Concept

Polygone régulier

Publications associées (25)

A Note on Lenses in Arrangements of Pairwise Intersecting Circles in the Plane

Let F be a family of n pairwise intersecting circles in the plane. We show that the number of lenses, that is convex digons, in the arrangement induced by F is at most 2n - 2. This bound is tight. Furthermore, if no two circles in F touch, then the geometr ...

Electronic Journal Of Combinatorics2024

Discontinuous Galerkin methods for Fisher-Kolmogorov equation with application to a-synuclein spreading in Parkinson's disease

Alfio Quarteroni, Francesca Bonizzoni

This spreading of prion proteins is at the basis of brain neurodegeneration. This paper deals with the numerical modelling of the misfolding process of a-synuclein in Parkinson's disease. We introduce and analyse a discontinuous Galerkin method for the sem ...

Elsevier Science Sa2023

Quadratic serendipity element shape functions on general planar polygons

Xiaodong Wei

This paper proposes a method for the construction of quadratic serendipity element (QSE) shape functions on planar convex and concave polygons. Existing approaches for constructing QSE shape functions are linear combinations of the pair-wise products of ge ...

ELSEVIER SCIENCE SA2022

An unrefinement algorithm for planar THB-spline parameterizations

Annalisa Buffa

Unrefinement is a tool that allows to perform faster numerical simulations by controlling the level of precision in the specified area. We introduce an algorithm that creates a coarser geometry from an initial regular geometry, which is represented with re ...

ELSEVIER2022

Perimeter Modes of Nanomechanical Resonators Exhibit Quality Factors Exceeding 10(9) at Room Temperature

Tobias Kippenberg, Guanhao Huang, Nils Johan Engelsen, Sergey Fedorov, Alberto Beccari, Amirali Arabmoheghi

Systems with low mechanical dissipation are extensively used in precision measurements such as gravitational wave detection, atomic force microscopy, and quantum control of mechanical oscillators via optomechanics and electromechanics. The mechanical quali ...

American Physical Society2022

Free Boundary Regularity for Almost Every Solution to the Signorini Problem

Xavier Fernandez-Real Girona

We investigate the regularity of the free boundary for the Signorini problem in Rn+1. It is known that regular points are (n−1)-dimensional and C∞. However, even for C∞ obstacles φ, the set of non-regular (or degenerate) points could be very large—e.g. wit ...

2021

Capture zone models of a multi-well system in aquifers bounded with regular and irregular inflow boundaries

David Andrew Barry

Being bounded by hydrological (inflow and barrier) boundaries, natural aquifers have regular/irregular shapes. Here, we consider aquifers bounded by segmental inflow (variable head) boundaries in which water is extracted/injected by a multi-well system. St ...

2020

Semi-discrete optimal transport: a solution procedure for the unsquared Euclidean distance case

Valentin Hartmann

We consider the problem of finding an optimal transport plan between an absolutely continuous measure and a finitely supported measure of the same total mass when the transport cost is the unsquared Euclidean distance. We may think of this problem as close ...

SPRINGER HEIDELBERG2020

A note on discrete lattice-periodic sets with an application to Archimedean tilings

Matthias Schymura

Cao and Yuan obtained a Blichfeldt-type result for the vertex set of the edge-to-edge tiling of the plane by regular hexagons. Observing that the vertex set of every Archimedean tiling is the union of translates of a fixed lattice, we take a more general v ...

SPRINGER HEIDELBERG2019

Particle size selection in capillary instability of locally heated coaxial fiber

François Gallaire, Pierre-Thomas Paul Brun, Isha Shukla

Harnessing fluidic instabilities to produce structures with robust and regular properties has recently emerged as a new fabrication paradigm. This approach is exemplified in the work of Gumennik et al. [Nat. Commun. 4, 2216 (2103)], in which the authors fa ...

AMER PHYSICAL SOC2019

The performance of collars on scour reduction at tandem piers aligned with different skew angles

Anton Schleiss, Giovanni De Cesare, Sargol Memar

Local scouring is a leading cause of bridge collapses. To protect bridges against local scouring, different countermeasures have been proposed and tested in the literature. In this study, the performance of collars was evaluated for scour reduction at two ...

2020

On Simplices in Diameter Graphs in R-4

Andrei Kupavskii

A graph G is a diameter graph in R-d if its vertex set is a finite subset in R-d of diameter 1 and edges join pairs of vertices a unit distance apart. It is shown that if a diameter graph G in R-4 contains the complete subgraph K on five vertices, then any ...

Maik Nauka/Interperiodica/Springer2017

Signal Analysis Based on Complex Wavelet Signs

Martin Kurt Storath

We propose a signal analysis tool based on the sign (or the phase) of complex wavelet coefficients, which we call a signature. The signature is defined as the fine-scale limit of the signs of a signal's complex wavelet coefficients. We show that the signat ...

Elsevier2017

Protrusion-retraction switches and traction forces in spontaneous cell polarization

Alicia Carine Bornert

Cell migration is a fundamental property of all animal cells which is involved in processes such as embryogenesis, immune response, tissue regeneration and cancer metastasis. Directional migration requires cell polarization which could happen in response t ...

EPFL2016

From Compact Semi-Toric Systems To Hamiltonian S-1-Spaces

Silvia Sabatini

We show how any labeled convex polygon associated to a compact semi-toric system, as de fined by V (u) over tilde Ngoc, determines Karshon's labeled directed graph which classifies the underlying Hamiltonian S-1-space up to isomorphism. Then we characteriz ...

Amer Inst Mathematical Sciences2015

Solvability analysis and numerical approximation of linearized cardiac electromechanics

Alfio Quarteroni, Ricardo Esteban Ruiz Baier

This paper is concerned with the mathematical analysis of a coupled elliptic–parabolic system modeling the interaction between the propagation of electric potential and subsequent deformation of the cardiac tissue. The problem consists in a reaction–diffus ...

World Scientific Publ Co Pte Ltd2015

Opaque Sets

János Pach

The problem of finding "small" sets that meet every straight-line which intersects a given convex region was initiated by Mazurkiewicz in 1916. We call such a set an opaque set or a barrier for that region. We consider the problem of computing the shortest ...

Springer2014

Small distances in convex polygons

Filip Moric

Let d(1) < d(2) < ... denote the set of all distances between two vertices of a convex n-gon. We show that the number of pairs of vertices at distance d(2) from one another is at most n + O(1). (C) 2013 Elsevier B.V. All rights reserved. ...

Elsevier2013

On Polygons Excluding Point Sets

Radoslav Fulek, Filip Moric, Balázs Keszegh

By a polygonization of a finite point set S in the plane we understand a simple polygon having S as the set of its vertices. Let B and R be sets of blue and red points, respectively, in the plane such that is in general position, and the convex hull of B c ...

Springer Japan2013

The number of distinct distances from a vertex of a convex polygon

János Pach, Rom Pinchasi, Gabriel Nivasch

Erd\H{o}s conjectured in 1946 that every n-point set P in convex position in the plane contains a point that determines at least floor(n/2) distinct distances to the other points of P. The best known lower bound due to Dumitrescu (2006) is 13n/36 - O(1). I ...

2013