故障预测与健康管理系统验证与确认方法综述

介绍了故障预测与健康管理验证与确认的研究动机,说明了该方法在整个系统设计中的地位;将验证和确认方法分为三大支撑技术：验证方法与性能评估、原型验证系统和不确定性管理,综述了这三种支撑技术的现有方法,分析比较了各方法的区别和联系,指出了具体的实现途径;点明了故障预测与健康管理系统验证与确认方法要关注的问题,明确了未来的发展趋势。     

某型惯性测量组合故障传播机理与建模分析

惯性测量组合(IMU)是航空机电控制系统中的关键部件,其易发生故障,且故障会在各功能单元之间进行传播.IMU中存在着故障传播路径复杂多样性和故障传播不确定性的问题,这两个问题使IMU中的故障传播过程难以描述.针对该问题,在对某型IMU故障传播机理进行分析的基础上,提出了一种将多信号流图与故障扩散强度函数相结合的模型构建...     

GIS属性数据不确定性及其传播研究

属性数据的不确定性直接影响地理信息系统(GIS)分析决策结果的准确性和可靠性。将GIS属性数据的整个生命周期分成数据采集与准备、数字化信息提取、信息综合和属性数据表达等阶段,研究属性数据不确定性在各阶段的传播,构造其传播模型,提出属性数据不确定性的合成算法与传播算法,实验结果验证了该模型的可用性与有效性。     

图像纹理特征数据挖掘的不确定性分析

不确定性分析是数据挖掘与知识发现的重要内容,对图像纹理特征数据挖掘的基本原理进行了分析、解释,从问题的求解、数据的产生、挖掘的过程以及最终的结果等几个角度分析了图像纹理特征数据挖掘中的不确定性,并讨论了目前不确定性问题分析与处理的若干方法,引入不确定性分析的有力工具--云模型,研究图像纹理特征数据挖掘中的不确定性,并给出了实验结果及分析.     

基于不确定性的故障预测方法综述

故障预测是实现视情维修策略的基础. 不确定性问题在故障预测中普遍存在, 对此, 总结了基于不确定性的故障预测方法的关键问题, 并以不确定性属性的特点将现有故障预测方法分为基于随机性、模糊性、灰性及混合不确定性等4 类. 综述了各类方法的研究现状与不足, 并展望了基于不确定性的故障预测方法的发展趋势, 探讨了基于区间不确定性的故障预测方法的可行性.

     

不确定性与自然计算并行性的内在关联

不确定性是量子力学中已获得证明的自然界基本规律。通过分析自然算法中的并行性与不确定性的内在关联认为,不确定性不但是并行性产生的根源,还是算法智能产生的根源。根据这一认识给出了算法的不确定性原理,并结合Shannon的信息熵原理建立了自然计算的不确定性智能模型(UIM)。这一模型认为先验知识信息和由不确定性所提供的信息共同构成了智能系统的基本模型。智能系统本质上就是一个信息系统,先验知识信息保证算法按正确的方向进行搜索,不确定性所提供的信息实现了算法对解空间的并行搜索,通过提高系统信息的含量将有效提高系统的智能水平。这一模型在Pi值的计算算法中也得到了印证。     

基于信息源特征的航空部附件故障预测研究

针对舰载机多机种一体化自主保障中机载设备的维修保障需求,提出了基于信息源特征分析的航空关键部附件故障预测方法;首先,从信息源数据特征、研究对象判定、用于预测的可用信息及不确定性4个角度对信息源特征的复杂性进行了分析;其次,根据航空部附件故障频率和平均停机维修时间采用四象限图实现航空关键部附件的判定;最后,基于信息源不同可用信息选择不同的故障预测方法,并介绍了智能融合的神经网络算法和能够消除不确定性的非线性滤波方法,提高了航空部附件故障预测方法的通用性和准确性。     

