Noise Cancellation Research Articles

Review of Hybrid Denoising Approaches in Face Recognition

Statistically, image denoising is one of the key pillars of image processing and picture acquisition, which also is utilized to clear the noisy images. Over the last years, there is an increase of study subjects that are devoting to designing and making noise cancellation methods. This study reviews all major image denoising techniques, with a special emphasis on integrated deep learning approaches as well as traditional signal processing methods. The review presents a broad array of techniques for instance convolutional neural networks (CNNs), wavelet transforms, hybrid models, and their emendations. The lecturer will focus on the advantages, as well as the disadvantages, of each methodology along with their appropriateness in various fields, from which the current state of the art image denoising can be concluded. On the other hand, the paper discusses critical barriers leading to further prospects of research in cybersecurity and cybercrime prevention This review is important in that it aims to serve researchers, practitioners, and enthusiasts who would like to peer into the new trends and developments in denoise image generation.

Comparative Analysis of Digital Self-Interference Cancellation Methods for Simultaneous Transmit and Receive Arrays

This paper provides a comprehensive theoretical derivation of the residual noise power and effective isotropic isolation (EII) signal models in baseband digital cancellation, aperture-level digital cancellation, and beamforming spatial cancellation models in simultaneous transmit and receive (STAR) arrays. We simulated and analyzed the isolation performance and self-interference (SI) noise cancellation of STAR systems using digital SI cancellation (SIC) and beamforming in a 32-element planar array. The simulation results show that in the absence of SIC or baseband digital SIC, the EII obtained by receive adaptive beamforming (ABF) is 20 dB higher than that obtained by transmit ABF. On the basis of aperture-level digital SIC, the EII obtained from transmit ABF and receive ABF is basically the same. The EII obtained by baseband digital SIC is 22.5 dB and 41.1 dB lower than that of transmit ABF and receive ABF, respectively. Therefore, baseband digital SIC technology is not required when using transmit ABF and receive ABF.

Earthquake source inversion by integrated fiber-optic sensing

We present an earthquake source inversion using a single time series produced by integrated fiber-optic sensing in a phase noise cancellation (PNC) system used for frequency metrology. Operating on a 123 km long fiber between Bern and Basel (Switzerland), the PNC system recorded the Mw3.9 Mulhouse earthquake that occurred on 10 September 2022 around 10 km north-west of the northern fiber end. A generalised least-squares inversion in the 4 - 13 s period band constrains the components of a double-couple moment tensor with an uncertainty that corresponds to around 0.2 moment magnitude units, nearly independent of prior information. Uncertainties for hypocenter location and original time are more variable, ranging between 4 - 20 km and 0.1 - 1 s, respectively, depending on whether injected prior information is realistic or almost absent. This work is a proof of concept that quantifies the resolvability of earthquake source properties under specific conditions using a single-channel stand-alone integrated (non-distributed) fiber-optic measurement. It thereby constitutes a step towards the integration of long-range phase-transmission fiber-optic sensors into existing seismic networks in order to fill significant seismic data gaps, especially in the oceans.

A new fault location method for high‐voltage transmission lines based on ICEEMDAN‐MSA‐ConvGRU model

AbstractGiven the complex form of distribution line faults, the accuracy of fault location using traditional artificial intelligence networks needs to be further improved. Here, a combined fault location method is proposed for a 110 kV distribution line based on the improved complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN), mantis search algorithm (MSA), and convolutional gate recurrent unit (ConvGRU). Firstly, the study used the ICEEMDAN algorithm to decompose the signals and discard the high‐frequency signals with low correlation so as to achieve the purpose of noise cancellation. Then, the study used the root mean square error (RMSE) of the ConvGRU model training as the adaptation value, optimized the internal parameters of the model using the MSA algorithm, and obtained a combined fault locating model. By using the proposed model, the effects of the fault form and transition impedance changes on the location accuracy were analysed, and the location accuracy was compared with other artificial intelligence methods. The location accuracy index showed that the proposed model had a better convergence speed of training error than the traditional model. Also, the RMSE of the localization results was reduced by 50%, with a higher fault location accuracy.

