Logarithmic Coefficients and Generalized Multifractality of Whole-Plane SLE

We consider the whole-plane SLE conformal map f from the unit disk to the slit plane, and show that its mixed moments, involving a power p of the derivative modulus |f'| and a power q of the map |f| itself, have closed forms along some integrability curves in the (p,q) moment plane, which depend continuously on the SLE parameter kappa. The generalization of this integrability property to the m-fold transform of f is also given. We define a generalized integral means spectrum corresponding to the singular behavior of the mixed moments above. By inversion, it allows for a unified description of the unbounded interior and bounded exterior versions of whole-plane SLE, and of their m-fold generalizations. The average generalized spectrum of whole-plane SLE takes four possible forms, separated by five phase transition lines in the moment plane, whereas the average generalized spectrum of the m-fold whole-plane SLE is directly obtained from a linear map acting in that plane. We also conjecture the form of the universal generalized integral means spectrum.Comment: 51 pages, 11 figures; considerably revised and extended version. Sections 4 and 5 fused, Section 7 deleted. Complete proof of Theorem 1.7 given. New Figures 2, 6 and

An automated approach for classifying reverse-engineered and forward-engineered UML class diagrams

UML Class diagrams are commonly used to describe the designs of systems. Such designs can be used to guide the construction of software. In practice, we have identified two main types of using UML: i) FwCD refers to diagrams are hand-made as part of the forward-looking development process; ii) RECD refers to those diagrams that are reverse engineered from the source code; Recently, empirical studies in Software Engineering have started looking at open source projects. This enables the automated extraction and analysis of large sets of project-data. For researching the effects of UML modeling in open source projects, we need a way to automatically determine the way in which UML used in such projects. For this, we propose an automated classifier for deciding whether a diagram is an FwCD or an RECD. We present the construction of such a classifier by means of (supervised) machine learning algorithms. As part of its construction, we analyse which features are useful in classifying FwCD and RECD. By comparing different machine learning algorithms, we find that the Random Forest algorithm is the most suitable algorithm for our purpose. We evaluate the performance of the classifier on a test set of 999 class diagrams obtained from open source projects

Calcul de la perméabilité en régime raréfié au travers de milieux poreux à l’aide de la méthode de Boltzmann sur réseau

