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Abdallah N.B.,CNRS Heuristic and Diagnostic Methods for Complex Systems | Mouhous-Voyneau N.,CNRS Urban Systems Engineering | Denoeux T.,CNRS Heuristic and Diagnostic Methods for Complex Systems
Proceedings of the 16th International Conference on Information Fusion, FUSION 2013 | Year: 2013

We present a methodology based on Dempster-Shafer theory to represent, combine and propagate statistical and epistemic uncertainties. This approach is first applied to estimate, via a semi-empirical model, the future sea level rise induced by global warming at the end of the century. Projections are affected by statistical uncertainties originating from model parameter estimation and epistemic uncertainties due to lack of knowledge of model inputs. We then study the overtopping response of a typical defense structure due to (1) uncertain elevation of the mean water level and (2) uncertain level of storm surges and waves. Statistical evidence is described by likelihood-based belief functions while imprecise evidence is modeled by subjective possibility distributions. Uncertain inputs are propagated by Monte Carlo simulation and interval analysis and the output belief function can be summarized by upper and lower cumulative distribution functions. © 2013 ISIF ( Intl Society of Information Fusi. Source

Ben Abdallah N.,CNRS Heuristic and Diagnostic Methods for Complex Systems | Mouhous-Voyneau N.,CNRS Urban Systems Engineering | Denoeux T.,CNRS Heuristic and Diagnostic Methods for Complex Systems
International Journal of Approximate Reasoning | Year: 2014

Estimation of extreme sea levels for high return periods is of prime importance in hydrological design and flood risk assessment. Common practice consists of inferring design levels from historical observations and assuming the distribution of extreme values to be stationary. However, in recent years, there has been a growing awareness of the necessity to integrate the effects of climate change in environmental analysis. In this paper, we present a methodology based on belief functions to combine statistical judgements with expert evidence in order to predict the future centennial sea level at a particular location, taking into account climate change. Likelihood-based belief functions derived from statistical observations are combined with random intervals encoding expert assessments of the 21st century sea level rise. Monte Carlo simulations allow us to compute belief and plausibility degrees for various hypotheses about the design parameter. © 2013 Elsevier Inc. All rights reserved. Source

Hissel F.,WaterWays | Hissel F.,Common Research Team CETMEF Avenues GSU | Morel G.,Common Research Team CETMEF Avenues GSU | Morel G.,CNRS Urban Systems Engineering | And 5 more authors.
Coastal Engineering | Year: 2014

The FP7 Theseus research project (2009-2013) aims to develop and assess innovative technologies and methodologies for coastal protection against erosion, flooding and environmental damages. While protection structures may help to reduce the level of hazard and the expected degree of loss, some danger of technical failures or human errors will always remain. For extreme events, the implementation of non-structural measures as early warning systems and disaster management practices is required to ensure the protection of population.During Theseus, a methodology for helping the local authorities to prepare an action plan in case of coastal flooding was developed and tested on the estuary of Gironde in France. The methodology builds over the return of experience from past events and tries to clearly identify all the stages of an evacuation and the thinking process that can lead to a robust evacuation plan. It relies on a conceptual framework - SADT - which helps to understand how data should be processed from its collection to its use in the plan. The risk scenarios were calculated for current and future conditions of the XXIst century, taking into account the effects of climate change. The methodology is supported by the OSIRIS software, prototyped during the FP5 eponymous project and later distributed by CETMEF and the French basin authorities of Loire and Meuse.The methodology for the preparation of evacuation plans was applied on a pilot city of Theseus, Bordeaux on the estuary of Gironde (France), and the software used to calculate evacuation times was tried out on Cesenatico near the Adriatic coast (Italy). This comparison verified the replicability of methodological guidelines in two different European contexts. The cultural and organizational differences and the different number of people involved underlined strong questions to be addressed when applying them. In order to assess the efficiency of an evacuation strategy and to compute the number of people successfully evacuated over time, a macroscopic model (not representing each individual vehicle but only flows of vehicles in congestion points) for the simulation of traffic congestion was used, based on the work of the University of Twente, Rijkswaterstaat and INFRAM. This model will be integrated in the Theseus decision support system for helping coastal managers to select their strategy for risk mitigation. © 2013 Elsevier B.V. Source

Sechilariu M.,CNRS Urban Systems Engineering | Locment F.,CNRS Urban Systems Engineering | Wang B.,Harbin Institute of Technology
Energies | Year: 2015

In the context of sustainable buildings, this paper investigates power flow management for an isolated DC microgrid and focuses on efficiency and energy cost reduction by optimal scheduling. Aiming at high efficiency, the local produced power has to be used where, when, and how it is generated. Thus, based on photovoltaic sources, storage, and a biofuel generator, the proposed DC microgrid is coupled with the DC distribution network of the building. The DC bus distribution maximizes the efficiency of the overall production-consumption system by avoiding some energy conversion losses and absence of reactive power. The isolated DC microgrid aims to minimize the total energy cost and thus, based on forecasting data, a cost function is formulated. Using a mixed integer linear programming optimization, the optimal power flow scheduling is obtained which leads to an optimization-based strategy for real-time power balancing. Three experimental tests, operated under different meteorological conditions, validate the feasibility of the proposed control and demonstrate the problem formulation of minimizing total energy cost. © 2015 by the authors. Source

Locment F.,CNRS Urban Systems Engineering | Sechilariu M.,CNRS Urban Systems Engineering
ENERGYCON 2014 - IEEE International Energy Conference | Year: 2014

This paper presents an urban DC microgrid based on photovoltaic which allows to charge the plug-in electric vehicles and to supply a DC load. Taking into account the public grid connection, the applied local control aims to extract maximum power from photovoltaic sources and manages the power flow with respect to electric vehicles state of charge and the DC load power demand. The urban DC microgrid is modeled by using Energetic Macroscopic Representation (EMR) and Maximum Control Structure (MCS). The simulation results for ensuring the maximal utilization of produced electricity, under different conditions, show the validity of the model and the feasibility of the proposed system design. © 2014 IEEE. Source

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