scholarly journals Forecasting Soil Moisture In The Soil Under The Caragana Shrubland Using Wavelet Analysis And NARX Neural Network

2021 ◽  
Author(s):  
Dong-Mei Bai ◽  
Zhong-Sheng Guo ◽  
Man-Cai Guo
Keyword(s):  
Neural Network ◽  
Soil Moisture ◽  
Wavelet Analysis ◽  
Soil Water ◽  
High Frequency ◽  
Sustainable Use ◽  
Low Frequency ◽  
Frequency Component ◽  
High Frequency Component ◽  
Narx Neural Network

Abstract Purpose: It is important for sustainable use of soil water resources to forecast soil moisture in forestland of water-limited regions. There are some soil moisture models. However, there is not a better method to forecast soil moisture.Methods: The change of soil moisture with time were investigated and the data of soil moisture were divided into a low frequency and a high frequency component using wavelet analysis, and then NARX neural network was used to build model I and model II. For model I, low frequency component was the input variable, and for model II, low frequency component and high frequency component were predicted.Results: the average relative error for model I is 3.5% and for model II is 0.3%. The average relative error of predicted soil moisture in100cm layer using model II is 0.8%, then soil water content in 40 cm and 200 cm soil depth is selected and the forecast errors are 4.9 % and 0.4 %.Using model II to predict soil water is well．Conclusion: Predicting soil water will be important for sustainable use of soil water resource and controlling soil degradation, vegetation decline and crop failure in water limited regions.

scholarly journals Extreme prolongation of expiration breathing: Effects on electroencephalogram and autonomic nervous function

2018 ◽  
Vol 10 (2) ◽  
pp. 62-65
Author(s):  
Teruhisa Komori
Keyword(s):  
High Frequency ◽  
Frequency Ratio ◽  
Low Frequency ◽  
Frequency Component ◽  
Small Sample ◽  
High Frequency Component ◽  
Deep Breathing ◽  
Continuous Eeg ◽  
Nervous Function ◽  
Electrocardiogram Ecg

To clarify the physiological and psychological effects of deep breathing, the effects of extreme prolongation of expiration breathing (Okinaga) were investigated using electroencephalogram (EEG) and electrocardiogram (ECG). Participants were five male Okinaga practitioners in their 50s and 60s. Participants performed Okinaga for 31 minutes while continuous EEG and ECG measurements were taken. After 16 minutes of Okinaga, and until the end of the session, the percentages of theta and alpha 2 waves were significantly higher than at baseline. After 20 minutes, and until the end of the session, the percentage of beta waves was significantly lower than at baseline. The high frequency component of heart rate variability was significantly lower after 12 minutes of Okinaga and lasted until 23 minutes. The low frequency/high frequency ratio was significantly lower after 18 minutes of Okinaga and until the end of the session. Okinaga produced relaxation, suggesting that deep breathing may relieve anxiety. However, study limitations include potential ambiguity in the interpretation of the low frequency/high frequency ratio, the small sample, and the fact that EEG was measured only on the forehead.

scholarly journals Extreme prolongation of expiration breathing: Effects on electroencephalogram and autonomic nervous function

2018 ◽  
Vol 10 (2) ◽  
Author(s):  
Teruhisa Komori
Keyword(s):  
High Frequency ◽  
Frequency Ratio ◽  
Low Frequency ◽  
Frequency Component ◽  
Small Sample ◽  
High Frequency Component ◽  
Deep Breathing ◽  
Continuous Eeg ◽  
Nervous Function ◽  
Electrocardiogram Ecg

To clarify the physiological and psychological effects of deep breathing, the effects of extreme prolongation of expiration breathing (Okinaga) were investigated using electroencephalogram (EEG) and electrocardiogram (ECG). Participants were five male Okinaga practitioners in their 50s and 60s. Participants performed Okinaga for 31 minutes while continuous EEG and ECG measurements were taken. After 16 minutes of Okinaga, and until the end of the session, the percentages of theta and alpha 2 waves were significantly higher than at baseline. After 20 minutes, and until the end of the session, the percentage of beta waves was significantly lower than at baseline. The high frequency component of heart rate variability was significantly lower after 12 minutes of Okinaga and lasted until 23 minutes. The low frequency/high frequency ratio was significantly lower after 18 minutes of Okinaga and until the end of the session. Okinaga produced relaxation, suggesting that deep breathing may relieve anxiety. However, study limitations include potential ambiguity in the interpretation of the low frequency/high frequency ratio, the small sample, and the fact that EEG was measured only on the forehead.

