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Journal articles on the topic 'Mechanical noise'

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Author: Grafiati

Published: 10 December 2022

Last updated: 29 January 2023

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1

Tapia-Rojo, Rafael, Álvaro Alonso-Caballero, and Julio M. Fernández. "Talin folding as the tuning fork of cellular mechanotransduction." Proceedings of the National Academy of Sciences 117, no. 35 (August 17, 2020): 21346–53. http://dx.doi.org/10.1073/pnas.2004091117.

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Cells continually sample their mechanical environment using exquisite force sensors such as talin, whose folding status triggers mechanotransduction pathways by recruiting binding partners. Mechanical signals in biology change quickly over time and are often embedded in noise; however, the mechanics of force-sensing proteins have only been tested using simple force protocols, such as constant or ramped forces. Here, using our magnetic tape head tweezers design, we measure the folding dynamics of single talin proteins in response to external mechanical noise and cyclic force perturbations. Our experiments demonstrate that talin filters out external mechanical noise but detects periodic force signals over a finely tuned frequency range. Hence, talin operates as a mechanical band-pass filter, able to read and interpret frequency-dependent mechanical information through its folding dynamics. We describe our observations in the context of stochastic resonance, which we propose as a mechanism by which mechanosensing proteins could respond accurately to force signals in the naturally noisy biological environment.

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2

Camossi, Roberto. "Mechanical low‐noise press." Journal of the Acoustical Society of America 93, no. 6 (June 1993): 3536–37. http://dx.doi.org/10.1121/1.405370.

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3

Koss, L. L., and W. Kowalczyk. "Punch press mechanical clutch engagement noise and noise reduction." Journal of Sound and Vibration 102, no. 4 (October 1985): 527–49. http://dx.doi.org/10.1016/s0022-460x(85)80112-7.

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4

Lilly, Jerry G. "Mechanical noise and vibration control." Journal of the Acoustical Society of America 150, no. 4 (October 2021): A23. http://dx.doi.org/10.1121/10.0007495.

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5

Keefe, Joseph. "Mechanical noise control case studies." Journal of the Acoustical Society of America 150, no. 4 (October 2021): A137. http://dx.doi.org/10.1121/10.0007895.

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6

Allardet-Servent, Jérôme. "Adding noise to mechanical ventilation." Critical Care Medicine 40, no. 9 (September 2012): 2725–26. http://dx.doi.org/10.1097/ccm.0b013e31825bc827.

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7

Sevier, Stuart A., David A. Kessler, and Herbert Levine. "Mechanical bounds to transcriptional noise." Proceedings of the National Academy of Sciences 113, no. 49 (November 22, 2016): 13983–88. http://dx.doi.org/10.1073/pnas.1612651113.

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Over the past several decades it has been increasingly recognized that stochastic processes play a central role in transcription. Although many stochastic effects have been explained, the source of transcriptional bursting (one of the most well-known sources of stochasticity) has continued to evade understanding. Recent results have pointed to mechanical feedback as the source of transcriptional bursting, but a reconciliation of this perspective with preexisting views of transcriptional regulation is lacking. In this article, we present a simple phenomenological model that is able to incorporate the traditional view of gene expression within a framework with mechanical limits to transcription. By introducing a simple competition between mechanical arrest and relaxation copy number probability distributions collapse onto a shared universal curve under shifting and rescaling and a lower limit of intrinsic noise for any mean expression level is found.

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8

Saulson, Peter R. "Thermal noise in mechanical experiments." Physical Review D 42, no. 8 (October 15, 1990): 2437–45. http://dx.doi.org/10.1103/physrevd.42.2437.

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9

Tikriti, Walid. "Pool equipment mechanical noise impact." Journal of the Acoustical Society of America 141, no. 5 (May 2017): 3686. http://dx.doi.org/10.1121/1.4988018.

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10

Fahey, S. O., and A. L. Wicks. "NOISE SOURCES IN MECHANICAL MEASUREMENTS." Experimental Techniques 24, no. 2 (March 2000): 40–43. http://dx.doi.org/10.1111/j.1747-1567.2000.tb02271.x.

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11

Shin, Jaehyun, Yongmin Zhong, and Chengfan Gu. "Real-Time Nonlinear Characterization of Soft Tissue Mechanical Properties." Journal of Sensors 2020 (March 4, 2020): 1–15. http://dx.doi.org/10.1155/2020/9873410.

