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Tit-for-tat
Tit for tat is an English saying meaning "equivalent retaliation". It developed from "tip for tap", first recorded in 1558. It is also a highly effective strategy in game theory. An agent using this strategy will first cooperate, then subsequently replicate an opponent's previous action. If the opponent previously was cooperative, the agent is cooperative. If not, the agent is not. Game theory Tit-for-tat has been very successfully used as a strategy for the iterated prisoner's dilemma. The strategy was first introduced by Anatol Rapoport in Robert Axelrod's two tournaments, held around 1980. Notably, it was (on both occasions) both the simplest strategy and the most successful in direct competition. An agent using this strategy will first cooperate, then subsequently replicate an opponent's previous action. If the opponent previously was cooperative, the agent is cooperative. If not, the agent is not. This is similar to reciprocal altruism in biology. History The term devel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iterated Prisoner's Dilemma
The Prisoner's Dilemma is an example of a game analyzed in game theory. It is also a thought experiment that challenges two completely rational agents to a dilemma: cooperate with their partner for mutual reward, or betray their partner ("defect") for individual reward. This dilemma was originally framed by Merrill Flood and Melvin Dresher while working at RAND in 1950. Albert W. Tucker appropriated the game and formalized it by structuring the rewards in terms of prison sentences and named it "prisoner's dilemma". William Poundstone in his 1993 book ''Prisoner's Dilemma'' writes the following version:Two members of a criminal gang are arrested and imprisoned. Each prisoner is in solitary confinement with no means of speaking to or exchanging messages with the other. The police admit they don't have enough evidence to convict the pair on the principal charge. They plan to sentence both to two years in prison on a lesser charge. Simultaneously, the police offer each prison ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reciprocal Altruism
In evolutionary biology, reciprocal altruism is a behaviour whereby an organism acts in a manner that temporarily reduces its fitness while increasing another organism's fitness, with the expectation that the other organism will act in a similar manner at a later time. The concept was initially developed by Robert Trivers to explain the evolution of cooperation as instances of mutually altruistic acts. The concept is close to the strategy of " tit for tat" used in game theory. In 1987 Trivers told a symposium on reciprocity that he had originally submitted his article under the title "The Evolution of Delayed Return Altruism", but reviewer W. D. Hamilton suggested that he change the title to "The Evolution of Reciprocal Altruism". Trivers changed the title, but not the examples in the manuscript, which has led to confusion about what were appropriate examples of reciprocal altruism for the last 50 years. In their contribution to that symposium, Rothstein and Pierotti (1988) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McGurk's Bar Bombing
On 4 December 1971, the Ulster Volunteer Force (UVF), an Ulster loyalist paramilitary group, detonated a bomb at McGurk's Bar in Belfast, Northern Ireland. The pub was frequented by Irish Catholics/nationalists. The explosion caused the building to collapse, killing fifteen Catholic civilians—including two children—and wounding seventeen more. It was the deadliest attack in Belfast during the Troubles. Despite evidence to the contrary, the British security forces asserted that a bomb had exploded prematurely while being handled by Irish Republican Army (IRA) members inside the pub, implying that the victims themselves were partly to blame. A report later found that the Royal Ulster Constabulary, the police force in Northern Ireland at the time, were biased in favour of this view, and that this hindered their investigation. The victims' relatives allege that the security forces deliberately spread disinformation to discredit the IRA. In 1977, UVF member Robert Campbell was sen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nash Equilibrium
In game theory, the Nash equilibrium, named after the mathematician John Nash, is the most common way to define the solution of a non-cooperative game involving two or more players. In a Nash equilibrium, each player is assumed to know the equilibrium strategies of the other players, and no one has anything to gain by changing only one's own strategy. The principle of Nash equilibrium dates back to the time of Cournot, who in 1838 applied it to competing firms choosing outputs. If each player has chosen a strategy an action plan based on what has happened so far in the game and no one can increase one's own expected payoff by changing one's strategy while the other players keep their's unchanged, then the current set of strategy choices constitutes a Nash equilibrium. If two players Alice and Bob choose strategies A and B, (A, B) is a Nash equilibrium if Alice has no other strategy available that does better than A at maximizing her payoff in response to Bob choosing B, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Handshake (Workshop Cologne '06)
A handshake is a globally widespread, brief greeting or parting tradition in which two people grasp one of each other's like hands, in most cases accompanied by a brief up-and-down movement of the grasped hands. Customs surrounding handshakes are specific to cultures. Different cultures may be more or less likely to shake hands, or there may be different customs about how or when to shake hands.Fist bump can pound out flu transmission __TOC__ History The handshake may have originated in as a demonstration of peaceful intent, since it shows that the hand holds no weapon. Another possibility is that it originated a ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lexicon
A lexicon is the vocabulary of a language or branch of knowledge (such as nautical or medical). In linguistics, a lexicon is a language's inventory of lexemes. The word ''lexicon'' derives from Greek word (), neuter of () meaning 'of or for words'. Linguistic theories generally regard human languages as consisting of two parts: a lexicon, essentially a catalogue of a language's words (its wordstock); and a grammar, a system of rules which allow for the combination of those words into meaningful sentences. The lexicon is also thought to include bound morphemes, which cannot stand alone as words (such as most affixes). In some analyses, compound words and certain classes of idiomatic expressions, collocations and other phrases are also considered to be part of the lexicon. Dictionaries are lists of the lexicon, in alphabetical order, of a given language; usually, however, bound morphemes are not included. Size and organization Items in the lexicon are called lexemes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
