We propose novel correlator receiver architecture with a PnpN optical thyristor operating as optical hard-limiter, and demonstrate a multiple-access interference rejection of the proposed correlator receiver. The proposed correlator receiver is composed of the 1×2 splitter, optical delay line, 2×1 combiner, and fabricated PnpN optical thyristor. The proposed correlator receiver enhances the system performance because it excludes some combinations of multiple-access interference patterns from causing errors as in optical code-division multiple access systems with conventional optical receiver shown in all previous works. It is found that the proposed correlator receiver can fully reject the interference signals generated by decoding processing and multiple access for two simultaneous users.
In medical area, many image segmentation methods have been proposed for the segmentation of the medical image. However, there are few multiscale segmentation methods that can segment the medical image so that various components within the image could be separated at multiple resolutions or scales. In this paper, we present a new algorithm for multiscale segmentation of high-resolution computed tomography (HRCT) images. With this new segmentation technique, we demonstrate that it is possible to segment the HRCT images into its
various components at multiple scales hence separating the information available in HRCT image. We show that the HRCT image can be segmented such that we get separate images for bones, tissues, lungs and anatomical structures within lungs. The processing is done in frequency domain using the Discrete Cosine Transform (DCT).