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Online soft tissue characterization is important for robotic-assisted minimally invasive surgery to achieve precise and stable robotic control with haptic feedback. This paper presents a new nonlinear recursive adaptive filtering methodology for online nonlinear soft tissue characterization. An adaptive unscented Kalman filter is developed based on the Hunt-Crossley model by windowing approximation to online estimate system and measurement noise covariances. To improve the accuracy of noise covariance estimations, a recursive formulation is subsequently developed for estimation of system and measurement noise covariances by introducing a weighting factor. This weighting factor is further modified to accommodate noise statistics of large variation which could be caused by rupture events and geometric discontinuities in robotic-assisted surgery. Simulations, experiments, and comparison analyses demonstrate that the proposed nonlinear recursive adaptive filtering methodology can characterize soft tissue parameters in the presence of system or measurement noise statistics in both small and large variations for robotic-assisted surgery. The proposed methodology can effectively estimate soft tissue parameters under system and measurement noises in both small and large variations, leading to improved filtering accuracy and robustness in comparison with UKF.

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12

Fan, Yi Bo, Feng Shou Gu, and Andrew Ball. "Acoustic Emission Monitoring of Mechanical Seals Using MUSIC Algorithm Based on Higher Order Statistics." Key Engineering Materials 413-414 (June 2009): 811–16. http://dx.doi.org/10.4028/www.scientific.net/kem.413-414.811.

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This paper presents the use of the MUSIC algorithm improved by higher order statistics (HOS) to extract key features from the noisy acoustic emission (AE) signals. The low signal-to-noise ratio of AE signals has been identified as a main barrier to the successful condition monitoring of pump mechanical seals. Since HOS methods can effectively eliminate Gaussian noise, it is possible in theory to identify a change in seal conditions from AE measurements even with low signal-to-noise ratios. Tests conducted on a test rig show that the developed algorithm can successfully detect the AE signal generated from the friction of seal faces under noisy conditions.

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13

Huang, Jingjing, and Longxi Zheng. "Noise analysis of the turbojet and turbofan engine tests." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 228, no. 13 (December 23, 2013): 2414–23. http://dx.doi.org/10.1177/0954410013518035.

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Aerogine noise leads to environment pollution largely when aerogine is tested. In this paper, the power spectrum analysis method of the aeroengine test noise was discussed, and the noise measurement and analysis experiments of a turbojet engine and a turbofan engine tests were carried out. The noise level, main noise resource, and noise characteristics of the two turbojet and turbofan engines were analyzed. Meanwhile, the indoor noise and far-field noise of the turbojet engine were both measured, the noise spread characteristics were analyzed and the noise reduction performance of the test bench was evaluated. The noise generated by the turbojet engine test had the discrete characteristic of high frequency. The higher frequencies when peak values occurred were the blade passage frequencies and the noises with lower frequencies were the broad band noises, especially the jet noise, and the maximum of the peak values occurred at the basic frequencies or harmonic frequencies of the compressor. Meanwhile, the noises generated by the turbofan engine, focused on the high frequencies and the peak values corresponded to the rotation noise of the fan blades. The experimental results were consistent with the theory basically, which indicated that the aeroengine operating status information could be identified by the noise power spectrum analysis. In addition to the aeroengine noise reduction research, the noise power spectrum analysis could also be used to diagnose the fault of the aeroengine structure and performance. On the other hand, the indoor and far-field noise measurement experimental results implied that the noise was suppressed from 136 dB to 85 dB and could provide the reference to the noise reduction design of the aeroengine test bench.

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14

Nishiwaki, M. "Generalized Theory of Brake Noise." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 207, no. 3 (July 1993): 195–202. http://dx.doi.org/10.1243/pime_proc_1993_207_180_02.

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Eliminating brake noises generated during brake application is an important issue in the improvement of comfort in vehicles. Brake noises (frequency 1–15 kHz) are often called brake squeal. On the other hand, brake noises (frequency 200–500 Hz) are often called brake groan noise. The studies on drum brake squeal, disc brake squeal and disc brake groan noise have already been presented in references (2), (3) and (4), where theoretical analyses on these brake noises were described. This paper shows that the equations of motion are represented by the same type of equations. Based on these analyses. It is clear that drum brake squeal, disc squeal and disc brake groan noise are generated by the same cause—dynamic instability of the brake system with friction force variations.

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15

Guo, Tie Neng, Ting Yu Wu, and Xiao Lei Song. "Identification of the Dynamic Properties of Mechanical Joints." Applied Mechanics and Materials 468 (November 2013): 114–18. http://dx.doi.org/10.4028/www.scientific.net/amm.468.114.

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The frequency response functions (FRFs) are frequently used to identify dynamic properties of the mechanical joints. However, the ill-posed problems of the system are caused by the contamination of measurement noise even if it is processed by reduction technique. In order to solve this problem, put the noised FRFs into identification equations to theoretical derivation, explained the degree of influence on the identified results by noised FRFs in theory. In order to make the identified results represent real properties of the joints, an improved FRFs method was developed based on subtraction term frequency selection, in which the measured data were processed could get high degree of anti-noise frequency before parameters identification. This method avoids the occurrence of ill-posed problems. The results of simulation show that the proposed method can solve the ill-posed problems, thus significantly improve the accuracy of identification.

