We report a systematic study of the dynamics of self-propelled particles (SPPs) over a one-dimensional periodic potential landscape, which is fabricated on a microgroove-patterned ...polydimethylsiloxane (PDMS) substrate. From the measured non-equilibrium probability density function of the SPPs, we find that the escape dynamics of the slow-rotating SPPs across the potential landscape can be described by an effective potential, once the self-propulsion force is included into the potential under the fixed angle approximation. This work demonstrates that the parallel microgrooves provide a versatile platform for a quantitative understanding of the interplay among the self-propulsion force, spatial confinement by the potential landscape, and thermal noise, as well as its effects on activity-assisted escape dynamics and transport of the SPPs.
Having a virtual avatar in virtual reality(VR) applications can increase immersion. However, most of the existing VR basic sets only contain limited tracking sensors to provide effective information ...for full-body motion capture and reconstruction. Therefore, we present a lightweight real-time full-body motion capture and reconstruction prototype system only using head-mounted display and motion controllers. The system constructs HeadIK and HandIK which are optimized based on the human inverse kinematics (IK) algorithm to reconstruct the upper body motion accurately. And we address the animation blending space and FootIK to achieve natural smooth lower body motion that is not neglected by blindfolded users. Meanwhile, the animation retargeting algorithm ensures that our system can adapt to various body shapes. Experiments show that our method can reconstruct the natural movement of the whole body using only consumer-grade VR basic sets. We demonstrate that our system can enhance immersion in the VR experience and can be used in most VR applications.
In virtual reality (VR), being able to see your own virtual avatar instead of floating head and hands can enhance the immersion. However, most consumer VR devices only provide limited tracker data. ...In order to reconstruct human upper body movements from rare tracking data, we propose the HeadIK method based on human inverse dynamics optimization, and our research shows that this method can achieve the reconstruction of upper body movements using only the head-mounted display and the handle, which can enhance the immersion of VR experience.
Based on the analysis of new high resolution gravity and magnetic data, combined with swath bathymetry, the Cenozoic evolution model of the South China Sea is revised. Two major sea‐floor spreading ...episodes were revealed with different dynamic mechanism, separated by a remarkable tectonic‐sedimentary event near 25 Ma. Sea‐floor spreading started firstly in the East and Northwest Sub‐basins from ~33.5 Ma to 25 Ma, and formed the original oceanic crust with E‐W or NEE‐oriented magnetic anomalies in the northern and southern side of the East Sub‐basin nowadays and whole Northwest Sub‐basin. Since 25 Ma the sea‐floor spreading continued with different direction until 16.5 Ma. The later NW‐SE‐oriented spreading made the NE‐oriented magnetic anomalies in the central East Sub‐basin and Southwest Sub‐basin. Different tectonic areas developed during these two episodic spreading in the oceanic basin. The whole oceanic basin could be divided into three subregions from north to south. The northern and southern sub‐regions are related to the first episodic sea‐floor spreading, while the central one was formed during the later sea‐floor spreading. And the central sub‐region could be further separated into six segments by NW‐NNW‐oriented transform faults. Evidence from magnetic anomalies showed that the sea‐floor spreading in the later episode began in the east segments with C6c anomaly (23.5 Ma), and continued with C6b (22.8 Ma) in the middle segments, and with C5e (18.5 Ma) in the west. We indicated that the central part of the East Sub‐basin and Southwest Sub‐basin experienced progressive rifting from east to west and the spreading direction changed in each segment between 25 Ma and 16.5 Ma. A NNW‐trending transform fault separated the East and Southwest Sub‐basins. It not only cuts the magnetic anomalies with different directions, but also makes a nearly 95 km sinistral offset of the spreading ridge. Before the collision of the Luzon arc with the Eurasia Plate, the South China Sea was a gulf‐shape marginal sea opening to the Pacific Ocean, resulting from westward propagation of a spreading center into the Sunda Continent, as in the case of the western Gulf of Aden.
