Showing papers on "Fundamental frequency published in 2017"
TL;DR: The results indicate that the brain is likely to operate on multiple frequency channels during rest, introducing a novel dimension for future models of large‐scale brain activity.
164 citations
TL;DR: In this paper, the authors demonstrate that elastic surface (Rayleigh) wave reflectors at very large wavelengths in structured soils can be achieved using a fully elastic layer periodically clamped to bedrock.
Abstract: The regularity of earthquakes, their destructive power, and the nuisance of ground vibration in urban environments, all motivate designs of defence structures to lessen the impact of seismic and ground vibration waves on buildings. Low frequency waves, in the range 1–10 Hz for earthquakes and up to a few tens of Hz for vibrations generated by human activities, cause a large amount of damage, or inconvenience; depending on the geological conditions they can travel considerable distances and may match the resonant fundamental frequency of buildings. The ultimate aim of any seismic metamaterial, or any other seismic shield, is to protect over this entire range of frequencies; the long wavelengths involved, and low frequency, have meant this has been unachievable to date. Notably this is scalable and the effects also hold for smaller devices in ultrasonics. There are three approaches to obtaining shielding effects: bragg scattering, locally resonant sub-wavelength inclusions and zero-frequency stop-band media. The former two have been explored, but the latter has not and is examined here. Elastic flexural waves, applicable in the mechanical vibrations of thin elastic plates, can be designed to have a broad zero-frequency stop-band using a periodic array of very small clamped circles. Inspired by this experimental and theoretical observation, all be it in a situation far removed from seismic waves, we demonstrate that it is possible to achieve elastic surface (Rayleigh) wave reflectors at very large wavelengths in structured soils modelled as a fully elastic layer periodically clamped to bedrock. We identify zero frequency stop-bands that only exist in the limit of columns of concrete clamped at their base to the bedrock. In a realistic configuration of a sedimentary basin 15 m deep we observe a zero frequency stop-band covering a broad frequency range of 0–30 Hz.
120 citations
TL;DR: Cavitation, chemical effect, and mechanical effect thresholds were investigated in wide frequency ranges from 22 to 4880kHz in terms of sound pressure at fundamental frequency and increased with increasing frequency.
99 citations
TL;DR: In this article, a new analytical procedure for selective harmonic elimination in five-level inverters operating at fundamental frequency is proposed, which has limited computational complexity, simple and cost-effective real-time implementation, and full capability of integration with closed loop control.
Abstract: In distributed generation, high power capability and high efficiency are very important requirements. For this reason, this paper proposes a new analytical procedure for selective harmonic elimination in five-level inverters operating at fundamental frequency. For each modulation index, the proposed method calculates all possible switching angles eliminating a specified odd harmonic from the output voltage. The method has limited computational complexity, simple and cost-effective real-time implementation, and full capability of integration with closed loop control. Simulation and experimental results highlight full elimination of selected harmonic.
76 citations
20 Aug 2017
TL;DR: An evaluation using two speech databases with electroglottograph (EGG) signals to compare Harvest with several state-of-the-art algorithms showed that Harvest achieved the best performance of all algorithms.
Abstract: A fundamental frequency (F0) estimator named Harvest is described. The unique points of Harvest are that it can obtain a reliable F0 contour and reduce the error that the voiced section is wrongly identified as the unvoiced section. It consists of two steps: estimation of F0 candidates and generation of a reliable F0 contour on the basis of these candidates. In the first step, the algorithm uses fundamental component extraction by many band-pass filters with different center frequencies and obtains the basic F0 candidates from filtered signals. After that, basic F0 candidates are refined and scored by using the instantaneous frequency, and then several F0 candidates in each frame are estimated. Since the frame-by-frame processing based on the fundamental component extraction is not robust against temporally local noise, a connection algorithm using neighboring F0s is used in the second step. The connection takes advantage of the fact that the F0 contour does not precipitously change in a short interval. We carried out an evaluation using two speech databases with electroglottograph (EGG) signals to compare Harvest with several state-of-the-art algorithms. Results showed that Harvest achieved the best performance of all algorithms.
57 citations
TL;DR: In this article, a NACA 0012 airfoil at Reynolds number 50 000 and angle of attack 5° with three different trailing edge shapes (straight, blunt, and serrated) was analyzed using dynamic mode decomposition.
