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Telegraph Key
A telegraph key, clacker, tapper or morse key is a specialized electrical switch used by a trained operator to transmit text messages in Morse code in a telegraphy system. Keys are used in all forms of electrical telegraph systems, including landline (also called wire) telegraphy and radio (also called wireless) telegraphy. An operator uses the telegraph key to send electrical pulses (or in the case of modern CW, unmodulated radio waves) of two different lengths: short pulses, called ''dots'' or ''dits'', and longer pulses, called ''dashes'' or ''dahs''. These pulses encode the letters and other characters that spell out the message. Types The first telegraph key was invented by Alfred Vail, an associate of Samuel Morse. Since then the technology has evolved and improved, resulting in a range of key designs. Straight keys A ''straight key'' is the common telegraph key as seen in various movies. It is a simple bar with a knob on top and an electrical contact underneat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Electronic Switch
In electronics, an electronic switch is a switch controlled by an Passivity (engineering), active electronic component or device. Without using moving parts, they are called solid state switches, which distinguishes them from mechanical switches. Electronic switches are considered Binary number, binary devices because they dramatically change the Electrical resistivity and conductivity, conductivity of a path in electrical circuit between two extremes when switching between their two states of ''on'' and ''off''. History Many people use metonymy to call a variety of devices that conceptually connect or disconnect signals and communication paths between electrical devices as "switches", analogous to the way mechanical switches connect and disconnect paths for electrons to flow between two conductors. The traditional relay is an electromechanical switch that uses an electromagnet controlled by a current to operate a mechanical switching mechanism. Other operating principles ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Bug Telegraph Key Made By Weston Hadden, C
Bug or BUG may refer to: Common uses * A terrestrial arthropod animal, usually with at least six legs ** Insect, a six-legged arthropod ***Hemiptera, the true bugs * A colloquialism for most minibeasts including arthropods, gastropods and worms. * Covert listening device, used in surveillance and espionage * Bug (engineering), a defect in an engineered system ** Software bug ** Hardware bug ** BUG (tag), a computer programming comment tag * Score bug, overlaid display of information in a sports broadcast *Pathogen, colloquially Arts, entertainment and media Fictional entities * Bug (comics), a superhero in Marvel Comics * Bug (DC Comics), different characters appearing in DC Comics * Bug (Starship Troopers), Bug (''Starship Troopers''), an alien race from the novel and film * Bug, Michael Lee (The Wire), Michael Lee's younger brother in ''The Wire'' * Bug, in the TV series ''WordWorld'' * Bobby "Bug" Guthrie, in the TV series ''Life Unexpected'' Film and television * Bug (197 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Traffic Analysis
Traffic analysis is the process of intercepting and examining messages in order to deduce information from patterns in communication. It can be performed even when the messages are encrypted. In general, the greater the number of messages observed, the greater information be inferred. Traffic analysis can be performed in the context of military intelligence, counter-intelligence, or pattern-of-life analysis, and is also a concern in computer security. Traffic analysis tasks may be supported by dedicated computer software programs. Advanced traffic analysis techniques which may include various forms of social network analysis. Traffic analysis has historically been a vital technique in cryptanalysis, especially when the attempted crack depends on successfully seeding a known-plaintext attack, which often requires an inspired guess based on how specific the operational context might likely influence what an adversary communicates, which may be sufficient to establish a short cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Operant Conditioning Chamber
An operant conditioning chamber (also known as a Skinner box) is a laboratory apparatus used to study animal behavior. The operant conditioning chamber was created by B. F. Skinner while he was a graduate student at Harvard University. The chamber can be used to study both operant conditioning and classical conditioning. Skinner created the operant conditioning chamber as a variation of the puzzle box originally created by Edward Thorndike. While Skinner's early studies were done using rats, he later moved on to study pigeons. The operant conditioning chamber may be used to observe or manipulate behaviour. An animal is placed in the box where it must learn to activate levers or respond to light or sound stimuli for reward. The reward may be food or the removal of noxious stimuli such as a loud alarm. The chamber is used to test specific hypotheses in a controlled setting. Name Skinner was noted to have expressed his distaste for becoming an eponym. It is believed that p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Harvard University
Harvard University is a Private university, private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the History of the Puritans in North America, Puritan clergyman John Harvard (clergyman), John Harvard, it is the oldest institution of higher learning in the United States. Its influence, wealth, and rankings have made it one of the most prestigious universities in the world. Harvard was founded and authorized by the Massachusetts General Court, the governing legislature of Colonial history of the United States, colonial-era Massachusetts Bay Colony. While never formally affiliated with any Religious denomination, denomination, Harvard trained Congregationalism in the United States, Congregational clergy until its curriculum and student body were gradually secularized in the 18th century. By the 19th century, Harvard emerged as the most prominent academic and cultural institution among the Boston B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Pigeon
