Optic flow fields provide rich information about the observer's self-motion. Besides estimation of the direction of self-motion human observers are also able to discriminate the travel distances of two self-motion simulations. Recent studies have shown that observers estimate the simulated ego velocity of the self-motion simulation and integrate it over time. Thus, observers use a 3-D percept o...

In this paper, the problem of landing an unmanned aerial vehicle (UAV) on a platform with unknown oscillating motion is investigated. A control architecture that enables fast, safe and precise landing process is proposed. This control architecture consists of three modules: a tracking control module, a trajectory generation module and a vision-based motion estimation module. For the tracking co...

Keeping nanometer-sized beams in collision is an essential component in achieving design luminosity in a linear collider. The NLC stabilization strategy is conservative by including enough redundancy so that if some part does not work to specification or the incoming beam motion is worse than expected, the beams will still be kept in collision. We show simulation results with both realistic and...

An inchworm locomotion device is presented that can walk on smooth terrain. It consists of a piezoelectric unimorph and two custom-designed legs. A mathematical model is formulated by superimposing the compliant and rigid-body components of the motion. The model is subsequently utilized to evaluate the ground reaction forces and horizontal velocity. Numerical simulation is performed to select t...

Stochastic nature of earthquake has raised a challenge for engineers to choose which record for their analyses. Clustering is offered as a solution for such a data mining problem to automatically distinguish between ground motion records based on similarities in the corresponding seismic attributes. The present work formulates an optimization problem to seek for the best clustering measures. In...

The produced electric and magnetic fields due to lightning strikes to mountainous ground are determined in this paper. For the sake of simplicity a cone-shaped ground with finite conductivity is assumed to represent a natural nonflat ground. By this assumption, we deal with an axillary symmetrical structure so we use the cylindrical 2D-FDTD to save the simulation memory and time, dramatically. ...

Attenuation relation (Ground-motion prediction equation) The term “attenuation relation” is a former short-hand notation in earthquake engineering for “empirical ground-motion attenuation relationship”, now referred to as “ground-motion prediction equation” (GMPE). Attenuation relations represent empirical scaling equations that relate observed ground-motion intensity measures to parameters of ...

This paper describes a local planning, control and learning framework enabling high-speed autonomous groundvehicle traversal of rough 3D terrain replete with bumps, berms, banked-turns and even jumps. We propose an approach based on fast physical simulation and prediction, which we find offers numerous benefits: first, it takes advantage of the full expressiveness of the inherently non-linear, ...

During an earthquake, the motion of the ground spatially changes, in both amplitude and phase. The spatial variation of seismic ground motions has an important effect on the response of large structures such as bridges and dams. To be able to simulate seismic ground motions which vary in space, a representing spatial variability model is required. Data collected from closely spaced arrays of se...