In this paper we develop and demonstrate a Linear Parameter Varying (LPV) stabilisation technique. The method systematically obtains a controller of a gain-scheduling nature that exhibits a certain level of robustness and performance for the LPV system. We propose a global approach to simultaneously design a robust controller as well as devise a procedure which uses the solution to the controll...

Anti-slug control in multiphase risers involves stabilizing an open-loop unstable operating point. Existing anti-slug control systems are not robust and tend to become unstable after some time, because of inflow disturbances or plant dynamic changes, thus, requiring constant supervision and retuning. A second problem is the fact that the ideal setpoint is unknown and we could easily choose a su...

Fast response tracer flux measurements are compared against flux footprint predictions from both a Lagrangian stochastic simulation and an analytical solution to the equation of diffusion over a canopy of intermediate roughness. A turbulent tracer flux experiment was conducted over a peach orchard for a range of mildly unstable to very unstable conditions. For this purpose, a line source was us...

A detailed solution of an initial value problem of a vertically localized initial perturbation in rotating magnetized vertically stratified disk is presented. The appropriate linearized MHD equations are solved by employing the WKB approximation and the results are verified numerically. The eigenfrequencies as well as eigenfunctions are explicitly obtained. It is demonstrated that the initial p...

one of the main steps within the geoid computation methodology without applying the stokes formula is downward continuation of the harmonic residual observables from the surface of the earth down to the surface of the reference ellipsoid. this downward continuation is done via the abel-poisson integral and its derivatives. this integral in which the unknowns, i.e. harmonic residual potential va...

We consider the mass-critical focusing nonlinear Schrödinger equation in the presence of an external potential, when the nonlinearity is inhomogeneous. We show that if the inhomogeneous factor in front of the nonlinearity is sufficiently flat at a critical point, then there exists a solution which blows up in finite time with the maximal (unstable) rate at this point. In the case where the crit...

We consider the family of long-wave unstable lubrication equations ht = −(hhxxx)x − (hhx)x with m ≥ 3. Given a fixed m ≥ 3, we prove the existence of a weak solution that becomes singular in finite time. Specifically, given compactly supported nonnegative initial data with negative energy, there is a time T∗ < ∞, determined by m and the H1 norm of the initial data, and a compactly supported non...

The essence of the complex dynamics originated by the interaction between the pilot–&–aircraft can be captured on labs, by means of unstable–underactuated mechanical systems. Thus, the unactuated links describe the autonomous aircraft dynamics (flight control system) and the actuated the manual one (pilot). It is well–known that, in some flight conditions, the pilot–&–aircraft interaction can r...

Common peer-to-peer (P2P) file sharing clients usually download at an unstable rate and hardly exploit the available bandwidth offered by low rate sources. The characteristic fluctuational throughput of the source peers might be caused by user behavior factors such as running other bandwidth consuming tasks, throttling of download speed by P2P software or even termination of the source. In this...

We construct center-stable and center-unstable manifolds, as well as stable and unstable manifolds, for the nonlinear Klein–Gordon equation with a focusing energy subcritical nonlinearity, associated with a family of solitary waves which is generated from any radial stationary solution by the action of all Lorentz transforms and spatial translations. The construction is based on the graph trans...