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Maria Adelaide Sneider
Maria Adelaide Sneider (6 December 1937 – 1 May 1989) (also known as Maria Adelaide Sneider Ludovici, her second surname being "Ludovici") was an Italian mathematician working on numerical and mathematical analysis. She is known for her work on the theory of electrostatic capacities of non-smooth closed hypersurfaces: Apart from the development of precise estimates for the numerical approximation of the electrostatic capacity of the unit cube, this work also led her to give a rigorous proof of Green's identities for large classes of hypersurfaces with singularities, and later to develop an accurate mathematical analysis of the points effect. She is also known for her contributions to the Dirichlet problem for pluriharmonic functions on the unit sphere of \mathbb^n.. Work Selected works *. *. An accurate analysis of the problem of calculation of capacitances of surfaces with singularities. *, is an analysis of the numerical performance of several one–dimensional quadr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asmara
Asmara ( ), or Asmera (), is the capital and most populous city of Eritrea, in the country's Central Region (Eritrea), Central Region. It sits at an elevation of , making it the List of capital cities by altitude, sixth highest capital in the world by altitude and the second highest capital in Africa. The city is located at the tip of an escarpment that is both the northwestern edge of the Eritrean Highlands and the Great Rift Valley, Ethiopia, Great Rift Valley in neighbouring Ethiopia. In 2017, the city was declared as a World Heritage Site, UNESCO World Heritage Site for its well-preserved modernist architecture. According to local traditions, the city was founded after four separate villages unified to live together peacefully after long periods of conflict. Asmara had long been overshadowed by nearby Debarwa, the residence of the ''Ethiopian aristocratic and court titles#Important regional offices, Bahr Negash'' or the governor of the coastal province, however it still existe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypersurface
In geometry, a hypersurface is a generalization of the concepts of hyperplane, plane curve, and surface. A hypersurface is a manifold or an algebraic variety of dimension , which is embedded in an ambient space of dimension , generally a Euclidean space, an affine space or a projective space. Hypersurfaces share, with surfaces in a three-dimensional space, the property of being defined by a single implicit equation, at least locally (near every point), and sometimes globally. A hypersurface in a (Euclidean, affine, or projective) space of dimension two is a plane curve. In a space of dimension three, it is a surface. For example, the equation :x_1^2+x_2^2+\cdots+x_n^2-1=0 defines an algebraic hypersurface of dimension in the Euclidean space of dimension . This hypersurface is also a smooth manifold, and is called a hypersphere or an -sphere. Smooth hypersurface A hypersurface that is a smooth manifold is called a ''smooth hypersurface''. In , a smooth hypersurface is ori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrature Formula
Quadrature may refer to: Mathematics * Quadrature (geometry), drawing a square with the same area as a given plane figure (''squaring'') or computing that area ** Quadrature of the circle ** ''Quadrature of the Parabola'' ** Quadrature of the hyperbola * Numerical integration is often called "numerical quadrature" or simply "quadrature" ** Gaussian quadrature, a special case of numerical integration * Quadrature (differential equations), expressing a differential equation solution in terms of integrals. * Formerly, a synonym for "integral" ** Integral ** Antiderivative Signal processing * Addition in quadrature, combining the magnitude of uncorrelated signals by taking the square root of the sum of their squares *Quadrature phase, oscillations that are said to be ''in quadrature'' if they are separated in phase by 90° (/2, or /4) *Quadrature component of a composite signal *Quadrature filter, the analytic signal of a real-valued filter *Quadrature amplitude modulation (QAM), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimension (mathematics)
In physics and mathematics, the dimension of a mathematical space (or object) is informally defined as the minimum number of coordinates needed to specify any point within it. Thus, a line has a dimension of one (1D) because only one coordinate is needed to specify a point on itfor example, the point at 5 on a number line. A surface, such as the boundary of a cylinder or sphere, has a dimension of two (2D) because two coordinates are needed to specify a point on itfor example, both a latitude and longitude are required to locate a point on the surface of a sphere. A two-dimensional Euclidean space is a two-dimensional space on the plane. The inside of a cube, a cylinder or a sphere is three-dimensional (3D) because three coordinates are needed to locate a point within these spaces. In classical mechanics, space and time are different categories and refer to absolute space and time. That conception of the world is a four-dimensional space but not the one that was found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atti Della Accademia Nazionale Dei Lincei , Italy, in the 13th-15th centuries
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Atti may refer to: *Atti, Jalandhar, a village in Punjab, India *Atti (film), a 2016 Tamil film *Atti Aboyni (1946), Hungarian-born Australian soccer player and manager *Isotta degli Atti (1433–1474), Italian noble and regent *Atti family, lords of Sassoferrato Sassoferrato is a town and ''comune'' of the province of Ancona in the Marche region of central-eastern Italy. It is one of I Borghi più belli d'Italia ("The most beautiful villages of Italy"). History Between Sassoferrato and Arcevia was t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walter Kurt Hayman
