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151.
二元域上n数组空间上的非线性置换在分组码,杂凑函数与流密码等密码学领域中有重要应用.域GF(2n)上的幂函数提供了二元域上n数组空间上的一类非线性置换.本文着重研究幂函数的强完全性、完全性与非线性度等密码学性质.作为结果,本文证明了幂函数具有完全性;证明了具有强完全性的函数必有较高的拓扑非线性度;木文找到一类具有强完全性的幂函数;周时也定出了幂函数的代数非线性度. 相似文献
152.
Liang Ruixi Peng Jun Shen Jianhua 《Annals of Differential Equations》2006,22(4):502-510
The boundedness of the every solution and the asymptotic behavior of all solutions of the nonlinear neutral delay differential equation [x(t) - P(t)x(t - t)]' Q1 (t)f(x{t-σ1))-Q2(t)f(x(t -σ2))=0,t≥t0 are investigated, whereτ,σ1,σ2∈(0,∞), P∈C([t0,∞),R), and Q1,Q2∈C([t0,∞),R), f∈C(R,R). The sufficient conditions obtained improve the existing results in the literatures. 相似文献
153.
金融时间序列分析与建模 总被引:1,自引:0,他引:1
胡锡健 《新疆大学学报(理工版)》2007,24(2):150-158
介绍了金融时间序列分析与建模的主要理论、方法,着重论述了近20多年发展起来的非平稳时间序列的建模方法及工具,指出进一步的研究方向.最后,对上证综合指数这一金融时间序列进行了实证分析. 相似文献
154.
崔霞 《高等学校计算数学学报(英文版)》2002,11(1):76-88
A new alternating direction (AD) finite element (FE) scheme for 3-dimensional nonlinear parabolic equation and parabolic integro-differential equation is studied. By using AD, the 3-dimensional problem is reduced to a family of single space variable problems, calculation work is simplified; by using FE, high accuracy is kept; by using various techniques for priori estimate for differential equations such as inductive hypothesis reasoning, the difficulty arising from the nonlinearity is treated. For both FE and ADFE schemes, the convergence properties are rigorously demonstrated, the optimal H1-and L2-norm space estimates and the 0((△t)2) estimate for time variable are obtained. 相似文献
155.
156.
157.
In this paper, oscillatory properties of solutions of certain hyperbolic partial differential equations with multi-delays are investigated and a series of sufficient conditions for oscillations of the equations are established. The results fully indicate that the oscillations are caused by delays. 相似文献
158.
The projector formalism of Zwanzig-Mori type is extended to obtain generalized Fokker-Planck and generalized nonlinear Langevin equations for coarse-grained variables when the underlying microscopic dynamics is dissipative and noisy (stochastic). 相似文献
159.
Relative permeability functions for immiscible displacements in porous media show a wide range of profiles. Although, this
behavior is well known, its impact on the stability of the displacement process is unexplored. Our analysis clearly demonstrates
for the first time that the viscous instability characteristics of two-phase flows are governed not only by their end point
values, but are strongly dependent on the actual profile of relative permeability functions. Linear stability analysis predicts
the capacity of the flow to develop large scale fingers which can result in substantial bypassing of the resident fluid. It
is observed that relative permeability functions attributed to drainage processes yield a more unstable displacement as compared
to functions related to imbibition processes. Moreover, instability is observed to increase for those relative permeability
functions which result from increased wettability of the wetting fluid. High accuracy numerical simulations show agreement
with these predictions and demonstrate how large amplitude viscous fingers result in significant bypassing for certain relative
permeability functions. In the nonlinear regime, the finger amplitude grows at a rate ∝ t1/2 initially, drops to t1/4 at a later time and finally grows ∝ t. The basic mechanisms of finger interaction, however, are not substantially influenced by relative permeability functions. 相似文献
160.
Inexact Newton methods for the nonlinear complementarity problem 总被引:2,自引:0,他引:2
Jong-Shi Pang 《Mathematical Programming》1986,36(1):54-71
An exact Newton method for solving a nonlinear complementarity problem consists of solving a sequence of linear complementarity
subproblems. For problems of large size, solving the subproblems exactly can be very expensive. In this paper we study inexact
Newton methods for solving the nonlinear, complementarity problem. In such an inexact method, the subproblems are solved only
up to a certain degree of accuracy. The necessary accuracies that are needed to preserve the nice features of the exact Newton
method are established and analyzed. We also discuss some extensions as well as an application.
This research was based on work supported by the National Science Foundation under grant ECS-8407240. 相似文献