scholarly journals Wavelet-based method for coherence analysis with suppression of low frequency envelope modulation in non-stationary signals

2020 ◽  
Author(s):  
Sopapun Suwansawang ◽  
David M. Halliday
Keyword(s):  
Low Frequency ◽  
Coherence Analysis ◽  
Stationary Signals ◽  
Envelope Modulation

scholarly journals Characterizing speech rhythm using spectral coherence analysis of jaw kinematics and speech temporal envelope: A proof of concept

2019 ◽  
Author(s):  
Lei He
Keyword(s):  
Low Frequency ◽  
Speech Comprehension ◽  
Coherence Analysis ◽  
Proof Of Concept ◽  
Spectral Coherence ◽  
Speech Rhythm ◽  
Temporal Envelope ◽  
Frequency Bands ◽  
Frequency Modulations

Lower modulation rates in the temporal envelope (ENV) constitute the rhythmic frames in speech and are crucial for speech comprehension in terms of neuronal entrainments at δ- and θ-rates. The jaw plays the role of a carrier articulator producing the low-frequency modulations in this process. This paper introduces a method to examine the joint roles of jaw oscillation and ENV in formulating rhythmic frames using spectral coherence. Relative powers in the frequency bands corresponding to the δ- and θ-oscillations were quantified and regressed on utterance duration. Two English corpora were analyzed for the proof of concept.

scholarly journals Analysis of Evoked EMG using Wavelet Transformation

2013 ◽  
Vol 5 (1) ◽  
pp. 41-51
Author(s):  
Zaid Bin Mahbub ◽  
JH Karami ◽  
K Siddique-e Rabbani
Keyword(s):  
Electrical Stimulation ◽  
Neurological Disorders ◽  
Healthy Subjects ◽  
Wavelet Transformation ◽  
Medical Physics ◽  
Low Frequency ◽  
Normal Subjects ◽  
Thenar Muscle ◽  
Stationary Signals ◽  
Stimulation Of

Evoked EMG M-responses obtained from the thenar muscle in the palm by electrical stimulation of the median nerve demonstrate a well-established smooth bipolar shape for normal healthy subjects while kinks are observed in certain neurological disorders, particularly in cervical spondylotic neuropathy. A first differentiation failed to identify these kinks because of comparable values obtained for normally rising and falling segments of the smooth regions, and due to noise. In this study, the usefulness of the wavelet transform (WT), that provides localized measures of non-stationary signals is investigated. The Haar WT was used to analyze a total of 36 M-responses recorded from the median nerves of 6 normal subjects (having smooth shape) and 12 subjects with assumed neurological disorders (having kinks), for two points of stimulation on the same nerve. Features in the time-scale representation of the M-responses were studied using WT to distinguish smooth M-responses from ones with kinks. Variations in the coefficient line of the WT were also studied to allow visualization of WT at different scales (inverse of frequency). The high and low frequency regions in the WT came out distinctively which helped identifications of kinks even of very subtle ones in the M-responses which were difficult to obtain using the differentiated signal. In conclusion, the wavelet analysis may be a technique of choice in identifying kinks in M-responses in relation to time, thus enhancing the accuracy of neurological diagnosis. DOI: http://dx.doi.org/10.3329/bjmp.v5i1.14667 Bangladesh Journal of Medical Physics Vol.5 No.1 2012 41-51

Coherence analysis in three bands of the low frequency spectrum of resting-state fMRI datasets

NeuroImage ◽  
2009 ◽  
Vol 47 ◽  
pp. S168 ◽  
Author(s):  
A Martins da Silva ◽  
LF Botelho ◽  
M Almeida ◽  
A Andrade
Keyword(s):  
Frequency Spectrum ◽  
Resting State ◽  
Low Frequency ◽  
Resting State Fmri ◽  
Coherence Analysis