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16

Yen, Chih-Ta, Ing-Jr Ding, and Zong-Wei Lai. "A STUDY OF DIGITAL WATERMARKING RECOGNITION USING ORTHOGONAL CODE SEQUENCES WITH A BACK-PROPAGATION NEURAL NETWORK." Transactions of the Canadian Society for Mechanical Engineering 37, no. 3 (September 2013): 459–65. http://dx.doi.org/10.1139/tcsme-2013-0035.

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Digital watermarking is an encryption technology commonly used to protect intellectual property and copyright. In this study, we restored watermarks that had already been affected by noise interference, used the Walsh–Hadamard codes as the watermark identification codes, and applied salt-and-pepper noise and Gaussian noise to destroy watermarks. First method, we used a low-pass filter and median filter to remove noise interferences. The second one, we used a back-propagation neural network algorithm to suppress noises. We removed nearly all noise and recovered the originally embedded watermarks of Walsh–Hadmard codes.

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17

Kim, Jae Chul, Hee-Min Noh, and Yang Soo Yun. "Local coating of curved rails by using low friction material for squeal noise reduction." Advances in Mechanical Engineering 12, no. 12 (December 2020): 168781402098065. http://dx.doi.org/10.1177/1687814020980650.

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Curve squeal noise is one of the most prominent noises among railway noises. High levels of noise are generated when a train passes through curved sections, resulting in several complaints from the residents and vehicle passengers. To mitigate this problem, the squeal noise was attempted to be mitigated by laser cladding the composite material on the head of the rail. First, the effect of the negative gradient of the coefficient of friction on the squeal noise was theoretically examined. A simple model analysis indicated that the vibration of the wheel increased rapidly when the vibration system involved instability characteristics. In addition, the change in the friction coefficient owing to the local coating of the rail with a low friction material was investigated using a roller rig test equipment. The results demonstrated that the negative friction coefficient did not occur when the contact position between the wheel and rail was locally coated. Furthermore, the effect of the low friction local coating on the squeal noise in the curve section was examined in operational rails. The comparison of the results obtained before and after the local coating confirmed that the local coating of the rail can effectively reduce the squeal noise.

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18

Shi, Yao-Wu, Chen Wang, Lan-Xiang Zhu, Li-Fei Deng, Yi-Ran Shi, and De-Min Wang. "1/f spectrum estimation based on α-stable distribution in colored Gaussian noise environments." Journal of Low Frequency Noise, Vibration and Active Control 38, no. 1 (December 4, 2018): 18–35. http://dx.doi.org/10.1177/1461348418813291.

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The main goal of this paper is to suppress the effect of unavoidable colored Gaussian noise on declining accuracy of transistor 1/f spectrum estimation. Transistor noises are measured by a nondestructive cross-spectrum measurement method, which is first to amplify the voltage signals through ultra-low noise amplifiers, then input the weak signals into data acquisition card. The data acquisition card collects the voltage signals and outputs the amplified noise for further analysis. According to our studies, the output 1/f noise can be characterized more accurately as non-Gaussian α-stable distribution rather than Gaussian distribution. Therefore, by utilizing the properties of α-stable distribution, we propose a cross-spectrum method effective in noisy environments based on samples normalized cross-correlation function. Simulation results and diodes output noise spectrum estimation results confirm the effectiveness of our method.

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19

Majorana, E., and Y. Ogawa. "Mechanical thermal noise in coupled oscillators." Physics Letters A 233, no. 3 (August 1997): 162–68. http://dx.doi.org/10.1016/s0375-9601(97)00458-1.

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20

Doege, E., and H. J. Seidel. "Noise Reduction on Mechanical Punch Presses." CIRP Annals 34, no. 1 (1985): 507–9. http://dx.doi.org/10.1016/s0007-8506(07)61822-8.

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21

Annovazzi-Lodi, V., and S. Merlo. "Mechanical–thermal noise in micromachined gyros." Microelectronics Journal 30, no. 12 (December 1999): 1227–30. http://dx.doi.org/10.1016/s0026-2692(99)00046-4.

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22

Leland, R. P. "Mechanical-thermal noise in MEMS gyroscopes." IEEE Sensors Journal 5, no. 3 (June 2005): 493–500. http://dx.doi.org/10.1109/jsen.2005.844538.

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23

Chiu, M.-C. "Noise identification in reverberant sound field by using simulated annealing." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 222, no. 2 (February 1, 2008): 163–79. http://dx.doi.org/10.1243/09544062jmes622.

