NCube/papyrus huggingface dataset:
Identification des mesures d’inégalité dans les modèles de sélection

In this master thesis, I consider a standard selection model with nonrandomly censored outcome. First, I discuss validity and sharpness of bounds on the interquantile range of the distribution of the uncensored outcome, derived by Blundell et al. (2007). Second, I give sharp bounds on the interquantile range respectively under stochastic dominance of the unobserved outcome distribution by the observed one, and in presence of an exclusion variable. Third, I discuss sharpness of the variance bounds given by Stoye (2010). I show that the bounds are not necessarily sharp and I provide sharp lower bounds on the variance and the coe fficient of variation.

Keyphrases: Identification partielle, Sample selection, Partial identification, Inequality measures
Influence de la mécanoréception faciale sur les comportements moteurs chez l’opossum nouveau-né, Monodelphis domestica

The opossum, Monodelphis domestica, is born very immature but crawls, unaided, with its forelimbs (FL) from the mother's birth canal to a nipple where it attaches to pursue its development. Sensory clues are needed to guide the newborn to the nipple and trigger its attachment to it. We postulated that the trigeminal system, responsible for sensory innervation of the face, is involved. Indeed, light pressure applied on the snout evokes FL movements in vivo, low intensity electrical stimulation of the trigeminal ganglion induces motor responses of the FL in vitro, and trigeminal fibers is distributed in the facial dermis and basal epidermis of the newborn. Also, slowly adapting mechanosensory receptors Merkel cells (AM1-43 positive) are present in the face epidermis. To determine if Merkel cells exert an influence on locomotion of newborn opossums, we analyzed the FL muscles responses following application of calibrated forces on the snout in in vitro preparations. Pressure applied to the face induced bilateral and simultaneous FL motor responses, which intensity is proportional to stimulation force. Following consecutive stimulations during 60 min, the responses tended to decrease. Removing the facial skin nearly abolished the responses. Bath applications of the glutamate metabotropic receptor antagonist YM298198, and of the purinergic receptors (P2) antagonist PPADS, decreased the muscles responses. These results support that touch sensitivity of the snout relayed by the trigeminal system is functional in newborn opossums and may influence FL movement, possibly contributing to guiding the animal to the nipple.

Keyphrases: Locomotion, Opossum, Merkel cells, Motor behavior, Trigeminal system
La conservation de la biodiversité dans les aires protégées en zones périurbaines : dynamique des communautés végétales au parc national du Mont-Saint-Bruno entre 1977 et 2013

This study aimed to determine whether a small suburban park, namely the Mont-Saint-Bruno National Park, managed to maintain the integrity of its flora over the last thirty years despite increasing human pressures and past natural disturbances, in addition to identify the main floristic changes during this period and the drivers of observed changes. To do so, a historical study was conducted by comparing past (1977) and recent (2013) floristic surveys. First, a striking increase in alpha diversity, driven mostly by native species and associated with a significant decline (30%) in the beta diversity over the last 35 years was found. Despite this taxonomic homogenization, the functional diversity of forest flora has increased, probably increasing its resistance to disruptive events. Furthermore, analyses revealed the progression of functional traits associated with overbrowsed forest habitats, revealing some influence of white-tailed deer on the composition and structure of the forest flora. Finally, my study also showed that herbarium specimens can be used as a reliable alternative to traditional methods to document and assess the impact of large herbivores on browsed plants morphology. In conclusion, this study showed that small suburban protected areas can play a major role in the preservation of the floristic diversity of rich forest habitats, particularly when their status strictly frames human activities.

Keyphrases: Conservation, Biodiversity, Protected areas, Suburban park, Beta diversity, Homogenization, Functional diversity, Functional trait, White-tailed deer, Legacy study
Désintégration du faux vide médiée par des kinks en 1+1 dimensions

In this thesis, we study the tunneling decay of the false vacuum, that is, a vacuum that is a relative minimum of a scalar potential. Topological defects in 1+1 dimension, called kinks, appear when the potential possesses a minimum that spontaneously breaks a discrete symmetry. In 3+1 dimensions, these kinks become domain walls. For instance, they appear in magnetic materials in condensed matter. A model with two coupled scalar fields will be studied, as well as the solutions to the equations of motion that arise from it. We will then analyze how the energy of the static solutions depend on the parameters of the model. A numerical survey of parameter space reveals that the stable solutions are located between dissociation zones, areas in parameter space where stable solutions no longer exist. The behavior of the unstable solutions in the dissociation zones can be very different depending on which dissociation zone a solution is found near the dissociation zone. The potential first consists in a sixth-order polynomial, to which is added a quartic polynomial multiplied by a coupling term, and is chosen such that the extremities of the kink are at distinct false vacua. The decay rate has been estimated by a semiclassical approximation to show the impact of topological defects on the stability of the false vacuum. The project consists in determining the conditions that allow the kinks to catalyze false vacuum decay. It appears that we found an expression for the critical kink density and that we understand what happens with most terms.

