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A Stochastic Model of Crystallization in an Emulsion - Laboratoire de ...

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the rst one is to use | w w | <strong>in</strong>stead <strong>of</strong> w w <strong>in</strong> the comput<strong>in</strong>g (see gure 11),<br />

n+1 n n+1 n<br />

Figure 11: With | w w |<br />

n+1 n<br />

the second one is to consi<strong>de</strong>r that wn+1 wn<br />

has a positive me<strong>an</strong> (<strong>in</strong>stead <strong>of</strong> 0,<br />

see gure 12).<br />

That is, to <strong>in</strong>troduce a <strong>de</strong>rive vector to the Wiener process i.e. to consi<strong>de</strong>r the equation<br />

<strong>in</strong>stead <strong>of</strong><br />

∂ϕ<br />

∂t<br />

∂w<br />

= (1 ϕ) J( u) + b( u, ϕ)( cte + ) , <strong>in</strong> <br />

∂t<br />

∂ϕ<br />

∂t<br />

= (1 ϕ) J( u) + b( u, ϕ) <br />

∂w<br />

, <strong>in</strong> .<br />

∂t<br />

Figure 12: With positive me<strong>an</strong><br />

The shapes <strong>of</strong> the temperature curves are the same as the experimental one (cf. gure 10).<br />

But, we do not prove <strong>an</strong>y mathematical results for this stochastic context.<br />

An other way to take <strong>in</strong>to account this phenomenon is to modify the <strong>de</strong>term<strong>in</strong>istic mo<strong>de</strong>l by<br />

<strong>in</strong>troduc<strong>in</strong>g some convection terms, <strong>in</strong> the above equation, for example. To our knowledge, such a<br />

mo<strong>de</strong>l does not actually exist.<br />

28

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