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Berenstein, Carlos A.

Publications and source records attributed to Berenstein, Carlos A..

Computerized tomographic imaging for space plasma physics

The measurement of plasma electron velocity distribution functions as a problem in imaging and image reconstruction is considered. A model instrument that measures the integral of the distribution function along lines in velocity space is presented. This allows the use of the powerful mathematical and numerical methods that have recently been so successful in other areas of imaging. It is found that this approach leads to classes of instruments that are qualitatively different from contemporary designs. An investigation of different methods of reconstruction of the distribution function from integral measurements reveals that the mathematical tools appropriate to one particular imaging problem may be very different from those required to deal with another.

Zhang, Yuhong

On the number of digital straight line segments

A closed-form expression has been reported in the literature for L(N), the number of digital line segments of length N that correspond to lines of the form y = (alpha)x + beta, (0 less than or equal to alpha, beta less than 1). An asymptotic estimate for L(N) that might prove useful for many applications is proved; namely, L(N) = (N cubed)/(pi squared) + O(N squared log N). An application to an image registration problem is given.

Berenstein, Carlos A.