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GravitySimulator
gravitySimulator is a novel supercomputer that incorporates special-purpose GRAPE hardware to solve the gravitational ''n''-body problem. It is housed in the Center for Computational Relativity and Gravitation (CCRG) at the Rochester Institute of Technology. It became operational in 2005. The computer consists of 32 nodes, each of which contains a GRAPE-6A board ("mini-GRAPE") in a Peripheral Component Interconnect (PCI) slot. The GRAPE boards use pipelines to compute pairwise forces between particles at a speed of 130 Gflops. The on-board memory of each GRAPE board can hold data for 128,000 particles, and by combining 32 of them in a cluster, a total of four million particles can be integrated, at sustained speeds of 4 Tflops. gravitySimulator is used to study the dynamical evolution of galaxies and galactic nuclei An active galactic nucleus (AGN) is a compact region at the center of a galaxy that has a much-higher-than-normal luminosity over at least some portion of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supercomputer
A supercomputer is a computer with a high level of performance as compared to a general-purpose computer. The performance of a supercomputer is commonly measured in floating-point operations per second ( FLOPS) instead of million instructions per second (MIPS). Since 2017, there have existed supercomputers which can perform over 1017 FLOPS (a hundred quadrillion FLOPS, 100 petaFLOPS or 100 PFLOPS). For comparison, a desktop computer has performance in the range of hundreds of gigaFLOPS (1011) to tens of teraFLOPS (1013). Since November 2017, all of the world's fastest 500 supercomputers run on Linux-based operating systems. Additional research is being conducted in the United States, the European Union, Taiwan, Japan, and China to build faster, more powerful and technologically superior exascale supercomputers. Supercomputers play an important role in the field of computational science, and are used for a wide range of computationally intensive tasks in var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravity Pipe
Gravity Pipe (abbreviated GRAPE) is a project which uses hardware acceleration to perform gravitational computations. Integrated with Beowulf-style commodity computers, the GRAPE system calculates the force of gravity that a given mass, such as a star, exerts on others. The project resides at Tokyo University. The GRAPE hardware acceleration component "pipes" the force computation to the general-purpose computer serving as a node in a parallelized cluster as the innermost loop of the gravitational model. Its shortened name, GRAPE, was chosen as an intentional reference to the Apple Inc. line of computers. Method The primary calculation in GRAPE hardware is a summation of the forces between a particular star and every other star in the simulation. Several versions (GRAPE-1, GRAPE-3 and GRAPE-5) use the logarithmic number system (LNS) in the pipeline to calculate the approximate force between two stars and take the antilogarithms of the ''x'', ''y'' and ''z'' components before ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N-body Problem
In physics, the -body problem is the problem of predicting the individual motions of a group of celestial objects interacting with each other gravitationally.Leimanis and Minorsky: Our interest is with Leimanis, who first discusses some history about the -body problem, especially Ms. Kovalevskaya's 1868–1888 twenty-year complex-variables approach, failure; Section 1: "The Dynamics of Rigid Bodies and Mathematical Exterior Ballistics" (Chapter 1, "The motion of a rigid body about a fixed point (Euler and Poisson equations)"; Chapter 2, "Mathematical Exterior Ballistics"), good precursor background to the -body problem; Section 2: "Celestial Mechanics" (Chapter 1, "The Uniformization of the Three-body Problem (Restricted Three-body Problem)"; Chapter 2, "Capture in the Three-Body Problem"; Chapter 3, "Generalized -body Problem"). Solving this problem has been motivated by the desire to understand the motions of the Sun, Moon, planets, and visible stars. In the 20th century, unde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Center For Computational Relativity And Gravitation
The Center for Computational Relativity and Gravitation (CCRG) is a research center of the College of Science (COS) and a Research Center of Excellence at Rochester Institute of Technology (RIT) dedicated to research at the frontiers of numerical relativity and relativistic astrophysics, gravitational-wave physics, its connection to experiments and observations, and high-performance computation and scientific visualization. Faculty members currently include Hans-Peter Bischof, Joshua Faber, Manuela Campanelli (Director), Carlos Lousto, David Merritt, John Whelan, Yosef Zlochower and Richard O'Shaughnessy. Computing facilities in the CCRG include gravitySimulator, a 32-node computer that uses special-purpose GRAPE A grape is a fruit, botanically a berry, of the deciduous woody vines of the flowering plant genus '' Vitis''. Grapes are a non- climacteric type of fruit, generally occurring in clusters. The cultivation of grapes began perhaps 8,000 years a ... hardware to achi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rochester Institute Of Technology
Rochester Institute of Technology (RIT) is a private university, private research university in the town of Henrietta, New York, Henrietta in the Rochester, New York, metropolitan area. The university offers undergraduate and graduate degrees, including Doctorate, doctoral and professional degrees and Online degree, online masters as well. The university was founded in 1829 and is the tenth largest private university in the United States in terms of full-time students. It is internationally known for its science, computer, engineering, and art programs, as well as for the National Technical Institute for the Deaf, a leading deaf-education institution that provides educational opportunities to more than 1000 deaf and hard-of-hearing students. RIT is known for its Cooperative education, C o-op program, which blends professional and industrial experience with traditional classroom based instruction. It has the fourth oldest and one of the largest co-op programs in the world. It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GravitySimulator
