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14,643 Results Found

  • Article
  • Open Access
8 Citations
3,171 Views
31 Pages

30 April 2025

With the widespread application of machine learning techniques in time series analysis, the interpretability of models trained on time series data has attracted increasing attention. Most existing explanation methods are based on time-domain features...

(This article belongs to the Section Intelligent Sensors)
  • Article
  • Open Access
51 Citations
8,558 Views
23 Pages

21 April 2015

In this paper, an improved joint time-frequency (TF) analysis method based on a reassigned smoothed pseudo Wigner–Ville distribution (RSPWVD) has been proposed in interference detection for Global Navigation Satellite System (GNSS) receivers. In the...

(This article belongs to the Section Physical Sensors)
  • Article
  • Open Access
24 Citations
7,982 Views
19 Pages

16 June 2016

Traditional artillery guidance can significantly improve the attack accuracy and overall combat efficiency of projectiles, which makes it more adaptable to the information warfare of the future. Obviously, the accurate measurement of artillery spin r...

(This article belongs to the Special Issue Giant Magnetoresistive Sensors)
  • Article
  • Open Access
5 Citations
1,914 Views
17 Pages

21 March 2025

Rapid multi-sensor fault detection is crucial for the battery management system (BMS). Almost all the existing fault diagnosis methods for current sensors are model-based, and the complexity of the models poses a huge challenge to their application i...

(This article belongs to the Special Issue Modeling, Design, Optimization and Maintenance of Intelligent Manufacturing Towards Industry 5.0)
  • Article
  • Open Access
12 Citations
2,870 Views
15 Pages

A Time–Frequency Domain Analysis Method for Variable Frequency Hopping Signal

  • Zhengzhi Zeng,
  • Chunshan Jiang,
  • Yuanming Zhou and
  • Tianwei Zhou

5 October 2024

A variable frequency hopping (VFH) signal is a kind of frequency hopping (FH) signal that varies both in frequency and dwell time. However, in radio surveillance, the existing methods for unidentified signals using VFH cannot be effectively handled....

(This article belongs to the Section Electronic Sensors)
  • Article
  • Open Access
4 Citations
1,782 Views
14 Pages

A Time–Frequency Image Quality Evaluation Method Based on Improved LIME

  • Yihao Bai,
  • Weidong Cheng,
  • Weigang Wen and
  • Yang Liu

29 March 2024

Deep learning has the characteristics of high efficiency, high accuracy and low knowledge dependence, and has become a hot method in the research field of rotating machinery fault diagnosis. The time–frequency transform can show both the time a...

  • Article
  • Open Access
5 Citations
3,222 Views
18 Pages

A Novel Time–Frequency Parameterization Method for Oscillations in Specific Frequency Bands and Its Application on OPM-MEG

  • Xiaoyu Liang,
  • Ruonan Wang,
  • Huanqi Wu,
  • Yuyu Ma and ,
  • Changzeng Liu,
  • Yang Gao,
  • Dexin Yu and
  • Xiaolin Ning
  • + 3 authors+ 0 author

Time–frequency parameterization for oscillations in specific frequency bands reflects the dynamic changes in the brain. It is related to cognitive behavior and diseases and has received significant attention in neuroscience. However, many studi...

(This article belongs to the Section Biosignal Processing)
  • Article
  • Open Access
661 Views
22 Pages

The frequency identification technology of differential frequency-hopping (DFH) signals is the key to decoding at the receiver. Aiming to improve frequency identification accuracy under low signal-to-noise ratio (SNR) conditions, a method based on su...

(This article belongs to the Section Microwave and Wireless Communications)
  • Article
  • Open Access
12 Citations
5,575 Views
17 Pages

22 February 2019

Traditional correlation analysis is analyzed separately in the time domain or the frequency domain, which cannot reflect the time-varying and frequency-varying characteristics of non-stationary signals. Therefore, a time–frequency (TF) correlat...

  • Article
  • Open Access
2 Citations
1,281 Views
24 Pages

A Detection Method for Frequency-Hopping Signals in Complex Environments Using Time–Frequency Cancellation and the Hough Transform

  • Huan Wang,
  • Lian Yang,
  • Jie Bin,
  • Chunyan Gou and ,
  • Baolin Hou and
  • Mingwei Qin
  • + 1 author+ 0 author

Frequency-hopping (FH) communication is widely employed in modern wireless communication systems due to its strong resistance to interference. Accurate detection of FH signals is therefore essential for effective spectrum monitoring and reliable comm...