scholarly journals Autonomic Conditions in Tinnitus and Implications for Korean Medicine

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Eun Ji Choi ◽  
Younghee Yun ◽  
Seungyeon Yoo ◽  
Kyu Seok Kim ◽  
Jeong-Su Park ◽  
...  
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Retrospective Chart Review ◽  
Frequency Component ◽  
Total Power ◽  
High Frequency Component ◽  
Chronic Patients ◽  
Research Attention ◽  
Korean Medicine ◽  
Significant Difference

Tinnitus patients suffer from not only auditory sensations but also physical, mental, and social difficulties. Even though tinnitus is believed to be associated with the autonomic nervous system, changes in autonomic conditions in tinnitus patients are not receiving much research attention. The aims of this study were to investigate the autonomic condition of tinnitus patients and to consider Korean medicine in the treatment of tinnitus with an evidence-based approach. We performed a retrospective chart review and compared the heart rate variability (HRV) parameters of 40 tinnitus patients (19 acute and 21 chronic) and 40 healthy controls. In tinnitus patients, the power of the high frequency component and total power of the HRV significantly decreased(P<0.05), and the low frequency to high frequency ratio significantly increased(P<0.05). There was no significant difference between the acute and chronic patients. When comparing each group with the controls, there was a tendency that the longer the duration of tinnitus was, the larger the observed HRV change was. In conclusion, tinnitus patients have vagal withdrawal and sympathetic overactivity, and chronic tinnitus more strongly affects autonomic conditions than acute tinnitus. This study provides evidence for Korean medical treatments of tinnitus, such as acupuncture and Qi-training, that cause modulation of cardiac autonomic function.

scholarly journals Different Coupling Modes Mediate Cortical Cross-Frequency Interactions

2015 ◽  
Author(s):  
Randolph F Helfrich ◽  
Christoph S Herrmann ◽  
Andreas K Engel ◽  
Till R Schneider
Keyword(s):  
Information Integration ◽  
Visual Processing ◽  
High Frequency ◽  
Low Frequency ◽  
Gamma Oscillations ◽  
Frequency Component ◽  
High Frequency Component ◽  
Alpha Power ◽  
Alpha Oscillation ◽  
Transcranial Alternating Current Stimulation

Cross-frequency coupling (CFC) has been suggested to constitute a highly flexible mechanism for cortical information gating and processing, giving rise to conscious perception and various higher cognitive functions in humans. In particular, it might provide an elegant tool for information integration across several spatiotemporal scales within nested or coupled neuronal networks. However, it is currently unknown whether low frequency (theta/alpha) or high frequency gamma oscillations orchestrate cross-frequency interactions, raising the question of who is master and who is slave. While correlative evidence suggested that at least two distinct CFC modes exist, namely phase-amplitude-coupling (PAC) and amplitude-envelope-correlations (AEC), it is currently unknown whether they subserve distinct cortical functions. Novel non-invasive brain stimulation tools, such as transcranial alternating current stimulation (tACS), now provide the unique opportunity to selectively entrain the low or high frequency component and study subsequent effects on CFC. Here, we demonstrate the differential modulation of CFC during selective entrainment of alpha or gamma oscillations. Our results reveal that entrainment of the low frequency component increased PAC, where gamma power became preferentially locked to the trough of the alpha oscillation, while gamma-band entrainment reduced alpha power through enhanced AECs. These results provide causal evidence for the functional role of coupled alpha and gamma oscillations for visual processing.

scholarly journals Antiforensics of Speech Resampling Using Dual-Path Strategy

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Diqun Yan ◽  
Yongkang Gong ◽  
Tianyun Liu
Keyword(s):  
High Frequency ◽  
Gaussian White Noise ◽  
Sampling Rate ◽  
Low Frequency ◽  
Frequency Component ◽  
High Frequency Component ◽  
Perceptual Quality ◽  
Median Filtering ◽  
Noise Perturbation

