Search results for "Détection"

RISQUE ASSOCIE A L'UTILISATION DE LA LOI DE BENFORD POUR DETECTER DES VENTES FRAUDULEUSES DE BIENS INNOVANTS A LA MODE

2010

Benford's law has been promoted as providing the auditors with a turnkey solution for fraud detection. The purpose of this paper is to show it is not always possible to detect fraudulent sales with that law. We use sales in volume of game consoles in Japan (since 1989), in United-States, in France, in Germany and in United-Kingdom (since 2000). After reviewing briefly the literature and our study design, the chi-square test and the bias analysis were used to measure the goodness-of-fit to Benford's law. Despite the absence of actual fraud, these sale series of fashion goods are not significantly in conformity with Benford's law. Thus, for the detection of fraudulent sales in this sector, th…

Analyse et détection des électrogrammes complexes fractionnés en vue de soigner la fibrillation auriculaire à l'aide de techniques d'ablation par rad…

2013

This manuscript presents research on the analysis and the detection of Complex Fractionated Atrial Electrograms (CFAE). In the first part, following a presentation over Atrial Fibrillation (AF) mechanisms and bioelectrical signals, the most commonly used tools for analyzing CFAE are presented. Linear tools are initially applied to signals from AF ablation procedures, then nonlinear tools are shown and integrated intoa CFAE detection algorithm. This one is based on the quantification of electrogram recurrence properties. In the second part, the cell and cardiac muscle tissue are described and simulated using mathematical models. Models such as FitzHugh Nagumo, Aliev Panfilov and Courtemanche…

Echo cancellation system for iso-frequency repeaters : contribution to the development of a new generation digital repeater

2014

On-frequency repeaters are a cost-effective solution to extend coverage and enhance wireless communications, especially in shadow areas. However, coupling between the receiving antenna and the transmitting antenna, called radio frequency echo, increases modulation errors and creates oscillations in the system when the echo power is high. According to the communication standards, extremely weak echoes decrease the transmission rate, while strong echoes damage electroni ccircuits because of power peaks. This thesis aims at characterizing the echo phenomenon under different modulations, and proposing an optimized solution directly integrated to industry. We have turned to digital solutions esp…

EVASPA (EVapotranspiration Assessment from SPAce) tool: an overview

2013

International audience; Evapotranspiration (ET) is a fundamental variable of the hydrological cycle and its estimation is required for irrigation management, water resources planning and environmental studies. Remote sensing provides spatially distributed cost-effective information for ET maps production at regional scale. We have developed EVASPA too for mapping ET from remote sensing data at spatial and temporal scales relevant to hydrological or agronomica studies. EVASPA includes several algorithms for estimating evapotranspiration and various equations for estimating the required input information (net radiation, ground heat flux, evaporative fraction…), which provides a way to assess …

Towards better privacy preservation by detecting personal events in photos shared within online social networks

2015

Today, social networking has considerably changed why people are taking pictures all the time everywhere they go. More than 500 million photos are uploaded and shared every day, along with more than 200 hours of videos every minute. More particularly, with the ubiquity of smartphones, social network users are now taking photos of events in their lives, travels, experiences, etc. and instantly uploading them online. Such public data sharing puts at risk the users’ privacy and expose them to a surveillance that is growing at a very rapid rate. Furthermore, new techniques are used today to extract publicly shared data and combine it with other data in ways never before thought possible. Howeve…

Semantic Analysis of the Driving Environment in Urban Scenarios

2021

Understanding urban scenes require recognizing the semantic constituents of a scene and the complex interactions between them. In this work, we explore and provide effective representations for understanding urban scenes based on in situ perception, which can be helpful for planning and decision-making in various complex urban environments and under a variety of environmental conditions. We first present a taxonomy of deep learning methods in the area of semantic segmentation, the most studied topic in the literature for understanding urban driving scenes. The methods are categorized based on their architectural structure and further elaborated with a discussion of their advantages, possibl…

Détection de ruptures de fibres au sein d'un composite unidirectionnel à l'aide d'un circuit micro-onde résonant

2006

International audience; Cet article présente une méthode novatrice de controle non destructif d'endommagement dans les matériaux composites. Elle est fondée sur l'observation et l'analyse des modifications des propriétés diélectriques d'un milieu dues à un endommagement. Plus précisément, son originalité réside dans le fait que le diagnostic cherché est obtenu via un circuit résonant microbande soumis à un champ électromagnétique dans la gamme des micro ondes. Cet article démontre la faisabilité de la méthode sur la détection de la rupture des fibres d'une éprouvette en comosite unidirectionnel soumise à un effort de flexion et indique en quoi elle possède potentiellement des atouts pour et…

Optimisation du protocole de recherche des Escherichia coli producteurs de Shiga-toxines (STEC) dans les aliments

2011

Enterohemorrhagic Escherichia coli (EHEC) are an important subset of Shiga toxin–producing E. coli (STEC) associated with foodborne infections. These bacteria can cause hemorrhagic diarrhoeal disease and Haemolytic and Uremic Syndrome which are associated with some predominant serotypes defined by AFSSA institute: O26, O103, O111, O145 and O157.Cattle are the primary reservoir of STEC. Although STEC transmission to humans is frequently associated with consumption of meat, dairy products have also been implicated in human cases. Sensitive and rapid detection methods for STEC are essential for the food industry to ensure a safe food supply. However, the detection of STEC in foods is problemat…

Lidar : traitement avancé des données et interprétation archéologique - cours 2016

2016

Data service platform for sentinel-2 surface reflectance and value-added products: System use and examples

2016

This technical note presents the first Sentinel-2 data service platform for obtaining atmospherically-corrected images and generating the corresponding value-added products for any land surface on Earth (http://s2.boku.eodc.eu/). Using the European Space Agency’s (ESA) Sen2Cor algorithm, the platform processes ESA’s Level-1C top-of-atmosphere reflectance to atmospherically-corrected bottom-of-atmosphere (BoA) reflectance (Level-2A). The processing runs on-demand, with a global coverage, on the Earth Observation Data Centre (EODC), which is a public-private collaborative IT infrastructure in Vienna (Austria) for archiving, processing, and distributing Earth observation (EO) data (http://www.…