Search results for "traffic"
showing 10 items of 598 documents
Analysis of Low-Altitude Aerial Sequences for Road Traffic Diagnosis using Graph Partitioning and Markov Hierarchical Models
2016
International audience; This article focuses on an original approach aiming the processing of low-altitude aerial sequences taken from an helicopter (or drone) and presenting a road traffic. Proposed system attempts to extract vehicles from acquired sequences. Our approach begins with detecting the primitives of sequence images. At the time of this step of segmentation, the system computes dominant motion for each pair of images. This motion is computed using wavelets analysis on optical flow equation and robust techniques. Interesting areas (areas not affected by the dominant motion) are detected thanks to a Markov hierarchical model. Primitives stemming from segmentation and interesting a…
An ABM to support collective reflection on the evolution of mobility
2021
International audience; Transport infrastructures play a large part in defining a smart, sustainable and resilient city. Planning transportation systems traditionally rely on well-known evolutions of roads or public transportation (roundabouts for security, etc.). Yet, infrastructures might also benefit from, or may have to adapt to, recent disruptive innovations concerning modalities, technologies and societal organization (autonomous cars, smart infrastructure, homeworking, etc.). However, innovative urban policies might either facilitate mobility and increase citizen well-being, or create negative side effects. Urban planning therefore requires the city to assess the impact of these disr…
Towards visual urban scene understanding for autonomous vehicle path tracking using GPS positioning data.
2019
This PhD thesis focuses on developing a path tracking approach based on visual perception and localization in urban environments. The proposed approach comprises two systems. The first one concerns environment perception. This task is carried out using deep learning techniques to automatically extract 2D visual features and use them to learn in order to distinguish the different objects in the driving scenarios. Three deep learning techniques are adopted: semantic segmentation to assign each image pixel to a class, instance segmentation to identify separated instances of the same class and, image classification to further recognize the specific labels of the instances. Here our system segme…
The Urban Exposome during Pregnancy and Its Socioeconomic Determinants
2018
Background: The urban exposome is the set of environmental factors that are experienced in the outdoor urban environment and that may influence child development. Objective: The authors’ goal was to describe the urban exposome among European pregnant women and understand its socioeconomic determinants. Methods: Using geographic information systems, remote sensing and spatio-temporal modeling we estimated exposure during pregnancy to 28 environmental indicators in almost 30,000 women from six population-based birth cohorts, in nine urban areas from across Europe. Exposures included meteorological factors, air pollutants, traffic noise, traffic indicators, natural space, the built environment…
Characterization of membrane structure modifications induced during plant defense signaling
2017
SPEIPMUBINRADOCT; Plasma membrane was long considered as a simple separation between internal and external cellular environment. But more, it is a dynamic interface, an exchange platform. Now, recent researches highlight its role in plant defense responses to biotic and abiotic stresses. We use the tobaccocryptogein model to study the early steps of plant cell responses to pathogen detection. The signaling cascade includes an oxidative burst triggering an increase of plasma membrane order. The level of membrane order informs us about both packing and arrangement of membrane components, this parameter being evaluated by spectrofluorimetric approaches using a lipidic environment-sensitive pro…
Réponses des cellules de Nicotiana tabacum à des molécules microbiennes : évènements de signalisation précoce, influence de la dynamique membranaire …
2018
Responses of Nicotiana tabacum cells to microbial molecule treatments: early signaling events,influence of membrane dynamics, and sugar fluxesIn their natural environment plants are in close interaction with beneficial, neutral, or pathogenicmicrobes, which are highly dependent on carbon resources exuded by plant roots. Sugar transport, which isa key process of plant physiology, is essential to support the fate of plant-microbe interactions. Duringevolution, plants have acquired the ability to perceive microbial molecules, initiating specific signaltransduction cascades and leading to adapted response for microbe lifestyles (avirulent, virulent, or benefic).Plant survival will depend on the…
The movement of People in the upper Seine basin during the Roman period (1st century BCE – 5th century CE): infrastructures and written testimony.
2021
Archaeological and historical data to do with the movement of populations and goods in the Seine catchment area have not yet been overviewed for the Roman period. The Arkéaube conference offers an opportunity to present research on this subject. We can observe that, during the Roman period, the Seine valley was a major thoroughfare located downstream from the confluence of the Seine and the Yonne. Upstream, the Yonne gradually replaced the Petite Seine as a major route across the south-east of the Paris Basin.
Estimation of pollutant emissions from road traffic by image processing techniques. A case study in a suburban area
2013
This paper suggests a methodology based on the image processing technique able to automatically calculate the vehicle traffic and its components (light vehicles, heavy vehicles and motorcycles). The method also allows to evaluate instant vehicle speeds and, where necessary, to rebuild vehicle trajectories. Traffic data obtained through the procedure described below (capacities and speeds) can be also usefully applied to estimate pollutant emissions from vehicle traffic per year; therefore, the suggested method employs the algorithms defined with CORINAIR procedures, implemented in Copert 4 software. In order to evaluate how effective is the methodology, an experiment has been carried out in…
Statistical Regularities in ATM: network properties, trajectory deviations and delays
2012
One of the key enabler to the productivity and efficiency shift foreseen by SESAR will be the business-trajectory concept. The path to a deep understanding of how this new concept impacts on the future SESAR Air Traffic Management scenario goes through a better understanding of the actual air traffic network, and this will be done in the present paper by analyzing traffic data within the framework of complex network analysis. In this paper we will consider flights trajectory data from the Data Demand Repository database. In a first investigation, we perform a network study of the air traffic infrastructure starting from the airports and then refining our analysis at the level of navigation …
ELSA Project: Toward a complex network approach to ATM delays analysis
2011
The paper presents the preliminary results delivered by the WPE project ELSA. After some introductory notes about the project aims and structure, the paper shows how tools borrowed by the Complex Network Theory can be used to study the issue of delays in the air traffic system.