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Fabio Leccese
A FIRST ANALYSIS OF PERCEIVED POWER QUALITY FOR DOMESTIC CUSTOMERS

The research shows as the deep lack of knowledge by low voltage and domestic customers is made the most by the producers/suppliers to impose their will disappointing the ISO 9000 certification. A new way to build the relationships between these actors is suggested with the declared aim to formulate new type of agreement based on the quality of electrical energy appropriately measured.

Corinne Curt, Aurélie Talon, Gilles Mauris
USING PHYSICAL MEASUREMENTS, SENSORY EVALUATIONS AND EXPERT JUDGEMENTS IN A DAM ASSESSMENT SUPPORT SYSTEM

In engineering system control, human beings can play various key roles in particular concerning measurement, global assessment and decision. It is recognised that in such complex systems many involved variables are evaluated with uncertainty. In this paper, we used a possibility theory based approach to formalise all the different uncertain pieces of information. An applicative example concerning the safety assessment of dams is presented.

Franco Pavese
SUBJECTIVELY- VS. OBJECTIVELY-BASED UNCERTAINTY EVALUATION IN METROLOGY AND TESTING

The general problem is wide and extensively treated in the literature. The paper intends to limit the discussion from the viewpoint of the metrologist to some aspects of the problems related to the concept of "true value", abandoned by GUM but still present in other international reference documents, and about the use of nonquantitative information or of prior knowledge in connection with the uncertainty evaluation in measurement.

Luca Mari, David Macii
ALTERNATIVE METHODS TO ESTIMATE MEASURAND VALUES: MODELS AND OPERATIVE IMPLICATIONS

This paper compares two alternative averaging methods commonly adopted to estimate measurand values, in agreement with the guidelines of the Guide to the Expression of Uncertainty in Measurement (GUM). According to the proposed analysis, validated in a simple case study, the choice of best estimation method should depend not only on the amount of nonlinearity of the measurement model, but also on the amount of definitional and acquisition uncertainty of the input measurands.

Kimmo Konkarikoski, Risto Ritala
OPTIMIZATION OF MEASUREMENT STRATEGY

Laboratory measurements are an integral part of process and quality management. Quite commonly, variables measured are statistically dependent and thus measurement of one variable is an indirect measurement of the others. Also, measurements are uncertain and thus there always is uncertainty about the quality. In this paper we formulate the optimal measurement scheduling problem of laboratory measurements. In particular, the objective is to minimize a weighted sum of measurement costs and uncertainty about whether the product confirms with given quality constraints or not. This problem is considered in the case when the joint probability density of variables is Gaussian, and when uncertainty evolves according to Ornstein-Uhlenbeck process.

Roald Taymanov, Ksenia Sapozhnikova
METROLOGICAL SELF-CHECK AND EVOLUTION OF METROLOGY

Indications of the crisis in the conventional methods of metrological assurance of sensors are analyzed. The analogy between biological and technical evolutions is discussed. It is shown that the near future is mass production of intelligent sensors and systems with metrological selfcheck, as well as the transition to a new stage in evolution of metrological assurance of sensors.

José Eduardo Manzoli, Patrícia C.P. Silva, Eduardo S. Moura, Carlos A. Zeituni, Maria Elisa C.M. Rostelato
INDIRECT MEASUREMENT OF RADIATION DOSE RATE FROM BRACHYTHERAPY 125 IODINE SEEDS BY NUMERICAL METHOD: PRELIMINARY COMPARISONS WITH ANALYTICAL CALCULATIONS

Brachytherapy, using radioactive iodine seeds, is a very important and efficient process of cancer treatment. These seeds are small sealed tubes of titanium, 4,50mm long, with the radioactive material inside. The amount of radiation to be imparted on a tumor has to be precisely evaluated, so any calculation process is welcome, beside the normative ones. In this work it is shown a numerical method to compute the exposure rate in the vicinity of the seed, and the results are compared with analytical calculations, in order to make a preliminary evaluation of the method.

Jerzy Hoja, Grzegorz Lentka
FAST IMPEDANCE SPECTROSCOPY METHOD USING SQUARE PULSE EXCITATION

The paper presents a fast impedance spectroscopy method for objects with very high impedance |Zx| = 1 GO modeled by multi-element two-terminal RC networks. The method is based on analysis of the object response in the time domain after square pulse excitation. The object impedance spectrum was obtained using continuous Fourier transform. Simulation tests were performed for different excitation pulse widths. Measurements in the realized system proved the usefulness of the method for parametric identification of equivalent circuits of the objects.

Sanowar H. Khan, Kirill Y. Aristovich, Alexey I. Borovkov
MATHEMATICAL MODELLING OF HUMAN BRAIN FOR MAGNETIC FIELD TOMOGRAPHY BASED ON MAGNETOENCEPHALOGRAPHY

This paper presents the methodology and some of the results of mathematical modelling of human brain in magnetic field tomography (MFT) by which sources of tiny bioelectric currents in the brain are located by measuring the magnetic field distribution produced by these current outside the head.

Reis M.L.C.C., Castro R.M., Falcão J.B.P.F., Barbosa I.M., Mello O.A.F.
CALIBRATION UNCERTAINTY ESTIMATION FOR INTERNAL AERODYNAMIC BALANCE

Aerodynamic balances are employed in wind tunnels to estimate the forces and moments acting on the model under test. This paper proposes a methodology for the assessment of uncertainty in the calibration of an internal multi-component aerodynamic balance. In order to obtain a suitable model to provide aerodynamic loads from the balance sensor responses, a calibration is performed prior to the tests by applying known weights to the balance. A multivariate polynomial fitting by the least squares method is used to interpolate the calibration data points. The uncertainties of both the applied loads and the readings of the sensors are considered in the regression. The data reduction includes the estimation of the calibration coefficients, the predicted values of the load components and their corresponding uncertainties, as well as the goodness of fit.

Page 784 of 936 Results 7831 - 7840 of 9356