627 research outputs found
Serial-EMD: Fast Empirical Mode Decomposition Method for Multi-dimensional Signals Based on Serialization
Empirical mode decomposition (EMD) has developed into a prominent tool for adaptive, scale-based signal analysis in various fields like robotics, security and biomedical engineering. Since the dramatic increase in amount of data puts forward higher requirements for the capability of real-time signal analysis, it is difficult for existing EMD and its variants to trade off the growth of data dimension and the speed of signal analysis. In order to decompose multi-dimensional signals at a faster speed, we present a novel signal-serialization method (serial-EMD), which concatenates multi-variate or multi-dimensional signals into a one-dimensional signal and uses various one-dimensional EMD algorithms to decompose it. To verify the effects of the proposed method, synthetic multi-variate time series, artificial 2D images with various textures and real-world facial images are tested. Compared with existing multi-EMD algorithms, the decomposition time becomes significantly reduced. In addition, the results of facial recognition with Intrinsic Mode Functions (IMFs) extracted using our method can achieve a higher accuracy than those obtained by existing multi-EMD algorithms, which demonstrates the superior performance of our method in terms of the quality of IMFs. Furthermore, this method can provide a new perspective to optimize the existing EMD algorithms, that is, transforming the structure of the input signal rather than being constrained by developing envelope computation techniques or signal decomposition methods. In summary, the study suggests that the serial-EMD technique is a highly competitive and fast alternative for multi-dimensional signal analysis.Fil: Zhang, Jin. Nankai University; ChinaFil: Feng, Fan. Nankai University; ChinaFil: Marti Puig, Pere. Central University of Catalonia; EspañaFil: Caiafa, César Federico. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Sun, Zhe. RIKEN; JapónFil: Duan, Feng. Nankai University; ChinaFil: Sole Casals, Jordi. Central University of Catalonia; Españ
Advancements in Arc Fault Detection for Electrical Distribution Systems: A Comprehensive Review from Artificial Intelligence Perspective
This comprehensive review paper provides a thorough examination of current
advancements and research in the field of arc fault detection for electrical
distribution systems. The increasing demand for electricity, coupled with the
increasing utilization of renewable energy sources, has necessitated vigilance
in safeguarding electrical distribution systems against arc faults. Such faults
could lead to catastrophic accidents, including fires, equipment damage, loss
of human life, and other critical issues. To mitigate these risks, this review
article focuses on the identification and early detection of arc faults, with a
particular emphasis on the vital role of artificial intelligence (AI) in the
detection and prediction of arc faults. The paper explores a wide range of
methodologies for arc fault detection and highlights the superior performance
of AI-based methods in accurately identifying arc faults when compared to other
approaches. A thorough evaluation of existing methodologies is conducted by
categorizing them into distinct groups, which provides a structured framework
for understanding the current state of arc fault detection techniques. This
categorization serves as a foundation for identifying the existing constraints
and future research avenues in the domain of arc fault detection for electrical
distribution systems. This review paper provides the state of the art in arc
fault detection, aiming to enhance safety and reliability in electrical
distribution systems and guide future research efforts
Advanced Fault Diagnosis and Health Monitoring Techniques for Complex Engineering Systems
Over the last few decades, the field of fault diagnostics and structural health management has been experiencing rapid developments. The reliability, availability, and safety of engineering systems can be significantly improved by implementing multifaceted strategies of in situ diagnostics and prognostics. With the development of intelligence algorithms, smart sensors, and advanced data collection and modeling techniques, this challenging research area has been receiving ever-increasing attention in both fundamental research and engineering applications. This has been strongly supported by the extensive applications ranging from aerospace, automotive, transport, manufacturing, and processing industries to defense and infrastructure industries
EEG-based Brain-Computer Interfaces (BCIs): A Survey of Recent Studies on Signal Sensing Technologies and Computational Intelligence Approaches and Their Applications.
Brain-Computer interfaces (BCIs) enhance the capability of human brain activities to interact with the environment. Recent advancements in technology and machine learning algorithms have increased interest in electroencephalographic (EEG)-based BCI applications. EEG-based intelligent BCI systems can facilitate continuous monitoring of fluctuations in human cognitive states under monotonous tasks, which is both beneficial for people in need of healthcare support and general researchers in different domain areas. In this review, we survey the recent literature on EEG signal sensing technologies and computational intelligence approaches in BCI applications, compensating for the gaps in the systematic summary of the past five years. Specifically, we first review the current status of BCI and signal sensing technologies for collecting reliable EEG signals. Then, we demonstrate state-of-the-art computational intelligence techniques, including fuzzy models and transfer learning in machine learning and deep learning algorithms, to detect, monitor, and maintain human cognitive states and task performance in prevalent applications. Finally, we present a couple of innovative BCI-inspired healthcare applications and discuss future research directions in EEG-based BCI research
Innovative Wireless Localization Techniques and Applications
Innovative methodologies for the wireless localization of users and related applications
are addressed in this thesis.