People Of Northern Ireland
Northern Irish people is a demonym for all people born in Northern Ireland or people who are entitled to reside in Northern Ireland without any restriction on their period of residence. Most Northern Irish people either identify as Northern Irish, Irish or British, or a combination thereof. National identity In Northern Ireland, national identity is complex and diverse. The question of national identity was asked in the 2011 census with the three most common identities given being British, Northern Irish and Irish. Most people of Protestant background consider themselves British, while a majority of people of Catholic background are native Irish. This has origins in the 17th-century Plantation of Ulster. In the early 20th century, most Ulster Protestants and Catholics saw themselves as Irish, although Protestants tended to have a strong sense of Britishness also.Walker, Brian"British or Irish - who do you think you are?" ''Belfast Telegraph'', 10 December 2008. Follo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
In Memoriam A
IN, In or in may refer to: Places * India (country code IN) * Indiana, United States (postal code IN) * Ingolstadt, Germany (license plate code IN) * In, Russia, a town in the Jewish Autonomous Oblast Businesses and organizations * Independent Network, a UK-based political association * Indiana Northeastern Railroad (Association of American Railroads reporting mark) * Indian Navy, a part of the India military * Infantry, the branch of a military force that fights on foot * IN Groupe , the producer of French official documents * MAT Macedonian Airlines (IATA designator IN) * Nam Air (IATA designator IN) Science and technology * .in, the internet top-level domain of India * Inch (in), a unit of length * Indium, symbol In, a chemical element * Intelligent Network, a telecommunication network standard * Intra-nasal ( insufflation), a method of administrating some medications and vaccines * Integrase, a retroviral enzyme Other uses * ''In'' (album), by the Outsiders, 1967 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hobbes
Thomas Hobbes ( ; 5/15 April 1588 – 4/14 December 1679) was an English philosopher, considered to be one of the founders of modern political philosophy. Hobbes is best known for his 1651 book ''Leviathan'', in which he expounds an influential formulation of social contract theory. In addition to political philosophy, Hobbes contributed to a diverse array of other fields, including history, jurisprudence, geometry, theology, and ethics, as well as philosophy in general. Biography Early life Thomas Hobbes was born on 5 April 1588 (Old Style), in Westport, now part of Malmesbury in Wiltshire, England. Having been born prematurely when his mother heard of the coming invasion of the Spanish Armada, Hobbes later reported that "my mother gave birth to twins: myself and fear." Hobbes had a brother, Edmund, about two years older, as well as a sister named Anne. Although Thomas Hobbes's childhood is unknown to a large extent, as is his mother's name, it is known that Hobbes's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geometric Series
In mathematics, a geometric series is the sum of an infinite number of terms that have a constant ratio between successive terms. For example, the series :\frac \,+\, \frac \,+\, \frac \,+\, \frac \,+\, \cdots is geometric, because each successive term can be obtained by multiplying the previous term by 1/2. In general, a geometric series is written as a + ar + ar^2 + ar^3 + ..., where a is the coefficient of each term and r is the common ratio between adjacent terms. The geometric series had an important role in the early development of calculus, is used throughout mathematics, and can serve as an introduction to frequently used mathematical tools such as the Taylor series, the complex Fourier series, and the matrix exponential. The name geometric series indicates each term is the geometric mean of its two neighboring terms, similar to how the name arithmetic series indicates each term is the arithmetic mean of its two neighboring terms. The sequence of geometric series ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Evolution Of Cooperation
''The Evolution of Cooperation'' is a 1984 book written by political scientist Robert Axelrod that expands upon paper of the same name written by Axelrod and evolutionary biologist W.D. Hamilton. The book details a theory on the emergence of cooperation between individuals, drawing from game theory and evolutionary biology. Since 2006, reprints of the book have included a foreword by Richard Dawkins and have been marketed as a revised edition. The book provides an investigation into how cooperation can emerge and persist (also known as cooperation theory) as elucidated by the application of game theory. The book provides a detailed explanation of the evolution of cooperation, beyond traditional game theory. Academic literature regarding forms of cooperation that are not easily explained in traditional game theory, especially when considering evolutionary biology, largely took its modern form as a result of Axelrod's and Hamilton's influential 1981 paper and the subsequent bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catholic
The Catholic Church, also known as the Roman Catholic Church, is the List of Christian denominations by number of members, largest Christian church, with 1.3 billion baptized Catholics Catholic Church by country, worldwide . It is among the world's oldest and largest international institutions, and has played a prominent role in the history and development of Western civilization.Gerald O'Collins, O'Collins, p. v (preface). The church consists of 24 Catholic particular churches and liturgical rites#Churches, ''sui iuris'' churches, including the Latin Church and 23 Eastern Catholic Churches, which comprise almost 3,500 dioceses and Eparchy, eparchies located List of Catholic dioceses (structured view), around the world. The pope, who is the bishop of Rome, is the Papal supremacy, chief pastor of the church. The bishopric of Rome, known as the Holy See, is the central governing authority of the church. The administrative body of the Holy See, the Roman Curia, has its pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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