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X NATIONAL CONFERENCE WITH INTERNATIONAL PARTICIPATION ELECTRONICA 2019 PROGRAMME 16 – 17 May 2019 Sofia National Science and Technical Centre 108 Rakovski Str.
X NATIONAL CONFERENCE
WITH INTERNATIONAL PARTICIPATION
ELECTRONICA 2019
PROGRAMME
16 – 17 May 2019
Sofia
National Science and Technical Centre
108 Rakovski Str.
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X NATIONAL CONFERENCE WITH INTERNATIONAL
PARTICIPATION “ELECTRONICA 2019”
Organized by:
The Union of Electronics, Electrical Engineering and
Telecommunications (CEEC),
Technical University of Sofia (TU-Sofia),
IEEE Bulgarian Section,
and Faculty of Electronic Engineering and Technologies (FEET)
In cooperation with:
Federation of the Scientific and Technical Unions in Bulgaria (FSTU),
Bulgarian Academy of Sciences (BAS),
University of Applied Sciences - Offenburg,
Riga Technical University,
VDE – Germany and
Leading Electronics Companies.
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X NATIONAL CONFERENCE WITH INTERNATIONAL
PARTICIPATION “ELECTRONICA 2019”
Honorary chairmen:
Georgi Mihov – TU - Sofia
Ivan Yatchev –- FSTU and CEEC
Conference chairmen:
Emil Manolov – TU - Sofia
Seferin Mirtchev – СЕЕС
Scientific Secretaries:
Nikolay Hinov – TU - Sofia
Local Organizing Committee:
Georgi Mladenov – СЕЕС
Oskars Krievs - RTU
Sanka Gateva - BAS
Georgi Stoyanov - IEEE Bul. Sec.
Anatolii Aleksandrov - TU - Gabrovo
Ilia G. Iliev - TU-Sofia
Dimitar Yudov – BFU - Burgas
Antoni Slavinski - ASTEL
Stefan Tabakov - CEEC
Rossitza Goleva - IEEE Bul. Sec.
Radi Romanski – СЕЕС
Ivan Vassilev - CEEC
Anna Andonova - TU - Sofia
Petar Jakimov - TU - Sofia
George Angelov – TU - Sofia
Vencislav Valchev -TU -Varna
Nikolay Madzharov - TU - Gabrovo
Sotir Sotirov - University "Prof. As. Zlatarov"
Bourgas
Nikola Durchev - Balkantel
Roumen Atanassov - BASSEL
Nikolay Iliev – Next Lab
Krasimir Pingelov - Electron Progress
Boris Borisov - Festo production
Petar Statev - ICT Cluster
Vladimor Stavrev - AMG Technology
Sylvain Collot -Melexis Bulgaria
Program Committee:
Alden Dochshanov, Italy
Andrius Chaziachmetovas, Lithuania
Darius Andriukaitis, Lithuania
Davy Pissoort, Belgium
Dimitar Arnaudov, Bulgaria
George Angelov, Bulgaria
Gennady Zinoviev, Russia
Ivo Iliev, Bulgaria
Juraj Breza, Slovakia
Lykourgos Magafas, Greece
Leonids Ribickis, Latvia
Marin Marinov, Bulgaria
Marin Hristov, Bulgaria
Miglena Dontschewa, Austria
Namyong Kim, Korea
Nicolae Muntean, Romania
Nikolay Hinov, Bulgaria
Octavian Cornea, Romania
Reinhard Bauer, Germany
Stefan Hensel, Germany
Stefan Pachedjiev, Bulgaria
Stoyan Stoyanov, UK
Vladislav Skorpil, Czech Republic
Zenon Gotra, Ukraine
Tzeno Galchev, USA
Vassil Palankovski, Austria
Viera Stopjaková - Slovakia
Secretariate
Stefan Patchedjiev – СЕЕС
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X NATIONAL CONFERENCE WITH INTERNATIONAL
PARTICIPATION “ELECTRONICA 2019”
Hour Event
9.00-12.00 Registration of participants
Hall 3
10.00-12.30
Opening Session
Invited Papers
Hall 4
12.30-13.30 Lunch break
Thursday 13.30-15.45 Career Forum
Hall 4
16 May 15.45-16.00 Coffee break
16.00-17.30
Discussion:
“University education in Electronics and business
needs".
„Alumni meeting” ,
Hall 3
18.00 Cocktail-party
Hall 3
Friday
17 May
09.00 -10.30
Scientific Session 1
Hall 3
Information and Communication Technologies
10.45 -12.15
Scientific Session 2
Hall 3
Circuits and Systems, Instrumentation and
Measurement, Industrial and Power Electronics
12.30-14.00
Scientific Session 3
Hall 3
Biomedical Engineering, Micro and optoelectronics,
Education and Learning Technologies
14.15 -14.45
FORUM “ELECTRONICA”
Hall 3
14.45
Seminar - NSF scientific projects
Hall 3
15.45 Closing Session
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I. Opening Session
Hall 4, Thursday 16 May 2019
10.00 - 12.30.
10.00 - Opening Session
I. Invited Papers
Hall 4, Thursday 16 May 2019
10.15 - 10.45
INFRARED THERMOGRAPHY: OLD ACHIEVEMENTS AND NEW
HORIZONS Prof. Vladimir VAVILOV
10.45 - 11.15
CHARACTERIZATION AND VALIDATION TECHNIQUES FOR THERMO-
MECHANICAL MODELS OF ELECTRONIC PACKAGES AND
ASSEMBLIES Prof. Stoyan STOYANOV
11.15 - 11.35
DAHUA - HEART OF CITY
Mario DINKOV
II. Career Forum
Hall 4, Thursday 16 May 2019
13.30 - 15.45 Meeting of employers and students (Companies Presentation)
III. Discussion Hall 3, Thursday 16 May 2019
16.00 -17.30 "University education in electronics and business needs".