Keyphrases: Kinks, Topological defects, Spontaneous symmetry breaking, False vacuum decay, Tunneling
La flèche du temps :  analyse philosophique d'une métaphore scientifique

The problem of the direction of time is a classical problem in both physics and philosophy. Although there are various ways to tackle this problem, the thermodynamic approach is the most commonly used. This approach considers the thermodynamic arrow of time as the fundamental arrow of which all others arrows are only manifestations. This essay aims to provide a philosophical analysis of this approach. To do this, we sketch the research question, we introduce various alternate theories and approaches set to answer this problem, and present the strong thesis underlying the thermodynamic approach. Then we will evaluate the use of statistical mechanics and cosmology that are used in attempt to mitigate the deficiencies of this approach. Finally, we will analyze how this approach, and more importantly the notion of entropy, can provide an adequate conceptual scheme to solve the problem of the arrow of time.

Keyphrases: Arrow of time, Entropy, Epistemology, Past Hypothesis, Realism
Développement d’un modèle de classification probabiliste pour la cartographie du couvert nival dans les bassins versants d’Hydro-Québec à l’aide de données de micro-ondes passives

Every day, decisions must be made about the amount of hydroelectricity produced in Quebec. These decisions are based on the prediction of water inflow in watersheds based on hydrological models. These models take into account several factors, including the presence or absence of snow. This information is critical during the spring melt to anticipate future flows, since between 30 and 40 % of the flood volume may come from the melting of the snow cover. It is therefore necessary for forecasters to be able to monitor on a daily basis the snow cover to adjust their expectations about the melting phenomenon. Some methods to map snow on the ground are currently used at the Institut de recherche d'Hydro-Québec (IREQ), but they have some shortcomings.  This master thesis's main goal is to use remote sensing passive microwave data (the vertically polarized brightness temperature gradient ratio (GTV)) with a statistical approach to produce snow maps and to quantify the classification uncertainty. In order to do this, the GTV has been used to calculate a daily probability of snow via a Gaussian mixture model using Bayesian statistics. Subsequently, these probabilities were modeled using linear regression models on logits and snow cover maps were produced. The models results were validated qualitatively and quantitatively, and their integration at Hydro-Québec was discussed.

Keyphrases: Logit, GTV, Bayesian statistics, Gaussian mixture model, Probabilistic model, Linear regression, Logit, Snow, Remote sensing, Snow cover
Régression logistique bayésienne : comparaison de 
densités a priori

Logistic regression is a model of generalized linear regression (GLM) used to explain binary variables. The model seeks to estimate the probability of success of this variable by the linearization of explanatory variables. When the goal is to estimate more accurately the impact of various incentives from a marketing campaign (coefficients of the logistic regression), the identification of the choice of the optimum prior density is sought. In our simulations, using the MCMC method of slice sampling, we compare different prior densities specified by different types of density, location and scale parameters. These comparisons are applied to samples of different sizes generated with different probabilities of success. The maximum likelihood estimate, Gelman’s method and Genkin’s method complement the comparative. Our simulations demonstrate that the MCMC method with a normal prior density centered at 0 with variance of 3,125, the MCMC method with a Student prior density with 3 degrees of freedom centered at 0 with variance of 3,125 and Gelman’s method with a Cauchy density centered at 0 with scale parameter of 2,5 get estimates that are globally the most accurate of the coefficients of the logistic regression.

Keyphrases: Simulation MCMC, Logistic regression, Bayesian, Prior density, MCMC simulation
Concept oriented biomedical information retrieval

Health and biomedical area is probably the area where there are the richest domain resources. In these resources, different expressions are clustered into well defined concepts. They are designed to facilitate public access to the health information and are widely believed to be useful for biomedical information retrieval. However the results of previous works are highly mitigated: in some studies, concepts slightly improve the retrieval performance, while in some others degradations are observed. It is however difficult to compare the results directly due to the fact that they have been performed on different test collections. It is still unclear whether and how medical information retrieval can benefit from these knowledge resources. In this thesis we aim at comparing in the same framework two families of approaches to exploit concepts - using concept IDs as the representation units or using synonymous concept expressions to expand the original query. Compared to a traditional bag-of-words (BOW) baseline, our experiments on test collections show that concept IDs always degrades retrieval effectiveness, whereas the second approach can lead to some improvements. In particular, by matching the concept expressions as either strict or flexible phrases, some methods can lead to significant improvement over the BOW baseline and even over MRF model on most query sets. This study shows experimentally that when concepts are used in a suitable way, it can help improve the effectiveness of medical information retrieval. We participated at the ShARe/CLEF 2014 eHealth Evaluation Lab. Our result was the best among all the participating systems.

