scholarly journals Analysis of the Spatial-Frequency Characteristics of the Photo-Assisted Method of a Quartz Rough Surface Nano-Polishing

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Vasyl Kanevskii ◽  
Serhii Kolienov ◽  
Valerii Grygoruk ◽  
Oleksandr Stelmakh ◽  
Hao Zhang
Keyword(s):  
Standard Deviation ◽  
Spatial Frequency ◽  
Rough Surface ◽  
Spatial Spectrum ◽  
Frequency Characteristics ◽  
Process Conditions ◽  
Quartz Surface ◽  
Gaussian Form ◽  
Maximum Slope ◽  
Profile Height

The relationship between the spatial-frequency parameters of a rough surface with a random profile, which has a Gaussian form of the correlation function, and the amplitude-frequency characteristics of the electric field created by this surface is determined. The numerical determination of the evanescent field optimal configuration formed near the quartz rough surface in the gaseous medium saturated with chlorine molecules when illuminated from the quartz side has been considered. The finite-element approach is used to solve the Helmholtz two-dimensional vector equation. It was found that at the initial stage of photochemical polishing different electrodynamic conditions are created for the etching process depending on the profile height standard deviation value. In particular, when the standard deviation is less than 1 nm, all surface protrusions, for which the spatial spectrum harmonics of the profile are located in the region of the maximum slope of the spectral function, are most actively etched. This leads to a decrease in the effective width of the spatial spectrum of a rough quartz surface and an increase in its correlation length. Therefore, simultaneously with decreasing the height of the protrusions, the surface becomes flatter. The paper shows the different character of quartz surface nano-polishing process conditions depending on the initial standard deviation of the profile height.

An investigation of spatial frequency characteristics of the complex receptive fields in the visual cortex of the cat

1976 ◽  
Vol 16 (8) ◽  
pp. 789-797 ◽  
Author(s):  
V.D. Glezer ◽  
A.M. Cooperman ◽  
V.A. Ivanov ◽  
T.A. Tsherbach
Keyword(s):  
Visual Cortex ◽  
Spatial Frequency ◽  
Receptive Fields ◽  
Frequency Characteristics

Sounds prevent selective monitoring of high spatial frequency channels in vision

2012 ◽  
Vol 25 (0) ◽  
pp. 40
Author(s):  
Alexis Pérez-Bellido ◽  
Joan López-Moliner ◽  
Salvador Soto-Faraco
Keyword(s):  
Standard Deviation ◽  
Spatial Frequency ◽  
Visual Processing ◽  
Reaction Times ◽  
High Spatial Frequency ◽  
Visual Signals ◽  
Sensory Interactions ◽  
Multisensory Interactions ◽  
Visual Targets ◽  
Selective Monitoring

Prior knowledge about the spatial frequency (SF) of upcoming visual targets (Gabor patches) speeds up average reaction times and decreases standard deviation. This has often been regarded as evidence for a multichannel processing of SF in vision. Multisensory research, on the other hand, has often reported the existence of sensory interactions between auditory and visual signals. These interactions result in enhancements in visual processing, leading to lower sensory thresholds and/or more precise visual estimates. However, little is known about how multisensory interactions may affect the uncertainty regarding visual SF. We conducted a reaction time study in which we manipulated the uncertanty about SF (SF was blocked or interleaved across trials) of visual targets, and compared visual only versus audio–visual presentations. Surprisingly, the analysis of the reaction times and their standard deviation revealed an impairment of the selective monitoring of the SF channel by the presence of a concurrent sound. Moreover, this impairment was especially pronounced when the relevant channels were high SFs at high visual contrasts. We propose that an accessory sound automatically favours visual processing of low SFs through the magnocellular channels, thereby detracting from the potential benefits from tuning into high SF psychophysical-channels.

Transfer of Learning in Transformed Random-Dot Stereostimuli

Perception ◽  
1982 ◽  
Vol 11 (4) ◽  
pp. 409-414 ◽  
Author(s):  
Nigel R Long
Keyword(s):  
Spatial Frequency ◽  
High Frequency ◽  
Transfer Of Learning ◽  
Low Frequency ◽  
Frequency Characteristics ◽  
Frequency Transformations

The transfer of learning between normal and monocularly-transformed small-disparity, random-dot stereostimuli has been examined under extended viewing conditions. When the disparity value was constant, transfer of learning between normal and monocularly-transformed stereostimuli was disrupted by both low-frequency and high-frequency transformations. These results suggest that stereolearning is restricted to disparity units that are selective to the same spatial-frequency characteristics.

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