  • Article
  • Open Access
28 Citations
6,060 Views
12 Pages

26 July 2017

Oil and gas reservoirs can cause increased attenuation of seismic waves, which can be revealed by time-frequency analysis for direct detection of hydrocarbons. In this paper, a new method applying the empirical wavelet transform (EWT) in association...

  • Article
  • Open Access
17 Citations
5,685 Views
20 Pages

A Fast and Robust Spectrogram Reassignment Method

  • Vittoria Bruni,
  • Michela Tartaglione and
  • Domenico Vitulano

19 April 2019

The improvement of the readability of time-frequency transforms is an important topic in the field of fast-oscillating signal processing. The reassignment method is often used due to its adaptivity to different transforms and nice formal properties....

  • Article
  • Open Access
14 Citations
5,986 Views
13 Pages

A Sound Source Localization Method Based on Frequency Divider and Time Difference of Arrival

  • Jianchun Zhao,
  • Guangyue Zhang,
  • Jierui Qu,
  • Jiayi Chen and ,
  • Shuang Liang,
  • Kaiqiang Wei and
  • Guan Wang
  • + 2 authors+ 0 author

18 May 2023

In recent years, sound source localization, as a passive localization technique with higher safety and convenience compared with other localization techniques such as active emission of electromagnetic waves, has received more and more attention in a...

  • Article
  • Open Access
1 Citations
1,874 Views
20 Pages

7 July 2025

Azimuth ambiguity caused by spectral aliasing severely degrades the quality of Synthetic Aperture Radar (SAR) images. To suppress azimuth ambiguity while preserving image details as much as possible, this paper proposes an azimuth ambiguity suppressi...

(This article belongs to the Special Issue Efficient Object Detection Based on Remote Sensing Images)
  • Article
  • Open Access
12 Citations
3,048 Views
16 Pages

23 February 2024

In response to the limitations posed by noise interference in complex environments and the narrow focus of existing diagnosis methods for jointless track circuit faults, an innovative approach is put forward in this study. It involves the application...

(This article belongs to the Special Issue Power System Protection and Fault Location Technologies in Smart Grid Systems)
  • Article
  • Open Access
2 Citations
2,017 Views
14 Pages

As a generalization of the short-time Fourier transform (STFT), the novel short-time fractional Fourier transform (NSTFRFT) has been introduced recently. In order to improve the concentration of the time–frequency representation (TFR) generated...

  • Article
  • Open Access
7 Citations
4,196 Views
25 Pages

8 February 2021

Spectrum analysis (SA) plays an important role in radar signal processing, especially in radar imaging algorithm design. Because it is usually hard to obtain the analytical expression of spectrum by the Fourier integral directly, principle of station...

(This article belongs to the Section Remote Sensing Image Processing)
  • Article
  • Open Access
5 Citations
1,394 Views
19 Pages

TF-Denoiser: A Time-Frequency Domain Joint Method for EEG Artifact Removal

  • Yinghui Meng,
  • Changxiang Yuan,
  • Wen Feng,
  • Duan Li and ,
  • Jiaofen Nan,
  • Yongquan Xia,
  • Fubao Zhu and
  • Jiaoshuai Song
  • + 3 authors+ 0 author

27 December 2025

Electroencephalography (EEG) signal acquisition is often affected by artifacts, challenging applications such as brain disease diagnosis and Brain-Computer Interfaces (BCIs). This paper proposes TF-Denoiser, a deep learning model using a joint time-f...

(This article belongs to the Section Bioelectronics)
  • Article
  • Open Access
18 Citations
7,851 Views
18 Pages

2 March 2016

To more completely extract useful features from low frequency oscillation (LFO) signals, a time-frequency analysis method using resonance-based sparse signal decomposition (RSSD) and a frequency slice wavelet transform (FSWT) is proposed. FSWT can cu...

(This article belongs to the Special Issue Electric Power Systems Research)
  • Article
  • Open Access
10 Citations
3,063 Views
17 Pages

20 March 2025

To improve the accuracy and robustness of bearing remaining useful life (RUL) prediction, this paper proposes a bearing RUL prediction method based on PELT state segmentation and time–frequency analysis, incorporating the Informer model for tim...

(This article belongs to the Section Physical Sensors)
  • Article
  • Open Access
1,666 Views
20 Pages

The acoustic signals of the drill pipe of a seafloor drill present weak features under noise interference such as marine environmental noise and the mechanical vibration of the seafloor drill. Accurately extracting the features of the weak acoustic s...

(This article belongs to the Section Ocean Engineering)
  • Article
  • Open Access
3 Citations
1,754 Views
17 Pages

27 September 2024

This paper presents a fault diagnosis method for a vacuum contactor using the generalized Stockwell transform (GST) of vibration signals. The objective is to solve the problem of low diagnostic performance efficiency caused by the inadequate feature...

