In this study, an optimization-based approach for simulating the walking motion of a digital human model is presented. A spatial skeletal model having 55 degrees of freedom is used to demonstrate the approach. Design variables are the joint angle profiles. Walking motion is generated by minimizing the mechanical energy subjected to basic physical and kinematical constraints. A formulation for s...

Motion estimation in X-ray images is a challenging task due to transparently overlapping structures from different depths. We propose to separate an X-ray sequence into a static and a dynamic layer to facilitate motion estimation. The method exploits the idea to use the minimum intensity over time and a spatial smoothness prior for both layers. For numerical optimization, we propose a condition...

Using a Monte Carlo method based on a random walk in ad hoc N-dimensional phase space, we construct N random time series having prescribed coherence spatial decay. We apply the method in seismology by designing a numerical experiment to investigate how the coherence of the bedrock motion relates to the coherence of the surface ground motion in a sedimentary valley. The main features of the cohe...

As we have discussed in Chapter 2, the current international standards for video coding (Motion JPEG, H.261, H.263, MPEG-1, MPEG-2 and MPEG-4) all make use of DCT-based encoding to remove spatial redundancy. For motion JPEG, each frame is partitioned into blocks of fixed size, and each block of pixels is transformed using DCT and then quantized. A block that contains little or no detail will re...

One of the central paradigms for classical and quantum chaos in conservative systems is the two-dimensional billiard in which particles are confined to a closed region in the plane, undergoing elastic collisions with the walls and free motion in between. We report the first realization of billiards using ultracold atoms bouncing off beams of light. These beams create the desired spatial pattern...

according to performance-based seismic design method by using energy concept, in this paper it is tried to investigate the duration and damping effects on elastic input energy due to strong ground motions. based on reliable iranian earthquake records in four types of soils, structures were analyzed and equivalent velocity spectra were computed by using input energy. these spectra were normalize...