The increasing complexity of modern manufacturing systems requires companies to design and develop a contemporary framework with high degree of accuracy and speed. The demand for precise and fast equipment in wood processing and other industries is topical within modern progress of Machine Learning, more powerful computing systems and approaches. To meet this challenge and to be in pace with...
Abstract: Aeration is a key support operation in agriculture, ecology and the balance of substances in the soil. It provides oxygen for the normal course of biological processes and in the absence of conditions for the development of plants and microorganisms deteriorate, soil compaction or stagnation of water can occur.
This article is related to the process of designing and developing a...
This paper presents the steps and the possibility realization a "Brute force" reduced attack implementation on 256_AES encrypted voice stream in a MATLAB Simulink environment. The research focus is selecting the correct decrypted ciphertext from many candidates. Possible selection hypoteses leading to the interpretation of the transmitted information are considered.
Abstract: This article analyses the results of a scientific and practical study regarding the security of monastic complexes — designated as immovable cultural property in Bulgaria — utilizing a field-tested methodology for fire risk assessment. First, it outlines the core elements of the fire protection management system for cultural assets. Second, the article presents a comprehensive risk...
The increasing digitalization of the judicial sector requires the implementation of complex information systems that ensure high levels of information security, especially when processing sensitive and classified data. However, the application of security requirements in such environments is often fragmented due to the complexity of regulatory frameworks and the lack of structured approaches...
This report presents an integrated conceptual model for risk management, adapted to the specifics of hybrid threats and cognitive warfare. In the conditions of a changed strategic environment, where the objects of attack are not only physical assets, but also human consciousness and social cohesion, traditional risk assessment models prove to be insufficient. The report analyzes the essence of...
The growing diversity of unmanned aircraft systems (UAS) in the recent conflicts has challenged the allocation of reusable and One-way Attack (OWA) unmanned platforms for specific air mission. This paper proposes a cost-oriented decision-making framework supporting automated mission planning under operational uncertainty. The approach formalizes the relationship between mission effectiveness,...
The increasing prevalence of distributed software development has intensified the
need for robust models that explain and predict collaboration performance in virtual
IT teams. This paper proposes a theoretical framework for AI-driven prediction of
collaboration efficiency, integrating concepts from software engineering,
organizational behavior, and machine learning. The model...
With the increasing use of cloud services in critical industrial and public systems, reliability assessment has become an important research and engineering challenge. Traditional approaches such as probabilistic models and Fault Tree Analysis (FTA) provide a solid analytical basis, but they are often limited in representing the dynamics and interdependencies of modern cloud infrastructures....
This study presents a hybrid approach that integrates probabilistic modeling and Failure Mode and Effects Analysis (FMEA) for the analysis and optimization of reliability and fault tolerance in AI-driven integrated security systems. With the increasing complexity of modern intelligent systems—incorporating video analytics, Internet of Digital Things (IoDT) sensors, autonomous drones, and...
Automated assembly of cylindrical joints is widely used in various sectors of the machine-building industry. The assembly operation can be performed by carrying out a series of technological steps. Vibrations of the assembly equipment, manufacturing errors in the parts, and positioning inaccuracies are the main causes of errors and failures during the joining of parts. The creation of...
Abstract: This article is part of a series describing the capability-based defense planning model as the main methodology for conducting Strategic Defense Reviews in the Republic of Bulgaria. The proposed prototype follows a sequence of abstract steps for conducting Strategic Defense Reviews to achieve the goal of ensuring adequate defense capabilities for the armed forces. The article focuses...
The transition towards sustainable logistics systems, driven by the European Green
Deal, necessitates the development of standardized performance evaluation
frameworks. This study proposes a comprehensive Key Performance Indicator
(KPI) framework for assessing the environmental, economic, and operational
performance of logistics networks in Bulgaria. The framework integrates...
This paper presents a Vienna-focused conceptual framework for urban microclimate analysis in smart sustainable city design. The study is based on a targeted review of microclimate monitoring approaches, GIS-based morphology indicators, and simulation workflows, which is used to identify recurring limitations and translate them into a multi-layer structure. This framework models how...
This scientific article proposes a modern mathematical algorithm designed to improve workflow and enhance the efficiency of reliability assessment in computer networks. The primary objective of the research is to develop an advanced method for predicting and analyzing potential failures in complex computer environments. The proposed algorithm incorporates contemporary modeling approaches,...
Digital technologies create conveniences for work and interaction of the human factors in an online
environment, but at the same time, problems arise when using them. The integration of digital technologies into
the business practice of high-tech enterprises is a natural process through which the human factors communicates
and creates business content. Since a large part of communication...
This paper presents a structured analysis of aviation technical terminology with a focus on its role in safety-critical communication within air force and aerospace engineering environments. Standardized terminology is a key component of reliable technical documentation, maintenance operations, and cross-disciplinary coordination, directly affecting operational safety and system...
Artificial intelligence has become part of daily life in universities, for both students and educators. However, despite the fact that we all understand that AI is shaping and changing the education paradigm, the question of how often and for what we use AI remains on the agenda. Yes, AI has made many daily tasks easier; however, are students using AI for tasks they could solve without it? The...
The use of Artificial Intelligence (AI) has become an inseparable part of the software development process, parts of which are routine, requiring precision rather than creativity. AI code generation speeds up productivity by automatically completing code fragments and frees up time and brainpower to perform more tasks that require creativity or problem-solving. When writing code, the...
The report explores the possibilities for applying artificial intelligence in EU funds management information systems, interpreting them through the prism of algorithmic management. The main thesis is that the implementation of AI leads to a qualitative transformation from administrative and expert-based management to automated management solutions based on data and algorithms. On this basis,...
The use of Artificial Intelligence (AI) has become an inseparable part of the software development process, parts of which are routine, requiring precision rather than creativity. AI code generation speeds up productivity by automatically completing code fragments and frees up time and brainpower to perform more tasks that require creativity or problem-solving. When writing code, the...
This paper presents a system-oriented experimental study on AI-enabled multi-sensor fusion for field detection of chemical warfare agents. The proposed framework integrates ion mobility spectrometry (IMS), portable Raman spectroscopy, and electrochemical sensing through feature-level fusion and interpretable machine learning. Its contribution is twofold: first, it formulates a practical fusion...
Man-in-the-Middle (MitM) attacks remain a significant threat to local area networks, particularly when implemented through Address Resolution Protocol (ARP) spoofing. Although infrastructure-level protection mechanisms such as Dynamic ARP Inspection (DAI) are effective against conventional ARP poisoning attempts, their detection capability is limited in low-rate and insider-like scenarios,...
In the context of digitalization of production and the development of the Industry 4.0 concept, the optimization of production processes and the effective organization of production areas are gaining increasing importance. An essential task in the design of production systems is the optimal placement of the technological equipment in order to minimize the material flows, reduce transport...
The focus of this report is on exploring the relationship between algorithmic management and the specifics of high-growth firms, emphasizing the mechanisms through which data and algorithms support the achievement of accelerated organizational development. The analysis examines the role of artificial intelligence in decision-making processes, resource optimization, and adaptation to a dynamic...
The focus of this report is on exploring the relationship between algorithmic management and the specifics of high-growth firms, emphasizing the mechanisms through which data and algorithms support the achievement of accelerated organizational development. The analysis examines the role of artificial intelligence in decision-making processes, resource optimization, and adaptation to a dynamic...
Abstract. This review article aims to systematize and critically examine recent developments in aluminium alloys and their applications in the aerospace industry. Particular emphasis is placed on the principal classes of aluminium alloys used in aeronautical and space engineering, with attention to their chemical composition, microstructural features, processing routes, and resulting...
This paper presents an adaptive Kalman filter for video-based object tracking, in which the covariance matrices of the process and measurement noise are dynamically updated in real time. The proposed approach is based on a linear stochastic model without introducing a control input, which is justified by the nature of video observation, where only measurement information from consecutive...
This paper presents an experimental investigation into the frequency response of an electro-pneumatic positioning system, which includes a rodless pneumatic cylinder and four 2/2-way high speed pneumatic valves operated via pulse width modulation. The experimental procedures are captured and analyzed in real-time using a dedicated virtual instrument.The amplitude and phase Bode plots for the...
This report examines the security of energy infrastructure as a complex system requiring integrated management of different types of risks. The main vulnerabilities related to technological, cyber, and organizational factors are analyzed. Emphasis is placed on the need to enhance cyber resilience and the reliability of critical systems. Contemporary approaches to risk management under...
