COM
S 321 LEC 01 12/17/2001 12:00 PM
HO 110
The exam will include only four questions and will last 2.5 hours
1. Consider the following Newton equation:
where the force
is a constant. Does the
integration of this equation of motion with the Euler algorithm conserve phase
space volume?
2. Design an algorithm that uses uniform random numbers
between zero and one and generates random numbers sampled from the probability
density
.
3. Design an algorithm that uses uniform random numbers
between zero and one and generates random numbers sampled from the probability
density
,
is a constant such
that the probability density is integrated to one.
4. We wish to overlap
protein structures of
the same length
against a single core
protein structure. We assume that all
the
structures are already
overlapped with respect to each other. Hence, we are only required to find a single
rotation matrix to optimally overlap the set of
shapes against the
single core structure. (a) Write down the required constrained optimization
formula using Lagrange multipliers. (b) By analogy to the problem we worked out
in class suggests an algorithm that will address the above problem.
5. Design a Monte Carlo procedure that will optimize the
alignment of two sequences
and
(including gaps)
using a fixed constant penalty for the gap and a known substitution matrix
,
are the types of the
amino acids.
6.
is a
positive definite
matrix. Design a steepest descent algorithm to find its largest eigenvalue.
7. A Markov chain
is computed using the
following criterion:
A step is accepted with a probability 
What is the equilibrium distribution?
8. It is possible to obtain mutations in cycles i.e. instead
of
we have
, design a Dynamic Programming procedure for sequences that are
related by cyclic transformations and with complexity of
.