|
CONTENTS
| 1. Janusz Mroczka, Damian Szczuczyñski - Inverse problems formulated in terms of first-kind Fredholm integral equations in indirect measurements | 333 |
| 2. Michael Thuy, Fernando Puente León - Non-linear multimodal object tracking based on 2d lidar data | 359 |
| 3. Martin Burghoff, Hans-Helge Albrecht, Stefan Hartwig, Ingo Hilschenz, Rainer Körber, Tilmann Sander-Thömmes, Hans-Jürgen Scheer, Jens Voigt, Lutz Trahms - Squid system for meg and low field magnetic resonance | 371 |
| 4. Flavio Galliana, Paolo Capra - Analysis of a national inter-laboratory comparisonof high dc resistance at 10 MΩ and 1 GΩ level | 377 |
| 5. Piotr Jantos, Damian Grzechca, Jerzy Rutkowski - Global parametric fault identification in analog electronic circuits | 391 |
| 6. Micha³ Lisowski - Minimization of the effect of dielectric specimen electrization on the results of measurement of volume resistivity | 403 |
| 7. Stefan Werling, Michael Mai, Michael Heizmann, Jürgen Beyerer - Inspection of specular and partially specular surfaces | 415 |
| 8. W³odzimierz Janke, Jaros³aw Kra¶niewski - Investigation of transient thermal characteristics of microwave transistors | 433 |
| 9. Michael Schwarz, Claudia Heilmann, Martin W. Krueger, Uwe Kiencke - Model based monitoring of hypothermic patients | 443 |
| 10. Mateusz Kotarski, Janusz Smulko - Noise measurement set-ups for fluctuations-enhanced gas sensing | 457 |
| 11. Francisco Corrêa Alegria - Contribution of jitter to the error of amplitude estimation of a sinusoidal signal | 465 |
| 12. Janusz Janiczek - Multiparameter approximation of transducer transfer function by kriging method | 479 |
| 13. Robert Æwirko, Joanna Æwirko, Zbigniew Bielecki - Measurement system for testing the optical radiation detectors in a broad temperature range | 491 |
| 14. Ma³gorzata Poniatowska - Research on spatial interrelations of geometric deviations determined in coordinate measurements of free-form surfaces | 501 |
| 15. Janusz Janiczek - Digital adjustment of analog-to-digital converter transfer function | 511 |
| 16. Gholam Reza Nabiyouni - Design and fabrication of nanomagnetic sensors based on electrodeposited GMR materials | 519 |
ABSTRACTS & FULL PAPERS
|
INVERSE PROBLEMS FORMULATED IN TERMS OF FIRST-KIND FREDHOLM INTEGRAL EQUATIONS IN INDIRECT MEASUREMENTS
Janusz Mroczka, Damian Szczuczyñski
Wroclaw University of Technology, Faculty of Electronics, Chair of Electronic and Photonic Metrology, B. Prusa 53/55, 50-317 Wroc³aw, Poland (damian.szczuczynski@pwr.wroc.pl, +48 691 399 966, janusz.mroczka@pwr.wroc.pl)
Abstract
Direct measurements of many properties of real-world systems are not possible. Information on these properties can only be inferred from the result of measurements of other quantities which may be measured directly. The process comprising direct measurements of certain characteristics of the object followed by inference on its sought-for properties from the directly measured characteristics based on a mathematical relation between unknown properties and measured characteristics is called indirect measurement, whereas inference is referred to as an inverse problem in indirect measurement.
In general an inverse problem consists either in determining the characteristics of a system under study, driven by controlled or known exciting signals, or in reconstructing exciting signals acting on a system whose internal characteristics are known. In both cases, it is formulated in terms of a mathematical model relating unknown and measured characteristics and signals. One can distinguish continuous and discrete inverse problems, depending on whether the measured and sought-for quantities are represented by functions or by vectors (tuples), respectively. Very many nontrivial inverse problems in indirect measurements are ill-posed which means that they have no solution or the solution exists but is non-unique or unstable, i.e. very small disturbances in the measurement data result in large disturbances in the result of inference. High error amplification is referred to as ill-conditioning. Ill-posedness and ill-conditioning result from the lack of information on sought-for quantities, carried by the measurement data. Therefore, a priori knowledge about the space of admissible solutions has to be employed for solving such inverse problems.
