24,356 research outputs found
Program for standard statistical distributions
Development of procedure to describe frequency distributions involved in statistical theory is discussed. Representation of frequency distributions by first order differential equation is presented. Classification of various types of distributions based on Pearson parameters is analyzed
Estimating statistical distributions using an integral identity
We present an identity for an unbiased estimate of a general statistical
distribution. The identity computes the distribution density from dividing a
histogram sum over a local window by a correction factor from a mean-force
integral, and the mean force can be evaluated as a configuration average. We
show that the optimal window size is roughly the inverse of the local
mean-force fluctuation. The new identity offers a more robust and precise
estimate than a previous one by Adib and Jarzynski [J. Chem. Phys. 122, 014114,
(2005)]. It also allows a straightforward generalization to an arbitrary
ensemble and a joint distribution of multiple variables. Particularly we derive
a mean-force enhanced version of the weighted histogram analysis method (WHAM).
The method can be used to improve distributions computed from molecular
simulations. We illustrate the use in computing a potential energy
distribution, a volume distribution in a constant-pressure ensemble, a radial
distribution function and a joint distribution of amino acid backbone dihedral
angles.Comment: 45 pages, 7 figures, simplified derivation, a more general mean-force
formula, add discussions to the window size, add extensions to WHAM, and 2d
distribution
Generating statistical distributions without maximizing the entropy
We show here how to use pieces of thermodynamics' first law to generate
probability distributions for generalized ensembles when only level-population
changes are involved. Such microstate occupation modifications, if properly
constrained via first law ingredients, can be associated not exclusively to
heat and acquire a more general meaning.Comment: 6 pages, no figures, Conferenc
Equilibrium, Adverse Selection, and Statistical Distributions
This paper addresses the problem of multiple equilibria in markets with adverse selection. Akerlof (1970) identified an unique equilibrium of the total market failure under adverse selection. Posterioly, Wilson (1979, 1980) argued that the presence of adverse selection may lead to multiple equilibria. In particular, this paper extends the work of Rose (1993), who stated that the existence of multiple equilibria depends on the distribution of quality. Rose found that multiple equilibria are highly unlikely for most standard probability distributions. This work considers additional statistical distributions for quality. The simulation results suggest the existence of multiple equilibria when the quality follows a beta normal distribution.Adverse Selection; Multiple Equilibria; Statistical Distributions; Akerlof-Wilson Model.
Statistical distributions in the folding of elastic structures
The behaviour of elastic structures undergoing large deformations is the
result of the competition between confining conditions, self-avoidance and
elasticity. This combination of multiple phenomena creates a geometrical
frustration that leads to complex fold patterns. By studying the case of a rod
confined isotropically into a disk, we show that the emergence of the
complexity is associated with a well defined underlying statistical measure
that determines the energy distribution of sub-elements,``branches'', of the
rod. This result suggests that branches act as the ``microscopic'' degrees of
freedom laying the foundations for a statistical mechanical theory of this
athermal and amorphous system
Power-Law tailed statistical distributions and Lorentz transformations
The present Letter, deals with the statistical theory [Phys. Rev. E {\bf 66},
056125 (2002) and Phys. Rev E {\bf 72}, 036108 (2005)], which predicts the
probability distribution , where, , is the collision invariant, and
, with
. This, experimentally observed distribution, at low energies
behaves as the Maxwell-Boltzmann exponential distribution, while at high
energies presents power law tails. Here we show that the function
and its inverse , can be obtained within
the one-particle relativistic dynamics, in a very simple and transparent way,
without invoking any extra principle or assumption, starting directly from the
Lorentz transformations. The achievements support the idea that the power law
tailed distributions are enforced by the Lorentz relativistic microscopic
dynamics, like in the case of the exponential distribution which follows from
the Newton classical microscopic dynamics
Encryption of Covert Information into Multiple Statistical Distributions
A novel strategy to encrypt covert information (code) via unitary projections
into the null spaces of ill-conditioned eigenstructures of multiple host
statistical distributions, inferred from incomplete constraints, is presented.
The host pdf's are inferred using the maximum entropy principle. The projection
of the covert information is dependent upon the pdf's of the host statistical
distributions. The security of the encryption/decryption strategy is based on
the extreme instability of the encoding process. A self-consistent procedure to
derive keys for both symmetric and asymmetric cryptography is presented. The
advantages of using a multiple pdf model to achieve encryption of covert
information are briefly highlighted. Numerical simulations exemplify the
efficacy of the model.Comment: 18 pages, 4 figures. Three sentences expanded to emphasize detail.
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