This paper addresses the synthesis of a predictive controller for a nonlinear process based on a fuzzy model of the Takagi–Sugeno (T–S) type, resulting in a stable closed-loop control system. Conditions are given that guarantee closed-loop robust asymptotic stability for open-loop bounded-input–boundedoutput (BIBO) stable processes with an additive 1-norm bounded model uncertainty. The idea is ...

In this paper we deal with the stability analysis problem of cascaded non autonomous nonlinear systems. In particular we answer to the following questions: (i) What happens with the solutions of a time-varying nonlinear system which is globally uniformly stable, when it is perturbed by the output of a globally exponentially stable system (GES), in particular, when both systems form a cascade?. ...

In order to maintain stability, one of the variables, say y, must be a “jump” variable (or a “control” variable) which can respond instantaneously to new information and/or shocks, while the other variable, x, must be a “sluggish” variable (or a “state” variable) which is constrained to evolve continuously at all times. Therefore, unlike the “jump” variable y, x cannot change instantaneously in...

In this paper a new variety of the digitized version of an analog phase locked loop has been proposed in order to overcome the conditionally stable nature of a software controlled phase locked loop. Also the conventional need of a low pass filter to filter out the high frequency components at the output of a phase detector is avoided through the use of In-phase and Quadrature signals. MATLAB si...

Our essay begins with explication of the notion of eigenform as pioneered by Heinz von Foerster in his papers (Foerster, 1981, pp. 258–271, pp. 274–285, pp. 288–309) and explored in papers of the author (Kauffman, 2003, pp. 73–90, 2005, pp. 129–150; 2009, pp. 121–137, 2010, pp. 48–89). In Foerster (1981, pp. 274–285) the familiar objects of our existence can be seen as tokens for the behaviors ...

Entropic stabilization of native protein structures typically relies on strategies that serve to decrease the entropy of the unfolded state. Here we report, using a combination of experimental and computational approaches, on enhanced thermodynamic stability conferred by an increase in the configurational entropy of the folded state. The enhanced stability is observed upon modifications of a lo...

Isothermal microcalorimetry is becoming widely used for monitoring biological activities in vitro. Microcalorimeters are now able to measure heat production rates of less than a microwatt. As a result, metabolism and growth of relatively small numbers of cultured bacteria, protozoans, human cells and even small animals can be monitored continuously and extremely accurately at any chosen tempera...

We consider the control design for a class of single-input single-output (SISO) switched linear systems of arbitrary order. Our approach is motivated by applications in which the major design objective is to achieve similar behaviour of the closed-loop system in each system mode ensuring stability for arbitrary switching. We study the stability of the resulting closed-loop system and exploit th...

Purpose – The purpose of the paper is to introduce the Dynamic Phasor Modelling (DPM) approach for stability investigation and control design of single-phase Phase Locked Loops PLLs. The aim is to identify the system instabilities not predicted using the existent analysis and design methods based on the simplified average model approach. Design/methodology/approach – This paper starts by invest...

A stability test for time invariant linear systems can also be derived in the frequency domain. It is known as Nyquist stability criterion. It is based on the complex analysis result known as Cauchy's principle of argument. Note that the system transfer function is a complex function. By applying Cauchy's principle of argument to the open-loop system transfer function, we will get information a...