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Noise control is important and essential in an enclosed machine room where the noise level is restricted by the occupational safety and health act. Before the appropriate noise abatement is performed, the identification work of location and free-field sound energy of equipment inside the reverberant sound field become crucial and an absolute prerequisite. Research on new techniques of single noise control and sound absorption system has been well addressed and developed; however, the research work on sound identification for an existing multi-noise enclosed room is rare and observably insufficient. Without the actual location and pure free-field noise level, noise control work will be improper and wasted; therefore, the numerical approach of noise recognition from the reverberant sound field becomes necessary and obligatory. In this paper, the novel technique of simulated annealing (SA) in conjunction with the method of minimized variation square is applied in the following numerical optimization. In addition, various sound monitoring systems in detecting the noise condition within the echo area is also introduced. Before noise identification can be carried out, the accuracy of the mathematical model in a single-noise enclosed system has to be checked by SoundPlan (a professional simulation package in sound field). Thereafter, the SA recognition of three kinds of multi-noise systems has to be exemplified and fully explored. The results reveal that either the locations or sound power levels (SWLs) of noises can be precisely distinguished. Consequently, this paper may provide an efficient and rapid way in distinguishing the location and free-field noise level of equipment in a complicated sound field.

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24

Vilău, Radu, Marin Marinescu, Octavian Alexa, Marian Truta, and Valentin Vinturis. "Diagnose Method Based on Spectral Analysis of Measured Parameters." Advanced Materials Research 1036 (October 2014): 535–40. http://dx.doi.org/10.4028/www.scientific.net/amr.1036.535.

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The paper presents a possible method to diagnose a mechanical fault of an automotive system. Starting from the point of view that every fault of a mechanical system should introduce an abnormal component within the signal that describes the time history of a mechanical parameter we tried to find a way to reveal it.We were performing some tests involving a military vehicle with respect to the performances of its braking system. The tests were aiming at identifying a way to bring up-to-date the old weapon system from the braking systems point of view. During these tests we observed some anomalies concerning the pressure evolution within the braking cylinders of the vehicle. Some unusual but also systematic noises occurred. As a main issue at this point, the source of the noise should have been identified and filtered if necessary. We had to decide whether the noisy component of the signal is just a noise that should be removed by filtering the signal or it is a physical component of the mechanical parameter itself (not noise but a useful information).These procedures take time and they also request accurate knowledge as well as fine expertise in automotive testing. Since our Dept. has a long and rich practice in this respect, we assumed to processing data and give them a thorough interpretation. So, the first thing we did was to perform a frequency analysis, using classical methods. Usually, a simple frequency analysis cant provide information about a time variation of the frequency spectra due to the Fourier Transforms behavior, since it freezes the signal in time. A much more accurate analysis is the time-frequency analysis. However, observing both the amplitude and power spectra can lead to a useful conclusion. We concluded that the noise we met within the signal is due to the brake drums loss of circular shape (they turned into an oval, the process being known as ovalization). Hence, we cant talk about a noise as it is usually defined.

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25

Kwon, Hyo-Chan, Chang-Hee Cho, Cheong-Wu Nam, Soo-Won Chae, Seong-Yun Seo, and Kwon-Hee Kim. "Reducing car audio button noise while maintaining tactile quality." Advances in Mechanical Engineering 10, no. 1 (January 2018): 168781401775259. http://dx.doi.org/10.1177/1687814017752596.

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Recently, interior noise levels of passenger cars have been significantly reduced. The reduction of major cabin noise led to the recognition of small noises that are previously unnoticed. Specifically, the button noises of electrical devices in passenger compartments have been identified as belonging to this category of noise. The aim of this study is to improve the auditory quality of a car audio button while maintaining its tactile quality that is familiar to users. The tactile and auditory qualities can be described by the load versus stroke characteristics and the operation noise level. For buttons with rubber domes, the buckling behavior of the domes governs the tactile and auditory qualities. To preserve the tactile quality, the sensitivity of load versus stroke characteristics to each of the eight identified parameters is obtained from the finite element analyses using model parameters varied by ±10%. Four parameters to which the tactile quality was insensitive are selected. To identify the contributions of these four design parameters to auditory quality, finite element analyses were performed in conjunction with design of experiments. The improved design obtained by the subsequent response surface methodology optimization was validated by a prototype test with a 12 dBA reduction in noise.

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26

V.S., Dmitriev, Kostyuchenko T.G., Minkov L.L., Derdiyashchenko V.V., and Panfilov D.S. "VIBROACTIVITY OF LOW-NOISE FANS." Vestnik Tomskogo gosudarstvennogo universiteta. Matematika i mekhanika, no. 68 (2020): 61–71. http://dx.doi.org/10.17223/19988621/68/6.

