Browsing by Author "Wang, Shih-Hao"

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A Low-Power and Bandwidth-Efficient Motion Estimation IP Core Design Using Binary Search
(2009-05-01)
Wang, Shih-Hao
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Tai, Shih-Hsin
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Chiang, Tihao
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
A new architecture design for motion estimation using binary matching criterion is proposed to achieve low power and bus bandwidth efficiency. Low power and high bus bandwidth efficiency are the two key issues for portable video applications. To address such issues, we first study an efficient algorithm called all binary motion estimation (ABME), and analyze its architecture issues in operational flow and bus access. Then, we propose an architecture for ABME with four new features: 1) macroblock level pre-processing; 2) efficient binary pyramid search structure; 3) parallel processing of 8 x 8 and 16 x 16 block searches; 4) parallel processing of bi-directional search. Such architecture leads to a superior performance in bus access, speed, and power. Our experiments show that the power consumption is as low as 763 mu W for IPPPP CIF 30 frames/s and 896 mu W for IPBPB CIF 30 frames/s. The bus bandwidth savings are 54.3% for P-frame search and 67.1% for B-frame search.
Synthesis and characterization of heterocyclic conjugated polymers containing planar benzo[c]cinnoline and tetraazapyrene structures for organic field-effect transistor application
(2019-03-01)
Lee, Shih-Wei
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Chien, Shih-Hsuan
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Chen, Jyh-Chien
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Wang, Shih-Hao
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Wang, Lee-Yih
Heterocyclic conjugated polymers BZCTVT and TAPTVT containing benzo[c]cinnoline (BZC) and tetraazapyrene (TAP), respectively, were prepared by using Stille coupling polymerization in microwave reactor. BZC and TAP act as acceptors and thiophene-vinylene-thiophene (TVT) acts as donors. Alkylated thiophene is the linker between acceptor and donor. This is the first time that tetraazapyrene was incorporated into conjugated polymers. The films of BZCTVT and TAPTVT showed maximum absorption wavelength at 522 and 534 nm, respectively. From cyclic voltammertry measurement, TAPTVT and BZCTVT exhibited low LUMO (-3.61 and -3.47 eV) and HOMO (-5.64 and -5.63 eV) energy levels. Even though BZC and TAP were planar structures, BZCTVT and TAPTVT showed large dihedral angles between alkylated thiophene and TVT (10.8-22.6 degrees), and between alkylated thiophene and BZC and TAP (22.2-30.3 degrees) based on their simulated energy-minimized geometry. The bottom-gate, top-contact OFETs based on TAPTVT and BZCTVT exhibited only p-channel behavior with hole mobility of 4.63 x 10(-4) and 1.04 x 10(-4) cm(2) V-1 s(-1) and current on/off ratios greater than 10(4) after thermal annealing. Grazing incidence X-ray diffraction (GIXRD) patterns suggested that thin films of TAPTVT and BZCTVT preferred edge-on orientation.