Статті в журналах: "Impulsive noise due to plasma"

1

Oh, Hyungkook, Dongho Seo, and Haewoon Nam. "Design of a Test for Detecting the Presence of Impulsive Noise." Sensors 20, no. 24 (December 12, 2020): 7135. http://dx.doi.org/10.3390/s20247135.

Повний текст джерела

Анотація:

This paper proposes a new test method of detecting the presence of impulsive noise based on a complementary cumulative density function (CCDF). Impulsive noise severely degrades performance of communication systems and the conventional Kolmogorov–Smirnov (K–S) test may not perform well, because the test does not consider the characteristics of impulsive noise. In order to detect the presence of impulsive noise reliably, the CCDF of measurement samples is analyzed and compared with the CCDF of additive white Gaussian noise to find the difference between those CCDFs. Due to the nature of heavy-tails in impulsive noise, only the maximum difference may not be sufficient for the accurate detection of impulsive noise. Therefore, the proposed method applies the test hypothesis using the weighted sum of all the differences between those CCDFs. Simulation results justify that the proposed test is more robust and provides lower miss detection probability than the K–S test in the presence of impulsive noise.

Стилі APA, Harvard, Vancouver, ISO та ін.

2

Lee, Sang Kwon, and Jung Soo Lee. "Design of Adaptive Filter for Health Monitoring on a Gearbox." Key Engineering Materials 321-323 (October 2006): 1237–40. http://dx.doi.org/10.4028/www.scientific.net/kem.321-323.1237.

Повний текст джерела

Анотація:

Impulsive vibration signals in gearbox are often associated with faults, which lead to due to irregular impacting. Thus these impulsive vibration signals can be used as indicators of machinery faults. However it is often difficult to make objective measurement of impulsive signals because of background noise signals. In order to ease the measurement of impulsive signal embedded in background noise, we enhance the impulsive signals using adaptive signal processing and then analyze them in time and frequency domain by using time-frequency representation. This technique is applied to the diagnosis of faults within laboratory gearbox.

Стилі APA, Harvard, Vancouver, ISO та ін.

3

Dai, Jiang’an, Tianshuang Qiu, Shengyang Luan, Quan Tian, and Jiacheng Zhang. "An Improved Toeplitz Approximation Method for Coherent DOA Estimation in Impulsive Noise Environments." Entropy 25, no. 6 (June 20, 2023): 960. http://dx.doi.org/10.3390/e25060960.

Повний текст джерела

Анотація:

Direction of arrival (DOA) estimation is an important research topic in array signal processing and widely applied in practical engineering. However, when signal sources are highly correlated or coherent, conventional subspace-based DOA estimation algorithms will perform poorly due to the rank deficiency in the received data covariance matrix. Moreover, conventional DOA estimation algorithms are usually developed under Gaussian-distributed background noise, which will deteriorate significantly in impulsive noise environments. In this paper, a novel method is presented to estimate the DOA of coherent signals in impulsive noise environments. A novel correntropy-based generalized covariance (CEGC) operator is defined and proof of boundedness is given to ensure the effectiveness of the proposed method in impulsive noise environments. Furthermore, an improved Toeplitz approximation method combined CEGC operator is proposed to estimate the DOA of coherent sources. Compared to other existing algorithms, the proposed method can avoid array aperture loss and perform more effectively, even in cases of intense impulsive noise and low snapshot numbers. Finally, comprehensive Monte-Carlo simulations are performed to verify the superiority of the proposed method under various impulsive noise conditions.

Стилі APA, Harvard, Vancouver, ISO та ін.

4

Karakuş, Oktay, Ercan E. Kuruoğlu, and Mustafa A. Altınkaya. "Modelling impulsive noise in indoor powerline communication systems." Signal, Image and Video Processing 14, no. 8 (June 4, 2020): 1655–61. http://dx.doi.org/10.1007/s11760-020-01708-1.

Повний текст джерела

Анотація:

Abstract Powerline communication (PLC) is an emerging technology that has an important role in smart grid systems. Due to making use of existing transmission lines for communication purposes, PLC systems are subject to various noise effects. Among those, the most challenging one is the impulsive noise compared to the background and narrowband noise. In this paper, we present a comparative study on modelling the impulsive noise amplitude in indoor PLC systems by utilising several impulsive distributions. In particular, as candidate distributions, we use the symmetric $$\alpha $$ α -Stable (S$$\alpha $$ α S), generalised Gaussian, Bernoulli Gaussian and Student’s t distribution families as well as the Middleton Class A distribution, which dominates the literature as the impulsive noise model for PLC systems. Real indoor PLC system noise measurements are investigated for the simulation studies, which show that the S$$\alpha $$ α S distribution achieves the best modelling success when compared to the other families in terms of the statistical error criteria, especially for the tail characteristics of the measured data sets.

Стилі APA, Harvard, Vancouver, ISO та ін.

5

Wang, Houyou, Yong Guo, and Lidong Yang. "Parameter Estimation of LFM Signals Based on FOTD-CFRFT under Impulsive Noise." Fractal and Fractional 7, no. 11 (November 15, 2023): 822. http://dx.doi.org/10.3390/fractalfract7110822.

Повний текст джерела

Анотація:

Due to the short duration and high amplitude characteristics of impulsive noise, these parameter estimation methods based on Gaussian assumptions are ineffective in the presence of impulsive noise. To address this issue, a LFM signal parameter estimation method is proposed based on FOTD and CFRFT. Firstly, the mathematical expression of FOTD is presented and its tracking performance is verified. Secondly, the tracked signal is subjected to discrete time CFRFT, and a mathematical optimization model for LFM signal parameter estimation is established on the fractional spectrum characteristic. Finally, a correction method for non-standard SαS distributed noise is proposed, and the performance of parameter estimation under both standard and non-standard SαS distributions are analyzed. The simulation results show that this method not only effectively suppresses the impact of impulsive noise on the fractional spectrum of LFM signal, but also has better parameter estimation accuracy and stability in the low GSNR. The proposed method is particularly effective under the measured noise environment, as it successfully suppresses the impact of impulsive noise and achieves high-precision parameter estimation.

Стилі APA, Harvard, Vancouver, ISO та ін.

6

Shafieipour, Mohammad, Heng-Siong Lim, and Teong-Chee Chuah. "Decoding of Turbo Codes in Symmetric Alpha-Stable Noise." ISRN Signal Processing 2011 (March 29, 2011): 1–7. http://dx.doi.org/10.5402/2011/683972.

Повний текст джерела

Анотація:

This paper investigates the decoding of turbo codes in impulsive symmetric α-stable (SαS) noise. Due to the nonexistence of a closed-form expression for the probability density function (pdf) of α-stable processes, numerical-based SαS pdf is used to derive branch transition probability (btp) for the maximum a posteriori turbo decoder. Results show that in Gaussian noise, the turbo decoder achieves similar performance using both the conventional and the proposed btps, but in impulsive channels, the turbo decoder with the proposed btp substantially outperforms the turbo decoder utilizing the conventional btp. Results also confirm that the turbo decoder incorporating the proposed btp outperforms the existing Cauchy-based turbo decoder in non-Cauchy impulsive noise, while the two decoders accomplish similar performance in Cauchy noise.

Стилі APA, Harvard, Vancouver, ISO та ін.

7

Tian, Tian, Kunde Yang, Fei-Yun Wu, and Ying Zhang. "Channel Estimation for Underwater Acoustic Communications in Impulsive Noise Environments: A Sparse, Robust, and Efficient Alternating Direction Method of Multipliers-Based Approach." Remote Sensing 16, no. 8 (April 13, 2024): 1380. http://dx.doi.org/10.3390/rs16081380.

