576 research outputs found
Mars Thermal Inertia and Surface Temperatures by the Mars Climate Sounder
No full textMars Thermal Inertia and Surface Temperatures by the Mars Climate Sounder
Sylvain Piqueux, David M. Kass, Armin Kleinböhl, Marek Slipski, Paul O. Hayne, Daniel J. McCleese, John T. Schofield, Nicholas Heavens
Jet Propulsion Laboratory, California Institute of Technology
4800 Oak Grove Drive
Pasadena, CA 91109
USA
Copyright 2023. All Rights Reserved.
Corresponding author: Sylvain Piqueux
Jet Propulsion Laboratory
M/S 183-301
4800 Oak Grove Drive
Pasadena, CA 91109
USA
[email protected]
Phone: 818-393-9595
Fax: 818-354-2494
Supporting files associated with the paper "Mars Thermal Inertia and Surface Temperatures by the Mars Climate Sounder
Atmospheric CO2 Depletion near the Surface in the Martian Polar Regions
No full textAtmospheric CO2 Depletion near the Surface in the Martian Polar Regions
Sylvain Piqueux, Paul O. Hayne, Armin Kleinböhl, David M. Kass, Mathias Schreier, Daniel J. McCleese, Mark I. Richardson, John T. Schofield, James H. Shirley, Nicholas Heavens
Jet Propulsion Laboratory, California Institute of Technology
4800 Oak Grove Drive
Pasadena, CA 91109
USA
Department of Astrophysical and Planetary Sciences and Laboratory for Atmospheric and Space Physics
University of Colorado Boulder
USA
Aeolis Research
USA
Space Science Institute
USA
Copyright 2022. All Rights Reserved.
Corresponding author: Sylvain Piqueux
Jet Propulsion Laboratory
M/S 183-301
4800 Oak Grove Drive
Pasadena, CA 91109
USA
[email protected]
Phone: 818-393-9595
Fax: 818-354-2494
Supporting information associated with the paper "Atmospheric CO2 Depletion near the Surface in the Martian Polar Regions" by Piqueux et al. consists of 17 files generated as part of this work and used to create the figures of this paper
Gardening of the Martian Regolith by Diurnal CO2 Frost and the Formation of Slope Streaks
No full textGardening of the Martian Regolith by Diurnal CO2 Frost and the Formation of Slope Streaks
L.Lange, S.Piqueux, C.S.Edwards
Jet Propulsion Laboratory, California Institute of Technology
Copyright 2022. All rights reserved.
Corresponding author: Sylvain Piqueux
Jet Propulsion Laboratory
M/S 183-301
4800 Oak Grove Drive
Pasadena, CA 91109
USA
[email protected]
Phone: 818-393-9595
Fax: 818-354-2494
Supporting information associated with the paper "Gardening of the Martian Regolith by Diurnal CO2 Frost and the Formation of Slope Streaks" by L. Lange et al. consists of 9 files generated as part of this work and used to generate several of the figures of this paper
Sylvain Pouvreau, valet de l´abbé de S. Cyran: protégé de S. Vincent de Paul
No full textEl autor del artículo ha encontrado un texto en el que se habla de un ayuda de cámara de S. Cyran que considera que es Sylvain Pouvreau. El autor describe las pruebas que tiene, hace una biografía de Sylvain y dice las fuentes de su informaciónThe author of the article has found a text which refers to a valet of San Cyran who is believed to be Sylvain Pouvreau. The author describes the evidence he has, and makes a biography of Sylvain, stating the sources of his informatio
Design Patterns for Multiagent Systems Design
No full text@inproceedings{ci-sauvage-2004-2, author = {Sauvage, Sylvain}, title = {Design Patterns for Multiagent Systems Design}, booktitle = {Mexican International Conference on Artificial Intelligence (MICAI'04)}, year = {2004}, address = {Mexico}, month = {April} }International audienc
MAS Development: Reusing through Agent Oriented Design Patterns
No full text@inproceedings{ci-sauvage-2004-1, author = {Sauvage, Sylvain}, title = {MAS Development: Reusing through Agent Oriented Design Patterns}, booktitle = {Eight World Multi-Conference on Systemics, Cybernetics and Informatics (SCI'04)}, year = {2004}, address = {Orlando, United States}, month = {July} }International audienc
Identification dynamique d'une colonne à distiller à garnissage
No full textL'objet de cette étude est d'identifier les paramètres d'une colonne à distiller à garnissage d’échelle pilote. L'identification en régime dynamique doit permettre 1'élaboration ultérieure des contrôles en boucle fermée visant à maintenir 1'operation du procédé à 1'équilibre, en dépit de perturbations éventuelles sur les variables d'entrée . Après avoir décrit le procédé et les problèmes expérimentaux dans le chapitre 1 , nous exposerons la méthode d'identification fréquentielle que nous avons utilisée dans un second chapitre. Un troisième chapitre sera entièrement dévolu à la description des paramètres d'équilibre de la colonne, car il nous semble fondamental d'avoir une bonne connaissance de ces caractéristiques avant d'envisager l'étude dynamique. L'accent sera mis sur l'estimation des coefficients des transfert de masse et de leurs variations avec le temps et avec la hauteur dans le lit garni . Le peu de points de mesures disponibles sur la colonne rendra celte estimation plus difficile et moins précise : cependant on proposera une loi de variation du coefficient de transfert global avec la hauteur qui est extrêmement vraisemblable. L'étude dynamique proprement dite consistera à étudier les réponses de la colonne a des perturbations sur le taux de reflux et sur le débit d'alimentation : le distillat et: le résidu seront les deux points de mesure choisis Ce sont ces résultats que 1'on présentera au chapitre 4 et que 1'on discutera au chapitre 6 . II