Browsing by Author "Wu, J. Y."

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DIGITAL ELEVATION QUALITY DERIVED FROM MEDIUM-FORMAT DIGITAL CAMERAS
(2013-12-01)
Shih, P. T. Y.
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Wu, J. Y.
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Teo, T. A.
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Tsai, J. C.
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交大名義發表
Medium-format digital cameras are a useful tool in airborne lidar missions to produce digital ortho-images. This study investigates the quality of digital elevation models (DEMs) and digital surface models (DSMs) derived from such cameras. An image-matching strategy is used to produce height information from highly overlapping images and the quality of the derived height information is analysed using synchronous lidar point clouds as the reference data. The evaluation focused on various types of land cover and DEM generation methods. The RMSE between lidar and image-derived height information for two datasets was 0054% and 0027% of the flying height in flat, bare-earth areas, but studies with manually edited vegetated areas using stereo photogrammetry revealed high uncertainties, especially in steep terrain.
Inactivation of E. coli and B. subtilis by a parallel-plate dielectric barrier discharge jet
(2010-08-15)
Chiang, M. H.
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Wu, J. Y.
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Li, Y. H.
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Wu, J. S.
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Chen, S. H.
Inactivation of Escherichia coli and Bacillus subtilis using the jet region of a parallel-plate air dielectric barrier discharge (DBD) driven by a distorted sinusoidal voltage power supply under atmospheric-pressure condition is reported. Various types of working gases, including pure N(2), pure O(2), and compressed air, were tested. Discharges were characterized electrically by measuring the discharge current, applied voltage and absorbed power, and optically by measuring the optical emission spectra in the UV-visible range and absorption spectra in the IR range. Results of survival rate show that both E. coil and B. subtilis cells (up to 10(7) CFU/mL) can be effectively inactivated using less than 18 passes (1.8 s of residence time in total) of exposure to the post-discharge jet region of compressed air and oxygen discharges at different treating distances in the range of 4-20 mm. Among these, the compressed-air discharge performs the best in inactivating both two types of the bacterial cells, because of the abundant ozone generation and probably through the assistance of nitrous oxide generated in the discharge. In summary, the post-discharge jet region of an oxygen-contained parallel-plate DBD driven by a distorted sinusoidal voltage power driven is very effective in inactivating both E. coli and B. subtilis cells under the present test conditions. Crown Copyright (c) 2010 Published by Elsevier B.V. All rights reserved.
Single-photon avalanche diodes in 0.18-mu m high-voltage CMOS technology
(2017-06-12)
Huang, L. D.
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Wu, J. Y.
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Wang, J. P.
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Tsai, C. M.
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Huang, Y. H.
We have designed and fabricated high-performance single-photon avalanche diodes (SPADs) by using 0.18-mu m high-voltage CMOS technology. Without any technology customization. the SPADs have low dark-count rate, high photon-detection probability, low afterpulsing probability, and acceptable timing jitter and breakdown voltage. Our design provides a low-cost and high-performance SPAD for various applications. (C) 2017 Optical Society of America
Superconductivity in an Aluminum Film Grown by Molecular Beam Epitaxy
(2012-08-01)
Liang, C. -T.
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Yeh, M. -R.
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Lin, S. D.
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Lin, S. W.
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Wu, J. Y.
We report on superconductivity in an aluminum film grown on a GaAs substrate by molecular beam epitaxy (MBE). We show that the quality of the MBE-grown sample is better than that of its counterpart prepared by electron gun evaporation. This is evidenced by the observed much lower resistivity, higher critical current, longer coherence length, and downward critical field-temperature characteristic H-c(T). Our results suggest that a MBE-grown Al thin film can be used to study superconductivity in a relatively clean metal.
Suppressing Device Variability by Cryogenic Implant for 28-nm Low-Power SoC Applications
(2012-10-01)
Yang, C. L.
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Tsai, C. H.
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Li, C. I.
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Tzeng, C. Y.
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Lin, G. P.
In this letter, we have demonstrated that cryogenic implant in the source and drain formation offers advantages for reducing the threshold voltage mismatch in pMOSFET. A discrete dopant profiling method is used to verify the presence of boron out-diffusion from the drain, which further induces the random dopant fluctuation. Results show that this boron out-diffusion can be greatly reduced in this new process. Two major factors in improving the device variability by cryogenic implant are discussed, i.e., the polysilicon grain size control and the embedded-SiGe dislocation defect reduction during source and drain formation.
The Effects of the Modulated Magnetic Fields on Electronic Structures of Graphene Nanoribbons
(2009-05-01)
Wu, J. Y.
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Chiu, Y. H.
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Lien, J. Y.
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Lin, M. F.
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物理研究所
The low-energy magnetoelectronic structures of nanographene ribbons under a modulated magnetic field are investigated by the Peierls tight-binding model. They are dominated by the field strength, period, phase, the ribbon width, and edge structure. The modulated magnetic field could add state degeneracy, modify energy dispersions, alter subband spacings, affect carrier-density distributions, create additional band-edge states, and cause semiconductor-metal transitions. The main features of energy bands are directly reflected in density of states, such as the position, height, structure, and number of the prominent peaks. These results immensely differ from those in a uniform magnetic field. Significant differences between a 1D graphene ribbon and a 2D electron gas are also found.