Abstract: Forensic photography is performed in uncontrolled environments where photographic and other devices are exposed to both direct impacts (blood and body fluids, dust/soot, chemical residues, water, mechanical impacts) and indirect risks, turning the equipment into a reservoir and a means of transferring traces and contamination between objects, different areas and subsequent...
This paper presents the development of an integrated simulation model for maritime cybersecurity training, based on a comparative analysis of existing training platforms. For the purposes of the study, leading international and industrial solutions were evaluated, including Cyber-SHIP Lab, Naval Cyber Range, CDeX Maritime Cybersecurity Scenario, SeaSAFER, K-Sim, and NavSim. Through the applied...
The introduction of models for analyzing the impact of script-based algorithms in web applications on overall CPU load is becoming increasingly important in modern computing environments. However, there is a limited availability of specialized analytical tools and models addressing this problem.
In response to this gap, a model has been developed to evaluate CPU load based on key scalar...
The choice of fixtures, the type of clamping, and the clamping force are key criteria for minimizing adverse effects that lead to a deterioration in the geometric characteristics of the machined surfaces. This article examines the accuracy of cylindrical and conical surfaces under different clamping schemes—in a chuck (three-jaw self-centering) and between a chuck and a center.
The accuracy...
This study presents a methodology for analyzing vehicle braking deceleration and the efficiency of braking systems. Using measured skid marks and the physical characteristics of the road surface, the actual deceleration and the efficiency coefficient are determined. MATLAB-based interactive and 3D visualizations enable dynamic evaluation across different speeds and braking distances. The...
In recent years, low-voltage networks have become particularly attractive. More and more small-capacity solar power plants are joining them. The motivation that owners receive is a combination of the affordable price of the systems, a simplified procedure for obtaining a design and construction permit. The creation of energy independence is also not in last place.
Despite their local impact,...
Cam mechanism are crucial for driving different types of drive trains. From simple mechanisms to metal cutting machines, combustion engines, filling machines and many other. Because many old machines do exist, and use such mechanism, a algorithm is proposed so that the position function can be obtain from a existing profile. Also a optimization is carried out so that the kinematics of the...
Abstract – The purpose of this study was to examine how the implementation of Industry 5.0 principles influenced the financial performance, economic indicators and innovation activity of Bulgarian industrial enterprises in 2021-2025. The methodology combined theoretical generalization of the Industry 5.0 concept, analysis of accounting approaches to innovation costs, and empirical examination...
This paper presents a structured analysis of existing software and organizational solutions that support innovation management in industrial enterprises within the context of Industry 4.0. The increasing digitalization of manufacturing systems, integration of cyber-physical technologies, and data-driven decision-making processes have significantly transformed how innovation activities are...
The paper presents an approach to detection, classification
and decision making for disaster relief scenarios, based on imaging
data, pose estimations, depth perception and scene understanding, utilizing AI while performing on low power hardware.
Air pollution is the presence of harmful substances in the atmosphere that can adversely impact human health and other living organisms. In urban environments such as Berlin, air pollution—particularly from traffic emissions and industrial activities—continues to be a significant concern. The Air Quality Index (AQI) is commonly used to represent the level of air quality in a given area, based...
Depopulated regions exert a direct, profound, and multidimensional negative impact on national security. Reducing such “demographic deserts” through their revitalization and resettlement requires governments to implement a complex set of measures that demand substantial resource investment. This report demonstrates how graph theory can be applied to analyze the demographic connectivity of...
Abstract – This report examines the potential of hybrid technologies that combine dielectric barrier discharge (DBD) plasma treatment and sol-gel nanocomposite coatings to enhance the functional performance of military textile materials. The study focuses on blended cotton/polyester (CO/PES) fabrics, which exhibit favorable performance characteristics but remain highly susceptible to thermal...
Abstract: The application of machine learning methods in the identification of various plant species aims to automate and increase the accuracy of classification processes. The main approaches in the field are presented, including the use of deep learning algorithms, such as convolutional neural networks (CNN), for processing and analyzing plant images.
The process of data collection and...
This paper examines a possible application of the Monte Carlo Method for the approximate estimation of the number of people subject to evacuation during disaster situations related to flooding in populated areas. The crisis scenarios are simulated using software that reproduces river overflows resulting from controlled dam releases or dam wall failures, as well as from prolonged and intense...
This article examines the applicability of the criminological “broken windows” theory in the context of military organizational behavior and the maintenance of military discipline. It analyzes the conceptual relationship between this theory and the phenomenon of the “normalization of deviance,” substantiating their complementarity in explaining the processes of disciplinary erosion within...
The paper examines the integration of steganography and machine learning for intelligent management of hidden information in the context of future communication systems. The emphasis is on methods for increasing resilience against attacks, dynamic optimization of hiding capacity, and adaptive detection of steganographic threats. The increasing complexity of 6G architectures, which include...
With the development of information technology, the process of project management in different areas of the economy has changed. Very often, new approaches use combinations of familiar, established project management methods to respond to .
This article examines an approach to project management using a combination of the PERT method and evolutionary algorithms. The goal is to improve the...
The aim of this article is to present an approach for preventing service overload in Elastic Compute Cloud (EC2) within Amazon Web Services (AWS). The study analyzes methods for preventing overload of virtual machines in AWS EC2 by comparing vertical and horizontal scaling. Developed block diagrams are presented to visually illustrate the architecture and processes involved in dynamic resource...
This paper discusses mathematical and simulation models that could be applied to shopping mall evacuation problems. The so-called macroscopic approaches are based on dynamic network flow models. The maximum dynamic flow problem and the quickest flow problem are formulated. The so-called microscopic approaches are based on simulation modelling through multi-agent systems. The possibilities for...
Considering that artificial intelligence (AI) is the computer technology that has seen the most explosive growth in recent years, we try to explore its application in the context of the concept of sustainable development, and our focus is on the possibilities of artificial intelligence to stimulate the development of renewable energy sources. This is dictated by the interconnectedness and...
Artificial intelligence reached thesis writing before universities had fully agreed on how it should be used. This paper looks at what students actually did with AI when preparing professional bachelor theses in one Lithuanian higher education institution. It compares two post-defence cohorts, from 2024 and 2025, and draws on 258 survey responses from a target population of 399 students. The...
The rapid advancement of artificial intelligence (AI) is reshaping the landscape of defense diplomacy and international security. In an environment characterized by hybrid threats, strategic competition, and accelerated decision-making cycles, AI technologies—particularly large language models (LLMs) and predictive analytics—offer enhanced capabilities for real-time intelligence processing,...
The aim of the paper is to analyze the impact of AI implementation on logistics performance and to develop an action framework that can be used to measure the improved efficiency achieved with AI in an environment of scarce available data. This paper examines the use of AI in the logistics sector in Bulgaria. The study assesses revenue distribution and market concentration to determine when...
The EU Digital Identity Wallet marks a pivotal evolution in Europe’s approach to identity management, embedding security by design into a system that will serve more than 400 million citizens under the eIDAS 2.0 framework. By 2026, all Member States must deploy a certified wallet capable of storing and using government‑issued digital credentials, a response to rising identity theft and...
The report presents an analysis of leading international cybersecurity standards and frameworks to assess their applicability in building a cyber incident response model at the political, strategic, operational and tactical levels. The emphasis is on examining the vertical and horizontal connections between the individual levels and standards, as well as on identifying the opportunities and...
Abstract. Weeds compete with crops for essential resources such as water, nutrients, light, and space, which significantly lowers both yield and quality, thereby reducing farmers' income and posing a major challenge in agricultural systems worldwide. Field experiments were carried out from 2022 to 2024 at the “Pluģi” farm, located in the Zemgale region of Latvia (GPS coordinates:...
Artificial Intelligence (AI) is entering all spheres of society and business, creating conditions for changing the way we work and perform operations. Along with industrial sectors, AI has enormous potential
for application in medicine, as a means of diagnosing diseases of the human body, medical research and working with document flow. As an emerging technology in healthcare, AI creates...
Modern enterprise infrastructures combine directory services, server operating systems, and database platforms, which significantly expand the attack surface and complicate security assessment. Manual reviews are often time-consuming, inconsistent, and difficult to reproduce across different environments. This paper presents an academic framework for automated vulnerability assessment in...
The automation of loading and unloading operations for CNC vertical milling centres has become increasingly important due to rising production costs, labour shortages, and the pursuit of higher productivity and efficiency. This paper investigates the challenges associated with automating these processes, particularly focusing on optimising workspace utilization, reducing auxiliary times, and...
