Clicker
A clicker, sometimes called a cricket, is any device that makes a clicking sound, usually when deliberately activated by its user. They usually consist of a piece of thin metal or plastic held in a casing so that the metal is slightly torqued; depressing one end of the metal causes it to pop out of alignment and releasing it causes it to pop back into alignment, each time making a sharp click. With some clickers, the user depresses the metal directly with thumb or finger; with others, a button extends above the surface of the casing so that depressing the button makes the metal click. Use in animal training Clickers were first used by marine mammal trainer Karen Pryor as a way of communicating with their animals. Dolphins and whales communicate underwater through a series of clicks and whistles known as echolocation, and the clicker allowed a trainer to produce signals they were more likely to understand. Nowadays, clickers are used to train all kinds of animals, most co ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Karen Pryor
Karen Pryor (née Wylie; born May 14, 1932) is an American author who specialized in behavioral psychology and marine mammal biology. She is a founder and proponent of clicker training. She was formerly a Marine Mammal Commissioner to the U.S. government. Personal life Pryor is the daughter of author Philip Wylie and antiques dealer Sally Ondeck Wylie. Her uncle was Max Wylie, co-creator of ''The Flying Nun''. Her cousin, Janice Wylie, was murdered in 1963 along with her roommate Emily Hoffert in what became known as the Career Girls Murders. She was first married to Tap Pryor from 1954 until their divorce in 1975. They had three children: Ted, Michael and Gale. Her second marriage was to Jon Lindbergh, son of aviator Charles Lindbergh and writer Anne Morrow Lindbergh Anne Spencer Morrow Lindbergh (June 22, 1906 – February 7, 2001) was an American writer and aviator. She was the wife of decorated pioneer aviator Charles Lindbergh, with whom she made many exploratory fli ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Recurve Bow
In archery, a recurve bow is one of the main shapes a bow can take, with limbs that curve away from the archer when unstrung. A recurve bow stores more energy and delivers energy more efficiently than the equivalent straight-limbed bow, giving a greater amount of energy and speed to the arrow. A recurve will permit a shorter bow than the simple straight limb bow for given arrow energy, and this form was often preferred by archers in environments where long weapons could be cumbersome, such as in brush and forest terrain, or while on horseback. Recurved limbs also put greater stress on the materials used to make the bow, and they may make more noise with the shot. Extreme recurves make the bow unstable when being strung. An unstrung recurve bow can have a confusing shape and many Native American weapons, when separated from their original owners and cultures, were incorrectly strung backwards and destroyed when attempts were made to shoot them. A test performed by Hepworth and S ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Metal
A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typically ductile (can be drawn into wires) and malleable (they can be hammered into thin sheets). These properties are the result of the ''metallic bond'' between the atoms or molecules of the metal. A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polymeric sulfur nitride. In physics, a metal is generally regarded as any substance capable of conducting electricity at a temperature of absolute zero. Many elements and compounds that are not normally classified as metals become metallic under high pressures. For example, the nonmetal iodine gradually becomes a metal at a pressure of between 40 and 170 thousand times atmospheric pressure. Equally, some materials regarded as metals c ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Toothed Whales
The toothed whales (also called odontocetes, systematic name Odontoceti) are a parvorder of cetaceans that includes dolphins, porpoises, and all other whales possessing teeth, such as the beaked whales and sperm whales. Seventy-three species of toothed whales are described. They are one of two living groups of cetaceans, the other being the baleen whales (Mysticeti), which have baleen instead of teeth. The two groups are thought to have diverged around 34 million years ago (mya). Toothed whales range in size from the and vaquita to the and sperm whale. Several species of odontocetes exhibit sexual dimorphism, in that there are size or other morphological differences between females and males. They have streamlined bodies and two limbs that are modified into flippers. Some can travel at up to 20 knots. Odontocetes have conical teeth designed for catching fish or squid. They have well-developed hearing, that is well adapted for both air and water, so much so that some can surviv ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Animal Echolocation
