April 2002, Volume 2, Number 1
Summary: 
Marek HIČÁR  Ladislav ZBORAY  Ladislav BALARA The Robust Control of the Crane’s Crab [full paper] This
paper deals with application of the pole region
assignment method for position control of a crane’s
crab. The same form of the track arc at uncertain burden
weight and rope length is required. To avoiding swinging
of the burden in the final position is also supposed.
Crab’s drive is realized by asynchronous motor fed from
a frequency converter. Simulation results have shown that
this control design may be successful for a certain
interval of system parameter variations. Robust control
method are derived by two different approaches:

YMERI, H.,
NAUWELAERS, B., MAEX, K., DE ROEST, D., VANDENBERGHE, S.,
STUCCHI, M.: CADOriented Analytic Formulas for Capacitance Matrix of Interconnects on Lossy Silicon Substrate [full paper] A
set of closedform expressions is derived for the
capacitance per unit length of the most common twodimensional
VLSI interconnect structures. The results have been
obtained by using an approximate electromagnetic analysis
of two coupled interconnect conductors over a ground
plane (silicon substrate). We assume that the electric
field meets the boundary conditions of a single isolated
infinite line; therefore the boundary conditions for the
conductors in the structure are approximately satisfied.
It is shown by the numerical results that the derived
formulas in this paper can provide an easytouse and
fasttocompute solver that results in accurate and
reliable capacitance per unit length values.

Rudolf Zetík  Jürgen SACHS Moisture Determination of Solid Materials by Means of UltraWideband Radar and TimeFrequency Signal Representations [full paper] This article deals with the
determination of moisture content in materials. Since
microwave methods (MM) meet the requirements of industry
in the best way only these methods are addressed here. MM
provide information about the relative electrical
permittivity (REP) of materialwater mixture in order to
determine moisture content. They take advantage of the
high REP of the water present in material. Current MMs
work usually in narrow bandwidth and therefore acquire
not enough information to determine moisture without
calibration diagrams. In order to overcome this drawback
this article proposes to apply ultrawideband radar (UWB).

Peter RADOCZI Motion Estimation via Block Matching Algorithms [full paper] Many
motion estimation techniques have been proposed. For
image sequence coding, two most commonly used approaches
have been classified as the pel recursive algorithms and
the block matching algorithms. The former estimates the
motion on a pixel by pixel basis, whereas the latter
predicts the motion on a block by block approach.
Furthermore, the block matching approach is most
appropriate for its applications to current standards
such as MPEG or H.26X, which are based on discrete cosine
transform coding (DCT).

Josef HYNEK Genetic Algorithms and NQueens Problem [full paper] The
nqueens problem is a classical combinatorial problem
that has been tackled by various problemsolving
strategies. This paper reviews prior attempts to solve
the problem with the particular stress on utilisation of
genetic algorithms. We present a new approach based on a
hybrid algorithm that exploits the power of specially
designed preprocessing operator and a mutation operator
based on a local search. The initial preprocessing
allows us to obtain very quickly a partial solution with
the relatively low number of conflicts and then the
special mutation operator does the soft part of the work
as it smoothes away the remaining conflicts. Using this
kind of a local space search we are able to speed up the
evolution process. This efficient algorithm is capable of
finding a solution for large size nqueens problems on a
common PC. We believe that our approach may be useful for
understanding other constrainbased search problems.

Ján KRIŠTOF  Eva OCELÍKOVÁ Composite Classifiers [full paper] This paper
deals with problems of composite classifier architectures.
There are three primary architectures for combining
classification algorithms: Stacked Generalization,
Boosting and Recursive Partitioning. Our attention is
focused on stacked generalization algorithm. In brief,
stacked generalization is a recursive layered framework
for classifier combination in which the layer of
classifiers at each level is used to combine the
predictions of the classifiers at the level immediately
below.

Milan GUZAN Limit Cycles and Trajectories in Multiplevalued Memory Cell [full paper] Topic of this article is
multiplevalued logic circuit analysis. The circuit
consists of two resonant tunneling diodes (RTD) connected
in series. One of RTD correspond to active element,
another represent a load. The load is characterized by
negative resistance region, therefore occurred a natural
question – how is behaviour of such complex [12].
Analysis of such structures is of great practical
importance, because they are able to operate in gigahertz
region according to foreign resources.

DSPMCOM 2001: Chairmans Message The 5th
International Scientific Conference on Digital Signal
Processing and Multimedia Communication 2001 (DSPMCOM
2001) held in November 27 – 29, 2001 in Košice was
organized on the occasion of the 50th anniversary of the
founding of The Technical University of Košice.

