# June 2006, Volume 15, Number 2

**T. Dostal**
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On Canonical Structures of ARC Biquadratic Filters with Single Transconductor

The paper deals with simple canonical structures of the second order ARC filters employing only single transconductor (OTA) and passive components R and C. A systematic design procedure of this circuits based on the given autonomous networks is described. Several appropriate general autonomous circuits are presented and studied.

- CHEN, W.K. The Circuits and Filters Handbook. CRC Press, Florida, 1995.
- GEIGER, R. L., SANCHEZ, S. E. Active filter design using operational transconductance amplifiers: a tutorial. IEEE Circuits and Devices Magazine, 1985, vol. 1, p. 20 - 32.
- SUN, Y., FIDLER, J. K. Novel OTA-C realizations of biquadratic transfer functions. International Journal of Electronics, 1993, vol. 75, p. 333 -348.
- SUN, Y., FIDLER J. K. Current-mode OTA-C realization of arbitrary filter characteristics. Electronics Letters, 1996, vol. 32, no. 13, p. 1181 -1182.
- ACAR, C., ANDAY, F., KUNTMAN, H. On the realization of OTA-C filters. International Journal of Circuit Theory and Application, 1993, vol. 21, no. 3, p. 331 - 341.
- DOSTAL, T., CAJKA, J., VRBA, K. Design procedure of oscillators and biquads based on current conveyors. In Proc. of 8th WSEAS International Conference on Circuits. Athens, 2004, p. 487-215.
- HAJEK, K., SEDLACEK, J. Generalized view on active single amplifier biquads (in Czech). Slaboproudy obzor, 1981, vol. 42, no. 12, p. 583 - 591.

Keywords: Analogue circuits, active RC filters, biquads, transconductors

**P. Kutin, M. Kasal**
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Novel Optimization Method of Active Frequency Multiplier Utilizing Harmonic Terminating Impedances with DGS

A novel method for the optimization of the active frequency multiplier utilizing the harmonic terminating impedances with the defected ground structures (DGS) has been developed. Furthermore, a new type of the low-pass filter with DGS for the higher harmonic suppression will be reported. Experimental conversion gains (14.52 dB for the doubler, 5.56 dB for the tripler and 0.43 dB for the quadrupler) and real power-added efficiency (32.76 % for the doubler, 10.15 % for the tripler and 1.42 % for the quadrupler) have been attained. To our knowledge, in the considered frequency range, these results represent the best performance reported up to date for the active frequency multipliers utilizing the low-cost BJTs.