Повний текст джерела

Анотація:

Channel estimation in Underwater Acoustic Communication (UAC) faces significant challenges due to the non-Gaussian, impulsive noise in ocean environments and the inherent high dimensionality of the estimation task. This paper introduces a robust channel estimation algorithm by solving an l1−l1 optimization problem via the Alternating Direction Method of Multipliers (ADMM), effectively exploiting channel sparsity and addressing impulsive noise outliers. A non-monotone backtracking line search strategy is also developed to improve the convergence behavior. The proposed algorithm is low in complexity and has robust performance. Simulation results show that it exhibits a small performance deterioration of less than 1 dB for Channel Impulse Response (CIR) estimation in impulsive noise environments, nearly matching its performance under Additive White Gaussian Noise (AWGN) conditions. For Delay-Doppler (DD) doubly spread channel estimation, it maintains Bit Error Rate (BER) performance comparable to using ground truth channel information in both AWGN and impulsive noise environments. At-sea experimental validations for channel estimation in Orthogonal Frequency Division Multiplexing (OFDM) systems further underscore the fast convergence speed and high estimation accuracy of the proposed method.

Стилі APA, Harvard, Vancouver, ISO та ін.

8

Enguix, Ivan Felis, Marta Sánchez Egea, Antonio Guerrero González, and David Arenas. "Acoustic Characterization of Impulsive Underwater Noise Present in Port Facilities: Practical Case in the Port of Cartagena." Proceedings 4, no. 1 (November 14, 2018): 57. http://dx.doi.org/10.3390/ecsa-5-05755.

Повний текст джерела

Анотація:

The data recording of underwater noise is a key aspect for the prevention and improvement of management systems of maritime spaces. Thus, due to the presence of activities potentially generating impulsive noise, ports deserve special attention. This article describes and shows the results of the spatial monitoring of both the basal noise and impulsive noise sources present in port facilities. A vessel was equipped with a smart digital hydrophone with a working frequency range between 10 and 200 kHz and an RVR (Received Voltage Response) of, approximately, −170 dB @ 1 V/µPa. Coupling the acoustic data together with the GPS coordinates of the vessel, a GIS map with spatiotemporal distribution of the basal sound pressure levels was made, identifying the sources of impulsive noise of interest and its temporal characteristics. This is a preliminary step for the development of future studies on underwater noise pollution and its potential impact on biodiversity in the environment of port facilities, with the maximum guarantees possible.

Стилі APA, Harvard, Vancouver, ISO та ін.

9

Lee, Sang Kwon, Jinhoi Gu, and Byung-Og Cho. "Damage Identification of an Automotive Engine Based on Detection of Impact Vibration Using an Adaptive Filter." Key Engineering Materials 306-308 (March 2006): 229–34. http://dx.doi.org/10.4028/www.scientific.net/kem.306-308.229.

Повний текст джерела

Анотація:

In an automotive engine, faults induce impulsive vibrations and thereby degrade engine performance, making it important for an automotive engineer to detect and analyze impulsive vibration signals for fault diagnosis. However, detecting and identifying impulsive signals is often difficult because of interfering signals such as those due to engine firing, harmonics of crankshaft speed and broadband noise components. These interferences hinder early fault detection. To overcome this difficulty we present a two-stage ALEF (Adaptive Line Enhancer Filter) that is capable of enhancing impulsive signals embedded in background noise. This method is used to pre-process signals prior to time-frequency analysis via higher order methods such as the combined higher order time-frequency.

Стилі APA, Harvard, Vancouver, ISO та ін.

10

Dou, Yuzi, and Sen Li. "Kernel Function-Based Ambiguity Function and Its Application on DOA Estimation in Impulsive Noise." Sensors 22, no. 18 (September 15, 2022): 6996. http://dx.doi.org/10.3390/s22186996.

Повний текст джерела

Анотація:

To solve the problem that the traditional ambiguity function cannot well reflect the time-frequency distribution characteristics of linear frequency modulated (LFM) signals due to the presence of impulsive noise, two robust ambiguity functions: correntropy-based ambiguity function (CRAF) and fractional lower order correntropy-based ambiguity function (FLOCRAF) are defined based on the feature that correntropy kernel function can effectively suppress impulsive noise. Then these two robust ambiguity functions are used to estimate the direction of arrival (DOA) of narrowband LFM signal under an impulsive noise environment. Instead of the covariance matrix used in the ESPRIT algorithm by the spatial CRAF matrix and FLOCRAF matrix, the CRAF-ESPRIT and FLOCRAF-ESPRIT algorithms are proposed. Computer simulation results show that compared with the algorithms only using ambiguity function and the algorithms only using the correntropy kernel function-based correlation, the proposed algorithms using ambiguity function based on correntropy kernel function have good performance in terms of probability of resolution and estimation accuracy under various circumstances. Especially, the performance of the FLOCRAF-ESPRIT algorithm is better than the CRAF-ESPRIT algorithm in the environment of low generalized signal-to-noise ratio and strong impulsive noise.

Стилі APA, Harvard, Vancouver, ISO та ін.

11

Luo, Ting, Menglei Sun, Hao Liu, Yongliang Wang, Jiongyang Shao, and Xingyao Yang. "A novel feedforward narrow-broadband hybrid active noise control system for excavator interior noise control." Noise Control Engineering Journal 72, no. 4 (July 1, 2024): 347–67. http://dx.doi.org/10.3397/1/377225.

Повний текст джерела

Анотація:

Excavator interior noise is a mixture of engine noise and impulsive noise produced by working device. Hybrid narrow-broadband active noise control (HANC) systems can efficiently eliminate the traditional mixed broad-narrowband noise. However, these HANC systems have drawbacks such as high computational complexity, unable to cope with impulsive noise and inability to obtain the best performance due to parameter selection method. To solve these problems, a novel feedforward narrow broadband HANC system consisting of four subsystems, namely, sinusoidal noise canceller (SNC) subsystem, robust broadband active noise control (RBANC) subsystem, delay narrowband active noise control (DNANC) subsystem, and supporting error calculating subsystem, is proposed. Combining the advantages of delayed least mean square algorithm in DNANC subsystem and Versoria criterion-based filtered-x least mean square algorithm in RBANC subsystem, both the computational efficiency and the robustness when encountering impulsive noise of the proposed HANC system are efficiently improved. In addition, the performance of the proposed HANC system is further improved by changing the key parameters selection method form trial-and-error method to improved particle swarm optimization (IPSO) algorithm with active factor. Both the superiority of the proposed HANC system over existing counterparts and the advantage of the IPSO algorithm with active factor in determining the key parameters are demonstrated by extensive simulations. Real-time HANC experiments in semi-anechoic chamber based on measured excavator interior mixed noise are conducted in this article. Experimental results illustrate that the proposed HANC system achieves good noise elimination performance and also being robust when encountering impulsive noise.

Стилі APA, Harvard, Vancouver, ISO та ін.

12

Rao, Y. K., A. K. Srivastava, J. G. Doyle, and B. N. Dwivedi. "Origin of impulsive plasma outflows due to magnetoacoustic shocks." Monthly Notices of the Royal Astronomical Society 470, no. 2 (May 9, 2017): 2449–56. http://dx.doi.org/10.1093/mnras/stx1115.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

13

Liu, Haoqiang, Hongbo Zhao, Xiaowen Chen, and Wenquan Feng. "An optimized initialization for LDPC decoding over GF(q) in impulsive noise environments." PLOS ONE 16, no. 5 (May 6, 2021): e0250930. http://dx.doi.org/10.1371/journal.pone.0250930.