The theory of inverse problems and - in particular - effective numerical methods for solving them are of great importance for measurement science and technology; they are crucial for the development of many measurement, imaging and diagnostic techniques. Indirect measurements may be formulated using various mathematical models of the measurement object followed by a measuring system. A broad class of inverse problems, being of importance for indirect measurements, is formulated in terms of Fredholm integral equations of the first kind. These problems are ill-posed and strongly ill-conditioned after discretization. Therefore, sophisticated inverse procedures, utilizing various kinds of a priori knowledge, are applied for solving them.
In this paper, theoretical and numerical aspects of inverse problem in indirect measurements are reviewed. In particular the concept of generalized solution (pseudosolution) and the notion of well-posedness is presented and analysed. The review is focused on inverse problems formulated in terms of Fredholm integral equations of the first kind: a general presentation of such problems, at the level of functional analysis, is followed by an overview of numerical aspects of their discretized versions. A concise presentation of selected groups of numerical methods, called inverse methods, for solving inverse problems is also provided.
Keywords: inverse problem, indirect measurements, ill-posedness, ill-conditioning, Fredholm integral equation of the first kind, inverse procedures, a priori information, regularization, Bayesian inferring.
© 2009 Polish Academy of Sciences. All rights reserved
|
|
NON-LINEAR MULTIMODAL OBJECT TRACKING BASED ON 2D LIDAR DATA
Michael Thuy, Fernando Puente León
Institut für Industrielle Informationstechnik, Karlsruhe Institute of Technology, Hertzstrasse 16, D-76187 Karlsruhe, Germany (thuy@iiit.uni-karlsruhe.de, +49 721 608 4517, puente@iiit.uni-karlsruhe.de)
Abstract
The contribution introduces a novel approach for tracking objects based on two-dimensional lidar data. As a central tracking engine, we employ a particle-filter-based solution which is capable of modelling non-linear dynamic processes as well as non-Gaussian noise distributions for the underlying process and sensor as well. In contrast to other lidar-based tracking approaches, no newly detected objects have to be associated to already known objects in an explicit manner. Since our weighting function is multi-modal, the association is done by the filter itself.
Keywords: fusion, lidar, data association, tracking.
© 2009 Polish Academy of Sciences. All rights reserved
|
|
SQUID SYSTEM FOR MEG AND LOW FIELD MAGNETIC RESONANCE
Martin Burghoff, Hans-Helge Albrecht, Stefan Hartwig, Ingo Hilschenz, Rainer Körber, Tilmann Sander-Thömmes, Hans-Jürgen Scheer, Jens Voigt, Lutz Trahms
Physikalisch-Technische Bundesanstalt, Biosignals, Abbestrasse 2-12, D-10587 Berlin, Germany (Martin.Burghoff@ptb.de, +49 30 348 7238, Hans-Helge.Albrecht@ptb.de, Stefan.Hartwig@ptb.de, Ingo.Hilschenz@ptb.de, Rainer.Koerber@ptb.de, Tillman.Sander-Thoemmes@ptb.de, Hans-Jurgen.Scheer@ptb.de, Jens.Voigt@ptb.de, Lutz.Trahms@ptb.de)
Abstract
A SQUID magnetometer system was developed for measuring sustained brain activity by magnetoencephalography (DC-MEG) and to record the free precession decay of protons (FPD) of the human brain at very low fields. The SQUID system has a white noise level of about 4 fT/√Hz. To generate the MR signal, two magnetic fields are used: a static polarisation field of a few mT and a static detection field of a few microtesla. To test the spectral resolution of the system, we measured the FPD of protons in distilled water having a spectral line width of about 156 mHz with an instrumental resolution of 2 mHz. The proton resonance line width of the human brain was found to be about 3.0 Hz. Using the same SQUID system we recorded a DC-MEG signal with an amplitude of about 1.5 pT upon motor stimulation. On the basis of these data, we discuss the possibility of detecting a shift of the resonance line due to the superposition of the neuromagnetic field generated by sustained brain activity.