- GOPINATH, A., RANKIN, J. B. Single-gate MESFET frequency doublers. IEEE Transactions on Microwave Theory and Techniques. 1982, vol. 30, no. 6, p. 869 - 875. ISSN 0018-9480.
- MAAS, S. A. Nonlinear Microwave and RF Circuit. Norwood: Artech House, 2003. 582 pages. ISBN 1-58053-484-8.
- FUDEM, H., NIEHENKE, E. C: Novell millimeter wave active MMIC triplers. In IEEE MTT-S Int. Microwave Symp. Baltimore, 1998, p. 387 - 390.
- O'CIARDHA, E., LIDHOLM, S. U., LYONS, B. Generic-device frequency-multiplier analysis-a unified approach. IEEE Transactions on Microwave Theory and Techniques. 2000, vol. 48, no. 7, p. 1134 - 1141. ISSN 0018-9480.
- RAUSCHER, CH. High-frequency doubler operation of GaAs field-effect transistors. IEEE Transactions on Microwave Theory and Techniques. 1983, vol. 31, no. 6, p. 462 - 473. ISSN 0018-9480.
- CAMARGO, E. Design of FET Frequency Multipliers and Harmonic Oscillators. Norwood: Artech House, 1998. 215 pages. ISBN 0-89006-481-4.
- BORG, M., BRANNER, G. R. Novel MIC bipolar frequency doublers having high gain, wide bandwidth and good spectral performance. IEEE Transactions on Microwave Theory and Techniques. 1991, vol. 39, no. 12, p. 1936 - 1946. ISSN 0018-9480.
- THOMAS, D. G., BRANNER, G. R. Optimization of active microwave frequency multiplier performance utilizing harmonic terminating impedances. IEEE Transactions on Microwave Theory and Techniques. 1996, vol. 44, no. 12, p. 2617 - 2624. ISSN 0018-9480.
- JOHNSON, J. E., BRANNER, G. R., MIMA, J. P. Design and optimization of large conversion gain active microwave frequency triplers. IEEE Microwave and Wireless Components Letters. 2005, vol. 15, no. 7, p. 457 - 459. ISSN 1531-1309.
- PARK, J. S. An equivalent circuit and modeling method for defected ground structure and its application to the design of microwave circuits. Microwave Journal. November 2003, p. 1 - 7.
- AHN, D., PARK, J. S., KIM, CH. S., KIM, J., QIAN, Y., ITOH, T. A design of the low-pass filter using the novel microstrip defected ground structure. IEEE Transactions on Microwave Theory and Techniques. 2001, vol. 49, no. 1, p. 86 - 93. ISSN 0018-9480.
- LIM, J. S., LEE, S. W., KIM, CH. S., PARK, J. S., AHN, D., NAM, S. A 4 : 1 unequal Wilkinson power divider. IEEE Microwave and Wireless Components Letters. 2001, vol. 11, no. 3, p. 124 - 126. ISSN 1531-1309.
- SUNG, Y. J., AHN, C. S., KIM, Y. S. Size reduction and harmonic suppression of rat-race hybrid coupler using defected ground structure. IEEE Microwave and Wireless Components Letters. 2004, vol. 14, no. 1, p. 7 - 9. ISSN 1531-1309.
- LIM, J. S., PARK, J. S., LEE, Y. T., AHN, D., NAM, S. Application of defected ground structure in reducing the size of amplifiers. IEEE Microwave and Wireless Components Letters. 2002, vol. 12, no. 7, p. 261 - 263. ISSN 1531-1309.
- PARK, J. S., JUNG, M. S. A novel defected ground structure for an active device mounting and its application to a microwave oscillator. IEEE Microwave and Wireless Components Letters. 2004, vol. 14, no. 5, p. 198 - 200. ISSN 1531-1309.

Keywords: Frequency multiplier, defected ground structure, DGS, harmonic terminating, low-pass filter, optimi-zation

**P. Pomenka, Z. Raida**
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Methodology of Neural Design: Applications in Microwave Engineering

In the paper, an original methodology for the automatic creation of neural models of microwave structures is proposed and verified. Following the methodology, neural models of the prescribed accuracy are built within the minimum CPU time.

Validity of the proposed methodology is verified by developing neural models of selected microwave structures. Functionality of neural models is verified in a design - a neural model is joined with a genetic algorithm to find a global minimum of a formulated objective function. The objective function is minimized using different versions of genetic algorithms, and their mutual combinations.

The verified methodology of the automated creation of accurate neural models of microwave structures, and their association with global optimization routines are the most important original features of the paper.