In last years, the widespread diffusion of pervasive wireless communication
(e.g., Wi-Fi) and global localization services (e.g., GPS) has boosted the interest
and the research on location information and services. Location-aware
applications are becoming fundamental to a growing number of consumers (e.g.,
navigation, advertising, seamless user interaction with smart places), private and
public institutions in the fields of energy efficiency, security, safety,
fleet management, emergency response. In this context, the position of the user - where
is often more valuable for deploying services of interest than the identity of the
user itself - who.
In detail, opportunistic approaches based on the analysis of electromagnetic
field indicators (i.e., received signal strength and channel state information) for
the presence detection, the localization, the tracking and the posture recognition
of cooperative and non-cooperative (device-free) users in indoor environments are
proposed and validated in real world test sites. The methodologies are designed
to exploit existing wireless infrastructures and commodity devices without any
hardware modification.
In outdoor environments, global positioning technologies are already available
in commodity devices and vehicles, the research and knowledge transfer
activities are actually focused on the design and validation of algorithms and
systems devoted to support decision makers and operators for increasing efficiency,
operations security, and management of large fleets as well as localized
sensed information in order to gain situation awareness. In this field, a decision
support system for emergency response and Civil Defense assets management
(i.e., personnel and vehicles equipped with TETRA mobile radio) is described in
terms of architecture and results of two-years of experimental validation
Motion Artifacts Correction from Single-Channel EEG and fNIRS Signals using Novel Wavelet Packet Decomposition in Combination with Canonical Correlation Analysis
The electroencephalogram (EEG) and functional near-infrared spectroscopy
(fNIRS) signals, highly non-stationary in nature, greatly suffers from motion
artifacts while recorded using wearable sensors. This paper proposes two robust
methods: i) Wavelet packet decomposition (WPD), and ii) WPD in combination with
canonical correlation analysis (WPD-CCA), for motion artifact correction from
single-channel EEG and fNIRS signals. The efficacy of these proposed techniques
is tested using a benchmark dataset and the performance of the proposed methods
is measured using two well-established performance matrices: i) Difference in
the signal to noise ratio ({\Delta}SNR) and ii) Percentage reduction in motion
artifacts ({\eta}). The proposed WPD-based single-stage motion artifacts
correction technique produces the highest average {\Delta}SNR (29.44 dB) when
db2 wavelet packet is incorporated whereas the greatest average {\eta} (53.48%)
is obtained using db1 wavelet packet for all the available 23 EEG recordings.
Our proposed two-stage motion artifacts correction technique i.e. the WPD-CCA
method utilizing db1 wavelet packet has shown the best denoising performance
producing an average {\Delta}SNR and {\eta} values of 30.76 dB and 59.51%,
respectively for all the EEG recordings. On the other hand, the two-stage
motion artifacts removal technique i.e. WPD-CCA has produced the best average
{\Delta}SNR (16.55 dB, utilizing db1 wavelet packet) and largest average {\eta}
(41.40%, using fk8 wavelet packet). The highest average {\Delta}SNR and {\eta}
using single-stage artifacts removal techniques (WPD) are found as 16.11 dB and
26.40%, respectively for all the fNIRS signals using fk4 wavelet packet. In
both EEG and fNIRS modalities, the percentage reduction in motion artifacts
increases by 11.28% and 56.82%, respectively when two-stage WPD-CCA techniques
are employed.Comment: 25 pages, 10 figures and 2 table
Data-driven vibration signal filtering procedure based on the α-stable distribution
A novel procedure for data-driven enhancement of informative signal is presented in this paper. The introduced methodology covers decomposition of the signal via time-frequency spectrogram into set of narrowband sub-signals. Furthermore, each of the sub-signals is considered as a sample of independent identically distributed random variables and we model the distribution of the sample, in contrast to the classical methodology where the simple statistics, for example kurtosis, for each sub-signal was calculated. This approach provides a new perspective in the signal processing techniques for local damage detection. Using our methodology one can eliminate potential risk related to high sensitivity towards single outlier. In the proposed procedure we model each sub-signal in time-frequency representation by α-stable distribution. This distribution is a generalization of standard Gaussian one and allows us for modeling sub-signals related to both informative and non-informative frequencies. As a result, we obtain distribution of stability parameter vs. frequencies that is analogy to spectral kurtosis approach well known in the literature. Such characteristic is basis for filter design used for raw signal enhancement. To evaluate efficiency of our method we compare raw and filtered signal in time, time-frequency and frequency (envelope spectrum) domains. Moreover, we present comparison to the spectral kurtosis approach. The presented methodology we applied to simulated signal and real vibration signal from two stage heavy duty gearbox used in mining industry
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