A NEW METHOD OF PATTERN SHOOTING

Geophysics ◽  
1955 ◽  
Vol 20 (3) ◽  
pp. 539-564 ◽  
Author(s):  
J. O. Parr ◽  
W. H. Mayne
Keyword(s):  
Finite Number ◽  
Finite Length ◽  
Vertical Line ◽  
New Method ◽  
Horizontal Line ◽  
Wavelength Band ◽  
Continuous Band ◽  
Reversed Polarity ◽  
Multiple Detectors ◽  
Horizontal Area

In areas where reflection shooting is difficult, it is often necessary to attenuate the energy in a broad continuous band of disturbing wavelengths to less than a few hundredths of what would be recorded if all units were bunched together. The wavelength band of the attenuated energy should be adjacent to the band of reflection wavelengths received. Attenuation of the undesired energy is best accomplished with multiple detectors or charges. In many areas the pattern should attenuate energy horizontally propagated in all directions, not just in the direction of the detector line. Neither a finite number of uniformly effective, uniformly spaced units in line nor a uniformly effective sheet of finite length will accomplish this result. A system for gradation of the effectiveness of units described in this paper does produce this result (not only for in‐line disturbances but also for disturbances coming in from the side of the line). The attenuation band can be made broad with good attenuation or narrower with still better attenuation, as desired. The variation of effectiveness can be applied to detectors or charges arranged in a horizontal line, over a horizontal area, in a vertical line, or over a vertical area. The principle of varying effectiveness can also be applied to reversed‐polarity detectors in order to accentuate certain apparent wavelengths.

scholarly journals Reliable Acoustic Path and Direct-Arrival Zone Spatial Gain Analysis for a Vertical Line Array

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3462 ◽  
Author(s):  
Chunyu Qiu ◽  
Shuqing Ma ◽  
Yu Chen ◽  
Zhou Meng ◽  
Jianfei Wang
Keyword(s):  
Sound Propagation ◽  
Correlation Coefficients ◽  
Deep Ocean ◽  
Vertical Line ◽  
Horizontal Line ◽  
Acoustic Path ◽  
Vertical Arrays ◽  
Peak Structure ◽  
Line Array ◽  
Propagation Properties

A method is developed in this paper to calculate the spatial gain of a vertical line array when the plane-wave assumption is not applicable and when the oceanic ambient noise is correlated. The proposed optimal array gain (OAG), which can evaluate the array’s performance and effectively guide its deployment, can be given by an equation in which the noise gain (NG) is subtracted from the signal gain (SG); hence, a high SG and a negative NG can enhance the performance of the array. OAGs and SGs with different array locations are simulated and analyzed based on the sound propagation properties of the direct-arrival zone (DAZ) and the reliable acoustic path (RAP) using ray theory. SG and NG are related to the correlation coefficients of the signals and noise, respectively, and the vertical correlation is determined by the structures of the multipath arrivals. The SG in the DAZ is always high because there is little difference between the multipath waves, while the SG in the RAP changes with the source-receiver range because of the variety of structure in the multiple arrivals. The SG under different conditions is simulated in this work. The “dual peak” structure can often be observed in the vertical directionality pattern of the noise because of the presence of bottom reflection and deep sound channel. When the directions of the signal and noise are close, the conventional beamformer will enhance the correlation of not only the signals but also the noise; thus, the directivity of the signals and noise are analyzed. Under the condition of having a typical sound speed profile, the OAG in some areas of the DAZ and RAP can achieve high values and even exceed the ideal gain of horizontal line array 10 logN dB, while, in some other areas, it will be lowered because of the influence of the NG. The proposed method of gain analysis can provide analysis methods for vertical arrays in the deep ocean under many conditions with references. The theory and simulation are tested by experimental data.

scholarly journals Correlation between spatial resolution and ball distortion rate of panoramic radiography

2020 ◽  
Author(s):  
Han-Gyeol Yeom ◽  
Sam-Sun Lee ◽  
Jo-Eun Kim ◽  
Kyung-Hoe Huh ◽  
Won-Jin Yi ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Spatial Resolution ◽  
Panoramic Radiography ◽  
Reference Value ◽  
Vertical Line ◽  
Line Pair ◽  
Horizontal Line ◽  
Student’S T ◽  
High Degree ◽  
Distortion Rate

