共查询到20条相似文献,搜索用时 15 毫秒
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介绍未确知数学方法,并用未确知数学方法分析处理物理实验数据,与传统的数据处理方法比较,未确知数学方法不必对数据作任何假设,因此更合理,也更符合实际。 相似文献
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Application of the Tikhonov regularization method to wind retrieval from scatterometer data I. Sensitivity analysis and simulation experiments 下载免费PDF全文
Scatterometer is an instrument which provides all-day and large-scale wind field information, and its application especially to wind retrieval always attracts meteorologists. Certain reasons cause large direction error, so it is important to find where the error mainly comes. Does it mainly result from the background field, the normalized radar cross-section (NRCS) or the method of wind retrieval? It is valuable to research. First, depending on SDP2.0, the simulated `true' NRCS is calculated from the simulated 'true' wind through the geophysical model function NSCAT2. The simulated background field is configured by adding a noise to the simulated 'true' wind with the non-divergence constraint. Also, the simulated 'measured' NRCS is formed by adding a noise to the simulated 'true' NRCS. Then, the sensitivity experiments are taken, and the new method of regularization is used to improve the ambiguity removal with simulation experiments. The results show that the accuracy of wind retrieval is more sensitive to the noise in the background than in the measured NRCS; compared with the two-dimensional variational (2DVAR) ambiguity removal method, the accuracy of wind retrieval can be improved with the new method of Tikhonov regularization through choosing an appropriate regularization parameter, especially for the case of large error in the background. The work will provide important information and a new method for the wind retrieval with real data. 相似文献
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A. A. Khokhlov 《Physics of Particles and Nuclei Letters》2011,8(5):494-497
This paper deals with the mathematical modeling of the interaction between the electromagnetic waves of the optical range
and multilayer optical structures, the application of which is highly popular today. A robust method for calculating the optical
properties of a single layer is described using the measured or required parameters. References to the scientific works reported
in this area are presented. 相似文献
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In most published work on the optical method of caustics, experimental results were obtained by manually measuring some characteristic dimensions of the shadow pattern and, therefore, used only a limited amount of data from the caustic. However, some previous work has been done using digital image processing and light intensity plots combined with least-squares techniques to analyse the shape of a caustic obtained from a particular problem. All of these methods have been developed to solve only one specific problem. This paper highlights the essential guidelines of an automated method, which has the novelty of generalising the whole analysis, such that only the parametric equations of a particular problem are required to solve it. In the proposed method the image is digitised, the central line of the caustic pattern is identified, and the parameters in the mapping equation of the caustic are determined. The method has been validated, and the aim of this paper is to describe the key features of the method, i.e. the optical arrangement, digital image processing, and numerical analysis. 相似文献
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《中国物理C(英文版)》2015,(10)
The concept of isochronous mass spectrometry(IMS) applying two time-of-flight(TOF) detectors originated many years ago at GSI. However, the corresponding method for data analysis has never been discussed in detail. Recently, two TOF detectors have been installed at CSRe and the new working mode of the ring is under test. In this paper, a data analysis method for this mode is introduced and tested with a series of simulations. The results show that the new IMS method can significantly improve mass resolving power via the additional velocity information of stored ions. This improvement is especially important for nuclides with Lorentz factor γ-value far away from the transition point γt of the storage ring CSRe. 相似文献
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Frequently the cross-section of a longitudinally homogeneous dielectric waveguide may be decomposed into rectangles with constant
permittivity. For points inside these rectangles the wave equation for modal fields is solved analytically by expanding into
functions with harmonic or exponential dependence on the transverse coordinates. Minimization of a least-squares expression
for the remaining misfit on the boundary lines allows us to determine propagation constants and fields for guided modes. Semivectorial
calculations for two sets of rib waveguides and the centre sections of a directional coupler and an MMI device show very good
agreement with results found in the literature.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
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V. D. Mur S. G. Pozdnyakov S. V. Popruzhenko V. S. Popov 《Physics of Atomic Nuclei》2003,66(11):1964-1971
