Search results for "Computer Vision"

Steady state γ-ray radiation effects on Brillouin fiber sensors

2015

International audience; Brillouin optical time-domain analysis (BOTDA) sensors offer remarkable advantages for the surveillance of the planned French deep geological radioactive wastes repository, called Cigéo1,2. In this work we study the performances of Brillouin distributed sensors in harsh environment. We evaluate the radiation tolerance of different sensor classes and their responses evolution during γ-ray exposition with 1kGy/h dose rate (to reach ~0.2MGy) and after 1, 3, 6 and 10 MGy accumulated doses. Measurements on strained Ge-doped SMF are reported to highlight the variation on Brillouin scattering proprieties, both intrinsic frequency position of Brillouin shift and its dependen…

An Integrated Neural and Algorithmic System for Optical Flow Computation

1997

Motion detection plays a central role in several visual environments: knowledge of object velocities and trajectories is fundamental in scene interpretation and segmentation. This task appears a simple problem, but detecting moving objects is very difficult, in fact this is a problem that cannot be considered completely solved today [1] [2] [3].

Deformation measurement of circular steel plates using projected fringes

2013

Published version of an article in the journal: The International Journal of Advanced Manufacturing Technology. Also available from the publisher at: http://dx.doi.org/10.1007/s00170-013-5276-3 Fringe projection is a versatile method for mapping the surface topography. In this paper, it is used to measure the deformation of steel plates under static penetration. Here, the surface shape changes continuously. Therefore, it is important to minimize the registration time. To achieve this, we apply a method of fringe location with subpixel accuracy that requires only a single exposure for each registration. This is in contrast to phase shifting techniques that require at least three separate exp…

Color Vision 2020: Introduction by the feature editors

2020

Explicit relationships for optimal designing rectangular microirrigation units on uniform slopes: The IRRILAB software application

2018

Abstract Many attempts have been made to provide easy tools for designing microirrigation units. However, most of these have dealt with numerical solutions, which require many trial-and-error attempts and time-consuming iterations, performed by applying the basic hydraulic equations from the manifold to the end of both the downhill and the uphill sides of the laterals. Recently, analytical procedures to optimally design paired drip laterals on uniform slopes were proposed, providing readily obtainable results and energy saving. Although these analytical solutions can be practically applied, they only make it possible to design a one-lateral unit; to be really interesting for practical appli…

A robust evolutionary algorithm for the recovery of rational Gielis curves

2013

International audience; Gielis curves (GC) can represent a wide range of shapes and patterns ranging from star shapes to symmetric and asymmetric polygons, and even self intersecting curves. Such patterns appear in natural objects or phenomena, such as flowers, crystals, pollen structures, animals, or even wave propagation. Gielis curves and surfaces are an extension of Lamé curves and surfaces (superquadrics) which have benefited in the last two decades of extensive researches to retrieve their parameters from various data types, such as range images, 2D and 3D point clouds, etc. Unfortunately, the most efficient techniques for superquadrics recovery, based on deterministic methods, cannot…

Image processing applications in object detection and graph matching : from Matlab development to GPU framework

2020

Automatically finding correspondences between object features in images is of main interest for several applications, as object detection and tracking, flow velocity estimation, identification, registration, and many derived tasks. In this thesis, we address feature correspondence within the general framework of graph matching optimization and with the principal aim to contribute, at a final step, to the design of new and parallel algorithms and their implementation on GPU (Graphics Processing Unit) systems. Graph matching problems can have many declinations, depending on the assumptions of the application at hand. We observed a gap between applications based on local cost objective functio…

Optimal design of an electro-hydraulic valve for heavy-duty vehicle clutch actuator with certain constraints

2016

Abstract The main objective of this paper is to investigate the sensitivity analysis and optimal design of a proportional solenoid valve (PSV) operated pressure reducing valve (PRV) for heavy-duty automatic transmission clutch actuators. The nonlinear electro-hydraulic valve model is developed based on fluid dynamics. In order to implement the sensitivity analysis and optimization for the PRV, the PSV model is validated by comparing the results with data obtained from a real test-bench. The sensitivity of the PSV pressure response with regard to the structural parameters is investigated by using Sobol׳s method. Finally, simulations and experimental investigations are performed on the optimi…

Average-case analysis in an elementary course on algorithms

1998

Average-case algorithm analysis is usually viewed as a tough subject by students in the first courses in Computer Science. Traditionally, these topics are fully developed in advanced courses with a clear mathematical orientation. The work presented here is not an alternative to this, but, it presents the analysis of algorithms (and average-case in particular) adapted to the mathematical background of students in an elementary course on Algorithms or Programming by using some specially selected examples.

Using Cellular Automata for feature construction - preliminary study

2007

When first faced with a learning task, it is often not clear what a good representation of the training data should look like. We are often forced to create some set of features that appear plausible, without any strong confidence that they will yield superior learning. Beside, we often do not have any prior knowledge of what learning method is the best to apply, and thus often try multiple methods in an attempt to find the one that performs best. This paper describes a new method and its preliminary study for constructing features based on cellular automata (CA). Our approach uses self-organisation ability of cellular automata by constructing features being most efficient for making predic…