基于层次主键模型的多维数据概念模型

以关系数据库为基础,介绍了基于E-R模型的层次主键模型及其优点,提出了E-R模型到层次主键模型的转换步骤,对层次主键模型的维层次关系进行了探讨,分析了层次主键模型到多维模型的转换方法。     

人大脑新皮层层级神经网络模型研究

提出了一种层级神经网络模型，其基本结构特点是：下级网络是上一级网络的单元，由神经元→局部回路→微柱→巨柱→功能中枢→功能中枢联结群逐级组织起来。     

改进模糊决策在风电产业评价中的应用

根据风力发电这一新能源技术产业的特点,选择风电产业评价的指标,建立风电产业的改进模糊决策模型,并采用基于优先传递矩阵的层次分析法确定模型中的权重.这一模型,既可以减少确定指标间判断矩阵的盲目性,又可以在建立指标间模糊优先关系矩阵时反映指标间的优劣差异程度,使综合评判结果有很好的分散性.应用实例验证了这一模型的有效性,具有实用价值.     

The generation of hierarchic structures via robust 3D topology optimisation

Commonly used building structures often show a hierarchic layout of structural elements. It can be questioned whether such a layout originates from practical considerations, e.g. related to its construction, or that it is (relatively) optimal from a structural point of view. This paper investigates this question by using topology optimisation in an attempt to generate hierarchical structures. As an arbitrarily standard design case, the principle of a traditional timber floor that spans in one direction is used. The optimisation problem is first solved using classical sensitivity and density filtering. This leads indeed to solutions with a hierarchic layout, but they are practically unusable as the floor boarding is absent. A Heaviside projection is therefore considered next, but this does not solve the problem. Finally, a robust approach is followed, and this does result in a design similar to floor boarding supported by timber joists. The robust approach is then followed to study a floor with an opening, two floors that span in two directions, and an eight-level concrete building. It can be concluded that a hierarchic layout of structural elements likely originates from being optimal from a structural point of view. Also clear is that this conclusion cannot be obtained by means of standard topology optimisation based on sensitivity or density filtering (as often found in commercial finite element codes); robust 3D optimisation is required to obtain a usable, constructible (or in the future: 3D printable) structural design, with a crisp black-and-white density distribution.     

分层递阶控制系统体系结构的Hopfield网络模型

在分析了分散控制、分布式控制和分层递阶控制系统体系结构的基础上，提出了分层递阶控制系统体系结构的Hopfield网络模型，指出这一模型可以用常规的DCS系统和现场总线控制系统来实现，并能实现其混合形式。通过比较发现这两种控制系统各有优缺点，DCS适用于大型递阶控制系统，而FCS适用于小型递阶控制系统，当FCS用于大型递阶控制系统时，必须采用物理上的递阶结构形式。     

几种改进遗传算法的性能比较

本文将标准遗传算法与分层策略和模拟退火思想相融合，设计出分层遗传算法、模拟退火遗传算法和模拟退火分层遗传算法三种改进的遗传算法。计算结果验证了算法的有效性和正确性。进一步算法性能分析证明了论文中所设计的改进的算法不仅能增强算法的全局收敛性，还能加快遗传进化速度。     

基于图层-地图-图集层次结构的电子地图数据组织方法

提出了一种基于图层－地图－图集层次结构的电子地图数据组织方法,系统地介绍了基于该结构的数据组织管理在电子地图制作与浏览软件EA2000中的应用。     

天然气长输管线设计方案优选方法研究

长输管线设计方案的优选是根据工程设计原则 ,从所提供的预选方案中 ,遴选出最佳设计方案。由于方案涉及到的设计参数和技术经济指标具有典型的层次特征 ,因而可以用层次分析方法来定量确定各种指标相对目标层的权重 ,结合密切值法对各个方案与理想方案逼近程度的计算 ,实现方案优劣排序。实例计算结果表明 ,在天然气长输管线设计方案优选指标体系及结构模型之中 ,AHP -MCZ能从多因素、定量与定性相结合的角度来确定出最优设计方案。为设计者选择技术上可行、经济上合理的设计方案提供了一种新方法     

Graph theoretical clustering based on limited neighbourhood sets

A method for clustering data according to a visual model of clusters is proposed. The method uses either of two graphs which are defined according to relative distance and based on the Gabriel graph and the relative neighbourhood graph respectively. The method is locally sensitive, hierarchic and based on the concept of limited neighbourhood sets. Clusters that are either disjoint or homogeneous and separable by sharp changes in point density may be detected.     

A hybrid method for inversion of 3D AC resistivity logging measurements

In this paper, we propose the use of a hybrid algorithm for the inversion of 3D Alternate Current (AC) resistivity logging measurements. The forward problem is solved using a goal-oriented self-adaptive hp-Finite Element Method (hp-FEM) that provides exponential convergence of the numerical error with respect to the mesh size. The inverse problem is solved using a Hierarchical Genetic Search (HGS) coupled with a Broyden–Fletcher–Goldfar–Shanno (BFGS) method. Individuals from the genetic populations represent the resistivity of the formation layers. The fitness function is estimated based on hp-FEM results. The hybrid method controls the accuracy of evaluation of particular individuals, as well as the accuracy of the genetic coding. After finding those regions where the fitness function has small values, the local search method by means of BFGS algorithm is executed. The paper is concluded with numerical results for the hybrid algorithm.