  We propose a method to evaluate parameters in the Hamiltonian of the Ising
chain under site-dependent transverse fields, with a proviso that we can
control and measure one of the edge spins only. We evaluate the eigenvalues of
the Hamiltonian and the time-evoultion operator exactly for a 3-spin chain,
from which we obtain the expectation values of $\sigma_x$ of the first spin.
The parameters are found from the peak positions of the Fourier transform of
the expectation value. There are four assumptions in our method, which are mild
enough to be satisfied in many physical systems.