„Alumni meeting“
18:00 - Cocktail-party
Hall 3, Thursday 16 May 2019
IV. Sessions
Hall 3, Friday 17 May 2019
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Session 1
Hall 3, Friday 17 May, 9.00-10.30
Chairpersons: Seferin MIRCHEV, Dimitar ARNAUDOV
Information Technologies
1. LATENCY EVALUATION FOR MESSAGING SERVICE AT THE NETWORK EDGE
Evelina Pencheva, Ivaylo Atanasov, Vladislav Vladislavov and Ventsislav Trifonov
Abstract – Short Messaging Service (SMS) is expected to continue to be an important use case in
fifth generation (5G) system. 5G messaging service is optimized for massive Machine Type
Communications which impose different requirements. The requirements for low latency, efficient
bandwidth utilization, and location awareness may be fulfilled by using Multi-access Edge
Computing (MEC) technology. MEC brings cloud capabilities at the network edge. The paper
studies two MEC deployment scenarios in radio access network, and provides performance analysis
on the signaling latency for SMS provided by MEC.
2. A HYBRID PSO&TS ALGORITHM FOR FJSSP
Asen Toshev
Abstract – A new hybrid meta heuristic algorithm based on Particle Swarm Optimization
(PSO) and Taboo Search (TS) procedures is proposed in the paper. It is designed to solve Flexible
Job Shop Scheduling Problems (FJSSP). Twelve benchmark test examples from different literature
sources are used for the experimental investigation of the algorithm. The obtained mean error for
the deviation from optimality is 1,6%. The test results are good basis for further refinement of the
proposed algorithm.
3. COMPUTATION OF SECOND AREA MOMENTS OF CROSS-SECTION USING AN
OPTICAL IMAGES
Borislav Bonev and Antonio Shopov
Abstract – The article proposes a method for automated calculation on second area moments of
random complex cross-sections using classical photography. The method uses representation of the
image pixel as geometric figure with own second area moments. The results from second area
moments calculation using the proposed method of real cross-section with known values of the
second area moments are presented.
4. COMPARATIVE ANALYSIS OF EXISTING SIMILARITY MEASURES USED FOR
CONTENT-BASED IMAGE RETRIEVAL
Miroslav Marinov, Irena Valova and Yordan Kalmukov
Abstract – Modern search engines and social media heavily rely on content-based image
retrieval methods to analyze, organize, process and search through millions of images uploaded
every day by their users. To be useful however, searching should be accurate and complete in a
reasonable amount of time. To meet the performance requirements, proper metadata should be
extracted from the images and then indexed and stored in a way that allows fast subsequent
processing. It is important that search results are sorted by similarity in descending order.
Similarity is usually calculated by an appropriate similarity measure that fits the chosen type of
metadata. This calculation, exactly, represents the most repeated (time consuming) operation in the
entire system. Furthermore, the similarity measure itself has the highest impact on the search
accuracy. So, choosing a proper measure is the key point in development of an accurate and
rapidly-responsive image retrieval system. This paper presents a comparative analysis of some of
the most commonly used similarity measures for comparing images based on their color content.
All metrics are experimentally evaluated and compared to real human judgements for perception of
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similarity. Additional experimental study and statistical analysis are performed to determine if and
how variations in size of the quantization block influence the accuracy of the calculated similarity.
5. CREATING ARCHITECTURE AND SOFTWARE OF EMBEDDED SYSTEMS WITH
CONSTRAINED RESOURCES AND THEIR COMMUNICATION TO THE IOT
CLOUD
Neven Nikolov and Ognyan Nakov
Abstract – This article described creating architecture, software and communication of IoT
devices with constrained resources to IoT Cloud. Also is described software realization and
architecture of IoT Cloud. Used physical environment is WiFi network, which is wide widely used
in home environment. In article is shown way for connection the constrained microcontrollers to
centralized Cloud, sending and receiving data between them.
6. RESEARCH OF COMMUNICATION BETWEEN IoT CLOUD STRUCTURE,
ANDROID APPLICATION AND IoT DEVICE USING TCP SOCKETS
Neven Nikolov and Ognyan Nakov
Abstract – This article research and describe communication between IoT cloud, Android
mobile application and IoT embedded systems. It is presented a way of transmitting temperature
and humidity of the IoT cloud using TCP sockets. A JSON type data format is used between the
cloud structure and the devices. Embedded systems STM32L4 discovery and Esp8266 are
transmited data to IoT cloud using TCP sockets. Mobile application realizes the representation of
temperature and humidity readings from a sensor. Presented is architecture and software
implementation of the experimental stage.
7. JUSTIFICATION OF THE METHOD AND ALGORITHM OF MULTIDIMENSIONAL
PARITY CONTROL IN DISTRIBUTED DATABASES OF INFORMATION SYSTEMS
A. Zh. Karibzhanova, K. M. Sagindykov and Kalin Dimitrov
Abstract – In the context of a sharp increase in storage volumes and the widespread use of
multi-disk storage, new methods of improving reliability are required. The authors consider the
storage method developed by the authors that meets the conflicting requirements for redundancy
and reliability in the framework of the distributed storage model with multidimensional parity
control, which has redundancy lower than in replications, and reliability at the level of complex
systems using reed-Solomon algorithms. The theoretical substantiation of the method and algorithm
of multidimensional parity control is carried out, and also the estimation of parameters of
reliability and advantages over existing methods of distributed storage is executed. Technology is
implemented in distributed databases.
8. NEURAL NETWORK PROCESSING MODEL FOR DATA FLOW OPTIMIZATION
Roumiana Ilieva and Yoto Nikolov
Abstract –This article focuses on a new concept for processing data flow in networks, a process
which will take place over the network, using NPU powered routers managing data and evaluating
packet flow and post process. Imagine all this data which wait in the queues of routers, processed
in a few nodes before delivery.
9. THE IMPACT OF AI & ML IN AGILE PRODUCTION
Roumiana Ilieva and Mario Nikolov
Abstract - Nowadays the industries and the organizations need to be flexible. Every modern
organization has one similar goal in their agenda and this is to become “more Agile”. The aims of
these industries are to obtain a flexible structure in order to be able to follow the rapid growth of
the trend. Some of the technologies that make possible an improvement of the “agile production”
are related with the Artificial Intelligence and, in particular, machine learning implemented into
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R&D phase of product development by implementing them into the design phase and by using 3D
printing.
