A note on admissibility of linear estimators in random models with a special structure

Author(s):  
Ewa Synówka-Bejenka ◽  
Stefan Zontek
Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3484
Author(s):  
Shuhan Sun ◽  
Lizhen Duan ◽  
Zhiyong Xu ◽  
Jianlin Zhang

Blind image deblurring, also known as blind image deconvolution, is a long-standing challenge in the field of image processing and low-level vision. To restore a clear version of a severely degraded image, this paper proposes a blind deblurring algorithm based on the sigmoid function, which constructs novel blind deblurring estimators for both the original image and the degradation process by exploring the excellent property of sigmoid function and considering image derivative constraints. Owing to these symmetric and non-linear estimators of low computation complexity, high-quality images can be obtained by the algorithm. The algorithm is also extended to image sequences. The sigmoid function enables the proposed algorithm to achieve state-of-the-art performance in various scenarios, including natural, text, face, and low-illumination images. Furthermore, the method can be extended naturally to non-uniform deblurring. Quantitative and qualitative experimental evaluations indicate that the algorithm can remove the blur effect and improve the image quality of actual and simulated images. Finally, the use of sigmoid function provides a new approach to algorithm performance optimization in the field of image restoration.


Nanoscale ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 6635-6643
Author(s):  
Die Su ◽  
Jing Dai ◽  
Min Yang ◽  
Jiaxing Wen ◽  
Jianping Yang ◽  
...  

TiO2-RP/CN was fabricated and found to possess a special structure and an excellent electronic conductivity, and the electrodes show outstanding energy storage in K half/full cells.


Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4305
Author(s):  
Takamasa Terada ◽  
Masahiro Toyoura ◽  
Takahide Sato ◽  
Xiaoyang Mao

In this work, we propose a fabric electrode with a special structure that can play the role of a noise reduction filter. Fabric electrodes made of the conductive fabric have been used for long-term ECG measurements because of their flexibility and non-invasiveness; however, due to the large impedance between the skin and the fabric electrodes, noise is easily introduced into the ECG signal. In contrast to conventional work, in which chip-type passive elements are glued to the electrode to reduce noise, the proposed electrode can obtain a noise-reduced ECG by changing the structure of fabric. Specifically, the proposed electrode was folded multiple times to form a capacitor with a capacitance of about 3 nF. It is combined with the skin-electrode impedance to form a low-pass filter. In the experiment, we made a prototype of the electrodes and measured ECG at rest and during EMG-induced exercise. As a result, the SNR values at rest and during exercise were improved about 12.02 and 10.29 , respectively, compared with the fabric electrode without special structure. In conclusion, we have shown that changing the fabric electrode structure effectively removes noise in ECG measurement.


2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Yazhou Li ◽  
Jiayi Li ◽  
Xin Wang

The optimal linear estimation problems are investigated in this paper for a class of discrete linear systems with fading measurements and correlated noises. Firstly, the fading measurements occur in a random way where the fading probabilities are regulated by probability mass functions in a given interval. Furthermore, time-delay exists in the system state and observation simultaneously. Additionally, the multiplicative noises are considered to describe the uncertainty of the state. Based on the projection theory, the linear minimum variance optimal linear estimators, including filter, predictor, and smoother are presented in the paper. Compared with conventional state augmentation, the new algorithm is finite-dimensionally computable and does not increase computational and storage load when the delay is large. A numerical example is provided to illustrate the effectiveness of the proposed algorithms.


RSC Advances ◽  
2016 ◽  
Vol 6 (15) ◽  
pp. 12467-12471 ◽  
Author(s):  
Qiong Luo ◽  
Liyong Chen ◽  
Binhua Duan ◽  
Zhizhi Gu ◽  
Jing Liu ◽  
...  

Hierarchical porous and hollow N-doped graphitic carbon with one-dimensional structure was successfully achieved by a sacrificial template method, and exhibited an enhanced electrocatalytic performance towards ORR due to its special structure.


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