1. Interaktivno upodabljanje digitalnega modela reliefa s štiriškim drevesomAnej Krajnc, 2025, undergraduate thesis Abstract: Diplomsko delo opisuje implementacijo upodabljanja digitalnega modela reliefa s štiriškim drevesom, trikotniško mrežo, z Blinn-Phongovo osvetlitvijo in sivinsko barvo. Cilj je pohitriti prikaz digitalnega modela reliefa s štiriškim drevesom. Ugotovili smo, da je prikaz s štiriškim drevesom hitrejši od prikaza celotnega modela reliefa, vendar ima večjo pomnilniško zahtevnost. Hitrost izrisa je odvisna tudi od števila oglišč, kar smo ugotovili z uporabo treh digitalnih modelov reliefa z različnim številom oglišč.
Keywords: štiriško drevo, digitalni model reliefa, trikotniška mreža, Blinn-Phongov osvetlitveni model, OpenGL
Published in DKUM: 08.05.2025; Views: 0; Downloads: 3
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2. Celostni model vpliva cikličnega gvanozin monofosfata na molekularne mehanizme znotrajcelične kalcijeve signalizacije v gladkih mišičnih celicah arterij : magistrsko deloKatarina Meštrović, 2025, master's thesis Abstract: V magistrski nalogi preučujemo molekularne mehanizme vpliva cikličnega gvanozin monofosfata (cGMP) na kalcijevo (Ca2+) signalizacijo v gladkih mišičnih celicah (GMC) arterij ter posledično na njihovo kontrakcijo oziroma relaksacijo. Obstoječi fizikalno-matematični model, ki vsebuje šest mehanizmov, preko katerih cGMP posredno ali neposredno vpliva na signal Ca2+, nadgradimo z dvema dodatnima mehanizmoma delovanja cGMP. To sta vpliv cGMP na od Ca2+ odvisne klorove (Cl-) kanale (ClCa), ki se nahajajo v celični membrani, in na črpalke za Ca2+ v membrani sarkoplazemskega retikuluma (SERCA). Študij vpliva cGMP na ClCa je zanimiv predvsem zaradi razlik med tipi teh kanalov v pljučni in mezenterični arteriji. Mezenterična arterija vsebuje dva tipa ClCa kanalov: od cGMP neodvisne ClCa in od cGMP odvisne ClCa (ClCacGMP), medtem ko pljučna arterija vsebuje zgolj od cGMP neodvisen tip teh kanalov (ClCa). S fizikalno-matematičnim modelom za oba tipa arterij simuliramo učinek cGMP na signal Ca2+ v GMC, ki se lahko izraža v obliki oscilacij ali stacionarnega stanja ter določimo povprečno koncentracijo Ca2+ v citoplazmi, ki odraža stopnjo kontrakcije. Poleg tega preučujemo tudi vpliv cGMP na SERCA. Rezultati simulacij kažejo, da visoka koncentracija cGMP v modelu, ki vključuje ClCacGMP, privede do povišane povprečne znotrajcelične koncentracije Ca2+. To se zgodi pri koncentracijah nad 10 µM. Nasprotno pa v modelu brez kanalov ClCacGMP višanje koncentracije cGMP zniža povprečno znotrajcelično koncentracijo Ca2+, kar je skladno s pričakovanji glede relaksacijskega učinka pri visokih koncentracijah cGMP. Iz simulacij je tudi razvidno, da je kanal ClCacGMP zaradi svoje večje občutljivosti na Ca2+ pri visokih koncentracijah cGMP odgovoren za povečan vstop Ca2+ v celico, kar povzroči višjo koncentracijo citosolnega Ca2+ v mezenterični arterij.