10. NEXTGEN HIGHTECH SOLUTIONS TO IMPROVE THE QOL IN CEREBRAL
STROKE CONSEQUENCES
Roumiana Ilieva and Vladimir Damyanov
Abstract -The nature of the next generation technologies and the potentials of AI and ML in
cerebral stroke diagnostics are discussed. A schematic workflow of supervised machine learning is
illustrated. New technologies implementation in cerebral stroke problems treatment and
rehabilitation for engaging and stimulating brain are analyzed. Innovative stroke recovery devices,
video games assistance, bio-robotics support, video conferencing with doctors, etc. are discussed.
Communication Technologies
11. BASED ON ARTIFICIAL INTELLIGENCE AND DEEP LEARNING HAND
GESTURE RECOGNITION FOR INTERACTION WITH MOBILE ROBOTS
Snezhana Pleshkova, Aleksander Bekyarski
Abstract –The proliferation of mobile robots in a wide range of professional and home
applications is a real stimulus of researches for more convenient natural ways and communication
skills of mobile robots to interact with human. Voice communicating with mobile robots is always
preferable but in many cases is inappropriate due to technical complexity, not enough accuracy and
inability of real time of voice recognition. That is why voice communications with mobile robots are
often replaced or combined with human interaction by hand gestures. Therefore, this is the goal of
this article, with proposition of realization based on artificial intelligence and deep learning.
12. LabView MODEL OF VOICE COMMANDS FOR MOBILE ROBOT MOTION
CONTROL USING INTERNET OF THINKS MODULE
Snezhana Pleshkova, Aleksander Bekyarski
Abstract –There are a lot of mobile robot application, when the people interact with mobile
robots. The natural way of interaction are voice commands send for navigate mobile robot motion.
To do this in this article is proposed to create a LabVIEW model for receiving and recognizing
voice commands send from a person to the robot. For the experiments and tests, the LabVIEW
model is implemented in an Internet of Thinks module mounted on mobile robot platform.
13. EFFICIENT FIR FILTER SYNTHESIS USING SIGMOIDAL FUNCTION
Peter Apostolov, Alexey Stefanov and Mariya Bagasheva
Abstract – The graph of the sigmoidal function represents a transfer function of a low pass filter.
Such function is the Complementary integral Gaussian error function - erfc. In this article, FIR
filter synthesis using erfc is examined. Analytical expressions of the filter parameters are proposed.
A comparison of filter selectivity and computational costs with Parks & McClellan FIR filter, and
analysis of the results is done. The conclusion that the proposed FIR filter has better selectivity and
faster computational time is made.
14. DEVELOPMENT OF A MODULE FOR RETRANSMISSION AND MONITORING OF
DVB-S/S2 SIGNALS OVER IP NETWORK
Krasen Angelov, Stanimir Sadinov and Panagiotis Kogias
Abstract – This paper presents the development of a module for reception and retransmission of
digital satellite (DVB-S/S2) signals over an IP network. The module is based on the SoC platform
Raspberry Pi. With properly used hardware capture and analyzing software, the module is capable
of real time monitoring and assessing the parameters of the received satellite signals. The proposed
solution is flexible, innovative and convenient to use at the head-end station sites due to its easy
installation and maintenance, low cost, small size and low consumption.
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15. FPGA IMPLEMENTATION OF SYSTEMATIC LINEAR BLOCK ENCODERS FOR
EDUCATIONAL PURPOSES
Adriana Borodzhieva
Abstract – The paper presents the theory and application, the generator matrices and code-word
vectors for all 24 possible (6, 3) linear block codes and FPGA implementation demonstrating the
process of encoding messages using these encoders. A laboratory board based on Spartan-6 devices
was developed in the University of Ruse and will be used in the educational process in the course
“Coding in Telecommunication Systems” introducing the students in the specialty “Internet and
Mobile Communications” to the topic of linear block codes.
16. STUDY OF PREEMPTIVE PRIORITY SINGLE-SERVER QUEUE WITH PEAKED
ARRIVAL FLOW
Seferin Mirtchev
Abstract – A single-server preemptive priority teletraffic system with peaked arrival flow and
generally distributed service time is studied in this paper. The Polya distribution is used to describe
the peaked traffic flows. New model of this teletraffic system is developed, based on a generalized
Pollaczek-Khinchin formula. It is shown that the peakedness of the input flow increases
significantly the mean service time of this preemptive priority teletraffic system.
17. STUDYING THE TRAFFIC FLOW BETWEEN A MODELED AND A REAL IP
NETWORK
Ivan Nedyalkov
Abstract – In the present work a collaboration between a virtual IP network and a real IP
network is made. A connection between the virtual network and the Internet via the real IP network
has been created. The traffic flow exchanged between the two networks has been studied. Survey of
the data flow between the two networks is done by using standard IP network monitoring tools. For
the purpose of the study a VoIP connection is established between a subscriber in the virtual
network and a subscriber in the real network. Additionally, Internet browsing from the virtual
network is realized.
18. STUDYING OF A MODELED IP – BASED NETWORK USING DIFFERENT
DYNAMIC ROUTING PROTOCOLS
Ivan Nedyalkov
Abstract – An IP - based network using different routing protocols - RIP, EIGRP, OSPF, RIPng
and OSPFv3, has been modeled with specialized software. The modeled network has been studied.
The transfer of different types of data on the network - files, e-mails, working with databases has
been modeled. The influence of the individual protocols on the modeled network is studied. The
modeling is done for both types of IP addressing - IPv4 and IPv6. In addition, the network response
was examined when a part of its parameters were changed. The used models of the network
equipment are made of real once.