Audio Pre-Processing and Beamforming Implementation on Embedded Systems

Since the invention of the microphone by Barina in 1876, there have been numerous applications of audio processing, such as phonographs, broadcasting stations, and public address systems, which merely capture and amplify sound and play it back. Nowadays, audio processing involves analysis and noise-filtering techniques. There are various methods for noise filtering, each employing unique algorithms, but they all require two or more microphones for signal processing and analysis. For instance, on mobile phones, two microphones located in different positions are utilized for active noise cancellation (one for primary audio capture and the other for capturing ambient noise). However, a drawback is that when the sound source is distant, it may lead to poor audio capture. To capture sound from distant sources, alternative methods, like blind signal separation and beamforming, are necessary. This paper proposes employing a beamforming algorithm with two microphones to enhance speech and implementing this algorithm on an embedded system. However, prior to beamforming, it is imperative to accurately detect the direction of the sound source to process and analyze the audio from that direction.

Molecular mechanisms of precise timing in cell lysis

Many biological systems exhibit precise timing of events, and one of the most known examples is cell lysis, which is a process of breaking bacterial host cells in the virus infection cycle. However, the underlying microscopic picture of precise timing remains not well understood. We present a novel theoretical approach to explain the molecular mechanisms of effectively deterministic dynamics in biological systems. Our hypothesis is based on the idea of stochastic coupling between relevant underlying biophysical and biochemical processes that lead to noise cancellation. To test this hypothesis, we introduced a minimal discrete-state stochastic model to investigate how holin proteins produced by bacteriophages break the inner membranes of gram-negative bacteria. By explicitly solving this model, the dynamic properties of cell lysis are fully evaluated, and theoretical predictions quantitatively agree with available experimental data for both wild-type and holin mutants. It is found that the observed threshold-like behavior is a result of the balance between holin proteins entering the membrane and leaving the membrane during the lysis. Theoretical analysis suggests that the cell lysis achieves precise timing for wild-type species by maximizing the number of holins in the membrane and narrowing their spatial distribution. In contrast, for mutated species, these conditions are not satisfied. Our theoretical approach presents a possible molecular picture of precise dynamic regulation in intrinsically random biological processes.

A novel feedforward narrow-broadband hybrid active noise control system for excavator interior noise control

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.

EXPLORING THE CONCEPT OF AMBIENT SOUND FOR WELL-BEING: A SYSTEMATIC REVIEW OF THEORIES AND EVIDENCEON

This study investigates the impact of ambient sound on well-being, focusing on its definition, theoretical foundations, and cultural interpretations. The objectives are to explore and analyse underlying theories and concepts, and to examine cultural perceptions of ambient sound’s influence on human life. The researchers searched multiple databases, including JSTOR, PubMed, and Scopus, using keywords related to ambient sound and its synonyms. A total of 162 articles were examined and only 46 articles were included in the review. The results of this review proposed that definition of ambient sound highlights its role as the comprehensive auditory backdrop that shapes individuals’ perceptions, understanding, and experiences of a specific location, incorporating various elements such as natural sounds, background noises, and human-generated sounds. This definition underscores the significance of ambient sound in shaping the overall sonic atmosphere and cultural interpretation of a particular space. Additionally, the perception of environmental noise varies across cultures, and cultural factors influence the use and acceptance of noise cancellation technology and the significance attributed to natural sounds. Further research is needed to explore the potential benefit of ambient sound as a background sound within a various settings such as therapeutic environment.