Keyphrases: MetaMap, Concept, Medical Information Retrieval, Language Model, Query Expansion, Dependency
Multi-view 3D reconstruction using virtual cameras

This master concentrates on the reconstruction of a 3D model from multiple images. The 3D model is built with a hierarchical representation of voxels using an octree. A cube surrounding the object is calculated from the camera's positions. This cube contains all the voxels and it defines the position of the virtual cameras. The 3d model is initialized by a visual hull that is based on the uniform color of the images’ background. This visual hull is used to pre-carve the 3D model. Then a cost is calculated to evaluate the quality of each voxel as being on the surface of the object. This cost takes into account the similarity of the pixels from each images associated to a virtual camera. Finally a surface is calculated for each virtual camera using the SGM method that is based on the voxel cost. The SGM method takes the surrounding voxels into account when calculating the depth and this master presents a variation to this method where we take the previously excluded voxels into account. The excluded voxels coming from the initialization step or from the carving done by another virtual camera. The resulting surface is used to carve the voxel representation. This master presents an innovative combination of steps leading to the creation of a 3D model from a set of existing images or from a series of images capture one after another leading to a real-time creation of a 3D model.

Keyphrases: 3D, Octree, Image, Cube, Voxel, 3D, Octree, Image, Cube, Camera, Voxel, Volumetric, Semi-global method
On Space-Time Trade-Off for Montgomery Multipliers over Finite Fields

The multiplication in a Galois field with 2^m elements (i.e. GF(2^m)) is an important arithmetic operation in coding theory and cryptography. In this thesis, we focus on the bit-  parallel multipliers over the Galois fields generated by trinomials. We start by introducing the GF(2^m) Montgomery multiplication, which calculates A(x)B(x)x^{-u} in GF(2^m)   with two polynomials A(x), B(x) in GF(2^m) and a properly chosen u. Then, we investigate the rule for multiplicand partition used by a divide-and-conquer algorithm PCHS   originally proposed for the multiplication over GF(2^m) with odd m. By adopting similar rules for splitting A(x) and B(x) in A(x)B(x)x^{-u}, we develop new Montgomery   multiplication formulae for GF(2^m) with m either odd or even. Based on this new approach, we develop the corresponding bit-parallel Montgomery multipliers for the Galois   fields generated by trinomials. A new bit-reusing trick is applied to eliminate redundant XOR gates from the new multiplier. The time complexity (i.e. the delay) and the   space complexity (i.e. the logic gate number) of the new multiplier are explicitly analysed:  1. This new multiplier is about 25% more efficient in the number of logic gates   than the previous trinomial-based Montgomery multipliers or trinomial-based Mastrovito multipliers on GF(2^m) with m big enough. It has a number of logic gates very close to   that of the Karatsuba multiplier proposed by Elia. 2. While having a significantly smaller number of logic gates, this new multiplier is at most two T_X larger in the total   delay than the fastest bit-parallel multiplier on GF(2^m), where T_X is the XOR gate delay. 3. We determine the space and time complexities of our multiplier on the two   fields  recommended by the National Institute of Standards and Technology (NIST). Having at most one more T_X in the total delay, our multiplier has a more-than-15% reduced   logic gate number compared with the other Montgomery or Mastrovito multipliers. Moreover, our multiplier is one T_X smaller in delay than the Elia's multiplier at the cost of   a less-than-1% increase in the logic gate number.

Keyphrases: Multiplication Montgomery, Multiplication Karatsuba, Parallel computation, Montgomery multiplication, Karatsuba multiplication, Irreducible trinomial
Investigating the Impact of Personal, Temporal and Participation Factors on Code Review Quality

Code review is an essential element of any mature software development project; it aims at evaluating code contributions submitted by developers. In principle, code review should improve the quality of code changes (patches) before they are committed to the project's master repository. In practice, the execution of this process can allow bugs to get in unnoticed. In this thesis, we present an empirical study investigating code review of a large open source project. We explore the relationship between reviewers'code inspections and personal, temporal and participation factors that might affect the quality of such inspections. We first report a quantitative study in which we applied the SZZ algorithm to detect bug-inducing changes that were then linked to the code review information extracted from the issue tracking system. We found that the reasons why reviewers miss bugs are related to both their personal characteristics, as well as the technical properties of the patches under review. We then report a qualitative study that aims at soliciting opinions from Mozilla developers on their perception of the attributes associated with a well-done code review. The results of our survey suggest that developers find both technical (patch size, number of chunks, and module) and personal factors (reviewer's experience and review queue) to be strong contributors to the review quality.

