1. Analysing flexural response in RC beams: a closed-form solution designer perspective from detailed to simplified modellingDenis Imamović, Matjaž Skrinar, 2024, izvirni znanstveni članek Opis: This paper presents a detailed analytical approach for the bending analysis of reinforced concrete beams, integrating both structural mechanics principles and Eurocode 2 provisions. The general analytical expressions derived for the curvature were applied for the transverse displacement analysis of a simply supported reinforced concrete beam under four-point loading, focusing on key limit states: the initiation of cracking, the yielding of tensile reinforcement and the compressive failure of concrete. The displacement’s results were validated through experimental testing, showing a high degree of accuracy in the elastic and crack propagation phases. Deviations in the yielding phase were attributed to the conservative material assumptions within the Eurocode 2 framework, though the analytical model remained reliable overall. To streamline the computational process for more complex structures, a simplified model utilising a non-linear rotational spring was further developed. This model effectively captures the influence of cracking with significantly reduced computational effort, making it suitable for serviceability limit state analyses in complex loading scenarios, such as seismic impacts. The results demonstrate that combining detailed analytical methods with this simplified model provides an efficient and practical solution for the analysis of reinforced concrete beams, balancing precision with computational efficiency.
Ključne besede: reinforced concrete structures, non-linear behaviour, transverse displacement, moment–curvature diagram, rotational spring model
Objavljeno v DKUM: 10.01.2025; Ogledov: 0; Prenosov: 2
 Celotno besedilo (1,82 MB)
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2. A genetic algorithm based ESC model to handle the unknown initial conditions of state of charge for lithium ion battery cellKristijan Korez, Dušan Fister, Riko Šafarič, 2025, izvirni znanstveni članek Opis: Classic enhanced self-correcting battery equivalent models require proper model parameters and initial conditions such as the initial state of charge for its unbiased functioning. Obtaining parameters is often conducted by optimization using evolutionary algorithms. Obtaining the initial state of charge is often conducted by measurements, which can be burdensome in practice. Incorrect initial conditions can introduce bias, leading to long-term drift and inaccurate state of charge readings. To address this, we propose two simple and efficient equivalent model frameworks that are optimized by a genetic algorithm and are able to determine the initial conditions autonomously. The first framework applies the feedback loop mechanism that gradually with time corrects the externally given initial condition that is originally a biased arbitrary value within a certain domain. The second framework applies the genetic algorithm to search for an unbiased estimate of the initial condition. Long-term experiments have demonstrated that these frameworks do not deviate from controlled benchmarks with known initial conditions. Additionally, our experiments have shown that all implemented models significantly outperformed the well-known ampere-hour coulomb counter integration method, which is prone to drift over time and the extended Kalman filter, that acted with bias.
Ključne besede: enhanced self-correcting model, state of charge estimation, lithium-ion cell parameter identification
Objavljeno v DKUM: 08.01.2025; Ogledov: 0; Prenosov: 1
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3. Priročnik za delo s programom PIPEOPT-SR za optimiranje visokotlačnih jeklenih cevovodov z ojačitvamiStojan Kravanja, Tomaž Žula, 2024, priročnik Opis: Pričujoči priročnik obravnava delo s programom – optimizacijskim modelom - za optimiranje visokotlačnih jeklenih cevovodov z ojačitvami, kakršni se vgrajujejo v izvrtan tunel v hribino. Cevovod je dimenzioniran kot samonosilna jeklena cilindrična lupina s krožnimi ojačitvami brez sodelovanja hribine in okoliškega betona. Cevovod je lahko obremenjen z notranjim ali zunanjim tlakom. Optimizacija cevovoda se izvede z nelinearnim programiranjem, NLP. V ta namen je bil modeliran optimizacijski program PIPEOPT-SR, verzija 1,0. Optimizacijski model vsebuje skalarje (vhodne podatke), spremenljivke in namensko funkcijo mase jeklene konstrukcije, ki je podvržena sistemu pogojnih (ne)enačb iz statične analize in dimenzioniranja cevovoda v skladu s C.E.C.T. priporočili. Na koncu priročnika je predstavljen primer optimizacije visokotlačnega cevovoda z ojačitvami črpalne hidroelektrarne Kozjak, locirane v bližini Maribora.
