High efficiency in a double-pass Brillouin amplifier with noise suppression

Author(s):  
Y. Glick ◽  
S. Sternklar
2014 ◽  
Vol 14 (01) ◽  
pp. 1550002 ◽  
Author(s):  
Luyao Shi ◽  
Yang Chen ◽  
Wenlong Yuan ◽  
Libo Zhang ◽  
BenQiang Yang ◽  
...  

Median type filters coupled with the Laplacian distribution assumption have shown a high efficiency in suppressing impulse noise. We however demonstrate in this paper that the Gaussian distribution assumption is more preferable than Laplacian distribution assumption in suppressing impulse noise, especially for high noise densities. This conclusion is supported by numerical experiments with different noise densities and filter models.


Author(s):  
Mohammed Y. Kamil ◽  
Eman A. Radhi

The accurate segmentation of tumours is a crucial stage of diagnosis and treatment, reducing the damage that breast cancer causes, which is the most common type of cancer among women, especially after the age of forty. The task of segmenting breast tumours in mammograms is very difficult, as its difficulty lies in the lack of contrast between the tumour and the surrounding breast tissue, especially when dealing with small tumours that are not clear boundaries and hidden under the tissues. As algorithms often lose an automatic path toward the boundaries of the tumour at try to determine the site of this type of tumour. The study aims to create a clear contrast between the tumour and the healthy breast area. For this purpose, we used a Gaussian filter as a pre-processing as it works to intensify the low-frequency components while reducing the high-frequency components as the breast structure is enhanced and noise suppression. Then, CLAHE was used to improve the contrast of the image, which increases the contrast between the tumour and the surrounding tissue and sharpens the edges of the tumour. Next, the tumour was segmented by using the Chan-Vese method with appropriate parameters defined. The proposed method was applied to all abnormal mammogram images taken from a publicly available mini-MIAS database. The proposed model was tested in two ways, the first is statistical that got results (90.1, 94.8, 95.5, 92.1, 99.5) for Jaccard, Dice, PF-Score, precision, and sensitivity respectively. And the other is based on the segmented region's characteristics that results showed the algorithm could identify the tumour with high efficiency.


2022 ◽  
Vol 148 ◽  
pp. 107767
Author(s):  
Chao Ma ◽  
Zhao Liu ◽  
Ke Liu ◽  
Yang Yu ◽  
Xiao-jun Wang ◽  
...  
Keyword(s):  

2006 ◽  
Vol 8 (11) ◽  
pp. 1019-1022 ◽  
Author(s):  
Yongnan Li ◽  
Fuyun Lu ◽  
Wengang Guo ◽  
Dai Wei

2019 ◽  
Vol 9 (2) ◽  
pp. 837 ◽  
Author(s):  
Dismas K. Choge ◽  
Huai-Xi Chen ◽  
Lei Guo ◽  
Guang-Wei Li ◽  
Wan-Guo Liang

2021 ◽  
Vol 26 (2) ◽  
pp. 184-196
Author(s):  
I.E. Vishnyakov ◽  
◽  
M.M. Masyagin ◽  
O.A. Odintsov ◽  
V.V. Sliusar ◽  
...  

The voice cleaning methods and algorithms play a key role both in preprocessing speech for further analysis and recognition, and in improving the quality of communication between users of information networks. The real-time streaming noise cleaning methods are the most important and complex area. The ability to process streaming data without delays imposes a number of significant restrictions on the algorithm: it cannot be iterative with a previously unknown number of iterations, and cannot explicitly use the data before or after the current block being processed. In the work, a modern adaptive noise reduction method for speech that can work with minimal signal transmission delays has been proposed. A large-scale study of existing approaches has been conducted, with special attention paid to two groups of algorithms: noise detection algorithms and noise suppression algorithms. Based on them the developed algorithm meeting the specified requirements has been built and analyzed. A set of audio data of Russian speech with various noises superimposed on it has been created. The testing of the algorithm has been made and its comparison with existing actual noise cleaning methods has been performed. The proposed adaptive method of noise cleaning without using specialized apparatus means and subsidiary information is able to operate in the real time conditions. The testing of the developed algorithm using the metrics of segment NC and PESQ have shown the high efficiency of the development and its superiority to common noise cleaning implementations Speex and WebRTC with respect to the noise cleaning quality and operation speed.


1988 ◽  
Vol 102 ◽  
pp. 41
Author(s):  
E. Silver ◽  
C. Hailey ◽  
S. Labov ◽  
N. Madden ◽  
D. Landis ◽  
...  

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.


Author(s):  
J. M. Cowley ◽  
R. Glaisher ◽  
J. A. Lin ◽  
H.-J. Ou

Some of the most important applications of STEM depend on the variety of imaging and diffraction made possible by the versatility of the detector system and the serial nature, of the image acquisition. A special detector system, previously described, has been added to our STEM instrument to allow us to take full advantage of this versatility. In this, the diffraction pattern in the detector plane may be formed on either of two phosphor screens, one with P47 (very fast) phosphor and the other with P20 (high efficiency) phosphor. The light from the phosphor is conveyed through a fiber-optic rod to an image intensifier and TV system and may be photographed, recorded on videotape, or stored digitally on a frame store. The P47 screen has a hole through it to allow electrons to enter a Gatan EELS spectrometer. Recently a modified SEM detector has been added so that high resolution (10Å) imaging with secondary electrons may be used in conjunction with other modes.


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