An Increase of Brain Wave Amplitude on High Frequency Ranges based EEG P300 Signals

2019 ◽  
Author(s):  
Arjon Turnip ◽  
Dwi Esti Kusumandari ◽  
Artha I. Simbolon ◽  
M. Agung Suhendra ◽  
Teddy Hidayat ◽  
...  
Keyword(s):  
High Frequency ◽  
Wave Amplitude ◽  
Brain Wave

scholarly journals Nonlinear tsunami generation mechanism

2001 ◽  
Vol 1 (4) ◽  
pp. 251-253 ◽  
Author(s):  
M. A. Nosov ◽  
S. N. Skachko
Keyword(s):  
Surface Wave ◽  
Surface Water ◽  
High Frequency ◽  
Water Wave ◽  
Wave Amplitude ◽  
Water Layer ◽  
Generation Mechanism ◽  
Tsunami Generation ◽  
Constant Depth ◽  
Nonlinear Mechanism

Abstract. The nonlinear mechanism of long gravitational surface water wave generation by high-frequency bottom oscillations in a water layer of constant depth is investigated analytically. The connection between the surface wave amplitude and the parameters of bottom oscillations and source length is investigated.

Anticipatory Adjustments during a Warning Interval: Cortical Negativity and Perceptual Sensitivity

1985 ◽  
Vol 29 (10) ◽  
pp. 958-962
Author(s):  
Thomas F. Sanquist
Keyword(s):  
Wave Amplitude ◽  
Detection Task ◽  
Detection Sensitivity ◽  
Perceptual Sensitivity ◽  
Response Requirement ◽  
Experimental Conditions ◽  
Brain Wave ◽  
Warning Interval ◽  
Processing Resources ◽  
Signal Detection Task

Cortical negative afterwaves were recorded while subjects performed a warned signal detection task. Warning intervals of 500, 1200 and 1900 msec, and immediate and delayed responses were employed as experimental conditions. Detection sensitivity was best at the 1200 msec warning interval, which coincided with maximum cortical negativity. The response requirement manipulation had no effect on detection performance or brain wave amplitude. The results are interpreted as indicating an arousal based allocation of processing resources, indexed by cortical negativity.

The high-frequency radiation of water waves by oscillating bodies

1985 ◽  
Vol 401 (1820) ◽  
pp. 89-115 ◽  
Keyword(s):  
High Frequency ◽  
Water Waves ◽  
Wave Amplitude ◽  
Three Dimensional ◽  
Finite Frequency ◽  
Wave Problem ◽  
Potential Problems ◽  
The Mean ◽  
Frequency Radiation ◽  
Asymptotic Forms

The aim of this work is to extend the known asymptotic forms, in heave and sway, of the wave amplitude radiated by bodies at high frequency. Both two- and three-dimensional geometries will be considered, the prototype problems being the circular cylinder and sphere respectively, each with its centre in the mean free surface. The method is, in principle, applicable to other geometries by way of the solution of certain potential problems much simpler than the finite-frequency surface-wave problem.

The Microstructure of Steatite (Protoenstatite)

1985 ◽  
Vol 43 ◽  
pp. 236-237
Author(s):  
W. E. Lee ◽  
A. H. Heuer
Keyword(s):  
High Frequency ◽  
Glass Ceramics ◽  
Magnesium Silicate ◽  
Beam Current ◽  
Glassy Matrix ◽  
Angle Of Incidence ◽  
X Ray ◽  
Mechanical And Electrical Properties ◽  
Argon Ions ◽  
High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

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.

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