Introspective sorting and selection revisited

We describe two improvements to introspective sorting and selection algorithms: a simple rule for fine‐grained introspection that detects potential worst‐case performance after only a small constant number of partitioning steps, and the use of remedial randomization as an intervention strategy in order to reduce the performance penalty for false positives. We present experimental results showing that these techniques provide significant improvements in the running time for worst‐case and other troublesome inputs, without sacrificing performance on well‐behaved inputs. Copyright © 2000 John Wiley & Sons, Ltd.     

基于组合遗传算法的产品形态创新设计研究*

通过分析组合原理与遗传算法在产品形态设计领域的应用现状与各自的优缺点,提出了一种利用组合原理与遗传算法在形态设计中的优点进行产品形态创新设计的混合算法,阐述了该算法的应用方式与步骤。通过一个洗衣机的实例验证了算法的可行性与实用性。结果显示,该算法能生成具有一定创新性的产品形态。     

Introspective Sorting and Selection Algorithms

Quicksort is the preferred in-place sorting algorithm in many contexts, since its average computing time on uniformly distributed inputs is Θ(N log N), and it is in fact faster than most other sorting algorithms on most inputs. Its drawback is that its worst-case time bound is Θ(N²). Previous attempts to protect against the worst case by improving the way quicksort chooses pivot elements for partitioning have increased the average computing time too much – one might as well use heapsort, which has a Θ(N log N) worst-case time bound, but is on the average 2–5 times slower than quicksort. A similar dilemma exists with selection algorithms (for finding the i-th largest element) based on partitioning. This paper describes a simple solution to this dilemma: limit the depth of partitioning, and for subproblems that exceed the limit switch to another algorithm with a better worst-case bound. Using heapsort as the ‘stopper’ yields a sorting algorithm that is just as fast as quicksort in the average case, but also has an Θ(N log N) worst case time bound. For selection, a hybrid of Hoare's FIND algorithm, which is linear on average but quadratic in the worst case, and the Blum–Floyd–Pratt–Rivest–Tarjan algorithm is as fast as Hoare's algorithm in practice, yet has a linear worst-case time bound. Also discussed are issues of implementing the new algorithms as generic algorithms, and accurately measuring their performance in the framework of the C+:+ Standard Template Library. ©1997 by John Wiley & Sons, Ltd.     

智能变电站GOOSE组网应用

为了保证智能变电站GOOSE报文传输的实时性和可靠性,分析和比较了MAC地址静态组播、虚拟局域网（VLAN）、组播注册协议（GMRP）3种多播报文过滤技术的特征,指出基于端口的VLAN划分方式是现阶段智能变电站GOOSE组网工程应用中切实可行的方案。分析了智能电子设备（IED）之间GOOSE报文的数据流向和交互范围,提出一种基于GOOSE信息分类和保护间隔的VLAN划分方案,最后结合工程实例给出了GOOSE组网配置方案,该方案易于实现,GOOSE数据流向清晰,能够有效隔离多播报文。     

某商务办公楼综合布线系统设计

结合某商务办公楼综合布线系统项目,介绍了综合布线系统设计的主要内容,阐述了各个组成部分的设计选型及通信线缆的选型。通过综合布线系统示意图,进一步闸述了该项目中各相对独立的商务办公楼之间的相互关联性及配置。最后对该系统的防雷和接地设计及综合布线系统的特点进行了介绍。     

智能建筑中综合布线系统的设计

介绍了当前在智能建筑设计中综合布线系统的具体设计方法,包括综合布线系统的结构组成、配置标准、方案选择、设计步骤与方法、安装工艺要求、系统电气接地等。并对工程设计中经常遇到的关键问题进行了分析。最后列举了典型工程案例,总结了实践经验,以供设计人员参考。     

City as Political Form: Four Archetypes of Urban Transformation

Pier Vittorio Aureli focuses on the category of archetype as an alternative to the idea of type. Four examples – the axial streets of Renaissance Rome, the 17th-century Parisian place, the 19th-century independent block in Berlin and the 20th-century Viennese superblock – are explored here to describe the emergence of modern urban forms that explicitly embody power relations.     

Computer simulation of production systems for woven fabric manufacture

This paper reports a research and development of a suite of generic software program entitled TEXSIM (TEXtile SIMulator). The software is mainly intended to create simulation models of weaving of production systems without any programming and automatically performs the simulation study and produces results to understand the stochastic behaviour of the system as well as to analyze the system performances to solve the real life weaving production management problems. The ’TEXSIM’ reads the input parameters from the user in an on-line session through its user-interface, written in FORTRAN’77, and interactively uses WITNESS, a manufacturing simulation package containing the basic simulation model building blocks, and creates the simulation model in accordance with the user’s specifications and conducts the simulation experiments and produces results. The objective is to focus on the practicality and simplicity of simulation model building of a weaving production system with a readily available suite of user-friendly program TEXSIM within few minutes without expertise and back ground of simulation technique and the knowledge of computer simulation programming as well as the skill of handling of commercial simulation package. It also highlights the importance of use of computer simulation technique as a modern, powerful and flexible management analysis tool in weaving factories. Textile engineers and technologists, particularly the managers who have no background of simulation can take full advantages of the use of simulation technique to analyze their present complex weaving production systems, rather than using the conventional analytical rule of thumb methods, to help the management to plan, design and operate their systems in an efficient manner to improve the manufacturing productivity. TEXSIM also facilitates the scheduling of production within the factory through simulation.     

基于遗传算法和神经网络的复杂对象的建模与优化

针对复杂对象全局优化结果较多,难以选取最佳参数组合的问题,提出了一种新适应度函数,其特点是使用了目标函数关于其影响参数的梯度之和。结合提出的新适应度函数,首先进行已知模型的遗传算法寻优,然后对神经网络构建的模型进行遗传算法寻优。两次试验结果都表明,搜索到的最佳性能目标对应的参数组合具有较强的鲁棒性。     

The impact of generic language about ability on children's achievement motivation.

Nuances in how adults talk about ability may have important consequences for children's sustained involvement and success in an activity. In this study, I tested the hypothesis that children would be less motivated while performing a novel activity if they were told that boys or girls in general are good at this activity (generic language) than if they were told that a particular boy or girl is good at it (non-generic language). Generic language may be detrimental because it expresses normative societal expectations regarding performance. If these expectations are negative, they may cause children to worry about confirming them; if positive, they may cause worries about failing to meet them. Moreover, generic statements may be threatening because they imply that performance is the result of stable traits rather than effort. Ninety-seven 4- to 7-year-olds were asked to play a game in which they succeeded at first but then made a few mistakes. Since young children remain optimistic in achievement situations until the possibility of failure is made clear, I hypothesized that 4- and 5-year-olds would not be affected by the implications of generic language until after they made mistakes; 6- and 7-year-olds, however, may be susceptible earlier. As expected, the older children who heard that boys or girls are good at this game displayed lower motivation (e.g., more negative emotions, lower perceived competence) from the start, while they were still succeeding and receiving praise. Four- and 5-year-olds who heard these generic statements had a similar reaction, but only after they made mistakes. These findings demonstrate that exposure to generic language about ability can be an obstacle to children's motivation and, potentially, their success. (PsycINFO Database Record (c) 2010 APA, all rights reserved)