Noise Analysis Research Articles

The Use of Polyimide as a Bonding Material to Improve the Mechanical Stability, Magnetic and Acoustic Properties of the Transformer Core Based on Amorphous Steel.

The constantly evolving electrification also entails an increase in requirements for the effective and efficient distribution of electricity with the lowest possible power losses. Such needs can be met by highly effective electrical devices, and one of them is a transformer whose main component is a magnetic core. Currently, one of the soft magnetic materials used alternatively for the production of transformer cores are amorphous metal strips with competitive losses. However, to successfully use these materials, a key problem must be solved: limited mechanical stability. The presented article describes the development and application of a polyimide-based binder for efficient bonding of an amorphous metal ribbon. The layered binder was characterized using confocal microscopy, scanning electron microscopy and Raman spectroscopy, and its anticorrosion and mechanical properties were examined. As a final step, a prototype of a toroidal magnetic core bonded with the binder was manufactured and subjected to the evaluation of no-load loss and the analysis of the emitted noise. It was confirmed that the proposed polyimide binder tremendously improved the mechanical stability while reducing core losses and audible noise.

Noise behavior in GaAs0.2Sb0.8/GaSb heterojunction Source-All-Around vertical Tunnel FET: A comprehensive study

This article offers a comprehensive noise analysis of a GaAs0.2Sb0.8/GaSb heterojunction Source-All-Around Vertical Tunnel FET (SAA-VTFET), examining generation-recombination (GRN), flicker (FN), and diffusion (DN) noise. It pioneers an investigation into noise behavior under the influence of interface traps, temperature variations, and frequencies. Analysis includes both output current noise power spectral density (Sid) and input voltage noise power spectral density (Svg). Furthermore, the sensitivity of noise PSD is noted to be maximum at lower Vgs (gate bias voltage), suggesting that trap-assisted tunneling (TAT) and Shockley-Read-Hall (SRH) recombination dominate over band-to-band tunneling in this region. For enhanced clarity, this study also includes an analysis of the impact of traps and temperature on both AC and DC characteristics.

Noise analysis of NC-GAAFET cylindrical nanowire with non-uniform interface trap charge

In this article, low to high frequency noise behavior analysis of negative capacitance gate-all-around field effect transistor (NC-GAAFET) MFIS structure Silicon Nanowire (SiNW) device, using Sentauras TCAD simulations, is investigated. The NC-GAAFET SiNW yields on current (ION) 5.31 times larger and off current (IOFF) is significantly reduced by ∼ 105 orders compared to baseline SiNW. The device exhibits an excellent switching ratio of 5.2 × 1014. Average subthreshold swing for the NC-GAAFET is 33 mV/dec compared to 64 mV/dec of baseline nanowire. The Negative-DIBL for the device is −20 mV/V which outshines earlier findings. Furthermore, the drain current noise power spectral density (PSD) Sid, and input referred gate voltage noise PSD (Svg) are comprehensively analyzed in the presence of Gaussian trap (non-uniform) distribution. The analysis indicates that, flicker or (1/f) noise dominates in low frequency regime, generation-recombination (G-R) noise is more influential in mid frequency regime whereas in very high frequency regime diffusion noise is leading. The device exhibits least Sid(NET) and Svg(NET) at tfe = 6 nm compared to baseline, tfe = 5 nm, and 7 nm.

Probing the design principles of photosynthetic systems through fluorescence noise measurement

Elucidating the energetic processes which govern photosynthesis, the engine of life on earth, are an essential goal both for fundamental research and for cutting-edge biotechnological applications. Fluorescent signal of photosynthetic markers has long been utilised in this endeavour. In this research we demonstrate the use of fluorescent noise analysis to reveal further layers of intricacy in photosynthetic energy transfer. While noise is a common tool analysing dynamics in physics and engineering, its application in biology has thus far been limited. Here, a distinct behaviour in photosynthetic pigments across various chemical and biological environments is measured. These changes seem to elucidate quantum effects governing the generation of oxidative radicals. Although our method offers insights, it is important to note that the interpretation should be further validated expertly to support as conclusive theory. This innovative method is simple, non-invasive, and immediate, making it a promising tool to uncover further, more complex energetic events in photosynthesis, with potential uses in environmental monitoring, agriculture, and food-tech.

