161 research outputs found
On Multistage Learning a Hidden Hypergraph
Learning a hidden hypergraph is a natural generalization of the classical
group testing problem that consists in detecting unknown hypergraph
by carrying out edge-detecting tests. In the given paper we
focus our attention only on a specific family of localized
hypergraphs for which the total number of vertices , the number of
edges , , and the cardinality of any edge ,
. Our goal is to identify all edges of by
using the minimal number of tests. We develop an adaptive algorithm that
matches the information theory bound, i.e., the total number of tests of the
algorithm in the worst case is at most . We also discuss
a probabilistic generalization of the problem.Comment: 5 pages, IEEE conferenc
Collapse of the critical state in superconducting niobium
Giant abrupt changes in the magnetic flux distribution in niobium foils were
studied by using magneto-optical visualization, thermal and magnetic
measurements. Uniform flux jumps and sometimes almost total catastrophic
collapse of the critical state are reported. Results are discussed in terms of
thermomagnetic instability mechanism with different development scenarios.Comment: arXiv.org produced artifacts in color images (three versions were
attempts to make better images). Download clean PDF and watch video-figures
at: "http://cmp.ameslab.gov/supermaglab/video/Nb.html
- …