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Morse code

Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called dots and dashes or dits and dahs. Morse code is named for an inventor of the telegraph; the International Morse Code encodes the 26 English letters A through Z, some non-English letters, the Arabic numerals and a small set of punctuation and procedural signals. There is no distinction between lower case letters; each Morse code symbol is formed by a sequence of dashes. The dot duration is the basic unit of time measurement in Morse code transmission; the duration of a dash is three times the duration of a dot. Each dot or dash within a character is followed by period of signal absence, called a space, equal to the dot duration; the letters of a word are separated by a space of duration equal to three dots, the words are separated by a space equal to seven dots. To increase the efficiency of encoding, Morse code was designed so that the length of each symbol is inverse to the frequency of occurrence in text of the English language character that it represents.

Thus the most common letter in English, the letter "E", has the shortest code: a single dot. Because the Morse code elements are specified by proportion rather than specific time durations, the code is transmitted at the highest rate that the receiver is capable of decoding; the Morse code transmission rate is specified in groups per minute referred to as words per minute. Morse code is transmitted by on-off keying of an information-carrying medium such as electric current, radio waves, visible light, or sound waves; the current or wave is present during the time period of the dot or dash and absent during the time between dots and dashes. Morse code can be memorized, Morse code signalling in a form perceptible to the human senses, such as sound waves or visible light, can be directly interpreted by persons trained in the skill; because many non-English natural languages use other than the 26 Roman letters, Morse alphabets have been developed for those languages. In an emergency, Morse code can be generated by improvised methods such as turning a light on and off, tapping on an object or sounding a horn or whistle, making it one of the simplest and most versatile methods of telecommunication.

The most common distress signal is SOS – three dots, three dashes, three dots – internationally recognized by treaty. Early in the nineteenth century, European experimenters made progress with electrical signaling systems, using a variety of techniques including static electricity and electricity from Voltaic piles producing electrochemical and electromagnetic changes; these numerous ingenious experimental designs were precursors to practical telegraphic applications. Following the discovery of electromagnetism by Hans Christian Ørsted in 1820 and the invention of the electromagnet by William Sturgeon in 1824, there were developments in electromagnetic telegraphy in Europe and America. Pulses of electric current were sent along wires to control an electromagnet in the receiving instrument. Many of the earliest telegraph systems used a single-needle system which gave a simple and robust instrument. However, it was slow, as the receiving operator had to alternate between looking at the needle and writing down the message.

In Morse code, a deflection of the needle to the left corresponded to a dot and a deflection to the right to a dash. By making the two clicks sound different with one ivory and one metal stop, the single needle device became an audible instrument, which led in turn to the Double Plate Sounder System; the American artist Samuel F. B. Morse, the American physicist Joseph Henry, Alfred Vail developed an electrical telegraph system, it needed a method to transmit natural language using only electrical pulses and the silence between them. Around 1837, therefore, developed an early forerunner to the modern International Morse code. William Cooke and Charles Wheatstone in Britain developed an electrical telegraph that used electromagnets in its receivers, they obtained an English patent in June 1837 and demonstrated it on the London and Birmingham Railway, making it the first commercial telegraph. Carl Friedrich Gauss and Wilhelm Eduard Weber as well as Carl August von Steinheil used codes with varying word lengths for their telegraphs.

In 1841, Cooke and Wheatstone built a telegraph that printed the letters from a wheel of typefaces struck by a hammer. The Morse system for telegraphy, first used in about 1844, was designed to make indentations on a paper tape when electric currents were received. Morse's original telegraph receiver used a mechanical clockwork to move a paper tape; when an electrical current was received, an electromagnet engaged an armature that pushed a stylus onto the moving paper tape, making an indentation on the tape. When the current was interrupted, a spring retracted the stylus and that portion of the moving tape remained unmarked. Morse code was developed so that operators could translate the indentations marked on the paper tape into text messages. In his earliest code, Morse had planned to transmit only numerals and to use a codebook to look up each word according to the number, sent. However, the code was soon expanded by Alfred Vail in 1840 to include letters and special characters so it could be used more generally.

Vail estimated the frequency of use of letters in the English language by counting the movable type he found in the type-cases of a local newspaper in Morristown. The shorter marks were called "dots" and the longer ones "dashes", the letters most used were assigned the shorter sequences of dots and dashes; this code was used since 1844 and became known as Morse landline code or American

Gopal Gaonkar

Gopal H. Gaonkar is a professor of engineering at Florida Atlantic University, Florida, his research interest is in Helicopter dynamics, Floquet theory and Large-Scale and parallel computing. Gaonkar is a recipient of American Helicopter Society's Fellow Award in 2005, was the Editor-in-Chief of the Journal of the American Helicopter Society, a member of the AHS Technical Council. Born and raised in Hanehalli village, Gaonkar completed his high school from the A. H. School, Bankikodla. Gaonkar earned a B. E. degree in Civil Engineering from B. V. B. College of Engineering & Technology, Hubli, a M. E. degree in Civil Engineering from VJTI, Mumbai and a D. Sc. degree in Helicopter Engineering from Washington University in St. Louis. Prior to joining FAU, Gaonkar was a research professor at the University of Southern Illinois, Edwardsville and a professor of Aerospace Engineering at the Indian Institute of Science, Bangalore. During the year 2009-2010, Gaonkar was a visiting professor at Washington University in St. Louis, his alma mater.

