Solutions to linear inverse problems on the sphere, common in geodesy and geophysics, are compared for Tikhonov's method of regularization, Wiener filtering and spectral smoothing and combination as well as harmonic analysis. It is concluded that Wiener and spectral smoothing, although based on different assumptions and target functions, yield the same estimator. Also, provided that the extra i...

A unique filtering approach designed to eliminating power-line noise on shallow seismic data without affecting the frequency content of signal provides a powerful harmonic noise suppression tool for data acquired with modern large dynamic range recording systems. Amplitudes and phases of sinusoids (functions of power-line noise) present before the first arrivals can be estimated using the Leven...

Ship microgrids have recently received increased attention, mainly due to the extensive use of power electronically interfaced loads and sources. Characteristics of these microgrids are similar to islanded terrestrial microgrids, except the presence of highly dynamic large loads, such as propulsion loads. The presence of such loads and sources with power-electronic converter interfaces lead to ...

Visual motion is sensed by low-level (energy-based) and high-level (feature-based) mechanisms. Ocular following responses (OFR) were elicited in humans by applying horizontal motion to vertical square-wave gratings lacking the fundamental ("missing fundamental stimulus"). Motion consisted of successive 1/4-wavelength steps, so the features and 4n+1 harmonics (where n=integer) shifted forwards, ...

Accounting for uncertainty in three-dimensional (3D) shapes is important in a large number of scientific and engineering areas including: biometrics, biomedical imaging, and multimodality image registration. It is well known that 3D star-shaped objects can be represented by Fourier descriptors such as spherical harmonics and double Fourier series. However, the statistics of these spectral shape...

We report on a new optical device allowing to efficiently add desired functionalities to a nonlinear interaction. This is achieved by focused ion beam patterning of a nano-layer of gold sputtered at the exit facet of a nonlinear crystal. The functionality is experimentally demonstrated with three examples: spatial filtering where a fundamental beam with a poor mode quality and its' frequency-do...

This paper proposes an optimal design method for Passive power filters (PPFs) power filters set at high voltage levels to satisfy the requirements of Harmonic filtering and reactive power compensation. Multi objective Optimization models for PPF were constructed. Detuning effects and faults were also considered by constructing Constraints during the optimal process, which improved the reliabili...

This paper considers the common sonobuoy configuration comprising two horizontal dipoles mounted orthogonally together with an omnidirectional sensor. Under the assumption that, within a narrow frequency band of interest, the acoustic power impinging on the sonobuoy consists of uncorrelated Gaussian noise processes, the paper examines how data collected by the sensor can be used to infer the di...

The pulse width modulated power inverters have been increasingly using to convert DC power to AC power in small wind plants. When these inverters are used for power conversion, the integrated output voltage waveform is inevitably distorted. Although increasing the switching frequency is one choice to achieve the smoother output voltage, it adds extra harmonics to the output. There are various t...

The aim of this paper is to identify an optimum control strategy of three-phase shunt active filters to minimize the total harmonic distortion factor of the supply current. A classical PIPI cascade control solution of the output current of the active filter and the voltage across the DC capacitor based on Modulus–Optimum criterion is taken into consideration. The control system operation has be...