Time–frequency analysis
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Second-Order Synchrosqueezing Transform or Invertible Reassignment? Towards Ideal Time-Frequency Representations Open
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High-Order Synchrosqueezing Transform for Multicomponent Signals Analysis—With an Application to Gravitational-Wave Signal Open
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Deep Learning Enabled Fault Diagnosis Using Time-Frequency Image Analysis of Rolling Element Bearings Open
Traditional feature extraction and selection is a labor-intensive process requiring expert knowledge of the relevant features pertinent to the system. This knowledge is sometimes a luxury and could introduce added uncertainty and bias to t…
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Channel Estimation for Orthogonal Time Frequency Space (OTFS) Massive MIMO Open
Orthogonal time frequency space (OTFS) modulation outperforms orthogonal\nfrequency division multiplexing (OFDM) in high-mobility scenarios. One\nchallenge for OTFS massive MIMO is downlink channel estimation due to the large\nnumber of ba…
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Low Complexity Modem Structure for OFDM-based Orthogonal Time Frequency Space Modulation Open
Orthogonal time frequency space (OTFS) modulation is a 2-D signaling technique that has recently emerged in the literature to tackle the time-varying (TV) wireless channels. OTFS deploys the Doppler-delay plane to multiplex the transmit da…
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A Deep Learning Method for Bearing Fault Diagnosis Based on Time-Frequency Image Open
Rolling element bearing is a critical component in rotating machinery that reduces the friction between moving pairs. Bearing fault diagnosis is always considered as a research hotspot in the field of prognostics and health management, esp…
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ConceFT: concentration of frequency and time via a multitapered synchrosqueezed transform Open
A new method is proposed to determine the time–frequency content of time-dependent signals consisting of multiple oscillatory components, with time-varying amplitudes and instantaneous frequencies. Numerical experiments as well as a theore…
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Adaptive Mode Decomposition Methods and Their Applications in Signal Analysis for Machinery Fault Diagnosis: A Review With Examples Open
Effective signal processing methods are essential for machinery fault diagnosis. Most conventional signal processing methods lack adaptability, thus being unable to well extract the embedded meaningful information. Adaptive mode decomposit…
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Radar‐based fall detection based on Doppler time–frequency signatures for assisted living Open
Falls are a major public health concern and main causes of accidental death in the senior U.S. population. Timely and accurate detection permit immediate assistance after a fall and, thereby, reduces complications of fall risk. Radar techn…
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Compressing Green's function using intermediate representation between imaginary-time and real-frequency domains Open
New model-independent compact representations of imaginary-time data are\npresented in terms of the intermediate representation (IR) of analytical\ncontinuation. This is motivated by a recent numerical finding by the authors\n[J. Otsuki et…
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Detection of epileptiform activity in EEG signals based on time-frequency and non-linear analysis Open
We present a new technique for detection of epileptiform activity in EEG signals. After preprocessing of EEG signals we extract representative features in time, frequency and time-frequency domain as well as using non-linear analysis. The …
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On Demodulation, Ridge Detection, and Synchrosqueezing for Multicomponent Signals Open
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Motor Imagery EEG Signals Classification Based on Mode Amplitude and Frequency Components Using Empirical Wavelet Transform Open
As one of the key techniques determining the overall system performances, efficient and reliable algorithms for improving the classification accuracy of motor imagery (MI) based electroencephalography (EEG) signals are highly desired for t…
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Frequency Diverse Coprime Arrays With Coprime Frequency Offsets for Multitarget Localization Open
Different from conventional phased-array radars, the frequency diverse array (FDA) radar offers a range-dependent beampattern capability that is attractive in various applications. The spatial and range resolutions of an FDA radar are fund…
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Rotating Machinery Fault Diagnosis Under Time-Varying Speeds: A Review Open
Rotating machinery often works under time-varying speeds, and nonstationary conditions as well as harsh environments make its key parts, such as rolling bearings and gears, prone to faults. Therefore, a number of fault diagnosis methods in…
