DEASUREMENT AND

INFORMATION S

EPARTMENT OF M

YSTEMS SERVING EDUCATION AND RESEARCH FOR

50 YEARS

1. ABOUT THE DEPARTMENT The predecessor of the Department of Measurement and Information Systems (formerly Department of Measurement and Instrument Engineering) was established in 1954. The history of the Department can be characterized by several important milestones: perhaps (1) the development of high-precision and automatic calibration equipment covering almost five decades, (2) the important telemetry applications in the seventies, (3) the industry standard MMT Microprocessor Application System in the eighties, and (4) the establishment of long-term international partnerships in the nineties can serve as prominent examples. All these activities were accompanied with intensive basic and applied

research, and immediate knowledge transfer to the students. Nowadays the educational, research and development activities of the department cover the following major areas: (1) embedded information systems, (2) intelligent system design and (3) dependable computing technology. A characteristic feature of the department is its expertise in linking and combining recent theoretical, technological and practical achievements in measurements, electronics and informatics to implement complex, high precision, high reliability procedures and services both on device and system level. The department serves also as a knowledge and technology transfer centre of its professional fields.

2. EDUCATION The Department provides courses and specializations for its students working for their MSc and/or PhD degrees both in electrical engineering (EE) and informatics (I). The core subjects offered are: (1) Digital Design I-II, (2) Measurement Technology, (3) Operating Systems, (4) Artificial Intelligence, (5) Laboratory I-II, (6) Electronics, (7) Formal Methods, (8) Embedded Information Systems. The major specializations elaborated and offered by the Department are: Embedded Information Systems (EE), Information Technology Infrastructure (I) and Integrated Intelligent Systems (I). These specializations include a two-semester Project Laboratory course and the Diploma Thesis. 3. RESEARCH DIVISIONS According to the main research directions, three research divisions have been formed at the department: Embedded Systems (head: Gábor Péceli), Intelligent Systems (head: Gábor Horváth) and Dependable Computing (head: András Pataricza). Our research projects have been supported by international, bilateral and Hungarian research funds. The funds financed by the Hungarian Government are: OTKA, OMFB, FKFP, TÉT and IKTA. 3.1. DIVISION OF EMBEDDED

SYSTEMS The contemporary solutions of measurement and instrumentation are based on dedicated computer systems and offer a wide variety of autonomous services. These services include primarily data acquisition, information processing, and control, but there are several other additional mechanisms to achieve high-quality overall performance. The majority of such applications can be considered as embedded systems due to the fact that, in addition to the sensors and the actuators, the dedicated computer system components are also invisibly embedded in the hosting environment. The role of these embedded systems is to measure or identify the behaviour of their environment which is followed by some real-time computations to provide proper characterization, influence and control. The Department of Measurement and Information Systems operates seven smaller laboratories working on problems related to various kinds of embedded systems and hosts the Embedded Information Technology Research Group of the Hungarian Academy of Sciences and the Budapest University of Technology and Economics.

Calibration Instruments Laboratory

Research interest: Current, voltage, impedance measurement, self-calibrating instruments, calibration of instrument transformers, artificial impedances. Staff: István Zoltán, Zoltán Benesóczky, András Görgényi, Balázs Vargha, József Dudás, Zoltán Román and Zsolt Szepessy. Resources and infrastructure: DC-Calibrator, AC-Calibrator, CT-Calibrator, VT-Calibrator, Standard CTs and Impedance Analyzer.

Major research and development projects The Department has a great tradition in research and development of precision electrical measurements and metrology including the complete innovation process. The main fields of the research activity are:

• Current, voltage, impedance and power measurement

• Self-calibrating, self-correcting instruments • Calibration of instrument transformers • Artificial impedances

Since suitable and accurate reference standards were not available before 1990, the calibration of high precision instruments was very difficult and expensive. From the beginning of the 1990's, the rapid development of the analogue, digital and mixed signal processing opened new possibilities in instrumentation. Thanks to this advancing hardware and software tools, the calibration functions of the devices could be integrated into the measuring instruments and even the automatic self-correction of the errors measured during the self-calibration process became possible. Based on these methods the following typical errors have become manageable:

• Errors of approximation • Calculable errors • Measurable errors • Errors caused by influence quantities • Thermal drift

Thanks to this approach the overall accuracy of the instruments can be even 1000-times better than that of the built-in components. This possibility basically changes the principles of development of measuring instruments. From the beginning of the 1990's, more and more PhD students have become involved in the research

of self-calibrating and self-correcting measuring instruments in the following fields:

• Artificial impedances • Self-calibrating amplifiers • Correction of thermal dynamic errors

• Impedance analysis Figure 2 1 ppm Standard Current Transformer used in

the 0.5….10000 A current range. • Calibration algorithm for current-output R-2R ladders

• Calibration of power measuring instruments The self-calibrating and self-correcting measuring instruments provide the possibility of low-cost and efficient remote calibration via Internet, foreseeing already the technology of the third millennium in precision measurement and metrology. The growing development-, manufacturing-, marketing-, and after sales service requirements related to the new, advanced calibration instruments required a more appropriate organization, thus the CALIN Electronics Ltd. was established in 1997.

Figure 3 Standard Additional Burden for voltage transformer calibration.

Parallel to this, the cooperation with the Department was successfully continued by CALIN Electronics Ltd. As a result of the joint efforts, in 1998 a new advanced generation of self-calibrating and self-correcting measuring instruments has been introduced to the international market. These instruments are used as national standards and also for automatic calibration in manufacturing of current and voltage transformers in Austria, Brazil, UK, Germany, Hungary, Romania and Taiwan.

Some recent products: Instrument Transformer Analyzer (Fig. 1), 1 ppm Standard Current Transformer (Fig. 2), Standard Additional Burden for voltage transformer calibration (Fig. 3) and Standard Current Transformer for calibration of watthour meters (Fig. 4).

Figure 4 Standard Current Transformer for calibration of

watthour meters.

Acknowledgement: The staff of the laboratory wishes to express his appreciation to the former contributors: László Schnell, Endre Tóth, Péter Osváth, Gyula Korányi, Péter Pataki, Ferenc Nagy, Zoltán Reguly, László Naszádos, László Gyöngy and Erik Bohus. Contact person: István Zoltán izoltan@mit.bme.hu

www.mit.bme.hu/~izoltan/ Figure 1 Instrument Transformer Analyzer composed of 1 ppm calibrator and programmable high-power artificial

impedance with 101442 settings.

Selected publications: 1. I. Zoltán, “A multi-function standard

instrument for current transformer

calibration,” OIML, Bulletin, Vol. XXXVI, No. 4, October 1995, pp. 28-32.

2. I. Zoltán, “Impedanzsynthese,” Technisches Messen 68 (2001) 4, Oldenbourg Verlag, Munich, Germany, pp. 179-181.

3. B. Vargha and I. Zoltán, “Calibration algorithm for current-output R-2R ladders,” IEEE Trans. on Instrumentation and Measurement, Vol. 50, No. 5, October 2001, pp. 1216-1220.

4. Zs. Szepessy and I. Zoltán, “Thermal dynamic model of precision wire-wound resistors,” IEEE Trans. on Instrumentation and Measurement, Vol. 51, No. 5, October 2002, pp. 930-934.

Biomedical Engineering Laboratory

Research interest: Electronic biomedical instruments, biosignal processing, marker-based movement analysis, home health monitoring.

www.mit.bme.hu/~jobbagy/biomed Staff: Ákos Jobbágy, András Görgényi and Károly Bretz jr. Education: Biomedical Instrumentation, Electronic Measuring Equipment. Resources and infrastructure: Passive marker-based motion analyzers: PRIMAS (precision 3D) and PAM (simple 2D), electronic biomedical instruments: (ECG, PPG, blood-pressure monitors, pulmonary analyzer), battery operated (scope meters, hand-held DMMs) and bench-top electrical instruments.

Major research and development projects Movement analysis: “Development of signal processing algorithms to compensate the non-ideal projection of passive marker-based motion analyzers,” financed by NWO and OTKA. (See: www.mit.bme.hu/

~jobbagy/parkinson/parkinson.htm, ~jobbagy/cdreklam/Markerbasedma.html)

Diagnosis and staging of patients with neural diseases is challenging, especially in the early phase. Passive marker-based motion analysis helps the objective assessment providing information about the movement of body segments during well-defined hand- and finger movements. We developed different feature extraction methods to evaluate the movement and thus the actual performance of the tested persons. These tests help in the early diagnosis of Parkinson's disease as well

as in setting the appropriate medication of patients. Our tests confirmed that Parkinson's disease manifests itself uniquely in the movement disorders of a patient. A simple and cheap image-based motion analyzer (PAM) has been developed at the Department that is affordable for routine clinical use. We offer also programs that evaluate the performance of tested persons, taking into account the regularity and the speed of the movements. Partners: E. Hans Furnée (TU Delft), Péter Harcos (Szt. Imre Hospital), Emil Monos (Semmelweis University) and Gábor Fazekas (Szt. János Hospital, OORI).