Abstract: Direct numerical simulations of the flow field around a NACA 0012 airfoil at Reynolds number 50 000 and angle of attack 5° with 3 different trailing edge shapes (straight, blunt, and serrated) have been performed. Both time-averaged flow characteristics and the most dominant flow structures and their frequencies are investigated using the dynamic mode decomposition method. It is shown that for the straight trailing edge airfoil, this method can capture the fundamental as well as the subharmonic of the Kelvin-Helmholtz instability that develops naturally in the separating shear layer. The fundamental frequency matches well with relevant data in the literature. The blunt trailing edge results in periodic vortex shedding, with frequency close to the subharmonic of the natural shear layer frequency. The shedding, resulting from a global instability, has an upstream effect and forces the separating shear layer. Due to forcing, the shear layer frequency locks onto the shedding frequency while the natural freque...
55 citations
TL;DR: In this paper, in-situ HST generated ground vibrations were measured in the embankment, culvert, viaduct and transition sections of Beijing-Shanghai high speed railway (HSR) in China.
54 citations
TL;DR: In this article, the authors demonstrate that elastic surface (Rayleigh) and body (pressure P and shear S) wave reflectors at very large wavelengths in structured soils modelled as a fully elastic layer periodically clamped to bedrock.
Abstract: The regularity of earthquakes, their destructive power, and the nuisance of ground vibration in urban environments, all motivate designs of defence structures to lessen the impact of seismic and ground vibration waves on buildings. Low frequency waves, in the range $1$ to $10$ Hz for earthquakes and up to a few tens of Hz for vibrations generated by human activities, cause a large amount of damage, or inconvenience, depending on the geological conditions they can travel considerable distances and may match the resonant fundamental frequency of buildings. The ultimate aim of any seismic metamaterial, or any other seismic shield, is to protect over this entire range of frequencies, the long wavelengths involved, and low frequency, have meant this has been unachievable to date.
Elastic flexural waves, applicable in the mechanical vibrations of thin elastic plates, can be designed to have a broad zero-frequency stop-band using a periodic array of very small clamped circles. Inspired by this experimental and theoretical observation, all be it in a situation far removed from seismic waves, we demonstrate that it is possible to achieve elastic surface (Rayleigh) and body (pressure P and shear S) wave reflectors at very large wavelengths in structured soils modelled as a fully elastic layer periodically clamped to bedrock.
We identify zero frequency stop-bands that only exist in the limit of columns of concrete clamped at their base to the bedrock. In a realistic configuration of a sedimentary basin 15 meters deep we observe a zero frequency stop-band covering a broad frequency range of $0$ to $30$ Hz.
53 citations
TL;DR: Based on time-variant behavior of metal-oxide-semiconductor field effect transistors in large-signal operations, harmonic translations and their mutual effects are analyzed in this paper.
Abstract: Based on time-variant behavior of metal-oxide–semiconductor field-effect transistors in large-signal operations, harmonic translations and their mutual effects are analyzed. Large amplitudes at terminal voltages of these transistors push them into different regions of operation. In this paper, harmonic translations are derived as a result of such changes in operation region of transistors. Operation in triode region for a portion of oscillation cycle results in iterative harmonic translations between fundamental frequency and second harmonic. They boost each other constructively for significantly stronger oscillation, more second harmonic output power, and enhanced dc-to-RF efficiency. Based on this analysis, a 215-GHz signal source, implemented in a TSMC 65-nm CMOS LP is presented. The proposed oscillator achieves a maximum output power of 5.6 dBm and a dc-to-RF efficiency of 4.6%. The measured phase noise is −94.6 dBc/Hz at 1-MHz offset. The proposed oscillator occupies only 0.08 mm2 of chip area.
52 citations
TL;DR: In this article, a low-pressure capacitively coupled radio frequency discharges operated in O2 and driven by tailored voltage waveforms are investigated experimentally and by means of kinetic simulations.
Abstract: Low-pressure capacitively coupled radio frequency discharges operated in O2 and driven by tailored voltage waveforms are investigated experimentally and by means of kinetic simulations. Pulse-type (peaks/valleys) and sawtooth-type voltage waveforms that consist of up to four consecutive harmonics of the fundamental frequency are used to study the amplitude asymmetry effect as well as the slope asymmetry effect at different fundamental frequencies (5, 10, and 15 MHz) and at different pressures (50–700 mTorr). Values of the DC self-bias determined experimentally and spatio-temporal excitation rates derived from phase resolved optical emission spectroscopy measurements are compared with particle-in-cell/Monte Carlo collisions simulations. The spatio-temporal distributions of the excitation rate obtained from experiments are well reproduced by the simulations. Transitions of the discharge electron heating mode from the drift-ambipolar mode to the α-mode are induced by changing the number of consecutive harmonics included in the driving voltage waveform or by changing the gas pressure. Changing the number of harmonics in the waveform has a strong effect on the electronegativity of the discharge, on the generation of the DC self-bias and on the control of ion properties at the electrodes, both for pulse-type, as well as sawtooth-type driving voltage waveforms The effect of the surface quenching rate of oxygen singlet delta metastable molecules on the spatio-temporal excitation patterns is also investigated.