This paper presents a Bayesian method for recursive fusion of prior and measurement information aimed at improving accuracy in video-based measurements. The approach is based on a probabilistic formulation of the estimation problem, where measurements are modeled as random variables with additive noise, and the system state is described by a prior distribution.
By applying a recursive...
The article focuses on conducting a benchmarking study to identify and analyze good practices for integrating artificial intelligence into strategic management at the company level. By comparing and evaluating effective models, tools, and approaches, key success factors, benefits, and risks in implementing AI in strategic planning processes, making informed management decisions, and achieving...
The constantly changing geostrategic security environment leads to the emergence of new geostrategic projects that have a strong impact on the Balkan Peninsula region.
It should be noted that Bulgaria and its National Security System are highly vulnerable to any project. Some of them seem regional at first glance, but nevertheless have a global impact, while others are global, but have a...
This study analyzes the critical interaction between centralized nuclear power capacities and emerging decentralized energy communities within the context of the full liberalization of the Bulgarian energy market by 2026. The primary focus is directed toward the regulatory dichotomy between the Energy Act (EA), which ensures systemic security through base-load capacities, and the Energy from...
The modern military education system is constantly faced with challenges provoked by the dynamics and diversity of modern threats, their speed of development and the scale of their consequences. Military leaders strive to respond to innovations by implementing technologies in various weapons systems, as well as by updating the content in the training of military personnel and experts in...
This report analyzes the key factors that hinder the development of autonomous energy microgrids in modern energy systems. The technological, economic, and regulatory aspects of their implementation are examined. Emphasis is placed on the role of decentralized energy solutions in enhancing the resilience and flexibility of energy systems. The possibilities for integrating renewable energy into...
Global climate change has become the primary driver behind the emergence of new biological hazards. In Bulgaria, the convergence of rising mean temperatures, shifting precipitation patterns, and the rapidly warming of the Black Sea basin is creating an ideal environment for non-native and dormant pathogens. As climate change alters the microbial landscape, there is a growing risk of outbreaks...
Climate change, along with political persecution, military conflicts, and poor socio-economic conditions, is one of the key drivers of forced migration. This issue has become increasingly relevant, especially in light of rising global temperatures, storms, droughts, sea-level rise, and resource depletion. However, international law currently offers limited protection for climate-displaced...
Increased competition in the international wood export markets, is vitally important for European wood processing companies. To ensure further competitive advantages digitalisation of wood processes is one of the contemporary strategies to ensure higher efficiency (reducing losses of useful material and improving quality), but also increasing productivity in order to reduce manual labour costs...
The ever growing threat of hostile and unauthorized drones drives the need for counter-action, starting with early detection and reaction. The low cost and availability of small and low flying drones increases both their extensive use in warfare and the accidents with them in civilian settings. Efficient and adequate counteraction requires a detailed study of the threat and a retrospective...
Colorizing monochromatic images is crucial for enhancing the informativeness of visual data in modern information technology and computer vision systems. However, automatic colorization poses an inherently ill-posed mathematical challenge due to the multimodal nature of color distributions, where multiple valid color mappings exist for any given grayscale input. This article conducts a...
This study presents a comparative investigation of the efficiency characteristics of a compression ignition engine operating in dual-fuel mode with methane (CNG) and hydrogen (H₂) as supplementary fuels. The research focuses on evaluating the variation in effective thermal efficiency when conventional diesel fuel is partially substituted by gaseous fuels under comparable operating...
Forecasting electricity consumption in industrial enterprises is essential for cost minimization and effective participation in balancing markets, particularly in the context of continuous production processes. The liberalization of energy markets and the increasing share of renewable energy sources further complicate the planning of electricity demand. This study aims to perform a comparative...
This study focuses on the dynamics of motivational factors for service in the Bulgarian Armed Forces. It aims to guide management policies toward enhancing motivation and retention of personnel within the context of a constantly changing security environment.
The analysis is based on a cross-sectional study of two independent representative samples of military personnel. Each of them...
Abstract: Laser hardening of steels is a modern technological process widely used in the automotive, aerospace, and tooling industries. In the present study, a comparative analysis between numerical modeling results and experimental data for the laser hardening process of 42CrMo4 steel samples is performed. Numerical calculations were used to determine preliminary operating intervals of power...
In the context of accelerated geopolitical confrontation, militarization of technology, and the “extension” of security to economic, cyber, and societal dimensions, the study of different national security strategies allows us to understand not only what states say in their strategies, but also why they say it. This is critically important for security decision-makers as it will help them...
This paper presents a mixed-methods needs analysis of Aviation English requirements for aircraft maintenance technicians operating in international and multilingual environments. The study addresses the role of precise and context-appropriate communication in maintenance, repair, and overhaul settings, where language use directly influences operational safety and reliability.
The research...
This study presents a unified theoretical framework integrating thermodynamic and radiative feedback mechanisms in the anthropogenically modified atmosphere. Building on two complementary approaches—an adiabatic-calorimetric model quantifying changes in specific heat capacity (cp) and adiabatic constant (γ) from O₂ and CO₂ mass variations, and a radiation-balance model linking albedo (ΔA) to...
In the era of rapid technological advancement, access to digital opportunities makes it possible to prepare students for the jobs of the future and have a positive influence on the development of their future-proof skills, which will be of paramount value. Amid unpredictable changes in the labor market, critical thinking skills are becoming increasingly strategic and enabling labor market...
This research described is focused on computer vision tools implemented for detection of a particular military object (or many objects) in a observed scene, given a reference image(s) of the object(s). An algorithm for detecting a specific object based on finding point correspondences between the reference and the target image is designed. It can detect objects despite a scale change or...
In this paper the problem of obtaining a complete picture of monitored military objects is resolved with computer vision tools. The research is focused on the necessity for the correctly arrangement of photos obtained in different ways to promptly obtain a comprehensive picture of the situation in an area of monitored military operation. The consecutive stages with functional operations are...
Abstract: Orthophotogrammetry is a specialized branch of photogrammetry aimed at creating accurate, scaled images. This paper aims to investigate the theoretical and applied aspects of Computer Vision algorithms in the creation of three-dimensional models of objects and terrains in order to generate high-precision geospatial products.
The article discusses the capabilities of the WebODM...
Rising electricity prices necessitate more efficient management of household electricity consumption. Home Energy Management Systems (HEMS) provide a technological foundation for such management; however, their practical effectiveness depends critically on their analytical capabilities. This study presents a comparative analysis of four representative HEMS platforms for household electricity...
The safe lifecycle management of conventional ammunition is a continuing challenge for defense organizations due to aging effects, variable storage conditions, incomplete historical records, and the need to maintain both operational readiness and safety assurance. In this context, non-destructive diagnostic data can provide a practical basis for more transparent and evidence-based lifecycle...
The concept of extended corporate social responsibility is explored in the context of increasing demands on companies to manage not only their own activities, but also the effects along the entire supply chain. The analysis focuses on the role of organizations in ensuring sustainable practices, including compliance with social and environmental standards by suppliers and partners. Special...
The modern state of law is a state of clear legal rules and justice. In such a democratic and humane state, national security is explained, regulated and protected by law as a significant social benefit. Moreover, national security is logically understood as one of the most valuable legally protected goods. National security and its protection arise directly from the law. The rule of law...
Abstract: This paper is the second in a series that describes the Model for risk management of Critical Infrastructure (CI) of the Republic of Bulgaria. The first one focuses on activities of developing rules and proposing a mathematical apparatus for identifying critical infrastructures and their assets. The present focuses on the activities for improving protection of critical...
This report analyzes the role of corporate social responsibility in the formation and development of human capital in organizations, emphasizing employee well-being as a fundamental and mandatory stage in achieving sustainable organizational development. The analysis examines contemporary approaches through which companies integrate mental health policies, work-life balance and employee...
In biology, parasitism is a form of symbiosis in which one organism—the parasite—extracts resources from another organism—the host—thereby progressively weakening its viability. When the parasitic burden exceeds a critical threshold, the host perishes, and not infrequently the parasite itself perishes as well. This biological analogy proves to be strikingly apt in the analysis of processes...
This paper presents a model for a Cyber Range platform designed for automated deployment and management of virtualized cybersecurity training infrastructures. The research focuses on reducing the time, complexity, and manual effort required to build realistic cyber exercise environments while maintaining flexibility and scalability. The proposed platform model is based on infrastructure...
One of the most effective ways to test a company’s security posture is through red team assessments and targeted penetration testing. This article defines one of the most effective approaches for determining the scope of the tests and the stages they go through.
The stages include getting to understand the potential attackers, their tactics, techniques and procedures, the modus operandi and...
