this paper presents a new observer design methodology for a time varying actuator fault estimation. a new linear matrix inequality (lmi) design algorithm is developed to tackle the limitations (e.g. equality constraint and robustness problems) of the well known so called fast adaptive fault estimation observer (fafe). the fafe is capable of estimating a wide range of time-varying actuator fault...

This paper presents a new observer design methodology for a time varying actuator fault estimation. A new linear matrix inequality (LMI) design algorithm is developed to tackle the limitations (e.g. equality constraint and robustness problems) of the well known so called fast adaptive fault estimation observer (FAFE). The FAFE is capable of estimating a wide range of time-varying actuator fault...

the aim of this work is to investigate the variational discretization and mixed finite element methods for optimal control problem governed by semi linear parabolic equations with integral constraint. the state and co-state are approximated by the lowest order raviart-thomas mixed finite element spaces and the control is not discreted. optimal error estimates in l2 are established for the state...

Integral quadratic constraints (IQC) arise in many optimal and/or robust control problems. The IQC approach can be viewed as a generalization of the classical multiplier approach in the absolute stability theory. In this paper, we study the relationship between the two approaches for robust stability analysis. The key result shows that for many applications, the existence of an IQC is equivalen...

It is generally accepted that residual stresses present in welded joints alter the conditions for fracture initiation by contributing to the crack-driving force. In this study, it is shown that weld residual stresses also alter crack-tip constraint, affecting fracture in an additional way. The fracture behavior of two crack geometries, a large pressure shell and a small fracture specimen, both ...

This paper presents the determination of power transfer between two buses that takes into account the dynamic security constraint. The dynamic security constraint based transient stability has been found to be one of the limiting factors in determining the power transfer so-called as the available transfer capability (ATC). The multimachine integral square generator angle (ISGA) index is used t...

We study the problem of linear instability in non-vacuum spacetimes. For vacuum spa.cetimes linear instability occurs when the spacetime has Killing vectors. In the non-vacuum case, one must prescribe how the sources are to vary. For one natural choice, we show that the signal for instability is the existence of Integral Constraint Vector fields. These vector fields lead, as in the vacuum case,...

This manuscript concerns robust stability analysis of discrete-time LTI systems with varying time delays. The stability problem is treated in the Integral Quadratic Constraint (IQC) framework. The novelty and main contribution of the manuscript is the integral quadratic constraint characterization of the discrete-time time-varying delay operator. The characterization enables the IQC analysis to...