3,520 research outputs found
Tree Contractions and Evolutionary Trees
An evolutionary tree is a rooted tree where each internal vertex has at least
two children and where the leaves are labeled with distinct symbols
representing species. Evolutionary trees are useful for modeling the
evolutionary history of species. An agreement subtree of two evolutionary trees
is an evolutionary tree which is also a topological subtree of the two given
trees. We give an algorithm to determine the largest possible number of leaves
in any agreement subtree of two trees T_1 and T_2 with n leaves each. If the
maximum degree d of these trees is bounded by a constant, the time complexity
is O(n log^2(n)) and is within a log(n) factor of optimal. For general d, this
algorithm runs in O(n d^2 log(d) log^2(n)) time or alternatively in O(n d
sqrt(d) log^3(n)) time
Multi-Objective Optimal Experimental Designs for ER-fMRI Using MATLAB
Designs for event-related functional magnetic resonance imaging (ER-fMRI) that help to efficiently achieve the statistical goals while taking into account the psychological constraints and customized requirements are in great demand. This is not only because of the popularity of ER-fMRI but also because of the high cost of ER-fMRI experiments; being able to collect highly informative data is crucial. In this paper, we develop a MATLAB program which can accommodate many user-specified experimental conditions to efficiently find ER-fMRI optimal designs.
Another look at charge fractionalization at finite temperature
We study again the phenomenon of charge fractionalization at finite
temperature. Our calculations are done in a framework in which the connection
between the induced fermion number and the chiral anomaly is manifest. We find
that the fractional fermion number induced on a soliton decreases as
temperature rises and vanishes at infinite temperature at one-loop level. These
results are consistent with previous studies. As an application of our
approach, we have also studied the behavior of the induced Chern-Simons term in
the (2+1)-dimensional QED at finite temperature.Comment: 9 pages, 2 figure
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