Rejection of Outliers

If one reading is a long way from the rest in a series of replicate determinations, or if in a least-squares analysis one reading is found to have a much greater residual than the others, there is temptation to reject it as spurious. Numerous criteria for the rejection of outliers have been proposed and discussed during the past 100 years. They seem always to have been regarded as something like significance tests, and attention has been focussed on rejection rates. It is suggested that rejection rules are not significance tests but insurance policies, and attention would be better focussed on error variance. A detailed study is made of the effect of routine application of rejection criteria to replicate determinations of a single value. Determinations in triplicate and quadruplicate are especially considered. Complex patterns of observations are also considered, especially factorial arrangements with high symmetry, and there is a study of the correlations between residuals. Attention is focussed mainly on rejection rules appropriate when the population variance is known, but some consideration is also given to Studentieed rules.     

气体传感器特性漂移抑制的研究

在对气体进行长期在线监测的场合，所要解决的关键问题之一就是气体传感特性漂移的抑制。传感器特性漂移会给气体的测量和识别带来误差。对此，本提出一种动态在线标定法。该方法能够对传感器漂移故障做出判定，同时可实现测量误差的修正。中对该方法进行了详细的描述和论证。计算仿真结果表明了该方法的有效性。     

空间观测图像宇宙线噪声去除算法

空间观测图像容易受到宇宙线噪声的干扰。本文提出一种空间观测图像宇宙线噪声去除算法。首先利用Top-hat变换抑制观测图像的杂散光,处理之后的观测图像背景均匀,直方图的近Gaussian形状得以恢复。然后利用形态学运算和中值滤波相结合的方法排除高亮过饱和恒星的干扰。最后利用Laplacians边缘检测算法检测宇宙线噪声像素,并利用邻域最小值滤波的方法对宇宙线像素的灰度值进行插值处理。实验结果表明,本文方法在不产生误检测的前提下,检测概率超过90%,综合性能优于本文中提到的其它三种宇宙线噪声去除方法。     

Rejection mechanisms of NF membranes

In this article, Andrij E. Yaroshchuk from The Ukrainian Centre of Fundamental Membrane Research, looks at the low rejection mechanisms in nanofiltration membranes can be identified using advanced characterization of membrane transport properties.     

纳滤膜对染料截留行为的研究

通过一系列实验 ,考察了几种纳滤膜在不同操作条件下对几种不同的染料的截留行为 .发现不同的纳滤膜对不同的染料的截留行为不同 ;反之 ,染料的品种和分子结构对纳滤膜的盐截留率、染料截留率和水通量也有影响 ,同时 ,操作条件如进料浓度、pH、压力对截留效果的影响也很大 .实验结果和结论可作为染料清洁生产实际应用的参考 .     

Nonrepeatable Run-out Rejection Using Online Iterative Control for High-Density Data Storage

The spectra of disturbances and noises affecting precise servo positioning for ultrahigh-density storage in future hard disk drives are time-varying and remain unknown. In this paper, we propose an online iterative control algorithm that sets the measured position error signal (PES) into the servo system to achieve high track densities by minimizing the square of the H₂-norm of the transfer function from nonrepeatable run-out (NRRO) disturbances to the true PES. It is not necessary to solve any algebraic Riccati equations and linear matrix inequalities. The algorithm constructs an online repeatable run-out estimator to extract NRRO components for gradient estimates, thereby preventing the controller parameters from being trapped in a local minima. Experimental results on a PC-based servo system for a spinstand show an improvement of 22% in 3sigma NRRO and suppression of baseline NRRO spectrum     

Fractional Order Linear Active Disturbance Rejection Control for Linear Flexible Joint System

A linear flexible joint system using fractional order linear active disturbance rejection control is studied in this paper. With this control scheme, the performance against disturbances, uncertainties, and attenuation is enhanced. Linear active disturbance rejection control (LADRC) is mainly based on an extended state observer (ESO) technology. A fractional integral (FOI) action is combined with the LADRC technique which proposes a hybrid control scheme like FO-LADRC. Incorporating this FOI action improves the robustness of the standard LADRC. The set-point tracking of the proposed FO-LADRC scheme is designed by Bode's ideal transfer function (BITF) based robust closed-loop concept, an appropriate pole placement method. The effectiveness of the proposed FO-LADRC scheme is illustrated through experimental results on the linear flexible joint system (LFJS). The results show the enhancement of the robustness with disturbance rejection. Furthermore, a comparative analysis is presented with the results obtained using the integer-order LADRC and FO-LADRC scheme.     

Thermoanemometers for measuring gas flow rates

Translated from Izmeritel'naya Tekhnika, No. 9, pp. 26–27, September, 1989.     

Rejection of Surface Background in Thermal Detectors

A challenging aspect of the next generation detector for rare events searches (i.e. neutrinoless double beta decay and dark matter searches) is the reduction of the background in the region of interest that can mimic the expected signals. In the field of thermal detectors, which have a leading role in rare events searches thanks to their excellent energy resolution and to the wide choice of absorber materials, the background coming from surface contaminations is frequently dominant. A background surface rejection detector is a scintillation-based approach for tagging this type of background. We discuss the innovative application of this technique in non-scintillating thermal detectors. We will report on the performances of the prototype bolometric detector, realized to prove the feasibility of this new technique.     

James-Stein estimators for failure rates and probabilities

A basic concept in this paper is that a group of components under study represents a sample from a common source (e.g. a factory) that has a failure rate distribution, with distribution parameters originally unknown. This concept is used to obtain generalized James-Stein estimators for individual component parameters. Such ‘shrinkage estimators’ are more accurate than conventional point estimates. They are developed here for component failure rate parameters based on Poisson data, and for failure probabilities based on binomial data. Optimal weights and shrinking factors are obtained as well as formulae for estimating the mean value and the variance of the source population, and the mean values and the variances of individual component estimates. Close connections to the empirical Bayesian estimation are shown     

A voitenko compressor for subsonic loading rates

Results are presented of experimental and theoretical investigations and the possibility is shown of producing a laboratory source of a dense low-temperature plasma.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 48, No. 4, pp. 670–675, April, 1985.