- CERNOHORSKY, D. et al. Analysis and Optimization of Microwave Structures (Analyza a optimalizace mikrovlnnych struktur). Brno: VUTIUM Publishing, 1999.
- RAIDA, Z. et al. Time Domain Analysis of Microwave Structures (Analyza mikrovlnnych struktur v casove oblasti). Brno: VUTIUM Publishing, 2003.
- RAIDA, Z. Modeling EM structures in neural network toolbox of Matlab. IEEE Antennas and Propagation Magazine, 2002, vol. 44, no. 6, p. 46-67.
- RAIDA, Z. Broadband design of planar transmission lines: feed-forward neural approach versus recurrent one. In Proceedings of the International Conference on Electromagnetics in Advanced Applications ICEAA 2003. Torino: Polytecnico di Torino, 2003, p. 155 to 158.
- RAIDA, Z. Wideband neural modeling of wire antennas: feed-forward neural networks versus recurrent ones. In Proceedings of the Progress in Electromagnetics Research Symposium PIERS 2003. Honolulu (Hawaii): The Electromagnetics Academy, 2003, p. 717.
- RAIDA, Z., LUKES, Z., OTEVREL, V. Modeling broadband microwave structures by artificial neural networks. Radioengineering, 2004, vol. 13, no. 2, p. 3-11.
- GOLDBERG, D. E. Genetic Algorithms in Search, Optimization and MachineLearning. New York: Addison-Wesley, 1989.
- HAUPT, R. L., HAUPT, S. E. Practical Genetic Algorithms. New York: John Wiley & Sons, 1998.
- DEB, K. Multi-Objective Optimization Using Evolutionary Algorithms. New York: J. Wiley & Sons, 2001.
- SAGIROGLU, S., GUNEY, K. Calculation of resonant frequency for an equilateral triangular microstrip antenna with the use of artificial neural networks. Microwave and Optical Technology Letters, 1997, vol. 14, no. 2, p. 89-93.
- BANDLER, J. W., ISMAIL, M. A., RAYAS-SANCHEZ, J. E., ZHANG, Q. J. Neuromodeling of microwave circuits exploiting space-mapping technology. IEEE Transactions on Microwave Theory and Techniques, 1999, vol. 47, no. 12, p. 2417-2427.
- WANG, S., WANG, F., DEVABHAKTUNI, V. K., ZHANG, Q.-J. A hybrid neural and circuit-based model structure for microwave modeling. In Proceedings of the 29th European Microwave Conference. Munich (Germany): European Microwave Association, 1999, p. 174 to 177.
- PATNIAK, A., PATRO, G. K., MISHRA, R. K., DASH, S. K. Effective dielectric constant of microstrip line using neural network. In Proceedings of the Asia Pacific Microwave Conference. New Delhi (India): Asian-Pacific Microwave Association, 1996, p. 955-957.
- POMENKA, P. Global Optimization of Microwave Structures. (Globalni optimalizace mikrovlnnych struktur). Dissertation Thesis. Brno, Brno University of Technology, 2006.
- SCOTT, C. Spectral Domain Method in Electromagnetics. Norwood: Artech House, 1989.
- HAYKIN, S. Neural Networks: A Comprehensive Foundation: Englewood Cliffs: Macmillan Publishing Company, 1994.
- CHRISTODOULOU, C., GEORGIOPOULOS, M. Applications of Neural Networks in Electromagnetics. Norwood: Artech House, 2000.
- DEMUTH, H., BEALE, M., Neural Network Toolbox for Use with Matlab: User's Guide. Version 4. Natick: The MathWorks Inc., 2000.

Keywords: Artificial neural networks, genetic algorithms, metho-dology of developing neural models Bayesian regula-rization, Levenberg-Marquardt algorithm

**P. Hazdra, M. Mazanek**
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L-System Tool for Generating Fractal Antenna Structures with Ability to Export into EM Simulators

An L-System (Lindenmayer system) is a scheme primarily developed in the area of the computer science for simulating the development of biological structures. It has also been found very useful for generating the geometry of various fractal antennas. A Matlab environment has been used for both implementing an in-plane L-systems algorithm and for creating appropriate files for widely used EM simulators like the IE3D and the CST Microwave Studio. Finally, the performance of the developed script is demonstrated on two fractal microstrip patch antennas.

- http://en.wikipedia.org/wiki/L-system
- PEITGEN, O., JURGENS, H., SAUPE, D. Chaos and Fractals, 2nd ed. Springer-Verlag. 2004.
- BAHL, I., GBARTIA, P., GARG, R., ITTIPIBOON, A. Microstrip Antenna Design Handbook. Artech House, 2001
- HAZDRA, P., MAZANEK, M. On the modal analysis of fractal microstrip patch antennas. In Radioelektronika 2004 Conference Proceedings. Bratislava: STU Bratislava, 2004.
- HAZDRA, P., MAZANEK, M. The miniature fractal patch antenna. In Radioelektronika 2005 Conference Proceedings. Brno: Brno University of Technology, 2005, p. 207-210. ISBN 80-214-2904-6.

Keywords: Fractal antennas, fractals, L-Systems, EM simulation, microstrip patch antennas

**E. D. L. H. Palmero, Z. Raida, R. L. Ruiz**
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Quad-Band U-Slot Antenna for Mobile Applications

In this paper, two different planar quad-band antennas are designed, modeled, fabricated and measured. Subsequently, the antennas are redesigned using an electromagnetic band gap substrate (EBG). Those new planar antennas operate in four frequency bands: 900 MHz, 1 800 MHz (both GSM), 1 900 MHz (USA) and 2 400 to 2 500 MHz (Bluetooth) The antenna has four narrow U-shaped slots etched to the patch. Using software, CST Microwave Studio [1], Zeland IE3D [2], and FEMLAB [3], simulations have been carried out to investigate the antenna\'s performance and characteristics. The antennas designed have been also built and measured to compare the real results with those obtained from the simulations.

