Spectral Analysis of Driver Steering Behavior

1982 ◽  
Vol 26 (3) ◽  
pp. 228-232
Author(s):  
Samuel P. Sturgis
Keyword(s):  
Spectral Analysis ◽  
Steady State ◽  
Novice Drivers ◽  
Frequency Bands ◽  
Driving Task ◽  
Rms Amplitude

In order to examine the utility of spectral analysis as a means of quantifying driver steering behavior in a steady-state (expressway) driving task, 10 novice and 10 experienced drivers drove an instrumented car on a 90-minute drive on an “uncongested” expressway, and (for the experienced drivers only) on a 60-minute drive on a “congested” expressway during rush-hour conditions. Results of analyses of variance of RMS steering amplitude in 0.025 hz-wide frequency bands indicated that novice drivers exhibited significantly greater RMS steering amplitude than experienced drivers in the two frequency bands 0–0.025 hz and 0.125–0.150 hz, and that experienced drivers exhibited significantly greater RMS amplitude on the “congested” expressway than the “uncongested” expressway in the six 0.025 hz-wide frequency bands between 0 and 0.150 hz. Significant differences were found between RMS amplitudes measured during the first and second halves of a number of the test drives, indicating that behavior in the two test halves was not equivalent.

A mechanical-reflex oscillator hypothesis for parkinsonian hand tremor

1976 ◽  
Vol 40 (6) ◽  
pp. 990-998 ◽  
Author(s):  
R. N. Stiles ◽  
R. S. Pozos
Keyword(s):  
Spectral Analysis ◽  
Steady State ◽  
Root Mean Square ◽  
Fold Increase ◽  
Normal Subjects ◽  
Single Frequency ◽  
Mean Square ◽  
Hand Tremor ◽  
S Period ◽  
Rms Amplitude

Spectral analysis was performed on postural hand tremor records obtained from 22 parkinsonian subjects. Of these 22 subjects, 18 had postural hand tremor that occurred primarily at a single frequency during any one 16-s period. In general, this tremor occurred at different steady-state frequencies (each calculated over 16 s) between about 4 Hz and 8–9 Hz. This frequency decreased approximately 1 Hz for each 10-fold increase in displacement amplitude (root-mean-square, rms, amplitude determined at 16 cm from the wrist), decreasing from 8–9 Hz at about 30 mum to 3.75–4.0 Hz at about 30,000 mum. The major finding was that the frequency of parkinsonian hand tremor was nearly the same as that for hand tremor from normal subjects when these frequenceis were compared at similar rms displacement levels. This comparison, plus a comparison between other aspects of these two kinds of tremor, indicate that the mechanism for parkinsonian hand tremor is similar to that for large-displacement (greater than 100 mum) hand tremor of normal subjects, i.e., a mechanical-reflex oscillator mechanism.

Spectral analysis of cytochromes in rat heart myocytes: Transient and steady-state photodiode array spectrophotometry measurements

1992 ◽  
Vol 299 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Paolo Sarti ◽  
Giovanni Antonini ◽  
Francesco Malatesta ◽  
Emilio D'Itri ◽  
Maurizio Brunori ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Steady State ◽  
Rat Heart ◽  
Photodiode Array ◽  
Rat Heart Myocytes ◽  
Transient And Steady State

scholarly journals Some results of analysis of inverted echo-sounder records from the Atlantic equatorial region

1985 ◽  
Vol 33 (2) ◽  
pp. 213-218
Author(s):  
Alberto dos Santos Franco ◽  
Joseph Harari ◽  
Afrânio Rubens de Mesquita
Keyword(s):  
Spectral Analysis ◽  
Internal Waves ◽  
Frequency Band ◽  
Equatorial Region ◽  
Temperature Series ◽  
The Other ◽  
Tidal Analysis ◽  
Frequency Bands ◽  
Inverted Echo Sounder ◽  
Even Harmonics

The tidal analysis of data from the Equatorial region, given by inverted echo-sounders, show considerable residuals in the frequency band of approximately 2 cycles per day. In the even harmonics of 4 and 6 cycles per day, tidal components statistically not negligible are also identified. Spectral analysis of temperature series from the same area show, on the other hand, variabilities in the same frequency bands, which suggests the occurrence of internal waves with energy distributed in these frequency bands, in the Atlantic Equatorial area.