Повний текст джерела

Анотація:

Modern navigation satellite communication has the characteristic of high transmitting rate. To avoid bit errors in data transmission, low density parity check (LDPC) codes are widely recognized as efficient ways for navigation communication. Conventionally, the LDPC decoding is applied for additive white Gaussian noise (AWGN) channel and degrades severely while facing the impulsive noise. However, navigation communication often suffers from impulsive interference due to the occurrence of high amplitude “spikes”. At this time, the conventional Gaussian noise assumption is inadequate. The impulsive component of interference has been found to be significant which influences the reliability of transmitted information. Therefore the LDPC decoding algorithms for AWGN channel are not suitable for impulsive noise environments. Consider that LDPC codes over GF(q) perform better than binary LDPC in resisting burst errors for current navigation system, it is necessary to conduct research on LDPC codes over GF(q). In this paper, an optimized initialization by calculating posterior probabilities of received symbols is proposed for non-binary LDPC decoding on additive white Class A noise (AWAN) channel. To verify the performance of the proposed initialization, extensive experiments are performed in terms of convergence, validity, and robustness. Preliminary results demonstrate that the decoding algorithm with the optimized initialization for non-binary LDPC codes performs better than the competing methods and that of binary LDPC codes on AWAN channel.

Стилі APA, Harvard, Vancouver, ISO та ін.

14

Radlak, Krystian, Lukasz Malinski, and Bogdan Smolka. "Deep Learning Based Switching Filter for Impulsive Noise Removal in Color Images." Sensors 20, no. 10 (May 14, 2020): 2782. http://dx.doi.org/10.3390/s20102782.

Повний текст джерела

Анотація:

Noise reduction is one of the most important and still active research topics in low-level image processing due to its high impact on object detection and scene understanding for computer vision systems. Recently, we observed a substantially increased interest in the application of deep learning algorithms. Many computer vision systems use them, due to their impressive capability of feature extraction and classification. While these methods have also been successfully applied in image denoising, significantly improving its performance, most of the proposed approaches were designed for Gaussian noise suppression. In this paper, we present a switching filtering technique intended for impulsive noise removal using deep learning. In the proposed method, the distorted pixels are detected using a deep neural network architecture and restored with the fast adaptive mean filter. The performed experiments show that the proposed approach is superior to the state-of-the-art filters designed for impulsive noise removal in color digital images.

Стилі APA, Harvard, Vancouver, ISO та ін.

15

Liu, Peng, Nobuyoshi Kouguchi, and Ying Li. "Velocity Measurement of Coherent Doppler Sonar Assisted by Frequency Shift, Kalman Filter and Linear Prediction." Journal of Marine Science and Engineering 9, no. 2 (January 21, 2021): 109. http://dx.doi.org/10.3390/jmse9020109.

Повний текст джерела

Анотація:

Velocity is vital information for navigation and oceanic engineering. Coherent Doppler sonar is an accurate tool for velocity measurement, but its use is limited due to velocity ambiguity. Velocity measured by frequency shift has no velocity ambiguity, yet its measurement error is larger than that of coherent Doppler sonar. Therefore, coherent Doppler sonar assisted by frequency shift is used to accurately measure velocity without velocity ambiguity. However, the velocity measured by coherent Doppler sonar assisted by frequency shift is affected by impulsive noise. To decrease the impulsive noise, Kalman filter and linear prediction are proposed to improve the velocity sensing accuracy. In this method, the Kalman filter is used to decrease measurement error of velocity measured by frequency shift, and linear prediction is used to remove the impulsive noise generated by a wrong estimate of the integer ambiguity. Lab-based experiments were carried, and the results have shown that coherent Doppler sonar assisted by frequency shift, Kalman filter and linear prediction can provide accurate and precise velocity with short time delay in a large range of signal to noise ratio.

Стилі APA, Harvard, Vancouver, ISO та ін.

16

Lyrintzis, A. S., and Y. Xue. "Acoustics of Transonic Flow Around an Oscillating Flap." Journal of Fluids Engineering 114, no. 2 (June 1, 1992): 240–45. http://dx.doi.org/10.1115/1.2910021.

Повний текст джерела

Анотація:

Investigation of noise mechanisms due to unsteady transonic flow is important for aircraft noise reduction. In this work, the near-field impulsive noise due to an oscillating flap is simulated numerically. The problem is modeled by the two-dimensional high frequency transonic small disturbance equation (VTRAN2 code). The three types of unsteady shock wave motion have been identified. Two different important disturbances exist in the pressure signal. The disturbances are related to the unsteady motion of the supersonic pocket and fluctuating lift, and drag forces. Pressure wave signatures, noise frequency spectra, and noise directivity are shown.

Стилі APA, Harvard, Vancouver, ISO та ін.

17

Adams, Christian. "Modelling of noise due to impulsive excitation using nonlinear time series analysis." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 267, no. 1 (November 5, 2023): 310–13. http://dx.doi.org/10.3397/no_2023_0062.

Повний текст джерела

Анотація:

Early acoustic machine design phases should target safety and comfort requirements, minimising the risk of hearing damage and noise exposure and ensuring a pleasant machine sound. Therefore, physical mechanisms of sound generation, propagation and radiation need to be modelled. Today, nonlinear physical relations in vibroacoustic models such as contact problems are mostly linearised. The aim of this paper is to increase the prediction quality of vibroacoustic models so that physical mechanisms behind sound generation due to complex physical, nonlinear phenomena can be better understood. The focus is on sound generation due to impulsive excitation, which is a significant sound generation mechanism in machinery, e.g. considering gears, forming processes (e.g. punching), or road loads of vehicles. We describe a model setup to simulate impulsive excitation on a laboratory scale, where structural vibrations can be analysed. Physical correlations including nonlinear correlations could be identified using nonlinear time series analysis. Recurrence plots will be used to identify features such as phase space contraction, e.g. to identify damping. These features form the basis to deepen the physical understanding of machinery noise, to contribute to enhanced acoustic machine designs and to enhance data-driven modelling using sparse regression in future research.

Стилі APA, Harvard, Vancouver, ISO та ін.

18

Li, Xinyu, Qing Shi, Shuangyi Xiao, Shukai Duan, and Feng Chen. "A Robust Diffusion Minimum Kernel Risk-Sensitive Loss Algorithm over Multitask Sensor Networks." Sensors 19, no. 10 (May 21, 2019): 2339. http://dx.doi.org/10.3390/s19102339.

Повний текст джерела

Анотація:

Distributed estimation over sensor networks has attracted much attention due to its various applications. The mean-square error (MSE) criterion is one of the most popular cost functions used in distributed estimation, which achieves its optimality only under Gaussian noise. However, impulsive noise also widely exists in real-world sensor networks. Thus, the distributed estimation algorithm based on the minimum kernel risk-sensitive loss (MKRSL) criterion is proposed in this paper to deal with non-Gaussian noise, particularly for impulsive noise. Furthermore, multiple tasks estimation problems in sensor networks are considered. Differing from a conventional single-task, the unknown parameters (tasks) can be different for different nodes in the multitask problem. Another important issue we focus on is the impact of the task similarity among nodes on multitask estimation performance. Besides, the performance of mean and mean square are analyzed theoretically. Simulation results verify a superior performance of the proposed algorithm compared with other related algorithms.

Стилі APA, Harvard, Vancouver, ISO та ін.

19

Larsen, Jakob Juul. "Model-based subtraction of spikes from surface nuclear magnetic resonance data." GEOPHYSICS 81, no. 4 (July 2016): WB1—WB8. http://dx.doi.org/10.1190/geo2015-0442.1.