Figure 5 Marker trajectories during the finger-tapping test. Performance of the right and left hand of a healthy

subject (above) and a newly diagnosed Parkinsonian (below).

Home health monitoring: “Artificial patient and model in medical informatics,” financed by FKFP, and “Home health monitoring,” financed by OTKA. World life expectancy more than doubled over the past two centuries, a further increase is estimated. National health care systems should be accommodated; the prevalence rates of many diseases substantially change over age. The average medical expenditure per person is significantly higher for the elderly than for younger people.

Selected publications: Keeping the healthiness of the population can be helped by home health monitoring. Many diseases can be treated more effectively and at a lower cost if early signs are detected.

1. Á. Jobbágy, L. Gyöngy and E. Monos, “Quantitative evaluation of long-term locomotor activity of rats,” IEEE Trans. on Instrumentation and Measurement, Vol. 51, No. 2, April 2002, pp. 393-397.

In Hungary, cardiovascular diseases are the leading cause of death, being responsible for about half of the deaths (www.bel2.sote.hu/hipertonia). It is estimated that 30% of the Hungarian population has hypertonia, above age 65 this ratio increases to approximately 65%. Diagnosis in the early stage would make it possible to start medication and treatment to prevent the deterioration of the patients.

2. Á. Jobbágy, E.H. Furnée, P. Harcos and M. Tárczy, “Early detection of Parkinson’s disease through automatic movement evaluation,” IEEE Engineering in Medicine and Biology Magazine, Vol. 17, No. 2, March-April 1998, pp. 81-88.

3. Á. Jobbágy, “Photoplethysmographic signal aids indirect blood-pressure measurement,” Proc. of MEDICON 2001, IX. Mediterranean Conf. on Medical and Biological Engineering and Computing, June 12-15, 2001, Pula, Croatia, pp. 262-264.

The presently existing blood-pressure meters either require trained operator or do not assure accurate measurement. Automatic and semi-automatic blood-pressure meters are simple-to-use thus widespread in home health monitoring. However, their results are not accurate and reproducible enough, the reliability of self-assessment is not satisfactory, medical doctors have reservations for the results. The best grade (A) in the British Hypertension Society standard allows 40% of the results deviate from the reference by more than 5 Hgmm, 15% of the results by more than 10 Hgmm and 5% of the results by more than 15 Hgmm. The aim of our research work has been to increase the accuracy and reproducibility of the indirect, cuff-based blood pressure measurement with the help of the photoplethysmographic (PPG) signal. A method has been developed to measure the systolic and diastolic pressure and not the mean pressure as it is done while using the oscillometric method. A patient monitoring device is being developed that is able to store daily physiological measurement results (blood pressure, 10-s ECG recording) for 2 months. The device is also able to analyze the recorded data and request help if needed via mobile phone.

Computer Networks Laboratory

Research interest: Communication of embedded systems, sensor networking, real-time and distributed communications, quality of service, wireless networking.

www.mit.bme.hu/projects/iiensor Staff: Csaba Tóth, Tamás Kovácsházy, László Kádár and Balázs Scherer. Education: Multimedia Networking, Informatics. Resources and infrastructure: Two laboratories, PC-based development systems for PIC (8 bit) and ARM (32 bit) micro-controllers, a sample network of voice over IP telephony (made by Siemens), IEEE 802.11bg wireless network, Gigabit Ethernet Cluster, 10/100Base-T networking components including switches, routers, firewalls, etc.

Major research and development projects Gigabit ethernet cluster: Workpackage of NEXT TTA – High Confidence Architecture for Distributed Control Applications, EU IST-2001-32111 Programme.

Partners: Gábor Halász (BUTE, Faculty of Mechanical Eng.) and Márk Kollai (Semmelweis University).

www.mit.bme.hu/projects/isensor/NEXT Contact person: The objective of NEXT TTA project was to develop and implement novel algorithms, tools and components to provide a generic architecture for

Ákos Jobbágy jobbagy@mit.bme.hu www.mit.bme.hu/~jobbagy/

safety-critical applications in different application domains (e.g., aerospace, automotive, and railway applications). NEXT TTA project was an integration of many different problem solutions that have been explored independently over many years in different research institutions.

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unfortunately, using non-standard protocols in the application layer. The goal of this project was to review the applicable Internet protocols and system architectures, to describe a solution for developing network capable smart sensors and actuators, with good system integration ability.

rten.mit.bme.hu/projects/isensor/IMTC2003

Figure 6 Network Laboratory I (NEXT TTA Gigabit Ethernet Cluster).

e Gigabit workpackage explored the achievable rformance, the limitations and bottlenecks of a A network composed of commercial off-the-shelf

gh-end state-of-the-art hardware components. In rticular, the workpackage set-up a TTA cluster nsisting of ordinary PCs, which are the nodes of e cluster, and a Gigabit Ethernet serving as the terconnection network. All the components could purchased at the “next door computer shop.” r workpackage implemented a Windows-based st for this TTA cluster and analyzed the whole stem by measuring its performance and attributes. dustrial application of modern info-mmunications technology (IKTA 164/2000, onsored by the Hungarian Ministry of Education),

cooperation with VERTESZ Kft. www.mit.bme.hu/projects/isensor/IKTA2000

ring the last five years a remarkable spreading of gh-level communication technologies, principally e Ethernet and Internet, was noticeable in the bedded system market. As a result, most of the ding embedded system manufacturers have rted offering solutions to connect their devices

to TCP/IP protocol based computer networks,

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Figure 7 Network Laboratory II.

e have developed an SNMP-based pseudo NCAP based on IEEE 1451) providing a transducer ndependent network accessible interface, useable to ormalise the control of devices with different unctions.

rten.mit.bme.hu/projects/isensor/IMTC2003

ontact person: saba Tóth

oth@mit.bme.hu ww.mit.bme.hu/~toth/

elected publications: . Cs. Tóth, B. Scherer, L. Kádár and T. Bakó,

“Implementation possibilities of networked smart transducers,” ICCC 2003, International Carpathian Control Conference, Tatranska Lomnica, Slovak Republic, May 26-29, 2003, pp. 198-201.

. B. Scherer, Cs. Tóth, T. Kovácsházy and B. Vargha, “SNMP-based approach to scalable smart transducer networks,” 2003 IEEE Instrumentation and Measurement Technology Conference (IMTC 2003), Vail, Colorado, USA, May 20-22, 2003, pp. 721-725.

3. T. Kovácsházy and R. Szabó, “Performance measurement tool for packet forwarding devices,” 2001 IEEE Instrumentation and Measurement Technology Conference (IMTC 2001), Budapest, Hungary, 2001, Vol. 2, pp. 860-863.

4. T. Péter and Cs. Tóth, “Quality of system monitoring in a complex Internet service provider - Case study,” IEEE International Conference on Intelligent Engineering Systems (INES’99), Slovakia, Nov. 1-3, 1999, pp. 629-633.

Logic Design Laboratory

Research interest: Digital system design, high level synthesis, advanced signal and image processing architectures, embedded microprocessor systems, dynamically reconfigurable computers and systems on a programmable chip implementations. Staff: Béla Fehér, Gábor Horváth, Lőrinc Antoni and Péter Szántó. Education: The laboratory has a central role in the practical education of the students of the Embedded Systems Branch. Our open laboratory policy makes the lab to a familiar working place not only for the curricula lectures, but also for the elaboration of the particular student ideas as well. Subjects related to the laboratory are Digital Technique, Logic Design, Microprocessor Systems, Design of SoPCs by FPGAs. Resources and infrastructure: The laboratory is equipped with 12 PCs configured as W2000 workstations. All important design softwares are available in the laboratory, including the Xilinx ISE and EDK FPGA development system, the Matlab Environment, the Mentor Graphics products such as ModelSim, FPGA Advantage, SystemVision, Seamless, and the Celoxica Handel-C tools. Tektronix TPA 700 LA, ARM MultiICE IDE, and development boards from Digilent and XESS are also available.

Major research and development projects The Logic Design laboratory is the centre of the department’s research work for the design of complex digital systems, with emphasis on the application of FPGAs and exploitation of the re- configurability. Significant results have been achieved with the application of FPGAs in the field of digital signal processing. Different basic linear FIR and IIR filter structures, DSP core generators and efficient finite word and distributed arithmetic

building blocks have been developed. Based on special recursive algorithm, high performance 1D and 2D linear transform modules (WHT, DCT) have been implemented in an area optimized way. Similar methods have been used to implement nonlinear median filters for high speed video signal processing. Current research is focused on FPGA implementation of advanced 3D rendering algorithms for portable applications with reconfigurable computing architectures.