19. STUDYING THE DDOS ATTACK EFFECT OVER SDN CONTROLLER
SOUTHBOUND CHANNEL
Branislav Mladenov
Abstract – The main goal of this paper is to research the effect of Distributed Denial of Service
attack over the data-to-controller management southbound channel. A successful attack may
exhaust the compute resources of the controller.
20. MESSAGE TRANSMISSION PROTOCOL IN VANET
Tsvetan Marinov, Maria Nenova and Georgi Iliev
Abstract – Nowadays, road accidents happend daily. Number of victims on the roads are
increasing every year. The harmful emissions emitted by cars are also a problem around the world.
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These alarming statistics make us think about the future and the safety of the road. These issues
need to be solved as soon as possible. VANET is a specialized network for communication between
vehicles. This communication is the key to solving those problems. This document presents a
protocol for transmitting messages to VANET.
Session 2
Hall 3, Friday 17 May, 10.45-12.15
Chairpersons: Marin MARINOV, Georgi NIKOLOV
Circuits and Systems
1. SYSTEM VIEW OF SYNCHRONOUS MODULATION AND DETECTION IN
THERMOGRAPHY – PART 1
Anna Stoynova, Dimitar Todorov and Stefan Rizanov
Abstract – Thermal drift and thermal noise worsen the quality of each thermographic
measurement system. A system approach is proposed for synchronized modulation and thermal
signal detection in non-destructive thermal testing. In this first part is proposed a system view and a
summary analysis of the procedure for the application modulation of the studied signals together
with their subsequent synchronous detection. A testing system structure is presented and the main
requirements toward their blocks are defined. In the second part of this research will be given
parameters and results related to the individual blocks in a specific thermographic system.
2. POST REFLOW REPAIR TECHNOLOGY WITH AUTOMATIC SMD ASSEMBLY
FOR BIG VOLUME OF PRODUCTS
Valentin Tsenev
Abstract – The existing work presents a new way of repairs by automating installation of SMD
components to a PCB with mounted and soldered components and a melted paste on the pads where
no components are installed. The technology includes selective dispensing of a suitable gel flux at a
soldering pads, automatic mounting of the SMD components and a suitable temperature profile for
the post reflow soldering process. The application of different fluxes and temperature soldering
profiles has been investigated. The results obtained are compared with the manual repair used in
such cases.
3. REAL-TIME LASER OBSTACLE DETECTION SYSTEM FOR AUTONOMOUS
MOBILE ROBOT NAVIGATION
Plamen Petrov, Veska Georgieva, Jordan Stojanov and Antonia Mihaylova
Abstract – This paper presents a laser obstacle detection system for mobile robot navigation.
Algorithms for segmentation where the set of measurements from 2D laser range finder is
separated into segments representing each obstacle, line fitting and corner extraction for polygonal
obstacles are developed. A graphical user interface (GUI) is also created in order to visualize the
localization of the obstacles in front of the robot in real time. Simulation and experimental results
are presented to illustrate the effectiveness of the developed real time laser obstacle detection
system for autonomous mobile robot navigation.
4. A METHODOLOGY FOR PHASE-FREQUENCY DETECTORS TESTING BASED ON
XILINX FPGA
Dimiter Badarov and Georgy Mihov
Abstract – A methodology for phase and phase-frequency detectors testing is developed and
implemented on Xilinx FPGA programmable logic device. Several test setups and circuits for
phase-to-amplitude response testing are proposed in this article. The circuits for test signals
generation are discussed. The output pulses of the tested phase detectors are converted to a digital
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value in order to obtain the phase-to-amplitude response of the examined detectors. The variations
of the circuits for the different phase detectors testing is discussed.
5. EFFECT OF DIFFERENT EXTERNAL RESISTANCE ON SEDIMENTATION
MICROBIAL FUEL CELLS PERFORMANCE
Blagovesta Midyurova
Abstract – The effect of external resistance on the performance of four sedimentation
microbial fuel cells was studied. The cells consisted of two cylindrical chambers (anode and
cathode) with a ceramic separator between them. Different resistors varying from R1=10Ω to
R12=10.38MΩ were connected to the cells. The total concentration of organics in the water was
determined by the permanganate oxidizability indicator, which were 70.4 - 88.0 mgO2/L at the
beginning of the experiment and 52.8 - 66 mgO2/L at the end.
6. STATIC BINARY MODELS OF SINGLE-CORE MICROPROCESSORS – GIVING
FLEXIBILITY TO THE DEVELOPERS
Lubomir Bogdanov and Racho Ivanov
Abstract – The paper presents implementation details for an enhancement of an existing
instruction set simulator (ISS) to support static single-core microprocessor models written in any
programming language. The model is invoked as an external tool from the command line and must
return a base energy cost of an instruction passed to it. The ISS reads back and parses the result
from the STDIO stream.
7. EXAMINATION OF THE CHARACTERISTICS OF A THERMOELECTRIC
COOLER IN CASCADE
Ivaylo Belovski and Anatoliy Aleksandrov
Abstract–Thermoelectric modules use the Peltier effect in their operation. As a result, one of
their sides cools down while the other heats up, i.e. they directly convert the electric energy into a
temperature gradient. Beside single modules, modules connected in a cascade are also offered. The
present paper presents the results from a study of a multi-stage Peltier module and the conclusions
made from them.
8. OPTIMIZATION AND MODELLING OF THERMAL RESISTANCE OF
THERMOELECTRIC PUMP HEAT SINK
Nadezhda Evstatieva, Ivaylo Belovski and Anatoliy Aleksandrov
Abstract– Thermoelectric cooling systems employing the Peltier effect have been widely used
in recent years. Their main unit is the thermoelectric pump with a Peltier module embedded. It is
solid state module consisting of two ceramic plates with serially connected thermoelectric elements
(thermocouples) made of semiconductors of different conductivity mounted between them and
connected at one end with a metal strip. For a more effective transfer and dissipation of the heat
generated at the hot side of the module, a heat sink and a fan are used. When designing a
thermoelectric pump, it is particularly important to choose and use suitable thermal grease and a
heat sink of a proper size and design. The aim of the present paper is to suggest a method for
calculating the optimal dimensions of one of the most commonly used heat sinks in thermoelectric
pumps, with parallel fins made of aluminium or copper, by modelling the energy exchange in the
sink.
