4,409 research outputs found
S-dual Amplitude and D3-Brane Couplings
Recently, it has been observed that the IIB scattering amplitudes are
compatible with the standard rules of S-duality. Inspired by this observation,
we will find the tree-level S-matrix elements of one Ramond-Ramond and three
open strings by imposing this symmetry on the tree-level S-matrix elements of
one Kalb-Ramond and three open strings. We also find a SL(2, R) invariant form
of the D3-brane effective action containing four gauge fields with derivative
corrections that was derived from one-loop level four-point amplitude. Using
the expansion of the nonlinear SL(2, R) invariant structures, we find the
action with derivative corrections at the level of more gauge fieldsComment: 18 page
On circular Bragg regimes in ellipsometry spectra of ambichiral sculptured thin films
The generalized ellipsometry formalism is used for a right handed ambichiral
sculptured thin film.The amplitude ratios and phase differences of this
structure are extracted from the amplitude transmission ratios. The results
showed that the circular Bragg regimes appear with abruptly changes in
ellipsometry spectrum as wavelength, where the selective circular transmission
is maximized.Comment: 3 figures. arXiv admin note: substantial text overlap with
arXiv:1206.042
Optical properties of gyrotropic polygonal chiral thin films
The optical response of gyrotropic and non-gyrotropic dielectric polygonal
chiral thin films were investigated using transfer matrix method. The influence
of gyrotropy factor, porosity and incident angle of light on Bragg regimes,
selective reflection and transmission were reported. The results revealed that
the Fabry-Perot oscillations were affected by gyrotropy factor and porosity of
polygonal chiral thin films.Comment: 10 figure
On optical rotation and selective transmission in ambichiral sculptured thin films
The optical rotation and selective transmission spectrum of ambichiral
sculptured thin films using transfer matrix method have been calculated. The
results of optical modeling showed that optical characteristics ambichiral
sculptured thin films are the same as chiral sculptured thin films in lower
angular rotations. In higher angular rotations appear two circular Bragg
regimes. The primary at shorter wavelengths reflects LCP light and the
secondary at longer wavelengths reflects RCP light. The optical properties of
ambichiral sculptured thin films with twist and layer defects as spectral holes
in circular Bragg regimes have been reported.Comment: 9 pages,3 figure
Using physiological measures in conjunction with other UX approaches for better understanding of the player's gameplay experiences
The goal of video games is to challenge and entertain the players. Successful
video games deliver experience that impact players on a level of arousal.
Therefore undertaking a user experience (UX) study is crucial to ensure that a
game achieves both critical and financial success. However, traditional
usability methods (observation, subjective reporting, questionnaire, and
interview) have a number of limitations on game user research. In this study we
capture player's physiological measures during a gameplay session, to indicate
micro-events that have caused changes in their body signals. At the
post-gameplay interviews we ask participants to comment and describe their
feelings on the selected events. The aim of this study is not to over-interpret
physiological measures, but on using blips in measures to help identify key
points in a game, which we then use to investigate further with the
participant. This approach provides a method that can identify not only the
negative user experience and usability issues but also the events which have a
positive impact on player's experience.Comment: 15 Pages. This paper has been presented at Games Research Methods
Seminar,8-9 April 2010,University of Tampere, Finlan
T-dual RR couplings on D-branes from S-matrix elements
Using the linear T-dual ward identity associated with the NSNS gauge
transformations, some RR couplings on D-branes have been found at order
. We examine the couplings with the S-matrix elements
of one RR, one graviton and one antisymmetric B-field vertex operators. We find
the consistency of T-dual S-matrix elements and explicit results of scattering
string amplitude and show that the string amplitude reproduces these couplings
as well as some other couplings. This illustration is found for
couplings in the literature which is extended to the couplings in
this paper.Comment: 23 pages. V2: it appears in PR
Optimal Trajectory-Planning of UAVs via B-Splines and Disjunctive Programming
This paper investigates an efficient algorithm for trajectory planning
problem of autonomous unmanned aerial vehicles which fly over three-dimensional
terrains. The proposed algorithm combines convex optimization with disjunctive
programming and receding horizon concept, which has many advantages, such as a
high computational speed. Disjunctive programming is applied in order to relax
the non-convex constraints of the problem. Moreover, the B-spline curves are
employed to represent the trajectories which should be generated in the
optimization process
Special Biserial Cluster-tilted Algebras
We give a complete description of all special biserial cluster-tilted
algebras over a finite dimensional hereditary algebra H over an algebraically
closed field K
Characteristics of plasmonic at a metal /chiral sculptured thin film interface
The propagation of surface plasmon polariton at an interface of metallic thin
film and chiral sculptured thin film theoretically has been investigated using
the transfer matrix method in the Kretschman configuration. The optical
absorption of structure as a function of polar incident angle for linear
polarization P and S has been calculated at different structural parameters.
The results show that exist multiple plasmon peaks for P-polarization, while
there are the weak plasmon peaks when incident of light is S- polarized plane
wave
Surface plasmon resonance of two segmented Au Cu nanowires in polycarbonate template
Two segmented gold copper nanowires were grown inside the pores of
polycarbonate track (PCT) etched membranes from two separate solutions by
electrodeposition method. Optical absorption spectra of two segmented Au Cu
nanowires in PCT template were shown a surface plasmon- polariton peak appeared
at about 900 nm for incident angle of theta = 65 degrees but for theta= 0 there
are not any peaks in spectra
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