anomalous feature
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Author(s):  
Kimberly N. Perry ◽  
Mark W. Scerbo ◽  
Sarah A. Powers

The goal of the present study was to examine the effects of cuing and task interruptions on change detection within dynamic scenes. Undergraduate students watched 24 brief videos (12 containing interruptions) for anomalous feature changes appearing in 8 videos. Half of the object changes occurred during a visual occlusion, while the others contained no interruption. All videos were unique and depicted various dynamic scenes. Participants were assigned at random to one of three conditions containing cues to the changes (reliable, unreliable, or no cue). The results showed that more object changes were detected during uninterrupted vs. interrupted trials. More object changes were detected with reliable vs. unreliable cues for uninterrupted trials. Providing reliable cues had no benefit over the other conditions when interruptions were present. Overall, these results suggest that visual interruptions may degrade information stored in memory, which could compromise visual monitoring tasks.



2020 ◽  
Vol 8 (3) ◽  
pp. T599-T609
Author(s):  
Qiang Guo ◽  
Wayne D. Pennington

Seismic interpretation is often based on the analysis of amplitude anomalies, which depend strongly on the seismic wavelet presented in the data. However, if the wavelet polarity or phase is unknown or fine-scale impedance variations are complex, interpretation of the anomaly can be ambiguous. The Stratton data volume contains a dome-like feature that may be interpreted as the top of a potential gas target, the top of a buried tight reef, or as a thin layer of either higher or lower impedance, depending on the interpreter’s assumption of polarity and phase. This observation provoked our interest in modeling the seismic response of domes using wavelets of differing polarity and phase on stacked data. Because there appears to be only a single event, perhaps the top of an anomalous feature, and not its base, a “gradational” decrease in impedance contrast with depth is included among our models. We have determined that the seismic response from a layer with an impedance contrast decreasing with depth is quite different from that of a layer with constant impedance contrast when the bed thickness exceeds one quarter of the wavelength; that is, a reflection from the base of a “thick” gradational layer is not visible, as expected. We independently determine the polarity and phase of the Stratton data, finding that the surface-based seismic and VSP data are of opposite polarity (European and American, respectively), and concluding that the dome structure represents the top of a gradational thick bed. A model based on a nearby reservoir containing thin gas, oil, and water zones supports this conclusion. This anomaly in the Stratton data appears to represent a hydrocarbon reservoir with thin layers of gas and oil, each with lower impedance than the surrounding beds but with stepwise decreasing contrast over a sufficient thickness to avoid a basal reflection at these wavelengths.



2017 ◽  
Vol 22 (1) ◽  
pp. 95-111 ◽  
Author(s):  
Pei Liu ◽  
Manman Ma ◽  
Zhenli Xu

AbstractThe interaction force between likely charged particles/surfaces is usually repulsive due to the Coulomb interaction. However, the counterintuitive like-charge attraction in electrolytes has been frequently observed in experiments, which has been theoretically debated for a long time. It is widely known that the mean field Poisson-Boltzmann theory cannot explain and predict this anomalous feature since it ignores many-body properties. In this paper, we develop efficient algorithm and perform the force calculation between two interfaces using a set of self-consistent equations which properly takes into account the electrostatic correlation and the dielectric-boundary effects. By solving the equations and calculating the pressure with the Debye-charging process, we show that the self-consistent equations could be used to study the attraction between like-charge surfaces from weak-coupling to mediate-coupling regimes, and that the attraction is due to the electrostatics-driven entropic force which is significantly enhanced by the dielectric depletion of mobile ions. A systematic investigation shows that the interaction forces can be tuned by material permittivity, ionic size and valence, and salt concentration, and that the like-charge attraction exists only for specific regime of these parameters.



Mycologia ◽  
2016 ◽  
Vol 108 (1) ◽  
pp. 174-178 ◽  
Author(s):  
Lancellotti Enrico ◽  
Fantini Paolo ◽  
Iotti Mirco ◽  
Franceschini Antonio ◽  
Zambonelli Alessandra
Keyword(s):  


2015 ◽  
Vol 28 (9) ◽  
pp. 3631-3649 ◽  
Author(s):  
Michael G. Bosilovich ◽  
Jiun-Dar Chern ◽  
David Mocko ◽  
Franklin R. Robertson ◽  
Arlindo M. da Silva

