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N. Michel 《Computer Physics Communications》2007,176(3):232-249
A new algorithm to calculate Coulomb wave functions with all of its arguments complex is proposed. For that purpose, standard methods such as continued fractions and power/asymptotic series are combined with direct integrations of the Schrödinger equation in order to provide very stable calculations, even for large values of |η| or |ℑ(?)|. Moreover, a simple analytic continuation for is introduced, so that this zone of the complex z-plane does not pose any problem. This code is particularly well suited for low-energy calculations and the calculation of resonances with extremely small widths. Numerical instabilities appear, however, when both |η| and |ℑ(?)| are large and comparable or smaller than |ℑ(?)|.
Program summary
Title of program: cwfcomplexCatalogue number:ADYO_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADYO_v1_0Program obtainable from: CPC Program Library, Queen's University of Belfast, N. IrelandLicensing provisions: noneComputers on which the program has been tested: DELL GX400Operating systems: Linux, WindowsProgramming language used: C++No. of bits in a word: 64No. of processors used: 1Has the code been vectorized?: noNo. of bytes in distributed program, including test data, etc.: 33 092No. of lines in distributed program, including test data, etc.: 3210Distribution format:tar.gzNature of physical problem: The calculation of Coulomb wave functions with all of their arguments complex is revisited. The new methods introduced allow to greatly augment the range of accessible ?, η, and z.Method of solution: Power/asymptotic series and continued fractions are supplemented with direct integrations of the Coulomb Schrödinger equation. Analytic continuation for is also precisely computed using linear combinations of the functions provided by standard methods, which do not follow the branch cut requirements demanded for Coulomb wave functions.Typical running time: N/AUnusual features of the program: none 相似文献2.
针对现有基于H/A/α 分解的全极化高分辨率距离像(HRRP) 特征提取方法没有考虑度量尺度对特征性能的影响问题, 引入动态互信息思想设计了度量尺度评价准则, 并提出了基于平均度量尺度、不定度量尺度和金字塔型度量尺度3 种特征提取方法. 采用两类飞机目标全极化HRRP 数据对提取的特征子集进行了有效性分析, 并通过识别多类飞机目标验证了3 种方法提取的特征子集具有良好的类别可分性和稳定性. 相似文献
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基于(α, λ)联系度容差关系的变精度粗糙集模型 总被引:2,自引:1,他引:1
基于传统粗糙集理论的方法不能有效地处理含噪音的不完备信息系统. 根据集对分析理论, 提出(α, λ)联系度容差关系. 将(α, λ)联系度容差关系与Ziarko提出的多数包含关系相结合, 提出变精度(α, λ)联系度粗糙集模型. 给出了该模型下基于正域相似度的启发式属性约简算法, 分析了算法的时间复杂度, 通过仿真实验验证了所提方法处理含噪音的不完备信息系统的有效性. 相似文献
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主要研究有限时间域的H∞预演控制问题. 我们从传统的解决最优控制问题的思路入手, 发现了经典方法解决该问题的症结所在后, 寻找并通过一个适当的线性变换来排除之, 获得了问题可解的充要条件和一个简单的预演控制器. 最后使用一个数值例子演示了H∞预演控制器改进系统闭环性能的有效性. 相似文献
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The performance of the method of angular moments on the ΔΓs determination from analysis of untagged decays is examined by using the SIMUB generator. The results of Monte Carlo studies with evaluation of measurement errors are presented. The method of angular moments gives stable results for the estimate of ΔΓs and is found to be an efficient and flexible tool for the quantitative investigation of the B0s→J/ψφ decay. The statistical error of the ratio ΔΓs/Γs for values of this ratio in the interval [0.03,0.3] was found to be independent on this value, being 0.015 for 105 events. 相似文献