RÉSUMÉ Le présent mémoire concerne l’application de la méthode de Boltzmann sur réseau à la simulation d’écoulements de gaz raréfiés au travers de milieux poreux complexes afin de calculer leur perméabilité. Cette étude doit permettre de mieux comprendre l’écoulement des gaz atmosphériques à travers les systèmes de protection thermique (ou TPS pour Thermal Protection Systems) à structure poreuse qui assurent la protection des véhicules spatiaux lors de la rentrée atmosphérique. Les TPS ont pour but de dissiper l’énergie thermique générée par friction avec l’atmosphère à l’aide de divers procédés physico-chimiques tels que la pyrolyse ou l’ablation. Cependant, leur part importante dans la masse totale du véhicule spatial fait de leur conception un enjeu crucial dans un souci d’optimisation des coûts de lancement. Pour comprendre les phénomènes simulés et l’application de la méthode à notre problématique, les phénomènes physiques qui apparaissent lors de la phase de rentrée atmosphérique au niveau des TPS seront identifiés dans un premier temps. Puis, les solutions numériques actuelles capables de simuler ces types d’écoulements à travers les TPS seront présentées avant de discuter de leurs limites qui nous poussent à préférer la méthode de Boltzmann sur réseau. La suite sera axée sur le développement théorique et algorithmique de la méthode choisie. Un code de calcul sera développé et validé par des cas tests simples en comparant les résultats numériques avec la littérature. Enfin, des structures géométriques 2D et 3D ordonnées et désordonnées simulant des milieux poreux seront également générées en vue du calcul de leur perméabilité en régime continu. Afin de recréer les conditions réelles auxquelles sont soumises les TPS lors de la rentrée atmosphérique, une attention particulière sera portée au traitement des gaz à faible pression (aussi appelé gaz raréfiés), dont le comportement est décrit par la théorie cinétique des gaz. Nous noterons en particulier la présence de glissement aux parois solides, contrairement à l’hypothèse de non-glissement valide en régime continu et qui modifie grandement l’écoulement. Nous détaillerons également les modifications conséquentes dans l’implémentation de la méthode de Boltzmann sur réseau qui seront par la suite validées en simulant un simple écoulement dans un tube. L’inclusion de l’aspect raréfié dans le calcul de la perméabilité se fera en deux temps : tout d’abord, à travers les structures générées en régime continu en 2D au travers de notre code « maison », puis en 3D en adaptant le code open source Palabos pour traiter des écoulements de gaz raréfiés. Sur Palabos, des géométries structurées en 3D générées selon le modèle 2D feront également office de milieux poreux, avant d’effectuer le calcul sur un échantillon réel obtenu numériquement par micro tomographie. En 2D comme en 3D, la variation de la perméabilité due à la raréfaction du fluide sera évaluée. L’analyse des résultats montre que la méthode de Boltzmann sur réseau est non seulement une méthode numérique adaptée à la simulation d’écoulements de fluide à travers des milieux complexes, mais qu’elle est également capable de capturer les effets discrets qui peuvent apparaître en présence d’un gaz raréfié. Finalement, on remarque que les effets discrets dus à la raréfaction du gaz négligeables en régime continu deviennent prépondérants au fur et à mesure que le taux de raréfaction augmente. La présence des effets raréfiés augmente significativement la perméabilité, dont la valeur peut être multipliée d’un facteur 100 en régime fortement raréfié.----------ABSTRACT The following thesis focuses on the application of the lattice Boltzmann method on simulating rarefied gas flows through complex porous media for permeability calculation. This study aims at better understanding the flow characteristics of atmosphere gases through porous thermal protection systems (TPS) which protects space vehicles during the atmosphere re-entry stage. TPS enable thermal energy (generated by atmosphere friction) dissipation through pyrolysis or ablation. However, as they take a great part of the total launch mass, carefully designing them becomes a critical issue in launch costs optimization. To understand how our chosen model can be applied for this issue, we’ll first take a brief look at physical phenomena which appear inside TPS during the atmosphere re-entry stage. Then, numerical models which are currently used to perform these simulations will be introduced. Finally, we will discuss about their computing limits in order to highlight the need of an alternative method which is embodied here by the lattice Boltzmann method. It will then be followed by a theoretical and algorithmic explanation of the chosen method. A computational code will be developed and validated by comparing numerical results for basic test cases. Finally, we’ll generate 2D and 3D structured and random geometries, in order to compute their permeability in the continuous regime. In order to simulate the real conditions during TPS atmosphere re-entry stage, low pressure gases (also called rarefied gases) will be carefully treated according to the kinetic theory of gases. One must note the occurrence of gas slippage effects at solid walls, which are neglected in the continuous regime, and have a significant impact on flow characteristics. We will also give details about the changes in the lattice Boltzmann algorithm that have to be implemented to account for rarefied gas effects and validated through a simple microchannel. Including rarefied gas effects on permeability calculation will be studied in two parts: first, through 2D generated structured geometries on our own code, and then with 3D simulations on open-source software Palabos with proper modifications for rarefied gas flows. On Palabos, 3D structures will have the same pattern as 2D ones to account for porous media. Ultimately, we aim at performing permeability calculation on a micro-tomography reconstructed real porous media. Variation of permeability with rarefaction rates will be investigated in 2D as well as in 3D. The analysis of the numerical results shows us that the lattice Boltzmann method is not only an adapted numerical method for fluid flow simulations though complex porous media, but is also able to capture discrete effects that occur as the gas is rarefied. Research studies finally show that rarefied discrete effects, which are neglected in the continuous regime, become significant in the total fluid flow as the rarefaction rate increases. Rarefied effects greatly increase computed permeability, which can multiply the permeability up to 100 for strong rarefaction rates

New General Models for Evaluating Interactions in Non-Regular Solutions and Adsorption Energies Based on Both Hansen's and Drago's Parameters

