Professor Wilken works on compiler optimization, an important method for speeding up computer programs. Until recently finding exact solutions to important compiler optimizations such as instruction scheduling and register allocation was considered intractable. However our research has shown such optimizations can be solved exactly in reasonable time using methods from combinatorial optimization. The research is extremely practical (new techniques are built inside a real compiler) while being theoretically rigorous. The research includes an interesting blend of computer engineering and applied mathematics.