Representation of functional micro-knowledge cell (FMKC) for conceptual design

The conceptual design process of a complex product concerns multidisciplinary design knowledge. This paper presents an approach of consistent knowledge representation for conceptual design. Firstly, the concept of functional micro-knowledge cell (FMKC) is presented, and the knowledge representation approach of FMKC is proposed. In the function layer, the functional ontology is used to provide a rich vocabulary. By constructing the mapping relationships between the function and structure layer, a systematic knowledge representation scheme is obtained. Secondly, the functional knowledge decomposition theory is proposed to unify the resolution of knowledge representation. Finally, the FMKC is applied to a hydraulic cylinder, which demonstrates the possibility in representing the multidisciplinary knowledge for conceptual design with a unified systematic representation scheme. In addition, the FMKC can be used in knowledge fusion and design reuse for our further study.     

基于移动最小二乘的传感器数据重构

纳米气体传感器的灵敏度易受温度变化的影响.为了有效改善纳米传感器的温度特性,方便确定其最佳工作条件,利用移动最小二乘法对其灵敏度-温度数据进行拟合,并建立相应的近似模型.移动最小二乘法通过紧支性加权的局部近似,使所建模型较常规最小二乘模型更精确、更光滑.实验证实了基于移动最小二乘拟合的近似性能.该方法在传感器数据精确重构领域具有良好的应用前景.     

高速突发模式误码测试仪的FPGA实现方案

突发模式误码测试仪与一般连续误码测试仪不同,其接收端在误码比对前要实现在十几位内,对具有相位跳变特点的信号进行时钟提取和数据恢复,并且在误码比对时须滤除前导码和定界符,仅对有效数据进行误码统计。本文提出一种基于FPGA实现的高速突发模式误码测试仪设计方案,并介绍该方案的总体设计过程,以及FPGA中主要功能逻辑模块的工作原理和控制系统的设计。该测试仪应用于1.25GHz GPON系统突发式光接收模块的误码测试中,具有较好的性能和实际意义。     

Effects of Perceived Interactivity,Perceived Web Assurance and Disposition to Trust on Initial Online Trust

We developed an interdisciplinary model to examine how online consumers' perceived interactivity, perceived Web assurance and disposition to trust affect their initial online trust. Perceived interactivity is theorized as an interpersonal‐based antecedent, disposition to trust as a personality‐based antecedent, and perceived Web assurance as an institution‐based antecedent to initial online trust. Results indicate that both consumers' perceived interactivity and perceived Web assurance positively influence their initial online trust. Therefore, it is of importance that e‐vendors make efforts to enhance online consumers' perceived interactivity of their Web sites as well as addressing consumers' major trust concerns by adopting third‐party Web assurance seals.     

Globally Exponential Stability for Delayed Neural Networks Under Impulsive Control

In this paper, the dynamic behaviors of a class of neural networks with time-varying delays are investigated. Some less weak sufficient conditions based on p-norm and ∞-norm are obtained to guarantee the existence, uniqueness of the equilibrium point for the addressed neural networks without impulsive control by applying homeomorphism theory. And then, by utilizing inequality technique, Lyapunov functional method and the analysis method, some new and useful criteria of the globally exponential stability with respect to the equilibrium point under impulsive control we assumed are derived based on p-norm and ∞-norm, respectively. Finally, an example with simulation is given to show the effectiveness of the obtained results.     

Modeling group structures in pedestrian crowd simulation

Grouping is a common phenomenon in pedestrian crowds and plays important roles in affecting crowd behavior. Group modeling is still an open challenging problem and has not been incorporated by existing crowd simulation models. Motivated by the need of group modeling for crowd behavior simulation, this paper presents a unified and well-defined framework for modeling the structure aspect of different groups in pedestrian crowds. Both intra-group structure and inter-group relationships are considered and their effects on the crowd behavior are modeled. Based on this framework, an agent-based crowd simulation system is developed and crowd behavior simulations using two different group structures are presented. The simulation results show that the developed framework allows different group structures to be easily modeled. Besides, different group sizes, intra-group structures and inter-group relationships can have significant impacts on crowd behaviors.     

Optimization of forging processes using Finite Element simulations

During the last decades, simulation software based on the Finite Element Method (FEM) has significantly contributed to the design of feasible forming processes. Coupling FEM to mathematical optimization algorithms offers a promising opportunity to design optimal metal forming processes rather than just feasible ones. In this paper Sequential Approximate Optimization (SAO) for optimizing forging processes is discussed. The algorithm incorporates time-consuming nonlinear FEM simulations. Three variants of the SAO algorithm—which differ by their sequential improvement strategies—have been investigated and compared to other optimization algorithms by application to two forging processes. The other algorithms taken into account are two iterative algorithms (BFGS and SCPIP) and a Metamodel Assisted Evolutionary Strategy (MAES). It is essential for sequential approximate optimization algorithms to implement an improvement strategy that uses as much information obtained during previous iterations as possible. If such a sequential improvement strategy is used, SAO provides a very efficient algorithm to optimize forging processes using time-consuming FEM simulations.     

一种基于多串口卡的中波发射机监控系统

提出基于多串口卡实现低成本的中波发射机通用实时监控方案;基于Windows API实现了多串口卡数据收发模块,并将中波发射机所需采集的模拟量、状态量以及执行命令分成实时数据和非实时数据两类,对这两类数据采用不同的采集频次,实现用户对实时数据监控的要求;对各发射机设备进行数据采集时采用了统一发送-流水接收的处理方式,即统一地给各发射机发送数据采集命令,而以流水的方式依次处理接收数据,提高数据采集的效率;监控系统在Delphi7.0+SQL2000平台下实现,实际运行表明,该监控方案是有效的。     

无线传感网络温湿度采集系统的设计及实现

一直以来,低功耗以及远距离传输是无线传感器网络多点测量的两大不足,成为阻碍其进一步普及的瓶颈;利用无线传感网络分布式多点测量的特点,设计了基于IRIS节点无线传感网络的温湿度采集系统,介绍了系统整体框架和软件体系的设计及实现过程,并进行了温湿度采集实验;实验结果表明,节点可通过无线通信方式形成一个多跳的自组织网络系统,网络具有自愈功能,节点能够精确地采集和处理温湿度数据,节点间可以成功地进行通信,具有低功耗和远距离传输的优点.     

基于词性的文本挖掘算法在IDS日志中的应用

提出一种以词性为参考值的文本挖掘算法,能有效挖掘与种子词有关的关联规则。基于Bootstrapping算法思想,既减少了预处理阶段对于词根还原的依赖,能处理日志中出现的中文词汇。增加了对于日志文本上下的理解,提高了关联规则的有效性,并应用与IDS日志挖掘之中,有效改善挖掘效率,为规则库提供关联规则。