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Method Of Moments (electromagnetics)
The method of moments (MoM), also known as the moment method and method of weighted residuals, is a numerical method in computational electromagnetics. It is used in computer programs that simulate the interaction of electromagnetic fields such as radio waves with matter, for example antenna simulation programs like NEC that calculate the radiation pattern of an antenna. Generally being a frequency-domain method, it involves the projection of an integral equation into a system of linear equations by the application of appropriate boundary conditions. This is done by using discrete meshes as in finite difference and finite element methods, often for the surface. The solutions are represented with the linear combination of pre-defined basis functions; generally, the coefficients of these basis functions are the sought unknowns. Green's functions and Galerkin method play a central role in the method of moments. For many applications, the method of moments is identical to the bou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Negative Reflection From Meta-mirrors
Negative may refer to: Science and mathematics * Negative number * Negative mass * Negative energy * Negative charge, one of the two types of electric charge * Negative (electrical polarity), in electric circuits * Negative result (other) * Negative lenses, uses to describe diverging optics Photography * Negative (photography), an image with inverted luminance or a strip of film with such an image * Original camera negative, the film in a motion picture camera which captures the original image * Paper negative, a negative image printed on paper used to create the final print of a photograph Linguistics * A negative answer, commonly expressed with the word ''no'' * A type of grammatical construction; see affirmative and negative *A double negative is a construction occurring when two forms of grammatical negation are used in the same sentence. Music * Negative (Finnish band), a Finnish band established in 1997 * Negative (Serbian band), a Serbian band est ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boundary Element Method
The boundary element method (BEM) is a numerical computational method of solving linear partial differential equations which have been formulated as integral equations (i.e. in ''boundary integral'' form), including fluid mechanics, acoustics, electromagnetics (where the technique is known as Method of moments (electromagnetics), method of moments or abbreviated as MoM), fracture mechanics, and contact mechanics. Mathematical basis The integral equation may be regarded as an exact solution of the governing partial differential equation. The boundary element method attempts to use the given boundary conditions to fit boundary values into the integral equation, rather than values throughout the space defined by a partial differential equation. Once this is done, in the post-processing stage, the integral equation can then be used again to calculate numerically the solution directly at any desired point in the interior of the solution domain. BEM is applicable to problems for which G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roger F
Roger is a given name, usually masculine, and a surname. The given name is derived from the Old French personal names ' and '. These names are of Germanic origin, derived from the elements ', ''χrōþi'' ("fame", "renown", "honour") and ', ' ("spear", "lance") (Hrōþigēraz). The name was introduced into England by the Normans. In Normandy, the Frankish name had been reinforced by the Old Norse cognate '. The name introduced into England replaced the Old English cognate '. ''Roger'' became a very common given name during the Middle Ages. A variant form of the given name ''Roger'' that is closer to the name's origin is ''Rodger''. Slang and other uses Roger is also a short version of the term "Jolly Roger", which refers to a black flag with a white skull and crossbones, formerly used by sea pirates since as early as 1723. From up to , Roger was slang for the word "penis". In ''Under Milk Wood'', Dylan Thomas writes "jolly, rodgered" suggesting both the sexual double enten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antena Espiral Con Diagrama De Radiación
Antenna ( antennas or antennae) may refer to: Science and engineering * Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g., TV or radio) waves * Antennae Galaxies, the name of two colliding galaxies NGC 4038 and NGC 4039 Biology * Antenna (biology), one of one or more pairs of appendages used for sensing in arthropods * ''Antenna'' (journal), the journal of the Royal Entomological Society Media Broadcasting * ANT1, a Greek-language terrestrial channel * Antena Internațional, a Romanian television channel * Antena 1 (Romania), a Romanian television channel * Antena 2 (Romania), a Romanian television channel * Antena 3 (Romania), a Romanian television channel * Antena 3 (Spain), a Spanish terrestrial television channel * Antenna TV, a U.S. television channel established in 2011 by Tribune Broadcasting * RDP Antena 1, Portuguese public radio station * RDP Antena 2, Portuguese public radio station * RDP Antena 3, Por ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Illinois Urbana-Champaign
The University of Illinois Urbana-Champaign (U of I, Illinois, University of Illinois, or UIUC) is a public land-grant research university in Illinois in the twin cities of Champaign and Urbana. It is the flagship institution of the University of Illinois system and was founded in 1867. Enrolling over 56,000 undergraduate and graduate students, the University of Illinois is one of the largest public universities by enrollment in the country. The University of Illinois Urbana-Champaign is a member of the Association of American Universities and is classified among "R1: Doctoral Universities – Very high research activity". In fiscal year 2019, research expenditures at Illinois totaled $652 million. The campus library system possesses the second-largest university library in the United States by holdings after Harvard University. The university also hosts the National Center for Supercomputing Applications and is home to the fastest supercomputer on a university campus. The u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yuen Tze Lo
