Power Spectrum Method Used for Comparing Film and Xeroradiography

1985 ◽  
Vol 14 (1) ◽  
pp. 25-30 ◽  
Author(s):  
I Kashima ◽  
B M Gratt ◽  
S C White
2014 ◽  
Vol 536-537 ◽  
pp. 911-914
Author(s):  
Ning Yang ◽  
Xu Qian

In this paper, Von Karman random media is constructed with power spectrum method. The random media with Von Karman autocorrelation cannot be constructed in time domain but in frequency domain. So power spectrum method is utilized to solve the problem. The spectrum of random function is generated in frequency domain with random field and auto-correlation function. With inverse Fourier transformation, the Von Karman random media model is constructed. With different correlation lengths, six group of Von Karman random media are constructed.


1998 ◽  
Vol 54 (8) ◽  
pp. 961-969
Author(s):  
TETSUO KIDA ◽  
HIDEO OONISHI ◽  
SATORU MATSUO ◽  
KAZUO NOMA ◽  
MASAHIRO YOSHIMURA ◽  
...  

2013 ◽  
Vol 787 ◽  
pp. 423-426
Author(s):  
Kai Xu ◽  
Jing Li ◽  
Gang Du ◽  
Chun Li Zhu ◽  
Peng Fei Li ◽  
...  

A microsphere trapped by optical tweezers moves according to the Brownian motion law, which can be described by the Langevin equation. Based on it, a quadrant photodiode (QD) is used to track the displacement of the microsphere with a diameter of 2.5um trapped by holographic optical tweezers, and power spectrum method is adopted to obtain radial trap stiffness. Experiments show that the trap stiffness increases with the increase of the laser power, and decreases as the distance between the optical trap and the inside bottom surface of the sample cell increases.


2012 ◽  
Vol 182-183 ◽  
pp. 1002-1006
Author(s):  
Wei Yan ◽  
Zhi Hua Chen ◽  
Tai Jiao Du ◽  
Jian Guo Wang

An algorithm is described which simulates atmospheric phase screen (PS) distorted by von Karman atmospheric turbulence by using Zernike expansion of randomly weighted Karhunen-Loeve function. The statistics of the PS generated by using power spectrum method which is most commonly used for generating PS poorly match up with the theoretical structure function, especially at low spatial frequency, while the algorithm described in the this paper can compensate for this shortcoming. And the accuracy of the PS is verified by comparing with the theoretical results. Furthermore, comparing with the existed methods which also use the Zernike expansion to simulate PS, algorithm presented in this paper is more accurate because the effects of the finite outer scale L0.is included


1998 ◽  
Vol 43 (17) ◽  
pp. 1447-1452
Author(s):  
Yongjun Li ◽  
Zunsheng Cai ◽  
Yanni Li ◽  
Dahai Song ◽  
Hao Song ◽  
...  

1999 ◽  
Vol 14 (2) ◽  
pp. 319-322 ◽  
Author(s):  
K. Venkatesh ◽  
M. S. Bobji ◽  
S. K. Biswas

The roughness of metallic surfaces generated by machining depends on the intended intervention by the tool and the inadvertent consequences determined by the response of metals. The roughness generated in four different metals by grinding is studied using the power spectrum method. It was found that the level of power is determined by the intended intervention such as the depth of cut and, to some extent, by hardness because of its possible influence on micropileup geometry. The power gradient is, however, influenced by inadvertent damage which may be related to material properties such as thermal conductivity and adhesion.


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