融合随机退化过程与失效率建模的设备剩余寿命预测方法

剩余寿命预测对于设备的维修与保养具有十分重要的意义。现有的剩余寿命预测方法大多只利用了设备的当前退化信息,对设备的历史寿命信息没有充分利用,而这些信息往往包含着设备寿命的演化信息,对于准确预测设备的剩余寿命具有重要意义。针对这个问题,提出了一种融合随机退化过程与失效率建模的设备剩余寿命预测方法。该方法首先将设备的退化过程建模为Wiener过程,然后利用Cox比例失效模型建模的方法融合设备退化过程对设备失效率的影响,由此达到利用设备历史监测信息的目的。进一步通过Bayes方法,利用当前退化监测信息对退化过程模型的参数进行更新,基于此进行剩余寿命预测,从而实现设备历史数据与当前数据的有效融合。最后,通过激光发生器的退化测量数据验证了提出的方法,说明该方法是有效的,具有一定的应用价值。     

基于随机退化数据建模的设备剩余寿命自适应预测方法

针对现有剩余寿命预测研究中需要多个同类设备历史数据离线估计模型参数的问题,本文提出了一种基于退化数据建模的服役设备剩余寿命自适应预测方法.该方法,利用指数随机退化模型来建模设备的退化过程,基于退化监测数据运用Bayesian方法更新模型的随机参数,进而得到剩余寿命的概率分布函数及点估计.区别于现有方法,本文方法基于设备到当前时刻的监测数据,利用期望最大化算法对模型中的非随机未知参数进行在线估计,由此无需多个同类设备历史数据.最后,通过数值仿真与实例分析,验证了本文方法在剩余寿命预测时的有效性.     

多源数据融合建模的寿命预测方法

针对单一传感器在设备状态监测期间不能很好地进行退化建模和剩余使用寿命预测的问题,提出了一种多源数据融合建模的寿命预测方法.首先,根据设备的退化性能,构造了复合健康指标;其次,使用非线性漂移维纳过程对设备进行退化建模,通过使用极大似然法估计模型参数后,推导出设备剩余寿命概率密度函数;最后,对所提出的方法进行了验证,并与单一传感器预测结果进行了对比,结果表明此方法具有较高的准确性.     

基于EM-EKF与隐含比例退化模型的机载电子设备剩余寿命自适应预测

针对现有机载电子设备剩余寿命自适应预测方法在新研小样本条件下,未能综合考虑设备隐含退化建模与漂移系数在线更新的问题,本文提出一种基于期望最大-扩展卡尔曼滤波(Expectation Maximization-Extended Kal-man Filter,EM-EKF)与隐含比例退化模型的机载电子设备剩余寿命自适应预测方法.首先,基于非线性Wiener过程构建带比例关系的设备隐含退化模型;其次,在引入漂移系数更新机制的基础上建立设备退化状态方程,并采用EKF算法同步更新设备退化状态与漂移系数;然后,采用EM-EKF算法实现对退化模型参数的自适应估计;最后,基于全概率公式,推导出设备剩余寿命的概率密度函数.通过对单台微机械陀螺仪实测数据进行分析,验证了本文所提方法具有更好的模型拟合性与预测准确性.     

不确定退化测量数据下的剩余寿命估计

剩余寿命估计是工程系统预测与健康管理的关键.目前,基于观测的系统退化数据进行剩余寿命估计得到了很大的关注.由于系统随机退化过程和测量误差的影响,测量数据中不可避免包含退化随机性和测量不确定性.然而,现有基于观测数据的剩余寿命估计研究中,没有将退化随机性和测量不确定性对估计的剩余寿命分布的影响同时考虑.鉴于此,提出了一种基于Wiener过程且同时考虑随机退化和不确定测量的退化建模方法,利用Kalman滤波技术,实现了潜在退化状态的实时估计.在退化状态估计的基础上,得到了同时考虑退化状态不确定性和测量不确定性的解析剩余寿命分布.此外,提出了一种基于极大似然方法的退化模型参数估计方法.最后,通过陀螺仪的退化测量数据验证了本文提出的方法优于不考虑测量不确定性的方法,可以提高剩余寿命估计的准确性.     

考虑不完全维护影响的随机退化设备剩余寿命预测

针对寿命周期中存在不完全维护影响的随机退化设备剩余寿命难以预测的问题,提出了一种考虑不完全维护影响的退化建模和剩余寿命预测方法.首先,在Wiener过程理论架下,建立了能够表征不完全维护影响的分阶段退化过程模型,然后从阶段时间服从的逆高斯分布出发,利用逆高斯分布的卷积特性,从理论上推导出存在不完全维护下寿命分布的解析解,并将维护效果的随机性和维护次数的影响传递到寿命分布中.进一步通过时间尺度变换,得到了考虑未来存在不完全维护影响下的剩余寿命分布解析解.通过极大似然估计和最小二乘法对模型未知参数进行了估计.最后将本文方法应用到陀螺仪的实际退化过程中,验证了所提方法的有效性.     

金属化膜脉冲电容器剩余寿命预测方法研究

 金属化膜脉冲电容器是惯性约束聚变激光装置的重要元器件之一,其寿命预测是激光装置维护和备件决策制定的依据.在分析金属化膜脉冲电容器退化失效机理的基础上,采用Wiener过程描述其性能退化过程.进一步考虑到各电容器之间的差异,将Wiener过程的漂移参数和扩散参数看成随机变量,提出了随机效果Wiener过程模型,由同一批电容器的历史性能退化数据拟合其分布.在对单个电容器进行寿命预测时,采用Bayes方法融合电容器总体信息与该电容器自身的性能退化信息,得到其剩余寿命参数的验后估计,因而在电容器性能退化数据较少时采用该方法能提高剩余寿命预测精度.     

宇航用光纤陀螺双应力步进加速退化技术

光纤陀螺在宇航环境中会承受多种环境应力的作用,针对光纤陀螺在单一加速应力作用下的极限问题,提出双应力交叉步进加速退化试验方法,实现了寿命和可靠性评估。通过建立包含剩余标准化系数的退化轨迹模型,描述了光纤陀螺退化量与应力水平的关系。基于累积损伤模型及时间折算的模型参数估计方法进行加速退化数据的统计分析,得到光纤陀螺在使用应力水平下的寿命及可靠性信息。以光纤陀螺为对象,验证了此方法的有效性。     

融合非线性加速退化模型与失效率模型的产品寿命预测方法

针对高可靠性产品寿命数据少、获取成本高的问题,基于充分利用产品在研制、加速试验等不同环境下的退化数据、失效数据等可靠性数据的思想,提出了一种融合非线性加速退化模型和失效率模型的产品寿命预测方法.首先,根据退化数据对非线性退化过程进行分析,估计退化过程的参数;然后,根据加速退化数据及相应的加速退化模型估计加速退化模型的参数,从而得到退化参数与应力之间的关系.进一步,利用比例风险模型融合产品的寿命数据和未失效截尾数据,并基于此计算产品的可靠度函数、预测产品的寿命.实例应用验证了所提方法的有效性,同时说明了所提方法的应用价值.     

基于维纳过程的卫星用光纤陀螺剩余寿命预测

卫星用光纤陀螺的剩余寿命预测是卫星健康状态管理中的一个关键问题。针对传统的退化过程建模不能考虑同批设备中个体差异的问题,提出采用一种基于维纳过程的随机变量模型对光纤陀螺在空间环境下的退化特性进行建模。该模型将维纳过程中的漂移系数看成随机变量以描述个体差异,传统的维纳过程是其特例。依据该模型,可以得到光纤陀螺的可靠性指标和剩余寿命信息。仿真试验表明,文中提出的退化建模方法的精度明显高于传统方法,具有一定的工程应用价值。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.