Damien COTTIER  Viktor FISCHER  Gerard JACQUET Voice over Internet Protocol Gateway Functionality upon the ST100 DSP Core Family [full paper] Voice
over Internet Protocol will probably be the next
revolution step on the telecom market. Indeed, for more
than one century, voice transport uses switched circuit
network (SCN). Actually, switched packet network
operators (like Internet provider), engaging huge
resources on this market, offering voice transport at
lower cost. However, the IP network, first designed to
transport data only, must deal today with multimedia
requirements. VoIP gateway will act like an
interoperability bridge between IP network and
conventional telecom network. This interoperability is
required to guarantee the universal telephone service.
Such gateway may be split into several independent
functional blocks. Each block has specific needs in terms
of hardware and software. STMicroelectronics is
benchmarking the ST100 DSP core family to assume VoIP
functionalities. Starting with analysis of overall core
capabilities, we try to define in this paper the optimum
topology of a ST100 VoIP gateway.

Věnceslav F. KROUPA  Jarmil ŠTURSA Spurious in PLLDDS Frequency Synthesizers [full paper] We
will discuss the basic parameters of the steering signal
that is built in the SD modulator and that controls
pulse removing in the PLL frequency synthesizer. The
knowledge of these parameters is important for the choice
of the bias of the steering signal and for the correct
evaluation of the synthesizer spectrum. We shall
investigate the dependence of these parameters on the
order of the SD modulator and show the spurious phase
spectrum of the considered fractionalN synthesizer for
the third and fourth modulator order.

Roman MARŠÁLEK  Vladimír ŠEBESTA Reducing the Effects of Power Amplifier Nonlinearities in Modern Communication Systems [full paper] This
paper is focusing on the nondesirable effects of the
nonlinearity of power amplifiers in new generations of
wireless communication systems, like GSMEDGE or HIPERLAN/2.
The criteria used for evaluation of these effects like
EVM or ACPR are described and their simulated values are
presented.

Dušan KOCUR  Rudolf ZETÍK Volterra Filter Application in DSSS Receiver for Narrowband Interference Suppresion [full paper] The
direct sequence spread spectrum (DSSS) transmission
system offers a promising solution to an overcrowded
frequency spectrum amid growing demand for mobile and
personal communication services. The overlay of DSSS
signals on existing narrowband users implies strong
interference for DSSS systems. In this paper, it will be
shown how the application of linear and nonlinear
estimators in the DSSS receivers can suppress this
interference. In our consideration, Wiener filters (WF)
and Volterra filters (VF) will be used as the estimators.
These filters will be included between demodulator and
despreading stage of a conventional receiver. Then, the
received signal is passed through the estimator, which
suppresses the narrowband interference prior to detection.
In order to demonstrate the ability of discussed DSSS
receivers to suppress interference, a number of computer
experiments will be done. The results of the experiment
will show that the application of VF in DSSS receivers
can outperform the WF application or DSSS receivers
based on simple application of matched filter (MF) in a
significant way.

Dušan KROKAVEC  Anna FILASOVÁ Neural Network Implementation of Robust Kalman Predictors [full paper] The purpose of the paper is to
present an algorithm to solve the optimization tasks
concerning with the robust discretetime Kalman predictor
design as well as the problem formulation for neural
network implementation of robust Kalman predictor, where
dual heuristic programming is used for realization. This
application can be considered as a task concerned the
class of problems referred to as reinforcement learning
algorithms and is based on the existence of a complete
model of the environment and the predicted error.

Stanislav MARCHEVSKÝ  Ľudmila MACEKOVÁ Detection and Reconstruction of Missing Data in Damaged Image Sequences [full paper] Our paper presents
several median based models of filters designated for
solution of the problem mentioned in headline. In the
motion picture industry, both, “dirt and sparkle”
often appear. These are flashes, i.e. more than one
pixel, of totally different brightness, unrelated to the
surrounding area of the frame, and also unrelated to
adjacent frames. To restore such image sequences, it is
possible to use median based multilevel filters, which
yield to quite good results and are computationally
modest. To avoid useless affect the other  uncorrupted 
pixels, these filters have to cooperate with operation of
missing data detection, which is also briefly described
in this submission. The results are declared by
representative frames as well as by numeric error
criteria.

*Václav ČÍŽEK  Hana ŠVANDOVÁ Application of the Cyclic Permutation for Analysis of Synthesized Sinusoidal Signal [full paper] The
contribution deals with the analysis of properties of
digital sinusoidal signal in both time and frequency
domain. Spectral properties of the amplitude quantized or
phasefunction quantized sinusoidal signal are analyzed
in detail. Specific manifestations of the phasefunction
quantization, that give rise to a restriction in the set
of spectral components depending on the number of
quantized levels, are highlighted.
