Pasquale Daponte

A measurement laboratory on geographic network for remote test experiments

A remote laboratory for teaching purposes in the field of measuring experiments was activated. Students can access automatic measuring setups and instruments via geographic network and directly carry out real experiments. With respect to current literature solutions, this has been realized on the basis of de-facto networking standards so that students are required to use only a simple commercial Web Internet browser. Moreover, a concurrence of more users on the same measuring setup is allowed. The remote laboratory concept allows measuring resources spread on different geographically remote sites to be utilized by a wide deal of students. In this way, a more complete educational proposal can be economically offered by several geographically remote laboratories specialized in different measuring fields.

Wavelet network-based detection and classification of transients

A methodology is presented for developing a digital signal-processing architecture capable of simultaneous and automated detection and classification of transient signals. The basic unit of the aforementioned architecture is the wavelet network, which combines the ability of the wavelet transform of analyzing nonstationary signals with the classification capability of artificial neural networks. By exploiting the modularity as well as original strategies concerning wavelet network implementation and training, the method succeeds in enhancing the classification performance with respect to other available solutions.

A state of the art on ADC error compensation methods

Analog-to-digital converters (ADCs) are critical components of signal processing systems. ADC errors can compromise the overall accuracy and the effectiveness of the whole system. This leads the researchers to direct an increasing attention to error correction topics. In the paper, some ADC error compensation methods are briefly introduced according to a classification criterion based on the main research trends.

Artificial neural networks in measurements

This paper, after a brief theoretical background to Artificial Neural Networks (ANNs) reviews their utilization in the field of measurements. The criteria used for choosing between the possible ANN software and hardware implementations are then discussed. The advantages and disadvantages of the possible analogue or digital hardware implementation are also detailed. Some of the applications of ANNs in the measurements field, variously utilizing software, analogue or digital hardware implementations are shown. In particular, the strategies for building suitable ANN-based software models of mixed analogue/digital measurement devices are presented. Successively, a method for designing a neural network able to pre-process signals in an analogue mode is described. Finally, the architecture of a DSP-based neural apparatus for the real-time measurement of the components of a dual-tone multi-frequency signal is given.

Remotely accessible laboratory for electronic measurement teaching

Abstract The paper presents a remotely accessible laboratory realised for didactic aims at the University of Sannio, Italy. The laboratory is based on a software framework, with modularity characteristics that allows the insertion of new applications or the modification of the realised ones. Thanking to its implementation in Java and C++ with a CORBA communication layer, some instruments have been made available to the students of electronic measurement courses through a simple web browser in the form of Virtual Instruments (VIs).

ANN-based error reduction for experimentally modeled sensors

A method for correcting the effects of multiple error sources in differential transducers is proposed. The difference in actual characteristics of the sensing elements of the differential scheme, and an easily controllable auxiliary quantity (e.g. supply voltage of conditioning circuit) provide independent information for the correction. This is carried out by a nonlinear multidimensional inverse model of the transducer based on an artificial neural network. Experimental results of the correction of a variable-reluctance displacement transducer, subject to the combined interference of structural and geometrical parameters, highlight the effectiveness of the proposed method.

ADC parameters and characteristics

Today, most of the signal processing performed in electronic systems is digital, and the performance of the analog-to-digital converters (ADCs) present at the borders of the digital domain become very important. The most recent applications in telecommunication, measurement, and consumer electronics call for ever-increasing ADC resolution and speed. The uncertainty of ADC performance strongly affects overall system accuracy. Both manufacturers and system integrators are intensely concerned with ADC performance.

Performance analysis of an ADC histogram test using small triangular waves

The histogram method using small-amplitude triangular waves for the quasi-static test of analog-to-digital converters has been proposed for standardization aims. In this paper, after a brief description of the test procedure, analytical closed-form relations for designing the test, as well as for its characterization in terms of efficiency and uncertainty, are provided. Numerical and experimental results of a comparative analysis with the IEEE 1057-standard static test highlight its better performance in terms of efficiency and accuracy.

Ultrasonic signal-processing techniques for the measurement of damage growth in structural materials

In recent years, the ultrasonic signal-processing technique, which has been enormously successful in material testing, has found few applications in the analysis of concrete damage because of the heterogeneous nature of this material. In the present study, frequency-domain analysis of the ultrasonic signals, based on the Segmented Chirp Z-Transform, has been used to both detect and monitor the crack growth in structural materials. In comparison with the usual methods of pulse velocity or attenuation measurement, a very sensitive and accurate testing method was obtained. The experimental setup is described and the preliminary results, relating to uniaxial compression tests carried out on cubic concrete specimens and bricks, discussed. >

A state of the art on ADC modelling

Abstract The state of the art of the research on modelling of analog-to-digital converter (ADC)-based measuring devices is surveyed. Main topics of modelling are reviewed according to the fields of prevailing scientific interest in metrological research such as quantization models, error models, and correction-aimed models. In these fields, recent developments are analysed with the aim of focusing both the contemporary situation and the imminent trends.