- CST Reference Manual. Darmstadt: Computer Simulation Technology, 2005.
- Zeland IE3D Reference Manual. Fremont: 2005.
- FEMLAB Reference Manual. Stockholm: COMSOL, 2005.
- SAINATI, R. A. CAD of Microstrip Antennas for Wireless Applications. Norwood: Artech House, 1996.
- GARG, B., BAHL, I. Microstrip Antenna Design Handbook. Norwood: Artech House, 2001.
- GONZALO, R., NAGORE, G. Simulated and measured performance of a patch antenna on a two dimensional photonic crystals substrate. In Proceedings of the Progress In Electromagnetics Research Symposium PIERS 2002. The Electromagnetics Academy, 2002, p. 257-269.
- BOUTAYEB, H., DENIDNI, T. A., MAHDJOUBI, K, TAROT, A. C., SEBAK, A. R., TALBI, L. Analysis and design of cylindrical EBG-based directive antenna. IEEE Transactions on Antennas and Propagation. 2006, vol. 54, no. 1, p. 211-219.
- ABEDIN, M. F., ALI, M. Effects of EBG reflection phase profiles on the input impedance and bandwidth of ultra-thin directional dipoles. IEEE Transactions on Antennas and Propagation. 2005, vol. 53, no. 11, p. 3664-3672.
- LLOMBART, N., NETO, A., GERINI, G., DE MAAGT, P. Planar circularly symmetric EBG structures for reducing surface waves in printed antennas. IEEE Transactions on Antennas and Propagation. 2005, vol. 53, no. 10, p. 3210-3218.
- CHEYPE, C., SERIER, C., THEVENOT, M., MONEDIERE, T., REINEX, A., JECKO, B. An electromagnetic bandgap resonator antenna. IEEE Transactions on Antennas and Propagation. 2002, vol. 50, no. 9, p. 1285-1290.
- FAN, Y., RAHMAT-SAMII, Y. Microstrip antennas integrated with electromagnetic band-gap (EBG) structures: a low mutual coupling design for array applications. IEEE Transactions on Antennas and Propagation. 2003, vol. 51, no. 10, p. 2936-2946.
- FAN, Y., RAHMAT-SAMII, Y. Reflection phase characterizations of the EBG ground plane for low profile wire antenna applications. IEEE Transactions on Antennas and Propagation. 2003, vol. 51, no. 10, p. 2691-2703.
- DE MAAGT, P., GONZALO, R., VARDAXOGLOU, Y. C., BARACCO, J. M. Electromagnetic bandgap antennas and components for microwave and (sub) millimeter wave applications. IEEE Transactions on Antennas and Propagation. 2003, vol. 51, no. 10, p. 2667 to 2677.
- CHAPPELL, W. J., GONG, X. Wide bandgap composite EBG substrates. IEEE Transactions on Antennas and Propagation. 2003, vol. 51, no. 10, p. 2744-2750.
- LEE, Y. J., YEO, J., MITTRA, R., PARK, W. S. Application of electromagnetic bandgap (EBG) superstrates with controllable defects for a class of patch antennas as spatial angular filters. IEEE Transactions on Antennas and Propagation. 2005, vol. 53, no. 1, p. 224-235.

Keywords: Multi-band planar antennas, perturbation slots, modal analysis, full-wave analysis, GSM, Bluetooth. EBG substrates

**J. Pavlovicova, M. Oravec, J. Polec, M. Kelesi, M. Mokos**
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Error Concealment using Neural Networks for Block-Based Image Coding

In this paper, a novel adaptive error concealment (EC) algorithm, which lowers the requirements for channel coding, is proposed. It conceals errors in block-based image coding systems by using neural network. In this proposed algorithm, only the intra-frame information is used for reconstruction of the image with separated damaged blocks. The information of pixels surrounding a damaged block is used to recover the errors using the neural network models. Computer simulation results show that the visual quality and the MSE evaluation of a reconstructed image are significantly improved using the proposed EC algorithm. We propose also a simple non-neural approach for comparison.