Instrumentation and Measurement
9. LEATHER AREA MEASURING SYSTEM
Petar Panaiotov and Goran Goranov
Abstract – The measurement and registration of the area in the production of leather of
different animal species is of great importance in the leather industrial. The irregular shape, the
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different thickness and the color of leather make the task a challenge. Mechanical planners are
used in the leather industry, and in recent years machines with photo bridge and software operating
under the DOS operating system. This paper presents a development of a leather area measurement
machine via a PLC controller and a Windows based PC with a USB camera. A program was
developed for both the PLC controller and the Windows PC system.
10. APPLIED METHODOLOGY FOR DYNAMIC ESTIMATION OF VISIBILITY
PARAMETERS: COLORS
Petya Pavlova
Abstract – The material presents first stage in development of techniques for estimation the
parameters of environment which influence to digital camera visibility. This includes calculation
the relative spectral power distribution of the fields of color checker assumed as illuminants;
colorimetrical calibration of radiometer by these spectral distributions and calculation the
correlated color temperature using particular measured signals.
11. WIRELESS CURRENT MEASUREMENT SYSTEM BASED ON INTEGRATED
FLUXGATE MAGNETIC SENSOR FOR ISOLATED CURRENT SENSING
Sotir Sotirov and Dimitar Tokmakov
Abstract – This paper deals with the design and development of a Wireless Current
Measurement System for isolated current sensing based on Integrated Fluxgate Magnetic Sensor.
The output voltage of the sensor is amplified and converted into digital value by 24-bit sigma-delta
analog to digital converter. The data from the measurements are transmitted from the
microcontroller to a personal computer through a Bluetooth module. User software has been
developed, allowing for: recording the obtained values from the measurements; their visualization
both in digital and analogue form. The system was calibrated in the range of -2.2A to + 2.2A using
a reference KEYTHLEY 2015 multimeter. Based on the obtained results, a calibration equation was
created, which is implemented in the user software, linearizing the measurement system in the
working range.
12. SMART MULTISENSOR NODE FOR ENVIRONMENTAL PARAMETERS
MONITORING IN URBAN AREAS
Marin Marinov, Ivan Topаlov, Boyanka Nikolova, Georgi Nikolov and Todor Djamiykov
Abstract – Quality of air has a very important impact on public health, the environment and
the economies of countries. The recent advances in gas sensor field and intelligent system
implementation have made it possible to obtain new, cost-effective, accurate and accessible air
quality monitoring tools. With this paper main environmental pollutants are measured in real time
with the help of low cost components. The chosen sensing elements are amperometric, incorporated
into a sensor array. An extra optical sensor is added as a reference. Furthermore, the presented
work describes the design challenges and obtained preliminary results.
13. SAMPLING TIME VARIATION OF THE EK-H5 BASED HUMIDITY DATA
ACQUISITION SYSTEM
Plamen Nikovski1, Bozhidar Markov and Nikolay Doychinov
Abstract – Experimental studies often require the registration of a certain number of physical
quantities (temperature, pressure, humidity, CO2 concentration, etc.). Usually data acquisition
systems (abbreviated with the acronym DAQ), are used for this purpose. The main objective of the
present work is to investigate the variation of the sampling time of the humidity data acquisition
system based on EK-H5 evolution kit by Swiss company Sensirion. It has been found that during the
operation the effective sampling time changes randomly closely following the Bernoulli distribution,
with the actual values being equal to or greater than the selected value. Probability of these were
respectively 0,3 and 0,7.
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Industrial and Power Electronics
Chairpersons: Nikolay HINOV, Dimitar ARNAUDOV
14. RESEARCH TRENDS FOR WIRELESS SOLUTIONS IN AUTOMOTIVE ETHERNET
Dimitar Vrachkov and Dimitar Todorov
Abstract – This study aims to examine and analyze existing ways of wireless communication
with Automotive Ethernet devices in the automotive industry. The study includes an analysis of the
existing solutions and the basic technical features of Automotive Ethernet. Proposals have been
made to implement any new concepts and methods that can be used in the future. System constraints
for data rate, length of communication bus are defined. Electromagnetic compatibility requirements
have been defined. Consider the advantages and disadvantages of the behavior of such a system in
terms of electromagnetic compatibility. Exemplary block diagrams and device models for wireless
communication with networks of this type are presented and the basic requirements for wireless
modules are defined.
15. CHARACTERISTICS OF A SERIES-RESONANT DC-DC CONVERTER WITH
VOLTAGE CLAMPING APPLIED TO PART OF THE TANK CAPACITOR
Stoyan Vuchev and Dimitar Arnaudov
Abstract – The following paper presents investigation of a series-resonant DC-DC converter
with voltage clamping applied to part of the tank capacitor. State-plane analysis of the circuit for
operation above the resonant frequency is performed. As a result, basic converter characteristics
are obtained for different ratios of the tank capacitor parts. The conditions for circuit operation as
a current source for battery charging applications are discussed. Considerations about the design
are made. The obtained results are verified with computer simulations in LTspice.
16. DESIGN CONSIDERATIONS FOR STAGES OF MODULAR TOPOLOGY FOR FAST
CHARGING OF ELECTRIC VEHICLES
Stoyan Vuchev and Dimitar Arnaudov
Abstract – The following paper presents investigation of a modular topology for EV fast
charging. Considerations about the operation of the stages in different modes are made on the base
of a performed state-plane analysis. Dependencies for the basic converter quantities are obtained in
normalized view. As a result, expressions for calculation of the tank elements values are derived.
The analytical results are verified with computer simulations in LTspice. The obtained expressions
can be used for different modifications of the half-bridge CVC-SRC circuit.
17. MODELLING LOOP COMPENSATION OF CURRENT MODE DC/DC BOOST
CONVERTER
Ivan Hristov and Nikolay Hinov
Abstract – The paper presents analytical modelling of loop compensation of current mode
boost converter. Results are applicable for adjustment and verification of regulator stability.
