503,912 research outputs found
Estimating Functions of Probability Distributions from a Finite Set of Samples, Part 1: Bayes Estimators and the Shannon Entropy
We present estimators for entropy and other functions of a discrete
probability distribution when the data is a finite sample drawn from that
probability distribution. In particular, for the case when the probability
distribution is a joint distribution, we present finite sample estimators for
the mutual information, covariance, and chi-squared functions of that
probability distribution.Comment: uuencoded compressed tarfile, submitte
Generating Opportunity from Uncertainty
Learning to deal with uncertainty makes organizations more robust. Leaders can take steps to help their organizations take advantage uncertainty. When continued success transitions from informed decision to luck, small differences in the ability of organizations to handle uncertainty can have a large impact. An example from military history is used to outline current day lessons for military and business leaders
Compactifications of moduli spaces inspired by mirror symmetry
We study moduli spaces of nonlinear sigma-models on Calabi-Yau manifolds,
using the one-loop semiclassical approximation. The data being parameterized
includes a choice of complex structure on the manifold, as well as some ``extra
structure'' described by means of classes in H^2. The expectation that this
moduli space is well-behaved in these ``extra structure'' directions leads us
to formulate a simple and compelling conjecture about the action of the
automorphism group on the K\"ahler cone. If true, it allows one to apply
Looijenga's ``semi-toric'' technique to construct a partial compactification of
the moduli space. We explore the implications which this construction has
concerning the properties of the moduli space of complex structures on a
``mirror partner'' of the original Calabi-Yau manifold. We also discuss how a
similarity which might have been noticed between certain work of Mumford and of
Mori from the 1970's produces (with hindsight) evidence for mirror symmetry
which was available in 1979. [The author is willing to mail hardcopy preprints
upon request.]Comment: 25 pp., LaTeX 2.09 with AmS-Font
The American Aircraft Industrial Base: On the Brink
An article reviewing the decline in the American aircraft industrial base
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