Resampling is an operation to convert a digital speech from a given sampling rate to a different one. It can be used to interface two systems with different sampling rates. Unfortunately, resampling may also be intentionally utilized as a postoperation to remove the manipulated artifacts left by pitch shifting, splicing, etc. To detect the resampling, some forensic detectors have been proposed. Little consideration, however, has been given to the security of these detectors themselves. To expose weaknesses of these resampling detectors and hide the resampling artifacts, a dual-path resampling antiforensic framework is proposed in this paper. In the proposed framework, 1D median filtering is utilized to destroy the linear correlation between the adjacent speech samples introduced by resampling on low-frequency component. And for high-frequency component, Gaussian white noise perturbation (GWNP) is adopted to destroy the periodic resampling traces. The experimental results show that the proposed method successfully deceives the existing resampling forensic algorithms while keeping good perceptual quality of the resampled speech.

scholarly journals Applying Wavelet Filters in Wind Forecasting Methods

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3181
Author(s):  
José Domínguez-Navarro ◽  
Tania Lopez-Garcia ◽  
Sandra Valdivia-Bautista
Keyword(s):  
Neural Network ◽  
Time Series ◽  
High Frequency ◽  
Physical Phenomenon ◽  
Frequency Component ◽  
High Frequency Component ◽  
Optimal Filtering ◽  
Wavelet Filter ◽  
Wavelet Filters ◽  
Forecasting Methods

Wind is a physical phenomenon with uncertainties in several temporal scales, in addition, measured wind time series have noise superimposed on them. These time series are the basis for forecasting methods. This paper studied the application of the wavelet transform to three forecasting methods, namely, stochastic, neural network, and fuzzy, and six wavelet families. Wind speed time series were first filtered to eliminate the high-frequency component using wavelet filters and then the different forecasting methods were applied to the filtered time series. All methods showed important improvements when the wavelet filter was applied. It is important to note that the application of the wavelet technique requires a deep study of the time series in order to select the appropriate family and filter level. The best results were obtained with an optimal filtering level and improper selection may significantly affect the accuracy of the results.

scholarly journals Medical image fusion based on quaternion wavelet transform

2020 ◽  
Vol 14 ◽  
pp. 174830262093129
Author(s):  
Zhang Zhancheng ◽  
Luo Xiaoqing ◽  
Xiong Mengyu ◽  
Wang Zhiwen ◽  
Li Kai
Keyword(s):  
Wavelet Transform ◽  
Image Fusion ◽  
High Frequency ◽  
Medical Image ◽  
Low Frequency ◽  
Frequency Component ◽  
High Frequency Component ◽  
Medical Image Fusion ◽  
Quaternion Wavelet Transform ◽  
Fused Image

Medical image fusion can combine multi-modal images into an integrated higher-quality image, which can provide more comprehensive and accurate pathological information than individual image does. Traditional transform domain-based image fusion methods usually ignore the dependencies between coefficients and may lead to the inaccurate representation of source image. To improve the quality of fused image, a medical image fusion method based on the dependencies of quaternion wavelet transform coefficients is proposed. First, the source images are decomposed into low-frequency component and high-frequency component by quaternion wavelet transform. Then, a clarity evaluation index based on quaternion wavelet transform amplitude and phase is constructed and a contextual activity measure is designed. These measures are utilized to fuse the high-frequency coefficients and the choose-max fusion rule is applied to the low-frequency components. Finally, the fused image can be obtained by inverse quaternion wavelet transform. The experimental results on some brain multi-modal medical images demonstrate that the proposed method has achieved advanced fusion result.

The de Hass-van Alphen effect in aluminium

1957 ◽  
Vol 249 (965) ◽  
pp. 299-320 ◽  
Keyword(s):  
Fermi Surface ◽  
High Frequency ◽  
Oscillation Amplitude ◽  
Low Frequency ◽  
Frequency Component ◽  
High Frequency Component ◽  
Field Orientation ◽  
Principal Axes ◽  
Detailed Interpretation ◽  
Periodic Components

