A. K. Rigler

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The utility of the back-propagation method in establishing suitable weights in a distributed adaptive network has been demonstrated repeatedly. Unfortunately, in many applications, the number of iterations required before convergence can be large. Modifications to the back-propagation algorithm described by Rumelhart et al. (1986) can greatly accelerate(More)
A novel artificial neural network, derived from neurobiological observations, is described and examples of its performance are presented. This DYnamically STable Associative Learning (DYSTAL) network associatively learns both correlations and anticorrelations, and can be configured to classify or restore patterns with only a change in the number of output(More)
-Use of the logistic derivative in backward error propagation suggests one source of ill-conditioning to be the decreasing multiplier in the computation of the elements of the gradient at each layer. A compensatory rescaling is suggested, based heuristically upon the expected value of the multiplier. Experimental results demonstrate an order of magnitude(More)
This paper offers an alternative to current practice in the specification of aspheric optical surfaces. Spline functions, a numerical analog of a flexible draftsman's curve, are used to represent a rotationally symmetric aspheric surface. We develop the interpolation formulas pertinent to ray tracing and apply an optimization procedure to design a simple(More)
The article deals with the planning of different acrylic dentures, i.e. immediate and temporary denture, transitional denture and overdenture as definitive oral rehabilitation. A case where on a single molar a telescope crown and an Ipsoclip anchor were used is described. By an Ipsoclip anchor an additional retention was provided. To achieve a successful(More)
Over a 3-yr period, 13 patients underwent surgery for a rectal tumor located between 5 and 7 cm from the anal verge. We modified Parks' procedure for a peranal sleeve anastomosis in order to avoid tension and retraction. Until now, the preferred operation for tumors at this location was abdominoperineal excision as devised by Miles. In the light of(More)