2,763 research outputs found
Linking Yitzhakiâs and Dagumâs Gini Decompositions
In this article we show that the Gini coefficient is simultaneously decomposable both by sources of income and by populations of income receivers for non-overlapping income distributions: the so-called first-best Gini multi-decomposition. We show that this multidimensional decomposition is useful for many reasons: (i) it is related to the degree of inequality aversion of the decision maker, (ii) it is especially well suited to study inequalities between poor and non-poor people, (iii) it enables one to measure within- and between-group Gini elasticities, which gauge the impact of global transfers on within- and between-group inequalities, respectively.
Lattice Boltzmann method for colloidal dispersions with phase change.
Colloidal dispersions are known to undergo phase transition in a number of processes. This often gives rise to formation of structures in a flowing medium. In this paper, we present a model for flow of a colloidal dispersion with phase change. Two distribution functions are used. The colloid is described as a non-ideal fluid capable of phase change, but rather than taking the dispersion medium as the second fluid, a better choice is the dispersion (water plus colloid) which can be considered as an incompressible fluid. This choice allows a standard Lattice Boltzmann (LB) model for incompressible fluids to be used in combination with for the 'free-energy' LB model for the colloid. The coupling between the two fluids is the drag force on the colloid and the dependence of the viscosity of the overall fluid on the particle volume fraction. The problems raised by characteristic times and lengths have been treated. The main application considered is the growth dynamics or domain structuration of protein dispersions during dead-end filtration on a membrane surface
Improving the Accuracy of Industrial Robots by offline Compensation of Joints Errors
The use of industrial robots in many fields of industry like prototyping, pre-machining and end milling is limited because of their poor accuracy. Robot joints are mainly responsible for this poor accuracy. The flexibility of robots joints and the kinematic errors in the transmission systems produce a significant error of position in the level of the end-effector. This paper presents these two types of joint errors. Identification methods are presented with experimental validation on a 6 axes industrial robot, STAUBLI RX 170 BH. An offline correction method used to improve the accuracy of this robot is validated experimentally
Caractérisation et modélisation d'un élastomÚre dissipatif: application au pré-dimensionnement de piÚces lamifiées élastomÚre-métal
National audienceDans cette communication, on présente des essais de caractérisation réalisés sur un caoutchouc chargé. A partir de ces résultats, nous proposons un nouveau modÚle de comportement capable de traduire les effets de la fréquence et de l'amplitude du chargement. Par une approche phénoménologique et en se basant sur la thermodynamique des processus irréversibles, ce modÚle est développé en grandes déformations et tient compte de la contrainte de faible compressibilité
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