by using LOLA (Foerster et al, 2018), a higher order ``theory-of-mind'' learning algorith, especially in more competitive scenarios. And third, that discrete protocols lend themselves better to learning fair, cooperative communication than continuous ones. Chapter 1 provides an introduction to the underlying learning techniques of the agents, Machine Learning and Reinforcement Learning, and provides an overview of approaches to Multi-Agent Reinforcement Learning for different types of games. It then gives a background on language emergence by motivating this study and examining the history of techniques and results across Biology, Evolutionary Game Theory, and Economics. Chapter 2 delves into the work on language emergence between selfish, competitive agents. Chapter 3 draws conclusion from the work and points out the intrigue and challenge of learning communication in a competitive setting, setting the stage for future work.

Keyphrases: deep learning, multi-agent reinforcement learning, emergent communication
Apprentissage de circuits quantiques par descente de gradient classique

We present a new learning algorithm for quantum circuits based on gradient descent. Since this subject unifies two areas of research, we explain each field for people working in the other domain. Consequently, we begin by introducing quantum computing and quantum circuits to machine learning specialists, followed by an introduction of machine learning to quantum computing specialists. To give context and motivate our results we then give a light literature review on quantum machine learning. After this, we present our model, its algorithms and its variants, then discuss our currently achieved empirical results. Finally, we criticize our models by giving extensions and future work directions. These last two parts are our main results. They can be found in chapter 4 and 5 respectively. Our code which helped obtain these results can be found on github at this link : https://github.com/ AldoLamarre/quantumcircuitlearning.

Keyphrases: circuit quantique, machine learning, quantum computing, quantum machine learning, quantum circuits, gradient descent, backpropagation, quantum circuit learning, optimisation on the Stiefel manifold
La photographie dans le cinéma d’essai et mon film Ouroboros

An essay on the relationship between the still image, that is, photography and moving images in the creation of the essay cinema. A research on some photographers-filmmakers with a historical perspective on the movements of documentary photography parallel to the advent of the essay cinema, as well as an analysis of my own film "Ouroboros".

Keyphrases: Photography, Cinema, Still, Documentary, Exploration, Art
L’enfermement des personnages féminins dans le cinéma tunisien : évolution d’un thème, des années 1990 à aujourd’hui

This master’s thesis examines the imprisonment of female characters in Tunisian cinema from the 1990 until today. The notion of imprisonment articulates relations of power within a spatial dimension, while integrating the temporal and corporal dimension. For this, we chose a corpus of four long-feature films directed by women: The Silences of the Palace (Moufida Tlatli, 1994), Bedwin Hacker (Nadia El Fani, 2002), Burried Secrets (Raja Amari, 2009) and Beauty and the Dogs (Kaouther Ben Hania, 2017). We think those movies are part of a female Tunisian cinematographic tradition dealing with oppressions felt by women and their desire for emancipation. However, we observe some variations in the way the heroines’ imprisonment is shown. This is emphasized by the mise en scène and the discourse of the directors about female characters and their emancipation. This corpus explores different spatial scales (domestic, public, global and virtual) and shows the diversity of oppression faced by the heroines. To begin with, we study the imprisonment of female characters in a domestic space, employing the notions of heterotopia and harem. Then, we examine the exit of those spaces and the occupation of public spaces to explore the institutional dimension of imprisonment. Finally, we analyze the possibility of overcoming this imprisonment in order to hold a discourse of emancipation.

Keyphrases: harem, Tunisian cinema, women, spaces, body, heterotopia, imprisonment, emancipation, nomadism, Arab Spring