Повний текст джерела

Анотація:

Surface nuclear magnetic resonance (surface NMR) has progressed significantly in recent years due to advances in instrumentation. In particular, the introduction of multichannel surface NMR instruments has been effective in improving the signal-to-noise ratio. The current methodology for noise reduction with multichannel instruments is, however, inadequate in complex noise environments, and there is a need for improved signal processing. We have evaluated a study of impulsive noise (spikes) in surface NMR data acquired with a Numis Poly instrument. We have determined how the spectral content can be used to classify spikes as originating from electric fences or sferics. Measurements of spikes from two electric fences were evaluated. The spikes were highly deterministic and can be modeled as impulsive excitations of the band-pass filter in the surface NMR receiver system. We investigated the feasibility of a model-based approach for subtraction of electric fence spikes. Model-based subtraction was shown to be possible, but it is limited by accidental fitting of the NMR signal in its current embodiment. We evaluated an example of a surface NMR data set in which subtraction of powerline harmonic noise and electric fence spike noise removed all coherence in the multichannel data, and the consequences for further noise reduction using multichannel methods were developed.

Стилі APA, Harvard, Vancouver, ISO та ін.

20

Aly, Kareem, John Vairo, and Mervyn Choy. "Characterization of Road noise levels increase due to installation of transverse rumble strips." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 266, no. 1 (May 25, 2023): 1271–82. http://dx.doi.org/10.3397/nc_2023_0172.

Повний текст джерела

Анотація:

Transverse rumble strips have been widely employed as a means to warn distracted. Noise emissions from traveling over the rumble strips negatively impact surrounding communities. Moreover, the distinguished noise characteristic of rumble strips makes this noise a nuisance to the surrounding community. Measurements of the noise emission generated from vehicles passing over transverse rumble strips have been completed adjacent to the 18-rumble strips. To determine the impact of the rumble strips on noise generation, sound level measurements were taken of vehicles traveling over smooth pavement prior to travelling over the rumble strips shortly after. The measurements were completed for uncontrolled normal road traffic and for controlled vehicle pass-by, where the vehicle speed was steady and controlled. The overall noise emission from the transverse rumble strips results with a 3-9 dB increase above the corresponding vehicle noise emission Leq on smooth pavement. The corresponding sound exposure level is calculated. The increase in the noise emission is largely dependent on the vehicle type and not correlated to vehicle speed. The rumble strip noise is characterized as quasi-steady impulsive sound for receptors, which may require an additional noise penalty. The results show that the rumble strips noise does not have any distinct tone.

Стилі APA, Harvard, Vancouver, ISO та ін.

21

Wodecki, Jacek, and Anna Michalak. "Fault-related impulsive component detection for vibration-based diagnostics in the presence of random impulsive noise." IOP Conference Series: Earth and Environmental Science 942, no. 1 (November 1, 2021): 012016. http://dx.doi.org/10.1088/1755-1315/942/1/012016.

Повний текст джерела

Анотація:

Abstract In this paper, the authors propose the methodology for vibration-based diagnostics towards local damage detection in rolling element bearings in the presence of non-Gaussian noise. In real-life cases, the main problem making the analysis difficult is the non-Gaussianity of the high-energy noise present in the operational environment. Because of this fact, popular impulsiveness-related detection techniques cannot be used. In the presented article, a real-life data measured in an industrial scenario will be presented and a proposition of an approach to cyclic component extraction will be discussed. The proposed approach takes advantage of the Cyclic Spectral Coherence (CSC) map as multidimensional data representation. It can be very useful for indicating cyclic modulated components in the otherwise non-cyclic signal content. However, due to the limitations of statistics used in CSC map calculation impacting the quality of CSC map in the presence of non-cyclic impulsive behavior in the signal, Nonnegative Matrix Factorization idea is used as a method for component separation. The presented method allows for obtaining carrier-related and modulation-related features of the component of interest. The main advantage of the presented method is pairing very useful multidimensional data representation (CSC) with very potent decomposition technique (NMF), that allows to reconstruct separated components in the final stage of the analysis. As a consequence, the time series of the component can be reconstructed based on the carrier feature.

Стилі APA, Harvard, Vancouver, ISO та ін.

22

Sun, Liping, Hongju Zhou, and Hongwei Zhou. "A Novel Second-OrderSine-Cost-Function-Derived Kernel Adaptive Algorithm for Non-Linear System Identification." Symmetry 15, no. 4 (March 29, 2023): 827. http://dx.doi.org/10.3390/sym15040827.

Повний текст джерела

Анотація:

A novel kernel recursive second-order sine adaptive (KRSOSA) algorithm was devised for identifying non-linear systems, which was constructed using a symmetry squared sine function to develop a novel kernel loss function and recursive scheme. In the proposed KRSOSA algorithm, the squared sine function provides resistance to impulsive noise due to the sine operation, which was well-derived and investigated in the framework of kernel adaptive filtering (KAF). The behavior of the proposed KRSOSA algorithm was investigated and analyzed using computer simulations, which provided good performance for identifying non-linear systems under impulsive noises.

Стилі APA, Harvard, Vancouver, ISO та ін.

23

Pradhan, Somanath, Guoqiang Zhang, Xiaojun Qiu, J. C. Ji, and Jeffrey Parnell. "Robust improved multiband-structured subband adaptive filter for active noise control with impulsive interference." Journal of the Acoustical Society of America 154, no. 4_supplement (October 1, 2023): A121. http://dx.doi.org/10.1121/10.0022987.

Повний текст джерела

Анотація:

The feedforward filtered-x least mean square algorithm is extensively implemented for active control of broadband noise. However, the control performance is substantially deteriorated due to colored noise and the presence of uncorrelated disturbances near the reference and error sensors. To tackle these issues, in this paper, a robust improved multiband-structured subband adaptive filter based on logarithmic and total least squares method is proposed for active control. Unlike the conventional method of total least squares, the proposed algorithm adopts logarithmic and Rayleigh quotient functions. The closed loop implementation of the improved multiband-structured subband adaptive filter is adopted to meet the delayless requirement. The proposed algorithm is well-suited for environments where the reference signal is highly correlated and the residual noise is contaminated by impulsive noise. Furthermore, an affine combination of the proposed algorithm is developed to meet the complementary requirements of faster convergence and improved noise reduction. Eventually, the stability and computational complexity are studied. Simulation results using measured acoustic paths in an anechoic chamber and a normal room illustrate the effectiveness of the proposed algorithm for controlling broadband noise with impulsive interference. In addition, the tracking control performance is evaluated in a time-varying acoustic environment.

Стилі APA, Harvard, Vancouver, ISO та ін.

24

Darus, N., Z. Haron, K. Yahya, M. H. Abd Halil, W. M. A. Norudin, M. H. Othman, and M. A. Hezmi. "Impulsivity of Noise due to Single Lightweight Vehicles Transit on Transverse Rumble Strip." E3S Web of Conferences 34 (2018): 02026. http://dx.doi.org/10.1051/e3sconf/20183402026.

Повний текст джерела

Анотація:

Transverse Rumble Strips (TRS) acts as safety device that alert inattentive drivers from potential dangers. However, the noise produced due to TRS was reported as noise annoyance among the nearby residents lived adjacent to roadways. Thus, this paper investigates the impulsivity characteristic of noise due to single lightweight vehicles transit on TRS. The objectives of this study are to determine the increase of sound level and to evaluate the impulsivity of noise. Two TRS profiles namely middle overlapped (MO) and middle layer overlapped (MLO) were selected. Three types of single lightweight vehicles which include hatchback, sedan and multipurpose (MPV) were tested at speed of 30, 50 and 70km/h. The sound level was measured using sound level meter (SLM). Noise indices such as LAeq, LAIeqT, LAImax, LAFmax and LASmax were obtained from the measurement. This study considered the differences of LAImax – LAFmax > 2dBA, LAFmax – LAeq ≥ 10dBA, LAIeqT – LAeq ≥ 2dBA and LAImax – LASmax > 6dBA to evaluate the impulsivity of noise. It was found that TRS increased the sound level by at most of 6dBA. Furthermore, all single lightweight vehicles transit on TRS show significant impulsive characteristic. These results proved that TRS produce significant impact to the nearby residents.

