scholarly journals The Tracking and Frequency Measurement of the Sway of Leafless Deciduous Trees by Adaptive Tracking Window Based on MOSSE

Forests ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 81
Author(s):  
Achuan Wang ◽  
Xinnian Yang ◽  
Dabo Xin
Keyword(s):  
Dynamic Properties ◽  
Frequency Measurement ◽  
Deciduous Trees ◽  
Target Area ◽  
Adaptive Tracking ◽  
Squared Error ◽  
Power Spectral ◽  
Power Spectral Densities ◽  
Tree Sway ◽  
Sway Frequency

The tree sway frequency is an important part of the dynamic properties of trees. In order to obtain trees sway frequency in wind, a method of tracking and measuring the sway frequency of leafless deciduous trees by adaptive tracking window based on MOSSE was proposed. Firstly, an adaptive tracking window is constructed for the observed target. Secondly, the tracking method based on Minimum Output Sum Of Squared Error Filter (MOSSE) is used to track tree sway. Thirdly, Fast Fourier transform was used to analyze the horizontal sway velocity of the target area on the trees, and the sway frequency was determined. Finally, comparing the power spectral densities (PSDs) of the x axis acceleration measured by the accelerometer and PSDs of the x axis velocity measured by the video, the fundamental sway frequency measured by the accelerometer is equal to the fundamental sway frequency measured by video. The results show that the video-based method can be used successfully for measuring the sway frequency of leafless deciduous trees.

Analysis of power spectral densities of electrocardiograms

1971 ◽  
Vol 12 (1-2) ◽  
pp. 41-51 ◽  
Author(s):  
Vrudhula K. Murthy ◽  
L. Julian Haywood ◽  
John Richardson ◽  
Robert Kalaba ◽  
Steven Salzberg ◽  
...  
Keyword(s):  
Spectral Densities ◽  
Power Spectral ◽  
Power Spectral Densities

scholarly journals Delta and Theta waves in Super Consciousness Meditation.

2020 ◽  
Author(s):  
Anil Kumar Bheemaiah
Keyword(s):  
Average Power ◽  
Spectral Densities ◽  
Theta Wave ◽  
Convolutional Networks ◽  
Theta Waves ◽  
Power Spectral ◽  
Power Spectral Densities ◽  
Lyapunov Coefficient ◽  
Fmri Time Series ◽  
Power Densities

Study on Kundalini Meditation of Super-conscious Meditation of the Himalayan Tradition and Sahaja Meditation, to determine the average power spectral densities and power ratios of TP9, AF7, AF8, and TP10, electrodes and two ear electrodes on a Muse Headset.These parameters are used to create quantitative criteria to indicate degree of meditation and to create a trigger for bird chirp events.We find an increase in Delta and Theta wave power densities, in the deep meditation state as compared to the initiation and restful states. keywords: Kundalini, super consciousness, neurosky, muse, chakra based meditation, alpha to beta ratio, delta to beta ratio, power spectral densities, differential power spectral densities, fMRi, time series, iD convolutional networks. Lyapunov coefficient

scholarly journals Differences Amplitude Based Improvement of Minimum Variance Distortionless Response Filter

2020 ◽  
Vol 8 (5) ◽  
pp. 1635-1637
Keyword(s):  
A Priori ◽  
Minimum Variance ◽  
Coherent Noise ◽  
Noise Interference ◽  
Power Spectral ◽  
Minimum Variance Distortionless Response ◽  
Power Spectral Densities ◽  
Noisy Signals ◽  
A New Technique ◽  
Priori Information

In this work, the author introduces a new technique for improving the performance of minimum variance distortionless response filter in condition of coherent noise. The proposal algorithm exploits a priori information of differences amplitude to balance power spectral densities of observed noisy signals. The output signal of MVDR filter is then processed by an additional post-filtering, which based speech presence probability to suppress more noise interference and increase quality speech. In experiments using two noisy signal recordings in anechoeic room, the modified MVDR-filter results provides that the suggested algorithm increases speech quality compared to the conventional MVDR filter.