Keyphrases: Code review, Code review quality, Bug-inducing changes, Mining software repositories, Mozilla, Empirical study, Quantitative analysis, Qualitative study, Survey
Étude comparative des moyens de paiement

The time we used to only have one option of method payment is now long gone. As a matter of fact, from the apparition of currency until the « thirty glorious years », nothing new in this field appeared. It is true, in the last decades we are witnessing the birth of many of means of payment, all more different from each other. This study, therefore, aims to confront the principal means of payment but also to discuss about the question of anonymity that may come with it. To do so, will be presented each of every means of payment separately while describing all their functions and technologies. Then, a comparison will be presented through an independent analysis that was carried out on specific elements such as: the protection of private life and properties ACID. Other elements like users'trust (security) and expectations from the financial institutions will also be considered. Finally, three problems solving in relation to the anonymity of the current means payment known today, will constitute the last section. The first solution focuses on the anonymous bank accounts, the second is inspired from the token system; The last, but not least, combines the two first systems in order to combine the advantages.

Keyphrases: ACID, Anonymity, Cryptography, Payment, Security
L'éducation morale des spectateurs face à l'image dans le cinéma de Michael Haneke

Michael Haneke is best known for his stark mise en scène, beginning with his earliest theatrical release. Onscreen, the filmmaker has depicted several characters in violent situations, whom are often in a densely mediatic environment. The following work seeks to identify the evolution of his artistic process concerning the presence of media in his cinematographic universe; to this effect, I have identified three distinct phases in his filmography. Using a different theoretical framework for each one, I will attempt to outline and define all three periods, namely: observation, with the writings of Marshall McLuhan; action, with Erving Goffman’s works on interaction and; assertion, a possible answer to the issue of guiding the viewer in the act of watching images with the writings of Serge Tisseron and Marie-José Mondzain. I will demonstrate, through analyses of Haneke’s films, that these different phases within his filmography ultimately serve the director’s intent to morally educate the viewers.

Keyphrases: viewer
Les musiques tziganes mises en scène : construction mémorielle et réappropriation de soi

The main focus of this Masters thesis is the historical and musical re-appropriation of gypsies in the docudrama, Latcho Drom (1993) by Tony Gatlif.  In the first chapter, the literary history of gypsies will be compared to their representation in Latcho Drom, in order to demonstrate how Gatlif challenges the dominant discourse with a totally new perspective through his unique use of audio-visual language. In this way, the camera is rendered a medium of empowerment for the gypsy community through a re-appropriation of their people and history. In the second chapter, a series of studies in ethnomusicology will be used to demonstrate how gypsy music (mainly because it is nomadic and not transcribed) is rapidly assimilated into the cultural heritage of European societies. Latcho Drom accurately reflects the musical expression inherent in the life of these communities while being at odds with certain methods of preserving oral music traditions (the “urgency of ethnomusicology”) and the territorial notion espoused by musicologists, who refuse to recognize gypsy music as legitimate and autonomous. The third chapter will discuss how the filmmaker invites the spectator into intimate rapport with the musical communities of Latcho Drom, arousing in him/her a sentiment of gratitude and empathy.

Keyphrases: tradition orale, Gypsy, history, music, memory, heritage, re-appropriation, disappropriation, ethnomusicology, musicology, oral tradition
Le rôle des festivals de cinéma internationaux dans l'émergence du cinéma iranien

Until the end of the twentieth century, studies on Iranian cinema consider the Islamic Revolution of 1979 as a turning point in the history of this cinema, i.e. they divide its history in two eras, pre-revolutionary and post-revolutionary. This research joins the recent idea that this national cinema emerged as a continuous progression dominated by contradictory and ambiguous cultural policies.  In the first chapter of this essay, we will paint a general picture of the history of Iranian cinema, and its festival culture in particular. We will clarify the political and cultural incentives that orchestrate the decisions of the authorities and the industry’s professionals. The second chapter will question the notion of national cinema, and will apply this notion to Iranian cinema. Special attention will be paid to the Farabi Cinema Foundation, a key institution in the promotion of Iranian national cinema and in the emergence of Iranian films in international film festivals. Thereafter, the third chapter will present the role of festivals in the film industry and an analysis of the evolution of Iranian films presented at the Montreal World Film Festival in order to demonstrate the influence of vague Iranian cultural policies on the presence of Iranian films in Western films festivals.

Keyphrases: cinema, national cinema, Iranian cinema, Iran, Farabi Cinema Foundation, festival, Fajr International Film Festival, Montreal World Film Festival, Festival international de films Fajr, festival