The rapid integration of Intelligent Transport Systems (ITS) into urban and interurban mobility has significantly improved efficiency, safety, and automation in transport operations. Nevertheless, the extensive connectivity enabled by vehicle-to-everything (V2X) communications, Internet of Things (IoT) devices, and cloud services has also increased exposure to cyber threats. The primary...
This paper examines the DCSync attack from an adversarial perspective, focusing on its operational logic, execution techniques and implications for both offensive tradecraft and defensive detection. Rather than treating DCSync solely as a credential access technique, the study situates it within the broader context of Active Directory exploitation and privilege abuse, emphasizing its role in...
The growing use of AI in software security is reshaping how development teams evaluate vulnerabilities and prioritize security decisions during the development process. Increasingly, teams rely on AI-supported systems that generate recommendations for risk assessment and threat detection. However, the extent to which these tools influence collective decision-making within secure software...
This paper deals with the synthesis of state controller with observer for an electro hydraulic power transmission system. There is shown a method for synthesis of the state controller with observer and the realization for electrohydraulic system. The controller coefficients are obtained from preliminary defined performance definitions. The system has been modeled and step responses curves are...
The article presents the results of designing an intelligent educational platform based on the synergy of immersive virtual reality (VR) technologies and large language models (LLMs, particularly GPT-4o). It is substantiated that the use of Unity as a graphical engine, in combination with neural network architectures, enables the creation of highly relevant simulations of pedagogical...
This paper presents the design and scenario development of a simulation platform for maritime cybersecurity training. In response to the increasing digitalization of shipboard systems and the growing exposure to cyber threats, the platform provides a web-based environment that simulates a ship bridge and enables hands-on training in cyber incident response. The system supports real-time...
When configuring temporary or hastily built, field or other computer networks, it is necessary that they meet all modern standards and requirements for computer networks and for cybersecurity when connecting to the Internet. This study proposes an approach for designing, configuring and setting up a firewall for a computer network, built and configured on the basis of a Raspberry Pi...
This paper examines the technological requirements for detecting disinformation influence through the lens of marketing, information integrity, and strategic communications. The study is grounded in the assumption that the identification of disinformation influence is not only a matter of content verification, but also of understanding how narratives are designed, targeted, amplified, and...
This article presents a series of investigations aimed at determining the optimal parameters for welding and underwater cutting of ship hull steel, specifically conducted on the Scientific Research Vessel RSV 421 "St. St. Cyril and Methodius". The research regarding underwater cutting focuses on the oxy-arc method, establishing the ideal oxygen pressure, electric current intensity, and...
In recent years, in the context of digital transformation, the concept of "digital maturity" has been increasingly used. The purpose of this study is to determine the organizational level of digital maturity of organizations in the service sector in the Republic of Bulgaria, in the context of the integration of technologies based on artificial intelligence. The focus is on identifying the main...
The industrial sector is focused on efficiency of an industrial vision through automation as one of the most popular solutions as in recent decades. The main bottleneck of the process is image processing due to high speed and precision. Graphic processing units (GPUs) and Field-Programmable Gate Array (FPGAs) have been proposed for real-time detection, where tasks are now performed repeatedly...
Temperature is one of the most commonly measured quantities in science and industry. Temperature can have a significant impact on the course of various processes therefore, its accurate measurement and control is a task of particular importance for every process in everyday life, science, and industry. Precise temperature measurement is used in all fields - electronics, communications,...
This paper proposes a comprehensive methodological framework for integrating intelligent technologies into engineering innovation management processes. In the context of rapid digital transformation, organizations increasingly rely on artificial intelligence (AI), machine learning (ML), and data-driven decision-making to enhance innovation performance. The study combines theoretical analysis...
Abstract: Catholyte is an aqueous solution with an alkaline reaction, obtained from the electrolysis of water, by separating the alkaline fraction. During the electrochemical process, the chemical properties of the water change, with a clear distinction between two types of water fractions - catholyte or alkaline fraction and anolyte or acidic fraction. During the process, the two fractions...
In the paper, machine learning knowledge is transferred to wood processing industry. А universal Machine Learning system has great potential for the scalability in wood processing industry. In order to increase the yield of high-quality material and reduce the influence of subjective factors in the assessment of the quality of the wood boards, a machine learning model was trained as part of...
Abstract
This chapter explores how digital transformation, smart HR tools, and AI-driven systems are reshaping Sustainable Human Resource Management (SHRM) and accelerating organizational progress toward the Sustainable Development Goals (SDGs). It argues that digital sustainability is not only a technological shift but a strategic framework that integrates automation, data analytics, digital...
This study examines the process of digital transformation of the traditional motif of the Bulgarian oil-bearing rose (Rosa damascena) within the context of sustainable fashion design through the use of specialized embroidery software. The research explores the adaptation of natural forms into a digital environment by combining artistic stylization and technological implementation. A...
This study explores the digitalization of ESG (Environmental, Social, Governance) reporting as a key driver of transparency and efficiency in corporate sustainability practices. It analyzes major trends, including the adoption of digital platforms, Big Data, and artificial intelligence for ESG data management. The research also identifies key challenges such as data quality, lack of...
This study examines the role of eco-leadership and Green Human Resource Management (Green HRM) as key drivers for strengthening environmental security and the resilience of critical infrastructure. In the context of increasing environmental risks, climate challenges, and the growing need for the protection of natural resources, organizations responsible for managing critical infrastructure...
This paper presents an educational approach to Computational Fluid Dynamics (CFD) simulation, focusing on the analysis of flow around an American football using ANSYS Fluent. The study aims to enhance students’ understanding of fluid flow phenomena, aerodynamic behavior, and the practical application of CFD tools in engineering education. The approach integrates theoretical knowledge of fluid...
Corruption in public procurement, financial transactions, and administrative processes presents substantial threats to national and international security, compromising integrity in defense logistics, resource distribution, and governance frameworks. Artificial intelligence, especially machine learning models for finding unusual patterns, spotting fraud, and predicting risk, has become a...
The main elements of electromagnetic protection (EP) such as ensuring electromagnetic compatibility measures, communication equipment protection measures, electromagnetic radiation management, preventive countermeasures against enemy radio intelligence have been examined. A definition, basic terms and the architecture of software-defined radio (SDR) have been given. A concept for adding...
In the contemporary digital environment, electronic evidence has become a fundamental element in both criminal and civil proceedings. The accelerated evolution and pervasive integration of information technologies into routine activities, communication, and business processes has led to a substantial augmentation in the volume and significance of digital data as potential evidence. This...
This paper presents an empirical study of incident response practices related to personal data breaches in Bulgarian organizations. The study examines how organizations detect, assess, and manage incidents involving personal data in accordance with personal data protection requirements. The research is based on data collected through a survey conducted among organizations from different...
The energy transition in agriculture is no longer only an environmental issue; it is increasingly an economic and strategic one. This paper examines how energy cost pressure affects the economic resilience of agricultural holdings in the European Union, with a particular focus on Bulgaria. The study combines Eurostat data on direct energy use in agriculture and forestry, non-household...
Bulgaria annually consumes about 50 Terawatt hours (TWh) of electricity. Production varies within the same limits. These are the values over the past 5 years. 30-40 years ago, production and consumption were significantly higher, for which there is a historical explanation. In the last century, production and export of electricity were significantly higher, with production significantly...
Innovation management systems enhance the quality and foster the continual improvement of industrial processes and products. Product innovations are often associated with inventions and breakthrough discoveries. When the output of innovation initiatives and actions results in a product that is significantly different from its competitors and adds value to interested parties, then usually...
This report examines the management of environmental risks through ESG (Environmental, Social, Governance) as a modern tool for enhancing the sustainability of systems and limiting environmental vulnerabilities. It analyzes the role of ESG frameworks in the identification, assessment, and management of climate and resource-related risks. Particular attention is paid to the effectiveness of...
This report focuses on mechanisms to ensure environmental security and in particular protection of the marine environment from pollution, including the impact from incidents, disasters, accidents and other emergency situations. The presented analysis at the complex of measures and activities implemented in Bulgaria for prevention and response to pollution of the marine environment reveals a...
The article is devoted to the extremely topical issue of fulfilling the environmental, sanitary and health requirements and ensuring radiation safety in the creation and operation of radiation hazardous facilities and the protection of the population, including their personnel. It examines some of the modern threats and dangers of radiation pollution; the role and importance of sources of...
The use of lake reeds for green energy is becoming an important component. It is important to determine the extent of reed areas, which in the future provides a forecast of the potential biomass volume and calculation of the carbon footprint. There are currently no significant results of research on the availability of reeds in Latvia. The main goal of this study is to develop a method for...
