Efficient Time-Domain DBP using Random Step-Size and Multi-Band Quantization

The spectral analysis of magnetotelluric (MT) data for impedance tensor estimation requires the stationarity of measured magnetic (H) and electric (E) fields. However, it is well known that noise biases timedomain tensor estimates obtained via an iterative search by a descent algorithm to determine the least‐mean‐square residual between measured and estimated E data obtained from H data. To limit the noise that slows down, or even prevents convergence, the steepest descent step size is based upon the statistics of the residual (Bayes’ estimation). With respect to uncorrelated noise, the time‐domain technique is more robust than frequency‐domain techniques. Furthermore, the technique requires only short‐time stationarity. The time‐domain technique is applied to data sets (Lincoln Line sites) from the EMSLAB Juan de Fuca project (Electromagnetic Sounding of the Lithosphere and Asthenosphere Beneath the Juan de Fuca Plate), as well as to data from a southern Italian site. The results of EMSLAB data analysis are comparable to those obtained by robust remote reference processing where larger data sets were used.

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Precise-Integration Time-Domain Formulation for Optical Periodic Media

Materials ◽

10.3390/ma14247896 ◽

2021 ◽

Vol 14 (24) ◽

pp. 7896

Author(s):

Joan Josep Sirvent-Verdú ◽

Jorge Francés ◽

Andrés Márquez ◽

Cristian Neipp ◽

Mariela Álvarez ◽

...

Keyword(s):

Time Domain ◽

Fdtd Method ◽

Fdtd Simulation ◽

Integration Time ◽

Periodic Media ◽

Step Size ◽

Time Step ◽

Precise Integration ◽

Time Step Size ◽

Wide Range

A numerical formulation based on the precise-integration time-domain (PITD) method for simulating periodic media is extended for overcoming the Courant-Friedrich-Levy (CFL) limit on the time-step size in a finite-difference time-domain (FDTD) simulation. In this new method, the periodic boundary conditions are implemented, permitting the simulation of a wide range of periodic optical media, i.e., gratings, or thin-film filters. Furthermore, the complete tensorial derivation for the permittivity also allows simulating anisotropic periodic media. Numerical results demonstrate that PITD is reliable and even considering anisotropic media can be competitive compared to traditional FDTD solutions. Furthermore, the maximum allowable time-step size has been demonstrated to be much larger than that of the CFL limit of the FDTD method, being a valuable tool in cases in which the steady-state requires a large number of time-steps.

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Mean first passage time calculation for the random walk with random step size

Journal of Physics A General Physics ◽

10.1088/0305-4470/39/7/004 ◽

2006 ◽

Vol 39 (7) ◽

pp. 1575-1580 ◽

Cited By ~ 10

Author(s):

R Murugan

Keyword(s):

Random Walk ◽

First Passage Time ◽

Passage Time ◽

Mean First Passage Time ◽

Step Size ◽

First Passage ◽

Time Calculation ◽

Random Step

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Adaptive Step-size Order Statistic LMS-based Time-domain Equalisation in Discrete Multitone Systems

Discrete Time Systems ◽

10.5772/13846 ◽

2011 ◽

Author(s):

Suchada Sitjongsataporn ◽

Peerapol Yuvapoositano

Keyword(s):

Order Statistic ◽

Time Domain ◽

Step Size ◽

Adaptive Step Size ◽

Discrete Multitone ◽

Adaptive Step

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Time-domain analysis of a CRLH coupled-line coupler using the CN-FDTD method

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078718001393 ◽

2018 ◽

Vol 11 (1) ◽

pp. 94-103 ◽

Cited By ~ 1

Author(s):

Mahdieh Gholami Mayani ◽

Shahrooz Asadi ◽

Shokrollah Karimian

Keyword(s):

Time Domain ◽

Finite Difference Time Domain ◽

Fdtd Method ◽

Time Domain Analysis ◽

Step Size ◽

Dramatic Decrease ◽

Coupled Line ◽

Left Handed ◽

Difference Time ◽

Good Agreement

In this study, the implicit Crank–Nicolson finite-difference time-domain (CN-FDTD) method is applied to discretize the governing telegrapher's equations of a composite right-/left-handed (CRLH) coupled-line coupler. The unconditionally stable CN-FDTD is compared with the conventional leap-frog (LF) FDTD method. The results obtained from the CN-FDTD scheme show up to 10 times increase in the temporal step size, reflecting in a dramatic decrease in processing time; in addition to having a good agreement with the LF method and the measurements.

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