Output expressions are verified for modelling and calculating of feedback network. They are useful
for educational and engineering purposes.
18. OUTPUT AND CONTROL CHARACTERISTICS OF AN LLC RESONANT DC/DC
CONVERTER
Tsvetana Grigorova, Aleksandar Vuchev and Ivan Maradzhiev
Abstract –The present paper discusses output characteristics derived from existing theoretical
studies for different values of the inductance ratio a and frequency ratio which provide operation
in ZVS mode. As a result of the unified analysis, the dependence of the control characteristic as a
function of the load is also obtained. The influence of the inductance ratio on the control
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characteristics and the properties of the circuit is analyzed. Comparative data from calculated,
simulated and experimentally obtained results is presented.
19. ANALYSIS OF LCC RESONANT DC-DC CONVERTER AS A CONTROLLED
CURRENT SOURCE
Yasen Madankov, Aleksandar Vuchev and Nikolay Bankov
Abstract – LCC resonant DC-DC converter with capacity filter in the load circuit is studied.
It operates at fixed switching frequency. The considered control parameter is the phase-shift angle
between the controlling impulses sent to the relevant switches in the inverter. On the base of the
proposed harmonic analysis the output and control characteristics are obtained, as well as the
phase-shift angle between the resonant current and the inverter switching voltage in dependency of
the output voltage and control angle.
20. A UNIFIED ANALYSIS OF LLC RESONANT DC/DC CONVERTER WITH
CAPACITIVE OUTPUT FILTER
Aleksandar Vuchev, Tsvetana Grigorova and Ivan Maradzhiev
Abstract – A unified analysis of the LLC resonant DC/DC converter with capacitive output
filter is proposed. For this purpose, a harmonic analysis is used. Expressions for determining the
main quantities of the converter are obtained. The areas of commutation of the power switches are
determined at both zero current and zero voltage.
21. VOLTAGE BALANCING IN SERIES CONNECTED ENERGY STORAGE
ELEMENTS
Krasimir Kishkin and Dimitar Arnaudov
Abstract -This paper presents analysis of power converter, part of energy storage system. The
converter is used to balance the voltage across each series connected supercapacitor cells, which
are part from energy storage system. Voltage balancing for each cell is done by resonant invertors
and synchronous rectifiers. Experimental research was done to verification the results from the
simulations.
Session 3
Hall 3, Friday 17 May, 12.30-14.00
Chairpersons: Ivo ILIEV, Emil MANOLOV, Nikolay HINOV
Biomedical Engineering
1. FRONT-END PROCESSING OF PHYSIOLOGICAL SIGNALS FOR THE
AUTOMATED DETECTION OF HIGH-AROUSAL NEGATIVE VALENCE
CONDITIONS
Kalin Kalinkov, Valentina Markova and Todor Ganchev
Abstract – In the present work, we propose a front-end which is purposely designed for the
needs of automated detection of high-arousal negative valence conditions based on physiological
signals. The front-end incorporates signal pre-processing of ECG and EDA signals, feature
extraction, and feature vectors post-processing stages. Different configurations of the front-end
were evaluated for the automated detection of high-arousal negative valence conditions. The
evaluation setup implements a common experimental protocol, which makes use of the MAHNOB-
HCI dataset. The experimental results support that the post-processing with scaling of all features
to the dynamic range [0, 1] is advantageous to other post-processing schemes and the raw features.
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2. APPLICATION OF TEXTILE ELECTRODES IN MEDICAL TELEMETRY
Elena Nikolova-Hadzhigenova
Abstract –Textile sensors and, in particular, textile electrodes are becoming more widely used
in medical practice due to their features: low cost, fast response, flexibility in electrode design. The
purpose of this paper is to present the design issues, performance evaluation and applications of
textile electrodes in context of long-term ambulatory (telemetric) measurements. The applications of
textile electrodes are summarized according to sensor features as well as to different applications
for registration of biomedical signals, predominantly relating to the heart activity of patients with
cardiovascular diseases.
3. OPTIMIZATION OF ECG REGISTRATION MODULE FOR PC
Goran Goranov and Gergana Mironova
Abstract – The measurement and recording of biopotentials and their fluctuations as a
function of time are of great importance for diagnosis as they can judge the state and functioning of
the organs. The study of the electrical activity of the heart allows the diagnosis of the pathologies
during the operation and the appropriate treatment of the patient. In this paper a proposed develop
of portable measurement electronic amplifier module, using the PC sound card or a smart phone -
tablet. Made an optimization of software, developed in Java for Windows operating system, which
has the add functions of low-frequency and high-frequency filters, continuous recording and ECG
printing.
Microelectronics and nanoelectronics
4. EVALUATING THE EFFICIENCY OF PIEZOELECTRIC ENERGY HARVESTER
OF COMPRESSION TYPE
Dimo Kolev, Rumyana Stoyanova and Velimira Todorova
Abstract – The current work has the aim to develop piezoelectric energy harvester which
utilizes cheap, affordable piezoelectric elements and scavenges the mechanical energy from the
traversing pedestrians. Also the initial research are carried out to evaluate the applicability and
possible path for development of such kind of devices.
5. TECHNICAL AND CIRCUIT SOLUTIONS AND SPICE MODELING OF OPTICAL
SENSORS
Zinoviy Mykytyuk1, Mariya Vistak, Gryhoriy Barylo, Roman Holyaka, Orest Sushynskyi and
Ruslan Politanskyi
Abstract – Paper represent the technical and circuit solutions of optoelectronic sensors
designing. The noise in information signal such as a parasitic effect of external (non-informative)
optical radiation and electromagnetic interference could be decreased by means of using hardware
and software "GIRATO" complex. The main results to this implementation by using SPICE
simulation was carried out in our paper.