Keywords: gladka mišična celica, ciklični gvanozin monofosfat, od kalcija odvisni klorovi kanali, pljučna arterija, mezenterična arterija, kalcijeva signalizacija, fizikalno-matematični model
Published in DKUM: 08.05.2025; Views: 0; Downloads: 4
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3. Primerjava med 1d in 3d cfd numerično simulacijo motornega prostora delovnega stroja : diplomsko deloTomaž Rejc Zagožen, 2024, undergraduate thesis Abstract: Namen zaključnega dela je primerjava med 1D in 3D CFD numerično simulacijo kompleksnega motornega prostora delovnega stroja. Zanima nas, ali je 1D CFD simulacija smiselna in dovolj natančna za nadaljni razvoj hladilnega sistema. CAD model delovnega stroja je bil uvožen v GEM3D ter primerno obdelan za izvoz v 1D model. 1D model je bil izdelan in simuliran v programski opremi GT-SUITE.
Končna ugotovitev je, da trenutno GT-SUITE še ne premore obdelovati tako kompleksnih modelov, vendar ima zelo dobro podlago za obdelavo modelov v začetni fazi razvoja modela.
Keywords: motorni prostor, delovni stroj, 1D CFD, primerjava med 1D in 3D CFD simulacijo, GT-SUITE, GEM3D, GT-ISE, CFD, 1D model, 3D model, numerična simulacija
Published in DKUM: 06.05.2025; Views: 0; Downloads: 2
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4. Primerjava različnih izvedb vibracijskega sita z uporabo numerične simulacije po metodi diskretnih elementov dem : magistrsko deloLuka Hojnik, 2025, master's thesis Abstract: Magistrsko delo se osredotoča na področje vibracijskih sit. V magistrskem delu smo se osredotočili na teorijo vibracijskih sit, analitični preračun vibracijskih sit, kalibracijo materialnega modela, DEM simulacijo in FEA simulacijo izbranega vibracijskega sita ter primerjava različnih izvedb vibracijskih sit.
Poudarek v magistrskem delu je na numeričnem delu. V okviru raziskave je bilo analiziranih devet različnih izvedb vibracijskih sit, ki se med seboj razlikujejo po obliki in naklonu vibracijskega sita. Primerjava je bila izvedena tako, da smo vseh 9 različic simulirali v programskem orodju Ansys Rocky, kjer smo simulacijo izvedli z metodo diskretnih elementov (DEM). Med sabo smo primerjali sejalne sposobnosti vsake različice vibracijskega sita. Rezultate, pridobljene v programskem orodju Ansys Rocky, smo primerjali med seboj iz česar smo analizirali lastnosti vsake izvedbe vibracijskega sita. Za končno ovrednotenje mehanske ustreznosti konstrukcije vibracijskega sita je bila izvedena še analiza s pomočjo metode končnih elementov (FEA), s katero je bila preverjena statična trdnost konstrukcije izbranega vibracijskega sita.
Keywords: vibracijsko sito, analitični preračun vibracijskega sita, DEM simulacija vibracijskega sita, MKE simulacija vibracijskega sita, Hertz-Mindl kontaktni model, primerjava izvedb vibracijskih sit, kalibracija materiala
Published in DKUM: 06.05.2025; Views: 0; Downloads: 15
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5. Discrete memristive Hindmarsh-Rose neural model with fractional-order differencesFatemeh Parastesh, Karthikeyan Rajagopal, Sajad Jafari, Matjaž Perc, 2025, original scientific article Abstract: Discrete systems can offer advantages over continuous ones in certain contexts, particularly in terms of simplicity and reduced computational costs, though this may vary depending on the specific application and requirements. Recently, there has been growing interest in using fractional differences to enhance discrete models' flexibility and incorporate memory effects. This paper examines the dynamics of the discrete memristive Hindmarsh-Rose model by integrating fractional-order differences. Our results highlight the complex dynamics of the fractional-order model, revealing that chaotic firing depends on both the fractional-order and magnetic strength. Notably, certain magnetic strengths induce a transition from periodic firing in the integer-order model to chaotic behavior in the fractional-order model. Additionally, we explore the dynamics of two coupled discrete systems, finding that electrical coupling leads to the synchronization of chaotic dynamics, while chemical coupling ultimately results in a quiescent state.