Ključne besede: program, optimizacijski model, optimizacija, nelinearno programiranje, visokotlačni jekleni cevovod z ojačitvami
Objavljeno v DKUM: 19.12.2024; Ogledov: 0; Prenosov: 7
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4. Minimal universal laser network model : synchronization, extreme events, and multistabilityMahtab Mehrabbeik, Fatemeh Parastesh, Karthikeyan Rajagopal, Sajad Jafari, Matjaž Perc, Riccardo Meucci, 2024, izvirni znanstveni članek Opis: The synchronization of chaotic systems has garnered considerable attention across various fields, including neuroscience and physics. Particularly in these domains, synchronizing physical systems such as laser models is crucial for secure and rapid information transmission. Consequently, numerous studies investigate the synchronizability of different laser networks by establishing logical network frameworks. In this study, we employed a minimal universal laser (MUL) model designed to capture the essential dynamics of an actual laser model within just three dimensions. Within the network model of MUL systems, we introduced the linear diffusive function of neighboring nodes' fast variables into the feedback term of the lasers, with models arranged in a global network structure. Our examination of synchronization within the constructed MUL network utilized master stability functions and the time-averaged synchronization error index. The findings suggest that while the network fails to achieve complete synchrony, it exhibits various synchronization phenomena, including cluster synchronization, chimera states, extreme events, and multistability. These results shed light on the complex dynamics underlying the synchronization of chaotic systems in networked environments, offering insights relevant to numerous applications across diverse fields.
Ključne besede: minimal universal laser model, synchronization, extreme events
Objavljeno v DKUM: 16.12.2024; Ogledov: 0; Prenosov: 3
Celotno besedilo (5,68 MB)
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5. Information technology for business sustainability : a literature review with automated content analysisDoroteja Vidmar, Marjeta Marolt, Andreja Pucihar, 2021, pregledni znanstveni članek Opis: An extremely dynamic and fast-moving environment is pushing enterprises to continuous innovation and change. Managing sustainability in a digitalized environment seems to be of central importance for policy makers, as information technologies (IT), in combination with sustainability objectives, offer a wide range of opportunities for positive change. Through a systematic literature review and the application of automated content analysis, this study aims to provide insights into the latest research in the interdisciplinary field of sustainable business models and information systems. The results of the analysis, combined with a researcher’s perspective, suggest that IT, which can be used to achieve sustainability objectives, are already in place and have an infinite number of potential implications in the future. The results suggest that positive economic, social, and environmental changes can be achieved by using IT as long as they are used to identify unsustainable actions and enable positive change. The analysis of research trends revealed a discrepancy between the research in the European Union and the rest of the world and pointed to several avenues for future research.
Ključne besede: information technology, enterprise, business model, sustainability, business sustainability, sustainable business model, IT, IS, BM, SBM
Objavljeno v DKUM: 11.12.2024; Ogledov: 0; Prenosov: 4
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6. Network representation of multicellular activity in pancreatic islets : Technical considerations for functional connectivity analysisMarko Šterk, Yaowen Zhang, Viljem Pohorec, Eva Paradiž, Jurij Dolenšek, Richard K. P. Benninger, Andraž Stožer, Vira Kravets, Marko Gosak, 2024, izvirni znanstveni članek Opis: Within the islets of Langerhans, beta cells orchestrate synchronized insulin secretion, a pivotal aspect of metabolic homeostasis. Despite the inherent heterogeneity and multimodal activity of individual cells, intercellular coupling acts as a homogenizing force, enabling coordinated responses through the propagation of intercellular waves. Disruptions in this coordination are implicated in irregular insulin secretion, a hallmark of diabetes. Recently, innovative approaches, such as integrating multicellular calcium imaging with network analysis, have emerged for a quantitative assessment of the cellular activity in islets. However, different groups use distinct experimental preparations, microscopic techniques, apply different methods to process the measured signals and use various methods to derive functional connectivity patterns. This makes comparisons between findings and their integration into a bigger picture difficult and has led to disputes in functional connectivity interpretations. To address these issues, we present here a systematic analysis of how different approaches influence the network representation of islet activity. Our findings show that the choice of methods used to construct networks is not crucial, although care is needed when combining data from different islets. Conversely, the conclusions drawn from network analysis can be heavily affected by the pre-processing of the time series, the type of the oscillatory component in the signals, and by the experimental preparation. Our tutorial-like investigation aims to resolve interpretational issues, reconcile conflicting views, advance functional implications, and encourage researchers to adopt connectivity analysis. As we conclude, we outline challenges for future research, emphasizing the broader applicability of our conclusions to other tissues exhibiting complex multicellular dynamics.
