18,728 research outputs found
About the Power to Enforce and Prevent Consensus by Manipulating Communication Rules
We explore the possibilities of enforcing and preventing consensus in
continuous opinion dynamics that result from modifications in the communication
rules. We refer to the model of Weisbuch and Deffuant, where agents adjust
their continuous opinions as a result of random pairwise encounters whenever
their opinions differ not more than a given bound of confidence \eps. A high
\eps leads to consensus, while a lower \eps leads to a fragmentation into
several opinion clusters. We drop the random encounter assumption and ask: How
small may \eps be such that consensus is still possible with a certain
communication plan for the entire group? Mathematical analysis shows that
\eps may be significantly smaller than in the random pairwise case. On the
other hand we ask: How large may \eps be such that preventing consensus is
still possible? In answering this question we prove Fortunato's simulation
result that consensus cannot be prevented for \eps>0.5 for large groups. %
Next we consider opinion dynamics under different individual strategies and
examine their power to increase the chances of consensus. One result is that
balancing agents increase chances of consensus, especially if the agents are
cautious in adapting their opinions. However, curious agents increase chances
of consensus only if those agents are not cautious in adapting their opinions.Comment: 21 pages, 6 figure
Short range miniaturized biotelemetry system
A biotelemetry system for measuring and transmitting EKG, EMG, and EEG data by an RF link to a receiver was designed, developed, and delivered. The system is battery operated with the batteries and transmitting electronics an integral part of the electrode sensors. The low frequency response of 0.05 Hz assures faithful reproduction of detailed EKG and all measurements are made by the utilization of two electrode sensors
String theory on and the symmetric orbifold of Liouville theory
For string theory on AdS with pure NS-NS flux a complete set of DDF
operators is constructed, from which one can read off the symmetry algebra of
the spacetime CFT. Together with an analysis of the spacetime spectrum, this
allows us to show that the CFT dual of superstring theory on for generic NS-NS flux is the symmetric
orbifold of Liouville theory. For the case
of minimal flux (), the Liouville factor disappears, and we just obtain
the symmetric orbifold of , thereby giving further support to a
previous claim. We also show that a similar analysis can be done for bosonic
string theory on .Comment: 33+10 page
Strings on
String theory on with pure NS-NS flux and minimal flux through one of the two 's is studied from a world-sheet perspective. It is shown that the
spacetime spectrum, as well as the algebra of spectrum generating operators,
matches precisely that of the symmetric orbifold of in the large limit. This gives strong support for the
proposal that these two descriptions are exactly dual to one another.Comment: 25+23 page
Survey and Experimental Testing of Nongravimetric Mass Measurement Devices
Documentation presented describes the design, testing, and evaluation of an accelerated gravimetric balance, a low mass air bearing oscillator of the spring-mass type, and a centrifugal device for liquid mass measurement. A direct mass readout method was developed to replace the oscillation period readout method which required manual calculations to determine mass. A protoype 25 gram capacity micro mass measurement device was developed and tested
The Worldsheet Dual of the Symmetric Product CFT
Superstring theory on with
the smallest amount of NS-NS flux (`') is shown to be dual to the
spacetime CFT given by the large limit of the free symmetric product
orbifold . To define the worldsheet theory at
, we employ the hybrid formalism in which the part is described by the WZW model (which is
well defined). Unlike the case for , it turns out that the string
spectrum at does {\it not} exhibit the long string continuum, and
perfectly matches with the large limit of the symmetric product. We also
demonstrate that the fusion rules of the symmetric orbifold are reproduced from
the worldsheet perspective. Our proposal therefore affords a tractable
worldsheet description of a tensionless limit in string theory, for which the
dual CFT is also explicitly known.Comment: 29+24 page
Higher spin algebras and large holography
A new family of higher spin algebras that arises upon restricting matrix
extensions of is found. We identify coset CFTs
realising these symmetry algebras, and thus propose new higher spin-CFT dual
pairs. These higher spin theories arise naturally as a subsector of string
theory on for
specific ratios of the radii of the two spheres.Comment: 22 page
A holographic dual for string theory on
The CFT dual of string theory on is conjectured to be the symmetric orbifold
of the theory, provided that one of the two
quantum numbers is a multiple of the other. We determine the BPS spectrum of
the symmetric orbifold in detail, and show that it reproduces precisely the BPS
spectrum that was recently calculated in supergravity. We also determine the
BPS spectrum of the world-sheet theory that is formulated in terms of WZW
models, and show that, apart from some gaps (which are reminiscent of those
that appear in the corresponding calculation), it also
reproduces this BPS spectrum. In fact, the matching seems to work as well as
for the familiar case, and thus our results give strong support
for this proposal.Comment: 41 pages, 2 figure
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