Analysis and denoising of electric noise in phased array ultrasonic testing system

Phased array ultrasonic testing (PAUT) is an advanced technique used for non-destructive testing (NDT) to detect and assess the integrity of materials or structures. In composite materials with significant acoustic attenuation, electrical noise significantly impacts PAUT detection accuracy, highlighting a crucial issue. This paper presents a comprehensive analysis of electrical noise, explains the relationship between electrical noise and inspection parameters, and proposes recommendations to reduce it. A time-varying filter empirical mode decomposition (TVF-EMD) joint wavelet thresholding method is proposed for denoising electrical noise after time-corrected gain (TCG). The ultrasonic echo signal goes through TVF-EMD decomposition, resulting in intrinsic mode functions (IMFs). Energy entropy is utilized to identify the signal-dominant IMFs, and wavelet thresholding is applied to further reduce noise within these selected IMFs. The proposed method effectively removes noise and ensures signal integrity by validating simulated and experimental signals.

Synthesis, characterization, and electronic transport properties of o-carborane-bridged thiophene derivatives

Here, α- or β-thiophene-substituted derivatives bridged by an o-carborane group were synthesized. Scanning tunneling microscope break junction techniques have revealed that the thiophene anchoring groups form a single-molecule junction with an Au electrode. Flicker noise analysis suggests the existence of through-space transmission pathways between the thiophene units. Furthermore, the electronic coupling of the β-thiophene substituted molecule with the electrode is found to be more stable, resulting in a 70 % increase in conductance compared to the α-isomer counterpart.These findings offer valuable insights for the design and development of o-carborane-based molecules, underscoring the significance of molecular backbones and substitution patterns on their electrical transport properties.

Analyzing Quantum Error Resilience for Quantum Communication in Guided and Unguided Media

AbstractThis research examines quantum key distribution and its applications in guided and unguided quantum communication. The importance of secure communication in the quantum era requires a thorough exploration of both guided and unguided quantum communication strategies. The research aims to address the challenges posed by guided channels, such as fiber optics, and unguided channels, such as free‐space quantum communication. This study addresses existing knowledge gaps in quantum error resilience management and signal processing techniques in unguided quantum communication. Advanced quantum gate analysis, environmental noise analysis, and quantum channel modeling techniques are employed. The research presents key findings on the impact of gate imperfections on quantum error resilience in guided media, the influence of noise‐induced errors in unguided media, and a unified metric for assessing various error sources in guided channels. Additionally, the study analyses stabilizer codes and surface codes for error mitigation through quantum error correction strategies. Simulation results provide a benchmark for theoretical predictions and guide the refinement of quantum communication protocols. In this context, machine learning‐based error prediction is introduced as a cutting‐edge approach to enhance the robustness of quantum communication systems.

Numerical analysis of jet noise for nozzles with different throat sizes

Numerical analysis of jet noise for nozzles with different throat sizes

Study on the coupling vibration characteristics of vertical unit and plant of large underground pumping station for water transfer project

Abstract To investigate the coupled vibration characteristics of vertical pumping unit and plant structure of large underground pumping station for water transfer project, the coupled vibration differential equations are established. The structure nodes of are simplified from horizontal direction and vertical direction respectively by force. The structural parameters and load parameters of the model are analyzed and calculated, and the vibration response of each node are calculated by solving the vibration differential equations. A spectral analysis of white noise is applied to the coupled model, and the natural frequencies and vibration structures of dominant vibration modals are obtained. Research indicates that the vertical vibration modes of the system exhibit a relatively low coupling degree with the plant structure. The shaft system and the plant structure mainly display combined vertical vibrations, while the plant structure predominantly exhibits independent vertical vibrations. This implies that vertical vibrations are jointly influenced by shaft system stiffness and plant structure properties. In horizontal vibration modes, a strong coupling characteristic is observed between the upper structure of the pump station unit and the plant structure. This is primarily manifested as coupled vibrations between the support and the plant structure, which are collectively influenced by support constraints, shaft system stiffness, and plant structural properties.

