Browsing by Author "Wu, Zheng-Wei"

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Metalworking Industry: Quality Management via Edge Computing-based Cloud Monitoring System
(2019-01-01)
Wu, Zheng-Wei
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Lin, Shang-Chih
;
Hu, Po-Chun
;
Su, Shun-Feng
;
Huang, Yennun
This study uses the edge computing system for fast quality screening in the metal processing industry, and the Internet of Things technology is responsible for delivering data to the cloud for visualization and analysis. First, the system consists of optical components and embedded systems. Further, a fast Fourier transform is used to make the image have frequency characteristics. However, the convolution operation between the random kernel model and the image is the main means of feature extraction. In order to evaluate the performance and convergence of the proposed method, a rapid screening mechanism for good/bad products is defined. Finally, the data is passed to the cloud (ThingSpeak) platform for visualization through the MQTT protocol, and the content is subscribed to the content by the background host to perform the quality decision of the fuzzy inference system. The result is released back to the cloud. The experimental results in the industrial example show that the proposed method can accurately and quickly complete the quality inspection of surface roughness, and the feature distribution is easy to understand. At the same time, the edge computing system has the advantages of instant response and low cost, while the Internet of Things technology brings more management and analysis convenience. In future research, the unsupervised learning algorithm based on convolutional neural networks is a potential application, which can learn the quality of good or bad through a large amount of data.
The Influence of Surface Oxide on the Growth of Metal/Semiconductor Nanowires
(2011-07-01)
Lu, Kuo-Chang
;
Wu, Wen-Wei
;
Ouyang, Hao
;
Lin, Yung-Chen
;
Huang, Yu
We report the critical effects of oxide on the growth of nanostructures through silicide formation. Under an in situ ultrahigh vacuum transmission electron microscope, it is observed from the conversion of Si nanowires into the metallic PtSi grains epitaxially through controlled reactions between lithographically defined Pt pads and Si nanowires. With oxide, instead of contact area, single crystal PtSi grains start forming either near the center between two adjacent pads or from the ends of Si nanowires, resulting in the heterostructure formation of Si/PtSi/Si. Without oxide, transformation from Si into PtSi begins at the contact area between them, resulting in the heterostructure formation of PtSi/Si/PtSi. The nanowire heterostructures have an atomically sharp interface with epitaxial relationships of Si(20-2)//PtSi(10-1) and Si[111]//PtSi[111]. Additionally, it has been observed that; the existence of oxide significantly affects not only the growth position but also the growth behavior and the growth rate by two orders of magnitude. Molecular dynamics simulations have been performed to support our experimental results and the proposed growth mechanisms. In addition to fundamental science, the significance of the study matters for future processing techniques in nanotechnology and related applications as well.