Periodic sequence of stabilized wave segments in an excitable medium

2018 ◽  
Vol 97 (3) ◽  
Author(s):  
V. S. Zykov ◽  
E. Bodenschatz
Keyword(s):  
Periodic Sequence ◽  
Excitable Medium

Wave evolution over a gradual slope with turbulent friction

1983 ◽  
Vol 133 ◽  
pp. 207-216 ◽  
Author(s):  
John W. Miles
Keyword(s):  
Friction Coefficient ◽  
Gravity Wave ◽  
Solitary Waves ◽  
Periodic Sequence ◽  
Relative Amplitude ◽  
Sinusoidal Wave ◽  
Turbulent Friction ◽  
Weakly Nonlinear ◽  
Wave Evolution

The evolution of a weakly nonlinear, weakly dispersive gravity wave in water of depth d over a bottom of gradual slope δ and Chezy friction coefficient Cf is studied. It is found that an initially sinusoidal wave evolves into a periodic sequence of solitary waves with relative amplitude a/d = α1 = 15δ/4Cf if α1 < αb, where αb is the relative amplitude above which breaking occurs. This prediction is supported by observations (Wells 1978) of the evolution of swell over mudflats.

Reconstruction of a Symbolic Periodic Sequence from a Sequence with Noise

2021 ◽  
Vol 27 (10) ◽  
pp. 531-541
Author(s):  
G. N. Zhukova ◽  
◽  
M. V. Ulyanov ◽  
◽  
Keyword(s):  
Fragment Length ◽  
Edit Distance ◽  
Periodic Sequence ◽  
Levenshtein Distance ◽  
Original Sequence ◽  
Fixed Length ◽  
Approximating Sequence ◽  
Period Estimate ◽  
Correct Comparison

The problem of constructing a periodic sequence consisting of at least eight periods is considered, based on a given sequence obtained from an unknown periodic sequence, also containing at least eight periods, by introducing noise of deletion, replacement, and insertion of symbols. To construct a periodic sequence that approximates a given one, distorted by noise, it is first required to estimate the length of the repeating fragment (period). Further, the distorted original sequence is divided into successive sections of equal length; the length takes on integer values from 80 to 120 % of the period estimate. Each obtained section is compared with each of the remaining sections, a section is selected to build a periodic sequence that has the minimum edit distance (Levenshtein distance) to any of the remaining sections, minimization is carried out over all sections of a fixed length, and then along all lengths from 80 to 120 % of period estimates. For correct comparison of fragments of different lengths, we consider the ration between the edit distance and the length of the fragment. The length of a fragment that minimizes the ratio of the edit distance to another fragment of the same length to the fragment length is considered the period of the approximating periodic sequence, and the fragment itself, repeating the required number of times, forms an approximating sequence. The constructed sequence may contain an incomplete repeating fragment at the end. The quality of the approximation is estimated by the ratio of the edit distance from the original distorted sequence to the constructed periodic sequence of the same length and this length.

Excitation of standing gravity-capillary waves at an interface between two immiscible liquids by a periodic sequence of ultrasound pulses

2016 ◽  
Vol 24 (2) ◽  
pp. 155-160 ◽  
Author(s):  
A. P. Brysev ◽  
F. Zoueshtiagh ◽  
P. Pernod ◽  
V. L. Preobrazhensky ◽  
S. V. Diwakar ◽  
...  
Keyword(s):  
Capillary Waves ◽  
Periodic Sequence ◽  
Immiscible Liquids

scholarly journals Spiral wave in an inhomogeneous excitable medium

2008 ◽  
Vol 57 (11) ◽  
pp. 6815
Author(s):  
Zhang Guo-Yong ◽  
Ma Jun ◽  
Gan Zheng-Ning ◽  
Chen Yong
Keyword(s):  
Spiral Wave ◽  
Excitable Medium

scholarly journals Some origins of the low excitability of a discrete excitable medium

2009 ◽  
Vol 58 (3) ◽  
pp. 1491
Author(s):  
Dai Yu ◽  
Tang Guo-Ning
Keyword(s):  
Excitable Medium

scholarly journals Front propagation in a noisy, nonsmooth, excitable medium

2009 ◽  
Vol 23 (3) ◽  
pp. 617-638 ◽  
Author(s):  
Mohar Guha ◽  
◽  
Keith Promislow ◽  
Keyword(s):  
Front Propagation ◽  
Excitable Medium

MANIPULATING PLANAR SHAPES WITH A LIGHT-SENSITIVE EXCITABLE MEDIUM: COMPUTATIONAL STUDIES OF CLOSED-LOOP SYSTEMS

2006 ◽  
Vol 16 (08) ◽  
pp. 2333-2349 ◽  
Author(s):  
SERGEY SKACHEK ◽  
ANDREW ADAMATZKY ◽  
CHRIS MELHUISH
Keyword(s):  
Closed Loop ◽  
Space Time ◽  
Excitable Medium ◽  
Computational Studies ◽  
Wave Fronts ◽  
Nonlinear Media ◽  
Time Dynamics ◽  
Distributed Manipulation ◽  
Closed Loop Systems ◽  
Planar Shapes

We study how to employ space-time dynamics in nonlinear media to achieve distributed manipulation of objects — positioning, orienting and transporting objects by wave-fronts and patterns in excitable medium. We present the results of computational experiments of a massive parallel actuator controlled by a cellular-automaton model of an excitable medium. The model incorporates closed-loop actuation where sites of the medium can be excited not only by their closest neighbors but also by the edges of the manipulated object. We analyze motion of basic planar shapes (either initially aligned along axes or randomly oriented) induced by an actuator controlled by excitable lattice with various excitation rules. We demonstrate that space-time excitation dynamics in discrete nonlinear media bears a huge potential in terms of sensible nontrivial manipulation of planar shapes.

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