基于MATLAB/VB的网络故障诊断软件设计

将VB调用Matlab的方法应用到基于神经网络的网络故障诊断系统软件的设计中;以VB编写诊断系统的主界面,利用ActiveX技术调用Matlab神经网络工具箱完成对网络故障的诊断,将两者的优势有机结合,从而缩短了程序开发周期,减少了程序员的工作量;该软件具有良好人机交互界面,便于网管人员的学习和掌握,且实例验证表明利用VB调用Matlab方法开发的网络故障诊断系统,其诊断结果可靠,能够满足网络实时故障诊断的要求.     

Automated extraction of PCB components based on specularity using layered illumination

This paper investigates the methodologies for locating and identifying components on a printed circuit board (PCB) used for surface mount device inspection. It’s the foundation of other inspections, such as solder joint inspection, component type recognization and so on. The proposed scheme consists of two stages: solder joint extraction and protective coating extraction. This work uses automatic multilevel thresholding approach for detecting specular areas which contain solder joints. Some invalid specular areas, such as markings and via-holes are recognized and removed by comparing the colour distribution features of the target objects and the reference objects. A novel approach based on connection graph and the segmented gray-scale PCB images is developed to classify all recognized solder joints as several clusters. And then, the protective coating is extracted by the positions of the clustered solder joints. Experimental results show that the proposed method can recognize most of components effectively.     

我国仪器仪表与测量控制科技的发展

从战略高度,深刻全面地论述了仪器仪表与测量控制在当今社会的重要地位和作用、我国仪器仪表与测量控制的基本概况以及今后发展的趋势和特点,特别指出我国工业自动化仪表与控制系统以及科学仪器未来发展的关注点.同时,阐述了我国仪器仪表与测量控制近年来的重大进展,指明了我国仪器仪表与测量控制自主创新发展的方向.     

工业控制系统信息安全审计系统分析与设计

目前工业控制系统(Industrial Control System,ICS)广泛应用于电力、水利、交通运输、大型制造行业以及国家基础公共设施,已经成为国家安全战略的重要部分。 传统的信息安全防护技术(如防火墙技术、入侵检测技术等)因其技术原理和适用协议的差异,使工业控制系统不能取得很好的防范效果。为了有效地提高ICS的安全防护能力,该文针对ICS的数据特点以及协议特点设计了一款ICS信息安全审计系统,该审计系统主要由数据采集模块、内容检测模块、异常行为判断模块、行为处理模块、审计响应模块等组成。实验结果表明,本系统能够对ICS进行全方位的安全审计,能够极大程度地提高ICS的安全防护能力。     

Sensitivity analysis of important parameters affecting contact pressure between a respirator and a headform

Respirator comfort and fit are two important parameters for respirator design, usage, and standard development. The contact pressure (as measured between a respirator and the wearer) plays an important role in comfort and fit. This work attempts to investigate the contact mechanism and factors that affect the contact pressure. This paper focuses on mechanical factors such as strap tension, strap orientation, strap location, friction, and seal material. A finite element (FE) model-based method was developed to assess the contact pressure. The FE models for both the headform and the respirator have multiple layers. The headform is a medium size headform developed by the National Institute for Occupational Safety and Health (NIOSH) and the respirator is an MSA Affinity Ultra respirator. The results show that the positive Z directional force of strap tension that forces the respirator to move towards the headform is the most important parameter for measuring pressure distribution. Other factors such as strap orientation, friction, strap location, and softness of the seal material were found to affect the contact pressure distribution in this study. Strap orientation and friction coefficient have no significant effect on maximum pressure and maximum shear stress. The dispersive strap location increased the contact pressure on the nose-bridge area of the wearer, while concentrated location had no considerable effect on contact pressure. A softer seal material causes larger deformations and transfers the location of the maximum pressure from the nose-bridge to the tip of the nose.

Relevance to industry

This study investigates the effect of important parameters on contact pressure between a respirator and a headform. The sensitivity analysis can provide insights of the interaction between a respirator and a headform. The findings are critical to respirator designers, users, and standard developers to ensure maximal respirator fit and comfort.     

基于Web的企业内部质量审核系统设计与实现

通过对基于Ｗｅｂ的企业内部质量审核系统的设计和实现,研究基于Ｗｅｂ的应用系统开发中的系统分析方法、实现环境和开发工具等。     

软件可靠性及其评估

介绍了软件可靠性问题的来源,阐述了软件可靠性的定义、软件的失效机理、及软件可靠性与硬件可靠性间的差异,并提出了基于模糊数算术运算的软件可靠性估计方法。     

长期施用含氮化肥对大豆生育及养分吸收的影响

从1984年起,在沈阳农业大学棕壤上没有氮化肥长期定位试验。结果表明,长期施用含氯化肥在大豆整个生育期内可促进株高、茎粗、根系等地上部及地下部的生长,氯对大豆氮、磷养分的吸收无明显影响,对钾的吸收有 促进作用。     

基于Windows NT局域网络全真模拟Internet操作测试功能的实现

文章介绍一种基于Ｗｉｎｄｏｗｓ ＮＴ局域网络,在Ｗｉｎｄｏｗｓ ９５／９８平台上使用的全真模拟Ｉｎｔｅｒｎｅｔ操作测试功能的实现方案,重点介绍了题库工作表结构,全真模拟Ｉｎｔｅｒｎｅｔ环境,操作考核主页设计及其相关技术要点。