529 research outputs found
The mass of odd-odd nuclei in microscopic mass models
Accurate estimates of the binding energy of nuclei far from stability that
cannot be produced in the laboratory are crucial to our understanding of
nuclear processes in astrophysical scenarios. Models based on energy density
functionals have shown that they are capable of reproducing all known masses
with root-mean-square error better than 800 keV, while retaining a firm
microscopic foundation. However, it was recently pointed out in [M. Hukkanen et
al., arXiv:2210.10674] that the recent BSkG1 model fails to account for a
contribution to the binding energy that is specific to odd-odd nuclei, and
which can be studied by using appropriate mass difference formulas. We analyse
here the (lacking) performance of three recent microscopic mass models with
respect to such formulas and examine possibilities to remedy this deficiency in
the future.Comment: 6 pages, 2 figures; Contribution to the proceedings of INPC 2022,
Cape Town, South Afric
DepQBF 6.0: A Search-Based QBF Solver Beyond Traditional QCDCL
We present the latest major release version 6.0 of the quantified Boolean
formula (QBF) solver DepQBF, which is based on QCDCL. QCDCL is an extension of
the conflict-driven clause learning (CDCL) paradigm implemented in state of the
art propositional satisfiability (SAT) solvers. The Q-resolution calculus
(QRES) is a QBF proof system which underlies QCDCL. QCDCL solvers can produce
QRES proofs of QBFs in prenex conjunctive normal form (PCNF) as a byproduct of
the solving process. In contrast to traditional QCDCL based on QRES, DepQBF 6.0
implements a variant of QCDCL which is based on a generalization of QRES. This
generalization is due to a set of additional axioms and leaves the original
Q-resolution rules unchanged. The generalization of QRES enables QCDCL to
potentially produce exponentially shorter proofs than the traditional variant.
We present an overview of the features implemented in DepQBF and report on
experimental results which demonstrate the effectiveness of generalized QRES in
QCDCL.Comment: 12 pages + appendix; to appear in the proceedings of CADE-26, LNCS,
Springer, 201
A Novel Mutation in the Upstream Open Reading Frame of the CDKN1B Gene Causes a MEN4 Phenotype
PubMed ID: 23555276This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Scaling of the distribution of fluctuations of financial market indices
We study the distribution of fluctuations over a time scale (i.e.,
the returns) of the S&P 500 index by analyzing three distinct databases.
Database (i) contains approximately 1 million records sampled at 1 min
intervals for the 13-year period 1984-1996, database (ii) contains 8686 daily
records for the 35-year period 1962-1996, and database (iii) contains 852
monthly records for the 71-year period 1926-1996. We compute the probability
distributions of returns over a time scale , where varies
approximately over a factor of 10^4 - from 1 min up to more than 1 month. We
find that the distributions for 4 days (1560 mins) are
consistent with a power-law asymptotic behavior, characterized by an exponent
, well outside the stable L\'evy regime . To
test the robustness of the S&P result, we perform a parallel analysis on two
other financial market indices. Database (iv) contains 3560 daily records of
the NIKKEI index for the 14-year period 1984-97, and database (v) contains 4649
daily records of the Hang-Seng index for the 18-year period 1980-97. We find
estimates of consistent with those describing the distribution of S&P
500 daily-returns. One possible reason for the scaling of these distributions
is the long persistence of the autocorrelation function of the volatility. For
time scales longer than days, our results are
consistent with slow convergence to Gaussian behavior.Comment: 12 pages in multicol LaTeX format with 27 postscript figures
(Submitted to PRE May 20, 1999). See
http://polymer.bu.edu/~amaral/Professional.html for more of our work on this
are
Evolution of the -ray strength function in neodymium isotopes
The experimental gamma-ray strength functions (gamma-SFs) of 142,144-151Nd
have been studied for gamma-ray energies up to the neutron separation energy.
The results represent a unique set of gamma-SFs for an isotopic chain with
increasing nuclear deformation. The data reveal how the low-energy enhancement,
the scissors mode and the pygmy dipole resonance evolve with nuclear
deformation and mass number. The data indicate that the mechanisms behind the
low-energy enhancement and the scissors mode are decoupled from each other.Comment: 14 pages and 10 figure
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