Browsing by Author "Chang, Wei-Chiao"

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EEG analysis of mixed-reality music rehabilitation system for post-stroke lower limb therapy
(2019-06-01)
Chang, Wei-Chiao
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Ko, Li-Wei
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Yu, Kuen-Han
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Ho, Yu-Chun
;
Chen, Chia-Hsin
Lots of evidence and guidelines recommended that stroke patients have to do the rehabilitation all the time, but in fact, the ratio of patients doing the rehabilitation is usually less than one third. In order to enhance the rehabilitation efficacy, we develop an innovative mixed-reality music rehabilitation (MR2) system, which is consisted of an MR goggle, inertial measurement unit sensors, and an EEG system. Several music contents with different levels are implemented into the MR system. While doing the rehabilitation task, our system can monitor patient's both gait information and electroencephalographic (EEG) signals to understand the rehabilitation performance in both central and peripheral nervous systems. The MR2 system has been pilot testing on two stroke patients and three healthy controls. Experiment results show that the patient's motor function is significantly activating when wearing the MR2 system during the rehabilitation task. Furthermore, the gait analysis results also show that flexion angle of the hemiplegic knee during walking was significantly improved when following the tempo of the MR music content in the rehabilitation. The pilot testing results provide new insights into the understanding of complex brain functions of patients actively and continuously performing the rehabilitation ordinary tasks within the mixed-reality applications.
Investigation of resistive switching in copper/InGaZnO/Al2O3-based memristor
(2019-09-30)
Gan, Kai-Jhih
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Chang, Wei-Chiao
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Liu, Po-Tsun
;
Sze, Simon M.
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電子工程學系及電子研究所
This work investigates the resistive switching mechanism in the Cu/TiW/InGaZnO/Al2O3/Pt-based memristor. By introducing the Al2O3 layer, the nanoscale diameter of the Cu filament decreased from 6.51 to 0.83 nm as the current compliance decreases from 1 mA to 50 mu A. The resistive switching memory characteristics, such as a large ratio of high-resistance state (HRS)/low-resistance state (LRS) (similar to 10(7)), stable switching cycle stability (>9 x 10(2)), and multilevel operation, are observed and apparently improved compared to the counterpart of the Cu/TiW/InGaZnO/Pt memory device. These results are attributed to the control of Cu formation/dissolution by introducing the Al2O3 nanolayer at the InGaZnO/Pt interface. The findings of this study can not only improve the performance of the amorphous InGaZnO memristor but also be promising for potential applications of next-generation flat-panel displays in wearable devices.
The Influence of Annealing Temperature on Amorphous Indium-Zinc-Tungsten Oxide Thin-Film Transistors
(2018-03-21)
Fu, Ruofan
;
Yang, Jianwen
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Chang, Wei-Chiao
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Chang, Wei-Cheng
;
Chang, Chien-Min
In this paper, the influence of annealing temperature on amorphous indium-zinc-tungsten-oxide (a-IZWO) thin-film transistors (TFTs) is investigated. As the annealing temperature increases, the IZWO films maintain an amorphous state, which is conducive to the uniformity of the TFT. The field effect mobility of the device increases as a function of annealing temperature and reaches 16.2cm(2)V(-1)s(-1) at 300 degrees C, along with an on/off current ratio of 1.6x10(8). Meanwhile, the corresponding positive bias stability is improved, as confirmed by the fact that the threshold voltage shift value reduces to 0.4V after being stressed for 1500s. This result can be ascribed to the decrease in electrons captured by the deep defects in a-IZWO TFTs.