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261.
A new method based on the independent electron-pair approximation
is developed to calculate the correlation energy and the
basis size truncation error. The formalisms for the nondegenerate systems are described in this paper.
Because all important terms are very efficiently selected and the calculations can be separated into several parts, this new method gives very accurate results and does not require expensive computing facilities.
As a test, the ground state energies (GSE) of the nonrelativistic
atoms for 3≤Ne≤10
are calculated using this new method.
The calculated results are found to be in close agreement with the most recent available version of the exact GSE which is derived from the experimental data after subtracting the contributions from the relativistic effect, QED radiative corrections, finite nucleon mass corrections, and the finite radius of the nuclear size. Those accurate results have not been
reproduced for Ne≥5
by any direct theoretical calculations in literatures. Since this method is not restrained to nonrelativistic or Coulomb systems, it should become powerful to study other quantum
interacting systems. 相似文献
262.
In this paper, the problem of modelling and controlling two manipulators handling a constrained object is addressed. At first, a reduced order dynamic model of the system is derived, and several of its properties are outlined. Using the reduced order model, an adaptive control scheme that guarantees the asymptotic convergence of the position of the object, and the forces acting on the object to their desired values is developed. Simulation results of two planar robots moving an object along a plane illustrate the effectiveness of the proposed control scheme. 相似文献
263.
264.
The exact solutions of the general nonlinear dynamic system in a new double-chain model of DNA are studiedkink shape excitations can be found in both the Conte's truncation expansion and the Pickering's truncation expansion.Three types of new localized excitations, the asymmetric kink-kink excitations, the soliton-kink excitation, and thekink-soliton excitations, are found by using the Pickering's nonstandard truncation expansion. 相似文献
265.
Harro Walk 《Annals of the Institute of Statistical Mathematics》2001,53(4):691-707
For semi-recursive and recursive kernel estimates of a regression of Y on X (d-dimensional random vector X, integrable real random variable Y), introduced by Devroye and Wagner and by Révész, respectively, strong universal pointwise consistency is shown, i.e. strong consistency P
X
-almost everywhere for general distribution of (X, Y). Similar results are shown for the corresponding partitioning estimates. 相似文献
266.
267.
This paper introduces a new, adaptive-filter-based controller that shows advantageous properties from the viewpoint of its communication requirement. The algorithm is called signed-error filtered-x LMS (SE-FxLMS). Its novelty is characterized by the fact that it makes possible data compression in the feedback path of adaptive-filter-based control loops in a very simple way. This feature is especially useful in such closed-loop systems where the feedback signals are transmitted over a low-bandwidth communication channel. This is a typical case in so-called networked control systems (NCS), where the communication is carried out over a shared communication channel, e.g., using a wireless sensor network. The paper introduces an analysis of the algorithm as well. 相似文献
268.
S.J. Kamkar A.M. Wissink V. Sankaran A. Jameson 《Journal of computational physics》2011,230(16):6271-6298
We develop locally normalized feature-detection methods to guide the adaptive mesh refinement (AMR) process for Cartesian grid systems to improve the resolution of vortical features in aerodynamic wakes. The methods include: the Q-criterion [1], the λ2 method [2], the λci method [3], and the λ+ method [4]. Specific attention is given to automate the feature identification process by applying a local normalization based upon the shear-strain rate so that they can be applied to a wide range of flow-fields without the need for user intervention. To validate the methods, we assess tagging efficiency and accuracy using a series of static vortex-dominated flow-fields, and use the methods to drive the AMR process for several theoretical and practical simulations. We demonstrate that the adaptive solutions provide comparable accuracy to solutions obtained on uniformly refined meshes at a fraction of the computational cost. Overall, the normalized feature detection methods are shown to be effective in driving the AMR process in an automated and efficient manner. 相似文献
269.
Speech signals recorded with a distant microphone usually are interfered by the spatial reverberation in the room, which severely degrades the clarity and intelligibility of speech. A speech dereverberation method based on spectral subtraction and spectral line enhancement is proposed in this paper. Following the generalized statistical reverberation model, the power spectrum of late reverberation is estimated and removed from the reverberation speech by the spectral subtraction method. Then, according to the human auditory model, a spectral line enhancement technique based on adaptive post-filtering is adopted to further eliminate the reverberant components between adjacent speech formants. The proposed method can effectively suppress the spatial reverberation and improve the auditory perception of speech. The subjective and objective evaluation results reveal that the perceptual quality of speech is greatly improved by the proposed method. 相似文献
270.