Zarko Zecevic

Improved Frequency Estimation in Unbalanced Three-Phase Power System Using Coupled Orthogonal Constant Modulus Algorithm

A new iterative method for frequency estimation in the unbalanced three-phase power system is proposed. The proposed solution is based on the transformation of unbalanced three-phase voltage signal into a complex exponential by using the orthogonal constant modulus algorithm. In addition, based on the transformed signal, a simple adaptive algorithm for frequency estimation is proposed. Beside the proposed approach, any frequency estimator designed for a single-tone complex exponential can be used here, which is also the advantage of the proposed method. Simulation results confirm that the proposed algorithm exhibits better performance compared to the considered algorithms.

Frequency-domain adaptive algorithm for improving the active noise control performance

A new block adaptive algorithm for active noise control systems is proposed. The proposed approach uses two adaptive filters, where the first one is used for identification of the unknown system. The second one is adapted using the coefficient of the first filter, with the purpose to minimise the output error. To reduce the computational complexity, implementation of new algorithm in the frequency domain is proposed. The analysis of this approach and simulation results show that the new algorithm exhibits faster convergence speed and smaller steady-state error, as compared with the filtered-x least mean square and its modifications.

Verification of the three-dimensional structure of synthesized molecule by molecular dynamic simulations

The paper presents comparison between molecular models made by using software packages, experimental results and performed simulations in molecular dynamics area with created molecule. Molecule was synthetized using organic synthesis strategy. After structural analysis, precise layout of all the atoms in space was determined. Molecule was converted into standard chemical format, visualized and prepared for simulations. Here we intend to show that it is possible, by using powerful computer infrastructure and related applications, to create good models of molecules, which can be used in simulations that produce valid characteristics of subject molecules interacting with various organic compounds.

Increasing the convergence speed of FxLMS algorithm in terms of white noise

Here we propose a modification of the FxLMS algorithm aimed to increase the convergence speed in terms of white noise. Secondary path distorts diagonality of autocorrelation matrix of white noise which causes a slower convergence of the FxLMS algorithm. Using information about the coefficients of the impulse response of secondary path, we propose the way to reduce the impact of secondary path and diagonalize the autocorrelation matrix. The simulation results confirm theoretical considerations in this paper.