Phase noise cancellation for digital holographic microscopy based on compressed sensing iterative adaptive sparse dictionary

Digital holographic microscopy (DHM), like other digital imaging techniques, will introduce severe coherent noise, which is called random noise, due to the high coherence of the required light source and the measurement experimental environment. Random noise seriously affects the accuracy of DHM surface topography measurements. To overcome this problem, this paper proposes a DHM phase noise cancellation method based on compressed sensing (CS) iterative adaptive sparse dictionary. The holographic image is first acquired using the proposed recording method. Then a sparse dictionary more suitable for the sample is trained by dictionary learning to sparsely encode the holographic image. Finally, reconstruction is performed using the improved orthogonal matching pursuit (IOMP), which can obtain almost noise-free holographic images. The experimental results show that the reconstructed phase peak signal-to-noise ratio (PSNR) is 33.2871, which is improved by 65.01 %. The sample feature similarity is 0.9553, which is improved by 45.41 %. The proposed method can also be used with different learning modes and learning objects. On top of the original results, the reconstructed phase PSNR was able to continue to improve by 5.99 % and its reconstruction time was also accelerated by 29.57 %.

Optical frequency dissemination via 103-km urban fiber link with remote passive phase stabilization.

In this paper, we propose a technique for a fiber-based optical frequency dissemination system with remote passive phase noise cancellation. At the remote site, a 1×2 fiber pigtailed acousto-optic modulator (AOM) with two diffraction order outputs (0 and -1 order) is employed as the phase-compensated device, the undesired phase noise of fiber link introduced by environmental perturbations are passively canceled at remote sites. Different from other existing schemes, the proposed technique harnesses the benefits of remote radio frequency (RF) independence and low-temperature sensitivity in this noise-suppression configuration. Consequently, the system noise floor of the proposed optical frequency dissemination system achieves 9.44 × 10-21 without requiring a precise remote RF reference, and the phase-temperature coefficient is reduced to about 2 fs/K. A real-world experiment is conducted over a noisy round-trip 103 km urban fiber link. After being passively compensated, we demonstrate a fractional frequency instability of 1.57 × 10-14 at the integration time of 1 s and scales down to 3.96 × 10-20 at 10,000 s in terms of modified Allan deviation. The frequency uncertainty of the retrieved light after transferring through this noise-compensated fiber link relative to that of the input light achieves 1.80 × 10-18. This work demonstrates the system's capability to disseminate the ultra-stable optical frequency standards and is a significant step towards realizing multi-node dissemination of the state-of-the-art optical clock signal with remote noise compensation via a tree-like topology fiber network.

Sigmoid distance metric-based spline adaptive filters for nonlinear adaptive noise cancellation

This article devises a spline adaptive filter (SAF) algorithm with robustness for nonlinear adaptive noise cancellation (NANC), called the SAF-SDM, which is built on a distance-based metric with a sigmoid kernel. The presented SAF-SDM delivers insignificant coefficient updates when the system is subjected to remarkable outliers, which leads to low steady-state errors. Additionally, we thoroughly analyze the mean behaviour and mean-square performance of the SAF-SDM at the theoretical level and validate the analysis results using nonlinear system identification (NSI) simulations. To fulfill the higher computational efficiency when a longer linear filter order is selected in the SAF, an improved SAF-SDM is developed through a frequency domain (FD) filtering program, called the FDSAF-SDM. Then, we provide an analysis of the calculation complexity of the two presented algorithms and compare them with those of several similar algorithms. Finally, simulation and experiment results demonstrate the excellence of the presented algorithms in NSI and NANC.

