Browsing by Author "Chang, F. H."

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The identification of positive clones in a general inhibitor model
(2007-11-01)
Hwang, F. K.
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Chang, F. H.
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應用數學系
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Department of Applied Mathematics
In using pooling designs to identify clones containing a specific subsequence called positive clones, sometimes there exist nonpositive clones which can cancel the effect of positive clones. Various models have been studied which differ in the power of cancellation. Although the various models pose interesting mathematical problems, and ingenious constructions of pooling designs have been proposed, in practice we rarely are sure about the true model and thus about which pooling design to use. In this paper we give a pooling design which fits all inhibitor models, and does not use more tests than in the more specific models. In particular, we obtain a I-round pooling design for the k-inhibitor model for which only sequential designs are currently known. (c) 2007 Elsevier Inc. All rights reserved.
The minimum number of e-vertex-covers among hypergraphs with e edges of given ranks
(2009-01-06)
Chang, F. H.
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Fu, H. L.
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Hwang, F. K.
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Lin, B. C.
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應用數學系
We study the problem that among all hypergraphs with e edges of ranks l(1), ..., l(e) an v vertices, which hypergraph has the least number of vertex-covers of size e. The problem is very difficult and we only get some partial answers. We show an application of our results to improve the error-tolerance of a pooling design proposed in the literature. (c) 2008 Elsevier B.V. All rights reserved.