Notes on D-optimal designs

The purpose of this paper is to exhibit new infinite families of D-optimal (0, 1)-matrices. We show that Hadamard designs lead to D-optimal matrices of size (j, mj) and (j − 1, mj), for certain integers j ≡ 3 (mod 4) and all positive integers m. For j a power of a prime and j ≡ 1 (mod 4), supplementary difference sets lead to D-optimal matrices of size (j, 2mj) and (j − 1, 2mj), for all positive integers m. We also show that for a given j and d sufficiently large, about half of the entries in each column of a D-optimal matrix are ones. This leads to a new relationship between D-optimality for (0, 1)-matrices and for (±1)-matrices. Known results about D-optimal (±1)-matrices are then used to obtain new D-optimal (0, 1)-matrices.     

On c‐Bhaskar Rao designs with block size 4

Several new families of c‐Bhaskar Rao designs with block size 4 are constructed. The necessary conditions for the existence of a c‐BRD (υ,4,λ) are that: (1)λ_min=?λ/3 ≤ c ≤ λ and (2a) c≡λ (mod 2), if υ > 4 or (2b) c≡ λ (mod 4), if υ = 4 or (2c) c≠ λ ? 2, if υ = 5. It is proved that these conditions are necessary, and are sufficient for most pairs of c and λ; in particular, they are sufficient whenever λ?c ≠ 2 for c > 0 and whenever c ? λ_min≠ 2 for c < 0. For c < 0, the necessary conditions are sufficient for υ> 101; for the classic Bhaskar Rao designs, i.e., c = 0, we show the necessary conditions are sufficient with the possible exception of 0‐BRD (υ,4,2)'s for υ≡ 4 (mod 6). © 2002 Wiley Periodicals, Inc. J Combin Designs 10: 361–386, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/jcd.10009     

桉树扦插育苗正交试验设计分析

根据扦插育苗试验表明，影响泰国赤桉苗高、根长及发根数的主要因素各不相同。综合分析表明：其主要因素是ＢＡ浓度，插条浸泡药液的时间和蔗糖浓度，其较优的插条处理方法是将插条在０．６％蔗糖＋３００ＰＰｍＩＢＡ溶液中浸泡２小时     

含有三个非球面的卡塞格林系统光学设计

介绍了一种含三个非球面的卡塞格林系统的设计思想，给出了一个设计结果。焦距２．８ｍ，Ｆ／５．６，视场３．２°，主镜、次镜均为６次方非球面，场镜含一４次方非球面，成像质量接近衍射极限，畸变也得到了校正。     

13单元双压电晶片变形反射镜控制电极的优化设计

双压电晶片变形反射镜具有动态范围大、工作电压低、结构简单、造价低廉等优点，是自适应光学系统中用作波前校正器的新型器件。利用ｋｏｋｏｒｏｗｓｋｉ导出的自由边界条件下双压电变形镜表面位移—电压所满足的偏微分方程，分别运用Ｇａｕｓｓ迭代法和Ｍｏｎｔｅ－Ｃａｒｌｏ法求解该方程的第一边界条件，得出变形镜的静态影响函数矩阵Ｚ（ｘ，ｙ）；按不同电极设计情况划分，以１３组Ｚ（ｘ，ｙ）为基，对Ｚｅｒｎｉｋｅ多项式低阶模进行逐项拟合，得出变形镜控制电极的大小、形状等优化参数，从而得到最佳静态影响函数矩阵以及反演电压矩阵。     

Complexity theory and collaboration: An agent-based simulator for a space mission design team

In this paper, we investigate how complexity theory can benefit collaboration by applying an agent-based computer simulation approach to a new form of synchronous real-time collaborative engineering design. Fieldwork was conducted with a space mission design team during their actual design sessions, to collect data on their group conversations, team interdependencies, and error monitoring and recovery practices. Based on the fieldwork analysis, an agent-based simulator was constructed. The simulation shows how error recovery and monitoring is affected by the number of small group, or sidebar, conversations, and consequent noise in the room environment. This simulation shows that it is possible to create a virtual environment with cooperating agents interacting in a dynamic environment. This simulation approach is useful for identifying the best scenarios and eliminating potential catastrophic combinations of parameters and values, where error recovery and workload in collaborative engineering design could be significantly impacted. This approach is also useful for defining strategies for integrating solutions into organizations. Narjès Bellamine-Ben Saoud is an Associate Professor at the University of Tunis and Researcher at RIADI-GDL Laboratory, Tunisia. After Computer Science engineering diploma (1993) of the ENSEEIHT of Toulouse, France, she received her PhD (1996), on groupware design applied to the study of cooperation within a space project, from the University of Toulouse I, France. Her main research interests concern studying complex systems particularly by modeling and simulating collaborative and socio-technical systems; developing Computer Supported Collaborative Learning in tunisian primary schools; and Software Engineering. Her current reserach projects include modeling and simulation of emergency rescue activities for large-scale accidents, modeling of epidemics and study of malaria, simulation of collabration artifacts. Gloria Mark is an Associate Professor in the Department of Informatics, University of California, Irvine. Dr. Mark received her Ph.D. in Psychology from Columbia University in 1991. Prior to UCI, she was a Research Scientist at the GMD, in Bonn, Germany, a visiting research scientist at the Boeing Company, and a research scientist at the Electronic Data Systems Center for Advanced Research. Dr. Mark’s research focuses on the design and evaluation of collaborative systems. Her current projects include studying worklife in the network-centric organization, multi-tasking of information workers, nomad workers, and a work in a large-scale medical collaboratory. Dr. Mark is widely published in the fields of CSCW and HCI, is currently the program co-chair for the ACM CSCW’06 conference and is on the editorial board of Computer Supported Cooperative Work: The Journal of Collaborative Computing, and e-Service Qu@rterly.     

Non-dynamical stochastic resonance: Theory and experiments with white and various coloured noises

Summary We describe the simplest system which shows stochastic resonance. A linear(ized) theory for white and (almost) arbitrarily coloured noise is presented. The presented new system has new, unique properties which originate from itsnon-dynamical character; for example, the strength and phase shift of periodic response of the system is independent of the frequency. Experiments have been carried out with the following noise processes: (physical) white noise, (physical) Lorentzian noise and (physical) 1/f noise. With a small extension of the system, its linear-response regime can be significantly increased. As the system is similar to some simple models of neurones, the new results might have not only physical but also biological importance. Paper presented at the International Workshop “Fluctuations in Physics and Biology: Stochastic Resonance, Signal Processing and Related Phenomena”, Elba, 5–10 June 1994.     

Min-cut clustering

We describe a decomposition framework and a column generation scheme for solving a min-cut clustering problem. The subproblem to generate additional columns is itself an NP-hard mixed integer programming problem. We discuss strong valid inequalities for the subproblem and describe some efficient solution strategies. Computational results on compiler construction problems are reported.This paper is dedicated to Phil Wolfe on the occasion of his 65th birthday.This research was supported by NSF grants DMS-8719128 and DDM-9115768, and by an IBM grant to the Computational Optimization Center, Georgia Institute of Technology.     

固体力学有限元体系的结构拓扑变化理论

本文是文[1]的继续.文[1]提出了杆件系统的结构拓扑变化理论和拓扑变化法本文将这一理论和方法推进到连续体有限元体系;且在此基础上揭示出有限元体系的一个新性质,称为基本位移之梯度的正交性定理,从而给出一套设计敏度的显式表达式,可直接用于计算.