Browsing by Author "Hwang, F"

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A construction of pooling designs with some happy surprises
(2005-10-01)
D'yachkov, A
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Hwang, F
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Macula, A
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Vilenkin, P
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Weng, CW
The screening of data sets for "positive data objects" is essential to modern technology. A ( group) test that indicates whether a positive data object is in a specific subset or pool of the dataset can greatly facilitate the identification of all the positive data objects. A collection of tested pools is called a pooling design. Pooling designs are standard experimental tools in many biotechnical applications. In this paper, we use the ( linear) subspace relation coupled with the general concept of a "containment matrix" to construct pooling designs with surprisingly high degrees of error correction ( detection.) Error-correcting pooling designs are important to biotechnical applications where error rates often are as high as 15%. What is also surprising is that the rank of the pooling design containment matrix is independent of the number of positive data objects in the dataset.
Combinatorics and algorithms - Preface
(2002-06-06)
Hwang, F
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Zhu, X
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應用數學系
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Department of Applied Mathematics
Lower bounds for wide-sense nonblocking Clos network
(2001-06-28)
Tsai, KH
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Wang, DW
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Hwang, F
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應用數學系
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Department of Applied Mathematics
The 3-stage Clos network is generally considered the most basic multistage interconnecting network (MIN). The nonblocking property of such network has been extensively studied in the past. However, there are only a few lower bound results regarding wide-sense nonblocking. We show that in the classical circuit switching environment, to guarantee wide-sense nonblocking for large r, 2n - 1 center switches are necessary, where I is the number of input switches and n is the number of inlets of each input switch. For the multirate environment, we show that for large r, any 3-stage Clos network needs atleast 3n - 2 center switches to guarantee wide-sense nonblocking. Our proof works even for the two-rate environment. (C) 2001 Elsevier Science B.V. All rights reserved.
Structure importance of consecutive-k-out-of-n systems
(1999-09-01)
Lin, FH
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Kuo, W
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Hwang, F
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應用數學系
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Department of Applied Mathematics
A consecutive-k-out-of-n : F system is an n-component system that fails when k consecutive components fail. The structure importance is a measure, which indicates the importance of a component relative to its positioning in the system. Through the relationship to the Fibonacci sequence with order k, a closed-form solution of structure importance for each component is obtained. We obtain a complete ordering of the components with respect to their structure importance for some consecutive-k-out-of-n : F systems, and a partial ordering for other systems. (C) 1999 Elsevier Science B.V. All rights reserved.