- CHEN, D. R., CHANG, R. F., HUANG, Y. L. Computer-aided diagnosis applied to US of solid breast nodules using neural networks. Radiology, 1999; 213 p. 407-412.
- CIOS, K. J., SHIN, I. Image recognition neural network: IRNN. Neurocomputing, 1995; no. 7, p. 159-185.
- MINGOLLA, E., ROSS, W., GROSSBERG, S. A neural network for enhancing boundaries and surfaces in synthetic aperture radar images. Neural Networks, 1999; no. 12, p. 499-511.
- KARAYIANNIS, N. G., PAI, P. I. Fuzzy algorithms for learning vector quantization. IEEE Trans. Neural Networks, 1996; no.7(5), p. 1196-1211.
- RIZVI, S. A., NASRABADI, N. M. Finite-state residual vector quantization using a tree structured competitive neural network. IEEE Trans Circuits Systems Video Technol., 1997; no. 7(2), p. 377-390.
- JIANG, J. Image compression with neural networks-A survey. Signal Processing: Image Commun., 1999; no. 14, p. 737-760.
- RUMELHART, D. E., HINTON, G. E., WILLIAMS R. J. Learning representation by backpropagation errors. Nature, 1986, 323, p. 533-536 18.
- HIROSE, Y., YAMASHITA, K., HIJIVA, S. Back-propagation algorithm which varies the number of hidden units. Neural Networks, 1991; no. 4, p. 61-66.
- WANG. Y., ZHU, Q. F.. Error control and concealment for video communication. A review. Proc IEEE, 1998; 86(5), p. 974-997.
- HAYKIN, S. Neural Networks - A Comprehensive Foundation. New York: Macmillan College Publishing Company, 1994.
- POGGIO, T., GIROSI, F. Networks for approximation and learning. Proc. of IEEE, 1990, vol. 78, no. 9, p. 1481-1497.
- HUANG, Y. L., CHANG R. F. Error concealment using adaptive multilayer perceptrons (MLPs) for block-based image coding. Neural Computing & Applications, 9, 2000, p. 83-92.
- VARGIC, R. Wavelet-based compression of segmented images. In Proceedings EC-VIP-MC 2003, Zagreb (Croatia), 2003, p. 347-351.
- KOTULIAKOVA, K., TOTH, N., BREZINA, A. Throughput analysis of hybrid ARQ schemes using BCH codes. In 5th EURASIP Conf. on Speech and Image Proc., Slovakia. 2005, ISBN 80-227-2257-X, p. 81-86.

Keywords: Block-based image coding, error concealment, image restoration multilayer perceptron, radial basis function network, mobile radio channels

**J. Mihalik, V. Michalcin**
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3D Motion Estimation of Human Head by Using Optical Flow

The paper deals with the new algorithm of estimation of large 3D motion of the human head by using the optical flow and the model Candide. In the algorithm prediction of 3D motion parameters in a feedback loop and with multiple iterations was applied. The prediction of 3D motion parameters does not require creating of the synthesized frames but directly uses the frames of input videosequence. Next the algorithm does not need extracting of feature points inside the frames because they are given by the vertices of the used calibrated model Candide. As achieved experimental results show, the iteration process in prediction of 3D motion parameters increased the accuracy of estimation above all the large 3D motion. Such a way the estimation error is decreased without its accumulation in long videosequence. Finally the experimental results show that for 3 iterations a state of saturation was achieved what means that by next increasing of the number of iterations practically no significant increasing of the accuracy of estimation of 3D motion parameters is occurred.

