首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
捷径冲突是AdHvc网络中QoS路由特有的一种现象,它由WenjianShao在[2]中首次提出.本文进一步研究了捷径冲突现象,给出了一个更加准确的定义,且给出了一个基于时分的分布式QoS路由算法成功地避免了捷径冲突现象.本算法是基于TDMA的分布式算法,每个节点只需了解网络的局部信息即可.数据分析表明本算法预留的最大带宽比较接近AdHoc网络中所能用的最大带宽.  相似文献   

2.
本文在局部分数阶导数定义的基础上给出了高阶局部分数阶导数定义,并据此得到了一般形式的分数阶Taylor公式.用该公式给出了分数阶光滑函数线性和二次插值公式余项的表达式,并进一步导出了分段线性插值的收敛阶估计.针对分数阶导数临界阶计算困难的问题,本文利用线性插值余项设计了一种外推算法,能够比较准确地求出函数在某点的局部分数阶导数的临界阶.最后通过编写算法的Mathematica程序,验证了理论分析的正确性,并用实例说明了算法的有效性.  相似文献   

3.
研究切换自治线性系统在切换镇定前提下的暂态性能优化.给出系统超调和调节时间的定义,提出基于分路径状态反馈切换的局部暂态优化的设计算法,获得暂态性能估计.  相似文献   

4.
本文分析了求解线性方程组的一维投影算法即最小剩余法。定义了长轴陷阱及陷阱深度,用它们刻划了该算法迭代过程中锯齿现象的几何特征。本文给出了基于残差序列的避开长轴陷阱的扰动技巧,即多维投影算法。数值试验表明,投影算法要优于现在流行的主要算法。  相似文献   

5.
本文研究约束优化问题的全局优化确定性方法.基于填充函数的定义,具体构造出了一个新的单参数填充函数并做了相关理论证明.结合SQP和BFGS局部极小化算法设计了新的填充函数全局优化算法.数值实验表明,该算法可行有效,具有良好的全局寻优能力.  相似文献   

6.
整数规划的一类填充函数算法   总被引:9,自引:0,他引:9  
填充函数算法是求解连续总体优化问题的一类有效算法。本文改造[1]的填充函数算法使之适于直接求解整数规划问题。首先,给出整数规划问题的离散局部极小解的定义,并设计找离散局部极小解的领域搜索算法。其次,构造整数规划问题的填充函数算法。该方法通过寻找填充函数的离散局部极小解以期找到整数规划问题的比当前离散局部极小解好的解。本文的算法是直接法,数值试验表明算法是有效的。  相似文献   

7.
针对城市物流配送中广泛存在的多车型问题,以及由于交通路况等因素导致的配送行程模糊化现象,给出了一种基于梯形模糊数的,以最小化行程费用为目标的具有模糊行程的动态费用多车型车辆调度问题模型.在问题求解方面,针对基本粒子群算法容易陷入局部最优的情况,引入混沌局部搜索策略,给出了一种基于混沌优化技术的混合粒子群算法.仿真实验表明,该算法具有可行性和有效性.  相似文献   

8.
本文定义了分片线性NCP函数,并对非线性约束优化问题,提出了带有这分片NCP函数的QP-free非可行域算法.利用优化问题的一阶KKT条件,乘子和NCP函数,得到对应的非光滑方程组.本文给出解这非光滑方程组算法,它包含原始-对偶变量,在局部意义下,可看成关扰动牛顿-拟牛顿迭代算法.在线性搜索时,这算法采用滤子方法.本文给出的算法是可实现的并具有全局收敛性,在适当假设下算法具有超线性收敛性.  相似文献   

9.
高次方程的判别式系统及其计算   总被引:1,自引:0,他引:1  
本文推广了高次方程判别式的定义使其可完全决定方程根的重数,基于吴氏算法与Groebner基算法,给出了五次方程的判别式系统并进行了比较。还研究了判别式系统的其它性质,得到了方程系数在变换X=y+h下的不变量的一种描述。  相似文献   

10.
针对模糊互补判断矩阵的一致性修正问题,本文从模糊一致矩阵传统定义出发,深入挖掘了一致性定义中所涉及到的三元素组之间的关系,在给出相关定理的基础上,提出了一种改善模糊互补判断矩阵一致性的新算法,从理论上分析了该算法的可行性,并利用模拟仿真的方法给出了与本算法相关的几种比较分析。  相似文献   

11.
在公众参与背景下,构建有限理性条件下中央政府与地方政府的环境保护演化博弈模型,分析公众参与下双方环境保护策略选择。结果表明,中央政府严格监管的成本和收益、环保不作为对地方政府声誉的负面影响、地方环保投入和收益、被公众揭发的可能性等是影响双方行为的重要因素。中央监管收益的增加、成本的下降,有助于提高中央政府监管的积极性;地方不作为对地方声誉影响越大、收入分成越少,是提升地方政府努力的有效手段;公众的积极参与,是破解信息不对称,督促央-地政府采取积极环保措施的重要手段。最后,结合理论分析和实际,提出保障地方政府努力开展环保工作的措施。  相似文献   

12.
An empirical mode decomposition (EMD) method based on Multi-Quadrics radial basis function (MQ-RBF) quasi-interpolation (the Quasi-MQ EMD method) is presented and applied to similarity analysis of DNA sequences. The MQ-RBF quasi-interpolation is taken to approximate the extrema envelopes during the intrinsic mode function (IMF) sifting process. Our method is simple, easy to implement, and does not require solving any linear system of equations. Then we use the classic EMD method and our method to compare the local similarities among DNA sequences respectively. The work tests our method’s suitability and better performance for local similarity analysis of DNA sequences by using the mitochondria of four different species.  相似文献   

