Abstract: In a method for performing a refractive index based measurement of a property of a fluid such as chemical composition or temperature, a chirp in the local spatial frequency of interference fringes of an interference pattern is reduced by mathematical manipulation of the recorded light intensity in the interference pattern or by the physical positioning and arrangement of a detector used for capturing the interference pattern.

Abstract: In a method for performing a refractive index based measurement of a property of a fluid such as chemical composition or temperature by observing an apparent angular shift in an interference fringe pattern produced by back or forward scattering interferometry, ambiguities in the measurement caused by the apparent shift being consistent with one of a number of numerical possibilities for the real shift which differ by 2n are resolved by combining measurements performed on the same sample using light paths therethrough of differing lengths.

Abstract: The invention relates to n-tuple or RAM based neural network classification methods and systems and, more particularly, to n-tuple or RAM based classification systems where the decision criteria applied to obtain the output sources and compare these output sources to obtain a classification are determined during a training process. Accordingly, the invention relates to a system and a method of training a computer classification system which can be defined by a network comprising a number of n-tuples or Look Up Tables (LUTs), with each n-tuple or LUT comprising a number of rows corresponding to at least a subset of possible classes and comprising columns being addressed by signals or elements of sampled training input data examples.