1,261 research outputs found
Energy Efficient Actuation with Variable Stiffness Actuators
Research effort in the field of variable stiffness actuators is steadily increasing, due to their wide range of possible applications and their advantages. In literature, var- ious control methods have been proposed, solving particular problems in human-robot and robot-environment interaction applications, in which the mechanical compliance introduced by variable stiffness actuators has been shown to be beneficial. In this work, we focus on achieving energy efficient actuation of robotic systems using variable stiffness actuators. In particular, we aim to exploit the energy storing properties of the internal elastic elements
Photon pair production at flavour factories with per mille accuracy
We present a high-precision QED calculation, with 0.1% theoretical accuracy,
of two photon production in annihilation, as required by more and
more accurate luminosity monitoring at flavour factories. The accuracy of the
approach, which is based on the matching of exact next-to-leading order
corrections with a QED Parton Shower algorithm, is demonstrated through a
detailed analysis of the impact of the various sources of radiative corrections
to the experimentally relevant observables. The calculation is implemented in
the latest version of the event generator BabaYaga, available for precision
simulations of photon pair production at colliders of moderately high
energies.Comment: 11 pages, 5 figures, 1 tabl
Human-like Walking with Compliant Legs
This work presents a novel approach to robotic bipedal walking. Based on the bipedal spring-mass model, which is known to closely describe human-like walking behavior, a robot has been designed that approaches the ideal model as closely as possible. The compliance of the springs is controllable by means of variable stiffness actuators. The controllable stiffness allows the gait to be stabilized against external disturbances
Multi-photon corrections to W boson mass determination at hadron colliders
The impact of higher-order final-state photonic corrections on the precise
determination of the W-boson mass at the Tevatron and LHC colliders is
evaluated. The W-mass shift from a fit to the transverse mass distribution is
found to be about 10 MeV in the W --> mu nu channel and a few MeV in the W -->
e nu channel. The calculation, which is implemented in the Monte Carlo event
generator HORACE for data analysis, can contribute to reduce the uncertainty
associated to the W mass measurement at present and future hadron collider
experiments.Comment: 3 pages, 2 figures, to appear in the proceedings of International
Europhysics Conference on High-Energy Physics (EPS 2003), Aachen, Germany,
17-23 Jul 200
A new approach to evaluate the leading hadronic corrections to the muon g-2
We propose a novel approach to determine the leading hadronic corrections to
the muon g-2. It consists in a measurement of the effective electromagnetic
coupling in the space-like region extracted from Bhabha scattering data. We
argue that this new method may become feasible at flavor factories, resulting
in an alternative determination potentially competitive with the accuracy of
the present results obtained with the dispersive approach via time-like data.Comment: 7 pages, 3 figures. Version accepted for publication in Phys. Lett.
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