3,288 research outputs found
August Wilson’s The Piano Lesson and the Limits of Law
August Wilson’s The Piano Lesson features a debate between an African American brother and sister over the ownership of a richly symbolic piano, a family heirloom that represents the Charles family’s slave heritage and its endurance through Reconstruction. Ownership questions like the one presented in The Piano Lesson can usually be resolved in the courts, but Wilson’s play suggests that the law might be unable to resolve property disputes so problematically entangled with the legacy of slavery. Wilson offers, instead, a non-legal resolution to the piano debate presented in his play
Distribution functions for resonantly trapped orbits in the Galactic disc
The present-day response of a Galactic disc stellar population to a
non-axisymmetric perturbation of the potential has previously been computed
through perturbation theory within the phase-space coordinates of the
unperturbed axisymmetric system. Such an Eulerian linearized treatment however
leads to singularities at resonances, which prevent quantitative comparisons
with data. Here, we manage to capture the behaviour of the distribution
function (DF) at a resonance in a Lagrangian approach, by averaging the
Hamiltonian over fast angle variables and re-expressing the DF in terms of a
new set of canonical actions and angles variables valid in the resonant region.
We then follow the prescription of Binney (2016), assigning to the resonant DF
the time average along the orbits of the axisymmetric DF expressed in the new
set of actions and angles. This boils down to phase-mixing the DF in terms of
the new angles, such that the DF for trapped orbits only depends on the new set
of actions. This opens the way to quantitatively fitting the effects of the bar
and spirals to Gaia data in terms of distribution functions in action space.Comment: 8 pages, 7 figures, accepted for publication in MNRA
A Performer\u27s Guide to Dean Gronemeier\u27s Nature Alley
This document is a resource designed to aid performers in preparation of Dean Gronemeier’s Nature Alley, an advanced four-mallet solo for marimba. A biographical sketch of Dean Gronemeier, general overview of the composition, and the seven main themes of Nature Alley are presented within this document. Specific attention will be given to the musical and technical considerations associated with each of the seven themes
D-SLATS: Distributed Simultaneous Localization and Time Synchronization
Through the last decade, we have witnessed a surge of Internet of Things
(IoT) devices, and with that a greater need to choreograph their actions across
both time and space. Although these two problems, namely time synchronization
and localization, share many aspects in common, they are traditionally treated
separately or combined on centralized approaches that results in an ineffcient
use of resources, or in solutions that are not scalable in terms of the number
of IoT devices. Therefore, we propose D-SLATS, a framework comprised of three
different and independent algorithms to jointly solve time synchronization and
localization problems in a distributed fashion. The First two algorithms are
based mainly on the distributed Extended Kalman Filter (EKF) whereas the third
one uses optimization techniques. No fusion center is required, and the devices
only communicate with their neighbors. The proposed methods are evaluated on
custom Ultra-Wideband communication Testbed and a quadrotor, representing a
network of both static and mobile nodes. Our algorithms achieve up to three
microseconds time synchronization accuracy and 30 cm localization error
Optimization of Single-Sided Charge-Sharing Strip Detectors
Simulation of the charge sharing properties of single-sided CZT strip detectors with small anode pads are presented. The effect of initial event size, carrier repulsion, diffusion, drift, trapping and detrapping are considered. These simulations indicate that such a detector with a 150 µm pitch will provide good charge sharing between neighboring pads. This is supported by a comparison of simulations and measurements for a similar detector with a coarser pitch of 225 µm that could not provide sufficient sharing. The performance of such a detector used as a gamma-ray imager is discussed
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