# uncertainty

## DIRECT SOLUTION OF POLYNOMIAL REGRESSION OF ORDER UP TO 3

This article presents results related to the direct solution of the polynomial regression parameters based on the analytical solving of regression equations. The analytical solution is based on the normalization of the values of independent quantity with equidistance steps. The proposed solution does not need to directly solve a system of polynomial regression equations. The direct expressions to calculate estimators of regression coefficients, their standard deviations, and also standard and expanded deviation of polynomial functions are given.

## CALIBRATION OF QUARTZ ELECTRONIC STOPWATCHERS COMPARISON METHOD USING A DIGITAL CAMERA

Measurement of time intervals with low accuracy on intervals from a few seconds to several hours or days is relevant for some broad applications in various fields of activity. Such measurements are widely used in the technological processes of various enterprises during the preparation and quality control of the preparation of medicines, during the maintenance of technical equipment and mechanisms, chemical technological processes, etc.

## Robust multi-objective optimization for solving the RFID network planning problem

Radio-frequency identification (RFID) is a new technology used for identifying and tracking objects or people by radio-frequency waves to facilitate automated traceability and data collection.  The RFID system consists of an electronic tag attached to an object, readers, and a middleware.  In the latest real applications based on the RFID technology, the deployment of readers has become a central issue for RFID network planning by means of optimizing several objectives such as the coverage of tags, the number of readers, and the readers/tags interferences.  In practice, the system is affect

## ANALYSIS OF CALORIMETRIC METHOD OF MEASUREMENT OF NATURAL GAS CALORIFIC VALUE

The article considers the current methods of measuring the calorific value of natural gas which are valid in the upto-date gasometry. The procedure for measuring the gross and net volume-basis specific calorific value of natural gas by the calorimetric method is analyzed. It is shown that to increase the accuracy and validity of measurement results, the experiment to determine the values of gross and net volume-basis specific calorific should be performed for at least 5 samples of the investigated gas.

## Modeling in the Field of Freight Transportation: Ambivalence of Management Decisions in the Conditions of Quarantine Restrictions and Economic Competition

The study focuses on the ambiguity of management decisions in conditions of economic competition and quarantine restrictions. It is concluded that in the field of freight transportation there are antagonistic interests of the environment in the process of making management decisions by managers of JSC “Ukrzaliznytsia”. The classification of information situations related to the uncertainty of the environment is used, according to which the fifth information situation most closely corresponds to the current situation in the market of transport services.

## LONG-TERM STABILITY OF Co-C AND Pd-C EUTECTIC FIXED POINTS FOR THERMOCOUPLES CALIBRATION

Eutectic fixed points are close to becoming a reference for high temperatures calibration, especially as the new International Temperature Scale (ITS) approach to issue after the re-definition of the Kelvin unit.

## On the asymptotic output sensitivity problem for a discrete linear systems with an uncertain initial state

This paper studies a finite-dimensional discrete linear system whose initial state $x_0$ is unknown.  We assume that the system is augmented by two output equations, the first one $z_i$ being representing measurements made on the unknown state of the system and the other $y_i$ being representing the corresponding output.  The purpose of our work is to introduce two control laws, both in closed-loop of measurements $z_i$ and whose goal is to reduce asymptotically the effects of the unknown part of the initial state $x_0$.  The approach that we present consists of both th

## UNCERTAINTIES OF THE ESTIMATORS AND PARAMETERS OF DISTRIBUTION IN MEASUREMENTS WITH MULTIPLY OBSERVATIONS

The article shows that the commonly used method of estimating the Type A uncertainty of measurements based on the standard deviation of estimators of population parameters does not meet the definition of uncertainty. For correct determination of the standard uncertainty, it is necessary to use the distribution of the corresponding population parameter at the values of population estimators determined from the experiment but not the probability distribution of the estimator.

## Processing of the length measuring results during comparisons or calibrations the distance meters and total stations on a field comparator

A method has been developed for the adjustment of the results of measurements of length during calibration of a field comparator for verification (calibration) of distance meters and distance metric parts of total stations. The method of processing the results of comparisons of distance meters to the field comparator using the least squares method (LSM) was also developed on its basis. The additive biases of length measurements by each distance meter are evaluated according to the LSM, as well as the biases that are entered to the results of length measurements by each reflector.

## Equation of Arithmetic Mean Deviation of Roughness Profile

In order to improve the accuracy of gas flowrate measurement by means of the differential pressure flowmeters, it is necessary to apply equations for determination of coefficients of gas flow equation, which would provide the lowest total relative expanded uncertainty of calculation, and to increase the accuracy of input values measurement in real time. One of these values is the arithmetic mean deviation of roughness profile of pipe internal surface. The equation for calculating the arithmetic mean deviation of roughness profile of pipe internal surface in real time was obtained.