注塑机注射速度的模型预测迭代学习控制

针对注射过程具有重复运行和非线性的特性,在对预测控制与迭代学习控制进行综合应用并加以改进的基础上,给出一种模型预测迭代学习复合控制新算法,研究了控制器的设计方案.同时,将迭代学习思想引入到预测步长的在线调整,提出了预测步长的迭代学习方法.仿真结果表明,该方法是有效的,其控制性能优于PID迭代学习控制系统.     

On guiding the augmentation of an automated test suite via mutation analysis

Mutation testing has traditionally been used as a defect injection technique to assess the effectiveness of a test suite as represented by a “mutation score.” Recently, mutation testing tools have become more efficient, and industrial usage of mutation analysis is experiencing growth. Mutation analysis entails adding or modifying test cases until the test suite is sufficient to detect as many mutants as possible and the mutation score is satisfactory. The augmented test suite resulting from mutation analysis may reveal latent faults and provides a stronger test suite to detect future errors which might be injected. Software engineers often look for guidance on how to augment their test suite using information provided by line and/or branch coverage tools. As the use of mutation analysis grows, software engineers will want to know how the emerging technique compares with and/or complements coverage analysis for guiding the augmentation of an automated test suite. Additionally, software engineers can benefit from an enhanced understanding of efficient mutation analysis techniques. To address these needs for additional information about mutation analysis, we conducted an empirical study of the use of mutation analysis on two open source projects. Our results indicate that a focused effort on increasing mutation score leads to a corresponding increase in line and branch coverage to the point that line coverage, branch coverage and mutation score reach a maximum but leave some types of code structures uncovered. Mutation analysis guides the creation of additional “common programmer error” tests beyond those written to increase line and branch coverage. We also found that 74% of our chosen set of mutation operators is useful, on average, for producing new tests. The remaining 26% of mutation operators did not produce new test cases because their mutants were immediately detected by the initial test suite, indirectly detected by test suites we added to detect other mutants, or were not able to be detected by any test.

通信芯片电压故障注入测试与功能安全评估方法

芯片是现代信息技术的核心和基础,芯片的功能安全在确保电子技术的可靠性方面发挥着重要作用。本研究以CAN通信芯片为对象,提出了一种基于电压故障注入的芯片功能安全评估方法。通过基于原型系统的自动化硬件故障注入测试,并结合自动触发信号与控制模块的设计,完善了目前CAN芯片安全性测试技术和功能实现上的不足。另外,基于该CAN芯片测试结果,提出了芯片对故障因素敏感的功能安全评估依据。结果表明,该电路通信芯片的某些管脚对标准工作电压范围下输入电压的幅值、脉宽和延迟毛刺较敏感。测试电路系统能够自动实现1.5~5.5 V大范围工作电压下的随机错误注入,以及错误要素敏感度分析,为提高通信芯片安全性提供更高效的评估依据。     

Reliable control strategy based on sliding mode observer against FDI attacks in smart grid

This paper is concerned with the reliable operation of cyber-physical systems under false data injection attacks. First of all, a robust adaptive sliding mode observer is designed to estimate the state of the power system; different from the traditional sliding mode observer, the observer we designed is not only robust to state errors but also can automatically adjust the parameter of attack identification. Secondly, a method of attack reconstruction has been given to estimate the actual attack signal. Finally, a reliable sliding mode control strategy is proposed to eliminate the impact of false data injection attacks; compared with the existing results, the designed defense strategy utilizes the reconstructed attack signal in the attack identification scheme and state error signal at the same time. Moreover, a power system with 3 generator buses and 6 load buses is taken as an simulation example to verify the availability of the proposed control strategy.     

基于Ⅳ-Ⅵ族化合物的胶体量子点太阳电池研究进展

基于Ⅳ-Ⅵ族化合物的胶体量子点具有易于合成、带隙可调等优点,被认为是一种非常有前途的窄带隙光伏材料。近年来,利用Ⅳ-Ⅵ族化合物制作的胶体量子点太阳电池最高转换效率已经突破10%。介绍了胶体量子点的合成方法、基本结构及其光电特性;着重分析了国内外关于肖特基和异质结胶体量子点太阳电池的研究现状,指出了目前该领域研究中存在的问题和发展趋势,并分析了未来需要重点解决的关键问题。     

电镀塑料制品对结构设计及成形工艺的要求

为保证电镀塑料制品的质量,提出了符合电镀要求的塑料制品设计原则,并且指出在注塑成形时,对塑料经过充分干燥,采用较高的注塑温度,较低的注射压力和较慢的注射速度,是使镀层获得良好结合强度的先决条件。     

An MRAS method for sensorless control of induction motor over a wide speed range

This paper addresses the problem of wide speed range sensorless control of induction motor.The proposed method is based on model reference adaptive system (MRAS),in which the current model serves as the adjustable model,and a novel hybrid model integrating the modified voltage model (MVM) and high-frequency signal injection method (HFSIM) are established to serve as the reference model.The HFSIM works together with MVM to improve the performance of the rotor speed and rotor flux position estimation at low speed,whereas at high speed,the MVM acts alone.In addition,a rotor resistance online estimation scheme is proposed to update the rotor resistance contained in the adjustable model and to ensure the estimation accuracy further.Experimental results show that the proposed MRAS method is very effective from low to high speed range,including zero speed.     

Web应用程序中SQL注入攻防策略的研究

当前全球进入网络信息一体化时代,网络信息安全问题应运而生。从列举日趋高发的SQL注入攻击事件入手,阐述了SQL注入攻击概念、特点,然后通过一个实例讲解了攻击的一般过程,最后按照从程序开发到应用这个顺序,提出了We b应用程序防御SQL注入攻击的全过程安全策略。     

政府网站运行的安全性问题研究

本文以政府部门计算机网络和网站在运行中碰到的安全问题,阐述了如何建设相对安全的网控中心,并对因特网上发布信息的网站所受到的各种攻击作出了说明,以及如何采用各种技术方法和措施填补漏洞、防范攻击,保障网站安全。