Category: Journal Automatica and Informatics

automatica
M. Hadjiski. Cyber Security of Industrial Control Systems

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Key Words: Advanced control; cyber security; industrial control system; networked control; resilience; simulation.

Abstract. An overview of the problems, research efforts and recent results on cyber security of Industrial Control Systems is provided. The interaction between the basic control sub-systems – the advanced control of the plant, the system for predictive safety maintenance and the cyber-security control system is considered. In the paper is shown that cyber security should be treated as a holistic problem and could be successfully solved if tight integration of technological, organizational and human aspects will be achieved. Several approaches for design of contra-actions via implementation simulation and Artificial Intelligence-based technologies are analyzed. Some problems of attack-resilient control of Industrial Control Systems are discussed.

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automatica
S. Yordanov, G. Mihalev. System for Automatic Reporting a Labour Productivity in Real Time Based on ESP32 Controller

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Key Words: Internet of Things (IoT); Wi-Fi module ESP32; Arduino IDE development environment; LPWAN technologies; electronic accounting technologies.

Abstract. In this paper, an ESP32 application in implementing systems for automated reporting of the utilization rate of production capacities in real time is considered. A technical solution of remote control and monitoring of the production process in a textile company, through a dedicated module for sending the time spent on a remote server via Wi-Fi, Lan or Bluetooth is proposed. The obtained information is used to control the production process in real time and determination of the remuneration of workers.

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V. Boishina. Situattion Predictive Control for Energetic Systems

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Key Words: Distributed diagnosis; supervisor control; case base reasoning; predictive control.

Abstract. The research is mainly focused of using of possibility to collect the historical information about the behavior of the control system. The main focus is to illustrate using of the Case Base Predictive Control, which optimizes the way of choosing the optimal way of control of the system in respect of taking the decisions according to the historical experience about system behavior and fast changing outdoor parameters. The paper described forming of cases which describing different system situations and the appropriate way of choosing of the right way of system control. The proposed research represented the possibility to aplly Case Base Reasoning (CBR), based on the previous knowledge about system behavior and possible system disturbances caused from different environment changes (climatic and economic ones). The research propose the way of optimizing the control of energetic control system based on previous known cases.

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informatics
Y. Aleksieva, H. Valchanov. Botnet Detection System Based on Genetic Algorithms

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Key Words: Botnet attacks; DoS attacks; intrusion detecting system; genetic algorithms.

Abstract. One of the most common attacks against information security is Botnet. Recognizing such attacks requires the development of effective security systems. Intrusion detection systems collect information from different sources in computer systems and networks. For most systems, this information is compared to predefined patterns of abuse to identify attacks and vulnerabilities. Much of the existing host-based systems for botnet detection use techniques based on anomalies or rules. This paper presents some aspects of the implementation of a host-based botnet attack detection system. The system uses an anomaly detection technique based on a genetic algorithm.

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achievements and applications
M. Gospodinov, E. Gospodinova. Mathematical Analysis of the Linear and Non-linear Properties of Electrocardiological Data

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Key Words: HRV; ECG; linear analysis; non-linear analysis; Poincaré plot.

Abstract. The article is devoted to the mathematical analysis of the linear and nonlinear properties of heart rate variability (HRV) determined by digital electrocardiological data. The advantage of the mathematical methods used is their ability to detect minor cardiovascular abnormalities and a way to evaluate the overall functional capabilities of the body. The quantitative dimensions of the studied parameters when using linear mathematical methods of analysis have significant clinical application because the boundaries of norm-pathology are known. The application of non-linear mathematical methods in data analysis provides additional information on the physiological status of patients. The article presents the results of the linear analysis of the studied data in the frequency domain and the results of the nonlinear analysis by applying the Poincare graphical method, which allows the doctors to see the whole electrocardiological record at a glance and quickly detect cardiovascular disorders if there are some. The analysis of HRV by applying linear and nonlinear methods provides ample opportunity for clinical and research applications.

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achievements and applications
P. Lebamovski, E. Petkov. Studying Stereometry in Secondary Schools Using 3D Technologies

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Key Words: 3D modeling; dynamic software; research approach; stereometry.