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Low-noise fans are widely used in the sphere of human life for sanitary and technological purposes. Creation of low-noise fans is currently an advanced scientific and technical area. In some fields of their application, reduced vibrations and noises are of paramount importance not only in terms of sanitation and health, but also from a scientific point of view. This work presents a comparison of the quality of low-noise fan development depending on the selected resistance type. The efficiency of the damping of mechanical system (a low-noise fan) vibrations according to the type of resistance moment used is confirmed analytically and practically. Nowadays, a number of fan types implemented in hundreds of designs have been developed and are in service. In this work, the whole variety of the produced nomenclature of low-noise fans is reduced to two basic types – axial and radial. The paper reports that to ensure minimum noise in the operating mode of the low-noise fans presented in the work, a wideband vibration damper is needed as a required functional unit, and the walls of the fan housing should be sandwich-like with layers made of sound absorbing, sound insulating, and vibration damping materials.

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27

Qu, Hongquan, Tingliang Feng, Yuan Zhang, and Yanping Wang. "Ensemble Learning with Stochastic Configuration Network for Noisy Optical Fiber Vibration Signal Recognition." Sensors 19, no. 15 (July 26, 2019): 3293. http://dx.doi.org/10.3390/s19153293.

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Optical fiber pre-warning systems (OFPS) based on Φ-OTDR are applied to many different scenarios such as oil and gas pipeline protection. The recognition of fiber vibration signals is one of the most important parts of this system. According to the characteristics of small sample set, we choose stochastic configuration network (SCN) for recognition. However, due to the interference of environmental and mechanical noise, the recognition effect of vibration signals will be affected. In order to study the effect of noise on signal recognition performance, we recognize noisy optical fiber vibration signals, which superimposed analog white Gaussian noise, white uniform noise, Rayleigh distributed noise, and exponentially distributed noise. Meanwhile, bootstrap sampling (bagging) and AdaBoost ensemble learning methods are combined with original SCN, and Bootstrap-SCN, AdaBoost-SCN, and AdaBoost-Bootstrap-SCN are proposed and compared for noisy signals recognition. Results show that: (1) the recognition rates of two classifiers combined with AdaBoost are higher than the other two methods over the entire noise range; (2) the recognition for noisy signals of AdaBoost-Bootstrap-SCN is better than other methods in recognition of noisy signals.

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28

Zhou, Qing, Yuanpeng He, Muxiao Li, Zhe Liu, Yulong He, and Xiaozhen Sheng. "A parametric study on the structural noise radiation characteristics of a steel spring floating slab track." Advances in Mechanical Engineering 14, no. 9 (September 2022): 168781322211199. http://dx.doi.org/10.1177/16878132221119921.

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It is a common experience that the interior noise of an underground train vehicle increases suddenly when it just runs into a track section with steel spring floating slabs, significantly reducing passengers’ comfort. This paper investigates the reasons, and control, of such noise through field tests and model simulations. The effect of rail surface irregularity on interior noise was investigated first by analysing data collected from interior noise tests, rail surface irregularity measurement and by analysing the modal behaviour of the slab. Noise radiation of the track slab was then analysed using the acoustic boundary element method while the vibration of the steel spring floating slab track is predicted based on an infinitely long periodic structure model; And finally with the prediction models, a parameter study was performed for the steel spring floating slab, on the purpose of improving the parameters to make the track less noisy. The research presented in this paper may provide a reference for the design of steel spring floating slabs in terms of noise control.

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29

Chen, Shinn-Horng, Jyh-Horng Chou, and Liang-An Zheng. "Robust Kalman-Filter-Based Frequency-Shaping Optimal Active Vibration Control of Uncertain Flexible Mechanical Systems." Journal of Mechanics 16, no. 3 (September 2000): 145–55. http://dx.doi.org/10.1017/s1727719100001805.

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ABSTRACTThis paper presents a time-domain control methodology, which is named as the robust Kalman-filter-based frequency-shaping optimal feedback (KFBFSOF) control method, to treat the active vibration control (or active vibration suppression) problem of flexible mechanical systems under simultaneously high frequencies unmodelled dynamics, residual modes, linear time-varying parameter perturbations in both the controlled and residual parts, noises (input noise and measurement noise),and noise uncertainties. Two robust stability conditions are proposed for the flexible mechanical system, which is controlled by a KFBFSOF controller and subject to mode truncation, noise uncertainties, and linear structured time-varying parameter perturbations simultaneously. The advantage of the presented KFBFSOF control methodology is that it can make the controlled closed-loop system to obtain both good robustness at high frequencies and good performance at low frequencies. Besides, the proposed robust stability criteria guarantee that the designed KFBFSOF controller can make the controlled flexible mechanical system to avoid the possibilities of both spillover-induced instability and time-varying-parameter-perturbation-induced instability. Two examples are given to illustrate the application of the presented control methodology to the active vibration control problems of a simply supported flexible beam and of a flexible rotor system.

