共查询到20条相似文献,搜索用时 31 毫秒
1.
P. S. Ramkumar T. Prabu Madhu Girimaji G. Marker leyulu 《Journal of Astrophysics and Astronomy》1994,15(3):343-353
A fast digital signal processor has been designed and built for survey and some observations of pulsars. The processor obtains
spectral information over a bandwidth of 16 MHz (256 channels) every 25μsecs Wedescribethe design ofthisprocessor and present
some test observations made with the Ooty Radio Telescope. 相似文献
2.
R. T. Schilizzi W. Aldrich B. Anderson A. Bos R. M. Campbell J. Canaris R. Cappallo J. L. Casse A. Cattani J. Goodman H. J. van Langevelde A. Maccafferri R. Millenaar R. G. Noble F. Olnon S. M. Parsley C. Phillips S. V. Pogrebenko D. Smythe A. Szomoru H. Verkouter A. R. Whitney 《Experimental Astronomy》2001,12(1):49-67
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In this paper we present a new symbolic processor specially suited for the Earth rotation theory. This processor works with a more general kind of Poisson series called Kinoshita series, which has resulted to be very useful in the Earth rotation theory. Its structure is adapted for dealing with the more general analytical expressions that appear in the Earth rotation theory. This new algebraic processor has been successfully used for computing different contributions to the nutation series of the rigid Earth.This revised version was published online in October 2005 with corrections to the Cover Date. 相似文献
5.
Arnold Rom 《Celestial Mechanics and Dynamical Astronomy》1971,3(3):331-345
An Echeloned Series Processor (ESP) has been implemented on a computer. The processor has certain similarities with MAO (MAO is a processor for Poisson series). Echeloned Series contain divisors in literal form. List processing and dynamic storage techniques are used to handle Echeloned Series by computer. 相似文献
6.
简单介绍了PCI总线协议以及PCI接口原理。给出了一种利用单片机与复杂可编程逻辑器件CPLD(complex programmable logic device)控制PCI网卡,实现以太网通信的方案设计。重点说明了如何使用CPLD芯片设计单片机与PCI网卡之间的PCI接口。 相似文献
7.
V. A. Brumberg S. V. Tarasevich N. N. Vasiliev 《Celestial Mechanics and Dynamical Astronomy》1988,45(1-3):149-162
Construction and application of the current high accuracy analytical theories of motion of celestial bodies necessitates the development of specialized software for the implementation of analytical algorithms of celestial mechanics. This paper describes a typical software package of this kind. This package includes a universal Poisson processor for the rational functions of many variables, a tensorial processor for purposes of relativistic celestial mechanics, a Keplerian processor valid for the solutions of the two body problem in the form of a Poisson series, Taylor expansions in powers of time and closed expressions, and an analytical generator of celestial mechanics functions, facilitating the immediate implementation of the present analytical methods of celestial mechanics. The package is completed with a numerical-analytical interface designed, in particular, for the fast evaluation of the long Poisson series. 相似文献
8.
The highlight of the 4th EVN/JIVE Symposium was the inauguration of the new EVN MkIV data processor at JIVE. This paper deals with the state of the processor in October 1998 and how it was used for fringe detection experiments. 相似文献
9.
This paper describes the design, tests and preliminary results of a real-time parallel signal processor built to aid a wide
variety of pulsar observations. The signal processor reduces the distortions caused by the effects of dispersion, Faraday
rotation, doppler acceleration and parallactic angle variations, at a sustained data rate of 32 Msamples/sec. It also folds
the pulses coherently over the period and integrates adjacent samples in time and frequency to enhance the signal-to-noise
ratio. The resulting data are recorded for further off-line analysis of the characteristics of pulsars and the intervening
medium. The signal processing for analysis of pulsar signals is quite complex, imposing the need for a high computational
throughput, typically of the order of a Giga operations per second (GOPS). Conventionally, the high computational demand restricts
the flexibility to handle only a few types of pulsar observations. This instrument is designed to handle a wide variety of
Pulsar observations with the Giant Metre Wave Radio Telescope (GMRT), and is flexible enough to be used in many other high-speed,
signal processing applications. The technology used includes field-programmable-gate-array(FPGA) based data/code routing interfaces,
PC-AT based control, diagnostics and data acquisition, digital signal processor (DSP) chip based parallel processing nodes
and C language based control software and DSP-assembly programs for signal processing. The architecture and the software implementation
of the parallel processor are fine-tuned to realize about 60 MOPS per DSP node and a multiple-instruction-multiple-data (MIMD)
capability. 相似文献
10.
We present a high-performance N-body code for self-gravitating collisional systems accelerated with the aid of a new SIMD instruction set extension of the x86 architecture: Advanced Vector eXtensions (AVX), an enhanced version of the Streaming SIMD Extensions (SSE). With one processor core of Intel Core i7-2600 processor (8 MB cache and 3.40 GHz) based on Sandy Bridge micro-architecture, we implemented a fourth-order Hermite scheme with individual timestep scheme (Makino and Aarseth, 1992), and achieved the performance of ∼20 giga floating point number operations per second (GFLOPS) for double-precision accuracy, which is two times and five times higher than that of the previously developed code implemented with the SSE instructions (Nitadori et al., 2006b), and that of a code implemented without any explicit use of SIMD instructions with the same processor core, respectively. We have parallelized the code by using so-called NINJA scheme (Nitadori et al., 2006a), and achieved ∼90 GFLOPS for a system containing more than N = 8192 particles with 8 MPI processes on four cores. We expect to achieve about 10 tera FLOPS (TFLOPS) for a self-gravitating collisional system with N ∼ 105 on massively parallel systems with at most 800 cores with Sandy Bridge micro-architecture. This performance will be comparable to that of Graphic Processing Unit (GPU) cluster systems, such as the one with about 200 Tesla C1070 GPUs (Spurzem et al., 2010). This paper offers an alternative to collisional N-body simulations with GRAPEs and GPUs. 相似文献
11.
