ECE 3704: System Stability
نویسنده
چکیده
Stability is an important concept in LTI systems theory because any (practical) signal processing system must be stable. Unstable systems have outputs which grow unbounded for a bounded input. Of course, real systems, having limited energy, outputs cannot grow to infinity. However they can move to one limit or another and stay there. For example in an electrical circuit the output voltage might become pinned to the supply voltage. Stability in general is a concept from physics. It is a property of systems described by differential equations. A system, initially at an equilibrium state 1, is stable at that equilibrium if, when disturbed 1 Equilibrium state: the derivative of all states is zero and thus the states do not change, i.e. q̇ = 0. (a brief input is applied), it returns to that equilibrium in finite time. If the differential equation is linear and time-invariant then we have an LTI system, which may or may not be stable in the above sense, called the internal stability. Laplace analysis may be applied to (stable or unstable) LTI systems, however Fourier analysis can only be applied to stable systems. So determining stability is an important first step in any analysis. After today you should be able to:
منابع مشابه
Colon cancer cell invasion is promoted by protein kinase CK2 through increase of endothelin-converting enzyme-1c protein stability
Endothelin-converting enzyme-1c (ECE-1c) is a membrane metalloprotease involved in endothelin-1 synthesis, which has been shown in vitro to have a role in breast, ovary and prostate cancer cell invasion. N-terminal end of ECE-1c displays three putative phosphorylation sites for the protein kinase CK2. We studied whether CK2 phosphorylates N-terminal end of ECE-1c as well as whether this has a r...
متن کاملRegulated expression of endothelin converting enzymes in glomerular endothelial cells.
Endothelin converting enzyme (ECE) constitutes a potential regulatory site for the production of active mature endothelins. Two cDNAs (ECE-1 and -2) encoding ECE have recently been cloned, but the regulation of the expression of these ECE has not been clarified. In the study presented here, an attempt was made to determine whether or not glomerular endothelial cells (GEN) express ECE-1 and -2, ...
متن کاملLyapunov functions for ℒ2 and input-to-state stability in a class of quantized control systems
L2 and input-to-state stability (ISS) properties of a class of linear quantized control systems are considered. The quantized control system differs slightly from the ones considered in the literature previously. A recently proposed hybrid modeling framework and corresponding Lyapunov analysis tools are used to calculate the finite gains of the closed loop system.
متن کاملRegulation of endothelin-1 synthesis by endothelin-converting enzyme-1 during wound healing.
Endothelin-1 (ET-1) is involved in the pathogenesis of a number of diseases, including wound healing. In cirrhosis, the wounding response of the liver, circulating ET-1 levels are elevated; moreover, ET-1 has potent effects on hepatic stellate cells, the key effectors of cirrhosis. In this study, we have examined the regulatory role of ECE-1, a critical enzyme involved in ET-1 synthesis, in the...
متن کامل