Space-time block codes which can be identified as rings

In this paper, we give a general criterion to determine when a complex space-time block code has a ring structure and then we provide a complete list of complex space-time block codes which have ring structures up to size 4.     

Adaptive generation of surfaces in volume data

A widespread approach to generating polygonal approximations of iso-surfaces or contour surfaces in volume data is the socalled marching-cubes algorithm. This algorithm, however, has the disadvantage that the number of polygonal chains generated is considerable. The splitting-box algorithm presented here reduces the number of polygonal chains by adapting their size to the shape of the surface. The resulting polygonal chains offer a wide spectrum for representing the contour surface. An exact representation is achieved by a new type of generic patches calculated from the polygonal chains. Approximations of different quality may be obtained by combining the algorithm generating the patches with simple triangulations.     

解读维克斯纳视觉艺术中心

维克斯纳视觉艺术中心在彼得·艾森曼的理论与实践中具有里程碑的地位,试图通过解读视觉艺术中心,探寻艾氏设计思维的核心体系。     

一种分析时序逻辑电路的补充方法

介绍一种分析时序逻辑电路的补充方法,并应用于教学实践中。其特点是原理简单、易于理解、直观方便,相对于传统的分析方法,避免了对次状态方程的分析处理计算,有时比传统方法简便、快捷。通过两个示例展示其优越性。     

单晶铜制备HSYV-5e 4×2×0.5数字通讯电缆的性能研究

用自制区域熔炼单晶化设备制备了直径为2.7 mm铜单晶线材,经过冷拔加工至直径为0.51 mm,采用信息产业部生产标准YD/T 1019-2001制成HSYV-5e 4×2×0.5数字通讯实心水平对绞电缆,分别对导体材料为变形单晶铜和普通无氧铜电缆的电气性能进行检测,对比试验结果表明:变形单晶铜比普通无氧铜电缆的直流电阻低4.59%;变形铜单晶电缆对信号的衰减作用有明显的改善;单晶铜线材冷拔变形后显微组织存在变形孪晶和晶界.     

基于图像分割的扭曲鼻纹识别模型仿真

鼻纹特征是当前最新研究的生物识别特征,对身份的鉴定有着重要的意义.鼻子的纹路较细小,只有在挤压过程中,才能留下纹理特征.但是,挤压过程本身对特征就形成了一定的破坏,使得特征扭曲变形,无法形成完整特征.传统的生物识别方法多是依靠完整生物特征,在鼻纹特征残缺或者挤压造成特征形变的情况下,虽然能识别出特征,但是对应过程会产生大量的干扰,造成假识别,漏识别的问题.提出采用鼻纹图像小区域分割的扭曲识别方法.针对扭曲鼻纹图像进行矩阵重组,根据重组结果进行分割,完成扭曲鼻纹图像的分类,利用自适应迭代出不同区域的识别阀值,设定识别过程中的最优阀值,最终完成扭曲鼻纹图像的识别.仿真结果表明,利用改进算法进行扭曲鼻纹图像识别,能够有效提高识别的准确率.     

Independent spanning trees vs. edge-disjoint spanning trees in locally twisted cubes

Fault-tolerant broadcasting and secure message distribution are important issues for numerous applications in networks. It is a common idea to design multiple spanning trees with a specific property in the underlying graph of a network to serve as a broadcasting scheme or a distribution protocol for receiving high levels of fault-tolerance and of security. A set of spanning trees in a graph is said to be edge-disjoint if these trees are rooted at the same node without sharing any common edge. Hsieh and Tu [S.-Y. Hsieh, C.-J. Tu, Constructing edge-disjoint spanning trees in locally twisted cubes, Theoretical Computer Science 410 (2009) 926-932] recently presented an algorithm for constructing n edge-disjoint spanning trees in an n-dimensional locally twisted cube. In this paper, we prove that indeed all spanning trees constructed by their algorithm are independent, i.e., any two spanning trees are rooted at the same node, say r, and for any other node v≠r, the two different paths from v to r, one path in each tree, are internally node-disjoint.     

Embedding multi-dimensional meshes into twisted cubes

The twisted cube is an important variant of the most popular hypercube network for parallel processing. In this paper, we consider the problem of embedding multi-dimensional meshes into twisted cubes in a systematic way. We present a recursive method for embedding a family of disjoint multi-dimensional meshes into a twisted cube with dilation 1 and expansion 1. We also prove that a single multi-dimensional mesh can be embedded into a twisted cube with dilation 2 and expansion 1. Our work extends some previously known results.     

Rule cubes for causal investigations

With the complexity of modern vehicles tremendously increasing, quality engineers play a key role within today’s automotive industry. Field data analysis supports corrective actions in development, production and after sales support. We decompose the requirements and show that association rules, being a popular approach to generating explanative models, still exhibit shortcomings. Interactive rule cubes, which have been proposed recently, are a promising alternative. We extend this work by introducing a way of intuitively visualizing and meaningfully ranking them. Moreover, we present methods to interactively factorize a problem and validate hypotheses by ranking patterns based on expectations, and by browsing a cube-based network of related influences. All this is currently in use as an interactive tool for warranty data analysis in the automotive industry. A real-world case study shows how engineers successfully use it in identifying root causes of quality issues.