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Brewster, John F., M. Ruth Graham, and W. Alan C. Mutch. "Convexity, Jensen's inequality and benefits of noisy mechanical ventilation." Journal of The Royal Society Interface 2, no. 4 (June 7, 2005): 393–96. http://dx.doi.org/10.1098/rsif.2005.0043.

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Mechanical ventilators breathe for you when you cannot or when your lungs are too sick to do their job. Most ventilators monotonously deliver the same-sized breaths, like clockwork; however, healthy people do not breathe this way. This has led to the development of a biologically variable ventilator—one that incorporates noise. There are indications that such a noisy ventilator may be beneficial for patients with very sick lungs. In this paper we use a probabilistic argument, based on Jensen's inequality, to identify the circumstances in which the addition of noise may be beneficial and, equally important, the circumstances in which it may not be beneficial. Using the local convexity of the relationship between airway pressure and tidal volume in the lung, we show that the addition of noise at low volume or low pressure results in higher mean volume (at the same mean pressure) or lower mean pressure (at the same mean volume). The consequence is enhanced gas exchange or less stress on the lungs, both clinically desirable. The argument has implications for other life support devices, such as cardiopulmonary bypass pumps. This paper illustrates the benefits of research that takes place at the interface between mathematics and medicine.

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31

Lontin, Kevin, and Muhammad Khan. "Interdependence of friction, wear, and noise: A review." Friction 9, no. 6 (April 19, 2021): 1319–45. http://dx.doi.org/10.1007/s40544-021-0500-x.

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AbstractPhenomena of friction, wear, and noise in mechanical contacts are particularly important in the field of tribomechanics but equally complex if one wants to represent their exact relationship with mathematical models. Efforts have been made to describe these phenomena with different approaches in past. These efforts have been compiled in different reviews but most of them treated friction, wear mechanics, and acoustic noise separately. However, an in-depth review that provides a critical analysis on their interdependencies is still missing. In this review paper, the interdependencies of friction, wear, and noise are analysed in the mechanical contacts at asperitical level. The origin of frictional noise, its dependencies on contact’s mechanical properties, and its performance under different wear conditions are critically reviewed. A discussion on the existing mathematical models of friction and wear is also provided in the last section that leads to uncover the gap in the existing literature. This review concludes that still a comprehensive analytical modelling approach is required to relate the interdependencies of friction, noise, and wear with mathematical expressions.

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32

Hwang, Myeong-Hwan, Hae-Sol Lee, and Hyun-Rok Cha. "Analysis of Torque Ripple and Cogging Torque Reduction in Electric Vehicle Traction Platform Applying Rotor Notched Design." Energies 11, no. 11 (November 6, 2018): 3053. http://dx.doi.org/10.3390/en11113053.

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Drive motors, which are used in the drive modules of electric cars, are interior permanent magnet motors. These motors tend to have high cogging torque and torque ripple, which leads to the generation of high vibration and noise. Several studies have attempted to determine methods of reducing the cogging torque and torque ripple in interior permanent magnet motors. The primary methods of reducing the cogging torque involve either electric control or mechanical means. Herein, the authors focused on a mechanical method to reduce the cogging torque and torque ripple. Although various methods of reducing vibration and noise mechanically exist, there is no widely-known comparative analyses on reducing the vibration and noise by designing a notched rotor shape. Therefore, this paper proposes a method of reducing vibration and noise mechanically by designing a notched rotor shape. In the comparative analysis performed herein, the motor stator and rotor were set to be the same size, and electromagnetic field analysis was performed to determine a notch shape that is suitable for the rotor and that generates reasonable vibration and noise.

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33

Pruvost, Laurent, Quentin Leclere, and Etienne Parizet. "Improved spectrofilter applied to diesel engine noise : combustion and mechanical noise separation." Journal of the Acoustical Society of America 123, no. 5 (May 2008): 3533. http://dx.doi.org/10.1121/1.2934492.

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34

Numata, Kenji, and Jordan Camp. "Estimation of frequency noise in semiconductor lasers due to mechanical thermal noise." Physics Letters A 376, no. 6-7 (January 2012): 798–802. http://dx.doi.org/10.1016/j.physleta.2012.01.013.

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35

Grigoriu, Mircea. "White Noise Processes." Journal of Engineering Mechanics 113, no. 5 (January 1987): 757–65. http://dx.doi.org/10.1061/(asce)0733-9399(1987)113:5(757).

