Flag semaphore (from the Greek σῆμα, sema, meaning sign and φέρω, phero, meaning to bear; altogether the sign-bearer) is the telegraphy system conveying information at a distance by means of visual signals with hand-held flags, rods, disks, paddles, or occasionally bare or gloved hands. Information is encoded by the position of the flags; it is read when the flag is in a fixed position. Semaphores were adopted and widely used (with hand-held flags replacing the mechanical arms of shutter semaphores) in the maritime world in the 19th century.[ citation needed ] It is still used during underway replenishment at sea and is acceptable for emergency communication in daylight or using lighted wands instead of flags, at night.[ citation needed ]
Telegraphy is the long-distance transmission of textual or symbolic messages without the physical exchange of an object bearing the message. Thus semaphore is a method of telegraphy, whereas pigeon post is not.
Replenishment at sea (RAS) or underway replenishment (UNREP) is a method of transferring fuel, munitions, and stores from one ship to another while under way. First developed in the early 20th century it was used extensively by the United States Navy as a logistics support technique in the Pacific theatre of World War II, permitting US carrier task forces to remain at sea indefinitely.
The current flag semaphore system uses two short poles with square flags, which a signal person holds in different positions to signal letters of the alphabet and numbers. The signalman holds one pole in each hand, and extends each arm in one of eight possible directions. Except for in the rest position, the flags do not overlap. The flags are colored differently based on whether the signals are sent by sea or by land. At sea, the flags are colored red and yellow (the Oscar flag), while on land, they are white and blue (the Papa flag). Flags are not required; their purpose is to make the characters more obvious.[ citation needed ]
The following 30 semaphore characters are presented as they would appear when facing the signalman:
A is the first letter and the first vowel of the modern English alphabet and the ISO basic Latin alphabet. It is similar to the Ancient Greek letter alpha, from which it derives. The uppercase version consists of the two slanting sides of a triangle, crossed in the middle by a horizontal bar. The lowercase version can be written in two forms: the double-storey a and single-storey ɑ. The latter is commonly used in handwriting and fonts based on it, especially fonts intended to be read by children, and is also found in italic type.
B or b is the second letter of the ISO basic Latin alphabet. It represents the voiced bilabial stop in many languages, including English. In some other languages, it is used to represent other bilabial consonants.
C is the third letter in the English alphabet and a letter of the alphabets of many other writing systems which inherited it from the Latin alphabet. It is also the third letter of the ISO basic Latin alphabet. It is named cee in English.
Numbers can be signaled by first signaling "Numerals". Letters can be signaled by first signaling "J".
The sender uses the "Attention" signal to request permission to begin a transmission. The receiver uses a "Ready to receive" signal not shown above to grant permission to begin the transmission. The receiver raises both flags vertical overhead and then drops them to the rest position, once only, to grant permission to send. The sender ends the transmission with the "Ready to receive" signal. The receiver can reply with the "Attention" signal. At this point, sender and receiver change places.
The Japanese merchant marine and armed services have adapted the flag semaphore system to the Japanese language.Because their writing system involves a syllabary of about twice the number of characters in the Latin alphabet, most characters take two displays of the flags to complete; others need three and a few only one. The flags are specified as a solid white square for the left hand and a solid red one for the right. The display motions chosen are not like the "rotary dial" system used for the Latin alphabet letters and numbers; rather, the displays represent the angles of the brush strokes used in writing in the katakana syllabary and in the order drawn. For example, the character for "O" [オ], which is drawn first with a horizontal line from left to right, then a vertical one from top to bottom, and finally a slant between the two; follows that form and order of the arm extensions. It is the right arm, holding the red flag, which moves as a pen would, but in mirror image so that the observer sees the pattern normally. As in telegraphy, the katakana syllabary is the one used to write down the messages as they are received. Also, the Japanese system presents the number 0 by moving flags in a circle, and those from 1 through 9 using a sort of the "rotary dial" system, but different from that used for European languages.
