Papers by Valeri Mladenov
Lecture Notes in Computer Science, 2012
The use of general descriptive names, registered names, trademarks, etc. in this publication does... more The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.
EEG alphabet speller with Neural Network classifier for P300 signal detection
2018 14th Symposium on Neural Networks and Applications (NEUREL)
This paper presents the implementation of a P300 alphabet speller study case. The speller is base... more This paper presents the implementation of a P300 alphabet speller study case. The speller is based on methodology in which alphabet symbols are displayed in real-time on screen to test subjects, with real-time electroencephalograph measurement of human brainwaves, with P300 event evoked potential signal detection. The implementation is done in MATLAB with Emotiv Epoc EEG+ headset.
International journal of systems applications, engineering & development, Sep 20, 2022
Control of various robots through signals from the brain activity
Proceedings of the 21st International Conference on Computer Systems and Technologies
The research of the brain and how it works is a hot topic and gaining popularity in recent years.... more The research of the brain and how it works is a hot topic and gaining popularity in recent years. Therefore, it is not surprising that more and more researchers, as well as young scientists, are interested in trying to connect different hardware with brain activity -- mind-controlled cars, planes, robots. In this presentation, a brief overview of how to record and proceed with the brain activity signals will be given. Special attention will be done on the developed brain activity management system that can successfully control "Baxter" [1] and "Nao v5" [2] robots. The system uses the Emotiv Epoc+ electroencephalograph [3] (EEG) to capture real-time brain activity. The hardware follows the International 10-20 Electrode Positioning System[4]. In order to achieve control with the mind, a user must create their own profile. This profile stores that user's specific personal brain activity data because each person has very unique brain activity. First, a neutral level of brain activity [5] must be recorded and then it is necessary to train the various commands to the robots. The current version of the system allows distinguishing between 5 different commands. The first command is relatively easy to train. But with each other successfully trained command it becomes more difficult to distinguish the individual command from the others. Training is done through a virtual cube, so over a period of time, a person can learn to control their brain activity. It can be moved in different directions, and if a person has a highly developed imagination, they can even make the cube disappear. The EEG data [6] from the device is processed and compared with that of the user's profile. When there is a coincidence between both the data from the device and the data already trained by the user, the command is sent to the robot in real-time for execution. Specially written Python scripts [7] are used to make the connection between Emotive Epoc + and the robots. Each robot can perform up to 5 different commands individually -- four movement commands and one command to return the robots to a neutral position. The results depend mainly on how well the system is trained and how long the training is done. With enough training time and the appropriate training methods, each of the five commands can be distinguished and executed. For comparison on average, most users manage to train up to 3 different commands correctly.
A linear programming implementation of a interval method for global non-linear DC analysis
1998 IEEE International Conference on Electronics, Circuits and Systems. Surfing the Waves of Science and Technology (Cat. No.98EX196)
ABSTRACT A modification of Kolev's (1997) previous method for finding the set of all oper... more ABSTRACT A modification of Kolev's (1997) previous method for finding the set of all operating points of non-linear resistive circuits is suggested. The original method is based on an approximation of every single variable function (circuit equations are in a hybrid representation form) by an appropriate linear interval function, i.e. by a real linear function having an additive interval constant. The improved approach uses linear programming technique to update the current interval “box” instead of the originally used interval hull of the solution set of the linearized interval system. Numerical experiments show that the version suggested reduces almost double the number of the iterations in comparison with the original method for the examples considered
WSEAS Transactions on Circuits and Systems archive, Feb 1, 2011
The balancing of an inverted pendulum by moving a cart along a horizontal track is a classic prob... more The balancing of an inverted pendulum by moving a cart along a horizontal track is a classic problem in the area of automatic control. In this paper two Neural Network controllers to swing a pendulum attached to a cart from an initial downwards position to an upright position and maintain that state are described. Both controllers are able to learn the demonstrated behavior which was swinging up and balancing the inverted pendulum in the upright position starting from different initial angles.
1998 Fifth IEEE International Workshop on Cellular Neural Networks and their Applications. Proceedings (Cat. No.98TH8359)
An approach is discussed to estimate the basin of attraction of stable equilibrium points in line... more An approach is discussed to estimate the basin of attraction of stable equilibrium points in linear systems, operating in a saturated mode (LSSM). The approach is valid for Full Range Cellular Neural Networks (FR CNNs) too as far as the dynamic properties of both systems are qualitatively similar. The approach is an extension to previous work on origina l CNNs. The used technique is based on the determination of the so called tree of regions for each stable equilibrium point and the additional separation of the regions where the boundaries between different basins are located. The obtained trees for each stable equilibrium point give the corresponding basin of attraction.
Proceeding of 10th WSEAS international conference on electronics, hardware, wireless and optical communications, and 10th WSEAS international conference on signal processing, robotics and automation, and 3rd WSEAS international conference on nanotechnology, and 2nd WSEAS international conference ...
