Search results for "Optimisation"
showing 10 items of 129 documents
Optimiser l'utilisation du temps scolaire pour répondre à la diversité des élèves
1998
International audience
Rechercher une meilleure répartition du temps scolaire en primaire pouir la favoriser la réussite au collège
2000
International audience; To favour secondary school performances of low achievers, it could be advisable to change teaching either from primary level, to help pupils to enter secondary school or at secondary level to back up the adjustment of less able pupils. We can endeavour to modify endogenous variables affecting learning process. Among these, time provision between various activities at both primary and secondary levels, is an especially relevent factor. To favour secondary school performances of low achievers, it could be advisable to change teaching either from primary level, to help pupils to enter secondary school or at secondary level to back up the adjustment of less able pupils. …
SURATRAM - Intelligent Transport System for freight management in urban areas
2022
The project developed in the framework of this thesis is part of a more global and ambitious research program that aims at proposing a new type of goods management system in urban centers. In order to do so, the project aims to approach the management of goods from a systemic point of view, by integrating the management into the field of Intelligent Goods Transport Systems (ITS). This systemic vision of the management of goods in urban areas requires the use of electric and autonomous vehicles to ensure the tasks of delivery and collection of goods. In addition, these vehicles will be able to use the existing public transport network of the cities to move from an urban distribution center (…
A Numerical Approach to the Keel Design of a Sailing Yacht
2008
This paper describes an approach to the keel design of a sailing yacht. The related software, which is fully automatic, permits to obtain an optimal shape by modifying the surface used to define the keel planform. B-spline curves and surfaces have been used because of their ability in following complex shapes. The algorithm integrates ad hoc implemented original software with Computational Fluid Dynamics (CFD) commercial ones. The optimisation procedure makes use of Genetic Algorithms (GAs) and a gradient – based optimiser for the refinement of the solution. A careful CAD and CFD modelling leads to a stable and efficient generalised method, which has been applied to the design of the centre…
INTERNAL PRESSURE AND COUNTERPUNCH ACTION DESIGN IN Y-SHAPED TUBE HYDROFORMING PROCESSES: A MULTI OBJECTIVE OPTIMISATION APPROACH
2009
In sheet metal forming most of the problems are multi-objective problems, generally characterised by conflicting objectives. A classical approach to investigate such kind of problems is focused on a combination of multiple objectives into a unique objective function to be optimised. Actually, in metal forming processes optimisation two main phases have to be developed in order to reach an optimal solution: the former is the modelling phase (definition of the design variables and objective function) and the latter concerns the computational aspect (numerical simulations or experiment to be developed). In this paper, an integration between numerical simulations, response surface methodology a…
New Power Conditioning System for Battery-free Satellite Buses with Maximum Power Point Tracking
2007
The purpose of this paper is describe a new conception of Power Conditioning Unit (PCU) developed to fulfill the requirements of BepiColombo Electronic Propulsion module. This load bus has very tough specification especially regarding transient response during total load switch-off ("beam out") which has to be less than 2% of the bus voltage. The conception we propose, is the new Sequential Switching Shunt Maximum Power Regulator (S3MPR) consisting in a S3R, to keep the SA voltage at its Maximum Power Point (MPP) followed by a Boost regulator to produce a constant 100V to supply the Electronic Propulsion (EP). This concept may also be of interest for other future missions involving high pow…
Comparison of power quality impact of different photovoltaic inverters- the viewpoint of the grid
2005
This paper presents the results of an experimental analysis performed with the aim of evaluating the effect of many photovoltaic plants on power quality of the grid. Several parameters as voltage and current distortion, flicker, voltage variations at fundamental frequency and power factor have been observed. The measured values have been compared with the limits reported in the standards and, when possibiIe, their dependence on the characteristics of the grid in terms of its impedance has been pointed out.
Influence of MV distribution networks structure on voltage dips propagation
2003
In this paper, transient behaviour due to voltage dips which occur in electric power MV distribution networks as a consequence of a fault by using an improved ATP circuit-breaker model are reported. The circuit-breaker is simulated by using a tool written in MODELS language and by arranging a time-variable differential arc-conductance based on the combination of Mayr's and Cassie's equations. An accurate analysis of the transient subsequent to circuit-breaker operation, in different fault conditions, are reported in order to show how the amplitude of the dip depends on the fault type, location and network structure.
Small world theory and the World Wide Web: linking small world properties and website centrality
2016
This qualitative paper aims to point out the incidence of small world characteristics in the World Wide Web. To this end, some theoretical implications of small world theory (SWT) are verified using information from focus groups and in-depth interviews administered to experts and users of the World Wide Web. The purpose of this study is to investigate whether it is possible to apply small world properties to online social networks while pointing out the key variables of website centrality in that context. Building on this, the paper traces possible contributions for better management of the World Wide Web in terms of the professional use of social media to facilitate information or product …
Reassessment of voltage stability for distribution networks in presence of DG
2016
There is a growing interest in integrating renewable energy based distributed generation (DG) in the electrical power distribution networks. The installation of DG units at distribution level impacts critically the planning and operation characteristics of the network. The type, location, number and capacity of the integrated DGs affects system behavior and performance. In this paper the effect of installing new DGs on the distribution network voltage stability is studied. The optimal location of the newly installed DGs are decided based on the Power Stability Index (PSI) and Voltage Stability Index (VSI). Moreover, Voltage Stability Margin (VSM) of the interconnected DG distribution networ…