Engineering topics

Perlee, Caroline J.

Publications and source records attributed to Perlee, Caroline J..

3 records

NASA NTRS1990

Effects of error sources on the parallelism of an optical matrix-vector processor

The error sources in a high accuracy optical matrix-vector processor are analyzed by numerical simulation in terms of their effects on the parallelism and speed of the processor. These effects are detailed for radices -2, -4 and -8. Radix -4 is shown to provide maximum parallel processing capabilities under the effects of the system's error sources. Processing speed is shown to be a function of matrix partitioning and the number of parallel processing channels. Consequently, radix -4 operation provides a higher processing speed than radix -2 and -8 for most matrix-vector multiplications when error source effects are considered.

Perlee, Caroline J.↗

NASA NTRS1989

Optical systems for digit-serial computation

High-accuracy optical systems for implementing digit-serial computations are discussed which incorporate parallelism and carry-free addition to achieve high processing speed. Employing on-line arithmetic, parallel calculations can be performed by the concurrent execution of operations. The algorithms are shown to be problem invariant and step invariant. Architectures using optical bistable devices and optical interconnects are discussed which can implement digit-serial addition, subtraction, multiplication, and division algorithms via the present approach.

Perlee, Caroline J.↗

NASA NTRS1988

Optical matrix-vector processing for computational fluid dynamics

An optical processor to solve partial differential equations for computational fluid dynamics applications is considered. This application is new and original for optical processors. The algorithms that are used are optical realizations of the Newton-Raphson method for nonlinear equations and a new optical LU direct decomposition and Gauss-Seidel iterative solution to the resultant linear algebraic equations. These algorithms are used to solve Burger's equation (a specific form of the momentum equation in fluid dynamics). The nonlinear equations provide 1-D velocity data at each time step. Simulation results of optical processing with these algorithms on computational fluid dynamics data is included.

Perlee, Caroline J.↗