2,542,513 research outputs found
Statistical Features for Image Retrieval: A Quantitative Comparison
In this paper we present a comparison between various statistical descriptors and analyze their goodness in
classifying textural images. The chosen statistical descriptors have been proposed by Tamura, Battiato and
Haralick. In this work we also test a combination of the three descriptors for texture analysis. The databases
used in our study are the well-known Brodatz’s album and DDSM(Heath et al., 1998). The computed features
are classified using the Naive Bayes, the RBF, the KNN, the Random Forest and Random Tree models. The
results obtained from this study show that we can achieve a high classification accuracy if the descriptors are
used all together
Quantum features in statistical observations of "timeless" classical systems
We pursue the view that quantum theory may be an emergent structure related
to large space-time scales. In particular, we consider classical Hamiltonian
systems in which the intrinsic proper time evolution parameter is related
through a probability distribution to the discrete physical time. This is
motivated by studies of ``timeless'' reparametrization invariant models, where
discrete physical time has recently been constructed based on coarse-graining
local observables. Describing such deterministic classical systems with the
help of path-integrals, primordial states can naturally be introduced which
follow unitary quantum mechanical evolution in suitable limits.Comment: 7 pages. Invited talk at Int. Workshop Trends and Perspectives on
Extensive and Non-Extensive Statistical Mechanics, Angra dos Reis (Brazil),
Nov. 2003. To appear in Physica
Nonextensive statistical features of the Polish stock market fluctuations
The statistics of return distributions on various time scales constitutes one
of the most informative characteristics of the financial dynamics. Here we
present a systematic study of such characteristics for the Polish stock market
index WIG20 over the period 04.01.1999 - 31.10.2005 for the time lags ranging
from one minute up to one hour. This market is commonly classified as emerging.
Still on the shortest time scales studied we find that the tails of the return
distributions are consistent with the inverse cubic power-law, as identified
previously for majority of the mature markets. Within the time scales studied a
quick and considerable departure from this law towards a Gaussian can however
be traced. Interestingly, all the forms of the distributions observed can be
comprised by the single -Gaussians which provide a satisfactory and at the
same time compact representation of the distribution of return fluctuations
over all magnitudes of their variation. The corresponding nonextensivity
parameter is found to systematically decrease when increasing the time
scales.Comment: 14 pages. Physica A in prin
INCORPORATION OF QUANTUM STATISTICAL FEATURES IN MOLECULAR DYNAMICS
We formulate a method for incorporating quantum fluctuations into molecular-
dynamics simulations of many-body systems, such as those employed for energetic
nuclear collision processes. Based on Fermi's Golden Rule, we allow spontaneous
transitions to occur between the wave packets which are not energy eigenstates.
The ensuing diffusive evolution in the space of the wave packet parameters
exhibits appealing physical properties, including relaxation towards quantum-
statistical equilibrium.Comment: 8 latex pages + 1 uuencoded ps figur
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