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## Mathematics

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**1**-**12**of**12**.Physics - Mathematics -

**09.09.2024**The counter-intuitive statistics of thermodynamics on a microscopic scale

Publication of the Physics Laboratory in the Physical Review Letters on July 31, 2024. Communication by CNRS Physics on September 2, 2024. Experiments on a classical microscopic system show that, while the second principle of thermodynamics is still valid on average, it can be circumvented experimentally in 95% of cases! A study conducted at the Physics Laboratory of ENS de Lyon, published in Physical Review Letters .

Computer Science - Mathematics -

**25.05.2024** Enter the matrixes!

Whether performed by a human or a computer, matrix multiplication is a tedious task. Researchers are battling to reduce the time and number of steps required to solve this type of operation. Excel spreadsheets, climate modeling, simulation of aircraft wing structure, neural network calculations, image processing.

Mathematics - Physics -

**07.12.2023**CEA-Leti Paper in Nature Communications Reports First Complete Memristor-Based Bayesian Neural Network Implementation For Real-World Task

Breakthrough Classifies Types of Arrhythmia Recordings With Precise Aleatoric and Epistemic Uncertainty - A team comprising CEA-Leti, CEA-List and two CNRS laboratories has published a new paper in Nature Communications presenting the first complete memristor-based Bayesian neural network implementation for a real-world task-classifying types of arrhythmia recordings with precise aleatoric and epistemic uncertainty.

Health - Mathematics -

**04.03.2021** COVID-19 Screening: A New Model for Assessing the Efficiency of Group Testing

How best to evaluate the performance of a group testing strategy for the SARS-CoV-2 virus, which involves pooling samples from multiple individuals in order to conduct a single RT-PCR test on the whole group? To do precisely that, scientists from the CNRS, l'université Grenoble Alpes, and l'université Sorbonne Paris Nord 1 have developed a model that evaluates the efficiency of such tests.

Health - Mathematics -

**21.07.2020** "Winter is coming": the influence of seasonality on pathogen emergence

Seasonal fluctuations drive the dynamics of many infectious diseases. For instance, the flu spreads more readily in winter. Two scientists from the University of Nantes 1 and the CNRS 2 in Montpellier have developed a mathematical model to predict the risk of the emergence of an epidemic, depending on the time of the year at which the pathogen is introduced.

Environment - Mathematics -

**06.07.2020** Behind the dead-water phenomenon

What makes ships mysteriously slow down or even stop as they travel, even though their engines are working properly? This was first observed in 1893 and was described experimentally in 1904 without all the secrets of this "dead water" being understood. An interdisciplinary team from the CNRS and the University of Poitiers has explained this phenomenon for the first time: the speed changes in ships trapped in dead water are due to waves that act like an undulating conveyor belt on which the boats move back and forth.

Mathematics - Sport -

**25.03.2020**How to break new records in the 200 metres?

Usain Bolt's 200m record has not been beaten for ten years and Florence Griffith Joyner's for more than thirty years. And what about if the secret behind beating records was to use mathematics' Thanks to a mathematical model, Amandine Aftalion, CNRS researcher at the Centre d'analyse et de mathématique sociales (CNRS/EHESS), and Emmanuel Trélat, a Sorbonne Université researcher at the Laboratoire Jacques-Louis Lions (CNRS/Sorbonne Université/ Université de Paris) have proved that the geometry of athletic tracks could be optimised to improve records.

Sport - Mathematics -

**22.11.2017**Towards better understanding of railway ballast

SNCF engineers have been using mathematical models for many years to simulate the dynamic behavior of railways. These models have not been able to take into account large portions of the track have been extremely limited at modelling ballast, the gravel layer located under railway tracks. This is why SNCF Innovation & Recherche asked for help from specialists in wave propagation for all types of media and at varied scales: CNRS and INSA Strasbourg 1 researchers.

Computer Science - Mathematics -

**29.09.2017** There are only 15 possible pentagonal tiles

Tiling the plane with a single pattern is a mathematical problem that has interested humans since Antiquity, notably for the aesthetic quality of tiles in mosaics or tiling. One of the unresolved problems in this field that has been puzzling the scientific community since 1918 has now been definitively resolved thanks to Michaël Rao of the Laboratoire d'informatique du parallélisme (CNRS/Inria/ENS de Lyon/Université Claude Bernard Lyon 1).

Earth Sciences - Mathematics -

**25.11.2016**Subduction zone geometry: a mega-earthquake risk indicator

Mega-earthquakes (with a magnitude greater than 8.5) mainly occur on subduction faults where one tectonic plate passes under another. But the probability of such earthquakes does not appear to be even across these zones. In a study published on 25 November 2016 in the journal Science , researchers from the University of Oregon and Géoazur laboratory (CNRS/Université Nice Sophia Antipolis/Observatoire de la Côte d'Azur/IRD) show that mega-earthquakes mostly occur on the flattest subduction zones.

Life Sciences - Mathematics -

**11.07.2016** How organ regularity emerges from cell randomness

Random directions of growth yield flowers of the correct size and shape. Credit S. Tsugawa, Hokkaido University. An international team (Cornell University, Hokkaido University, Max Planck Institute, Ecole normale supérieure de Lyon / Université Claude Bernard Lyon 1 / CNRS / INRA) unravels how random cell growth contributes to making organs reach the correct size and shape.

Mathematics - Chemistry -

**23.05.2016** Ocean pollution: focusing on the fragmentation of plastic waste

First discovered by sailors, the masses of plastic debris floating at the center of vast ocean vortices called gyres are today under close scrutiny by scientists. To better understand the fragmentation of microplastics under the effect of light and abrasion by waves, researchers combined physico-chemical analyses with statistical modeling.