automatica
M. Hadjiski, N. Deliiski, N. Tumbarkova. Latent Heat of Fluids during their Phase Changes in Capillary Porous Materials

Кey Words: Latent heat; fluids; crystallization; melting; vaporization; liquefaction; free water; bound water.

Abstract. Some basic characteristics and terms of the latent heat of solidification, fusion, vaporization, and liquefaction of the substances are being considered in this work. The processes of crystallization and vaporization of the substances have been described and analyzed. Theoretical foundations of the solidification and vaporization processes of the substances are in short given. Using data from the specialized literature, approaches for the calculation of the specific latent heat of fusion and vaporization of both the free and the bound water in capillary porous materials has been presented. The information about the specific latent heat of the water in mentioned materials is needed for scientifically based computing the non-stationary temperature distribution and energy consumption during their freezing, defrosting, drying, and model based control.

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automatica
D. Slavov. Mobile Robot Control Using Machine Vision Smart Camera

Key Words: Mobile robot; automatic control; computer vision; machine vision; Arduino; Pixy; line tracking.

Abstract. This paper presents ways to control a mobile robot system for two different tasks: line tracking; and finding and passing through an opening in a vertical plane. The system is constructed of a threewheel platform, Arduino microcontroller and a smart camera Pixy2 for machine vision. For the line tracking task, based on the x and y coordinates at both ends of the visible line, measured by the camera, vector gradient is calculated and weight factors are adaptively determined for generating a two-component error fed to a PID controller. The feedback control successfully drives the robot over the line even in the presence of sharp turns. For the hole-passing task, the robot locates a color-illuminated opening in a vertical plane, moves frontally and passes through it. The system finds the frontal position by repeatedly measuring the opening width while maneuvering straight and diagonally towards it. Both tasks are successfully implemented despite the variable ambient lightning conditions.

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automatica
K. Arabadzhiev. Cask Ale Brewery Control System

Key Words: Cask Ale Brewery; control; automation; Siemens control system.

Abstract. This article is about an automated Cask Ale Brewery Control System. Technical solution of controlling whole plant using Siemens S7-400, The standards and good automation practices of Briggs of Burton are applied. The document also defines how the control system will be structured to meet the User Requirements.

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informatics
B. Toskov, A. Toskova. Multi-agent Sensor Network

Key Words: JADEX intelligent agents; BDI architecture; MQTT communication; Internet of Things; WiFi sensor network.

Abstract. This publication presents an experimental model of the architecture of an intelligent guard system developed on the concept of IoT. The Guard System is part of the cyber-physical space of the Faculty of Mathematics and Informatics at Plovdiv University. This model is built with JADEX intelligent agents and hardware sensors working on WiFi sensor network.

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informatics
V. Hadjiev, A. Rashidov. Overview and Analysis of Methods and Models for Data Structuring, Storage and Processing in the Internet

Key Words: Data-storage; Data-processing; Data-warehouse; Internet models; SWOT analysis; Cloud Database.

Abstract. This paper aims to review and analyze known models and methods for data structuring, storing and processing in the Internet. A SWOT analysis has been made to look at the strengths and weaknesses of known models.

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informatics
A. Panayotov, P. Ruskov. Implementing Cryptocurrency in Car Renting via Blockchain Protocol

Key Words: Cryptocurrency; blockchain; smart contract; protocol; car renting.

Abstract. Car renting is spreading, while cars are increasingly smart and connected allowing autonomous behavior like self-driving, self-parking, etc. The process of renting, however, is usually cumbersome, involves transfer of sensitive data, is not entirely digital, is heavily regulated and involves different parties directly or indirectly. Therefore, the security, validity and traceability of the data involved is of vital importance. In this paper the authors discuss the blockchain opportunity to innovate the car renting business and present a model where the process is digitalized, simplified and data authenticity and security are guaranteed by using blockchain protocols, smart contracts and cryptocurrency.

