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A new method to approximate the least squares multi-harmonic fitting is proposed. The basic idea is to expand in Taylor’s series the derivative on ω of the least squares cost function around a central value, so reducing the frequency estimation to a calculation of a root of a polynomial. In this way the method provides a frequency estimation in a closed form avoiding the recursion that is necessary in the classical approach. The results show that the proposed algorithm reaches the Cramer–Rao bound in a narrow range of frequency around a pre-estimation. Increasing the approximation orders of the Taylor’s expansion the range of maximum accuracy widens. This method is particularly suitable in grid frequency estimation due its low variability. The proposed algorithm, preserving the accuracy, requires an execution time up to 8 times lower compared to a single iteration of the classical recursive approach.

A non-recursive version of Nonlinear Least Squares Fitting for frequency estimation is presented. This problem yields a closed-form solution exploiting a Taylor’s series expansion. Respecting some conditions, the computational complexity is reduced, but equally the method assures that the accuracy reaches the Cramer-Rao Bound. The proposed method requires a frequency pre-estimate. A series of simulations has been made to determine how accurate the pre-estimate should be in order to ensure the achievement of the Cramer-Rao Bound in various conditions for different periodic signals. The execution time of the proposed algorithm is smaller compared to a single iteration cycle of the standard approach. The proposed method is useful in applications that require a high accuracy fitting of periodic signals, especially when limited computational resources are available or a real-time evaluation is needed.

In this paper, we propose a new sensor for the detection and analysis of dusts (seen as powders and fibers) in indoor environments, especially designed for applications in the field of Cultural Heritage or in other contexts where the presence of dust requires special care (surgery, clean rooms, etc.). The presented system relies on image processing techniques (enhancement, noise reduction, segmentation, metrics analysis) and it allows obtaining both qualitative and quantitative information on the accumulation of dust. This information aims to identify the geometric and topological features of the elements of the deposit. The curators can use this information in order to design suitable prevention and maintenance actions for objects and environments. The sensor consists of simple and relatively cheap tools, based on a high-resolution image acquisition system, a preprocessing software to improve the captured image and an analysis algorithm for the feature extraction and the classification of the elements of the dust deposit. We carried out some tests in order to validate the system operation. These tests were performed within the Sistine Chapel in the Vatican Museums, showing the good performance of the proposed sensor in terms of execution time and classification accuracy.

This article describes a new instrument for power quality (PQ) measurements based on the Raspberry-Pi. This is the latest step of a long study started by the Electric and Electronic Measurements Laboratory of “Roma Tre” University 12 years ago. During this time, the Laboratory developed and refined instrumentation for high accuracy power quality measurements. Through its own architecture, the new instrument allows the use of the Raspberry instead of a personal computer (PC). The data acquired and locally processed are then sent to a remote server where they can be shown to users. Imagines of the system and of the data prove the activity of the system.

The aim of this work is to propose a metrological system for the definition of the Extra Virgin Olive Oil Quality based on Panel Test. The information was obtained by a Kohonen neural network that simulates the biological perception mechanisms. This approach allowed to get a two-dimensional mapping of the flavors based on non-linear model. The predominant flavors are not evenly distribute on the map but they are located in specific zone. It is also possible to identify a separation between negative and positive attributes that defines a “quality direction” from low grade to high quality Extra Virgin Olive Oils. Moreover, the overlaps of different flavors on the same neuron of the map suggest possible correlations between them. This is an important starting point to identify the minimum number of independent attributes in order to optimize the Panel Test questionnaire.

A distributed web-based system for temporal and spatial power quality analysis has been realized and tested. Connecting by internet local instruments able to perform high accuracy measurements in real time, the Power Quality information, locally measured, can be sent to a remote central server which aim is to plot them and stored the data for future analysis. The remote instruments have been realized, tested and placed in two Italian cities, Palermo and Rome, where actually work while the server works in Rome. The web application allows to select the single instrument and to show its stored PQ information.

The UMTS appear to be the communication system of the next future. In this system all the communication services will be included. This means that the Quality of Service (QoS) will have a great importance. So is envisaged that the management of the system will take in account the momentary system capabilities continually determined in real time. Until now, the quality of the links is determined by end-to-end in line procedures based on Bit Error Rate (BER) measurements. It is clear that an end-to-end procedure cannot detect the worse section of the link. To overcome this inconvenient the more recent trend of QoS management is to realise a distributed monitoring of the whole system. Following this last trend this paper proposes a distributed off-line monitoring of the system based on the analysis of the Quality of Analog Signal (QoAS). This proposed analysis implies a high-speed analog to digital conversion of the Intermediate Frequency signal and a very complex processing. In this paper, the state-of-the-art researches performed in this perspective are described.

