Polygonal Building Segmentation by Frame Field Learning

While state of the art image segmentation models typically output segmentations in raster format, applications in geographic information systems often require vector polygons. To help bridge the gap between deep network output and the format used in downstream tasks, we add a frame field output to a deep segmentation model for extracting buildings from remote sensing images. We train a deep neural network that aligns a predicted frame field to ground truth contours. This additional objective improves segmentation quality by leveraging multi-task learning and provides structural information that later facilitates polygonization; we also introduce a polygonization algorithm that utilizes the frame field along with the raster segmentation. Our code is available at https://github.com/Lydorn/Polygonization-by-Frame-Field-Learning.Comment: CVPR 2021 - IEEE Conference on Computer Vision and Pattern Recognition, Jun 2021, Pittsburg / Virtual, United State

Banc d'essai CEM pour onduleur photovoltaïque

Avec l’arrivée de plus en plus de consommateurs et de producteurs sur le réseau électrique, la compatibilité entre tous ces appareils est impérative. Une étude parue en avril 2017 a montré que les compteurs intelligents pouvaient, dans certains cas, mesurer jusqu’à 20% en dessous de la valeur réelle. Un tel écart avec la réalité n’est pas acceptable, surtout avec l’inversion des flux de puissance, l’augmentation de la complexité du réseau électrique et les particuliers, normalement consommateurs, qui deviennent producteurs grâce à des installations photovoltaïques. Les distributeurs de réseaux se basant principalement sur les compteurs installés chez les particuliers pour les calculs de facturations, redevances, ou de mise à niveaux des lignes et câbles, il convient qu’ils doivent disposer de mesures fiables

Five Conferences on Undecidability

These five lectures on undecidability were given to students with a good level in mathematics but with no special knowledge on logic. The first conference presents the formalization of mathematics with a short historical survey, the language of first order predicates and the axioms of set theory. The second and third lectures explain the incompleteness phenomena from the Hilbert program until Gödel's theorems with a presentation of the sequent calculus of Gentzen.The fourth talk deepens model theory reasoning in the case of the continuum hypothesis, and the last conference gives examples of effective computability results

Étude de la relation entre structure, dynamique et fonction de l’ARN par l’ingénierie du ribozyme VS de Neurospora

L’activité et la fonction des ARN catalytiques sont étroitement liées à leur structure tridimensionnelle et à leur dynamique. Mieux comprendre la nature précise de ce lien permettrait potentiellement d’adapter ces ARN à de nouveaux substrats et modifier leurs caractéristiques cinétiques d’une manière rationnelle. Le ribozyme Varkud Satellite (VS) de Neurospora est un petit ribozyme nucléolytique caractérisé biochimiquement de manière approfondie. Son activité dépend d’une interaction boucle-boucle de type kissing-loop entre la boucle V du ribozyme et la boucle I de son substrat replié en tige-boucle. Ces caractéristiques en font un excellent modèle pour des études portant sur le lien entre structure, dynamique et activité des ARN catalytiques à des fins d’ingénierie. Bien que notre compréhension de la structure du ribozyme VS se soit largement améliorée depuis le début de mes travaux de thèse, elle reste essentiellement d’une nature statique. Il est ainsi important d’une part d’approfondir les connaissances relatives au potentiel d’ingénierie du ribozymes VS et d’autre part de brosser un portrait dynamique de sa fonction de clivage dans le but de procéder à son ingénierie rationnelle. Dans cette optique, il a été entrepris de démontrer en premier lieu que le ribozyme VS était capable de reconnaitre et cliver des substrats de longueur différentes mais également qu’il était possible de modifier la longueur de l’hélice V afin de cliver des substrats trop courts ou trop longs pour être clivés par le ribozyme naturel. Une fois cette démonstration faite, la possibilité de substituer l’interaction de type kissing-loop I/V, sous-domaine crucial pour la reconnaissance du substrat, par des interactions de même type et structuralement similaires a été confirmée. Finalement, les données cinétiques récoltées sur des ribozymes incorporant soit ces variantes, soit l’interaction naturelle ont été comparées aux capacités dynamiques intrinsèques de ces interactions kissing-loop, évaluées en dynamique moléculaire, afin de relier leur structure, leur dynamique et leur activité. Ces travaux auront permis de mieux comprendre dans quelle mesure et de quelle façon le ribozyme VS pouvait être modifié pour être adapté à de nouveaux substrat. Mais plus généralement, ils nous ont offert une compréhension accrue des paramètres structuraux et dynamiques important à considérer afin de procéder à l’ingénierie rationnelle d’un ARN fonctionnel.The activity and function of catalytic RNAs are closely related to their three-dimensional structure and dynamics. Better understanding the precise nature of this link would potentially allow to adapt these RNAs to cleave new substrates and modify their kinetic characteristics in a rational way. Neurospora Varkud Satellite (VS) ribozyme is a small nucleolytic ribozyme that has been very well characterized biochemically. Its activity depends on a kissing-loop interaction between loop V of the ribozyme and loop I of its substrate folded into a stem-loop. These features make it an excellent model for studying the link between structure, dynamics, and activity of catalytic RNAs for engineering purposes. Although our understanding of the structure of the VS ribozyme has greatly improved since the beginning of my PhD., it remains essentially a static depiction. It is therefore important to know more about the engineering potential of the VS ribozyme and to draw a dynamic portrait of its cleavage function, in order to proceed to its rational engineering. From this perspective, efforts were made to demonstrate that the VS ribozyme could recognize and cleave substrates of different lengths and furthermore that it was possible to modify the length of helix V to cleave substrates that were too short or too long to be cleaved by the natural ribozyme. The possibility of substituting the I/V kissing-loop interaction, a subdomain crucial for the recognition of its substrate, for structurally similar interactions of the same type was then confirmed. Finally, the kinetic data collected on ribozymes containing either these variants or the natural interaction were compared to the intrinsic dynamics of the kissing-loop interactions, evaluated in molecular dynamics, in order to link their structure, dynamics and activity. This work helped us better understand to what extent and how the VS ribozyme could be modified to be adapted to new substrates. More generally, it gave us an increased understanding of the important structural and dynamic parameters to take into account in order to rationally engineer a functional RNA

