数据仓库技术在高校招生工作中的应用研究

以四川交通职业技术学院为例,讨论如何建立数据仓库,通过SQL Server Integration Service将招生数据经过清洗、转换加载到数据仓库,建立以招生为主题的多维数据集,使用OLAP工具对招生数据进行分析,使用Excel将分析结果展现给决策者。     

层次立方体(H-Cube)的自适应计算

多维数据立方（Cube）的计算对联机分析处理（online analytical processing，OLAP）有着极为重要的作用。针对传统的多维数据Cube计算中的不足，提出了自适应的计算方法，并给出了带有层次的Cube计算算法HCA算法。     

一种新柱式

文章介绍了在计算机的帮助下产生的一种全新的柱式。它基于一种基本的折叠手法,其结果所呈现的极其丰富的细节超越了传统cAD工具能够绘制的极限,也超越了肉眼所能观察的极限。这些出乎意料的形式与极其微小的细节来自计算机程序的反复迭代,它们超出了建筑师的经验、教育和历史认知,无论从手法还是结果来看,都是一种彻底的创新。文章还指出,建造如此复杂的细节需要现代化的数字加工技术与独特的加工技巧。     

国家游泳中心钢结构施工卸载过程及运营期间应变健康监测及计算模拟分析

空间结构施工卸载过程和运营状态受力是十分复杂的。本文在对100余种工况受力分析的基础上,依据应变传感器位置选择原则,首先设计国家游泳中心(简称"水立方")应变监测系统;其次,建立水立方施工卸载过程模拟的有限元模型和运营状态的有限元模型;采用应变监测系统和有限元模型分别监测和模拟水立方施工卸载过程关键杆件的应力变化,以及脚手架的应力变化全过程,分析关键杆件应变变化规律。在此基础上,对水立方运营阶段的温度变化及其产生的应变进行监测,并采用有限元模型进行温度变形计算。结果表明,监测期间,水立方其他荷载较小,温度是主要控制荷载,随温度升高,应变增加,最高温度达到75℃,最大温度应变变化接近500με。     

与天空对话的巨石 福克萨斯建筑事务所设计的福利尼奥圣保罗教堂综合体

文章通过对意大利福利尼奥圣保罗教堂综合体的阅读,介绍福克萨斯建筑事务所如何从研究两个互相嵌套的立方体之间的关系开始,对这个由来已久的历史性主题进行现代诠释。通过在最基本的空间和光线层面的操作,尽可能集中而直接地表达今天宗教建筑的含义。     

Exploratory mining in cube space

Data Mining has evolved as a new discipline at the intersection of several existing areas, including Database Systems, Machine Learning, Optimization, and Statistics. An important question is whether the field has matured to the point where it has originated substantial new problems and techniques that distinguish it from its parent disciplines. In this paper, we discuss a class of new problems and techniques that show great promise for exploratory mining, while synthesizing and generalizing ideas from the parent disciplines. While the class of problems we discuss is broad, there is a common underlying objective—to look beyond a single data-mining step (e.g., data summarization or model construction) and address the combined process of data selection and transformation, parameter and algorithm selection, and model construction. The fundamental difficulty lies in the large space of alternative choices at each step, and good solutions must provide a natural framework for managing this complexity. We regard this as a grand challenge for Data Mining, and see the ideas discussed here as promising initial steps towards a rigorous exploratory framework that supports the entire process. Bee-Chung Chen is supported by a Microsoft Research graduate fellowship.     

Real time discrete shading

A shading technique for voxel-based images, termedcongradient shading, is presented. As the surface information is not available in voxel representation, the surface normal must be recovered from the 3D discrete voxel map itself. The technique defines the normal as one of a finite set of neighborhood-estimated gradients and can thus employ precalculated look-up tables. Furthermore, a table-driven mechanism permits changing the light source parameters by merely redefining the look-up table. The technique uses only simple arithmetic operations and is thus suitable for hardware implementation. Since it has been implemented not as a post-processor, but as part of the projection pipeline of the cube architecture, congradient shading can be executed in real time. Two versions of the technique in real time. Two versions of the technique have been conceived and implemented:unidirectional shading, in which the gradient is estimated only from neighborhoods along the scan-lines;bidirectional shading, in which both horizontal and vertical components of the gradient are considered. In spite of the simplicity of the technique, the results are practically indistinguishable from images generated by conventional techniques.This work was supported by the National Science Foundation under grants DCR 8603603, CCR 8743478, CCR 8717016, and MIP 8805130     

On the role of constitutive model in the forming limit of FCC sheet metal with cube orientations

The effect on forming-limit diagrams (FLD) of an initial cube texture and its evolution was studied using the well-known M-K approach in conjunction with a viscoplastic crystal plasticity model (VPSC). We focused on how the strength of the cube texture affects localized necking. In particular, we addressed the results of Wu et al. [Effect of cube texture on sheet-metal formability. Materials Science and Engineering A 2004;364:182-7] who found that a spread about cube exhibits unexpectedly high limit strains. The FLD and yield loci were determined for several spreads about {1 0 0}〈0 0 1〉 with uniform or Gaussian distributions. A smooth transition in predicted limit strains from the ideal cube, through textures with increasing cut-off angles, to a random texture was calculated using the MK-VPSC approach. Results indicate that the constitutive model selected has a critical importance for predicting the behavior of materials that exhibit a qualitative change in the crystallographic texture, and hence, evolve anisotropically during mechanical deformation.