Nowadays, the check of the organoleptic characteristics for the evaluation of extra virgin olive oil (EVOO) quality is regulated by the European Union (EU) authorities, which indicate the use of the panel test (PT). It is composed by a team of specialists that give a numerical value to many characteristics about flavours, synthesising a sensory analysis. Each expert answers questions about the aroma by assigning the adequate scores to each oil. The evaluation becomes objective by applying the statistical analysis of all the scores given by the participants: This is the definition of “measure” of Russell. The PT can be considered a true standard “metrological system” (considering the number of questions in the questionnaire), while the perceptions of the testers are the solicitations of it. To allow access to an expensive evaluation process by small companies, this work proposes to “disseminate” the properties of the metrology represented by PT. The results of the PT are arranged in an unsupervised artificial neural network (ANN), the Kohonen map, which represents the synthesis of self-organised output that has only the goal, in this paper, to make readable PT results. The dissemination process is obtained by the gas chromatographic (GC) analysis of each oil sample and through the identification of peaks corresponding to the perceptions. These signals are used for the training of the supervised Multi Layer Perceptron (MLP) ANN, with the back propagation algorithm, whose outputs are represented by the results of the PT. This procedure is exact a “metrological dissemination of a standard” and also the aim of the work: to classify EVOO without always resorting to PT.

""The problem of the electrical energy price, evaluated considering its quality, has been analyzed in this article. The electrical energy quality is directly defined by the customers as an output of a complex procedure which uses as inputs both the power quality technical parameters and the human experience. The procedure shows as the accuracy in the quality definition is strongly related with the accuracy of the sensors used for the power quality measurements, especially regarding their synchronization. An analysis of the synchronization of the sensors placed on a spread territory is also made. A solution for a centralized control of the sensors time course is also suggested."" It has been taken into account the problem of the price of the electrical energy considering its quality. This last is defined by the customers after a complex procedures which considers as inputs both the technical parameters and the human experience. In Following this procedure the final accuracy in the quality definition is strongly related with the accuracy of the sensors used for the power quality measurements especially regarding their synchronization which becomes particularly problematic considering their distribution on spread territory. Moreover we suggest the solutions for a centralized control of their time course.

Starting from gas-chromatograms of extra virgin olive oil samples, choosing the most significant peaks, authors try to define a standard ortho-normal base to be deposited for quality valuation.

An important problem in industrial system, both working in low and medium power, is the possibility that some circuits have a current dispersion, with a subsequent increasing in local temperature. This situation, if not immediately corrected, can produce, in some cases, firing accidents, with a great amount of money loss and long period of out-of-order systems. Although procedures based on Infrared Thermography to analyze and find critical situations already exist, these are always based on long manual procedures and usually are used for analysis of complex industrial systems. In this paper, after a short review of the common manual thermograph investigation, an automatic system based on two infrared thermograph cameras and an image processing real time analysis is proposed. The device demonstrates the possibility to take under control some critical systems and preventing firing accident in automatic way. This solution can be easily integrated in a SCADA architecture for monitoring and alerting the supervisor about over-temperature or current dissipation cases.

Starting from a previous work, a new Data Acquisition USB Device has been designed, developed, realized and characterized to be used in Power Quality and Smart Grid applications. The system simultaneously manages 8 data acquisition channels to allow voltages and currents monitoring on tri-phases lines. It can get external both certified time and voltage references to warranty certified measurements, but it also use internal references for non certified ones. The USB card is in PCI form factor and can be placed inside a common PC slot or in external shielded housing. FTDI Virtual ComPort drivers yield to a flexible multiplatform device, without requiring any advanced programming skill. The proposed device has been tested with custom software written in C# and VB6 languages, moreover it has been characterized applying the most common ADC performing test to verify its behavior.

This paper proposes an FPGA based device. implementing a signal generator for power quality analysis. The device simulates the behavior of an ADC connected to the power grid. It’s main goal is to make it easy to have real-time tests on algorithms implemented on embedded hardware.

An instrument based on FPGA to determine in few. periods the fundamental frequency of a electrical grid signal has. been realized. A classic algorithm as Curve Fitting Algorithm has. been analyzed and modified to reduce its numerical complexity.. This paper shows how the floating point software algorithm has. been implemented on hardware architecture in fixed point. representation, controlling the accuracy.

