共查询到20条相似文献,搜索用时 0 毫秒
1.
Simple method allowing for adaptive cubic spline interpolation
of fluorescence decay functions is proposed. In the first step of the
method, the interpolated function is integrated using the known adaptive
algorithm based on Newton-Cotes quadratures. It is shown that, in this
step, application of the Simpson's rule provides the smallest number of
calls of the interpolated function. In the second step of the method,
a typical cubic spline approximation is used to find values of the
interpolated function between the points evaluated in the first step. 相似文献
2.
3.
传统的空间数据插值方法在米散射激光雷达剖面扫描数据的距离高度显示图可视化应用方面具有一定的局限性.本文分析了米散射激光雷达剖面扫描数据以仰角为基础的空间位置关系与大气参数的空间分布特性,分别在垂直与水平位置上合理选取参考数据,给出位置相关性权重,基于三次样条函数法进行数据变化趋势的平滑性修正,完成缺失数据插值.实验结果表明,该方法能够有效提高米散射大气激光雷达扫描数据空间插值的准确性,插值数据误差小,距离高度显示图图形趋势过度平滑,符合大气参数的整体变化规律. 相似文献
4.
5.
This paper presents a parallel implementation of fractional solvers for the incompressible Navier–Stokes equations using an algebraic approach. Under this framework, predictor–corrector and incremental projection schemes are seen as sub-classes of the same class, making apparent its differences and similarities. An additional advantage of this approach is to set a common basis for a parallelization strategy, which can be extended to other split techniques or to compressible flows. 相似文献
6.
S.P. Hirshman K.S. PerumallaV.E. Lynch R. Sanchez 《Journal of computational physics》2010,229(18):6392-6404
A block tridiagonal matrix is factored with minimal fill-in using a cyclic reduction algorithm that is easily parallelized. Storage of the factored blocks allows the application of the inverse to multiple right-hand sides which may not be known at factorization time. Scalability with the number of block rows is achieved with cyclic reduction, while scalability with the block size is achieved using multithreaded routines (OpenMP, GotoBLAS) for block matrix manipulation. This dual scalability is a noteworthy feature of this new solver, as well as its ability to efficiently handle arbitrary (non-powers-of-2) block row and processor numbers. Comparison with a state-of-the art parallel sparse solver is presented. It is expected that this new solver will allow many physical applications to optimally use the parallel resources on current supercomputers. Example usage of the solver in magneto-hydrodynamic (MHD), three-dimensional equilibrium solvers for high-temperature fusion plasmas is cited. 相似文献
7.
A probabilistic representation for initial value semilinear parabolic problems based on generalized random trees has been derived. Two different strategies have been proposed, both requiring generating suitable random trees combined with a Pade approximant for approximating accurately a given divergent series. Such series are obtained by summing the partial contribution to the solution coming from trees with arbitrary number of branches. The new representation greatly expands the class of problems amenable to be solved probabilistically, and was used successfully to develop a generalized probabilistic domain decomposition method. Such a method has been shown to be suited for massively parallel computers, enjoying full scalability and fault tolerance. Finally, a few numerical examples are given to illustrate the remarkable performance of the algorithm, comparing the results with those obtained with a classical method. 相似文献
8.
We discuss the scalable parallel solution of the Poisson equation within a Particle-In-Cell (PIC) code for the simulation of electron beams in particle accelerators of irregular shape. The problem is discretized by Finite Differences. Depending on the treatment of the Dirichlet boundary the resulting system of equations is symmetric or ‘mildly’ nonsymmetric positive definite. In all cases, the system is solved by the preconditioned conjugate gradient algorithm with smoothed aggregation (SA) based algebraic multigrid (AMG) preconditioning. We investigate variants of the implementation of SA-AMG that lead to considerable improvements in the execution times. We demonstrate good scalability of the solver on distributed memory parallel processor with up to 2048 processors. We also compare our iterative solver with an FFT-based solver that is more commonly used for applications in beam dynamics. 相似文献
9.
10.
Wavefront sensor-less adaptive optics technology has a much higher requirement for the processing speed than ever before. To improve the efficiency of particle swarm optimization (PSO), this paper proposes a novel parallel mutation particle swarm optimization (PMPSO) algorithm based on a master-slave model. The parallel system based on PMPSO algorithm is applied in a 61-element adaptive optics system to control the deformable mirror. The experimental results show that the parallel system based on PMPSO algorithm has a rapid convergence speed, which can effectively correct the wavefront aberration. 相似文献
11.
Optical Review - The principle of hyperspectral imaging leads to a variety of stripe noise in hyperspectral images, especially the wide-stripe noise, which brings great obstacles to the... 相似文献
12.
