3,217 research outputs found
Des hommes engagés pour les droits des femmes: le féminisme masculin au-delà des idées reçues
La sensibilité de nombreux hommes aux questionnements féministes - voire leur engagement actif pour les droits des femmes - est une réalité ancienne, mais toujours peu connue ou mal comprise. Cette étude tente de remettre en question un certain nombre d'idées reçues à ce sujet
L'émancipation masculine au nom des droits des femmes: les traités ideologiques d'hommes féministes en France, aux Pays-Bas et aux Etats-Unis (1970-1990)
Le discours féministe d'Emma Watson aux Nations Unies (20 septembre 2014)
Le 21 septembre 2014, l’actrice britannique Emma Watson, âgée de 24 ans, fait un bref discours devant l’Assemblée des Nations Unies à New York, appelant les hommes à se soucier de la question de l’égalité des sexes et à s’engager en faveur des droits des femmes. La jeune femme vient d’être nommée, quelques mois auparavant, ambassadrice onusienne des droits des femmes. Cette allocution constitue le point de départ d’une vaste campagne de sensibilisation nommée HeForShe (« Lui pour elle »), présentant explicitement le féminisme comme un combat d’intérêt général, auquel les hommes peuvent – et devraient – légitimement s’identifier. Les réactions de soutien – mais aussi les nombreuses critiques – que Watson a reçues pour ce discours nous offrent l’occasion d’aborder une question importante dans le débat public sur le militantisme pour les droits des femmes : le féminisme est-il destiné à tout le monde ? En d’autres termes, tout le monde peut-il devenir féministe et se définir comme tel
Se nommer pour les féministes, un acte militant (1967-1991)
Les groupes féministes portent des noms qui ont souvent une signification politique, symbolique ou historique. Un bref aperçu de la dénomination des principaux mouvements féministes autonomes, nés entre 1967 et 1991 en Europe, révèle des influences et/ou des intentions importantes pour le combat des droits des femmes, dans des contextes nationaux fort différents. Ces noms à vocation révolutionnaire prônent la
« libération des femmes » ou l’intégration des hommes dans le combat féministe soulignent la proximité du féminisme avec le socialisme ou l’espoir d’un avenir démocratique après la chute d’un régime dictatorial. Le terme « féministe » est revendiqué pour mobiliser les femmes autour d’une cause commune. L’humour et l’autodérision sont également présents dans le choix des noms des mouvements féministes, tout comme l’hommage aux générations précédentes de femmes militantes
Uncertainty Modeling of Wind Power Generation for Power System Planning and Stability Study
To reduce greenhouse gas emissions, higher penetration levels of renewable energy resources are added to existing power grids. Among them, wind energy resources are becoming a major source of electricity generation. However, wind energy production has a critical downside: intermittency. The intermittent nature of wind energy in combination with the load demand uncertainties, make it difficult to maintain power system stability and reliability. In addition, the uncertainty and variability of wind power generation (WPG) forces power utilities to retain higher levels of spinning reserves (SRs) to maintain power balance in the system. While necessary to ensure grid reliability, the utilization of those reserves often leads to an increase in operating costs of the power system.
To ensure the continuous operation of reliable and economically efficient power systems, system operators and planners need to study the impact of WPGs on bulk power systems and determine the best ways to manage their variability. Such studies require efficient and effective probabilistic models characterizing the variable nature of wind power. Therefore, this dissertation develops new methodologies for modeling the uncertainty and variability of WPG. The developed methods are combined with stability indices to form analytical tools for analyzing the impact of increased penetration of wind energy on power system steady-state stability. The case study results show that the developed methods simulate real-world wind power scenarios, which lead to an accurate assessment of the impact of wind generation uncertainty on power systems.
