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李世平 《系统工程与电子技术》1992,(11)
本文讨论研究了系统跳变参数估计的故障诊断方法。利用卡尔曼滤波法检测及估计跳变参数,从而减少了系统模型参数辨识的计算量。通过选择跳变模型参数集、非跳变模型参数集以及基于知识的方法,减少方程p=f~(-1)(θ)的待求变量数量,提高了故障定位速度。用广义Newton—Raphson方法求解故障定位方程,保证了较高的故障定位精度。 相似文献
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基于RBF网络和ARX模型的液压系统故障诊断方法 总被引:3,自引:0,他引:3
提出了基于径向基函数(Radial Basis Function,RBF)网络和有源自回归(Auto-Regressive with Extra Inputs,ARX)模型的液压系统的故障诊断方法.作为一种性能优越的网络分类器,RBF网络比传统的反向传播(Back Propagation,BP)网络表现出更好的分类效果,非常适合于故障特征识别.故障诊断方法首先针对目标故障状态建立 ARX模型,提取 ARX 模型的自回归系数作为故障特征向量.然后将故障特征向量作为RBF网络训练样本,建立RBF网络故障分类器,进一步根据RBF网络的输出结果来判断故障的类型.通过建立挖掘机铲斗部分液压系统仿真模型,验证了于基于RBF网络和 ARX 模型的故障诊断方法的有效性. 相似文献
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针对线性时不变系统提出了一种基于故障跟踪估计器的故障诊断新方法。首先引入一个可调参数,称作虚拟故障,构建线性时不变系统的故障跟踪估计器。然后,设计迭代学习算法,在选取的优化周期内通过反复迭代学习运算来动态调节虚拟故障,使之估计出系统中实际发生的故障。该方法可以同时检测和估计出系统中发生的故障,而且和发生的故障类型无关。最后,在垂直升降飞行器的线性化模型上进行了仿真研究,仿真结果表明了所设计算法的可行性和有效性。 相似文献
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介绍了几种常用的故障诊断方法:广义似然比法(GLT)、均值检验法,以及局部估计方法。以六陀螺冗余惯性组件为平台,验证了这几种方法在检测小故障时实际应用的不同效果,分析了影响各自检测能力及故障时延的原因及在工程应用中的优缺点,并对小故障检测能力、故障检测时延和实时计算量这几项指标进行了比较研究。 相似文献
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Lü Min 《系统工程与电子技术(英文版)》2008,19(3)
To study the uncertain optimization problems on implementation schedule, time-cost trade-off and quality in enterprise resource planning (ERP) implementation, combined with program evaluation and review technique (PERT), some optimization models are proposed, which include the implementation schedule model, the timecost trade-off model, the quality model, and the implementation time-cost-quality synthetic optimization model. A PERT-embedded genetic algorithm (GA) based on stochastic simulation technique is introduced to the optimization models solution. Finally, an example is presented to show that the models and algorithm are reasonable and effective, which can offer a reliable quantitative decision method for ERP implementation. 相似文献
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A calculus for services innovation 总被引:1,自引:1,他引:0
Innovation in the services area - especially in the electronic services (e-services) domain - can be systematically developed by first considering the strategic drivers and foci, then the tactical principles and enablers, and finally the operational decision attributes, all of which constitute a process or calculus of services innovation. More specifically, there are four customer drivers (i.e., collaboration, customization, integration and adaptation), three business foci (i.e., creation-focused, solution-focused and competition-focused), six business principles (i.e., reconstruct market boundaries, focus on the big picture not numbers, reach beyond existing demand, get strategic sequence right, overcome organizational hurdles and build execution into strategy), eight technical enablers (i.e., software algorithms, automation, telecommunication, collaboration, standardization, customization, organization, and globalization), and six attributes of decision informatics (i.e., decision-driven, information-based, real-time, continuously-adaptive, customer-centric and computationally-intensive). It should be noted that the four customer drivers are all directed at empowering the individual - that is, at recognizing that the individual can, respectively, contribute in