JOURNAL SCIENTIFIC AND APPLIED RESEARCH

Content of vol. 31, 2026, Journal Scientific and Applied Research

Petar Boyanov — Fri, 06 Nov 2026 00:00:00 +0200

Content of vol. 31, 2026, Journal Scientific and Applied Research

SCENARIO-BASED METHODOLOGY FOR EVALUATING A HYBRID ACCESS CONTROL METHOD IN UNIVERSITY INFORMATION SYSTEMS

Radostin Lefterov — Fri, 06 Nov 2026 00:00:00 +0200

This paper presents a scenario-based methodology for evaluating a hybrid access control method intended for university information systems. The proposed approach combines role-based and attribute-based access control with contextual information, SIEM and EDR signals, and dynamic risk assessment. A structured set of ten evaluation scenarios is defined for student, lecturer, and administrative access, including normal conditions, insufficient permissions, changed context, increased risk, and critical security situations. The methodology also defines comparative criteria for examining the expected behaviour of traditional RBAC, RBAC combined with ABAC, and the proposed hybrid method. The presented scenarios do not represent completed experimental results, but provide a consistent basis for subsequent implementation and validation in a controlled university information system environment.

EVALUATING AN INTERACTIVE LECTURE MODEL FOR TEACHING COMPLEX NUMBERS: A COMPARISON WITH TRADITIONAL INSTRUCTION

Valentina Todorova-Lazarova — Fri, 06 Nov 2026 00:00:00 +0200

In this paper, an interactive lecture model for teaching complex numbers through coordinated algebraic, geometric, and trigonometric representations is examined. Two existing groups of first-year engineering students received traditional (n = 17) or interactive instruction (n = 24). A common post-test was administered immediately after the 45-minute lecture, followed by a questionnaire in the interactive group.
A higher overall mean score was obtained by the interactive group (5.92 versus 4.12 out of 10; p = 0.035, Hedges’ g = 0.66). For the six conversion and coordination questions, the difference was not statistically significant (3.38 versus 2.47 out of 6; p = 0.117). Higher performance was also observed on within-representation questions; therefore, a representation-specific advantage was not established. Attention and active involvement were generally reported, while understanding of relationships among representations was less consistently endorsed.
Higher immediate achievement was associated with interactive instruction. Causal conclusions and evidence of lasting differences are limited by non-random group assignment and assessment after a single lecture.

CONCEPTUAL MODEL FOR GENDER PREDICTION BASED ON USER INPUT

Valentin Atanasov — Fri, 06 Nov 2026 00:00:00 +0200

The present study examines an approach to the synthesis of a conceptual model for gender prediction based on user input. The predictive capability of the model is grounded in statistical differences observed within specific datasets and in the applicability of a machine-learning classification model. The predictive analysis is governed by a set of parameters, including language, the specifications of the peripheral input device, sample size, and biological indicators. It should be noted that reliable classification of a user's gender is a function of predefined key indicators.

TECHNOLOGICAL CHALLENGES TO THE EFFECTIVE USE OF SPECIAL INTELLIGENCE MEANS

Donika Dimanova, Silviya Kirilova — Fri, 06 Nov 2026 00:00:00 +0200

The development of information and communication technologies is significantly transforming the environment in which special intelligence means are used. Encrypted communications, virtual private networks, and anonymization technologies limit the effectiveness of traditional methods, while big data analytics, automated processing, and artificial intelligence create new analytical opportunities. The paper examines the impact of the digital environment on the effectiveness of special intelligence means, the role of traffic data, and the possibilities for technological development while ensuring legality and the protection of fundamental rights.

DUAL-QUEUE SCHEDULING AND AN ENGINEERING DELAY BOUND UNDER OVERLOAD

Dragomir Vasilev, Srebrin Sharbanov — Fri, 06 Nov 2026 00:00:00 +0200

One shared queue under overload is considered. Seven of every ten extractions are taken from the tail and three from the head. An engineering upper bound on the wait of jobs removed from the head is derived for a sustained hybrid and a constant share θ. With eight servers, mean service 40 ms and a full buffer of 1000 jobs, the bound is about 16.7 s and sits above a 3 s threshold. A 10 Hz guard is therefore included in the sizing: it replaces LIFO with the hybrid when the head has waited more than 3 s. A measured P99 is not reported.