Design of a high-speed MCML D-Latch at 0.6 V in 45 nm CMOS technology

Metal oxide semiconductor (MOS) current mode logic (MCML) is generally preferred for high-speed circuit design. In this paper, a novel low voltage folded (LVF) MCML D-Latch is designed. The existing topologies of the MCML D-Latch consume more power and operate at 1 V. The proposed D-Latch can operate at 0.6V with better delay and power management. MCML circuits minimize delay and perform fast operations, hence it can be used in high-frequency applications. The proposed LVF MCML D–Latch is analyzed with the parameters such as power, delay, power delay product and output noise using cadence virtuoso in 45 nm complementary metal oxide semiconductor (CMOS) technology at a voltage of 0.6 V and a temperature of 27 °C. The proposed technique achieves 62.11% of power reduction, transient response speed improved by 51.23% and noise cancellation becomes 26.13% improvement over the existing circuit. It also achieves 96% of output swing which is more efficient compared to others. Finally, the parametric analysis is performed with different temperatures to verify the stability of the proposed circuit. From the simulated results, it is clear that the proposed LVF MCML D-Latch provides better performance in high-speed phase locked loop (PLL) applications.

Survey on Noise Cancellation Using Adaptive Filters for PCG Signal

Survey on Noise Cancellation Using Adaptive Filters for PCG Signal

Conjugate gradient‐based active noise cancellation

AbstractActive noise cancellation schemes should synthesize proper secondary perturbations without relevant prior information. Their performance depends strongly on their adaptive mechanisms, which, sometimes, do not fulfill the severe requirements of practical setups. This research demonstrates for the first time that the adaptive conjugate gradient optimization method can be used for active noise cancellation tasks. Additionally, a stochastic model is devised for estimating its steady‐state solution, even when the secondary path is not correctly estimated. Such a theoretical analysis demonstrates the asymptotic unbiasedness of the proposed scheme when the secondary plant is perfectly estimated. Simulations reveal that the devised method can attain better asymptotic performance and a higher convergence rate than the traditional FX‐LMS algorithm, at the expense of an increased computational burden. Furthermore, simulations show that the method outperforms the standard ones for nonstationary inputs (such as speech signals).

A Quadrature Balanced N-Path Receiver for Frequency Division Duplex With Thermal and Phase Noise Cancellation Under Antenna VSWR

A Quadrature Balanced <i>N</i>-Path Receiver for Frequency Division Duplex With Thermal and Phase Noise Cancellation Under Antenna VSWR

A broadband single-ended active-feedforward -noise-canceling LNA with IP2 enhancement in stacked n/pMOS configurations

In this paper, we present a broadband low-noise amplifier (LNA), using active-feedforward noise-cancellation and complementary n/pMOS configurations. Based on traditional common-gate (CG) and common-source (CS) noise canceling topology, the applied active feedforward stage reduces the CG's dc current and alleviates its resistive load tradeoff between noise and headroom. Meanwhile, the active feedforward stage follows the same noise cancellation (NC) principle as the CG transistors. A low noise figure is thus obtained. In addition, the complementary n/pMOS configuration is used to cancel second-order distortions and double current efficiency. Two π-type matching networks are utilized to broaden the bandwidth of S11 and gain. After applying these techniques, an LNA prototype was designed in standard 65 nm CMOS technology. Simulation results display a gain of 14–17 dB and a noise figure (NF) of 2.45–3.45 dB within a bandwidth of 1–12 GHz. The linearity of IIP3 and IIP2 are −2.4 and 23 dBm at 5 GHz. The presented circuit consumes only 7.8 mW of dc power while occupying an area of 0.21 mm2.

A STUDY ON MARKETING STRATEGIES USED BY boAt

boAt is an Indian startup which was established in the year 2016 by its founders Aman Gupta and Sameer Mehta with the objective to provide high quality products at an affordable and suitable price for the consumers. The company offers to its consumers an affordable range of headphones, earphones, speakers and other accessories. The reason for the companys success can solely be credited to its affordable and cheap prices than compared to other competitors in the market and also because it caters to needs and preferences of the younger generations or the Gen-Z s in India. It also lays strong emphasis on design, boAt products often feature trendy aesthetics, vibrant colors, and unique designs, appealing to fashion-conscious consumer preferences. The companys ongoing product development demonstrates its dedication to innovation and technology , adding features like Bluetooth connectivity, waterproofing, and noise cancellation to enhance the user experience. KEYWORDS: Marketing Strategies, boAt, Consumer Preferences

