On the resolution of statics, structure, and residual normal moveout

Geophysics ◽  
1981 ◽  
Vol 46 (7) ◽  
pp. 984-993 ◽  
Author(s):  
Michael O. Marcoux

The problem of separation of reflection times into the component parts of source static, receiver static, structure time, and residual normal moveout (RNMO) is presented. A new solution is derived which is valid for wavelengths ranging from a group interval at the short end to a distance equal to the separation between the full‐fold positions at the long end. In the absence of RNMO, this solution, though not unique, is, however, optimum with regard to stability against noise in general. In the presence of RNMO, the solution is most stable against white noise. Additionally, it is concluded that the underconstrained nature of the problem is of minor practical consequence. The new method is based on the two‐dimensional (2-D) spectrum of the reflection times considered as a function of the spatial variables of common depth point (CDP) and offset. The resultant equations yield a simple, explicit solution for each separate wavelength. The computation is rapid and directly controllable by selection of the desired wavelengths. Synthetic examples are used to demonstrate the properties of this method of solution.

2015 ◽  
Vol 235 (6) ◽  
pp. 518-538 ◽  
Author(s):  
Gebhard Flaig

Summary The HP filter is the most popular filter for extracting the unobserved trend and cycle components from a time series. Many researchers consider the smoothing parameter λ = 1600 as something like a universal constant. It is well known that the HP filter is an optimal filter under some restrictive assumptions, especially that the “cycle” is white noise. In this paper we show that we can get a good approximation of the optimal Wiener-Kolmogorov filter for autocorrelated cycle components by using the HP filter with a much higher smoothing parameter than commonly used. In addition, a new method - based on the properties of the differences of the estimated trend - is proposed for the selection of the smoothing parameter.


1996 ◽  
Vol 8 (3) ◽  
pp. 133-144 ◽  
Author(s):  
María del Mar del Pozo Andrés ◽  
Jacques F A Braster

In this article we propose two research techniques that can bridge the gap between quantitative and qualitative historical research. These are: (1) a multiple regression approach that gives information about general patterns between numerical variables and the selection of outliers for qualitative analysis; (2) a homogeneity analysis with alternating least squares that results in a two-dimensional picture in which the relationships between categorical variables are graphically presented.


Author(s):  
Mark E. Benden ◽  
Kristen Miller ◽  
Eric Wilke ◽  
Eduardo Ibarra

In this article the authors illustrate how individual expert ratings can be employed to prioritize specifications for use in forced rankings. Those rankings are then used to select a design with the best overall usability. The authors provide an example of this approach in the selection of a medical transport vehicle seat to produce a more ergonomic product that could improve patient outcomes and driver safety.


1990 ◽  
Vol 05 (16) ◽  
pp. 1251-1258 ◽  
Author(s):  
NOUREDDINE MOHAMMEDI

We find the relationship between the Jackiw-Teitelboim model of two-dimensional gravity and the SL (2, R) induced gravity. These are shown to be related to a two-dimensional gauge theory obtained by dimensionally reducing the Chern-Simons action of the 2+1 dimensional gravity. We present an explicit solution to the equations of motion of the auxiliary field of the Jackiw-Teitelboim model in the light-cone gauge. A renormalization of the cosmological constant is also given.


1993 ◽  
Vol 14 (1) ◽  
pp. 259-265 ◽  
Author(s):  
Andrea Boffini ◽  
Pierre Prentki

Author(s):  
L F Campanile ◽  
R Jähne ◽  
A Hasse

Classical beam models do not account for partial restraint of anticlastic bending and are therefore inherently inaccurate. This article proposes a modification of the exact Bernoulli–Euler equation which allows for an exact prediction of the beam's deflection without the need of two-dimensional finite element calculations. This approach offers a substantial reduction in the computational effort, especially when coupled with a fast-solving schema like the circle-arc method. Besides the description of the new method and its validation, this article offers an insight into the somewhat disregarded topic of anticlastic bending by a short review of the published theories and a selection of representative numerical results.


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