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A process of making physical objects directly from digital models, usually layer by layer; also known as additive manufacturing (AM). 3D printing has been hailed by many as the technology that will revolutionize how we live. As information…

Any device connected internally or externally to a computer and used in the transfer of data to or from a computer. A personal computer (PC) processes information. Data (unprocessed information) must get into the computer, and the processed…

An interdisciplinary field focused on the interactions between human users and computer systems, including the user interface and the underlying processes that produce the interactions. The contributing disciplines include computer science,…

The means by which radio waves move from one place to another. A radio wave is an electromagnetic wave that has a frequency within the radio-frequency spectrum, from 3 kHz (3000 Hz, where Hz is the symbol for hertz, a unit of frequency defined as…

A hissing, crackling, or other sudden sharp noise that tends to interfere with the reception, utilization, or enjoyment of desired signals or sounds. Perhaps the commonest form of static is that heard in ordinary broadcast receivers during…

The transmission of stereophonic audio signals over broadcast radio systems, including terrestrial analog amplitude-modulation (AM), frequency-modulation (FM) systems, and digital radio systems (terrestrial and satellite). Stereophonic…

A cable laid on the ocean floor to transmit signals. The challenge for submarine cables has been to convey signals long distances under water where there is no opportunity for easy access at intervening points. In the 1850s these were direct-current…

In a broad sense, teleconferencing encompasses the various ways and means by which people communicate with one another over some distance. In a narrow sense, a teleconference is a two-way, interactive meeting among individuals or relatively small…

A method of communication employing electrical signaling impulses produced and received manually or by machines. Telegraph signals are transmitted over open wire or cable land lines, submarine cables, or radio. Telegraphy as a communication…

The branch of engineering, also called telemetry, which is concerned with collection of measurement data at a distant or inconvenient location, and display of the data at a convenient location. One example of a complex telemetering system is used to…

A handheld device that permits communication over a network between persons who are in different locations. A traditional telephone instrument, also called a set, contains a transmitter for converting the acoustic signals of a person's voice to…

The technology of providing many types of communications services via networks that transmit voice, data, image facsimile, and video by using both analog and digital encoding formats. Component sectors and core technologies Telephone services…

Construction of the physical components of the telephone system from the central office to the end user. The telephone system can be roughly divided into three major components: outside plant, switching equipment, and interoffice facilities. The…

The electrical transmission and reception of transient visual images. Like motion pictures, television consists of a series of successive images which are registered in the brain as a continuous picture because of the persistence of vision. Each…

An electrooptical system used to pick up and convert a visual image or scene into an electrical signal called video. The video may be transmitted by cable or wireless means to a suitable receiver or monitor some distance from the actual scene. It…

Arrangements of communications channels, suitable for transmission of video and accompanying audio signals, which link together groups of television broadcasting stations or closed-circuit television users in different cities so that programs…

The process used to convert a three-dimensional image intensity into a one-dimensional television signal waveform. The image information captured by a television camera conveys color intensity (in terms of red, green, and blue primary colors) at…

The accepted criteria for a television system, including the image aspect ratio, number of lines per frame, type of scanning, original video signal bandwidth, transmission format and bandwidth, reception, demodulation, decoding, and sound system.…

A facility designed for the production of television programs, which may be broadcast live concurrently with the production or recorded for later broadcast. A television studio consists of the studio room, wherein the actual program takes place, and…

An electronic display that allows a user to interact with a computer system by touching an area or areas on the display. Touch-screen displays have been in use for many years in ATMs, checkout registers, and other applications, but gained mass…

Electronic systems that transmit radio-frequency (RF) energy with either (1) an instantaneous bandwidth of at least 500 MHz, or (2) a 10-dB fractional bandwidth (ratio of the instantaneous bandwidth measured at the –10 dB points to the center…