Keywords: SQUID, MEG, low field MR, neuronal currents.
© 2009 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 402kB) |
|
ANALYSIS OF A NATIONAL INTER-LABORATORY COMPARISONOF HIGH DC RESISTANCE AT 10 MΩ AND 1 GΩ LEVEL
Flavio Galliana, Paolo Capra
National Institute of Metrological Research, (INRM) str. delle Cacce, 91 - 10135, Turin, Italy (f.galliana@inrim.it, + 39 011 391 9334,p.capra@inrim.it)
Abstract
A national comparison of dc resistance at 10 MΩ and 1GΩ level was organized by the Electromagnetic Division of National Institute of Metrological Research (INRIM, Italy) and piloted by the same Division. This comparison took place between January and April of 2008 with the participation of 8 secondary Laboratories accredited by the Italian Accreditation of Calibration Laboratories Service (SIT). The travelling package included a wire-wound 10 MΩ standard and a thick film-type 1 GΩ standard in a wooden anti-shock container designed by INRIM. The obtained results indicate that the differences at 10 MΩ and 1 GΩ between each laboratory's value and its reference value are all within the expanded relative uncertainties of these differences.
© 2009 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 967kB)
|
|
GLOBAL PARAMETRIC FAULT IDENTIFICATION IN ANALOG ELECTRONIC CIRCUITS
Piotr Jantos, Damian Grzechca, Jerzy Rutkowski
Silesian University of Technology, Institute of Electronics, Faculty of Automatic Control, Electronics and Computer Science, Akademicka 16, 44-100 Gliwice, Poland (pjantos@polsl.pl, +48 32 237 1984, dgrzechca@polsl.pl, jrutkowski@polsl.pl)
Abstract
A method of global parametric fault diagnosis in analog integrated circuits is presented in this paper. The method is based on basic features calculated from a circuit under the test's time domain response to a voltage step, i.e. locations of maxima and minima of the circuit-under-test response and its first order derivative. The testing and diagnosis process is executed with the use of an artificial neural network. The neural network is supplied with extracted basic features. After evaluation and discrimination, the output indicates the circuit state. The proposed diagnosis method has been verified with the use of exemplary integrated circuits - an operational amplifier μA741, a sinewave oscillator and an integrated band-pass filter.
Keywords: global parametric fault, identification, artificial neural networks.
© 2009 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 433kB)
|
|
MINIMIZATION OF THE EFFECT OF DIELECTRIC SPECIMEN ELECTRIZATION ON THE RESULTS OF MEASUREMENT OF VOLUME RESISTIVITY
Micha³ Lisowski
Wroclaw University of Technology, Institute of Electrical Engineering and Technology Fundamentals, Wybrze¿e Wyspiañskiego 27, 50-370 Wroc³aw, Poland (michal.lisowski@pwr.wroc.pl, +48 71 320 2607)
Abstract
The impact of electric charge, gathered in a tested specimen before a testing voltage has been applied to it, on the results of measurement of its volume resistivity is considered. It was shown that the specimen should be discharged before the measurement. The alternating polarity test method, employed by Keithley's 6517 Hi-R Test program, does not eliminate completely the effect of electric charge. A modification of the method, enabling the elimination from the measurement results of the electric charge which could be the reason of de-electrization current flow (background current) and resorption current, has been proposed.
Keywords: solid dielectrics, volume resistivity, measurement error, electrization impact, elimination of specimen electrification .