Figure 8 48-tap, 16-bit FIR filter in a 5k gates FPGA.

Figure 9 LOGSYS-BLOXES FPGA Educational Board.

Significant work has been done to offer a modular FPGA/PLD development board family for the students, called LOGSYS-BLOXES. Three levels of boards have been made, supporting the different needs of the education at basic, entry level logic design and later in the implementation of more complex DSP units and communication systems including chip development and verification. A simple, standardized USB-based debugger, control and power interface is also provided with a rich set of interesting peripheral interface modules.

Unique property of dynamic reconfiguration (DRC) capability of some SRAM technology based FPGAs makes very special applications possible, for example, the dependability and fault tolerance analysis of complex digital systems. DRC is used to inject Single Event Upset (SEU) or stuck-at-1 (or 0) like errors into the logic and evaluate the behaviour in real time. This research was done in cooperation with Prof. Régis Leveugle, TIMA, France. Efficient arithmetic modules were also developed exploiting the DRC in the frame of a national FKFP project Re-configurable Computing Architectures (0413/1997). Partners were University of Veszprém and University of Miskolc. The Logic Design Laboratory also serves as a Technology Expertise Center (TEC) in different national and EC projects. It offers consultation and design services for SMEs interested in advanced embedded system design methodologies. The EC funded FP5 technology transfer project JENET (Joint European Network of Embedded Internet Technologies, IST IST-2000-28422) is a good example of this activity. JENET is promoting the use of the new communication capabilities in industrial applications, especially the embedded Internet

Figure 10 JENET presentation at Exhibitions of Magyar Regula, held in Budapest, 2003.

technology in products and systems developed by European enterprises. JENET is carried out by a network of 7 TECs and 27 User Companies (UCs) from Belgium, Germany, Hungary, Italy, Poland, Romania and United Kingdom. Local partner SMEs are Infoware Co., Meldetechnik Ltd., Silex Ltd., the

project coordinator is CRR, Italy. For more information visit: www.eurojenet.com.

Contact Person: Béla Fehér feher@mit.bme.hu www.mit.bme.hu/~feher/ Selected publications: 1. B. Fehér, “Efficient Synthesis of Distributed

Vector Multipliers,” Journal of Microprocessors and Microprogramming, Vol. 38, No. 1-5, 1993.

2. B. Fehér, “New Inner Product Algorithm of the 2D DCT,” Digital Video Compression: Algorithm and Technologies, Proc. SPIE, Vol. 2419, ISBN 0-8194-1766-1.

3. P. Szántó and B. Fehér, “3D Rendering using FPGAs,” IFIP International Conference on VLSI SOC, December 1-3, 2003, Darmstadt, Germany.

4. L. Antoni, R. Leveugle, and B. Fehér, “Using run-time reconfiguration for fault injection applications,” IEEE Trans. on Instrumentation and Measurement, Vol. 52, No. 5, October 2003.

Digital Signal Processing Laboratory

Research interest: Signal modeling, adaptive signal processing, digital filter structures, transform-domain signal processing. Signal processing in complex measurement systems. Staff: László Sujbert, László Naszádos, Balázs Bank and Károly Molnár. Part-time contributors: Gábor Péceli, Tamás Dabóczi and Gyula Simon. Education: Embedded Systems Laboratory, Information Systems Laboratory. Resources and infrastructure:

• DSP development boards (Analog Devices, Motorola, Texas Instruments)

• Vibro-acoustic transducers, signal conditioners (Brüel&Kjaer)

• Digital storage scopes, spectrum analyzers, special generators (LeCroy, HP)

Major research and development projects Active noise control is an old idea for acoustic noise suppression, but it could be implemented only since the digital signal processors have been available. The solution is based on the destructive interference phenomenon. We have developed a

dedicated method for suppressing periodic noise components. The method is the extension of the resonator-based observer developed at the Department. The advantages of the resonator-based noise controller are its fast convergence (compared to other methods) and its low computational burden. Based on the experiences with the resonator-based periodic noise controller, we have developed a modified version of the well-known filtered-X LMS algorithm allowing faster convergence for broadband noise control.

• University of Padua, Department of Information Engineering

www.dei.unipd.it

Figure 12 Transfer function measurement of a violin

body. One of our latest industrial projects is the development of a DSP-based system for in-motion weighing of railway carriages. It is a two-level system that comprises of 16 or 24 DSP-based Measurement Units (MU) and a powerful HOST PC. The MUs store the deformation signals of the rail caused by the wheels of an in-motion train. The deformation is measured by strain gauges. AD converters sample the signal of the strain gauge bridge, and this signal is processed by DSP. The HOST collects the stored data, and a large database is built for each train.

Figure 11 Typical performance of an active noise control

system. Grants, international relations: • OTKA: Acoustic applications of digital signal

processing, F 035060 • TPD-TNO Delft, the Netherlands,

www.tpd.tno.nl Digital sound synthesis of musical instruments has been acclaimed at the department in the last years. It needs very precise measurements and poses serious signal processing problems. The results achieved in this field can be utilized generally, e.g., in system identification or in filter design. We have synthesized successfully the sounds of organ, violin and piano. Most of the research results were achieved for piano sound synthesis, where an important version of digital waveguide model has been used. Grants, international relations:

Contact person: László Sujbert sujbert@mit.bme.hu www.mit.bme/~sujbert/ Selected publications: • OTKA: Acoustic applications of digital

signal processing, F 035060 1. L. Sujbert and G. Péceli, “Signal model based periodic noise controller design,” Measurement - the Journal of the IMEKO, Vol. 20, No. 2, pp. 135-141.

• MOSART IHP (Improving Human Potential) Training Network, HPRN-CT-2000-00115

2. L. Sujbert, “A new filtered LMS algorithm for active noise control,” Proc. of the Active '99 - The International EAA Symposium on Active Control of Sound and Vibration, December 2-4, 1999, Fort Lauderdale, Florida, USA, pp. 1101-1110.

www.diku.dk/forskning/musinf/mosart • Helsinki University of Technology,

Laboratory of Acoustics and Audio Signal Processing

www.acoustics.hut.fi

3. B. Bank and V. Välimäki, “Robust loss filter design for digital waveguide synthesis of string tones,” IEEE Signal Processing Letters, Vol. 10, No. 1, pp. 18-20, January 2003.

Chaotic signals are inherently wideband signals that may be generated with high power efficiency using simple nonlinear circuits in any frequency band and at arbitrary power level. In chaotic communication, the digital information to be transmitted is mapped directly into a wideband chaotic waveform. Chaotic communication offers a low cost alternative solution to conventional spread spectrum communication.

Chaotic Signals and Systems Laboratory Research interest: Chaotic communication systems, analysis and computer simulation of data communication systems, frequency synthesis, phase-locked loop.

Seven European universities collaborated in the INSPECT Esprit Project to find applications for chaotic signals in communication and watermarking of digital pictures. Our Chaotic Systems Team coordinated the research and implementation of a working prototype of frequency-modulated chaos-shift keying (FM-DCSK) communication system. We have invented FM-DCSK (the most robust chaotic modulation scheme), derived exact expressions for the noise performance of correlator-based chaotic modulation schemes, developed an ultra fast computer simulator to evaluate the system performance of digital communication systems under various channel conditions, and elaborated the system proposal and determined the system level parameters for the INSPECT FM-DCSK chaotic data communication system.

www.mit.bme.hu/research/chaos/ Staff: Géza Kolumbán, Gábor Kis, Zoltán Jákó, Zoltán Szabó and Béla Frigyik. Education: Electronics I and II, Theory and Applications of Nonlinear Theory and Chaos (PhD course), System Level Design and Analysis. Resources and infrastructure: Linux-based PCs.

Major research and development projects Development and analysis of novel signal processing architectures for system-on-a-chip (SoC) integrated circuits: T038083, financed by OTKA, 2002-2005. The project has been launched to find new transceiver and frequency synthesizer configurations for communication and measurement purposes. The INSPECT FM-DCSK radio shown in Fig. 13

operated in the 2.4-GHz ISM band and was successfully tested in 2001. To illustrate its excellent multipath performance, the bit error rate (BER) curves of conventional differential phase-shift keying (DPSK) and chaotic FM-DCSK are compared in Fig. 14. Although the single-ray performance of FM-DCSK is worse than that of DPSK, in the indoor multipath channels the DPSK

Partners: G. Chen (City University of Hong Kong), C. M. Lau and C K. Tse (The Hong Kong Polytechnic University). Innovative signal processing exploiting chaotic dynamics (INSPECT): Esprit Project 31103, Open LTR – 2 phase, Financed by European Commission, 1998-2001.

nd

www.cordis.lu/esprit/src/31103.htm www.mit.bme.hu/research/chaos/inspect/

Figure 13 Picture of the 2.4-GHz FM-DCSK prototype receiver built in the framework of INSPECT Esprit Project.

fails completely (see dash-dotted curve) while FM-DCSK has only a 4-dB loss in the system performance (see dashed and dotted curves). Partners: M. P. Kennedy (University College Cork), M. Hasler (Swiss Federal Institute of Technology, Lausanne).

