56,693 research outputs found
Game Based Learning for Safety and Security Education
Safety and security education are important part of technology related education, because of recent number of increase in safety and security related incidents. Game based learning is an emerging and rapidly advancing forms of computer-assisted instruction. Game based learning for safety and security education enables students to learn concepts and skills without the risk of physical injury and security breach. In this paper, a pedestal grinder safety game and physical security game have been developed using industrial standard modeling and game development software. The average score of the knowledge test of grinder safety game was 82%, which is higher than traditional lecture only instruction method. In addition, the survey of physical security game shows 84% average satisfaction ratio from high school students who played the game during the summer camp. The results of these studies indicated that game based learning method can enhance students' learning without potential harm to the students
Enhancement of magnetoresistance in manganite multilayers
Magnanite multilayers have been fabricated using La0.67Ca0.33MnO3 as the
ferromagnetic layer and Pr0.7Ca0.3MnO3 and Nd0.5Ca0.5MnO3 as the spacer layers.
All the multilayers were grown on LaAlO3 (100) by pulse laser deposition. An
enhanced magnetoresistnace (defined (RH- R0)/R0) of more than 98% is observed
in these multilayers. Also a low field magnetoresistance of 41% at 5000 Oe is
observed in these multilayer films. The enhanced MR is attributed to the
induced double exchange in the spacer layer, which is giving rise to more
number of conducting carriers. This is compared by replacing the spacer layer
with LaMnO3 where Mn exists only in 3+ state and no enhancement is observed in
the La0.67Ca0.33MnO3 / LaMnO3 multilayers as double exchange mechanism can not
be induced by external magnetic fields.Comment: 13 pages, 5 Figure
Nucleon Sigma Term and In-medium Quark Condensate in the Modified Quark-Meson Coupling Model
We evaluate the nucleon sigma term and in-medium quark condensate in the
modified quark-meson coupling model which features a density-dependent bag
constant. We obtain a nucleon sigma term consistent with its empirical value,
which requires a significant reduction of the bag constant in the nuclear
medium similar to those found in the previous works. The resulting in-medium
quark condensate at low densities agrees well with the model independent linear
order result. At higher densities, the magnitude of the in-medium quark
condensate tends to increase, indicating no tendency toward chiral symmetry
restoration.Comment: 9 pages, modified version to be publishe
Semi-Inclusive B\to K(K^*) X Decays with Initial Bound State Effects
The effects of initial quark bound state for the semi-inclusive decays
are studied using light cone expansion and heavy quark
effective theory methods. We find that the initial bound state effects on the
branching ratios and CP asymmetries are small. In the light cone expansion
approach, the CP-averaged branching ratios are increased by about 2% with
respect to the free -quark decay. For , the
CP-averaged branching ratios are sensitive to the phase and the CP
asymmetry can be as large as 7% (14%), whereas for the CP-averaged branching ratios are not sensitive to and
the CP asymmetries are small (). The CP-averaged branching ratios are
predicted to be in the ranges [] for and [] for , depending on the value of the CP violating phase . In
the heavy quark effective theory approach, we find that the branching ratios
are decreased by about 10% and the CP asymmetries are not affected. These
predictions can be tested in the near future.Comment: 29 pages, 12 ps figure
A generalization of heterochromatic graphs
In 2006, Suzuki, and Akbari & Alipour independently presented a necessary and
sufficient condition for edge-colored graphs to have a heterochromatic spanning
tree, where a heterochromatic spanning tree is a spanning tree whose edges have
distinct colors. In this paper, we propose -chromatic graphs as a
generalization of heterochromatic graphs. An edge-colored graph is
-chromatic if each color appears on at most edges. We also
present a necessary and sufficient condition for edge-colored graphs to have an
-chromatic spanning forest with exactly components. Moreover, using this
criterion, we show that a -chromatic graph of order with
has an -chromatic spanning forest with exactly
() components if for any
color .Comment: 14 pages, 4 figure
Fluctuating volume-current formulation of electromagnetic fluctuations in inhomogeneous media: incandecence and luminescence in arbitrary geometries
We describe a fluctuating volume--current formulation of electromagnetic
fluctuations that extends our recent work on heat exchange and Casimir
interactions between arbitrarily shaped homogeneous bodies [Phys. Rev. B. 88,
054305] to situations involving incandescence and luminescence problems,
including thermal radiation, heat transfer, Casimir forces, spontaneous
emission, fluorescence, and Raman scattering, in inhomogeneous media. Unlike
previous scattering formulations based on field and/or surface unknowns, our
work exploits powerful techniques from the volume--integral equation (VIE)
method, in which electromagnetic scattering is described in terms of
volumetric, current unknowns throughout the bodies. The resulting trace
formulas (boxed equations) involve products of well-studied VIE matrices and
describe power and momentum transfer between objects with spatially varying
material properties and fluctuation characteristics. We demonstrate that thanks
to the low-rank properties of the associatedmatrices, these formulas are
susceptible to fast-trace computations based on iterative methods, making
practical calculations tractable. We apply our techniques to study thermal
radiation, heat transfer, and fluorescence in complicated geometries, checking
our method against established techniques best suited for homogeneous bodies as
well as applying it to obtain predictions of radiation from complex bodies with
spatially varying permittivities and/or temperature profiles
- …