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R. Krivec 《Few-Body Systems》1998,25(4):199-238
A review of hyperspherical-harmonics (HH) methods from the standpoint of their applications is given. In the first lecture,
the symmetrized and unsymmetrized HH bases and symmetrization methods are presented. The physical obstacles to the straightforward
application of the HH expansion are discussed, and expansion acceleration methods are described. In the second lecture, the
main HH methods are described, including the correlation function hyperspherical harmonic method (CFHHM), the potential harmonic
(PH) methods, and the correlated HH methods (PHH, CHH). The third lecture discusses the advantages and limitations of different
HH methods in applications, and compares the results for specific few-body problems obtained by HH methods as well as non-HH
methods. 相似文献
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Jianke Yang 《Journal of computational physics》2009,228(18):7007-7024
In this paper, the Newton-conjugate-gradient methods are developed for solitary wave computations. These methods are based on Newton iterations, coupled with conjugate-gradient iterations to solve the resulting linear Newton-correction equation. When the linearization operator is self-adjoint, the preconditioned conjugate-gradient method is proposed to solve this linear equation. If the linearization operator is non-self-adjoint, the preconditioned biconjugate-gradient method is proposed to solve the linear equation. The resulting methods are applied to compute both the ground states and excited states in a large number of physical systems such as the two-dimensional NLS equations with and without periodic potentials, the fifth-order KdV equation, and the fifth-order KP equation. Numerical results show that these proposed methods are faster than the other leading numerical methods, often by orders of magnitude. In addition, these methods are very robust and always converge in all the examples being tested. Furthermore, they are very easy to implement. It is also shown that the nonlinear conjugate gradient methods are not robust and inferior to the proposed methods. 相似文献
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A. L. Cherezov N. V. Schukin A. A. Semyonov D. A. Solov’yov 《Physics of Atomic Nuclei》2011,74(14):1900-1907
The reactivity determination methods which are based on the neutron field reconstruction procedure and the spectral-projection
method are analyzed. The approximate methods of reactivity determination which can be used in practice are offered. The efficiency
of the proposed methods in comparison to that of the methods applied in operation of nuclear power plants is demonstrated
using computational models. 相似文献
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High resolution methods for delay estimation 总被引:3,自引:0,他引:3
I.IntroductionInapplicationssuchasradar,sonar,geo1ogica1cxplorationandmedica1image,it'sncccs-sarytoobtainthecharacteristicsofscattcrcrs(targetS)fromactiveechoes.Oneofthecharacter-isticsisthede1ayparametersbctweenmultip1etargets.Thus,wcarefacedwiththeprob1cmsofresolvjnganunknownnumberofc1oseIy,over1appcdandnoisyechoesofasignalwiththeshapeprioriknown,andestimatingthedelayparametcrs.Ingeneral,anachvcechocscanbere-gardedasaconvolutionmode1x(t)=s(t)*h(t) w(t)(l)wherex(t)istheechowave,s(t)isthecmi… 相似文献
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采用两种不同的方法分别测量了双光束干涉法中两个虚光源之间的距离,并对两种方法对实验结果的误差影响进行了比较分析,分析表明两种方法各有优劣,分别适合不同类型的学生。 相似文献
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Constrained Hamiltonian systems with singular higher-order Lagrangians are investigated by using two methods: the Dirac's and the Hamilton-Jacobi methods. Three examples are studied and it is shown that the equations of motion which are obtained by these two methods are in exact agreement. 相似文献