The rapid advancement of Artificial Intelligence (AI) is reshaping military operations and communication systems, introducing both opportunities and challenges. This article explores the intersection of AI and military communications, emphasising current trends, requirements, and potential applications. It discusses how communication disruptions can impact military operations and suggests...
The present study aims to investigate the combined influence of cutting parameters and tool holder type on the surface roughness obtained in side milling operations. The experimental study was conducted on specimens made of alloy steel 42CrMo4 QT (ISO 683-17) using a pre-designed experimental plan based on a central composite design. The investigated factors include cutting speed (Vc), radial...
Recent advances in artificial intelligence have enabled autonomous decision systems capable of interpreting complex multimodal data streams. However, many real world environments such as healthcare infrastructures, cyber physical systems, and distributed IoT networks operate under strict privacy and security constraints that prevent centralized data aggregation. Traditional machine learning...
Аbstract: Although the concept of national security has been extensively examined in scholarly literature, the notion of fiscal security has received comparatively limited academic attention. Fiscal security can be understood as a state of budgetary stability in which public financial interests are adequately safeguarded. Its core function is to ensure the availability of financial resources...
Although the concept of national security has been extensively examined in scholarly literature, the notion of fiscal security has received comparatively limited academic attention. Fiscal security can be understood as a state of budgetary stability in which public financial interests are adequately safeguarded. Its core function is to ensure the availability of financial resources necessary...
The paper presents the most topical issues in food security in modern world presenting it as a critical pillar in national and international security. Considering the four main dimensions of food security – availability, access, utilization and sustainability, some of the global initiatives are analyzed and presented. Special emphasis is put on global challenges as climate change and extreme...
The report explores the possibilities for applying artificial intelligence in EU funds management information systems, interpreting them through the prism of algorithmic management. The main thesis is that the implementation of AI leads to a qualitative transformation from administrative and expert-based management to automated management solutions based on data and algorithms. On this basis,...
This paper examines the application of gamification in customer service within the retail sector, with a specific focus on a grocery store environment. The study is based on an experiment involving 314 respondents and investigates the implementation of gamified service mechanics in the context of fast-moving consumer goods retail. The analysis addresses two main dimensions: the extent to which...
This paper examines the application of gamified simulation design in higher education through evidence from an undergraduate advertising course that integrates game mechanics and simulation-based learning tasks. The study is positioned within the broader search for technology-enhanced teaching approaches capable of increasing student participation, supporting experiential learning, and...
The article presents an original generalized net model (GN-model) for using artificial intelligence in assessing the protection of the population and infrastructure in disasters. It includes assessments of basic components such as population, infrastructure, personnel and procedures using intuitionistic fuzzy logic. A simulation of the GN-model was conducted in the GN IDE simulation...
The paper presents a orginal model of the e-learning process, developed using the Generalized Net (GN) apparatus. The main stages in digital education are modeled - from access to learning resources in electronic platforms to ongoing control and final assessment. Through the GN-specific transitions, the logical connections and information flows between learners, teachers and learning...
This paper presents an approach to improving the ground operational picture by applying direct georeferencing techniques from an unmanned aerial system (UAS). The study addresses the growing need for rapid and accurate target localization within time-critical operational environments, where minimizing latency and maximizing spatial accuracy are essential.
The proposed methodology leverages...
This white paper presents the Electro-Plasma-Acoustic Shield (EPAS), a unified multi-layerelectromagnetic architecture operating in two distinct modes: broadcast (outward coherenceprojection) and defence (inward harmonic filtering, designated Project Druid). The system integratesthree major technological components into a single φ²-scaled coherence field architecture.Key Technical Findings:•...
The article provides a comprehensive analysis of the transformation of human capital development in Ukraine during wartime and the post-war period, with a particular focus on the application of artificial intelligence (AI) technologies. It is substantiated that wartime challenges, including demographic losses, forced migration, declining employment, and disruption of educational systems,...
The integration of artificial intelligence into software development is increasingly influencing how security-related decisions are made during the design and implementation of secure systems. While AI tools can support threat detection, risk analysis, and vulnerability identification, their effectiveness depends on how development teams interpret and integrate AI-generated insights into their...
After cyberspace built its own individual image and after the opinions that this new space has potential to be a war domain, the question about opportunities for undertaking hybrid warfare in it is gaining relevance. The present study is looking for the characteristics of this type of hybrid warfare and their relations with technological sovereignty in the field of national security. This...
Modern requirements in shipbuilding and marine engineering necessitate continuous improvement of propulsion systems, with particular emphasis on waterjet propulsors due to their high maneuverability and efficiency at elevated speeds. This study presents a detailed analysis of hydrodynamic reaction forces generated during the interaction of a high-speed water jet with deflector surfaces of...
The article represents a literature review of artificial intelligence over the distribution channels in tourism. The fourth industrial revolution and the deep penetration of digital technologies in the social and economic sphere of life made AI-driven distribution channels in tourism an integral part of the consumer experience. The industry has already adopted omnichannel distribution...
The project introduces an innovative waste collection system featuring an autonomous electric garbage truck powered by artificial intelligence. It is designed to service publicly accessible waste containers. The truck is equipped with a specialized mechanical gripper that automatically lifts the containers and empties their contents into the vehicle. Each waste container is fitted with a GPS...
The modern New World – the World of the 21st century – has turned out to be a world existing in constant crises and conflicts of the most diverse nature and scope both at the local, regional and global levels. Crisis situations are sometimes caused by man, but sometimes they are of a natural or mixed nature. In this context, serious issues facing every government and community – be they local,...
Modern day full text search relies on a simple yet robust inverted index data structure to find documents matching a text query. However, this approach is limited by the required spelling checker, which often has memory requirements comparable to the index itself. In this work, a novel approach to text indexing is introduced. Based on the navigable small world data structure, it offers a...
This paper discusses a method for improving the kinematic accuracy of gear trains through precise analysis and decomposition of the errors of individual gears during assembly. Through mathematical modeling and analysis of collected data, the optimal meshing of the gear wheels is determined, allowing for the minimization of the total error.
One of the main indicators of the manufactured parts quality and the efficiency of the technological processes in mechanical engineering is machining accuracy. During the machining process, errors of various nature occur, which can lead to deviations from the specified dimensions and geometric parameters. This requires the implementation of modern approaches to controlling and managing the...
Increasing global requirements regarding CO₂ emissions are forcing manufacturers in many industries to develop lighter and more environmentally friendly products and structures. The use of low-weight materials such as aluminum, magnesium, and polymers can significantly reduce greenhouse gas emissions.
Friction Stir Welding (FSW) is one of the most innovative joining methods developed in...
At present, data on the influence of boroaluminizing on the mechanical properties of steels are scarce and contradictory. This publication presents a mathematical model for determining the strength characteristics of medium-alloyed quality steel and their influence on the technological characteristics of the boroaluminizing process (saturation times, quenching and tempering temperatures)....
This report examines the contemporary aspects of managing marketing and logistics relationships with customers in the industrial sector, emphasizing the need for their integration in the context of digital transformation. In the context of increased competition and growing customer requirements in a B2B environment, effective interaction between marketing activities and logistics processes is...
Critical infrastructure has become increasingly vulnerable to complex cyber threats characteristic of the contemporary hybrid security environment. The convergence of digital attacks, information operations, and potential physical disruptions necessitates integrated risk assessment approaches that capture both technological and operational dimensions of infrastructure systems. This study...
The anthropogenic increase in atmospheric greenhouse gases, particularly carbon dioxide (CO₂), has significant impacts on the thermal and chemical state of the world’s oceans. This study presents an integrated analysis of ocean warming, CO₂ absorption, and ocean acidification resulting from anthropogenic emissions. The research focuses on the relationship between heat accumulation in ocean...
This study examines the integration of Bulgarian national identity into sustainable fashion design through the application of digital technologies. The research focuses on the use of CAD systems and digital textile design tools for the transformation and adaptation of traditional Bulgarian motifs into contemporary garment design. Emphasis is placed on preserving the cultural, symbolic, and...
This report examines the possibilities for integrating green building principles within the defense sector with the aim of improving the efficiency and sustainability of military infrastructure. It analyzes the relationship between resource efficiency and the operational capability of military facilities. Particular attention is given to the adaptation of construction standards to the specific...
The current paper explores the transformative role of the digital tools and Artificial Intelligence in the field of mental healthcare. As global demand for psychological support outpaces the availability of human specialists, digital and AI-driven solutions offer a scalable bridge to fill this gap. The study examines the transition from traditional diagnostic methods to data-driven, predictive...
