Publications associées à Segment (mathématiques)

Bootstrapping smooth conformal defects in Chern-Simons-matter theories

The expectation value of a smooth conformal line defect in a CFT is a conformal invariant functional of its path in space-time. For example, in large N holographic theories, these fundamental observables are dual to the open-string partition function in Ad ...

Springer Nature2024

Fully solvable finite simplex lattices with open boundaries in arbitrary dimensions

Fabrizio Minganti

Finite simplex lattice models are used in different branches of science, e.g., in condensed-matter physics, when studying frustrated magnetic systems and non-Hermitian localization phenomena; or in chemistry, when describing experiments with mixtures. An n ...

Amer Physical Soc2023

Region Extraction in Mesh Intersection

Annalisa Buffa, Pablo Antolin Sanchez, Emiliano Cirillo

Region extraction is a very common task in both Computer Science and Engineering with several applications in object recognition and motion analysis, among others. Most of the literature focuses on regions delimited by straight lines, often in the special ...

2023

ON THE INDEPENDENCE NUMBER OF INTERSECTION GRAPHS OF AXIS-PARALLEL SEGMENTS

Jana Tabea Cslovjecsek

We prove that for any triangle-free intersection graph of n axis-parallel line segments in the plane, the independence number alpha of this graph is at least alpha n/4+ohm(root n). We complement this with a construction of a graph in this class satisfying ...

Carleton Univ, Dept Mathematics & Statistics2023

Interactions of Cavitation Bubbles with Deformable Interfaces

Armand Baptiste Sieber

Cavitation is a topic that has long been of interest due to the large and growing range of applications associated with it. This is mainly because the collapse of cavitation bubbles releases a considerable amount of energy into the surrounding environment. ...

EPFL2023

Results on Sparse Integer Programming and Geometric Independent Sets

Jana Tabea Cslovjecsek

An integer linear program is a problem of the form max{c^T x : Ax=b, x >= 0, x integer}, where A is in Z^(n x m), b in Z^m, and c in Z^n. Solving an integer linear program is NP-hard in general, but there are several assumptions for which it becomes fixed ...

EPFL2023

Flexural-tensegrity snapping tails for bio-inspired propulsion in fluids

Pedro Miguel Nunes Pereira de Almeida Reis, Claudio Boni

Many aquatic animals propel themselves by flapping their tails. Leveraging a recently proposed snapping cantilever beam based on the concept of flexural tensegrity, we propose a bio-inspired propulsion device. The design comprises a segmental beam with hol ...

ELSEVIER2022

Dynamics of cavitation bubbles near granular boundaries

Mohamed Farhat, Davide Bernardo Preso, Armand Baptiste Sieber

We study the dynamics of a cavitation bubble near beds of sand of different grain sizes. We use high-speed imaging to observe the motion of the bubble and the sand for different values of the stand-off parameter gamma (dimensionless bubble-boundary distanc ...

Cambridge University Press2022

Deploying an Instance Segmentation Algorithm to Implement Social Distancing for Prosthetic Vision

Silvestro Micera, Daniela De Luca

The COVID-19 pandemic outbreak is causing a dramatic worsening in the already complicated living conditions of blind and visually impaired individuals. Social distancing is the most effective strategy to limit virus spread, but is extremely difficult for b ...

IEEE2022

Experimental Observation and Spin Texture of Dirac Node Arcs in Tetradymite Topological Metals

Emmanouil Frantzeskakis, Ji Dai

We report the observation of a nontrivial spin texture in Dirac node arcs, i.e., novel topological objects formed when Dirac cones of massless particles extend along an open one-dimensional line in momentum space. We find that such states are present in al ...

AMER PHYSICAL SOC2021

Visual feature integration: how long can it last?

Michael Herzog, Leila Drissi Daoudi - Kleinbauer, Lukas Vogelsang

Spatiotemporal features are integrated along motion trajectories. For example, when a central line is followed by pairs of flanking lines, two motion streams diverging from the center are perceived. The central line is rendered invisible by the subsequent ...

SAGE Publishing2021

Theory and simulations of homonuclear three-spin systems in rotating solids

David Lyndon Emsley, Gabriele Stevanato, Pinelopi Moutzouri, Bruno Simões de Almeida

The homonuclear dipolar coupling is the internal spin interaction that contributes the most to the line shapes in magic-angle-spinning (MAS) H-1 NMR spectra of solids, and linewidths typically extend over several hundred Hertz, limiting the H-1 resolution. ...

2021

Uncontrolled manifold analysis of the effects of a perturbation-based training on the organization of leg joint variance in cerebellar ataxia

Silvestro Micera

Walking patterns of persons affected by cerebellar ataxia (CA) are characterized by wide stride-to-stride variability ascribable to: the background pathology-related sensory-motor noise; the motor redundancy, i.e., an excess of elemental degrees of freedom ...

SPRINGER2021

Mechanical Characterization of Integrally-Attached Timber Plate Structures: Experimental studies and macro modeling technique

Aryan Rezaei Rad

Spurred by the recent advancements in Computer-Aided Design (CAD), Integral Mechanical Attachment (IMA) technique has been resurrected. Using IMAs, connections between timber elements are established through their form, instead of using additional connecto ...

EPFL2020

A finite element framework based on bivariate simplex splines on triangle configurations

Xiaodong Wei, Juan Cao

Recently, triangle configuration based bivariate simplex splines (referred to as TCB-spline) have been introduced to the geometric computing community. TCB-splines retain many attractive theoretic properties of classical B-splines, such as partition of uni ...

ELSEVIER SCIENCE SA2019

Cross-sections of line configurations in R-3 and (d-2)-flat configurations in R-d

Andres Jacinto Ruiz Vargas

We consider sets L = {l(1),..., l(n)} of n labeled lines in general position in R-3, and study the order types of point sets {p(1),..., p(n)} that stem from the intersections of the lines in L with (directed) planes Pi, not parallel to any line of L, that ...

ELSEVIER SCIENCE BV2019

Approximating the rectilinear crossing number

János Pach

A straight-line drawing of a graph G is a mapping which assigns to each vertex a point in the plane and to each edge a straight-line segment connecting the corresponding two points. The rectilinear crossing number of a graph G, (cr) over bar (G), is the mi ...

2019

SUBDIVIDE AND CONQUER Active Contours and Surfaces for Biomedical Image Segmentation

Anaïs Laure Marie-Thérèse Badoual

Ongoing advances in imaging techniques create new demands regarding the analysis of images in medicine and biology. Image segmentation is a key step of many image analysis pipelines and its proper execution is a particularly challenging task. This thesis i ...

EPFL2019

On-line micro-vibration measurement method for Lorentz-type magnetic-bearing space actuators

Yves Perriard, Douglas Martins Araujo, Leopoldo Rossini, Guzmán Borque Gallego

A novel, cost-effective, real-time and on-line method for measuring the generated micro-vibrations and iden- tifying the forces in a magnetic bearing space actuator is proposed. For its validation, an actively-controlled electrodynamic (Lorentz-type) magne ...

2019

Joint Inertial Sensor Orientation Drift Reduction for Highly Dynamic Movements

Kamiar Aminian, Benedikt Fasel, Julien Chardonnens

Inertial sensor drift is usually corrected on a single-sensor unit level. When multiple sensor units are used, mutual information from different units can be exploited for drift correction. This study introduces a method for a drift-reduced estimation of t ...

2018