Noise Gate Research Articles

Comparative study on the evaluation and benchmarking information hiding approaches based multi-measurement analysis using TOPSIS method with different normalisation, separation and context techniques

This paper presents a comparative study of evaluation and benchmarking information hiding approaches based on multi-measurement analysis using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method in terms of different parameter settings because several settings of TOPSIS are continually making complex decisions within any study case. The problem is extended from original TOPSIS in terms of different contexts, distance and normalisation techniques. However, each technique changes the behaviour of data differently. The literature presents no evidence that any of those techniques affects the final decision. Supporting results are needed to justify which technique is the best for this particular study on evaluation and benchmarking digital watermarking approaches. For these purposes, two experiments are performed. In the first experiment, a noise-gate-based digital watermarking approach is developed, and a scheme for noise gate digital watermarking approach is enhanced. A total of 60 audio samples with different audio styles are tested using the two algorithms. A total of 120 samples are evaluated according to three different metrics, namely, quality, payload and complexity, to generate a set of digital watermarking samples. In the second experiment, three different weights are selected in the decision making process. For the first weight, 50% of importance is given to size and 25% each for quality and complexity. In the second weight, 50% is given to quality and 25% each to size and complexity. In the last weight, 50% of importance is given to complexity and 25% each to size and quality. In the decision making solution, the algorithm adjustment and parameter selection of TOPSIS are identified and tested based on three parameters, namely, normalisation, separation and contexts. In the normalisation process, two different linear normalisation and vector normalisation techniques are used. In the separation process, two different techniques, namely, Manhattan and Euclidean distances, are used, and each of these measurements has different philosophies. In the context process, two different contexts, such as decision making based on signal and group, are used. The results are as follows: (1) The preferred normalisation technique is followed by vector normalisation. (2) We recommend linear normalisation with TOPSIS by integrating the results from our experiment and the literature experiment. (3) The separation measurement has an effect on decision making algorithms, and the Euclidean measurement in the separation process reflects more accurate results than the Manhattan measurement. (4) The framework selects one of the two context settings, that is, group or individual, which will give the same results. However, group decision making is the recommended approach in the case of selection where priority weights are generated from the evaluators.

Fibre-integrated noise gating of high-purity heralded single photons

We present an all-fibre source of high-purity heralded single photons with an integrated conditional optical gate that reduces uncorrelated noise by almost an order of magnitude. Generating photon pairs by four-wave mixing in photonic crystal fibre, we observe with the noise gate active a factor of 7 reduction in the rate of single counts in the heralded channel with no measurable drop in coincidence count rate. In contrast to electronic post-selection of coincidence events, the real reduction in the flux of unwanted photons is beneficial for example to avoid bleaching light-sensitive samples or in generating entangled states.

A New Approach Based on Multi-Dimensional Evaluation and Benchmarking for Data Hiding Techniques

This paper presents a new approach based on multi-dimensional evaluation and benchmarking for data hiding techniques, i.e., watermarking and steganography. The novelty claim is the use of evaluation matrix (EM) for performance evaluation of data hiding techniques; however, one major problem with performance evaluation of data hiding techniques is to find reasonable thresholds for performance metrics and the trade-off among them in different data hiding applications. Two experiments are conducted. The first experiment included LSB techniques (eight approaches) based on different payload results and the noise gate approach; a total of nine approaches were used. Five audio samples with different audio styles are tested using each of the nine approaches and considering three evaluation criteria, namely, complexity, payload, and quality, to generate watermarked samples. The second experiment involves the use of various decision-making techniques simple additive weighting (SAW), multiplicative exponential weighting (MEW), hierarchical adaptive weighting (HAW), technique for order of preference by similarity to ideal solution (TOPSIS), weighted sum model (WSM) and weighted product method (WPM) to benchmark the results of the first experiment. Mean, standard deviation (STD), and paired sample t-test are then performed to compare the correlations among different techniques on the basis of ranking results. The findings are as follows: (1) A statistically significant difference is observed among the ranking results of each multi-criteria decision-making (MCDM) technique, (2) TOPSIS-Euclidean is the best technique to solve the benchmarking problem among digital watermarking techniques. (3) Among the decision-making techniques, WSM has the lowest rank in terms of solving the benchmarking problem. (4) Under different circumstances, the noise gate watermarking approach performs better than LSB algorithms.