Keywords: memristive Hindmarsh-Rose model, discrete systems, fractional-order differences
Published in DKUM: 06.05.2025; Views: 0; Downloads: 0
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6. Software self-hosting : a systematic review of quantitative research☆Luka Hrgarek, Lili Nemec Zlatolas, 2025, original scientific article Abstract: In an era marked by heightened concerns surrounding personal privacy and data security, software self-hosting has gained significance as a means for individuals and organizations to reclaim control over their digital assets. This systematic review aims to identify relevant research gaps in the quantitative analysis of self-hosting, primarily focusing on studies employing Structural Equation Modeling (SEM) and regression techniques. Employing a refined version of the Systematic Mapping Process, we analyzed 49 quantitative research papers whose concepts were grouped into 12 substantive groups. The findings reveal a predominant concentration on constructs related to the Technology Acceptance Model (TAM), with limited exploration of self-hosting specifically, overshadowed by an emphasis on cloud computing, the Internet of Things (IoT), and privacy aspects. Our review provides a comprehensive overview of the existing literature and highlights the need for more focused research on self-hosting itself. This systematic review serves as a foundational resource for researchers and practitioners aimed at advancing the discourse on self-hosting.
Keywords: self-hosting, social networking sites, privacy, quantitative, data sovereignty, technology acceptance model, systematic literature review
Published in DKUM: 23.04.2025; Views: 0; Downloads: 8
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7. Optimization-based downscaling of satellite-derived isotropic broadband albedo to high resolutionNiko Lukač, Domen Mongus, Marko Bizjak, 2025, original scientific article Abstract: In this paper, a novel method for estimating high-resolution isotropic broadband albedo is proposed, by downscaling satellite-derived albedo using an optimization approach. At first, broadband albedo is calculated from the lower-resolution multispectral satellite image using standard narrow-to-broadband (NTB) conversion, where the surfaces are considered Lambertian with isotropic reflectance. The high-resolution true orthophoto for the same location is segmented with the deep learning-based Segment Anything Model (SAM), and the resulting segments are refined with a classified digital surface model (cDSM) to exclude small transient objects. Afterwards, the remaining segments are grouped using K-means clustering, by considering orthophoto-visible (VIS) and near-infrared (NIR) bands. These segments present surfaces with similar materials and underlying reflectance properties. Next, the Differential Evolution (DE) optimization algorithm is applied to approximate albedo values to these segments so that their spatial aggregate matches the coarse-resolution satellite albedo, by proposing two novel objective functions. Extensive experiments considering different DE parameters over an 0.75 km2 large urban area in Maribor, Slovenia, have been carried out, where Sentinel-2 Level-2A NTB-derived albedo was downscaled to 1 m spatial resolution. Looking at the performed spatiospectral analysis, the proposed method achieved absolute differences of 0.09 per VIS band and below 0.18 per NIR band, in comparison to lower-resolution NTB-derived albedo. Moreover, the proposed method achieved a root mean square error (RMSE) of 0.0179 and a mean absolute percentage error (MAPE) of 4.0299% against ground truth broadband albedo annotations of characteristic materials in the given urban area. The proposed method outperformed the Enhanced Super-Resolution Generative Adversarial Networks (ESRGANs), which achieved an RMSE of 0.0285 and an MAPE of 9.2778%, and the Blind Super-Resolution Generative Adversarial Network (BSRGAN), which achieved an RMSE of 0.0341 and an MAPE of 12.3104%.
