Synthetic aperture imaging is a high-resolution imaging technique employed in radar and sonar applications, which construct a large aperture by constantly transmitting pulses while moving along a scene of interest. In order to avoid azimuth image ambiguities, spatial sampling requirements have to be fulfilled along the aperture trajectory. The latter, however, limits the maximum speed and, ther...

A multiple-reference complex-based controller is proposed for three-phase power converters feeding nonlinear and unbalanced loads. The control scheme incorporates a stable multiple-complex coefficient filter with bandwidths that are set arbitrarily independently every harmonic under consideration. applied to an uninterruptible supply system voltage source converter. Each controlled using standa...

Sound fields are essentially band-limited phenomena, both temporally and spatially. This implies that a spatially sampled sound field respecting the Nyquist criterion is effectively equivalent to its continuous original. We describe Sound Field Reconstruction (SFR)—a technique that uses the previously stated observation to express the reproduction of a continuous sound field as an inversion of ...

We analyze impulsive systems with independent and identically distributed intervals between jumps. Our approach is based on a Volterra renewal-type equation that allows us to characterize the transitory and asymptotic behavior of the system. Necessary and sufficient conditions are given for mean square stability, stochastic stability and mean exponential stability, and the relation between the ...

In this paper, applying frequency domain approach, a delayed competitive web-site system is investigated. By choosing the parameter α as a bifurcation parameter, it is found that Hopf bifurcation occurs as the bifurcation parameter α passes a critical values. That is, a family of periodic solutions bifurcate from the equilibrium when the bifurcation parameter exceeds a critical value. Some nume...

Consensus of mobile agent system is a question with practical significance in the complex dynamics system. In this paper, an adjustable multiagent moving system with the heterogeneous communication delays is studied under the hypothesis of fixed, undirected and connected topology. The consensus of the multi-agent system is a weighted average consensus that can be adjusted by setting the paramet...

The stability of feedback systems consisting of linear time-delay plants and PID controllers has been investigated for many years by means of several methods, of which the Nyquist criterion, a generalization of the Hermite-Biehler Theorem, and the root location method are well known. The main purpose of these researches is to determine the range of controller parameters that allow stability. Ex...

Transient processes in the systems controlled by second-order sliding mode (SOSM) algorithms are analyzed in the frequency domain. A methodology of the frequency-domain analysis of transient processes that feature a decaying oscillation of variable frequency is developed. A simple criterion of the existence of finite-time convergence is proposed. It is shown that the convergence rate in a syste...

In this paper a two terminal VSC-HVDC system embedded in a strong grid ACenvironment is considered, emphasizing modeling, controllers design and small-signal stability analysis. Traditionally, DC cables are most often modeled by Π-sections, and when using them for higher frequencies or in case of transmission over long distances, approximation accuracy aspects must be considered. Here, a distri...

Geometric modeling from range scanners can be vastly improved by sampling the scene with a Nyquist criterion. This work presents a method to estimate frequency content a priori from intensity imagery using wavelet analysis and to utilize these estimates in efficient single-view sampling. The key idea is that under certain constrained and estimable image fo rmation conditions, images are a stron...