Abstract. The article presents a new approach to the training of students in Stereometry in the secondary schools. The aim is to create an application that presents the learning material of the textbooks in a way that is easily understood by learners while at the same time excites them and motivates them for new knowledge. Graphics are presented which can be implemented in two ways: solid and wireframe (transparent), their advantages and disadvantages are considered. An analysis of 3D modeling techniques such as LOD (Level of Details), voxels and sweep representation is also done. The study highlights the advantage of the system, which is the stereoscopic perspective. Its implementation is realized by a system without immersion or projector. The constructivism and the connectivism are considered as suitable methodologies in case of application-based training in mathematics.

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M. Hadjiski. Model-based ot Model-free Approach in Control

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Key Words: Artificial intelligence; automatic control; data driven methods; machine learning; model-based control; model-free control.

Abstract. Classical model-free control methods, which still have extremely large application in industry are considered in historical perspective and in accordance with their advantages and disadvantages. Some of the most popular model-free approaches, adopted last three decades (ultra-local model-based, rule-based, express system-based) are treated tacking into account their pros and cons, depending on the complexity of the control problem and the business aspect. A special attention is paid to contemporary very actual data-driven approaches. The most promising of them, oriented to AI-based technologies (especially machine learning) are discussed. A comparative analysis is carried out in order to clarify the advantages, disadvantages and challenges of model-based and model-free approaches implementation in control in big data era.

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automatica
V. Hristov, S. Gramatikov, G. Georgiev, E. Genchev. Virtual Tool for Improvement of a Stand for the Study of the Characteristics of a Direct Current Motor

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Key Words: DC motor; virtual instrument; LabVIEW; mechanical characteristics.

Abstract. This article is an enhancement of an existing bench by creating an instrumental tool through LabVIEW for automated mechanical characteristics removal of a DC motor on a system generator-motor. By using the Arduino microcontroller for analogue-to-digital conversion from the sensor (modules) and for connection to the computer, it allows with a relatively small amount of resources to upgrade an existing stand. Voltage dividers for voltage measurement and built-in virtual instrument and graphical screen for visualizing the system’s operation processes were built.

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automatica
N. Perchemliev, A. Grancharova, K. Boshnakov. Hierarchical Control System for Gas Condensate Stripping Installation in the Ammonia Production Process

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Key Words: Ammonia production; gas condensate stripping; hierarchical control system; profit loop; supervisory control.

Abstract. In this paper examines an existing industrial plant for gas condensate stripping, which is part of ammonia production. Processes and apparatuses are described. Real industrial measurements were made on the basis of which analyses were made. A conceptual architecture of a hierarchical control system for installation’s control is presented. The suggested architecture can be implemented and tested with the existing Honeywell’s Experion PKS. The main purpose of the hierarchical control system is to improve the efficiency of heat sources and the quality of the stripped gas condensate. This will improve the economic performance of the entire ammonia plant.

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automatica
A. Pavlov, N. Nikolov, M. Alexandrova. PLC-Based Process Control System for Catalytic Vacuum Pyrolysis Installation of Waste Raw Materials

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Key Words: Catalytic vacuum pyrolysis; state space; state observer; state controller; MATLAB Simulink; PLC; SISO; Unity Pro XL.

Abstract. This paper discusses problem designing PLC-based process control system for catalytic vacuum pyrolysis. Paper presented PLC-based discrete state modal controller for SISO systems. It is based on observer of Luenberger. The state controller is synthesized as a functional block in programming environment Unity Pro XL for PLC series Modicon M340 of Schneider Electric.

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informatics
V. Aleksieva, A. Hulian. Crypto-token Based on Smart-contract of Ethereum Blockchain

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Key Words: Ethereum; block chain; smart contract; crypto-token; crypto-currency.

Abstract. The proposed paper realized a smart contract based on Ethereum blockchain. The decentralized crypto-token is created for Initial Coin Offering (ICO) and based on ERC20 standard. A web-based interface is created for sale of these crypto-tokens. The results from experimental tests are presented.

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achievements and applications
G. Georgieva-Tsaneva, M. Gospodinov, E. Gospodinova. Analysis of Heart Rate Variability through Statistical Parameters

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Key Words: Heart Rate Variability; Statistical Analysis; Atrial Fibrillation; Premature Ventricular Contraction; Normal Sinus Rhythm; Orthogonal Transforms.