Figure 14 BER curves of conventional DPSK and chaotic FM-DCSK in a single-ray additive white

Gaussian noise (AWGN) channel (solid and dashed, respectively) and in an indoor multipath channel (dash-

dotted and dotted, respectively). Spread spectrum communication exploiting chaos: Office of Naval Research (ONR), USA, 1995-1996. The goal of this project was to propose an underwater chaotic communication scheme for the submarines of US Navy. In the project we have elaborated a comprehensive theory for chaotic waveform communication. Partners: L. O. Chua (University of California, Berkeley) and M. P. Kennedy (University College Dublin). Contact person: Géza Kolumbán, kolumban@mit.bme.hu www.mit.bme.hu/~kolumban/ Selected publications: 1. G. Kolumbán, M. P. Kennedy, Z. Jákó and

G. Kis, “Chaotic communications with correlator receiver: Theory and performance limits,” invited paper, Proceedings of the IEEE, Vol. 90, pp. 711-732, May 2002.

2. M. P. Kennedy and G. Kolumbán, guest editors, Special Issue on “Noncoherent Chaotic

Communications,” IEEE Trans. Circuits and Syst. I, Vol. 47, pp. 1661-1732, December 2000.

3. G. Kolumbán, M.P. Kennedy and L.O. Chua, “The role of synchronization in digital communications using chaos,” IEEE Trans. Circuits and Syst. I, Part I: “Fundamentals of digital communications,” Vol. 44, 927-936, October 1997; Part II: “Chaotic modulation and chaotic synchronization,” Vol. 45, 1129-1140, November 1998; Part III: “Performance bounds,” Vol. 47, 1673-1683, December 2000.

4. G. Kolumbán, “Theoretical noise performance of correlator-based chaotic communications schemes,” IEEE Trans. Circuits and Syst. I, Vol. 47, pp. 1702-1711, December 2000.

5. G. Kolumbán, “The theory and implementation of a robust chaotic digital communications system,” invited talk at 2003 Microwave Symposium Workshop, IEEE International Microwave Symposium, Philadelphia, USA, June 9, 2003. www.ims2003.org/technical/workshop/WMA.htm System Identification Laboratory

Research interest: Identification of linear systems, parameter estimation, SISO/MIMO modeling, effect of nonlinear disturbances, signal reconstruction using known measurement system models (inverse filtering). Staff: István Kollár, Tamás Dabóczi, Gyula Simon, József Németh, László Balogh, János Márkus, Balázs Vödrös and Zoltán Bilau. Education: Digital Signal Processing, System Identification, Embedded Systems.

Major research and development projects Identification in the Frequency Domain The close cooperation between our department and the Department ELEC at the Vrije Universiteit Brussel, Belgium (wwwtw.vub.ac.be/elec/), is continuous since 1989. One of the major results of this cooperation is the Frequency Domain System Identification Toolbox for MATLAB. The peculiarity of the frequency domain methods is that they solve the maximum likelihood equations in the frequency domain, making it possible to fully exploit the advantages of harmonic excitations. An important step in identification is the validation of the results. We always have to check whether the result really satisfies our requirements, is in no contradiction with the preliminary assumptions, and corresponds to the data. A program can only offer

tools for this purpose: the validation itself is the task of the person who performs the identification.

Successful applications of inverse filtering are: • High voltage lightning measurements:

compensating the distortion of high voltage dividers. Cooperating party: Swiss Federal Institute of Technology, Zürich, Switzerland, High Voltage Laboratory

The toolbox effectively uses the following advanced MATLAB tools:

• Graphical user interface • Automatic procedures and

• Calibration of ultra high-speed oscilloscopes. Cooperating party: National Institute of Standards and Technology, NIST, USA

• Data structures The investigated system can be anything from electrical systems (filters, machines) to mechanical systems (airplanes, cars, robot arm) and acoustical systems (airplane cabin, loudspeaker). • Restoration the sound of old movies, kept on

film

• High voltage generator, chopping gap and high voltage dividers – HV laboratory of the ETH Zürich

Figure 15 Compare and Evaluate Models window

of the GUI of the fdident toolbox.

The toolbox is now in use throughout the world. Linear modeling is currently being extended to characterize slight nonlinear distortions and to model multiple input – multiple output systems.

Figure 16 Measured and reconstructed high voltage lightning impulses.

Inverse filtering

The accuracy of time domain waveform measurements is limited by the finite bandwidth of the measurement instrument. This means that high frequency components of the signal will be suppressed and the phase of the different frequency components will be modified. The result is a distorted waveform; the fast changes of the signal are rounded, rapid transitions are stretched out. Digital post-processing of the measured data can improve the result. This is called inverse filtering. This problem is usually ill-posed, that is, small changes in the measured output signal cause large fluctuations in the estimation of the input signal.

Figure 17 High voltage lightning impulse measurement

setup.

Different inverse filtering techniques provide different approaches to suppress the amplified noise without significantly distorting the useful signal.

Recent Research Grants: OTKA, National Institute of Standards and Technology (NIST, USA), Hungarian Ministry of Education.

Contact persons:

István Kollár Tamás Dabóczi kollar@mit.bme.hu daboczi@mit.bme.hu www.mit.bme.hu/~kollar/ www.mit.bme.hu/~daboczi/ Selected publications: 1. FDIDENT (1999-2003), Frequency Domain

System Identification Toolbox Developers’ Page: elec.vub.ac.be/fdident/.

2. I. Kollár, R. Pintelon, Y. Rolain, J. Schoukens, and Gy. Simon, “Frequency domain system identification toolbox for MATLAB: Automatic processing – from data to models,” IFAC Symposium on System Identification, SYSID 2003, August 2003, Rotterdam.

3. T. Dabóczi, I. Kollár, Gy. Simon, and T. Megyeri, “How to test graphical user interfaces?” IEEE Instrumentation and Measurement Magazine, Vol. 6, No. 3, pp. 27-33, September 2003.

4. J. Deyst, N. G. Paulter, T. Dabóczi, G. N. Stenbakken and T. M. Souders, “A fast pulse oscilloscope calibration system,” IEEE Trans. on Instrumentation and Measurement, Vol. 47, No. 5, pp. 1037-1041, 1998.

3.2. DIVISION OF INTELLIGENT

SYSTEMS System is basic notion for all of the engineering

sciences. System models are a kind of knowledge representation about the world, environment, task, problem, etc., and constitute a kernel information for diagnosis, design, control, prediction and multitude of other related tasks. The key issue is what mathematical formalism underlies the system models, in what sense they are “computable.” Here we have a whole spectrum of sciences ranging from complex analysis to artificial intelligence.

The more complicated, involved is the problem, the more is the chance that the real break-through requires the management of many different kinds of models, drawing typically from numerically

intensive methods to describe physical reality and from symbolic techniques to catch the elements of human expertise.

Artificial intelligence deals with systems that behave rationally or similarly to humans. The main goal is to understand the rules of rational behaviour and to construct intelligent systems whose operations simulate it in some respect. The field of intelligent systems is rather diverse, it covers the perception and retrieval of information, processing of information of various forms (numerical, text, speech, images, etc.), modeling and control of complex systems, planning of complex actions and developing such decision processes which work similarly to human decision making.

In our Department a group of 10-15 colleagues have been studying different theoretical and practical problems of sophisticated system models and dealing with the development and construction of intelligent systems since the beginning of the eighties. The field of artificial intelligence plays also an important role in the graduate and postgraduate education of the Department. Actually about 10 PhD students take part in the research work of the group. They work for their PhD theses, most of them in international cooperation. The group has fruitful and longtime cooperation with Vrije Universiteit, Brussels, but there are good research contacts with other universities from Great Britain and Belgium.

Intelligent systems are engineering products and they are not “purely intelligent.” Instead, they can be considered as “hybrid” systems that integrate traditional engineering knowledge and the results of artificial intelligence. The research and development activity of the Intelligent Systems Group is also related to the analysis and construction of such complex hybrid systems for various application fields, e.g., finance, steel industry, medical diagnosis. In the sequel the results of some ongoing or recently finished projects will be presented shortly. The application fields vary, however, there is a common motive in all these projects: the problem must be faced with multiple techniques and models and a place must be made to model and incorporate human expertise as well.