Spectral Analysis of Nonlinear Phase Noise Arising in Coherent Fiber-Optic Transmission Systems of OFDM Signals

Spectral Analysis of Nonlinear Phase Noise Arising in Coherent Fiber-Optic Transmission Systems of OFDM Signals

A self-referenced optical phase noise analyzer for quantum technologies.

Second generation quantum technologies aim to outperform classical alternatives by utilizing engineered quantum systems. Maintaining the coherence required to enable any quantum advantage requires detailed knowledge and control over the noise that the hosting system is subjected to. Characterizing noise processes via their power spectral density is routinely done throughout science and technology and can be a demanding task. Determining the phase noise power spectrum in leading quantum technology platforms, for example, can be either outside the reach of many phase noise analyzers or prohibitively expensive. In this work, we present and characterize a low-complexity, low-cost optical phase noise analyzer based on the short-delay optical self-heterodyne measurements for quantum technology applications. Using this setup, we compare two ≈1Hz linewidth ultra-stable oscillators near 729nm. Their measurements are used as a baseline to determine and discuss the noise floor achieved in this measurement apparatus with a focus on limitations and their tradeoffs. The achieved noise floor in this all-stock-component implementation of an optical phase noise analyzer compares favorably with commercial offerings. This setup can be used particularly without a more stable reference or operational quantum system as a sensor as would be the case for many component manufacturers.

A Study of Noise Effect in Feedback Control with White Noise Analysis

In proportional-integral-derivative (PID) control, it is well known that the selection of a method to deal with noise is an important issue and various methods have been proposed. However, similar methods to determine the response to noise have not been studied in probability theory. In this paper, a new method called “weak form” is proposed and a probabilistic analysis of filtered derivatives is performed using this method. The method discussed in this paper is considered effective when it is not a feedback control.

Electrolyte gated based pH sensing vertical TFET biosensor: Design, simulation and noise analysis

In this manuscript, a pH-based stepped oxide gate underlap vertical tunnel field-effect transistor (hetero-pHVTFET) biosensor with GaSb-doped layers is explored. A novel feature of the proposed device involves the use of stepped oxides with underlapped cavity gates. During the fabrication of devices, several challenges have emerged. A vertical tunnel field-effect transistor (VTFET) is proposed in this study for the detection of biological molecules such as proteins, enzymes, deoxyribonucleic acids, and others using label-based electrical recognition through the Stern layer. The simulation model provides a generalized solution for biological molecule detection, featuring the effects of pH sensing. Surface potential and device current (IDS) are investigated in relation to pH changes. Moreover, pH sensors have also been used to measure changes in hydrogen ion concentration within electrolyte solutions and to examine the sensitivity of proposed biological sensors based on alterations in the density of states. A 40 nm cavity length of the proposed hetero-pHVTFET biosensor is estimated to have a drain current sensitivity of 9.2 × 105.

Acoustic analysis and control measures for noise in university: a case study of Adrar University, Algeria

The purpose of this research is to investigate the complex dynamics of noise pollution at the University of Adrar-Algeria, with a particular emphasis on the impact that the dry desert climate has on the acoustic environment of the campus. With the goal of cultivating an environment that is characterised by tranquilly, comfort, and optimal conditions for attention, learning, and practical engagement, the research attempts to achieve the goal of enhancing the existing discourse on noise management inside academic institutions. The inquiry makes use of a methodical approach in order to investigate the many climatological characteristics that are unique to the desert climate and that lead to increased noise levels within the university grounds. In addition, the research investigates the ways in which noise emissions from various sources alter inside the confines of Adrar University, taking into account the ways in which the harsh desert climate influences the parameters that control these emissions. The investigation of human behaviour patterns is relevant to this investigation. In particular, the investigation will focus on instances of protracted assemblage in air-conditioned places, which correlates with increased noise levels. In light of the fact that noise control is an essential component of the academic environment, the research being conducted at the University of Adrar includes the collection of questionnaires, the administration of on-site sound measurements, and the creation of an all-encompassing noise map. The findings shed light on the climatic factors that are primarily responsible for the excessive amount of noise that exceeds the standards that are suggested by the World Health Organisation (WHO).