COMPLIANCE OF VIDEO SURVEILLANCE SYSTEMS WITH PERSONAL DATA PROTECTION REQUIREMENTS: ANALYSIS OF PROVIDER PRACTICES

Deyan Ivanov, Donika Dimanova — Fri, 06 Nov 2026 00:00:00 +0200

Video surveillance is widely used as a security measure, but its operation is directly associated with the processing of personal data and the need to comply with data protection requirements. This paper analyzes the main criteria for assessing the compliance of video surveillance systems with the General Data Protection Regulation (GDPR) and the applicable national legislation, with particular emphasis on their practical implementation by companies operating in the video surveillance sector. An exploratory survey was conducted among representatives of six companies to examine the existence of internal policies, the technical protection measures applied, the organization of access to video data, staff training, and the main difficulties encountered in meeting personal data protection requirements. The results are interpreted as indicative of the surveyed group and reveal both positive practices and gaps in organizational preparedness and the implementation of compliance measures. On this basis, guidelines are formulated for improving personal data protection in the use of video surveillance systems.

EXPERIMENTAL SIMULATION AND ANALYSIS OF LAYER 2 ATTACK VECTORS: ARP/DNS SPOOFING AND MITM

Denis Zvezdelinov, Zdravko Kuzmanov — Fri, 06 Nov 2026 00:00:00 +0200

This report examines the security of the Data Link Layer (Layer 2) of the OSI model, focusing on fundamental vulnerabilities in core local communication protocols. It addresses the concept of "implicit trust" inherent in the design of the Address Resolution Protocol (ARP) and the Domain Name System (DNS), which enables Man-in-the-Middle (MITM) attacks. The report analyzes the theoretical mechanisms of ARP cache poisoning and DNS spoofing. Network traffic was intercepted and subjected to forensic analysis through controlled simulations in an isolated laboratory environment. Key packet-level Indicators of Compromise (IoCs) were identified, including duplicate MAC addresses, an anomalous frequency of unsolicited ARP responses (Gratuitous ARP), and unusually low DNS resolution response times. In conclusion, architectural and software-based protective measures are outlined, including the implementation of Dynamic ARP Inspection (DAI), Port Security, and encrypted DNS protocols (DoH/DoT).

APPROACH TO MODELING PHOTOVOLTAIC ENERGY YIELD USING CHEBYSHEV POLYNOMIALS

Iliyana Ivanova, Donika Dimanova — Fri, 06 Nov 2026 00:00:00 +0200

Photovoltaic energy yield varies in response to changes in meteorological conditions. The main factors affecting the amount of electricity generated include solar irradiance and air temperature, as well as seasonal and daily variations. This paper examines the relationships between these factors and photovoltaic energy yield and presents an approach to modeling those using orthogonal Chebyshev polynomials. The main input variables, data-preprocessing steps, and structure of the approximation model are defined.

IMPLEMENTATION OF VULNERABILITY WEB SCANNERS IN THE COMPUTER NETWORKS

Petar Boyanov — Fri, 06 Nov 2026 00:00:00 +0200

In this scientific article implementation of vulnerability web scanners in the computer networks is presented. The article focuses on web vulnerability scanning and how it can find weaknesses in locally tested web servers. Two scans on the web servers running on the victim and attacking computers were performed.

IMPROVING THE RELIABILITY OF WATER TANK LEVEL CONTROL

Hristo Hadzhiivanov, Tihomir Trifonov — Fri, 06 Nov 2026 00:00:00 +0200

Water resources management has always been important, especially in the recent decades. Automatic methods for regulating tank levels have existed since ancient times; however, modern automatic control systems are completely different.
A primary aim in industrial control is achieving maximum reliability at minimum cost. This article presents a method for regulating tank levels using various control devices (PLC, HMI, etc.), aiming to achieve superior control with a minimal number of components.