As a direct consequence of the increasing demand. of energy and the need to decrease pollution in order to cope. with global warming, political, industrial and scientific interests. have combined to understand the way ICT technologies can. help to review all phases of energetic cycle, from generation. (through renewable sources), to accumulation and. transportation, until distribution. The union between ICT and. energy is usually identified as “Smart Grid”, to emphasize an. expectation change in what will be the Power Grid of the. incoming future. The aim of this study is to give some ideas. about the experimentation of new techniques of energy. acquisition through renewable sources (solar, chp, wind, etc.).. These techniques would guarantee more accessible prices for. production, improving performances, the overcome of those. constraints that did not allow the exploitation of potential. energy capacity of renewable sources. This grid will be made of. devices forming a control cycle that will check the station of. energy generation as much as the behaviour of single. consumers.

A Data Acquisition USB Device has been. designed, developed, realized and characterized to be used in. Power Quality monitoring activities. The system. simultaneously manage 8 data acquisition channels to allow. acquisition on tri-phases plus neutral lines working at 499. samples per 50 Hz period. It can get external certified time and. voltage references to warranty certified measurements. The. system is directly powered by USB interface and use a. multiplatform FTDI Virtual ComPort drivers to yield a simpleto-. use and scalable device able to send and receive data over. High Speed RS232 virtual interfaces, without requiring any. advanced programming skill. The virtual serial communication. makes data acquisition software portable over many platforms,. regardless development environment and programming. language. The proposed device has been tested with custom. software written in C# and VB6, than in LabView and MatLab. environment, moreover it has been characterized applying the. most common ADC performing test to verify its behaviour.

A Data Acquisition USB Device has been realized to be used in Power Quality monitoring activities. The adopted solution allows to perform 8 channel simultaneous data acquisition with external certified time and voltage references, working at 499 samples per 50 Hz period. The self-powered USB interface combined to multiplatform FTDI Virtual ComPort drivers yields a simple-to-use and scalable device; it can be driven simply sending and receiving data over High Speed RS232 virtual interfaces, without requiring any advanced programming skill. The virtual serial communication makes data acquisition software portable over many platforms, regardless development environment and programming language. The proposed device has been tested with custom software written in C# and VB6, than in LabView and MatLab environment.

Power quality is an important subject to correctly dimension protection devices and back up power systems for next generation of telecommunication network. In this paper it is presented an overview of some power quality data obtained using integrated instruments put inside Chloride's UPS, widely distributed in the world and active for quite a few years, allow statistical evaluations to derive some important convictions about the power quality situation, which are the electrical energy parameters particularly important for the design of new generation tIc apparatuses. The article is focused on the Italian situation and in detail analyzes the mains failures for each Italian region.

The need to deploy distributed power quality monitoring systems requires the development of circuits able to yield an accurate time reference that is easy to disseminate on specific monitoring sites. In this paper, the design and initial realization of a time reference continuously traceable to a Cs133 atomic standard is proposed. Such reference is based on the locking of the Cesium-derived L1 GPS satellites carrier and would simply require visibility of one GPS satellite in order to be operative. In particular, attention is focused on the hybrid design and realization of the carrier tracking section, with particular emphasis on its fundamental building blocks, such as the voltage controlled oscillator, mixers, and power dividers. The design procedure for the different blocks and some prototypes are discussed and preliminary measurements showing their functionality are presented.

This work shows an example of power quality (PQ) data of four important telecommunication sites placed in Rome, Italy. The data are collected, elaborated and analyzed by four self made instruments developed for this purpose and inserted in four automatic telecommunication exchanges kindly at our disposal by TELECOM, the most important Italian telecommunication company. The analysis shows the active and reactive power consumption and, for one site, the harmonic distortion.

The problem discussed in this chapter relate directly to the economic, sociological and psychological aspects of, and also the scientific-technical elements connected with electric power production, distribution and fruition. For this reason, only the international rules connected with the technical, economic and environmental fields will be considered, if possible, working in the industrial world. These are the set of ISO 9000 rules for the quality that will influence the ISO 14000 rules for the environment (not discussed here).

The calibration cost of an instrument is so expensive that is necessary, to reduce the number of calibrated points, in the scale. There is the necessity to exploit as well as possible the metrological valence of few calibrated points to extend all over the instrumental range. The choice of the number and the position of such few points is the problem faced in the work. Utilizing the Shannon sampling procedure in the transposed domain of the input entities of the instrument, with respect to the time, the truncation error of the cardinal series has faced utilizing the Helms and Thomas upper bound evaluation. To enhance the efficiency of the procedure, has been utilized the minimax procedure searching the optimal indication on better determination. In every case the efficiency of the procedure is lower on the edge of the instrumental scale. To upgrade the edge calibration, making as even as possible the calibration, upon the scale, one has been utilized the generalized sampling theorem by Papoulis that allows to chose the calibration points more frequent at the edge, with respect of the central part of the scale. An algorithm to guide the calibration procedure is tempted.

