Gilead Tadmor

TL;DR: In this article, the induced norm of the input/output operators in linear systems with L2 input and output signals is investigated and upper bounds on their induced norm are provided. But the main idea is to transform the original problem into a parametized set of indefinite LQ optimization problems, and the existence of solutions to the latter is equivalent to the solvability of a boundary value hamiltonian system or, equivalenty, of an infinite Riccati equation.

Abstract: A reduced-ordermodelling (ROM) strategy is pursued to achieve a mechanistic understanding of jet flow mechanisms targeting jet noise control. Coherent flow structures of the jet are identified by the proper orthogonal decomposition (POD) and wavelet analysis. These techniques are applied to an LES data ensemble with velocity snapshots of a three-dimensional, incompressible jet at a Reynolds number of Re=3600. A low-dimensionalGalerkin model of a three-dimensional jet is extracted and calibrated to the physical dynamics. To obtain the desired mechanistic understanding of jet noise generation, the loudest flow structures are distilled by a goal-oriented generalisation of the POD approach we term ’most observable decomposition’ (MOD). Thus, a reduction of the number of dynamically most important degrees of freedom by one order of magnitude is achieved. Capability of the presented ROM strategy for jet noise control is demonstrated by suppression of loud flow structures.

TL;DR: A real-time PIV system which exploits the low-level parallelism of the cross-correlation computation by implementing it with reconflgurable hardware and can be easily expanded to a more parallel design for faster processing given su‐cient hardware resources.

TL;DR: A novel concept of tuned Galerkin models is suggested, by which the global model interpolates a succession of similar-structure local models, which is an enabler for both improved tracking performance, as well as for optimized control hardware placement, taking into account the entire dynamic range of interest.

TL;DR: In this article, a dissipativity-based framework for the study of low-frequency oscillations in power systems and for power system stabilizer design is described, which leads to a robust controller design formulation, amenable to both H/sub /spl infin// and QFT tools.