1. Optimizing abrasive water jet milling of alumina ceramics with RBF neural networksY.T. Feng, Z.R. Shi, X. Yang, W. Huang, X. Luo, Y.H. Li, L. Yu, 2025, original scientific article Abstract: Abrasive water jet technology is an advanced machining method that combines high-pressure water jet with solid abrasives. Owing to its unique coldprocessing characteristics, high flexibility, and environmental bebefits, it has been widely applied in aerospace, medical devices, microelectronics, defense and other fields. Focusing on alumina ceramic plates, this study systematically investigates abrasive water jet (AWJ) milling through an integrated experimental and modeling approach. The research framework consists of three main phases: the development of an experimental design for abrasive water jet milling of alumina ceramics; systematic parameter optimization using single-factor and orthogonal array experiments, with material removal rate and milling depth as key performance indicators; and the application of a radial basis function (RBF) neural network model for milling depth prediction. The experimental results demonstrate that optimal parameter combinations improve machining efficiency by 38 % compared to baseline conditions. The developed RBF model achieves exceptional predictive accuracy, with maximum absolute and relative errors of 0.30 mm and 18.8 %, respectively, and a mean absolute error of 12.01 % across validation trials. This work provides a theoretical foundation for precision machining of advanced ceramics while demonstrating a viable pathway toward intelligent process optimization in AWJ technology.
Keywords: abrasive water jet, AWJ, milling, alumina ceramic, precisio machining, material removal rate, single-factor experiment, orthogonal array, RFB neural network
Published in DKUM: 22.01.2026; Views: 0; Downloads: 0
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2. Seasonal influenza vaccination uptake among health and medical college students : a discrete choice experimentMonika Lamot, Andrej Kirbiš, 2025, original scientific article Abstract: Seasonal influenza is a highly contagious virus posing significant health risks, especially tochildren, pregnant women, and older adults. Despite its crucial role in prevention andreducing severity, vaccination rates among medical and health students, who frequentlyinteract with vulnerable groups, remain low. This study investigates attributes of influenzavaccines that predict vaccination decisions within this population, while also examininghow these preferences vary based on the health literacy levels of the respondents.Between May and June 2024, 239 Slovenian medical and health students completed anonline discrete choice experiment presenting vaccines varying in efficacy, side effects, andadministration site. Preferences were analyzed to identify key attributes. Results showedthat higher efficacy and fewer side effects drove vaccine choice across all disciplines.Medical students favored faculty-based vaccination, whereas nursing and other healthdiscipline students preferred GP offices and NIPH units. Health literacy did not alter theimportance of efficacy and safety, but those with sufficient literacy showed a strongerpreference for GP settings over faculty sites. Campaigns should emphasize vaccine efficacyand the low risk of severe side effects, reassuring that mild reactions are transient.Facilitating GP-based vaccination for nursing and other health discipline students mayfurther improve uptake.
Keywords: seasonal influenza, vaccination, decision-making, health behavior, students, discrete choice experiment
Published in DKUM: 25.08.2025; Views: 0; Downloads: 9
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4. Response of the invasive alien plant Duchesnea indica (Andrews) Teschem. to different environmental and competitive settingsMaja Kreća, Nina Šajna, Mirjana Šipek, 2025, original scientific article Abstract: Indian mock strawberry (Duchesnea indica, syn. Potentilla indica), a clonal invasive plant native to Asia, has rapidly spread in Europe, where its ecological adaptation allows it to thrive under varying environmental conditions. It is mostly found in urban habitats such as lawns, parks, and urban and peri-urban forests, where it thrives in various plant communities. It can become dominant in certain communities, indicating its competitive advantage over native plants. Due to similar habitat preferences, it often coexists with the native species Glechoma hederacea, with which it shares other characteristics such as clonal growth. This study investigates the effects of light, nutrients, and competition on the growth, morphology, and physiology of D. indica. A controlled pot experiment exposed plants to combinations of sunlight and shade, optimal and increased nutrient levels, and competitive scenarios with the native plant G. hederacea. The plant traits of biomass, leaf and ramet number, stolon and flower production, leaf greenness, the photosynthetic efficiency of Photosystem II, and stomatal conductance were assessed. Results revealed that light and nutrient availability significantly enhanced growth metrics. In shaded conditions, D. indica adapted with elongated petioles and increased specific leaf area. Competition significantly reduced growth, with G. hederacea outperforming D. indica. These findings highlight the complex interplay between abiotic and biotic factors in influencing invasive species impact, providing essential insights for ecosystem management.
