制造网格中资源管理系统研究

为实现制造业的资源共享和协同工作, 以开放网格服务架构(OGSA)为系统框架, 以GT3(Globus Toolkit 3.0)为开发工具, 提出了制造网格的概念. 然而, 由于制造资源的复杂性、多样性、特殊性和分散性, 制造网格中的资源管理问题明显比其他网格应用项目困难得多. 因此, 开发了制造网格信息服务(MGIS), 该服务通过有效集成检测查询服务(MDS)和各种类型的资源封装模板, 实现了制造资源的远程封装、注册、发现和监控. 同时, MGIS与GRAM(globus resource allocation manager)共同构建了制造网格的资源管理系统, 解决了制约制造网格应用的瓶颈问题. 最后, 给出了该系统的应用框架, 并通过制造网格试验床中的一个具体应用实例说明了其实际应用过程.     

双栅极空气计数管的工作电压研究

Based on analysis of the discharging course in double grid air counter(DGAC),the dischargin model is built up by applying the conception of average ionizaing free path.An effective algorithm is presented for the working voltage of DGAC using this model.The working voltage is nearly related to the geometric parameters of DGAC,the sensitivity of the circuitry and the number of discharges,computing results confirm that the working voltage increases with the ratio of the radius of the anode to that of the cathode.The number of discharges follows the similar rule.     

基于制造网络的虚拟企业多层制造系统及成员企业选择和任务分配策略

In order to improve efficiency of virtual enterprise, a manufacturing grid and multilevel manufacturing system of virtual enterprise is built up. When selecting member enterprises and task assignment based on the manufacturing grid, key activities are assigned to the suitable critical member enterprises by task decomposition, enterprise node searching and characteristic matching of manufacturing resources according to the characteristic matching strategy. By task merger, some ordinary activities are merged with corresponding key activities and assigned to corresponding critical member enterprises. However, the other ordinary activities are assigned to the related ordinary member enterprises with enterprise node searching and characteristic matching of manufacturing resources. Finally, an example of developing the artificial hip joint in the virtual enterprise is used to demonstrate that efficiency of the virtual enterprise is improved by using the manufacturing grid and the proposed strategies for member enterprise selection and task assignment.     

利用复合网格进行电磁场分析

本描述了对有需要看重分析的局部区域的电磁场进行有限元分析的复合网格法．这种方法基于通常的有限元方法，有总体分析，局部分析和修正后的总体分析3个基本步骤．在前2步中，利用较粗的网格进行总体分析，得到节点的电势，将其作为后续进一步分析的局部区域的人工边界条件．将这些有了边界条件的局部区域用更精细的网格进行分析，得到更为精确的电势与密度分布．在第3步中，进行修正后的总体分析，通过迭代不断改进结果，直到满足给定的求解精度，得到更好的电势与密度分布的结果．数值实验表明，与通常的有限元方法相比，复合网格法在得到同样求解精度的结果时所耗的计算时间要少得多．     

福建省制造业竞争力研究——基于因子分析的实证

制造业的竞争力已经成为福建省经济持续增长的重要动力和支撑点。文章通过构建制造业竞争力评估指标体系，采用因子分析对福建省制造业28个行业的竞争力水平进行综合评价，结果显示，福建省制造业相对有竞争力的行业并没有遥遥领先于国内平均水平；福建省重点扶持的产业竞争力总体上还比较弱；福建省的高新技术产业正处于发展之中，尚难在工业增长中充分发挥先导作用；福建主导产业的产业集中度还不是很高，规模经济效应并不是非常明显，产业竞争力尚需大大加强；《海峡西岸经济区建设纲要（试行）》中确定的主导、支柱产业基本上尚未形成优势，竞争力较强的产业基本上是低技术、劳动密集型产业。     

柔性制造单元中机器人行走系统的实验模态分析

介绍了柔性制造单元中机器人行走系统的结构设计.通过机械结构动态设计的主要途径——实验模态分析法（EMA）对设计结果进行了研究,并结合有限元模态分析法（FEM）对2种分析结果进行了比较.通过实验模态分析以及对比结果,能够有效地识别出行走系统的薄弱部位,为行走系统的优化设计和动态性能的提高奠定了理论基础.     

