A computational method for simulating growth patterns in unicell propagation

The modelling of natural phenomena through the use of computer-generated graphics has attracted much interest recently. It is believed that such methods will lead to new breakthroughs in understanding nature. One of the most popular methods used is the cell automata method, where cells are made to propagate and form cellular patterns according to certain predefined rules. Although much of the work in this area is for recreational purposes, as in the Game of Life, there can be more serious aspects to it. One of these is in the use of such methods to predict and simulate the growth behaviour of cell clusters in real-life situations. In this study, an attempt is made to formalise certain rules for modelling the growth characteristics of unicell populations. The methodology proposed models three fundamental factors: first, the generic propagational characteristics of a cell; second, the effect of adverse factors to growth; and, third, the effect of spatial constraints. The first two factors, relating to the population of a cell colony, can be modelled mathematically; the third factor determines the visual appearance of the cell colony. Patterns resulting from some computational simulations are presented and discussed.     

Wicking into porous polymer-derived ceramic monoliths fabricated by freeze-casting

Silicon oxycarbide monoliths of different pore size distribution were fabricated by freeze-casting. The samples revealed a lamellar pore structure with an axial anisotropy. To evaluate the capillary transport abilities we performed wicking experiments. The sample weight measurement method was applied during the imbibition. The samples show deviations in permeability from 10% to 49% at different sample orientations that quantifies the impact of the anisotropy in the axial direction. The deviations were larger for the samples with smaller pore size. For these samples we also observed larger differences in the wicking behaviour. The samples with bigger pore size demonstrated higher permeability and faster wicking. Imbibition results at both sample orientations showed a good agreement with a prediction via the Lucas–Washburn equation with gravity effects. We demonstrate hereby, that our approach of macroscopic modelling predicts wicking behaviour in anisotropic structures reasonably well, providing a simple tool for further porous material investigations.     

关于Lucas数方幂和

设Um，Vn是Lucas数，用发生函数的方法得到方幂和∑k=1 n Uk及正负相单间方幂和∑k=1(-1)^kUk的计算方法，并给出一些例子。     

Making a Bang

‘Design is a performance and a process, a form of seeking, a journey where the caravan expands and contracts.’ Guest-editor Bob Sheil describes the extraordinary make-up and approach of the studio of the accomplished maker Thomas Heatherwick. With Ron Packman , he also describes how this translates into physical form in the making of the sculpture The B of Big Bang. Copyright © 2005 John Wiley & Sons, Ltd.     

In My Craft and Sullen Art or Sketching the Future by Drawing on the Past

Whether made digitally or by hand, remotely or locally, realisation of architecture is still reliant on the agency of dialogue from a practice that stems from oral exchange. Professor Michael Stacey , a global figure in the development of digital fabrication in architecture, and author of Component Design, draws from his broad experience in manufacturing, practice and research. This grounded text is a prompt for architectural practice to adopt digital fabrication technologies with clear reference and understanding of their origins and, thus, redefine itself as a form of live research. Copyright © 2005 John Wiley & Sons, Ltd.     

基于Lucas序列的数字签名方案

数字签名是消息认证系统中的重要内容之一,近年来受到厂泛重视。本文介绍了一种新的基于Lucas序列的数字签名方案,通过将Lucas序列与数字签名思想有效结合,完善了这种新的数字签名方案的描述,并首次给出了该方案中签名认证方程的证明,最后用一实例证明了算法的正确性和有效性。     

Making Waves at East Beach Café

Howard Watson describes how Littlehampton on the Sussex coast has become the unlikely home to a cutting-edge structure. The ‘rippling, ribbed, brown steel mollusc’ form of this year-round café-restaurant, realised by Heatherwick Studio and Adams Kara Taylor, celebrates its fresh seafood menu and beachside site. Copyright © 2008 John Wiley & Sons, Ltd.     

电网规划指标的相关性分析及融合算法

目前决策指标体系中,大多忽略了指标的相关性问题,这将影响整个电网规划的可靠性、经济性。针对指标决策中不确定性问题,提出一种基于概率盒理论的指标相关性分析模型及融合算法。首先对指标采用Lucas模型进行相关性分析;然后对相关性的指标建立概率盒,并根据相关系数进行概率盒融合;最后利用重叠因子进行定量分析。以某省电网规划方案的底层指标为例进行了实验,结果表明,该方法对解决相关性及其融合问题具有良好的实效性和精准度。