Marijana Pavlov-Kagadejev - Academia.edu (original) (raw)

Papers by Marijana Pavlov-Kagadejev

Artificial intelligence review, Feb 12, 2024

Power supply from renewable energy is an important part of modern power grids. Robust methods for... more Power supply from renewable energy is an important part of modern power grids. Robust methods for predicting production are required to balance production and demand to avoid losses. This study proposed an approach that incorporates signal decomposition techniques with Long Short-Term Memory (LSTM) neural networks tuned via a modified metaheuristic algorithm used for wind power generation forecasting. LSTM networks perform notably well when addressing time-series prediction, and further hyperparameter tuning by a modified version of the reptile search algorithm (RSA) can help improve performance. The modified RSA was first evaluated against standard CEC2019 benchmark instances before being applied to the practical challenge. The proposed tuned LSTM model has been tested against two wind production datasets with hourly resolutions. The predictions were executed without and with decomposition for one, two, and three steps ahead. Simulation outcomes have been compared to LSTM networks tuned by other cutting-edge metaheuristics. It was observed that the introduced methodology notably exceed other contenders, as was later confirmed by the statistical analysis. Finally, this study also provides interpretations of the best-performing models on both observed datasets, accompanied by the analysis of the importance and impact each feature has on the predictions.

2023 16th International Conference on Advanced Technologies, Systems and Services in Telecommunications (TELSIKS)

The Copper Mining and Smelting Complex Bor (RTB Bor) in the Republic of Serbia has a long history... more The Copper Mining and Smelting Complex Bor (RTB Bor) in the Republic of Serbia has a long history of computer control and computer-aided data processing. Working within the confines of the Cold War era, RTB implemented and developed four generations of computers, becoming a major influence in the IT sector and the primary computer training resource in the region

Mining and Metallurgy Engineering Bor

Arduino microcontroller platforms are frequently in use in the last few years. The reason is thei... more Arduino microcontroller platforms are frequently in use in the last few years. The reason is their simplicity, low cost, and availability of a large number of ready-made solutions on the Internet. The Arduino Integrated Development Environment itself has a Serial Monitor and Serial Plotter tools for data presentation. The Serial Monitor displays the textual and numeric values of the data obtained through the serial port. By using the Serial Plotter, measurement results from the Arduino serial port can be seen in the form of Real-Time diagrams. The deficiency of such a way of data visualization is that it does not provide many opportunities for change and adaptation to the user needs. This paper presents examples of several different programming environments which provide the good opportunities for presentation the results generated by the Arduino boards. Some hardware modules used to display data from the Arduino boards are also described in this paper.

Mining and Metallurgy Engineering Bor, 2016

The Mining and Smelting Complex Bor (RTB) is one of the biggest electrical energy consumers in Se... more The Mining and Smelting Complex Bor (RTB) is one of the biggest electrical energy consumers in Serbia, with costs that exceed 3 million USD per month, or between 30 and 40 million USD per year. A complex technological process of copper production comprises mining, concentrate production (flotation), smelting and electrolytic refining. In all these stages a large amount of energy is consumed. The electricity is supplied from the power plants using 5 substations: two of them located in Bor, and the remaining three in Majdanpek. The conditions for delivery and billing of the electrical energy were defined by the contract with the supplier. The methods of billing (calculation) the electrical energy costs were changed several times in the previous 25 years. Although the consumed energy is the largest part of the overall costs, there were also some indirect costs affecting the final monthly price. It is clear that even a minor percentage decrease of costs can lead to substantial savings in the total amount. Hence, different technological and organizational activities were undertaken to reduce these costs. The paper presents primarily the effects of administrative measures on the amount of total electrical energy costs in copper production.

Serbian Journal of Electrical Engineering, 2015

The most exact temperature measurement can be made by using platinum sensors. Temperatures from -... more The most exact temperature measurement can be made by using platinum sensors. Temperatures from -254.3?C up to +850?C can be measured with Pt100 sensor. The relationship between resistance and temperature is relatively linear, but for measurements of very high precision, Pt100 working curve should be a little bit improved. The paper describes an efficient way of measurement characteristic linearization by using the analogue electric circuits. The obtained results proved the initial considerations and the Pt100 becomes rather transducer than pure sensor.

In this paper selected examples of laboratory exercises related to data acquisition systems are d... more In this paper selected examples of laboratory exercises related to data acquisition systems are described. The examples are realized by using PC and microcontroller-based data acquisition systems. Basic elements of the analog signal conditioning, multiplexing, and analog to digital conversion are shown. The illustrated laboratory exercises can be used in the courses linked with the basis of automatic control systems as well as with programming languages. Because of its simplicity, the presented examples can significantly contribute to better understanding of the planned curriculums.

Serbian Journal of Electrical Engineering, 2014

The dual-slope ADC (DSADC) is a type of analog-to-digital conversion with low input bandwidths. I... more The dual-slope ADC (DSADC) is a type of analog-to-digital conversion with low input bandwidths. It is pretty slow, but its ability to reject high-frequency noise and fixed low frequencies such as 50 Hz or 60 Hz makes it useful in noisy industrial environments and applications. It provides very good resolution. For the practical measurements in the Institutes laboratory an instrument is designed and realized. The base DSADC method is used, but improved by multiple conversions to make the measuring more precise and the time shorter. The special attention is paid to the problems occurred in practical realization and the way to overcome them. The paper describes the proposed and applied solutions, functional principles and achieved performances of the realized instrument.

