Browsing by Author "Lai, SC"

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Mechanism for slow switching effect in advanced low-voltage, high-speed Pb(Zr1-XTiX)O-3 ferroelectric memory
(2005-06-01)
Tsai, CW
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Lai, SC
;
Yen, CT
;
Lien, HM
;
Lung, HL
Slow-switching effect in PZT ferroelectric memory under low-voltage and high-speed operation is observed. The slow-switching effect becomes worse at lower operation voltage and elevated temperature. This effect significantly reduces the sensing margin and causes severe reliability issue for advanced ferroelectric memory, particularly for low-voltage and high-speed applications. This slow-switching effect is believed to be attributed to slowing down of polarization switching caused by band bending from Schottky built-in potential at the electrode/ferroelectric interface. The proposed mechanism is supported by the polarity dependence in an asymmetric LNO/PZT/Pt sample.
Structural analysis model for mat foundations
(1996-09-01)
Liou, GS
;
Lai, SC
;
交大名義發表
;
土木工程學系
;
National Chiao Tung University
A simplified structural analysis model for mat foundations with grid floor beams as stiffeners is presented here. In the model, the Winkler type of subgrade reaction spring is assumed for the whole area under the mar foundation, and the yield-line theory of slab is used to lump the Winkler springs under slabs to the corresponding locations under the adjacent floor beams of the slabs. Therefore, each floor beam is now supported by springs with a segmentally linearly varied spring constant. The total analysis model for the mat foundation is then simplified to be a grid beam system on an elastic foundation with a segmentally linearly varied spring constant, and is subjected to loadings from the columns of the building structure. Some numerical comparisons with the results by a sophisticated finite-element model are made in order to demonstrate the effectiveness and efficiency of the presented analysis model.