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 546 毫秒
1.
刘熠  秦亚  刘好斌  许雷 《控制与决策》2020,35(8):2021-2028
基于Pythagorean模糊迭代多准则决策(TODIM)方法和简化的TODIM方法,首先给出简化的q-ROF TODIM方法,并分析该方法产生的悖论;其次,结合广义TODIM方法的思想,提出广义q-ROF TODIM方法;再次,通过一个实例来说明广义q-ROF TODIM方法的可行性和有效性;最后,结合该实例,将所提出的方法与其他q-ROF决策方法进行比较分析,同时分析参数的变化对决策结果的影响,进一步阐明所提出方法的优越性.  相似文献   

2.
Yubazaki have proposed a “single input rule modules connected type fuzzy reasoning method (SIRMs method)” in which its final output is obtained by summarizing the product of importance degree and inference result from single input fuzzy rule modules. This paper proposes a “functional-type SIRMs method,” which is an extended version of the SIRMs method, and clarifies the relationship between the Takagi--Sugeno (T--S) reasoning method and the functional-type SIRMs method. The functional-type SIRMs method can be shown to be transformed to the T--S reasoning method, but generally the conversion to functional-type SIRMs method from the T--S reasoning method is impossible. It is shown, however, that the T--S reasoning method can be transformed to the functional-type SIRMs method when the T--S reasoning method fills some conditions. For this reason, it is shown that the functional-type SIRMs method is the subset of the T--S reasoning method.   相似文献   

3.
PID调节器自整定的PM法及其公式推导   总被引:32,自引:1,他引:31  
本文提出了一种只基于给定相位裕度的自整定方法,并推导出一套相应的自整定公式。对PM法,临界比例度法,理想继电特性法作了比较性研究。研究结果说明,PM法优于Z-N法和Astrom法。该法现已用于“玻纤拉丝漏板的智能温度控制仪“的科研项目中,并取得了满意的控制效果。  相似文献   

4.
一种新的矢量数据多边形的快速裁剪算法   总被引:2,自引:0,他引:2       下载免费PDF全文
张钧  王鹏 《中国图象图形学报》2008,13(12):2409-2413
为实现飞行地理环境中高效的数据调用,以满足实时性要求,就需要对飞行地理环境中海量的栅格数据与矢量数据进行统一的数据组织。这种统一的数据组织方法不仅要对海量的栅格数据进行矩形分块组织,同时也要对海量的矢量数据进行矩形分块组织。为了高效地对海量的矢量数据进行矩形分块组织,就需要采用高效的矢量数据矩形分块裁剪算法。现有的多边形裁剪算法中,Sutherland-Hodgeman算法和Maillot算法对于裁剪的结果多边形有多个分离部分时都得不到正确的裁剪结果,而Weiler-Atherton算法、Vatti算法和Greiner-Hormann算法却总能得到正确的裁剪结果。后3种算法中,虽然Greiner-Hormann算法在空间消耗和时间消耗上都是性能最好的,但仍不能满足实际工程的要求。为进一步提高裁剪速度,提出了一种新的快速有效的矩形窗口的多边形裁剪算法。该新算法不仅继承了后3种算法在连接形成裁剪的结果多边形时的优点,而且还对Greiner-Hormann算法在插入交点时的处理方式进行了改进,并采用了比Greiner-Hormann算法中应用的双向链表更为简单的单向链表的数据结构。实验结果表明,新算法不仅能得到正确的裁剪结果,而且在空间消耗和时间消耗上的性能优于Greiner-Hormann算法,可满足实际工程的要求。  相似文献   

5.
基于2011年WorldView-2高分辨率遥感影像, 采取面向对象的分类方法和四种传统的基于像元的分类方法分别提取平潭县海坛岛中北部研究样区土地利用信息, 并以目视解译结果图为参考, 得到每种分类方法的总体分类精度, 且从数量分歧和分配分歧两方面对土地利用信息提取结果进行整体评价和单类别评价, 结果表明: (1)不同分类方法平均总体分类精度为75.00%, 其中最高的是面向对象法, 总体精度为84.25%, 分类总体精度最低的为最大似然法, 仅为62.00%. (2)面向对象分类方法具有最低的数量分歧, 为4.25%, 其次依次为神经网络法<支持向量机法<马氏距离法<最大似然法. 在分配分歧方面, 支持向量机方法其值最低, 为5.75%, 其次依次为最大似然法<神经网络法<马氏距离法<面向对象法. (3)在单类别精度评价中, 耕地的精度对影像整体分类结果影响最为显著, 其数量分歧比例大小依次为最大似然法(28.75%)>马氏距离法(21.50%)>支持向量机法(14.75%)>神经网络法(11.00%)>面向对象法(3.00%), 分配分歧比例大小依次为面向对象法(10.50%)>神经网络法(5.00%)>支持向量机法(1.50%)>最大似然法(0.50%)>马氏距离法(0.00%).  相似文献   

6.
三对角线性方程组的分布式并行算法   总被引:4,自引:1,他引:4  
文中回顾了Michielse&Vorst算法,分析了影响M&V.算法并行效率的主要因素,根据分布治之思想提出了一种求解三对角方程组的并行算法,新算法通信建立次数的M&V算法的50%,数据传输量为其33%,最后的工作站网络环境下实现了新算法,就并行效率与M&V算法进行了比较,结果表明在由6台工作站的组成的网络中新算法必能提高可达到40%。  相似文献   

7.
通过实例,分别介绍了加权反距离插值法、克里格法、最小曲率法、最近邻点法、多项式回归法、径向基函数法、带线性插值的三角剖分法等常用网格化方法的选取方法,适用范围及参数设置等使用技巧及其在区域自动气象站数据服务中的实际应用。  相似文献   

8.
从理论上研究在盐水溶解平衡计算中,自由能最小化法与溶度积法的关系,并比较两种计算方法,二者计算结果完全一致。对于低四元的体系,溶度积法较为方便,而对更高元的体系,自由能最小化法有其优越之处。计算中,采用合适的算法至关重要。一维搜索法、插值法、多项式拟合求解法、坐标轮换法、MatLab求解最优化问题的函数等,均可以顺利实现盐—水溶解平衡的体系自由能最小化计算;对于溶度积法,二分法、弦截法、优选法、牛顿法、最速下降法、抛物线法及MatLab求解联立方程问题的函数等都很有效。  相似文献   

9.
Organizations that implement a company-wide method to standardize the way that systems development is carried out still have a need to adapt this method to specific projects. When adapting this method the end results should align with the basic philosophy of the original method. To this end, goal-driven situational method engineering has been proposed. However, there are no longitudinal studies on systems developers’ use of such approaches and their intentions to balance their need of adaptation with the basic philosophy of the original method. This paper explores how goal-driven method configuration has been used by two project teams in six successive systems development projects, with the intention to balance the goals and values of a specific method with the systems developers’ need for method adaptation. We do that through the use of method rationality resonance theory. Through content examples of method configurations, we report on (a) lessons learned from the project teams’ work on balancing the goals of the company-wide method with their needs and (b) theoretical development of the method rationality resonance theory.  相似文献   

10.
In this article, we give the acceleration of the block successive overrelaxation (SOR) method for solving the rank-deficient least-squares problem. Santos and Silva proposed the two-block SOR method and the three-block SOR method. Here, we consider the acceleration of the two-block SOR method and the three-block SOR method using the Chebyshev polynomial and derive what we term the C-2-block SOR method and the C-3-block SOR method. The advantage of our methods is that we can get good results with very small iteration number. The comparison between the C-2-block method and the C-3-block method is presented. Finally, numerical examples are given.  相似文献   

11.
In order to solve the structural optimization problem of long-span transmission tower, topology combination optimization (TCO) method and layer combination optimization (LCO) method based on discrete variables are presented, respectively. An adaptive genetic algorithm (AGA) is proposed as optimization algorithm. Four methods: cross-section size optimization (CSSO) method, shape combination optimization (SCO) method, the TCO method and the LCO method, are utilized to optimize the transmission steel tower, respectively. The topology optimization rules are presented for the TCO method, and the layering optimization rules are presented for the LCO method. A high-voltage steel tower is analyzed as a numerical example to illustrate the performance of the proposed methods. The simulation results demonstrate that the calculated results of both the proposed TCO method and the LCO method are obviously better than those of the CSSO method and the SCO method.  相似文献   