High-risk facilities (HRF) are subject to strict regulatory oversight, encompassing mandatory registration, periodic technical inspections, and systematic maintenance of technical documentation. In practice, the management of these processes is hindered by a range of organizational shortcomings: facility data are scattered across heterogeneous registers and files, there are no automated...
The article presents the application of smart manufacturing and the digitalization of business processes in mechanical engineering enterprises in the Northeastern region of Bulgaria. The aim is to investigate the impact of Industry 4.0 technologies on energy efficiency, productivity, and return on investment. The applied methodology uses energy indicators such as energy intensity, energy per...
The report analyzes the requirements in the Republic of Bulgaria for the construction of building water supply installations for fire extinguishing with internal fire hydrants installed on them in residential and public buildings. The registered fires in which internal fire hydrants were used are analyzed. The results of surveys on the knowledge of the population about operating with internal...
The Bulgarian scientific research vessel RSV 421 "St. St. Cyril and Methodius" conducts regular maritime expeditions from Bulgaria to Antarctica. During these missions, the ship navigates through diverse global waters, encountering a wide range of seawater temperatures and salinity levels, extreme weather conditions, and severe environmental challenges. Ensuring the structural integrity of the...
Milling is one of the most common methods for processing flat surfaces, providing satisfactory accuracy and low surface roughness at high production rates. This paper presents the results of a study on the surface roughness of machined parts made of GJL-250 gray cast iron and S235JR carbon structural steel, obtained by milling with a single-tooth milling cutter with Al2O3/TiC mixed ceramic...
Additive manufacturing has undergone significant development over the past decade and is becoming increasingly prevalent in manufacturing. Additive printing technologies facilitate the expeditious and straightforward fabrication of prototypes and components for a range of applications, which can be utilised across diverse industrial sectors. A substantial corpus of studies has been amassed in...
Composites based on thermosetting polymers (epoxy, polyester, and vinyl ester resins) with incorporated carbon particles have been developed. Multi-walled carbon nanotubes (MWNTs) and amorphous carbon, a waste by-product from the production of “green” hydrogen, were used.
The influence of different concentrations (0.02 wt%, 0.06 wt%, 0.1 wt%, 1 wt%, and 2 wt%) of both types of particles on...
Laser technologies play a key role in modern space exploration, providing highly accurate determination of the orbit of artificial Earth satellites (ESAs), navigation and data transmission. The main method used is satellite laser ranging (SLR), which allows measuring distances to satellites with an accuracy of a few millimeters. The range of tasks solved using satellite laser ranging, and...
In the 21st century, laser marking is increasingly used. Very good results are achieved when working on resistant materials such as plexiglass or chromium-nickel samples, where good color marking is also achieved.
Products that are made of or coated with chromium-nickel are used in the manufacture of a number of parts and products. This is especially true for products that are produced in the...
Strict hygiene procedures are necessary to provide food safety, which could be obtained by different methods. Most known and frequently used hygiene methods are washing with water, cleaning solutions and using mechanical devices such as bristles, scrapers and materials such as cloth with paper. In food processing used materials by itself could be self-cleaning, when they have repelling...
Laser technology has revolutionized the study, detailed documentation and digital preservation of rock-cut monuments (RCMs), including prehistoric observatories, rock monasteries, tombs, petroglyphs, rock temples, etc. This allows for contactless and highly accurate digital recording of objects. The main tool is terrestrial laser scanning (TLS), which creates detailed 3D models. Moreover, this...
A two-layered analytical approach was applied to assess the influence of actual experience with the state and functioning of procedural justice, trust in leadership, and the level of digitalization of equipment in military formations in a peacetime context on service members’ expectations regarding the performance of strategic, operational, and tactical levels of leadership in the command and...
This report analyzes the fundamental regulatory transformation of the Bulgarian energy sector, stemming from the transition from the traditional centralized model to a decentralized legal framework for renewable energy sources. The primary research focus is directed toward the conceptual alignment and existing contradictions between the Energy Act and the Energy from Renewable Sources Act....
Quantum machine learning (QML) has recently emerged as a promising research direction at the intersection of artificial intelligence, quantum computing, and cybersecurity. Among its potential applications, intrusion detection remains particularly relevant due to the growing complexity of cyber threats and the increasing need for adaptive and efficient detection mechanisms. This paper explores...
Heat-treated steels (hardened with subsequent high-temperature tempering) are widely used in the manufacture of critical parts subjected to elastic and impact loads. The publication examines their machinability when machining on CNC lathes with robotic feed. The average roughness of the machined surfaces – Ra – was used as a criterion for their machinability. Based on the experimental results,...
This paper proposes a mathematical framework for modeling the safe distance between a vehicle and a pedestrian, addressing a critical aspect of road safety and collision avoidance. The model is derived from kinematic principles and incorporates key parameters, including vehicle speed, pedestrian speed, and pedestrian displacement prior to potential conflict.A closed-form analytical expression...
A variety of factors have been shown to influence each measurement process, including environmental elements, the characteristics of the measured object, and the capabilities of the measuring instrument. These factors can be categorised into several overarching groups: external factors, the measurement object, the measuring instrument, and the operator. The present paper sets out a methodology...
Rolling bearings are machine components widely used in mechanical engineering. They are used under various operating and load conditions. Their widespread use makes it necessary to test them under certain conditions to study their behavior. This paper presents a methodology for testing bearings using the damped oscillation method. A specially designed test rig is used in accordance with the...
This article presents a comprehensive study of classical and modern approaches to enhancing images captured in low-light conditions. An adaptive ensemble method is proposed that combines four classical image processing algorithms and automatically weights them based on local quality. The developed system uses CLAHE, gamma correction, the Retinex algorithm, and automatic contrast stretching as...
Abstract: In the context of digital transformation, data has become one of the most valuable strategic assets for contemporary organizations. Beyond facilitating routine operational activities, it plays a critical role in informing and supporting strategic decision-making processes. Organizational data may encompass a wide range of sources, including clinical research records, customer...
An important factor in increasing productivity and optimal use of resources in mechanical engineering production is the effective organization of material flows. Under the conditions of the modern production systems, alternative technological processes for machining parts often exist, which creates opportunities for more flexible production planning, complicating, at the same time, material...
The electropneumatic drive system with PWM control is used in machines and equipment where it is necessary for the actuator to be positioned at a significant distance from the control valves. This leads to changes in the dynamic characteristics of the systems, depending on the length of the connecting pneumatic lines. The report presents a mathematical model of an electropneumatic positioning...
The external cylindrical grinding of long stepped shafts, performed by combining axial and radial feeds, is widely used in the machine-building industry. Finding ways to machine all rotational surfaces in a single setup and remove allowances of varying sizes while fully automating the manufacturing process is a pressing challenge. Modern machines are equipped with CAM systems that calculate...
Abstract ─ A subject of this article is to model a vibroisolation systems for a sterile air compressor. The goal is to investigate the main parameters involved in analyzing the system, which consists of mounting structure, modeled as absolutely rigid body, the compressor itself, modeled by inertial mass, with disturbance forces in operational conditions. In the course of the study several...
Abstract: The addition of an anomegator to the oil directly affects the change in the tribotechnical parameters of the friction pair by changing its operating environment.
The article presents a multivariate study of the influence of the addition of an anomega to the lubricating medium on the change in the tribotechnical parameters of a friction pair. The main objective is to evaluate the...
In the context of the internationalisation of higher education and the growing role of English as a global language of science and technology, the development of both communicative and research skills among engineering students has become increasingly important. This study investigates the effectiveness of a multimodal approach to teaching English as a factor in improving engineering students’...
The importance of renewable energy has grown enormously in recent years, with the EU's target for renewables to achieve a share of 42.5% of gross energy consumption by 2030. This is related not only to stimulating technological developments in the field and increasing investments, but also to legislative changes to accelerate the modernization of networks, remove regulatory barriers and...
This paper systematises the destructive characteristics of ion-nitrided and carbonitrided layers on BH11 (4Cr5MoVSi) and D2 (Cr12MoV) tool steels produced in a glow-discharge plasma at 550 °C and ~400 Pa, and investigates their suitability for calibrating and validating non-destructive testing (NDT) methods. Two principal NDT techniques are examined—eddy current testing (ECT) and the...
This study presents a comprehensive numerical investigation of conjugate heat transfer (CHT) between a fluid and a solid domain, a phenomenon of critical importance for the design and optimization of engineering systems such as heat exchangers, electronic cooling devices, and industrial reactors. The simulations were carried out using ANSYS Fluent, enabling detailed analysis of heat transfer...