He is married to Anasuya Gaonkar, has two daughters. He has two granddaughters; the Smithsonian/NASA Astrophysics Data System How to Modify a Helicopter... without a Helicopter Listing of AHS Technical Fellow Award

Anderson Troop

Anderson Troop was an independent cavalry company that served in the Union Army during the American Civil War. It had an authorized strength of 110 officers and men, served for 18 months at the headquarters of Generals Don Carlos Buell and William S. Rosecrans, commanders of the Department and Army of the Ohio and Cumberland; the unit was referred to as "Anderson Troop, Pennsylvania Cavalry", while identified as the 15th Pennsylvania Cavalry because its officers raised and organized that regiment, it was never a part. The Anderson Troop was organized at Carlisle, Pennsylvania in October-November 1861 and mustered in on November 30, 1861 under the command of Captain William Jackson Palmer of Philadelphia, its organizer; the company was raised for headquarters and escort duty with Gen. Robert Anderson in Kentucky but instead became a unit of "elite scouts." Palmer, a Quaker, recruited a number of men of his faith to serve in the company, all members were hand-picked after nomination by upstanding citizens of Pennsylvania.

Among the requirements for enrollment was an oath to abstain from consumption of liquor for the duration. In July 1862 Captain Palmer, 1st Lt. William Spencer, 12 men were detailed to raise three additional companies of similar recruits to form a battalion to be known as the 1st Anderson Cavalry, with the Anderson Troop as its Company A; the recruiters, received sufficient applications to raise an entire regiment, authorized and became the 15th Pennsylvania Volunteer Cavalry. Palmer left the troop to become Spencer the lieutenant colonel. Although known as the "Anderson Cavalry," the regiment nonetheless did not incorporate the company into its ranks when it elected to remain independent under the command of its second lieutenant, Thomas Maple. 11 of its 17 officers and non-commissioned officers, with 21 of 90 privates, had joined the 15th, the majority of them commissioned as officers. With the 15th Pennsylvania Cavalry designated to become his headquarters cavalry, General William Rosecrans felt that the two units could not serve side-by-side without friction and offered the remaining 53 men of the Anderson Troop the opportunity to muster out of service, done on March 24, 1863.

Maple continued in service as a assistant army quartermaster. Moved to Louisville, Ky. December 2–7, 1861. Duty there until February 1862. Moved with headquarters Army of the Ohio to Nashville, Tenn. February 24. March to Savannah, Tenn. to reinforce the Army of the Tennessee March-April. Battle of Shiloh April 7. Advance on and siege of Corinth, Miss. April 29-May 30. Pursuit to Booneville May 31-June 12. Buell's middle Tennessee June to August. March to Louisville, Ky. in pursuit of Bragg August 21-September 26. Pursuit of Bragg into Kentucky October 1–22. Springfield October 6. Battle of Perryville October 8. March to Nashville, Tenn. October 22-November 7, duty there until December 26. Advance on Murfreesboro December 26–30. Lavergne December 26–27. Wilkinson's Cross Roads December 29. Battle of Stones River December 30–31, 1862 and January 1–3, 1863. Overall's Creek December 31, 1862. Lavergne January 1, 1863. Lytle's Creek January 5. At Murfreesboro until March 24, 1863; the company lost a total of 6 men during service.

Captain William Jackson Palmer - promoted to colonel, 15th Pennsylvania Cavalry, September 8, 1862 1st Lieutenant William Spencer - promoted to lieutenant colonel, 15th Pennsylvania Cavalry, October 1, 1862 2nd Lieutenant Thomas S. Maple List of Pennsylvania Civil War Units Pennsylvania in the Civil War Bates, Samuel P. History of the Pennsylvania Volunteers, 1861-65, 1869-1871. Dyer, Frederick H. A Compendium of the War of the Rebellion, 1908. Kirk, Charles H. History of the Fifteenth Pennsylvania Volunteer Cavalry: Which was Recruited and Known as the Anderson Cavalry in the Rebellion of 1861-1865, 1906. Williams, John A. B. Leaves from a Trooper's Diary, 1869. Attribution This article contains text from a text now in the public domain: Dyer, Frederick H.. A Compendium of the War of the Rebellion. Des Moines, IA: Dyer Publishing Co. History of Anderson Troop Roster of Anderson Troop Biography of William Jackson Palmer