Enhanced control of DFIG-used back-to-back PWM VSC under unbalanced grid voltage conditions

This paper presents a unified positive-and negative-sequence dual-dq dynamic model of wind-turbine driven doubly-fed induction generator(DFIG) under unbalanced grid voltage conditions. Strategies for enhanced control and operation of a DFIG-used back-to-back(BTB) PWM voltage source converter(VSC) are proposed. The modified control design for the grid-side converter in the stationary αβ frames diminishes the amplitude of DC-link voltage ripples of twice the grid frequency,and the two proposed control targets for the rotor-side converter are alternatively achieved,which,as a result,improve the fault-ride through(FRT) capability of the DFIG based wind power generation systems during unbalanced network supply. A complete unbalanced control scheme with both grid-and rotor-side converters included is designed. Finally,simulation was carried out on a 1.5 MW wind-turbine driven DFIG system and the validity of the developed unified model and the feasibility of the proposed control strategies are all confirmed by the simulated results.     

基于SLS技术的汽车油过滤器接头零件快速原型制造

为了快速获得汽车油过滤器接头零件的样件，提出了基于SLS技术的快速原型制造技术，介绍了SLS技术的成型原理、成型工艺过程以及烧结汽车油过滤器接头零件时工艺参数的确定。     

Comparative study and error analysis of digital elevation model interpolations

Researchers in P. R. China commonly create triangulate irregular networks （TINs） from contours and then convert TINs into digital elevation models （DEMs）. However, the DEM produced by this method can not precisely describe and simulate key hydrological features such as rivers and drainage borders. Taking a hilly region in southwestern China as a research area and using ArcGISTM software, we analyzed the errors of different interpolations to obtain distributions of the errors and precisions of different algorithms and to provide references for DEM productions. The results show that different interpolation errors satisfy normal distributions, and large error exists near the structure line of the terrain. Furthermore, the results also show that the precision of a DEM interpolated with the Australian National University digital elevation model （ANUDEM） is higher than that interpolated with TIN. The DEM interpolated with TIN is acceptable for generating DEMs in the hilly region of southwestern China.     

Computation of average run length for residual-based T 2 control chart for multivariate autocorrelated processes

The expression of residual is obtained according to its dynamic response to mean shift,then the distribution of T 2 statistic applied to the residual is derived,thus the probability of the T 2 statistic lying outside the control limit is calculated.The above-mentioned results are substituted into the infinite definition expression of the average run length(ARL),and then the final finite ARL expression is obtained.An example is used to demonstrate the procedures of the proposed method.In the comparative study,eight autocorrelated processes and four different mean shifts are performed,and the ARL values of the proposed method are compared with those obtained by simulation method with 50,000 replications.The accuracy of the proposed method can be illustrated through the comparative results.     

Special education transition issues over the past 60 years: social network analysis on Web of Science exploration

This research identified the potential special education transition development trajectories by tracing the priorities and hierarchical structure of published transition issues in special education. Social network analysis (SNA) of the 1900–2015 data from the Web of Science (WOS) database achieves a transition exploration flow by citation-based main path analysis (MPA). The first main finding was that 517 papers were published relating to special education transition over the past 60 years. Special education transition literature emerged in 1957, was systematically explored after 1987, and grew rapidly in the 1990s. The second main finding was that the trajectories contained various topics that can be broken down into two mainstream fields: curriculum and employment. The third main finding was that there are five sub-branches of the mainstream fields: legislation; team working; accountability; individualised transition programmes (ITP); and self-determination. This research is the first to use MPA techniques in SNA for special education transition. The findings indicate that more foci deserve to be explored to attain the transition working exhaustively and smooth transitions between each career stage for individuals with disabilities.     

LMI-based approach for global asymptotic stability analysis of continuous BAM neural networks

Studies on the stability of the equilibrium points of continuous bidirectional associative memory (BAM) neural network have yielded many useful results. A novel neural network model called standard neural network model (SNNM) is ad- vanced. By using state affine transformation, the BAM neural networks were converted to SNNMs. Some sufficient conditions for the global asymptotic stability of continuous BAM neural networks were derived from studies on the SNNMs’ stability. These co…     

利用复杂网络分析方法研究基因本体隐藏结构信息（英文）

为解决大规模本体理解问题,提出了一个从复杂网络分析的角度研究大规模本体结构信息和重要概念挖掘的方法.通过将基因本体的各种视图转换为网络进行全面分析,证明了整个基因本体具有明显的复杂网络特征,尤其是＂小世界特性＂和＂无标度特性＂;但其子本体的复杂网络特性没有这么明显,往往只具有＂无标度特性＂而没有＂小世界特性＂.同时,利用网络分析中常用的节点重要性度量算法对本体中的重要概念进行挖掘.在此基础上,提出了基于MEDLINE信息检索结果的概念重要性评价算法,评估几种节点重要性算法用于本体重要概念挖掘任务的正确性.实验结果表明介数中心性算法在各种节点重要性度量算法中最适合于本体重要概念挖掘.     