The French astronomer Jean Picard was the first to make physical measurements of the Sun's radius in the 17th century. In the modern era, from 2010 to 2014, instruments on board the Picard microsatellite allowed for extremely accurate data on the Sun's radius, rotation speed, polar oblateness, and radiated power. This allowed us to learn more about the internal structure of our Sun and its...
This article considers the method of posterior predictive distributions as an effective tool for checking the correspondence between data and the
statistical model. The examples considered show that in the role of posterior predictive testing statistics, dispersion measures should be taken, because the central tendency measures do not give the natural expected results.
In modern ship power plants with electric propulsion motors, the main ship power system consists of powerful multi-cylinder diesel generators. The engine and the generator are mounted on a common frame, which is attached to the ship's hull through resilient (elastic) elements.
Minimizing the vibrations induced in the ship's hull is achieved by refining the mechano-mathematical models. In the...
The report examines the transformation of operational art under the influence of cognitive warfare. The main focus is on the strategic asymmetry between the leading global military doctrines. Through a systematic analysis, differences in approaches are revealed – NATO’s reactive-defensive model aimed at societal resilience; the US’s proactive model striving for cognitive dominance; Russia’s...
The subject of the article is the theoretical and methodological aspects of business project management as a proven effective tool used by companies from the industrial sector to respond to the dynamic internal environment. The report analyzes the principles and approaches to business project management and the construction of effective project teams, combining management knowledge and...
This paper presents a method for evaluating the machining accuracy and process stability of the gear cutting and gear hobbing of cylindrical gears. Through statistical analysis and the use of mathematical evaluation criteria, the stability of the machining process has been established. This makes it possible to determine the optimal setup parameters and predict the maximum number of parts that...
This paper presents an optimization-based approach for the first-order design of infrared triplet systems in the LWIR spectral range. The method is based on paraxial optical theory and formulates the design task as a multi-parameter optimization problem aimed at minimizing chromatic aberrations and Petzval curvature under given constraints. Numerical optimization techniques are applied to...
A review of modern methods for organizing and conducting rescue operations in water bodies is made. The methods are improved using artificial intelligence (AI) to support rescue divers in underwater operations for searching and rescuing victims in accidents. Modern technologies for processing data obtained from sonar systems, video streams and sensor information are considered. Machine...
This paper presents the design and experimental evaluation of Generic Routing Encapsulation over Internet Protocol Security tunnels in dynamic routing networks. The study is motivated by the need to provide secure inter site connectivity while preserving support for dynamic route exchange between remote network segments. A laboratory topology is developed to examine the behavior of the...
Physical security is an essential yet often underestimated aspect of an overall cybersecurity strategy. While most efforts focus on protecting software and network infrastructure, the physical vulnerabilities of cyber systems also pose a significant threat. This study analyzes the interconnection between physical security and cybersecurity by examining both the risk factors leading to the...
The Pitot tube is a classical and widely used instrument for measuring fluid flow velocity, with applications across various engineering fields, including marine engineering systems and modern mechatronic applications. This paper presents a numerical simulation of a Pitot tube performed using ANSYS Fluent, aiming to demonstrate its operating principle, measurement accuracy, and significance as...
During research of creating better stainless steel surfaces for food processing using laser treatment, there was conclusion, that hydrophobic surfaces may have only limited use due to their high roughness, despite their water repelling effect. On other hand, polishing, that is used for centuries, makes surfaces very smooth, which has positive effect on hygiene of materials that are used in...
In clean and fine turning on CNC machine tools, it is advisable to carry out active control by measuring the parts after their processing. With this type of active control, accuracy is highly dependent on dimensional dispersion caused by random factors. A solution for reducing these errors and increasing the accuracy of active control is the use of adaptive control of roughing accuracy.
This paper presents a theoretical framework and critical feasibility analysis for Project Alfie, a novel ground-based launch system concept. The system is designed to propel a 3,000 kg payload to low Earth orbit using a hybrid propulsion method that synergistically combines staged electromagnetic acceleration with acoustic levitation and stabilization. The proposed architecture consists of a...
This report analyzes the role of psychological qualities of strategic leaders as a critical determinant of the effectiveness, resilience, and legitimacy of the national security system. Security is approached not only as an institutional and normative framework but also as a function of the human factor, which plays a central role in strategic decision-making under conditions of uncertainty,...
The accelerating processes of digital and energy transformation are fundamentally reshaping contemporary societies, economies, and governance systems. While technological innovation and the transition to sustainable energy are essential for long-term development, their success increasingly depends on the level of public trust. In this context, trust emerges as a critical factor and a central...
This report evaluates the radiogenic heat production (A) within the continental crust of Bulgaria, emphasizing the dominant role of the Rhodope Massif. The generation of thermal energy through the radioactive decay of uranium (U), thorium (Th), and potassium (K) is a primary component of the Earth's heat flow.
The analysis first establishes a baseline for Bulgaria by assessing the average...
Nowadays, computer networks generate large and complex data sets, which leads to problems related to the detection of new, modified threats. Classic Intrusion Detection Systems – IDS, based on static rules and signatures, have difficulty identifying masked - as legitimate or previously unseen malicious activities. The challenge they face is reverse shell attacks, in which the attacker...
Radionuclides are mainly bound within soil layers and exist in the Earth’s crust as mineral-like substances that are resistant to heat and electrical воздействия and can split into thin layers, making them difficult to wash out easily. Therefore, in order to extract radionuclides from radiation-contaminated soil layers and reduce their specific activity, it is necessary to separate them using...
Radionuclides affect human health and living organisms through external and internal exposure. This causes acute effects at high doses and an increased risk of cancer and genetic damage at long-term low-level exposure. Radionuclides generally affect health, toxicology and public health through chemical and radiation effects - internal uptake (ingestion/inhalation) of specific isotopes such as...
Companies operate in the conditions of environmental factors, some of which do not directly affect their activities, but through indirect influence. The subject of the development are the macro factors of the companies' environment, and the object is the business in the Veliko Tarnovo region. The main goal is to present the reactions to changes in the macro factors of the environment and how...
Enterprises operate within an environment that directly influences their activities. Different industries react specifically to individual elements of this environment. The main purpose of the research is to demonstrate the company's reactions to the stimuli from the environment, which has a direct impact on the activity. The subject of the research are the microelements of the marketing...
The continuous increase in requirements for the surface quality of elements in machine-building products, particularly gear transmissions, necessitates the improvement of machining and control methods. A major influence on the smoothness and noiseless operation of power transmissions is the correct selection of the method for machining the base holes of gears.
The methods currently known for...
The widespread adoption of disposable electronic cigarettes has created a rapidly growing waste stream containing embedded lithium-ion batteries. In most cases, these batteries are discarded together with the device once the e-liquid reservoir is depleted, despite the possibility that the electrochemical lifetime of the cell significantly exceeds the functional lifetime of the product. This...
This paper examines the key risks associated with the integration of Artificial Intelligence (AI) and Machine Learning (ML) systems into military command chains. The analysis covers the main components of the decision-making process, including data, algorithms and models, software and system integration, communication infrastructure, and the human factor. The study emphasises that while AI...
Abstract—Durable color laser markings on stainless steel are attractive for traceability, product authentication, and identification of industrial components exposed to mechanical contact. In this work, the scratch-test response of nanosecond fiber-laser-marked AISI 304 stainless steel was evaluated for a 7 × 7 processing matrix. The laser-marking parameters were: average power P = 3–15 W and...
Secure and resilient operation is a critical requirement for modular Power-to-Liquid e-fuel plants supplied by intermittent renewable energy. This paper investigates a modular e-fuel production architecture powered by a hybrid photovoltaic-wind-battery system and evaluates its response to short-duration renewable disturbances. A deterministic operational model is formulated for renewable...
This study investigates the development of secure cross-border innovation clusters within the context of Industry 4.0, focusing on the Burgas–Edirne region. The main objective is to develop and empirically demonstrate a conceptual and analytical model for evaluating the interrelationship between technological development, cybersecurity, trust, and entrepreneurial activity within innovation...
This article considers the Dirichlet type integrals, for which closed form formulas have been obtained. In particular, it is proven that all these integrals are rational numbers. The Lobachevsky integral formula is also considered.
This paper deals with the synthesis of state controller for an electrohydraulic power transmission system. There are shown the mathematical model of the electrohydraulic system and state controller synthesis method with state space feedbacks. The controller coefficients are obtained from preliminary defined error performance index. The response curves are obtained from computer simulation. The...