Design and Analysis of an Interior Permanent Magnet Synchronous Motor for a Traction Drive Using Multiobjective Optimization

With the development of new energy industries, the demand for the driving range and power quality of electric vehicle (EV) drive systems is growing rapidly. The drive motor is faced with the challenge of continuously improving power density and performance. This paper proposes a multiobjective optimization method for an interior permanent magnet synchronous motor for a traction drive (IPMSMTD). Based on the flat wire winding technology, the multiobjective optimization design of the IPMSMTD is carried out to improve the motor power density and high-efficiency range, reduce the torque ripple, and suppress the electromagnetic vibration and noise. The structure and size equation of the IPMSMTD are described. The mathematical model considering iron losses is established, and the optimization objectives are determined. Based on the genetic algorithm, a multiobjective optimization mechanism of the magnetic pole structure is established. The operation performance of the motor is analyzed by the finite element simulation and efficiency map. In order to ensure the comprehensive operation index of the IPMSMTD, the vibration noise and modal analysis are carried out, which verifies the rationality of the designed motor and the optimization method.

Effect of genomic and cellular environments on gene expression noise

BackgroundIndividual cells from isogenic populations often display large cell-to-cell differences in gene expression. This “noise” in expression derives from several sources, including the genomic and cellular environment in which a gene resides. Large-scale maps of genomic environments have revealed the effects of epigenetic modifications and transcription factor occupancy on mean expression levels, but leveraging such maps to explain expression noise will require new methods to assay how expression noise changes at locations across the genome.ResultsTo address this gap, we present Single-cell Analysis of Reporter Gene Expression Noise and Transcriptome (SARGENT), a method that simultaneously measures the noisiness of reporter genes integrated throughout the genome and the global mRNA profiles of individual reporter-gene-containing cells. Using SARGENT, we perform the first comprehensive genome-wide survey of how genomic locations impact gene expression noise. We find that the mean and noise of expression correlate with different histone modifications. We quantify the intrinsic and extrinsic components of reporter gene noise and, using the associated mRNA profiles, assign the extrinsic component to differences between the CD24+ “stem-like” substate and the more “differentiated” substate. SARGENT also reveals the effects of transgene integrations on endogenous gene expression, which will help guide the search for “safe-harbor” loci.ConclusionsTaken together, we show that SARGENT is a powerful tool to measure both the mean and noise of gene expression at locations across the genome and that the data generatd by SARGENT reveals important insights into the regulation of gene expression noise genome-wide.

An improved hidden Markov model with magnetic Barkhausen noise and optimized Gaussian mixture feature for fatigue prediction

Evaluating fatigue states of metallic materials is essential for predicting their failures and ensuring structural safety. Magnetic Barkhausen noise (MBN) analysis, a non-destructive testing method, provides efficient and reliable methods for identifying and categorising material parameters such as hardness and residual stresses. To establish a quantitative relationship between MBN signals and fatigue states, an improved hidden Markov model (HMM) is proposed based on optimised Gaussian mixture features (GMFs) and the Kullback–Leibler (KL) divergence measure for fatigue prediction. The MBN-GMFs replicate the probability characteristics of MBN signals and track the fatigue degradation trend throughout the fatigue life; thus, they are superior to some widely used statistical features. A Gaussian component optimisation algorithm is proposed to automatically adjust the appropriate number of components in the Gaussian mixture model and enhance the representation of MBN-GMFs. Then, the KL divergence is introduced to quantify the similarity and accurately classify the degree of MBN-GMF migration. The HMM is constructed to obtain the probability transfer relationship between the observations and states and obtain accurate fatigue predictions. Experiments on two 20R metallic materials at three excitation frequencies are conducted to collect the MBN signals. The experimental results and comparisons indicate that the proposed HMM can accurately predict fatigue states and provide a practical and robust analysis tool for MBN-based fatigue predictions.

