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A. Sabatini, A. Moschitta, P. Carbone
ΣΔ-BASED REMOVAL OF UNWANTED SPECTRAL COMPONENTS FOR SINEWAVE SYNTHESIS

This paper addresses the generation of spectrally pure sinewaves by combining the feedback structure of a ΣΔ loop with digital cancellation of unwanted spectral components in the output signal. In particular, the non-linearities of the in-loop Digital to Analog Converter (DAC) are compensated by applying a digital pre-distortion to the DAC input, and the feedback architecture is used to enhance the performance of the all digital estimation and cancellation algorithm.

G.Betta, D.Capriglione, C.Spataro, G.Tinè
SITE-TO-SITE REPRODUCIBILITY IN CONDUCTED IMMUNITY TESTS ON PC-BASED DATA ACQUISITION SYSTEMS

This paper deals with electromagnetic susceptibility of PC-based data acquisition systems (DASs) when subjected to electromagnetic disturbances considered in the EMC applicable standards. A suitable measurement procedure that allows the DAS susceptibility to be highlighted is proposed. Furthermore, a preliminary analysis of the measurement reproducibility is carried out with the aim of investigating some aspects that could affect the result reliability: the environmental and instrumentation features, the configuration set-up. To these aims, a number of tests are carried out by considering many data acquisition systems, different test set-up, and performing the experiments in two different sites. The connected results are compared and commented.

Zbigniew Czaja
TESTING METHOD OF ANALOG PARTS FOR MIXED SIGNAL MICROSYSTEMS BASED ON MICROCONTROLLERS

In the paper a new method of fault detection and location of a single soft fault in analog parts of mixed signal microsystems based on microcontrollers is presented. The idea of the method bases on the transformation which maps changes of the time response of the tested circuit on a square impulse resulting from changes of values of respective elements onto identification curves on a plane. The method consists of two stages. In the first stage a fault dictionary of an analog part in the form of a family of identification curves is generated and it is placed in the program memory of the microcontroller. In the second stage detection and a location of the fault are carried out.. This method does not require extra hardware in the microsystem. The measuring-diagnosis procedure is realised only by the microcontroller already existing in the microsystem.

Jan Chládek, Pavel Jurák, Josef Halámek, Igor Nestrašil, Robert Roman, Ivan Rektor
EVENT DIFFERENTIATION IN AVERAGED SIGNALS BY METHOD OF THE CREDITS

Presented Method of the Credits and its application are based on the determination of the statistically significant signal in the accumulated data. The method helps to determinate whether EEG signal is rather stimulus related than response related.

M. Gagliarducci, D.A. Lampasi, L. Podestà
REMOTE MONITORING AND CONTROL OF PHOTOVOLTAIC PLANTS BY MEANS OF GSM SYSTEM

This paper describes a system to remotely monitor and control complex stand-alone photovoltaic plants. In normal conditions the developed system registers and reports the overall performances; in case of incorrect behaviors it seasonably informs the operators. Moreover through appropriate instructions sent by users it allows to change the configurations of the plant and the settings of the measurement system as well. Several means of communications are available due to the need to adapt the system to the different operative conditions. However for a more general and flexible implementation, the remote control is carried out through the GSM network and in special way exploiting the SMS (Short Message Service) feature.

L.Breniuc, C.G. Haba, A.Salceanu
LEARNING REMOTE TEMPERATURE MEASUREMENT IN INSTRUMENTATION LABORATORY

In our paper we present a laboratory temperature measuring system that can be remotely accessed by Internet. The system is based on the DS18B20 and DS1822 digital temperature sensors controlled with the aid of a microcontroller board PCB80c552. The system is used to measure and monitor the temperature in different places inside a computer. Using a web browser we can remotely configure the operating mode of each temperature sensor as well as we can read measured temperature in each measuring point. Using this system student can learn: use of integrated temperature sensors, software implementation of a 1-Wire interface, distributed measurement systems based on 1-Wire interface, microcontroller based instrumentation, web based monitoring and control of measurement systems.

Andrea Boni, Dario Petri, Ivan Biasi
DIGITAL ARCHITECTURES FOR ADAPTIVE PROCESSING OF MEASUREMENT DATA

In this paper we describe the design of digital architectures suitable for the implementation of measurement data classification based on Support Vector Machines (SVMs). The performance of such architectures are then analyzed. The proposed approach can be applied for solving identification and inverse modelling problems, and for processing complex measurement data. Two very different case studies where real-time processing is of paramount importance are discussed: a nonlinear channel equalization and a high energy physics classification task.

F. Adamo, F. Attivissimo, N. Giaquinto, M. Savino
A NEW TECHNIQUE FOR GLASS QUALITY CONTROL

The paper deals with the problem of pointing out and then measuring the manufacturing defects (scratches and halos) of handmade satin glasses by an accurate, real-time and cheap method. A wavelet-based de-noising technique is used to obtain surface information about glasses under inspection. The proposed algorithm first obtains a two-dimensional wavelet transform of a high resolution image of the glass under inspection which, according to multi-resolution analysis, produces a suitable number of decomposition levels of the image, and then it carries out a thresholding operation on details. Finally, using the threshold levels estimated considering the present noise level, it assesses and characterizes the defects. The final aim of the work is the realization of an automatic and in-line computer vision system for glasses analysis; it must be able both to accurate inspection and to quality degree assessment of the final products as they come out from the production chain.

Luka Ferković
APPLICATION OF ISOLATION AMPLIFIER IN MEASUREMENT OF FLOATING AC SIGNAL

Measuring procedures in some cases require connection of two measuring objects or parts of equipment which terminals should not have common potential. Achievement of these requirements is inappropriate by using the transformer coupling because of its non-linear transfer function. Optical transfer of digital signals by using optocoupler provides the precision and stability needed to accurately signal monitoring.

C. Donciu, M. Cretu, I. Prisecaru, M. Temneanu
VIRTUAL STAND FOR TESTING STEPPING MOTORS USED AS INCREMENTAL ENCODER

In the present paper, prototype architecture for a virtual stand for stepping motors converted as rotary encoder study is illustrated.

Page 751 of 936 Results 7501 - 7510 of 9356