Browsing by Author "Tan, YH"

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On existence and construction of stabilizing switching laws between two unstable linear systems
(2005)
Liang, YW
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Tan, YH
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Xu, SD
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Chang, JL
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電控工程研究所
Issues regarding the application of two equivalent sufficient conditions for the existence of stabilizing switching laws between two unstable linear systems are studied. One of the conditions is effective for theoretical derivation, while the other is easily implementable. To further understand the geometrical insight of the conditions, an equivalent condition involving the information of eigenvalues and eigenvectors of system dynamics is presented for planar cases. With the help of the equivalent relation, a condition for the existence of controllers and stabilizing switching laws between two unstabilizable linear control systems is also presented. The controllers and stabilizing switching laws are explicitly constructed through the use of an existed algorithm.
Transport spectroscopy in a time-modulated open quantum dot
(2003-05-15)
Tang, CS
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Tan, YH
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Chu, CS
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電子物理學系
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Department of Electrophysics
We have investigated the time-modulated coherent quantum transport phenomenon in a ballistic open quantum dot. Conductance G and the electron dwell time in the dots are calculated by a time-dependent mode-matching method. Under high-frequency modulation, the traversing electrons are found to exhibit three types of resonant scatterings. They are intersideband scatterings into quasibound states in the dots, into true bound states in the dots, and into quasibound states just beneath the subband threshold in the leads. Dip structures or fano structures in G are their signatures. Our results show structures due to 2 (h) over bar omega intersideband processes. At the above scattering resonances, we have estimated, according to our dwell time calculation, the number of round-trip scatterings which the traversing electrons undertake between the two dot openings.