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achievements and applications
D. Hristov, G. Georgiev, A. Stoyanova-Doycheva. Academic Pubication System

Key Words: Virtual Physical Space; digital library; institutional repository; publication system.

Abstract. This article describes and analyzes the problems and tasks associated with the storage and processing of data in the Virtual Physical Space (ViPS), a scientific project of the University of Plovdiv Paisii Hilendarski. Existing storage platforms, in particular DSpace – an institutional repository application, and the possibilities of their application are being explored, not only as a publication tool, but also in a way that allows the integration of a digital library in ViPS and its interaction with the other components of the virtual space. A functional intelligent Web-based academic publication system is presented, created by implementing DSpace REST API, a programmatic interface to DSpace communities, collections, items, and bitstreams and by using the BDI (belief-desire-intention) software model for its agent part.

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automatica
S. Yordanov, K. Ormandzhiev, G. Mihalev. Some Possibilities for Robust Control of a Double-Operating Water Turbine

Key Words: Robust control; cross-flow water turbine; H∞-norm; system uncertainty; load disturbance.

Abstract. A mathematical model describing the operation of the cross-flow water turbine has been developed in this paper. A robust governor has been synthesized using H∞ techniques to replace the conventional governor of the water turbine . The transient processes in the system are compared to the processes where the classical PID controller is used. The simulations are carried out using MATLAB and the results show that the overall system output performance can be improved using the proposed H∞ robust governor.

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informatics
V. Hadjiev, A. Rashidov. Overview and Analysis of Architectures for Data Structuring, Storage and Processing in the Cloud

Key Words: Data-storage; data-architectures; data-processing; data-warehouse; SWOT analysis; cloud architectures.

Abstract. This paper aims to review known architectures with application in data structuring, storage and processing. Concepts of architectures used in the construction of data warehouses have been discussed. A comparative analysis has been made, to look at the advantages and disadvantages of these architectures.

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intelligent systems
R. Trifonov, G. Pavlova, G. Tsochev. Problems of Collaborative Work of Humans and Robots

Key Words: Collaborative work; humans and robots; standards; risk management.

Abstract. Robots are a huge part of all human activities. In the industry is proven that collaborative work of humans and robots is more effective, than the production technologies without humans. This, in turn, a new range of problems was created, both in terms of productivity and in safe collaboration, especially for people. The present work sets out to solve the most essential problems for ensuring conflict-free operation while guaranteeing high performance and quality of the functional tasks performed.

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intelligent systems
S. Stankov. Finding Dangerous Objects with the Help of Artificial Neural Networks

Key Words: Deep Neural Networks; R-CNN; object detection; classification; Safety system.

Abstract. Current paper presents an application of Deep Neural Networks in the field of detecting dangerous objects and violence in different areas. Using machine vision, combined with Deep Neural Networks makes possible to improve the safety of citizens in different areas such as the mall, local store and others where guards cannot act fast enough in case of a danger situation.

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intelligent systems
A. Toskova. Model of Recommended System in Intelligent Game-Based Learning Platform

Key Words: Content recommendation; gamе-based learning; special educational needs; personalized learning; machine learning.

Abstract. This article presents an approach for creating a content recommendation model in a gamе-based learning platform designed for students with special educational needs. Various referral systems and existing opportunities for intelligent delivery of personalized learning content tailored to the individual needs of children are addressed.

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achievements and applications
D. Nikolov, M. Lazarova. Metaheuristics for Optimization in Resource Planning and Business Process Management

Key Words: Enterprise resource planning; business process management; optimization; job shop scheduling; metaheuristics; machine learning.

Abstract. The paper presents a metaheuristics based framework for resource planning optimization and business project management. Possibilities for utilization of metaheuristic algorithms are presented in view of solving job shop scheduling problem for resource planning in ERP. A general framework for resource planning and business process management is suggested that utilizes several metaheuristics approaches. The proposed framework allows integration in ERP based on development of an optimization agent in multiagent framework.

