scholarly journals A Hybrid Restoration Approach of Defocused Image Using MGAM and Inverse Filtering

Author(s):  
Fenglan Li ◽  
Liyun Su ◽  
Yun Jiang ◽  
Min Sun

The study of the transport and capture of particles moving in a fluid flow in a porous medium is an important problem of underground hydromechanics, which occurs when strengthening loose soil and creating watertight partitions for building tunnels and underground structures. A one-dimensional mathematical model of long-term deep filtration of a monodisperse suspension in a homogeneous porous medium with a dimensional particle retention mechanism is considered. It is assumed that the particles freely pass through large pores and get stuck at the inlet of small pores whose diameter is smaller than the particle size. The model takes into account the change in the permeability of the porous medium and the permissible flow through the pores with increasing concentration of retained particles. A new spatial variable obtained by a special coordinate transformation in model equations is small at any time at each point of the porous medium. A global asymptotic solution of the model equations is constructed by the method of series expansion in a small parameter. The asymptotics found is everywhere close to a numerical solution. Global asymptotic solution can be used to solve the inverse filtering problem and when planning laboratory experiments.


2020 ◽  
Vol 68 ◽  
pp. 4987-5002
Author(s):  
Robert Mattila ◽  
Cristian R. Rojas ◽  
Vikram Krishnamurthy ◽  
Bo Wahlberg

1986 ◽  
Vol 108 ◽  
pp. 337-343
Author(s):  
J. Font ◽  
J. Muntasell ◽  
J. Navarro ◽  
J.LI. Tamarit ◽  
E. Cesari

2010 ◽  
Vol 09 (04) ◽  
pp. 387-394 ◽  
Author(s):  
YANG CHEN ◽  
YIWEN SUN ◽  
EMMA PICKWELL-MACPHERSON

In terahertz imaging, deconvolution is often performed to extract the impulse response function of the sample of interest. The inverse filtering process amplifies the noise and in this paper we investigate how we can suppress the noise without over-smoothing and losing useful information. We propose a robust deconvolution process utilizing stationary wavelet shrinkage theory which shows significant improvement over other popular methods such as double Gaussian filtering. We demonstrate the success of our approach on experimental data of water and isopropanol.


2012 ◽  
Vol 16 (4) ◽  
pp. 487-500 ◽  
Author(s):  
Martin Magnevall ◽  
Mikael Lundblad ◽  
Kjell Ahlin ◽  
Göran Broman

2016 ◽  
Vol 55 (10) ◽  
pp. 2791 ◽  
Author(s):  
Zhixu Wu ◽  
Hua Bai ◽  
Xiangqun Cui

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