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A fire alarm annunciator panel is located where it is accessible to fire-fighting crews, such as at building entrances/exits. The annunciator panel will indicate the system status using lamps (or LEDs), an audible warning tone, and depending on the system technology, the exact location or approximate physical location of the source of a fire ...
A television station may show a video and photo montage set to the national anthem or other patriotic piece of music. The accompanying television video may include images of the national flag , the head of state , national heroes , national military soldiers, national symbols , and other nationalistic imagery (especially on state-owned ...
Also AM radio or AM. Used interchangeably with kilohertz (kHz) and medium wave. A modulation technique used in electronic communication where the amplitude (signal strength) of the wave is varied in proportion to that of the message signal. Developed in the early 1900s, this technique is most commonly used for transmitting an audio signal via a radio wave measured in kilohertz (kHz). See AM ...
The full-color image shows 1080 resolution. 1080p (1920 × 1080 progressively displayed pixels; also known as Full HD or FHD, and BT.709) is a set of HDTV high-definition video modes characterized by 1,920 pixels displayed across the screen horizontally and 1,080 pixels down the screen vertically; [1] the p stands for progressive scan, i.e. non ...
The ratio of width to height for a traditional television screen is 4:3, or about 1.33:1. High-definition televisions use an aspect ratio of 16:9, or about 1.78:1. The aspect ratio of a full 35 mm film frame with soundtrack (also known as the Academy ratio) is 1.375:1. [14] [15]
1801: James Pillans, headmaster and geography teacher at the Old High School in Edinburgh, Scotland, is credited with inventing the first modern blackboard. [1]1925: George Brooks of Topeka, Kansas is issued a patent for the use of corkboard as a bulletin board which you could stick tacks into. [2]
A video wall controller (sometimes called “processor”) is a device that splits a single image into parts to be displayed on individual screens. Video wall controllers can be divided into groups: Hardware-based controllers. Software-based PC & video-card controllers. Hardware-based controllers are electronic devices built for specific ...
HD Voice, or wideband audio; Heavy Duty (disambiguation) High density, a diskette density; High-definition television (HDTV), a resolution that is substantially higher than that of standard-definition television 720p (HD), a progressive HDTV signal format with 720 horizontal lines/1280 columns and an aspect ratio (AR) of 16:9; 1080p (Full HD ...