13,257 research outputs found
Shell Model Monte Carlo Methods
We review quantum Monte Carlo methods for dealing with large shell model
problems. These methods reduce the imaginary-time many-body evolution operator
to a coherent superposition of one-body evolutions in fluctuating one-body
fields; the resultant path integral is evaluated stochastically. We first
discuss the motivation, formalism, and implementation of such Shell Model Monte
Carlo (SMMC) methods. There then follows a sampler of results and insights
obtained from a number of applications. These include the ground state and
thermal properties of {\it pf}-shell nuclei, the thermal and rotational
behavior of rare-earth and -soft nuclei, and the calculation of double
beta-decay matrix elements. Finally, prospects for further progress in such
calculations are discussed
First Experiences Integrating PC Distributed I/O Into Argonne's ATLAS Control System
First Experiences Integrating PC Distributed I/O Into Argonne's ATLAS Control
System The roots of ATLAS (Argonne Tandem-Linac Accelerator System) date back
to the early 1960s. Located at the Argonne National Laboratory, the accelerator
has been designated a National User Facility, which focuses primarily on
heavy-ion nuclear physics. Like the accelerator it services, the control system
has been in a constant state of evolution. The present real-time portion of the
control system is based on the commercial product Vsystem [1]. While Vsystem
has always been capable of distributed I/O processing, the latest offering of
this product provides for the use of relatively inexpensive PC hardware and
software. This paper reviews the status of the ATLAS control system, and
describes first experiences with PC distributed I/O.Comment: ICALEPCS 2001 Conference, PSN WEAP027, 3 pages, 1 figur
Results from Shell Model Monte Carlo Studies
We review results obtained using Shell Model Monte Carlo (SMMC) techniques.
These methods reduce the imaginary-time many-body evolution operator to a
coherent superposition of one-body evolutions in fluctuating one-body fields;
the resultant path integral is evaluated stochastically. After a brief review
of the methods, we discuss a variety of nuclear physics applications. These
include studies of the ground-state properties of pf-shell nuclei, Gamow-Teller
strength distributions, thermal and rotational pairing properties of nuclei
near N=Z, -soft nuclei, and -decay in ^{76}Ge. Several
other illustrative calculations are also reviewed. Finally, we discuss
prospects for further progress in SMMC and related calculations
A Formal, Resource Consumption-Preserving Translation of Actors to Haskell
We present a formal translation of an actor-based language with cooperative
scheduling to the functional language Haskell. The translation is proven
correct with respect to a formal semantics of the source language and a
high-level operational semantics of the target, i.e. a subset of Haskell. The
main correctness theorem is expressed in terms of a simulation relation between
the operational semantics of actor programs and their translation. This allows
us to then prove that the resource consumption is preserved over this
translation, as we establish an equivalence of the cost of the original and
Haskell-translated execution traces.Comment: Pre-proceedings paper presented at the 26th International Symposium
on Logic-Based Program Synthesis and Transformation (LOPSTR 2016), Edinburgh,
Scotland UK, 6-8 September 2016 (arXiv:1608.02534
SMMC method for two-neutrino double beta decay
Shell Model Monte Carlo (SMMC) techniques are used to calculate two-neutrino
double beta decay matrix elements. We validate the approach against direct
diagonalization for Ca in the complete -shell using the KB3
interaction. The method is then applied to the decay of Ge in the
model space using a newly calculated realistic
interaction. Our result for the matrix element is MeV, in
agreement with the experimental value.Comment: 10 pages, 3 figures available at
http://www.krl.caltech.edu/preprints/MAP.htm
Insurer and Employer Views on Pediatric Obesity Treatment: a Qualitative Study
This is the peer reviewed version of the following article: Hampl, S.E., Davis, A.M., Sampilo, M.L., Stephens, K.L. and Dean, K. (2013), Insurer and employer views on pediatric obesity treatment: A qualitative study. Obesity, 21: 795–799. doi:10.1002/oby.20112, which has been published in final form at http://doi.org/10.1002/oby.20112. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.OBJECTIVE The effectiveness of group-based comprehensive, multidisciplinary (stage 3) pediatric weight management programs is backed by a growing body of literature, yet insurance coverage of these programs is scarce to nonexistent, limiting their reach and long-term survival. The objective of this study was to better understand the perspectives of insurers and large employers on the issue of group-based treatment coverage. DESIGN AND METHODS The authors performed a qualitative study utilizing structured interviews with these stakeholders, following accepted techniques. RESULTS Six major themes emerged: cost, program effectiveness, corporate social responsibility, secondary parental (employee) benefits, coverage options and new benefit determination. CONCLUSION Future efforts to secure payment for group-based pediatric weight management programs should address these key themes
A Survey for Low-Surface-Brightness Galaxies Around M31. I. The Newly Discovered Dwarf Andromeda V
We present images and a color-magnitude diagram for And V, a new dwarf
spheroidal companion to M31 that was found using a digital filtering technique
applied to 1550 square degrees of the second Palomar Sky Survey. And V resolves
into stars easily in follow-up 4-m V- and I-band images, from which we deduce a
distance of 810 +/- 45 kpc using the tip of the red giant branch method. Within
the uncertainties, this distance is identical to the Population II distances
for M31 and, combined with a projected separation of 112 kpc, provides strong
support for a physical association between the two galaxies. There is no
emission from And V detected in H alpha, 1.4 GHz radio continuum, or IRAS
bandpasses, and there is no young population seen in the color-magnitude
diagram that might suggest that And V is an irregular. Thus, the classification
as a new dwarf spheroidal member of the Local Group seems secure. With an
extinction-corrected central surface brightness of 25.2 V mag per square
arcsec, a mean metal abundance of [Fe/H] approximately -1.5, and no evidence
for upper AGB stars, And V resembles And I & III.Comment: Accepted for publication in The Astronomical Journal, November 1998
issue; 4 embedded PostScript figures, 4 JPEG figures; see
http://aloe.tuc.noao.edu/jacoby/dwarfs.html for a complete full-resolution
PostScript versio
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