IMEKO Event Proceedings

Page 10 of 855 Results 91 - 100 of 8545

Yufan Ding, Jose Mirao, Pedro Redol, Luis Dias, Patricia Moita, Emma Angelini, Sabrina Grassini, Nicola Schiavon
A combined petrographic and geochemical metrological approach to assess the provenance of the building limestone used in the Batalha Monastery (Portugal)

To verify the provenances of limestones that were used for construction and restoration of the Batalha Monastery, limestone quarries in central Portugal were investigated. Samples were collected from quarries and monastery in field investigation. The elements-alignment of calcium and strontium based on XRF result has suggested the source of fragments from different parts the monastery. Observation of the thin sections has supplemented petrographic evidence for this identification. XRD, TGA were also used for acquiring mineral information and chemical composition of the stones. This origin tracing result supplies foundation for further research of stone decay and reservation of the Batalha Monastery.

Ausilio Ernesto, Zimmaro Paolo
A combined technique approach for the study of a landslide in the Calabria region

In the detection and monitoring of a landslide a large number of variables should be taken into account. Several techniques and approaches should be used to fully understand the phenomenon in order to facilitate landslide stabilization design especially for complex cases. In this paper the case history of the Gimigliano landslide (Southern Italy) is investigated taking advantage of a combinedtechnique approach based on conventional geotechnical measurements used together with modern technologies such as electromagnetic sensing techniques and electrical resistivity tomography. The application of this methodology shows that combining the information taken from the different techniques is possible to validate the measurements obtained by conventional and modern approaches and enhance the accuracy of each other.

Alessia Bramanti, Alessandro Sciva, Giuseppe Campobello, Pier Paolo Capra, Silvia Marino, Placido Bramanti, Nicola Donato
A compact monitoring system for patients affected by neurodegenerative diseases

In this paper we report about the development of a compact monitoring system for people affected by neurodegenerative diseases as Parkinson and Alzheimer. The electronic interface is based on a Linkit ONE development board, and it is equipped with an array of up to four ADXL345 accelerometers. By considering the main symptoms of Parkinson subjects, it is possible to monitor tremors/movements and accidental falls of people wearing the system and to send data to a supervisor by Wi-Fi, Bluetooth and GSM connections. Furthermore, the geo-tagging functions, developed by means of a GPS feature, already equipped in the board, allow the monitoring of the movements and the position of Alzheimer subjects, avoiding the lost for memory failures.

Giovanni Betta, Domenico Capriglione, Claudio De Capua, Carmine Landi
A COMPARATIVE ANALYSIS IN TERMS OF CONDUCTED SUSCEPTIBILITY OF PC-BASED DATA ACQUISITION SYSTEMS

In this paper, a performance comparison between PC-based data acquisition systems is carried out with reference to their immunity to electromagnetic conducted disturbances. The aim is to identify suitable measurement procedures at present not available both in the literature and in EMC standards. The data acquisition system (personal computer and data acquisition board) is approached as a whole system and subjected to the more relevant conducted interference considered by EN standards, electrical fast transient and noise by conducted radio frequency field. Experimental tests, carried out in a shielded environment, highlight the relevance of a specific EMI characterisation of this apparatus.

Claudio De Capua, Emilia Romeo
A COMPARATIVE ANALYSIS OF FUZZY T-NORM APPROACHES TO THE MEASUREMENT UNCERTAINTY EVALUATION

The demands of statistical investigations in measurements inspired the remarkable development of probabilistic methods. However, the probability theory didn’t prove to be fully adequate for all types of uncertainty. Probability theory is excellent if the ambiguity is to be modelled, but its attempts to describe vagueness is quite inconsistent with common sense. Fuzzy theorists have often argued that a major motive behind the theory of fuzzy sets has been the treatment of uncertainty. In particular way, it’s well accepted that a measurement result (no matter what kind of instruments we are using in our process) is just a number which is only known to lie within an interval, and this is the reason for which fuzzy sets can be successfully applied. To consider both systematic and random effect of measurement operation, in agreement with [4], we have chosen to use Random Fuzzy Variables, proposing to describe the correlation or interaction of repeated measurements by triangular norm based arithmetics.