This study aims at providing a model for the internal mixing energy of two liquids. The concerned variables are the solute molar volume V (cm3/mol.), the cohesion parameters and the Drago's parameters. The model is based on the following fundamental novelties: The fragmentation of molar cohesive energy ∆Ecoh (kJ/mol) into two distinct categories. Indeed, the dispersive and polar cohesion energies are magnetic and electrical in nature, and the cohesive energy of the chemical bonds (Hydrogen Bond) is due to charge transfer and orbital overlap. The origins of these two categories of energy are different, requiring two different treatments in use. For the first time, a relationship has been established between the cohesive energy from chemical bonds ∆Eh (kJ/mol) and Drago's parameters Ea, Eb, Ca, and Cb (KJ1/ 2mol-1/2). A simple equation has been proposed for the salvation energy of a gaseous solute in a liquid solvent. This equation contains a term for the perturbation energy of the solvent in the presence of the solute, namely the cavity formation energy, and different types of interaction energies between the solvent and the solute at infinite dilution. Based on calorimetric data published, the proposed model is compared with the classic model in terms of the mixing energy. The result shows a clear advantage of the new model over the old or conventional one. Clearly, this new model should provide a new method to determine the interaction parameters or interaction capacities of complex pharmaceutical molecules using a series of simple and well-chosen solvents

Long-Term Recording of LTP in Cultured Hippocampal Slices

Long-term potentiation (LTP) was elicited by high frequency stimulation in hippocampal slices cultured on multi-electrode arrays. LTP lasting more than 1 h was recorded in 75% of slices, and a significant number of slices exhibited a non-decaying LTP that lasted more than 48 h. LTP induction was completely and reversibly blocked by an antagonist of the NMDA receptor, APV. Our results suggest the possibility of using chronic recording in hippocampal slices cultured on multi-electrode arrays to study the mechanisms underlying LTP maintenance and stabilization

Temporal and spatial analyses on seismo-electric anomalies associated with the 27 February 2010 M = 8.8 Chile earthquake observed by DEMETER satellite

International audienceThis paper studies seismo-electromagnetic anomalies observed by the French satellite DEMETER (Detection of ElectroMagnetic Emissions Transmitted from Earthquake Regions) during the 27 February 2010 M = 8.8 Chile earthquake. The nighttime electron density (N e), electron temperature (T e), ion density (N i), ion temperature (T i) and whistler counts (C w) are investigated. A statistical analysis of the box-and-whisker method is applied to see if data of two or more groups under study are significantly different. A cross-examination of temporal variations before and after shows that N e and N i (C w) increases (decreases) appear 10–20 days before the earthquake. A comparison of data over the epicenter and those over its reference area can be employed to discriminate the earthquake-related anomalies from global effects. Results prove that anomalous enhancements of N e , N i , and T i occur specifically around the epicenter area. The intersection of the temporal and spatial results confirms that N e and N i are useful and sensitive detecting anomalous related to the 2010 M = 8.8 Chile earthquake

Does UML modeling associate with lower defect proneness?:a preliminary empirical investigation

The benefits of modeling the design to improve the quality and maintainability of software systems have long been advocated and recognized. Yet, the empirical evidence on this remains scarce. In this paper, we fill this gap by reporting on an empirical study of the relationship between UML modeling and software defect proneness in a large sample of open-source GitHub projects. Using statistical modeling, and controlling for confounding variables, we show that projects containing traces of UML models in their repositories experience, on average, a statistically minorly different number of software defects (as mined from their issue trackers) than projects without traces of UML models.</p

Cyclopentane hydrates – A candidate for desalination?

International audienceThis article presents a systematic review on the past developments of Hydrate-Based Desalination process using Cyclopentane as hydrate guest. This is the first review that covers all required fundamental data, such as multiphase equilibria data, kinetics, morphology, or physical properties of cyclopentane hydrates, in order to develop an effective and sustainable desalination process. Furthermore, this state-of-the-art describes research and commercialization perspectives. When compared to traditional applications, cyclopentane hydrate-based desalination process could be a promising solution. Indeed, it operates under normal atmospheric pressure, lower operation energies are required, etc… However, there are some challenges yet to overcome. A decision aid in the form of a diagram is proposed for a new cyclopentane hydrates-based desalination process. Hopefully, concepts reviewed in this study will suggest new ideas to advance technical solutions in order to make commercial hydrate-based desalination processes a reality

Mesh update techniques for free-surface flow solvers using spectral element method

This paper presents a novel mesh-update technique for unsteady free-surface Newtonian flows using spectral element method and relying on the arbitrary Lagrangian--Eulerian kinematic description for moving the grid. Selected results showing compatibility of this mesh-update technique with spectral element method are given