Proof Certificates for Algebra and their Application to Automatic Geometry Theorem Proving

Post-proceedings of ADG 2008 (Automated Deduction in Geometry)International audienceIntegrating decision procedures in proof assistants in a safe way is a major challenge. In this paper, we describe how, starting from Hilbert's Nullstellensatz theorem, we combine a modified version of Buchberger's algorithm and some reflexive techniques to get an effective procedure that automatically produces formal proofs of theorems in geometry. The method is implemented in the Coq system but, since our specialised version of Buchberger's algorithm outputs explicit proof certificates, it could be easily adapted to other proof assistants

Proceedings of the 19th Sound and Music Computing Conference

Proceedings of the 19th Sound and Music Computing Conference - June 5-12, 2022 - Saint-Étienne (France). https://smc22.grame.f

Build WebAudio and JavaScript Web Applications using JSPatcher: A Web-based Visual Programming Editor

International audienceMany visual programming languages (VPLs) such as Max [1] or PureData [2] provide a graphic canvas to allow developers to connect functions or data between them. This canvas, also known as a patcher [3], is basically a graph meant to be interpreted as dataflow computation by the system. Some VPLs are used for multimedia performance or content generation as the UI system is often an important part of the language. This paper presents a webbased VPL, JSPatcher, which allows not only to build audio graphs using the WebAudio API, but also to design graphically AudioWorklet DSPs with FAUST toolchain, [4] [5] or to create interactive programs with other language built-ins, Web APIs or any JavaScript modules

Analyse d'images SAR polarimétriques au moyen d'outils temps-fréquence

Cet article illustre l'intérêt des outils temps-fréquences en imagerie SAR au travers de deux applications. Une nouvelle méthode d'analyse des cibles mobiles est présentée. Elle s'appuie sur un algorithme de Matching-Pursuit bidimensionnel et l'utilisation d'un dictionnaire temps-fréquence. Une étude des zones urbaines dans le cadre temps-fréquence est proposée. Le comportement fréquentiel des réflecteurs est mis à profit pour effectuer une classification des zones urbaines à l'aide de deux indicateurs

Analyse de la texture dans les images SAR appliquée au filtrage de speckle

·Cet article propose un nouveau modèle pour les statistiques d'ordre deux de la texture spatiale dans les images SAR. La fonction d'auto-covariance est approximée localement par un noyau gaussien anisotrope (AGK) 2-D dans le but de décrire la texture en termes d'orientation et d'anisotropie locales. L'estimation des paramètres de la texture à une échelle donnée est basée sur l'opérateur nommé tenseur de structure et ne requiert pas l'estimation explicite de l'auto-covariance. Enfin, un nouveau filtre nommé AGK-MMSE prenant en compte cette information spatiale est introduit et comparé au filtre MMSE géométrique classique. Le filtre proposé présente de meilleures performances en termes de préservation de la texture et d'amélioration des structures

Making Computer Music on the Web with JSPatcher

International audienceWeb technology through the internet and a web browser, is attractive to modern computer music artists as it provides high accessibility and interactivity and opens to possibilities. Since the development of JSPatcher [1], an online visual programming language (VPL) for audio processing and interactive web-based programs, we have recently added various music-related features to the application, including important features that common music computing practices need, such as file management, audio buffer handling, audio plugin support, and computer-assisted composition functions. It aims to make it easier for musicians, composers or designers of multimedia projects who might be familiar with VPLs on native platforms like Max [2], PureData [3] or OpenMusic [4], to bring or create their work on the web with less effort. This paper presents the concept, implementation details and examples of these newly added features

JSPatcher, a Visual Programming Environment for Building High-Performance Web Audio Applications

International audienceMany visual programming languages (VPLs) which include Max or PureData provide a graphic canvas for connecting between functions or data. This canvas, also called a patcher, is basically a graph meant to be interpreted as a dataflow computation by the system. Some VPLs are used for multimedia performance or content generation since the UI system is generally a significant element of the language. This paper presents a web-based VPL, JSPatcher, which allows you to build audio graphs using the Web Audio API. Users can use a web browser to graphically design and run DSP algorithms using domain specific languages (DSL) for audio processing such as FAUST or Gen and execute them in a dedicated high priority thread called AudioWorklet. The application can also be utilized to create interactive programs and shareable artworks online with other JavaScript language built-ins, Web APIs, web-based audio plugins or external JavaScript modules

Modelling the distribution of the Ocellated Lizard in France : implications for conservation

The Ocellated Lizard, Timon lepidus (Daudin 1802) occupies the Mediterranean regions of southwestern Europe (Portugal, Spain, France, and the extreme northwest of Italy). Over the last decades, a marked decline in its population has been observed, particularly on the northern edge of its distribution. As a result, it is currently considered a threatened species, especially in France and Italy. In France, a national action plan for its conservation has been put in place. In this study, ecological niche modelling (ENM) was carried out over the entire area of France in order to evaluate the species' potential distribution, more accurately define its ecological niche, guide future surveys, and inform land use planning so this species can be better taken into consideration. The modelling used data representing 2,757 observation points spread over the known range of the species, and 34 ecogeographical variables (climate, topography, and vegetation cover) were evaluated. After removing correlated variables, models were fitted with several combinations of variables using eight species distribution model (SDM) algorithms, and then their performance was assessed using three model accuracy metrics. Iterative trials changing the input variables were used to obtain the best model. The optimized model included nine determining variables. The results indicate the presence of this species is linked primarily to three climate variables: precipitation in the driest month, precipitation seasonality, and mean temperature in the driest quarter. The model was checked by a sample dataset that was not used to fit the model, and this validation dataset represented 25% of the overall field observations. Of the known occurrence locations kept aside to check the results, 94% fell within the presence area predicted by the modelled map with a presence probability greater than 0.7, and 90% fell within the area with a presence probability ranging from 0.8 to 1, which represents a very high predictive value. These results indicate that the models closely matched the observed distribution, suggesting a low impact of either geographical factors (barriers to dispersal), historical factors (dispersal process), or ecological factors (e.g., competition, trophic resources). The overlap between the predicted distribution and protected areas for this species reveals that less than 1% of the potential distribution area is protected by strong regulatory measures (e.g., national parks and natural reserves). The knowledge obtained in this study allows us to recommend some guidelines that would favor the conservation of this species.Peer reviewe