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Reasonable Parameters (reasonable + parameter)

Distribution by Scientific Domains

Physics and Astronomy	50%

Selected Abstracts

AN ON-THE-JOB SEARCH MODEL OF CRIME, INEQUALITY, AND UNEMPLOYMENT*

INTERNATIONAL ECONOMIC REVIEW, Issue 3 2004
Kenneth Burdett
We extend simple search models of crime, unemployment, and inequality to incorporate on-the-job search. This is valuable because, although simple models are useful, on-the-job search models are more interesting theoretically and more relevant empirically. We characterize the wage distribution, unemployment rate, and crime rate theoretically, and use quantitative methods to illustrate key results. For example, we find that increasing the unemployment insurance replacement rate from 53 to 65 percent increases unemployment and crime rates from 10 and 2.7 percent to 14 and 5.2 percent. We show multiple equilibria arise for some fairly reasonable parameters; in one case, unemployment can be 6 or 23 percent, and crime 0 or 10 percent, depending on the equilibrium. [source]

Prediction of vapor,liquid equilibrium for polymer solutions based on the COSMO-SAC model

AICHE JOURNAL, Issue 10 2010
Li Yang
Abstract To extend the application of the COSMO-SAC model to phase-equilibrium calculations of polymer solutions, a new strategy for estimating the charge-density profile, the cavity volume and the cavity surface area of polymer molecules is proposed by finding reasonable parameters for the corresponding repeating structure units. The molecular parameters for polymers are obtained by summing up the corresponding COSMO calculated values of the repeating units calculated by the algorithms of DMol3 (a density functional theory) or MOPAC (a semi-empirical method). Combining with the COSMO-SAC model, the activities and equilibrium pressures for several typical polymer solutions are satisfactorily predicted indicating that the proposed method can be used for the prediction of vapor,liquid equilibrium of polymer solutions. It was also found that both DMol3 and MOPAC can be used though the results obtained from them are slightly different. The results in this paper show that the method proposed has the potential to predict other phase-equilibrium properties of polymer systems. © 2010 American Institute of Chemical Engineers AIChE J, 2010 [source]

A multi-mode model of a non-classical atom laser produced by outcoupling from a Bose-Einstein condensate with squeezed light

LASER PHYSICS LETTERS, Issue 12 2005
S. A. Haine
Abstract We examine the properties of an atom laser produced by outcoupling from a Bose-Einstein condensate with squeezed light. We introduce a method which allows us to model the full multimode dynamics of the squeezed optical field and the outcoupled atoms. We show that for experimentally reasonable parameters that the quantum statistics of the optical field are almost completely transferred to the outcoupled atoms, and investigate the robustness to the coupling strength and the two-photon detuning. [source]

The kinetic power of jets magnetically accelerated from advection-dominated accretion flows in radio galaxies

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY: LETTERS (ELECTRONIC), Issue 1 2010
Shuang-Liang Li
ABSTRACT There is a significant non-linear correlation between the Eddington ratio (Lbol/LEdd) and the Eddington-scaled kinetic power (Lkin/LEdd) of jets in low luminosity active galactic nuclei (AGNs). It is believed that these low luminosity AGNs contain advection-dominated accretion flows (ADAFs). We adopt the ADAF model developed by Li & Cao, in which the global dynamics of ADAFs with magnetically driven outflows is derived numerically, to explore the relation between the bolometric luminosity and the kinetic power of jets. We find that the observed relation, , can be well reproduced by the model calculations with reasonable parameters for ADAFs with magnetically driven outflows. Our model calculations are always consistent with the slope of the correlation independent of the values of the parameters adopted. Compared with the observations, our results show that over 60 per cent of the accreted gas at the outer radius escapes from the accretion disc in a wind before the gas falls into the black holes. The observed correlation between the Eddington-scaled kinetic power and Bondi power can also be qualitatively reproduced by our model calculations. Our results show that the mechanical efficiency varies from 10,2 to10,3, which is roughly consistent with that required in AGN feedback simulations. [source]