Yuen Tze Lo ( zh, 罗远祉; January 31, 1920 – May 10, 2002) was a Chinese American electrical engineer and academician. He was a professor emeritus at the Department of Electrical and Computer Engineering at University of Illinois at Urbana–Champaign. He is best known for his contributions to the theory and design of antennas. He is the editor of the textbook series, ''Antenna Handbook''. The Yuen T. Lo Outstanding Research Award at University of Illinois at Urbana–Champaign is named after him. Biography Lo was born on January 31, 1920 in Hankou, Republic of China. He received his bachelor's degree in electrical engineering from National Southwestern Associated University in 1942. Between 1946 and 1948, he worked at the National Tsing Hua University in Kunming as an instructor; he worked briefly at the Yenching University as well. He obtained his M.S. and PhD degrees in electrical engineering from University of Illinois at Urbana in 1949 and 1952, respectively. Betw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Victor H
The name Victor or Viktor may refer to: * Victor (name), including a list of people with the given name, mononym, or surname Arts and entertainment Film * ''Victor'' (1951 film), a French drama film * ''Victor'' (1993 film), a French short film * ''Victor'' (2008 film), a 2008 TV film about Canadian swimmer Victor Davis * ''Victor'' (2009 film), a French comedy * ''Victor'', a 2017 film about Victor Torres by Brandon Dickerson * ''Viktor'' (film), a 2014 Franco/Russian film Music * ''Victor'' (album), a 1996 album by Alex Lifeson * "Victor", a song from the 1979 album ''Eat to the Beat'' by Blondie Businesses * Victor Talking Machine Company, early 20th century American recording company, forerunner of RCA Records * Victor Company of Japan, usually known as JVC, a Japanese electronics corporation originally a subsidiary of the Victor Talking Machine Company ** Victor Entertainment, or JVCKenwood Victor Entertainment, a Japanese record label ** Victor Interactive So ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nathan Marcuvitz
Nathan Marcuvitz (1913 - 2010) was an American electrical engineer, physicist, and educator who worked in the fields of microwave and electromagnetic field theory. He was head of the experimental group of the Radiation Laboratory (MIT). He was a member of the National Academy of Engineering. He had a PhD in electrical engineering from Polytechnic Institute of Brooklyn. Biography Marcuvitz was born on December 29, 1913, in Brooklyn, New York. Marcuvitz was a significant figure on the field of electromagnetic waves.©2010 IEEE. Portions reprinted, with permission, from A. Oliner, "Transitions. Dr. Nathan Marcuvitz", IEEE Microwave Magazine, Dec. 2010, pg. 120, http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=05590341. The crucial period in the development of the microwave field occurred during World War II, when the magnetron furnished a reliable source of electromagnetic waves and made radar feasible, but progress was initially slow because designs had employed empirical and c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julian Schwinger
Julian Seymour Schwinger (; February 12, 1918 – July 16, 1994) was a Nobel Prize winning American theoretical physicist. He is best known for his work on quantum electrodynamics (QED), in particular for developing a relativistically invariant perturbation theory, and for renormalizing QED to one loop order. Schwinger was a physics professor at several universities. Schwinger is recognized as one of the greatest physicists of the twentieth century, responsible for much of modern quantum field theory, including a variational approach, and the equations of motion for quantum fields. He developed the first electroweak model, and the first example of confinement in 1+1 dimensions. He is responsible for the theory of multiple neutrinos, Schwinger terms, and the theory of the spin-3/2 field. Biography Early life and career Julian Seymour Schwinger was born in New York City, to Ashkenazi Jewish parents, Belle (née Rosenfeld) and Benjamin Schwinger, a garment manufacturer, who had e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microwave
Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ranges as microwaves; the above broad definition includes both UHF and EHF (millimeter wave) bands. A more common definition in radio-frequency engineering is the range between 1 and 100 GHz (wavelengths between 0.3 m and 3 mm). In all cases, microwaves include the entire SHF band (3 to 30 GHz, or 10 to 1 cm) at minimum. Frequencies in the microwave range are often referred to by their IEEE radar band designations: S, C, X, Ku, K, or Ka band, or by similar NATO or EU designations. The prefix ' in ''microwave'' is not meant to suggest a wavelength in the micrometer range. Rather, it indicates that microwaves are "small" (having shorter wavelengths), compared to the radio waves used prior to microwave te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calculus Of Variations
The calculus of variations (or Variational Calculus) is a field of mathematical analysis that uses variations, which are small changes in functions and functionals, to find maxima and minima of functionals: mappings from a set of functions to the real numbers. Functionals are often expressed as definite integrals involving functions and their derivatives. Functions that maximize or minimize functionals may be found using the Euler–Lagrange equation of the calculus of variations. A simple example of such a problem is to find the curve of shortest length connecting two points. If there are no constraints, the solution is a straight line between the points. However, if the curve is constrained to lie on a surface in space, then the solution is less obvious, and possibly many solutions may exist. Such solutions are known as ''geodesics''. A related problem is posed by Fermat's principle: light follows the path of shortest optical length connecting two points, which depends up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
