广义q-ROF TODIM方法及应用

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.     

On the Generalization of Single Input Rule Modules Connected Type Fuzzy Reasoning Method

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.      

一种新的矢量数据多边形的快速裁剪算法

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。     

盐-水体系溶解平衡计算的自由能最小化和溶度积方法比较

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。     

Structural topology optimization of high-voltage transmission tower with discrete variables

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.     

三对角线性方程组的分布式并行算法

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％。     

一种实时数据库查询执行方法的设计

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。     

A Numerical Method for Free-Surface Flows and Its Application to Droplet Impact on a Thin Liquid Layer

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).     

Chebyshev polynomial acceleration for block SOR methods for solving the rank-deficient least-squares problem

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.     

Longitudinal use of method rationale in method configuration: an exploratory study

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.