When the spacecraft flies much faster than the sound speed (~1200 km/h), the airflow disturbances deflected forward from the spacecraft cannot get away from the
Sensing coverage is a fundamental problem in sensors networks. Different from traditional isotropic sensors with sensing disk, directional sensors may have a li
A project of elimination of potentially dangerous asteroid Apophis which April 13, 2029 year approaches to Earth at a distance of 36,000 km is considered. The e