Search results for "angulation"
showing 10 items of 70 documents
Quantum gravity with THESEUS
2021
AbstractIn this paper we explore the possibility to search for a dispersion law for light propagation in vacuo with a sample of Gamma-Ray Bursts detected by the THESEUS satellite. Within Quantum Gravity theories, different models for space-time quantization predict relative discrepancies of the speed of photons w.r.t. the speed of light that (in a series expansion) depend on a given power of the ratio of the photon energy to the Planck energy. This ratio is as small as 10− 23 for photons in the soft γ −ray band (100 keV). The dominant effect is determined by the first significant term of this expansion. If the first order in this expansion is relevant, these theories imply a Lorentz Invaria…
A new solver for incompressible non-isothermal flows in natural and mixed convection over unstructured grids
2022
Abstract In the present paper we propose a new numerical methodology for the solution of 2D non-isothermal incompressible flows for natural and mixed convection in irregular geometries. The governing equations are the Incompressible Navier-Stokes Equations and the Energy Conservation Equation. Fluid velocity and temperature are coupled in the buoyancy term of the momentum equations according to the Oberbeck–Boussinesq approximation. The governing equations are discretized over unstructured triangular meshes satisfying the Delaunay property. Thanks to the Oberbeck–Boussinesq hypothesis, the flow and energy problems are solved in an uncoupled way, and two fractional time step procedures are s…
Free admission in museums and monuments : An exploration of some perceptions of the audiences.
2008
This paper considers the theme of the audiences' perceptions of free admission in national French museums and monuments. The results show that, from an individual perspective, perceptions of free admission are linked to perceptions of price, money and payment, hence complementing perceptions expressed in a collective perspective (a symbolic, political measure causing either adhesion or rejection). These perspectives are generally put forward by both advocates and opponents of the measure in their discussions. These different visions of free admission have managerial implications for managers of museums and monuments. Copyright © 2007 John Wiley & Sons, Ltd.
Detection of surfaces for projection of texture
2007
Augmented reality is used to improve color segmentation on human's body or on precious no touch artefacts. We propose a technique based on structured light to project texture on a real object without any contact with it. Such techniques can be apply on medical application, archeology, industrial inspection and augmented prototyping. Coded structured light is an optical technique based on active stereovision which allows shape acquisition. By projecting a light pattern onto the surface of an object and capturing images with a camera, a large number of correspondences can be found and 3D points can be reconstructed by means of triangulation.
High-velocity Impact Location on Aircraft panels Using Macro-fiber Composite piezoelectric Rosettes
2010
In this article, an approach based on an array of macro-fiber composite (MFC) transducers arranged as rosettes is proposed for high-velocity impact location on isotropic and composite aircraft panels. Each rosette, using the directivity behavior of three MFC sensors, provides the direction of an incoming wave generated by the impact source as a principal strain angle. A minimum of two rosettes is sufficient to determine the impact location by intersecting the wave directions. The piezoelectric rosette approach is easier to implement than the well-known time-of-flight-based triangulation of acoustic emissions because it does not require knowledge of the wave speed in the material. Hence, th…
Shape Distortion and Thickness Distribution during SPIF Processes: Expermental and Numerical Analysis
2011
Single Point Incremental Forming (SPIF) is a quite new sheet forming process which offers the possibility to deform complex parts without dedicated dies using only a single point tool and a standard 3-axis CNC machine. The process mechanics enables strains much higher than traditional sheet forming processes, but particular attention must be given to the final part geometrical accuracy. In this paper the capabilities of a dedicated explicit numerical model are quantitatively analyzed on pyramid-shaped parts. In particular a comparison between experimental and numerical results is reported. Three different shapes at the varying of the stamping angle were considered and the final shape was ac…
SIFT Matching by Context Exposed
2023
This paper investigates how to step up local image descriptor matching by exploiting matching context information. Two main contexts are identified, originated respectively from the descriptor space and from the keypoint space. The former is generally used to design the actual matching strategy while the latter to filter matches according to the local spatial consistency. On this basis, a new matching strategy and a novel local spatial filter, named respectively blob matching and Delaunay Triangulation Matching (DTM) are devised. Blob matching provides a general matching framework by merging together several strategies, including rank-based pre-filtering as well as many-to-many and symmetri…
Dirac equation as a quantum walk over the honeycomb and triangular lattices
2018
A discrete-time Quantum Walk (QW) is essentially an operator driving the evolution of a single particle on the lattice, through local unitaries. Some QWs admit a continuum limit, leading to well-known physics partial differential equations, such as the Dirac equation. We show that these simulation results need not rely on the grid: the Dirac equation in $(2+1)$--dimensions can also be simulated, through local unitaries, on the honeycomb or the triangular lattice. The former is of interest in the study of graphene-like materials. The latter, we argue, opens the door for a generalization of the Dirac equation to arbitrary discrete surfaces.
An exploratory study of the implications of free admission to museums and monuments : perceptions and effects on visiting behaviors.
2007
International audience; What perceptions of free admission to museums and monuments do French visiting and non-visiting audiences have ? What are the consequences of such perceptions on individuals' perceptions, visit-planning and behavior patterns in museums and monuments ? Research conducted between 2002 and 2003 tried to answer these questions by multiangulation applied to data production and analysis. Results show that free admission alter the perceptions of museums and monuments, it is secondary in planning and implementation of visit-planning, and finally it can spark a learning process from the visit that results in the appropriation of a free admission scheme. Conclusions are relate…
Une étude exploratoire des représentations de la gratuité et de ses effets sur le comportement des publics des musées et des monuments
2007
What perceptions of free admission to museums and monuments do French visiting and non-visiting audiences have ? What are the consequences of such perceptions on individuals' perceptions, visit-planning and behavior patterns in museums and monuments ? Research conducted between 2002 and 2003 tried to answer these questions by multiangulation applied to data production and analysis. Results show that free admission alter the perceptions of museums and monuments, it is secondary in planning and implementation of visit-planning, and finally it can spark a learning process from the visit that results in the appropriation of a free admission scheme. Conclusions are related to the need to create …