Development of web-based software for environmental impact assessment focusing on road traffic noise

In the Republic of Korea, Environmental Impact Assessment (EIAs) precedes development projects to predict and analyze potential environmental effects. Generally, EIA noise evaluations utilize 2D noise prediction equations and correction coefficients. This method, however, offers only a sectional noise evaluation and has limitations in complex environments with diverse noise sources. Moreover, the determination of various variables during the EIA process based on subjective human judgment raises concerns about the reliability of the results. Thus, this study aims to develop software accessible via a web environment for user-friendly EIA noise evaluations. This software supports integrated data management and generates a 3D noise prediction model for more precise and realistic analysis of noise impacts, specifically focusing on road-traffic noise at this stage of development. The 3D noise prediction model and noise map generated by the developed software have been validated against through comparison with the results of onsite noise measurements and commercial EIA software, SoundPLAN. This validation aimed to assess the practical utility of the application.

THz-TDS with gigahertz Yb-based dual-comb lasers: noise analysis and mitigation strategies

We investigate terahertz time-domain spectroscopy using a low-noise dual-frequency-comb laser based on a single spatially multiplexed laser cavity. The laser cavity includes a reflective biprism, which enables generation of a pair of modelocked output pulse trains with slightly different repetition rates and highly correlated noise characteristics. These two pulse trains are used to generate the THz waves and detect them by equivalent time sampling. The laser is based on Yb:CALGO, operates at a nominal repetition rate of 1.18 GHz, and produces 110 mW per comb with 77 fs pulses around 1057 nm. We perform THz measurements with Fe-doped photoconductive antennas, operating these devices with gigahertz 1 µm lasers for the first time, to our knowledge, and obtain THz signal currents approximately as strong as those from reference measurements at 1.55 µm and 80 MHz. We investigate the influence of the laser’s timing noise properties on THz measurements, showing that the laser’s timing jitter is quantitatively explained by power-dependent shifts in center wavelength. We demonstrate reduction in noise by simple stabilization of the pump power and show up to 20 dB suppression in noise by the combination of shared pumping and shared cavity architecture. The laser’s ultra-low-noise properties enable averaging of the THz waveform for repetition rate differences from 1 kHz to 22 kHz, resulting in a dynamic range of 55 dB when operating at 1 kHz and averaging for 2 s. We show that the obtained dynamic range is competitive and can be well explained by accounting for the measured optical delay range, integration time, as well as the measurement bandwidth dependence of the noise from transimpedance amplification. These results will help enable a new approach to high-resolution THz-TDS enabled by low-noise gigahertz dual-comb lasers.

Source term inversion of nuclear accidents based on ISAO-SAELM model

The release source term of radioactivity becomes a critical foundation for emergency response and accident consequence assessment after a nuclear accident Rapidly and accurately inverting the source term remains an urgent scientific challenge. Today source term inversion based on meteorological data and gamma dose rate measurements is a common method. But gamma dose rate actually includes all nuclides information, and the composition of radioactive nuclides is generally uncertain. This paper introduces a novel nuclear accident source term inversion model, which is Improve Snow Ablation Optimizer-Sensitivity Analysis Pruning Extreme Learning Machine (ISAO-SAELM) model. The model inverts the release rates of 11 radioactive nuclides (I-131, Xe-133, Cs-137, Kr-88, Sr-91, Te-132, Mo-99, Ba-140, La-140, Ce-144, Sb-129). It does not require the use of the physical field of the reactor to obtain prior information and establish a dispersion model. And the robustness is validated through noise analysis test. The mean absolute errors of the release rates of 11 nuclides are 15.52 %, 15.28 %, 15.70 %, 14.99 %, 14.85 %, 15.61 %, 15.96 %, 15.42 %, 15.84 %, 15.13 %, 17.72 %, which show the significant superiority of ISAO-SAELM. ISAO-SAELM model not only achieves notable advancements in accuracy but also receives validation in terms of practicality and feasibility.