AN OVERVIEW OF NETWORK ADDRESS AND PROTOCOL MESSAGE SPOOFING ATTACKS

Dimitar Iliev — Fri, 06 Nov 2026 00:00:00 +0200

Network protocols use addresses and control messages to exchange data and establish communication between devices. When this information is not properly verified, attackers can replace it with false information. This paper presents an overview of IP spoofing, MAC spoofing, NDP spoofing, and DNS spoofing. It explains how these attacks work, what conditions they require, and how they can affect network security. Their connection with man-in-the-middle attacks is also discussed. The paper compares basic protective measures, including source address filtering, port security, protection of IPv6 discovery messages, DNSSEC, and encrypted communication with proper authentication. The review shows why different spoofing attacks require different protection measures and why network addresses alone should not be treated as proof of identity.

IDENTIFICATION OF OBJECTS IN QGIS FROM AN ORTHOPHOTOMOSAIC COMPOSED BY PHOTOGRAMMETRY

Nikolay Zhelyazkov, Evgeni Stoykov — Fri, 06 Nov 2026 00:00:00 +0200

Orthophotomosaics are among the main outputs of processed photogrammetric surveys. By analyzing their elements, we can determine geometric parameters of objects of interest for certain tasks in applied geodesy, geomorphology, agronomy, forestry, ecology, construction, etc.

CYBERSECURITY IN MUNICIPAL ADMINISTRATIONS – RISKS, VULNERABILITIES AND OPPORTUNITIES FOR INCREASING RESILIENCE

Iliana Simeonova — Fri, 06 Nov 2026 00:00:00 +0200

This paper examines cybersecurity in municipal administrations as a key component of administrative security and sustainable functioning of public services. The main cyber threats, vulnerabilities and factors affecting the level of protection of information resources are analyzed. Emphasis is placed on the management and assessment of cyber risk, the protection of critical information assets and the role of the human factor. An author's Model 5K for municipal cyber resilience has been developed, combining identification, assessment, protection, monitoring and resilience. The proposed approaches are aimed at incident prevention, effective response and restoration of municipal information systems and services.

CONTEMPORARY TRANSFORMATIONS OF ILLICIT DRUG TRAFFICKING: SECURITY RISKS, CRIMINAL NETWORKS AND CHALLENGES FOR BULGARIA

Tsvetelina Metodieva — Fri, 06 Nov 2026 00:00:00 +0200

The article examines illicit trafficking of narcotic substances as a multidimensional transnational security threat, with particular emphasis on the Bulgarian context. The research systematizes the conceptual, legal and institutional foundations of drug control and analyses the interaction between transnational trafficking flows, domestic distribution and production, adaptive criminal networks and emerging technological channels. The analysis covers the international and European regulatory framework, the security dimensions of drug trafficking, the role of precursors and new psychoactive substances, synthetic opioids, maritime and land routes, and the digitalization of retail distribution. Particular attention is devoted to selected Bulgarian indicators for 2024–2025 and to the implications of these developments for administrative capacity, interinstitutional coordination and risk management. The study argues, on the basis of the analysed source material, that seizures and criminal-case statistics alone do not adequately capture the security dimension of the phenomenon. A more comprehensive perspective requires assessment of vulnerabilities along the entire criminal supply chain and integration of law-enforcement, customs, judicial, financial, technological, health and preventive capacities.

DISINFORMATION AS A SOCIAL THREAT TO NATIONAL SECURITY (IN THE CONTEXT OF THE RUSSIAN-UKRAINIAN WAR)

Iliana Simeonova — Fri, 06 Nov 2026 00:00:00 +0200

The article examines disinformation as an essential social factor influencing national security in the modern world. In the context of digitalization and rapid dissemination of information, disinformation is becoming a powerful tool for influencing public attitudes, trust in institutions and the stability of the state.
The article analyzes the main characteristics and mechanisms of disinformation, as well as its social, political and psychological effects. The relationship between disinformation and the processes of public polarization, reducing trust in state institutions and creating a sense of insecurity among citizens is examined.
Special emphasis is placed on the manifestations of disinformation in the context of the Russia-Ukraine war, where information warfare plays a key role alongside traditional military operations. It analyzes how different countries use media and digital platforms to spread propaganda narratives and influence the international and domestic public environment.