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36

Huynh, Tuan Van, and Vu Quang Huynh. "Study on method of filtering noises from electroencephalography signals and its application for identification of several electroencephalography signals." Science and Technology Development Journal - Natural Sciences 1, T4 (December 31, 2017): 95–104. http://dx.doi.org/10.32508/stdjns.v1it4.497.

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Electroencephalographic (EEG) signals have usually been affected by different types of noise as 50 Hz noise, mechanical noise caused by body movements, heart disturbance, eye noise... In this paper, methods such as: independent component analysis (independent component analysis-ICA), discrete wavelet transform and design of digital filters, were used to filter the noises, to classify the basic components for EEG signals. Then the mean of energy value was calculated to identify the status of the EEG signals such as blink, thoughts, emotion, smoking and blood pressure. The results of calculations and simulations of signals EEG could demonstrate the efficiency of the method.

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Wang, Yuan Gan. "Ring-Space Array Torque Measure System and Signal Singularity Detection." Advanced Materials Research 629 (December 2012): 741–46. http://dx.doi.org/10.4028/www.scientific.net/amr.629.741.

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Torque is the most important dynamic characteristics of the mechanically-driven system. In order to monitor the mechanical principal axis in real time, a new non-contact torque measurement system based on ring-space array sensor is proposed. This system can be used for the analysis of dynamic characteristics of the mechanical system’s axis under various loads and hard working environments. Singularity in the collected signals is most important with the mechanical system. Because of much noise was contained in collected signals, which always interferes the signal’s singularity detection. According to the different behaves of signal and noise under wavelet transform, a method with wavelet filtering and singularity detection combined is proposed. This method could realize two-dimension filtering reconstruction in both time and frequency domain, in which the singularity information in signal can be kept well while the noise will be filtered. The proposed method is suitable for singularity detection of signals under serious noise.

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Murphy, John A. "Earcup assembly incorporating mechanical active noise reduction." Journal of the Acoustical Society of America 93, no. 3 (March 1993): 1675. http://dx.doi.org/10.1121/1.406750.

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Rugar, D., and P. Grütter. "Mechanical parametric amplification and thermomechanical noise squeezing." Physical Review Letters 67, no. 6 (August 5, 1991): 699–702. http://dx.doi.org/10.1103/physrevlett.67.699.

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Jameson, Randall W. "Issues in mechanical draft cooling tower noise." Journal of the Acoustical Society of America 101, no. 5 (May 1997): 3039. http://dx.doi.org/10.1121/1.418602.

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Condat, C. A., and G. J. Sibona. "Noise-enhanced mechanical efficiency in microorganism transport." Physica A: Statistical Mechanics and its Applications 316, no. 1-4 (December 2002): 203–12. http://dx.doi.org/10.1016/s0378-4371(02)01496-6.

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Soultan, M., X. Kleber, J. Chicois, and A. Vincent. "Mechanical Barkhausen noise during fatigue of iron." NDT & E International 39, no. 6 (September 2006): 493–98. http://dx.doi.org/10.1016/j.ndteint.2006.03.003.

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Liu, H., Y. Meng, H. W. Zhao, and D. M. Chen. "Active mechanical noise cancellation scanning tunneling microscope." Review of Scientific Instruments 78, no. 7 (July 2007): 073705. http://dx.doi.org/10.1063/1.2755399.

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Viner, Hen, Ido Nitsan, Liel Sapir, Stavit Drori, and Shelly Tzlil. "Mechanical Communication Acts as a Noise Filter." iScience 14 (April 2019): 58–68. http://dx.doi.org/10.1016/j.isci.2019.02.030.

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Chiu, Min-Chie, M. G. Prasad, K. T. Chen, Chao-Nan Wang, and Wojciech P. Rdzanek. "The Assessment of Noise Estimation and Noise Control Work." Advances in Mechanical Engineering 6 (January 1, 2014): 642715. http://dx.doi.org/10.1155/2014/642715.

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Liu, Enbin, Shanbi Peng, and Tiaowei Yang. "Noise-silencing technology for upright venting pipe jet noise." Advances in Mechanical Engineering 10, no. 8 (August 2018): 168781401879481. http://dx.doi.org/10.1177/1687814018794819.

