A Response Surface Methodology for Modeling Time Series Response Data

This article introduces extensions to classical response surface methods specifically for modeling and exploiting time series response data such as found in aircraft flight test. Classical response surface methods focus on the analysis of discrete response data. In some complex, nonlinear systems, analysts are concerned with the behavior of time series response data. To date, there does not appear to be any formal methods for examining and exploiting these data within a response surface framework. Thus, a mathematical framework is defined and then demonstrated through a sample analysis of empirical flight test data. Copyright © 2012 John Wiley & Sons, Ltd.     

Practical Considerations for Estimating Road Vehicle Frequency Response Functions from Response Data

This paper describes the application of a practical method to estimate the dynamic characteristics (frequency response function) of road vehicles using only on‐the‐road vertical vibration response data measured during nominally constant operating speeds. While several methods exist to estimate these dynamic characteristics, they are generally either inexact or prohibitively resource intensive. A review of two analytical approaches for estimating the frequency response function of road vehicles using only on‐the‐road vibration response data is presented. The first approach is based on the assumption that the road elevation profile takes the form of a specified spectral function. The second approach is based on the random decrement technique. A practical, step‐by‐step guide to undertaking on‐the‐road vehicle vibration measurements is included and provides numerous useful tips and considerations that should be taken into account. An investigation was also undertaken into the minimum record length (i.e. fraction of road length) required to accurately estimate the dynamic characteristics of road vehicles using a Monte Carlo simulation. From the study, it was found that a minimum road length of 10 – 15 km is sufficient to obtain a reasonably accurate estimate. Copyright © 2017 John Wiley & Sons, Ltd.     

网络空间安全应急与应对

从我国网络空间安全的现状及面临的问题出发,指出网络空间安全应从应急转变为应对,并从网络空间安全监测、网络空间安全总体保障能力及网络空间安全人才队伍建设三个方面提出了相应的转变策略。     

Response Rate Choice for Reactivity Meters

Simulation has been used to estimate the error in reactivity measurement in relation to the response rate in an instrument which integrates the input signal or by a converter with a constant measurement time without integration.     

Response surface approximations for structural optimization

Response surface methodology can be used to construct global and midrange approximations to functions in structural optimization. Since structural optimization requires expensive function evaluations, it is important to construct accurate function approximations so that rapid convergence may be achieved. In this paper techniques to find the region of interest containing the optimal design, and techniques for finding more accurate approximations are reviewed and investigated. Aspects considered are experimental design techniques, the selection of the ‘best’ regression equation, intermediate response functions and the location and size of the region of interest. Standard examples in structural optimization are used to show that the accuracy is largely dependent on the choice of the approximating function with its associated subregion size, while the selection of a larger number of points is not necessarily cost-effective. In a further attempt to improve efficiency, different regression models were investigated. The results indicate that the use of the two methods investigated does not significantly improve the results. Finding an accurate global approximation is challenging, and sufficient accuracy could only be achieved in the example problems by considering a smaller region of the design space. © 1998 John Wiley & Sons, Ltd.     

一种可见光响应纳米 TiO2粉体的光响应特性表征

利用有机溶剂水热法制备了一种新型的可见光响应纳米TiO2粉体光催化剂．对其进行光响应特性表征，研究发现：固相粉末漫反射吸收谱反映了该TiO2粉体具有类似改性TiO2的可见光响应的特征；而在纳米颗粒稀悬浮液的特定条件下，紫外-可见吸收谱给出了该纳米TiO2粉体的类似本征TiO2的光响应特征，观测不到其可见光响应特征；分析表明，该现象可能与在稀悬浮液的条件下，声子参与的光致电子跃迁过程的退化有关．     

On Designing Intelligent Response System for Medicine

Behaviormetrika - Since early 1970’s several groups both in Japan and in the United States have worked on a new approach to computer-aided clinical decision making. The special feature which...     

频率响应函数估计方法综述

回顾了近年来以线性系统为基础模型的频率响应函数估计方法的理论研究和发展现状.根据干扰误差主要成分的不同分为几个方面讨论,包括加性随机噪声、加窗泄漏引起的噪声、非线性系统失真引起的噪声等.综合论述了各种干扰误差下,各种频率响应函数估计方法的原理、特点及其在工程中的应用.最后对文章内容进行了总结并对频率响应函数估计领域的发展前景进行了探讨和展望.     

Response Surface Designs for Experiments with Mixtures

In estimating a response surface where the k variables represent proportions in a mixture, the experimenter is often interested in a reasonably well-defined region of interest which may, for example, center about current operating levels. Previously developed designs are difficult to use except in exploring the entire factor space, and even then there are several disadvantages to these designs. A general method of constructing designs from familiar response surface designs in k ? 1 independent variables and the appropriate analysis for a general polynomial is given. Special attention is given to the first and second order polynomials.     

结构地震响应控制的优化方法

针对大跨空间结构地震响应主动控制,以超磁致伸缩材料为核心元件设计了一种可以应用于大跨空间结构振动主动控制中的超磁致伸缩作动器,制作出了作动器的原型并对其进行了输出性能测试。使用遗传算法对大跨空间结构主动控制作动器的布置位置进行了优化设计,最后进行了优化效果的数值模拟分析。以此验证了超磁致伸缩作动器具有良好的作动效应,利用遗传算法在大大提高结构主动控制优化设计效率时,可以保证实现对结构的整体优化以及作动器能高效、经济地实现对结构进行主动控制的目的。     

损伤材料的动力响应特性

研究了工程材料在动力载荷下损伤演化的计算模型。提出了一般材料在各向异性损伤状态下的两种动力损伤模型。第一种以有效应力的等效值的幂函数为基础 ,第二种以损伤应变能释放率为基础。通过数值分析研究了损伤结构元件的动力响应及损伤材料的动力特性。说明了结构元件中损伤发展的分析方法和它们的有限元程序的执行过程。该研究表明 :损伤结构的频谱下移 ,损伤材料的阻尼比变高 ,响应的振幅明显增加 ,损伤结构可能发生由于损伤发展引起的共振。     

基于频响函数矩阵计算阻尼系统动力响应的新方法

首先引入模态坐标变换及矩阵函数变换,将阻尼系统转化为无阻尼系统,再通过分析无阻尼系统的模态参数的特点,推导出计算其频率响应矩阵的公式,然后使用矩阵函数逆变换和模态坐标反变换,推导出原阻尼系统响应的精确表达式,本文方法应用于经典阻尼系统时,取得了与传统的振型迭加法等价的解析表达式,同时对于无法直接使用振型迭加法处理的非经典阻尼系统,也获得了解析解。数值算例表明了本文方法的正确性及有效性。     

Response

Many systems experience recurrent events. Recurrence data are collected to analyze quantities of interest, such as the mean cumulative number of events. Methods of analysis are available for recurrence data with left and/or right censoring. Due to practical constraints, however, recurrence data are sometimes recorded only in windows. Between the windows are gaps over which the process cannot be observed. This article extends existing statistical methods, both nonparametric and parametric, to window-observation recurrence data. The nonparametric estimator requires minimum assumptions but will be inconsistent if the size of the risk set is not positive over the entire period of interest. No such difficulty arises when using a parametric model for the recurrence data. For cases in which the size of the risk set is zero for some period of time, we propose and compare two alternative hybrid estimators. We illustrate the methods with two example applications.     

Response

Mixed linear models arise in many areas of application. Standard estimation methods for mixed models are sensitive to bizarre observations. Such influential observations can completely distort an analysis and lead to inappropriate actions and conclusions. We develop case-deletion diagnostics for detecting influential observations in mixed linear models. Diagnostics for both fixed effects and variance components are proposed. Computational formulas are given that make the procedures feasible. The methods are illustrated using examples.     

Implementation-Friendly Constraint for Adaptive Finite Impulse Response Filters for Equalization

In read channels in magnetic recording systems, a finite impulse response (FIR) filter is often used as an equalizer, and the filter coefficients are adapted via a least mean squares (LMS) algorithm. This equalizer adaptation loop can interfere with the timing recovery (TR) loop and the automatic gain control (AGC) loop that are also present in such channels. In a previous paper by L. Du et al., a linear constraint is proposed for the LMS loop so that it is decoupled from the TR and the AGC loops. In this paper, we generalize that constraint, and propose a new constraint that offers the advantage of easier implementation.     

Demodulation of Fiber-Optic Sensors for Frequency Response Measurement

The neural-network-based processing of extrinsic Fabry-Perot interferometric (EFPI) strain sensors was investigated for the special case of sinusoidal strain. The application area is modal or cyclic testing of structures in which the frequency response to periodic actuation must be demodulated. The nonlinear modulation characteristic of EFPI sensors produces well-defined harmonics of the actuation frequency. Relationships between peak strain and harmonic content were analyzed theoretically. A two-stage demodulator was implemented with a Fourier series neural network to separate the harmonic components of an EFPI signal and a backpropagation neural network to predict the peak-to-peak strain from the harmonics. The system performance was tested using theoretical and experimental data. The error for high-strain cases was less than about 10% if at least 12 harmonics were used. The frequency response of an instrumented cantilever beam provided the experimental data. The demodulator processing closely matched the actual strain levels     

军用保障与快速反应的包装技术

介绍了外军快速反应包装技术的发展计划和做法,分析了国内军用包装的发展现状和差距,指出了国内快速反应的军用包装技术的发展方向.旨在探讨先进、科学、适用的军用快速反应的包装技术,以适应现代军事战争对军用包装的需求.