599 research outputs found
Dynamic Analysis of Algebraic Structure to Optimize Test Generation and Test Case Selection
Where no independent specification is available, object-oriented unit testing is limited to exercising all interleaved method paths, seeking unexpected failures. A recent trend in unit testing, that interleaves dynamic analysis between each test cycle, has brought useful reductions in test-set sizes by pruning redundant prefix paths. This paper describes a dynamic approach to analyzing the algebraic structure of test objects, such that prefix paths ending in observer or transformer operations yielding unchanged, or derived states may be detected and pruned on-the-fly during testing. The fewer retained test cases are so close to the ideal algebraic specification cases that a tester can afford to confirm or reject these cases interactively, which are then used as a test oracle to predict many further test outcomes during automated testing. The algebra-inspired algorithms are incorporated in the latest version of the JWalk lazy systematic unit testing tool suite, which discovers key test cases, while pruning many thousands of redundant test cases
Thermodynamic description of the C-Ge and C-Mg systems
The thermodynamic modeling for the C-Ge and C-Mg systems is performed by the CALPHAD method. The enthalpy of formation for Mg2C3, the experimental value of which is not available in the literature, is obtained via first-principles calculation to refine the thermodynamic modeling of the C-Mg system. A comparison of the thermodynamic calculations with the available literature data shows that the presently obtained two sets of thermodynamic parameters for the C-Ge and C-Mg systems can well describe the these two systems
OWL-POLAR : semantic policies for agent reasoning
The original publication is available at www.springerlink.comPostprin
Boty-II, a novel LTR retrotransposon in Botrytis cinerea B05.10 revealed by genomic sequence
Botrytis cinerea is a necrotrophic pathogen causing pre- and
post-harvest diseases in at least 235 plant species. It manifests
extraordinary genotype and phenotype variation. One of the causes of
this variation is transposable elements. Two transposable elements have
been discovered in this fungus, the retrotransposon (Boty), and the
transposon (Flipper). In this work, two complete (Boty-II-76 and
Boty-II-103) and two partial (Boty-II-95 and Boty-II-141) long terminal
repeat (LTR) retrotransposons were identified by an in silico genomic
sequence analysis. Boty-II-76 and Boty-II-103 contain 6439 bp
nucleotides with a pair of LTRs at both ends, and an internal deduced
pol gene encoding a polyprotein with reverse transcriptase and DDE
integrase domains. They are flanked by 5 bp direct repeats (ACCAT,
CTTTC). In Boty-II-141, two LTRs at both ends, and a partial internal
pol gene encoding a protein with a DDE integrase domain were
identified. In Boty-II-95, a right LTR and a partial internal pol gene
encoding a protein with no conserved domains were identified. Boty-II
uses a self-priming mechanism to initiate synthesis of reverse
transcripts. The sequence of the presumed primer binding site for
first-strand reverse transcription is 5'-TTGTACCAT-3'. The
polypurine-rich sequence for plus-strand DNA synthesis is
5'-GCCTTGAGCGGGGGGTAC-3'. Fourteen Boty-II LTRs that contain 125-158 bp
nucleotides and share 69.1 ~ 100% identities with the short inverted
terminal repeats of 5 bp (TGTCA\u2026TGACA) were discovered. Analysis
of structural features and phylogeny revealed that Boty-II is a novel
LTR retrotransposon. It could potentially be used as a novel molecular
marker for the investigation of genetic variation in B. cinerea
Tests of the random phase approximation for transition strengths
We investigate the reliability of transition strengths computed in the
random-phase approximation (RPA), comparing with exact results from
diagonalization in full shell-model spaces. The RPA and
shell-model results are in reasonable agreement for most transitions; however
some very low-lying collective transitions, such as isoscalar quadrupole, are
in serious disagreement. We suggest the failure lies with incomplete
restoration of broken symmetries in the RPA. Furthermore we prove, analytically
and numerically, that standard statements regarding the energy-weighted sum
rule in the RPA do not hold if an exact symmetry is broken.Comment: 11 pages, 7 figures; Appendix added with new proof regarding
violation of energy-weighted sum rul
Single Spin Asymmetry in Polarized Proton-Proton Elastic Scattering at GeV
We report a high precision measurement of the transverse single spin
asymmetry at the center of mass energy GeV in elastic
proton-proton scattering by the STAR experiment at RHIC. The was measured
in the four-momentum transfer squared range \GeVcSq, the region of a significant interference between the
electromagnetic and hadronic scattering amplitudes. The measured values of
and its -dependence are consistent with a vanishing hadronic spin-flip
amplitude, thus providing strong constraints on the ratio of the single
spin-flip to the non-flip amplitudes. Since the hadronic amplitude is dominated
by the Pomeron amplitude at this , we conclude that this measurement
addresses the question about the presence of a hadronic spin flip due to the
Pomeron exchange in polarized proton-proton elastic scattering.Comment: 12 pages, 6 figure
Evolution of the differential transverse momentum correlation function with centrality in Au+Au collisions at GeV
We present first measurements of the evolution of the differential transverse
momentum correlation function, {\it C}, with collision centrality in Au+Au
interactions at GeV. {\it C} exhibits a strong dependence
on collision centrality that is qualitatively similar to that of number
correlations previously reported. We use the observed longitudinal broadening
of the near-side peak of {\it C} with increasing centrality to estimate the
ratio of the shear viscosity to entropy density, , of the matter formed
in central Au+Au interactions. We obtain an upper limit estimate of
that suggests that the produced medium has a small viscosity per unit entropy.Comment: 7 pages, 4 figures, STAR paper published in Phys. Lett.
Longitudinal double-spin asymmetry and cross section for inclusive neutral pion production at midrapidity in polarized proton collisions at sqrt(s) = 200 GeV
We report a measurement of the longitudinal double-spin asymmetry A_LL and
the differential cross section for inclusive Pi0 production at midrapidity in
polarized proton collisions at sqrt(s) = 200 GeV. The cross section was
measured over a transverse momentum range of 1 < p_T < 17 GeV/c and found to be
in good agreement with a next-to-leading order perturbative QCD calculation.
The longitudinal double-spin asymmetry was measured in the range of 3.7 < p_T <
11 GeV/c and excludes a maximal positive gluon polarization in the proton. The
mean transverse momentum fraction of Pi0's in their parent jets was found to be
around 0.7 for electromagnetically triggered events.Comment: 6 pages, 3 figures, submitted to Phys. Rev. D (RC
Partonic flow and -meson production in Au+Au collisions at = 200 GeV
We present first measurements of the -meson elliptic flow
() and high statistics distributions for different
centralities from = 200 GeV Au+Au collisions at RHIC. In
minimum bias collisions the of the meson is consistent with the
trend observed for mesons. The ratio of the yields of the to those of
the as a function of transverse momentum is consistent with a model
based on the recombination of thermal quarks up to GeV/,
but disagrees at higher momenta. The nuclear modification factor () of
follows the trend observed in the mesons rather than in
baryons, supporting baryon-meson scaling. Since -mesons are
made via coalescence of seemingly thermalized quarks in central Au+Au
collisions, the observations imply hot and dense matter with partonic
collectivity has been formed at RHIC.Comment: 6 pages, 4 figures, submit to PR
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