Категория: АВТОМАТИКА И ИНФОРМАТИКА 1-2, 2021 г.

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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Кey Words: Case-Base Reasoning (CBR); mathematical modeling; operational conditions; scheduling; suboptimal control; Thermal Treatment Process (TTP).

Abstract. An intelligent system for control of the thermal treatment process (TTP) of wood materials addressed toward manufacturing with necessity of often rescheduling is proposed via combination of model-based and data-driven approaches. Using First-principle mathematical model of TTP presented by Partial Differential Equations in 2D space with suboptimal model-based control algorithm and Case-Based Reasoning (CBR) approach an explicit suboptimal control system is investigated in different operational conditions. A set of virtual subspaces for feasible operational situations for variety of objective criteria of value assessment is created using traditional problem-decision representation. As the search spaces are well structured, the search procedure based on traditional K–NN algorithm is strongly simplified. In this way the complicated computer simulation of the TTP at each time step due to the plant’s parameter distribution, nonlinearity and operational or environmental disturbances are fulfilled off-line. On-line are accomplished relatively small part of the calculations connected with the traditional R4–operations in CBR, objective functions estimation, some databased and rule-based control parameter corrections and possible adaptation from charge to charge. Some results of the simulation experiments are presented and analyzed.

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Key Words: Information theory; entropy; hierarchy; energy mix; renewable energies.

Abstract. The dynamics of development and distribution of resources are key questions for characterizing the complexity of systems in a large number of areas. Traditionally, the natural sciences (physics, chemistry, computer science, telecommunications, and others) have used Shannon’s information theory and the concept of entropy to assess diversity, uncertainty, and chaos. Social sciences (economics, competition law, etc.) prefer to consider these issues from the opposite point of view – the concentration of resources, reflecting the dominance and hierarchy in competition interactions. Energy systems are a typical example of complex and dynamic systems and their study is of particular interest in theoretical and practical terms. Becoming the engine of innovation in energy technologies, renewable energy sources play an important role in the evolution and dynamics of energy balances at the international, national and local levels. The article presents the possibilities of the original method developed by the author for estimating the hierarchy of information, its advantages in comparison with the traditional methods of Shannon’s entropy and Herfindahl concentration and its application for improving the analysis of energy balances and the role of renewable energy sources.

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Key Words: Internet of Things; data transmission; communication protocols; big data.

Abstract. Communication models and protocols in Internet of Things (IoT) are relatively new field of research and use due to the fact, that connecting objects by digital means in Internet has occurred only in the last decade. However, the rapid grow of applications of this paradigm in almost all areas of human activity has led to enormous volume of data generated from all kind of sources (things) and transmitted all over the global digital network. This, in turn, has led to the creation of new models and protocols for data transmission in IoT. The paper gives an overview of the main approaches / models for communication in IoT. The requirement for scalability and simplicity is amongst the most important when IoT and Big data are involved. Four models are presented – the Push, Request/Response, Subscribe/Notify and Publish/Subscribe. A classification and layered approach is made for protocols used in IoT. Three of the most widely used for data transmission in IoT are taken for further investigation – MQTT, CoAP and AMQP. They are compared in terms of bandwidth, overhead, size of transmitted data, reliability and security. Then are compared with HTTP, which is well known and widely used on the Internet. The conclusions are that the most popular model for IoT and Big data communication is the Publish/Subscribe one, whether in regard to the use and recommendation for data protocol, one cannot point a clear leader at present (unlike the protocols in the TCP/IP stack for Internet), so there is the tendency that for the time being, different data protocols will be used in different IoT and Big data applications.

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Key Words: G Code; vectorization; colors reduction; plotting.

Abstract. G Code instructions are used for CNC machines. In order, such machines to produce objects or drawings visual information should be vectorized. Transformation of full-color image to set of 16 colors is achieved by color reduction algorithm. Pixels in the image are replaced with simple shapes (strokes) in such a way that these simple graphic primitives to be drawn by CNC driven 2D plotter. Each stroke should be drawn by a single loading of oil paint. This goal cannot be achieved by standard G Code generation and this research.

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Key Words: Particulate matter PM10 and PM2.5; sensors for РМ; temperature and light; Arduino Nano 3.0.

Abstract. Air pollution causes damage to human health and ecosystems. Large parts of the population do not live in a healthy environment in accordance with current standards. Today, almost every city has problems with particulate matter concentration, especially in time of temperature inversions. This article introduces an automated system for monitoring and analyzing fine particulates in ambient air, temperature and light. It can be used in the workplace, at home, and in particular in student classrooms and laboratories, not only for monitoring, but also for training and refinement involving students, in various disciplines or informal аactivities.

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Кеу Words: Cybersecurity; OPC-UA applications; security; formal verification; information modeling; timed automata models; temporal logic.

Abstract. Cybersecurity protect the confidentiality, integrity and availability of computing devices and networks, hardware and software, and most importantly, data and information. The main aim of the paper is to analyze the capabilities and to propose an approach for increasing the security of OPC-UA applications based on the use of formal verification, and its integration into the development lifecycle model and information modeling capabilities provided by OPC-UA. The formal verification is based on using model checking based on timed automata models of the system and cybersecurity properties, defined by using temporal logic.

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На 18 и 19 юни 2021 г. се състоя двадесет и второто издание на Международната научна конференция CompSysTech’21.
Международната конференция CompSysTech’21 се организира от българската Академична общност по компютърни системи и информационни технологии (АОКСИТ) и нейната цел е да засили информационния обмен на резултати в теоретичните изследвания и практическите разработки в областта.

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