(This article belongs to the Special Issue Reliability Verification and Diagnosis Methods for Mechanical Equipment)
  • Article
  • Open Access
3 Citations
1,933 Views
17 Pages

12 January 2023

This paper mainly studied the analytical solutions of three types of Van der Pol-Duffing equations. For a system with parametric excitation frequency, we knew that the ordinary homotopy analysis method would be unable to find the analytical solution....

(This article belongs to the Special Issue Modeling and Analysis in Dynamical Systems and Bistability)
  • Article
  • Open Access
5 Citations
4,546 Views
12 Pages

15 October 2018

Time-frequency analysis is usually used to reveal the appearance of different frequency components varying with time, in signals, of which time-frequency spectrogram is an important visual tool to display the information. The Mesh Surface Generation...

(This article belongs to the Special Issue Fault Detection and Diagnosis in Mechatronics Systems)
  • Article
  • Open Access
13 Citations
3,369 Views
24 Pages

31 July 2022

An integrated energy system (IES) is vulnerable to network attacks due to the coupling features of multi-energy systems, as well as the deep integration between a physical system and an information system. The anomaly detection of the time-series dat...

(This article belongs to the Section A1: Smart Grids and Microgrids)
  • Article
  • Open Access
17 Citations
6,140 Views
36 Pages

21 May 2024

Radio frequency interference (RFI) significantly hampers the target detection performance of frequency-modulated continuous-wave radar. To address the problem and maintain the target echo signal, this paper proposes a priori assumption on the interfe...

(This article belongs to the Section Radar Sensors)
  • Article
  • Open Access
1 Citations
1,222 Views
15 Pages

3 July 2025

P-wave first-motion polarity is a critical parameter for determining earthquake focal mechanisms. Extracting relative P-wave arrival times and polarity information using waveform cross-correlation techniques can enhance the accuracy of earthquake loc...

(This article belongs to the Special Issue Automatic Detection of Seismic Signals—Second Edition)
  • Article
  • Open Access
668 Views
24 Pages

2 June 2026

To provide a ground-based experimental reference for free-space optical time–frequency synchronization in future space applications, this paper investigates the impact of beam drift and dynamic link-state variations on free-space laser links. A...

(This article belongs to the Special Issue Cutting-Edge Developments in Optical Communications, Perception and Computing)
  • Article
  • Open Access
400 Views
25 Pages

3 October 2026

Accurate extraction of temperature-induced structural responses from bridge monitoring data is the core prerequisite for constructing a more precise regression model linking the temperature field to temperature-induced responses, whose outputs can pr...

(This article belongs to the Special Issue Smart and Automated Technologies for Lifecycle Management of Built Assets)
  • Article
  • Open Access
1 Citations
634 Views
26 Pages

Deep learning-based methods have achieved promising results in planetary gearbox fault diagnosis. However, complex vibration signals often contain redundant information and disturbance-related responses, and varying operating conditions can cause dis...

(This article belongs to the Special Issue Intelligent Predictive Maintenance and Machine Condition Monitoring)
  • Article
  • Open Access
1 Citations
838 Views
21 Pages

A Novel Bearing Fault Diagnosis Method with Wavelet Packet Decomposition Time-Frequency Feature Enhancement

  • Dengfeng Zhao,
  • Chaoyang Tian,
  • Zhijun Fu,
  • Kaixin Huang and ,
  • Shesen Dong,
  • Jinquan Ding,
  • Junjian Hou and
  • Chaohui Liu
  • + 3 authors+ 0 author

Accurate bearing fault diagnosis in electric drive systems is crucial for ensuring the safety and reliability of new energy vehicles. Aiming at the problem of inaccurate bearing fault diagnosis caused by the failure to fully utilize the time-frequenc...

(This article belongs to the Section Vehicle Control and Management)
  • Article
  • Open Access
5 Citations
3,573 Views
18 Pages

15 December 2022

Power systems have an increasing demand for operational condition monitoring and safety control aspects. Low-frequency oscillation mode identification is one of the keys to maintain the safe and stable operation of power systems. To address the probl...