Influence of gate leakage current induced shot noise on the Minimum Noise Figure of InAlAs/InGaAs double-gate HEMT

In this paper, the influence of hot electron injection induced gate leakage current on the noise performance of InAlAs/InGaAs double-gate HEMT has been studied following a comprehensive analytical approach. The presence of two gates on both sides of the channel in a double-gate HEMT not only provides significant improvement in its ultra-high speed and noise performance, but is also responsible for higher gate leakage current which becomes very dominant in high field conditions. Therefore, in order to explore the reliability and potential of this device under high gate and drain bias conditions, a thorough investigation of the effect of gate leakage current induced shot noise gate current on the Minimum Noise Figure of the device has been carried out.

A new digital watermarking evaluation and benchmarking methodology using an external group of evaluators and multi‐criteria analysis based on ‘large‐scale data’

SummaryDigital watermarking evaluation and benchmarking are challenging tasks because of multiple evaluation and conflicting criteria. A few approaches have been presented to implement digital watermarking evaluation and benchmarking frameworks. However, these approaches still possess a number of limitations, such as fixing several attributes on the account of other attributes. Well‐known benchmarking approaches are limited to robust watermarking. Therefore, this paper presents a new methodology for digital watermarking evaluation and benchmarking based on large‐scale data by using external evaluators and a group decision making context. Two experiments are performed. In the first experiment, a noise gate‐based digital watermarking approach is developed, and the scheme for the noise gate digital watermarking approach is enhanced. Sixty audio samples from different audio styles are tested with two algorithms. A total of 120 samples were evaluated according to three different metrics, namely, quality, payload, and complexity, to generate a set of digital watermarking samples. In the second experiment, the situation in which digital watermarking evaluators have different preferences is discussed. Weight measurement with a decision making solution is required to solve this issue. The analytic hierarchy process is used to measure evaluator preference. In the decision making solution, the technique for order of preference by similarity to the ideal solution with different contexts (e.g., individual and group) is utilized. Therefore, selecting the proper context with different aggregation operators to benchmark the results of experiment 1 (i.e., digital watermarking approaches) is recommended. The findings of this research are as follows: (1) group and individual decision making provide the same result in this case study. However, in the case of selection where the priority weights are generated from the evaluators, group decision making is the recommended solution to solve the trade‐off reflected in the benchmarking process for digital watermarking approaches. (2) Internal and external aggregations show that the enhanced watermarking approach demonstrates better performance than the original watermarking approach. © 2016 The Authors. Software: Practice and Experience published by John Wiley & Sons Ltd.

Electrical characterization of a gate-recessed AlGaN/GaN high-electron-mobility transistor with a p-GaN passivation layer

A novel passivation technique was developed that reduces the electron-surface-hopping-induced leakage current of AlGaN/GaN high-electron-mobility transistors (HEMTs) and enhances their electrical properties under high drain bias operation. The key aspect of this passivation technique entailed growing a p-type GaN layer on a traditional depletion-mode AlGaN/GaN HEMT; this p-GaN passivation layer was also used as the spacer layer of a field-plate metal. The originally exposed gate-to-source and gate-to-drain areas were passivated by the p-GaN cap layer. Thus, a surface depletion region was formed between the p-GaN passivation layer and an n-type AlGaN/GaN two-dimensional electron gas channel. This extra surface depletion region depleted the channel carriers far from the surface to reduce the probability of the carriers being trapped by surface defects. Therefore, the carrier-hopping-induced leakage current in the gate-to-drain area, which was strongly temperature-dependent, was suppressed. Low-frequency noise (LFN) measurement revealed that the traditional chemical-vapor-deposited SiO2 layer still exhibited a surface trap center. Moreover, the slope of a plot of noise spectra versus gate overdrive voltage was approximately −3. At a cryogenic temperature, the LFN of the p-GaN—passivated device improved by 3 orders of magnitude, whereas the high surface trap density of the standard passivated device resulted in a high LFN, even at a cryogenic temperature.

