4,320 research outputs found
Task allocation among multiple intelligent robots
Researchers describe the design of a decentralized mechanism for allocating assembly tasks in a multiple robot assembly workstation. Currently, the approach focuses on distributed allocation to explore its feasibility and its potential for adaptability to changing circumstances, rather than for optimizing throughput. Individual greedy robots make their own local allocation decisions using both dynamic allocation policies which propagate through a network of allocation goals, and local static and dynamic constraints describing which robots are elibible for which assembly tasks. Global coherence is achieved by proper weighting of allocation pressures propagating through the assembly plan. Deadlock avoidance and synchronization is achieved using periodic reassessments of local allocation decisions, ageing of allocation goals, and short-term allocation locks on goals
The Goldberger -- Treiman Relation, and at
The Goldberger-Treiman relation is shown to persist in the chiral limit at
finite temperatures to order . The dependence of turns out to
be the same as for , , while is temperature independent to this order. The baryon octet and
couplings also behave as if only pions are massless in the
pseudoscalar meson octet.Comment: 7p, NSF-ITP-93-145, BUTP-93/27, PUTP-1433, November 199
Impact for Agents
Impact for agents. Most of the agent research community has been predicting greater impact for years and many of us have been working to help the process along. Yet the tremendous growth on the research front has not been met with
Non-Perturbative Study of the Light Pseudoscalar Masses in Chiral Dynamics
We perform a non-perturbative chiral study of the masses of the lightest
pseudoscalar mesons. In the calculation of the self-energies we employ the
S-wave meson-meson amplitudes taken from Unitary Chiral Perturbation Theory
(UCHPT) that include the lightest nonet of scalar resonances. Values for the
bare masses of pions and kaons are obtained, as well as an estimate of the mass
of the \eta_8. The former are found to dominate the physical pseudoscalar
masses. We then match to the self-energies from Chiral Perturbation Theory
(CHPT) to O(p^4), and a robust relation between several O(p^4) CHPT
counterterms is obtained. We also resum higher orders from our calculated
self-energies. By taking into account values determined from previous chiral
phenomenological studies of m_s/\hat{m} and 3L_7+L^r_8, we determine a tighter
region of favoured values for the O(p^4) CHPT counterterms 2L^r_6-L^r_4 and
2L^r_8-L^r_5. This determination perfectly overlaps with the recent
determinations to O(p^6) in CHPT. We warn about a likely reduction in the value
of m_s/\hat{m} by higher loop diagrams and that this is not systematically
accounted for by present lattice extrapolations. We also provide a favoured
interval of values for m_s/\hat{m} and 3L_7+L^r_8.Comment: 26 pages, 9 figures. Original new material is included. Major
rewriting when comparing with lattice QC
Using click-evoked auditory brainstem response waveforms to measure hearing Loss in the bottlenose dolphin (Tursiops truncatus)
Developing an improved methodology for efficient and informative hearing assessment in marine mammals would prove insightful in expanding current knowledge regarding marine mammal hearing sensitivity, particularly in studying the effects of anthropogenic noise. This study examines the click-evoked auditory brainstem response in relation to upper frequency limit of hearing in the bottlenose dolphin (Tursiops truncatus) as a proxy for hearing capacity
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Internet Monitor 2014: Reflections on the Digital World: Platforms, Policy, Privacy, and Public Discourse
This publication is the second annual report of the Internet Monitor project at the Berkman Centerfor Internet & Society at Harvard University. As with the inaugural report, this year’s edition is a collaborative effort of the extended Berkman community. Internet Monitor 2014: Reflections on the Digital World includes nearly three dozen contributions from friends and colleagues around the world that highlight and discuss some of the most compelling events and trends in the digitally networked environment over the past year.
The result, intended for a general interest audience, brings together reflection and analysis on a broad range of issues and regions — from an examination of Europe’s “right to be forgotten” to a review of the current state of mobile security to an exploration of a new wave of movements attempting to counter hate speech online — and offers it up for debate and discussion. Our goal remains not to provide a definitive assessment of the “state of the Internet” but rather to provide a rich compendium of commentary on the year’s developments with respect to the online space.