12.
We propose a simple and practical numerical method for free surface flows. The method is based various methods, the level set method of an interface capturing method, the THINC/WLIC (tangent of hyperbola for interface capturing/weighed line interface calculation) method of an interface tracking method, the CIP-CSL (constrained interpolation profile conservative semi-Lagrangian) method of a conservation equation solver, VSIAM3 (volume/surface integrated average based multi-moment method) of a fluid solver and the CSF (continuum surface force) model of a surface force model. The level set method and the THINC/WLIC method are combined by using a CLSVOF (coupled level set and volume-of-fluid) framework. The method is applied to Rayleigh-Taylor instability with surface tension force and droplet impact on a thin liquid layer (milk crown).  相似文献   

13.
VE中虚拟器件仿真与建模方法的研究*   总被引:3,自引:0,他引:3  
结合实际项目的开发,采用面向对象和组件思想提出了一种面向对象和基于组件的虚拟器件仿真与建模方法。面向对象的仿真与建模方法具有良好的直观性、可扩展性和可重用性。基于组件的仿真与建模思想来源于面向对象,但与面向对象的方法相比,基于组件的仿真与建模分析的粒度较大,可重用性更好。  相似文献   

14.
《国际计算机数学杂志》2012,89(7):1459-1470
A five-point one-step block method based on the Newton backward divided difference formulae for the solution of first-order delay differential equations is derived. The proposed block method will approximate the solutions of initial value problems at five points simultaneously using variable step size. The approximation of the delay term is calculated using Neville's interpolation. The block method will be formulated in terms of linear multistep method, but the method is equivalent to one-step method. The order of the block method will be discussed. The P-stability and Q-stability regions of the block method using Neville's interpolation for the delay term are presented for a fixed step size. Numerical results are given to show the efficiency of the proposed method and compared with the existing method.  相似文献   

15.
张彦军 《微型电脑应用》2012,28(10):58-60,64
通过把正交几何椭圆拟合与代数拟合和椭圆定义的迭代拟合进行比较分析,考虑到原有拟合存在的缺陷,充分应用正交的概念及最小二乘法(LS)原理和方法的优点,对椭圆进行正交的几何拟合。实验表明,正交几何拟合很好地弥补了其它拟合方法的缺陷,取得良好的效果。  相似文献   

16.
The paper describes a Modified Secant Newton method (MSN) which is derived from the variable metric method. The present procedure differs from the Secant Newton method (SN) in that in the MSN method the iterative displacement change involves only a scalar multiple of the usual unaccelerated change. Both the MSN method and the SN method are based on a Secant approach, but the MSN method leads to a reduction in the required number of iterations compared to the SN method. Two numerical examples involving elasto-plastic behaviour are presented.  相似文献   

17.
提出社会群体角色本体的知识获取方法、建模方法和本体表示方法,包括社会群体、社会群体角色、社会群体角色动作、社会群体角色关系、社会群体角色关系公理等相关知识的获取方法。采用模板技术对社会群体角色本体进行建模,运用框架语言描述本体,实现社会群体角色本体中的公理获取及自动生成。  相似文献   

18.
图像分割是数字图像处理中的关键技术之一,研究了边缘检测和阈值分割方法实现图象分割。归纳总结了多种分割算法,包括极小值法,求导法,直方图变换法,迭代法,平均法,大律法和边缘检测法。  相似文献   

19.
有限单元法被广泛的采用来描述柔性体的弹性变形,然而有限元节点坐标数目庞大,将会给动力学方程求解带来巨大的计算负担.如何降低柔性体的自由度,是当前柔性多体系统动力学研究的一个重要命题.本文以中心刚体-柔性梁系统为例,采用Krylov方法和模态方法进行降价.然后分别采用有限元全模型、Krylov降阶模型和模态降阶模型,对中心刚体-柔性梁进行刚-柔耦合动力学仿真.仿真结果表明,与采用模态降阶方法相比,采用Krylov模型降阶方法只需要较低的自由度,就可以得到与采用有限元方法完全一致的结果.说明Krylov模型降阶方法能够有效的用于柔性多体系统的模型降价研究.  相似文献   

20.
一种实时数据库查询执行方法的设计   总被引:1,自引:0,他引:1  
在深入分析实时数据库常用的查询执行方法---指针法缺点基础上,给出了一种新的实时数据库查询执行方法---D/S方法。该方法结合了指针法、实体化方法和流水线方法的优点,可有效地节省查询执行的内存需求,并扩展了实时数据库查询优化的空间。  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