(This article belongs to the Special Issue Artificial Intelligence Applications in Power and Energy Systems)
  • Article
  • Open Access
8 Citations
3,057 Views
16 Pages

Proposal and Experimental Study on a Diagnosis Method for Hermetic Refrigeration Compressor Using Dual Time-Frequency Image Fusion

  • Kang Li,
  • Zhe Sun,
  • Huaqiang Jin,
  • Yingjie Xu and ,
  • Jiangping Gu,
  • Yuejin Huang,
  • Qinjian Zhang and
  • Xi Shen
  • + 3 authors+ 0 author

16 March 2022

The hermetic refrigeration compressor is the core component of the refrigeration system, failure of which will cause energy waste and reduce service life. Fault diagnosis based on vibration signal is a research hotspot. However, it is challenging to...

(This article belongs to the Special Issue Refrigeration and Heat Dissipation: Refrigeration System, Low-GWP Refrigerants, and Cooling Technology for High Heat Flux Space)
  • Article
  • Open Access
591 Views
22 Pages

Deep Time–Frequency Residual Neural Network Method for Bearing Fault Diagnosis Under Constantly Speed Changing

  • Shunming Li,
  • Wenbei Shi,
  • Jianfen Zhang,
  • Jun Zhang and ,
  • Haibo Zhang and
  • Jiantao Lu
  • + 1 author+ 0 author

Identifying a consistent diagnostic approach for bearing faults in the same mechanical equipment operating under continuously varying rotational speeds remains a critical challenge. In this study, a time–frequency residual neural network method...

  • Article
  • Open Access
10 Citations
4,162 Views
14 Pages

25 April 2019

In this paper, a joint method combining Hough transform and reassigned smoothed pseudo Wigner-Ville distribution (RSPWVD) is presented to detect time-varying interferences with crossed frequency for a Global Navigation Satellite System (GNSS) receive...

(This article belongs to the Section Remote Sensors)
  • Article
  • Open Access
2 Citations
2,748 Views
15 Pages

30 March 2022

In practice, the modeling and analysis of nonlinear rotor-bearing systems are difficult due to the nonlinearity and complexity. In the previous studies, finite element simulation and mathematical modeling methods are mostly adopted to conduct the ana...

  • Article
  • Open Access
1,019 Views
41 Pages

A Three-Branch Time-Frequency Feature Fusion Method Based on Terahertz Signals for Identifying Delamination Defects in Composite Materials

  • Shengkai Yan,
  • Jianguo Gao,
  • Qiang Wang,
  • Qiuhan Liu and ,
  • Jiayang Yu,
  • Jiajin Li and
  • Gaocheng Chen
  • + 2 authors+ 0 author

15 April 2026

Composite materials are critical components in advanced equipment such as aerospace, however, delamination defects that readily arise during manufacturing and in service present serious risks to equipment safety. Terahertz non-destructive testing is...

(This article belongs to the Section Fault Diagnosis & Sensors)
  • Article
  • Open Access
4 Citations
2,542 Views
16 Pages

16 October 2023

The underground pressure disaster caused by the exploitation of deep mineral resources has become a major hidden danger restricting the safe production of mines. Microseismic monitoring technology is a universally recognized means of underground pres...

(This article belongs to the Special Issue Statistical Methods for Earthquake Hazard Assessment and Risk Analysis)
  • Article
  • Open Access
4 Citations
947 Views
21 Pages

6 March 2026

To address the challenges of insufficient transformer winding fault samples and the effective fusion of heterogeneous multi-source data, this study proposes an intelligent fault diagnosis method based on a time–frequency diffusion model and Con...

(This article belongs to the Section Electrical, Electronics and Communications Engineering)
  • Article
  • Open Access
2 Citations
793 Views
27 Pages

29 September 2025

In this paper, a full-domain stochastic response analysis is performed based on the meshless method to reveal the time–frequency dynamic characteristics, including the power spectral density (PSD) responses in the frequency domain and the evolv...

(This article belongs to the Section Aeronautics)
  • Article
  • Open Access
14 Citations
4,213 Views
23 Pages

A Time-Frequency Joint Time-Delay Difference Estimation Method for Signal Enhancement in the Distorted towed Hydrophone Array

  • Chuanqi Zhu,
  • Shiliang Fang,
  • Qisong Wu,
  • Liang An and ,
  • Xinwei Luo and
  • Hongli Cao
  • + 1 author+ 0 author

15 November 2021

To acquire the enhanced underwater ship-radiated noise signal in the presence of array shape distortion in a passive sonar system, the phase difference of the line-spectrum component in ship-radiated noise is often exploited to estimate the time-dela...

  • Article
  • Open Access
2 Citations
1,917 Views
17 Pages

Machine Learning Use Cases in the Frequency Symbolic Method of Linear Periodically Time-Variable Circuits Analysis

  • Yuriy Shapovalov,
  • Spartak Mankovskyy,
  • Dariya Bachyk,
  • Anna Piwowar and ,
  • Łukasz Chruszczyk and
  • Damian Grzechca
  • + 1 author+ 0 author

5 September 2024

This manuscript presents an analysis of machine learning (ML) usage in the Frequency Symbolic Method (FSM) to enhance the diagnosis of faults in parametric circuit analysis and optimization, with a particular focus on Linear Periodically Time-Variabl...