- MIHALIK, J. Image Coding in Videocommunnications. Mercury-Smekal ISBN-80-89061-47-8, Kosice, 2001. (In Slovak).
- MIHALIK, J. Adaptive hybrid coding of images. Journal of Electrical, vol. 44, no.3, 1993, p.85-89. (In Slovak).
- FORCHHEIMER, R., KROMANDER, T. Image coding - from waveforms to animation. IEEE Trans. Acoust., Speech and Signal Proc., vol. 37, no. 12, 1989, p.2008-2023.
- PEARSON, D. E. Development in model-based video coding. Proc. IEEE, vol.83, no.6, 1995, p. 892-906.
- ANTOSZCZYSZYN, P. M., HANAH, J. M., GRANT, P. M. A new approach to wire-frame tracking for semantic model-based coding moving image, Coding, Signal Processing: Image Communication 15, 2000, p. 567-580.
- ZHANG, L. Estimation of eye and mouth corner point position in a knowledge-based coding system. Proc. SPIE, vol. 2952, 1996, p.21-28.
- DAVIS, M., TUCERYAN, M. Coding of facial image sequences by model-based optical flow. In Proceedings of the Inter. Workshop on Synthetic-Natural Hybrid Coding and Three Dimensional Imaging. Rhodes (Greece), September 1997, p. 192-194.
- LI, H., ROIVAINEN, P., FORCHHEIMER, R. 3-D motion estimation in model-based facial image coding. IEEE Transaction on Pattern Analysis and Machine Intelligence, vol. 15, no. 6, June 1993, p. 545-555.
- MIHALIK, J., MICHALCIN, V. 3D Motion tracking of human head. In Proc. of the 13th International Czech-Slovak Scient. Conf. "Radioelektronika 2003", ISBN 80-214-2383-8, Brno (Czech Republic), 6-7 May 2003, p. 111-114.
- DECARLO, D., METAXAS, D. The integration of optical flow and deformable models with applications to human face shape and motion estimation. In Proc.IEEE Conf. Computer Vision and Pattern Recognition. IEEE CS Press, Los Alamitos (Calif.), 1996, p.231-238.
- HUANG, T. S., REDDY, S., AIZAWA, K. Human facial motion analysis and synthesis for video compression. In SPIE Symposium on Visual Comm. and Image Proc. Boston (MA, USA), November 1991, p. 234-241.
- PRAT, W. K. Digital Image Processing. John Wiley & Sons. New York, 1978.
- MIHALIK, J., MICHALCIN, V.: 3D motion estimation and texturing of human head model. Radioengineering, vol. 13, no. 1, 2004, ISSN 1210-2512, p. 26-31.
- AHLBERG, J. Candide-3: An Updated Parameterised Face. Rep. No. LiTH-ISY-R-2326, January 2001.
- MICHALCIN, V. Calibration of 3D wire frame model of human head. In Proc. of the IIIth Doctoral conference FEI TU, Kosice 2003, p. 65-66.
- MIHALIK, J., MICHALCIN, V. Texturing of surface of 3D human head model. Radioengineering, ISSN1210-2512, Vol.13, No.4, 2004, p. 44- 47.
- The special issue of the IEEE Trans.on Circuits and Systems for Video Technology on MPEG-4 SNHC, July 2004.

Keywords: Optical flow, 3D motion, estimation, prediction, modeling, human head, algorithm

**Z. Smekal**
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Difference Equations with Forward and Backward Differences and Their Usage in Digital Signal Processor Algorithms

In the paper the relation is given between linear difference equations with constant coefficients those obtained via the application of forward and backward differences. Relation is also established between input-output difference equations and state-space difference equations, which define the state of inner quantities of a discrete system. In conclusion, the state-space representation of a discrete system is given, which is suitable for implementing a discrete system in the microprocessor and digital signal processor. The resultant solution consists of the response to input signal and the response to non-zero initial conditions.

- ELAYDI S.N. An Introduction to Difference Equations. Second Edition. New York: Springer, 1999.
- ZADEH, L.A. DESOER, C.A. Linear System Theory: The State-Space Approach. New York: McGraw-Hill, 1963.
- SIEBERT, W. McC. Circuits, Signals, and Systems. New York: The MIT Press, McGraw-Hill Company, 1986.
- KWAKERNAK, H., SIVAN, R., STRUBOS, R.C.W. Modern Signals and Systems. New Jersey: Prentice Hall, 1991.
- JURY, E.I. Theory and Application of the z-Transform Method. New York: Wiley, 1964.
- VICH, R. Z-Transform Theory and Applications. Dordrecht: D. Reidel Publishing Company. 1987.
- MITRA, S.K. Digital Signal Processing: A Computer Based Approach. Fourth Edition., New York: McGraw-Hill, 2006.
- VICH R., SMEKAL Z. Digital Filters. Prague: Academia, 2000.
- SMEKAL, Z., SYSEL, P. Digital Signal Processors and their Applications. Prague: Sdelovaci technika s.r.o, 2006 (In Czech).
- VLACH, J., SINGHAL, K. Computer Methods for Circuit Analysis and Design. Van Nostrand Reinhold Company, 1983.
- TASSIGNON, H., SMEKAL, Z. Semi-symbolic CAD discrete system analysis. In Proceedings of the 16th International Conference on Electronic Speech Signal Processing joined with 15th Czech-German Workshop "Speech Processing". Dresden: TUD Press, 2005, p. 466 to 471.
- PSENICKA, B., UGALDE, F.G. Synthesis of digital structure by matrix method. In Proceedings of the 7th IASTED International Conference on Signal and Image Processing. Honolulu (USA), 2005, p.190-194.
- PSENICKA, B., BUSTAMANTE BELLO, R., RODRIGUEZ, M. A. Analysis and synthesis of digital structure by matrix method. In Proceedings of the 2nd International Conference on Informatics in Control, Automation and Robotics. Barcelona (Spain), 2005, p.22-29.
- DIBLIK, J., SMEKAL, Z. About solution of difference equation of y(n+2)-1,25y(n+1) + 0,78125y(n) = x(n+2)-x(n). Elektrorevue - Internet journal (http://www.elektrorevue.cz), ISSN 1213-1539, 2005, no. 1, p.1-14. (In Czech)