A possibility to obtain a new time reference constantly locked to the Caesium-derived GPS satellites carriers was investigated by means of a new GPS receiver architecture able to lock the two GPS carriers and mix them to obtain a reference frequency with an accuracy close to the GPS one. This is very important in Perceived Power Quality distributed measurements systems where the exact knowledge of the events on the geographic compass is strongly joined to the capability to associate them an accurate time. A simulation of the carrier tracking loop has been performed. It shows how choosing appropriately the frequency of the low-pass filter of Costas loop, a modified PLL typically used in GPS system, it is possible to recover carriers in presence of high noise to signal ratio too. The front-end of the system able to select GPS frequencies, which is the first block of the entire system, was also realized.

Artwork counterfeiting is a wide problem in the art market, both for private subject and museums. For this reason, it is important introducing innovative authentication solutions, based on state-of-the-art technologies. In particular, in this paper, the proposed solution is based on a mobile architecture, starting from the consideration that nowadays mobile phones include quality photo and video cameras, access to wireless networks and the internet, GPS assistance and other innovative systems. The proposed solution uses smartphones as simple, robust and efficient sensor for artworks authentication. When we buy an artwork object, the seller issues a certificate of authenticity, which contains specific details about the artwork itself. Unscrupulous sellers can duplicate the classic certificates of authenticity, and then use them to “authenticate” non-genuine works of art. In this way, the buyer will have a copy of an original certificate to attest that the “not original artwork” is an original one. A solution for this problem would be to insert a system that links together the certificate and the related specific artwork. To do this it is necessary, for a single artwork, to find unique, unrepeatable, and unchangeable characteristics. In this article we propose an innovative and not-invasive method for the authentication of artworks based on random intrinsic object characteristics. This approach is based on biometry paradigm (analogue fingerprinting). The paper present a stand-alone solution, and an internet-based one, necessary for granting security verification also in case of problem with the used RFID tag. The proposed method uses an RFID Tag and a 2D barcode, in conjunction with an Internet-based Authentication Archive.

Many computing techniques are used to evaluate Power Quality parameters, each showing specific advantages and disadvantages. This paper presents an improvement of Curve Fitting Algorithm (CFA) having good accuracy in the estimation of the signal’s power quality parameters.

The Perceived Power Quality by costumers has been faced, starting from ISO 9000 Quality definition. An experimental investigation is presented on customers of Rome (Italy). By the results one demonstrates that fluxes of parameters defined on own manner by costumers, can be determined.

Quality parameters, each showing specific advantages. This paper presents an improvement of Curve Fitting Algorithm (CFA), having good accuracy in the estimation of the signal’s power quality parameters, in order to compare the Perceived Power Quality of complex networks electric systems explored, out of line, by a questionnaire supplied to people Pertaining to the Technology of Commerce that operate as a Filter

Artificial neural networks can be successfully used for short-term load forecasting and it is well known that better forecasting performances can be obtained taking into account the weather influence on electric load. An extensive analysis has been conducted for selecting the monitoring sites most representative of the Italian general weather conditions. The selection activity has been based on the computation of correlation functions. The analysis of the results thus obtained has permitted the identification of correlated and noncorrelated sites for each meteorological variable. The variables identified have been used for integrating the training set of an available ANN in order to test its forecasting performance. The paper reports on research activity aimed at carrying out an adequate model permitting correct representation of weather influence on Italian electric hourly load.

In this paper are presented the preliminary measurements of electrical losses in oxide compounds that are usually present on the surface of bronze artifacts. These measurement are currently not found in literature and could allow a non-destructive analysis of the bronze surface oxide layer composition. An automatic measurement method, based on a capacitive sensor and a multi-frequency excitation waveshape, is studied.

A model of a vessel in which the blood flows in laminar regime is settled. A data acquisition parallel structure able to on line elaborate data is briefly described. Introductory results in heavy conditions referred to the theory development show the robustness of theory and functionality of experimental apparatus.