《New Astronomy》2007,12(3):169-181
The main performance bottleneck of gravitational N-body codes is the force calculation between two particles. We have succeeded in speeding up this pair-wise force calculation by factors between 2 and 10, depending on the code and the processor on which the code is run. These speed-ups were obtained by writing highly fine-tuned code for x86_64 microprocessors. Any existing N-body code, running on these chips, can easily incorporate our assembly code programs.In the current paper, we present an outline of our overall approach, which we illustrate with one specific example: the use of a Hermite scheme for a direct N2 type integration on a single 2.0 GHz Athlon 64 processor, for which we obtain an effective performance of 4.05 Gflops, for double-precision accuracy. In subsequent papers, we will discuss other variations, including the combinations of N log N codes, single-precision implementations, and performance on other microprocessors. 相似文献
12.
Reza Raymond Karimi Daniele Mortari 《Celestial Mechanics and Dynamical Astronomy》2011,109(2):167-180
A novel approach for initial orbit determination based on multiple angles-only observations is presented. The proposed technique
is iterative and uses Lagrangian coefficients, f and g. The proposed method does not show singularity for the coplanar cases. In addition, the method is capable of handling multiple
observations, providing higher accuracy, whereas the level of the algorithm complexity and processor running time remain almost
invariant. The technique presented is compared with the Double r-iteration and Gauss’ methods using data corrupted by noise to simulate true measurements. Results show that the proposed
method is a valid alternative to the classical methods of orbit determination. 相似文献
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A. Abad A. Elipe M. L. Sein-Echaluce 《Celestial Mechanics and Dynamical Astronomy》1988,45(1-3):99-102
An algebraic processor plus an interactive graphics system transform a desk computer into a very handy tool for research in non linear mechanics. 相似文献
15.
D. S. Schmidt 《Celestial Mechanics and Dynamical Astronomy》1988,45(1-3):201-206
The Hamiltonian function of the restricted problem of three bodies near the triangular Lagrangian point is normalized through sixth order terms with the help of MACSYMA. The same calculations were done previously with an algebraic processor in order to establish the stability at a critical value of the mass ratio. 相似文献
16.
介绍了一种基于数字信号处理器(DSP)和现场可编程门阵列(FPGA)的低频时码接收机的硬件组成,描述了该接收机系统实现时间同步的方法,阐述了DSP和FP-GA的软件设计,给出了测试和仿真结果。该设计方案具有精度高、可靠性强、扩展性好等优点。 相似文献
17.
Tamara Ivanova 《Celestial Mechanics and Dynamical Astronomy》2001,80(3-4):167-176
A specialized Echeloned Poisson Series Processor (EPSP) is proposed. It is a typical software for the implementation of analytical algorithms of Celestial Mechanics. EPSP is designed for manipulating long polynomial-trigonometric series with literal divisors. The coefficients of these echeloned series are the rational or floating-point numbers. The Keplerian processor and analytical generator of special celestial mechanics functions based on the EPSP are also developed. 相似文献
18.
We consider an algorithm to construct averaged motion equations for four-planetary systems by means of the Hori–Deprit method. We obtain the generating function of the transformation, change-variable functions and right-hand sides of the equations of motion in elements of the second Poincaré system. Analytical computations are implemented by means of the Piranha echeloned Poisson processor. The obtained equations are to be used to investigate the orbital evolution of giant planets of the Solar system and various extrasolar planetary systems. 相似文献
19.
Edward J. Rhodes Jr. Robert F. Howard Roger K. Ulrich Edward J. Smith 《Solar physics》1983,82(1-2):245-258
In this paper we describe a new observing system which is currently nearing completation at the Mount Wilson Observatory. This system has been designed to obtain daily measurements of solar photospheric and subphotospheric rotational velocities from the frequency splitting of non-radial solar p-mode oscillations of moderate to high degree (i.e. l > 150). The completed system will combine a 244 × 248 pixel CID camera with a high-speed floating point array processor, a 32-bit minicomputer, and a large-capacity disc storage system. We are integrating these components into the spectrograph of the 60-foot solar tower telescope at Mount Wilson in order to provide a facility which will be dedicated to the acquisition of oscillation data. 相似文献
20.
Parallel processor computers represent a new technology that has recently become available for astronomical applications. We have implemented an N-body code on a TMC Connection Machine CM-2 in order to investigate the advantages of a massively parallel computer over serial machines, including conventional supercomputers. For collisionless problems following N stars, a direct integration code scales as O(N2) on serial machines and on the CM-2 as O(log(N)) for small N and O(N log(N)) for large N. The CM-2 outperforms workstations for N>50 and supercomputers for N>4000. 相似文献