Search results for "Engineering sciences"
showing 10 items of 2347 documents
Experimental determination of flow concentration for pneumatic conveying systems of air-seeders
2014
International audience; Taking into account the complexity of wide width air-seeders, they remain less studied. The chief point for air-seeder designers is conception of the pneumatic conveying system. It must be precise in terms of uniformity so that that the agro-technical goals should be achieved. It must also ensure high rates without causing damages to seeds. This paper provides a theoretical analysis of pneumatic conveying designing applied to air-seeders. It shows that the conveying of particles (seeds, fertilizers or their mixture) in a given pipe depends on two interconnected parameters: flow concentration and air velocity. The knowledge of these two parameters is a necessity for t…
Evaluation Metric for Rate of Background Detection
2016
International audience; This paper proposes an evaluation metric which derive the effectiveness of background modeling algorithms. Background modeling is a key process on developing visual surveillance systems. The requirement of adapting to dynamic environments has motivated researchers to modify existing background modeling algorithms and develop new algorithms with better adaptability. Having the algorithms developed, credentials of each of the algorithms have to be assessed to exploit their effectiveness. Various evaluation metrics have been used for evaluating the rate of foreground extraction, foreground detection, and overall accuracy. However, the rate of background detection has no…
Modélisation numérique de structures composites réparées par collage de patchs externes en traction
2014
National audience; Request PDF on ResearchGate \textbar On Dec 30, 2014, Lingling Peng and others published Modélisation numérique de structures composites réparées par collage de patchs externes en traction
PV-Alert: Fog Computing based Architecture for Safeguarding Vulnerable Road Users
2018
High volumes of pedestrians, cyclists and other vulnerable road users (VRUs) have much higher casualty rates per mile; not surprising given their lack of protection from an accident. In order to alleviate the problem, sensing capabilities of smartphones can be used to detect, warn and safeguard these road users. In this research we propose an infrastructure-less fog-based architecture named PV-Alert (Pedestrian-Vehicle Alert) where fog nodes process delay sensitive data obtained from smartphones for alerting pedestrians and drivers before sending the data to the cloud for further analysis. Fog computing is considered in developing the architecture since it is an emerging paradigm that has p…
Improving the logistic process of orders dispatching through a multi-criteria decision-making perspective
2020
International audience; Far from being a mere production-oriented mission, competition among companies has to be considered as a much wider concept, largely based on effective supply chain management. Implementing suitable supply chain strategies is indeed crucial for enterprises seeking to strengthen their own position in the market against their competitors. With this recognition, one of the main issue in the logistic field is the suppliers and orders management, that is a complex decision-making problem depending on a wide set of aspects mutually correlated and often conflicting each other. This is the reason why assuming a Multi-Criteria Decision-Making (MCDM) perspective is useful to d…
Context-Aware Model Applied to Hog Descriptor for People Detection
2018
International audience; This work proposes and implements a method based on Context-Aware Visual Attention Model (CAVAM), but modifying the method in such way that the detection algorithm is replaced by Histograms of Oriented Gradients (HOG). After reviewing different algorithms for people detection, we select HOG method because it is a very well known algorithm, which is used as a reference in virtually all current research studies about automatic detection. In addition, it produces accurate results in significantly less time than many algorithms. In this way, we show that CAVAM model can be adapted to other methods for object detection besides Scale-Invariant Feature Transform (SIFT), as …
Spot spraying in oilseeds and protein crops
2019
International audience; Currently, spraying chemical products in agriculture became the main means of weed controlbecause this cultural practice is very fast, inexpensive and very effective. However, awarenessof their negative impacts (environment, human health) requires thinking about new technicaland agronomic solutions. New technologies are promising techniques for a site-specific weedmanagement through the development of localized spraying.Some sprayers (often small width) located on the row may be able to answer thoseexpectations but they are most often expensive. In this context, the objective of the project“PLEVOP” (development of spot sprayer in oilseed and protein crops), proposed …
High sensing potentialities of tetra-tert-butyl-metallophthalocyaninesbased acoustic microsensors for xylenes measurement in air at room temperature
2022
International audience; Xylenes, classified as Volatil Organic Compounds, is a very harmful pollutant for human health that can be absorbed into the body via all exposures routes: inhalation, ingestion, or dermal. As defined by the US Environmental Protection Agency, the occupational exposure limi-tes are set to 100 ppm while the guidelines in non-occupational context are fixed to 50 ppm. For the concentration measurements in the at-mosphere, authorities commonly used sampling methods with post-exposure chemical titration or chromatography. A strong interest remains on the development of low cost, low power consumption and easy implemented microsensors able to deliver real-time indicative m…
MULTI AXIAL TESTING OF ADHESIVELY BONDEDJOINTS OF FIBER REINFORCED THERMOPLASTIC POLYMERS
2015
International audience; In order to predict the mechanical behaviorof adhesively bonded joints, it is necessary to develop robust numerical models.This robustness is only reached if an extensive experimental database with tensile, shear and complex combined peel and shear loads can beestablished. The purpose of this study is to present a multi axialdevice for testing adhesively bonded joints, using KS2-type specimens traditionally utilized for spot-weld characterization. The tests were conducted on a glass fiber reinforced thermoplastic polymer(PA6-6) composite adhesively bonded with a flexible polyurethane adhesive. This adhesive/substrate combination allowsshort process times and good per…
Caractérisation physique de matériaux poreux pour l'étude des interactions acoustique/structure
2005
Cette thèse d'habilitation synthétise les dix ans de recherche qui suivirent ma thèse de doctorat dans les domaines des paramètres physiques et de l'acoustique des milieux poreux et des interactions fluide/squelette. Ce mémoire est divisé en trois parties principales A, B et C correspondant aux trois principales périodes de ma carrière scientifique: la période entre 1994 et 1997 passée au Laboratorium voor Akoestiek en Thermische Fysica de la K. U. Leuven en Belgique en collaboration avec le Laboratoire d'Acoustique de l'Université du Maine au Mans, la période entre 1997 et 2003 passée à Bradford (UK) en tant que chercheur (1997-2000) et les trois années passées à Hull (UK) en tant que maît…