A syllabary is a set of written symbols that represent the syllables or moras which make up words. A symbol in a syllabary, called a syllabogram, typically represents an (optional) consonant sound followed by a vowel sound (nucleus)—that is, a CV or V syllable—but other phonographic mappings such as CVC, CV- tone, and C are also found in syllabaries.
The Latin or Roman alphabet is the writing system originally used by the ancient Romans to write the Latin language. Due to its use in writing Germanic, Romance, and other languages first in Europe and then in other parts of the world and due to its use in Romanizing writing of other languages, it has become widespread. It is also used officially in China and has been adopted by Baltic and some Slavic states. The Latin alphabet evolved from the visually similar Cumaean Greek version of the Greek alphabet, which was itself descended from the Phoenician abjad, which in turn derived from Egyptian hieroglyphics. The Etruscans, who ruled early Rome, adopted the Cumaean Greek alphabet, which was modified over time to become the Etruscan alphabet, which was in turn adopted and further modified by the Romans to produce the Latin alphabet.
Katakana is a Japanese syllabary, one component of the Japanese writing system along with hiragana, kanji, and in some cases the Latin script. The word katakana means "fragmentary kana", as the katakana characters are derived from components or fragments of more complex kanji. Katakana and hiragana are both kana systems. With one or two minor exceptions, each syllable in the Japanese language is represented by one character, or kana, in each system. Each kana represents either a vowel such as "a" ; a consonant followed by a vowel such as "ka" ; or "n", a nasal sonorant which, depending on the context, sounds either like English m, n, or ng, or like the nasal vowels of Portuguese.
Semaphore flags are also sometimes used as means of communication in the mountains where oral or electronic communication is difficult to perform. Although they do not carry flags, the Royal Canadian Mounted Police officers have used hand semaphore in this manner. Some surf-side rescue companies, such as the Ocean City Maryland Beach Patrol, use semaphore flags to communicate between lifeguards.The letters of the flag semaphore are also a common artistic motif. One enduring example is the peace symbol, adopted by the Campaign for Nuclear Disarmament in 1958 from the original logo created by a commercial artist named Gerald Holtom from Twickenham, London. Holtom designed the logo for use on a protest march on the Atomic Weapons Establishment at Aldermaston, near Newbury, England. On 4 April 1958, the march left Trafalgar Square for rural Berkshire, carrying Ban the Bomb placards made by Holtom's children making it the first use of the symbol. Originally, it was purple and white and signified a combination of the semaphoric letters N and D, standing for "nuclear disarmament," circumscribed by a circle.
The Royal Canadian Mounted Police is the federal and national police force of Canada. The RCMP provides law enforcement at the federal level. It also provides provincial policing in eight of Canada's provinces and local policing on contract basis in the three territories and more than 150 municipalities, 600 aboriginal communities, and three international airports. The RCMP does not provide provincial or municipal policing in either Ontario or Quebec.
In art and iconography, a motif
The Campaign for Nuclear Disarmament (CND) is an organisation that advocates unilateral nuclear disarmament by the United Kingdom, international nuclear disarmament and tighter international arms regulation through agreements such as the Nuclear Non-Proliferation Treaty. It opposes military action that may result in the use of nuclear, chemical or biological weapons and the building of nuclear power stations in the UK.
The album cover for the Beatles' 1965 album Help! was to have portrayed the four band members spelling "help" in semaphore, but the result was deemed aesthetically unpleasing, and their arms were instead positioned in a meaningless but aesthetically pleasing arrangement.Along with Morse code, flag semaphore is currently used by the Navy and also continues to be a subject of study and training for young people of Boy Scouts. In a satirical nod to the flag semaphore's enduring use into the age of the Internet, on April Fools' Day 2007 the Internet Engineering Task Force standards organization outlined the Semaphore Flag Signaling System, a method of transmitting Internet traffic via a chain of flag semaphore operators. The second episode in the second series of Monty Python's Flying Circus depicted famous stories retold using various communication systems, including Wuthering Heights in semaphore.
