|
Ralph Hartley
Ralph Vinton Lyon Hartley (November 30, 1888 – May 1, 1970) was an American electronics researcher. He invented the Hartley oscillator and the Hartley transform, and contributed to the foundations of information theory. His legacy includes the naming of the hartley, a unit of information equal to one decimal digit, after him. Biography Hartley was born in Sprucemont, Nevada, and attended the University of Utah, receiving an A.B. degree in 1909. He became a Rhodes Scholar at St Johns, Oxford University, in 1910 and received a B.A. degree in 1912 and a B.Sc. degree in 1913. He married Florence Vail of Brooklyn on March 21, 1916. The Hartleys had no children. He returned to the United States and was employed at the Research Laboratory of the Western Electric Company. In 1915 he was in charge of radio receiver development for the Bell System transatlantic radiotelephone tests. For this he developed the Hartley oscillator and also a neutralizing circuit to eliminate triode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hartley Oscillator
The Hartley oscillator is an electronic oscillator circuit in which the oscillation frequency is determined by a tuned circuit consisting of capacitors and inductors, that is, an LC oscillator. The circuit was invented in 1915 by American engineer Ralph Hartley. The distinguishing feature of the Hartley oscillator is that the tuned circuit consists of a single capacitor in parallel with two inductors in series (or a single tapped inductor), and the feedback signal needed for oscillation is taken from the center connection of the two inductors. History The Hartley oscillator was invented by Hartley while he was working for the Research Laboratory of the Western Electric Company. Hartley invented and patented the design in 1915 while overseeing Bell System's transatlantic radiotelephone tests; it was awarded patent number 1,356,763 on October 26, 1920. In 1946 Hartley was awarded the Institute of Radio Engineers Medal of Honor "for his early work on oscillating circuits e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sprucemont, Nevada
Sprucemont is a ghost town in Elko County, in the U.S. state of Nevada. The GNIS classifies it as a populated place. History The community took its name from nearby Spruce Mountain, as it is located on the western foothills of the mountain. Variant names were "Spruce City" and "Spruce Mount". A post office called Sprucemount was established in 1880, the name was changed to Spruce in 1895, the name was changed again to Sprucemont in 1929, and the post office was discontinued in 1935. The population was 17 in 1940. Ralph Vinton Lyon Hartley, pioneer of Information Theory, was born in Sprucemont, Nevada on November 30, 1888. See also * List of ghost towns in Nevada Most ghost towns in Nevada in the United States are former mining boomtowns that were abandoned when the mines closed. Those that were not set up as mining camps were usually established as locations for mills, or supply points for nearby mini ... References External links Ghost towns in Nevada Ghost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
St John's College, Oxford
St John's College is a Colleges of the University of Oxford, constituent college of the University of Oxford. Founded as a men's college in 1555, it has been coeducational since 1979.Communication from Michael Riordan, college archivist Its founder, Sir Thomas White (merchant), Thomas White, intended to provide a source of educated Roman Catholic clerics to support the Counter-Reformation under Mary I of England, Queen Mary. St John's is the wealthiest college in Oxford, with assets worth over £790 million as of 2022, largely due to nineteenth-century suburban development of land in the city of Oxford of which it is the ground landlord. The college occupies a site on St Giles', Oxford, St Giles' and has a student body of some 390 undergraduates and 250 postgraduates. There are over 100 academic staff, and a like number of other staff. In 2018 St John's topped the Norrington Table, the annual ranking of Oxford colleges' final results, and in 2021, St John's ranked second with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Review
''Physical Review'' is a peer-reviewed scientific journal. The journal was established in 1893 by Edward Nichols. It publishes original research as well as scientific and literature reviews on all aspects of physics. It is published by the American Physical Society (APS). The journal is in its third series, and is split in several sub-journals each covering a particular field of physics. It has a sister journal, '' Physical Review Letters'', which publishes shorter articles of broader interest. History ''Physical Review'' commenced publication in July 1893, organized by Cornell University professor Edward Nichols and helped by the new president of Cornell, J. Gould Schurman. The journal was managed and edited at Cornell in upstate New York from 1893 to 1913 by Nichols, Ernest Merritt, and Frederick Bedell. The 33 volumes published during this time constitute ''Physical Review Series I''. The American Physical Society (APS), founded in 1899, took over its publicati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Consultant
A consultant (from "to deliberate") is a professional (also known as ''expert'', ''specialist'', see variations of meaning below) who provides advice or services in an area of specialization (generally to medium or large-size corporations). Consulting services generally fall under the domain of professional services, as contingent work. The Harvard Business School defines a consultant as someone who advises on "how to modify, proceed in, or streamline a given process within a specialized field". Subject-matter expert vs. consultant According to ''Institute of Management Consultants USA'', "The value of a consultant s compared to a subject-matter expert (SME)is to be able to correctly diagnose and effectively transform an often ill-defined problem and apply information, resources and processes to create a workable and usable solution. Some experts are good consultants and vice versa, some are neither, few are both." Another differentiation would be that a consultant sells adv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Repeater