The complex quasienergy, including the level width Γ, is calculated for a loosely bound atomic state in an intense monochromatic laser field of circular polarization. The method proposed by Zeldovich for regularizing divergent integrals that involve the Gamow wave function is employed in this calculation. The convergence of the method is demonstrated, and the conditions of its applicability are indicated. 相似文献
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On the inversion of diffusion NMR data: Tikhonov regularization and optimal choice of the regularization parameter 总被引:1,自引:0,他引:1
Day IJ 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2011,211(2):178-185
The analysis of diffusion NMR data in terms of distributions of diffusion coefficients is hampered by the ill-posed nature of the required inverse Laplace transformation. Na?ve approaches such as multiexponential fitting or standard least-squares algorithms are numerically unstable and often fail. This paper updates the CONTIN approach of the application of Tikhonov regularization to stabilise this numerical inversion problem and demonstrates two methods for automatically choosing the optimal value of the regularization parameter. These approaches are computationally efficient and easy to implement using standard matrix algebra techniques. Example analyses are presenting using both synthetic data and experimental results of diffusion NMR studies on the azo-dye sunset yellow and some polymer molecular weight reference standards. 相似文献
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R. G. Zhbankov D. K. Buslov L. A. Meleshchenko 《Journal of Applied Spectroscopy》1989,51(3):1006-1011
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 51, No. 3, pp. 523–531, September, 1989. 相似文献
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A simple and accurate approach for analysis of dielectric periodic structures is proposed in this paper. The method combines the coupled-mode theory with Floquet theory and joins the eigenmode expansion with the space harmonic expansion properly. As a result, the whole analysis procedure is significantly simplifid. Numerical results for the filter characteristics of some dielectric periodic structures show that the present method is effective, accurate and useful.Supported by The National Natural Science Foundation of China and The Foundation of State Educational Commission. 相似文献
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R. Meuldermans 《Nuclear Physics B》1975,86(2):355-359
We indicate a practical way of applying the dimensional regularization scheme in the presence of infrared divergences, consisting of a finite subtraction procedure. 相似文献
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The representation of the AC electrical data in the complex plane reveal two major classifications of the relaxation processes known as ideal (Debye) and non-ideal (non-Debye) types. The non-Debye relaxation has been empirically observed via Cole-Cole (C-C), Davidson-Cole (D-C), and Havriliak-Negami (H-N) responses. Each of these non-Debye relaxations is visualized with an equivalent circuit similar to the ideal relaxation. Both ideal and C-C relaxations reveal semicircular behavior in the complex plane while D-C and H-N relaxations deviate from the usual semicircular loci known as skewed behavior. The extracted equivalent circuit elements are essentially non-Debye for both D-C and H-N relaxations possessing complexity in the relaxation time. The analytical method of extracting these elements in conjunction with the empirical parameters of the D-C relaxation is described using conventional (real) domain and complex domain. The curve fitting procedure provided extremely small error for the complex domain analysis. The behavior of the D-C relaxation function and the depression parameter β are also discussed using ωτ=1 and ωτ≠1 corresponding to the maximum of the imaginary part of the impedance (Z*) or permittivity (ε*). 相似文献
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Variational assimilation in combination with the regularization method for sea level pressure retrieval from QuikSCAT scatterometer data I: Theoretical frame construction 下载免费PDF全文
A new method of constructing a sea level pressure field from satellite microwave scatterometer measurements is presented. It is based on variational assimilation in combination with a regularization method using geostrophic vorticity to construct a sea level pressure field from scatterometer data that are given in this paper, which offers a new idea for the application of scatterometer measurements. Firstly, the geostrophic vorticity from the scatterometer data is computed to construct the observation field, and the vorticity field in an area and the sea level pressure on the borders are assimilated. Secondly, the gradient of sea level pressure (semi-norm) is used as the stable functional to educe the adjoint system, the adjoint boundary condition and the gradient of the cost functional in which a weight parameter is introduced for the harmony of the system and the Tikhonov regularization techniques in inverse problem are used to overcome the ill-posedness of the assimilation. Finally, the iteration method of the sea level pressure field is developed. 相似文献
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Letters in Mathematical Physics - As is well known to physicists, the axial anomaly of the massless free fermion in Euclidean signature is given by the index of the corresponding Dirac operator. We... 相似文献