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Aikaterini Kalaitzopoulou, Vasileios Konstantakos, Theodore Laopoulos
A Methodology for Designing Power Management in Autonomous Low-power Nodes

A methodology is presented for the development of a power management configuration, based on a microcontroller, for use in autonomous low-power systems. First, the work presents an overview of the different approaches in the literature about the appropriate considerations towards evaluating power consumed by different operations in such systems, and then proposes a new design procedure. A case study is implemented on the basis of the proposed methodology, by using conventional hardware (microcontroller, modules) in a typical application. The power consumption behavior of this case study is explored by real experimental powerconsumption measurements. All the above steps form a methodology which is proposed as a general approach to power management design of low-power autonomous nodes, as usually is needed in most wireless sensor networks based on energy harvesting.

Gianluigi De Giuseppe, Alfonso Centuori, Angelo Malvasi
Energy harvesting using piezoelectric cantilever: improved SPICE model, simulations and measurements

Piezoelectric materials enable the conversion of ambient vibration into electrical energy. The development of piezoelectric energy harvesting systems needs accurate models for systemperformance evaluation. Mechanical researchers build distributed models for energy scavengers, simplifying the energy harvesting circuit and using analytical derivation, while electrical researchers focus on the modeling of the energy harvesting circuit and simplifying the structural conditions of the scavenging devices. The challenges for accurate modeling of such electro-mechanical systems remain, when complicated mechanical conditions and practical energy harvesting circuits are considered in system design. This article addresses the abovementioned problem, employing an equivalent circuit, which bridges the structural modeling and electrical functionality, allowing simulations of complex circuitry. The equivalent circuit has been simulated using SPICE software. Measurements are performed for verification of the proposed model.

Jürgen Funck, Clemens Gühmann
Design of a flexible filter for synchronous resampling in wireless sensor networks

Many tasks in the context of data acquisition with a wireless sensor network, e.g. jitter compensation or angular resampling, can be solved by reconstructing a uniformly sampled signal from a nonuniformly sampled one. A filter structure that is capable of performing this task is adopted from the literature and a practical design is evaluated. It is verified that its implementation on a resource constrained wireless sensor node is feasible. Two simulation examples demonstrate the effectiveness of the designed filter and a comparison with alternative resampling methods is given.

Alessandro Ferrero, Marco Prioli, Simona Salicone
An application to combine and compare measurement results expressed in terms of Random-Fuzzy Variables

In the last years, the Authors have proposed the use of the Random-Fuzzy Variables (RFVs) to represent measurements results. An RFV is an extension of a fuzzy variable, which is the natural variable in the mathematical possibility theory (in the same way the random variable is the natural variable in the probability theory). The aim of this presentation is to show, through a remotely controlled Virtual Instrument (VI) (accessible via the web page http://131.175.120.11:8000/RFVcalculator.html), how RFVs are built, starting from the available information about the uncertainty contributions affecting the measurement results; how they are combined, considering also the possible correlations between the uncertainty contributions; and how they are compared.

Vilmos Pálfi, Tamás Virosztek, István Kollár
ADC Test Tool for LabVIEW

An easy-to-use LabVIEW tool for ADC testing is presented. The tool provides a comprehensive collection of data processing algorithms which are able to ensure the best possible results in ADC testing, and to help to recognize bad parameter settings during the measurement. The core routines are migrated without change from our well tested MATLAB toolbox. Full test of the ADC can be done easily by almost everyone, since use of the tool needs no thorough knowledge about ADC testing. Moreover, the tool can be freely downloaded from the site: http://www.mit.bme.hu/projects/adctest/.

Tamás Virosztek, István Kollár
ADCTest Toolbox for MATLAB

The IEEE standards for ADC and Digitizing waveform recorder testing (IEEE 1241, IEEE 1057) define the main characteristics of the testing procedures, but cannot determine every detail of them. Implementation of the procedures needs extensive programming and testing of the programs. Moreover, iterative methods need settings of the convergence criteria, maximum number of iterations, etc. Finally, the standards define least squares (LS) fitting, but do not deal with more advanced (however slower) maximum likelihood (ML) methods. Therefore, there is a need for software which is readily available, gives reproducible results, is numerically robust, has a graphical user interface, and can compare LS and ML fits. Many engineers and researchers use MATLAB in their work, therefore we decided to develop a tool according to the above requirements. It is available on the web as http://www.mit.bme.hu/projects/adctest/.

Ján Šaliga, Jozef Lipták, Vojtech Vitkovič, Linus Michaeli
ADC test library in LabVIEW

ADC testing requires post processing of the acquired data for the estimation of ADC parameters. LabVIEW, as a very popular tool for development of various control and measurement applications, offers many specialized toolkits and libraries, but a specialized library of functions focused at data processing from ADC testing has been missing until now. Therefore, on the basis of previous works and experience, the Authors have developed a specialized library fully programed in LabVIEW, which offers a variety of high and low level functions – VIs or Virtual Instruments – which markedly simplify the development of any data processing software based on standard test methods. One example of application of the library is the demonstration software accessible across the Internet in the form of web application. It enables performing simulated measurements according to all basic ADC test methods (static, histogram, and dynamic, with processing in time domain and spectral domain). By choosing from among different test condition, the user can also learn and find out how the test conditions can affect the achieved results.

Antonio Moschitta, Paolo Carbone
Advanced software tools for parametric identification based on quantized data

Parametric estimation of signals, based on quantized data, is often carried out by means of least squares (LS) or averaging techniques. Such an approach often leads to optimal performance, resulting in almost unbiased estimators when the quantization error can approximately be modeled as an additive white Gaussian noise, or when other additive white Gaussian noise sources are larger than the quantization error. When such hypotheses are not satisfied, however, averaging may produce suboptimal, and biased estimators. In such a case, maximum likelihood or quantile based identification techniques can be shown to lead to more performing estimators, mostly unbiased and with a lower mean square error than that of an LS estimator. A software tool is presented, capable of estimating a DC level, a DC level corrupted by Additive White Gaussian Noise (AWGN), and sinewave parameters when the frequency is known, using data quantized by a nonuniform ADC.

Leopoldo Angrisani, Felice Cennamo, Giacomo Ianniello, Aniello Stellato
Failure Analysis Based on Emulation Systems

To increase the throughput of electronic manufacturing companies, design, prototyping, production, installation and maintenance processes of electronic devices are generally complemented by a number of performance and parametric tests, known as Failure Analysis (FA). In this paper, major FA proposals are considered. In particular, two noninvasive solutions are presented in detail: an advanced boundary scan, using an FPGA to speed up the tests, and a logic combinational test procedure, performed by means of a fault injectable emulation system. Moreover, an innovative CPU emulation approach is proposed, particularly suited to devices that include CPU chips. In order to detect hardware faulty, the approach provides for the emulation of the same boot code designed for DUT normal operation.

Ch. Jesus, Fabiola Socorro, Manuel Rodriguez de Rivera, Hector Jesus Rodriguez de Rivera, Roberto Sarmiento
Calorimetric sensor to measure local calorific dissipations in the human body

A calorimetric sensor for medical application has been developed in order to measure surface and localized calorific dissipations in the human body. The instrument tries to evaluate the calorific power that is transmitted by conduction, through a thermopile, between the human body and a thermostat at a constant temperature. The detection area of the prototype is 36 cm2 and the sensor resolution is 50 mW. From the equations of heat transport by conduction, we propose a model based on the sensor decomposition in different domains connected to each other. The model is validated experimentally. The sensor operation domain is indicated and some practical applications to the human body are shown.

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