|MEASUREMENT SCIENCE REVIEW Volume 7, Section 1 Main Page|
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|Theoretical Problems of Measurement|
Osanna P.H., Durakbasa N.M., Kräuter L., Güclü E.:
describes the importance of certification of personnel working both in the
fields of metrology and quality assurance on the one side in industry and
economics in general and on the other side in any other kind of
organisations both in the service and in the public domain. In Europe exists
a harmonised scheme for the international registration and certification of
quality personnel that is fully recognised between more than thirty
countries throughout whole Europe and similar educational activities have
already been proposed recently for education in metrology and to train
metrology personnel and experts in the field of metrology.
quality management, quality personnel, accreditation, certification,
Abstract: At many universities and training institutes education in metrology or measurement science is in strong competition with upcoming disciplines. Its importance for science and engineering remains, however, evident. Advanced instruments make measuring almost a routine activity, but it is shown that a critical approach when performing and evaluating measurements is still of vital importance.
Keywords: education, measurement science, metrology
Štolc S., Bajla I.:
Abstract: This In the year 2003, World Anti-Doping Agency (WADA) initiated an international project with the goal to develop a suitable and easy to use software system aimed at the standardized quantitative analysis of digital images acquired during the process of erythropoietin (Epo) doping control. Within the cooperation between Austrian Research Centers GmbH and Institute of Measurement Science, Slovak Academy of Sciences, improved image preprocessing method has been developed. The proposed method – Band Straightening Algorithm (BSA) – significantly reduces local geometric distortions in Epo images that cause band detection problems, especially incases with geometrically distorted and disrupted bands. The accuracy of the band detection is one of the most critical points of the Epo image analysis. In the year 2006, the proposed method has been implemented in the latest release of the software package GASepo 2.1, which is used in Doping-Control laboratories worldwide.
Keywords: Epo doping control, image segmentation, band detection, image filtering, geometrical distortion correction, correlation analysis
Hofmann D., Linss G.:
Vision sensors are innovative measurement systems for visual quality control
with digital imaging. Vision sensors are convenient, reliable and
affordable. Their bulk application is forthcoming. Unreliable measurements
with vision sensors are possible due to unreflected error sources. Aim ot
the paper is to call attention to particular features of optical
measurements to reduce operating errors by undefined metrological standards
Mosiadz M., Orzepowski M.:
Resistors calibration gives
high level of measurement accuracy. Analysis of results and uncertainty
budget should consider influence of temperature changes on resistance.
Article describes resistors temperature properties, influence of temperature
changes for results, and influence of temperature coefficients uncertainties
for uncertainty budget.
Palenčár R., Halaj M., Kureková E.:
Nowadays many modern production machines require positioning in thousandths
of millimeter. Therefore a big attention must be paid to prepare such a
controlling software that drives individual axes of the production machine
which minimises deviations between the desired position and actually reached
position. The so called positional deviation (difference between the actual
and target position) belongs to the important criteria that describe the
performance of numerically controlled axes. The procedure for determination
of such deviation is described in the international standard ISO 230-2:1997.
This standard provides calculation of the positional deviation only in
several discrete (measuring) points. Moreover it does not consider effects
of the measuring instrument on the obtained results. Thus the new
methodology must be adopted that enables estimation of the positional
deviation in any point of the axis travel, together with the uncertainty of
such estimate. Obtained results can be incorporated into a control system in
the form of corrections enhancing positioning possibilities of individual
Abstract: Cancer is one of the leading causes of death in the world. Breath analysis is a possible diagnostic tool for early detection of lung and esophageal cancer (for more details consult e.g. the FP6 project of European Commission BAMOD – Breath-gas analysis for molecular oriented detection of minimal diseases). In this paper we deal with estimating generalized confidence intervals for the ratio and the difference of log-normal means, which are based on generalized pivotal quantities. We provide series of computer simulations and apply this method to the breath analysis data. We present the estimated 95% generalized confidence intervals for the ratio and the difference of mean concentrations of selected volatile organic compounds for patients with lung cancer and healthy volunteers. From results we would like to find potential bio-marker of lung cancer.
Keywords: breath compounds, confidence intervals, generalized pivotal approach, generalized pivotal quantities
Kamenský M., Kováč K.:
Abstract: Iterative method of measurement error correction is presented. The method is useful for digital measurements e.g. for successive approximation ADC. In this case method impact on accuracy could be enhanced using oversampling and averaging as proved on the basis of experimental results with evaluation of ENOB and SNR.
Keywords: measurement error correction, iterative method, oversampling
Mocak J., Janiga I., Rievaj M., Bustin D.:
Abstract: Differentiation or integration with fractional order (differintegration) is favourable mainly in the form of the semiintegral or semiderivative of the original measured signal. It is used for substantial improvement of the signal shape and, consequently, the way how the measurement is evaluated. In the case of semidifferentiation also a better signal resolution is observed. A new, effective GS numerical algorithm of differintegration is here presented.
Keywords: signal shape, fractional differentiation, fractional integration
Abstract: Finite sample performance of two non-affine invariant multi-sample location parameter tests based on spatial medians is studied by simulations in case of spherically symmetric distributions of the samples. We demonstrate that the decrease of the powers of the tests in case of extreme ellipticity depends also on the distances of the true location parameters. It is also shown how can the ellipticity of the samples have also a positive effect.
Keywords: multi-sample location problem, spatial median, spherical and elliptical symmetry, affine invariance, power of test
The paper suggests
algorithms enabling self-calibration of measurement channels with linear as
well as nonlinear conversion functions. To approximate conversion
characteristics interpolation methods are used. They are widely known,
however the essence of the suggested selfcalibration method is current
modernization of interpolating functions parameters due to suitable
procedure. It enables correction of the two essential error components,
which may appear in the measurement channel, by means of evaluating of the
current value of the real slope of the conversion characteristic as well as
of the components describing nonlinearity generated (or modified) by
disturbing factors. In the paper methods of self-calibration for measurement
channels cooperating with non-electrical quantities sensors have been
compared. Interpolation of conversion functions has been assumed as linear
in intervals and polynomial.
The paper is devoted to
comparison of different confidence intervals for a variance component
corresponding to the random factor in mixed linear models with two variance
components. Namely, generalized confidence intervals (based on fiducial
generalized pivots (FGP), see Hannig et al. (2006)) are compared to an
approximate solution suggested by El-Bassiouni (1994). We focus on FGPs of
certain types that were shown to yield exact intervals in some limiting
situations. This makes them more equivalent counterparts to the
El-Bassiouni’s interval, if frequentist properties are the main concern. A
simulation study is presented that reveals, how besides sharing the limiting
properties, these FGPs and the mentioned approximate interval perform with
respect to each other. We also comment on a relationship between the
considered types of FGPs.
Witkovsky V., Wimmer G.:
We consider the problem of
evaluation of the measurement results from the interlaboratory comparisons
in metrology. It is assumed that the laboratories have either normally,
uniformly, or triangularly distributed systematic errors (biases). We
propose an approximate interval estimator for the common mean, i.e. the true
value of the measurand. The empirical coverage probabilities of the
suggested interval estimator were estimated and compared by large Monte
Carlo simulations for different experimental designs. The suggested approach
is based on a metrological methodology and is fully consistent with the
Supplement 1 to the Guide to the Expression of Uncertainty in Measurement -
Propagation of Distributions Using a Monte Carlo Method.