دانلود گزارش کارورزی و کار آموزی

چکیده :

We deal with the question of uniqueness, namely to decide when an unknown finite set of

points in Z2 is uniquely determined by its X-rays corresponding to a given set S of lattice

directions. In Hajdu (2005) [11] proved that for any fixed rectangle A in Z2 there exists a

non trivial set S of four lattice directions, depending only on the size of A, such that any

two subsets of A can be distinguished by means of their X-rays taken in the directions in

S. The proof was given by explicitly constructing a suitable set S in any possible case. We

improve this result by showing that in fact whole families of suitable sets of four directions

can be found, for which we provide a complete characterization. This permits us to easily

solve some related problems and the computational aspects.