Absorption and scattering imaging of tissue with steady-state second-differential spectral-analysis tomography

2004 ◽  
Vol 29 (17) ◽  
pp. 2043 ◽  
Author(s):  
Heng Xu ◽  
Brian W. Pogue ◽  
Hamid Dehghani ◽  
Keith D. Paulsen ◽  
Roger Springett ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Steady State

scholarly journals Multiresolution Wavelet Analysis of the Dynamics of a Cracked Rotor

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Jerzy T. Sawicki ◽  
Asok K. Sen ◽  
Grzegorz Litak
Keyword(s):  
Vibration Signal ◽  
Discrete Wavelet ◽  
Cracked Rotor ◽  
External Excitation ◽  
Harmonic Force ◽  
Frequency Bands ◽  
The Difference ◽  
Multiresolution Wavelet Analysis ◽  
Force Excitation ◽  
Rms Amplitude

We examine the dynamics of a healthy rotor and a rotor with a transverse crack, which opens and closes due to its self weight. Using discrete wavelet transform, we perform a multiresolution analysis of the measured vibration signal from each of these rotors. In particular, the measured vibration signal is decomposed into eight frequency bands, and the rms amplitude values of the healthy and cracked rotors are compared in the three lowest-frequency bands. The results indicate that the rms vibration amplitudes for the cracked rotor are larger than those of the healthy rotor in each of these three frequency bands. In the case of externally applied harmonic force excitation to the rotor, the rms values of the vibration amplitude of the cracked rotor are also found to be larger than those of a healthy rotor in the three lowest-frequency bands. Furthermore, the difference in the rms values between the healthy and cracked rotors in each of the three lowest-frequency bands is more pronounced in the presence of external excitation than that with no excitation. The obtained results suggest that the present multiresolution approach can be used effectively to detect the presence of a crack in a rotor.

scholarly journals Nonlinear transverse steady-state periodic forced vibration of 2-dof discrete systems with cubic nonlinearities

2011 ◽  
pp. 143-166
Author(s):  
Ahmed Eddanguir ◽  
Zitouni Beidouri ◽  
Rhali Benamar
Keyword(s):  
Spectral Analysis ◽  
Steady State ◽  
Frequency Response ◽  
Forced Vibration ◽  
Transverse Vibration ◽  
Frequency Response Function ◽  
Discrete Systems ◽  
Nonlinear Frequency ◽  
Transverse Vibrations ◽  
Nonlinear Frequency Response

A method based on Hamilton’s principle and spectral analysis has been applied recently to nonlinear transverse vibrations of discrete systems with cubic nonlinearities, leading to calculation of the nonlinear free modes of transverse vibration and their associated nonlinear frequencies. The objective of the present work was the extension of this method to the nonlinear forced transverse steady-state periodic response of 2-dof system leading to nonlinear frequency response function in the neighbourhood of the two modes

scholarly journals EEG Power Spectral Analysis of Abnormal Cortical Activations During REM/NREM Sleep in Obstructive Sleep Apnea

2021 ◽  
Vol 12 ◽  
Author(s):  
Shuling Liu ◽  
Jiucheng Shen ◽  
Yezhou Li ◽  
Jing Wang ◽  
Jianhua Wang ◽  
...  
Keyword(s):  
Obstructive Sleep Apnea ◽  
Spectral Analysis ◽  
Power Spectral Analysis ◽  
Nrem Sleep ◽  
The Other ◽  
Frequency Bands ◽  
Delta Band ◽  
Power Spectral ◽  
Obstructive Sleep ◽  
Eeg Power

Objective: To characterize electroencephalogram (EEG) power in different frequency bands during rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep in patients with obstructive sleep apnea (OSA).Methods: Retrospective data on 151 patients were collected and divided into three groups: primary snoring group (AHI < 5/h), mild-moderate OSA group (6 ≤ AHI < 30/h), and severe OSA group (AHI ≥ 30/h). EEG recordings in the frontal, central, and occipital regions were extracted from both REM and NREM sleep, to compute the normalized spectral power densities in the delta, theta, alpha, sigma, beta, and gamma frequency bands, using Fast Fourier Transform. Correlations between the computed EEG power and PSG parameters were analyzed.Results: In NREM sleep, elevated normalized power spectral density (PSD) in the delta band was observed in the severe OSA group compared to the other two groups. In contrast, the PSD of the other frequency bands showed a corresponding decrease in the severe OSA group. In REM sleep, similar changes were observed in the frontal region. Delta band PSD was positively correlated with Apnea Hypopnea Index (AHI) (r = 0.33), longest time of apnea, oxygen desaturation index (ODI) (r = 0.34), percent sleep time below 90% SaO2 (T90%) (r = 0.30), Arousal Index (ArI) (r = 0.29), and negatively correlated with N3%, minimum oxygen saturation (minSaO2).Conclusion: Our findings provide neurophysiological evidence for pathological cortical activation during REM/NREM sleep, which may be associated with the arousals and cognitive impairments in OSA. The technique of power spectral analysis could prove a potentially useful tool in complementing traditional PSG parameters in assessing disease burden to guide therapeutic decisions.

Sign in / Sign up

Export Citation Format

Share Document