The Self-Organizing Map (SOM) is one of the popular Artificial Neural Networks which is a useful in clustering and visualizing complex high dimensional data. Conventional SOMs are based on the two-dimensional (2D) grid structure, which usually results in less accurate representation of the data. Several SOMs using spherical data structures have been proposed to remove the “border effect”. In th...

The two-dimensional discrete cosine transform (2D-DCT) is at the core of image encoding and compression applications. We present a new architecture for the 2D-DCT which is based on row-column decomposition. An efficient architecture to compute the one-dimensional fast direct (1D-DCT) and inverse cosine (1D-IDCT) transforms, which is based in reordering the butterflies after their computation, i...

A water-soluble crude polysaccharide preparation (GFP) was obtained from Grifola frondosa fruit bodies by hot water (100 °C) extraction, followed by ethanol (75%) precipitation. Purified polysaccharides, GFP75-2D was obtained from the crude material by successive fractionation using DEAE-Sepharose Fast Flow ion exchange chromatography and Sephacryl S gel filtration chromatography. GFP75-2D main...