The Experimental and Analysis of Automobile Brake Groan

2013 ◽  
Vol 409-410 ◽  
pp. 1492-1495
Author(s):  
Xian Jie Meng ◽  
Ren Fei Yuan
Keyword(s):  
Power Spectrum ◽  
Coordinate System ◽  
Spectrum Analysis ◽  
Low Frequency ◽  
Experimental Spectrum ◽  
Power Spectrum Analysis ◽  
Coherence Analysis ◽  
Vehicle Speed ◽  
Low Frequency Vibration ◽  
Brake Pressure

To seize the feature of brake groan and the relay route of the vibration and noise,an experiment is done on brake groan and all signals are done the auto-power spectrum analysis and coherence analysis. The result of experiment and analysis shows that brake groan is a low frequency vibration and noise happened under the low vehicle speed and low brake pressure, the noise of the interior of cab has good coherence with the noise beside the brake caliper when the brake groan takes place, and also with the vibration of tangent orientation of brake caliper, Y orientation of vehicle coordinate system on arm of cross pattern and Z orientation on the top dead center of suspension. The coherence analysis roughly illustrates that the relay route of the brake groan have two paths, the vibration and noise are transferred from the arm of cross pattern and suspension to automobile chassis and body Keywords: brake groan, experimental,spectrum analysis,relay route

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

Lectin Binding to Human Breast Tumor Cells

1976 ◽  
Vol 34 ◽  
pp. 34-35
Author(s):  
Robert E. Nordquist ◽  
J. Hill Anglin ◽  
Michael P. Lerner
Keyword(s):  
Carcinoma Cell ◽  
Ricinus Communis ◽  
Lectin Binding ◽  
Low Frequency ◽  
Breast Carcinoma Cell Line ◽  
Human Breast ◽  
Human Breast Tumor ◽  
Duct Carcinoma ◽  
Specific Antigens ◽  
Ricin Agglutinin

A human breast carcinoma cell line (BOT-2) was derived from an infiltrating duct carcinoma (1). These cells were shown to have antigens that selectively bound antibodies from breast cancer patient sera (2). Furthermore, these tumor specific antigens could be removed from the living cells by low frequency sonication and have been partially characterized (3). These proteins have been shown to be around 100,000 MW and contain approximately 6% hexose and hexosamines. However, only the hexosamines appear to be available for lectin binding. This study was designed to use Concanavalin A (Con A) and Ricinus Communis (Ricin) agglutinin for the topagraphical localization of D-mannopyranosyl or glucopyranosyl and D-galactopyranosyl or DN- acetyl glactopyranosyl configurations on BOT-2 cell surfaces.

Practical High Resolution Microscopy

1968 ◽  
Vol 26 ◽  
pp. 302-303
Author(s):  
P. A. Marsh ◽  
T. Mullens ◽  
D. Price
Keyword(s):  
High Resolution ◽  
Magnetic Fields ◽  
Low Frequency ◽  
Resolving Power ◽  
Careful Attention ◽  
Electron Microscopes ◽  
The Relationship ◽  
High Resolution Microscopy ◽  
New Facilities

It is possible to exceed the guaranteed resolution on most electron microscopes by careful attention to microscope parameters essential for high resolution work. While our experience is related to a Philips EM-200, we hope that some of these comments will apply to all electron microscopes.The first considerations are vibration and magnetic fields. These are usually measured at the pre-installation survey and must be within specifications. It has been our experience, however, that these factors can be greatly influenced by the new facilities and therefore must be rechecked after the installation is completed. The relationship between the resolving power of an EM-200 and the maximum tolerable low frequency interference fields in milli-Oerstedt is 10 Å - 1.9, 8 Å - 1.4, 6 Å - 0.8.