Keywords: isotropic broadband albedo, high-resolution albedo, Sentinel-2 albedo, true orthophoto, anything model, differential evolution
Published in DKUM: 23.04.2025; Views: 0; Downloads: 0
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8. Kompetence trenerjev alpskega smučanjaTimi Gašperin, 2025, master's thesis Abstract: Namen magistrskega dela je bil razviti kompetenčni model za trenerje alpskega smučanja, ki bi pomagal pri opredelitvi ključnih kompetenc, potrebnih za uspešno izvajanje trenerskih nalog v različnih situacijah, vključno s kriznimi. Raziskava je bila izvedena z uporabo dveh glavnih metod. Prvi del raziskave je vključeval teoretično analizo obstoječih virov, pri kateri smo uporabili komparativno in deskriptivno metodo. V empiričnem delu smo izvedli intervjuje z izbranimi trenerji alpskega smučanja, ki delujejo na najvišji ravni, pri čemer smo uporabili kvantitativno metodo za analizo podatkov in oblikovanje kompetenčnega modela. Rezultati raziskave so pokazali, da so za uspeh trenerjev ključne tako tehnične kot mehke kompetence, med katerimi izstopajo sposobnosti učinkovitega vodenja, motivacije, prilagajanja treningov individualnim potrebam športnikov ter obvladovanja kriznih situacij. Na osnovi ugotovitev smo razvili kompetenčni model, ki vključuje vse ključne kompetence za trenerje alpskega smučanja. Priporočamo, da se ta model vključi v programe usposabljanja in profesionalnega razvoja trenerjev, saj lahko znatno prispeva k izboljšanju njihove učinkovitosti ter sposobnosti obvladovanja izzivov, s katerimi se soočajo na terenu. Prav tako predlagamo, da se v prihodnosti izvedejo nadaljnje raziskave, ki bi podrobneje preučile vpliv stresnih delovnih pogojev na razvoj specifičnih kriznih kompetenc pri trenerjih alpskega smučanja.
Keywords: vodenje in management, kompetence, kompetenčni model
Published in DKUM: 23.04.2025; Views: 0; Downloads: 1
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9. Education for future? Investigating the role of education in explaining active green engagement : a multilevel moderated mediation analysisMatthias Penker, Andrej Kirbiš, 2025, original scientific article Abstract: Despite extensive literature emphasizing the role of education in promoting engagement in environmental movements, international comparative research has yet to fully elucidate the mechanisms underlying this relationship. Using data from 44,100 respondents across 28 countries in the ISSP's fourth environmental module, we demonstrate that individuals' willingness to pay for environmental protection (WTP) partially mediates the relationship between education and environmental public sphere behavior (PSB). Furthermore, drawing on the Quality of Government literature, we show that the link between education and WTP is significantly stronger in countries with low corruption levels, a pattern that extends to the indirect effect of education on PSB. Although the magnitude of this effect is reduced, the direct positive association between education and PSB persists even in high-corruption contexts. These findings underscore the transnational importance of education in shaping environmentally significant attitudes and behaviors, as well as the crucial role of corruption in moderating how education translates into both WTP and PSB.
Keywords: politic sphere behaviour, environmental activism, education, moderated mediation analyses, multilevel model
Published in DKUM: 16.04.2025; Views: 0; Downloads: 2
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10. Assessing the effects of a hydropower plant basin on fish spawning in an upstream river tributaryGorazd Hren, Andrej Predin, Matej Fike, Marko Pezdevšek, 2024, original scientific article Abstract: This paper presents a combined modeling approach to evaluate the ecological effects on the habitat of an upstream tributary of a river with a series of hydropower plants. The influence is investigated of the last planned hydropower plant to be built, which has a large impact on the river ecosystem. The new hydropower plant basin will affect the tributary with hydropeaking in the upstream basin. A simulation was conducted of spawning conditions for two protected fish species. The analysis combined a hydro-morphological model with a fish module that considers the water depth and velocity necessary for fish reproduction. The different river discharge scenarios were simulated, incorporating the hydropeaking effects of the new hydropower plant basin on the upstream tributary. With the new hydropower plant, sustainable measures are planned to prevent the damaging negative impacts that could lead to the degradation of the river ecosystem and the destruction of the existing ecosystem at the river’s confluence. The results indicate that, after the hydropower plant begins operation, the habitat`s suitability will decrease, and the planned sustainable measures will not provide a fully satisfactory solution.
Keywords: environmental impact, habitat sustainability, hydro-dynamic model
Published in DKUM: 11.04.2025; Views: 0; Downloads: 10
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