BPEL(business process execution language)是一种可执行的Web服务组合语言.与传统程序相比,BPEL程序在编程模型、执行方式等方面存在较大差异.这些新特点使得如何定位并修改测试阶段发现的BPEL程序故障成为挑战,面向传统软件的故障修...BPEL(business process execution language)是一种可执行的Web服务组合语言.与传统程序相比,BPEL程序在编程模型、执行方式等方面存在较大差异.这些新特点使得如何定位并修改测试阶段发现的BPEL程序故障成为挑战,面向传统软件的故障修复技术难以直接应用于BPEL程序.从变异分析角度出发,提出一种基于模板匹配的BPEL程序故障修复方法BPELRepair.为了克服基于变异分析的故障修复技术计算开销高的缺点,从补丁生成、测试用例选择以及终止条件3个角度提出多种优化策略.开发一个BPEL故障修复支持工具,提高故障修复的自动化程度与效率.采用经验研究的方式,评估所提故障修复技术及优化策略的有效性.实验结果表明,所提故障修复方法能够成功修复约53%的BPEL程序故障;所提优化策略能够显著降低搜索匹配、补丁程序验证、测试用例执行与故障修复等方面的开销.展开更多
In many areas, reliability of the digital circuits has become the key factor to restrict circuit development. Fault-tolerant design is the commonly used method to improve the reliability of digital circuits. The curre...In many areas, reliability of the digital circuits has become the key factor to restrict circuit development. Fault-tolerant design is the commonly used method to improve the reliability of digital circuits. The current fault-tolerant design methods are based on triple modular redundancy( TMR) or multiple modular redundancy( MMR). These redundancy designs rely on the experience of the designers,and the designed circuits have poor adaptabilities to a complex environment. However, evolutionary design of digital circuits does not rely on prior knowledge. During the evolution, some novel and optimal circuit topologies can be found, and the evolved circuits can feature strong adaptive capacities. Based on Cartesian genetic programming( CGP), a novel method for designing fault-tolerant digital circuits by evolution is proposed,key steps of the evolution are introduced,influences of function sets on evolution are investigated,and as a preliminary result,an evolved full adder with high fault-tolerance is shown.展开更多
在工业物联网的某些故障诊断场景中,由于缺少电信网络覆盖,采集信号通过远距离无线电(Long Range Radio,LoRa)技术实现无线可靠回传,但其较低的传输速率会限制故障诊断的精度。针对LoRa窄带宽的技术限制,提出了采样频率和量化分辨率固...在工业物联网的某些故障诊断场景中,由于缺少电信网络覆盖,采集信号通过远距离无线电(Long Range Radio,LoRa)技术实现无线可靠回传,但其较低的传输速率会限制故障诊断的精度。针对LoRa窄带宽的技术限制,提出了采样频率和量化分辨率固定条件下的时域信号非均匀量化方案。首先,通过建立基于核密度估计(Kernel Density Estimation,KDE)的非参数拟合模型,重点研究了带宽受限场景中合适的核函数类型和带宽确定准则,拟合生成传感信号幅度的概率密度函数(Probability Density Function,PDF)。其次,以PDF为输入,以最小化量化噪声为目标函数,通过非线性规划,输出最佳的一组非均匀量化电平值。其特点在于针对出现频次最高的时域幅度,采用更小的量化间隔,实现量化噪声的最小化。最后,以轴流风机状态检测为例进行了实验,结果表明,基座松动和轴承故障对量化电平的影响更大。随着量化分辨率的增加,KDE量化逐渐趋近均匀量化,相较于高斯量化的优势逐渐缩小。因此,提出的KDE量化方案适合窄带宽条件下的非均匀量化,可提高信道利用率,并在传输带宽和量化噪声之间取得折中。展开更多
A common software to analyze fuze fault tree is developed to simplify the trivialness in generating the fuze fault tree and reduce the manual calculation work. The overall structure, function and implementation of the...A common software to analyze fuze fault tree is developed to simplify the trivialness in generating the fuze fault tree and reduce the manual calculation work. The overall structure, function and implementation of the system are introduced. The software based on Windows platform is used to generate the fuze fault tree in graphics mode. A quantitative analysis of fuze fault tree can be obtained by the method of minimum cut sets. A calculation example is used to verify the function of the software. Consequently, the expected requirements of this software system are achieved to a certain level.展开更多
A variety of Software Reliability Growth Models (SRGM) have been presented in literature. These models suffer many problems when handling various types of project. The reason is;the nature of each project makes it dif...A variety of Software Reliability Growth Models (SRGM) have been presented in literature. These models suffer many problems when handling various types of project. The reason is;the nature of each project makes it difficult to build a model which can generalize. In this paper we propose the use of Genetic Programming (GP) as an eVolutionary computation approach to handle the software reliability modeling problem. GP deals with one of the key issues in computer science which is called automatic programming. The goal of automatic programming is to create, in an automated way, a computer program that enables a computer to solve problems. GP will be used to build a SRGM which can predict accumulated faults during the software testing process. We evaluate the GP developed model and compare its performance with other common growth models from the literature. Our experiments results show that the proposed GP model is superior compared to Yamada S-Shaped, Generalized Poisson, NHPP and Schneidewind reliability models.展开更多
文摘BPEL(business process execution language)是一种可执行的Web服务组合语言.与传统程序相比,BPEL程序在编程模型、执行方式等方面存在较大差异.这些新特点使得如何定位并修改测试阶段发现的BPEL程序故障成为挑战,面向传统软件的故障修复技术难以直接应用于BPEL程序.从变异分析角度出发,提出一种基于模板匹配的BPEL程序故障修复方法BPELRepair.为了克服基于变异分析的故障修复技术计算开销高的缺点,从补丁生成、测试用例选择以及终止条件3个角度提出多种优化策略.开发一个BPEL故障修复支持工具,提高故障修复的自动化程度与效率.采用经验研究的方式,评估所提故障修复技术及优化策略的有效性.实验结果表明,所提故障修复方法能够成功修复约53%的BPEL程序故障;所提优化策略能够显著降低搜索匹配、补丁程序验证、测试用例执行与故障修复等方面的开销.
