156 research outputs found
Wealth, income, earnings and the statistical mechanics of flow systems
This paper looks at empirical data from economics regarding wealth, earnings and income, alongside a
flow model for an economy based on the general Lotka-Volterra models of Levy & Solomon. The data and modelling suggest that a simple economic system might provide a tractable model for giving an exact statistical mechanical solution for an 'out of equilibrium' flow model. This might also include an exact mathematical definition of a 'dissipative structure' derived from maximum entropy
considerations. This paper is primarily a qualitative discussion of how such a mathematical proof might be achieved
Wealth, income, earnings and the statistical mechanics of flow systems
This paper looks at empirical data from economics regarding wealth, earnings and income, alongside a flow model for an economy based on the general Lotka-Volterra models of Levy & Solomon. The data and modelling suggest that a simple economic system might provide a tractable model for giving an exact statistical mechanical solution for an 'out of equilibrium' flow model. This might also include an exact mathematical definition of a 'dissipative structure' derived from maximum entropy considerations. This paper is primarily a qualitative discussion of how such a mathematical proof might be achieved.wealth; earnings; income; entropy; lotka; volterra; dissipative
Modeling complex ecological economic systems: toward an evolutionary, dynamic understanding of people and nature
Recent understanding about system dynamics and predictability that has emerged from the study of complex systems is creating new tools for modeling interactions between anthropogenic and natural systems. A range of techniques has become available through advances in computer speed and accessibility and by implementing a broad, interdisciplinary systems view
The Use of Non-Parametric Criteria for the Evaluation of Similar Patterns in the Behaviour of the Economic System
The statistics made by the International Monetary Fund of a sample of 30 countries analysed to assess the degree of synchronicity of changes under the impact of the crisis
on macroeconomic indicators such as increase in: GDP, the exchange rate of the national currency; a country’s international investment position (which characterizes the external liabilities of residents to non-residents); foreign exchange reserves; the value of government bonds. In order to quantify the changes observed, the values of the Kendall concordance coefficient were calculated for equal periods of time – in the crisis and post-crisis periods
Self-oscillation
Physicists are very familiar with forced and parametric resonance, but
usually not with self-oscillation, a property of certain dynamical systems that
gives rise to a great variety of vibrations, both useful and destructive. In a
self-oscillator, the driving force is controlled by the oscillation itself so
that it acts in phase with the velocity, causing a negative damping that feeds
energy into the vibration: no external rate needs to be adjusted to the
resonant frequency. The famous collapse of the Tacoma Narrows bridge in 1940,
often attributed by introductory physics texts to forced resonance, was
actually a self-oscillation, as was the swaying of the London Millennium
Footbridge in 2000. Clocks are self-oscillators, as are bowed and wind musical
instruments. The heart is a "relaxation oscillator," i.e., a non-sinusoidal
self-oscillator whose period is determined by sudden, nonlinear switching at
thresholds. We review the general criterion that determines whether a linear
system can self-oscillate. We then describe the limiting cycles of the simplest
nonlinear self-oscillators, as well as the ability of two or more coupled
self-oscillators to become spontaneously synchronized ("entrained"). We
characterize the operation of motors as self-oscillation and prove a theorem
about their limit efficiency, of which Carnot's theorem for heat engines
appears as a special case. We briefly discuss how self-oscillation applies to
servomechanisms, Cepheid variable stars, lasers, and the macroeconomic business
cycle, among other applications. Our emphasis throughout is on the energetics
of self-oscillation, often neglected by the literature on nonlinear dynamical
systems.Comment: 68 pages, 33 figures. v4: Typos fixed and other minor adjustments. To
appear in Physics Report
Wealth, income, earnings and the statistical mechanics of flow systems
This paper looks at empirical data from economics regarding wealth, earnings and income, alongside a
flow model for an economy based on the general Lotka-Volterra models of Levy & Solomon. The data and modelling suggest that a simple economic system might provide a tractable model for giving an exact statistical mechanical solution for an 'out of equilibrium' flow model. This might also include an exact mathematical definition of a 'dissipative structure' derived from maximum entropy
considerations. This paper is primarily a qualitative discussion of how such a mathematical proof might be achieved
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