Keywords: non-native species, light availability, nutrient availability, intraspecific competition, interspecific competition, pot experiment, morphological traits, ecophysiological traits
Published in DKUM: 23.06.2025; Views: 0; Downloads: 13
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5. Balancing software and training requirements for information securityDamjan Fujs, Simon Vrhovec, Damjan Vavpotič, 2023, original scientific article Abstract: Information security is one of the key areas of consideration to assure reliable and dependable information systems (IS). Achieving an appropriate level of IS security requires concurrent consideration of the technical aspects of IS and the human aspects related to the end users of IS. These aspects can be described in the form of information security requirements. We propose an approach that helps select and balance information security software requirements (iSSR) and information security training requirements (iSTR) according to the information security performance of end users. The approach was tested in an experiment involving 128 IS professionals. The results showed that using the proposed approach helps IS professionals with limited experience in information security make significantly better decisions regarding iSSR and iSTR.
Keywords: kibernetska varnost, eksperiment, informacijsko varnostni standardi, inženirstvo zahtev, usposabljanje končnih uporabnikov, informacijska varnost, cyber security, experiment, information security standard, requirements engineering, end user training, information security
Published in DKUM: 13.11.2024; Views: 0; Downloads: 8
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6. Exploring the neglected voices of children in sustainable tourism development : a comparative study in six european tourist destinationsMarko Koščak, Mladen Knežević, Daniel Binder, Antonio Pelaez-Verdet, Cem Işik, Vladimir Mićić, Katarina Borisavljević, Tina Šegota, 2023, original scientific article Abstract: For years, sustainable tourism has commanded the attention of academics and practitioners given its achievement through participatory planning. However, much research in the area has neglected to consider all voices of those (i.e., children) affected by tourism. This study, employing a post-test only experimental design, addresses this gap by including the voices of 498 children from six diverse European destinations concerning perceptions of tourism. Results show that children are willing to express their opinions given the opportunity. Moreover, their attitude towards tourists is negative, while they perceive locals to hold a subordinate position to tourists. In general, this study offers insight into children's attitudes to tourism from the host perspective, demonstrating that there is a unique insider's perspective that needs further research.
Keywords: tourism, sustainable development, environmental protection, children, sustainable tourism, resident attitudes, experiment, involvement
Published in DKUM: 27.08.2024; Views: 95; Downloads: 18
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7. Computer science education in ChatGPT Era: experiences from an experiment in a programming course for novice programmersTomaž Kosar, Dragana Ostojić, Yu David Liu, Marjan Mernik, 2024, original scientific article Abstract: The use of large language models with chatbots like ChatGPT has become increasingly popular among students, especially in Computer Science education. However, significant debates exist in the education community on the role of ChatGPT in learning. Therefore, it is critical to understand the potential impact of ChatGPT on the learning, engagement, and overall success of students in classrooms. In this empirical study, we report on a controlled experiment with 182 participants in a first-year undergraduate course on object-oriented programming. Our differential study divided students into two groups, one using ChatGPT and the other not using it for practical programming assignments. The study results showed that the students’ performance is not influenced by ChatGPT usage (no statistical significance between groups with a p-value of 0.730), nor are the grading results of practical assignments (p-value 0.760) and midterm exams (p-value 0.856). Our findings from the controlled experiment suggest that it is safe for novice programmers to use ChatGPT if specific measures and adjustments are adopted in the education process.
