scholarly journals Boomerang uniformity of a class of power maps

2021 ◽  
Author(s):  
Sartaj Ul Hasan ◽  
Mohit Pal ◽  
Pantelimon Stănică
Keyword(s):  
Power Maps

scholarly journals Group Analysis of Q Values Calculated with Tangential Radius of Curvature from Human Anterior Corneal Surface

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Zheren Xia ◽  
Chengmin Lin ◽  
Xueping Huang ◽  
Jinglu Ying ◽  
Mingguang Shi ◽  
...  
Keyword(s):  
Linear Regression ◽  
Group Analysis ◽  
Radius Of Curvature ◽  
Linear Regression Equation ◽  
Adult Group ◽  
Corneal Surface ◽  
Power Maps ◽  
Adults And Children ◽  
The Mean ◽  
Orbscan Ii

Objective. To calculate the Q values from the human anterior corneal surface with the tangential radius of curvature and analyze its distribution characteristics in different age and refractive status groups. Methods. Tangential power maps of the anterior cornea from Orbscan II were acquired for 201 subjects’ right eyes. They were divided into groups of adults and children and then divided further into subgroups according to the refraction status. The Q values of each semimeridian were calculated by the tangential radius with a linear regression equation. The Q value distribution in both the nasal cornea and temporal cornea were analyzed. Results. The mean temporal Q values of the emmetropia group of adults and all children’s groups were significantly different from the mean nasal Q value. The mean nasal corneal Q values were more negative in children. The adult group showed differences only in the low myopia group. The mean Q value of the nasal cornea among different refractive groups of children was significantly different, and so was the temporal cornea between the adult myopia and emmetropia group. Conclusion. The method using the tangential radius of curvature combined with linear regression to obtain anterior surface Q values for both adults and children was stable and reliable. When we analyzed the anterior corneal Q value, area division was necessary.

The use of wavelet transforms for improved interpretation of airborne transient electromagnetic data

Geophysics ◽  
2013 ◽  
Vol 78 (3) ◽  
pp. E117-E123 ◽  
Author(s):  
Vanessa Nenna ◽  
Adam Pidlisecky
Keyword(s):  
Wavelet Transforms ◽  
Oil And Gas ◽  
Spatial Scales ◽  
Data Sets ◽  
Data Set ◽  
Topographic Features ◽  
Transient Electromagnetic ◽  
Power Maps ◽  
Southern Alberta ◽  
Cultural Noise

The continuous wavelet transform (CWT) is used to create maps of dominant spatial scales in airborne transient electromagnetic (ATEM) data sets to identify cultural noise and topographic features. The introduced approach is applied directly to ATEM data, and does not require the measurements be inverted, though it can easily be applied to an inverted model. For this survey, we apply the CWT spatially to B-field and dB/dt ATEM data collected in the Edmonton-Calgary Corridor of southern Alberta. The average wavelet power is binned over four ranges of spatial scale and converted to 2D maps of normalized power within each bin. The analysis of approximately 2 million soundings that make up the survey can be run on the order of minutes on a 2.4 GHz Intel processor. We perform the same CWT analysis on maps of surface and bedrock topography and also compare ATEM results to maps of infrastructure in the region. We find that linear features identified on power maps that differ significantly between B-field and dB/dt data are well correlated with a high density of infrastructure. Features that are well correlated with topography tend to be consistent in power maps for both types of data. For this data set, use of the CWT reveals that topographic features and cultural noise from high-pressure oil and gas pipelines affect a significant portion of the survey region. The identification of cultural noise and surface features in the raw ATEM data through CWT analysis provides a means of focusing and speeding processing prior to inversion, though the magnitude of this affect on ATEM signals is not assessed.

Density factor approach to representing impact of die power maps on thermal management

2005 ◽  
Vol 28 (4) ◽  
pp. 659-664 ◽  
Author(s):  
J. Torresola ◽  
Chia-Pin Chiu ◽  
G. Chrysler ◽  
D. Grannes ◽  
R. Mahajan ◽  
...  
Keyword(s):  
Thermal Management ◽  
Power Maps ◽  
Density Factor

scholarly journals Power maps in rings.

1961 ◽  
Vol 8 (1) ◽  
pp. 29-32 ◽  
Author(s):  
I. N. Herstein
Keyword(s):  
Power Maps

scholarly journals Power maps and epicyclic spaces

1994 ◽  
Vol 96 (1) ◽  
pp. 1-14 ◽  
Author(s):  
D. Burghelea ◽  
Z. Fiedorowicz ◽  
W. Gajda
Keyword(s):  
Power Maps

Sensitivity of CTF Solution to Subchannel Window Size

2018 ◽  
Author(s):  
Roman Mukin ◽  
Marcus Seidl ◽  
Ivor Clifford ◽  
Hakim Ferroukhi
Keyword(s):  
Heat Flux ◽  
Window Size ◽  
Local Heat ◽  
Nucleate Boiling ◽  
Pressurized Water Reactor ◽  
Reference Case ◽  
Pressurized Water ◽  
Local Flow ◽  
Power Maps ◽  
Fuel Assemblies

In this work, a so-called mini-core consisting of a 3 × 3 array of 17 × 17 pressurized water reactor (PWR) fuel assemblies (FA) is considered with the aim of identifying the most conservative window size for hot channel analysis of bowed fuel assemblies. Overall, five different mini-core configurations are analyzed: one is the reference case, i.e. without FA displacement and four different cases with diagonal and parallel FA displacements. Rod power maps for these mini-cores were exported from neutronic calculations with CASMO-SIMULATE codes. Subchannel modelling with COBRA-TF code of all five mini-cores allows one to identify the rod position with a minimum departure from the nucleate boiling ratio (DNBR) and to construct input decks with different rod window sizes around the previously identified rod position. Overall, eight different window sizes are considered: 3 × 3, 5 × 5, 7 × 7, 9 × 9, 11 × 11, 13 × 13, 15 × 15 and 17 × 17. Results of subchannel analysis for a mini-core and different subchannel window configurations are compared with the help of DNBR parameter, which is the ratio between the critical heat flux (CHF) and the actual local heat flux on a rod. An assessment of three different CHF models is applied in this work: Groeneveld CHF look-up table (LUT), W3 CHF correlation, and Doroschuk CHF LUT. The general conclusion of this work is that for deformed core configurations, an appropriate rod window size needs to be determined to adequately capture the local flow redistribution. For large displacements (the largest displacement considered in this work is 10 mm), the DNBR ratio can drop to one. DNBRs obtained with the W3 CHF correlation give the most conservative results.

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