48 citations
TL;DR: A setup for the measurement of the frequency response of voltage measurement transformers under actual waveform conditions is presented, based on a two step procedure that makes use of high voltage gas insulated capacitors and a digital bridge.
Abstract: A setup for the measurement of the frequency response of voltage measurement transformers under actual waveform conditions is presented. It is based on a two-step procedure that makes use of high voltage gas insulated capacitors and a digital bridge. It allows calibrations using distorted waveforms, with a fundamental tone at medium voltage level and superimposed harmonics up to 20% and 15 kHz. Combined standard uncertainty in the measurement of the voltage transformer (VT) error is estimated at 200 $\mu \text{V}/\text{V}$ for the ratio error and $300~\mu $ rad for the phase displacement up to 10 kHz. First applications to the measurement of the frequency response of VTs with different rated primary voltages up to 50 kV are presented.
TL;DR: In this article, an acoustic metastructure and a double-clamped piezoelectric bimorph plate were designed by utilizing a doubly coiled-up configuration for strong confinement of the sound energy inside the acoustic metamaterial cavity in the low frequency range.
Abstract: A new sound energy harvesting system that comprises an acoustic metastructure and a double-clamped piezoelectric bimorph plate is presented. A subwavelength-scale acoustic metastructure is specially designed by utilizing a doubly coiled-up configuration for the strong confinement of the sound energy inside the acoustic metamaterial cavity in the low frequency range. The amplified sound pressure in the acoustic metamaterial cavity then substantially increases the vibratory motions of the piezoelectric bimorph plate. For the purpose of generating more electricity from the sound, the resonant frequency of the acoustic metamaterial cavity is tuned to the fundamental frequency of the piezoelectric bimorph plate. The numerical and experiment results show that the proposed sound energy harvesting system increase a sound pressure level (SPL) by up to ~16 dB, and yields an output voltage that is 6.32 times higher than that of the conventional piezoelectric energy harvesting plate. For the incident SPL of 100 dB, the maximum output power is measured as approximately 0.345 μW at a resonant frequency of 600 Hz.
TL;DR: In this paper, the authors used wavelet analysis to identify the fundamental frequency of a bridge in order to visualize the bridge damage represented as changing the fundamental frequencies of the bridge's structural integrity.
Abstract: In recent years, the concept of bridge monitoring using indirect measurements from a passing vehicle has been rapidly developed. This concept is known as “drive-by bridge inspection”. Most of the methods proposed under this approach utilize the dynamic characteristics of the bridge as an indicator of damage, such as the natural frequency of the bridge. The natural frequency is often estimated using fast Fourier transform (FFT). However, FFT has a low frequency resolution at the condition of higher velocity of a passing vehicle; therefore, it is not appropriate to be used to monitor the frequency change caused by the degradation of the bridge structural integrity. This paper introduces a new frequency identification technique based on wavelet analysis. Wavelet transform is characterized by its high-frequency resolution and can, therefore, be used to visualize the bridge damage represented as changing the fundamental frequency of the bridge. The paper will implement this approach using an implicit Vehicle-Bridge Interaction (VBI) algorithm to simulate the passage of the inspection vehicle over the bridge. The acceleration signals are then processed using wavelet analysis to extract the bridge frequency. In addition, the study will investigate the use of a subtracted signal from two consecutive axles. The latter point has the advantage of substantially removing the effect of the road roughness from the recorded acceleration history.
TL;DR: In this paper, an approach to realize coherent radiation at the fundamental frequency of the wave that is resonant with the electron beam in a Smith-Purcell free-electron laser (FEL) was proposed.
Abstract: This letter reports an approach to realize coherent radiation at the fundamental frequency of the wave that is resonant with the electron beam in a Smith-Purcell (SP) free-electron laser (FEL). We found that a two-dimensional grating structure equipped with a dielectric substrate could provide an electromagnetic mode which shows the property of a surface wave in the vacuum region where the beam-wave interaction occurs, and operates as a radiative wave in the dielectric region. Thus, an electron beam holding medium energy resonant with the mode could radiate at the fundamental frequency, which is different from the typical Smith-Purcell free-electron laser that radiates only at harmonics of the resonant frequency.
