The use of Gaussian trend surfaces for modelling glacio-isostatic crustal rebound

2004 ◽  
Vol 40 (2) ◽  
pp. 175-179 ◽  
Author(s):  
P. Fretwell ◽  
I. R. Peterson ◽  
D. E. Smith

SynopsisThe behaviour of the Earth's continental crust and mantle may be modelled as a buoyant floating plate on a viscous liquid, and the variations of load imposed by an ice sheet may be modelled as a time-dependent force. In recent work it has been shown that the mathematical solution of this problem can be subdivided into a propagating far-field forebulge term and a non-propagating near-field term. The latter often dominates and can be approximated satisfactorily by a generalized Gaussian function. Here we fit empirical data from the Main Postglacial Shoreline of northern Britain to a Gaussian trend surface. We show that the fit is significantly better than that of a polynomial trend surface previously published, and that the method has the potential to predict the likely sea surface level offshore at the zero isobase for the shoreline.

2020 ◽  
Vol 74 (7) ◽  
pp. 780-790
Author(s):  
Dominik J. Winterauer ◽  
Daniel Funes-Hernando ◽  
Jean-Luc Duvail ◽  
Saïd Moussaoui ◽  
Tim Batten ◽  
...  

This work introduces hyper-resolution (HyRes), a numerical approach for spatial resolution enhancement that combines hyperspectral unmixing and super-resolution image restoration (SRIR). HyRes yields a substantial increase in spatial resolution of Raman spectroscopy while simultaneously preserving the undistorted spectral information. The resolving power of this technique is demonstrated on Raman spectroscopic data from a polymer nanowire sample. Here, we demonstrate an achieved resolution of better than 14 nm, a more than eightfold improvement on single-channel image-based SRIR and [Formula: see text] better than regular far-field Raman spectroscopy, and comparable to near-field probing techniques.


Author(s):  
W. T. Brown ◽  
M. F. Schmidt ◽  
P. T. Dzwilewski

Electromagnetic radiation accompanying the detonation of chemical explosives was first reported in 1954. Such emissions result from detonations of both bare and cased explosives. However, the dominant wavelengths of emissions from these two types of explosions generally differ by as much as three or four orders of magnitude. We present results of far-field and near-field experimental measurements of electric fields emitted by metal encased explosives, and show that metal fracture is the dominant mechanism leading to these emissions. Additionally, we present results of computational analysis of explosive fracture of steel cylinders performed to investigate the correlation between the time-dependent fragment size distribution and the pattern of electromagnetic emissions.


Author(s):  
Mondher Dhaouadi ◽  
M. Mabrouk ◽  
T. Vuong ◽  
A. Ghazel

2005 ◽  
Author(s):  
J. C. Allen ◽  
R. E. Goshorn ◽  
B. Zeidler ◽  
A. A. Beex
Keyword(s):  
Phase 1 ◽  

1998 ◽  
Vol 38 (10) ◽  
pp. 323-330
Author(s):  
Philip J. W. Roberts

The results of far field modeling of the wastefield formed by the Sand Island, Honolulu, ocean outfall are presented. A far field model, FRFIELD, was coupled to a near field model, NRFIELD. The input data for the models were long time series of oceanographic observations over the whole water column including currents measured by Acoustic Doppler Current Profilers and density stratification measured by thermistor strings. Thousands of simulations were made to predict the statistical variation of wastefield properties around the diffuser. It was shown that the visitation frequency of the wastefield decreases rapidly with distance from the diffuser. The spatial variation of minimum and harmonic average dilutions was also predicted. Average dilution increases rapidly with distance. It is concluded that any impact of the discharge will be confined to a relatively small area around the diffuser and beach impacts are not likely to be significant.


2015 ◽  
Vol 23 (04) ◽  
pp. 1540007 ◽  
Author(s):  
Guolong Liang ◽  
Wenbin Zhao ◽  
Zhan Fan

Direction of arrival (DOA) estimation is of great interest due to its wide applications in sonar, radar and many other areas. However, the near-field interference is always presented in the received data, which may result in degradation of DOA estimation. An approach which can suppress the near-field interference and preserve the far-field signal desired by using a spatial matrix filter is proposed in this paper and some typical DOA estimation algorithms are adjusted to match the filtered data. Simulation results show that the approach can improve capability of DOA estimation under near-field inference efficiently.


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