In the present paper we propose a method for studying extreme-wave appearance based on the HigherOrder Spectral (HOS) technique proposed by West et al. (1987) and Dommermuth and Yue (1987). The enhanced HOS model we use is presented and validated on test cases. Investigations of freak-wave events appearing within longtime evolutions of 2-D and 3-D wavefields in open seas are then realized, and ...

In this research, the behaviour of the differential equation governing volume flow through a pressure-controlled valve is examined with particular attention given to the rather troublesome transition between an open and closed valve. A closed-form solution for the time evolution of volume flow is given and used to derive an update for the volume flow. The result is a smooth, nearly alias free t...

In this paper, a method is proposed to construct spectral-efficient unitary space-time codes for high-rate differential communications over multiple-antenna channels. Unlike most of the known methods which are designed to maximize the diversity product (the minimum determinant distance), our objective is to increase the spectral efficiency. The simulation results indicate that for high spectral...

This paper is concerned with the use of spectral analysis to analyze data generated by computer simulation experiments with models of economic systems. An example model serves to illustrate two different applications of spectral analysis. First, spectral analysis is used to construct confidence bands and to test hypotheses for the purpose of comparing the results of the use of two or more alter...

The problem of sinusoidal frequency estimation in heavy-tailed noise environment is addressed. A method based on the robust M -periodogram is proposed. Specifically, a suboptimal coarse frequency estimate provided by the robust M -periodogram is improved using the modified dichotomous search. Simulations that consider most common heavytailed noise models demonstrate that the proposed method out...

The importance of mucosal wave detection and estimation has been stressed in literature regarding the automatic classification and recognition of larynx pathologies from voice records. Using a new estimation method of the mucosal wave correlate and simulation results from a 2-mass model of the vocal folds the present paper shows that the main fingerprints found in the power spectral density of ...

Abstract Isotropic Gaussian random fields on the sphere are used in astronomy, geophysics, oceanography, climatology and remote sensing applications. However, to date, there is a lack of simulation algorithms that reproduce spatial covariance structure without any approximation and, at same time, parsimonious terms computation time memory storage requirements. This work presents two such rely s...

As a new inertial navigation device, the resonant optical gyroscope offers advantages that include high precision, device integration, impact resistance, and solid-state realization. This will be widely used in future military civil applications. Following consideration of factors affect accuracy improvement fiber optic gyroscopes, relationships among insertion loss, coupling coefficient, unit ...