Echolocation, also called bio sonar, is a biological sonar used by several animal species. Echolocating animals emit calls out to the environment and listen to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects. Echolocation is used for navigation, foraging, and hunting in various environments. Echolocating animals include some mammals (most notably Laurasiatheria) and a few birds, especially some bat species and odontocetes (toothed whales and dolphins), but also in simpler forms in other groups such as shrews, and two cave-dwelling bird groups, the so-called cave swiftlets in the genus ''Aerodramus'' (formerly ''Collocalia'') and the unrelated oilbird ''Steatornis caripensis''. Early research The term ''echolocation'' was coined in 1938 by the American zoologist Donald Griffin, who, with Robert Galambos, first demonstrated the phenomenon in bats. As Griffin described in his book, the 18th centur ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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D-Day Cricket Issued To Allied Paratroopers Preceding And During Operation Overlord
The Normandy landings were the landing operations and associated airborne operations on Tuesday, 6 June 1944 of the Allied invasion of Normandy in Operation Overlord during World War II. Codenamed Operation Neptune and often referred to as D-Day, it was the largest seaborne invasion in history. The operation began the liberation of France (and later western Europe) and laid the foundations of the Allied victory on the Western Front. Planning for the operation began in 1943. In the months leading up to the invasion, the Allies conducted a substantial military deception, codenamed Operation Bodyguard, to mislead the Germans as to the date and location of the main Allied landings. The weather on D-Day was far from ideal, and the operation had to be delayed 24 hours; a further postponement would have meant a delay of at least two weeks, as the invasion planners had requirements for the phase of the moon, the tides, and the time of day that meant only a few days each month wer ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, massa ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Operation Overlord
Operation Overlord was the codename for the Battle of Normandy, the Allied operation that launched the successful invasion of German-occupied Western Europe during World War II. The operation was launched on 6 June 1944 (D-Day) with the Normandy landings. A 1,200-plane airborne assault preceded an amphibious assault involving more than 5,000 vessels. Nearly 160,000 troops crossed the English Channel on 6 June, and more than two million Allied troops were in France by the end of August. The decision to undertake a cross-channel invasion in 1944 was taken at the Trident Conference in Washington in May 1943. General Dwight D. Eisenhower was appointed commander of Supreme Headquarters Allied Expeditionary Force, and General Bernard Montgomery was named commander of the 21st Army Group, which comprised all the land forces involved in the invasion. The coast of Normandy of northwestern France was chosen as the site of the invasion, with the Americans assigned to land at sectors ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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People Counter
A people counter is an electronic device that is used to measure the number of people traversing a certain passage or entrance. Examples include simple manual clickers, smart-flooring technologies, infrared beams, thermal imaging systems, WiFi trackers and video counters using advanced machine learning algorithms. They are commonly used by retail establishments to judge the effectiveness of marketing campaigns, building design and layout, and the popularity of particular brands. Industries Retail stores Conversion rate: People counting systems in the retail environment are used to calculate the conversion rate, which is the percentage of total visitors versus the number that make purchases. Marketing effectiveness: Shopping mall marketing professionals rely on visitor statistics to measure the effectiveness of the current marketing campaign. Often, shopping mall owners measure marketing effectiveness with the same conversion rate as retail stores. Staff planning: Retailers can use ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Board Games
Board games are tabletop games that typically use . These pieces are moved or placed on a pre-marked board (playing surface) and often include elements of table, card, role-playing, and miniatures games as well. Many board games feature a competition between two or more players. To show a few examples: in checkers (British English name 'draughts'), a player wins by capturing all opposing pieces, while Eurogames often end with a calculation of final scores. ''Pandemic'' is a cooperative game where players all win or lose as a team, and peg solitaire is a puzzle for one person. There are many varieties of board games. Their representation of real-life situations can range from having no inherent theme, such as checkers, to having a specific theme and narrative, such as ''Cluedo''. Rules can range from the very simple, such as in snakes and ladders; to deeply complex, as in ''Advanced Squad Leader''. Play components now often include custom figures or shaped counters, and ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |