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1.
《国际计算机数学杂志》2012,89(5):1142-1157
In this paper, a new modified homotopy perturbation method (NHPM) is introduced for solving systems of Volterra integral equations of the second kind. Theorems of existence and uniqueness of the solutions to these equations are presented. Comparison of the results of applying the NHPM with those of the homotopy perturbation method and Adomian's decomposition method leads to significant consequences. Several examples, including the system of linear and nonlinear Volterra integral equations, are given to demonstrate the efficiency of the new method.  相似文献   

2.
《国际计算机数学杂志》2012,89(5):1186-1194
In this paper, a new homotopy perturbation method (NHPM) is introduced to obtain exact solutions of system of nonlinear integro-differential equations. Theoretical considerations are discussed. Two examples are given to demonstrate the efficiency of NHPM to the classical HPM and variational iteration methods.  相似文献   

3.
针对出租车空载率高、司机寻客难的问题,提出泊松-卡尔曼组合预测模型(PKCPM)。首先,采用加权非齐次泊松模型,针对出租车历史数据进行建模,得到目标时刻的估计值;其次,基于当天的实时数据,将临近时刻乘客需求的平均值作为目标时刻预测值;最后,将预测值和估计值作为卡尔曼滤波模型的输入参数,实现对目标时刻出租车乘客需求的预测,同时引入误差反向传播机制,减小下一次预测误差。基于郑州市出租车轨迹数据集,对组合模型与非齐次泊松模型(NHPM)、加权非齐次泊松模型(WNHPM)、支持向量机(SVM)等三种模型进行对比,实验结果显示PKCPM的误差比WNHPM、SVM分别降低了8.85个百分点、14.9个百分点。该模型能对不同时段内、不同空间网格的乘客需求进行预测,为出租车寻找乘客提供可靠的依据。  相似文献   

4.
The present study introduces a novel and simple analytical method for the solution of fractional order Riccati differential equation. In this approach, the solution considered as a Taylor series expansion converges rapidly to the nonlinear problem. New homotopy perturbation method (NHPM) depends only on two components of the homotopy series. The method is illustrated by applications and the results obtained are compared with those of the exact solution. Moreover, comparing the methodology with some known techniques shows that the present approach is relatively easy and efficient.  相似文献   

5.
图的表示方法很多,各有其优缺点.采用不同的表示方法,可获得图的不同的时空性能.本文阐述了图的一种新表示方法,该方法用一种命名规则将有向图表示为节点标签表,给出了由节点标签表产生节点链的算法.并用这种称为表方法研究了有向图的回路性质,特别地将它应用于研究de Bruijn回路、欧拉回路和哈密顿回路,给出了计算欧拉回路和哈密顿回路的新方法.本研究表明该方法具有较好的理论和实用价值.  相似文献   

6.
Lyapunov functions have been derived for various authors to study the stability of solutions for certain fourth-order non-linear autonomous differential equations. Cartwright (1956) has studied (1) and (2) applying the method of analogy with linear systems, Ku (1964) has proposed a matrix method to study (3) and Skidmore (1966) has derived another Lyapunov function for (1) applying an extension to the method proposed by Leighton (1963). The intrinsic method proposed by Chin (1988 a, b) is applied to derive the Lyapunov functions obtained by Cartwright, Ku and Skidmore. Further, new Lyapunov functions are derived for (1), (2) and (3) applying the intrinsic method that are shown to be far less restrictive than those obtained by the various authors in the literature.  相似文献   

7.
This paper proposes a new fuzzy ranking method named relative distance metric method, which can overcome some of the shortcomings for previous ranking methods and select the best alternative in selecting weapon systems. There are two objectives in this paper. Firstly, we propose a new ranking method and compare our method with other methods by many examples. The second objective is applying the proposed method to rank the best self-propelled Howitzers and main battle tanks.  相似文献   

8.
非结构粘性直角网格通过对内面进行光顺、投影及分层加密等方法,在内面与物面间生成了粘性层网格,解决了直角网格在计算粘性流场时遇到的难题。但在光顺和投影之后,物形可能发生改变,从而丧失了某些原来物体具有的特征,对流场计算产生影响。提出了物面相贯线修正方法,在投影之后对各投影点的位置进行修正,解决了物面变形的问题,并通过生成DLR-F4等复杂外形的网格,对此方法进行验证。  相似文献   

9.
地下油气藏烃类微渗漏雷达勘查机理与技术   总被引:1,自引:0,他引:1       下载免费PDF全文
雷达勘查地下油气藏烃类微渗漏是70年代在美国出现的一种新型油气勘探方法。经过不断的研究应用,这种方法的效用已得到了较充分验证。与此同时,其技术方法和应用不断完善,观测机理方面的理论与实验研究也有所进展,但尚未得到有说服力的一致结果。本文通过对涉及该方法研究与应用有关资料的分析研究,总结了雷达勘查地下油气藏烃类微渗漏技术方法的发展过程,应用水平和今后的发展趋势。并对其观测机理与勘查技术做了分析探讨。提出了在我国开展雷达勘查烃类微渗漏观测机理与技术方法研究应用工作的一些考虑和建议。  相似文献   

10.
利用位势理论把Helmholtz方程外问题转化为第二类积分方程的求解问题.在处理积分算子核时,采用了一种新的裂解方式,再利用Nystrom方法求解数值结果.最后针对该方法给出数值实例,以表明此方法的有效性.  相似文献   

11.
文章介绍了一种新式飞机氧气测试装置,详述了其组成、工作原理和软硬件的设计方法。新式飞机氧气测试装置基于虚拟仪器技术,采用计算机控制,彻底解决了旧式氧气测试装置测试精度低和操作繁琐的问题,该测试装置巳获得成功的应用,达到了设计目的。  相似文献   

12.
软件体系结构:一个新的研究领域   总被引:12,自引:0,他引:12  
计算机软件系统中软件成分越来越复杂,系统规模不断扩大,使得软件体系结构越来越庞杂,软件系统的质量和性能已经不再仅仅取决于软件实现算法和数据结构,软件系统体系结构在一定程度上决定系统的优劣,因此软件体系结构(Software Architecture,AS)研究已经逐渐地引起计算机界的重视。软件体系结构作为一个新兴的计算机学科,它的理论体系和解决问题的方法尚未形成。加强其基础理论和应用方法的研究,不论对学科发展,还是对软件生产都具有理论意义和现实意义。  相似文献   

13.
工艺美术字计算机变形设计研究   总被引:3,自引:0,他引:3  
本文提出了一种美术字计算机自动设计的新方法.该方法利用“显示字库”所提供的字形笔划结构特征信息,运用多级数学模型,通过计算机软件功能,对字形自动再加工、再造型、美工优化、艺术化,设计出形式多样的新的艺术字型,是一种新的动态软字库技术.设计字型可应用于电视字幕、广告、印刷排版、电脑动画、大屏幕显示、软件包装等领域。  相似文献   

14.
基于空域相关的小波域硬阈值滤波   总被引:1,自引:1,他引:1  
论文提出一种新的基于小波域相关性的自适应阈值滤波算法。首先构造了一种基于空域相关系数的硬阈值函数,通过极小化该阈值函数对应的SURE估计得到均方差意义下自适应于信号和噪声的最优阈值。应用该阈值作用于小波域的空域相关系数,以达到去除噪声的目的。仿真实验表明,该方法可得到很好的滤波效果。  相似文献   

15.
提出了一种快速易行的时间序列图像自动配准算法:首先对两幅图像分别进行离散小波变换,然后对分解后的两幅低频网像计算联合直方图,最后采用改进的联合直方图区域计数方法来设计目标函数并进行配准参数优化。实验结果与对比分析表明:在基本不影响图像配准精度的情况下,算法大大加快了图像配准速度。  相似文献   

16.

This draft addresses the exponential stability problem for semi-Markovian jump generalized neural networks (S-MJGNNs) with interval time-varying delays. The exponential stability conditions are derived by establishing a suitable Lyapunov–Krasovskii functional and applying new analysis method. Improved results are obtained to guarantee the exponential stability of S-MJGNNs through improved reciprocally convex combination and new weighted integral inequality techniques. The method in this paper shows the advantages over some existing ones. To verify the advantages and benefits of employing proposed method is explained through numerical examples.

  相似文献   

17.
A new method to the problem of fairing planar cubic B-spline curves is introduced in this paper. The method is based on weighted progressive iterative approximation (WPIA for short) and consists of following steps: finding the bad point which needs to fair, deleting the bad point, re-inserting a new data point to keep the structm-e of the curve and applying WPIA method with the new set of the data points to obtain the faired curve. The new set of the data points is formed by the rest of the original data points and the new inserted point. The method can be used for shape design and data processing. Numerical examples are provided to demonstrate the effectiveness of the method.  相似文献   

18.
Abstract— The plasma‐display panel (PDP) is a type of flat‐panel display that can display a high‐quality image. However, when moving images are displayed, annoying disturbances such as false contour noise occurs. This noise is called dynamic false contour (DFC). To achieve a higher‐quality image, DFC has to be reduced. Therefore, a new method to reduce DFC is proposed. To find a way to reduce DFC, a new evaluation value for it has been defined: the evaluation value of dynamic false contour (EVDFC). This value is defined on the basis of a person's subjective evaluation. By applying this value, the cause that generates DFC can be identified. On the basis of these studies, a new method for reducing DFC by applying frame‐rate control (FRC) with suppression of the side effect is proposed. This improved method can be used to provide high‐quality images.  相似文献   

19.
马田系统与SVM相集成的模式识别技术研究   总被引:1,自引:0,他引:1       下载免费PDF全文
为了解决现有马田系统阈值确定方法的不足,基于超球面支持向量机算法,构建了单类及二类超椭球面支持向量机算法,并理论上证明了此算法可转换为二次规划模型。推导了基于超椭球面支持向量机的马田系统阈值确定公式。将所提出的方法应用于故障诊断,得到了较高的判别正确率。  相似文献   

20.
本文提出一种新的时滞划分方法—变时滞划分法,以解决连续延时Takagi-Sugeno模糊系统的稳定性和镇定性问题.不同于已有的文献,用可变参数将时变时滞区间[0,d(t)]划分为若干个可变子区间,并得出模糊时滞系统的新的时滞相关稳定性准则.本文提出的新方法能充分利用时滞子区间的内部信息,因此新的时滞相关稳定性准则比以往结果具有更小的保守性.基于Lyapunov稳定性理论,以线性矩阵不等式形式给出T--S模糊系统的新的时滞相关稳定性准则,并将稳定性和镇定性研究结果扩展到具有不确定参数的T--S模糊系统.仿真实例证明了本文方法降低保守性的有效性.  相似文献   

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