基于特征的空间数据不确定性管理模型

从空间数据的质量表达方法和管理的角度出发，对基于特征的空间数据不确定性管理模型进行研究。首先对现行的元数据质量管理方法进行了分析，指出其不足。随后根据GIS发展的趋势，指出空间数据质量管理面临的挑战和问题，进一步提出了基于特征的空间数据不确定性管理模型，并对模型中几个关键的问题进行了探讨。     

空间数据挖掘不确定性及其传播

首先分析空间数据的不确定性类型和来源、不确定性度量和传播模型以及空间数据挖掘过程中的不确定性来源。在此基础上，把空间数据挖掘整个过程看作为一个复杂的工程控制系统中的线性串联处理系统，建立了基于可信度因子的模糊逻辑不确定性传播模型，包括可信度因子的获取和表示、组合证据不确定性的合成、不确定性传播和结论不确定性的合成等。最后，讨论了空间数据挖掘不确定性处理和传播所涉及的几个关键问题。     

随时间演化的不确定区域间拓扑关系判定

不确定性处理是时空数据库技术研究的新领域,现有研究成果集中在时空不确定性的表示模型方面,缺乏不确定性对象间时空关系特别是拓扑关系的分析.提出了利用3维拓扑分析模型来分析2维运动对象的时空关系,针对随时间演化的2维不确定性区域,将Egg/Yolk模型中的RCC（region connection calculus）区域扩充至3维,得到46种联合完备且互不相交的基本拓扑关系,根据各基本拓扑关系的时空特性,将46种基本关系归类为21类不确定性时空关系.     

A spreadsheet approach to facilitate visualization of uncertainty in information

Information uncertainty is inherent in many problems and is often subtle and complicated to understand. Although visualization is a powerful means for exploring and understanding information, information uncertainty visualization is ad hoc and not widespread. This paper identifies two main barriers to the uptake of information uncertainty visualization: firstly, the difficulty of modeling and propagating the uncertainty information; and secondly, the difficulty of mapping uncertainty to visual elements. To overcome these barriers, we extend the spreadsheet paradigm to encapsulate uncertainty details within cells. This creates an inherent awareness of the uncertainty associated with each variable. The spreadsheet can hide the uncertainty details, enabling the user to think simply in terms of variables. Furthermore, the system can aid with automated propagation of uncertainty information, since it is intrinsically aware of the uncertainty. The system also enables mapping the encapsulated uncertainty to visual elements via the formula language and a visualization sheet. Support for such low-level visual mapping provides flexibility to explore new techniques for information uncertainty visualization.     

平面连杆机构分析与仿真专家系统

任意平面连杆机构，在拓扑组成上，可表示为无向图，本文研究了从机构无向图出发建立机械运动生成链和分离可独立求解杆件组，建立规则库自动按照约束性质生成约束方程式和采遥用变异几何方法数值求解机构运动，本文介绍了一个按上述原理实现的任意连杆机构分析仿真专家系统。     

Computer based support of reasoning in the presence of fuzziness and uncertainty

Decision making tasks require that we access (possibly large volumes of) data, transform it in various ways by performing computations on it, as well as reason with such raw or transformed data. Also, imprecision is almost omnipresent in practical decision making environments. In order to provide computer based support for reasoning activities in such environments, it is therefore necessary to develop schemes to represent imprecise knowledge and mechanically manipulate it. A previous paper developed such a scheme for fuzzy knowledge. This paper extends that representation to capture uncertainty as well. Mechanisms for propagating uncertainty during the reasoning process are also developed. The propagation mechanism allows interaction between fuzziness and uncertainty during the course of reasoning. The scheme developed here has been tested on a prototype implementation. The robustness of the representation and its use are demonstrated with an example.     

