12,835 research outputs found
Heavy-tailed Distributions In Stochastic Dynamical Models
Heavy-tailed distributions are found throughout many naturally occurring
phenomena. We have reviewed the models of stochastic dynamics that lead to
heavy-tailed distributions (and power law distributions, in particular)
including the multiplicative noise models, the models subjected to the
Degree-Mass-Action principle (the generalized preferential attachment
principle), the intermittent behavior occurring in complex physical systems
near a bifurcation point, queuing systems, and the models of Self-organized
criticality. Heavy-tailed distributions appear in them as the emergent
phenomena sensitive for coupling rules essential for the entire dynamics
Labor Supply Effects of Social Insurance
This chapter examines the labor supply effects of social insurance programs. We argue that this topic deserves separate treatment from the rest of the labor supply literature because individuals may be imperfectly informed as to the rules of the programs and because key parameters are likely to differ for those who are eligible for social insurance programs, such as the disabled. Furthermore, differences in social insurance programs often provide natural experiments with exogenous changes in wages or incomes that can be used to estimate labor supply responses. Finally, social insurance often affects different margins of labor supply. For example, the labor supply literature deals mostly with adjustments in the number of hours worked, whereas the incentives of social insurance programs frequently affect the decision of whether to work at all. The empirical work on unemployment insurance (UI) and workers' compensation (WC) insurance finds that the programs tend to increase the length of time employees spend out of work. Most of the estimates of the elasticities of lost work time that incorporate both the incidence and duration of claims are close to 1.0 for unemployment insurance and between 0.5 and 1.0 for workers' compensation. These elasticities are substantially larger than the labor supply elasticities typically found for men in studies of the effects of wages or taxes on hours of work. The evidence on disability insurance and (especially) social security retirement suggests much smaller and less conclusively established labor supply effects. Part of the explanation for this difference probably lies in the fact that UI and WC lead to short-run variation in wages with mostly a substitution effect. Our review suggest that it would be misleading to apply a universal set of labor supply elasticities to these diverse problems and populations.
Small World Graphs by the iterated "My Friends are Your Friends'' Principle
We study graphs obtained by successive creation and destruction of edges into
small neighborhoods of the vertices. Starting with a circle graph of large
diameter we obtain small world graphs with logarithmic diameter, high
clustering coefficients and a fat tail distribution for the degree. Only local
edge formation processes are involved and no preferential attachment was used.
Furthermore we found an interesting phase transition with respect to the
initial conditions.Comment: Latex, 12 pages with 10 figure
Coupled Cluster Treatment of the XY model
We study quantum spin systems in the 1D, 2D square and 3D cubic lattices with
nearest-neighbour XY exchange. We use the coupled-cluster method (CCM) to
calculate the ground-state energy, the T=0 sublattice magnetisation and the
excited state energies, all as functions of the anisotropy parameter .
We consider in detail and give some results for higher . In 1D these
results are compared with the exact results and in 2D with Monte-Carlo
and series expansions. We obtain critical points close to the expected value
and our extrapolated LSUBn results for the ground-state energy are
well converged for all except very close to the critical point.Comment: 11 pages, Latex, 4 postscript figure, accepted by J.Phys.: Condens.
Matte
"Valuing the Visual Disamenity of Offshore Wind Projects at Varying Distances from the Shore: An Application on the Delaware Shoreline"
Several offshore wind power projects are under consideration in the United States. A concern with any wind power project is the visual disamenity it may create. Using a stated preference choice model, we estimated the external costs to residents of the State of Delaware for offshore wind turbines located at different distances from the coast. The annual costs to inland residents was 9, 0 (200680, 35, and $27 for the same increments.Windfarms, View Disamenity, Valuation
Rocket ozone sounding network data
During the period December 1976 through February 1977, three regular monthly ozone profiles were measured at Wallops Flight Center, two special soundings were taken at Antigua, West Indies, and at the Churchill Research Range, monthly activities were initiated to establish stratospheric ozone climatology. This report presents the data results and flight profiles for the period covered
Influence of a solar proton event on stratospheric ozone
Ozone depletion in the stratosphere associated with the solar proton event of August 4, 1972, was observed with the backscattered ultraviolet experiment on the Nimbus 4 satellite. An abrupt ozone decrease in the 75-80 deg N zone of about 0.002 atm-cm above 4 mb was observed to persist throughout the month of August. A decrease was noted in the 55-65 deg N zone on days 219 and 220, but recovery occurred on day 221. Thereafter, a more gradual decrease was observed. The equatorial zone also showed gradual decrease after day 218, but these were not uniquely distinguished from seasonal variations. The observed change in total ozone following the event was -0.003 atm-cm for the 75-80 deg N zone, corresponding to a 1.3 percent reduction in the 0.305 atm-cm zonal average, but within the 0.019 atm-cm standard deviation. Above the 10 mb surface in the 75-80 deg N zone however, a decrease of 0.004 atm-cm may be compared with a standard deviation of 0.001 atm-cm
Addressing Non-Emergent Medical Transportation Barriers For Rural Vermont Patients
Access to transportation is a Social Determinant of Health, yet many rural Vermonters face barriers to adequate transportation. Consequently, patients face difficulties accessing primary care and completing recommended health screenings. Destigmatizing ride programs and effective communication are key components of connecting patients with transportation resources. This project sought to develop a reference tool for clinic staff to improve communication about transportation barriers with patients and ultimately improve health outcomes.https://scholarworks.uvm.edu/fmclerk/2004/thumbnail.jp
- …