Serbian Journal of Electrical Engineering, 2013

The paper presents the real instrument functional characteristics and describes the way of practi... more The paper presents the real instrument functional characteristics and describes the way of practical solutions of its performance improvement. It presents the design process of the instrument made for resistance measuring. In order to achieve desired objectives, a great number of experiments have been carried out during the development. Basically, the comparison method has been applied. At first, it was intended for the small resistor measuring as a single range unit. Later, the device has been improved and upgraded for a wide range resistance measuring. Finally, some of the difficulties have been detected and explained as well. The paper contains solutions developed and applied for their overcoming.

Journal of Electrical Engineering, 2012

One Way of Output Voltage Hold Circuit Improvement at Low Resistance Comparator The article prese... more One Way of Output Voltage Hold Circuit Improvement at Low Resistance Comparator The article presents a way of improvement the important performances of an electronic low resistance comparator. The practical usage of a realized instrument prototype shows some disadvantages: the time until the result appears at the display is to long (the stationary state establishing sequence should be shorter) because of the negative influence of parasitic voltages. Modification of output voltage hold circuit gives quite convenient instrument response time. The parasitic voltage disturbance is decreased to acceptable value, even though the comparator is modified for multirange measurement. The paper describes some details of a solution and its conformation in practical usage.

Mining and Metallurgy Engineering Bor, 2018

The most of previously realized and implemented Distributed Control Systems (DCS) for the electri... more The most of previously realized and implemented Distributed Control Systems (DCS) for the electricity consumption control are based on a control at the transformer substations level (transformer output cells level). In order to make such DCS systems, applicable to a wide variety of consumers, the new components are added into the existed DCS (transducers, controllers, communication modules, etc.). In that way, the realized DCS becomes easily applicable to almost all types of electricity consumers. Also, the DCS should be low-cost, to be available to the targeted customer groups. This paper presents the characteristics of recently realized transducer (AC current to DC voltage). The application of such device in the realized DCS enables measurement the electricity consumption of almost all electrical consumers in the industrial facilities, as well as in the households.

Sensors & Transducers, 2009

One of activities of the Mining and Metallurgy Institute is production of thermocouple elements m... more One of activities of the Mining and Metallurgy Institute is production of thermocouple elements made of precious metals. Since this is a complex technological process and the quality control of produced elements is performed by other institutions, sometimes the whole series of products can happen to be bad and not useful. This is increasing costs and time of production, as well. To prevent wasting of time and money, the special measuring system is developed. The kernel of the system is already existing microprocessor measuring station - MMS. The MMS's hardware configuration, initially designed for industrial process control requirements with suitable input channel characteristics and adequate response time is adapted for the purpose of thermocouple calibration. Appropriate software solution is developed, as well. This article describes the practical solution for thermocouple testing and calibration. Hardware interface, principles of system integration and developed software are ...

One solution of task priority ordering in microprocessor measuring station

All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.

Information Technology and Control, 2015

Microprocessor Measuring Station (MMS) is a type of programmable logic controller fully developed... more Microprocessor Measuring Station (MMS) is a type of programmable logic controller fully developed and designed in Mining and metallurgy institute Bor, Serbia, for monitoring and process control, mainly in copper production plants. It is based on MC68HC11 microcontroller. The paper presents a structure of executive and control program with respect to synchronization of two most important events: measuring and communication. The results of practical implementation are also included.

Development of the new technologies in telecommunications, electronics and electrical engineering... more Development of the new technologies in telecommunications, electronics and electrical engineering is a very dynamic process. It creates the need of constantly improving teaching programs in the field of electrical engineering. That includes exercise-related items like the use of computers and microcontrollers in automatic control systems. Accordingly, the presented examples of laboratory exercises can significantly contribute to better understanding of the planned curriculums.

2013 36th International Convention on Information and Communication Technology, Electronics and Microelectronics (MIPRO), 2013

This paper presents a historical overview of development and application of a distributed system ... more This paper presents a historical overview of development and application of a distributed system for monitoring and control of electrical energy consumption in the Copper Mining and Smelting Complex Bor (RTB), which is one of the greatest consumers of electrical energy in the Republic of Serbia. Realization of the real time monitoring and control system started in early 1990s. The main characteristics and performances of three generations of the system are described in this paper.

The paper describes a practical way of design and realization one simple real time software, bett... more The paper describes a practical way of design and realization one simple real time software, better say: executive system. It is applied on an own programmable logic controller - microprocessor measuring station (MMS). In hardware point of view it is a modular unit based on M68HC11 microcontroller. All its functions are driven and controlled by a special real time working

Electronics and Electrical Engineering, 2012

… Proceedings of the …, 2011

Monitoring and management of technological processes in the complex production units requires int... more Monitoring and management of technological processes in the complex production units requires interaction with the process. Timely transfer of information about the actual state of the process to the point of interaction is a key feature of any supervisory system. ...