The paper illustrates two different Artificial Neural Networks (ANN) architectures for electric Short-Term Load Forecasting (STLF). Two multi-layer perceptron ANN using the back-propagation learning algorithm have been implemented which provide different, although complementary, forecasting approaches (static and dynamic). In order to test the potentialities of the architectures implemented, the ANN have been applied to the Short-Term Forecasting of Italian hourly electric load. The importance of this load (peak demands up to about 38 000 MW) requires tools for STLF which must be as more accurate and precise as possible. This fact has imposed the adoprequires tools for STLF which must be as more accurate and precise as possible. This fact has imposed the adoption of some algorithmic enhancements to the basic back-propagation algorithm formulation. Since an adequate formulation of the influence exerted on hourly electric load by the main meteorological and climatic factors is not known at present, the data set used for ANN training phase has concerned only historical series of electric hourly demand. The paper illustrates the two ANN architectures as well as the computational platforms used for implementation. Finally, some results obtained from the application of the two ANN to the short-term forecasting of Italian electric load relevant to three different weeks of the year 1993 are comparatively reported.

After a short description of a parallel acquisition system an information-based calibration method is described. The method is based on sampling the Shannon's theorem and a Helms and Thomas (1962) upper bound modified near the calibration range boundaries. The paper studies the coupling problem due to the board on which the sampler is mounted on.

The paper illustrates a part of the research activity conducted by the authors in the field of electric short term load forecasting (STLF) based on artificial neural network (ANN) architectures. Previous experiences with basic ANN architectures have shown that, even though these architectures provide results comparable with those obtained by human operators for most normal days, they evidence some accuracy deficiencies when applied to "anomalous" load conditions occurring during holidays and long weekends. For these periods a specific procedure based upon a combined (unsupervised/supervised) approach has been proposed. The unsupervised stage provides a preventive classification of the historical load data by means of a Kohonen's self-organizing map (SOM). The supervised stage, performing the proper forecasting activity, is obtained by using a multi-layer perceptron with a backpropagation learning algorithm similar to the ones mentioned above. The unconventional use of information deriving from the classification stage permits the proposed procedure to obtain a relevant enhancement of the forecast accuracy for anomalous load situations.

Harmonic distortion is introduced by nonlinear flash analog-to-digital converters (ADCs) and even small-scale dithering does not reduce this unwanted effect. Large-scale dithering has been proposed to overcome this limitation. However, large-scale dithering is difficult to implement and, in addition, it severely reduces the ADC input dynamic range. In the paper, a new architecture is presented, based on ordinary flash conversion and dynamic element matching, that strongly reduces nonlinear distortion by randomizing the resistor positions in the resistor string used to generate the voltage references. Some properties of this architecture are analysed and simulation results are presented that validate the theoretical assumptions.

In this paper, the design and characterization of a 7-bit CMOS stochastic-flash analog-to-digital converter is illustrated by means of simulations including level-3 CMOS models and estimated dither-based spectra. The conversion scheme and its main properties are briefly recalled, and a possible design of the voltage reference generator proposed. It is shown that mismatches among the resistors in the ladder employed to generate these voltages are largely compensated by the presented architecture when small-scale dithering is employed.

The need to correlate as accurately as possible Time to the power quality events pushes towards the necessity to develop circuits able to yield a time reference that is referable to International Time Standards. Moreover, the necessity to deploy distributed power quality monitoring systems requires these time references to be easy to disseminate, making them available on specific monitoring sites. In this paper, the possibility to obtain a time reference continuously traceable to a Cs133 atomic standard is proposed, by locking the Cesium-derived L1 GPS satellites carrier by means of a specifically designed GPS receiver. Such time reference would simply require visibility of one GPS satellite in order to be operative. In particular, the overall architecture of such receiver will be first outlined and then attention will be focused on the design and realization of the VCO which is one of its fundamental building blocks. Measurements carried out on a prototype of the proposed VCO show that its performances are adequate for the aim.

A new platform for Power Quality measurement based on PIC 32 family microcontroller has been realized and tested. The board is able to determine the frequency of the mains implementing the Curve Fitting Algorithm and is able to detect punctual events as short interruptions. The device allows performing high accuracy measurements and is a good candidate as platform to use in civil suit in the subject of Power Quality analysis.

The problem of useful echoes identification in an Ultra Sound (U.S.) signal is faced. The used approach consists in the time re-arrangement of a paths matrix built utilizing the electro-acoustic equivalence. Some acoustic parameter identification of slabs encountered by U.S. wave has been demonstrated been possible, in particular cases. The precise time positioning of identified useful echoes has been obtained applying an improved Maximum Likelihood Estimator (M.L.E.). The great computational load of the method has been faced by a parallel computational structure measurement. Experimental on software performances are presented too.

In the paper Kalman filter-based estimation of noisy sinewave signals has been considered. The design of tuning parameters has been taken into account with the aim of providing information on how to obtain given requirements in terms of filter smoothing and tracking capabilities. Then, a multiple-hypotheses filter has been designed to show the performance obtainable through this technique when a step-change in the sinewave amplitude is assumed. The results are further validated by computer simulations.