74,534 research outputs found
Parallel processing for digital picture comparison
In picture processing an important problem is to identify two digital pictures of the same scene taken under different lighting conditions. This kind of problem can be found in remote sensing, satellite signal processing and the related areas. The identification can be done by transforming the gray levels so that the gray level histograms of the two pictures are closely matched. The transformation problem can be solved by using the packing method. Researchers propose a VLSI architecture consisting of m x n processing elements with extensive parallel and pipelining computation capabilities to speed up the transformation with the time complexity 0(max(m,n)), where m and n are the numbers of the gray levels of the input picture and the reference picture respectively. If using uniprocessor and a dynamic programming algorithm, the time complexity will be 0(m(3)xn). The algorithm partition problem, as an important issue in VLSI design, is discussed. Verification of the proposed architecture is also given
Dominant moving species in the formation of amorphous NiZr by solid-state reaction
The displacements of W and Hf markers have been monitored by backscattering of MeV He to study the growth of the amorphous NiZr phase by solid-state reaction. We find that the Ni is the dominant moving species in this reaction
Effect of thermodynamics on ion mixing
Ion mixing of elemental 4d-5d metallic bilayers at 77 K by 600 keV Xe + + ions has been studied to test the validity of the phenomenological model of ion mixing that predicts a dependence on the chemical heats of mixing, DeltaHmix, and on the cohesive energies, DeltaHcoh, of the bilayer elements. A series of samples was chosen to minimize the variation in kinematical properties between samples while maximizing the variation in heats of mixing. The experimental results agree well with the model's predictions, and the experimentally determined constants K1=0.034 Ã… and K2=27 agree with those of previous work
Chirally symmetric but confining dense and cold matter
The folklore tradition about the QCD phase diagram is that at the chiral
restoration phase transition at finite density hadrons are deconfined and there
appears the quark matter. We address this question within the only known
exactly solvable confining and chirally symmetric model. It is postulated
within this model that there exists linear Coulomb-like confining interaction.
The chiral symmetry breaking and the quark Green function are obtained from the
Schwinger-Dyson (gap) equation while the color-singlet meson spectrum results
from the Bethe-Salpeter equation. We solve this model at T=0 and finite
chemical potential and obtain a clear chiral restoration phase transition
at the critical value \mu_{cr}. Below this value the spectrum is similar to the
previously obtained one at \mu = 0. At \mu > \mu_{cr} the quarks are still
confined and the physical spectrum consists of bound states which are arranged
into a complete set of exact chiral multiplets. This explicitly demonstrates
that a chirally symmetric matter consisting of confined but chirally symmetric
hadrons at finite chemical potential is also possible in QCD. If so, there must
be nontrivial implications for astrophysics.Comment: 7 pp; the paper has been expanded to make some technical details more
clear; 3 new figures have been added. To appear in PR
Correlation between the cohesive energy and the onset of radiation-enhanced diffusion in ion mixing
A correlation between the cohesive energy of elemental solids and the characteristic temperature Tc for the onset of radiation-enhanced diffusion during ion mixing is established. This correlation enables one to predict the onset of radiation-enhanced diffusion for systems which have not yet been investigated. A theoretical argument based on the current models of cascade mixing and radiation-enhanced diffusion is provided as a basis for understanding this observation
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