共查询到20条相似文献,搜索用时 296 毫秒
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分层教学的Bayes分析 总被引:3,自引:0,他引:3
对学校分层教学进行了初步探索 ,提出了分层分班的 Bayes决策 ,介绍了分层分班方法 ,获得了一些结论 ,并完成了对这些结论的证明 ,从理论上论述了分层教学是实施“因材施教”教育原则和素质教育的有效途径 ,给出了应用实例 . 相似文献
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秩为1矩阵的性质及应用 总被引:1,自引:0,他引:1
给出了秩1矩阵的结构,讨论了这类矩阵在矩阵运算、对角化、标准型等方面的性质,推广和改进了文[1]的一些相关结果,并指出了它的若干应用,重点讨论了一类矩阵,得到了有关结论和方法. 相似文献
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概述了干扰管理理论的内涵、意义以及目标,依据未来不确定因素引起飞机备件需求量变化以及备件供应时限性增强的实际情况,创建了时限一致度算子,优化了备件需求泊松分布模型,提高了备件供应的精确度,并选取了优化后的模型中的多个参量,进行了多因素的扰动性分析,最后构造了算例,验证了本方法的科学性和有效性. 相似文献
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在一次集体教研活动中,通过对一道试题的探究、引申、延展,不仅深化了教师的思维,提升了“四基”“四能”,强化了学科素养的渗透,提高了教学站位,更难能可贵的是激发了教师们的教研热情,唤醒了他们的专业自觉,充分彰显了集体智慧和集体力量的伟大. 相似文献
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改进的PROMETHEE方法在招标中的应用研究 总被引:3,自引:0,他引:3
针对 PROMETHEE方法的局限性 ,对 PROMETHEE方法进行了改进 ,用效用函数取代了优先函数 ,提出了属性权重的确定方法 .应用改进的 PROMETHEE方法 ,对某装备招标中的 6个方案进行了评价 ,取得了较好的效果 相似文献
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Ben Warhurst 《Geometriae Dedicata》2007,130(1):59-69
With the exception of the three step real free Lie algebra on two generators, all real free Lie algebras of step at least
three are shown to have trivial Tanaka prolongation. This result, together with the known results concerning the step two
real free Lie algebras and the step three real free Lie algebra on two generators, gives a complete list of Tanaka prolongations
for real free Lie algebras.
相似文献
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In this paper, we apply the two‐step Newton method to solve inverse eigenvalue problems, including exact Newton, Newton‐like, and inexact Newton‐like versions. Our results show that both two‐step Newton and two‐step Newton‐like methods converge cubically, and the two‐step inexact Newton‐like method is super quadratically convergent. Numerical implementations demonstrate the effectiveness of new algorithms. 相似文献
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欧诗德 《数学的实践与认识》2009,39(9)
为了有效估计认股权证的隐含波动率,以及有利于观测权证的市场风险,对常用的迭代算法进行改进可加快计算速度.利用认股权证的Delta、Vega和Theta值以及多元泰勒公式导出认股权证隐含波动率变化与权证价格变化关系的不等式.根据导出的这个不等式给出了具体算法.实证结果说明这一算法改进了原有的算法,从而这个算法解决了原来的随意给定一个价格后不断修正的算法. 相似文献
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Mihai Anitescu 《Mathematical Programming》2006,105(1):113-143
We present a time-stepping method to simulate rigid multibody dynamics with inelastic collision, contact, and friction. The
method progresses with fixed time step without backtracking for collision and solves at every step a strictly convex quadratic
program. We prove that a solution sequence of the method converges to the solution of a measure differential inclusion. We
present numerical results for a few examples, and we illustrate the difference between the results from our scheme and previous,
linear-complementarity-based time-stepping schemes. 相似文献
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P. N. Vabishchevich A. O. Vasil’ev 《Computational Mathematics and Mathematical Physics》2017,57(5):843-853
An algorithm is proposed for selecting a time step for the numerical solution of boundary value problems for parabolic equations. The solution is found by applying unconditionally stable implicit schemes, while the time step is selected using the solution produced by an explicit scheme. Explicit computational formulas are based on truncation error estimation at a new time level. Numerical results for a model parabolic boundary value problem are presented, which demonstrate the performance of the time step selection algorithm. 相似文献
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In solving a nonlinear equation by the use of a continuation method one of the crucial problems is the choice of the step sizes. We present a model for the total computational cost of a standard numerical continuation process and solve the problem of optimal step size control for this model. Using the theoretical results as a basis, we develop an adaptive step size algorithm for Newton's method. This procedure is computationally inexpensive and it gives quite satisfactory results compared to some other numerical experiments found in the literature. 相似文献
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In the prediction-correction method for variational inequality (VI) problems, the step size selection plays an important role for its performance. In this paper, we employ the Barzilai-Borwein (BB) strategy in the prediction step, which is efficient for many optimization problems from a computational point of view. To guarantee the convergence, we adopt the line search technique, and relax the conditions to accept the BB step sizes as large as possible. In the correction step, we utilize a longer step length to calculate the next iteration point. Finally, we present some preliminary numerical results to show the efficiency of the algorithms. 相似文献
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X. M. Wang 《Optimization》2018,67(1):179-194
The subgradient algorithms for convex optimizations on Riemannian Manifolds of sectional curvatures bounded from below are studied; and the convergence results of the algorithms (employing diminishing step sizes and dynamic step sizes) are established. Some numerical experiments are provided to illustrate the convergence performances of the algorithms. 相似文献
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The selection of time step plays a crucial role in improving stability and efficiency in the Discontinuous Galerkin (DG) solution of hyperbolic conservation laws
on adaptive moving meshes that typically employs explicit stepping. A commonly
used selection of time step is a direct extension based on Courant-Friedrichs-Levy
(CFL) conditions established for fixed and uniform meshes. In this work, we provide
a mathematical justification for those time step selection strategies used in practical
adaptive DG computations. A stability analysis is presented for a moving mesh DG
method for linear scalar conservation laws. Based on the analysis, a new selection
strategy of the time step is proposed, which takes into consideration the coupling
of the $α$-function (that is related to the eigenvalues of the Jacobian matrix of the
flux and the mesh movement velocity) and the heights of the mesh elements. The
analysis also suggests several stable combinations of the choices of the $α$-function
in the numerical scheme and in the time step selection. Numerical results obtained
with a moving mesh DG method for Burgers' and Euler equations are presented. For
comparison purpose, numerical results obtained with an error-based time step-size
selection strategy are also given. 相似文献
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杨干山 《数学物理学报(A辑)》1997,(Z1)
该文首先给出了关于两个非紧凸集可被强分离的充分必要条件,它是[1,2]中一个定理的改进,然后利用它改进了[4-7]中一些定理和[8]中的一个结果. 相似文献