An album cover is the front of the packaging of a commercially released audio recording product, or album. The term can refer to either the printed cardboard covers typically used to package sets of 10 in (25 cm) and 12 in (30 cm) 78-rpm records, single and sets of 12 in (30 cm) LPs, sets of 45 rpm records, or the front-facing panel of a CD package, and, increasingly, the primary image accompanying a digital download of the album, or of its individual tracks.
The Beatles were an English rock band formed in Liverpool in 1960. With members John Lennon, Paul McCartney, George Harrison and Ringo Starr, they became regarded as the foremost and most influential music band in history. Rooted in skiffle, beat and 1950s rock and roll, the group were integral to pop music's evolution into an art form and to the development of the counterculture of the 1960s. They often incorporated classical elements, older pop forms and unconventional recording techniques in innovative ways, and later experimented with several musical styles ranging from pop ballads and Indian music to psychedelia and hard rock. As the members continued to draw influences from a variety of cultural sources, their musical and lyrical sophistication grew, and they were seen as an embodiment of the era's sociocultural movements.
Help! is the fifth studio album by English rock band the Beatles and the soundtrack from their film Help!. It was released on 6 August 1965. Produced by George Martin, it was the fifth UK album release by the band, and contains fourteen songs in its original British form. Seven of these, including the singles "Help!" and "Ticket to Ride", appeared in the film and took up the first side of the vinyl album. The second side contained seven other releases including the most-covered song ever written, "Yesterday".
In communications and information processing, code is a system of rules to convert information—such as a letter, word, sound, image, or gesture—into another form or representation, sometimes shortened or secret, for communication through a communication channel or storage in a storage medium. An early example is the invention of language, which enabled a person, through speech, to communicate what he or she saw, heard, felt, or thought to others. But speech limits the range of communication to the distance a voice can carry, and limits the audience to those present when the speech is uttered. The invention of writing, which converted spoken language into visual symbols, extended the range of communication across space and time.
An electrical telegraph is a telegraph that uses electrical signals, usually conveyed via dedicated telecommunication circuit or radio.
Morse code is a character encoding scheme used in telecommunication that encodes text characters as standardized sequences of two different signal durations called dots and dashes or dits and dahs. Morse code is named for Samuel F. B. Morse, an inventor of the telegraph.
Semaphore usually refers to flag semaphore. It may also refer to;
The Transmission Control Protocol (TCP) is one of the main protocols of the Internet protocol suite. It originated in the initial network implementation in which it complemented the Internet Protocol (IP). Therefore, the entire suite is commonly referred to as TCP/IP. TCP provides reliable, ordered, and error-checked delivery of a stream of octets (bytes) between applications running on hosts communicating via an IP network. Major internet applications such as the World Wide Web, email, remote administration, and file transfer rely on TCP. Applications that do not require reliable data stream service may use the User Datagram Protocol (UDP), which provides a connectionless datagram service that emphasizes reduced latency over reliability.
A communication channel or simply channel refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel in telecommunications and computer networking. A channel is used to convey an information signal, for example a digital bit stream, from one or several senders to one or several receivers. A channel has a certain capacity for transmitting information, often measured by its bandwidth in Hz or its data rate in bits per second.
A semaphore telegraph is a system of conveying information by means of visual signals, using towers with pivoting shutters, also known as blades or paddles. Information is encoded by the position of the mechanical elements; it is read when the shutter is in a fixed position. The most widely used system was invented in 1792 in France by Claude Chappe, and was popular in the late eighteenth to early nineteenth centuries. Lines of relay towers with a semaphore rig at the top were built within line-of-sight of each other, at separations of 5 to 20 miles. Operators at each tower would watch the neighboring tower through a spyglass, and when the semaphore arms began to move spelling out a message, they would pass the message on to the next tower. This system was much faster than post riders for conveying a message over long distances, and also had cheaper long-term operating costs, once constructed. Semaphore lines were a precursor of the electrical telegraph, which would replace them half a century later, and would also be cheaper, faster, and more private. The line-of-sight distance between relay stations was limited by geography and weather, and prevented the optical telegraph from crossing wide expanses of water, unless a convenient island could be used for a relay station. Modern derivatives of the semaphore system include flag semaphore and the heliograph.