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achievements and applications
R. Draganov, K. Haralampiev, P. Ruskov. Blockchain Service Control Platform in Smart Hotel

Key Words: Innovation; tourism; smart enterprise; blockchain; JEL Classification: Z32.

Abstract. Smart blockchain services control platform in the smart hotel is applied to enable optimal control of the services provided in the tourist enterprises by reducing the cost of business transactions and increase the trust among participants in the process, by using intelligent devices and equipment, the Internet of Things (IoT), and blockchains. The paper is focused on a useful model for IoT-enabled telematic devices in a smart hotel via a blockchain-based smart contract. At the tourist site, smart sensors and devices are mounted on the various devices and technological blocks in an intelligent platform providing an efficient economy for tourist services. The purpose of the utility model is based on the principle of the intelligent blockchain system for the implementation of secure and certified provision and payments of services in a tourist complex, without relying on a third party, trusted or not, through the introduction of blockchain platform for the execution of the service and payment.

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automatica
V. Dimitrov, L. Popov. Method of Fully Operational Identification of Slow-Response Objects with Variable Parameters

Key Words: Aperiodic unit; time constant; transmission coefficient; parallel correction.

Abstract. A method for full operational identification of objects or units approximated to an aperiodic unit of the first order where electromagnetic inertia or time-delay are negligible. These are low-power electromechanical systems and small chamber furnaces. The method identifies the time constant T and the transmit coefficient k on the object. Robust control of a first-inertia object is developed – a small electric furnace with forced cooling, for which a predetermined transition process of cooling the material has to be provided. The corresponding parallel correction scheme is implemented, which turns the object into a deinterleaving tracking system.

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automatica
Е. Dimitrovа. GPS Dispatch System for Monitoring and Control in Automobile Transport

Кey Words: Dispatching system; GPS; navigation; transport vehicles.

Abstract. A GPS dispatching system for monitoring and managing of transport vehicles has been developed. It is reliable, easy to use, offers a wide range of features that can be used to optimize financial costs. It increases the productivity and efficiency of work, reduces fuel costs and eliminates abuses. It is available in different variants depending on the investments available. Varied modules can be added and security, navigation and driver monitoring can be ensured.

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automatica
V. Hristov, S. Petrov. Solar Tracking System by Microcontroller Arduino

Key Words: DC motor; solar tracking system; Arduino; photoresistor.

Abstract. This article presents the development of a two-axis platform for laboratory-based solar tracking system. The platform has the ability to rotate on the horizontal and vertical surfaces by two direct current motor. The use of an open source Arduino microcontroller makes it convenient to experiment with a variety of platform control algorithms and maximize performance. Its compact size makes it mobile to experiment with in different work environments. An algorithm is used to monitor the illumination of four photo resistors located on a cross.

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automatica
S. Lekova, D. Gocheva. Statistical Analysis of Measurement Data

Key Words: Statistical analysis of data; linear and rank correlation; analysis of variance.

Abstract. Good laboratory practice requires laboratories to ensure the quality of analyzes and assess the extent of human exposure to different chemicals and reagents. The subject of research and analysis are data from measurement of samples between two laboratories, by two different methods, in the processing of ore in the Ellatzite-Med AD Mine Complex. Of particular importance is the reliable measurement of the products (concentrations) from the flotation process (content of copper in the ore, intermediate products, concentrate and waste) as well as the production of molybdenum (feed, concentrate and waste). As a result of the sampling and depending on the characteristic to be determined and the test method, the concentration of the identifiable element is measured differently and with different technical means. The statistical analysis of data of parallel measurements from two or three laboratories involves calculating a linear or rank correlation and analyzing how significant the influence of a laboratory factor is, as well as studying and modeling the relationship between the presence of chemical elements in the ore, waste and concentrate in the process of laboratory control.

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