1,853 research outputs found
Betatron modulation of microwave instability in small isochronous ring
A novel coupling of the transverse betatron motion to the longitudinal
microwave instability is studied. Besides the radial coherent dipole mode space
charge field, simulation and theoretical studies in this paper show that the
longitudinal coherent dipole mode space charge field due to centroid wiggles
also plays an important role in the isochronous regime, it induces betatron
oscillation frequencies in temporal evolutions of spectra of longitudinal
charge densities, radial centroid offsets and coherent energy deviations of
local centroids.Comment: 13 page
Modelling and prediction of foam structure
The primary objective of this thesis is to explore the relationship between the surface
and underlying structure of dry foams. This relationship is important for both research
and industry because the surface film size distribution is typically the only
information available in opaque foams when referring to the underlying bubble size
distribution. This study is carried out by simulating foams with free surfaces.
Firstly, the method of simulating 3D dry foams with free surfaces is presented. The
simulation method is verified for foams with uniform bubble sizes by comparing their
simulation results to experimental values reported in literature. The validity of the
method and its ability to accurately model the structure of both surface and internal
bubbles is demonstrated by the excellent agreement between the experimental study
and the simulation results.
Secondly, the simulation results are shown for the relationship between the surface
film size distribution and the surface bubble size distribution. The results show that,
for a given surface bubble size, there is a distribution of possible surface film sizes.
However, for the range of polydispersity used in this thesis, the distribution of the
ratio of film size to the size of bubble to which it is attached is found to be
independent of the underlying bubble size distribution. A functional form of this
relationship is obtained by nonlinear regression. Based on the functions obtained, the
surface film size distributions can be computed using the underlying surface bubble
size distribution. This is the inverse of what is acquired and therefore a numerical
procedure for obtaining the surface bubble size distributions using the corresponding
surface film size distribution is developed. This method is demonstrated to accurately
reproduce the results from the full structural foam simulations
An Efficient Dynamic Programming Algorithm for the Generalized LCS Problem with Multiple Substring Exclusion Constrains
In this paper, we consider a generalized longest common subsequence problem
with multiple substring exclusion constrains. For the two input sequences
and of lengths and , and a set of constrains
of total length , the problem is to find a common subsequence of and
excluding each of constrain string in as a substring and the length of
is maximized. The problem was declared to be NP-hard\cite{1}, but we
finally found that this is not true. A new dynamic programming solution for
this problem is presented in this paper. The correctness of the new algorithm
is proved. The time complexity of our algorithm is .Comment: arXiv admin note: substantial text overlap with arXiv:1301.718
A note on the largest number of red nodes in red-black trees
In this paper, we are interested in the number of red nodes in red-black
trees. We first present an time dynamic programming solution for
computing , the largest number of red internal nodes in a red-black tree
on keys. Then the algorithm is improved to some time recursive
and nonrecursive algorithms. Based on these improved algorithms we finally find
a closed-form solution of
Complete Solutions for a Combinatorial Puzzle in Linear Time
In this paper we study a single player game consisting of black checkers
and white checkers, called shifting the checkers. We have proved that the
minimum number of steps needed to play the game for general and is . We have also presented an optimal algorithm to generate an optimal
move sequence of the game consisting of black checkers and white
checkers, and finally, we present an explicit solution for the general game
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