Annalisa Liccardo, Nicola Pasquino, Nello Polese
A comparative analysis of induction and electronic active energy meters

A comparative analysis of induction and electronic meters with regards to active energy measurements is presented, based on results obtained by application of a designed plan involving several input factors such as power voltage amplitude, power frequency, voltage total harmonic distortion (THD) and flicker severity.

Václav Matz, Pedro M. Ramos, Nuno B. Brás, A. Cruz Serra
A COMPARATIVE EVALUATION BETWEEN FREQUENCY ESTIMATION ALGORITHMS FOR POWER QUALITY ASSESSMENT IN DSP IMPLEMENTATION

Numerous frequency estimation algorithms are available for power quality assessment of frequency. In this paper, a comparative study in terms of accuracy, number of operations and memory cost is presented to select the best solution for implementation in a digital signal processor, in the context of typical power quality frequency disturbances measurements.

Livio D Alvia, Eduardo Palermo, Zaccaria Del Prete, Erika Pittella, Stefano Pisa, Emanuele Piuzzi
A comparative evaluation of patch resonators layouts for moisture measurement in historic masonry units

Monitoring water content in cultural heritage materials through non-invasive and easy-touse TDR/TDT (time-domain reflectometry / timedomain transmission) measurement systems has the potential to enhance conservation/restoration activities. In this study, two different probes for TDR/TDT technology, Square Patch Resonator (SPR) and Split Ring Resonator (SRR), were compared. The two probes were tested on two different materials (leccese and gentile stone), each one of them at three different levels of water content. All tests were conducted ten times with two different external impressed forces (hand pressure and 2 kg). Resonant frequencies (fr), fractional bandwidth (FBW), and standard deviation (σ) were evaluated to assess accuracy and repeatability in water content estimation. Results revealed optimum performance, FBW lower than 7 % and higher repeatability (σ < 5 MHz) with external mass, for the SRR probe. Our results reveal the possibility of monitoring the moisture level in the stone through a microwave tool based on a split ring and TDT device.

Jerzy Augustyn
A COMPARATIVE EVALUATION OF SOME LMS-BASED ALGORITHMS FOR CALCULATING OF IMPEDANCE COMPONENTS IN THE SAMPLING SENSOR INSTRUMENT

The properties of some algorithms based on digital signal processing for the impedance components evaluation in circuits with sampling sensor have been analysed. It is supposed that the voltage and current are sampled synchronously to the fundamental frequency of the generated sinusoidal signal. Two groups of fitting sine wave algorithms, which are based on the least mean square (LMS) technique, have been described. The first one reconstructs indirect measurement method. The second group of algorithms estimates the unknown impedance components by direct method. In all these algorithms to simplify the calculations one can use different form of input matrix. The uncertainty’s propagation by described algorithms can be analysed by means of covariance matrix. In order to verify the performance of the considered algorithms (e.g., accuracy, estimator bias and convergence) the Monte Carlo simulations are realised in MATLAB. It is shown that those algorithms provide minimisation of uncertainty for selected number of samples and phase angles. The influence of the quantization error of the AD converters and jitters of the sampling time upon the uncertainty of the processing results of described algorithms have been carried out.

Nicolae Daniel Irimia, Florin Ioan Lazar
A Comparative Study of Different BLDC Motor Construction Types Used in Automotive Industry under Specific Command Strategies

The automotive industry future focus is based on the construction of hybrid and fully electric vehicles, with the trend towards autonomous driving. Different electric drive subsystems from the structure of these electric vehicles are aiming to achieve a higher efficiency, which is why permanent magnet synchronous machines of either BLDC / PMSM type are currently being used as main actuators in their construction. These types of electrical machines are known in the literature as having sufficient power density and efficiency to meet the criteria and requirements of the automotive building industry. That's why an important area of interest is the construction and the control topology specific to these electrical machines. Based on these considerations, the paper purpose is to present a comparative study regarding different constructive types concepts of BLDC electrical machines and different control methods related to them. In order to validate the theoretical aspects of this study, two distinct ways of modelling and simulation were used in parallel: the first method is based on FEM (Finite Element Method) analysis and the second analytical method uses the MATLAB / Simulink software package.

Page 10 of 855 Results 91 - 100 of 8545