共查询到20条相似文献,搜索用时 70 毫秒
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在经济建设、国防建设和科学技术各部门都离不开角度计量问题。诸如切削刀具的测量 ,零件有关角度的测量 ,仪器或机床导轨的检验和装调 ,以及天文研究 ,大地测量 ,水利、交通建设 ,导弹和卫星的发射等 ,都跟角度计量有密切联系。角度测量分为直接测量和间接测量两种。一、直接测量全组合互比法一般用来检定高精度的圆分度器件 ,如用多面棱体检定多齿分度台、测角仪、光学分度头等的分度误差。它是根据多面棱体和被检仪器的度盘都具有圆周封闭的特点 ,用多面棱体的各工作角与被检仪器的同一分度间距相比较 ,利用封闭原理消除多面棱体各角值误… 相似文献
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评价了数显仪特征部分误差分析方法,包括:采样/保持电路、模数转换单元的误差,并通过典型例子和列表数据分析了多种误差源及其综合计算方法.此外,还通过对现代动态范围内平均位误差风险因子量化(BERF)的评述,进一步探讨了传统意义上的数值化模拟系统与现代的建立在BERF-ε原理基础上的数显仪量化误差极限分析之间的关系.正因为后者建立在揭示噪声量子涨落性的直方图和量子相关性的功率谱密度测量上,所以能更客观地表征噪声的量子特性. 相似文献
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时域同步平均的相位误差累积效应研究 总被引:1,自引:0,他引:1
时域同步平均是提高振动信号信噪比的常用方法,由于估计误差的存在性,相位误差累积效应是基于周期的时域同步平均方法的固有现象.对相位误差累积效应的产生机理进行了深入分析,表明这一效应是由取整运算误差和频率估计误差引起的.为统一分析这两种误差的影响,定义了相位误差累积因子,用其定量分析了相位误差累积效应的产生机理.为评估相位误差累积效应对时域同步平均效果的影响,系统分析了相位误差累积因子、信号分量阶次和平均段数等主要分析参数对时域同步平均信号幅值的影响规律.研究表明,一定范围内这几个参数的增大都会增强相位误差累积效应导致的时域同步平均信号幅值的衰减.因此,需要根据相位误差累积因子和信号分量阶次的范围慎重选择平均段数. 相似文献
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Deborah Sater Carstens 《Theoretical Issues in Ergonomics Science》2013,14(6):525-549
The aim of the research was to provide a valid theoretical frame consisting of both task and error analyses methods to analyse elder patients’ clinical pathway within a healthcare system. The research study consisted of (a) utilizing a task analysis method to identify the process workflow affiliated with elder patients transitioning through different continuums of care to receive medical treatment; (b) utilizing an error analysis method to identify opportunities for improvement in the workflow that enhances both patient safety and healthcare worker efficiency and; (c) developing an ideal process workflow that incorporates the recommendations for improvement. The study findings contribute towards a larger research effort being proposed consisting of the development and implementation of a shared web-based patient community information system enabling hospitals and nursing homes to share patient information resulting in increased knowledge of a patient's medical history, decreased errors and enhanced patient safety. 相似文献
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V. V. Andrushchuk 《Measurement Techniques》1979,22(7):816-819
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Zi‐Cai Li John Y. Chiang C. Y. Suen 《International journal of imaging systems and technology》2011,21(4):323-335
For digital images and patterns under the nonlinear geometric transformation, T: (ξ, η) → (x, y), this study develops the splitting algorithms (i.e., the pixel‐division algorithms) that divide a 2D pixel into N × N subpixels, where N is a positive integer chosen as N = 2 k(k ≥ 0) in practical computations. When the true intensity values of pixels are known, this method makes it easy to compute the true intensity errors. As true intensity values are often unknown, the proposed approaches can compute the sequential intensity errors based on the differences between the two approximate intensity values at N and N/2. This article proposes the new splitting–shooting method, new splitting integrating method, and their combination. These methods approximate results show that the true errors of pixel intensity are O(H), where H is the pixel size. Note that the algorithms in this article do not produce any sequential errors as N ≥ N0, where N0 (≥2) is an integer independent of N and H. This is a distinctive feature compared to our previous papers on this subject. The other distinct feature of this article is that the true error bound O(H) is well suited to images with all kinds of discontinuous intensity, including scattered pixels. © 2011 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 21, 323–335, 2011 相似文献
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提出将气体静压轴系径向节流孔所在截面简化成平面汇交力系,并与边界约束条件一起构成误差方程,应用静力学的理论求解了一些典型情况,并推导出了典型状态下的误差均化值,发现其与过去的实验结果相符且得到了很有意义的结果,从而为进一步建立精确的数学模型进行仿真分析提供了必要的基础. 相似文献
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