Long Term Geo-Electric Potential Signal Analysis using the Teager Huang Transform

The aim of this work is to analyse the mechanical response of the masonry specimens under long-term action by means of cyclic tests. To this end laboratory tests were carried out at the Non-Destructive Testing Laboratory of the Politecnico di Torino. The Acoustic Emission technique was employed to assess the damage evolution, and the mechanical properties decay in order to evaluate the extent and the evolution of micro and macro-cracking due to cyclic action until structural collapse in masonry blocks and mortar layers.

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Improved online event detection and differentiation by a simple gradient-based nonlinear transformation: Implications for the biomedical signal and image analysis

10.1101/2020.08.16.253435 ◽

2020 ◽

Author(s):

Anastasia Sokolova ◽

Yuri Uljanitski ◽

Airat R. Kayumov ◽

Mikhail I Bogachev

Keyword(s):

Observational Data ◽

Event Detection ◽

Signal Analysis ◽

Early Event ◽

Data Series ◽

Online Detection ◽

Suggested Approach ◽

Term Operation ◽

Gradient Based

ABSTRACTDespite recent success in advanced signal analysis technologies, simple and universal methods are still of interest in a variety of applications. Wearable devices including biomedical monitoring and diagnostic systems suitable for long-term operation are prominent examples, where simple online signal analysis and early event detection algorithms are required. Here we suggest a simple and universal approach to the online detection of events represented by abrupt bursts in long-term observational data series. We show that simple gradient-based transformations obtained as a product of the signal and its derivative lead to the improved accuracy of the online detection of any significant bursts in the observational data series irrespective of their particular shapes. We provide explicit analytical expressions characterizing the performance of the suggested approach in comparison with the conventional solutions optimized for particular theoretical scenarios and widely utilized in various signal analysis applications. Moreover, we estimate the accuracy of the gradient-based approach in the exact positioning of single ECG cycles, where it outperforms the conventional Pan-Tompkins algorithm in its original formulation, while exhibiting comparable detection efficacy. Finally, we show that our approach is also applicable to the comparative analysis of lanes in electrophoretic gel images widely used in life sciences and molecular diagnostics like restriction fragment length polymorphism (RFLP) and variable number tandem repeats (VNTR) methods.

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Revisiting the long-term decreasing trend of atmospheric electric potential gradient measured at Nagycenk, Hungary, Central Europe

Annales Geophysicae ◽

10.5194/angeo-39-627-2021 ◽

2021 ◽

Vol 39 (4) ◽

pp. 627-640

Author(s):

Attila Buzás ◽

Veronika Barta ◽

Tamás Horváth ◽

József Bór

Keyword(s):

Time Series ◽

Electric Field ◽

Central Europe ◽

Electric Potential ◽

Potential Gradient ◽

Time Dependent ◽

Shielding Effect ◽

Term Variation ◽

Atmospheric Electric Potential Gradient

Abstract. In 2003, a decreasing trend was reported in the long-term (1962–2001) fair weather atmospheric electric potential gradient (PG) measured in the Széchenyi István Geophysical Observatory (NCK; 47∘38′ N, 16∘43′ E), Hungary, Central Europe. The origin of this reduction has been the subject of a long-standing debate, due to a group of trees near the measurement site which reached significant height since the measurements have started. Those trees have contributed to the lowering of the ambient vertical electric field due to their electrostatic shielding effect. In the present study, we attempt to reconstruct the true long-term variation of the vertical atmospheric electric field at NCK. The time-dependent shielding effect of trees at the measurement site was calculated to remove the corresponding bias from the recorded time series. A numerical model based on electrostatic theory was set up to take into account the electrostatic shielding of the local environment. The validity of the model was verified by on-site measurement campaigns. The changing height of the trees between 1962 and 2017 was derived from national-average age–height diagrams for each year. Modelling the time-dependent electrical shielding effect of the trees at NCK revealed that local effects played a pivotal role in the long-term decrease. The results suggest that earlier attempts could not quantify the shielding effect of the trees at NCK accurately. In this work it is found that the reconstructed PG time series at NCK exhibits an increase between 1962 and 1997 followed by a decaying trend since 1997. It is pointed out that long-term variation in summertime and wintertime PG averages should be analysed separately as these may contribute to trends in the annual mean values rather differently.

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Study on Potential of Meridian Acupoints of Traditional Chinese Medicine

Journal of Healthcare Engineering ◽

10.1155/2021/5599272 ◽

2021 ◽

Vol 2021 ◽

pp. 1-16

Author(s):

Qiuping Li ◽

Tianxia Zhao ◽

Xin’an Wang ◽

Changpei Qiu ◽

Bing Zhou ◽

...

Keyword(s):

Chinese Medicine ◽

Traditional Chinese Medicine ◽

Electric Potential ◽

Classification Accuracy ◽

Low Cost ◽

Principal Component ◽

Accuracy Rate ◽

Good Therapeutic Effect ◽

Acquisition Scheme ◽

Potential Signal

In recent years, Traditional Chinese Medicine (TCM) has attracted more and more attention due to its good therapeutic effect, low cost, and convenience. This research is also a part of the goal of the modernization of TCM. Based on the meridian electric potential acquisition system independently developed by our project team, in this paper, we designed the human body's meridian electric potential acquisition scheme. We use principal component analysis (PCA) to prove that the meridional potential signal is derived from the ECG signal. Then, Inception ResNet V2 was used to classify acupoints and nonacupoints. Finally, the classification accuracy rate reached 86.59045265, and the F1 score = 0.72161642. This shows that acupoints and nonacupoints can be distinguished by their surface potential.

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