234,607 research outputs found
The Effects of the Massless O(alpha_s^2), O(\alpha\alpha_s), O(\alpha^2) QCD and QED Corrections and of the Massive Contributions to Gamma(H^0\rightarrow b\overline{b})
We consider in detail various theoretical uncertainties of the perturbative
predictions for the decay width of process in
the region . We calculate the order
-contributions to the expression for
through the pole quark mass and demonstrate that they are important for the
elimination of the numerical difference between the corresponding expression
and the one through the running -quark mass. The order
and massless and order massive corrections to
are also calculated. The importance of the latter
contributions for modeling of the threshold effects is demonstrated. The
troubles with identifying of the 4 recent L3 events with the decay of a Standard Higgs boson are discussed.Comment: 16 pages, 6 figures (can be optained by mail after the request from
the authers, e-mails: [email protected]; [email protected]); LATEX,
modified version of ENSLAPP.-A.-407/92 preprin
Grappling with Issues of Learning Science from Everyday Experiences: An Illustrative Case Study
There are different perceptions among researchers with regard to the infusion of everyday experience in the teaching of science: 1) it hinders the learning of science concepts; or, 2) it increases the participation and motivation of students in science learning. This article attempts to contemplate those different perspectives of everyday knowledge in science classrooms by using everyday contexts to teach grade 3 science in Singapore. In this study, two groups of grade 3 students were presented with a scenario that required them to apply the concept of properties of materials to design a shoe. Subsequently, the transcripts of classroom discussions and interactions were analyzed using the framework of sociocultural learning and an interpretative analytic lens. Our analysis suggests that providing an authentic everyday context is insufficient to move young learners of science from their everyday knowledge to scientific knowledge. Further, group interactions among young learners of science to solve an everyday issue need to be scaffolded to ensure meaningful, focused, and sustained learning. Implications for research in science learning among younger students are discussed
Nanowire formation on sputter eroded surfaces
Rotated ripple structures (RRS) on sputter eroded surfaces are potential
candidates for nanoscale wire fabrication. We show that the necessary condition
for RRS formation is that the width of the collision cascade in the
longitudinal direction has to be larger than that in the transverse direction,
which can be achieved by using high energy ion beams. By calculating the
structure factor for the RRS we find that they are more regular and their
amplitude is more enhanced compared to the much studied ripple structure
forming in the linear regime of sputter erosion.Comment: 3 pages, 5 figures, 2 column revtex format, submitted to Appl. Phys.
Let
On Types of Elliptic Pseudoprimes
We generalize the notions of elliptic pseudoprimes and elliptic Carmichael
numbers introduced by Silverman to analogues of Euler-Jacobi and strong
pseudoprimes. We investigate the relationships among Euler Elliptic Carmichael
numbers , strong elliptic Carmichael numbers, products of anomalous primes and
elliptic Korselt numbers of Type I: The former two of these are introduced in
this paper, and the latter two of these were introduced by Mazur (1973) and
Silverman (2012) respectively. In particular, we expand upon a previous work of
Babinkostova et al. by proving a conjecture about the density of certain
elliptic Korselt numbers of Type I that are products of anomalous primes.Comment: Revised for publication. 33 page
Multivariate p-dic L-function
We construct multivariate p-adic L-function in the p-adic number fild by
using Washington method.Comment: 9 page
A Package for the Automated Classification of Periodic Variable Stars
We present a machine learning package for the classification of periodic
variable stars. Our package is intended to be general: it can classify any
single band optical light curve comprising at least a few tens of observations
covering durations from weeks to years, with arbitrary time sampling. We use
light curves of periodic variable stars taken from OGLE and EROS-2 to train the
model. To make our classifier relatively survey-independent, it is trained on
16 features extracted from the light curves (e.g. period, skewness, Fourier
amplitude ratio). The model classifies light curves into one of seven
superclasses - Delta Scuti, RR Lyrae, Cepheid, Type II Cepheid, eclipsing
binary, long-period variable, non-variable - as well as subclasses of these,
such as ab, c, d, and e types for RR Lyraes. When trained to give only
superclasses, our model achieves 0.98 for both recall and precision as measured
on an independent validation dataset (on a scale of 0 to 1). When trained to
give subclasses, it achieves 0.81 for both recall and precision. In order to
assess classification performance of the subclass model, we applied it to the
MACHO, LINEAR, and ASAS periodic variables, which gave recall/precision of
0.92/0.98, 0.89/0.96, and 0.84/0.88, respectively. We also applied the subclass
model to Hipparcos periodic variable stars of many other variability types that
do not exist in our training set, in order to examine how much those types
degrade the classification performance of our target classes. In addition, we
investigate how the performance varies with the number of data points and
duration of observations. We find that recall and precision do not vary
significantly if the number of data points is larger than 80 and the duration
is more than a few weeks. The classifier software of the subclass model is
available from the GitHub repository (https://goo.gl/xmFO6Q).Comment: 16 pages, 11 figures, accepted for publication in A&
Chimpanzee hand preference for throwing and infant cradling:implications for the origin of human handedness
Off-diagonal magnetoimpedance in field-annealed Co-based amorphous ribbons
The off-diagonal magnetoimpedance in field-annealed CoFeSiB amorphous ribbons
was measured in the low-frequency range using a pick-up coil wound around the
sample. The asymmetric two-peak behavior of the field dependence of the
off-diagonal impedance was observed. The asymmetry is attributed to the
formation of a hard magnetic crystalline phase at the ribbon surface. The
experimental results are interpreted in terms of the surface impedance tensor.
It is assumed that the ribbon consists of an inner amorphous region and surface
crystalline layers. The coupling between the crystalline and amorphous phases
is described through an effective bias field. A qualitative agreement between
the calculated dependences and experimental data is demonstrated. The results
obtained may be useful for development of weak magnetic-field sensors.Comment: 19 pages, 6 figure
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