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Full-Text Articles in Engineering
Endless State-Of-Polarization Control For Coherent Optical Communication Systems Using Nematic Liquid Crystal, Scott H. Rumbaugh
Endless State-Of-Polarization Control For Coherent Optical Communication Systems Using Nematic Liquid Crystal, Scott H. Rumbaugh
Dissertations and Theses
One of the obstacles to coherent fiber-optic communications is the unpredictable polarization drift which necessitates the use of an active polarization controlling system to match the polarizations of the signal and local oscillator. The polarization match must be maintained during the reset of any of the finite range components to prevent loss of data. We present a novel and practical system which uses three liquid crystal devices for the polarization matching process. Also, the required reset control algorithm and its derivation are described in detail.
Invariant Pattern Recognition Algorithm Using The Hough Transform, Duwang Li
Invariant Pattern Recognition Algorithm Using The Hough Transform, Duwang Li
Dissertations and Theses
A new algorithm is proposed which uses the Hough Transform to recognize two dimensional objects independent of their orientations, sizes and locations. The binary image of an object is represented by a set of straight lines. Features of the straight lines, namely the lengths and the angles of their normals, their lengths and the end point positions are extracted using the Hough Transform. A data structure for the extracted lines is constructed so that it is efficient to match the features of the lines of one object to those of another object, and determine if one object is a rotated …