The de Haas-van Alphen effect in aluminium has been studied by measuring the oscillatory variation with magnetic field of the torque on a single crystal at liquid-helium temperatures in fields up to 15.4 kG. The torques were measured by an electronic feed-back device designed to reduce the twisting motion of the crystal during torque measurement. Particular attention was paid to the variation of the periods of the relatively high-frequency components of the oscillations with the orientation of the field relative to the crystal axes. A consistent interpretation was obtained by supposing that there are three such periodic components for each field direction, though often the relative amplitude of one or two of these is negligibly small. In terms of Onsager’s theory, the period is inversely proportional to the maximum area of cross-section of the Fermi surface by planes normal to the field, and the three periodic components have been shown to correspond to three identical cushion-shaped pieces of the Fermi surface with their principal axes mutually perpendicular. The location of these pieces in relation to the Brillouin zone is discussed and the characteristic dimensions of each piece have been calculated. Some results on the variation of the period of the relatively low-frequency component with field orientation in a (100) plane are described, but no detailed interpretation in terms of the shape of appropriate parts of the Fermi surface has been obtained. A few results on the variation of the oscillation amplitude with field orientation and on the temperature-dependence of amplitude are also presented. Alloying the aluminium with up to 0.26 % magnesium increases the period of the low-frequency component by about 2.3 % ; this suggests that this component arises from electrons rather than holes. The period of the high-frequency component is not significantly changed by alloying.

scholarly journals Stress Recovery Effects of High- and Low-Frequency Amplified Music on Heart Rate Variability

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yoshie Nakajima ◽  
Naofumi Tanaka ◽  
Tatsuya Mima ◽  
Shin-Ichi Izumi
Keyword(s):  
Heart Rate ◽  
White Noise ◽  
High Frequency ◽  
Low Frequency ◽  
Frequency Component ◽  
High Frequency Component ◽  
Stress Recovery ◽  
Recovery Ratio ◽  
Autonomic Responses ◽  
Frequency Components

Sounds can induce autonomic responses in listeners. However, the modulatory effect of specific frequency components of music is not fully understood. Here, we examined the role of the frequency component of music on autonomic responses. Specifically, we presented music that had been amplified in the high- or low-frequency domains. Twelve healthy women listened to white noise, a stress-inducing noise, and then one of three versions of a piece of music: original, low-, or high-frequency amplified. To measure autonomic response, we calculated the high-frequency normalized unit (HFnu), low-frequency normalized unit, and the LF/HF ratio from the heart rate using electrocardiography. We defined the stress recovery ratio as the value obtained after participants listened to music following scratching noise, normalized by the value obtained after participants listened to white noise after the stress noise, in terms of the HFnu, low-frequency normalized unit, LF/HF ratio, and heart rate. Results indicated that high-frequency amplified music had the highest HFnu of the three versions. The stress recovery ratio of HFnu under the high-frequency amplified stimulus was significantly larger than that under the low-frequency stimulus. Our results suggest that the high-frequency component of music plays a greater role in stress relief than low-frequency components.

Audio Watermarking Based on Wavelet Transform

2012 ◽  
Vol 229-231 ◽  
pp. 2784-2788 ◽  
Author(s):  
Mahmoud A. Osman ◽  
Nasser H. Ali
Keyword(s):  
Wavelet Transform ◽  
High Frequency ◽  
Low Frequency ◽  
Audio Signal ◽  
Frequency Component ◽  
Binary Image ◽  
Audio Watermarking ◽  
High Frequency Component ◽  
Discrete Wavelet ◽  
Copyright Information

The process of hiding the information like text, binary image, audio etc. into another signal source like image, audio etc. is called watermarking. The approach involved in watermarking the binary image signal in the wavelet domain of the audio signal was implemented using MATLAB. In this paper, we propose a Discrete Wavelet Transform low frequency to high frequency. Besides, the high frequency spectrum is less sensitive to human ear. That is the reason why the high frequency component is usually discarded in the compression process. Therefore, information to be hidden can be embedded into the low frequency component to against the compression attack. The characteristic of this scheme is that the user can not only use the DAW to embed the text file in to the audio but also binary image. In this paper we embeds copyright information into audio files as a proof of their ownership, we propose an effective, robust, and an inaudible audio watermarking algorithm. The effectiveness of the algorithm has been brought by virtue of applying the discrete wavelets transform (DWT) . Experimental results will be presented in this paper to demonstrate the effectiveness of the proposed algorithm.

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