a collaborative situation, receive customized or personalized attention, access an integrated system or process, and obtain adaptive real-time or just-in-time input. The developed process or calculus serves to identify the potential white spaces or blue oceans for innovation. In addition to expanding on current innovations in services and related experiences, white spaces are identified for possible future innovations; they include those that can mitigate the unforeseen consequences or abuses of earlier innovations, safeguard our rights to privacy, protect us from the always-on, interconnected world, provide us with an authoritative search engine, and generate a GDP metric that can adequately measure the growing knowledge economy, 相似文献
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论生物系统中的功能不守恒性 总被引:1,自引:0,他引:1
张知彬 《复杂系统与复杂性科学》2004,1(2):43-51
根据能量守恒定律,能量一次转换所做的总功应等于输入的总能量。但在生物系统中,能量的转换是多次的,其总功之和大于系统输入的总能量,此现象称之为功能不守恒性。能量转换效率越高,功能差别越大。能量通过细胞水平的多次转换,总功可提高至2倍左右。能量通过生态系统水平多次转换,总功可提高至1.4倍左右。通过系统内各子系统能流之和称为序能,反映了系统有序性大小,它取决于系统输入总能量和能量转换效率。根据序能原理,用GDP^2/9(GDP为国内生产总值,Q为能量总输入)反映人类社会功能和效率,要比单纯用GDP更客观。绿色GDP应同时考虑使GDP^2/Q增长最大和使自然生态系统的序能最大。人的经济行为和动物的行为对策也符合序能原理。 相似文献
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This paper is about the Wuli, Shili, Renli (WSR) systems methodology. An important concept within this, Renli, has been developed from Confucian philosophy to clarify to Chinese researchers the necessity of dealing with human relations in systems practice. At present, the only formal means of operationalizing Renli that people are exploring in China is to import from the West methods for organizing debate. However, the concept of Renli suggests that more is needed than methods alone. In particular, facilitation skills are required. It is argued that the development of facilitation skills can be enhanced if researchers can gain both theoretical and practical knowledge of group dynamics, and engage in activities of self-reflection to look at, and alter, their own roles in these dynamics and the wider sociopolitical system. There are therefore three aspects to Renli: the use of systems methods for organizing debate, the acquisition of facilitation skills, and self-reflection geared toward the development of facilitation skills and enhanced critical awareness of the politics of intervention. 相似文献
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李弋 《系统工程理论与实践》2011,(Z2):70-74
随着云计算的发展,新的应用不断涌现,但电子邮件服务依然占有着重要的地位.邮件服务器是一种I/O密集的应用.在云计算时代,越来越多的用户邮件保存在服务器端,邮件在从客户端传输到服务器端之前,邮件或者邮件的部分内容在服务器端可能已经存在.基于这种现象,提出了一种方案,通过引入计算的代价来降低通信量,从而提高邮件服务器的处理能力.对电子邮件的格式和SMTP协议进行了扩充,引入了附件和正文分离传输的模式.在邮件传输时,客户端先计算附件的散列值,并作为正文的一部分传输到服务器端,服务器端再根据散列值来判断附件是否需要传输. 相似文献
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金工工艺的优化设计 总被引:2,自引:0,他引:2
邹庆化 《系统工程理论与实践》1996,10(11):106-112
运用价值工程与运筹工程理论, 在金工工艺单项设计指标优化的基础上, 对其设计指标也进行了全面优化。 相似文献
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《系统工程理论与实践》2014,(4)
正August 10-14,2015Beijing,China The International Congress on Industrial and Applied Mathematics(IClAM)is the premier international congress in the field ofapplied mathematics held every four years under the auspices ofthe International Council for Industrial and Applied Mathematics.From August 10 to 14,2015,mathematicians,scientists and entrepreneurs fiom around the world will gather in Beijing,China for the 8th IClAM to be held at 相似文献