Keywords: Forward and backward differences, difference equations, digital signal processor algorithms

**I. Baronak, P. Kvackaj**
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Statistical CAC Methods in ATM

Admission control is a very useful tool for a network operator. It enables effective link utilization with QoS guaranty. Without doubts, CAC function will be important part in evolution of next generation networks. The question, how to choose suitable CAC method as admission control, is crucial for effective exploitation of CAC function. In this paper, we compare three statistical CAC methods providing their suitability as control for specific traffic: Method of Effective Bandwidth, Diffusion Approximation Method and Gaussian Approximation Method.

- BARONAK, I., KAJAN, R. Quality of ATM services and CAC methods. FEI Dept. of Telecommun., Bratislava, 1999 (in Slovak).
- KVACKAJ, P. CaC methods for traffic control used in ATM. Dipl. work. FEI Dept. of Telecommun., Bratislava, 2004 (in Slovak).
- SHIOMOTO, K., YAMANAKA, N., TAKAHASHI, T. Overview of measurement-based connection admission control methods in ATM networks. IEEE Communications Surveys. First Quarter, 1999.
- MARZO I LAZARO, J. L. Enhanced Convolution Approach for CAC in ATM Networks, an Analytical Study and Implementation. Girona, 1996, ISBN 84-8458-106-53.
- GELENBE, E., MANG, X., ONVURAL, R. Diffusion based statistical call admission control in ATM. Performance Evaluation 27-28. 1996, p. 411-436.
- The ATM Forum: "Traffic Management Specification Version 4.0", af-95-0013R13. Letter Ballot, April 1996.
- KNIGHTLY, E., SHROFF, N. Admission control for statistical QoS: theory and practice. IEEE Network. March/April, 1999.
- ADAS, A. Traffic models in broadband networks. IEEE Communications Magazine, July, 1997, p. 82-89.
- KOUVATSOS, D. Performance evaluation and applications of ATM networks. Kluwer Academic Publishers. 2002, ISBN 0-306-47023-3.
- MOORE, A. V. Measurement-based Management of Network Resources. Technical Report no. 528. Univ. of Cambridge, 2002.
- KELLY, F. P. Notes on effective bandwidth. In Stochastic Networks: Theory and Applications (Editors F.P. Kelly, S. Zachary and I.B. Ziedins). Oxford University Press, 1996, p. 141-168.
- BARONAK, I., TRSKA, R. Traffic control in ATM networks. In 27th Int. Conference TSP 2004. Brno (Czech Republic), 2004, p. 59-62.
- GALAJDA, P., MARCHEVSKY, S., KOCUR, D., BENCO, S. Mobile learning at the Technical Univ. of Kosice. In 9th IEEE Int. Conf. on Intelligent Engineering Systems 2005 (INES'2005). Cruising on Mediterranean Sea, September, 2005, p. 233-237.
- SIMAK, B., KOSKA, K. Processing of audio and video signals transferred over ATM networks. In Proc. of Workshop 2001. Prague (CR) CTU, 2001. vol. A, p. 314, ISBN 80-01-02335-4.
- FILKA, M., SLAVICEK, K., PETRENKO, M., DOSTAL, O. Transmission capacities for evolution and image medical information. In Int. Scientific Conf. COFAX 2004, COFAX 2004. Bratislava (Slovak Republic), 2004, p. 125-128.

Keywords: Connection Admission Control, Method of Effective Bandwidth, Diffusion Approximation Method, Gaussian Approximation Method