Modeling and Identification of Linear and

Nonlinear Systems Most systems are only approximately linear.

Hence, a linear model will never describe these systems perfectly. Nevertheless, these models are intensively used because they are intuitively easy to understand, and many simple design methods are based on them. On the other hand modeling nonlinear systems is very involved. Each problem is different and in general a dedicated model is required for each different system. In many applications, the time and skill are not present to identify such a model. Moreover, the utmost precision is usually not needed. Many users would

be delighted if they could identify fast an approximate nonlinear model.

2. Flemish-Hungarian Bilateral Cooperation Agreement, “Modeling and Identification of Nonlinear Systems,” Flemish-Hungarian Bilateral Research Project, TÉT B-1/1999, 2000-2002.

3. Flemish-Hungarian Bilateral Cooperation Agreement, “Identification of Linear and Nonlinear Systems,” Flemish-Hungarian Bilateral Research Project, TÉT B-15/02, 2003-2004.

Selected publications

1. J. Schoukens R. Pintelon, T. Dobrowiecki and Y. Rolain, “Identification of linear systems with nonlinear distortions,” Plenary lecture, 13th IFAC Symposium on System Identification, 27-29 August, 2003, Amsterdam.

Figure 18 Nonlinear additive noise model for nonlinear systems described by the convergent Volterra series. 2. J. G. Németh, “Identification of nonlinear

systems using interpolated Volterra Models,” PhD Thesis, Dept ELEC, Vrije University Brussel, 2003.

In cooperation with Department ELEC of the Vrije Universiteit Brussel (wwwtw.vub.ac.be/elec/) a full theoretical framework has been developed to understand the impact of such nonlinear distortions. As a result, a general nonlinear additive noise model had been developed for nonlinear systems described by the convergent Volterra series, with many particular results shaped for Wiener-Hammerstein systems. Consequently, we are not only able to generate improved error bounds, the new insight is also directly applicable in the identification of nonlinear systems, in the improved stability analysis of nonlinear feedback systems and in designing better experiments.

3. J. Schoukens, T. Dobrowiecki and R. Pintelon, “Identification of the stability of feed back systems in the presence of nonlinear distortions,” IFAC 15th Triennal World Congress, Barcelona, Spain, July 21-26, 2002, pp. 418-423.

4. J. Schoukens, R. Pintelon and T. Dobrowiecki, “Linear modeling in the presence of nonlinear distortions,” IEEE Trans of Instrumentation and Measurement, Vol. 51, No. 4, 2002, pp. 786-792. The class of models that we propose can be used in

many applications such as (1) control: the stability of the nonlinear models that we use is very easy to verify; (2) linearization: using these techniques we can linearize the behavior of a nonlinear system; (3) simulation: many simulators allow to bring in user defined models. This allows replacing detailed simulation of complex components by a general behavior model.

5. T. Dobrowiecki and J. Schoukens, “Practical choices in the FRF measurement in the presence of nonlinear distortions,” IEEE Trans. on Instrumentation and Measurement, 2001, Vol. 50, No. 1, pp. 2-8.

6. J. G. Németh, I. Kollár and J. Schoukens, “Identification of Volterra kernels using interpolation,” IEEE Trans. on Instrumentation and Measurement, Vol. 51, No. 4, pp. 770-775, 2002, (Best paper award for 2002 in the I&M Transactions).

Staff: Tadeusz Dobrowiecki, Gábor Horváth, Péter Antal and László Sragner. Contact person: Tadeusz Dobrowiecki dobrowiecki@mit.bme.hu

7. J. Schoukens, R. Pintelon, Y. Rolain and T. Dobrowiecki, “Frequency response functions measurements in the presence of nonlinear distortions,” Automatica, Vol. 37, 2001, pp. 939-946.

www.mit.bme.hu/~tade/ Projects

1. Flemish-Hungarian Bilateral Cooperation Agree-ment, “Modeling and Identification of Nonlinear Systems,” Flemish-Hungarian Bilateral Research Project, TÉT B-2/96, 1997-2000.

8. J. Schoukens T. Dobrowiecki and R. Pintelon, “Parametric and non-parametric identification of linear systems in the presence of nonlinear distortions. A frequency domain approach,” IEEE Trans. on Automatic Control, Vol. 43, No. 2., 1998, pp. 176-190.

InformationCumulating

Environment

TargetEnvironment

Information Utilization Environment

DocumentRetrieval and

AnalysisInformation

Extraction andStorage Information

Access

Manager End-user

resultsnew

documentsanswer

answer

search

searchpatterns query

query9. L. Sragner, J. Schoukens and G. Horváth,

“Modelling of a slightly nonlinear systems: A neural network approach,” NOLCOS 2004 - Stuttgart, IFAC Symposium on Nonlinear Control Systems, September 1-3, 2004.

Figure 19 Information flow about the target (physical

clients) between information (electronic data about clients) and user (retrieving institution) environments.

Ontology-based Information Retrieval

Systems Making effective decisions in finances is becoming

more and more tedious. Usually it is hard to develop explicit models of the input-output relations, despite the huge amount of information available and stored in information systems. This information could be used to extract direct information about clients and transactions, to generate a competitive advantage and improved quality of service. Data mining deals with a nontrivial extraction of implicit, previously unknown, and potentially useful information from large databases. Information retrieval means gathering of information from unstructured text documents (books, papers, and electronic documents). Both information retrieval and data mining however do not use the meaning of the information they are looking for. Knowledge retrieval represents such a significant advancement over simple search engines and conventional retrieval methods. To this purpose, the process of a human information retrieval must be at least partially copied. Its advantage consists of the use of linguistic competence and the benefits of background knowledge. Since linguistics techniques are already rapidly being added to information retrieval systems, the construction, mapping and incorporation of background knowledge becomes the biggest challenge. This involves abandoning the solely index-based searching methods, and requires making use of a logical apparatus to describe the system of concepts the knowledge is built from.

In designing the knowledge to be incorporated into the retrieval system, the notion of ontology was used as a backbone do define the architecture and the services of the system. Such developments served also as a basis for the development of the suitable Hungarian enterprise ontology. Architecture of the system evolves around the trichotomy of the target (physical clients), information (electronic data about clients), and user (retrieving institution) environments and the hierarchy of data. Ontologies, describing the relations between concepts, provide the most abstract content-based description of the data.

Figure 20 Ontology based architecture of the knowledge retrieval system.

The ontologies are described by means of ontology grammars. Grammars are used to grasp the content, both the general (not application oriented) and task oriented. Processing schemes are use mainly to describe (XML based) transformations of the data or the ways to visualize it. Finally data objects store the system data (numerical, textual, image, etc.) in the form described by the grammars. Data objects are the actual data of the above mentioned three categories also, i.e., a grammar, an ontology, an actual processing scheme, etc.

System modeling and diagnostics: A Staff: Tadeusz Dobrowiecki, Tamás Mészáros, György Strausz, Péter Antal, Gergely Héja, Péter Varga and Csaba Dezsényi.

hybrid-neural approach In complex modeling problems one often finds,

that exact or even approximate theoretical/mathematical model of a system cannot be formulated. The reasons behind this can be the unsatisfactory knowledge we have about the basic underlying physical behavior, chemical reactions, etc., or the high complexity of the operation of the system.

Contact person: Tadeusz Dobrowiecki dobrowiecki@mit.bme.hu www.mit.bme.hu/~tade/

In these cases experimental model can be constructed only. To construct experimental models a general modeling structure and appropriate experimental knowledge are needed.

Projects:

1. IKTA 4-00181/2000, “Information and Knowledge Fusion,” ML Consulting and Computing Ltd., DMIS-BUTE, Morphologic Ltd. (part of “Information and Knowledge Fusion” Eureka Project: E12235), May 2001 – December 2003.

One of the most efficient ways of building experimental models is to use neural networks. Neural network-based models can be constructed using a large amount of input-output data about the system/process. However, the measured data may be noisy or imprecise, or some important parameters cannot be measured at all, so appropriate model using only the available data cannot be constructed. A more accurate model – a hybrid model – of a system can be obtained if all available knowledge - independently of their form – are utilized. Such knowledge can be available in the form of propositional rules (symbolic information) or in the forms of mathematical equations which at least partly describe the operation of a system.

2. IKTA 5-00126/2002, “LOBO – Logic Based Management of Ontologies,” IQSOFT Intelligent Software Ltd., Semmelweis University, 3rd Surgery Clinics, DMIS-BUTE, January 2003 – September 2004.

