Browsing by Author "Chen, ZH"

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A neural network based transcoder for MPEG2 video compression
(1999)
Fu, HC
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Chen, ZH
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Xu, YY
;
Wang, CH
;
資訊工程學系
In this paper, we proposed a neural network method for the high efficiency requatization in the design of a transcoder In our design, there are two types of video bitrate control in the proposed transcoder. One is the global adjusting of quantizer scales in which the adjusting is based on the complication of the whole frame, the other is the adaptive adjusting of quantizer scales, that the adjusting is the complication of the current macroblock. From our experimental results, the prototype transcoder can achieve desirable bitrate (1.5 Mbps) with an acceptable image quality. In additional, we constructed a video multiplexer for PPV or NVOD applications on the proposed transcoder.
Near-infrared femtosecond laser-induced crystallization of amorphous silicon
(2004-08-16)
Shieh, JM
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Chen, ZH
;
Dai, BT
;
Wang, YC
;
Zaitsev, A
Amorphous silicon (a-Si) was crystallized by femtosecond laser annealing (FLA) using a near-infrared (lambdaapproximate to800 nm) ultrafast Ti:sapphire laser system. The intense ultrashort laser pulses lead to efficient nonlinear photoenergy absorption and the generation of very dense photoexcited plasma in irradiated materials, enabling nonlinear melting on transparent silicon materials. We studied the structural characteristics of recrystallized films and found that FLA assisted by spatial scanning of laser strip spot constitutes superlateral epitaxy that can crystallize a-Si films with largest grains of similar to800 nm, requiring laser fluence as low as similar to45 mJ/cm(2), and low laser shots. Moreover, the optimal annealing conditions are observed with a significant laser-fluence window (similar to30%). (C) 2004 American Institute of Physics.