22,395 research outputs found
Social interaction as a heuristic for combinatorial optimization problems
We investigate the performance of a variant of Axelrod's model for
dissemination of culture - the Adaptive Culture Heuristic (ACH) - on solving an
NP-Complete optimization problem, namely, the classification of binary input
patterns of size by a Boolean Binary Perceptron. In this heuristic,
agents, characterized by binary strings of length which represent possible
solutions to the optimization problem, are fixed at the sites of a square
lattice and interact with their nearest neighbors only. The interactions are
such that the agents' strings (or cultures) become more similar to the low-cost
strings of their neighbors resulting in the dissemination of these strings
across the lattice. Eventually the dynamics freezes into a homogeneous
absorbing configuration in which all agents exhibit identical solutions to the
optimization problem. We find through extensive simulations that the
probability of finding the optimal solution is a function of the reduced
variable so that the number of agents must increase with the fourth
power of the problem size, , to guarantee a fixed probability
of success. In this case, we find that the relaxation time to reach an
absorbing configuration scales with which can be interpreted as the
overall computational cost of the ACH to find an optimal set of weights for a
Boolean Binary Perceptron, given a fixed probability of success
On the size of the fibers of spectral maps induced by semialgebraic embeddings
Let be the ring of (continuous) semialgebraic functions on
a semialgebraic set and its subring
of bounded semialgebraic functions. In this work we compute the size of the
fibers of the spectral maps and induced by the
inclusion of a semialgebraic subset of .
The ring can be understood as the localization of at the multiplicative subset of those bounded
semialgebraic functions on with empty zero set. This provides a natural
inclusion that reduces both problems above to an analysis of
the fibers of the spectral map . If we denote , it holds that the restriction map
is a homeomorphism.
Our problem concentrates on the computation of the size of the fibers of at the points of . The size of the fibers of prime ideals
`close' to the complement provides valuable information
concerning how is immersed inside . If is dense in , the map
is surjective and the generic fiber of a prime ideal
contains infinitely many elements. However, finite fibers
may also appear and we provide a criterium to decide when the fiber is a finite set for .Comment: 33 pages, 3 figure
Strong statistical stability of non-uniformly expanding maps
We consider families of transformations in multidimensional Riemannian
manifolds with non-uniformly expanding behavior. We give sufficient conditions
for the continuous variation (in the -norm) of the densities of absolutely
continuous (with respect to the Lebesgue measure) invariant probability
measures for those transformations.Comment: 21 page
To Begin the World Over Again: A Reimagining of Millennial Expectations in Colonial America as Source to the Revolution
The study’s controlling question is to determine the extent millennialism as an intellectual movement informed the thinking of Colonial America. The evidence gathered suggests a kind of smorgasbord with no uniform thought. What can be deduced from the literature, however, is the fluidity of millennialism and its ability to adapt and contort to the political ideology of the era. Moreover, millennialism provided a sense of purpose for the American continent with the Great Awakening serving as the legitimizing movement which both popularized and diffused the millennium. From the 1750s, American millennialism began its evolution from a spiritual consummation of all things to a more politicized millennium, mirroring England. By the time of the Revolution, millennial themes, symbols, and language dominated the American continent far more than Whig ideology
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