With large-scale adoption of renewable energy, a significant amount of conventional generation units could be replaced with wind energy resources. The best way to use the variable WPG and the remaining conventional generation resources, for continuous balance between load and generation, remains to be determined. Within this context, this dissertation investigates the problem of optimal substitution of conventional generation units by wind-powered generators, while considering the variability of WPG and the uncertainties of energy demand. The goal is to ensure that during unplanned wind power unavailability, the system has the ability to meet the load demand, and maintain steady acceptable voltage levels in the grid. A two-stage solution methodology is proposed to the problem in consideration. The first stage determines the best candidates, among conventional generator (CG) resources, for retirement and replacement by WPG resources. The best candidates for wind replacement are selected such that the adverse impacts of wind power intermittency on system stability and reliability are minimized. In the second stage, the expected amount of wind generation to be added at each retired CG bus is determined. The simulation results show that the developed method facilitates the integration of high wind energy with a reduced need for additional spinning reserves in the system
Cooling antihydrogen ions for the free-fall experiment GBAR
We discuss an experimental approach allowing to prepare antihydrogen atoms
for the GBAR experiment. We study the feasibility of all necessary experimental
steps: The capture of incoming ions at keV energies in a deep
linear RF trap, sympathetic cooling by laser cooled Be ions, transfer to a
miniaturized trap and Raman sideband cooling of an ion pair to the motional
ground state, and further reducing the momentum of the wavepacket by adiabatic
opening of the trap. For each step, we point out the experimental challenges
and discuss the efficiency and characteristic times, showing that capture and
cooling are possible within a few seconds.Comment: 10 pages, 5 figure
THE ''FORGOTTEN'' PROCESS : the emission stimulated by matter waves.
submitted in European Journal of PhysicsIn a famous paper where he introduces the A and B coefficients, Einstein considered that atomic decays of excited atoms can be stimulated by light waves. Here we consider that atomic decays can also be stimulated by atomic waves. It is however necessary to change the Maxwell-Boltzmann statistics of thermal equilibrium into Bose-Einstein statistics and to introduce a coefficient C which complements the list of the coefficients introduced by Einstein. Stimulated emission of light can be considered as the first step towards the laser. Similarly, stimulated production of matter waves can be considered as the basic phenomenon for an atom-laser. Most of the results that we obtain here are not new. However, the method that we use remains very close to elementary classical physics and emphasizes the symmetry between electromagnetic and matter waves from various points of view
3D tracking of laparoscopic instruments using statistical and geometric modeling
International audienceDuring a laparoscopic surgery, the endoscope can be manipulated by an assistant or a robot. Several teams have worked on the tracking of surgical instruments, based on methods ranging from the development of specific devices to image processing methods. We propose to exploit the instruments' insertion points, which are fixed on the patients abdominal cavity, as a geometric constraint for the localization of the instruments. A simple geometric model of a laparoscopic instrument is described, as well as a parametrization that exploits a spherical geometric grid, which offers attracting homogeneity and isotropy properties. The general architecture of our proposed approach is based on the probabilistic Condensation algorithm
Loess and palaeosols on the High Terrace at Sierentz (France), and implications for the chronology of terrace formation in the Upper Rhine Graben
Pedological investigations in combination with luminescence dating have been used to reconstruct the genesis and chronology of a sediment succession at Sierentz, France. The sequence comprises loess and palaeosols on top of gravel attributed to the High Terrace of River Rhine. According to the dating results, three phases of soil development occurred during different warm phases of Marine Isotope Stage (MIS) 7 (245-190ka). Soil development on top of the gravel occurred either during early MIS 7 or during an earlier warm phase, possibly MIS 9. The results imply a minimum age of 250ka for the formation of the High Terrace in this part of the Upper Rhine Graben, contrary to previous assumptions that correlated gravel sheet deposition with MIS 6 (ca. 150ka). These results and recent findings at other sites suggest that the chronological setting of terrace formation north of the Alps is much more complex than previously assume
HD139614: the interferometric case for a group-Ib pre-transitional young disk
The Herbig Ae star HD 139614 is a group-Ib object, which featureless SED
indicates disk flaring and a possible pre-transitional evolutionary stage. We
present mid- and near-IR interferometric results collected with MIDI, AMBER and
PIONIER with the aim of constraining the spatial structure of the 0.1-10 AU
disk region and assess its possible multi-component structure. A two-component
disk model composed of an optically thin 2-AU wide inner disk and an outer
temperature-gradient disk starting at 5.6 AU reproduces well the observations.
This is an additional argument to the idea that group-I HAeBe inner disks could
be already in the disk-clearing transient stage. HD 139614 will become a prime
target for mid-IR interferometric imaging with the second-generation instrument
MATISSE of the VLTI.Comment: SPIE Astronomical Telescopes and Instrumentation conference, June
2014, 11 pages, 7 Figure
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