Abstract. Cardiovascular diseases are among the first causes of death. The main cardiovascular diseases are myocardial ischemia, various types of arrhythmias, reduced ability to contract the left ventricle. Cardiac testing is performed non-invasively by electrocardiograph or Holter monitoring. The paper examines, through the application of orthogonal transforms, the continuous holter recordings of individuals with Atrial Fibrillation, Premature Ventricular Contraction and Normal Sinus Rhythm. The mathematical analysis is performed in the time domain. The results show characteristic differences between patients with both types of arrhythmias and in healthy individuals. The presented results can be of benefit to cardiology practice in Bulgaria and worldwide.

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M. Hadjiski. Does Automation Become a Routine Engineering Discipline

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Key Words: Artificial intelligence; automation; control theory; knowledge.

Abstract. During the second half of the twentieth century Automation was doubtlessly one of the most dominant scientific and engineering directions. In control theory a number of original concepts with a fundamental importance received a quick and deep development – dynamic systems, feedback, stability, modeling, identification, optimization, robustness, controllability and observability. These new concepts rendered a strong interdisciplinary paradigmal impact on a variety of scientific areas of advanced activities – computer science, decision making as well as on classic sciences like neuroscience, psychology, medicine, economics, education and many others. On the other hand contemporary Automation absorbs in a natural way lots of relevant achievements in other scientific directions like the fuzzy logic, the approximation theory, the neural nets, the network approach, learning, elements of the artificial intelligence, etc. But during the last fifteen years there was an obvious decrease of the verbal attendance of the Automation problematics in societal debates about the emerging challenges in a globalizing world. In the present paper it is argued that Automation continues to be a solid reactive and proactive factor in the formation of the societal strategy and in the running advanced technological and scientific policy because: (i) Automation speeds up its internal advanced development solving new emerging problems, (ii) Automation possesses relevant tools to predict corresponding scientific challenges and to Overcome Them, (Iii) Automation Will Be Together With Artificial Intelligence The Most Powerful Action In The Social Digitalization In The Near Future.

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automatica
G. Mihalev, H. Stoycheva. Synthesis of a Linear Quadratic Controller for Vibratory Bowl Feeder

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Key Words: Vibratory bowl feeder; LQR controller; robust analysis.

Abstract. In this paper, a synthesis of the LQR control unit for a vibratory feeding and orientation module is presented. The device representing the control object is considered as a two-mass resonating system. In the presence of parametric uncertainty, a linear model of the system in state space is produced. A robust closed-loop analysis has been accomplished, showing the robust quality and robust stability of the system provided by the LQR controller.

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automatica
E. Mihailov, K. Boshnakov, I. Petrova. Risk Assessment of Liguid Steel Breakout in Metallurgical Ladle

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Key Words: Risk assessment; liquid steel breakout; metallurgical ladle; infrared thermography.

Abstract. In the present paper is considered the risk assessment for liquid steel breakouts from metallurgical ladle. The damages with different form are investigated. Mathematical models for geometric dimensions of damages and temperature field on metallurgical ladle are created. The temperature field is measured by infrared thermo camera.

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automatica
N. Deliiski, D. Angelski, N. Trichkov, Z. Gochev. Computation of the Average Mass Temperature of Wood Details during their One Sided Heating

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Кey Words: Average mass temperature; oak details; one sided heating; plasticizing; bending.

Abstract. An approach for computing the average mass temperature of the wood and the rate of its change during one sided heating of flat wood details, has been suggested. The approach is based on the use of the solutions of own non-linear model for the calculation of the non-stationary 1D temperature distribution along the thickness of subjected to one sided conductive heating flat wood details aimed at their plasticizing in the production of curved back parts of chairs. A software program has been prepared in the calculation environment of Visual FORTRAN Professional for solving of the model. With the help of the program, the 1D non-stationary temperature field in flat oak details with an initial temperature of 20 oC, moisture content of 0.15 kg.kg-1, thickness of 12 mm, 16 mm, and 20 mm during their 30 min one sided heating at temperature of 80 oC and 120 oC of the heating metal body has been calculated. After integration of the temperature field, the average mass wood temperature and the rate of its change of the subjected to one sided heating oak details has been calculated. The obtained results are graphically presented and analyzed.