6. VIRTUAL SYSTEM FOR SHEET RESISTANCE MEASUREMENT OF INKJET
PRINTED CONDUCTIVE LAYERS
Georgi Nikolov, Elitsa Gieva, Boyanka Nikolova and Ivelina Ruskova
Abstract – In the present publication, we have presented the development of a virtual
measuring system for sheet resistance of conductive layers. Conducting layers are printed with
InkJet technology. The methods and systems for measuring sheet resistance are examined and
described. The calculation methods, as well as the advantages and disadvantages of the standard
methods, are shown. The developed and presented virtual system is an automated measurement
system for sheet resistance by Van der Pauw method.
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7. ANALYSES OF ENERGY HARVESTING METHODS AND DEVICES FOR USE IN
TRANSPORT NOISE HARVESTING
Elitsa Gieva, Krasimir Nedelchev, Ivan Kralov and Ivelina Ruskova
Abstract – Analyses of energy harvesting methods and devices for use in transport noise
harvesting is done in this study. An overall review of most often used systems for vibration to
electricity energy conversion is presented. A classification of these systems is made based on
comparison of their fields of application, conversion effectiveness, advantages and disadvantages.
Special attention is given on possible implementation of these systems in passive transport acoustic
noise barriers aiming acoustic energy harvesting as well as active noise reduction.
8. INVESTIGATION OF LEAD-FREE POTASSIUM NIOBATE THIN FILMS ON
SILICON FOR PIEZOELECTRIC TRANSDUCERS
Tsvetozar Tsanev, Mariya Aleksandrova, Tatyana Ivanova and Georgi Dobrikov
Abstract – KNbO3 thin films are investigated with possible application as piezoelectric
transducers. The films are grown by vacuum radiofrequency sputtering and their thickness,
uniformity, composition and piezoelectric response are studied as a function of the sputtering
voltage, sputtering pressure and plasma power. Single layer sensing structure with aluminum
electrodes is fabricated. Relation between the deposition conditions and the structure’s capacity
and piezoelectric voltage is established. Peak value of the generated voltage is 2.89 V and its
effective value is ~483 mV.
9. SINTERING TEMPERATURE INFLUENCE OVER SHEET RESISTANCE OF
INKJET PRINTED LAYERS
Boyanka Nikolova, Elitsa Gieva, Georgi Nikolov, Ivelina Ruskovaand Mladen Mladenov
Abstract – Printing technologies for the production of conductive layers and electronic
devices are well developed because they use cheap materials and printers as well as fast methods
for layers’ treatment. Still a major challenge for their application is that there is no information on
the electrical parameters of the used inks and substrates, especially depending on the method of
obtaining the structures. This paper explores the influence of the sintering temperature on the sheet
resistance of three topologies on two types of substrates.
10. MODIFIED TAMPON PRINTING OF SMD SOLDERING PASTE
Valentin Videkov
Abstract – Tis paper presents the results of a modified tampon printing applied to a soldering
paste. An analysis of the tampon printing possibilities has been made for a flexible and quick
solution when delivering a bonding paste to a contact pad. A method combining the high precision
of paste mask printing and the ability to transfer the print to another contact site in a difficult to
access area is developed. Process tools and requirements are defined. Errors at print transfer and
topological formation of the transferred paste are investigated. The method is applied in industrial
environment - company for electronic devices mounted with surface mounting.
11. TRANSISTOR BASED MULTIDIMENSIONAL MAGNETOMETER
Siya Lozanova, Avgust Ivanov and Chavdar Roumenin
Abstract – A single-chip 3-D multidimensional bipolar p-n-p transistor (BMT) sensor for
subsequent measurement of the three orthogonal magnetic-field components using one and the
same transducer zone is presented. Three successive collector coupling arrangements realize two
parallel-field and one orthogonal BMT devices. The respective sensitivities are Sx ≈ 37.5μA/T,
Sy≈75μA/T and Sz≈104μA/T. The proposed approach employs the same element, but at different
time. The subsequent measurement method allows obtaining an unusual high resolution using one
and the same “spot” region.
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Education and Learning Technologies
12. VIRTUAL SIMULATION AND MODELING OF AN INDUCTOR-PIECE SYSTEM
FOR INDUCTION COOKER
Nikolay Hinov and Hristo Ibrishimov
Abstract – The present work considers virtual simulations and modeling of an inductor-piece
system for induction cooker. As a result of the study an approach for calculating the equivalent
parameters of an induction-piece system in an induction cooker, based on the finite element method.
The computer investigation and analysis are expanded by modelling processes in COMSOL
Multiphysics 5.4. An electromagnetic and temperature model of the equivalent inductor-piece
system in an induction cooker is proposed. Electromagnetic and temperature field modelling at
different operating frequencies of the power supply has been performed. The results obtained are
used in virtual prototyping and industrial electronics training. The proposed methodology, coupled
with modern computing, provides new opportunities for optimizing and improving the energy
performance of industrial and home devices and systems.
13. SPECTRAL ANALYSIS OF OUTPUT VOLTAGE FOR BUSK AND BOOST DC-DC
CONVERTER
Zoran Zlatev and Nikolay Hinov
Abstract – With improving the stability of the electronic devices that we are using every day,
we often have to make some analysis in order to see the behavior of the electronic device under
certain work conditions. Although, very often, the output voltage is at first look in range that seems
to be regular, when we test the device, it is of great importance to make specific analysis such as
“Spectral Analysis” for closer look of the highest peaks in specific time intervals. There are several
software platforms that are providing such type of analysis. In our case will be used “LabVIEW” by
National Instruments.
14. ARDUINO-BASED HARDWARE PLATFORM FOR THE REALIZATION OF AN
INTELLIGENT HOME THROUGH THE FOCUS OF ENGINEERING EDUCATION
Slavi Lyubomirov, Daniela Shehova and Katya Asparuhova
Abstract – This article presents the Arduino-based hardware platform for the realization of a
smart home by students trained in the engineering specialties of the Plovdiv University "Paisii
Hilendarski". Studying the Arduino environment by students during their training is an excellent
choice for implementing a home automation system. Arduino environment based on Wiring, turns it
into a multi-platform application that manages LCD displays and various types of sensors for the
design and implementation of "Smart home".
