We report on the experimental test of a new concept for reducing limitation on short-term frequency stability of passive frequency standards due to local oscillator phase noise. Systems that use sinewave modulation to interrogate a stable resonance are limited in short-term frequency stability by phase noise at the second harmonic of the modulation, f,. This effect limits the fractional frequen...

In this paper we propose a technique for the decomposition of a 3D image into a set of low level patterns associated to phase congruency, which we call visual patterns. Those patterns have frequency components in a wide range of bands that are aligned in phase. The method involves clustering of the band-pass filtered versions of the image according to a measure of congruence in phase or, what i...

This paper addresses the design and implementation of digital unbiased finite impulse response (FIR) filters with polynomial impulse response functions. The transfer function, its fundamental properties, and a general block-diagram are discussed for the impulse response represented with the l-degree Taylor series expansion. As a particular results, we show a fundamental identity uniquely featur...

To represent the local orientation and energy of a 1-D image signal, many models of early visual processing employ bandpass quadrature filters, formed by combining the original signal with its Hilbert transform. However, representations capable of estimating an image signal's 2-D phase have been largely ignored. Here, we consider 2-D phase representations using a method based upon the Riesz tra...

Phase-inserted fiber gratings (PI-FGs) refer to those where there exist a number of the phase-shifts (spatial spacing) among different sections (or local periods) themselves. All PI-FGs developed date can mainly be divided into three categories: phase-shifted gratings, phase-only sampled and phase-modulated which utilized could either Bragg ones (FBGs) or long-period (LPGs). As results proposed...

The multiobjective design of digital filters using the powerful Taguchi optimization technique is considered in this paper. This relatively new optimization tool has been recently introduced to the field of engineering and is based on orthogonal arrays. It is characterized by its robustness, immunity to local optima trapping, relative fast convergence and ease of implementation. The objectives ...

The structure multivector is an operator for analysing the local structure of an image. It combines ideas from the structure tensor, steerable filters, and quadrature filters where the advantages of all three approaches are brought into a single method by means of geometric algebra. The proposed operator is efficient to implement and linear up to a final steering operation. In this paper we der...

The multiobjective design of digital filters using spiral optimization technique is considered in this paper. This new optimization tool is a metaheuristic technique inspired by the dynamics of spirals. It is characterized by its robustness, immunity to local optima trapping, relative fast convergence and ease of implementation. The objectives of filter design include matching some desired freq...