Iskanje po katalogu digitalne knjižnice

Opis: The aim of this paper is to present a novel and comprehensive methodology for the dynamic modeling and experimental validation of a photovoltaic/thermal system. The dynamic model is divided into thermal and electrical subsystems, encompassing the photovoltaic/ thermal module and the thermal energy storage. The thermal subsystem of both the photovoltaic/thermal module and the thermal energy storage is described by a one-dimensional dynamic model of heat transfer mechanisms and optical losses, while the electrical subsystem is presented as an electrical equivalent circuit of double diode solar cell. Model validation was conducted on a modern experimental photovoltaic/thermal system over an extended operational period at a five-minute resolution, with validation days classified as sunny, cloudy, or overcast based on weather conditions, thereby demonstrating an applied approach. The results demonstrate the lowest deviation values reported to date, confirmed using six quantitative indicators. The added value of the proposed methodology, not previously addressed in the literature, lies in the following contributions: (i) comprehensive modeling of the entire photovoltaic/thermal system, (ii) accurate consideration of optical losses in the photovoltaic/thermal module, and (iii) long-term experimental validation. Overall, the proposed methodology provides a reliable and efficient framework for PV/T system design, optimization, and long-term performance assessment.
Ključne besede: photovoltaic/thermal system, thermal energy storage, dynamic modeling, experimental validation, heat transfer mechanism, temperature, electrical power
Objavljeno v DKUM: 10.11.2025; Ogledov: 0; Prenosov: 0
Celotno besedilo (7,15 MB)
Gradivo ima več datotek! Več...

Opis: Diplomsko delo opisuje razvoj spletne aplikacije za obdelavo slik v oblaku z uporabo tehnologij AWS in Next.js. Sistem temelji na brezstrežniški arhitekturi, kjer ključne funkcionalnosti izvajajo storitve AWS, kot so Lambda, S3, DynamoDB in ECR. Za avtentikacijo uporabnikov se uporablja Clerk, medtem ko je za obdelavo slik implementirana lastna rešitev v okolju Docker. Poseben poudarek je na večplatformski funkcionalnosti, razširljivosti in enostavni uporabi sistema, ki omogoča shranjevanje, obdelavo in prikazovanje naloženih slik na učinkovit način. V okviru testiranja je bilo ugotovljeno, da ima med parametri obdelave največji vpliv na čas obdelovanja ločljivost slik. Pri simulaciji sočasnih nalaganj se je ta čas predvidljivo povečeval s številom uporabnikov, vendar je sistem kljub obremenitvam ohranil stabilno in zanesljivo delovanje.
Ključne besede: spletna aplikacija, Amazon Web Service, obdelava slik
Objavljeno v DKUM: 23.09.2025; Ogledov: 0; Prenosov: 9
Celotno besedilo (2,42 MB)

Opis: Tehnologija LiDAR človeku omogoča nove načine odkrivanja svojega okolja, v katerem se skrivajo arheološki ostanki naših prednikov in namigi k optimizaciji vsakdanjika. V magistrskem delu smo raziskovali pot, ki je vodila do daljinskega zaznanja, in rešitve, ki so omogočile njeno raziskovanje. Algoritme iskanja po drevesih in gručanja smo vgradili v tri rešitve, ki so iz podatkov LiDAR, zajetih z letalnikom in letalom, poskušale razpoznati linije vinske trte. Zagoni rešitev so temeljili na cevovodu, ki je izvorne .laz datoteke vodil do ciljnih oblik. Izplene zagonov smo predstavili v okviru njihove statistične analize, s katero smo izpostavili prednosti in slabosti posamičnega pristopa.
Ključne besede: LiDAR, DBSCAN, RANSAC, vinogradništvo, daljinsko zaznavanje
Objavljeno v DKUM: 04.09.2025; Ogledov: 0; Prenosov: 29
Celotno besedilo (2,38 MB)

Opis: V magistrski nalogi predstavimo nevronsko mrežo za napoved deformacij kože tridimenzionalnih karakterjev. Osredotočamo se na tehnike redukcije dimenzionalnosti, kot sta metoda glavnih komponent in samokodirnik. Primerjamo zmogljivost obeh pristopov glede natančnosti, uporabnosti in časovne zahtevnosti ter podamo smernice za njihovo praktično uporabo pri generiranju realistično animiranih karakterjev v filmih, računalniški grafiki in realnočasovnih okoljih. Rezultati kažejo, da samokodirnik zagotavlja višjo kakovost napovedi in boljše posploševanje kompleksnih deformacij, medtem ko PCA izstopa po hitrosti in preprosti implementaciji. Ugotovitve potrjujejo, da je izbira metode odvisna od specifičnih zahtev problema, kar omogoča prilagodljiv in učinkovit pristop za različne scenarije v računalniški grafiki.
Ključne besede: PCA, samokodirnik, nevronska mreža, fizikalna simulacija, deformacija mreže
Objavljeno v DKUM: 04.09.2025; Ogledov: 0; Prenosov: 15
Celotno besedilo (2,49 MB)

Opis: 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%.
Ključne besede: isotropic broadband albedo, high-resolution albedo, Sentinel-2 albedo, true orthophoto, anything model, differential evolution
Objavljeno v DKUM: 23.04.2025; Ogledov: 0; Prenosov: 1
Celotno besedilo (20,47 MB)