Dusan Maga

Distance Practical Education with DelftWebLab

Virtual and distance laboratories extend the application area of the Web, which leads to an openly integrated environment for sharing teaching and learning materials and hardware and software resources. In this paper distance learning and in particular the experiments are investigated. DelftWebLab for a practical experience in power electronic education is designed as a project with leading idea and clear targets

Electromechanical actuators WEB-lab

Faculty of Mechatronics (FM TnUAD), as one of EDIPE (Leonardo da Vinci) project partners, has built a laboratory of electromechanical actuators, controlled and measured by available Web services. The preliminary results have been presented at important world-wide conference proceedings or journals. The recent state in electromechanical actuators Web-lab will be presented at paper. The used control technology, as well as the measuring equipment and technologies, will be described and discussed. Also the very first experience with designed technology will pre presented with special attention paid to viewpoint of end-user and laboratory staff. Also the basic ideas of booking systems, developed by University of Maribor, and its connection to laboratories in Trencin will be presented.

Modified LEACH protocol for heterogeneous wireless networks

Wireless sensor networks have strict constrains in size, weight and energy. The conflict of long lifetime and strict energy constrain brings a natural integration of energy harvesting into wireless sensor networks. A modified low energy adaptive clustering hierarchy (LEACH) protocol has been proposed to increase the network life time. Modified LEACH is divided into two main phases at the first setup phase and at the second steady state phase. Setup phase has been modified such that cluster head (CH) selection will be selected only from advanced nodes. Results showed significant improvement in WSN overall lifetime. Simulations show number of dead nodes vs rounds. Comparison between pure LEACH and modified one showed significant improvement in lifetime, also comparison between modified LEACH and energy aware multi-hop multi-path (EAMMH) protocol shows significant improvement in performance.

Kiwiki: Open-Source Portal for Education in Mechatronics

With arise of modern interdisciplinary subjects as mechatronics; a huge demand for new technologies in education appears. This leads to a broad spread of modern technologies both in education (eg. distance laboratories [1, 2]) and educational materials [3-5]. A systematic pressure is applied to universities due to insufficient availability of relevant educational literature and materials. Since many years ago, this has been a question of the budget (because of the price of printed material, which usually becomes out of date after 2-4 years), but today it is a question of technology. The times when the base medium of materials has been changed from paper to digital are here today. The today’s technology offers a better approach – interactive, open and free knowledge based form. One of the offered technologies is the one created by authors – portal kiwiki, specialized in mechatronics. It is available at kiwiki.info web sites.

Mechatronic System with a Turbo-Generator of Two Different Frequencies

The goal of the research is to improve the technical characteristics of the mechatronic system consisting of electric power turbo-generator of two different frequencies - an increased frequency of 200 Hz and an industrial frequency of 50 (60) Hz - at a rotor speed of 628 rad-1 (6,000 rpm) equal to the turbine rotation frequency, complete with matrix frequency converter (MFC), included in the circuit of a three-phase winding of an additional part of the rotor.

Socio-political view of smart grid implementation — A survey

This paper deals with smart grids and social acceptance of them and based on various studies from this field attempts to answer questions such as how the society perceives this new technology, what are the sources of an influence, and what should be done in order to achieve a smooth implementation of smart grids with as few obstacles as possible. Rather new technologies are necessary for implementation of the smart grids. These must also focus on households, since these can be considered as a part of the complete system executives. So it is important that costumers understand their role and feel their involvement as an advantage for them. The base of the success lays on better relation between all business partners with particular respect to customers. The public opinion, probably one of the most important aspects in this transition to smart grids, can be influenced by not only media and marketing strategies of the energy providers, but also by a community as a whole. Since the economy and technology as well are still the priorities, consumers and communities should also be seen as one of the most crucial parts for successful implementation of smart grids.

21st Century Lecturer – from University to Secondary and Primary Schools

CedupointTM (Continuing Education Point) is an integral part of the Department of Telecommunication Engineering at the Czech Technical University in Prague, Faculty of Electrical Engineering. Due to its mission, it provides a lot of activities focused on promotion of university education techniques and technologies to primary and secondary schools. The activity presented in this paper is based on introduction of touchscreen devices (tablets) into education at small- and medium-sized primary and secondary schools. The paper presents a summary of all related activities and provides an overview of relevant technologies and technical solutions as well as fundamental ideas of the designed education program; nevertheless, it is focused on the major activity related to classroom management systems designed for teachers of these schools.

FE model of EM shielding textile materials

Technical textile materials can be successfully used also as a protection against external electromagnetic field. There are available technologies to improve the material surface - with use of different (galvanize, plate, etc.) technologies. The paper deals with woven textiles - compound of cotton, polyester and conductive fibers. The paper presents the impact of electromagnetic field on special woven textile materials and describes the shielding principles. The measurement technique used at FEL CTU in Prague is also described and the base measuring technologies are discussed. Nevertheless, the major part of the paper is dedicated to experience of authors with numerical (FE) modeling of shielding textiles and to description of designed and used methodology of FE model evaluation. The numerical results are compared to measurement and to mathematical (Matlab) model results.

Graph based inversed matrix in electric circuits solutions

The matrix calculus is very frequently used in electrical engineering to calculate the different parameters of (but not only) electric circuits. One of the most important points of mathematical background of this analysis is the calculation of inverse matrix. This can be realised by numerous well-known algebraic methods (unit/identity matrix, different algebraic supplements, etc.) or numerical techniques. Inverting of matrixes is a well-known method; nevertheless, idea of alternating paths (presented in the paper) is completely new and unpublished. The electric circuit can be represented in the form of a graph and this graph structure rewritten into the form of matrixes. The paper shows the inverse matrix acquisition without using any algebraic technique - directly from graph structure. The presented technology can further be used as an input for any numerical method used for circuit parameters analysis or on- and off-line simulation. Practically, this is based on the following steps: the electric circuit is transformed into the graph structure. A new graph structure is created using the presented algorithm. The matrix system describing this graph structure, obtained without use of any conventional technique, is the inverse matrix of the original graph. The proposed utilization of alternative paths essentially differs from work of other authors.

Genetic algorithms in design of a synchronous reluctance motor

The work handles with dependency of variations in the rotor design on the performance of a three phase synchronous-reluctance motor (SRM). Analytical geometry-dependant equations for the d- and q-axis SRM magnetizing inductances are derived. The finite element analyze was used to include the magnetic nonlinearities and saturation effects on SRM performance calculation. The use of genetic algorithms (GA) as global optimization procedure in generating and optimization of un-predetermined rotor shape is shown. Rotor materials used in this analyze have two characteristics: non-ferromagnetic and nonlinear ferromagnetic. Goal of un-predetermined rotor design optimization is to achieve maximum torque for a given rotor volume.