Source Traffic Modelling in WSN for Acoustic Sensing in Reverberant Environment

Recent research efforts show that Wireless Sensor Networks (WSN) for acoustic sensing have the potential for ubiquitous sensing. The key challenge in delivering such WSN architecture is the trade-off between the cost of wireless sensors and acoustic analysis complexity. In this paper, we are proposing a source traffic modelling considering a system in which sensors are connected to a cloud based processing service. Acoustic sensing in practice generates great amount of traffic, and therefore a new model of sensing in a reverberant environment is necessary for better understanding of traffic nature and its volume. To lower the sensor cost, we have considered low-complexity acoustic event detection on the sensor side for preventing unnecessary traffic. The proposed acoustic sensor acts like a noise gate. Sound propagation in reverberant environment is modelled using the modified Image-Source Modelling (ISM) method. The source traffic model is validated in Matlab simulation and in real reverberant environment. Results show an example of bandwidth used by a simple acoustic sensor. DOI: http://dx.doi.org/10.5755/j01.eee.21.5.13335

Modeling Channel Thermal Noise and Induced Gate Noise in Junctionless FETs

This paper presents analytical expressions for channel noise, induced gate noise (IGN), and cross-correlation noise in a long-channel junctionless (JL) double-gate MOSFET. The analytical relationships, which have been derived from a coherent charge-based model, are validated with technology computer-aided design simulations, and the figures of merit have been compared with the inversion mode FETs. For a given current, we found that the channel thermal noise is very similar for both architectures, whereas the IGN is slightly decreased in the JL FETs.

The Effect of Forward Gate Bias Stress on the Noise Performance of Mesa Isolated GaN HEMTs

This study investigates degradation of gallium nitride (GaN) high-electron mobility transistor (HEMT) noise performance after both dc and RF stress with forward gate current. The results are used to facilitate optimization of the robustness of GaN low-noise amplifiers (LNAs). It is shown that forward biasing the gate of a GaN HEMT results in permanent degradation of noise performance and gate current leakage, without affecting S-parameters and drain current characteristics. The limit of safe operation of the 2 × 50 μm devices in this study is found to be between 10 and 20 mW dissipated in the gate diode for both dc and RF stress. We propose that degradation could be caused by excessive leakage through the mesa sidewalls at the edges of each gate finger. Circuit simulations may be used together with device robustness rating to optimize LNAs for maximum input power tolerance. Using a resistance in the gate biasing network of 10 kΩ, it is estimated that an LNA utilizing a 2 × 50 μm device could withstand input power levels up to 33 dBm without degradation in noise performance.

Entanglement-free certification of entangling gates

Not all quantum protocols require entanglement to outperform their classical alternatives. The nonclassical correlations that lead to this quantum advantage are conjectured to be captured by quantum discord. Here we demonstrate that discord can be explicitly used as a resource: certifying untrusted entangling gates without generating entanglement at any stage. We implement our protocol in the single-photon regime, and show its success in the presence of high levels of noise and imperfect gate operations. Our technique offers a practical method for benchmarking entangling gates in physical architectures in which only highly-mixed states are available.

Towards undistorted and noise-free speech in an MRI scanner: Correlation subtraction followed by spectral noise gating

Noise cancellation in an MRI environment is difficult due to the high noise levels that are in the spectral range of human speech. This paper describes a two-step method to cancel MRI noise that combines operations in both the time domain (correlation subtraction) and the frequency domain (spectral noise gating). The resulting filtered recording has a noise power suppression of over 100 dB, a significant improvement over previously described techniques on MRI noise cancellation. The distortion is lower and the noise suppression higher than using spectral noise gating in isolation. Implementation of this method will aid in detailed studies of speech in relation to vocal tract and velopharyngeal function.

