57,161 research outputs found
Acyclic orientations on the Sierpinski gasket
We study the number of acyclic orientations on the generalized
two-dimensional Sierpinski gasket at stage with equal to
two and three, and determine the asymptotic behaviors. We also derive upper
bounds for the asymptotic growth constants for and -dimensional
Sierpinski gasket .Comment: 20 pages, 8 figures and 6 table
Some Exact Results for Spanning Trees on Lattices
For -vertex, -dimensional lattices with , the number
of spanning trees grows asymptotically as
in the thermodynamic limit. We present an exact closed-form result for the
asymptotic growth constant for spanning trees on the
-dimensional body-centered cubic lattice. We also give an exact integral
expression for on the face-centered cubic lattice and an exact
closed-form expression for on the lattice.Comment: 7 pages, 1 tabl
Turbulence Time Series Data Hole Filling using Karhunen-Loeve and ARIMA methods
Measurements of optical turbulence time series data using unattended
instruments over long time intervals inevitably lead to data drop-outs or
degraded signals. We present a comparison of methods using both Principal
Component Analysis, which is also known as the Karhunen--Loeve decomposition,
and ARIMA that seek to correct for these event-induced and mechanically-induced
signal drop-outs and degradations. We report on the quality of the correction
by examining the Intrinsic Mode Functions generated by Empirical Mode
Decomposition. The data studied are optical turbulence parameter time series
from a commercial long path length optical anemometer/scintillometer, measured
over several hundred metres in outdoor environments.Comment: 8 pages, 9 figures, submitted to ICOLAD 2007, City University,
London, U
Spanning Trees on Lattices and Integration Identities
For a lattice with vertices and dimension equal or higher
than two, the number of spanning trees grows asymptotically
as in the thermodynamic limit. We present exact integral
expressions for the asymptotic growth constant for spanning trees
on several lattices. By taking different unit cells in the calculation, many
integration identities can be obtained. We also give on the
homeomorphic expansion of -regular lattices with vertices inserted on
each edge.Comment: 15 pages, 3 figures, 1 tabl
Study on laser welding of dual phase steel
In this paper, Neodymium-doped Yttrium Aluminum Garnet crystal laser welding machine is used to study the laser welding process of dual phase steel. The electric current, pulse width and frequency are selected as variables for welding, and the maximum force of weldment under different parameters is detected by tensile testing machine. Through the analysis of the experimental results, find out the influence of different parameters on the welding quality, select the best welding parameters. The analysis shows that the current has the most significant effect on the welding quality, followed by the frequency, and the pulse width has almost no effect
Study on laser welding of dual phase steel
In this paper, Neodymium-doped Yttrium Aluminum Garnet crystal laser welding machine is used to study the laser welding process of dual phase steel. The electric current, pulse width and frequency are selected as variables for welding, and the maximum force of weldment under different parameters is detected by tensile testing machine. Through the analysis of the experimental results, find out the influence of different parameters on the welding quality, select the best welding parameters. The analysis shows that the current has the most significant effect on the welding quality, followed by the frequency, and the pulse width has almost no effect
Spanning trees on the Sierpinski gasket
We obtain the numbers of spanning trees on the Sierpinski gasket
with dimension equal to two, three and four. The general expression for the
number of spanning trees on with arbitrary is conjectured. The
numbers of spanning trees on the generalized Sierpinski gasket
with and are also obtained.Comment: 20 pages, 8 figures, 1 tabl
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