117 research outputs found
Case Study of Landslide in NH –13 at Kethikal Near Mangalore – India
The disastrous slope failure occurred at the Kethikal hill, in the outskirts of Mangalore city in NH 13, India, during the month of June 1998 soon after the heavy and continuous monsoon rains. Many closely built dwelling houses at the top of hill are damaged and the traffic along the road is also diverted for some duration. Typical stratified slope with three layers is considered for the stability analysis and the general computer program is developed in C language for optimization of factor of safety. The factor of safety is calculated using Janbu’s generalized procedure of slices and Davidon-Fletcher-Powel (DFP) technique for optimization. The road is acting as a berm in Kethikal slope. The program gives factor of safety and the co ordinates of critical slip surface. The program is modified to take the effect of tension crack and the effect of berm. The automated stability analysis program gave least value of factor of safety in base failure with tension crack and a berm. The obtained result matches with the field observation. Kethikal landslide is due to the development of high pore pressure in soil
DWT Feature Extraction Based Face Recognition using Intensity Mapped Unsharp Masking and Laplacian of Gaussian Filtering with Scalar Multiplier
AbstractFace recognition under varying illumination and poses at certain angles is challenging, and hence improved edge prominence and contrast enhancement techniques are an effective approach to solve this problem. This paper proposes two novel techniques, namely, Intensity Mapped Unsharp Masking (IMUM) which provides a much finer outline of the face image by reducing the background intensity, and Laplacian of Gaussian based filtering with Scalar Multiplier (LOGSM) which provides an improved edge detection. Individual stages of the FR System are examined and an attempt is made to improve each stage. A Binary Particle Swarm Optimization (BPSO) based feature selection algorithm is used to search the feature vector space for the optimal feature subset. Experimental results, obtained by applying the proposed algorithm on ORL, UMIST, Extended YaleB, ColorFERET face databases, show that the proposed system outperforms other FR systems. A significant increase in the overall recognition rate and a substantial reduction in the selected features are observed
Electronic structures of CrX (X=S, Te) studied by Cr 2p soft x-ray magnetic circular dichroism
Cr 2p core excited XAS and XMCD spectra of ferromagnetic CrTe
with several concentrations of =0.11-0.33 and ferrimagnetic
CrS have been measured. The observed XMCD lineshapes are found to
very weakly depend on for CrTe. The experimental results
are analyzed by means of a configuration-interaction cluster model calculation
with consideration of hybridization and electron correlation effects. The
obtained values of the spin magnetic moment by the cluster model analyses are
in agreement with the results of the band structure calculation.The calculated
result shows that the doped holes created by the Cr deficiency exist mainly in
the Te 5porbital of CrTe, whereas the holes are likely to be in Cr
3d state for CrS.Comment: 8 pages, 6 figures, accepted for publication in Physical Review
Giant Rashba splitting of quasi-1D surface states on Bi/InAs(110)-(21)
Electronic states on the Bi/InAs(110)-(21) surface and its
spin-polarized structure are revealed by angle-resolved photoelectron
spectroscopy (ARPES), spin-resolved ARPES, and density-functional-theory
calculation. The surface state showed quasi-one-dimensional (Q1D) dispersion
and a nearly metallic character; the top of the hole-like surface band is just
below the Fermi level. The size of the Rashba parameter ()
reached quite a large value (5.5 eV\AA). The present result would provide
a fertile playground for further studies of the exotic electronic phenomena in
1D or Q1D systems with the spin-split electronic states as well as for advanced
spintronic devices.Comment: 8 pages (double column), 7 figures and 1 tabl
Observation of spin-polarized bands and domain-dependent Fermi arcs in polar Weyl semimetal MoTe
We investigate the surface electronic structures of polar 1T'-MoTe2, the Weyl
semimetal candidate realized through the nonpolar-polar structural phase
transition, by utilizing the laser angle-resolved photoemission spectroscopy
(ARPES) combined with first-principles calculations. Two kinds of domains with
different surface band dispersions are observed from a single-crystalline
sample. The spin-resolved measurements further reveal that the spin
polarizations of the surface and the bulk-derived states show the different
domain-dependences, indicating the opposite bulk polarity. For both domains,
some segment-like band features resembling the Fermi arcs are clearly observed.
The patterns of the arcs present the marked contrast between the two domains,
respectively agreeing well with the slab calculation of (0 0 1) and (0 0 -1)
surfaces. The present result strongly suggests that the Fermi arc connects the
identical pair of Weyl nodes on one side of the polar crystal surface, whereas
it connects between the different pairs of Weyl nodes on the other side.Comment: 13 pages, 4 figure
Evidence of non-thermal X-ray emission from radio lobes of Cygnus A
Using deep Chandra ACIS observation data for Cygnus A, we report evidence of
non-thermal X-ray emission from radio lobes surrounded by a rich intra-cluster
medium (ICM). The diffuse X-ray emission, which are associated with the eastern
and western radio lobes, were observed in a 0.7--7 keV Chandra$ ACIS image. The
lobe spectra are reproduced with not only a single-temperature Mekal model,
such as that of the surrounding ICM component, but also an additional power-law
(PL) model. The X-ray flux densities of PL components for the eastern and
western lobes at 1 keV are derived as 77.7^{+28.9}_{-31.9} nJy and
52.4^{+42.9}_{-42.4} nJy, respectively, and the photon indices are
1.69^{+0.07}_{-0.13} and 1.84^{+2.90}_{-0.12}, respectively. The non-thermal
component is considered to be produced via the inverse Compton (IC) process, as
is often seen in the X-ray emission from radio lobes. From a re-analysis of
radio observation data, the multiwavelength spectra strongly suggest that the
seed photon source of the IC X-rays includes both cosmic microwave background
radiation and synchrotron radiation from the lobes. The derived parameters
indicate significant dominance of the electron energy density over the magnetic
field energy density in the Cygnus A lobes under the rich ICM environment.Comment: 8 pages, 5 figures, accepted for publication in Ap
- …