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In this paper, the concept of an (α, β)-fuzzy generalized bi-ideal in an ordered semigroup is introduced, which is a generalization of the concept of a fuzzy generalized bi-ideal in an ordered semigroup. Using this concept, some characterization theorems are provided. The upper/lower parts of an (∈, ∈ ∨ q)-fuzzy generalized bi-ideal are introduced and some characterizations of regular ordered semigroups are given. Also, we consider the concept of implication-based fuzzy generalized bi-ideals in an ordered semigroup. In particular, the implication operators in Lukasiewicz system of continuous-valued logic are discussed. 相似文献
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The α scale spaces is a recent theory that open new possibilities of phase-based image processing. It is a parameterised class (α∈]0,1]) of linear scale space representations, which allows a continuous connection beyond the well-known Gaussian scale space (α=1). In this paper, we make use of this unified representation to derive new families of band pass quadrature filters, built from derivatives and difference of the α scale space generating kernels. This construction leads to generalised α kernel filters including the commonly known families derived from the Gaussian and the Poisson kernels. The properties of each family are first studied and then experiments on one- and two-dimensional signals are shown to exemplify how the suggested filters can be used for edge detection. This work is complemented by an experimental evaluation, which demonstrates that the new proposed filters are a good alternative to the commonly used Log-Gabor filter. 相似文献
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-Perfect graph is defined and some classes of -perfect graphs are described, although the characterization of the complete class of -perfect graphs remains an open question. A bound on the chromatic number for graphs without even holes is derived.Translated from Kibernetika, No. 2, pp. 8–11, March–April, 1990. 相似文献
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本文研究了离散时间线性时不变系统的量化动态输出反馈 H 无穷控制问题. 所考虑的动态量化器由动态调节参数和静态量化器组成. 静态量化器范围具有一定的实际意义, 这一点在本文充分考虑. 首先, 在考虑量化误差影响的情况下, 本文给出了既依赖于控制器状态又依赖于系统测量输出的量化控制策略使得闭环系统渐进稳定且具有指定的 H 无穷性能指标. 然后, 在这一结果的基础上, 又提出了基于线性矩阵不等式的迭代的优化算法来优化静态量化器范围, 从而得到能保证系统 H 无穷性能需求且具有最小量化器范围的量化控制策略. 最后通过仿真例子验证了所提出方法的有效性. 相似文献
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基于数乘变换是灰色系统建模过程中数据处理的基础,讨论了GM(n,h)模型与其他几类灰色模型的内在联系.将各类灰色模型统一于共同的分析体系,并在此基础上研究了数乘变换对GM(n,h)模型参数取值的影响.指出了模型的模拟和预测值只与因变量的数乘变换有关,而与自变量的变换无关.最后分析了几个特殊灰色模型的数乘变换性质,该结果对研究系列灰色模型参数特征有重要意义.
相似文献15.
研究了基于观测器的非线性系统H∞模糊可靠控制问题.采用T-S模糊模型对非线性系统进行建模,用模糊观测器重构系统状态.在系统发生故障时满足给定H∞性能的约束下,最小化正常情况下的H∞性能,实现次优H∞模糊可靠控制.提出了两种应用线性矩阵不等式(LMI)的H∞模糊可靠控制器设计方法.分别采用两步法和相似变换法将双线性矩阵不等式问题转化为LMI问题.仿真示例验证了所提出方法的有效性.
相似文献16.
本文研究了线性离散时间系统由有限字长影响的非脆弱滤波问题. 假定所设计的滤波器具有加性增益变量, 此增益变量反映了滤波器执行时的有限字长的影响. 为了解决该非脆弱滤波问题, 提出了一个结构的顶点分离器的概念, 并采用该分离器, 基于线性矩阵不等式给出了非脆弱滤波器设计的充分条件. 设计的结果使得误差系统渐进稳定且具有一定的性能水平. 数值例子验证了方法的有效性. 相似文献
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本文研究了基于第二 FM 模型的两维离散状态滞后系统 H∞ 控制问题. 给出了这类两维系统具有一定 H∞ 扰动抑制度的一个线性矩阵不等式条件, 并通过求解一个凸优化问题得到一个最优 H∞ 控制器. 最后通过一个仿真例子验证所提结果的有效性. 相似文献
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研究了含有多面体参数摄动Delta算子系统的参数依赖H∞控制问题.基于Delta算子系统有界实引理"提出了扩展参数依赖H∞性能准则.利用该准则,以参数化的线性矩阵不等式形式给出了参数依赖H∞控制器存在的充分条件,并通过求解优化问题设计控制器.研究结果表明该方法保守性较低,且物理概念清晰.数值示例验证了所提方法的有效性.
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