Thymic epithelial tumours: from basic principles to individualised treatment strategies

Thymic epithelial tumours represent a wide range of anatomical, clinical, histological and molecular malignant entities that may be aggressive and difficult to treat. The histopathological classification distinguishes thymomas from thymic carcinomas. Thymomas may be associated with autoimmune disorders. The management of thymic epithelial tumours is a paradigm of co-operation between clinicians, surgeons and pathologists, from establishing the diagnosis to organising the multimodal therapeutic strategy. Surgery is the mainstay of the curative-intent treatment, as complete resection represents the most significantly favourable prognostic factor on overall survival. In case of invasion of intra-thoracic structures and/or dissemination to the pleura and the pericardium, precluding complete resection to be achieved, primary chemotherapy has been used to reduce the tumour burden, possibly allowing subsequent surgery and/or radiotherapy. Novel strategies are needed, especially for refractory, recurrent tumours and thymic carcinomas, which carry a poor prognosis. Personalised approaches are currently being developed, as potentially “druggable” molecular targets are emerging from recent integrated genomic analyses. Along with the large variety of questions relative to the treatment strategy, thymic epithelial tumours represent a model of therapeutic implementation and achievement in orphan thoracic oncology, showing how the advent of new results induces new questions, as well as diversifies further clinical research directions and international collaborative initiatives

Event-based control of linear hyperbolic systems of conservation laws

International audienceIn this article, we introduce event-based boundary controls for 1-dimensional linear hyperbolic systems of conservation laws. Inspired by event-triggered controls developed for finite-dimensional systems, an extension to the infinite dimensional case by means of Lyapunov techniques, is studied. The main contribution of the paper lies in the definition of two event-triggering conditions, by which global exponential stability and well-posedness of the system under investigation is achieved. Some numerical simulations are performed for the control of a system describing traffic flow on a roundabout

Conservation law and Hamilton-Jacobi equations on a junction: the convex case

The goal of this paper is to study the link between the solution to an Hamilton-Jacobi (HJ) equation and the solution to a Scalar Conservation Law (SCL) on a special network. When the equations are posed on the real axis, it is well known that the space derivative of the solution to the Hamilton-Jacobi equation is the solution to the corresponding scalar conservation law. On networks, the situation is more complicated and we show that this result still holds true in the convex case on a 1:1 junction. The correspondence between solutions to HJ equations and SCL on a 1:1 junction is done showing the convergence of associated numerical schemes. A second direct proof using semi-algebraic functions is also given. Here a 1:1 junction is a simple network composed of two edges and one vertex. In the case of three edges or more, we show that the associated HJ germ is not a L 1-dissipative germ, while it is the case for only two edges. As an important byproduct of our numerical approach, we get a new result on the convergence of numerical schemes for scalar conservation laws on a junction. For a general desired flux condition which is discretized, we show that the numerical solution with the general flux condition converges to the solution of a SCL problem with an effective flux condition at the junction. Up to our knowledge, in previous works the effective condition was directly implemented in the numerical scheme. In general the effective flux condition differs from the desired one, and is its relaxation, which is very natural from the point of view of Hamilton-Jacobi equations. Here for SCL, this effective flux condition is encoded in a germ that we characterize at the junction

Regulatory mechanism of transforming growth factor beta receptor type II degradation by interleukin-1 in primary chondrocytes.

International audienceInterleukin-1β (IL-1β), a key-cytokine in osteoarthritis, impairs TGFβ signaling through TβRII down-regulation by increasing its degradation. Here, we investigated the molecular mechanism that controls TßRII fate in IL-1ß treated cells. Chondrocytes were treated with IL-1ß in the presence of different inhibitors. TßRII and Cav-1 expression were assayed by Western blot and RT-PCR. We showed that IL-1ß-induced degradation of TßRII is dependent on proteasome and on its internalization in caveolae. In addition, IL-1ß enhances Cav-1 expression, a major constituent of lipid raft. In conclusion, we enlighten a new mechanism by which IL-1ß antagonizes TGFß pathway and propose a model of TßRII turnover regulation upon IL-1ß treatment