A novel approach to adaptive relational association rule mining

The paper focuses on the adaptive relational association rule mining problem. Relational association rules represent a particular type of association rules which describe frequent relations that occur between the features characterizing the instances within a data set. We aim at re-mining an object set, previously mined, when the feature set characterizing the objects increases. An adaptive relational association rule method, based on the discovery of interesting relational association rules, is proposed. This method, called ARARM (Adaptive Relational Association Rule Mining) adapts the set of rules that was established by mining the data before the feature set changed, preserving the completeness. We aim to reach the result more efficiently than running the mining algorithm again from scratch on the feature-extended object set. Experiments testing the method's performance on several case studies are also reported. The obtained results highlight the efficiency of the ARARM method and confirm the potential of our proposal.     

未结盟大学的联盟

通过梳理管理学界对战略联盟的定义，发现价值链的鸸释同样适用于大学问的战略联盟。通过对已有的大学战略联盟的分析，提出了名校联盟与非名校联盟间的若干差异，最后提出了我国大学联盟战略的若干建议。     

Deformation behaviour of iron-doped alumina

Compressive creep tests in air were carried out on 1 cat.% Fe-doped alumina at a temperature T=1400 °C. Iron doping affected the plastic deformation by different ways in relation with Fe²⁺ cations population. Fe²⁺ cations sped up the deformation rates. FeAl₂O₄ spinel precipitates were identified and they were found (i) to interact with alumina grain boundaries (ii) to limit the grain growth within a range of strain. The Fe²⁺ cations underwent oxidation and this resulted in the dissolution of the some precipitates and in the decrease of deformation rates. It was suggested that deformation sped up this evolution through mass transport and that time was not a dominating parameter.     

Fabrication of nano-porous silicon oxide layers by plasma polymerisation methods

We report on the synthesis of nano-porous silicon oxide (SiO₂) layers by gas phase polymerisation reactions of hexamethy disiloxane and oxygen. The SiO₂ layers are deposited onto one or more layers of poly(methylmethacrylate) (PMMA) particles spin coated onto the substrate surface. Subsequent annealing of the films to high temperature (500 °C) leads to the pyrolysis of the polymeric particles resulting in a 3D nanoporosity in the film. X-ray Photoelectron (XPS) and Fourier Transform Infra Red Spectroscopy (FTIR) show an SiO₂-like surface chemistry and virtually complete removal of the organic components. These materials offer a very high surface area-to-volume ratio suitable for sensing applications.     

Preparation of ultra-fine polyimide fibers containing silver nanoparticles via in situ technique

Ultra-fine polyimide fibers containing silver nanoparticles were prepared by electrospinning from poly(amic acid)/(trifluoroacetylacetonoto)silver(I) (PAA/AgTFA) solution. Thermal curing of the silver(I)-containing fibers led to cycloimidization of the poly(amic acid) into polyimide with concomitant silver(I) reduction. The polyimide–silver fibers were characterized by FT-IR, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The average diameters of silver nanoparticles and ultra-fine PI fibers electrospun from solutions with different amounts of AgTFA were studied, and the crystal structure of silver nanoparticles was also presented.     

用SY87721实现城域网波分复用系统的多业务接入

为了使城域网的DWDM（密集波分复用）系统可以接入多种信号速率和格式，以满足用户的要求，首先介绍了一种波长转换板的设计方法，使用SY87721自适应提取28Mbit／s～2.7Gbit/s之间任意速率信号的时钟，其次介绍了SY87721提取时钟的工作原理、与单片机和CPLD（复杂可编程逻辑器件）的接口方式、对寄存器的配置和读出方式。最后介绍了使用参考时钟测量接入信号频率的方法，这会在系统维护时带来较大的方便。     

多输入的二阶广义分布参数系统的控制综合问题

广义分布参数系统具有广泛的实际背景.如复合材料中的温度分布,电缆中的信号传播,电磁耦合超导线路中的电压分布,飞行器姿态控制等问题研究中都会出现这样的系统.极点配置与反馈稳定性是这类系统研究的重要方面.本文应用泛函分析及算子理论讨论了Hilbert空间中多输入的二阶广义分布参数系统的极点配置与反馈稳定性问题,获得了这类系统极点可配置与可镇定的一些充分条件,并利用复分析、复级数、有界线性算子的广义逆等方法建立了反馈控制律的构造性表达式.本文结论不仅具有重要的实际意义,而且对广义分布参数系统的控制综合问题研究具有重要的理论价值.     

锡焊机中PLC与单片机之间通信的设计

介绍了本公司锡焊机中S7-200系列PLC与单片机进行通信的方法,包含通信设置,程序设计等。其中硬件以PLC为主机,单片机为从机,AT89C51单片机输出信号通过RS-485总线与S7-200系列PLC进行通信,并简单介绍了通信协议。     

纳米压痕法对304不锈钢残余应力的研究

利用纳米压痕法研究了304不锈钢的残余应力,采用Suresh理论模型恒定载荷时的公式计算残余应力,最大加载载荷依次为500μN、1 000μN、1 500μN、2 000μN、2500μN。结果表明,不锈钢硬度和弹性模量为定值,退火前后的硬度分别为5.3GPa和4.0 GPa,弹性模量分别为110 GPa和100 GPa。利用Ansys分析软件模拟了压痕过程,发现不锈钢在受压过程中有Sink-in现象发生。纳米压痕法测得了未退火不锈钢存在残余压应力,大小为381 MPa;用XRD测得了未退火不锈钢中有350 MPa±23 MPa的残余压应力,两种测量结果吻合良好,说明了纳米压痕法在残余应力测试时的准确性与可靠性。