In telecommunications, a repeater is an electronic device that receives a signal and retransmits it. Repeaters are used to extend transmissions so that the signal can cover longer distances or be received on the other side of an obstruction. Some types of repeaters broadcast an identical signal, but alter its method of transmission, for example, on another frequency or baud rate. There are several different types of repeaters; a telephone repeater is an amplifier in a telephone line, an optical repeater is an optoelectronic circuit that amplifies the light beam in an optical fiber cable; and a radio repeater is a radio receiver and transmitter that retransmits a radio signal. A broadcast relay station is a repeater used in broadcast radio and television. Overview When an information-bearing signal passes through a communication channel, it is progressively degraded due to loss of power. For example, when a telephone call passes through a wire telephone line, some of the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell Laboratories
Nokia Bell Labs, commonly referred to as ''Bell Labs'', is an American industrial research and development company owned by Finnish technology company Nokia. With headquarters located in Murray Hill, New Jersey, the company operates several laboratories in the United States and around the world. As a former subsidiary of the American Telephone and Telegraph Company (AT&T), Bell Labs and its researchers have been credited with the development of radio astronomy, the transistor, the laser, the photovoltaic cell, the charge-coupled device (CCD), information theory, the Unix operating system, and the programming languages B, C, C++, S, SNOBOL, AWK, AMPL, and others, throughout the 20th century. Eleven Nobel Prizes and five Turing Awards have been awarded for work completed at Bell Laboratories. Bell Labs had its origin in the complex corporate organization of the Bell System telephone conglomerate. The laboratory began operating in the late 19th century as the Wester ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Direction Finder
Direction finding (DF), radio direction finding (RDF), or radiogoniometry is the use of radio waves to determine the direction to a radio source. The source may be a cooperating radio transmitter or may be an inadvertent source, a naturally-occurring radio source, or an illicit or enemy system. Radio direction finding differs from radar in that only the direction is determined by any one receiver; a radar system usually also gives a distance to the object of interest, as well as direction. By triangulation, the location of a radio source can be determined by measuring its direction from two or more locations. Radio direction finding is used in radio navigation for ships and aircraft, to locate emergency transmitters for search and rescue, for tracking wildlife, and to locate illegal or interfering transmitters. During the Second World War, radio direction finding was used by both sides to locate and direct aircraft, surface ships, and submarines. RDF systems can be used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War I
World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting took place mainly in European theatre of World War I, Europe and the Middle Eastern theatre of World War I, Middle East, as well as in parts of African theatre of World War I, Africa and the Asian and Pacific theatre of World War I, Asia-Pacific, and in Europe was characterised by trench warfare; the widespread use of Artillery of World War I, artillery, machine guns, and Chemical weapons in World War I, chemical weapons (gas); and the introductions of Tanks in World War I, tanks and Aviation in World War I, aircraft. World War I was one of the List of wars by death toll, deadliest conflicts in history, resulting in an estimated World War I casualties, 10 million military dead and more than 20 million wounded, plus some 10 million civilian de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patent
A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling disclosure of the invention."A patent is not the grant of a right to make or use or sell. It does not, directly or indirectly, imply any such right. It grants only the right to exclude others. The supposition that a right to make is created by the patent grant is obviously inconsistent with the established distinctions between generic and specific patents, and with the well-known fact that a very considerable portion of the patents granted are in a field covered by a former relatively generic or basic patent, are tributary to such earlier patent, and cannot be practiced unless by license thereunder." – ''Herman v. Youngstown Car Mfg. Co.'', 191 F. 579, 584–85, 112 CCA 185 (6th Cir. 1911) In most countries, patent rights fall under private la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiotelephone
A radiotelephone (or radiophone), abbreviated RT, is a radio communication system for conducting a conversation; radiotelephony means telephony by radio. It is in contrast to ''radiotelegraphy'', which is radio transmission of telegrams (messages), or ''television'', transmission of video, moving pictures and sound. The term is related to radio broadcasting, which transmit audio one way to listeners. Radiotelephony refers specifically to two-way radio systems for bidirectional person-to-person voice communication between separated users, such as CB radio or marine radio. In spite of the name, radiotelephony systems are not necessarily connected to or have anything to do with the public switched telephone network, telephone network, and in some radio services, including General Mobile Radio Service, GMRS, interconnection is prohibited. Design Mode of emission The word ''phone'' has a long precedent beginning with early US wired voice systems. The term means ''voice'' as oppos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell System
The Bell System was a system of telecommunication companies, led by the Bell Telephone Company and later by the AT&T Corporation, American Telephone and Telegraph Company (AT&T), that dominated the telephone services industry in North America for over 100 years from its creation in 1877 until United States v. AT&T (1982), its antitrust breakup in 1983. The system of companies was often colloquially called Ma Bell (as in "Mother Bell"), as it held a vertical monopoly over telecommunication products and services in most areas of the United States and Canada. At the time of the breakup of the Bell System in the early 1980s, it had assets of $150 billion (equivalent to $ billion in ) and employed over one million people. Beginning in the 1910s, American antitrust regulators had been observing and accusing the Bell System of abusing its monopoly power, and had brought legal action multiple times over the decades. In 1974 the United States Department of Justice Antitrust Division, Anti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