15. HARDWARE AND SOFTWARE FOR LEARNING ANALOG-TO-DIGITAL
CONVERTERS IN ENGINEERING EDUCATION
Daniela Shehova, Slavi Lyubomirov and Katya Asparuhova
Abstract – The paper presents an open source code-based module designed to help students
undergraduate in the engineering programs of higher education in learning analogue-to-digital
conversion (ADC).The developed Successive Approximation ADC (SAR ADC) was implemented
with integrated circuits DAC 7821 and TL 082 CP and Arduino Mega 2560. The proposed strategy
for researching and teaching ACDs provides new opportunities for knowledge organization and
new ways of learning and learning aimed at achieving higher quality of learning outcomes in
engineering education. The results of the experimental studies were show and discussed.
16. DEVELOPMENT OF HARDWARE AND SOFTWARE METHODS AND TOOLS FOR
A SUCCESSFUL PLC TRAINING
Peter Yakimov, Atanas Iovev, Nikolay Tuliev and Emiliya Balkanska
Abstract – The implementation of the paradigm Industry 4.0 will be successful when the
ubiquitous automation of the industrial processes and equipment becomes a reality. For this
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purpose the training of the future engineers must give them a theoretical knowledge and practical
skills in the PLC software development. The paper describes the possibilities of a PLC training
simulator and some software examples which are intended for learning the basics of the PLC
programming. The learning by doing approach is suggested in order to allow the students to master
the knowledge step by step which is expected to lead to sustainable results.
17. DESIGN AND DEVELOPMENT OF CLASS-D AUDIO POWER AMPLIFIERS
LABORATORY KIT FOR AN ELECTRONIC ENGINEERING EDUCATION
Eltimir Stoimenov, Hristo Antchev and Ivailo Pandiev
Abstract – A class-D audio power amplifier laboratory kit has been developed and tested for
an electronic engineering education. The laboratory kit consists of EVAL-SSM2380Z – development
board, Arduino Uno R3 microcontroller board and several passive components, used to support the
proper dynamic operation. The key component of the developed kit is a SM2380 monolithic class-D
power amplifier that uses Σ-Δ modulation to determine the switching pattern of the output
waveforms. The microcontroller board is based on an ATmega328 AVR microcontroller and is used
to produce the I2C control interface to SM2380. Moreover, with the laboratory kit it is possible to
study the basic electrical characteristics and parameters of Class-D power amplifier at autonomous
and programmable operational modes. In addition it is possible to test the mode of automatic level
control of the output signal according to a reference value. The proposed laboratory kit is intended
to the first-year students from master degree program “Electronics engineering”, studied in the
Technical University of Sofia, Bulgaria.
18. FPGA IMPLEMENTATION OF CODE CONVERTERS OF DECIMAL DIGITS FROM
BCD CODES TO SEVEN-SEGMENT DISPLAY CODE
Adriana Borodzhieva
Abstract – A laboratory board based on Spartan-6 devices, created in the University of Ruse,
is presented in the paper. It will be used in the educational process in the courses “Digital
Circuits” and “Pulse and Digital Devices” introducing students of the electrical specialties to the
main topics in digital electronics. In the courses, different combinational circuits are studied. One
of the topics is “Synthesis and analysis of code converters of the decimal digits from any binary-
decimal code to seven-segment display code”.
19. DESIGN AND DEVELOPMENT OF LOW-POWER MULTISTAGE AMPLIFIERS
LABORATORY KIT FOR AN ELECTRONIC ENGINEERING EDUCATION
Ivailo Pandiev and Eltimir Stoimenov
Abstract – A low-power multistage amplifiers laboratory kit has been developed and tested
for an engineering education. The laboratory kit consists of multistage amplifier, which represents
operational amplifier, is assembled from discrete elements as a transistor circuit. The key
components of the circuit are differential amplifier as an input stage, followed by common-collector
amplifier as a voltage buffer and an output stage. The output stage includes common-emitter
amplifier section with current-source load and output section with two complementary bipolar
transistors. Moreover, it is possible to study the operational principle of the basic amplifier stages
and the effect of the negative feedback to a multistage voltage amplifier at non-inverting operation.
The proposed laboratory kit is intended to the second-year students from bachelor degree program
“Electronic engineering” in the Technical University of Sofia.
20. DEVELOPMENT OF CONTROL SYSTEM BASED ON THE FUZZY CONTROLLER
Petar Panaiotov and Goran Goranov
Abstract – This paper presents the development of a system for processing and managing data
based on Fuzzy Controller. The system is designed to test the feasibility and effectiveness of a new
software model applicable to powerful transducers built according to the principles of object-
oriented programming.
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FORUM “ELECTRONICA”
Hall 3, Friday 17 May, 14.15-14.45
Chairperson: Nikolay HINOV
SEMINAR - NSF SCIENTIFIC PROJECTS
Hall 3, Friday 17 May, 14.45-15.45
Chairperson: Nikolay HINOV
Project DN 17/16/12.12.2017 funded by National Science Fund of Bulgaria with
title: OPTIMIZATION OF ACTIVE THERMOGRAPHY METHODS FOR INFRARED
THERMAL NONDESTRUCTIVE DIAGNOSTIC AND CONTROL
Project ДН07/06/15.12.2016 funded by National Science Fund of Bulgaria with
title: MODEL BASED DESIGN OF POWER ELECTRONIC DEVICES WITH GUARANTEED
PARAMETERS
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INFORMATION
ELECTRONICA 2019 is technically Co-Sponsored by IEEE.
(IEEE Conference record # 47796)
The presented papers will be submitted for inclusion in the IEEE Xplore on-line digital
library.
ДНТ
Address for correspondence
Address:
CEEC (Union of electronics, electrical engineering and telecommunications),
1000 Sofia, 108 Rakovski Str.
Phones:
+359 2 987 97 67
e-mail:
Web site:
http://ceec.fnts.bg
http://e-university.tu-sofia.bg/e-conf/?konf=128