Analysis of earth motions and seismic sources by power spectral density

1969 ◽  
Vol 59 (3) ◽  
pp. 1071-1091
Author(s):  
Dean V. Power
Keyword(s):  
Spectral Density ◽  
Power Spectral Density ◽  
High Explosive ◽  
Peak Velocity ◽  
Test Site ◽  
Nevada Test Site ◽  
Spectral Densities ◽  
Power Spectral ◽  
Power Spectral Densities ◽  
Velocity Spectra

abstract Ground motion records from six high-explosive cratering events in northeastern Montana, ten contained nuclear explosive events at the Nevada Test Site, and motions of an earth-fill dam during the Gasbuggy underground nuclear explosion in New Mexico were analyzed for power spectral density, peak velocity and velocity spectra. The high-explosive events included four 20-ton single charges at depths of burst which varied between 42 to 57 feet, a 140-ton row charge consisting of three 20-ton and two 40-ton charges at optimum cratering depths of burst, and a 0.5-ton charge at the optimum depth of burst. It was found that at these depths and charge weights an increase in depth of burst resulted in an increase in peak velocities and power-spectral densities as measured at distant points (> 5 km). Power spectral density was found to be approximately proportional to the first power of yield. For this region it was determined that power spectral density varied inversely as radial distance to the 3.55 power. Three analysis techniques—peak velocity, velocity spectra and power spectral density—are compared, and it is shown that power spectral density is the most consistent method when comparing records from different measuring stations. An analysis of power-spectral density measured at one station for the ten events at the Nevada Test Site shows that a significant shift in the frequency of the energy in the seismogram occurs when the source location changes. For events in the Yucca Flat area the peak energy at Mercury was consistently at 1.0 Hz, while for events in the Pahute Mesa area this peak occurs at 2.5 Hz. A comparison of the power spectral densities on and near the Navajo Dam revealed that the natural frequencies and first harmonics of the dam are 1.4, 2.0 and 2.5 Hz in the mode where motion is parallel to the canyon axis. A simple model makes use of these frequencies to calculate a shear-wave velocity of 1130 ft/sec. A method of using power spectral density to measure earthquake magnitudes and measure the yield of underground explosions is proposed.

Using COVID19 as an Opportunity to Measure Seismic Silences and Bring Geoscience Projects to Students

2021 ◽  
Author(s):  
Artash Nath
Keyword(s):  
Northwest Territories ◽  
World Health ◽  
Virtual Classrooms ◽  
Power Spectral ◽  
Essential Services ◽  
Power Spectral Densities ◽  
The World ◽  
Seismic Vibrations ◽  
Health Organization ◽  
Almost All

<p>On 11 March 2020, the World Health Organization declared Covid19 a pandemic. Countries around the world rushed to declare various states of emergencies. Canada also implemented emergency measures to restrict the movements of people including the closure of borders, non-essential services, and schools and offices to slow the spread of Covid19. I used this opportunity to measure changes in seismic vibrations registered in Canada before, during, and after the lockdown due to the slowdown in transportation, economic, and construction activities. I analyzed continuous seismic data for 6 Canadian cities: Calgary and Edmonton (Alberta), Montreal (Quebec), Ottawa, and Toronto (Ontario), and Yellowknife (Northwest Territories). These cities represented the wide geographical spread of Canada. The source of data was seismic stations run by the Canadian National Seismograph Network (CNSN). Python and ObSpy libraries were used to convert raw data into probabilistic power spectral densities. The seismic vibrations in the PPSDs that fell between 4 Hz and 20 Hz were extracted and averaged for every two weeks period to determine the trend of seismic vibrations. The lockdown had an impact on seismic vibrations in almost all the cities I analyzed. The seismic vibrations decreased between 14% - 44% with the biggest decrease in Yellowknife in the Northwest Territories. In the 3 densely populated cities with a population of over 1 million - Toronto, Montreal, and Calgary, the vibrations dropped by over 30%.</p><p>To enable other students to undertake similar projects for their cities, I created a comprehensive online training module using Jupyter notebooks available on Github. Students can learn about seismic vibrations, how to obtain datasets, and analyze and interpret them using Python. They can share their findings with local policymakers so that they become aware of the effectiveness of the lockdown imposed and are better prepared for lockdowns in the future. When we make data and technology accessible, then lockdowns because of pandemics can be an opportunity for students to take up practical geoscience projects from home or virtual classrooms.</p>

scholarly journals EOG feature relevance determination for microsleep detection

2017 ◽  
Vol 3 (2) ◽  
pp. 815-818
Author(s):  
Martin Golz ◽  
Sebastian Wollner ◽  
David Sommer ◽  
Sebastian Schnieder
Keyword(s):  
Cross Correlation ◽  
Feature Reduction ◽  
Support Vector ◽  
Spectral Bands ◽  
Automatic Relevance Determination ◽  
Signal Features ◽  
Power Spectral ◽  
Vector Machines ◽  
Power Spectral Densities ◽  
Feature Relevance

