Technique of Calibration of a Working Standard of the Energy Unit of Narrow-Pulse Laser Radiation and Results of Trial Use of the Standard

Questions related to the design and testing of a technique of calibrating a working energy unit of narrow-pulse laser radiation by means of an electrical working system and determining the degree of equivalence of the optical and electrical conversion ratios of a calorimetric detector are considered. Results from calibration of the standard in the course of a trial period are also presented.     

运用人工神经网络对物理标准的量值进行预先估计

通过建立物理标准的某一物理量值与该物理标准的其它特性指标之间的神经网络模型,求解得出该物理量值。研究结果表明此方法性能良好,可望成为预先估计物理标准量值的有效手段。     

Results of Comparisons of the Working Standards of Frequency Deviation

The results of comparisons of six working standards of frequency deviation, carried out using a new comparator, are considered.     

Estimating the Uncertainty of a Primary Acoustic Standard by Numerical Methods

It is proposed using numerical methods to estimate the accuracy characteristics of complicated functions such as those of the primary acoustic standard. Two methods are considered: a numerical method, in which the component of the uncertainty (or error) in the measured quantity is related to input quantity k and is determined as the partial increment in the model function, and simulation (Monte Carlo method), which gives the best results.__________Translated from Izmeritel’naya Tekhnika, No. 5, pp. 15–19, May, 2005.     

Choice of Agreement Criterion for Determining the Distribution Law of a Measured Quantity

The method of simulation modeling was used to perform a comparative analysis of the characteristics of a number of agreement criteria under conditions of restricted sampling. A method is proposed for modifying the ² criterion for the purpose of broadening its range of application.     

National Standards of the Harmonic Coefficient Unit of the Russian Federation and the Republic of Belarus: Results of Comparisons

Measurement Techniques - The article presents the results of supplementary comparisons of the national standards of the harmonic coefficient unit of the Russian Federation (VNIIFTRI) and the...     

中国参加温度关键比对结果分析

本文介绍了国际计量委员会(CIPM)组织国际关键比对的背景和已经开展的温度比对项目。对中国计量科学研究院参加的温度比对项目进行了系统介绍和结果分析。     

中国参加温度关键比对结果分析

本文介绍了国际计量委员会(CIPM)组织国际关键比对的背景和已经开展的温度比对项目。对中国计量科学研究院参加的温度比对项目进行了系统介绍和结果分析。     

Theoretical Principles for Measuring the Components of a Vector Physical Quantity

The concept of a vector multicomponent physical quantity is used in defining a method space and formalizing the procedure for systems synthesis and resolving problems of measuring components of compound displacements and strains in multidimensional mechanical objects.     

Maximum-Likelihood Estimation of the Parameters of a Four-Parameter Generalized Gamma Population from Complete and Censored Samples

Consider the four-parameter generalized Gamma population with location parameter c, scale parameter a, shape/power parameter b, and power parameter p (shape parameter d = bp) and probability density function f(x; c, a, b, p) = p(x — c) ^bp–1 exp {–[(x – c)/a] ^p }/a ^bp Γ(b), where a, b, p > 0 and x ≥ c ≥ 0. The likelihood equations for parameter estimation are obtained by equating to zero the first partial derivatives, with respect to each of the four parameters, of the natural logarithm of the likelihood function for a complete or censored sample. The asymptotic variances and covariances of the maximum-likelihood estimators are found by inverting the information matrix, whose components are the limits, as the sample size n → ∞, of the negatives of the expected values of the second partial derivatives of the likelihood function with respect to the parameters. The likelihood equations cannot be solved explicitly, but an iterative procedure for solving them on an electronic computer is described. The results of applying this procedure to samples from Gamma, Weibull, and half-normal populations are tabulated, as are the asymptotic variances and covariances of the maximum-likelihood estimators.     

1．2—24K（ITS—90）国家温度工作基准组的建立

介绍了1．2－24K（ITS－90）国家温度工作基准组的建立及不确定度的分析，并对工作基准组进行了考核，用从NPL引进的5支铑铁电阻温度计的平均值作为1．2－24K温区的标准，实验分析表明，工作基准组在1．2－24K温区的总不确定度为2.7mK.     

Method and Installation for Transferring the Unit of Flow Measurement from Standards to Working Measuring Instruments

A new, effective method is proposed for transferring the unit of flow measurement by using more comparators (flowmeters) simultaneously. A device for implementing the method is described and calculations are made for new, more accurate flow-measuring installations.     

Design of and Preliminary Results on a Cesium-Beam Standard at the Radio Research Laboratories

A laboratory type cesium beam standard is being constructed for experimental use as a working standard at the RRL of Japan. Ihe structural design and experimental results on the phase adjustment of Ramsey cavity, the beam optics employing hexapole magnets, and an axial C-field, and the digital servo system are described. Methods for evaluating the beam velocity distribution employing a pulse technique and the analysis of the Ramsey pattern are examined. Observed intensity of Ramsey signal proved satisfactory, and other experiments are now proceeding.     

Method of Estimating the Effectiveness of a System for Transferring the Sizes of the Units of Physical Quantities

A method is proposed for estimating the effectiveness of a system which is based on transferring the sizes of the structural units of a regression model. The regression model is a function of the basic factors influencing the effectiveness of the system.     

Increasing the Accuracy of Reproduction of Pressure by Means of the Ukrainian Secondary Standard of the Unit of Pressure

The estimated components of the error in the determination of the effective area of a measuring piston-cylinder assembly of a piston manometer with a non-sealed piston are reported. Such manometers are incorporated into the secondary standard of the unit of pressure.     

Interval Estimation of the Parameters of a Distribution from a Sample of a Random Quantity

A program is developed for solving the problem of making an interval estimation of the parameters of a distribution from a single sample of a random quantity, based on a statistical modeling method. The results of a solution of the problem for certain symmetric and asymmetric distributions are presented. The average error in estimating the confidence intervals and their limits is 4–15% in the range of values of the confidence level of 0.8 P 0.998 for a sample volume of N = 500–1000.