Keywords: large language models, ChatGPT, artificial intelligence, controlled experiment, object-oriented programming, software engineering education
Published in DKUM: 12.08.2024; Views: 59; Downloads: 22
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8. The Impact of Code Bloat on Genetic Program Comprehension: Replication of a Controlled Experiment on Semantic InferenceTomaž Kosar, Željko Kovačević, Marjan Mernik, Boštjan Slivnik, 2023, original scientific article Keywords: genetic programming, controlled experiment, program comprehension, replication, semantic inference, attribute grammars
Published in DKUM: 22.05.2024; Views: 171; Downloads: 19
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9. An experimental investigation of BPMN-based corporate communications modelingGregor Polančič, Boštjan Orban, 2023, original scientific article Abstract: Purpose
Despite corporate communications having an immense impact on corporate success, there is a lack of dedicated techniques for their management and visualization. A potential strategy is to apply business process management (BPM) approach with business process model and notation (BPMN) modeling techniques.
Design/methodology/approach
The goal of this study was to gain empirical insights into the cognitive effectiveness of BPMN-based corporate communications modeling. To this end, experimental research was performed in which subjects tested two modeling notations – standardized BPMN conversation diagrams and a BPMN extension with corporate communications-specific concepts.
Findings
Standard conversation diagrams were demonstrated to be more time-efficient for designing and interpreting diagrams. However, the subjects made significantly fewer mistakes when interpreting the diagrams modeled in the BPMN extension. Subjects also evolved positive perceptions toward the proposed extension.
Practical implications
BPMN-based corporate communications modeling may be applied to organizations to depict how formal communications are or should be performed consistently, effectively and transparently by following and integrating with BPM approaches and modeling techniques.
Originality/value
The paper provides empirical insights into the cognitive effectiveness of corporate communications modeling based on BPMN and positions the corresponding models into typical process architecture.
Keywords: corporate communication, BPMN, controlled experiment, conversation diagrams, cognitive effectiveness, modeling
Published in DKUM: 26.03.2024; Views: 224; Downloads: 34
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10. Experimental analysis of cavitation erosion in a particle-laden flowFilip Jovanovski, 2023, undergraduate thesis Abstract: Cavitation erosion is a problem that presents a challenge for the engineers in different industries, as it erodes the machinery which leads to lower efficiency and higher maintanance costs. An experimental investigation has been conducted to evaluate cavitation and cavitation erosion with and without the presence of solid particles in a Venturi channel. The methodology is based on observing and analysing the evolution of the vapour structures and occurence of cavitation erosion on the sample surface in the Venturi channel. To conduct experiments the cavitation tunnel was used, with the central component being a transparent test section with a Venturi-like channel (constructed from Plexiglass walls and a metal insert) to monitor the process of cavitation. To detect the damage caused by cavitation erosion and abrasion, the most effective solution was found to be an indicator in the form of black acrylic paint thinned with water (at a ratio of 1:2). On the sample surface, a self-adhesive aluminium tape was applied to protect the aluminium base from erosive characteristics from cavitation Furthermore, a comparison between cavitation with and without solid particles was made to determine the effects of solid particles on both cavitation and abrasion of the sample surface. The observation revealed that no matter the solid particles, damage from cavitation erosion appears at the separation point and in proximity to the location of the detached cloud collapse. The spherical glass particles with diameters between 40 µm and 70 µm added an abrasive effect on the sample surface only in the presence of cavitation structures. It was determined, that the intensity of cavitation erosion and abrasion increases when the cavitation number decreases and volumetric flow rate increases. Also, an economic analysis was conducted, to determine which is the more cost beneficial solution between replacement of the metal insert and application of protective coatings over the metal insert.
Keywords: cavitation erosion, solid particles, abrasion, experiment
Published in DKUM: 28.02.2024; Views: 230; Downloads: 37
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