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S. Sakano, H. Takagi
THE MEASUREMENT AND EVALUATION SYSTEM OF THE ENVIRONMENT SOUNDS

We are surrounded by many various sounds every day. There are sounds as displeasing sound and there are pleasing sounds like music by the degree of the sounds to us. A sound is one of very important common means in man-machine interface. Some investigations of how human feel to the sounds such as music, ordinary sounds and noises. We try to construct a sound evaluation system using MTS (Mahalanobis-Taguch System) in the paper. The aim of the study is to develop a system for evaluating various sounds to support the sound design like electric sound design. And the sounds such as noises are evaluated using the constructed sound evaluation system.

Francesco Adamo, Filippo Attivissimo, Nicola Giaquinto, Mario Savino
FREQUENCY DOMAIN ANALYSIS FOR INTEGRAL NONLINEARITY MEASUREMENT IN A/D CONVERTERS WITH DITHER

The paper examines the problem of achieving a fast measurement of nonlinearity for a dithered converter. It is shown that, since dither removes small-scale systematic errors, measuring the remaining large-scale (smooth) nonlinearity can be efficiently achieved via a fast frequency domain test, formerly analyzed by the authors for conventional converters without dither. The test appears especially suited for dithered converters, and can be useful for the periodic adjustment of a look-up table intended for removing large-scale nonlinearities.

Guillermo Robles, Romano Giannetti
FREQUENCY RESPONSE OF A MAGNETOOPTIC SENSOR USING MAGNETIC PULSES

The great advantage of using thin cobalt films as magnetooptic material in sensors to measure currents or magnetic fields is its wide bandwidth because it can reach the magnitude of several GHz. Though this fact is widely known, no effective measures have been taken. The aim of this paper, is to measure the frequency response and the bandwidth of a magnetooptic sensor based on thin cobalt films. Two experiments have been mounted regarding the range of frequencies in study. In the first stage, almost 200 Hz were reached using a sinusoidal magnetic field created with a Helmholtz coil. This frequency is suitable to measuring power lines currents or magnetic fields. Due to the fact that this coil has an extremely high impedance at high frequencies, an alternative method based on magnetic impulses has been developed. The range of frequencies is improved considerabily up to MHz.

C. Anagnostopoulos, I. Anagnostopoulos, E. Kayafas, V. Loumos
FUZZY LOGIC RULES FOR TURBOMACHINE MONITORING INSTRUMENTATION

Turbomachines’ maintenance diagnostic procedures are generally performed manually by expert engineers and technicians. However, there is a strong interest for expert systems to assist them in these complex fault identification procedures. The purpose of this paper is to describe and evaluate the implementation of a Fuzzy Logic (FL) system for fault diagnosis based on thermodynamic measurements of temperature and pressure. The measurements were taken in regular aerodynamic stations located lengthwise the engine. These stations are placed adequately in order to facilitate its performance monitoring.

Kresimir Malaric, Mirta Tkalec, Juraj Bartolic
USE OF GTEM-CELL IN BIOMEDICAL EXPERIMENTS

Use and application of the GTEM-cell, which is a transmission structure based on a TEM-cell approach, are described. The cell can be used for calibrating small antennas, for immunity and emission testing, and for biomedical experiments. It provides homogenous electromagnetic fields with TEM (transversal electromagnetic mode) distribution, similar to the free space. It has a shield to prevent radiation from the outside, which would interfere with our measurement. Plant Lemna minor has been exposed to the electric field similar to those of the cellular phones and the effect on the growth has been studied. The experiments included exposure to the frequencies of 400 MHz and 900 MHz with strength of electric field being 22 V/m. The time of exposure was 2 and 4 hours. The influence of AM (80%) 1 kHz sine modulation was also tested. Our investigations confirmed that electromagnetic field of frequencies produced by mobile phones or base stations can affect plant growth.

Consolatina Liguori, Alfredo Paolillo, Antonio Pietrosanto
AN ON-LINE STEREO-VISION SYSTEM FOR DIMENSIONAL MEASUREMENTS ON RUBBER EXTRUSIONS

The paper deals with the on-line measurement of dimensional parameters of rubber gaskets in automotive industries. The paper tackles the problem of the 3-D reconstruction, starting from couples of 2-D images, of object shapes. After a brief description of both the gasket production line and the measurement system, the edge detection, 3-D reconstruction and measurement algorithm are discussed in detail. Finally some information on the system metrological performance is given.

Jan Holub, Josef Vedral
EVALUATION OF FREQUENCY DEPENDENCY OF EFFECTIVE NUMBER OF BITS BY MEANS OF STOCHASTIC TESTING SIGNAL

The article describes a new method of Analog-to-Digital Converters testing that is suitable for testing of highresolution AD converters (e.g. Σ-Δ or dither-based) or on the contrary ultra high-speed AD converters. The method is based on the histogram test driven by stochastic signal with defined probability density function. By repeating of the test for different settings of band-pass filter that is inserted to the input testing signal path it is possible to obtain an estimation of frequency dependency of effective number of bits. This important information was obtainable by deterministic test only. Practical demonstration confirmed the usability of the method.

L. Angrisani, A. Baccigalupi, M. D’Arco, L. Ferrigno
A NEW DIGITAL SIGNAL PROCESSING METHOD FOR ACCURATE PHASE NOISE MEASUREMENT

The enhancement of a previous digital signal processing method, already proposed by the authors for phase noise measurement, is presented in this paper. The method shows itself particularly suitable for evidencing “close-to-the-carrier” phase-noise, which requires very high frequency resolution. Moreover, its input range results to be much wider than that characterizing the previous method, thus allowing a direct analysis of very high frequency carriers as well. The paper begins with the presentation of the key idea underlying the method; then, it describes in detail the proposed measurement procedure; finally, it points up the results obtained in some experimental tests in order to show the new method perspective.

Constantin Sarmasanu, Liviu Breniuc, Alexandru Salceanu, Veronica Sarmasanu
FUZZY- SYMBOLIC ION ACTIVITY MEASUREMENT IN TEST SOLUTIONS

This paper deals with several possible variants of selective electrodes used for measuring the concentration of ions that exist in test solutions. It presents the basic principles of the method, the possibilities of expanding it with a view to obtaining useful collateral information. Finally, a fuzzy-symbolic ion activity measurement and the configuration of a multi-sensor, computer piloted measuring system, capable of offering such information is presented.

M. Aiello, A. Cataliotti, S. Nuccio
A NEW MOTOR SPEED MEASUREMENT ALGORITHM BASED ON ACCURATE SLOT HARMONIC SPECTRAL ANALYSIS

In this paper a new induction motor speed method based on Chirp-Z Transform and zero padding of the supply current is presented. The algorithm has been implemented on a microprocessor. A virtual instrument has been built to control and to monitor on line motor speed. The motor speed method has been tested on a 7.5 kW induction motor driven by a pulse width modulation voltage source inverter for different load and supply frequency conditions. The proposed method has been compared to a FFT based one implemented on the same microprocessor. Thanks to a shorter sampling time window errors related to not stationary current signal are reduced. Then the achieved goal is an increased accuracy due to shorter sampling time window and better spectral resolution. Moreover the processing time has been reduced increasing algorithm speed response.

Page 431 of 977 Results 4301 - 4310 of 9762