Lynn Korwatch located on top of Telegraph Hill. George F. Sweeney and Theodore F. Baugh were the two individuals to present the idea of a wooden semaphore on top of Telegraph Hill. A semaphore is a system in which one uses two flags or poles and sends signals in an alphabetic code. Sweeney and Baugh expanded their system by placing a signal station on Point Lobos, which is located 20–30 miles from port in San Francisco. The reasoning behind this was that there was high demand from people wanting to know when the ships were arriving at an earlier time so that
Two-out-of-five code to, but strictly stronger than, a parity check. All constant-weight codes, including the two-out-of-five code, can not only detect any single-bit error, but also detect any unidirectional errors -- any case where all errors in a codeword are of a single type (0→1 or 1→0). Two-out-of-five code In telecommunication, a two-out-of-five code is an m of n code that provides exactly ten possible combinations, and thus is popular for representing decimal digits using five bits. There are ways to assign weights to each bit such that the set bits sum to the desired value, with an exception for zero. According