563 research outputs found
Метод оптимизации ярусно-параллельной формы представления задачи для реконфигурируемых вычислительных систем
В роботі запропонований метод оптимізації структури графа задачі, поданого в ярусно-паралельній формі, що враховує вимоги мінімізації часу виконання задачі та обмеження апаратних ресурсів, та дозволяє підвищити продуктивність реконфігурованих обчислювальних систем.The method of optimizing the structure of the task graph represented by a macro dataflow graph, is proposed. The method takes into account the requirement to minimize execution time and the limitations of hardware resources. The method improves the performance of reconfigurable computing systems.В статье предложен метод оптимизации структуры графа задачи, представленного в ярусно-параллельной форме, который учитывает требования минимизации времени выполнения задачи, ограничения аппаратных ресурсов и позволяет повысить производительность реконфигурируемых вычислительных систем
Dual circuit radio frequency identification system of animals
У роботі проаналізовано вплив технічних і біологічних факторів на ефективність роботи систем радіоідентифікації великої рогатої худоби при використанні рідерів з рамковими антенами. Встановлено, що у таких системах достовірність читання кодів транспондерів у значній мірі залежить від відстані і взаємоорієнтації антен транспондерів і рідерів. Для підвищення достовірності читання кодів транспондерів запропоновано використовувати конструктив проходу тварин у якості двоконтурної просторової антени, що індуктивно пов'язана з антеною рідера.This is analyzed the influence of technical and biological factors on the performance of radioidentification
systems of cattle by using readers with loop antennas. It is found that the reliability of of reading transponders
codes largely depends on the distance and interaction orientation of antennas and transponder readers. To improve
the reliability of reading the transponder codes is suggested to use the constructive passage of animals as a twodimensional
antenna which inductively is connected with the antenna reade
Diamagnetism above Tc in underdoped Bi2.2Sr1.8Ca2Cu3O10+d
Single crystals of (Bi2223) with were grown by a traveling solvent floating
zone method in order to investigate the superconducting properties of highly
underdoped Bi2223.Grown crystals were characterized by X-ray diffraction, DC
susceptibility and resistivity measurements, confirming Bi2223 to be the main
phase.The crystals were annealed under various oxygen partial pressures to
adjust their carrier densities from optimally doped to highly underdoped.The
fluctuation diamagnetic component above the superconducting transition
temperature extracted from the anisotropic normal state
susceptibilities () and ()
was found to increase with underdoping, suggesting a decrease in the
superconducting dimensionality and/or increase in the fluctuating vortex liquid
region.Comment: 6 pages, 7 figures, corrected fig.4 and references, published in J.
Phys. Soc. Jpn. 79, 114711 (2010
Построение оптимальных маршрутов на цифровых растровых картах
У статті запропоновано підхід до розв’язку навігаційної задачі трасування маршрутів руху мобільних об’єктів на прямокутній картографічній області. Показано, що для вирішення завдання оптимізації прокладання траси по цифрових картах найбільш придатним є алгоритм Беллмана. Запропоновано привести растрове зображення карти до вигляду прямокутної решітки, придатної до обробки методом Беллмана шляхом блокового квантування. Наведено результати роботи розробленого програмного забезпечення.In-process offered approach to the decision of navigation task of tracing of routes of motion of mobile objects on a rectangular cartographic area. It is shown that for the decision of task to optimization of gasket of route on digital maps most suitable is the use of algorithm of Bellman. It is suggested to bring a raster map over to the type of rectangular grate, suitable to treatment the method of Bellman by a sectional quantum. Job of the worked out software performances over are brought.В работе предложен подход к решению навигационной задачи трассировки маршрутов движения мобильных объектов на прямоугольной картографической области. Показано, что для решения задания оптимизации прокладки трассы по цифровым картам наиболее пригодным является использование алгоритма Беллмана. Предложено привести растровую карту к виду прямоугольной решетки, пригодной к обработке методом Беллмана путем блочного квантования. Приведены результаты работы разработанного программного обеспечения
Observation of charge asymmetry dependence of pion elliptic flow and the possible chiral magnetic wave in heavy-ion collisions
We present measurements of and elliptic flow, , at
midrapidity in Au+Au collisions at 200, 62.4, 39, 27,
19.6, 11.5 and 7.7 GeV, as a function of event-by-event charge asymmetry,
, based on data from the STAR experiment at RHIC. We find that
() elliptic flow linearly increases (decreases) with charge asymmetry
for most centrality bins at and higher.