Energies, 2022
The paper’s main objective is to demonstrate the trading and flexibility of services amongst TSOs... more The paper’s main objective is to demonstrate the trading and flexibility of services amongst TSOs, DSOs, and Prosumers in a transparent, secure, and cost-effective manner using Blockchain-based TSO-DSO flexibility marketplace (EFLEX). The aim is to look for ways to help DSOs/TSOs be more flexible and more directly engaged in managing energy flows on the network. EFLEX will streamline the needs of both TSO and DSO on the same platform. Based on the paper’s proposed services, the pilot service demonstration will be carried out in Bulgaria and Romania, and the main focus will be on congestion management, TSO-DSO Coordination, and Marketplace. The proposed objective is achieved by using Blockchain-based smart contracts and distributed ledger technology.
Genomic Signals
Neural networks for prediction of nucleotide sequences by using genomic signals
Delta-Sigma
design procedure for finding optimal third order
Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 2018
An average human spends about one third of his life sleeping so quality of sleep is essential for... more An average human spends about one third of his life sleeping so quality of sleep is essential for the human being to maintain good physical and emotional health. Sleep disorders may introduce severe physical effects, e.g. cognitive impairments and mental health complications. So being able to measure and evaluate sleep behavior is important for health practitioners and the users themselves. In this paper, we present the implementation of the Sleep Lifestyle Reasoner part of AAL platform which allows detection of minor or major deviations in the sleeping patterns in MCI and COPD patients indicating changes in their health status. The output of the reasoner is fed to the My Sleep Web Application that provides recommendations to improve sleep hygiene and coaches the users into a healthy sleeping behavior, based on their personal rhythms and problems. It also supports the informal caregiver by providing insights on the sleeping behavior of the patient.
Network flexibility and risk assessment as part of NordPool energy market
2020 12th Electrical Engineering Faculty Conference (BulEF), 2020
The paper presents preliminary information on IT integration, taking into consideration existing ... more The paper presents preliminary information on IT integration, taking into consideration existing processes and infrastructure in demonstration markets, data streams. It introduces the Flexible Energy Grid architecture, its applications, Risk analysis is also carried out. The use case is tested form Independent Bulgarian Energy Exchange which is part of NordPool day-ahead and intraday markets.
This article describes the translation of a digital circuit behavior of digital superconductive c... more This article describes the translation of a digital circuit behavior of digital superconductive circuits into high-level logical descriptions. The work is based on Rapid Single Flux Quantum (RSFQ) electronics. The basic electronic circuits, such as AND, XOR and a signal splitter are evaluated in order to extract the logical behavior as well as timing issues by analog circuit simulations. The timing condition of the adder circuit for a special input configuration in terms of their arrival time as well as their bit pattern is extracted. We use dual rail logic to analyze an RSFQ 4-bit ripple carry adder using analog and VHDLbased simulations and comparing their results in terms of total delay and simulation time.
Humanoid Robot Detecting Animals via Neural Network
2018 14th Symposium on Neural Networks and Applications (NEUREL), 2018
The recognition of objects via neural networks is gaining increasing popularity and usability in ... more The recognition of objects via neural networks is gaining increasing popularity and usability in the world around us. For example - in the production lines of the factories where the details are recognized and then automatically sorted, in the fully automated stores where the camera systems and deep learning algorithms recognize the products we take from shelves and adds them to a virtual shopping cart, in banks where robots recognize people’s faces and offers them different services that the banks provide, or in the autonomous cars where it is needed quick and accurate recognition of the environment around the vehicles. This paper presents a neural network that can identify animals - with an existing set of pictures for training, it can recognize any animal. The pictures are taken from the robot’s camera. They’re then processed via a convolution neural network which is implemented via Tensorflow on a personal computer. As a result, the robot can identify and say the name of the animal standing in front of it.
Nonlinear Programming Approach for Design of High Performance Sigma–Delta Modulators
In this chapter we present a nonlinear programming approach to the design of third-order sigma–de... more In this chapter we present a nonlinear programming approach to the design of third-order sigma–delta modulators with respect to maximization of the signal-to-noise ratio, taking into account the modulator’s stability. The proposed approach uses an analytic formula for calculation of the signal-to-noise ratio and an analytic formula for stability of the modulator. Thus the goal function becomes maximization of the signal-to-noise ratio and constraints come from stability issues and bounds of the modulator noise transfer function coefficients. The results are compared with the optimal third-order modulator design provided by DStoolbox. The proposed procedure has low computation requirements. It is described for third-order modulators with one real pole of the loop filter transfer function and can be extended easily and generalized to higher-order modulators.
Proceedings of the 9th WSEAS international conference on Applied informatics and communications
On Solitary and Periodic Waves in One-dimensional FitzHugh-Nagumo CNN's
Proceedings of the 4th WSEAS international conference on Computational intelligence
On the nonlinear dynamics propagation in positive feedback camparators for A/D converters
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Papers by Valeri Mladenov