TOWARD A CONCEPT OF LOGISTICS ERGONOMICS: HUMAN FACTORS IN INTELLIGENT WAREHOUSE SYSTEMS

Yordanka Yankova-Yordanova — Fri, 06 Nov 2026 00:00:00 +0200

Digitalisation and automation have transformed warehouse operations, but they have not removed the human operator from the logistics system. Instead, warehouse work increasingly combines physical handling with digital instructions, time pressure, exception management and interaction with intelligent technologies. This conceptual paper develops logistics ergonomics as an engineering-logistics perspective that considers physical workload, cognitive workload, the technological environment, work organisation and logistics performance within a single analytical frame. The study synthesises established ergonomic methods and recent warehouse research and proposes a preliminary Logistics-Ergonomics Risk Indicator (LERI), implemented as a four-domain screening profile for identifying operations that warrant deeper ergonomic assessment. LERI is not presented as a validated risk scale and is not intended to replace RULA, REBA, NASA-TLX, the Revised NIOSH Lifting Equation or other specialised methods. The framework is intended to connect human-factor analysis with warehouse design and operational decision making and to provide a basis for subsequent expert validation and empirical testing.

EVOLUTION OF INDUSTRIAL SYSTEMS: FROM THE HUMANIZATION OF INDUSTRY 5.0 TO THE BIO-DIGITAL SYMBIOTIC INDUSTRY 6.0

Nikolai Nedev, Anton Antonov — Fri, 06 Nov 2026 00:00:00 +0200

At the beginning of the 21st century, the world witnessed the Fourth Industrial Revolution (Industry 4.0), which laid the foundations for digitalization, cloud computing, and the Internet of Things (IoT). Despite undeniable technological successes, Industry 4.0 faced criticism for its "technocentricity" a model in which machine efficiency often took precedence over human well-being and ecological balance.

HYBRID SPARE-PARTS LOGISTICS IN ENGINEERING SYSTEMS: A 3S MODEL FOR STORE, SOURCE, OR SYNTHESIZE DECISIONS

Yordanka Yankova-Yordanova, Nikolay Yordanov — Fri, 06 Nov 2026 00:00:00 +0200

Spare-parts availability is a critical condition for technical continuity in production, transport and other engineering systems. Traditional inventory strategies provide rapid response but may create high holding costs, obsolescence and tied capital, whereas external sourcing introduces lead-time dependence. Additive manufacturing adds a third option by enabling selected components to be produced on demand from digital data. This conceptual paper develops a hybrid decision framework that combines these alternatives in a 3S model: Store, Source, Synthesize. The model evaluates spare parts according to criticality, supply lead time, downtime cost, demand frequency, additive-manufacturing feasibility, material and quality requirements, legal and warranty constraints, and lifecycle economics. The study synthesizes peer-reviewed research on additive manufacturing in spare-parts supply chains and positions 3D printing as a selective logistics option rather than a universal substitute for physical inventory. The resulting framework is intended for preliminary classification and decision support; it requires organisation-specific validation before quantitative thresholds are introduced.

INFLUENCE OF FAMILY SUPPORT ON ENTREPRENEURIAL ATTITUDES - A CASE FROM BULGARIA

Daniel Pavlov, Denitsa Zagorcheva — Fri, 06 Nov 2026 00:00:00 +0200

This report examines the dynamics between the perceived support from one’s immediate social circle and the degree of personal autonomy in decision-making and the undertaking of new initiatives. Based on quantitative research (using a 5-point Likert scale among 645 respondents from Bulgaria in 2025 and 2026), the study analyzes attitudes regarding exclusive trust, emotional confidence, and the need for external approval. The results reveal a pattern of „supported autonomy“, wherein high levels of psychological security and acceptance do not lead to complete individual independence, but rather to a form of regulated social interdependence. The study’s design incorporates methodological controls to validate the reliability of the findings.