A Focus Detection Method for Ground-Based Solar Telescope

2017 ◽  
Vol 37 (7) ◽  
pp. 0711003
Author(s):  
方玉亮 Fang Yuliang ◽  
柳光乾 Liu Guangqian ◽  
金振宇 Jin Zhenyu ◽  
李鹏飞 Li Pengfei ◽  
刘 忠 Liu Zhong
2007 ◽  
Vol 364-366 ◽  
pp. 74-79
Author(s):  
Yu Rong Chen ◽  
Xu Dong Yang ◽  
Tie Bang Xie

Focus detection method is one of non-contact profile measurement methods. However, the measurement accuracy of current focus detection method is limited by voice coil motor adopted by it. In this paper, based on an improved Foucault focus detection method, a new non-contact displacement sensor with diffraction grating metrology system is presented. Driven by a piezoelectric actuator instead of a voice coil motor, and a diffraction grating metrology system being with it, the sensor has high measurement accuracy. During surface profile sampling, according to focusing deviation signal, the focusing lens was driven to move vertically by the piezoelectric actuator so that its focus was always located on the workpiece surface, synchronously the vertical displacement of the focusing lens was obtained by the diffraction grating metrology system as the profile height of sampling points. The displacements of all sampling points gave the whole profile of the measured surface, which can be processed by a characterization software to obtain the measurement result. The resolution of the non-contact displacement sensor was 10 nm.


2021 ◽  
Author(s):  
Weiwei Wang ◽  
Xinjie Zhao ◽  
Yanshu Jia

Abstract To improve the diagnostic efficiency and accuracy of corona virus disease 2019 (COVID-19), and to study the application of artificial intelligence (AI) in COVID-19 diagnosis and public health management, the computer tomography (CT) image data of 200 COVID-19 patients are collected, and the image is input into the AI auxiliary diagnosis software based on the deep learning model, "uAI the COVID-19 intelligent auxiliary analysis system", for focus detection. The software automatically carries on the pneumonia focus identification and the mark in batches, and automatically calculates the lesion volume. The result shows that the CT manifestations of the patients are mainly involved in multiple lobes, and in density, the most common shadow is the ground glass opacity. The detection rate of manual detection method is 95.30%, misdiagnosis rate is 0.20% and missed diagnosis rate is 4.50%; the detection rate of AI software focus detection method based on deep learning model is 99.76%, the misdiagnosis rate is 0.08%, and the missed diagnosis rate is 0.08%. Therefore, it can effectively identify COVID-19 focus and provide relevant data information of focus to provide objective data support for COVID-19 diagnosis and public health management.


1995 ◽  
Author(s):  
Kyoichi Suwa ◽  
Hiroki Tateno ◽  
Nobuyuki Irie ◽  
Shigeru Hirukawa

2003 ◽  
Vol 69 (8) ◽  
pp. 4983-4984 ◽  
Author(s):  
Angela L. Gennaccaro ◽  
Molly R. McLaughlin ◽  
Walter Quintero-Betancourt ◽  
Debra E. Huffman ◽  
Joan B. Rose

ABSTRACT Water samples collected throughout several reclamation facilities were analyzed for the presence of infectious Cryptosporidium parvum by the focus detection method-most-probable-number cell culture technique. Results revealed the presence of infectious C. parvum oocysts in 40% of the final disinfected effluent samples. Sampled effluent contained on average seven infectious oocysts per 100 liters. Thus, reclaimed water is not pathogen free but contains infectious C. parvum.


2000 ◽  
Vol 179 ◽  
pp. 141-147
Author(s):  
G. Ai ◽  
S. Jin ◽  
S. Wang ◽  
B. Ye ◽  
S. Yang

AbstractThe design of the space solar telescope (SST) (phase B) has been completed. The manufacturing is under development. At the end of 2000, it will be assembled. The basic aspect will be introduced in this paper.


Author(s):  
K. Pegg-Feige ◽  
F. W. Doane

Immunoelectron microscopy (IEM) applied to rapid virus diagnosis offers a more sensitive detection method than direct electron microscopy (DEM), and can also be used to serotype viruses. One of several IEM techniques is that introduced by Derrick in 1972, in which antiviral antibody is attached to the support film of an EM specimen grid. Originally developed for plant viruses, it has recently been applied to several animal viruses, especially rotaviruses. We have investigated the use of this solid phase IEM technique (SPIEM) in detecting and identifying enteroviruses (in the form of crude cell culture isolates), and have compared it with a modified “SPIEM-SPA” method in which grids are coated with protein A from Staphylococcus aureus prior to exposure to antiserum.


Author(s):  
Weihai Sun ◽  
Lemei Han

Machine fault detection has great practical significance. Compared with the detection method that requires external sensors, the detection of machine fault by sound signal does not need to destroy its structure. The current popular audio-based fault detection often needs a lot of learning data and complex learning process, and needs the support of known fault database. The fault detection method based on audio proposed in this paper only needs to ensure that the machine works normally in the first second. Through the correlation coefficient calculation, energy analysis, EMD and other methods to carry out time-frequency analysis of the subsequent collected sound signals, we can detect whether the machine has fault.


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