Davidson, Shelby J. (born: 1868 - died: 1931) Born in Lexington, Davidson became a lawyer. He invented a paper rewinding device for a tabulating machine and an adding machine attachment for automatically adding in set amounts. Shelby Davidson's Papers are at Howard University. For more see World of Invention. History's most significant inventions and the people behind them, 2nd ed., by K. A. McGrath and B. Travers.
Unicode can be implemented by different character encodings. The most commonly used encodings are UTF-8, UTF-16 and the now-obsolete UCS-2. UTF-8 uses one byte for any ASCII character, all of which have the same code values in both UTF-8 and ASCII encoding, and up to four bytes for other characters.
For example, in a Unicode database (UTF8), you must define a VARCHAR2 column that can store up to five Chinese characters together with five English characters. In byte semantics, this would require (5*3 bytes) + (1*5 bytes) = 20 bytes; in character semantics, the column would require 10 characters.