Variable timescales of repeated spike patterns in synfire chain with Mexican-hat connectivity

Repetitions of precise spike patterns observed both in vivo and in vitro have been reported for more than a decade. Studies on the spike volley (a pulse packet) propagating through a homogeneous feedforward network have demonstrated its capability of generating spike patterns with millisecond fidelity. This model is called the synfire chain and suggests a possible mechanism for generating repeated spike patterns (RSPs). The propagation speed of the pulse packet determines the temporal property of RSPs. However, the relationship between propagation speed and network structure is not well understood. We studied a feedforward network with Mexican-hat connectivity by using the leaky integrate-and-fire neuron model and analyzed the network dynamics with the Fokker-Planck equation. We examined the effect of the spatial pattern of pulse packets on RSPs in the network with multistability. Pulse packets can take spatially uniform or localized shapes in a multistable regime, and they propagate with different speeds. These distinct pulse packets generate RSPs with different timescales, but the order of spikes and the ratios between interspike intervals are preserved. This result indicates that the RSPs can be transformed into the same template pattern through the expanding or contracting operation of the timescale.     

Failure propagating simulation and nonfailure paths search in network systems

This paper describes a method for identifying failure propagation paths in networks. It also assesses the risks associated with failure propagation and identifies the nonfailure paths remaining in the network after failure propagation has occurred. The method employs the following procedure: (1) selection of elements with likelihood of failure; (2) determination of failure source; (3) drawing of failure propagating network; (4) simulation of failure propagation; (5) risk assesment; and (6) search for nonfailure paths.     

人工生命行为选择情绪机制研究进展

基于智能的行为选择机制(BSM)存在两个缺陷:不确定性环境下,不能实现自主行为选择,在相同环境条件下,缺乏行为反应的多样性.受情绪机制应用于情感计算与强化学习研究的启发,将其应用于行为选择机制研究,以解决上述问题.从而,提出三类情绪行为选择机制:情绪影响机制、情绪驱动机制、情绪涌现机制.但这些机制存在:未能将其所需涉及的基本因素进行涵盖,有系统性缺陷;各种选择机制体系结构和情绪计算模型彼此各异,没有继承性;基于设计思想,缺乏相关学科关于情绪行为理论的支撑.另外,研究方法上,也存在各行为机制之间、智能机制和情绪机制之间缺乏系统性分析和比较的问题.提出,要揭示情绪行为选择机制,应从认真挖掘动物行为学、心理学、经济学等领域有关情绪研究结果之间的内在一致性入手.同时,比较方法的使用,将是加速这一过程的有效手段.     

Uncertainty estimation in robot kinematic calibration

Currently, the results of a robot calibration procedure are expressed generally in terms of the position and orientation error for a set of locations and orientations, which have been obtained from the previously identified kinematic parameters. In this work, a technique is presented to evaluate the calibration uncertainty for a robot arm calibrated using the circle point analysis method. The method developed is based on the probability distribution propagation calculation recommended by the Guide to the Expression of Uncertainty of Measurement and on the Monte Carlo method. This method makes it possible to calculate the uncertainty in the identification of each single robot parameter, and thus, to estimate the robot positioning uncertainty due to the calibration uncertainty, rather than based on a single set locations and orientations that are previously defined for a unique set of identified parameters. Additionally, this technique allows for the establishment of the best possible conditions for the data capture test, which identifies parameters and determines which of them have the least possible calibration uncertainty. This determination is based on the variables involved in the data capture process by propagating their influence up to the final robot accuracy.     

动态信息流分析的漏洞利用检测系统

安全相关的函数使用了来自网络用户输入或配置文件的非可信数据,由于未经过严格验证,引发了软件安全问题.大量软件漏洞都与非可信数据传播相关.非可信数据传播分析的漏洞利用检测系统将从网络用户输入或配置文件中获得的非可信数据标记为污染数据,使用信息流方法分析污染数据的传播范围,对可能使用污染数据的函数使用多种策略进行污染检查.借助开源的虚拟机代码实现动态信息流跟踪的漏洞检测原型系统,并优化了漏洞利用检测过程.