Optical communication, also known as optical telecommunication, is communication at a distance using light to carry information. It can be performed visually or by using electronic devices. The earliest basic forms of optical communication date back several millennia, while the earliest electrical device created to do so was the photophone, invented in 1880.
Asynchronous serial communication is a form of serial communication in which the communicating endpoints' interfaces are not continuously synchronized by a common clock signal. Instead of a common synchronization signal, the data stream contains synchronization information in form of start and stop signals, before and after each unit of transmission, respectively. The start signal prepares the receiver for arrival of data and the stop signal resets its state to enable triggering of a new sequence.
Base64 is a group of similar binary-to-text encoding schemes that represent binary data in an ASCII string format by translating it into a radix-64 representation. The term Base64 originates from a specific MIME content transfer encoding. Each Base64 digit represents exactly 6 bits of data. Three 8-bit bytes can therefore be represented by four 6-bit Base64 digits.
Flag signals can mean any of various methods of using flags or pennants to send signals. Flags may have individual significance as signals, or two or more flags may be manipulated so that their relative positions convey symbols. Flag signals allowed communication at a distance before the invention of radio and are still used especially in connection with ships.
Gerald Herbert Holtom was a British artist and designer. He designed the ND logo,which was adopted, non-exclusively, by the British Campaign for Nuclear Disarmament (CND), and became an international peace symbol.
The International Code of Signals (ICS) is an international system of signals and codes for use by vessels to communicate important messages regarding safety of navigation and related matters. Signals can be sent by flaghoist, signal lamp ("blinker"), flag semaphore, radiotelegraphy, and radiotelephony. The International Code is the most recent evolution of a wide variety of maritime flag signalling systems.
ACP-131 is the controlling publication for the listing of Q codes and Z codes. It is published by the Combined Communications Electronics Board (CCEB) countries, and revised from time to time. When the meanings of the codes contained in ACP-131 are translated into various languages, the codes provide a means of communicating between ships of various nations, such as during a NATO exercise, when a common language is not in effect.
Signalman was a U.S. Navy rating for sailors that specialized in visual communication. See Signaller for more about the roles of Signalmen.
In computer networking, Semaphore Flag Signaling System (SFSS) is a humorous proposal to carry Internet Protocol (IP) traffic by semaphores. Semaphore Flag Signaling System was initially described in, an April Fools RFC issued by the Internet Engineering Task Force edited by J. Hofmueller, et al. and released on April Fool's Day 2007. It is one of several April 1 RFCs.
In packet switching networks, traffic flow, packet flow or network flow is a sequence of packets from a source computer to a destination, which may be another host, a multicast group, or a broadcast domain.defines traffic flow as "an artificial logical equivalent to a call or connection." defines traffic flow as "a sequence of packets sent from a particular source to a particular unicast, anycast, or multicast destination that the source desires to label as a flow. A flow could consist of all packets in a specific transport connection or a media stream. However, a flow is not necessarily 1:1 mapped to a transport connection." Flow is also defined in as "a set of IP packets passing an observation point in the network during a certain time interval."
A Request for Comments (RFC), in the context of Internet governance, is a type of publication from the Internet Engineering Task Force (IETF) and the Internet Society (ISOC), usually describing methods, behaviors, research, or innovations applicable to the working of the Internet and Internet-connected systems.
The Stream Control Transmission Protocol (SCTP) is a computer networking communications protocol which operates at the transport layer and serves a role similar to the popular protocols TCP and UDP. It is standardized by IETF in.
He [Gerald Holtom] considered using a Christian cross motif but, instead, settled on using letters from the semaphore – or flag-signalling – alphabet, super-imposing N (uclear) on D (isarmament) and placing them within a circle symbolising Earth.
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