13.
Miriam Amit  Dorit Neria 《ZDM》2008,40(1):111-129
This study focuses on the generalization methods used by talented pre-algebra students in solving linear and non-linear pattern problems. A qualitative analysis of the solutions of three problems revealed two approaches to generalization: recursive–local and functional–global. The students showed mental flexibility, shifting smoothly between pictorial, verbal and numerical representations and abandoning additive solution approaches in favor of more effective multiplicative strategies. Three forms of reflection aided generalization: reflection on commonalities in the pattern sequence’s structure, reflection on the generalization method, and reflection on the “tentative generalization” through verification of the pattern sequence. The latter indicates an intuitive grasp of the mathematical power of generalization. The students’ generalizations evinced algebraic thinking in the discovery of variables, constants and their mutual relations, and in the communication of these discoveries using invented algebraic notation. This study confirms the centrality of generalizations in mathematics and their potential as gateways to the world of algebra.  相似文献   

14.
This paper considers the bending behaviors of composite plate with 3-D periodic configuration.A second-order two-scale(SOTS)computational method is designed by means of construction way.First,by 3-D elastic composite plate model,the cell functions which are defined on the reference cell are constructed.Then the effective homogenization parameters of composites are calculated,and the homogenized plate problem on original domain is defined.Based on the Reissner-Mindlin deformation pattern,the homogenization solution is obtained.And then the SOTS’s approximate solution is obtained by the cell functions and the homogenization solution.Second,the approximation of the SOTS’s solution in energy norm is analyzed and the residual of SOTS’s solution for 3-D original in the pointwise sense is investigated.Finally,the procedure of SOTS’s method is given.A set of numerical results are demonstrated for predicting the effective parameters and the displacement and strains of composite plate.It shows that SOTS’s method can capture the 3-D local behaviors caused by3-D micro-structures well.  相似文献   

15.
One of a new generation of combat models is examined to determine how its behaviour differs from older approaches based on first-order linear differential equations. This new methodology, which uses ‘cellular automaton’ or ‘agent-based’ models, has been around for a decade, prompting closer scrutiny. The method gives entities within a combat simulation the autonomy to react to circumstances in their local area. The reaction is determined by each entity's ‘personality’. It is found that the automata tend to either fight as a massed force, or form dispersed patterns of clusters within clusters. Such a pattern is known as a ‘fractal’. By adopting this pattern, a non-intuitive relationship between the kill probability of the automata and the force attrition rate develops. This provides a compelling example of how the result presented by earlier workers—that automaton models may evolve into fractal distributions—can have significance for operational researchers.  相似文献   

16.
模糊模式识别方法在学生综合素质评价中的应用   总被引:3,自引:0,他引:3  
给出了一种基于模糊模式识别的学生综合素质评判方法 ,并且考虑了各因素不同的重要程度 ,对其他评价方法作了有益的补充 .  相似文献   

17.
Urban population density always follows the exponential distribution and can be described with Clark’s model. Because of this, the spatial distribution of urban population used to be regarded as non-fractal pattern. However, Clark’s model differs from the exponential function in mathematics because that urban population is distributed on the fractal support of landform and land-use form. By using mathematical transform and empirical evidence, we argue that there are self-affine scaling relations and local power laws behind the exponential distribution of urban density. The scale parameter of Clark’s model indicating the characteristic radius of cities is not a real constant, but depends on the urban field we defined. So the exponential model suggests local fractal structure with two kinds of fractal parameters. The parameters can be used to characterize urban space filling, spatial correlation, self-affine properties, and self-organized evolution. The case study of the city of Hangzhou, China, is employed to verify the theoretical inference. Based on the empirical analysis, a three-ring model of cities is presented and a city is conceptually divided into three layers from core to periphery. The scaling region and non-scaling region appear alternately in the city. This model may be helpful for future urban studies and city planning.  相似文献   

18.
定性定量相结合方法是战争设计工程的技术基础,如何有效地运用定性定量相结合去解决战争复杂系统的设计问题,是战争设计工程的关键.在战争设计工程的基础上,分析了战争设计工程中定性定量相结合的特点,论述了战争设计工程中定性定量在任务逻辑上、专家上和人与计算机上的分工机制及战争设计工程中定性定量的结合模式,给出战争设计工程解决问题的技术路线.  相似文献   

19.
We present a weaker convergence analysis of Newton’s method than in Kantorovich and Akilov (1964), Meyer (1987), Potra and Ptak (1984), Rheinboldt (1978), Traub (1964) on a generalized Banach space setting to approximate a locally unique zero of an operator. This way we extend the applicability of Newton’s method. Moreover, we obtain under the same conditions in the semilocal case weaker sufficient convergence criteria; tighter error bounds on the distances involved and an at least as precise information on the location of the solution. In the local case we obtain a larger radius of convergence and higher error estimates on the distances involved. Numerical examples illustrate the theoretical results.  相似文献   

20.
In this paper we generalize recent theoretical results on the local continuation of parameter-dependent non-linear variational inequalities. The variational inequalities are rather general and describe, for example, the buckling of beams, plates or shells subject to obstacles. Under a technical hypothesis that is satisfied by the simply supported beam, we obtain the existence of a continuation of both the solution and the eigenvalue with respect to a local parameter. A numerical continuation method is presented that easily overcomes turning points. Numerical results are presented for the non-linear beam.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号