Wednesday, January 6, 2010

Coffee overload?

Since November I've been drinking black coffee two to four times a week.  I've always felt unhealthy after drinking coffee; similar to the feeling I get after a meal at McDonald's.  But today was the first time I've ever felt that I would vomit if I drank another sip of my coffee.  Maybe because I had an semi-empty stomach?  I think it is time for me to go back to fun (but expensive and less caffeinated) drinks like Frappuccinos.

Friday, January 1, 2010

Feynman-Kac No.1

Here is a problem that I found from an old homework assignment.  I've modified the original to make it shorter.  Let Wt be Brownian motion and let 1z(x) = 1 if x > z and equals 0 otherwise. Consider the function



where ε is a small number.  Write down the PDE satisfied by uε(x,t ; a, T).  Show that as ε tends to zero, uε(x,t; a, T) approaches the solution of boundary value problem.  Find an analytical expression for uε(x,t; a, T).  Use Monte Carlo simulation to evaluate uε(0, 0 ; 1/2, 1) where ε = 0.1, 0.001, and 0.0001.

I'll post my attempt at the solution later. Feel free to add a solution.