Burrowing robots are a class of robot that can move themselves in soil for geotechnical site investigation, search and rescue, sensor deployment, inspection, monitoring, and construction purposes. Moving through soil is a challenging problem due to high drag force and complex underground environments. Many organisms adopt well-evolved strategies and...

Automatic face authorization has long been an active research area for its wide potential applications, such as law enforcement, security access, and man-machine interaction. Among various approaches, Principal Components Analysis (PCA) to face imaging is now a cornerstone in face recognition. However, 2-D face recognition methods are in general unable...