3. IKTA 5-00149/2002, “Terminology Server Based, Practical Medical Decision Support, Web Based Knowledge Intensive System,” DSS Consulting Informatics and Advisory Ltd., Semmelweis University, Medical Informatics Department Group, January 2003 – December 2004.

Hybrid intelligent systems that are built from neural networks and expert systems, and that can utilize the traditional algorithmic solutions combine the advantageous properties of the different approaches. In the department both theoretical and practical problems of hybrid systems are investigated. The theoretical results are related to the modeling and generalization capability of certain neural networks, the construction of efficient dynamic neural architectures, the handling of noisy data. The practical works are aimed at the development of a general methodology for constructing hybrid-intelligent solutions as well as to apply this methodology in rather different application fields.

Selected publications

1. P. Varga, T. Mészáros, Cs. Dezsényi and T. P. Dobrowiecki, “An Ontology-Based Information Retrieval System,” Proc. of AEI/AIE-2003, Loughborough, UK, Springer Lecture Notes in Artificial Intelligence, Vol. 2718/ 2003.

2. T. Mészáros, Zs. Barczikay, F. Bodon, T. Dobrowiecki and Gy. Strausz, “Building an Information and Knowledge Fusion System,” Proc. of AEI/AAI-2001, Budapest, 2001, Springer Lecture Notes in Artificial Intelligence Vol. 2070, pp. 82-91.

One of the application fields is steel-making: modeling of a Linz-Donawitz (LD) converter and constructing an intelligent advisory system for determining the necessary amount of oxygen for obtaining steel of prescribed quality. Steel-making with an LD converter is a complex physico-chemical process where the input compounds, the parameters of the compounds and the making process have influences on the quality of the resulted steel.

3. P. Antal, T. Mészáros, B. De Moor and T. Dobrowiecki, “Annotated Bayesian networks: A tool to integrate textual and probabilistic knowledge,” The 14th IEEE Symp. on Computer-Based Medical Systems (CBMS), July 26-27, 2001, Bethesda, Maryland, pp. 177-180.

Figure 21 An LD steel converter (Dunaferr Co.). The main phase of the whole process is blasting

when the fluid compound of raw iron, waste iron and several additives are blasted through with pure oxygen to oxidize the unwanted contamination. The quality of steel is mainly determined by the way of blasting and the amount of oxygen used during blasting so one of the most important tasks is to predict the amount of oxygen required by the steel-making process. For obtaining oxygen prediction a model of the steel converter must be constructed.

System

Neural Model

Σ ε

parameters temperature

predictedó lt temperature

+

-

oxygen

Measured temperature

parameters

Σε

-

+

Copy of Model

predicted oxygen

Inverse

Model

Model output temperature

Figure 22 The inverse modeling task. The VSzR decision support system was developed

in cooperation with Dunaferr Co. and University of Miskolc. It builds a hybrid-neural inverse model, and gives an oxygen prediction. The system has three layers. The first (input) layer is an expert system and it is responsible for data preprocessing, data filtering, data correction, filling the gaps in the

database, etc. The second layer contains the direct modeling devices. It is formed from different neural models that can work with the data belonging to different operating conditions. The system allows to build into this layer any other modeling device (e.g., mathematical models or expert systems) too.

Figure 23 The functional architecture of the hybrid-neural advisory system.

The third or output layer is the decision-maker of the whole modeling system. It has two main tasks: to validate the results and to make the final prediction using some direct information from the first layer. This layer also uses symbolic rules. It validates the result of the second layer and makes a decision if the result can be accepted at all.

Staff: Gábor Horváth, Béla Pataki, György Strausz József Valyon, Péter Berényi and László Sragner.

Contact person: Gábor Horváth horvath@mit.bme.hu www.mit.bme.hu/~horvath/

Projects

1. OMFB ALK-00216-98, “Hybrid-Neural Modeling of the LD Converter Steelmaking Process,” 1998-2001.

2. OTKA T 033058, “Hybrid Intelligent Methods in Modeling,” 2000-2003.

3. FKFP (0207/2001), “Development of a Hybrid Intelligent System,” 2001-2003.

4. Flemish-Hungarian Bilateral Cooperation Agreement, “Modeling and Identification of Nonlinear Systems,” Flemish-Hungarian

The objective of this application is the development of new procedures using the methods of artificial intelligence and machine learning, and with the application of these procedures the development of a hybrid decision support system. The work that is being done in cooperation with Semmelweis University and Kopint-Datorg Co. uses various procedures of image processing as well as neural networks and expert systems, so again a hybrid intelligent system is being developed. The project is primarily based on the opportunities of the existing equipment in the medical institutes, i.e., the objective is the analysis of traditional X-ray pictures (films). The standardized scanned X-ray images are computer processed.

Bilateral Research Project, TÉT B-2/96, 1997-2000.

Selected publications

1. G. Horváth, “Neural Networks in Systems Identification,” (Chapter 4. in: S. Ablameyko, L. Goras, M. Gori and V. Piuri (Eds.) Neural Networks in Measurement Systems) NATO ASI, IOS Press, pp. 43-78. 2002.

2. B. Pataki, G. Horváth, Gy. Strausz and Zs. Talata, “Inverse neural modeling of a Linz-Donawitz steel converter,” e & i Elektrotechnik und Informationstechnik, Vol. 117, No. 1, 2000, pp. 13-17.

Főnix

Főnixdatabase

Scanner

Image MedicalAcquisition Station

Image MedicalPractice Builder

IMLoader& IMInfodatabase

DICOMdatabase

BME IMLoader& IMInfo

3. Gy. Strausz, G. Horváth and B. Pataki “Effects of database characteristics on the neural modeling of an industrial process,” Proc. of the International ICSC/IFAC Symposium on Neural Computation, NC’98, September 1998, Vienna, pp. 834-840.

4. G. Horváth, B. Pataki and Gy. Strausz, “Black box modeling of a complex industrial process,” Proc. of the 1999 IEEE Conference and Workshop on Engineering of Computer Based Systems, Nashville, TN, USA, 1999, pp. 60-66.

5. P. Berényi, J. Valyon and G. Horváth, “Neural Modeling of an Industrial Process with Noisy Data,” IEA/AIE-2001, Budapest, Lecture Notes in Artificial Intelligence, 2001, Springer, pp. 269-280.

Figure 24 Mammography database system.

6. P. Berényi, G. Horváth, B. Pataki and Gy. Strausz, “Hybrid-neural modeling of a complex industrial process,” IMTC'2001, Budapest, May 21-23, 2001, Vol. III, pp. 1424-1429.

Mammographic advisory system Another application field is medical diagnosis: to

develop a decision support system for medical application. The task of the system is to detect andidentify certain patterns in X-ray images, and tosupport the assessment of a wide range of medical screen tests namely the breast cancer screen tests.

Figure 25 Mass detection in mammographic image set.

The assessment of mammography screen tests requires considerable human resources. The in-depth mammography screen tests in Hungary require the production of roughly 2 million pictures annually, out of which the tests susceptible of positive results account for about 30000-60000 cases. A system that can safely filter at least 50 percent of the negative results can exempt the specialists from the tedious work of analyzing one million pictures a year.

Staff: Gábor Horváth, Béla Pataki, György Strausz, László Sragner, Nóra Székely, László Lasztovicza, Norbert Tóth, József Valyon, Ákos Horváth and Gábor Takács.

Fault Tolerant Systems Research Group Contact persons: Research interests: Model based dependability analysis, model transformation systems, verification and validation, design and analysis of fault tolerant and safety-critical systems, robust production processes, project management optimization.

Staff: András Pataricza, Endre Selényi, Ferenc Vajda, István Majzik, Tamás Bartha, Gábor Huszerl, András Petri jr., Dániel Varró, Orsolya Dobán, Szilvia Gyapay, Gergely Pintér, Béla Tolvaj, László Gönczy, Péter Domokos and Ákos Szőke.

Béla Pataki Gábor Horváth

Former members: György Csertán, Dániel Petri, Balázs Polgár, Balázs Sallay, Balázs Benyó and Béla Varga-Balázs.

Pataki@mit.bme.hu horvath@mit.bme.hu www.mit.bme.hu/~pataki/ www.mit.bme.hu/~horvath/

Education: The Selected publications group has a central role in the education of Formal Methods (core subject), Software Verification and Validation (PhD subject), and Information Technology Infrastructure specialization (8 subjects).

1. N. Székely and B. Pataki, “Detecting lesions in a mammogram,” EURASIP'03, Zagreb, Croatia, July 2003.

2. Gy. Strausz, G. Horváth, B. Pataki, L. Lasztovicza and N. Székely, “Intelligent solution for mammography image diagnosis,” Engineering Application of Neural Networks Conference, September 2003, Malaga, Spain.

