Security state monitoring method for perception node in power Internet of things based on low rank model

Author(s):  
Dangdang Dai ◽  
Rongtao Liao ◽  
Zhihua Xiao ◽  
Yixi Wang
2017 ◽  
Vol 13 (7) ◽  
pp. 155014771772181 ◽  
Author(s):  
Seok-Woo Jang ◽  
Gye-Young Kim

This article proposes an intelligent monitoring system for semiconductor manufacturing equipment, which determines spec-in or spec-out for a wafer in process, using Internet of Things–based big data analysis. The proposed system consists of three phases: initialization, learning, and prediction in real time. The initialization sets the weights and the effective steps for all parameters of equipment to be monitored. The learning performs a clustering to assign similar patterns to the same class. The patterns consist of a multiple time-series produced by semiconductor manufacturing equipment and an after clean inspection measured by the corresponding tester. We modify the Line, Buzo, and Gray algorithm for classifying the time-series patterns. The modified Line, Buzo, and Gray algorithm outputs a reference model for every cluster. The prediction compares a time-series entered in real time with the reference model using statistical dynamic time warping to find the best matched pattern and then calculates a predicted after clean inspection by combining the measured after clean inspection, the dissimilarity, and the weights. Finally, it determines spec-in or spec-out for the wafer. We will present experimental results that show how the proposed system is applied on the data acquired from semiconductor etching equipment.


2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Chunxiao Xue ◽  
Kaichong Li ◽  
Lingwei Kong

China is the country with the longest mileage in the construction of sandstorms in the world. The railway system is often affected by wind sand flow, which seriously affects the operation safety of trains. Firstly, this article introduces the formation mechanism, movement state, monitoring method and structural characteristics of the wind-sand flow. Then the sand hazard formation mechanism of railway embankments, cuts, bridges and culverts is explained based on aerodynamic performance. Moreover, the sand prevention measures are classified, and the advantages and disadvantages of various measures are discussed. Finally, two kinds of sand prevention and control systems are proposed in combination with the topography and regional wind-sand flow characteristics, and the problems that need to be solved urgently in the prevention and treatment of railway sand and sand disasters in the future are prospected.


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