Abdallah K. Cherri

Generalization of the Ronchi, sinusoidal, and triangular rulings for Gaussian-laser-beam-diameter measurements.

Transmittance (or reflectance) characteristics of generalized gratings are described for Gaussian-laserbeam-diameter measurements. The generalized gratings provide for accurate measurement of both small and large Gaussian beam diameters and are superior to the Ronchi, the triangular, and the sinusoidal rulings. Also the proposed generalized gratings account for all width variations of the opaque, transparent, and transitional regions within a selected ruling.

Morphological transformations based on optical symbolic substitution and polarization-encoded optical shadow-casting systems

Abstract By conbining two powerful optical computing techniques, namely, optical symbolic substitution (OSS) and polarization-encoded optical shadow-casting (POSC), morphological or shape transformation operations are demonstrated. Accordingly, erosion, dilation, opening, and closing operations are realized using both OSS and POSC schemes. These morphological operations are used for noise removal in binary images.

Periodic exponential ruling for the measurement of Gaussian laser beam diameters

The spot size measurement of a Gaussian laser beam is extended to wide dynamic range through the formulation of a novel exponential grating. It is found that the exponential grating provides accurate measurement for both extremely small and large Gaussian beam diameters and proves to be superior to Ronchi, triangular, and sinusoidal rulings.

Image enhancement using optical symbolic substitution

Rotation-invariant image sharpening schemes based on Roberts operators, difference operators, Laplacian, and high-frequency emphasis are realized using optical symbolic substitution. Symbolic systems based on both optical content-addressable memory and phase-only holograms are considered for these image enhancement schemes.

Fuzzy route choice: an enhancement to future automotive navigation systems

A fuzzy model of the route choice process was developed based on the present production Automap Navigation System and then simulated using the Cubicalc fuzzy simulator package. The simulation ranked the route alternatives in the same order as the production navigation system. This model was then greatly simplified and re-simulated, with performance equal to the original model. The route choice model was then extended to include additional input variables not present in the Automap System and a possible scenario was simulated. The project conclusion is that for present automotive navigation systems, the use of fuzzy set theory merely complicates the system without improving performance. However, future navigation systems which use more input data may benefit from fuzzy rules.<<ETX>>

Full-wave rectified sinusoidal ruling for measuring Gaussian beam diameters.

A novel full-wave rectified sinusoidal grating is proposed for the measurement of Gaussian laser beam diameters. It is found that this new grating provides accurate measurement for both small and large Gaussian beam diameters and has proved to be superior to the Ronchi, triangular, and sinusoidal rulings.

Logical equivalence of optical symbolic substitution and shadow-casting schemes

Abstract The logical equivalence between two powerful optical computing techniques, namely, optical symbolic substitution and optical shadow-casting is investigated. A common basis for both schemes is developed and their roots are traced back to fundamental principles of logic design. Both shadow-casting and symbolic substitution based optical computing operations are shown to be equivalent to logical sum of product operations.

Restoration of moving binary images degraded owing to phosphor persistence

The degraded images of dynamic objects obtained by using a phosphor-based electro-optical display are analyzed in terms of dynamic modulation transfer function (DMTF) and temporal characteristics of the display system. The direct correspondence between the DMTF and image smear is used in developing real-time techniques for the restoration of degraded images.

Multi-bit parallel digital adder using a symmetric signed-digit numbers

A new recoding truth-table (using redundant signed-digit numbers) with a symmetrical complemented relationship between input minterms and their corresponding output bits is developed. Multi-bit parallel digital circuits for both the recoding algorithm and the adder logical functions are realized using OR-AND and AND-OR realizations.<<ETX>>

Morphological hit-or-miss transformation using polarization-encoded optical shadow casting and optical symbolic substitution

By combining two powerful optical computing techniques, namely, optical symbolic substitution (OSS) and polarization-encoded optical shadow-casting (POSC), an optical morphological hit-or-miss transformation is demonstrated and used in the recognition of perfect and imperfect shapes.