在许多声信号处理系统中,常常需要在一实序列的相邻两个样值之间进行快速离散内插.本文提出了一种基于FHT的离散信号快速内插算法.该算法所需的实乘次数只有Hsu-Lin算法实乘次数的60%左右,而实加次数还不到Hsu-Lin算法的60%.此外,它允许内插率L可为任意整数,且适用于并行处理.本文算法已用软件实现,对实际声信号处理行之有效. 相似文献
13.
An Euler solver based on locally adaptive discrete velocities 总被引:2,自引:0,他引:2
B. T. Nadiga 《Journal of statistical physics》1995,81(1-2):129-146
A new discrete-velocity model is presented to solve the three-dimensional Euler equations. The velocities in the model are of an adaptive nature—both the origin of the discrete-velocity space and the magnitudes of the discrete velocities are dependent on the local flow—and are used in a finite-volume context. The numerical implementation of the model follows the near-equilibrium flow method of Nadiga and Pullin and results in a scheme which is second order in space (in the smooth regions and between first and second order at discontinuities) and second order in time. (The three-dimensional code is included.) For one choice of the scaling between the magnitude of the discrete velocities and the local internal energy of the flow, the method reduces to a flux-splitting scheme based on characteristics. As a preliminary exercise, the result of the Sod shock-tube simulation is compared to the exact solution. 相似文献
14.
通过对已有的各种电子秤的分析,从硬件和软件两个方面,提出提高电子秤测量精度的方法。硬件上采用专门为高精度设计的24位A/D转换芯片HX711,该芯片具有分辨率高、线性度好、功耗低等优点,特别适合低频高精度的应用场合。软件上引入样条函数,用光滑的参数曲线段逼近折线多边形,实现对非线性称重关系特性曲线的拟合和自校准,达到减小误差的目的。最后通过实验证明了该方法的有效性。 相似文献
15.
研究了先正向计算波前传播时间,再根据波前传播时间反向确定声线路径的三维非均匀介质声线追踪算法。在正向步骤,根据程函方程,使用基于水平集的GMM(Group Marching Method)波前扩展算法,从声源开始,逐步计算离散介质网格节点上的波前传播时间。在反向步骤,利用正向步骤计算出的网格节点上的波前传播时间,从接收点开始,向声源方向逐单元追踪声线路径。在每个长方体单元内,首先把任意点上的波前传播时间用该单元网格节点上的已知波前传播时间的线性插值函数来表示,再根据Fermat原理,提出了确定三维声线路径的方法。实验结果表明,本文方法提高了三维声线追踪的精度和计算速度。 相似文献
16.
在等离子体平衡重建迭代计算过程中,需要快速求解Grad-Shafranov方程(G-S方程)。构造了具有四阶精度紧致差分格式的离散方程,采用离散正弦变换技术对其进行快速求解并采用CUDATM实现GPU并行加速,将其应用到EAST等离子体平衡重建PEFIT代码中,实现基于紧致差分格式的快速G-S方程求解。结果表明,在65×65的网格下,给定方程右端项电流分布的前提下,使用GPU求解G-S方程所需时间为大约34μs。 相似文献
17.
18.
提出了一种基于谱线幅值归零的加窗插值FFT谐波检测方法用于分析复杂电网信号中的各次谐波.该检测方法将每一次在离散频谱中找到的最大谱线及其左右两侧的数根谱线幅值归零,直到各次谐波分析完毕.通过仿真实验分析了在基波频率稳定时对模拟信号的测量精度,研究了基波频率波动对谐波分析的影响.通过对EAST实验数据的分析,验证了该谐波... 相似文献
19.
基于FPGA并行处理的实时图像相关速度计 总被引:2,自引:1,他引:2
研究制作了一种采用高速线阵CCD的实时相关速度计,其测量数据的输出速率可达每秒一万次。针对以往光学相关测速方法的问题进行了讨论,探讨了适合FPGA并行处理的算法,制作了高速线阵CCD摄像机及其处理装置。通过实验验证了系统的可行性和可实现性。 相似文献
20.
Dapeng Hu Shanghong Zhao Zihang Zhu Xuan Li Kun Qu Tao Lin Kun Zhang 《Optical Review》2018,25(1):109-115
A simple photonic microwave image-reject mixer (IRM) using two parallel phase modulators is proposed. First, a photonic microwave mixer with phase shift ability is achieved using two parallel phase modulators (PMs), an optical bandpass filter, three polarization controllers, three polarization beam splitters and two balanced photodetectors. At the output of the mixer, two frequency downconverted signals with tunable frequency difference can be obtained. By adjusting the phase difference as 90° and utilizing an electrical 90° hybrid, the useless components can be eliminated, and the image reject operation is realized. The key advantage of the proposed scheme is the usage of PM, which avoid the DC bias shifting problem and make the system simple and stable. A simulation is performed to verify the proposed scheme, a relative ??90° or 90° phase shift can be obtained between the two output ports of the photonic microwave mixer, at the output of the IRM, 60 dB image-reject ratio is obtained. 相似文献