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991.
We introduce a single step memory dependence in the fully chaotic logistic map. This makes it a two dimensional system in general. However, we show that by using composite functions to define two one dimensional maps, it is possible to obtain some analytic results for the bifurcation structure. Numerical results support the calculated bifurcation scheme and, in addition, yield a further insight which allows the calculation of the convergence ratio for a new period adding scenario. 相似文献
992.
Xing-yuan Wang Ming-jun Wang 《Nonlinear Analysis: Theory, Methods & Applications》2009,71(12):6126-6134
This paper analyzes some Routh-Hurwitz stability conditions generalized to the fractional order case, and discusses the stability region of the fractional order system. We analyze the chaotic behavior of the fractional order modified coupled dynamos system concretely, and provide the conditions suppressing chaos to unstable equilibrium points, then use the feedback control method to control chaos in the fractional order modified coupled dynamos system. Numerical simulations show the effectiveness of the method. 相似文献
993.
A recently introduced similarity measure is extended here for comparing two-dimensional spectra. Its applicability is demonstrated with heteronuclear single-quantum correlation (HSQC) NMR spectra. For testing the compatibility of a spectrum with the proposed chemical structure, first, the spectrum is predicted on the basis of that structure and then, the proposed comparison algorithm is applied. In this context, the topics of optimization are peak picking, signal intensity measures, and optimizing the parameters of the two-dimensional comparison method. The performance is analyzed with a test set of 289 structures of organic compounds and their HSQC and 1H NMR spectra. The results obtained with HSQC spectra are better than those achieved using the previously described one-dimensional similarity test with 1H NMR spectra alone. 相似文献
994.
T. Binder L. Blank W. Dahmen W. Marquardt 《Journal of Optimization Theory and Applications》2001,111(3):529-551
Usually, direct methods are employed for the solution of linear systems arising in the context of optimization. However, motivated by the potential of multiscale refinement schemes for large problems of dynamic state estimation, we investigate in this paper the application of iterative solvers based on the concepts developed in Ref. 1. Specifically, we explore the effect of different system reductions for various Krylov-space iteration methods as well as three concepts of preconditioning. The first one is the normalization of states and outputs, which also favors error analysis. Next, diagonal scale-dependent preconditioners are compared; they all bound the condition numbers independently of the refinement scale, but exhibit significant quantitative differences. Finally, the effect of the regularization parameter on condition numbers and iteration numbers is analyzed. It turns out that a so-called simplified Uzawa scheme with Jacobi preconditioning and suitable regularization parameter is most efficient. The experiments also reveal that further improvements are necessary. 相似文献
995.
This paper is concerned with the coordination of inventory control in three-echelon serial and distribution systems under
decentralized control. All installations in these supply chains track echelon inventories. Under decentralized control the
installations will decide upon base stock levels that minimize their own inventory costs. In general these levels do not coincide
with the optimal base stock levels in the global optimum of the chain under centralized control. Hence, the total cost under
decentralized control is larger than under centralized control.
To remove this cost inefficiency, two simple coordination mechanisms are presented: one for serial systems and one for distribution
systems. Both mechanisms are initiated by the most downstream installation(s). The upstream installation increases its base
stock level while the downstream installation compensates the upstream one for the increase of costs and provides it with
a part of its gain from coordination. It is shown that both coordination mechanisms result in the global optimum of the chain
being the unique Nash equilibrium of the corresponding strategic game. Furthermore, all installations agree upon the use of
these mechanisms because they result in lower costs per installation. The practical implementation of these mechanisms is
discussed. 相似文献
996.
As a first endeavor, a mixed differential quadrature (DQ) and finite element (FE) method for boundary value structural problems in the context of free vibration and buckling analysis of thick beams supported on two-parameter elastic foundations is presented. The formulations are based on the two-dimensional theory of elasticity. The problem domain along axial direction is discretized using finite elements. The resulting system of equations and the related boundary conditions are discretized in the thickness direction and in strong-form using DQM. The method benefits from low computational efforts of the DQ in conjunction with the effectiveness of the FE method in general geometry and systematic boundary treatment resulting in highly accurate and fast convergence behavior solution. The boundary conditions at the top and bottom surface of the beams are implemented accurately. The presented formulations provide an effective analysis tool for beams free of shear locking. Comparisons are made with results from elasticity solutions as well as higher-order beam theory. 相似文献
997.
Infinite-dimensional parameter-dependent optimization problems of the form ‘minJ(u;p) subject to g(u)?0’ are studied, where u is sought in an L∞ function space, J is a quadratic objective functional, and g represents pointwise linear constraints. This setting covers in particular control constrained optimal control problems. Sensitivities with respect to the parameter p of both, optimal solutions of the original problem, and of its approximation by the classical primal-dual interior point approach are considered. The convergence of the latter to the former is shown as the homotopy parameter μ goes to zero, and error bounds in various Lq norms are derived. Several numerical examples illustrate the results. 相似文献
998.
介绍了在VISUAL BASIC环境中研华公司的ADAM-5510数据采集控制器和上位机通信实现的方法。 相似文献
999.
多元自相关过程的VAR控制图 总被引:1,自引:0,他引:1
为了解决多元自相关过程的残差T~2控制图对小偏移不灵敏的问题,本文利用批量-均值法的思想,结合VAR模型的渐近分布,设计了多元自相关过程的向量自回归(VAR)控制图.只要子组样本量足够大,VAR控制图可以对过程出现的各种偏移进行有效控制.通过对比残差T~2控制图的控制效果,得出VAR控制图对小偏移灵敏、残差T~2控制图对大偏移灵敏的结论,联合使用VAR控制图和残差T~2控制图可更有效地监控多元自相关过程。 相似文献
1000.
对于一类不确定状态时变时滞系统,利用基于时滞划分的Lyapunov-Krasovskii泛函讨论其稳定性,并得到以LMI形式给出的一种保守性小的稳定性条件,最后通过分析并给出了保证系统鲁棒稳定的H_\infty控制器,数值实例表明了方法的有效性. 相似文献