Ključne besede: islets of Langerhans, beta cells, calcium signaling, intercellular communication, functional networks, myosin model
Objavljeno v DKUM: 09.12.2024; Ogledov: 0; Prenosov: 3
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7. An Assessment of socio-economic status of women on family farms: Slovenian case studyJernej Prišenk, Urška Vesenjak, Črtomir Rozman, Jernej Turk, Karmen Pažek, 2024, izvirni znanstveni članek Opis: The question of gender equality is increasingly being raised today and is present at all
levels of society. The topicality of the issue on farms is particularly evident, due to the particular
inheritance processes on farms, the clear division of labour, and intergenerational cooperation that
characterise the agricultural sector. In this research, a multi-criteria model (DEX-SOCIAL) was
developed to understand the broader aspect of rural sociology and the issue of women’s status on
the farm. The paper discusses the status of women on a farm and assesses their social and economic
situation. The methodology includes an online questionnaire in which women in the Eastern and
Western Cohesion Regions participated, as well as other farm members and owners. Subsequently,
the questions were transformed for the requirements of the assessment model, which assessed the life
prospects of women on farms in both the Eastern and Western Cohesion Regions who were aged both
over and under 40 years (criteria for “young successor”). The results of the study show that there
is a clear difference in the qualitative assessment of women’s socio-economic position in relation
to the East–West cohesion region. The social position of women does not differ according to age
structure. The conclusions of the study also present broader applications of the results in the field of
rural development and rural sociology.
Ključne besede: woman, socio-economic status, family farms, multi-criteria model, DEX
Objavljeno v DKUM: 29.11.2024; Ogledov: 0; Prenosov: 2
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8. Mathematical modeling of the floating sleeper phenomenon supported by field measurements : Mojmir Uranjek, Denis Imamović and Iztok PerušMojmir Uranjek, Denis Imamović, Iztok Peruš, 2024, izvirni znanstveni članek Opis: This article aims to provide an accurate mathematical model with the minimum number of degrees of freedom for describing the floating sleeper phenomenon. This was accomplished using mathematical modeling supported by extensive field measurements of the railway track. Although the observed phenomenon is very complex, the simplified single degree of freedom (SDOF) mathematical model proved accurate enough for its characterization. The progression of the deterioration of the railway track was successfully correlated to changes in the maximal dynamic factor for different types of pulse loading. The results of the presented study might enable the enhanced construction and maintenance of railroads, particularly in karst areas.
Ključne besede: floating sleepers, dynamic factor, pulse loading, field measurements, SDOF mathematical model
Objavljeno v DKUM: 28.11.2024; Ogledov: 0; Prenosov: 4
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9. Komunikacijski model književne vzgoje v digitalno podprtih učnih okoljih za prvo vzgojno-izobraževalno obdobje : doktorska disertacijaPolonca Legvart, 2024, doktorska disertacija Opis: Vpliv učnega okolja na književno vzgojo v začetnih letih šolanja je redkeje obravnavan vidik in še posebej digitalna podpora pri tem postavlja pedagoškemu raziskovanju nova vprašanja. Med njimi je ključno, ali lahko z didaktično uporabo digitalnih učnih pomagal izboljšamo recepcijo književnosti pri učencih. Razlogi za raziskovalno poglobitev v to vprašanje so v razmerah, ko otroci že v polni meri živijo čas digitalne družbe, cilj književne vzgoje pa je, da ta okoliščina ne bi povzročila njihovega odmika od književnosti, pač pa zbližanje z njo, saj jim književnost zagotavlja bistvene kompetence, vire in strategije za soočanje z izzivi kronične krize 21. stoletja.