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Multiple-Time-Scales Hierarchical Frequency Stability Control Strategy of Medium-Voltage Isolated Microgrid Open
In this paper, an islanded medium-voltage (MV) microgrid placed in Dongao Island is presented, which integrates renewable-energy-based distributed generations (DGs), energy storage system (ESS), and local loads. In an isolated microgrid wi…
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The Sliding Singular Spectrum Analysis: A Data-Driven Nonstationary Signal Decomposition Tool Open
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Short-Frequency Fourier Transform for Fault Diagnosis of Induction Machines Working in Transient Regime Open
[EN] Transient-based methods for fault diagnosis of induction machines (IMs) are attracting a rising interest, due to their reliability and ability to adapt to a wide range of IM's working conditions. These methods compute the time-frequen…
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A time–frequency analysis approach for condition monitoring of a wind turbine gearbox under varying load conditions Open
This paper deals with the condition monitoring of wind turbine gearboxes under varying operating conditions. Generally, gearbox systems include nonlinearities so a simplified nonlinear gear model is developed, on which the time–frequency a…
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An Effective Dual Self-Attention Residual Network for Seizure Prediction Open
As one of the most challenging data analysis tasks in chronic brain diseases, epileptic seizure prediction has attracted extensive attention from many researchers. Seizure prediction, can greatly improve patients' quality of life in many w…
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Self-Supervised Contrastive Pre-Training For Time Series via Time-Frequency Consistency Open
Pre-training on time series poses a unique challenge due to the potential mismatch between pre-training and target domains, such as shifts in temporal dynamics, fast-evolving trends, and long-range and short-cyclic effects, which can lead …
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Frequency and Time-Frequency Analysis of Cutting Force and Vibration Signals for Tool Condition Monitoring Open
Tool condition monitoring systems are essential in micromilling applications. A tool's slenderness requires high-precision monitoring systems for online measurements. In most cases, tool health is indirectly estimated by processing and ana…
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STFT spectrogram based hybrid evaluation method for rotating machine transient vibration analysis Open
The main purpose of this paper is to represent a methodenabling vibration components to be extracted from a high-resolution Short-Time Fourier-Transformation (STFT) based spectrogram assessed as an image to support transient analysis on ro…
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EEG-Based Emotion Recognition Using Quadratic Time-Frequency Distribution Open
Accurate recognition and understating of human emotions is an essential skill that can improve the collaboration between humans and machines. In this vein, electroencephalogram (EEG)-based emotion recognition is considered an active resear…
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Fault Analysis of Wind Power Rolling Bearing Based on EMD Feature Extraction Open
In a wind turbine, the rolling bearing is the critical component. However, it has a high failure rate. Therefore, the failure analysis and fault diagnosis of wind power rolling bearings are very important to ensure the high reliability and…
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Time-Frequency Strategies for Increasing High-Frequency Oscillation Detectability in Intracerebral EEG Open
The H 0 z-score provides an optimal framework for representing and detecting HFOs, independent of a baseline and a priori frequency bands.
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Structure-Aware Bayesian Compressive Sensing for Frequency-Hopping Spectrum Estimation With Missing Observations Open
In this paper, we address the problem of spectrum estimation of multiple\nfrequency-hopping (FH) signals in the presence of random missing observations.\nThe signals are analyzed within the bilinear time-frequency (TF) representation\nfram…
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Chirp Rate and Instantaneous Frequency Estimation: Application to Recursive Vertical Synchrosqueezing Open
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Comparative Analysis of Wavelet Transform for Time-Frequency Analysis and Transient Localization in Structural Health Monitoring Open
A critical problem facing data collection in structural health monitoring, for instance via sensor networks, is how to extract the main components and useful features for damage detection. A structural dynamic measurement is more often a c…
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Learning of Time-Frequency Attention Mechanism for Automatic Modulation Recognition Open
Recent learning-based image classification and speech recognition approaches\nmake extensive use of attention mechanisms to achieve state-of-the-art\nrecognition power, which demonstrates the effectiveness of attention\nmechanisms. Motivat…