We consider the problem of boundary feedback control single-input-single-output one-dimensional linear hyperbolic systems when sensing and actuation are anti-located. The main issue output stabilization is that it requires dynamic laws include delayed values (directly or through state observers) which may not be robust to infinitesimal uncertainties on characteristic velocities. purpose this pa...

Tracking of a reference signal (assumed bounded with essentially bounded derivative) is considered for multi-input, multi-output linear systems satisfying the following structural assumptions: (i) arbitrary – but known – relative degree, (ii) the “high-frequency gain” matrix is sign definite – but of unknown sign, (iii) exponentially stable zero dynamics. The first control objective is tracking...

We consider boundary stabilization for a multi-dimensional wave equation with boundary control matched disturbance that depends on both time and spatial variables. The active disturbance rejection control (ADRC) approach is adopted in investigation. An disturbance estimator is designed to estimate, in real time, the disturbance, and the disturbance is canceled in the feedback loop with its appr...

Many modern database applications require content-based similarity search capability in numeric attribute space. Further, users’ notion of similarity varies between search sessions. Therefore online techniques for adaptively refining the similarity metric based on relevance feedback from the user are necessary. Existing methods use retrieved items marked relevant by the user to refine the simil...

Feedback systems are important in applications, for example, optical feedback lasers, phase-locked frequency synthesizers and wave equations with feedback stabilization at the boundary, and the problem regarding sensitivity and robustness of the feedback system with respect to time delays has attracted a lot of attention. In this paper we continue the discussion on sensitivity and robustness of...