HAL Portal UTC Université de Technologie de Compiègne
Not a member yet
11652 research outputs found
Sort by
MULi-Ev: Maintaining Unperturbed LiDAR-Event Calibration
No full textAccepted at CVPR 2024 Workshop on Autonomous Driving. Copyright 2024 IEEEInternational audienceDespite the increasing interest in enhancing perception systems for autonomous vehicles, the online calibration between event cameras and LiDAR - two sensors pivotal in capturing comprehensive environmental information - remains unexplored. We introduce MULi-Ev, the first online, deep learning-based framework tailored for the extrinsic calibration of event cameras with LiDAR. This advancement is instrumental for the seamless integration of LiDAR and event cameras, enabling dynamic, real-time calibration adjustments that are essential for maintaining optimal sensor alignment amidst varying operational conditions. Rigorously evaluated against the real-world scenarios presented in the DSEC dataset, MULi-Ev not only achieves substantial improvements in calibration accuracy but also sets a new standard for integrating LiDAR with event cameras in mobile platforms. Our findings reveal the potential of MULi-Ev to bolster the safety, reliability, and overall performance of event-based perception systems in autonomous driving, marking a significant step forward in their real-world deployment and effectiveness
The Bahadur representation for empirical and smooth quantile estimators under association
No full textInternational audienceIn this paper, the Bahadur representation of the empirical and Bernstein polynomials estimators of the quantile function based on associated sequences are investigated. The rate of approximation depends on the rate of decay in covariances, and it converges to the optimal rate observed under independence when the covariances quickly approach zero. As an application, we establish a Berry-Esseen bound with the rate assuming polynomial decay of covariances. All these results are established under fairly general conditions on the underlying distributions. Additionally, we perform Monte Carlo simulations to evaluate the finite sample performance of the suggested estimators, utilizing an associated and non-mixing model
Ensuring Equitable Controller Placement: A Probabilistic Optimization Framework
No full textInternational audienc
Risk-based imprecise post-remediation soil quality objectives
No full textInternational audienceWhile risk-based contaminated land management is an essential component of sustainable remediation, uncertainty is an unavoidable aspect of risk assessment, since most of the parameters that influence risk are typically affected by uncertainty. Uncertainty may be of different origins; i.e., stochastic or epistemic. Stochastic (or aleatoric) uncertainty arises from random variability related to natural processes, while epistemic uncertainty arises from the incomplete/imprecise nature of available information. But the latter is rarely considered in risk assessments, with the result that risk-based soil quality objectives are almost invariably presented as precise (unique) threshold values. In this paper it is shown: (i) how the joint treatment of stochastic and epistemic uncertainty in risk assessment can lead to soil quality objectives presented as intervals rather than precise values and (ii) how this provides an upper risk-based safeguard for post-remediation monitoring values. The proposed method is illustrated by a real case of soils contaminated by arsenic located in the North-East of France. At this site steel manufacturers have gradually filled up a small valley with slag and dust, over more than a century. These materials are enriched in various metal(loid)s, including arsenic and lead. As the environmental authority has asked for a conversion of the site to other uses that may involve access by the general public, an investigation of human health risk was performed based on a sampling campaign and chemical characterizations including various types of extractions and an analysis of bioaccessibility. While further investigations are required to improve the bioaccessibility model, the human health risk presented herein shows how partial or imprecise information can be incorporated in the analysis while taking into account underlying uncertainties
Un progetto di edizioni digitali per il corpus Chimenti: dalla salvaguardia di un patrimonio dimenticato alla sua valorizzazione
No full textInternational audienc
Apprendre à travailler ensemble : influences de l’espace de travail numérique sur l’engagement dans la collaboration
No full textInternational audienceThis article examines the conditions for learners to engage in a joint project as well as the conditions for the development of specific collaboration skills. To better understand engagement in collaboration and the associated skills, we draw on the results of an experiment using multi-touch, multi-user tactile tables. We sought to measure the effects on learner engagement of such a socio-technical training device by comparing three different forms of instrumentation for collaborative activity: a tactile horizontal table and vertical table; a vertical table alone; digital tablets with a vertical table. This allows us to compare how the design of these spaces influences the involvement of individuals in collaboration and the collaborative skills developed.Cet article examine les conditions d’un engagement des apprenants dans un projet commun ainsi que les conditions de développement de compétences spécifiques pour collaborer. Pour mieux comprendre l’engagement dans la collaboration et les compétences qui y sont associées, nous nous appuyons sur les résultats d’une expérimentation mobilisant des tables et tableaux multitouches et multiutilisateurs. Nous avons cherché à mesurer les effets sur l’engagement des apprenants d’un tel dispositif sociotechnique de formation en comparant trois formes différentes d’instrumentation de l’activité collaborative : une table et un tableau tactiles ; un tableau tactile seul ; des tablettes numériques avec un tableau tactile. Cela nous permet de comparer comment la conception de ces espaces influence l’implication des individus dans la collaboration et les compétences collaboratives développées
