7,119 research outputs found
Window-based Streaming Graph Partitioning Algorithm
In the recent years, the scale of graph datasets has increased to such a
degree that a single machine is not capable of efficiently processing large
graphs. Thereby, efficient graph partitioning is necessary for those large
graph applications. Traditional graph partitioning generally loads the whole
graph data into the memory before performing partitioning; this is not only a
time consuming task but it also creates memory bottlenecks. These issues of
memory limitation and enormous time complexity can be resolved using
stream-based graph partitioning. A streaming graph partitioning algorithm reads
vertices once and assigns that vertex to a partition accordingly. This is also
called an one-pass algorithm. This paper proposes an efficient window-based
streaming graph partitioning algorithm called WStream. The WStream algorithm is
an edge-cut partitioning algorithm, which distributes a vertex among the
partitions. Our results suggest that the WStream algorithm is able to partition
large graph data efficiently while keeping the load balanced across different
partitions, and communication to a minimum. Evaluation results with real
workloads also prove the effectiveness of our proposed algorithm, and it
achieves a significant reduction in load imbalance and edge-cut with different
ranges of dataset
Suppression of spin-pumping by a MgO tunnel-barrier
Spin-pumping generates pure spin currents in normal metals at the ferromagnet
(F)/normal metal (N) interface. The efficiency of spin-pumping is given by the
spin mixing conductance, which depends on N and the F/N interface. We directly
study the spin-pumping through an MgO tunnel-barrier using the inverse spin
Hall effect, which couples spin and charge currents and provides a direct
electrical detection of spin currents in the normal metal. We find that
spin-pumping is suppressed by the tunnel-barrier, which is contrary to recent
studies that suggest that the spin mixing conductance can be enhanced by a
tunnel-barrier inserted at the interface
Effect of culture conditions on viability of mouse and rat embryos developed in vitro
Currently in vitro culture of mouse preimplantation embryos has become a very important technique to investigate different mechanisms of early embryogenesis. However, there is a big difference in the preimplantation development between mammalian species. Despite close relatedness to mice, in vitro cultivation of rat preimplantation embryos is still delicate and needs further investigation and optimizations. In this study we have compared the in vitro developmental potential of mouse and rat embryos cultured at different culture conditions in parallel experiments. Interestingly, mouse zygotes developed in vitro until blastocyst stage even in inadequate medium without any phosphates and with low osmolarity which was formulated especially for cultivation of rat embryos. Rat parthenotes and zygotes developed in M16 medium formulated for mouse embryos only till 2-cell stage and further development is blocked completely at this stage. Moreover, developmental ability of rat embryos in vitro was significantly lower in comparison with mouse even in special rat mR1ECM medium. Mouse and rat embryos at 2-cell stage obtained in vivo developed until blastocyst stages significantly more efficiently compared to zygotes. Culture of mouse zygotes in glass capillaries resulted in a significantly higher rate of morula and blastocyst development compared with dishes. The Well-of-the-Well system resulted in a significant improvement when compared with dishes for the culture of rat zygotes only until morula stage. Reduced oxygen tension increased the developmental rate of rat but not mouse zygotes until blastocyst stage. This study demonstrates that development of early preimplantation embryos is altered by different culture conditions and show strong differences even between two related species such as mice and rats. Therefore, for understanding the fundamental mechanisms of early mammalian development it is very important to use embryos of various species
Relationships Among Need Achievement Themes and Ethnic and Gender Identities in Elementary Literature Series
Educators agree that students succeed when reading materials are suitable to their backgrounds and contain ideas that are motivating. Interest in achievement motivation dates back to at least 1910, but until the pioneering work of Atkinson and McClelland, little progress was made in developing achievement motive theory emphasizing both clinical and experimental models (Heckhausen, 1967). McClelland, Atkinson, Clark and Lowell (1953; 1976) formulated the theory of achievement motivation through the use of the Thematic Apperception Test (Murray, 1938) measuring individual differences in the motive to enter an achievement situation. McClelland (1961) defines n-Ach (need achievement) motivation as competition with a standard of excellence. The individual strives to do something well or to accomplish a goal for personal satisfaction, for intrinsic rewards. Achievement motivation theory emphasizes the importance and measurement of individual differences in assessing people\u27s interactions with their environment. The strength of n-Ach is measured by a score devised by coding the thought content of imaginative stories
Surface spin flip probability of mesoscopic Ag wires
Spin relaxation in mesoscopic Ag wires in the diffusive transport regime is
studied via nonlocal spin valve and Hanle effect measurements performed on
permalloy/Ag lateral spin valves. The ratio between momentum and spin
relaxation times is not constant at low temperatures. This can be explained
with the Elliott-Yafet spin relaxation mechanism by considering the momentum
surface relaxation time as being temperature dependent. We present a model to
separately determine spin flip probabilities for phonon, impurity and surface
scattering and find that the spin flip probability is highest for surface
scattering.Comment: 5 pages, 4 figure
Detection and quantification of inverse spin Hall effect from spin pumping in permalloy/normal metal bilayers
Spin pumping is a mechanism that generates spin currents from ferromagnetic
resonance (FMR) over macroscopic interfacial areas, thereby enabling sensitive
detection of the inverse spin Hall effect that transforms spin into charge
currents in non-magnetic conductors. Here we study the spin-pumping-induced
voltages due to the inverse spin Hall effect in permalloy/normal metal bilayers
integrated into coplanar waveguides for different normal metals and as a
function of angle of the applied magnetic field direction, as well as microwave
frequency and power. We find good agreement between experimental data and a
theoretical model that includes contributions from anisotropic
magnetoresistance (AMR) and inverse spin Hall effect (ISHE). The analysis
provides consistent results over a wide range of experimental conditions as
long as the precise magnetization trajectory is taken into account. The spin
Hall angles for Pt, Pd, Au and Mo were determined with high precision to be
, , and ,
respectively.Comment: 11 page
Surface-enhanced optical third-harmonic generation in Ag island films
Surface-enhanced optical third-harmonic generation (THG) is observed in
silver island films. The THG intensity from Ag nanoparticles is enhanced by
more than two orders of magnitude with respect to the THG intensity from a
smooth and homogeneous silver surface. This enhancement is attributed to local
plasmon excitation and resonance of the local field at the third-harmonic
wavelength. The diffuse and depolarized component of the enhanced THG is
associated with the third-order hyper-Rayleigh scattering in a 2-D random array
of silver nanoparticles.Comment: 4 pages, 2 figure
Frequency content analysis of R&D projects of the EC framework programs with the participation of Euro-Mediterranean partnership countries
On the basis of the CORDIS data on FP5-FP7 programs the activity of MEDA countries in these projects was studied in the priority areas of action. A content analysis of the participation MEDA country organizations in FP5-FP7 has been performed and 25 large-scale investigation areas have been identifiedyesBelgorod State Universit
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