3,097 research outputs found
Constitutional Law - Double Jeopardy - Juvenile Court Procedure - State Exceptions to Master\u27s Proposals
The Supreme Court of the United States has held that a Maryland juvenile rule that allows the state to file exceptions to a master\u27s proposed findings and recommendations with a juvenile judge does not violate the double jeopardy clause even though the juvenile judge is free to accept, reject, or modify the proposals or to supplement the record, since the master\u27s hearing and review by the judge constitutes a single proceeding.
Swisher v. Brady, 98 S. Ct. 2699 (1978)
Hydrogen-Bubble Flow-Visualization: Limitations in Drag Reducing Polymer Solutions
Hydrogen-bubble flow-visualization experiments have demonstrated that distinct bubble pulses cannot be obtained in water solutions of polyacrylamide of high enough molecular weight to cause drag reduction at low shear stresses. Good bubble pulses were obtained in poly(ethylene oxide) and in surfactant solutions, but they did not cause drag reduction at feasible shear stresses
Assessing Post-ADA Employment: Some Econometric Evidence and Policy Considerations
This article explores the relationship between the Americans with Disabilities Act (âADAâ) and the relative labor market outcomes for people with disabilities. Using individual-level longitudinal data from 1981 to 1996 derived from the previously unexploited Panel Study of Income Dynamics (âPSIDâ), we examine the possible effect of the ADA on (1) annual weeks worked; (2) annual earnings; and (3) hourly wages for a sample of 7120 unique male household heads between the ages of 21 and 65 as well as a subset of 1437 individuals appearing every year from 1981 to 1996. Our analysis of the larger sample suggests the ADA had a negative impact on the employment levels of disabled persons relative to non-disabled persons but no impact on relative earnings. However, our evaluation of the restricted sample raises questions about these findings. Using these data, we find little evidence of adverse effects on weeks worked but strong evidence of wage declines for the disabled, albeit declines beginning in 1986, well before the ADAâs passage. These results therefore cast doubt on the adverse ADA-related impacts found in previous studies, particularly Acemoglu and Angrist (2001). The conflicting narratives that emerge from our analysis shed new light on, but also counsel caution in reaching final conclusions about, the impact of the ADA on employment outcomes for people with disabilities
Assessing Post-ADA Employment: Some Econometric Evidence and Policy Considerations
This article explores the relationship between the Americans with Disabilities Act (âADAâ) and the relative labor market outcomes for people with disabilities. Using individual-level longitudinal data from 1981 to 1996 derived from the previously unexploited Panel Study of Income Dynamics (âPSIDâ), we examine the possible effect of the ADA on (1) annual weeks worked; (2) annual earnings; and (3) hourly wages for a sample of 7120 unique male household heads between the ages of 21 and 65 as well as a subset of 1437 individuals appearing every year from 1981 to 1996. Our analysis of the larger sample suggests the ADA had a negative impact on the employment levels of disabled persons relative to non-disabled persons but no impact on relative earnings. However, our evaluation of the restricted sample raises questions about these findings. Using these data, we find little evidence of adverse effects on weeks worked but strong evidence of wage declines for the disabled, albeit declines beginning in 1986, well before the ADAâs passage. These results therefore cast doubt on the adverse ADA-related impacts found in previous studies, particularly Acemoglu and Angrist (2001). The conflicting narratives that emerge from our analysis shed new light on, but also counsel caution in reaching final conclusions about, the impact of the ADA on employment outcomes for people with disabilities
Transverse momentum dependence of the angular distribution of the Drell-Yan process
We calculate the transverse momentum Q_{\perp} dependence of the helicity
structure functions for the hadroproduction of a massive pair of leptons with
pair invariant mass Q. These structure functions determine the angular
distribution of the leptons in the pair rest frame. Unphysical behavior in the
region Q_{\perp} --> 0 is seen in the results of calculations done at
fixed-order in QCD perturbation theory. We use current conservation to
demonstrate that the unphysical inverse-power and \ln(Q/Q_{\perp}) logarithmic
divergences in three of the four independent helicity structure functions share