Abstract BackgroundThe purpose of this study was to analyze the correlation between spatial resolution and ball distortion rate of panoramic radiography and to elucidate the minimum criterion for ball distortion rate, which is very relevant to clinical readability.MethodsHorizontal and vertical spatial resolution and ball distortion rates were calculated in the same position, such as the incisor, premolar, molar, and temporomandibular joint area with various object depths corresponding to 48 mm. Three devices were evaluated. A region showing spatial resolution above the reference standard was selected, and the ball distortion rate corresponding to the same region was divided into horizontal and vertical phantom groups.The mean and standard deviation of the obtained ball distortion rates were calculated. Student’s t-test was used to statistically analyze the mean difference in ball distortion rates between vertical and horizontal phantom groups.ResultsIn all devices, the horizontal line pair phantom, but not the vertical line pair phantom, was readable in all areas measured at the line pair value of at least 1.88 lp/mm. The line pair value tended to be higher toward the center and lower toward the outside. The ball distortion rate tended to decrease closer to the center and increased further away. In addition, ball distortion rates could not be measured at some areas as they were not recognized as balls due to the high degree of distortion at the outermost and innermost sides. The number of balls satisfying the reference value using the horizontal line pair phantom was 102 (mean of ball distortion rates, 20.98; standard deviation, 15.25). The number of balls satisfying the reference value using the vertical line pair phantom was 49 (mean of ball distortion rates, 16.33; standard deviation, 14.25). However, mean ball distortion rate was not significantly different between the two groups.ConclusionsFocal layer of panoramic radiography could be evaluated by the spatial resolution using horizontal and vertical line pair phantoms and by assessing ball distortion rates through a ball-type panorama phantom. A ball distortion rate of 20% could be used as a threshold to evaluate the focal layer of panoramic radiography.

To: “A new method for shear wave logging,” Choro Kitsunezaki, (GEOPHYSICS, v. 45, p. 1489–1506)

Geophysics ◽  
1981 ◽  
Vol 46 (5) ◽  
pp. 816-816 ◽  
Keyword(s):  
Shear Wave ◽  
New Method ◽  
Reversed Polarity

The author of “A new method for shear wave logging,” Choro Kitsunezaki, (Geophysics, v. 45, p. 1489–1506), has forwarded the following changes in the paper. The y‐component (bottom traces of Figures 16 and 17) described in the subsection “Records” on p. 1498 is actually the—x‐component (reversed polarity).

The Role of Figure Orientation and Apparent Depth in the Perception of the Horizontal—Vertical Illusion

Perception ◽  
1975 ◽  
Vol 4 (1) ◽  
pp. 79-83 ◽  
Author(s):  
Harvey R Schiffman ◽  
Jack G Thompson
Keyword(s):  
Stimulus Figure ◽  
Vertical Line ◽  
Apparent Depth ◽  
Horizontal Line ◽  
Size Constancy ◽  
Illusory Effect

An experiment was performed which examined the role of figural orientation directly, and the role of an inappropriately invoked size-constancy mechanism indirectly, in the actuation and magnitude of the horizontal—vertical illusion. When the vertical line of the stimulus figure was aligned above the horizontal line, the illusory effect was significant and positive; in contrast, when the vertical line was located below the horizontal line, the illusion was negative. Under the assumption that a vertical line can appear as a foreshortened line in depth, these findings support an explanation based on the operation of a misapplied size-constancy mechanism.

Direct comparison of the haptic and visual horizontal–vertical illusions using traditional figures and single lines

2012 ◽  
Vol 25 (0) ◽  
pp. 182
Author(s):  
Jacqui Howell ◽  
Mark Symmons ◽  
George Van Doorn
Keyword(s):  
Literature Review ◽  
Stimulus Size ◽  
Current Paper ◽  
Vertical Line ◽  
Percentage Error ◽  
Horizontal Line ◽  
Visual Phenomenon ◽  
Critical Literature

The horizontal–vertical illusion (HVI) has been widely and extensively reported as a visual phenomenon in which a vertical line is perceived as shorter than a horizontal line of the same length. Like a number of geometric illusions, the HVI has also been found to occur haptically, though there is less agreement in the literature as to the extent and direction of the illusion. The relatively small number of haptic HVI papers coupled with a variety of stimuli and procedures used make it difficult to make direct comparison between the visual and haptic versions of the illusion. After a brief critical literature review, the current paper reports a study in which the visual and haptic HVIs are directly compared. In a bid to reconcile previous shortcomings, three sets of stimuli were used: L-figures, inverted T-figures, and separated horizontal and vertical lines. The stimuli were presented in two lengths: 3 and 9 cm. The dependent variable was percentage error between the horizontal and vertical — no error represents an absence of illusion. As expected, inverted T-figures produced an illusion significantly stronger than both the L-figures and single lines, which in turn did not differ from each other. Further, the illusion was present to the same extent in both modalities. Stimuli of 9 cm produced relatively stronger illusions than those that measured 3 cm, and stimulus size interacted with modality. The consequences of these findings for earlier research and proffered suggestions as to what causes this and other illusions are discussed.

