1,439 research outputs found
Corners-based composite descriptor for shapes
In this paper, a composite descriptor for shape retrieval is proposed. The composite descriptor is obtained based upon corner-points and shape region. In an earlier paper, we proposed a composite descriptor based on shape region and shape contour, however, the descriptor was not effective for all perspective and geometric transformations. Hence, we modify the composite descriptor by replacing contour features with corner-points features. The proposed descriptor is obtained from Generic FourierDescriptors (GFD) of the shape region and the GFD ofthe corner-points. We study the performance of the proposed composite descriptor. The proposed method is evaluated using Item S8 within the MPEG-7 Still Images Content Set. Experimental results show that the proposed descriptor is effective.<br /
One-loop Structure of Higher Rank Wilson Loops in AdS/CFT
The half-supersymmetric Wilson loop in SYM is arguably the
central non-local operator in the AdS/CFT correspondence. On the field theory
side, the vacuum expectation values of Wilson loops in arbitrary
representations of are captured to all orders in perturbation theory by
a Gaussian matrix model. Of prominent interest are the -symmetric and
-antisymmetric representations, whose gravitational description is given in
terms of D3- and D5-branes, respectively, with fluxes in their world volumes.
At leading order in and the agreement in both cases is exact. In
this note we explore the structure of the next-to-leading order correction in
the matrix model and compare with existing string theory calculations. We find
agreement in the functional dependence on but a mismatch in the numerical
coefficients.Comment: 5 pages, one figure. v2: A crucial minus sign acknowledged; agreement
now claimed only at the functional level. Changes in abstract and tex
CKM and PMNS mixing matrix from flavor symmetry
The relation between quark masses and CKM mixing is studied based on an
approximate chiral flavor symmetry of quark mass
matrix. In mass hierarchy limit, the mass ratio effect to CKM mixing is
suppressed, which separates mass hierarchy and quark flavor mixing into two
independent problems. We show that CKM mixing is dominated by two left-handed
symmetry while mass hierarchy only provides slight corrections.
The same mixing structure is generalized to lepton sector with extended Dirac
neutrinos. The common flavor mixing provides a novel comprehension on the
relation between quark CKM mixing and lepton PMNS mixing.Comment: 6 papers 1 figur
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