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Laurentiu-Dan Milici, Mihai Cretu, Mariana-Rodica Milici
FRACTAL ANALISYS METHODS IN ESTIMATION AND PREDICTION OF SOME METEOROLOGICAL PARAMETERS

The estimating methods of the meteorological parameters at Meteorology and Hydrology National Agency (ANMH) standard offers sufficient data to answered at the requirements of the population. Thus, it was ascertained that through the determination of fractal dimension of temporal series obtains different values for neighboring zones, values which should complete the already existing information and which should offer supplementary data concerning the efficiency of such stations.

Pasquale Arpaia, Fabrizio Clemente, Mario Rapone, Carmine Romanucci
EVOLUTIONARY PATTERN RECOGNITION FOR MEASUREMENT OF VEHICLE EMISSION FACTORS IN CRITICAL DRIVING CONDITIONS

A research project on the measurement of emission factors in critical driving conditions arising from a cooperation among University of Sannio, Istituto Motori of CNR, and some companies of Italian Regione Campania is started. In particular, in this paper, a procedure of automatic feature extraction and data classification of vehicle driving sequences by means of Wavelet analysis and Cultural Algorithms is proposed. The procedure improves the lack of sensitivity of the state-of-the-art statistical methods to variations of vehicles instantaneous kinematic parameters (e.g. speed, acceleration) through a simple heuristic link between vehicle speed and road traffic data.

Jan Hlavácek, Karel Draxler, Radek Procházka
CURRENT TRANSFORMER USAGE FOR NONHARMONIC PERIODIC CURRENTS

This paper deals with composite error determination of current transformers (CT) for purpose of nonharmonic periodic current measurements. The experiment was performed for typical nonharmonic periodic waveforms that occur in power grids with frequency 50 Hz. The area of measurements was extended also for higher fundamental frequency values.

Sergey V. Muravyov, Valery N. Borikov, Stanislav A. Kaysanov
COMPUTER SYSTEM FOR MEASUREMENT OF WELDING PROCESS PARAMETERS

This paper presents both hardware and software of system for measurement of welding process electric parameters.
The distinctive feature of the system is its application for control of the process of high-quality contact micro-welding of critical destination products which is characterized by the pulse current in the range from 100 A to 20kA and by the pulse duration from a few to hundreds of milliseconds. The system is portable and consists of the measuring coaxial shunt, oscillograph and computer with a software. Structure and main principles of constructing the system components are described. Its technical and metrological parameters are given.

Celso Fabricio de Melo, Ricardo Luiz Araújo, Leonardo Morozowski Ardjomand Nilton S. Ramos Quoirin, Minoru Ikeda, Alexandre Albarello Costa
CALIBRATION OF MAGNETIC FIELD METERS AT 60 Hz USING A HELMHOLTZ COIL: CONSTRUCTIVE ASPECTS AND CALCULATION OF ASSOCIATED UNCERTAINTIES

This paper describes the construction of a Helmholtz coil to be used as a magnetic field generator during the calibration of magnetic field sensors. A magnetic field meter was calibrated using the coil to test its efficiency. The obtained results were then compared to the meter’s calibration sheet.

Pietro Vincenzo Barbaro, Antonio Cataliotti, Valentina Cosentino, Salvatore Nuccio
BEHAVIOUR OF REACTIVE ENERGY METERS IN POLLUTED POWER SYSTEMS

The reactive energy meters used in electric distribution networks are based on a conventional definition of reactive energy (or power) for sinusoidal voltages and currents, containing only the fundamental frequency component. As a consequence, the performances of reactive energy meters in the presence of harmonic distortion are not tested and their accuracy specifications can be very different from the nominal ones, that are evaluated in sinusoidal conditions. In this paper the authors present a comparative study of the performances of different reactive energy meters, both electromechanical and static, in the presence of harmonic distortion; the study is supported by several simulations and experimental tests.

Nico Deblauwe, Valentin Enescu, Leo Van Biesen
AN OPEN SOURCE BASED TELECOM MEASUREMENT SETUP BASED ON COMMERCIALLY AVAILABLE MOBILE PHONES

This paper presents a mobile measurement setup, VUBmeas, which is based on open source software and commercially available mobile phones. The system design, both from a hardware and software point of view and the possibilities will be looked at. Two examples of applications are given to show its broad usability: one more in the field of positioning, the original field of research it was developed for.

Jerzy Nabielec, Jacek Nalepa
A SIMULATION INVESTIGATION OF DIFFERENTIAL ALGORITHM FOR THE “BLIND CORRECTION” OF DYNAMIC ERROR IN MEASURING CHANNELS WITH PERIODIC NONSTATIONARITY

The paper presents the application of a differential algorithm for the “blind correction” method with respect to measuring systems where both: the measured signal and parameters of the measuring channels are varying with the same fundamental frequency. The influence of the measuring channels’ parameters on the effectiveness of correction was investigated for the polyharmonic case, using the simulation methods.

Stanislaw Moskowicz
FLUXGATE SENSOR WITH A SPECIAL RING-CORE

In the proposed design of a ring-core sensor, three windings, namely the exciting, the sensing and the compensating ones are applied directly on a special ringcore. The core is also wrapped with an additional winding that controls the so-called virtual air-gap. The virtual air-gap enables the sensor sensitivity to be adjusted in wide range. In the paper the design and test results of the proposed sensor are presented.

V. Pop, P.P.L. Regtien, H.J. Bergveld, P.H.L. Notten, J.H.G. Op het Veld
UNCERTAINTY ANALYSIS IN A REAL-TIME STATE-OF-CHARGE EVALUATION SYSTEM FOR LITHIUM-ION BATTERIES

Lithium-ion (Li-ion) is the most commonly used battery chemistry in portable applications nowadays. Accurate State-of-Charge (SoC) and remaining run-time (tr) calculation for portable devices is important for the user convenience and to prolong the lifetime of batteries. A new SoC algorithm for Li-ion batteries that combines adaptivity with direct measurement and book-keeping systems has been developed and implemented in a real-time evaluation system.
In this paper the error sources in the real-time SoC evaluation system with possible calibration solutions are described. The goal of the SoC system is to predict the remaining run-time of a Li-ion battery with an uncertainty of 1 minute or better under all realistic user conditions, including a wide variety of load currents and a wide temperature range.

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