Traditionally, it has been thought that civilization in the Middle East and the Eastern Mediterranean began in two centers, Sumer in the east between the Tigris and Euphrates, and Egypt in the west along the Nile. The earliest cities are believed to have been built in the flood plains of southern Mesopotamia during the mid-4th millennium BC.
Product life cycle management or PLM is an all-encompassing approach for innovation, new product development and introduction (NPDI) and product information management from ideation to end of life.
Pulse-position modulation (PPM) is a form of signal modulation in which M message bits are encoded by transmitting a single pulse in one of possible required time-shifts.This is repeated every T seconds, such that the transmitted bit rate is bits per second. complete PPM frame is about 22.5 ms (can vary between manufacturer). Signal low state is always 0.3 ms. It begins with a start frame (state high for more than 2 ms). Each channel (up to 8) is encoded by the time of the high state (PPM high state + 0.3 x (PPM low state) = servo PWM pulse width).