© 2009 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 234kB)
|
|
INSPECTION OF SPECULAR AND PARTIALLY SPECULAR SURFACES
Stefan Werling1), Michael Mai1), Michael Heizmann2), Jürgen Beyerer1,2)
1) Universität Karlsruhe, Institut für Anthropomatik, Lehrstuhl für Interaktive Echtzeitsysteme (IES), Adenauerring 4, D-76131 Karlsruhe, Germany (werling@kit.edu, +49 721 608 5915, mai@kit.edu, beyerer@iitb.fraunhofer.de)
2) Fraunhofer Institut für Informations und Datenverarbeitung IITB, Fraunhoferstraße 1, D-76131 Karlsruhe, Germany (heizmann@iitb.fraunhofer.de)
Abstract
The inspection of specular surfaces differs significantly from the case of non-specular surfaces. In contrast to the non-specular case, the appearance of a specular surface is dominated by the reflections of the environment that are visible in it. The transfer of this observation into automated visual inspection is called deflectometry. The main principle of deflectometric surface acquisition is to use a highly controllable environment, where a screen on which a well-defined pattern is presented is observed via the specular reflecting surface. Knowing that pattern, it is possible to inspect the surface qualitatively and - at least with certain additional knowledge - to reconstruct the surface under test. In this paper, we introduce the theoretical background of deflectometry. After presenting some properties of the deflectometric inspection itself, we describe the qualitative and quantitative evaluation of the deflectometric observation in detail. We will show that an inspection of specular and partially specular objects is feasible in an industrially applicable inspection system. For complexly formed and/or large objects, we propose a robot-based inspection setup.
Keywords: shape from Specular Reflection, deflectometry, specular surface, reconstruction, regularization, robot based inspection.
© 2009 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 1929kB)
|
|
INVESTIGATION OF TRANSIENT THERMAL CHARACTERISTICS OF MICROWAVE TRANSISTORS
W³odzimierz Janke, Jaros³aw Kra¶niewski
Technical University of Koszalin, Department of Electronics and Computer Science, J. J. ¦niadeckich 2, 75-453 Koszalin, Poland (wjanke@man.koszalin.pl, +48 94 3468 745, krasniew@ie.tu.koszalin.pl)
Abstract
The transient thermal characteristics of modern microwave transistors may strongly influence the performance of many microwave circuits. In the paper, the method and the exemplary results of measurements of transient thermal impedance of microwave transistors are presented. Special attention is devoted to measurements in very short time periods after step change of power. The presented results are not available in typical datasheets of microwave transistors. Apart from measurements, an analytical approximation of thermal impedance is presented and the exemplary sets of its parameters obtained by curve fitting.
Keywords: transient thermal impedance, microwave transistors, measurement systems.
© 2009 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 269kB)
|
|
MODEL BASED MONITORING OF HYPOTHERMIC PATIENTS
Michael Schwarz1), Claudia Heilmann2), Martin W. Krueger3), Uwe Kiencke1)
1) Universität Karlsruhe (TH), Institut für Industrielle Informationstechnik, Hertzstr. 16, 76187 Karlsruhe, Germany (schwarz@iiit.uni-karlsruhe.de, +49 721 608-4521, kiencke@iiit.uni-karlsruhe.de)
2) Universitätsklinikum Freiburg Herz-Kreislauf Zentrum, Elsässer Str. 2n, 79110 Freiburg, Germany (claudia.heilmann@uniklinik-freiburg.de)
3) Universität Karlsruhe, Institut für Biomedizinische Technik, Kaiserstr. 12, 76128 Karlsruhe, Germany (martin.krueger@ibt.uni-karlsruhe.de)
Abstract
In open heart surgery the patient is connected to a heart-lung machine which pumps and oxygenizes the blood. The body core temperature is reduced by cooling the blood in a heat exchanger to reduce oxygen consumption of the tissues and so protect organs from hypoxia. Monitoring of vital parameters is crucial for safety of the patient. However, only little information is available from direct measurement. Models of haemodynamics and heat exchange in the human body are presented in this paper which provide the perfusionist with detailed data on blood flow and temperature in regions of the body which cannot be accessed by measurement devices. Simulation is performed on a real-time hardware platform which receives measured signals from the heart-lung machine via a serial interface.
