2,343 research outputs found
Delayed information flow effect in economy systems. An ACP model study
Applying any strategy requires some knowledge about the past state of the
system. Unfortunately in the case of economy collecting information is a
difficult, expensive and time consuming process. Therefore the information
about the system is known at the end of some well defined intervals, e. g.
company reports, inflation data, GDP etc. They describe a (market) situation in
the past. The time delay is specific to the market branch. It can be very short
(e.g. stock market offer is updated every minute or so and this information is
immediately available) or long, like months in the case of agricultural market,
when the decisions are taken based on the results from the previous harvest.
The analysis of the information flow delay can be based on the ACP model of
spatial evolution of economic systems. The entities can move on a square
lattice and when meeting take one of the two following decisions: merge or
create a new entity. The decision is based on the system state, which is known
with some time delay. The effect of system's feedback is investigated. We
consider the case of company distribution evolution in a heterogenous field.
The information flow time delay implies different final states, including
cycles.Comment: Presented at APFA
Electrical and thermal transport properties in high T_c superconductors : effects of a magnetic field
Experimental studies of the electric and heat currents in the normal,
superconducting and mixed states of high T superconductors (HTcS) lead to
characterization, complementary to data obtained from equilibrium property
based techniques. A magnetic field superimposed on the superconducting sample
generates {\it magneto-transport phenomena}, from which an excess electrical
resistivity, an excess thermoelectric power, the Hall or the Nernst effect.
Different behavioral effects allow one to distinguish various dissipation
mechanisms, like quasi particle scattering, vortex motion dissipation and
superconductivity fluctuations, in particular when the Corbino geometry is
used. Moreover bulk measurements of the thermal conductivity and the
electrothermal conductivity in a magnetic field give us sure indications of the
order parameter symmetry. The location of the mixed state phase transition
lines in the technological phase diagram of HTcS are briefly pointed out
through precise measurements performed over broad temperature and magnetic
field ranges. The results are mainly reviewed with the aim of defining further
investigation lines.Comment: 9 pages, no figures; to appear in Physica
Influence of information flow in the formation of economic cycles
A microscopic approach to macroeconomic features is intended. A model for
macroeconomic behavior based on the Ausloos-Clippe-Pekalski model is built and
investigated. The influence of a discrete time information transfer is
investigated. The formation of economic cycles is observed as a function of the
time of information delay. Three regions of delay time are recognized: short
(IS - iteration steps) - the system evolves toward a
unique stable equilibrium state, medium or , the
system undergoes oscillations: stable concentration cycles appear in the
system. For long information flow delay times, , the systems may
crash for most initial concentrations. However, even in the case of long delay
time the crash time may be long enough to allow observation of the system
evolution and to introduce an appropriate strategy in order to avoid the
collapse of the e.g. company concentration. In the long time delay it is also
possible to observe an "economy resonance" where despite a long delay time the
system evolves for a long time or can even reach a stable state, which insures
its existence.Comment: 18 pages,16 figures, to be published in Verhulst 200 Proceedings, M.
Ausloos and M. Dirickx, Eds. (in press
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