Browsing by Author "Lin, C. -C."

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A comprehensive study of enhanced characteristics with localized transition in interface-type vanadium-based devices
(2020-06-01)
Lin, C. -Y.
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Chen, P. -H.
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Chang, T. -C.
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Huang, W. -C.
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Tan, Y. -F.
In this research, we investigated the conduction mechanism in metal-insulator transition (MIT) materials. Among these MIT materials (NbOx, NiOx, VOx, and TaS2), vanadium oxide-based selectors have been widely investigated because of their high switching speed (similar to 10-ns transition time), sufficient nonlinearity (>10(3)), and endurance stability (similar to 10(10)). Abnormal temperature-dependent degradation in the high resistive state was observed, as was studied in detail by a current fitting analysis and explored theoretically by electric (E-MIT) and thermal (T-MIT) modeling. The results suggest the existence of a MIT region located between the electrode and the localized filament. To improve the localized transition efficiency, we propose an enhanced-type MIT architecture to bypass the E-MIT and T-MIT universal rule with the novel structure of vanadium top electrode device. As compared with a vanadium oxide middle-layer device, the electrical transition efficiency is improved 2-fold as evidenced by thermal cycling material analysis, as well as boosting endurance reliability to 10(7) at 65 degrees C. Finally, for the first time, a potential neuromorphic computing application featuring a damping oscillator has been demonstrated in this enhanced-type MIT architecture, with a high damping ratio with 10-fold smaller area and 5-fold smaller energy than complementary metal-oxide-semiconductor (CMOS) devices. This presents a promising milestone for ultralow power neuromorphic system design and solutions in the near future. (C) 2020 Elsevier Ltd. All rights reserved.
A high-payload, reversible data hiding scheme based on histogram modification in JPEG bitstream
(2016)
Liu, X. -L.
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Chang, C. -C.
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Lin, C. -C.
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Yuan, S. -M.
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資訊工程學系
In this paper, we have presented a high-payload, reversible data hiding scheme that is focused on embedding secret data into joint photographic experts group (JPEG) bitstream by using histogram modification. In JPEG, for AC coefficients, 162 different variable length codes (VLCs) are defined and assigned by Huffman coding for all 162 run/size possibilities. After parsing VLC usage in the bitstream, we generated a histogram of run/size. According to a peak point and the nearest zero point of the histogram, the secret data were embedded by modifying the corresponding VLC values slightly. The experimental results and comparing the performance of our scheme with those of other existing schemes demonstrated that the proposed scheme preserved the quality of the image with no distortion and achieved the goal of high embedding capacity.
Key factors contributing to the failure of VITEK 2 to distinguish Candida tropicalis from Candida parapsilosis
(2013-06-01)
Yang, Y. -L.
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Chu, W. -L.
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Lin, C. -C.
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Tsai, S. -H.
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Lo, H. -J.
Oropharyngeal yeast colonization in HIV-infected outpatients in southern Taiwan: CD4 count, efavirenz therapy and intravenous drug use matter
(2012-05-01)
Wu, C. -J.
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Lee, H. -C.
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Yang, Y. -L.
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Chang, C. -M.
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Chen, H. -T.
To understand the status of oropharyngeal yeast colonization in human immunodeficiency virus (HIV) -infected outpatients in the era of highly active antiretroviral therapy (HAART), we conducted a prospective, cross-sectional study from October 2009 to January 2010 at a medical centre in southern Taiwan. Fungal cultures of the oropharyngeal swabs were performed on 327 enrolled patients. At enrolment, 258 (79%) patients had been receiving HAART, and 42 (12.8%), 73 (22.3%) and 212 (64.8%) patients had CD4 cell counts =200, 201350, and >350 cells/mm3, respectively. Oral yeast colonization was detected in 193 (59%) patients, among whom 157 (81.3%), 25 (13.0%), and 11 (5.7%) were colonized by a single, two and more than two species, respectively. Multivariate analysis showed that receipt of efavirenz-containing regiments and CD4 cell counts >200 cells/mm3 were associated with lower risks of oral yeast colonization, while intravenous drug users were at a higher risk. Among the 241 isolates recovered, Candida albicans accounted for 69.7%, followed by C.similar to dubliniensis (9.5%), C.similar to glabrata (8.3%), C similar to tropicalis (3.3%), C.similar to intermedia (2.1%), C.similar to parapsilosis (1.7%), and 11 other species (5.4%). Overall, 230 (95.4%), 236 (97.9%) and 240 (99.6%) isolates were susceptible to fluconazole, voriconazole and amphotericin B, respectively. In conclusion, colonization by C.similar to dubliniensis has emerged in recent years. In addition to a CD4 cell count =200 cells/mm3, which is a known risk factor for oropharyngeal yeast colonization in HIV-infected patients that was identified in our previous studies, two risk factors, non-receipt of efavirenz-based combinations and intravenous drug use, were first identified in the present study. Fluconazole remained effective in vitro against the yeasts colonizing the oropharynx in this population.
THE MESH PROPERTY OF THE STEEL INVOLUTE CYLINDRICAL WORM WITH A PLASTIC INVOLUTE HELICAL GEAR
(2014-04-01)
Liu, Z. -Y.
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Huang, C. -C.
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Hao, Y. -H.
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Lin, C. -C.
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機械工程學系
With the increasing use of plastic gears in substitution of conventional steel ones, a plastic involute helical gear has been introduced to engage with a steel involute worm thus forming a novel plastic-steel worm-gear pair. The geometry and kinematics of this kind of worm-gear pair has been established first to derive its meshing properties which have been further verified by the finite element simulation. And it turns out that the contact area of this worm-gear pair is a point or an ellipse instead of a line. Further, a discrete dynamic model has been applied to investigate the dynamic transmission of motion and power of this worm-gear pair through the dynamic mesh force and the driven plastic involute helical gear. And the effects of angular and distance assembling errors have also been included.