基金National Natural Science Foundations of China(Nos.61271153,61372039)
文摘In many areas, reliability of the digital circuits has become the key factor to restrict circuit development. Fault-tolerant design is the commonly used method to improve the reliability of digital circuits. The current fault-tolerant design methods are based on triple modular redundancy( TMR) or multiple modular redundancy( MMR). These redundancy designs rely on the experience of the designers,and the designed circuits have poor adaptabilities to a complex environment. However, evolutionary design of digital circuits does not rely on prior knowledge. During the evolution, some novel and optimal circuit topologies can be found, and the evolved circuits can feature strong adaptive capacities. Based on Cartesian genetic programming( CGP), a novel method for designing fault-tolerant digital circuits by evolution is proposed,key steps of the evolution are introduced,influences of function sets on evolution are investigated,and as a preliminary result,an evolved full adder with high fault-tolerance is shown.
文摘主要探讨在自动化生产线中,可编程逻辑控制器(Programmable Logic Controller,PLC)编程的关键技巧及其应用。通过分析不同类型的生产线需求,着重介绍了PLC编程在提高生产效率、确保系统稳定性和提升自动化程度方面的作用。首先,讨论了PLC编程在设计和实施过程中的基本原则,包括模块化设计、代码优化和错误处理。其次,深入分析了如何利用PLC进行故障诊断和系统维护,以减少停机时间并提升生产连续性。再次,还探讨了先进的PLC编程技术,如数据采集和分析,以及如何集成到物联网(Internet of Things,IoT)中以提升智能制造水平。最后,通过案例研究展示了PLC编程在实际生产线中的应用效果,证明了其在优化生产流程和提高效率方面的重要性。
文摘在工业物联网的某些故障诊断场景中,由于缺少电信网络覆盖,采集信号通过远距离无线电(Long Range Radio,LoRa)技术实现无线可靠回传,但其较低的传输速率会限制故障诊断的精度。针对LoRa窄带宽的技术限制,提出了采样频率和量化分辨率固定条件下的时域信号非均匀量化方案。首先,通过建立基于核密度估计(Kernel Density Estimation,KDE)的非参数拟合模型,重点研究了带宽受限场景中合适的核函数类型和带宽确定准则,拟合生成传感信号幅度的概率密度函数(Probability Density Function,PDF)。其次,以PDF为输入,以最小化量化噪声为目标函数,通过非线性规划,输出最佳的一组非均匀量化电平值。其特点在于针对出现频次最高的时域幅度,采用更小的量化间隔,实现量化噪声的最小化。最后,以轴流风机状态检测为例进行了实验,结果表明,基座松动和轴承故障对量化电平的影响更大。随着量化分辨率的增加,KDE量化逐渐趋近均匀量化,相较于高斯量化的优势逐渐缩小。因此,提出的KDE量化方案适合窄带宽条件下的非均匀量化,可提高信道利用率,并在传输带宽和量化噪声之间取得折中。
文摘A common software to analyze fuze fault tree is developed to simplify the trivialness in generating the fuze fault tree and reduce the manual calculation work. The overall structure, function and implementation of the system are introduced. The software based on Windows platform is used to generate the fuze fault tree in graphics mode. A quantitative analysis of fuze fault tree can be obtained by the method of minimum cut sets. A calculation example is used to verify the function of the software. Consequently, the expected requirements of this software system are achieved to a certain level.
文摘A variety of Software Reliability Growth Models (SRGM) have been presented in literature. These models suffer many problems when handling various types of project. The reason is;the nature of each project makes it difficult to build a model which can generalize. In this paper we propose the use of Genetic Programming (GP) as an eVolutionary computation approach to handle the software reliability modeling problem. GP deals with one of the key issues in computer science which is called automatic programming. The goal of automatic programming is to create, in an automated way, a computer program that enables a computer to solve problems. GP will be used to build a SRGM which can predict accumulated faults during the software testing process. We evaluate the GP developed model and compare its performance with other common growth models from the literature. Our experiments results show that the proposed GP model is superior compared to Yamada S-Shaped, Generalized Poisson, NHPP and Schneidewind reliability models.
