Although structural constraints such as model order and time delay have been incorporated in the continuous time system identification since its origin, the constraints on the estimated model parameters were rarely enforced. This paper proposes a continuous time system identification approach with constraints. It shows that by incorporating physical parameter information known a priori as hard ...

Geometrically sharp “isoperimetric” estimates on eigenvalues of the Laplacian and the Schrödinger operator help us understand how frequencies and energies of physical systems are constrained by the shape and size of the domain in which the physical process takes place. For example, the Faber–Krahn inequality (Rayleigh’s conjecture) tells us precisely how low the frequency of a drum can be, if t...

Reverberant signals recorded by multiple microphones can be described as sums of sources convolved with different parameters. Blind source separation of this unknown linear system can be transformed to a set of instantaneous mixtures for every frequency band. In each frequency band, we may use the simultaneous diagonalization algorithms to separate the sources. In addition to our previous simul...

A frequency domain design method of fixed structure multivariable PID controllers that satisfy the performance index of the standard H∞ control problem with the LMI (linear matrix inequality) constraints of the PID gains is proposed. Frequency dependent bilinear matrix inequalities on the PID gain are derived and they are approximated by LMI’s for each frequency. By solving an LMI problem itera...

non-fragile observer design is the main problem of this paper. using continuous frequency distribution, the stability conditions based on integer order lyapunov theorem are derived for lipschitz class of nonlinear fractional order systems. the proposed observer is stable beside the existence of both gain perturbation and input disturbance. for the first time, in this paper a systematic method i...

most of the researches in the domain of fuzzy number comparisons serve the fuzzy number ordering purpose. for making a comparison between two fuzzy numbers, beyond the determination of their order, it is needed to derive the magnitude of their order. in line with this idea, the concept of inequality is no longer crisp however it becomes fuzzy in the sense of representing partial belonging or de...