102,631 research outputs found
Hydrodynamic flow at RHIC
We review the apparently hydrodynamic behaviour of low transverse momentum
particles (p_T < 1.5 GeV/c) produced in central and semicentral (b < 7 fm)
heavy ion collisions at RHIC. We investigate the impact parameter dependence of
various observables, elaborating on radial and elliptic flow and particle
multiplicities. We also discuss possible ambiguities in the initialization of
the hydrodynamic system and present observables that should allow for their
resolution.Comment: 10 pages, Proceedings of the 17th Winter Workshop on Nuclear
Dynamics, Park City, Utah, 200
Hydrodynamic aspects of relativistic heavy ion collisions at RHIC
The current status of the application of hydrodynamics to ultrarelativistic
heavy ion collisions is reviewed. We elaborate on the arguments for strong
transverse flow and rapid thermalization and discuss future applications and
trends in hydrodynamics.Comment: Invited plenary talk at SEWM04, Helsinki, June 16-19 200
Illinois Government Research no. 56 1983: Prison Capacity and Sentencing Severity: A Look at Illinois, Michigan, and Pennsylvania
After a brief lull in the late seventies and early eighties, crime
is once again a prime concern among a large number of
Americans. More people are mentioning crime in periodic
surveys of public problems than in the previous decade, and
the 1982 governor's race in California may have been won at
the eleventh hour by a strong law and order appeal. In the
minds of many, criminal punishment is an integral part of the
crime problem and society's efforts to combat it. It is viewed
as both a real and a symbolic deterrent to crime, every bit
as important as a mobile, effective police force. This has led
to a reexamination of sentencing practices and a revision of
sentencing codes, an increase in minimum punishments, and
even new prison construction. Illinois, for example, moved
from an interdeterminate to a determinate sentencing code,
abolished its parole board, and enacted Class X legislation
providing more severe sentences for selected heinous crimes.
More recently it has embarked upon a campaign to increase
its state penal capacity. Indeed, a recent report of the Illinois
Economic and Fiscal Commission shows that the Department
of Corrections received 75 percent of all new capital project
dollars for FY 1983 ??? in excess of $80 million.
Many students of criminal courts have doubted the effectiveness
of these reforms. They note the low visibility of most
sentencing decisions and the vested interest of most criminal
court practitioners in the status quo. Of particular concern
are the long-established "going rates" for routine offenses
on which county plea bargaining practices are based. To
better understand the sentencing process ??? and improve
our chances to reform it ??? we undertook a long-term comparative
study of criminal courts. The focus of the present
essay is on factors that affect sentencing severity. Such
factors are, of course, of special interest to those concerned
with increasing the deterrent effect of sentencing.published or submitted for publicatio
Bayesian Models and Decision Algorithms for Complex Early Phase Clinical Trials
An early phase clinical trial is the first step in evaluating the effects in
humans of a potential new anti-disease agent or combination of agents. Usually
called "phase I" or "phase I/II" trials, these experiments typically have the
nominal scientific goal of determining an acceptable dose, most often based on
adverse event probabilities. This arose from a tradition of phase I trials to
evaluate cytotoxic agents for treating cancer, although some methods may be
applied in other medical settings, such as treatment of stroke or immunological
diseases. Most modern statistical designs for early phase trials include
model-based, outcome-adaptive decision rules that choose doses for successive
patient cohorts based on data from previous patients in the trial. Such designs
have seen limited use in clinical practice, however, due to their complexity,
the requirement of intensive, computer-based data monitoring, and the medical
community's resistance to change. Still, many actual applications of
model-based outcome-adaptive designs have been remarkably successful in terms
of both patient benefit and scientific outcome. In this paper I will review
several Bayesian early phase trial designs that were tailored to accommodate
specific complexities of the treatment regime and patient outcomes in
particular clinical settings.Comment: Published in at http://dx.doi.org/10.1214/09-STS315 the Statistical
Science (http://www.imstat.org/sts/) by the Institute of Mathematical
Statistics (http://www.imstat.org
Expansion rates at RHIC
A detailed description of the temporal evolution of the thermodynamic fields
in heavy ion collisions is presented within a hydrodynamic framework.
Particular attention is devoted to the evolution of the collective flow fields
and their space-time gradients.Comment: Proceedings for the 19th Winter Workshop on Nuclear Dynamics,
Breckenridge, Colorado, March 8-15, 2003, 6 page
On the stability of thin-shell wormholes
A thin-shell wormhole is theoretically constructible by surgically grafting
together two Schwarzschild spacetimes using the so-called cut-and-paste
technique. By describing such a wormhole as the limiting case of a spherical
shell, it is shown that the structure must be unstable to linearized radial
perturbations. Some earlier studies by the author et al. have shown, however,
that under certain conditions, thin-shell wormholes can be stable.Comment: 5 pages, no figure
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