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:
- methods based on stability condition of the characteristic polynomial or the state equation by means Lyapunov criterion. Some of them consider the reference damping (exponential stability),
- methods shifting poles of the characteristic polynomial into the G - region situated in the left part of the complex plain.
Crab of the crane may be loaded by certain burden weight and also the rope length may vary within an interval. Then robust control with constant controller parameters is advantageously applied ensuring the same arc. We applied for the reduced system the method from Ackermann of system robustness. After specification the conditions for improving of the control system, which lead to stabilizing and damping the vibrations, is eliminated such stage, which could cause the instability of a system. We get the area after longwinded mathematical modification of potential selection for position of the controllers and by feedback control we ensured the certain interval of the burden weights at the rope length.

A set of closed-form expressions is derived for the capacitance per unit length of the most common two-dimensional 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 easy-to-use and fast-to-compute solver that results in accurate and reliable capacitance per unit length values.

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 material-water 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 ultra-wideband radar (UWB).
The captured signals are usually processed in time or in frequency domain. However, nor time nor frequency domain is capable to suitable illustrate frequency dependence of the REP, that is used in MMs to determine the moisture. In all narrowband MMs, the frequency dependence of the water REP is neglected. This article proposes to reveal this information from measured data and use this additional information to help to solve the problem of moisture determination. In order to describe this information a time-frequency signal representation (TFSR) is applied.

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).
This paper presents at first performance of full search algorithm in sense of difficulty implementation following criteria of distortion: normalised cross-correlation function, method of correlation coefficients, mean square error, mean absolute difference, minimized maximum error and pixel difference classification. Evaluation of full search algorithm has been evaluated for three different pair of frames in the raw-format, according to by peak-signal-to-noise ratio (PSNR) formula.
Block motion estimation using the full search is computationally exacting. Several efficient techniques have been recently proposed to reduce the computational complexity of block matching for motion estimation in video sequence coding. The goal is efficient motion estimation with minimal error in the motion compensated predicted image. This paper presents in the second part results of efficiency block matching motion estimation algorithms in sense to achieve the best PSNR values. The evaluation has been done for 21 different block matching algorithms. The main idea has been to provide a complex review of block motion estimation algorithms and its efficiency in image sequence coding.

The n-queens problem is a classical combinatorial problem that has been tackled by various problem-solving 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 pre-processing operator and a mutation operator based on a local search. The initial pre-processing 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 n-queens problems on a common PC. We believe that our approach may be useful for understanding other constrain-based search problems.

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.

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.
The paper shows a graphical interpretation of cross-sections of the boundary surfaces. It represents a boundary between the attraction regions, which includes stable states: stable singularities, or stable limit cycles respectively. Except stable states, analyzed structure consist of only one absolutely unstable limit cycle which lies on four attraction regions boundary. Mentioned unstable limit cycle was obtained by negative integration step. Analysis of character of saddle-points N1, N2 by capacity change (C1=C2) when induction L is constant and resistance R equals to zero was carried out. This analysis make possible to detect three different types of unstable singularities: saddle-type singularity, unstable node and “center” respectively. In case “center”-type singularities, trajectory, which create closed curve is placed exactly on tangential plane of boundary surface passing through “center” N1 or N2. Because also the most precise numerical calculation is charged by error, it is possible to find the closed trajectory only by negative integration step.

The 5th International Scientific Conference on Digital Signal Processing and Multimedia Communication 2001 (DSP-MCOM 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.
DSP-MCOM 2001 has been the successor of four successful International Scientific Conferences on Digital Signal Processing ’90 - ’99 organized by The Department of Electronics and Multimedia Communications of the Faculty of Electrical Engineering of the Technical University of Košice. The conference was devoted to a broad spectrum of recent achievements in the traditional digital signal processing fields like digital filtering, image compression and enhancement, speech processing, biomedical signal processing, pattern recognition, neural networks, etc. With regard to the rapid development of communication technology, special attention was put also on digital signal processing applications in multimedia communications. Therefore, topics such as multimedia signal processing, mobile communications, spread spectrum communication systems, were included in the conference program. In the conference proceedings more than 40 contributions were included.
We assume that DSP-MCOM was the traditional scientific event where a lot of new and interesting ideas and research results stimulating future research and development in the field of digital signal processing and communication technology were presented.
In this issue of Acta Electrotechnica et Informatica, you can find several contributions originally submitted to DSP-MCOM 2001. These contribution were selected and recommended for publication in journal Acta Electrotechnica et Informatica by conference chairs in order to illustrate conference intention. We assume also that they will be interesting for readers of Acta Electrotechnica et Informatica.

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.

We will discuss the basic parameters of the steering signal that is built in the S-D 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 S-D modulator and show the spurious phase spectrum of the considered fractional-N synthesizer for the third and fourth modulator order.

This paper is focusing on the non-desirable effects of the nonlinearity of power amplifiers in new generations of wireless communication systems, like GSM-EDGE or HIPERLAN/2. The criteria used for evaluation of these effects like EVM or ACPR are described and their simulated values are presented.
Second part of this paper deals with one of the basic methods for nonlinearities reducing - digital baseband adaptive predistoriton. Paper shows the influence of the predistortion method to EVM, signal spectrum etc.

The direct sequence spread spectrum (DS-SS) transmission system offers a promising solution to an overcrowded frequency spectrum amid growing demand for mobile and personal communication services. The overlay of DS-SS signals on existing narrowband users implies strong interference for DS-SS systems. In this paper, it will be shown how the application of linear and non-linear estimators in the DS-SS 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 DS-SS 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 DS-SS receivers can outperform the WF application or DS-SS receivers based on simple application of matched filter (MF) in a significant way.

The purpose of the paper is to present an algorithm to solve the optimization tasks concerning with the robust discrete-time 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.

Our paper presents several median based models of filters designated for solution of the problem mentioned in head-line. 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.

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 phase-function quantized sinusoidal signal are analyzed in detail. Specific manifestations of the phase-function quantization, that give rise to a restriction in the set of spectral components depending on the number of quantized levels, are highlighted.
The analysis is based on the employment of the index transformation for cyclic permutation and its expression in DFT. This affords the analysis to be confined to just one period of the sinusoidal signal and to get, by using this transformation, the distribution of spectral components for multiple frequencies. Expressions for complex amplitudes of the individual spectral components are derived for amplitude and phase quantization.