9,649 research outputs found
Listening: Projects for the Self and Social Action
Listening is becoming more of a rarity in this increasingly busy world, especially between those who see a particular issue differently. The question, âBy conducting listening projects as trainers, what can we learn about ourselves and social action work?â is explored in this capstone paper to see how listening can benefit us both personally and professionally as trainers. Numerous articles, commentaries, and literature around listening, listening projects, and their meaning are examined in this paper.
Five different types of listening projects are explored through listening sessions: Oral histories, Oral artistries, âButton-pushingâ challenges, Single-issue testimonies, and Life stories. With the exception of âbutton-pushingâ challenges, which comes from the Training for Social Action (TSA) class, the types of listening projects come from Hugo Slimâs Listening for Change and were all studied during the TSA class. Building upon and deepening learnings from best practices and studies in TSA; themes for the listening sessions were determined by the authorâs own experiences which prompted this personal journey in listening to ten people, their lives, and their perspectives. For each type of project, two participants were selected. A total of ten participants were listened to: five who the inquirer previously knew and five who were strangers.
Best practices are determined for listening projects as a whole; best practices for individual types of projects, similarities, and differences are also suggested. Key learnings are shared about the act of listening, listening projects, the self, and how all of these concepts can enhance training. Further connections are made in how listening lands within the realm of social action. Both training practitioners and their work can benefit from slowing down and listening. As is found by both the author and the literature: â âListening is social action.
Recovering full coherence in a qubit by measuring half of its environment
When quantum systems interact with the environment they lose their quantum
properties, such as coherence. Quantum erasure makes it possible to restore
coherence in a system by measuring its environment, but accessing the whole of
it may be prohibitive: realistically one might have to concentrate only on an
accessible subspace and neglect the rest. If that is the case, how good is
quantum erasure? In this work we compute the largest coherence that we can expect to recover in a qubit, as a function of
the dimension of the accessible and of the inaccessible subspaces of its
environment. We then imagine the following game: we are given a uniformly
random pure state of qubits and we are asked to compute the largest
coherence that we can retrieve on one of them by optimally measuring a certain
number of the others. We find a surprising effect around the
value : the recoverable coherence sharply transitions between 0
and 1, indicating that in order to restore full coherence on a qubit we need
access to only half of its physical environment (or in terms of degrees of
freedom to just the square root of them). Moreover, we find that the
recoverable coherence becomes a typical property of the whole ensemble as
grows.Comment: 4 pages, 5 figure
Nonlinear coherent transport of waves in disordered media
We present a diagrammatic theory for coherent backscattering from disordered
dilute media in the nonlinear regime. The approach is non-perturbative in the
strength of the nonlinearity. We show that the coherent backscattering
enhancement factor is strongly affected by the nonlinearity, and corroborate
these results by numerical simulations. Our theory can be applied to several
physical scenarios like scattering of light in nonlinear Kerr media, or
propagation of matter waves in disordered potentials.Comment: 4 pages, 3 figure
Flutter suppression control law synthesis for the Active Flexible Wing model
The Active Flexible Wing Project is a collaborative effort between the NASA Langley Research Center and Rockwell International. The objectives are the validation of methodologies associated with mathematical modeling, flutter suppression control law development and digital implementation of the control system for application to flexible aircraft. A flutter suppression control law synthesis for this project is described. The state-space mathematical model used for the synthesis included ten flexible modes, four control surface modes and rational function approximation of the doublet-lattice unsteady aerodynamics. The design steps involved developing the full-order optimal control laws, reducing the order of the control law, and optimizing the reduced-order control law in both the continuous and the discrete domains to minimize stochastic response. System robustness was improved using singular value constraints. An 8th order robust control law was designed to increase the symmetric flutter dynamic pressure by 100 percent. Preliminary results are provided and experiences gained are discussed
Post Big Bang Processing of the Primordial Elements
We explore the Gnedin-Ostriker suggestion that a post-Big-Bang
photodissociation process may modify the primordial abundances of the light
elements. We consider several specific models and discuss the general features
that are necessary (but not necessarily sufficient) to make the model work. We
find that with any significant processing, the final D and He abundances,
which are independent of their initial standard big bang nucleosynthesis (SBBN)
values, rise quickly to a level several orders of magnitude above the
observationally inferred primordial values. Solutions for specific models show
that the only initial abundances that can be photoprocessed into agreement with
observations are those that undergo virtually no processing and are already in
agreement with observation. Thus it is unlikely that this model can work for
any non-trivial case unless an artificial density and/or photon distribution is
invoked.Comment: 12 page Latex file (AASTEX style). Tarred, gzipped, and uuencoded
postscript files of seven figures. Also available (with ps file of paper) at
ftp://www-physics.mps.ohio-state.edu/pub/nucex/phot
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