the same origin as the divergent terms in fixed-order calculations of the
angular-integrated cross section. We show that the resummation of these
divergences to all orders in the strong coupling strength \alpha_s can be
reduced to the solved problem of the resummation of the divergences in the
angular-integrated cross section, resulting in well-behaved predictions in the
small Q_{\perp} region. Among other results, we show the resummed part of the
helicity structure functions preserves the Lam-Tung relation between the
longitudinal and double spin-flip structure functions as a function of
Q_{\perp} to all orders in \alpha_s.Comment: 18 pages, 4 figures; typos corrected, references updated, a few
clarifications recommended by the referee. Paper accepted for publication in
Physical Review
Analysis of longitudinal bunching inan FEL driven two-beam accelerator
Recent experiments [1] have explored the use of a free-electron laser (FEL)
as a buncher for a microwave two-beam accelerator, and the subsequent driving
of a standing-wave rf output cavity. Here we present a deeper analysis of the
longitudinal dynamics of the electron bunches as they are transported from the
end of the FEL and through the output cavity. In particular, we examine the
effect of the transport region and cavity aperture to filter the bunched
portion of the beam.
[1] T. Lefevre, et. al., Phys. Rev. Lett. 84 (2000), 1188.Comment: 3 pages, 8 figures. Submitted to XX Int'l LINAC Conferenc
A Two-Dimensional, Self-Consistent Model of Galactic Cosmic Rays in the Heliosphere
We present initial results from our new two-dimensional (radius and
latitude), self-consistent model of galactic cosmic rays in the heliosphere. We
focus on the latitudinal variations in the solar wind flow caused by the
energetic particles. Among other things our results show that the cosmic rays
significantly modify the latitudinal structure of the solar wind flow
downstream of the termination shock. Specifically, for A>0 (corresponding to
the present solar minimum) the wind beyond the shock is driven towards the
equator, resulting in a faster wind flow near the current sheet, while for A<0
the effect is reversed and the wind turns towards the pole, with a faster flow
at high latitudes. We attribute this effect to the latitudinal gradients in the
cosmic ray pressure, caused by drifts, that squeeze the flow towards the
ecliptic plane or the pole, respectively.Comment: 10 pages, 4 Postscript figures, uses AAS LaTeX v4.0, to be published
in The Astrophysical Journal Letter
Optimal Service-Based Competition with Heterogeneous Suppliers
We investigate how a competition can be designed to maximize expected profit for a buyer who wishes to allocate demand among a diverse set of suppliers when his profit is dependent on the supplierâs service levels. The candidate suppliers are heterogeneous in their capacities and cost structures, and compete for shares of the buyerâs demand based on their promised service levels. To characterize the optimal competition, we first identify a family of allocation functions that are service maximizing, meaning they can intensify the competition to a point where each supplier provides its maximum feasible service level and the outcome of the competition is a predefined set of demand shares. We show that using a service maximizing allocation function is a necessary condition for solving the buyerâs problem. We then characterize the optimal demand allocation set and, when they are endogenous, the optimal procurement prices. When both demand allocation and procurement prices can be chosen by the buyer, we find that the competition also maximizes supply chain profit. Through a set of numerical examples, we show that the benefit of using this optimal competition design, including its specified demand allocation function and suggested procurement prices, can be significant
Quantum-limited time-frequency estimation through mode-selective photon measurement
By projecting onto complex optical mode profiles, it is possible to estimate
arbitrarily small separations between objects with quantum-limited precision,
free of uncertainty arising from overlapping intensity profiles. Here we extend
these techniques to the time-frequency domain using mode-selective
sum-frequency generation with shaped ultrafast pulses. We experimentally
resolve temporal and spectral separations between incoherent mixtures of
single-photon level signals ten times smaller than their optical bandwidths
with a ten-fold improvement in precision over the intensity-only Cram\'er-Rao
bound.Comment: Six pages, three figures. Comments welcome
- âŠ