A multistage hierarchical algorithm for hand shape recognition

This paper represents a multistage hierarchical algorithm for hand shape recognition using principal component analysis (PCA) as a dimensionality reduction and a feature extraction method. The paper discusses the effect of image blurring to build data manifolds using PCA and the different ways to construct these manifolds. In_order to classify the hand shape of an incoming sign object and to be invariant to linear transformations like translation and rotation, a multistage hierarchical classifier structure is used. Computer generated images for different Irish Sign Language shapes are used in testing. Experimental results are given to show the accuracy and performance of the proposed algorithm

A review on formability prediction and constitutive damage models of sheet forming of magnesium alloys

In recent years, the demand for using magnesium (Mg) alloys has significantly increased in several industrial fields. Due to their favorable strength/weight ratio thus Mg alloy demonstrating a valid replacement for aluminum alloys and High Strength Steels particularly for the production of lightweight parts in aerospace and automotive industries. However the formability of Mg at cold forming conditions is significantly poor and determination of the material formability need special testing procedures and understanding of material failure mechanism. FLD is commonly used to characterize the formability of materials and the key feature of FLD is the forming limit curve (FLC). This paper provides a review on the determination of strain-based and stress-based forming limit diagrams is introduced in this paper. In addition, the constitutive damage models for predicting and characterizing the forming limits of magnesium alloy sheet metals under a wide range of forming conditions at both industrial and scientific level

Nonlinearity reduction of manifolds using Gaussian blur for handshape recognition based on multi-dimensional grids

This paper presents a hand-shape recognition algorithm based on using multi-dimensional grids (MDGs) to divide the feature space of a set of hand images. Principal Component Analysis (PCA) is used as a feature extraction and dimensionality reduction method to generate eigenspaces from example images. Images are blurred by convolving with a Gaussian kernel as a low pass filter. Image blurring is used to reduce the non-linearity in the manifolds within the eigenspaces where MDG structure can be used to divide the spaces linearly. The algorithm is invariant to linear transformations like rotation and translation. Computer generated images for different hand-shapes in Irish Sign Language are used in testing. Experimental results show accuracy and performance of the proposed algorithm in terms of blurring level and MDG size

Photocatalytic degradation of an azo-dye on TiO2/ activated carbon composite material

A sequential adsorption/photocatalytic regeneration process to remove tartrazine, an azo-dye in aqueous solution, has been investigated. The aim of this work was to compare the effectiveness of an adsorbent/photocatalyst composite – TiO2 deposited onto activated carbon (AC) – and a simple mixture of powders of TiO2 and AC in same proportion. The composite was an innovative material as the photocatalyst, TiO2, was deposited on the porous surface of a microporous-AC using metal-organic chemical vapour deposition in fluidized bed. The sequential process was composed of two-batch step cycles: every cycle alternated a step of adsorption and a step of photocatalytic oxidation under ultra-violet (365 nm), at 25◦C and atmospheric pressure. Both steps, adsorption and photocatalytic oxidation, have been investigated during four cycles. For both materials, the cumulated amounts adsorbed during four cycles corresponded to nearly twice themaximumadsorption capacities qmax proving the photocatalytic oxidation to regenerate the adsorbent. Concerning photocatalytic oxidation, the degree of mineralization was higher with the TiO2/AC composite: for each cycle, the value of the total organic carbon removal was 25% higher than that obtained with the mixture powder. These better photocatalytic performances involved better regeneration than higher adsorbed amounts for cycles 2, 3 and 4. Better performances with this promising material – TiO2 deposited onto AC – compared with TiO2 powder could be explained by the vicinity of photocatalytic and AC adsorption sites

Vers un système ubiquitaire d'aide à la décision in-vivo dédié au Manufacturing

National audienceAfin de s'assurer du bon déroulement des différentes tâches, les industriels mettent à disposition de leurs employés de nombreux outils d'assistance, tout au long du cycle de vie du produit, notamment des outils d'acquisition et de réutilisation des connaissances métiers. Cependant, malgré les grands efforts réalisés par les éditeurs de logiciels sur les aspects ergonomiques, l'augmentation exponentielle des fonctionnalités de ces outils d'assistance rend leur accès et leur manipulation par les opérateurs de plus en plus complexe. De plus, il est très difficile de trouver l'information dont l'opérateur a besoin au bon moment afin de pouvoir interagir avec le produit ou le processus sur lequel il travaille. Les développements récents dans les domaines de la réalité virtuelle et la réalité augmentée peuvent amener une grande assistance aux utilisateurs pour leur faciliter la représentation et la manipulation des informations dont ils ont besoin. C'est particulièrement le cas quand il s'agit des opérateurs ne maitrisant pas forcement les systèmes d'information classiques. Dans ce contexte, l'objectif de nos travaux est de concevoir et développer un " compagnon virtuel d'entreprise ". Ce concept se traduit par un système d'aide à la décision supporté par les atouts des TIC et de la réalité virtuelle afin d'assister les opérateurs dans la réalisation de leurs tâches quotidiennes. Les Systèmes d'Aide à la Décision (SAD) sont des systèmes qui se caractérisent par une grande capacité de raisonnement dans le but de fournir aux utilisateurs l'ensemble des informations nécessaires à la réalisation des tâches complexes de prise de décision

An Info*Engine based architecture to support interoperability with Windchill system

International audienceThis paper deals with the complex issue of interoperability methods and technologies especially in PLM field. Windchill is one of the most popular PLM software proposing robust solutions to support communication with external information systems. The purpose of this paper is to prospect the interoperability mechanisms offered by PTC editor as a solution to interoperability issue. A new interoperability framework is proposed as a Webservice based solution using the capacities embedded in the Windchill Info*Engine mechanisms and J2EE application technology