19 research outputs found
Winning strategies in congested traffic
One-directional traffic on two-lanes is modeled in the framework of a
spring-block type model. A fraction of the cars are allowed to change
lanes, following simple dynamical rules, while the other cars keep their
initial lane. The advance of cars, starting from equivalent positions and
following the two driving strategies is studied and compared. As a function of
the parameter the winning probability and the average gain in the
advancement for the lane-changing strategy is computed. An interesting
phase-transition like behavior is revealed and conclusions are drawn regarding
the conditions when the lane changing strategy is the better option for the
drivers.Comment: 5 pages, 5 figure
Spring-block model for a single-lane highway traffic
A simple one-dimensional spring-block chain with asymmetric interactions is
considered to model an idealized single-lane highway traffic. The main elements
of the system are blocks (modeling cars), springs with unidirectional
interactions (modeling distance keeping interactions between neighbors), static
and kinetic friction (modeling inertia of drivers and cars) and spatiotemporal
disorder in the values of these friction forces (modeling differences in the
driving attitudes). The traveling chain of cars correspond to the dragged
spring-block system. Our statistical analysis for the spring-block chain
predicts a non-trivial and rich complex behavior. As a function of the disorder
level in the system a dynamic phase-transition is observed. For low disorder
levels uncorrelated slidings of blocks are revealed while for high disorder
levels correlated avalanches dominates.Comment: 6 pages, 7 figure
Impact parameter method calculations for fully differential ionization cross sections
In this work our previous fully differential ionization cross section
calculations using the semiclassical, impact parameter method are improved by a
new method suitable to calculate impact parameter values corresponding to
different momentum transfers. This goal is achieved by two successive steps.
First, using the transverse momentum balance different projectile scattering
angles are calculated for the binary and recoil peak regions as a function of
the transferred momentum. Then, by treating the projectile scattering as a
classical potential scattering problem, impact parameters are assigned to these
scattering angles. The new method, which no longer contains empirical
considerations, is tested calculating by fully differential ionization cross
sections for single ionization of helium produced by fast C ions.Comment: 4 pages, 3 figure
Semiclassical model for calculating fully differential ionization cross sections of the H molecule
Fully differential cross sections are calculated for the ionization of H
by fast charged projectiles using a semiclassical model developed previously
for the ionization of atoms. The method is tested in case of 4 keV electron and
6 MeV proton projectiles. The obtained results show good agreement with the
available experimental data. Interference effects due to the two-center
character of the target are also observed and analyzed.Comment: 11 pages, 4 figure
Shake-induced order in nanosphere systems
Self-assembled patterns obtained from a drying nanosphere suspension are
investigated by computer simulations and simple experiments. Motivated by the
earlier experimental results of Sasaki and Hane and Schope, we confirm that
more ordered triangular lattice structures can be obtained whenever a moderate
intensity random shaking is applied on the drying system. Computer simulations
are realized on an improved version of a recently elaborated
Burridge-Knopoff-type model. Experiments are made following the setup of Sasaki
and Hane, using ultrasonic radiation as source for controlled shaking.Comment: 7 pages, 10 figure
Ionization-excitation of lithium by fast charged projectiles
Abstract Cross sections for the double K-shell vacancy production of lithium atoms in collision with fast charged projectiles are calculated. For these ionizationexcitation processes, the relative importance of the different first-and secondorder mechanisms and the dependence of the cross sections on the sign of projectile charge are investigated. Our studies confirm the strong influence of electron-electron correlations on the behaviour of the cross sections. The obtained results are in reasonable agreement with the data as observed in recent experiments
Semiclassical description of the kinematically complete experiments
Based on the semiclassical, impact parameter method a theoretical model is
constructed to calculate totally differential cross sections for single
ionization of helium by impact with fast C ions. Good agreement with the
experiment is achieved in the scattering plane, while in the perpendicular
plane a similar structure to that observed experimentally is obtained. The
contribution of different partial waves to the cross section is also
investigated.Comment: 9 pages, 6 figure
Spring-Block Model Reveals Region-Like Structures
A mechanical spring-block model is used for realizing an objective space partition of settlements from a geographic territory in region-like structures. The method is based on the relaxation-dynamics of the spring-block system and reveals in a hierarchical manner region-like entities at different spatial scales. It takes into account in an elegant manner both the spatiality of the elements and the connectivity relations among them. Spatiality is taken into account by using the geographic coordinates of the settlements, and by detecting the neighbors with the help of a Delaunay triangulation. Connectivity between neighboring settlements are quantified using a Pearson-like correlation for the relative variation of a relevant socio-economic parameter (population size, GDP, tax payed per inhabitant, etc.). The method is implemented in an interactive JAVA application and it is applied with success for an artificially generated society and for the case of USA, Hungary and Transylvania
Remarks on the Cauchy functional equation and variations of it
This paper examines various aspects related to the Cauchy functional equation
, a fundamental equation in the theory of functional
equations. In particular, it considers its solvability and its stability
relative to subsets of multi-dimensional Euclidean spaces and tori. Several new
types of regularity conditions are introduced, such as a one in which a complex
exponent of the unknown function is locally measurable. An initial value
approach to analyzing this equation is considered too and it yields a few
by-products, such as the existence of a non-constant real function having an
uncountable set of periods which are linearly independent over the rationals.
The analysis is extended to related equations such as the Jensen equation, the
multiplicative Cauchy equation, and the Pexider equation. The paper also
includes a rather comprehensive survey of the history of the Cauchy equation.Comment: To appear in Aequationes Mathematicae (important remark: the
acknowledgments section in the official paper exists, but it appears before
the appendix and not before the references as in the arXiv version);
correction of a minor inaccuracy in Lemma 3.2 and the initial value proof of
Theorem 2.1; a few small improvements in various sections; added thank