Keywords: biomedical engineering, human modelling, real-time application.
© 2009 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 2198kB)
|
|
NOISE MEASUREMENT SET-UPS FOR FLUCTUATIONS-ENHANCED GAS SENSING
Mateusz Kotarski, Janusz Smulko
Gdansk University of Technology, Faculty of Electronics, Telecommunication and Informatics, G. Narutowicza 11/12, 80-952 Gdañsk, Poland (jsmulko@eti.pg.gda.pl, +48 58 348 6095, kotarski@interecho.com)
Abstract
Resistance fluctuations observed as voltage fluctuations across resistance gas sensors can increase the sensibility and selectivity of gas sensing. This conclusion leads to the question how to prepare in practice a cheap measurement system for gas detection when resistance gas sensors of various resistance are applied. Therefore it is valuable to consider different noise measurement systems that would apply fluctuation-enhanced gas sensing. This study presents two solutions of noise systems that can be used for noise measurements in Taguchi gas sensors currently available on the market and the prototype monosized nanoparticle gas sensors having much greater DC resistance than the sensors currently on sale.
Keywords: gas sensors, gas detection, noise.
© 2009 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 396kB)
|
|
CONTRIBUTION OF JITTER TO THE ERROR OF AMPLITUDE ESTIMATION OF A SINUSOIDAL SIGNAL
Francisco Corrêa Alegria
Instituto de Telecomunicaçoes e Instituto Superior Técnico, Av. Rovisco Pais, 1, 1049-001 Lisbon, Portugal (falegria@lx.it.pt, +351 218 418 376)
Abstract
Jitter and phase noise are non-ideal effects that lead to uncertainties in estimating the parameters of a sinusoidal signal. In this paper, the particular case of the bias induced by these effects on the amplitude estimation is considered. An analytical expression is derived for the relative error of amplitude estimation as a function of number of samples and phase noise standard deviation. It is demonstrated that, in the case of coherent sampling, the relative error is independent of sinusoidal amplitude and offset.
Keywords: analogue-to-digital conversion, jitter, phase noise, uncertainty, sinusoidal signal.
© 2009 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 250kB)
|
|
MULTIPARAMETER APPROXIMATION OF TRANSDUCER TRANSFER FUNCTION BY KRIGING METHOD
Janusz Janiczek
Wroclaw University of Technology, Department of Electronics, Chair of Electronic and Photonic Metrology, B. Prusa 53/55, 51-317 Wroc³aw, Poland (janusz.janiczek@pwr.wroc.pl, +48 71 320 6290)
Abstract
The paper presents an application of the ordinary kriging method to predict multiparameter transfer function values in selected points in a transducer. This method allowed to soften the severity of measuring regime during determination of the transducer transfer function.
Keywords: correction of transducer transfer function, kriging.
© 2009 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 216kB)
|
|
MEASUREMENT SYSTEM FOR TESTING THE OPTICAL RADIATION DETECTORS IN A BROAD TEMPERATURE RANGE
Robert Æwirko, Joanna Æwirko, Zbigniew Bielecki
Military University of Technology, Faculty of Electronics, Institute of Electronic Systems, Gen. Sylwestra Kaliskiego 2, 00-908 Warszawa, Poland (rcwirko@wel.wat.edu.pl, +48 22 683 7123, jcwirko@wel.wat.edu.pl, zbielecki@wat.edu.pl)
Abstract
IR, VIS and UV detectors are used in scientific research and industrial or military applications. An integrated system used for spectral characteristic measurements of UV, VIS and IR semiconductor detectors is presented in the paper. The system was developed in the Military University of Technology (MUT). Measurements, including noise measurements, can be carried out in a broad temperature range - from 10 K to 450 K. Selected measurement results for UV detectors are presented in the paper, too.
