3,356 research outputs found
Young Wall Realization of Crystal Bases for Classical Lie Algebras
In this paper, we give a new realization of crystal bases for finite
dimensional irreducible modules over classical Lie algebras. The basis vectors
are parameterized by certain Young walls lying between highest weight and
lowest weight vectors.Comment: 27page
NMR study on the stability of the magnetic ground state in MnCrO
The canting angles and fluctuation of the magnetic ion spins of spinel oxide
MnCrO were studied by nuclear magnetic resonance (NMR) at low
temperatures, which has a collinear ferrimagnetic order below and a
ferrimagnetic spiral order below . Contrary to previous reports,
only one spin canting angle of Cr ions was observed. The spin canting angles of
Mn and Cr ions in the ferrimagnetic spiral obtained at a liquid-He temperature
were 43\,^{\circ} and 110\,^{\circ}, respectively. The nuclear spin-spin
relaxation was determined by the Suhl-Nakamura interaction at low temperatures
but the relaxation rate increases rapidly as the temperature
approaches . This indicates that the fluctuation of the spiral component
becomes faster as the temperature increases but not fast enough to leave an
averaged hyperfine field to nuclei in the time scale of nuclear spin precession
in the ferrimagnetic phase, which is on the order of s. The spiral
volume fraction measured for various temperatures reveals that the collinear
and the spiral ferrimagnetic phases are mixed below the transition temperature
of the spiral order. The temperature hysteresis in the volume fraction implies
that this transition has first-order characteristics.Comment: 13 pages, 5 figure
Locomotion Control of a Compliant Legged Robot from Slow Walking to Fast Running Regular Paper
In this paper, we propose a locomotion control method for a compliant legged robot from slow walking to fast running. We also examine the energy efficiency of the compliant legged robot controlled by the proposed locomotion control method. Experimentally, we obtain the robot running speed of about 4.3m/s with the initial compliant leg length of 0.1m. In addition, we obtain very good energy efficiency. In the best case, the mechanical cost of transport(Cmt), known as an energy efficiency measure, is obtained at about 0.2. Comparing with the other energy efficient robots, our robot exhibits very good energy efficiency. ยฉ 2012 Kim et al.; licensee InTech.1
Electronic structures of hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films
We investigated the electronic structure of multiferroic hexagonal RMnO3 (R =
Gd, Tb, Dy, and Ho) thin films using both optical spectroscopy and
first-principles calculations. Using artificially stabilized hexagonal RMnO3,
we extended the optical spectroscopic studies on the hexagonal multiferroic
manganite system. We observed two optical transitions located near 1.7 eV and
2.3 eV, in addition to the predominant absorption above 5 eV. With the help of
first-principles calculations, we attribute the low-lying optical absorption
peaks to inter-site transitions from the oxygen states hybridized strongly with
different Mn orbital symmetries to the Mn 3d3z2-r2 state. As the ionic radius
of the rare earth ion increased, the lowest peak showed a systematic increase
in its peak position. We explained this systematic change in terms of a
flattening of the MnO5 triangular bipyramid
Total Reflection and Negative Refraction of Dipole-Exchange Spin Waves at Magnetic Interfaces: Micromagnetic Modeling Study
We demonstrated that dipole-exchange spin waves traveling in geometrically
restricted magnetic thin films satisfy the same laws of reflection and
refraction as light waves. Moreover, we found for the first time novel wave
behaviors of dipole-exchange spin waves such as total reflection and negative
refraction. The total reflection in laterally inhomogeneous thin films composed
of two different magnetic materials is associated with the forbidden modes of
refracted dipole-exchange spin waves. The negative refraction occurs at a 90
degree domain-wall magnetic interface that is introduced by a cubic magnetic
anisotropy in the media, through the anisotropic dispersion of dipole-exchange
spin waves.Comment: 13 pages, 5 figure
Prediction of Individual Propofol Requirements based on Preoperative EEG Signals
The patient must be given an adequate amount of propofol for safe surgery
since overcapacity and low capacity cause accidents. However, the sensitivity
of propofol varies from patient to patient, making it very difficult to
determine the propofol requirements for anesthesia. This paper aims to propose
a neurophysiological predictor of propofol requirements based on the
preoperative electroencephalogram (EEG). We exploited the canonical correlation
analysis that infers the amount of information on the propofol requirements.
The results showed that the preoperative EEG included the factor that could
explain the propofol requirements. Specifically, the frontal and posterior
regions had crucial information on the propofol requirements. Moreover, there
was a significantly different power in the frontal and posterior regions
between baseline and unconsciousness periods, unlike the alpha power in the
central region. These findings showed the potential that preoperative EEG could
predict the propofol requirements.Comment: 5 pages, 1 figure, 1 tabl
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