Стилі APA, Harvard, Vancouver, ISO та ін.

25

Hebda-Sobkowicz, Justyna, Radosław Zimroz, and Agnieszka Wyłomańska. "Selection of the Informative Frequency Band in a Bearing Fault Diagnosis in the Presence of Non-Gaussian Noise—Comparison of Recently Developed Methods." Applied Sciences 10, no. 8 (April 12, 2020): 2657. http://dx.doi.org/10.3390/app10082657.

Повний текст джерела

Анотація:

The vibration signals acquired on machines usually have complex spectral structure. As the signal of interest (SOI) is weak (especially at an early stage of damage) and covers some frequency range (around structural resonance), it requires its extraction from a raw observation. Until now, most of the techniques assumed the presence of Gaussian noise. Unfortunately, there are cases when the non-informative part of the signal (considered as the noise) is non-Gaussian due to the random disturbances or nature of the process executed by the machine. Thus, the problem can be formulated as the extraction of the SOI from the non-Gaussian noise. Recently this problem has been recognized by several authors and some new ideas have been developed. In this paper, we would like to compare these techniques for benchmark signals (Gaussian noise, cyclic impulsive signals, non-cyclic impulsive signals with random amplitudes and locations of impulses and a mixture of all of them). Our analysis will cover spectral kurtosis, kurtogram, stability index (Alpha selector), conditional variance-based selector, spectral Gini index, spectral smoothness index and infogram. Finally, a discussion on the efficiency of each method is provided.

Стилі APA, Harvard, Vancouver, ISO та ін.

26

Wei, Zhouchao, Yuxi Li, Irene Moroz, and Wei Zhang. "Melnikov-type method for a class of planar hybrid piecewise-smooth systems with impulsive effect and noise excitation: Heteroclinic orbits." Chaos: An Interdisciplinary Journal of Nonlinear Science 32, no. 10 (October 2022): 103127. http://dx.doi.org/10.1063/5.0106073.

Повний текст джерела

Анотація:

The classical Melnikov method for heteroclinic orbits is extended theoretically to a class of hybrid piecewise-smooth systems with impulsive effect and noise excitation. We assume that the unperturbed system is a piecewise Hamiltonian system with a pair of heteroclinic orbits. The heteroclinic orbit transversally jumps across the first switching manifold by an impulsive effect and crosses the second switching manifold continuously. In effect, the trajectory of the corresponding perturbed system crosses the second switching manifold by applying the reset map describing the impact rule instantaneously. The random Melnikov process of such systems is then derived by measuring the distance of perturbed stable and unstable manifolds, and the criteria for the onset of chaos with or without noise excitation is established. In this derivation process, we overcome the difficulty that the derivation method of the corresponding homoclinic case cannot be directly used due to the difference between the symmetry of the homoclinic orbit and the asymmetry of the heteroclinic orbit. Finally, we investigate the complicated dynamics of a particular piecewise-smooth system with and without noise excitation under the reset maps, impulsive effect, and non-autonomous periodic and damping perturbations by this new extended method and numerical simulations. The numerical results verify the correctness of the theoretical results and demonstrate that this extended method is simple and effective for studying the dynamics of such systems.

Стилі APA, Harvard, Vancouver, ISO та ін.

27

Ngandu Kalala, Gauthier, Xavier Chiementin, Lanto Rasolofondraibe, Abir Boujelben, and Bovic Kilundu. "Modeling Impulsive Ball Mill Forces Effects on the Dynamic Behavior of a Single-Stage Gearbox." Machines 10, no. 4 (March 23, 2022): 226. http://dx.doi.org/10.3390/machines10040226.

Повний текст джерела

Анотація:

Gearboxes are frequently used in the mining industry, especially for power transmission between the electric drive and the ball mill; besides the extreme complexity of a ball mill gear transmission system, the fault diagnosis by vibration analysis can be easily distorted by the presence of impulsive noises due to the ball pulses on the mill shell. Although several works in the literature are related to the influence of an impulsive noise on the accuracy of the diagnosis, no dynamic model exists yet in the literature that can explain the influence of these forces on the dynamic behavior of gearboxes. This paper presents a new approach to determine the influence of the grinding forces in crack defects diagnosis. This approach is based on a hybrid numerical model of a 24-degree-of-freedom gearbox, simulating one gear train and two drive shafts. The impact forces of the mill drum are modelled by a discrete element method (DEM). The ball-filling rate (Fr), the mill speed (Nr), and the ball size (Db) are considered to study this phenomenon. The simulations results show by a time series representation, fast Fourier transform, and short-time Fourier transform (STFT), that the acceleration is significantly affected by the presence of the grinding forces, developing an impulsive noise due to the impact of the balls governed by the studied parameters.

Стилі APA, Harvard, Vancouver, ISO та ін.

28

Wu, Yaohui, Pengfei Shao, Shaozhong Zhang, and Youming Li. "Adaptive Channel Estimation for Underwater Acoustic OFDM System in Impulsive Noise Environment." Wireless Communications and Mobile Computing 2022 (January 17, 2022): 1–11. http://dx.doi.org/10.1155/2022/1455526.

Повний текст джерела

Анотація:

Applying the orthogonal matching pursuit (OMP) to estimate the underwater acoustic (UWA) orthogonal frequency division multiplexing (OFDM) channels is attractive because of its high estimation accuracy and low computational cost. However, most existing OMP-based algorithms suffer the limited estimation accuracy in impulsive noise (IN) cases. Through the studies can be found, only part of channels’ estimation is affected due to the random IN which appears transient and intermittent in time and frequency. Based on this observation, joint time-frequency OMP (JTF-OMP) method is proposed, where the estimation of the affected channels benefits adaptively from that of adjacent channels in time or frequency. It is well known that preliminary Doppler scale estimation is key to the subsequent OMP algorithm, which is difficult to deal with due to the IN. To solve this problem, an adaptive Doppler scale estimation (ADSE) method is proposed. It involves generating two shorter identical cyclic prefixes (CPs) for each OFDM symbol, placed before two adjacent OFDM symbols. The repetition pattern can adaptively defend the IN which appears randomly and shortly in time. Simulation results show that the proposed algorithms integrating JTF-OMP with ADSE can achieve much higher estimation accuracy and better system reliability than the OMP in the IN environment.

Стилі APA, Harvard, Vancouver, ISO та ін.

29

ZHAO, TONG-JUN, YI-ZHONG ZHUO, YONG ZHAN, QING JI, and TIAN-GUANG CAO. "TWO-DIMENSIONAL RATCHETS WITH NON-CONSERVATIVE IMPULSIVE FORCE." Modern Physics Letters B 16, no. 26 (November 10, 2002): 999–1006. http://dx.doi.org/10.1142/s0217984902004706.

Повний текст джерела

Анотація:

We discuss the directed motion of overdamped Brownian particles based on a two-dimensional ratchet model with a non-conservative impulsive force field. We consider the combined effects on the stationary current due to local spatial asymmetry in the longitudinal direction as well as the constrained harmonic force in the transverse direction. We notice that the current reversal is induced by the change of colored noise strength and the dynamics in the transverse direction influences the directed motion in the longitudinal direction significantly. The non-conservative impulsive force that represents the chemical energy consumed in the conformation changing process is a crucial factor to the directed motion of the Brownian motors.

Стилі APA, Harvard, Vancouver, ISO та ін.