Finite element reliability analysis of slope stability

The method of nonlinear finite element reliability analysis （FERA） of slope stability using the technique of slip surface stress analysis （SSA） is studied. The limit state function that can consider the direction of slip surface is given, and the formulations of FERA based on incremental tangent stiffness method and modified Aitken accelerating algorithm are developed. The limited step length iteration method （LSLIM） is adopted to calculate the reliability index. The nonlinear FERA code using the SSA technique is developed and the main flow chart is illustrated. Numerical examples are used to demonstrate the efficiency and robustness of this method. It is found that the accelerating convergence algorithm proposed in this study proves to be very efficient for it can reduce the iteration number greatly, and LSLIM is also efficient for it can assure the convergence of the iteration of the reliability index.     

基于人工神经网络的等离子熔积层形貌试验研究

1IntroductionPlasma deposition manufacturing(PDM)is a newlydeveloped direct metal fabrication process based onplasma transferred arc surfacing[1],as shown in Fig.1.Unlike most existing rapid prototyping techn-ologies,this technique is characterized by sup…     

Stability analysis of discrete-time BAM neural networks based on standard neural network models

To facilitate stability analysis of discrete-time bidirectional associative memory (BAM) neural networks, they were converted into novel neural network models, termed standard neural network models (SNNMs), which interconnect linear dynamic systems and bounded static nonlinear operators. By combining a number of different Lyapunov functionals with S-procedure, some useful criteria of global asymptotic stability and global exponential stability of the equilibrium points of SNNMs were derived. These stability conditions were formulated as linear matrix inequalities (LMIs). So global stability of the discrete-time BAM neural networks could be analyzed by using the stability results of the SNNMs. Compared to the existing stability analysis methods, the proposed approach is easy to implement, less conservative, and is applicable to other recurrent neural networks.     

新完善的WAPI协议安全性分析

在深入研究中国无线局域网安全标准WAPI接入鉴别过程的基础上,利用CK模型并结合BAN逻辑,对其认证和密钥协商过程安全性进行了形式化分析,证明其能够实现所声称的各种认证及密钥协商目标.进一步的分析结果表明,WAPI不仅具有所声称的各种安全属性,同时还能够有效地实现实体间相互认证、密钥的相互控制、密钥确认、消息完整性校验等安全属性.如果协议中所采用的椭圆曲线加密算法和杂凑算法足够安全,则该协议能够实现STA和AP之间的相互身份认证,可以用于替代原来的无线局域网国际标准中的安全机制,以增强无线局域网的安全性.     

IPTV系统组成及关键技术

IPTV是一种集互联网、多媒体、通信等多种技术于一体的全新系统,在从内容制作到终端接收的整个实现过程中,涉及到包括编码、数字版权管理、内容分发网络、机顶盒等许多关键技术,本文对这些关键技术进行了详细介绍和分析,并针对现有IPTV集中交换模式的缺陷,提出了基于集中式P2P技术的IPTV系统,提高了IPTV服务质量和系统性能。     

Financing constraints and corporate investment: an empirical analysis of china''s manufacturing firms

With the measurement of dividend payout ratio, logistic regression index value and the firm size financing constraints, this paper investigated the investment behavior of China's manufacturing firms over the period from 1998 to 2003, and the relationship between financing constraints and corporate investment using the OLS regression method. The empirical evidence shows that there are certain extent financing constraints in China's manufacturing firms, but the results are different with different variables to measure the financing constraints.     

A path analysis of pre-service teachers' attitudes to computer use: applying and extending the technology acceptance model in an educational context

The purpose of this study is to examine pre-service teachers' attitudes to computers. This study extends the technology acceptance model (TAM) framework by adding subjective norm, facilitating conditions, and technological complexity as external variables. Results show that the TAM and subjective norm, facilitating conditions, and technological complexity were significant determinants of pre-service attitudes to computer use. A multiple square correlation revealed that the proposed model in this study explained 48.7% of the attitude to computer use. Various contributions to research and practice are discussed.