Obeid J.,CNRS Physical Eletrochemistry Materials and Interfaces Lab |
Flaus J.-M.,CNRS Laboratory of Sciences for Design, Optimization and Production |
Adrot O.,CNRS Laboratory of Sciences for Design, Optimization and Production |
Magnin J.-P.,CNRS Physical Eletrochemistry Materials and Interfaces Lab |
Willison J.C.,CNRS Chemistry and Biology of Metals Laboratory
International Journal of Hydrogen Energy | Year: 2010
This paper addresses the problem of estimating the states of an anaerobic photosynthetic process used for biohydrogen production by the photosynthetic bacterium Rhodobacter capsulatus. The process is described by a non-linear, time-discrete model and the state estimation is solved using an observer based on the Moving-Horizon State Estimation Method (MHSE). This approach is based on the minimization of a criterion (a non-linear function), in this case, the difference between the estimated output and the measured output of the system over a considered time horizon, where the solution is computed by using a numerical interval method. The observer was successfully applied to hydrogen production by R. capsulatus strain B10 in a batch process. © 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.
Moinet M.,Laboratoire dIngenierie des Systemes Mecaniques et des MAteriaux EA 2336 |
Mandil G.,CNRS Laboratory of Sciences for Design, Optimization and Production |
Serre P.,Laboratoire dIngenierie des Systemes Mecaniques et des MAteriaux EA 2336
CAD Computer Aided Design | Year: 2014
This paper proposes a new tool for decision support to address geometric over-constrained problems in Computer Aided Design (CAD). It concerns the declarative modeling of geometrical problems. The core of the coordinate free solver used to solve the Geometric Constraint Satisfaction Problem (GCSP) was developed previously by the authors. This research proposes a methodology based on Michelucci's witness method to determine whether the structure of the problem is over-constrained. In this case, the authors propose a tool for assisting the designer in solving the over-constrained problem by ensuring the consistency of the specifications. An application of the methodology and tool is presented in an academic example. © 2013 Elsevier Ltd. All rights reserved.
Khalaf R.E.H.,CNRS Laboratory of Sciences for Design, Optimization and Production |
Penz B.,CNRS Laboratory of Sciences for Design, Optimization and Production
Journal of Intelligent Manufacturing | Year: 2010
To design an efficient product family, designers have to anticipate the production process and, more generally, the supply chain costs. But this is a difficult problem, and designers often propose a solution which is subsequently evaluated in terms of logistical costs. This paper presents a design problem in which the product and the supply chain design are considered at the same time. It consists in selecting a set of modules that will be manufactured at distant facilities and then shipped to a plant close to the market for final, customized assembly under time constraints. The goal is to obtain the bill of materials for all the items in the product family, each of which is made up of a set of modules, and specifying the location where these modules will be built, in order to minimize the total production costs for the supply chain. The objective of the study is to analyze both, for small instances, the impact of the costs (fixed and variable) on the optimal solutions, and to compare an integrated approach minimizing the total cost in one model with a two-phases approach in which the decisions relating to the design of the products and the allocation of modules to distant sites are made separately. © 2009 Springer Science+Business Media, LLC.
Flaus J.-M.,CNRS Laboratory of Sciences for Design, Optimization and Production
Advances in Safety, Reliability and Risk Management - Proceedings of the European Safety and Reliability Conference, ESREL 2011 | Year: 2012
Lack of formal modelling methodologies for risk analysis is a problem for improving the quality of risk analysis, for knowledge capitalization and for a full exploitation of the results. In this paper, we present an approach for systemic modeling of complex systems suited for model driven risk based analysis. This methodology provides a framework for modelling the system under analysis, and the result of the analysis. This framework may be used to perform a model based risk analysis with a classical approaches such as FMEA, PHA, HAZOP in order to get more consistent analysis and to allow knowledge capitalization. © 2012 Taylor & Francis Group.
Schrenk S.,CNRS Laboratory of Sciences for Design, Optimization and Production |
Finke G.,CNRS Laboratory of Sciences for Design, Optimization and Production |
Cung V.-D.,CNRS Laboratory of Sciences for Design, Optimization and Production
Mathematical and Computer Modelling | Year: 2011
We analyze degeneracy characterizations for two classical problems: the transportation paradox in linear transportation problems and the pure constant fixed charge transportation problem. Solving the pure constant fixed charge problem is equivalent to finding a basic tree solution with maximum degree of degeneracy. Problems possess degenerate solutions if the equal subsum property is satisfied for the supplies and demands. Determining the existence of degeneracy is an NP-complete problem. But this NP-hardness remains even if all equal subsums are known in advance. For the second problem, the transportation paradox, there exists a vast literature that typically describes methods, derived within the framework of the classical transportation algorithm, for determining solutions where the more-for-less phenomenon occurs. We show how to solve this problem as a simple standard network flow problem. The paradox is linked to overshipment solutions, which belong to supply and demand configurations that tend to have a high degree of degeneracy. © 2011 Elsevier Ltd.