30

Carrascal García, Teresa, Amelia Romero Fernández, and Belén Casla Herguedas. "Applying Spanish Acoustic Regulations to mechanical ventilation with heat recovery systems. Case study." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 265, no. 5 (February 1, 2023): 2271–80. http://dx.doi.org/10.3397/in_2022_0325.

Повний текст джерела

Анотація:

Due to recent changes in IAQ (Indoor Air Quality) and energy efficiency requirements, MVHR (Mechanical Ventilation with Heat Recovery) has become increasingly common in Spanish new build dwellings. Regarding acoustics, Spanish Decree RD 1367/2007 sets out limits for sound pressure levels due to building services and describes the noise measurement and assessment procedure, which applies also to ventilation noise. The assessment procedure consists of a series of measurements of different noise parameters and then the calculation of corrections due to tonal, low frequency and impulsive components. This paper shows an example of a MVHR fan unit installed in the ceiling of a common dwelling, where some measurements were performed. Based on these measurements, this paper discusses the noise measurement and assessment procedures and proposes some improvements for the Spanish acoustic regulations. In addition, it also analyses the available calculation methods (ASHRAE and VDI 2081) and their application to comply with Spanish requirements.

Стилі APA, Harvard, Vancouver, ISO та ін.

31

Inban, Prayuth, Rachu Punchalard, and Chawalit Benjangkaprasert. "Phase Error Criterion Based Adaptive Algorithm for Frequency Estimation." International Journal of Antennas and Propagation 2024 (March 18, 2024): 1–13. http://dx.doi.org/10.1155/2024/9055869.

Повний текст джерела

Анотація:

A simple phase error criterion (PEC-)-based adaptive algorithm for estimating the frequency of a complex sinusoidal signal in additive white Gaussian and impulsive noises is proposed. The proposed technique makes use of the instantaneous phase response of a first-order complex linear predictor (CLP) as a driving function to update the frequency parameter of the CLP. The proposed PEC is attractive due to its simplicity and high impulsive noise robustness. Theoretical analysis for the mean value of the estimated frequency and the steady-state mean square error (MSE) of the frequency estimate are derived in closed forms. Computer simulations are drawn to show the performance of the proposed frequency estimator.

Стилі APA, Harvard, Vancouver, ISO та ін.

32

Cui, Junyan, Wei Pan, and Haipeng Wang. "Direction of Arrival Estimation Method Based on Eigenvalues and Eigenvectors for Coherent Signals in Impulsive Noise." Mathematics 12, no. 6 (March 12, 2024): 832. http://dx.doi.org/10.3390/math12060832.

Повний текст джерела

Анотація:

In this paper, a Toeplitz construction method based on eigenvalues and eigenvectors is proposed to combine with traditional denoising algorithms, including fractional low-order moment (FLOM), phased fractional low-order moment (PFLOM), and correntropy-based correlation (CRCO) methods. It can improve the direction of arrival (DOA) estimation of signals in impulsive noise. Firstly, the algorithm performs eigenvalue decomposition on the received covariance matrix to obtain eigenvectors and eigenvalues, and then the Toeplitz matrix is created according to the eigenvectors corresponding to its eigenvalues. Secondly, the spatial averaging method is used to obtain an unbiased estimate of the Toeplitz matrix, which is then weighted and added based on the corresponding eigenvalues. Next, the noise subspace of the Toeplitz matrix is reconstructed to obtain the one that has less angle information. Finally, the DOA of the coherent signal is estimated using the Multiple Signal Classification (MUSIC) algorithm. The improved method based on the Toeplitz matrix can not only suppress the effect of impulsive noise but can also solve the problem of aperture loss due to its decoherence. A series of simulations have shown that they have better performances than other algorithms.

Стилі APA, Harvard, Vancouver, ISO та ін.

33

Chloupek, Petr, Eva Voslářová, Jan Chloupek, Iveta Bedáňová, Vladimíra Pištěková, and Vladimír Večerek. "Stress in Broiler Chickens Due to Acute Noise Exposure." Acta Veterinaria Brno 78, no. 1 (2009): 93–98. http://dx.doi.org/10.2754/avb200978010093.

Повний текст джерела

Анотація:

Stress effects from acute noise exposure were monitored in a group of ROSS 308 broiler chickens (n = 80), aged 42 days. The experiment simulated slaughterhouse sounds to which the broilers were exposed for 10 min in the test enclosure. Effects of acute noise exposure at two different levels (80 dB and 100 dB) were evaluated on the basis of examinations of selected biochemical plasma indicators and tonic immobility tests. Noise stimuli of both 80 dB and 100 dB intensities for 10 min induced a significant elevation in plasma corticosterone levels. Broilers that were exposed to noise stimuli of 100 dB also exhibited a significant increase in the cholesterol level and total protein level. Exposure to noise stimuli did not influence the glucose level and triglyceride concentrations. The duration of tonic immobility was not affected by noise stimuli in our experiment. However, noise exposure at a 100 dB level decreased the number of attempts to induce tonic immobility in broilers.

Стилі APA, Harvard, Vancouver, ISO та ін.

34

Shin, Jaewook, Jeesu Kim, Tae-Kyoung Kim та Jinwoo Yoo. "ℒp-Norm-like Affine Projection Sign Algorithm for Sparse System to Ensure Robustness against Impulsive Noise". Symmetry 13, № 10 (12 жовтня 2021): 1916. http://dx.doi.org/10.3390/sym13101916.

Повний текст джерела

Анотація:

An improved affine projection sign algorithm (APSA) was developed herein using a Lp-norm-like constraint to increase the convergence rate in sparse systems. The proposed APSA is robust against impulsive noise because APSA-type algorithms are generally based on the L1-norm minimization of error signals. Moreover, the proposed algorithm can enhance the filter performance in terms of the convergence rate due to the implementation of the Lp-norm-like constraint in sparse systems. Since a novel cost function of the proposed APSA was designed for maintaining the similar form of the original APSA, these have symmetric properties. According to the simulation results, the proposed APSA effectively enhances the filter performance in terms of the convergence rate of sparse system identification in the presence of impulsive noises compared to that achieved using the existing APSA-type algorithms.

Стилі APA, Harvard, Vancouver, ISO та ін.

35

Min Hwang, Yu, Young Ghyu Sun, Issac Sim, and Jin Young Kim. "Iterative Approach for Performance Improvement of PLC Systems." International Journal of Engineering & Technology 7, no. 4.4 (September 15, 2018): 7. http://dx.doi.org/10.14419/ijet.v7i4.4.19592.

Повний текст джерела

Анотація:

In this paper, we propose Turbo equalizer scheme using zero-forcing (ZF) and simulate in power line communication (PLC) systems with high speed. Due to impulsive noise and multipath fading in PLC systems, inter-symbol interference (ISI) happens. We employ Turbo equalizer scheme to get over ISI and improve performance. From simulation results, it is confirmed that the proposed Turbo equalizer can remarkably improve PLC system performance.

Стилі APA, Harvard, Vancouver, ISO та ін.

36

Arenas, Jorge, Jorge Cardenas, Christian Robertson, and Jose L. Urnia. "Assessment of hearing loss risk due to impact noise in industrial environments." INTER-NOISE and NOISE-CON Congress and Conference Proceedings 265, no. 1 (February 1, 2023): 6362–68. http://dx.doi.org/10.3397/in_2022_0954.

