Wave-equation migration velocity analysis (WEMVA) is a velocity estimation technique designed to invert for velocity information using migrated images. Its capacity for handling multi-pathing makes it appropriate in complex subsurface regions characterized by strong velocity variation. WEMVA operates by establishing a linear relation between a velocity model perturbation and a corresponding mig...

The three-phase-lag model and Green–Naghdi theory without energy dissipation are employed to study the deformation of a two-temperature fiber-reinforced medium with an internal heat source that is moving with a constant speed under a hydrostatic initial stress and the gravity field.  The modulus of the elasticity is given as a linear function of the reference temperature. The exact expressions ...

A numerical study based on large eddy simulation is performed to investigate a bottom boundary layer under an oscillating tidal current. The focus is on the boundary layer response to an external stratification. The thermal field shows a mixed layer that is separated from the external stratified fluid by a thermocline. The mixed layer grows slowly in time with an oscillatory modulation by the t...

Lakes, Australia (e-mail: [email protected]; fax: +61 8 8302 5344). Abstract—A controller design technique for shaping the frequency response of a process is described. A general linear model (GLM) is used to define the form of a lag or lead compensator in discrete time using a prescribed set of basis functions. The model is then transformed via the complex z-domain into a difference eq...

To restrain the effects of vehicle-guideway dynamic interaction, a bandstop filter is introduced into the maglev levitation controller. To compensate these phase-lags in some particular band produced by the bandstop filter, an allpass filter is designed, which can not only attenuate the amplitude at the resonance frequency, but also decrease the phase-lag in relative-wide band. The simulation r...

We present a study of the complex phase lag behavior of the low-frequency (<20 Hz) quasi-periodic oscillations (QPOs) in the X-ray transient and black-hole candidate XTE J1550–564 during its very high state. We distinguish two different types of low-frequency QPOs, based on their coherence and harmonic content. The first type is characterized by a 6 Hz QPO with a Q (the QPO frequency divided by...