Investigation of broadcasting signal overlay using high-frequency filtering characteristics of RSOA in ASE seeded WDM access network

2012 ◽  
Vol 285 (3) ◽  
pp. 249-257
Author(s):  
Hyun-Seung Kim ◽  
Se-Hoon Yang ◽  
Yong-Hwan Son ◽  
Sang-Kook Han
Keyword(s):  
High Frequency ◽  
Access Network ◽  
Frequency Filtering

Metamaterials-inspired technologies applied to ultra high-frequency filtering structures

2010 ◽  
Vol 52 (8) ◽  
pp. 1868-1872
Author(s):  
A. L. Borja ◽  
J. Carbonell ◽  
V. E. Boria ◽  
M. Chaubet ◽  
D. Lippens
Keyword(s):  
High Frequency ◽  
Frequency Filtering ◽  
Ultra High Frequency

Comparative Intelligibility of Word Lists and Continuous Discourse

1963 ◽  
Vol 6 (4) ◽  
pp. 349-358 ◽  
Author(s):  
Thomas G. Giolas ◽  
Aubrey Epstein
Keyword(s):  
Magnetic Tape ◽  
High Frequency ◽  
Frequency Filtering ◽  
Monosyllabic Word ◽  
Central Institute ◽  
Word Lists ◽  
Recording Conditions ◽  
Intelligibility Score

Intelligibility scores on Harvard Phonetically Balanced (PB-50) Word Lists, Central Institute for the Deaf (W-22) Monosyllabic Word Lists, and a sample of continuous discourse were compared. Speech samples were recorded on magnetic tape under seven high frequency filtering conditions. One-hundred and seventy-five normally hearing subjects were divided into seven groups, each group listening to all speech samples under one particular condition of filtering. Word lists were scored in terms of number of words correct and the continuous discourse in terms of items correct on a test covering information presented in the continuous discourse. The following results were obtained: (1) Consistently higher scores were achieved with the W-22 word lists than with the PB-50 word lists, even when the influence of dissimilar recordings was eliminated. Such differences were attributed to a combination of differences in list content and recording conditions. (2) Monosyllabic word lists and continuous discourse are affected in the same way by frequency distortion; that is, errors increase as distortion increases. (3) No accurate intelligibility score prediction for the continuous discourse could be made on the basis of scores obtained on the PB-50 and W-22 lists.

scholarly journals Modeling of Memristors under Periodic Signals of Different Parameters

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7264
Author(s):  
Bartłomiej Garda
Keyword(s):  
High Frequency ◽  
Measurement Data ◽  
Optimization Method ◽  
Internal Variable ◽  
Optimal Parameters ◽  
Frequency Filtering ◽  
Voltage Wave ◽  
Periodic Signals ◽  
Future Work

In this paper, the problem of modeling memristors is studied. Two types of memristors with carbon and tungsten doping fabricated by the Knowm Inc. are tested. The memristors have been examined with either sinusoidal or triangle voltage wave periodic excitation. Some different frequencies, amplitudes and signal shapes have been applied. The collected data have been averaged and subjected to high frequency filtering. The quality of measurement data has also been discussed. The averaged measurement has been modeled using three popular memristor models: Strukov, Biolek and VTEAM. Some additional feathers to the considered models have been proposed and tested. Memristor is usually modeled by a set of algebraic-differential equations which link both electrical values (i.e., voltage and current) and the internal variable(s) responsible for the element dynamics. The interior-point with box constrains optimization method has been used to obtain the optimal parameters of the memristor model that fit best to the collected data. The results of the optimization process have been discussed and compared. The sensitivity to the different frequency range has been also examined and reviewed. Some conclusions and future work ideas have been postulated.

scholarly journals The method of increasing the information content of microfocus X-ray images

2021 ◽  
Vol 9 (6) ◽  
pp. 57-63
Author(s):  
N. E. Staroverov ◽  
A. Y. Gryaznov ◽  
I. G. Kamyshanskaya ◽  
N. N. Potrakhov ◽  
E. D. Kholopova
Keyword(s):  
Image Processing ◽  
Information Content ◽  
High Frequency ◽  
Noise Suppression ◽  
Projection Data ◽  
Frequency Filtering ◽  
X Ray ◽  
Morphological Image Processing ◽  
Morphological Image ◽  
Image Details

A method for processing microfocus X-ray images is described. It is based on high-frequency filtration and morphological image processing, which increases the contrast of the X-ray details. One of the most informative X-ray techniques is microfocus X-ray. In some cases, microfocus X-ray images cannot be reliably analyzed due to the peculiarities of the shooting method. So, the main disadvantages of microfocus X-ray images are most often an uneven background, distorted brightness characteristics and the presence of noise. The proposed method for enhancing the contrast of fine image details is based on the idea of combining high-frequency filtering and morphological image processing. The method consists of the following steps: noise suppression in the image, high-frequency filtering, morphological image processing, obtaining the resulting image. As a result of applying the method, the brightness of the contours in the image is enhanced. In the resulting image, all objects will have double outlines. The method was tested in the processing of 50 chest radiographs of patients with various pathologies. Radiographs were performed at the Mariinsky Hospital of St. Petersburg using digital stationary and mobile X-ray machines. In most of the radiographs, it was possible to improve the images contrast, to highlight the objects boundaries. Besides, the method was applied in microfocus X-ray tomography to improve the information content of projection data and improve the reconstruction of the 3D image of the research object. In both the first and second cases, the method showed satisfactory results. The developed method makes it possible to significantly increase the information content of microfocus X-ray images. The obtained practical results make it possible to count on broad prospects for the method application, especially in microfocus X-ray.

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