At , the slope of the difference of
between and as a function of exhibits a
centrality dependence, which is qualitatively similar to calculations that
incorporate a chiral magnetic wave effect. Similar centrality dependence is
also observed at lower energies.Comment: 6 pages, 4 figure
Azimuthal anisotropy in U+U and Au+Au collisions at RHIC
Collisions between prolate uranium nuclei are used to study how particle
production and azimuthal anisotropies depend on initial geometry in heavy-ion
collisions. We report the two- and four-particle cumulants, and
, for charged hadrons from U+U collisions at =
193 GeV and Au+Au collisions at = 200 GeV. Nearly fully
overlapping collisions are selected based on the amount of energy deposited by
spectators in the STAR Zero Degree Calorimeters (ZDCs). Within this sample, the
observed dependence of on multiplicity demonstrates that ZDC
information combined with multiplicity can preferentially select different
overlap configurations in U+U collisions. An initial-state model with gluon
saturation describes the slope of as a function of multiplicity in
central collisions better than one based on Glauber with a two-component
multiplicity model.Comment: Final paper version accepted for publication in Phys. Rev. Lett. New
version includes comparisons to a constituent quark glauber mode
Centrality and transverse momentum dependence of elliptic flow of multi-strange hadrons and meson in Au+Au collisions at = 200 GeV
We present high precision measurements of elliptic flow near midrapidity
() for multi-strange hadrons and meson as a function of
centrality and transverse momentum in Au+Au collisions at center of mass energy
200 GeV. We observe that the transverse momentum dependence of
and is similar to that of and , respectively,
which may indicate that the heavier strange quark flows as strongly as the
lighter up and down quarks. This observation constitutes a clear piece of
evidence for the development of partonic collectivity in heavy-ion collisions
at the top RHIC energy. Number of constituent quark scaling is found to hold
within statistical uncertainty for both 0-30 and 30-80 collision
centrality. There is an indication of the breakdown of previously observed mass
ordering between and proton at low transverse momentum in the
0-30 centrality range, possibly indicating late hadronic interactions
affecting the proton .Comment: 7 pages and 4 figures, Accepted for publication in Physical Review
Letter
Observation of Transverse Spin-Dependent Azimuthal Correlations of Charged Pion Pairs in at GeV
We report the observation of transverse polarization-dependent azimuthal
correlations in charged pion pair production with the STAR experiment in
collisions at RHIC. These correlations directly probe quark
transversity distributions. We measure signals in excess of five standard
deviations at high transverse momenta, at high pseudorapidities eta>0.5, and
for pair masses around the mass of the rho-meson. This is the first direct
transversity measurement in p+p collisions. Comparing the results to data from
lepton-nucleon scattering will test the universality of these spin-dependent
quantities.Comment: 11 pages, 5 figures, 15 tables. Submitted to PR
Energy dependence of acceptance-corrected dielectron excess mass spectrum at mid-rapidity in Au+Au collisions at and 200 GeV
The acceptance-corrected dielectron excess mass spectra, where the known
hadronic sources have been subtracted from the inclusive dielectron mass
spectra, are reported for the first time at mid-rapidity in
minimum-bias Au+Au collisions at = 19.6 and 200 GeV. The excess
mass spectra are consistently described by a model calculation with a broadened
spectral function for GeV/. The integrated
dielectron excess yield at = 19.6 GeV for
GeV/, normalized to the charged particle multiplicity at mid-rapidity, has
a value similar to that in In+In collisions at = 17.3 GeV. For
= 200 GeV, the normalized excess yield in central collisions is
higher than that at = 17.3 GeV and increases from peripheral to
central collisions. These measurements indicate that the lifetime of the hot,
dense medium created in central Au+Au collisions at = 200 GeV
is longer than those in peripheral collisions and at lower energies.Comment: 9 pages, 6 figure
Isolation of Flow and Nonflow Correlations by Two- and Four-Particle Cumulant Measurements of Azimuthal Harmonics in 200 GeV Au+Au Collisions
A data-driven method was applied to measurements of Au+Au collisions at
200 GeV made with the STAR detector at RHIC to isolate
pseudorapidity distance -dependent and -independent
correlations by using two- and four-particle azimuthal cumulant measurements.
We identified a component of the correlation that is -independent,
which is likely dominated by anisotropic flow and flow fluctuations. It was
also found to be independent of within the measured range of
pseudorapidity . The relative flow fluctuation was found to be for particles of transverse momentum
less than GeV/. The -dependent part may be attributed to
nonflow correlations, and is found to be relative to the
flow of the measured second harmonic cumulant at
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