17 resultados para Ajaccio-aéroport


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A nonlinear suboptimal guidance scheme is developed for the reentry phase of the reusable launch vehicles. A recently developed methodology, named as model predictive static programming (MPSP), is implemented which combines the philosophies of nonlinear model predictive control theory and approximate dynamic programming. This technique provides a finite time nonlinear suboptimal guidance law which leads to a rapid solution of the guidance history update. It does not have to suffer from computational difficulties and can be implemented online. The system dynamics is propagated through the flight corridor to the end of the reentry phase considering energy as independent variable and angle of attack as the active control variable. All the terminal constraints are satisfied. Among the path constraints, the normal load is found to be very constrictive. Hence, an extra effort has been made to keep the normal load within a specified limit and monitoring its sensitivity to the perturbation.

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In this paper a nonlinear optimal controller has been designed for aerodynamic control during the reentry phase of the Reusable Launch Vehicle (RLV). The controller has been designed based on a recently developed technique Optimal Dynamic Inversion (ODI). For full state feedback the controller has required full information about the system states. In this work an Extended Kalman filter (EKF) is developed to estimate the states. The vehicle (RLV) has been has been consider as a nonlinear Six-Degree-Of-Freedom (6-DOF) model. The simulation results shows that EKF gives a very good estimation of the states and it is working well with ODI. The resultant trajectories are very similar to those obtained by perfect state feedback using ODI only.

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The product lifecycle management (PLM) system has a significant role to support the collaboration and manage the partnership between OEM and supplier to enable the success of supplier integration. Today great rates of cooperation as suppliers have been dedicated to SMEs. Since one of the PLM task is to control the collaboration between OEM and suppliers, this paper provide supplier (SMEs) a framework to find their level of relationship with OEM and the steps that they can improve it. To respond to this trend, we defined a methodology based on collaborative matrix maturity levels and four PLM axes of strategic, organization, process and tools levels. Finally, according to this matrix, we proposed a structure of a proper questionnaire and example that shows suppliers how to evaluate their positions in terms of collaboration in PLM.

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Translation: Sir, It will probably be difficult for you to remember among the many strangers who annoy you with their admiration of a person to whom you kindly made civilities last year1 during a pleasant conversation about Corsica. I would be grateful if you could take a look at this sketch of his history.2 I present here the first of two letters. If you agree to them, I will send you the end. My brother, whom I recommend not to forget his deputies' commission to escort Paoli to his country,3 and to come and receive a lesson in virtue and humanity, will give them to you. I respectfully your most humble and obedient servant.4 Buonaparte, artillery officer Ajaccio, [Corsica] June 24 the first year of freedom [1790]5 1 Relations between Napoleon and Raynal have begun in 1789, which seems to confirm a confidence to Las Cases ( Memorial of St. Helena , La Pléiade , vol. I, p. 83) . 2 Latest version of history project of Corsica : Letters on Corsica to Abbe Raynal . 3 Joseph is part of a delegation sent by the city of Ajaccio to host Paoli 's return from exile in London . In doing so he has to go through Marseille where Raynal resides. 4 Shipping autograph, National Archives , 400 AP Biography 1. In the first years of Napoleon Bonaparte (1840) , Coston gives a rough version of this letter that it dates from 1786 , which is impossible because Raynal did not return to France that ' in 1787. Published for the first time in the Memories of Lord Holland (1851) , shipping is now kept in the national Archives Napoleons funds . 5 The letter is dated "June 24, the first year of freedom" (the word "freedom" is underlined twice). Given the dates of stay in Corsica Napoleon, it seems that is present in Ajaccio the month of June in 1790.

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A letter written by Napoleon Buonaparte (Bonaparte) to Guillaume Thomas Francois Raynal, dated at Ajaccio [Corsica] June 24 the first year of freedom [1790]. The letter is written in French. A transcription and a translation of the letter are also available.

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En 1969, le gouvernement de Pierre Elliott-Trudeau réalisa la plus grande expropriation de l’histoire du pays au nom du développement, pour construire le plus grand aéroport au monde : Mirabel. Le projet fut un cuisant échec pour plusieurs raisons sociales, politiques et économiques. Ce mémoire se concentre surtout sur les impacts post-expropriation sur la population de Mirabel et le positionnement politique de ces-derniers.

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Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

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Passengers comfort in terms of acoustic noise levels is a key train design parameter, especially relevant in high speed trains, where the aerodynamic noise is dominant. The aim of the work, described in this paper, is to make progress in the understanding of the flow field around high speed trains in an open field, which is a subject of interest for many researchers with direct industrial applications, but also the critical configuration of the train inside a tunnel is studied in order to evaluate the external loads arising from noise sources of the train. The airborne noise coming from the wheels (wheelrail interaction), which is the dominant source at a certain range of frequencies, is also investigated from the numerical and experimental points of view. The numerical prediction of the noise in the interior of the train is a very complex problem, involving many different parameters: complex geometries and materials, different noise sources, complex interactions among those sources, broad range of frequencies where the phenomenon is important, etc. During recent years a research plan is being developed at IDR/UPM (Instituto de Microgravedad Ignacio Da Riva, Universidad Politécnica de Madrid) involving both numerical simulations, wind tunnel and full-scale tests to address this problem. Comparison of numerical simulations with experimental data is a key factor in this process.

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When dealing with the design of a high-speed train, a multiobjective shape optimization problem is formulated, as these vehicles are object of many aerodynamic problems which are known to be in conflict. More mobility involves an increase in both the cruise speed and lightness, and these requirements directly influence the stability and the ride comfort of the passengers when the train is subjected to a side wind. Thus, crosswind stability plays a more relevant role among the aerodynamic objectives to be optimized. An extensive research activity is observed on aerodynamic response in crosswind conditions.

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A numerical simulation of the aerodynamic behavior of high-speed trains under synthetic crosswinds at a 90º yaw angle is presented. The train geometry is the aerodynamic train model (ATM). Flow description based on numerical simulations is obtained using large eddy simulation (LES) and the commercial code ANSYSFluent V14.5. A crosswind whose averaged velocity and turbulence characteristics change with distance to the ground is imposed. Turbulent fluctuations that vary temporally and spatially are simulated with TurbSim code. The crosswind boundary condition is calculated for the distance the train runs during a simulation period. The inlet streamwise velocity boundary condition is generated using Taylor?s frozen turbulence hypothesis. The model gives a time history of the force and moments acting on the train; this includes averaged values, standard deviations and extreme values. Of particular interest are the spectra of the forces and moments, and the admittance spectra. For comparison, results obtained with LES and a uniform wind velocity fluctuating in time, and results obtained with Reynolds averaged Navier Stokes equations (RANS), and the averaged wind conditions, are also presented.

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Includes indexes.