Quaternions are still largely misunderstood and often considered an “exotic” signal
representation without much practical utility despite the fact that they have been around the …

Rotationally symmetric systems can exhibit acoustic fluctuations in the azimuthal direction. In
experimental works the nature (standing or spinning) of these fluctuations is often described …

Vector acoustic field properties measured during the 2017 Seabed Characterization
Experiment (SBCEX17) are presented. The measurements were made using the Intensity …

In ocean acoustics, shallow water propagation is conveniently described using normal mode
propagation. This article proposes a framework to describe the polarization of normal …

This paper suggests a new method for detecting and diagnosing bearing faults in three-
phase asynchronous devices using the periodogram estimation of the Power Spectral …

This paper proposes a new method called multiscale quaternion Weber local descriptor
histogram (MQWLDH) for feature extraction of hyperspectral images (HSIs), which is used to …

This article introduces quaternion non-negative matrix factorization (QNMF), which
generalizes the usual non-negative matrix factorization (NMF) to the case of polarized …

A complete framework for the linear time-invariant (LTI) filtering theory of bivariate signals is
proposed based on tailored quaternion Fourier transform. This framework features a direct …

We investigate the beamforming method for detecting signals and estimating their directions
of arrival for an acoustic vector-sensor linear array mounted near a baffle. The array …

It is well known that a complex circulant matrix can be diagonalized by a discrete Fourier
matrix with imaginary unit. The main aim of this paper is to demonstrate that a quaternion …