Our research focuses on the comparative analysis of strategic models for the management of renewable energy sources (RES). They are assessed at the level of institutional development in Bulgaria. This is being done in the context of the global energy transition, driven by decentralization and smart management decisions. It is based on the fact that the domestic environment is showing signs of...
University training within the Fourth Industrial Revolution should equip students with knowledge and skills to face the challenges of the labour market and, more importantly, successfully navigate their daily personal and professional lives. Given the ongoing development of digital technologies, learning in the 21st century is a significant challenge. Although the use of AI tools in the...
Abstract: The use of different oil additives to reduce performance parameters is not new. The use of oil anamegators is also aimed at changing some operating parameters, such as fuel consumption, power, noise and smoke content of tractors, which determine the complex behavior of the tractor, manifested by the balance between economy, power, environmental friendliness, comfort and...
The natural frequencies affect ride comfort and stability of vehicle. This paper presents the results of the natural frequencies of a quarter car MacPherson suspension system, obtained with different tire pressures and by using bushings made from different materials. The natural frequencies and mode shapes were obtained from finite element analysis (FEA) and the natural frequencies were also...
The present study examines the surface modification of tool steel 1.2343 by ion nitriding. Prior to the chemical-thermal treatment process, the specimens of the investigated steel were subjected to quenching and tempering. The heat treatment included vacuum quenching and triple tempering, achieving structural stabilization before the diffusion saturation process.
Ion nitriding was carried out...
Sustainable development and energy transition require a new type of management information. Smart energy grids create large volumes of data on consumption, efficiency and environmental impact. This puts the focus on the role of sustainable accounting as part of modern enterprise information systems.
The subject of the study is sustainable accounting in enterprises during digitalization and...
Proposed is a method for dynamic impact protection mechanisms undergoing strong percussive effects due to detonation devices used in special military equipment destined for geostationary navigation and targeting of artillery and aviation complexes. Developed algorithm synthesis of friction damper damping fluctuations in programming environment MatLAB 7.0 for Windows. Studied the functions of...
The publication traces the influence of the type of iron powder and the sintering process in the presence of a liquid phase on the tensile strength of powder metallurgical samples from the Fe-C-Cu system. Powder metallurgical samples of three types of iron powders – ASC 100.29, SC 100.26 and NC 100.2 – were studied. The iron matrix is alloyed with 2.5%Cu and 0.2÷0.8%C. After sintering, their...
test variant
The study analyzes the geopolitical crisis surrounding Greenland as a fundamental test of the sustainability of the international legal order and the institutional capacity of NATO and the EU. The focus is on the conceptual clash between the outdated model of “territory purchase” and the modern liberal legalism affirming the right to self-determination of the Greenlandic people. The...
Abstract
Climate change over the past 30 years has affected the frequency of extreme weather events. The changes occurring in the atmosphere, oceans, cryosphere, and biosphere unequivocally indicate that the world is warming (Ivanova, 2023). The impact of climate change is of significant importance for the energy produced by photovoltaic systems. These systems are a key tool in combating...
The research paper focuses on the important role of Small and Medium Sized Enterprises (SMEs) in the development of the European defence ecosystem with emphasis on quantum technologies, incl. with dual use. The research is based on interdisciplinary approach. In addition to the methods of analysis and synthesis of primary and secondary sources of information, generalization, inductive and...
Mobile tourism applications are expected to provide not only functional usability but also emotionally engaging experiences. This study explores how visual style influences emotional engagement in mobile tourism interfaces. Focusing on a comparative sample of Bulgarian tourism apps, the research applies a mixed-method UX design combining user ratings, emotional assessment, and targeted...
This research focuses on the role of artificial intelligence in educational technologies in higher education. The modern vision and needs of current and future professions set new requirements for the training of future specialists related to the use and application of high-tech training resources. The relevance of the issues under consideration stems from the need to adapt the training to the...
This study examines the challenges posed by deepfake technologies as a tool for influencing electoral processes and their implications for national security, particularly through the manipulation of individuals and social groups and the shaping of their attitudes toward the electoral process. In the context of the increasing digitalization of society and the pervasive influence of social...
Terrestrial Trunked Radio (TETRA) remains a core technology for critical communications, while 5G mission-critical systems extend the broadband capabilities increasingly required by public safety networks. Current standardization has successfully defined interworking between TETRA and 5G mission-critical systems, but this primarily supports interoperability between two independent technology...
Abstract — This study examines the progressive transformation of individual ballistic and tactical protective systems, tracing the transition from conventional camouflage textiles to advanced architectures based on metamaterials. In the modern multispectral battlespace, where high-resolution visual and thermal detection enables rapid target detection and engagement, traditional camouflage...
Nowadays, unmanned aerial systems play a very important role in the economy, environmental protection, research, and military operations. This is accompanied by constantly increasing requirements for the quality and accuracy of the information received and the commands issued.
The elements of these systems operate and perform their tasks by transmitting data and commands over communication...
The formation of the concept aims to further develop the innovative idea and transform it into a real innovative product intended for the market, as well as to bring consumer desires into a production-feasible product. Usually, a company has at least several innovative ideas for one product. The life cycle of innovations is presented, as well as the degree of novelty of products and processes...
In the contemporary field of international affairs, the China’s economical, geopolitical, and military rise is a significant factor in the challenges of international affairs. The focus of this study falls on the response which these circumstances find in the context of national security in two states of established economical and geopolitical standing. In this scientific framework,...
We would like to present the dictionary we are collecting already for two decades as well as the electronic lexicographical system which is used for the creation of this dictionary and was especially developed twenty three years ago for this purpose. It is a good example of almost-without-financing long-term development strategies of IT systems for language technology purposes, and it could be...
In the 21st century, laser technology is widely utilized across numerous fields. Modern daily life would be significantly different without the invention of lasers, as many commonly used devices, such as rangefinders, barcode scanners, DVD players, and high-speed data transmission systems based on optical fiber, depend on this technology.
However, the applications of lasers extend beyond...
Abstract: Preservation and provision of access to documentary cultural heritage constitute a significant challenge in the context of contemporary digital transformation. The development of information technologies creates new opportunities for the digitization, preservation, and dissemination of archival and library resources, as well as for expanding access to knowledge. University libraries...
Pollution of continental water resources has emerged as one of the most significant environmental problems in recent decades. This affects both the natural ecosystems inhabiting water areas and the quality of life of the population. The unregulated disposal of large amounts of plastic, construction and household waste into rivers, lakes and adjacent territories leads to significant...
The rapid development of quantum technologies leads to new possibilities applying certain cryptographic attacks against symmetric algorithms. This paper discusses a verifying method an different approach to applying an "Brute force" attack on 256 - AES encrypted voice stream. While the classical attack application emphasizes computing power, here the focus is on signal processing.
The Bulgarian Black Sea Coast is characterised by specific biological diversity and is an extremely important region for the conservation of biological diversity on the Balkan Peninsula and Europe. Wild medicinal and aromatic plants represent both a vital ecological asset and a valuable Bulgarian export. Despite an established regulatory framework, the unregulated overharvesting of medicinal...
Abstract— This study examines the exploitation of water resources in Bulgaria within the framework of water security, with particular emphasis on the structural transformation of water supply systems and the increasing strategic role of groundwater. The analysis is based on River Basin Management Plans (2022–2027), national statistical data, and a comprehensive assessment of water abstraction...
Results are presented for the influence of the type of chemical-thermal treatment in single-component surface enrichment on the wear resistance of the formed diffusion layers on samples of chromium tool steels (1÷5%Cr). Wear resistance is defined as mass loss per unit area (g/cm2 ) after a distance of 1÷5 km. The loading in the wear process is carried out by a lever system with a load of 3÷100...
Effective diagnostics of WEB services distribution is an important prerequisite for adequate traffic load service planning in information and communication infrastructures in serving corporate clients. Network administrators play a key role in specification and transmission medium metrics analysis in web traffic management. The paper proposes a Machine Learning approach for WEB traffic streams...
This paper presents a comparative analysis of the command-and-control (C2) frameworks PoshC2 and SliverC2, examined within the context of evolving adversarial tradecraft, shifting infrastructure paradigms and the increasing maturity of defensive capabilities. While C2 frameworks are traditionally associated with the post-exploitation phase, this study adopts a broader perspective, arguing that...
The text analyzes the fundamental link between economic stability and national security, focusing on the 2025 U.S. National Security Strategy. This strategy reaffirms the view that the economy is the foundation of power and that military superiority is impossible without a strong industrial base, technological innovation, and energy independence. Furthermore, it posits that economic...