Columbidae is a bird family consisting of doves and pigeons. It is the only family in the order Columbiformes. These are stout-bodied birds with small heads, relatively short necks and slender bills that in some species feature fleshy ceres. They feed largely on plant matter, feeding on seeds ( granivory), fruit ( frugivory), and foliage ( folivory). In colloquial English, the smaller species tend to be called "doves", and the larger ones "pigeons", although the distinction is not consistent, and there is no scientific separation between them. Historically, the common names for these birds involve a great deal of variation. The bird most commonly referred to as "pigeon" is the domestic pigeon, descendant of the wild rock dove, which is a common inhabitant of cities as the feral pigeon. Columbidae contains 51 genera divided into 353 species. The family occurs worldwide, often in close proximity to humans, but the greatest diversity is in the Indomalayan and Australasi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Operant Conditioning
Operant conditioning, also called instrumental conditioning, is a learning process in which voluntary behaviors are modified by association with the addition (or removal) of reward or aversive stimuli. The frequency or duration of the behavior may increase through reinforcement or decrease through punishment or Extinction (psychology), extinction. Origins Operant conditioning originated with Edward Thorndike, whose law of effect theorised that behaviors arise as a result of consequences as satisfying or discomforting. In the 20th century, operant conditioning was studied by Behaviorism, behavioral psychologists, who believed that much of mind and behaviour is explained through environmental conditioning. Reinforcements are environmental stimuli that increase behaviors, whereas punishments are stimuli that decrease behaviors. Both kinds of stimuli can be further categorised into positive and negative stimuli, which respectively involve the addition or removal of environmental stim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Iamb (poetry)
An iamb ( ) or iambus is a metrical foot used in various types of poetry. Originally the term referred to one of the feet of the quantitative meter of classical Greek prosody: a short syllable followed by a long syllable (as in () "beautiful (f.)"). This terminology was adopted in the description of accentual-syllabic verse in English, where it refers to a foot comprising an unstressed syllable followed by a stressed syllable (as in ''abóve''). Thus a Latin word like , because of its short-long rhythm, is considered by Latin scholars to be an iamb, but because it has a stress on the first syllable, in modern linguistics it is considered to be a trochee. Etymology R. S. P. Beekes has suggested that the ''iambos'' has a Pre-Greek origin. An old hypothesis is that the word is borrowed from Phrygian or Pelasgian, and literally means "Einschritt", i. e., "one-step", compare ''dithyramb'' and '' thriambus'', but H. S. Versnel rejects this etymology and suggests instead a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
YouTube
YouTube is an American social media and online video sharing platform owned by Google. YouTube was founded on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim who were three former employees of PayPal. Headquartered in San Bruno, California, it is the second-most-visited website in the world, after Google Search. In January 2024, YouTube had more than 2.7billion monthly active users, who collectively watched more than one billion hours of videos every day. , videos were being uploaded to the platform at a rate of more than 500 hours of content per minute, and , there were approximately 14.8billion videos in total. On November 13, 2006, YouTube was purchased by Google for $1.65 billion (equivalent to $ billion in ). Google expanded YouTube's business model of generating revenue from advertisements alone, to offering paid content such as movies and exclusive content produced by and for YouTube. It also offers YouTube Premium, a paid subs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Trochee
In poetic metre, a trochee ( ) is a metrical foot consisting of a stressed syllable followed by an unstressed syllable, unstressed one, in qualitative meter, as found in English, and in modern linguistics; or in quantitative meter, as found in Latin and Ancient Greek, a heavy syllable followed by a light one (also described as a long syllable followed by a short one). In this respect, a trochee is the reverse of an iamb (poetry), iamb. Thus the Latin word , because of its short-long rhythm, in Latin metrical studies is considered to be an iamb, but since it is stressed on the first syllable, in modern linguistics it is considered to be a trochee. The adjective form is ''trochaic''. The English word ''trochee'' is itself trochaic since it is composed of the stressed syllable followed by the unstressed syllable . Another name formerly used for a trochee was a choree ( ) or choreus. Etymology ''Trochee'' comes from French language, French , adapted from Latin , originally from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Iamb (poetry)
An iamb ( ) or iambus is a metrical foot used in various types of poetry. Originally the term referred to one of the feet of the quantitative meter of classical Greek prosody: a short syllable followed by a long syllable (as in () "beautiful (f.)"). This terminology was adopted in the description of accentual-syllabic verse in English, where it refers to a foot comprising an unstressed syllable followed by a stressed syllable (as in ''abóve''). Thus a Latin word like , because of its short-long rhythm, is considered by Latin scholars to be an iamb, but because it has a stress on the first syllable, in modern linguistics it is considered to be a trochee. Etymology R. S. P. Beekes has suggested that the ''iambos'' has a Pre-Greek origin. An old hypothesis is that the word is borrowed from Phrygian or Pelasgian, and literally means "Einschritt", i. e., "one-step", compare ''dithyramb'' and '' thriambus'', but H. S. Versnel rejects this etymology and suggests instead a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