Last year’s report examined the dynamics of Internet controls and online activity through the actions of government, corporations, and civil society. We focus this year on the interplay between technological platforms and policy; growing tensions between protecting personal privacy and using big data for social good; the implications of digital communications tools for public discourse and collective action; and current debates around the future of Internet governance.
The report reflects the diversity of ideas and input the Internet Monitor project seeks to invite. Some of the contributions are descriptive; others prescriptive. Some contain purely factual observations; others offer personal opinion. In addition to those in traditional essay format, contributions this year include a speculative fiction story exploring what our increasingly data-driven world might bring, a selection of “visual thinking” illustrations that accompany a number of essays, a “Year in Review” timeline that highlights many of the year’s most fascinating Internet-related news stories (and an interactive version of which is available at the netmonitor.org), and a slightly tongue-in-cheek “By the Numbers” section that offers a look at the year’s important digital statistics. We believe that each contribution offers insights, and hope they provoke further reflection, conversation, and debate in both offline and online settings around the globe
Error estimates for pi-pi scattering threshold parameters in Chiral Perturbation Theory to two loops
Using the analysis of ChPT to two loops, we perform an error analysis of the
threshold and low energy parameters, based on the uncertainties for the one
loop low energy parameters and the resonance saturation mechanism. Different
sets of one loop low energy constants have been considered.Thus, the predictive
power of the effective field theory is quantified on the basis of the present
experimental uncertainties.Comment: 12 pages, 2 tables, 3 figures. Numerics upgraded to v2 of ref.(8).
New reference added. Typos corrected. New figure for SU(3) parameters
include
Chiral two-loop pion-pion scattering parameters from crossing-symmetric constraints
Constraints on the parameters in the one- and two-loop pion-pion scattering
amplitudes of standard chiral perturbation theory are obtained from explicitly
crossing-symmetric sum rules. These constraints are based on a matching of the
chiral amplitudes and the physical amplitudes at the symmetry point of the
Mandelstam plane. The integrals over absorptive parts appearing in the sum
rules are decomposed into crossing-symmetric low- and high-energy components
and the chiral parameters are finally related to high-energy absorptive parts.
A first application uses a simple model of these absorptive parts. The
sensitivity of the results to the choice of the energy separating high and low
energies is examined with care. Weak dependence on this energy is obtained as
long as it stays below ~560 MeV. Reliable predictions are obtained for three
two-loop parameters.Comment: 23 pages, 4 figures in .eps files, Latex (RevTex), our version of
RevTex runs under Latex2.09, submitted to Phys. Rev. D,minor typographical
corrections including the number at the end of the abstract, two sentences
added at the end of Section 5 in answer to a referee's remar
Factors associated with appropriate inhaler use in patients with COPD - lessons from the REAL survey
The authors thank Clarice Field (PhD) and Paul McKiernan (PhD) of Novartis for providing medical writing support, which was funded by Novartis AG, Basel, Switzerland, in accordance with Good Publication Practice (GPP3) guidelines (http://www.ismpp.org/gpp3). Pankaj Goyal and Joao Mendes, Novartis Pharma AG, Basel, contributed to the design and conceptualization of study. The survey was designed by PDD, London, United Kingdom, and GfK Switzerland AG, Basel, Switzerland. The survey was conducted by GfK Switzerland AG, Basel, Switzerland, and sponsored by Novartis Pharma AG, Basel, Switzerland.Peer reviewedPublisher PD
Chiral Perturbation Theory for the Quenched Approximation of QCD
[This version is a minor revision of a previously submitted preprint. Only
references have been changed.] We describe a technique for constructing the
effective chiral theory for quenched QCD. The effective theory which results is
a lagrangian one, with a graded symmetry group which mixes Goldstone bosons and
fermions, and with a definite (though slightly peculiar) set of Feynman rules.
The straightforward application of these rules gives automatic cancellation of
diagrams which would arise from virtual quark loops. The techniques are used to
calculate chiral logarithms in , , , and the ratio of
to . The leading
finite-volume corrections to these quantities are also computed. Problems for
future study are described.Comment: 14 page
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