The main purpose of this paper is concerned with the sensitivity analysis of main rotor dynamic response pertaining to variation of some relevant system parameters effectively supports the preliminary design of both articulated and hingeless helicopter rotor configurations. The methodology is laid out based on Galerkin solution of partial differential equation (PDE) of main rotor with flexible ...

We report the first experimental observation of Beliaev damping of a collective excitation in a Bose-condensed gas. Beliaev damping is not predicted by the Gross-Pitaevskii equation and so this is one of the few experiments that tests BEC theory beyond the mean field approximation. Measurements of the amplitude of a high frequency scissors mode, show that the Beliaev process transfers energy to...

In this paper we present the first extension of the backstepping methods developed for control of parabolic PDEs (modeling thermal, fluid, and chemical reaction dynamics, including Navier-Stokes equations and turbulence) to secondorder PDE systems (often referred loosely as hyperbolic) which model flexible structures and acoustic. We introduce controller and observer designs capable of adding d...

We study the relation between PageRank and other parameters of information networks such as in-degree, out-degree, and the fraction of dangling nodes. We model this relation through a stochastic equation inspired by the original definition of PageRank. Further, we use the theory of regular variation to prove that PageRank and in-degree follow power laws with the same exponent. The difference be...

in this paper, the unified power flow controller (upfc) is enhanced with a chaotic particle swarm optimization (cpso) damping controller in order to mitigate the low frequency oscillations (lfo) in a single machine infinite bus (smib) power system. the designed damping controller is an optimized lead-lag controller, which extracts the speed deviation of the generator rotor and generates the out...

Glass fiber reinforced resol/vac-eha composites have been fabricated in laboratory to determine the dynamic behavior of glass fiber reinforced composites. Resol solution was blended with vinyl acetate-2-ethylhexyl acrylate (vac-eha) resin in an aqueous medium with varying volume fraction of glass fibers. The role of fiber/matrix interactions in glass fibers reinforced composites were investigat...

Soft storey buildings are characterized by having a storey which has a lot of open spaces. This soft storey creates a major weak point in an earthquake. Since soft stories are classically associated with retail spaces and parking garages, they are often on the lower stories of a building, which means that when they collapse, they can take the whole building down with them, causing serious struc...