TL;DR: In this paper, an innovative 3-D mechanically tunable frequency selective surface (FSS) was proposed, which is inspired by the classical flat square slot FSS, which can be tuned from 2.4 to 4 GHz.
Abstract: We introduce an innovative 3-D mechanically tunable frequency selective surface (FSS), which is inspired by the classical flat square slot FSS. The proposal improves the performance of classical 2-D FSS designs, and it also represents a novel method of achieving mechanical frequency tuning, despite other 3-D designs that consist of a collection of stacked 3-D layers exist. In our proposal, the rotation of an inner element provides tuning capability to the squared cell structure, consisting of metallic grids with a movable inner element. An aluminum prototype was built, which can be tuned from 2.4 to 4 GHz, and also compared its measured performance and numerical simulations. Some characteristics of the proposed structure are the rejection level at main polarization, up to 20 dB, and the maximum frequency sweep of approximately 50% of the fundamental frequency. The prototype showed a stable frequency response for angles of incidence up to 45°. Since results are in good agreement with simulations, we provide parametric equations to design 3-D structures at desired frequencies.
TL;DR: In this paper, the scaling laws of the free vibration of a shear deformable composite I-beam are analyzed using similarity transformation to derive scaling laws. And a systematic approach is proposed to design partially similar scaled-down models with totally different layup from those of the full-scale I-beams.
Abstract: Scaled models of large and expensive structures facilitate in understanding the physical behavior of the large structure during operation but on a smaller scale in both size and cost. These reduced-sized models also expedite in tuning designs and material properties, but also could be used for certification of the full-scale structure (referred to as the prototype). Within this study, the applicability of structural similitude theory in design of partially similar composite structures is demonstrated. Particular emphasis is placed on the design of scaled-down composite I-beams that can predict the fundamental frequency of their corresponding prototype. Composite I-beams are frequently used in the aerospace industry and are referred to as the back bone of large wind turbine blades. In this study, the governing equations of motion for free vibration of a shear deformable composite I-beam are analyzed using similarity transformation to derive scaling laws. Derived scaling laws are used as design criteria to develop scaled-down models. Both complete and partial similarity is discussed. A systematic approach is proposed to design partially similar scaled-down models with totally different layup from those of the full-scale I-beam. Based on the results, the designed scaled-down I-beams using the proposed technique show very good accuracy in predicting the fundamental frequency of their prototype.
TL;DR: In this paper, a new design methodology is presented to optimize the natural frequencies of axially functionally graded beams and arches by tailoring appropriately their material distribution, where the objective function requires the solution of a free vibration problem of an arch with variable mass and stiffness properties.
09 Jul 2017
TL;DR: In this article, a multi-harmonic linearization method is used to model small-signal responses of two-level voltage source converters (VSC) in a vector form that allows all possible coupling effects to be captured, and the coupled response is shown to be at a frequency which is apart from the injected perturbation by two times the fundamental frequency and is most noticeable near the fundamental.
Abstract: Sequence impedance is a new tool for small-signal analysis and design of three-phase converters and systems, and has been proven effective especially for studying system resonance involving wind turbines, PV inverters and/or HVDC converters. As a small-signal characterization method, sequence impedance measures the response of current to a voltage perturbation at the same frequency. Under certain conditions, the current response at a frequency different from the frequency of the voltage perturbation may be significant and this has raised questions about whether sequence impedance analysis should be expanded to include such frequency-domain coupling in general. This paper is part of the effort to provide a practical answer to the question. A systematic method called multi-harmonic linearization is used to model small-signal responses of two-level voltage source converters (VSC) in a vector form that allows all possible coupling effects to be captured. Fast phase locked loop (PLL) design, and high dc bus impedance are identified as two common causes for possible coupling. A general small-signal model that takes into account both factors is developed and used to study the characteristics of coupling. Simplified models are then presented for two special cases each considering one of the factors to provide insights into how the degree of coupling depends on converter and circuit design. The coupled response is shown to be at a frequency which is apart from the injected perturbation by two times the fundamental frequency and is found to be most noticeable near the fundamental. The modeling and analysis results are validated by detailed circuit simulation.
TL;DR: Simulation and experimental results demonstrate the effectiveness of the proposed method to detect the BRB fault in inverter-fed IMs during a soft startup transient based on a non-uniform resampling algorithm.
