Changes in cerebral blood flow (CBF) because of functional activation are used as a surrogate for neural activity in many functional neuroimaging studies. In these studies, it is often assumed that the CBF response is a linear-time invariant (LTI) transform of the underlying neural activity. By using a previously developed animal model system of electrical forepaw stimulation in rats (n = 11), ...

Lyapunov exponents and direction elds are used to characterize the time-scales and geometry of general linear time-varying (LTV) systems of di erential equations. Lyapunov exponents are already known to correctly characterize the time-scales present in a general LTV system; they reduce to real parts of eigenvalues when computed for linear time-invariant(LTI) systems and real parts of Floquet ex...

Two approaches to moment matching based model reduction of aperiodically sampled data systems are given. The term “aperiodic sampling” is used in the paper to indicate that the time between two consecutive sampling instants can take its value from a pre-specified finite set of allowed sampling intervals. Such systems can be represented by discrete-time linear switched (LS) state space (SS) mode...

In this paper, we consider protection schemes for linear timeinvariant (LTI) controllers in switched systems. These controllers are often digital in nature and, as such, are subject to internal hardware malfunctions (faults). A discrete-time (DT) LTI system is usually protected against faults by embedding the state-space of the original system into the state-space of a higher dimensional redund...

Most of control systems in vogue are Linear Time Invariant (LTI) systems and are characterized by several parameters such as settling time, over shoot and rise time etc. Optimization of these parameters is required to meet the desired system response and smooth operation of the system. In this paper, an optimization based compensator is designed and implemented for a closed loop LTI system and ...

The minimum phase systems have ultimately been redefined for LTI discrete-time systems, at first SISO and later square MIMO ones, as those systems for which minimum variance control (MVC) is asymptotically stable, or in other words those systems who have ‘stable’ zeros, or at last as ‘stably invertible’ systems. The redefinition has soon been extended to nonsquare discrete-time LTI MIMO systems...

The development of secondary lymphoid organs, such as lymph nodes (LNs), in the embryo results from the reciprocal action between lymphoid tissue inducer (LTi) cells and stromal cells. However, the initial events inducing LN anlagen formation before the LTi stromal cells cross-talk interactions take place are not fully elucidated. In this study, we show that the inguinal LN anlagen in mouse emb...