Optimal radiometric detection of band-limited noise signal

Author(s):  
V. K. Volosyuk ◽  
V. V. Pavlikov ◽  
S. S. Zhyla ◽  
O. V. Odokienko
Author(s):  
Masoud Zarepoor ◽  
Onur Bilgen

Large loads due to fluid-structure interaction can lead to high bending stresses and fatigue failure in wings and wind turbine blades. A solution for the mentioned problem is using a bistable composite laminate for load alleviation. A bistable composite laminate is capable of attaining two statically stable shapes, and it can be designed to alleviate a critical load, such as wind gust, by snapping from one stable position to the other. Piezocomposite actuators can be used to reverse the snap-through and bring back the structure to its original optimal aerodynamic shape, after the gust load is alleviated. However, there will always be a limit on the size of the piezocomposite actuator used; hence, severe force and energy constraints exist to achieve the snap-through. In this context, this paper focuses on the minimum required actuation energy for performing snap-through of a bistable structure. The paper shows how the required energy for cross-well transfer varies as a function of damping ratio and frequency ratio at specific harmonic force amplitude when the system is externally disturbed with a band-limited noise signal. A band-limited noise signal is chosen to model external/ambient disturbances. This paper uses the Duffing-Holmes equation as a one-degree-of-freedom representative model of a bistable structure. This equation is numerically solved to calculate the required energy for cross-well oscillation under different system and forcing conditions. Various non-dimensional parameters are used to highlight interesting phenomena. It is found that the domain of low energy regions decreases by increasing the level of noise.


2018 ◽  
Vol 18 (04) ◽  
pp. 1850047 ◽  
Author(s):  
Masoud Zarepoor ◽  
Onur Bilgen

Bistable structures have two stable equilibrium positions and can be utilized to maintain a static shape with no energy consumption. This paper focuses on the minimum energy required for performing snap-through of a bistable structure subjected to noise disturbance. This paper uses the Duffing–Holmes equation as a one-degree-of-freedom representative model of a bistable structure. This equation is numerically solved to calculate the energy required for cross-well oscillation under different system and forcing conditions. The paper shows how the energy required for cross-well transfer varies as a function of damping ratio and frequency ratio at specific harmonic force amplitude when the system is externally disturbed with a band-limited noise signal. A magneto-elastic bistable beam is fabricated and tested to validate the used mathematical model. Various nondimensional parameters are used to highlight interesting phenomena. The relationships between signal-to-noise ratio (SNR), dynamic-to-static force ratio, and damping ratio to the response behavior are shown. It is found that the domain of low energy regions decreases by increasing the level of noise. Additionally, underactuated bistable and linear systems behave similarly for high levels of noise. This paper specifically identifies the critical force ratio, which allows for snap-through as a function of critical nondimensional system parameters.


2008 ◽  
Vol 128 (7) ◽  
pp. 1117-1122 ◽  
Author(s):  
Tetsuji Uebo ◽  
Noboru Nakasako ◽  
Norimitsu Ohmata ◽  
Hanae Itagaki

2010 ◽  
Vol 93 (7) ◽  
pp. 53-60
Author(s):  
Tetsuji Uebo ◽  
Noboru Nakasako ◽  
Norimitsu Ohmata ◽  
Hanae Itagaki

2019 ◽  
pp. 34-39 ◽  
Author(s):  
E.I. Chernov ◽  
N.E. Sobolev ◽  
A.A. Bondarchuk ◽  
L.E. Aristarhova

The concept of hidden correlation of noise signals is introduced. The existence of a hidden correlation between narrowband noise signals isolated simultaneously from broadband band-limited noise is theoretically proved. A method for estimating the latent correlation of narrowband noise signals has been developed and experimentally investigated. As a result of the experiment, where a time frag ent of band-limited noise, the basis of which is shot noise, is used as the studied signal, it is established: when applying the Pearson criterion, there is practically no correlation between the signal at the Central frequency and the sum of signals at mirror frequencies; when applying the proposed method for the analysis of the same signals, a strong hidden correlation is found. The proposed method is useful for researchers, engineers and metrologists engaged in digital signal processing, as well as developers of measuring instruments using a new technology for isolating a useful signal from noise – the method of mirror noise images.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mahmoud M. A. Eid ◽  
Vishal Sorathiya ◽  
Sunil Lavadiya ◽  
Huda Said Abd El-Hamid ◽  
Ahmed Nabih Zaki Rashed

Abstract Article clarified the optimum fiber amplifiers length for wide band fiber system applications. Optical suppressed carrier transceiver with various fiber amplifier lengths in long haul applications is simulated by using optisystem simulation program version 13. Max. Q coefficient and min. BER can be tested for various fiber amplifiers lengths from 5 to 30 m. The optimum performance efficiency is achieved with 5 m amplifier length which the max. Q coefficient is 62.5 and bits error rate is tended to zero. Peak power amplitude level, noise signal power level, noise signal amplitude level (NSAL) and peak signal amplitude level after channel with a 45 km length for optimum fiber optic amplifier length of 5 m are measured.


2021 ◽  
Vol 11 (14) ◽  
pp. 6288
Author(s):  
Hang Su ◽  
Chang-Myung Lee

The generalized sidelobe canceller (GSC) method is a common algorithm to enhance audio signals using a microphone array. Distortion of the enhanced audio signal consists of two parts: the residual acoustic noise and the distortion of the desired audio signal, which means that the desired audio signal is damaged. This paper proposes a modified GSC method to reduce both kinds of distortion when the desired audio signal is a non-stationary speech signal. First, the cross-correlation coefficient between the canceling signal and the error signal of the least mean square (LMS) algorithm was added to the adaptive process of the GSC method to reduce the distortion of the enhanced signal while the energy of the desired signal frame was increased suddenly. The sidelobe pattern of beamforming was then presented to estimate the noise signal in the beamforming output signal of the GSC method. The noise component of the beamforming output signal was decreased by subtracting the estimated noise signal to improve the denoising performance of the GSC method. Finally, the GSC-SN-MCC method was proposed by merging the above two methods. The experiment was performed in an anechoic chamber to validate the proposed method in various SNR conditions. Furthermore, the simulated calculation with inaccurate noise directions was conducted based on the experiment data to inspect the robustness of the proposed method to the error of the estimated noise direction. The experiment data and calculation results indicated that the proposed method could reduce the distortion effectively under various SNR conditions and would not cause more distortion if the estimated noise direction is far from the actual noise direction.


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