Повний текст джерела

Анотація:

Impact noises are often found in industrial environments and they are predominant in mining, construction, factories, workshops, and shipyards. It is well-known that impact noises are more likely to cause noise-induced hearing loss than continuous noise of equal energy. Impulse noises are characterized by their high intensity over a short period of time and many countries have defined impulse noise exposure limits and criteria in occupational settings. They are based on the sound level measurements made using standard sound pressure level meters and dosemeters. However, because of their metrological limitations, it is not appropriate to use these instruments when dealing with such high peak levels and short duration times. Extensive research on hearing damage produced by impulse noise generated by firearms has been presented, mainly on police and military personnel. These studies have led to damage risk criteria contained in various versions of the standard MIL-STD-1474. Although industrial noises can reach similar peak sound pressure levels, not many results have been published on the subject. In this work, several common sources of industrial impact noise were measured in-situ, at the worker locations, using a specialized system equipped with high-dynamic-range microphones and a very high data acquisition rate. The signals were post-processed to obtain the main metrics defined for impulse noise exposure assessment. Then, occupational hearing loss risk was estimated using different criteria. It is shown that many common industrial processes reported a very high risk of impulsive noise to human hearing.

Стилі APA, Harvard, Vancouver, ISO та ін.

37

Tsukagoshi, Tsuneo, Shuichi Nitta, and Atsuo Mutoh. "An analysis on malfunction of a flip-flop due to impulsive noise on power supply." Electronics and Communications in Japan (Part II: Electronics) 86, no. 10 (September 10, 2003): 36–50. http://dx.doi.org/10.1002/ecjb.10187.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

38

Ding, Liang, Hui Zhao, and Yixin Dou. "Sparse Signal Inversion with Impulsive Noise by Dual Spectral Projected Gradient Method." Mathematical Problems in Engineering 2017 (2017): 1–17. http://dx.doi.org/10.1155/2017/2736306.

Повний текст джерела

Анотація:

We consider sparse signal inversion with impulsive noise. There are three major ingredients. The first is regularizing properties; we discuss convergence rate of regularized solutions. The second is devoted to the numerical solutions. It is challenging due to the fact that both fidelity and regularization term lack differentiability. Moreover, for ill-conditioned problems, sparsity regularization is often unstable. We propose a novel dual spectral projected gradient (DSPG) method which combines the dual problem of multiparameter regularization with spectral projection gradient method to solve the nonsmooth l1+l1 optimization functional. We show that one can overcome the nondifferentiability and instability by adding a smooth l2 regularization term to the original optimization functional. The advantage of the proposed functional is that its convex duality reduced to a constraint smooth functional. Moreover, it is stable even for ill-conditioned problems. Spectral projected gradient algorithm is used to compute the minimizers and we prove the convergence. The third is numerical simulation. Some experiments are performed, using compressed sensing and image inpainting, to demonstrate the efficiency of the proposed approach.

Стилі APA, Harvard, Vancouver, ISO та ін.

39

Zhao, Xin, Lijun Wang, Pankaj Kumar Tiwari, He Liu, Yi Wang, Jianbing Li, Min Zhao, Chuanjun Dai, and Qing Guo. "Investigation of a nutrient-plankton model with stochastic fluctuation and impulsive control." Mathematical Biosciences and Engineering 20, no. 8 (2023): 15496–523. http://dx.doi.org/10.3934/mbe.2023692.

Повний текст джерела

Анотація:

<abstract><p>In this paper, we investigate a stochastic nutrient-plankton model with impulsive control of the nutrient concentration and zooplankton population. Analytically, we find that the population size is nonnegative for a sufficiently long time. We derive some sufficient conditions for the existence of stable periodic oscillations, which indicate that the plankton populations will behave periodically. The numerical results show that the plankton system experiences a transition from extinction to the coexistence of species due to the emergence of impulsive control. Additionally, we observe that the nutrient pulse has a stronger relationship with phytoplankton growth than the zooplankton pulse. Although the frequency of impulsive control and appropriate environmental fluctuations can promote the coexistence of plankton populations, an excessive intensity of noise can result in the collapse of the entire ecosystem. Our findings may provide some insights into the relationships among nutrients, phytoplankton and zooplankton in a stochastic environment.</p></abstract>

Стилі APA, Harvard, Vancouver, ISO та ін.

40

EL GHZAOUI, Mohammed. "Performance Analysis of MIMO System over an In-home PLC Channel." ASM Science Journal 15 (May 17, 2021): 1–10. http://dx.doi.org/10.32802/asmscj.2020.460.

Повний текст джерела

Анотація:

Power line communication (PLC) system is an attractive technology for Smart Grid applications. One key benefit of PLC is its low installation cost because, in PLC technology, we do not need to install any extra cable to extend a network due to the accessibility to low voltage power network. Orthogonal frequency division multiplexing (OFDM) is widely used in PLC networks. Currently, Multiple Input Multiple Output (MIMO) technology is one of the processing techniques appropriate to PLC networks, allowing high data rate. In this work, the MIMO-OFDM system is established to provide better performance over the PLC system by providing communication links with substantial diversity and capacity. However, adapting MIMO to the PLC network involves solving several issues such as MIMO PLC channel modelling and optimisation of the modulation parameters. In this paper, we present measurements results of the transfer function and impulsive noise in the extended frequency range 2-100 MHz. In the simulation part, we evaluate the performance of the proposed receivers in 2×2 MIMO-PLC channels. It is shown that the minimum mean square error (MMSE) receiver can be one of the appropriate candidates for MIMO PLC channels due to its bite error rate (BER) characteristics under impulsive noise.

Стилі APA, Harvard, Vancouver, ISO та ін.

41

CHAN, RAYMOND H., HAI-XIA LIANG, and JUN MA. "POSITIVELY CONSTRAINED TOTAL VARIATION PENALIZED IMAGE RESTORATION." Advances in Adaptive Data Analysis 03, no. 01n02 (April 2011): 187–201. http://dx.doi.org/10.1142/s1793536911000817.

Повний текст джерела

Анотація:

The total variation (TV) minimization models are widely used in image processing, mainly due to their remarkable ability in preserving edges. There are many methods for solving the TV model. These methods, however, seldom consider the positivity constraint one should impose on image-processing problems. In this paper we develop and implement a new approach for TV image restoration. Our method is based on the multiplicative iterative algorithm originally developed for tomographic image reconstruction. The advantages of our algorithm are that it is very easy to derive and implement under different image noise models and it respects the positivity constraint. Our method can be applied to various noise models commonly used in image restoration, such as the Gaussian noise model, the Poisson noise model, and the impulsive noise model. In the numerical tests, we apply our algorithm to deblur images corrupted by Gaussian noise. The results show that our method give better restored images than the forward–backward splitting algorithm.

Стилі APA, Harvard, Vancouver, ISO та ін.

42

Żak, Grzegorz, Marek Teuerle, Agnieszka Wyłomańska та Radosław Zimroz. "Measures of Dependence for α-Stable Distributed Processes and Its Application to Diagnostics of Local Damage in Presence of Impulsive Noise". Shock and Vibration 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/1963769.

Повний текст джерела

Анотація:

Local damage detection in rotating machinery is simply searching for cyclic impulsive signal in noisy observation. Such raw signal is mixture of various components with specific properties (deterministic, random, cyclic, impulsive, etc.). The problem appears when the investigated process is based on one of the heavy-tailed distributions. In this case the classical measure can not be considered. Therefore, alternative measures of dependence adequate for such processes should be considered. In this paper we examine the structure of dependence of alpha-stable based systems expressed by means of two measures, namely, codifference and covariation. The reason for using alpha-stable distribution is simple and intuitive: signal of interest is impulsive so its distribution is heavy-tailed. The main goal is to introduce a new technique for estimation of covariation. Due to the complex nature of such vibration signals applying novel methods instead of classical ones is recommended. Classical algorithms usually are based on the assumption that theoretical second moment is finite, which is not true in case of the data acquired on the faulty components. Main advantage of our proposed algorithm is independence from second moment assumption.

Стилі APA, Harvard, Vancouver, ISO та ін.

