3,887 research outputs found
A Simple Non-Markovian Computational Model of the Statistics of Soccer Leagues: Emergence and Scaling effects
We propose a novel algorithm that outputs the final standings of a soccer
league, based on a simple dynamics that mimics a soccer tournament. In our
model, a team is created with a defined potential(ability) which is updated
during the tournament according to the results of previous games. The updated
potential modifies a teams' future winning/losing probabilities. We show that
this evolutionary game is able to reproduce the statistical properties of final
standings of actual editions of the Brazilian tournament (Brasileir\~{a}o).
However, other leagues such as the Italian and the Spanish tournaments have
notoriously non-Gaussian traces and cannot be straightforwardly reproduced by
this evolutionary non-Markovian model. A complete understanding of these
phenomena deserves much more attention, but we suggest a simple explanation
based on data collected in Brazil: Here several teams were crowned champion in
previous editions corroborating that the champion typically emerges from random
fluctuations that partly preserves the gaussian traces during the tournament.
On the other hand, in the Italian and Spanish leagues only a few teams in
recent history have won their league tournaments. These leagues are based on
more robust and hierarchical structures established even before the beginning
of the tournament. For the sake of completeness, we also elaborate a totally
Gaussian model (which equalizes the winning, drawing, and losing probabilities)
and we show that the scores of the "Brasileir\~{a}o" cannot be reproduced. Such
aspects stress that evolutionary aspects are not superfluous in our modeling.
Finally, we analyse the distortions of our model in situations where a large
number of teams is considered, showing the existence of a transition from a
single to a double peaked histogram of the final classification scores. An
interesting scaling is presented for different sized tournaments.Comment: 18 pages, 9 figure
The Incidence of Lead Shot in Waterfowl of the Pacific Flyway, With Special Reference to the Great Salt Lake Basin
This study was conducted to determine basic data on the incidence of lead shot in ducks us ing the Great Salt Le.lee Basin. The study has been divided into two parts; (1) incidence of ducks carrying lead shot in their tissues and (2) incidenoe of ducks carrying ingested lead shot
Local Properties of the Potential Energy Landscape of a Model Glass: Understanding the Low Temperature Anomalies
Though the existence of two-level systems (TLS) is widely accepted to explain
low temperature anomalies in the sound absorption, heat capacity, thermal
conductivity and other quantities, an exact description of their microscopic
nature is still lacking. We performed computer simulations for a binary
Lennard-Jones system, using a newly developed algorithm to locate double-well
potentials (DWP) and thus two-level systems on a systematic basis. We show that
the intrinsic limitations of computer simulations like finite time and finite
size problems do not hamper this analysis. We discuss how the DWP are embedded
in the total potential energy landscape. It turns out that most DWP are
connected to the dynamics of the smaller particles and that these DWP are
rather localized. However, DWP related to the larger particles are more
collective
Loss of control in pattern-directed nucleation: a theoretical study
The properties of template-directed nucleation are studied close to the
transition where full nucleation control is lost and additional nucleation
occurs beyond the pre-patterned regions. First, kinetic Monte Carlo simulations
are performed to obtain information on a microscopic level. Here the
experimentally relevant cases of 1D stripe patterns and 2D square lattice
symmetry are considered. The nucleation properties in the transition region
depend in a complex way on the parameters of the system, i.e. the flux, the
surface diffusion constant, the geometric properties of the pattern and the
desorption rate. Second, the properties of the stationary concentration field
in the fully controlled case are studied to derive the remaining nucleation
probability and thus to characterize the loss of nucleation control. Using the
analytically accessible solution of a model system with purely radial symmetry,
some of the observed properties can be rationalized. A detailed comparison to
the Monte Carlo data is included
Non Markovian persistence in the diluted Ising model at criticality
We investigate global persistence properties for the non-equilibrium critical
dynamics of the randomly diluted Ising model. The disorder averaged persistence
probability of the global magnetization is found to decay
algebraically with an exponent that we compute analytically in a
dimensional expansion in . Corrections to Markov process are
found to occur already at one loop order and is thus a novel
exponent characterizing this disordered critical point. Our result is
thoroughly compared with Monte Carlo simulations in , which also include a
measurement of the initial slip exponent. Taking carefully into account
corrections to scaling, is found to be a universal exponent,
independent of the dilution factor along the critical line at , and
in good agreement with our one loop calculation.Comment: 7 pages, 4 figure
Origin of non-exponential relaxation in a crystalline ionic conductor: a multi-dimensional 109Ag NMR study
The origin of the non-exponential relaxation of silver ions in the
crystalline ion conductor Ag7P3S11 is analyzed by comparing appropriate
two-time and three-time 109Ag NMR correlation functions. The non-exponentiality
is due to a rate distribution, i.e., dynamic heterogeneities, rather than to an
intrinsic non-exponentiality. Thus, the data give no evidence for the relevance
of correlated back-and-forth jumps on the timescale of the silver relaxation.Comment: 4 pages, 3 figure
- …