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When a natural gas transmission and distribution station performs a planned or emergency venting operation, the jet noise produced by the natural gas venting pipe can have an intensity as high as 110 dB, thereby severely affecting the production and living environment. Jet noise produced by venting pipes is a type of aerodynamic noise. This study investigates the mechanism that produces the jet noise and the radiative characteristics of jet noise using a computational fluid dynamics method that combines large eddy simulation with the Ffowcs Williams–Hawkings acoustic analogy theory. The analysis results show that the sound pressure level of jet noise is relatively high, with a maximum level of 115 dB in the low-frequency range (0–1000 Hz), and the sound pressure level is approximately the average level in the frequency range of 1000–4000 Hz. In addition, the maximum and average sound pressure levels of the noise at the same monitoring point both slightly decrease, and the frequency of the occurrence of a maximum sound pressure level decreases as the Mach number at the outlet of the venting pipe increases. An increase in the flow rate can result in a shift from low-frequency to high-frequency noise. Subsequently, this study includes a design of an expansion-chamber muffler that reduces the jet noise produced by venting pipes and an analysis of its effectiveness in reducing noise. The results show that the expansion-chamber muffler designed in this study can effectively reduce jet noise by 10–40 dB and, thus, achieve effective noise prevention and control.

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Gabrielson, T. B. "Fundamental Noise Limits for Miniature Acoustic and Vibration Sensors." Journal of Vibration and Acoustics 117, no. 4 (October 1, 1995): 405–10. http://dx.doi.org/10.1115/1.2874471.

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Recent technological advances in microfabrication and fiber optics have made practical the construction of very small, sensitive sensors for acoustic or vibration measurements. As the sensitivity is increased or the size is decreased, a sensor becomes more susceptible to mechanical noise resulting from molecular agitation. Traditional noise analysis is often focused exclusively on electrical or optical noise; consequently, mechanical-thermal noise may not be considered in new types of sensors until the prototype testing reveals an unexpectedly high noise floor. Fortunately, mechanical-thermal noise is relatively easy to estimate early in the design process because the equivalent noise force is only a function of the temperature and the mechanical losses in the sensor There are a number of specific techniques that are applicable for evaluating either the total mechanical-thermal noise or the spectral distribution of that noise for simple or complex sensors. These techniques are presented and, in addition, a summary of other noise components is given in the context of design guidelines for high-sensitivity sensors.

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Kang, Yimei, and Wang Pan. "A Novel Approach of Low-Light Image Denoising for Face Recognition." Advances in Mechanical Engineering 6 (January 1, 2014): 256790. http://dx.doi.org/10.1155/2014/256790.

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Illumination variation makes automatic face recognition a challenging task, especially in low light environments. A very simple and efficient novel low-light image denoising of low frequency noise (DeLFN) is proposed. The noise frequency distribution of low-light images is presented based on massive experimental results. The low and very low frequency noise are dominant in low light conditions. DeLFN is a three-level image denoising method. The first level denoises mixed noises by histogram equalization (HE) to improve overall contrast. The second level denoises low frequency noise by logarithmic transformation (LOG) to enhance the image detail. The third level denoises residual very low frequency noise by high-pass filtering to recover more features of the true images. The PCA (Principal Component Analysis) recognition method is applied to test recognition rate of the preprocessed face images with DeLFN. DeLFN are compared with several representative illumination preprocessing methods on the Yale Face Database B, the Extended Yale face database B, and the CMU PIE face database, respectively. DeLFN not only outperformed other algorithms in improving visual quality and face recognition rate, but also is simpler and computationally efficient for real time applications.

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He, Wentao, Cancan Yi, Yourong Li, and Han Xiao. "Research on Mechanical Fault Diagnosis Scheme Based on Improved Wavelet Total Variation Denoising." Shock and Vibration 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/3151802.

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Wavelet analysis is a powerful tool for signal processing and mechanical equipment fault diagnosis due to the advantages of multiresolution analysis and excellent local characteristics in time-frequency domain. Wavelet total variation (WATV) was recently developed based on the traditional wavelet analysis method, which combines the advantages of wavelet-domain sparsity and total variation (TV) regularization. In order to guarantee the sparsity and the convexity of the total objective function, nonconvex penalty function is chosen as a new wavelet penalty function in WATV. The actual noise reduction effect of WATV method largely depends on the estimation of the noise signal variance. In this paper, an improved wavelet total variation (IWATV) denoising method was introduced. The local variance analysis on wavelet coefficients obtained from the wavelet decomposition of noisy signals is employed to estimate the noise variance so as to provide a scientific evaluation index. Through the analysis of the numerical simulation signal and real-word failure data, the results demonstrated that the IWATV method has obvious advantages over the traditional wavelet threshold denoising and total variation denoising method in the mechanical fault diagnose.

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Hua, Chunrong, Yadong Zhang, Dawei Dong, Bin Yan, and Huajiang Ouyang. "Aerodynamic noise numerical simulation and noise reduction study on automobile alternator." Journal of Mechanical Science and Technology 31, no. 5 (May 2017): 2047–55. http://dx.doi.org/10.1007/s12206-017-0402-z.

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