https://en.formulasearchengine.com/api.php?action=feedcontributions&feedformat=atom&user=68.231.124.189formulasearchengine - User contributions [en]2026-05-24T15:42:40ZUser contributionsMediaWiki 1.43.0-wmf.28https://en.formulasearchengine.com/index.php?title=Johnson_circles&diff=17482Johnson circles2014-01-03T21:49:34Z<p>68.231.124.189: /* Properties */</p>
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<div>== Summary ==<br />
Image 2 (state at t=10) of a sequence showing a Turing bifurcation from a noisy ground state to a hexagonal state in a two-component reaction-diffusion system of Fitzhugh-Nagumo type, generated by Dr. H. U. Bödeker.<br />
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The system reads: <br />
<br />
:<math><br />
\begin{array}{rl}<br />
\partial_t u &= d_u^2 \Delta u + u -u^3 - v + \kappa,\\<br />
\tau \partial_t v &= d_v^2 \Delta v + u - v<br />
\end{array}<br />
</math><br />
<br />
with ''&tau;'' = 0.1, ''d<sub>u</sub><sup>2</sup>'' = 0.00028, ''d<sub>v</sub><sup>2</sup>'' = 0.005, ''&kappa;'' = - 0.05<br />
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and was solved using a finite-element algorithm.<br />
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== Licensing ==<br />
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<br />
== Licensing ==<br />
{{self|GFDL|cc-by-sa-2.5,2.0,1.0|migration=relicense}}<br />
<br />
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