Combined fungal and chemical pretreatment of lignocellulosic biomass for biogas production enhancement: effect of pretreatment order and fungal strains
No full textInternational audienceCombining fungal and chemical pretreatment has been shown to reduce the drawbacks of sole pretreatment while improving biofuel yields. White rot fungi are well known for their unique oxidative enzyme system which is capable of mineralizing lignin. However, their uncertainty of performance and long reaction time make them limited in their application. Therefore, combining fungal with Fenton pretreatment which is a type of reaction used naturally by the fungi to oxidize the biomass, could help to improve the efficiency of the fungal pretreatment. Therefore, in this project, the efficiency of combined white rot fungal and Fenton pretreatment to improve the methane production from wheat straw is assessed against sole fungal pretreatment. The efficiency of two different fungi strains and the order of the sequential pretreatment is also evaluated
Body Water Volume Estimation Using Bio Impedance Analysis: Where Are We?
No full textInternational audienceBioImpedance Analysis (BIA) is a safe, simple, and noninvasive technology to measure body composition. By measuring theelectrical impedance of biological tissues, BIA provides valuable biological insights such as body composition, hydration status,and some health conditions. This method has found widespread applications in clinical medicine, sports science, nutritionassessment, and wellness monitoring, offering a quick and cost-effective way to gather health data. The principle is to apply anelectric current to body segments, which water content and conductivity are characteristics, and to determine the electric impedancedepending on body tissues passed through. This technique is currently integrated into numerous connected devices, for quick andeasy self-assessment of health condition. However, these measurements are indirectly related to body composition and intensivelydepend on limited and imprecise assumptions to estimate mathematical models. This is the source of methodological andexperimental challenges. BIA is very promising to offer non-invasive and portable solutions to assess health status and well-being,but challenges have to be considered: they impact technological limitations, methodological standardization, and datainterpretation. Advancements in BIA require to address these hurdles to improve accuracy, reliability, and applicability in diversesettings. In this article, we reviewed in depth these challenges based on a systematic review of literature.Our review underlines clearly the need to reduce these challenges with the multiplication of biostatistical sources, the definition ofpersonalized models, and the adjustment of mathematical assumptions, to improve BIA reliability and adoption in e-health orspecific applications
SHADED: Shapley Value-Based Deceptive Evidence Detection in Belief Functions
No full textInternational audienceDeceptive evidence detection is an important issue in the theory of belief functions, which can be used to solve the problem of conflicts among evidence and to assess the credibility of evidence sources. In this paper, we first define strong and weak deceptive evidence. Then, we propose a deceptive evidence detection approach that directly investigates the process of Dempster's combination rule and decision-making based on the pignistic transformation. It can distinguish between strong and weak deceptive evidence and assess the importance of each piece of evidence. Several numerical examples are used to illustrate the effectiveness and efficiency of our proposed approach
Investigating Kinematics and Electromyography Changes in Manual Handling Tasks with an Active Lumbar Exoskeleton
No full textInternational audienceCompanies are becoming increasingly aware of the health of their employees and are now integrating exoskeleton solutions for both prevention and job maintenance. However, the effect of using exoskeletons is still an open question. Therefore, this study aimed to evaluate the impact of an active lumbar exoskeleton and its passive belt on trunk kinematics and muscle activity using instrumented motion analysis. Twenty-three healthy subjects volunteered to perform three handlings of a 5 kg load (free lifting, squat lifting, and load transfer) under three different experimental conditions. The “Control” condition was when the subject did not wear any device, the “Belt” condition was when the subject wore only the passive part of the exoskeleton, and the “Exo” condition was when the subject wore the active exoskeleton. Based on the Rapid Upper Limb Assessment scale, the exoskeleton reduced the time spent in angles that were considered dangerous for the back, according to ergonomic evaluations. Furthermore, for the handling sessions, it was observed that the exoskeleton did not modify muscle activity in the abdominal–lumbar region