Mathieux F.,CNRS Laboratory of Sciences for Design, Optimization and Production |
Mathieux F.,University of Technology of Troyes |
Brissaud D.,CNRS Laboratory of Sciences for Design, Optimization and Production
Resources, Conservation and Recycling | Year: 2010
End-of-life products contain valuable materials that should be efficiently recovered to contribute to the sustainable use of resources. Material flow analysis is known as an efficient tool to map material flows and stocks across the economy. This tool is increasingly applied to waste recovery, although its application to specific products is rather limited. In this paper, a comprehensive step by step method to build an end-of-life product-specific material flow analysis is proposed. Its main originality is to mix a top-down approach based on the analysis of databases with a bottom-up approach resorting to the contribution of experts involved in the product and material life cycles. Another contribution of the paper is to present results of the method when applied to aluminum coming from end-of-life commercial vehicles. The method shows useful results concerning the product and material: identification and quantification of relevant processes and flows; identification of material sinks in a region; graphical presentation of material flows and stocks. For example, it was shown that most of the 129,000 tons of aluminum contained in commercial vehicles leaving use in Europe in 2003 was recovered locally. The study also demonstrated differences in behavior for different product types. © 2010 Elsevier B.V. All rights reserved.
Surbier L.,CNRS Laboratory of Sciences for Design, Optimization and Production |
Alpan G.,CNRS Laboratory of Sciences for Design, Optimization and Production |
Blanco E.,CNRS Laboratory of Sciences for Design, Optimization and Production
Production Planning and Control | Year: 2014
In the context of globalisation, the companies are urged to innovate the products and the services they provide to their customers, in order to keep their competitive edge. New product introduction in an already existing production environment generates numerous perturbations to handle in the supply chain and operations management during the production ramp-up. The purpose of this article is to present a thorough state of the art on the production ramp-up. Different overviews of the research body are given: comparing definitions, characteristics and problems of the ramp-up phase, classifying research papers according to their industrial context and organising them in different classifications (by keywords, focus extent.). Interesting issues that could be addressed in future research about the production ramp-up phase are identified. © 2013 Taylor and Francis.
Simeu-Abazi Z.,CNRS Laboratory of Sciences for Design, Optimization and Production |
Di Mascolo M.,CNRS Laboratory of Sciences for Design, Optimization and Production |
Knotek M.,Honewell HTSL
Reliability Engineering and System Safety | Year: 2010
This paper proposes an effective way for diagnosis of discrete-event systems using a timed-automaton. It is based on the model-checking technique, thanks to time analysis of the timed model. The paper proposes a method to construct all the timed models and details the different steps used to obtain the diagnosis path. A dynamic model with temporal transitions is proposed in order to model the system. By "dynamical model", we mean an extension of timed automata for which the faulty states are identified. The model of the studied system contains the faultless functioning states and all the faulty states. Our method is based on the backward exploitation of the dynamic model, where all possible reverse paths are searched. The reverse path is the connection of the faulty state to the initial state. The diagnosis method is based on the coherence between the faulty occurrence time and the reverse path length. A real-world batch process is used to demonstrate the modelling steps and the proposed backward time analysis method to reach the diagnosis results. © 2009 Elsevier Ltd. All rights reserved.
Benabid F.,CNRS Laboratory of Sciences for Design, Optimization and Production
Specialty Optical Fibers, SOF 2014 | Year: 2014
We give a historical perspective on the major results that led to the advent of the photonic bandgap guiding hollow core photonic crystal fiber (PBG HC-PCF) and to that of inhibited-coupling one (IC HC-PCF). We review the progress made on gas-filled HC-PCF and photonic microcells, along with their applications for coherent optics, Raman comb generation laser metrology, discharge based lasers and high field optics. © 2014 OSA.
Arghira N.,CNRS Laboratory of Sciences for Design, Optimization and Production |
Arghira N.,Polytechnic University of Bucharest |
Hawarah L.,CNRS Laboratory of Sciences for Design, Optimization and Production |
Ploix S.,CNRS Laboratory of Sciences for Design, Optimization and Production |
Jacomino M.,CNRS Laboratory of Sciences for Design, Optimization and Production
Energy | Year: 2012
This paper presents methods for prediction of energy consumption of different appliances in homes. The aim is to predict the next day electricity consumption for some services in homes. Historical data for a set of homes in France was used. Two basic predictors are tested and a stochastic based predictor is proposed. The performance of the predictors is studied and it shows that the proposed predictor gives better results than other approaches. Two processings are proposed to improve the performance of the predictor, segmentation and aggregation of data. Application results are provided. © 2012 Elsevier Ltd.