Estimation of absorption coefficient in bottom regions in multi-layered turbid media based on the time-domain depth sensitivity: a Monte Carlo investigation

2008 ◽  
Author(s):  
Chie Sato ◽  
Miho Shimada ◽  
Yoko Hoshi
Keyword(s):  
Monte Carlo ◽  
Absorption Coefficient ◽  
Time Domain ◽  
Turbid Media ◽  
Monte Carlo Investigation ◽  
Depth Sensitivity ◽  
The Time Domain

Simulation of Jack-Up Overturning Using the Monte Carlo Method With Artificially Increased Significant Wave Height

2010 ◽  
Author(s):  
Jo̸rgen Juncher Jensen
Keyword(s):  
Monte Carlo ◽  
Wave Height ◽  
Time Domain ◽  
Significant Wave Height ◽  
Reliability Index ◽  
Form Analysis ◽  
Significant Wave ◽  
The Mean ◽  
The Time Domain ◽  
Jack Up

It is well known from linear analyses in stochastic seaway that the mean out-crossing rate of a level r is given through the reliability index, defined as r divided by the standard deviation. Hence, the reliability index becomes inversely proportional to the significant wave height. For non-linear processes the mean out-crossing rate depends non-linearly on the response level r and a good estimate can be found using the First Order Reliability Method (FORM), see e.g. Jensen and Capul (2006). The FORM analysis also shows that the reliability index is strictly inversely proportional to the significant wave height irrespectively of the non-linearity in the system. However, the FORM analysis only gives an approximation to the mean out-crossing rate. A more exact result can be obtained by Monte Carlo simulations, but the necessary length of the time domain simulations for very low out-crossing rates might be prohibitive long. In such cases the property mentioned above for the FORM reliability index can be assumed valid in the Monte Carlo simulations making it possible to increase the out-crossing rates and thus reduced the necessary length of the time domain simulations by applying a larger significant wave height than relevant from a design point-of-view. The mean out-crossing rate thus obtained can then afterwards be scaled down to the actual significant wave height. Some previous results using this property have been presented by Tonguc and So¨ding (1986), albeit in a more empirical way. In the present paper the usefulness of this property to estimate extreme wave loads will be evaluated considering the overturning of a jack-up rig.

THEORETICAL SEISMOGRAMS WITH FREQUENCY AND DEPTH DEPENDENT ABSORPTION

Geophysics ◽  
1962 ◽  
Vol 27 (6) ◽  
pp. 766-785 ◽  
Author(s):  
A. W. Trorey
Keyword(s):  
Absorption Coefficient ◽  
Time Domain ◽  
Network Theory ◽  
Digital Computer ◽  
Arrival Time ◽  
Synthetic Seismograms ◽  
Multiple Reflections ◽  
Frequency Spectra ◽  
Dependent Absorption ◽  
The Time Domain

In the computation of conventional theoretical (or “synthetic”) seismograms, the effects of the variation of frequency‐dependent absorption with depth are presently ignored. Such absorption can produce significant differences in both the relative amplitudes and frequency spectra of primary and multiple reflections having the same arrival time. This paper describes a feasible way, using a digital computer of the IBM 7090 class, for computing theoretical seismograms which properly take into account the variation of absorption with both frequency and depth, it being assumed that the absorption coefficient varies linearly with frequency. It is pointed out that attempts to solve the problem using Fourier analysis in the frequency domain would lead to significant aliasing errors. Consequently a method borrowed from the field of network theory utilizing deconvolution is devised whereby solutions are obtained directly in the time domain. Both “primary” and “primary‐plus‐all‐multiple” traces are computed, the former including the “peg‐leg” multiples described by Anstey (1960) and Webster (1960). These calculations demonstrate that absorption can reduce the multiple content of theoretical seismograms.

scholarly journals Determination of the optical properties of three-layered turbid media in the time domain using the P3 approximation

OSA Continuum ◽  
2019 ◽  
Vol 2 (6) ◽  
pp. 1889 ◽  
Author(s):  
Simeon Geiger ◽  
Dominik Reitzle ◽  
André Liemert ◽  
Alwin Kienle
Keyword(s):  
Optical Properties ◽  
Time Domain ◽  
Turbid Media ◽  
The Time Domain

Faking and the Validity of Personality: A Monte Carlo Investigation

2005 ◽  
Author(s):  
Shawn Komar ◽  
Jennifer Theakston ◽  
Douglas J. Brown ◽  
Chet Robie
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Investigation
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