Abstract: Fault detection in inverter-fed induction motors (IMs) is an actual industrial need. Many line-fed machines are being replaced by inverter-fed drives for improving control during startup and also for saving energy. Broken rotor bars (BRBs) in IMs is one of the most difficult faults to be detected, particularly when the motor is fed by an inverter in a soft startup. The difficulty of detecting BRBs is that the characteristic fault-related frequencies are very close to the fundamental frequency, and the amplitude of the fundamental is significantly higher than the fault-related frequency components. This paper proposes an effective method that allows the detection of the BRB fault in inverter-fed IMs during a soft startup transient based on a non-uniform resampling algorithm. The proposed algorithm transforms the nonstationary fundamental frequency into a stationary component by non-uniform resampling, whereas the fault-related components are considerably separated from the fundamental one, making easier to follow their evolution during the startup transient. Simulation and experimental results demonstrate the effectiveness of the proposed method to detect the fault.
TL;DR: The results show that the proposed algorithm can get more accurate phasor estimations than the previous work at most of the time with the cost of minor increase of computational power.
Abstract: When the power system is suffered from disturbances, such as unbalance, load variation, and fault occurrence, not only the phase and magnitude of the power signal will change but also the fundamental frequency can deviate away from the nominal one up to 5 Hz as per IEEE standard C37.118. As large frequency deviation will lead to great errors on Taylor approximation, the accuracy can be improved by expanding the dynamic characteristics in form of Taylor series near real fundamental frequency of supplied signals instead of nominal frequency (50/60 Hz). The corresponding coefficient against the different frequency estimations is applied to the dynamic phasor estimator to yield accurate synchrophasor estimation with the consideration of large frequency deviation. First, raw phasors attained by short time Fourier transform, are employed to provide the frequency estimation. Then, according to the frequency estimation, the coefficient matrix calculated off-line in form of lookup table is selected to calculate phasor estimation at the center of data window. Finally, a shift process is taken to give phasor estimation at report time. Simulated signals, PSCAD-generated signal, RTDS-generated data, and field data are employed to evaluate the performance of the proposed algorithm. The results show that the proposed algorithm can get more accurate phasor estimations than our previous work at most of the time with the cost of minor increase of computational power.
TL;DR: In this paper, a modulation strategy for multilevel multiphase diode-clamped dc-ac converters is proposed to keep the dc-link capacitor voltages balanced under passive front ends.
Abstract: This paper proposes a modulation strategy for multilevel multiphase diode-clamped dc–ac converters (also applicable to other functionally equivalent topologies) able to keep the dc-link capacitor voltages balanced under passive front ends, low frequency modulation indices (i.e., low number of switching transitions per fundamental cycle), any value of the amplitude modulation index, and any ac-side displacement power factor. A suitable phase voltage pattern with minimum number of switching transitions is presented for the n -level three-phase case. Subsequently, it is extended to higher number of switching transitions per fundamental cycle and to higher number of phases. Simulation results with three, four, and five levels; three and five phases; and several frequency-modulation-index values are presented to validate the proposed modulation strategy. Experimental results obtained with a four-level three-phase dc–ac converter prototype are also provided. The proposed modulation strategy enables the use of this type of converters in applications where the ac fundamental frequency may be close to the switching frequency, such as in high-power systems and variable-speed motor drives.
TL;DR: This study investigated the neural representation of pitch in human auditory cortex using model‐based encoding and decoding analyses of high field functional magnetic resonance imaging (fMRI) data collected while participants listened to a wide range of real‐life sounds.
TL;DR: The spectral and spatial dynamics of second harmonic generation in an all-optically poled multimode graded-index fiber and how this affects the spatial distribution of guided light for both colors is studied.
Abstract: We study experimentally and numerically the spectral and spatial dynamics of second harmonic generation in an all-optically poled multimode graded-index fiber. In contrast with poled single-mode fibers, in a multimode graded-index fiber a pump can generate a series of sharp sidebands around its second harmonic (SH) that originate from the sub-millimetric periodic evolution of the intensity at the fundamental frequency. The mutual interaction between the fundamental and its SH may also strongly affect the spatial distribution of guided light for both colors: when increasing the pump power, both fundamental and SH output beams evolve from disordered multimode speckles into two bell-shaped beams.
TL;DR: In this article, a narrowband active noise and vibration control (ANVC) algorithm with orthogonal pair-wise reference frequency regulator is proposed to compensate for the reference frequency mismatch (RFM) problem.
