An encryption algorithm management system has a terminal unit and a center unit that have a common cipher-key to a ciphered encryption algorithm. Wavefronts of the ultrasonic waves emitted by the one or the plurality of ultrasonic emitting units are sphere surfaces with uniform radius, and the one or the plurality of ultrasonic emitting units can reflect ultrasound. A computer associated with a given travel service provider is then operated to determine whether the employee was identified in a previously received travel notification message. An image-guided radiation therapy system is provided including a treatment delivery system, a multi-energy imaging system, and a system processor.