The Learn UI Design course by Erik Kennedy is the most comprehensive course on UI Design on the web. It covers everything from typography, color, elements, and process. If you are new to web development or design I highly recommend this course.
A Emergency Responder Radio Communications System (ERRCS), also known as a Public Safety or First Responder DAS (Distributed Antenna System), has become a mandated in-building requirement for many municipalities around the country. This network essentially re-transmits Fire or Police radio frequencies from outside a building, where the signal is presumably stronger, into the building, where it usually is weaker or non-existent.