Resources and infrastructure: The group manages a laboratory with 10 PCs, a Convolo high availability cluster and two IBM pSeries servers. Several CA and IBM system management and e-business products and the full range of Rational UML design tools are available for education and research.

3. L. Lasztovicza, B. Pataki, N. Székely and N. Tóth, “Neural network based microcalcification detection in a mammographic CAD system,” Intelligent Data Acquisition and Advanced Com-puting Systems, September 2003, Lviv, Ukraine.

Major research and development projects The main research area of the group is the quality assessment of information services which is realized through a unified approach based on the principles and tools of system design and implementation. The ongoing research and development projects of the FTSRG can be grouped into three categories:

4. G. Horváth, J. Valyon, Gy. Strausz, B. Pataki, L. Sragner, L. Lantovicza and N. Székely, “Intelligent advisory system for screening mammography,” IMTC 2004, Como, Italy.

5. N. Székely, N. Tóth and B. Pataki, “A hybrid system for detecting masses in mammographic images,” IMTC 2004, Como, Italy.

• Model-based dependability analysis and design,

• Model transformation methodology, 3.3. DIVISION OF DEPENDABLE • Optimization of production and business

processes. COMPUTING The dependability of a system is known as the reliance that can justifiably be placed on the service delivered by the system. Dependability has become an important aspect of computer systems since our everyday life increasingly depends on the malfunction of computers. The causes to these malfunctions can potentially be introduced in every step of their development, deployment and operation. In addition to inadvertent faults, systems must be able to survive intentional abuses and the malicious exploitation of their vulnerability.

Model based dependability analysis and design: The main trend in modern IT system design is the model driven development of the target application. This strategy uses a gradually refined set of semi-formal specifications starting from the initial re-quirements to the final implementation. During the last five years it became obvious that one of the main advantages of using a formal or semi-formal modeling paradigm is the possibility of model-based dependability analysis. Recent standardization efforts (e.g., extensions of UML, the Unified Modeling Language) may serve as a basis for the mechanized analysis and proof of correctness for engineering models. FTSRG deals, together with several national and international research partners, with the problem of integrating the modeling technology with formal analysis and optimization methods

Two groups of the Department, the Fault Tolerant Systems Research Group (FTSRG) and the Security Evaluation Analysis and Research Laboratory (SEARCH) are working in the field of dependable computing. Despite the fact that the FTSRG was founded only in 1994, research and development activities in this field date back as long as two decades.

. These efforts resulted in several tools that support the evaluation of availability, safety, testability and

functional correctness of the software design by • checking the completeness and consistency

of the behavioural specification, • computing the availability of the system on

the basis of components' availability attributes,

• verification of the logic correctness (safety and liveness properties) of program control flow,

• estimation of error propagation and testability properties of the design by fault simulation and test generation.

UML model

Mathematical model

Dependability attributes

Figure 26 Dependability analysis based on UML models.

Related projects: 1. High-level Integrated Design Environment for

Dependability (HIDE). ESPRIT Open LTR 27439 supported by the EC. Cooperation with Pisa Dependable Computing Centre, Italy; University of Erlangen, Germany; Intecs Sistemi SpA, Italy; MID GmbH, Germany.

2. Framework for the Development and Testing of Dependable and Safety-Critical Systems. IKTA 065/2000 supported by the Ministry of Education. Cooperation with Prolan Process Control Co., B-Braun Medical Hungary Ltd., Magic Onyx Ltd., 2000-2003.

3. Development of Robust Object-Oriented Sys-tems. FKFP 103/2001 supported by the Ministry of Education, 2001-2003.

4. Dependability Evaluation of Object-Oriented Systems. Italian-Hungarian Intergovernmental S&T Cooperation Programme, with CNUCE-CNR, Pisa, Italy, 2000-2002.

5. Operation Research Methods for the Analysis and Verification of Information Technology Systems. OTKA T038027 supported by the Hungarian National Scientific Research Fund, 2002-2004.

Selected publications: 1. A. Bondavalli, M. Dal Cin, D. Latella, I. Majzik,

A. Pataricza and G. Savoia, “Dependability analysis in the early phases of UML based

system design,” Int. Journal of Computer Systems - Science & Engineering, Vol. 16, No. 5, pp. 265-275, CRL Publishing Ltd, September 2001.

2. I. Majzik, A. Pataricza, and A. Bondavalli, “Stochastic Dependability Analysis of System Architecture based on UML Models,” in R. de Lemos, C. Gacek and A. Romanovsky: Architecting Dependable Systems. LNCS-2677, pp. 219-244, Springer Verlag, Berlin, 2003.

3. G. Huszerl, I. Majzik, A. Pataricza, K. Kosmidis and M. Dal Cin, “Quantitative analysis of UML statechart models of dependable systems,” The Computer Journal, Vol. 45, No. 3, pp. 260-277, British Computer Society, 2002.

Model transformation methodology: Model-based dependability analysis necessitates a mathematically precise formulation and execution of a series of model transformations. UML models are first transformed automatically into various mathematical domains (such as data-flow networks, hierarchical automata, etc.) to carry out formal analysis. Finally, the results of the analysis are back-annotated to the original UML-based system model. VIATRA (VIsual Automated model TRAnsformations) is our general-purpose model transformation framework designed to specify and automate model transformations within and between arbitrary modeling languages defined visually in a UML notation (by their corresponding metamodels).

StandardUML

Metamodel ofmathematical

paradigm

Mathematicalmodelinglanguage

Mathematicalanalysis

tool

TransformationrulesUML

TransformationProfile

VIATRAcode generator

Transformationprogram

VIATRAtransformation

kernel Figure 27 The VIATRA model transformation

framework.

The VIATRA approach delivered significant improvements in the following areas:

Specification of modeling languages. To support the easy-to-understand definition of modeling languages taken from either engineering or mathematical domains, a new visual yet mathematically precise metamodeling framework (VPM) has been developed that solves many problems of the

industrial MOF metamodeling standard with keeping backward compatibility.

Specification of model transformations. Model transformations within and between modeling lan-guages are specified in an intuitive, formal but visual way using the paradigm of graph transformation, which offers a rule and pattern based manipulation of graph based models. Graph transformation rules can also be defined in a UML notation.

Automated model and program generation. Previous experiments have demonstrated that the im-plementation of a complex model transformation is costly and highly error prone. As a solution, VIATRA automatically generates a Prolog program from the UML representation of graph transforma-tion rules, and executes it afterwards to an arbitrary model of the language.

Formal verification of model transformations. As model transformations can also be erroneous, their correctness has to be formally verified as well to prove that the transformation itself will not introduce new errors to the design. The CheckVML tool maps graph transformation rules into input languages of model checkers. As a result, the formal verification of model transformations can be carried out automatically, and without user assistance. Selected publications: 1. Gy. Csertán, G. Huszerl, I. Majzik, Zs. Pap, A.

Pataricza and D. Varró, “VIATRA - Visual automated model transformations for formal verification and validation of UML models,” Proc. 17th Intl. Conf. on Automated Software Engineering (ASE), pp. 267-270, IEEE, 2002.

2. D. Varró and A. Pataricza, “VPM: A visual, precise and multilevel metamodeling framework for describing mathematical domains and UML,” Journal of Software and Systems Modeling, Vol. 2(3), pp. 1-24, Springer, 2003.

3. D. Varró, G. Varró and A. Pataricza, “Designing the automatic transformations of visual languages,” Science of Computer Programming, Vol. 44(2), pp. 205-227, Elsevier, 2002.

4. D. Varró and A. Pataricza, “Metamodeling mathematics: A precise and visual framework for describing semantics domains of UML models,” Proc. UML 2002, the 5th Intl. Conf. on the Unified Modeling Language, LNCS-2460, pp. 18-33, Springer, 2002.

Optimization of business processes: Nowadays simple e-commerce applications are replaced by e-business applications. The design and

implementation of these applications are characterized by the fact that the internal business processes of the company are realized by computers. Quality of Service (QoS) is a crucial property of an e-business application, since the operation of the company depends on it. The main problem is that these systems are composed not only of hardware and software but they depend on several other factors like human operators, external and internal non-computational resources. Accordingly, the optimization of QoS properties like dependability and performance, needs sophisticated analysis and construction methods. The efforts of FTSRG aim at methods that allow the development of robust e-business applications and business processes supported by optimized project management. FTSRG offers

• a solution to cope with the low quality of service originating from the unreliability and failures of resources in heterogeneous application environments;

• a methodology to extend the scope of UML from software design to model the logical, qualitative and quantitative behaviour of production and management processes;

• a unified model that combines the UML based description of the development process, the COCOMO and COCOTS-based cost estimators assigned to the individual system components and the human resource related information, allowing in this way the minimization of the development cost, the estimation of the development time and its optimal scheduling.