AbstractAutomatic relevance determination (ARD) was applied to two-channel EOG recordings for microsleep event (MSE) recognition. 10 s immediately before MSE and also before counterexamples of fatigued, but attentive driving were analysed. Two type of signal features were extracted: the maximum cross correlation (MaxCC) and logarithmic power spectral densities (PSD) averaged in spectral bands of 0.5 Hz width ranging between 0 and 8 Hz. Generalised learn-ing vector quantisation (GRLVQ) was used as ARD method to show the potential of feature reduction. This is compared to support-vector machines (SVM), in which the feature reduction plays a much smaller role. Cross validation yielded mean normalised relevancies of PSD features in the range of 1.6 - 4.9 % and 1.9 - 10.4 % for horizontal and vertical EOG, respectively. MaxCC relevancies were 0.002 - 0.006 % and 0.002 - 0.06 %, respectively. This shows that PSD features of vertical EOG are indispensable, whereas MaxCC can be neglected. Mean classification accuracies were estimated at 86.6±b 1.3 % and 92.3±b 0.2 % for GRLVQ and SVM, respec-tively. GRLVQ permits objective feature reduction by inclu-sion of all processing stages, but is not as accurate as SVM.

scholarly journals Calculation of the cross and auto power spectral densities for low neutron counting from pulse mode detectors

2019 ◽  
Vol 131 ◽  
pp. 138-147 ◽  
Author(s):  
Alberto Talamo ◽  
Yousry Gohar ◽  
Toshihiro Yamamoto ◽  
Masao Yamanaka ◽  
Cheol Ho Pyeon
Keyword(s):  
Pulse Mode ◽  
Spectral Densities ◽  
Power Spectral ◽  
Power Spectral Densities ◽  
Neutron Counting ◽  
The Cross

scholarly journals Frequency Domain Response of Jacket Platforms under Random Wave Loads

2019 ◽  
Vol 7 (10) ◽  
pp. 328
Author(s):  
Xiaoshuang Han ◽  
Weiliang Qiao ◽  
Bo Zhou
Keyword(s):  
Design Stage ◽  
Response Analysis ◽  
Random Wave ◽  
Preliminary Design ◽  
Wave Loads ◽  
Spectral Densities ◽  
Spectral Moments ◽  
Jacket Platform ◽  
Power Spectral ◽  
Power Spectral Densities

This article presents a procedure that simplifies an offshore jacket platform as a non-uniform cantilever beam subjected to an axial force. A Ritz method combined with a pseudo-excitation method is then used to analyze the responses of the jacket platform under random wave loads with the associated power spectral densities, variances and higher spectral moments. The theoretical basis and pertinent governing equations are derived. The proposed procedure not only eases the process of determining the pseudo wave loads, but also requires only the rudimentary structural details that are typically available at the preliminary design stage. Additionally, the merit of the proposed procedure is that the process does not require one to compute the normal modes, which saves time and is particularly convenient for the dynamic-response analysis of a complex structure (such as an offshore platform). An illustrative example based on a three-deck jacket platform is presented to demonstrate the procedure used to obtain the power spectral densities, variances and second spectral moments of jacket-top displacement and the bending moment of the jacket at the mud line. The results obtained are compared with those obtained using a Finite Element Mothed (FEM) model. Based on the findings of the study and good agreement shown in the comparison of results, it is concluded that the proposed method is effective, simple and convenient, and can be a useful tool for the preliminary design analysis of offshore platforms.

Railway Truck Response to Random Rail Irregularities

1975 ◽  
Vol 97 (3) ◽  
pp. 957-964 ◽  
Author(s):  
Neil K. Cooperrider
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Tangential Force ◽  
Contact Forces ◽  
Guidance Force ◽  
Power Spectral ◽  
Power Spectral Densities ◽  
Rail Irregularities ◽  
Frequency Domain Techniques

This paper discusses the random response of a seven degree of freedom, passenger truck model to lateral rail irregularities. Power spectral densities and root mean square levels of component displacements and contact forces are reported. The truck model used in the study allows lateral and yaw degrees of freedom for each wheelset, and lateral, yaw and roll freedoms for the truck frame. Linear creep relations are utilized for the rail-wheel contact forces. The lateral rail irregularities enter the analysis through the creep expressions. The results described in the paper were obtained using frequency domain techniques to solve the equations of motion. The reported results demonstrate that the guidance force needed when traveling over irregular rail at high speed utilizes a significant portion of the total available tangential force between wheel and rail.

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