149 research outputs found
A generalization of the integer linear infeasibility problem
Does a given system of linear equations with nonnegative constraints have an
integer solution? This is a fundamental question in many areas. In statistics
this problem arises in data security problems for contingency table data and
also is closely related to non-squarefree elements of Markov bases for sampling
contingency tables with given marginals. To study a family of systems with no
integer solution, we focus on a commutative semigroup generated by a finite
subset of and its saturation. An element in the difference of the
semigroup and its saturation is called a ``hole''. We show the necessary and
sufficient conditions for the finiteness of the set of holes. Also we define
fundamental holes and saturation points of a commutative semigroup. Then, we
show the simultaneous finiteness of the set of holes, the set of non-saturation
points, and the set of generators for saturation points. We apply our results
to some three- and four-way contingency tables. Then we will discuss the time
complexities of our algorithms.Comment: This paper has been published in Discrete Optimization, Volume 5,
Issue 1 (2008) p36-5
Statistical analysis on detecting recombination sites in DNA-beta satellites associated with the old world geminiviruses
Although an exchange of genetic information by recombination plays an
important role in the evolution of viruses, it is not clear how it generates
diversity. {\it Geminiviruses} are plant viruses which have ambisense
single-stranded circular DNA genomes and one of the most economically important
plant viruses in agricultural production. Small circular single-stranded DNA
satellites, termed DNA-, have recently been found associated with some
geminivirus infections. In this paper we analyze a satellite molecule
DNA- of geminiviruses for recombination events using phylogenetic and
statistical analysis and we find that one strain from ToLCMaB has a
recombination pattern and is possibly recombinant molecule between two strains
from two species, PaLCuB-[IN:Chi:05] (major parent) and ToLCB-[IN:CP:04] (minor
parent).Comment: 8 figures and 2 tables. To appear in Frontiers in Systems Biolog
Network Classification with Incomplete Information
NPS NRP Executive SummaryNetwork Classification with Incomplete InformationOffice of Naval Intelligence (ONI)This research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.
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