SECTION 1                          Download and print the front cover  ->>  

 No. 1

Volaufova J.:

Statistical Methods in Biomedical Research and Measurement Science

Abstract:  In this paper we concentrate on few statistical methods that are widely used in the analysis of clinical trials and clinical studies and are also used in theory of measurement science.

Keywords:  Mixed linear model, two-way mixed models, bias of a measurement, uncertainty of a measurement, methods comparison

Otomanski P.:

Calculation of the approximate coverage factor value for the convolution of two Student’s distributions and one rectangular distribution

Abstract:  The result of examining error evaluation of the coverage factor in indirect measurement has been presented in the paper. To determine coverage factor value, the use of mathematical model, for analysed convolution of component distributions has been presented. The knowledge of coverage factor characteristics for the convolution of two Student’s distributions and one rectangular distribution was used for the examination.

Keywords:  Expanded uncertainty, mathematical model, coverage factor

 No. 2

Duris S., Palencar R.:

The Influence of Covariance on the Uncertainty of Temperature Measurement by Resistance Thermometer

Abstract:  Results of the measurements shall be presented with the corresponding uncertainties. In accordance with the international accepted documents the covariance should be taken into account if possible. In this paper the standard platinum resistance thermometer (SPRT) calibrated at the defining fixed points (DFPs) is considered. This thermometer is used for temperature measurement in the range from 0 °C up to 660 °C. Value of temperature is determined in accordance with the International temperature scale 1990 (ITS – 90) by using of inverse reference function. The law of propagation of uncertainties for the interpolation of temperature between the DFPs is applied. In the conclusion is the discussion concerning the influence of covariance caused by the triple point of water (TPW) to the result of measurement, specifically to the evaluation of the uncertainties.

Keywords:  Temperature measurement, propagation of uncertainties, covariance, SPRT calibration

Witkovsky V.:

Comparison of some Exact and Approximate Interval Estimators for Common Mean

Abstract:  In this paper we compare several exact and approximate interval estimators, suggested in recent statistical literature, for the common mean in the one-way fixed effects model. The common mean problem is also known in metrology where the experiments based on interlaboratory comparisons are provided in order to identify the comparison reference value (CRV).

Keywords:  Interlaboratory studies, comparison reference value, common mean, confidence interval

 No. 3

Rublik F.:

On Rank Based Multiple Comparisons for the Balanced Sample Sizes

Abstract:  It is shown that neither the Nemenyi rule based on the joint ranking, nor the Dwass, Steel, Critchlow-Fligner rule based on the pairwise ranking, is preferable to each other, if the number of the underlying populations is k = 3 or k = 4, the sample sizes from all sampled populations are the same and the rules are used in conjunction with the Kruskal-Wallis test. The assessment of the multiple comparisons rules is based on the simulation estimates of their effectiveness and reliability, expressed in terms of conditional probabilities of good and wrong decision.

Keywords:  Multiple comparisons procedure, joint ranking, pairwise ranking, Kruskal-Wallis test

Savin A.:

Confidence Intervals for Common Mean in One-way Classification Model with Fixed Effects

Abstract:  In this paper we consider the various methods for interval estimation of the common mean - the problem that appears in interlaboratory studies but is also closely related to the multicenter clinical trials and meta-analysis. Here we present the statistical properties (based on large simulation study) of the proposed confidence intervals.

Keywords: Interlaboratory study, common mean, one-way classification model, fixed effects

 No. 4

Stein G. J.:

On Calibration Uncertainty Estimation in Ratio-metric Measurements

Abstract:  The formula for uncertainty estimation of the result of a ratio-metric measurement is derived. The result uncertainty decisively depends on the knowledge of the statistical correlation between the measurements by two measuring chains, assumingly of same kind and same metrological quality. A calibration procedure is stipulated and a practical example is treated, based on some recently published data. The same approach could be used in other ratio-metric measurements and such measurement calibration procedure as well.

Keywords:  Ratio-metric measurement, measurement uncertainty, calibration uncertainty

Szolik I., Kovac K., Smiesko V.:

Influence of Noncoherent Sampling Upon an Error of Power Quality Parameters Measurement

Abstract:  The paper deals with errors which rise up during discrete realisation of harmonic analysis for power quality measurements. By this the coherence of sampling interval has a significant influence upon the error of measurement. Presented paper analyses the influence of window function type upon the resulting error of analysis as well as the influence of length of analysing interval. The analysis is performed for frequency fluctuations allowed according to conditions given in technical standards.

Keywords: Power quality measurement, harmonic analysis, noncoherent sampling, window functions

 No. 5

Michaeli L., Michalko P., Saliga J.:

ADC Testing by Decomposition of the Error Model

Abstract:  Improvements in technology, increasing in resolution and various correction techniques of analogue-to-digital converters (ADC) makes linearity testing of ADC difficult and time-consuming task. New methods and approaches are examined. Static and histogram tests require long time measurement and huge amount of data to be analysed. This paper deals with original approach for ADC modelling and testing that reduces time of measurement, providing information about linearity errors character with a good precision.

Keywords: ADC testing and modelling, error model

Szlachta A.:

Conditional Averaging of a Delayed Signal Module in Measurements of the Phase Shift of Sinusoidally Noised Voltages

Abstract:

That study presents a new measuring method of a phase shift angle measurement with use of conditional averaging of interfered signals.

Keywords:  Phase angle, noisy signals, conditional averaging, models

 No. 6

Surmacz T. R.:

Measurement of Data Flow in Usenet News Management

Abstract:  Usenet news is a worldwide network of servers providing discussion forums with topics ranging from scientific research to hobbies, entertainment or politics. Current volume of news stream can take up to 200 gigabytes per day if binary groups are included, so appropriate tools for measuring data flow between servers are needed to allow the optimal usage of the underlying network bandwidth. The paper describes methods of measuring the flow of articles, delays introduced by message transmission and other data, as well as problems of detecting anomalies and dealing with them in order to assure a smooth operation of the whole system. Conclusions are drawn from the data gathered over the last 12 months.

Keywords:  Usenet news, data flow measurement

Stofanik V., Vretenar V., Bohac V.:

Compensation of Systematic Error due to Sampling Rate versus Temperature Dependency utilizing a Dual-Mode Crystal Oscillator

Abstract:  The paper describes a novel approach of the system clock frequency versus temperature dependency compensation. Realized digital signal processing system reduces the systematic error due to sampling frequency versus temperature dependency below ± 0.15 ppm over a temperature range between -45°C and +95°C. The system clock signal is derived from a dual-mode crystal oscillator. Since all the necessary temperature information are obtained directly from a crystal itself rather than from an external sensor, temperature offset and lag effects are eliminated.

Keywords:  Dual-mode crystal oscillator, sampling rate, frequency stability, DSP

Khalili K., Razavi S. A., Karimzadgan D.:

High Resolution Measurements Using a Low Resolution System

Abstract:  The resolution of any measuring device influences significantly the achievable accuracy of the system. In this paper, the resolution limitation of measuring devices has been addressed. A theory is developed that allows a measuring device to measure beyond its resolution capability. It is theoretically proved that a very high resolution can be achieved with a very low resolution system. The application of the theory is suggested to be employed by vision system, however, the methodology is applicable to other digital measuring devices.

Keywords:   Resolution, metrology, machine vision, automated measurement