est très important de souligner des maintenant que les résultats auxquels on aboutit , tant en régime transitoire qu'en régime d'équilibre, sont intimement liés aux conditions opératoires dans lesquelles on travaillait, et ne sauraient donc être généralisés sans prudence à d'autres conditions . Une approche analytique des fonctions de transfert sera faite au chapitre 5 : elle conduira a des résultats intéressants du point de vue physique sans nécessiter des hypothèses simplificatrices grossières. Au chapitre 7 nous ébaucherons une méthode de modelage numérique que nous situerons dans le contexte d'autres approches mathématiques qui nous semblent dignes d'intérêt. Enfin, dans un dernier chapitre, quelques critiques propres à la construction de la colonne seront formulées afin d'expliquer certains phénomènes et, surtout , de proposer des améliorations au procédé actuel en vue de la continuation ultérieure de cette étude
La vague condillacienne
No full textLa vague condillacienne (S. Auroux) The author draws a graph of the successive editions of Condillac's works on logic and compares these editions with the various editions of the main treatises of logic.Auroux Sylvain. La vague condillacienne. In: Histoire Épistémologie Langage, tome 4, fascicule 1, 1982. Les idéologues et les sciences du langage. pp. 107-110
Agent Oriented Design Patterns: a Case Study
No full text@inproceedings{ci-sauvage-2004, author = {Sauvage, Sylvain}, title = {Agent Oriented Design Patterns: a Case Study}, booktitle = {Third International Joint Conference on Autonomous Agents & Multi Agent Systems (AAMAS'04)}, year = {2004}, address = {New York, United States}, month = {July} }International audienc
Some Insights on Open Problems in Blockchains: Explorative Tracks for Tezos (Invited Talk)
No full textBlockchain is an emerging field that started with the advent of Bitcoin, the first cryptocurrency launched in 2008. Since then, new distributed applications (DApps) based on blockchain have emerged, such as non-fungible tokens (NFT) or decentralized finance (DeFi). All this contributes to an ever-increasing use of blockchains and poses many technological and scientific challenges.
The first challenge is related to scalability, usually measured by the number of transactions per second (TPS) that a blockchain can process. Recent solutions, such as Rollups, implement the concept of Layer 2, a secondary framework built on top of an existing blockchain that allows transactions to be managed off-chain for efficiency. The primary blockchain is used to secure the exchanges of the second layer by regularly recording its exchanges and its current state. A first experiment of Optimistic Rollups has been implemented in the Blockchain Tezos. The TORUs (Transaction Optimistic Rollups) allow efficient financial assets exchanges in the form of Michelson tickets. A generalization to Smart contracts Optimistic Rollups (SCORU) is currently under development.
Another challenge is to improve the efficiency of the data structures used in blockchain implementations. The main explorative tracks are to reduce and improve disk usage (compact representations, serialization of big data, sharing, ...), increase the speed of access operations (efficient caching strategies, asynchronous I/O, ...). For example, recent improvements to the storage layer of Octez, Tezos' most popular node implementation, have shown that it is possible to significantly speed up transactions, stabilize average transaction latency, and significantly reduce memory usage.
The security issues associated with blockchains also raise many challenges. Indeed, the economic protocols or consensus algorithms implemented in blockchains use incentive mechanisms to discourage nodes from engaging in bad behavior or in launching attacks. A fine tuning of these incentives is difficult in situations where decision makers interact. Game theory can be used to develop incentives, in particular its integration into verification tools (model-checkers, proof assistants, deductive program verification) or machine-learning tools could be very promising.
Finally, given the financial amounts managed by blockchains, it is essential to have a very precise specification of the algorithms, protocols and data structures used in blockchain implementations in order to guarantee the reliability of these very complex software. Whether it is for the programming of smart contracts, consensus algorithms or the P2P layer, the introduction of formal methods in the development cycle of blockchains is a major challenge in this domain. A lot of work in formal methods has been done for the Tezos blockchain. Among others, the formalization in TLA+ of Tenderbake, a PBFT-style consensus algorithm which offers deterministic finality to Tezos.
Author Bio. Sylvain Conchon is Professor in Computer Science at University Paris-Saclay since 2013. He is a member of LMF (Formal Methods Laboratory) and his research focuses on automatic deduction and model-checking, using techniques based on SMT (Satisfiabilty Modulo Theories) solvers. He is one of the designers of the SMT solver Alt-Ergo and the model-checker Cubicle. In collaboration with Nomadic-Labs, he is currently working on the use of formal methods to design and verify several aspects related to the blockchain Tezos, such as Michelson smart contracts or the Tenderbake consensus algorithm
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