(This article belongs to the Special Issue Artificial Intelligence in Fault Diagnosis and Signal Processing)
  • Article
  • Open Access
10 Citations
4,255 Views
29 Pages

11 May 2023

Instantaneous frequency (IF) is commonly used in the analysis of electroencephalogram (EEG) signals to detect oscillatory-type seizures. However, IF cannot be used to analyze seizures that appear as spikes. In this paper, we present a novel method fo...

(This article belongs to the Special Issue EEG Signal Processing Techniques and Applications—2nd Edition)
  • Article
  • Open Access
7 Citations
2,638 Views
12 Pages

Post-Earthquake Damage Identification of Buildings with LMSST

  • Roshan Kumar,
  • Vikash Singh and
  • Mohamed Ismail

The structure is said to be damaged if there is a permanent shift in the post-event natural frequency of a structure as compared with the pre-event frequency. To assess the damage to the structure, a time-frequency approach that can capture the pre-e...

(This article belongs to the Section Building Structures)
  • Article
  • Open Access
1 Citations
1,412 Views
23 Pages

Cascaded Detection Method for Ship Targets Using High-Frequency Surface Wave Radar in the Time–Frequency Domain

  • Zhiqing Yang,
  • Hao Zhou,
  • Yingwei Tian,
  • Gan Liu and ,
  • Bing Zhang,
  • Yao Qin,
  • Peng Li and
  • Weimin Huang
  • + 3 authors+ 0 author

24 July 2025

Compact high-frequency surface wave radars (HFSWRs) utilize miniaturized antennas, resulting in lower antenna gain and a reduced signal-to-noise ratio (SNR) for target echoes. Due to noise interference, ship echoes in the noise region often fall belo...

  • Article
  • Open Access
9 Citations
2,815 Views
19 Pages

1 December 2022

An artificial-intelligence (AI)-based method for fault diagnosis is a strong candidate for industrial applications in the health management of rolling bearings. However, traditional fault diagnosis methods fail to improve the detection accuracy becau...

  • Article
  • Open Access
1,031 Views
15 Pages

A Time–Frequency Fusion GAN-Based Method for Power System Oscillation Risk Scenario Generation

  • Bo Zhou,
  • Yunyang Xu,
  • Xinwei Sun,
  • Xi Wang and ,
  • Baohong Li and
  • Congkai Huang
  • + 1 author+ 0 author

With the large-scale integration of renewable energy and the increasing use of power electronics, the issue of wide-band oscillations in power grids has become increasingly prominent. The scarcity and uneven distribution of oscillation samples pose s...

  • Article
  • Open Access
48 Citations
6,008 Views
17 Pages

25 July 2019

Accurate and timely misfire fault diagnosis is of vital significance for diesel engines. However, existing algorithms are prone to fall into model over-fitting and adopt low energy-concentrated features. This paper presents a novel extreme gradient b...

(This article belongs to the Special Issue Advanced Signal Processing in Intelligent Systems for Health Monitoring)
  • Article
  • Open Access
397 Citations
27,839 Views
27 Pages

Deep PPG: Large-Scale Heart Rate Estimation with Convolutional Neural Networks

  • Attila Reiss,
  • Ina Indlekofer,
  • Philip Schmidt and
  • Kristof Van Laerhoven

12 July 2019

Photoplethysmography (PPG)-based continuous heart rate monitoring is essential in a number of domains, e.g., for healthcare or fitness applications. Recently, methods based on time-frequency spectra emerged to address the challenges of motion artefac...

(This article belongs to the Section Intelligent Sensors)
  • Article
  • Open Access
507 Views
24 Pages

An Acoustic Fault Diagnosis Method for Oil and Gas Pipelines Based on Time–Frequency Diagrams and Parallel CNN-GRU

  • Yang Peng,
  • Shaomu Wen,
  • Yongbo Wang,
  • Kedu Ma and ,
  • Qin Bie and
  • Wei He
  • + 1 author+ 0 author

27 July 2026

Oil and gas pipelines are the core infrastructure of energy transportation, and their safe operation is crucial to national energy security. Aiming at the difficulty of feature extraction and insufficient diagnosis accuracy of pipeline acoustic fault...

(This article belongs to the Special Issue Condition Monitoring and Fault Diagnosis)

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