In the paper output feedback control of Boolean control networks (BCNs) is investigated. First, necessary and sufficient conditions for the existence of a time-invariant output feedback (TIOF) law, stabilizing the BCN to some equilibrium point, are given, and constructive algorithms to test the existence of such a feedback law are proposed. Two sufficient conditions for the existence of a stabi...

The 3D pendulum consists of a rigid body, supported at a fixed pivot, with three rotational degrees of freedom; it is acted on by gravity and it is fully actuated by control forces. The 3D pendulum has two disjoint equilibrium manifolds, namely a hanging equilibrium manifold and an inverted equilibrium manifold. This paper shows that a controller based on angular velocity feedback can be used t...

Many basic analog blocks and structures, which contain positive feedback loops, are vulnerable to the presence of one or more undesired stable equilibrium points. The phenomena of multiple equilibrium points is investigated with emphasis on using a temperature-domain representation to identify equilibrium points in some circuits that have a single positive feedback loop. By example, it is shown...

A pair of muscles powering the human joint in an antagonistic configuration exemplifies the main difference between standard industrial robots and biological motor systems. Since muscles have a natural stiffness that varies with the muscle activation level, the central nervous system (CNS) can generate stable equilibrium postures, towards which the arm is attracted, by properly regulating the a...

A coarse resolution coupled ocean-atmosphere simulation where surface albedo feedback is suppressed by prescribing surface albedo is compared to one where snow and sea ice anomalies are allowed to affect surface albedo. Canonical CO -doubling experiments were performed with both models to assess the impact of this feedback on equilibrium response to external forcing: It accounts for about half ...

Different mechanisms, including equilibrium and non-equilibrium processes, have been taken into account as possible theoretical explanations of species coexistence. Despite the ample evidence on the existence of negative plant /soil feedback in both agriculture and natural vegetation, the role of these processes in the organization and dynamics of plant communities has so far been neglected. In...

Homeostatic processes that provide negative feedback to regulate neuronal firing rates are essential for normal brain function. Indeed, multiple parameters of individual neurons, including the scale of afferent synapse strengths and the densities of specific ion channels, have been observed to change on homeostatic time scales to oppose the effects of chronic changes in synaptic input. This rai...

We investigate the large spread of the response to anthropogenic forcing simulated by state-of-the-art climate models in the Arctic. A feedback analysis framework specific to the Arctic is developed to address this issue. The feedback analysis shows that a large part of the spread of Arctic climate change is explained by the longwave feedback parameter. The large spread of the negative longwave...

This paper discusses the problem of obtaining feedback laws to asymptotically stabilize relative equilibria of mechanical systems with symmetry. We show how to stabilize an internally unstable relative equilibrium using internal actuators. The methodology is that of potential shaping, but the system is allowed to be underactuated, i.e., have fewer actuators than the dimension of the shape space...