Simulations of high-resolution images of amorphous silicon films

1986 ◽  
Vol 44 ◽  
pp. 544-545
Author(s):  
G. Y. Fan ◽  
J. M. Cowley
Keyword(s):  
Electron Microscope ◽  
High Frequency ◽  
Fourier Transformation ◽  
Amorphous Materials ◽  
Low Frequency ◽  
Chromatic Aberration ◽  
Structure Information ◽  
Frequency Components ◽  
High Resolution Images ◽  
Spatial Frequency Spectrum

It is well known that the structure information on the specimen is not always faithfully transferred through the electron microscope. Firstly, the spatial frequency spectrum is modulated by the transfer function (TF) at the focal plane. Secondly, the spectrum suffers high frequency cut-off by the aperture (or effectively damping terms such as chromatic aberration). While these do not have essential effect on imaging crystal periodicity as long as the low order Bragg spots are inside the aperture, although the contrast may be reversed, they may change the appearance of images of amorphous materials completely. Because the spectrum of amorphous materials is continuous, modulation of it emphasizes some components while weakening others. Especially the cut-off of high frequency components, which contribute to amorphous image just as strongly as low frequency components can have a fundamental effect. This can be illustrated through computer simulation. Imaging of a whitenoise object with an electron microscope without TF limitation gives Fig. 1a, which is obtained by Fourier transformation of a constant amplitude combined with random phases generated by computer.

SEM image sharpness analysis

1996 ◽  
Vol 54 ◽  
pp. 142-143
Author(s):  
M. T. Postek ◽  
A. E. Vladar
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Quantitative Information ◽  
Primary Electron ◽  
Image Sharpness ◽  
Critical Dimensions ◽  
Sem Image ◽  
Frequency Changes ◽  
Electron Microscopes ◽  
Scanning Electron

Fully automated or semi-automated scanning electron microscopes (SEM) are now commonly used in semiconductor production and other forms of manufacturing. The industry requires that an automated instrument must be routinely capable of 5 nm resolution (or better) at 1.0 kV accelerating voltage for the measurement of nominal 0.25-0.35 micrometer semiconductor critical dimensions. Testing and proving that the instrument is performing at this level on a day-by-day basis is an industry need and concern which has been the object of a study at NIST and the fundamentals and results are discussed in this paper.In scanning electron microscopy, two of the most important instrument parameters are the size and shape of the primary electron beam and any image taken in a scanning electron microscope is the result of the sample and electron probe interaction. The low frequency changes in the video signal, collected from the sample, contains information about the larger features and the high frequency changes carry information of finer details. The sharper the image, the larger the number of high frequency components making up that image. Fast Fourier Transform (FFT) analysis of an SEM image can be employed to provide qualitiative and ultimately quantitative information regarding the SEM image quality.

Real Ear Sound Pressure Levels Developed by Three Portable Stereo System Earphones

1992 ◽  
Vol 1 (4) ◽  
pp. 52-55 ◽  
Author(s):  
Gail L. MacLean ◽  
Andrew Stuart ◽  
Robert Stenstrom
Keyword(s):  
High Frequency ◽  
Sound Pressure ◽  
Low Frequency ◽  
Test System ◽  
Output Frequency ◽  
Frequency Effects ◽  
Adult Men ◽  
Frequency Responses ◽  
Significant Difference ◽  
Sound Pressure Levels

Differences in real ear sound pressure levels (SPLs) with three portable stereo system (PSS) earphones (supraaural [Sony Model MDR-44], semiaural [Sony Model MDR-A15L], and insert [Sony Model MDR-E225]) were investigated. Twelve adult men served as subjects. Frequency response, high frequency average (HFA) output, peak output, peak output frequency, and overall RMS output for each PSS earphone were obtained with a probe tube microphone system (Fonix 6500 Hearing Aid Test System). Results indicated a significant difference in mean RMS outputs with nonsignificant differences in mean HFA outputs, peak outputs, and peak output frequencies among PSS earphones. Differences in mean overall RMS outputs were attributed to differences in low-frequency effects that were observed among the frequency responses of the three PSS earphones. It is suggested that one cannot assume equivalent real ear SPLs, with equivalent inputs, among different styles of PSS earphones.

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