Comparison of Multirate two-channel Quadrature Mirror Filter Bank with FIR Filters Based Multiband Dynamic Range Control for audio

This paper proposes a Comparison of Multirate two-channel Quadrature Mirror Filter QMF bank with FIR filters based Multiband Dynamic Range Control DRC for audio. Two-channel QMF decomposes input audio signals into low and high frequency bands with the help of analysis filters, and these sub-bands are decimated by a factor of 2 and inputted to DRC up-sampled by a factor of 2 after which need to be combined to reconstruct the original signal with the help of synthesis filters with increased amplitude in the audio compared to when only FIR filters are used. The filters used here are Finite Impulse Response FIR using Kaiser Window. The reconstructed signal is an exact replica of input signal with some delay called perfect reconstruction. In DRC, multi-band compressor is used to apply compression differently to different frequency bands of the input signal, which uses minimum gain method. This allows the user to be selective about how compression is applied to a signal and only add power to certain parts of the frequency spectrum. Here limiter, compressor, expander and noise gate are used in the DRC, which protects the AD converter from overload. Index Terms: Analog to digital converter (A/D), Dynamic Range Control (DRC), Finite Impulse Response (FIR), Quadrature Mirror Filter (QMF).

Robust measurement, monitoring and analysis of partial discharges in transformers and other HV apparatus

This paper describes and practically illustrates modern methods for robust, and at the same time sensitive measurement of partial discharges; applied in the laboratory, onsite and during on-line monitoring of HV apparatus. For conventional, electrical measurements, the principle of dynamic noise gating is illustrated. Above this, amplitude-based and spectrum-based impulse correlations allow for discrimination between noise and partial discharges, but also for separation of several discharge sources. Automatic pattern recognition then classifies the separated sources and provides basic risk assessment. Acoustic waves of partial discharge events serve for PD localization, but, due to their high damping, often require combination with electrical or electro-magnetic methods. Measurements in the UHF range, well-known from gas-insulated equipment, are of particular benefit for noise-immune analysis of oil-filled equipment, too and compared to the traditional, electrical method in this paper.

Guest Editorial Special Issue on GaN Electronic Devices

Due to the rapid advances taking place in the development and application of GaN electronics, there is an immediate need to take cognizance of the recent technological improvements and bring the potential and opportunities that exist in the area to a wider device community. The primary goal of this special issue is, therefore, to put together works in different aspects, including modeling, design, technology, characterization and applications so that this special issue will not only be of great archival value but also attract new researchers into this area for Digital Object Identifier 10.1109/TED.2013.2278653 further accelerating the application of III-N devices in building reliable, cheaper, and high-performance electronic systems. The papers collected in this special issue have been grouped into six topics. They are: 1) Fabrication and characterization of GaN-based devices. 2) High power GaN HEMTs for power switching applications. 3) High speed GaN HEMTs for RF applications. 4) Reliability and parasitic issues in GaN HEMTs. 5) Simulation-based development of GaN HEMTs devices. 6) GaN-based low noise amplifiers and gate drive circuits.

Maintaining intelligibility at high speech intensities: Evidence of lateral inhibition in the lower auditory pathway

Three experiments examined the intelligibility enhancement produced when noise bands flank high intensity narrowband speech. Enhancement was unaffected by noise gating (experiment 1), ruling out peripheral adaptation as a source, and was also unaffected by interaural decorrelation of noise bands flanking diotic speech (experiment 2), indicating that enhancement occurs prior to binaural processing. These results support previous suggestions that intelligibility loss at high intensities is reduced by lateral inhibition in the cochlear nuclei. Results from a final experiment suggest that this effect is only ipsilateral, implicating a specific population of inhibitory neurons.