Abstract The assimilation of observations in reanalyses incurs the potential for the physical terms of budgets to be balanced by a term relating the fit of the observations relative to a forecast first guess analysis. This may indicate a limitation in the physical processes of the background model or perhaps assimilating data from an inconsistent observing system. In the MERRA reanalysis, an area of long-term moisture flux divergence over land has been identified over the central United States. Here, the water vapor budget is evaluated in this region, taking advantage of two unique features of the MERRA diagnostic output: 1) a closed water budget that includes the analysis increment and 2) a gridded diagnostic output dataset of the assimilated observations and their innovations (e.g., forecast departures). In the central United States, an anomaly occurs where the analysis adds water to the region, while precipitation decreases and moisture flux divergence increases. This is related more to a change in the observing system than to a deficiency in the model physical processes. MERRA’s Gridded Innovations and Observations (GIO) data narrow the observations that influence this feature to the ATOVS and Aqua satellites during the 0600 and 1800 UTC analysis cycles, when radiosonde information is not prevalent. Observing system experiments further narrow the instruments that affect the anomalous feature to AMSU-A (mainly window channels) and Atmospheric Infrared Sounder (AIRS). This effort also shows the complexities of the observing system and the reactions of the regional water budgets in reanalyses to the assimilated observations.



2009 ◽  
Vol 27 (4) ◽  
pp. 1363-1375 ◽  
Author(s):  
A. V. Pavlov ◽  
N. M. Pavlova

Abstract. We present a statistical study of variations in the F2-layer peak electron density, NmF2, and altitude, hmF2, over the Argentine Islands ionosonde. The critical frequencies, foF2, and, foE, of the F2 and E-layers, and the propagation factor, M(3000)F2, measured by the ionosonde during the 1957–1959 and 1962–1995 time periods were used in the statistical analysis to determine the values of NmF2 and hmF2. The probabilities to observe maximum and minimum values of NmF2 and hmF2 in a diurnal variation of the electron density are calculated. Our study shows that the main part of the maximum diurnal values of NmF2 is observed in a time sector close to midnight in November, December, January, and February exhibiting the anomalous diurnal variations of NmF2. Another anomalous feature of the diurnal variations of NmF2 exhibited during November, December, and January when the minimum diurnal value of NmF2 is mainly located close to the noon sector. These anomalous diurnal variations of NmF2 are found to be during both geomagnetically quiet and disturbed conditions. Anomalous features are not found in the diurnal variations of hmF2. The statistical study of the NmF2 winter anomaly phenomena over the Argentine Islands ionosonde was carried out. The variations in a maximum daytime value, R, of a ratio of a geomagnetically quiet daytime winter NmF2 to a geomagnetically quiet daytime summer NmF2 taken at a given UT and for approximately the same level of solar activity were studied. The conditional probability of the occurrence of R in an interval of R, the most frequent value of R, the mean expected value of R, and the conditional probability to observe the F2-region winter anomaly during a daytime period were calculated for low, moderate, and high solar activity. The calculations show that the mean expected value of R and the occurrence frequency of the F2-region winter anomaly increase with increasing solar activity.



1996 ◽  
Vol 427 ◽  
Author(s):  
Yu-Jane Mei ◽  
Ting-Chang Chang ◽  
Jeng-Dong Sheu ◽  
Wen-Kuan Yeh ◽  
Fu-Ming Pan ◽  
...  

AbstractSelective tungsten chemical vapor deposition (W-CVD) is one of the most attractive technique for filling deep submicron contact hole and via hole for the ULSI application. In this work, we firstly find out the anomalous selective W growth for the contact hole. The tungsten only nucleates from the side ring of the contact hole bottom. Several predeposition treatments prior to W growth can improve this anomalous feature and excellently selective W growth can be achieved. Auger electron spectroscopy (AES) is utilized to investigate the interface of Si/W. A model has been proposed to explain this anomalous selective tungsten growth.



Geophysics ◽  
1994 ◽  
Vol 59 (10) ◽  
pp. 1542-1550 ◽  
Author(s):  
Richard S. Smith ◽  
R. N. Edwards ◽  
G. Buselli

Coincident‐loop TEM sounding data are often presented by plotting the half‐space apparent conductivity as a function of delay time. A new algorithm generates an improved presentation that plots the apparent conductivity as a function of depth. The resulting data may be further processed to sharpen or “spike” the smoothly varying apparent‐conductivity/depth curves in an attempt to better represent the rapid changes in conductivity that often exist in the earth. The algorithm described involves an approximation, but is simple, easy to use, and computationally efficient. A layered conductivity structure is assumed, so the algorithm is best for areas where the geology is approximately horizontal. However, the algorithm can also be used to identify anomalous features that are not infinite horizontal layers. The spiked conductivity models derived from synthetic data are consistent with the original layered‐earth models and show a greater resolution than the apparent‐conductivity/depth curves, and sometimes amplify noise in the data. When data are collected along a profile line, the conductivity/depth information can be converted to a color image. For profile data collected over the Elura orebody, the image of the spiked conductivity section shows an anomalous feature at the orebody, and the color contrast is more marked than it is on the apparent‐conductivity/depth image.



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