Displacement response waveform restoration of simply supported bridge during train passage using measured acceleration integration based on linear vibration theory

This study proposes a method for restoring the displacement waveform during train passage using the acceleration integration based on linear vibration theory and noise cancellation techniques. This method replaces the low-frequency region affected by noise with a linear theoretical solution; however, this method uses the actual measurement data around the natural frequency, where nonlinearities (such as concrete member cracks and the train–bridge interaction) can be observed. The method identifies only the ratio of single axle weight to modal stiffness. Numerical experiments clarify that the method can estimate the maximum displacement of a bridge from acceleration with an error of approximately 5% or less. Improved prediction accuracy can be achieved using the proposed noise cancellation technique not only in the high-speed range but also into the lower-speed ranges as well. Furthermore, the proposed method is applied to acceleration monitoring data, and results show that the displacement waveform can be restored from the acceleration waveform.

Analysis of Transient Thermoacoustic Characteristics and Performance in Carbon Nanotube Sponge Underwater Transducers.

Recent advancements in marine technology have highlighted the urgent need for enhanced underwater acoustic applications, from sonar detection to communication and noise cancellation, driving the pursuit of innovative transducer technologies. In this paper, a new underwater thermoacoustic (TA) transducer made from carbon nanotube (CNT) sponge is designed to achieve wide bandwidth, high energy conversion efficiency, simple structure, good transient response, and stable sound response, utilizing the TA effect through electro-thermal modulation. The transducer has potential application in underwater acoustic communication. An electro-thermal-acoustic coupled simulation for the open model, sandwich model, and encapsulated model is presented to analyze the transient behaviors of CNT sponge TA transducers in liquid environments. The effects of key design parameters on the acoustic performances of both systems are revealed. The results demonstrate that a short pulse excitation with a low duty cycle could greatly improve the heat dissipation of the encapsulated transducer, especially when the thermoacoustic response time becomes comparable to thermal relaxation time.

An open-access simultaneous electrocardiogram and phonocardiogram database

Objective. The EPHNOGRAM project aimed to develop a low-cost, low-power device for simultaneous electrocardiogram (ECG) and phonocardiogram (PCG) recording, with additional channels for environmental audio to enhance PCG through active noise cancellation. The objective was to study multimodal electro-mechanical activities of the heart, offering insights into the differences and synergies between these modalities during various cardiac activity levels. Approach. We developed and tested several hardware prototypes of a simultaneous ECG-PCG acquisition device. Using this technology, we collected simultaneous ECG and PCG data from 24 healthy adults during different physical activities, including resting, walking, running, and stationary biking, in an indoor fitness center. The data were annotated using a robust software that we developed for detecting ECG R-peaks and PCG S1 and S2 components, and overseen by a human expert. We also developed machine learning models using ECG-based, PCG-based, and joint ECG-PCG features, like R–R and S1–S2 intervals, to classify physical activities and analyze electro-mechanical dynamics. Main results. The results show a significant coupling between ECG and PCG components, especially during high-intensity exercise. Notable micro-variations in S2-based heart rate show differences in the heart’s electrical and mechanical functions. The Lomb-Scargle periodogram and approximate entropy analyses confirm the higher volatility of S2-based heart rate compared to ECG-based heart rate. Correlation analysis shows stronger coupling between R–R and R-S1 intervals during high-intensity activities. Hybrid ECG-PCG features, like the R-S2 interval, were identified as more informative for physical activity classification through mRMR feature selection and SHAP value analysis. Significance. The EPHNOGRAM database, is available on PhysioNet. The database enhances our understanding of cardiac function, enabling future studies on the heart’s mechanical and electrical interrelationships. The results of this study can contribute to improved cardiac condition diagnoses. Additionally, the designed hardware has the potential for integration into wearable devices and the development of multimodal stress test technologies.