TL;DR: In this paper, the authors consider frequency comb generation in dispersive singly resonant second-harmonic-generation cavity systems and analyze comb generation, continuous wave bistability, and modulational instability.
Abstract: We consider frequency comb generation in dispersive singly resonant second-harmonic-generation cavity systems. Using a single temporal mean-field equation for the fundamental field that features a noninstantaneous nonlinear response function, we model the temporal and spectral dynamics and analyze comb generation, continuous wave bistability, and modulational instability. It is found that, owing to the significant temporal walk-off between the fundamental and second-harmonic fields, modulational instability can occur even in the complete absence of group-velocity dispersion. We further consider the relation of our model to a previously proposed modal expansion approach, and present a derivation of a general system of coupled mode equations. We show that the two models provide very similar predictions and become exactly equivalent in the limit that absorption losses and group-velocity dispersion at the fundamental frequency are neglected. Finally, we perform numerical simulations that show examples of the variety of comb states that are possible in phase-matched quadratic resonators, and discuss the dynamics of the comb formation process.
TL;DR: This is the first study that reports gender-specific behavior in switching FFRs across languages in bilingual speech, and cross-linguistic differences in FFR were found to be consistent across female bilinguals but random across male bilinguals.
Abstract: Purpose We investigated cross-linguistic differences in fundamental frequency range (FFR) in Welsh-English bilingual speech. This is the first study that reports gender-specific behavior in switchi...
TL;DR: In this article, the design and performance analysis of a harmonic planar transponder on paper, which conjugates compactness and scalability, are presented, targeted for a fundamental frequency of 1.2 GHz, is based on a frequency doubler with a single lumped component and a system of nested tapered annular slot antennas.
Abstract: In this letter, the design and performance analysis of a harmonic planar transponder on paper, which conjugates compactness and scalability, are presented. The tag, targeted for a fundamental frequency of 1.2 GHz, is based on a frequency doubler with a single lumped component (a low-barrier Schottky diode) and a system of nested tapered annular slot antennas. Both antennas, orthogonally placed, feature a maximum gain around 3 dBi. The frequency doubler is optimized for power levels in the order of −13 dBm, where it achieves a conversion loss of 15.7 dB. A complete prototype has been tested in a wireless indoor experiment, demonstrating a coverage of at least 4 m, insensitive to tag-to-reader rotations (transmitter effective isotropic radiated power 16 dBm).
01 Jun 2017
TL;DR: In this paper, a zero-power wireless crack sensor based on the harmonic radar principle is presented, which is targeted for a fundamental frequency f 0 = 2.45 GHz (ISM band) and consists of a system of two nested annular slots, a frequency doubler and a stub behaving as a bandstop filter.
Abstract: A novel zero-power wireless crack sensor based on the harmonic radar principle is presented. The tag, fabricated on a paper substrate by means of the copper adhesive tape technology, is targeted for a fundamental frequency f 0 =2.45 GHz (ISM band) and consists of a system of two nested annular slots, a frequency doubler and a stub behaving as a band-stop filter. In presence of a crack, the stub, placed at the input of the doubler, is torn off and an alarm is sent to the receiver. Such a system is suitable for scenarios which involve the detection of any crack increase in a massively distributed population of cracked wall sensors. A wireless experiment demonstrates an operating range of the sensor from 1 to 5 m for a transmitted power EIRP of 25 dBm.
TL;DR: In this article, an up-to-date rational superposition method in the symplectic space is used for free vibration of rectangular thick plates with an edge free and the others clamped.
TL;DR: The experiments demonstrate that replacing the mixture phase with the estimated clean spectral phase consistently improves perceptual speech quality, predicted speech intelligibility, and source separation performance across all signal-to-noise ratio and noise scenarios.
Abstract: Time-frequency masking is a common solution for the single-channel source separation (SCSS) problem where the goal is to find a time-frequency mask that separates the underlying sources from an observed mixture. An estimated mask is then applied to the mixed signal to extract the desired signal. During signal reconstruction, the time-frequency–masked spectral amplitude is combined with the mixture phase. This article considers the impact of replacing the mixture spectral phase with an estimated clean spectral phase combined with the estimated magnitude spectrum using a conventional model-based approach. As the proposed phase estimator requires estimated fundamental frequency of the underlying signal from the mixture, a robust pitch estimator is proposed. The upper-bound clean phase results show the potential of phase-aware processing in single-channel source separation. Also, the experiments demonstrate that replacing the mixture phase with the estimated clean spectral phase consistently improves perceptu...