Keywords: UV, VIS and IR detectors, integrated measurement system, lock-in detection, cryogenic measurements and spectral response of photodetectors.
© 2009 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 1288kB)
|
|
RESEARCH ON SPATIAL INTERRELATIONS OF GEOMETRIC DEVIATIONS DETERMINED IN COORDINATE MEASUREMENTS OF FREE-FORM SURFACES
Ma³gorzata Poniatowska
Bialystok Technical University, Chair of Materials Engineering and Mechanical Technology, Wiejska 45C, 15-351 Bia³ystok, Poland (mponiat@pb.edu.pl, +48 85 746 9261)
Abstract
Coordinate measurements are the source of digital data in the form of coordinates of the measurement points of a discrete distribution on the measured surface. The geometric deviations of free-form surfaces are determined (at each point) as normal deviations of these points from the nominal surface (the CAD model). Different sources of errors in the manufacturing process result in deviations of different character, deterministic and random. The contribution of random phenomena on the surface depends on the type of processing. The article suggests an innovation in applying the methods of analysis of spatial data in research on the geometric deviations randomness of free-form surfaces, consisting in testing their spatial autocorrelation. In the research on spatial autocorrelation of free-form surface deviations, Moran's I statistic was applied.
Keywords: coordinate measurements, free-form surface, geometric deviations, spatial autocorrelation.
© 2009 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 2440kB)
|
|
DIGITAL ADJUSTMENT OF ANALOG-TO-DIGITAL CONVERTER TRANSFER FUNCTION
Janusz Janiczek
Wroclaw University of Technology, Department of Electronics, Chair of Electronic and Photonic Metrology, B. Prusa 53/55, 51-317 Wroc³aw, Poland (janusz.janiczek@pwr.wroc.pl, +48 71 320 6290)
Abstract
The paper presents a method for digital adjustment of the analog-to-digital converter transfer function. A converter with such adjustments is a useful tool for correcting non-linearity of transducers, especially those with high linearity, in case of which the numerical correction would lead to loss of resolution.An implementation of such a converter to adjust a carbon monoxide sensor transducer has been presented.
Keywords: correction of transducer transfer function, A/D converter.
© 2009 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 193kB)
|
|
DESIGN AND FABRICATION OF NANOMAGNETIC SENSORS BASED ON ELECTRODEPOSITED GMR MATERIALS
Gholam Reza Nabiyouni
University of Arak, Department of Physics, Beheshti Avenue, Arak 38156, Iran (g-nabiyouni@araku.ac.ir, +98 861 276 5004)
Abstract
The operation of magnetic sensors is based on different physical principles, leading to the fabrication of different magnetic sensor types. Commercially available magnetic sensors such as Hall effect devices, inductive coil and fluxgate magnetometers have their own advantages and limitations. Magnetoresistive sensors are based on the change of the electric resistivity when they are subjected to a magnetic field. We introduce a low-cost method i.e. electrodeposition of magnetic multilayers, in order to fabricate sensitive magnetic sensors. We have successfully grown Co/Cu and Ni/Cu multilayers on n-type (100) Si substrate, from a single electrochemical electrolyte containing either both (Co+2 and Cu+2) or both (Ni+2 and Cu+2) ions, for growing Co/Cu and Ni/Cu multilayers respectively. While a maximum change of 12 percent was observed in the electric resistivity of the Co/Cu films when they were subjected to a magnetic field of 2000 Oe, the maximum change in resistivity for Ni/Cu multilayers was only 3.5 percent. Nevertheless, the sensitivity of multilayer Ni/Cu films in low magnetic fields (up to 100 Oe) was found to be almost twice that obtained for Co/Cu films.
Keywords: electrodeposition, magnetic sensors, multilayer thin films.
© 2009 Polish Academy of Sciences. All rights reserved
Full paper (PDF, 464kB)
|
|