gravitySimulator is a novel supercomputer that incorporates special-purpose GRAPE hardware to solve the gravitational ''n''-body problem. It is housed in the Center for Computational Relativity and Gravitation (CCRG) at the Rochester Institute of Technology. It became operational in 2005. The computer consists of 32 nodes, each of which contains a GRAPE-6A board ("mini-GRAPE") in a Peripheral Component Interconnect (PCI) slot. The GRAPE boards use pipelines to compute pairwise forces between particles at a speed of 130 Gflops. The on-board memory of each GRAPE board can hold data for 128,000 particles, and by combining 32 of them in a cluster, a total of four million particles can be integrated, at sustained speeds of 4 Tflops. gravitySimulator is used to study the dynamical evolution of galaxies and galactic nuclei An active galactic nucleus (AGN) is a compact region at the center of a galaxy that has a much-higher-than-normal luminosity over at least some portion of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peripheral Component Interconnect
Peripheral Component Interconnect (PCI) is a local computer bus for attaching hardware devices in a computer and is part of the PCI Local Bus standard. The PCI bus supports the functions found on a processor bus but in a standardized format that is independent of any given processor's native bus. Devices connected to the PCI bus appear to a bus master to be connected directly to its own bus and are assigned addresses in the processor's address space. It is a parallel bus, synchronous to a single bus clock. Attached devices can take either the form of an integrated circuit fitted onto the motherboard (called a ''planar device'' in the PCI specification) or an expansion card that fits into a slot. The PCI Local Bus was first implemented in IBM PC compatibles, where it displaced the combination of several slow Industry Standard Architecture (ISA) slots and one fast VESA Local Bus (VLB) slot as the bus configuration. It has subsequently been adopted for other computer types. Typic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gigaflop
In computing, floating point operations per second (FLOPS, flops or flop/s) is a measure of computer performance, useful in fields of scientific computations that require floating-point calculations. For such cases, it is a more accurate measure than measuring instructions per second. Floating-point arithmetic Floating-point arithmetic is needed for very large or very small real numbers, or computations that require a large dynamic range. Floating-point representation is similar to scientific notation, except everything is carried out in base two, rather than base ten. The encoding scheme stores the sign, the exponent (in base two for Cray and VAX, base two or ten for IEEE floating point formats, and base 16 for IBM Floating Point Architecture) and the significand (number after the radix point). While several similar formats are in use, the most common is ANSI/IEEE Std. 754-1985. This standard defines the format for 32-bit numbers called ''single precision'', as well as 64-b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teraflop
In computing, floating point operations per second (FLOPS, flops or flop/s) is a measure of computer performance, useful in fields of scientific computations that require floating-point calculations. For such cases, it is a more accurate measure than measuring instructions per second. Floating-point arithmetic Floating-point arithmetic is needed for very large or very small real numbers, or computations that require a large dynamic range. Floating-point representation is similar to scientific notation, except everything is carried out in base two, rather than base ten. The encoding scheme stores the sign, the exponent (in base two for Cray and VAX, base two or ten for IEEE floating point formats, and base 16 for IBM Floating Point Architecture) and the significand (number after the radix point). While several similar formats are in use, the most common is ANSI/IEEE Std. 754-1985. This standard defines the format for 32-bit numbers called ''single precision'', as well as 64-b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxies
A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. Galaxies, averaging an estimated 100 million stars, range in size from dwarfs with less than a hundred million stars, to the largest galaxies known – supergiants with one hundred trillion stars, each orbiting its galaxy's center of mass. Most of the mass in a typical galaxy is in the form of dark matter, with only a few percent of that mass visible in the form of stars and nebulae. Supermassive black holes are a common feature at the centres of galaxies. Galaxies are categorized according to their visual morphology as elliptical, spiral, or irregular. Many are thought to have supermassive black holes at their centers. The Milky Way's central black hole, known as Sagittarius A*, has a mass four million times greater than the Sun. As of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galactic Nuclei
An active galactic nucleus (AGN) is a compact region at the center of a galaxy that has a much-higher-than-normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars. Such excess non-stellar emission has been observed in the radio, microwave, infrared, optical, ultra-violet, X-ray and gamma ray wavebands. A galaxy hosting an AGN is called an "active galaxy". The non-stellar radiation from an AGN is theorized to result from the accretion of matter by a supermassive black hole at the center of its host galaxy. Active galactic nuclei are the most luminous persistent sources of electromagnetic radiation in the universe, and as such can be used as a means of discovering distant objects; their evolution as a function of cosmic time also puts constraints on models of the cosmos. The observed characteristics of an AGN depend on several properties such as the mass of the central black hole, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David Merritt
David Roy Merritt (born November 16, 1955 in Los Angeles) is an American astrophysicist. Until 2017 he was a professor at the Rochester Institute of Technology in Rochester, New York. He received in 1982 his PhD in Astrophysical Sciences from Princeton University with thesis advisor Jeremiah P. Ostriker and held postdoctoral positions at the University of California, Berkeley and the Canadian Institute for Theoretical Astrophysics in Toronto. Merritt's fields of specialization include dynamics and evolution of galaxies, supermassive black holes, and computational astrophysics. Merritt is a former Chair of the Division on Dynamical Astronomy of the American Astronomical Society. He is a founding member of the Center for Computational Relativity and Gravitation at RIT. His scientific contributions include Osipkov–Merritt models, black hole spin flips, the Leonard–Merritt mass estimator, the M–sigma relation, stellar systems with negative temperatures, and the Schw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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