Identification of nonlinear dynamic systems using functional link artificial neural networks.

We have presented an alternate ANN structure called functional link ANN (FLANN) for nonlinear dynamic system identification using the popular backpropagation algorithm. In contrast to a feedforward ANN structure, i.e., a multilayer perceptron (MLP), the FLANN is basically a single layer structure in which nonlinearity is introduced by enhancing the input pattern with nonlinear functional expansion. With proper choice of functional expansion in a FLANN, this network performs as good as and in some cases even better than the MLP structure for the problem of nonlinear system identification.

Nonlinear channel equalization for QAM signal constellation using artificial neural networks.

Application of artificial neural networks (ANN's) to adaptive channel equalization in a digital communication system with 4-QAM signal constellation is reported in this paper. A novel computationally efficient single layer functional link ANN (FLANN) is proposed for this purpose. This network has a simple structure in which the nonlinearity is introduced by functional expansion of the input pattern by trigonometric polynomials. Because of input pattern enhancement, the FLANN is capable of forming arbitrarily nonlinear decision boundaries and can perform complex pattern classification tasks. Considering channel equalization as a nonlinear classification problem, the FLANN has been utilized for nonlinear channel equalization. The performance of the FLANN is compared with two other ANN structures [a multilayer perceptron (MLP) and a polynomial perceptron network (PPN)] along with a conventional linear LMS-based equalizer for different linear and nonlinear channel models. The effect of eigenvalue ratio (EVR) of input correlation matrix on the equalizer performance has been studied. The comparison of computational complexity involved for the three ANN structures is also provided.

Fragility of erythrocytes in animals affected by lantana poisoning.

Clinical observations on four male cow calves and three other lantana poisoned animals under field conditions have been made along with hematological studies, including observations on plasma bilirubin content and osmotic fragility of erythrocytes. Four healthy male cow calves served as control. Five clinically advanced cases succumbed within 1 to 10 days of observation. Hematocrit values in four of the seven affected animals were abnormally high. The total plasma bilirubin content in the fatal cases was of the order of 5 to 50 times the normal value while, in calves that recovered, it was not more than 3 times. The osmotic fragility of erythrocytes was measured by the rate of hemolysis in decreasing concentrations of saline. The erythrocytes of normal animals resisted hemolysis till the saline concentration was lowered to 0.60%, and it was complete at the low saline concentration of 0.30%. However, in lantana poisoned animals, hemolysis started even in 0.72% saline and was complete at a saline concentration of 0.44%. The hemolysis curves of animals that died were far removed from the normal, but those of the calves that recovered and the one that died but had the lowest bilirubin content closely approached the normal curve.