In multi-class communication networks, traffic surges due to one class of users can significantly degrade the performance for other classes. During these transient periods, it is thus of crucial importance to implement priority mechanisms that conserve the quality of service experienced by the affected classes, while ensuring that the temporarily unstable class is not entirely neglected. In thi...

This paper studies the instability of multiclass queueing networks. We prove that if a uid limit model of the queueing network is weakly unstable, then the queueing network is unstable in the sense that the total number of customers in the queueing network diverges to innnity with probability one as time t ! 1. Our result provides a converse to a recent result of Dai 2] which states that a queu...

We consider the problem of stabilizing unstable equilibria by discrete controls (the controls take discrete values at discrete moments of time). We prove that discrete control typically creates a chaotic attractor in the vicinity of an equilibrium. Artificial neural networks with reinforcement learning are known to be able to learn such a control scheme. We consider examples of such systems, di...

The occurrence of complex dynamic behavior (i.e bifurcation processes, strange and chaotic attractors) in autonomous space-invariant cellular neural networks (CNNs) is investigated. Firstly some sufficient conditions for the instability of CNNs are provided; then some classes of unstable template are identified. Finally it is shown that unstable CNNs often exhibit complex dynamics and for a cas...

Microtubules (MTs) are linked to cell mechanobiology. "Stable" and "dynamically unstable" microtubule (MT) subtypes are differentially sensitive to growth and distribution in serum starved (SS) versus full serum (FS) conditions. Atomic Force and Immunofluorescence microscopies were used to study the nanomechanical properties of the cell membrane in response to serum conditions and nocodazole. N...

for calculation of the displacements of points in micro geodesy networks, it is essential to discover stable and unstable points. without knowing stable points, calculated displacements are due to datum deficiency. in this case, calculated displacements are not valid. there are two methods to discover stable and unstable points: a-congruency robust method b- l1 norm minimization in this study t...

Networks of steps, seen in STM observations of vicinal surfaces on Au and Pt (110), are analyzed. A simple model is introduced for the calculation of the free energy of the networks as function of the slope parameters, valid at low step densities. It predicts that the networks are unstable, or at least metastable, against faceting and gives an equilibrium crystal shape with sharp edges either b...

Complex networks are generally composed of dense sub-networks called communities. Many algorithms have been proposed to automatically detect such communities. However, they are often unstable and behave nondeterministically. We propose here to use this non-determinism in order to compute groups of nodes on which community detection algorithms agree most of the time. We show that these groups of...

We present a theoretical approach for understanding the interrelations between dynamics and structure of signal transduction pathways. We consider large sets of networks with a specific number of kinases and phosphatases. Our methods are based on nonlinear differential equations and pathway dynamics is characterised in terms of signal amplification and signal duration. We show that networks wit...