Embedding a Noise Gate Pedal in an Instrument to Avoid Unwanted Noises

Embedding a Noise Gate Pedal in an Instrument to Avoid Unwanted Noises

Detection and parameters interception of a radar pulse signal based on interrupt driven algorithm

This paper presents the development of a new algorithm for radar pulse signal acquisition and parameters interception. The parameters are measured based on digitizing intermediate frequency input stream and signal storing only on signal presence. In this framework, two activities are implemented. Firstly, the data acquisition and preprocessing activity, which reads incoming data stream, converts it into video signal, refines incoming data by applying predefined double threshold noise gate, and stores radar pulse data upon signal existence. Secondly, the data analysis activity, which measures the processed signal parameters. It includes the measurement of intermediate frequency, pulse width, time of arrival, time of departure, pulse repetition frequency and pulse amplitude. The implemented software consists of three main units connected through different buffers hierarchy. These units are: the input unit, digital signal processing unit, and the human computer interface unit. These units can operate in parallel allowing simple algorithms to be executed concurrently thereby fast radar signal parameters interception. Key words: Radar signal detection, signal identification, radar pulse analysis, data acquisition system, radar signal processing.

Automatic Noise Gate Settings for Drum Recordings Containing Bleed from Secondary Sources

An algorithm is presented which automatically sets the attack, release, threshold, and hold parameters of a noise gate applied to drum recordings which contain bleed from secondary sources. The gain parameter which controls the amount of attenuation applied when the gate is closed is retained, to allow the user to control the strength of the gate. The gate settings are found by minimising the artifacts introduced to the desirable component of the signal, whilst ensuring that the level of bleed is reduced by a certain amount. The algorithm is tested on kick drum recordings which contain bleed from hi-hats, snare drum, cymbals, and tom toms.

Cobalt Nano Particle Size Dependence of Noise Modulations in Relation to Nonlinearity

Carbon nanotubes (CNTs) are low-dimensional materials, and their surface therefore affects several properties of CNTs. For example, CNT field effect transistors (CNTFETs) are well known as noisy devices caused by the adhesion of molecules on the surface. However, nonlinear systems sometimes have advantages in working with noise. Therefore, we combined the noise CNTFET and another transistor of CNT for a trial nonlinear system. The sine wave amplification in the transistor with noise was then measured. In this system, the control of noise is required for operation of the device and this might be common for nano-sized devices. We can control the noise properties of CNTFET through the control of the Co nano particles catalyst. Depending on fabrication conditions, the noise of a CNTFET has different noise intensity and gate voltage (Vg) dependence with 1/f type noise. Noise in CNTFETs grown on small Co particles can be controlled within the small |Vg|, and the control range for noise is wide. We studied the modification of nonlinearity using our trial nonlinear system. It was governed by the ratio of the signals and the noise, and shows the robustness of modification. [DOI: 10.1380/ejssnt.2010.115]

A Novel Embedding Method to Increase Capacity and Robustness of Low-bit Encoding Audio Steganography Technique Using Noise Gate Software Logic Algorithm

In this study, we developed a novel method that is able to shift the limit for transparent data hiding in audio from the fourth LSB layer to the eighth LSB layer, thus the method has improved the capacity and robustness of data hiding in the audio file using a two steps approach. In the first step, noise gate software logic used to obtain a desired signal for embedding the secret message of the input host audio signal (carrier). In the second step, standard 8th LSB layer embedding has been done for this desired signal. Audio quality evaluation has used to evaluate our purposed method in two ways. First, objective test showed the algorithm succeeds in this task, while increasing SNR values of our algorithm comparing to SNR values obtained by standard LSB embedding in the 8th bits LSB layer and the comparison of the histogram audio excerpts has proved this also. Second, subjective listening test proved that high perceptual transparency is accomplished even if eight LSB of host audio signal are used for data hiding.