Search results for "direction"

Sparse Image Representation by Directionlets

2010

Despite the success of the standard wavelet transform (WT) in image processing in recent years, the efficiency and sparsity of its representation are limited by the spatial symmetry and separability of its basis functions built in the horizontal and vertical directions. One-dimensional discontinuities in images (edges or contours), which are important elements in visual perception, intersect too many wavelet basis functions and lead to a non-sparse representation. To capture efficiently these elongated structures characterized by geometrical regularity along different directions (not only the horizontal and vertical), a more complex multidirectional (M-DIR) and asymmetric transform is requi…

ADI schemes for valuing European options under the Bates model

2018

Abstract This paper is concerned with the adaptation of alternating direction implicit (ADI) time discretization schemes for the numerical solution of partial integro-differential equations (PIDEs) with application to the Bates model in finance. Three different adaptations are formulated and their (von Neumann) stability is analyzed. Ample numerical experiments are provided for the Bates PIDE, illustrating the actual stability and convergence behaviour of the three adaptations.

Studies on a new potential dopaminergic agent: in vitro BBB permeability, in vivo behavioural effects and molecular docking evaluation.

2015

2-Amino-N-[2-(3,4-dihydroxy-phenyl)-ethyl]-3-phenyl-propionamide (DA-PHEN) has been previously synthesized to obtain a potential prodrug capable of release dopamine (DA) into CNS. However, DA-PHEN could act per se as a dopaminergic drug. In this study, the permeability transport (Pe), obtained by parallel artificial permeability assay (PAMPA), indicated a low passive transcellular transport (Pe = 0.32 ± 0.01 × 10(-6 )cm/s). Using the Caco-2 cell system, the Papp AP-BL in absorptive direction (3.36 ± 0.02 × 10(-5 )cm/s) was significantly higher than the Papp BL-AP in secretive direction (1.75 ± 0.07 × 10(-5 )cm/s), suggesting a polarized transport. The efflux ratio (Papp AP-BL/Papp BL-AP = 0…

L’auto-évaluation au service du développement professionnel des personnels de direction stagiaires

2022

Déterminants d'accès aux fonctions de direction, déroulement des carrières et rapport à l'exercice de la profession

1999

International audience

Biorthonormal-basis method for the vector description of optical-fiber modes

1998

This paper gives the theoretical basis for the development of real vector modal methods to describe optical-fiber modes. To this end, the vector wave equations, which determine the electromagnetic fields, are written in terms of a pair of linear, nonself-adjoint operators, whose eigenvectors satisfy biorthogonality relations. The key of our method is to obtain a matrix representation of the vector wave equations in a basis that is defined by the modes of an auxiliary system. Our proposed technique can be applied to fibers with any profile, even those with a complex refractive index. An example is discussed to illustrate our approach.

An Embedded Fingerprints Classification System based on Weightless Neural Networks

2009

Automatic fingerprint classification provides an important indexing scheme to facilitate efficient matching in large-scale fingerprint databases in Automatic Fingerprint Identification Systems (AFISs). The paper presents a new fast fingerprint classification module implementing on embedded Weightless Neural Network (RAM-based neural network). The proposed WNN architecture uses directional maps to classify fingerprint images in the five NIST classes (Left Loop, Right Loop, Whorl, Arch and Tented Arch) without anyone enhancement phase. Starting from the directional map, the WNN architecture computes the fingerprint classification rate. The proposed architecture is implemented on Celoxica RC20…

Proximités et médiations à travers deux romans francophones : "Les Nuits de Strasbourg" (1997) de Djebar et "Le Village de l’Allemand ou le journal d…

2021

International audience; Cette communication porte sur différentes proximités et médiations à travers deux romans francophones, "Les Nuits de Strasbourg" (1997) d'Assia Djebar et "Le Village de l'Allemand ou le journal des frères Schiller" (2008) de Boualem Sansal. La première partie traite de la posture (Meizoz) ou de l'image de ces auteurs dans le champ littéraire (Bourdieu, Casanova), telle que médiée par ces ouvrages. Ensuite, nous nous intéresserons à la mémoire multidirectionnelle (Rothberg) dans ces romans car l'intertextualité et l'intermédialité médient des proximités mémorielles et interculturelles. Enfin, la lecture sera considérée comme une potentielle médiation du réel.

A new bi-faced log periodic printed antenna

2005

In this paper, a new design of a broadband planar printed antenna based on the academic log periodic antenna is presented. The antenna consists of a series of printed dipoles, distributed on both faces of the substrate. Some configurations are explored, with a different number of printed dipoles. These are designed, simulated, fabricated, and measured. The calculated and measured return losses and radiation patterns are presented. The utility of the proposed antenna associated with its frequency bandwidth is better than 80%. The measured absolute gain is 6.5 dBi, and the front-to-back ratio is around 8 dB. The presented antenna should find wide applications in wireless communication systems…

Analysis of Offshore Knuckle Boom Crane - Part One: Modeling and Parameter Identification

2013

This paper presents an extensive model of a knuckle boom crane used for pipe handling on offshore drilling rigs. The mechanical system is modeled as a multi-body system and includes the structural flexibility and damping. The motion control system model includes the main components of the crane's electro-hydraulic actuation system. For this a novel black-box model for counterbalance valves is presented, which uses two different pressure ratios to compute the flow through the valve. Experimental data and parameter identification, based on both numerical optimization and manual tuning, are used to verify the crane model. The demonstrated modeling and parameter identification techniques target…