December 2015, Volume 15, Number 4

PIETRIKOVÁ, E.
Audience Response Systems: Benefits & Utilization

SULÍR, M. — JUHÁR, J.
Hidden Markov Model Based Speech Synthesis System in Slovak Language with Speaker Interpolation

MAYER, D. — ULRYCH, B. — KROPÍK, P.
Heating of Three-Phase Shielded Supply at Short Circuit

KOVÁČ, O. — LUKÁCS, P. — PIETRIKOVÁ, A.
Software Tool for Scripting and Image Processing Applied in Jetlab Inkjet Printers

GAŠPAR, V. — ANDOGA, R.
Design of a Laboratory Information System for Data Processing and Efficiency Evaluation

HACHEMI, H. — MERABET BOULOUIHA, H. — ALLALI, A. — TAHR, A. — TAIBI, A.
Multivariable Robust Grid Currents Control of a Squirrel Cage Induction Generator Connected to a Wind Turbine

DJEGHADER, Y. — ZELLOUMA, L.
Using Hybrid Power Filter to Mitigate Currents and Voltages Harmonics in Three Phase System

Summary:
Emília PIETRIKOVÁ
AUDIENCE RESPONSE SYSTEMS: BENEFITS & UTILIZATION [full paper]

The following article deals with Audience Response Systems (ARS). The main goal is to provide a survey on utilization possibilities of ARS in various forms, with a focus on particular advantages. The article is dedicated to those readers who interact with an audience or a larger group of people. Particular attention is paid to technologies available to construct one’s own ARS, whether as a combination of existing and custom solutions, or only one’s own solution. Separate part deals with an experimental comparison of two of the available technologies. Combination of Arduino and Java as a combination of hardware and software on one hand, and combination of PHP and web on the other hand. The conclusion includes an overall evaluation of the tested solutions.


Martin SULÍR - Jozef JUHÁR
HIDDEN MARKOV MODEL BASED SPEECH SYNTHESIS SYSTEM IN SLOVAK LANGUAGE WITH SPEAKER INTERPOLATION [full paper]

This paper describes the first experiments with speaker interpolation in Slovak speech synthesis system. The interpolation provides an approach to voice characteristic conversion for hidden Markov model based text-to-speech synthesis system. The main idea of this technique is to synthesize an artificial speech with unseen and untrained output speech characteristic by interpolating of the existing sets of the pretrained models. The use of this technique allows to create new voices without the need to add additional data into training procedure. This is a major advantage especially for the low resources languages, such as Slovak language, where it is often difficult to obtain the necessary amount of data. The obtained results shows that the characteristics of the synthesized speech is changed from one male speaker to another one with the help of the interpolation ratio by which the Slovak voices with the new characteristics may be crated.


Daniel MAYER - Bohuš ULRYCH - Petr KROPÍK
HEATING OF THREE-PHASE SHIELDED SUPPLY AT SHORT CIRCUIT [full paper]

Following the calculation of the mechanical forces acting on the shielded three-phase line published in [1] and [2], an algorithm describing numerical calculation of its temperature rise due to short-circuit currents is presented. Given are the equation for determining the electromagnetic sources of heating, heat transfer equation for propagation of heat in the line and another equation for a simplified calculation of the temperature rise of the line provided that the investigated temperature process is adiabatic. The methodology is illustrated with a typical example.


Ondrej KOVÁČ - Peter LUKÁCS - Alena PIETRIKOVÁ
SOFTWARE TOOL FOR SCRIPTING AND IMAGE PROCESSING APPLIED IN JETLAB INKJET PRINTERS [full paper]

The aim of this paper is development of the additional scripting software for jetlab® 4xl-A inkjet printer used in the Department of Technologies in Electronics at Technical University of Kosice. The developed software significantly contributes to the simplification of the technological process and thereby eliminates the main disadvantages of the control software provided with the device. The developed software in Matlab allows changing the main properties of designed structures such as the resolution of image, resize the image, set the offset and deposition parameters. Before the development of the scripting software, all parameters of the image or deposition process had to be written manually in the script form which caused the mistakes in the deposition process.


Vladimír GAŠPAR - Rudolf ANDOGA
DESIGN OF A LABORATORY INFORMATION SYSTEM FOR DATA PROCESSING AND EFFICIENCY EVALUATION
[full paper]

This paper presents the evolution of techniques and methods used for data processing, obtained from measurements in the Laboratory of Intelligent Control Systems of Aircraft Engines (LIRS LM). The task of evaluating the quality and its components (especially efficiency) is also presented. The overview shows the progress and steps that were necessary to achieve semi-automatic or automatic data collecting and processing, including respective analyzes and visualizations. The data processes in LIRS LM are covered by the developed and deployed state-of-art scientific research information system (SRIS), as well as other auxiliary applications (MPM analyzer, remote monitoring, interactive wiring, etc.). With respect to the nature of the studied object (iSTC-21v turbojet engine), the system also supports knowledge discovery and allows evaluating the quality by utilizing key performance indicators (KPI), which are mostly known from economic and business sector. The currently created and deployed software equipment in LIRS LM, forms an integrated platform for both the bureaucracy (publications, form templates) and scientific work (experiments planning, measurements processing, data visualization, quality evaluation, remote monitoring).


H. Hachemi - H. Merabet Boulouiha - A. Allali - A. Tahr - A. Taibi
MULTIVARIABLE ROBUST GRID CURRENTS CONTROL OF A SQUIRREL CAGE INDUCTION GENERATOR CONNECTED TO A WIND TURBINE [full paper]

In this paper, a multivariable robust control strategy of a variable speed wind energy conversion system based on a squirrel cage induction generator (SCIG) is presented. Optimal speed control of the SCIG is achieved by a conventional PI controller combined with a Maximum Power Point Tracking (MPPT) strategy. The Indirect Field Oriented Control (IFOC) technique based on a simple Park (d-q) reference model is used to implement the proposed controller. Active and reactive power flow between the grid and the inverter is controlled via simultaneous H-infinity control of active and reactive currents of the grid and the DC link voltage. The switching technique of the inverter which is connected directly to the grid is controlled by a programmed PWM look-up table wave shaping. The robustness and performance of the proposed control scheme is evaluated on a comprehensive model of the wind energy conversion system using Matlab/Simulink.


Y. DJEGHADER - L.ZELLOUMA
USING HYBRID POWER FILTER TO MITIGATE CURRENTS AND VOLTAGES HARMONICS IN THREE PHASE SYSTEM [full paper]

This paper describes different power quality problems in distribution systems and their solutions with power electronics based equipment. A hybrid power filter in combined system of shunt passive and series active power filter has been designed and simulate with Matlab/Simulink. This filter is a three level PWM voltage source inverter and we use a fuzzy logic controller algorithm to control the harmonic voltages. The viability of the proposed algorithm is validated in this work. This hybrid power filter is able to compensate the reactive power (showed that source voltage is sinusoidal and in phase with source current), and harmonics (voltage & current) for three phase of the non linear load current proposed with RL and RC load. The proposed solution has achieved an improvement of power quality in distribution system specifically the reduction of currents and voltages harmonics, we see that through the values of THDI and THDV that are still below the IEC (61000) standard after filtering.


 

Publisher

    Faculty of Electrical Engineering and Informatics, Technical University of Košice, Slovak Republic

    Reg. No.: EV 2921/09,
    thematic group B1,
    ISSN 1335-8243
    The editorial board assumes no responsibility for damages suffered due to use of acts, methods, products, instructions for use or other ideas published by the article authors whatsoever.
EAN 9771335824005