Walter Kurt Hayman FRS (formerly Haymann; 6 January 1926 – 1 January 2020) was a British mathematician known for contributions to complex analysis. He was a professor at Imperial College London. Life and work Hayman was born in Cologne, Germany, the son of Roman law professor Franz Haymann (1874-1947) and Ruth Therese Hensel, daughter of mathematician Kurt Hensel. He was a great-great-grandson of acclaimed composer Fanny Mendelssohn. Because of his Jewish heritage, he left Germany, then under Nazi rule, alone by train in 1938. He continued his schooling at Gordonstoun School, and later at St John's College, Cambridge under John Edensor Littlewood and his doctoral advisor Mary Cartwright. He taught at King's College, Newcastle, and the University of Exeter. In 1947, he married Margaret Riley Crann after they met at a Quaker meeting. Together, they founded the British Mathematical Olympiad. The pair had three daughters, including the peace activist Carolyn Hayman and the film ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphere
A sphere (from Ancient Greek, Greek , ) is a surface (mathematics), surface analogous to the circle, a curve. In solid geometry, a sphere is the Locus (mathematics), set of points that are all at the same distance from a given point in three-dimensional space.. That given point is the center (geometry), ''center'' of the sphere, and the distance is the sphere's ''radius''. The earliest known mentions of spheres appear in the work of the Greek mathematics, ancient Greek mathematicians. The sphere is a fundamental surface in many fields of mathematics. Spheres and nearly-spherical shapes also appear in nature and industry. Bubble (physics), Bubbles such as soap bubbles take a spherical shape in equilibrium. The Earth is spherical Earth, often approximated as a sphere in geography, and the celestial sphere is an important concept in astronomy. Manufactured items including pressure vessels and most curved mirrors and lenses are based on spheres. Spheres rolling, roll smoothly in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pluriharmonic Function
In mathematics, precisely in the theory of functions of several complex variables, a pluriharmonic function is a real valued function which is locally the real part of a holomorphic function of several complex variables. Sometimes such a function is referred to as ''n''-harmonic function, where ''n'' ≥ 2 is the dimension of the complex domain where the function is defined. However, in modern expositions of the theory of functions of several complex variablesSee for example the popular textbook by and the advanced (even if a little outdated) monograph by . it is preferred to give an equivalent formulation of the concept, by defining pluriharmonic function a complex valued function whose restriction to every complex line is a harmonic function with respect to the real and imaginary part of the complex line parameter. Formal definition . Let be a complex domain and be a (twice continuously differentiable) function. The function is called pluriharmonic if, for every complex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dirichlet Problem
In mathematics, a Dirichlet problem asks for a function which solves a specified partial differential equation (PDE) in the interior of a given region that takes prescribed values on the boundary of the region. The Dirichlet problem can be solved for many PDEs, although originally it was posed for Laplace's equation. In that case the problem can be stated as follows: :Given a function ''f'' that has values everywhere on the boundary of a region in \mathbb^n, is there a unique continuous function u twice continuously differentiable in the interior and continuous on the boundary, such that u is harmonic in the interior and u=f on the boundary? This requirement is called the Dirichlet boundary condition. The main issue is to prove the existence of a solution; uniqueness can be proven using the maximum principle. History The Dirichlet problem goes back to George Green, who studied the problem on general domains with general boundary conditions in his ''Essay on the Application o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Points Effect
A point is a small dot or the sharp tip of something. Point or points may refer to: Mathematics * Point (geometry), an entity that has a location in space or on a plane, but has no extent; more generally, an element of some abstract topological space * Point, or Element (category theory), generalizes the set-theoretic concept of an element of a set to an object of any category * Critical point (mathematics), a stationary point of a function of an arbitrary number of variables * Decimal point * Point-free geometry * Stationary point, a point in the domain of a single-valued function where the value of the function ceases to change Places * Point, Cornwall, England, a settlement in Feock parish * Point, Lewis, a peninsula in the Outer Hebrides, Scotland * Point, Texas, a city in Rains County, Texas, United States * Point, the NE tip and a ferry terminal of Lismore, Inner Hebrides, Scotland * Points, West Virginia, an unincorporated community in the United States Business and fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green's Identities
In mathematics, Green's identities are a set of three identities in vector calculus relating the bulk with the boundary of a region on which differential operators act. They are named after the mathematician George Green, who discovered Green's theorem. Green's first identity This identity is derived from the divergence theorem applied to the vector field while using an extension of the product rule that : Let and be scalar functions defined on some region , and suppose that is twice continuously differentiable, and is once continuously differentiable. Using the product rule above, but letting , integrate over . Then \int_U \left( \psi \, \Delta \varphi + \nabla \psi \cdot \nabla \varphi \right)\, dV = \oint_ \psi \left( \nabla \varphi \cdot \mathbf \right)\, dS=\oint_\psi\,\nabla\varphi\cdot d\mathbf where is the Laplace operator, is the boundary of region , is the outward pointing unit normal to the surface element and is the oriented surface element. This the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