Division and Orientation in the Vertical-Horizontal Illusion

1972 ◽  
Vol 34 (3) ◽  
pp. 899-902 ◽  
Author(s):  
James A. Becker
Keyword(s):  
The Other ◽  
Vertical Line ◽  
Horizontal Line

This study attempted to determine the influence of the division (bisection of the horizontal line by the vertical line) and orientation (vertical line seems longer than horizontal line) factors on the vertical-horizontal illusion. 100 Ss were divided into two groups, one with knowledge of the division and orientation factors and the other group without knowledge of these factors. The results indicated that the amount of error for the group with knowledge was significantly smaller than for the group without knowledge.

To: “A new method for shear‐wave logging,” October 1980, GEOPHYSICS (v. 45, p. 1489–1506)

Geophysics ◽  
1982 ◽  
Vol 47 (7) ◽  
pp. 1131-1131
Keyword(s):  
Shear Wave ◽  
New Method ◽  
Hand Column ◽  
Right Hand ◽  
Entire Sentence ◽  
Reversed Polarity

The author of “A new method for shear‐wave logging,” Chōrō Kitsunezaki, has forwarded us further changes to his paper which appeared in October 1980 Geophysics (v. 45, p. 1489–1506) and an Errata which appeared in May 1981 Geophysics, v. 46, p. 816. In the paper, caption for Figure 16, p. 1497, should read “Transmitter—F = 88 N, . . .” instead of “Transmitter F = . . .” On p. 1498, 8th line from the bottom of right hand column should be “−x‐ and x‐directions” instead of “x‐ and y‐directions.” In the Errata, delete the entire sentence, “The y‐component . . . (reversed polarity).”

scholarly journals Posterior Cortical Atrophy with Right Lower Egocentric Quadrantic Neglect and Lower Vertical Allocentric Neglect

2020 ◽  
Vol 35 (4) ◽  
pp. 448-457
Author(s):  
Usama Tariq ◽  
Alicia Parker ◽  
Leila Saadatpour ◽  
Leilani Doty ◽  
Kenneth M Heilman
Keyword(s):  
Parietal Lobe ◽  
Visual Space ◽  
Vertical Line ◽  
Cortical Atrophy ◽  
Horizontal Line ◽  
Posterior Cortical Atrophy ◽  
Lower Quadrant ◽  
Visuospatial Neglect ◽  
Parietal Lobes ◽  
The Right

Abstract Background/Objectives Whereas rare cases of hemispatial visual neglect have been reported in patients with a neurodegenerative disease, quadrantic visuospatial neglect has not been described. We report a patient with probable posterior cortical atrophy who demonstrated lower right-sided quadrantic visuospatial neglect, together with allocentric vertical neglect. Methods/Results A 68-year-old man initially noted deficits in reading and writing. Subsequently, he developed other cognitive deficits. On vertical line bisections, he deviated upward, and on horizontal line bisections, he deviated to the left. These deviations together suggest that this man’s neglect might be most severe in his right (head/body-centered) lower (below eye level) visual space. When attempting to perform vertical line bisections in all four egocentric quadrants, his upward deviations were largest in the right lower quadrant. On a cancelation test, he revealed bilateral lower (ventral) allocentric neglect but not egocentric neglect. This patient’s magnetic resonance imaging revealed cortical atrophy, most prominent in the left parietal lobe. Discussion Previous research in stroke patients has demonstrated that the parietal lobes are important in mediating attention to contralateral and inferior visual space. The presence of left parietal atrophy may have induced this right lower (ventral) egocentric inattention as well as bilateral ventral allocentric inattention. Although to our knowledge there have been no prior reports of a patient with right lower quadrantic and lower vertical allocentric visuospatial neglect, patients are rarely tested for these forms of neglect, and this patient illustrates the importance of evaluating patients for these and other forms of neglect.

Sign in / Sign up

Export Citation Format

Share Document