43

DuBois, Ami M., Edward Thomas, William E. Amatucci, and Gurudas Ganguli. "Experimental characterization of broadband electrostatic noise due to plasma compression." Journal of Geophysical Research: Space Physics 119, no. 7 (July 2014): 5624–37. http://dx.doi.org/10.1002/2014ja020198.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

44

Aranda de Toro, Miguel Angel, Rodrigo Ordoñez, Karen Reuter, and Dorte Hammershøi. "Is it necessary to penalize impulsive noise +5 dB due to higher risk of hearing damage?" Journal of the Acoustical Society of America 129, no. 6 (June 2011): 3808–17. http://dx.doi.org/10.1121/1.3573981.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

45

Patanavijit, Vorapoj, and Kornkamol Thakulsukanant. "An innovative vigorous outlier recognition placed on LROAD for fix-amplitude impulsive noise." Bulletin of Electrical Engineering and Informatics 11, no. 4 (August 1, 2022): 2044–53. http://dx.doi.org/10.11591/eei.v11i4.4168.

Повний текст джерела

Анотація:

Due to large current applications on digital images in these recent years, outlier suppression is one of the primary stages for modern computer vision implementations thereupon there are tremendously invented for creating an efficient and practical outlier suppression, which ordinarily are composed of outlier recognition stage and outlier rebuilt stage. The localised rank ordered difference (LROAD) approach, which is progressed from rank-ordered absolute differences (ROAD), has been invented since 2016. Later, the LROAD approach evolved to be one of the efficient outlier recognition stages from its eminent effectiveness. The paper focus to propose the innovative vigorous outlier recognition placed on localised rank-ordered logarithmic differences (LROLD) approach, which is progressed from LROAD and rank-ordered logarithmic differences (ROLD), which is higher effectiveness than the ordinary LROAD, for applying on FAIN. From the computer experiments, which are examined on many depictions such as Girl, Pepper F16 and Lena, the innovative vigorous outlier recognition placed on LROLD approach has higher eminent effectiveness then the stage-of-art approach such as LROAD and ROAD approaches at numerous consistencies of FAIN.

Стилі APA, Harvard, Vancouver, ISO та ін.

46

Lee, Sang-Kwon. "Sliced Wigner Fourth Order Moment Spectra Smoothed byγ-Method and Its Application to Detection of Valve System Faults in an Engine". Shock and Vibration 8, № 6 (2001): 339–48. http://dx.doi.org/10.1155/2001/128143.

Повний текст джерела

Анотація:

The research proposes a method for detecting valve system faults in an engine. The methodology is based on the detection of impulsive sound embedded in the high level of background noise by using the sliced Wigner fourth order moment spectra (SWFOMS) which is inherently more robust in the presence of random (Gaussian) noise. However, in previous work, the SWFOMS for multiple signals had problems with its application which were due to the existence of non-oscillating cross-terms not smoothed by conventional methods. In this paper, the γ-method is developed to smooth non-oscillation cross-terms. Finally, the techniques developed are applied to the diagnosis of valve system faults in an engine.

Стилі APA, Harvard, Vancouver, ISO та ін.

47

Acciani, G., V. Amoruso, G. Fornarelli, and A. Giaquinto. "SOM-Based Approach for the Analysis and Classification of Synchronous Impulsive Noise of an In-Ship PLC System." ISRN Artificial Intelligence 2012 (October 16, 2012): 1–9. http://dx.doi.org/10.5402/2012/105694.

Повний текст джерела

Анотація:

The interest in wideband data transmission over power line communications has increased rapidly. This technology offers a convenient and inexpensive medium to transmit data, reducing the number of cables. This advantage is particularly appealing in many fields, like the railway, naval, and aeronautical ones. Nevertheless, several problems have to be faced to obtain a high data rate. In particular, the presence of noise makes the transmission difficult, degrading the quality of received signals and prohibiting the full application of these communication frameworks. In this paper the behaviour of an in-ship powerline communication system is analyzed in the presence of synchronous periodic impulsive noise. Such noise is modelled at source and its effects on the transmission of wideband signals are evaluated by means of a simulation circuit model. The obtained results allow to identify the characteristics of the channel and the critical conditions due to noise. Subsequently, an unsupervised technique based on principal component analysis and fuzzy c-mean classifier detects the presence and classifies the specific noises. Numerical results show that the proposed approach enables to achieve this target accurately under different operating conditions, proving to be an effective tool to enhance the performances of the considered technology.

Стилі APA, Harvard, Vancouver, ISO та ін.

48

Mohamad Ansor, N., Z. S. Hamidi, and N. N. M. Shariff. "On propagation of gradual and impulsive Coronal Mass Ejections (CMEs)." Journal of Physics: Conference Series 2793, no. 1 (July 1, 2024): 012009. http://dx.doi.org/10.1088/1742-6596/2793/1/012009.

Повний текст джерела

Анотація:

Abstract Coronal Mass Ejection (CME) is a significant solar activity that releases magnetic field and plasma out of the corona and they are known as the main driver of space weather. In general, CMEs are characterized as gradual and impulsive based on their kinematic properties that include velocity and acceleration. This paper is aimed to analyze the differences in behaviour of gradual and impulsive CME based on recent events (dates) in solar cycle 25 and to justify their characterizations that have been demonstrated a while ago. Data analysis is conducted by studying the height-time, height-velocity and height-acceleration profiles for each event, based on SOHO LASCO Catalogue. Results show that impulsive CME travels a lot faster than gradual CME, with average velocity of 1239 km/s and 503.6 km/s respectively. It is believed that M6.7 flare accompanying the impulsive CME has been the main reason to high velocity due to its ability to contribute more heat energy and enhances the energy conversion during magnetic reconnection. Deceleration is observed in impulsive CME that is caused by the loss of momentum as interacting with the background solar wind and small-scale acceleration is manifested by gradual CME all through the propagation.

Стилі APA, Harvard, Vancouver, ISO та ін.

49

Thiery, L., and C. Meyer‐Bisch. "Hearing loss due to partly impulsive industrial noise exposure at levels between 87 and 90 dB(A)." Journal of the Acoustical Society of America 84, no. 2 (August 1988): 651–59. http://dx.doi.org/10.1121/1.396844.

Повний текст джерела

Стилі APA, Harvard, Vancouver, ISO та ін.

50

Ryan, Tim E., Ryan A. Downie, Rudy J. Kloser, and Gordon Keith. "Reducing bias due to noise and attenuation in open-ocean echo integration data." ICES Journal of Marine Science 72, no. 8 (August 8, 2015): 2482–93. http://dx.doi.org/10.1093/icesjms/fsv121.

Повний текст джерела

Анотація:

Abstract Measurements of mean volume backscattering strength (Sv, dB re 1 m−1) at ocean-basin scale were made using 38-kHz hull-mounted echosounders on ships of opportunity as part of Australia's Integrated Marine Observing System. The data were collected on vessels of various designs, none of which were purposely built for collecting high-quality acoustic data. A full range of weather extremes affected the quality of the data and could cause large biases in Sv. To remove first-order biases and improve processing efficiency, a sequence of new and existing data processing filters were applied in a semi-automated procedure. These filters were designed to mitigate the effects of three types of noise: impulsive (less than one ping), transient (multiple pings), and background (hours or longer). A filter was also applied to identify signals that were attenuated by air bubbles beneath the transducer. These filters were applied to data from transits across the Southwest Pacific, Indian, and Southern Oceans to produce quality-controlled Sv datasets that are now available from a publicly accessible repository. These filters may be relevant to other open-ocean acoustic observing endeavours, and one or more could be used to mitigate bias in data from a range of acoustic applications.

Стилі APA, Harvard, Vancouver, ISO та ін.

Статті в журналах з теми "Impulsive noise due to plasma"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями