我国量块计量技术概况与发展趋势

该文介绍了我国量块计量技术与国际接轨的进程,并提出了量块计量技术发展需要研究的课题。     

NONSPECIFICITY IN Rn

Open problems posed by Klir and Wierman (1998) for a nonspecificity measure are solved; the measure is proven additive, and its extension to nonconvex sets given. Several different proofs of additivity are given, to suggest certain techniques of wider applicability in system problems and to motivate further research possibihties. A study is initiated to refine nonspecificity separately to each dimension k≤n for the bodies residing in Rⁿ.     

UNCERTAINTY IN THE DEMPSTER-SHAFER THEORY: A CRITICAL RE-EXAMINATION

Measures of two types of uncertainty that coexist in the Dempster-Shafer theory are overviewed. A measure of one type of uncertainty, which expresses nonspecificity of evidential claims, is well justified on both intuitive and mathematical grounds. Proposed measures of the other types of uncertainty, which atlempt to capture conflicts among evidential claims, are shown to have some deficiencies. To alleviate these deficiencies, a new measure is proposed. This measure, which is called a measure of discord, is not only satisfactory on intuitive grounds, but has also desirable mathematical properties. A measure of total uncertainty, which is defined as the sum of nonspecificity and discord, is also discussed. The paper focuses on conceptual issues. Mathematical properties of the measure of discord are only slated; their proofs are given in a companion paper.¹⁵     

热轧带肋钢筋拉伸试验结果的不确定度评定

根据钢筋检验及评定标准,对3件热轧带肋钢筋用直接评定法进行了强度检验结果的不确定度评定,给出了合成及扩展不确定度的评定结果。     

Sensitivity analysis for reliable design verification of nuclear turbosets

In this paper, we present an application of sensitivity analysis for design verification of nuclear turbosets. Before the acquisition of a turbogenerator, energy power operators perform independent design assessment in order to assure safe operating conditions of the new machine in its environment. Variables of interest are related to the vibration behaviour of the machine: its eigenfrequencies and dynamic sensitivity to unbalance. In the framework of design verification, epistemic uncertainties are preponderant. This lack of knowledge is due to inexistent or imprecise information about the design as well as to interaction of the rotating machinery with supporting and sub-structures. Sensitivity analysis enables the analyst to rank sources of uncertainty with respect to their importance and, possibly, to screen out insignificant sources of uncertainty. Further studies, if necessary, can then focus on predominant parameters. In particular, the constructor can be asked for detailed information only about the most significant parameters.     

Application of step‐response test for evaluation of uncertainty of standard measuring system for lightning‐impulse high voltage

In evaluating the uncertainty of the standard measuring system for lightning‐impulse high voltages, which is composed of a standard voltage divider, a digital recorder, and calibrators, step‐response tests of the standard voltage divider may be useful. In this paper, a convolution algorithm is employed to calculate the output impulse voltage waveforms from measured step‐response waveforms. The uncertainties of peak‐value measurement due to the influence of the nominal epoch, uncertainty of the peak‐value measurement due to dispersion of the AC scale factor, and uncertainty of the virtual front‐time measurement due to long‐term stability are evaluated. Furthermore, the error of the virtual front time of the output waveforms is discussed. The front part of the step‐response waveform, t≤ T₃₀%, does not influence the error of the virtual front time. Therefore, for the standard voltage divider, the step‐response parameters, that is, the experimental response time, partial response time, settling time, and overshoot, have almost nothing to do with the error of the virtual front time. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 180(2): 24–32, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21279     

一种基于像素差值编码度量不确定SAR图像相似性的新方法

在SAR图像目标识别、图像匹配等应用中,定义合理可靠的相似度尤为重要。该文在分析现有SAR图像相似度基础上,提出一种基于像素差值编码的相似度准则。首先将SAR图像按照相邻像素灰度差异生成编码图像,然后以编码图像之间的一致性作为相似度。该文从理论上证明了该相似度对SAR图像中相干斑噪声、部分遮挡和模糊等因素的鲁棒性和适应性,还讨论了将该准则应用于SAR图像匹配时,如何针对不确定性,给出一定置信水平下所有合理的匹配位置。理论和实验结果表明该文提出的相似度准则对SAR图像上相干斑噪声、部分遮挡以及模糊不敏感,能有效应用于不确定SAR图像的匹配。     

分光法测量LED颜色的不确定度分析

分析了分光法测试发光二极管(LED)颜色的测量不确定度,着重分析了光谱功率分布测量不确定度和波长不确定度对颜色测量的不确定度影响,给出了几种典型LED的分析结果,结果表明,5%的光谱功率分布测量不确定度和0.5 nm的波长不确定度在一般情况下可以满足精度要求为0.001的LED颜色测量.     

一种空间相机辐射定标用大面积辐射光源的研制

针对目前空间光学遥感器向着大口径、高精度方向发展相应需要大出光面的积分球辐射光源,本文研制了一种大口径空间相机用积分球辐射定标光源,并使用自制的积分球辐射性能测试装置测试了大口径积分球光源的均匀性、余弦特性和稳定性。研制的积分球辐射定标光源内径为3000mm,出光面直径为1 000mm。测试结果表明,积分球的最大幅亮度为240.13 W·m-2·sr-1,辐亮度调节范围为371.5∶1,辐亮度不稳定性为0.04%/h,光源出口面非均匀性为1.7%,辐射定标光源的不确定度为5%。     

直流数字电压表的不确定度评定

详细叙述了直流数字电压表测量结果的不确定度评估,分析了影响测量不确定度的原因,计算了各不确定度分量并给出合成标准不确定度。通过对测量结果不确定度分析,提高了测量准确度和工作效率。