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automatica
R. Vladova, E. Kirilova, N. Vaklieva-Bancheva. Method for Overcoming Uncertainties and Increasing Resilience through Heat Integration of Flows in Batch Production Systems

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Key Words: Heat integration; batch processes; stochastic optimization; flexibility index.

Abstract. By definition, sustainable development is a way of using natural resources that aims to meet human needs while maintaining the natural balance with the environment, so that these needs can be met both now and for future generations. The creation of highly efficient technological processes, energy efficiency in every sphere of the economy and society, the production of energy from renewable energy sources, the economy of materials, the use of renewable natural resources, the development of green and eco-technologies, prevention of harmful waste; effective governance of the economy, society and the environment are part of the most important policies underlying the European Union’s (EU) Sustainable Development Strategy. Creating energy efficient production systems involves less impact on the environment. One of the most powerful tools for creating this type of system is the integration of energy and mass processes. Process integration covers a wide range of system-oriented methods and approaches that are used in the design and reconstruction of industrial processes to obtain optimal use of resources. In recent years, the focus on energy integration of processes has shifted from the integration of processes in continuous systems to the integration in systems with batch processes. From the conducted researches it is clear that the production systems with batch processes have sufficient energy potential, which can be used to improve their energy efficiency. The recovery and use of this heat is complicated by the batch nature of the processes, and the task is further complicated by the impact of stochastically changing flow parameters such as temperature, volume, etc., overcoming which is a serious challenge to the sustainability of batch production systems. The aim of the present study is to propose a method for dealing with uncertainties and increasing resilience through heat integration of flows in periodic production systems. The method includes three main stages: 1. Uncertainty analysis and selection of a suitable scheme for energy integration of processes and its mathematical description; 2. Defining the problem of optimal redesign of an energy-integrated batch production system by incorporating the integration model within a stochastic optimization problem and its solution; 3. Assessment and decision making to choose the most appropriate solution, whereby the production system is sustainable of the impact of the uncertain parameters in the widest borders, by defining the flexibility index.

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informatics
E. Otsetova-Dudin, I. Kurtev. ModSecurity Rules for Web-Server Protection

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Key Words: ModSecurity; HTTP; OWASP; Web Application; Firewall.

Abstract. The security of the information in the contemporary dynamic and information world is by priority importance. Every day the entire world alarms for different in their nature and object hacker’s attacks. The damages of those attacks are as well fiscal and moral. The most popular attacks against the web-applications are those with causing service denial (Denial of Service – DoS), the blocking of the functioning of different sites or entire systems. Protection opportunities of web-servers, functioning in real time of OWASP (Open Web Application Security Project) are presented in that material. The module ModSecurity provides a set of protection rules, based on control of the ingoing and outgoing traffic from the point of view of the server

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informatics
K. Dimitrov. Analysis of the Information Security in WLAN Standards IEEE 802.11

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Key Words: Wireless LAN (WLAN) security; WEP; RC4; IEEE 802.11; IEEE 802.1X; IEEE 802.11i; WPA; TKIP; WPA2; AES; CCMP; KRACK attack.

Abstract. On the basis of extensive research in the specialized literature, a critical analysis of information security protocols in the standards for IEEE 802.11 wireless LAN (WLAN, WiFi) has been carried out. Finally, some conclusions and recommendations are made. The first WLAN security protocol – WEP is extremely insecure and should not be used. Due to the inherited vulnerabilities of WEP and the fact that some parts of TKIP (such as the Michael function) have some security deficiencies, WPA has already exhausted its role as a temporary WEP fix for legacy hardware and is not recommended. Despite the mathematically proven cryptographic security of the AES standard in CBC mode, a weakness in the cryptographic key management process makes it vulnerable and leads to a security breach of WPA2 in October 2017. Although the vulnerability is removable by patch, probably a lot of WiFi-Devices have not been updated, which puts users at risk. In addition, despite updates of the firmware and recommendations from information security professionals to circumvent and/or block the protocol breach, reports emerged in October 2018 that the vulnerability to KRACK was still being exploited.

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