Potrebne so spremembe tradicionalnega pouka književnosti z vidika upoštevanja digitalno podprtega učnega okolja, integriranja tehnologije v pedagoški pristop (TPACK in SAMR), digitalne pismenosti, digitalnega razkoraka in podpiranja »drugega tira« za otroke iz literarno manj spodbudnih okolij. Odločilno oporo nudi uveljavljeni model literarnorecepcijske in didaktične komunikacije pri književni vzgoji, ki ga je mogoče nadgraditi za digitalno podprto učno okolje.
Empirična raziskava se je osredotočila na pripravljenost učiteljev kot ključnih dejavnikov didaktičnih sprememb za vključevanje digitalnih tehnologij v izvajanje književne vzgoje. Podan je podrobnejši prikaz priprave, izvedbe in evalvacije primerov didaktičnih enot književne vzgoje v digitalno podprtem učnem okolju prvih treh razredov (1. VIO) s pristopom spojenega (blended) učenja. Glede na kompleksnost obravnavanega pojava književne vzgoje v digitalno podprtem učnem okolju je za preučevanje le-tega izbranih več raziskovalnih metod tako kvantitativnega kot kvalitativnega značaja ter komplementarni način njihovega kombiniranja ter triangulacije.
Tako teoretična izhodišča kot praktična pedagoška izkušnja ter kvalitativna in kvantitativna evalvacija le-te potrjujejo, da je komunikacijski model književne vzgoje ob ustreznih prilagoditvah izvedljiv tudi v digitalno podprtem učnem okolju. To se je kljub vsiljeni izvedbi vendarle pokazalo pri izobraževanju na daljavo zaradi epidemije COVID-19, primeri premišljene izvedbe digitalno podprte književne vzgoje v poepidemičnem obdobju pa dokazujejo, da je mogoče na ta način dodatno motivirati učence in poglobiti njihovo recepcijo literarnega dela ter tako uspešno razvijati njihovo recepcijsko zmožnost.
Pomen navedenih raziskovalnih dognanj bi lahko vplival na preobrat k pozitivni naravnanosti učiteljev do vključevanja digitalnih tehnologij v pedagoške pristope pri književni vzgoji in nasploh. S tem bi šola prevzela odločilnejšo vlogo pri usmerjanju mladih ljudi glede načinov uporabe novih komunikacijskih tehnologij.
Ključne besede: komunikacijski model književne vzgoje, digitalno podprta učna okolja, digitalna pismenost, prvo vzgojno-izobraževalno obdobje, didaktična enota, spojeno učenje, drugi tir književne vzgoje
Objavljeno v DKUM: 26.11.2024; Ogledov: 0; Prenosov: 16
Celotno besedilo (12,24 MB) |
10. Priročnik za delo s programom za optimiranje sovprežnega stropnega sistema s plastično odpornostjo nosilca z jeklenimi IPE profili : COMBOPT-PIPE, verzija 1,0Tomaž Žula, Stojan Kravanja, 2024 Opis: Priročnik predstavlja delo s programom za optimiranje sovprežnega stropnega sistema, ki se lahko uporablja pri gradnji večetažnih stavb. Konstrukcija je sestavljena iz armiranobetonske plošče in jeklenih IPE nosilcev. Optimiranje je izvedeno z mešanim celoštevilskim nelinearnim programiranjem (MINLP). Razvit je bil optimizacijski model COMBOPT-PIPE s podrobno namensko funkcijo lastnih izdelavnih stroškov. Poleg namenske funkcije optimizacijski model vsebuje vhodne podatke, spremenljivke, pogojne (ne)enačbe, poznane iz analize in dimenzioniranja sovprežnih konstrukcij, celoštevilske in mešane celoštevilske pogojne (ne)enačbe. Pogoji dimenzioniranja so definirani v skladu z Evrokod 4. Na koncu priročnika je predstavljen računski primer optimizacije sovprežnega stropnega sistema.
Ključne besede: program, optimizacijski model, optimizacija, mešano celoštevilsko nelinearno programiranje, sovprežni stropni sistem
Objavljeno v DKUM: 22.11.2024; Ogledov: 0; Prenosov: 15
Celotno besedilo (3,21 MB)
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