Figure 28 Unified model of the development process. Related projects: 1. IBM Faculty Award, 2004. 2. BPM Based Robust E-Business Application

Development. IKTA 173/200 supported by the Ministry of Education, with University of Veszprém, Center of Information Technology of

Staff: Zoltán Hornák, Kristóf Kerényi, Imre Vincze, Ernő Jeges, Karolina Demcu, Gergely Tóth and Csilla Endrődi.

the Budapest University of Technology and Economics, Balatontourist Co., 2002-2004.

3. Integrated Project Management Optimization. IKTA 194/2000 supported by the Ministry of Education, with University of Veszprém, AAM Management Information Consulting Ltd., Sysdata Information Technology Ltd., 2001-2003.

Education: IT Security Teaching Web portal development and maintenance (www.biztostu.hu).

Major research and development projects SEARCH, the mobile networks security research laboratory was founded at the department in 1999, with the financial help of Nokia Hungary Ltd. Dur-ing the past years the laboratory executed several security evaluation projects aiming to discover vul-nerabilities in mobile operator server products and in mobile phones as well. New and emerging technolo-gies, like the Wireless Application Protocol, WTLS encryption protocol, micro payment solutions, Wireless Identity Module (SIM based cryptographi-cally strong user identification), mobile digital sig-natures, Symbian operating system, possibility of mobile viruses were analyzed and several improve-ments were suggested.

4. Object-oriented Modeling and Optimization of Industrial Processes. FKFP supported by the Ministry of Education, with University of Economics, Budapest, Széchenyi University, Győr, 1999-2001.

5. UML Based Modeling and Design of Technological Processes. DAAD-MÖB Hungarian-German Researchers Exchange Program, with Friedrich-Alexander-University Erlangen-Nürnberg, Germany, 2000-2001.

Security of Mobile Networks: Beyond the university education the activity of the SEARCH laboratory covers the following main areas:

Selected publications: 1. Gy. Csertán, A. Pataricza, P. Harang, O.

Dobán, G. Biros, A. Dancsecz and F. Friedler, “BPM based robust e-business application development,” Proc. of EDCC-4, the 4th European Dependable Computing Conf., Toulouse, France, LNCS-2485, pp. 32-40, Springer, 2002.

• Security evaluation of products and technologies: The evaluation process follows a systematic way, where (1) applied protection techniques are discovered, their adequate implementation is checked – we look for 'proof of correctness' rather than attack possibilities; (2) formerly discovered vulnerabilities in other products are checked whether they are also relevant in the actual product; (3) threat analysis based on human intelligence – new technologies usually generates new threats that can be handled only manually.

2. O. Dobán and A. Pataricza, “Cost estimation driven software development process,” Proc. of the 27th Euromicro Conference, pp. 208-215, Warsaw, Poland, September 4-6, 2001.

3. Sz. Gyapay and A. Pataricza,. “A combination of Petri nets and process network synthesis,” 2003 IEEE Int. Conf. on Systems, Man & Cybernetics, Washington, D.C., USA, pp. 1167-1174, 2003.

• Industrial research projects: based on industry needs specific problems are researched, where the goal is to elaborate long-term, theoretically grounded, 'best solutions'.

• Government and EU funded long-term researches: Topics of funded research projects cover a wide area within security related fields. They include data mining based evaluation of IT security warnings and log files, managing disaster recovery actions, combining biometrics and digital signatures, researching digital right management systems, developing an anonymity protocol, side channel attacks of cryptographic algorithms, etc.

Further information about FTSRG can be found at www.inf.mit.bme.hu/FTSRG/

Contact person: András Pataricza pataric@mit.bme.hu www.mit.bme.hu/~pataric/ Beyond the evaluation tasks several researches were

done to find solutions to the discovered vulnerabilities.

Security Evaluation, Analysis and Research Laboratory

Most significant research results in this field: Research interest: Security of mobile networks, biometrics, disaster recovery, cryptology, anonymity, digital signatures.

• WTLS-SSL protocol conversion is a patented method (patent number: WO 02/15523 A1)

that solves the secure interconnection of mobile devices using WTLS and existing Internet SSL servers without any software or hardware modification in the deployed systems. In 2002 this solution received the ‘Young innovator of the year’ prize from the Foundation for the Technological Progress of the Industry (IMFA).

• Overload protection of mobile networks. Mobile networks were found to be very vulnerable to overloads, especially to malicious denial-of-service type attacks. A new queuing method was developed, which provided maximum throughput efficiency while detecting and handling moderate flood and blocking type attacks. A working prototype was also developed to prove efficient operation.

• Handshake result evaluation solved the problem that mobile users are easily deceivable, since the small display is inadequate to describe the possible security situation. HRE provided such an intelligent analyzer that in each case could decide the actual level of security without annoying user notifications. Completeness and uniqueness of the analyzer was formally proven.

WAP - WLTS

e-mail, WWW, SSL

WIM, digitalsignatures,

Wallet

JAVA MIDP 1.0

Symbian Operating System:e-mail, WAP, WWW, WTLS, SSL

Symbian Operating System:downloadable applications,

messaging, MMS, built-in camera

Figure 29 Mobile products security research. Security related funded projects: SEARCH Laboratory, since its foundation, executed many IT security related project, beyond the mobility related topics, like a Central Supervision of IT Security Devices, Disaster Recovery Management of

Distributed Databases, or Biometric Digital Signature. The most significant Hungarian government funded projects:

Development of Remote Security Management System (IKTA-3 00149/2000) The objective of this project was to develop a remote security monitoring and management system, which – in addition to centralized event handling – applies episode recognition data mining methods in order to recognize and filter false alarms. The project was finished successfully in 2002, resulting in a prototype remote monitoring software.

On-line Disaster Recovery Management of Distributed Databases (IKTA-4 00085/2001) Within the confines of the project we intend to create a framework assisting in the creation and maintenance of recovery plans, on-line monitoring of preparing activities (e.g., backups, regular supervision) and controlling of recovery actions in disaster situations for large distributed computer systems through a universal structural model. The system will be able to monitor the transactions and data flow between the supervised subsystems and to synchronize their backups in order to ensure consistency during the recovery of such distributed subsystems, thereby avoiding the so-called “domino effect.”

Biometric Digital Signatures (IKTA-5 00160/2002) One of the crucial problems of digital signature technology is key handling. While the cryptographic algorithms used for signing can be made stronger by increasing the length of the used key, the weak part of the system is that the secret key can be stolen from the rightful owner; therefore the digital signature can only be associated with a certain person indirectly. Generally the secret key is stored on an intelligent chipcard (smartcard), hence extraction of this secret is practically impossible. In case of a typical application the user can only utilize the secret key by owning the card and knowing the associated PIN code. However, the card and the code can both be stolen, therefore currently available solutions cannot offer guaranteed security. Only signature technologies connected to the signing person, that is, methods using biometric identification can provide the adequate level of security. The goal of the project is to develop a system that enables the creation of biometric digital signatures based on fingerprint data. The main idea of the used method is to generate a bit sequence that is unique to the user, by converting the fingerprint information to a binary number. This so-called biometric vector can be used to unambiguously calculate the public-secret key pair. Using this method the digital signatures can be created in the usual

Information Security Educating e-Learning Portal (ITEM 00350/2002)

way, and the process of verification remains unchanged.

The goal of our project is to create a computer security-related e-learning web portal. Unlike currently available pages of similar content, it does not concentrate on technology and product specific issues, but the forming of a security-centric approach, the recognition and memorization of generally applicable rules of thumb and as a result this will strengthen the consciousness, the feeling of security and trust. Unfortunately, significant lack of knowledge can be experienced in this field on the level of society.

ECC

010100111010010001

+

master secret+

biometric vector

error correction

011100011010010101

Chipcard

signing secret key

Further information about SEARCH can be found at www.mit.bme.hu/searchlab/

Contact person: Zoltán Hornák hornak@mit.bme.hu www.mit.bme.hu/~hornak/

Figure 30 Biometric digital signatures.

For further information contact: For further information contact:Prof. Gábor Péceli Head of Department peceli@mit.bme.hu www.mit.bme.hu/~peceli/

Department of Measurement and Information Systems Magyar tudósok körútja 2 Budapest XI.

Postal address: Budapest University of Technology and Economics Department of Measurement and Information Systems Budapest, Hungary H-1521

Phone: (+36-1) 4632057 Fax: (+36-1) 4634112 E-mail: mitadm@mit.bme.hu URL: www.mit.bme.hu/