1. Post-fault energy usage optimization for multilevel inverter with integrated batteryRok Friš, Jure Domajnko, Nataša Prosen, Mitja Truntič, 2025, izvirni znanstveni članek Opis: This paper presents a novel sorting algorithm for modular multilevel inverters (MMCs) with integrated batteries, designed to ensure the uninterrupted operation of electric vehicles (EVs) under post-fault conditions. The proposed system structure consists of an MMC with four full-bridge modules per phase, where one module acts as a spinning reserve during normal operation. The algorithm addresses a single switch fault per phase by operating the faulted module in half-bridge mode, ensuring all batteries remain operational and maintaining full power output and battery capacity without any noticeable changes for the vehicle operator. Unlike conventional fault-tolerant strategies that often reduce power output or disable affected modules, the proposed algorithm isolates the faulty switch while preserving system output. This approach avoids derating and eliminates the need for immediate maintenance, enabling the EV to continue operating under fault conditions. Simulation and experimental results validate the effectiveness of the algorithm under a single switch fault scenario, demonstrating its ability to maintain autonomy and consistent power delivery. This work demonstrates a fault-tolerant MMC principle, offering a robust and scalable solution for enhancing reliability and user satisfaction in EV power systems.
Ključne besede: modular multilevel converter, fault tolerance, redundancy, uninterrupted operation, sorting algorithm
Objavljeno v DKUM: 09.04.2025; Ogledov: 0; Prenosov: 4
 Celotno besedilo (10,18 MB) |
2. Using a region-based convolutional neural network (R-CNN) for potato segmentation in a sorting processJaka Verk, Jernej Hernavs, Simon Klančnik, 2025, izvirni znanstveni članek Opis: This study focuses on the segmentation part in the development of a potato-sorting system that utilizes camera input for the segmentation and classification of potatoes. The key challenge addressed is the need for efficient segmentation to allow the sorter to handle a higher volume of potatoes simultaneously. To achieve this, the study employs a region-based convolutional neural network (R-CNN) approach for the segmentation task, while trying to achieve more precise segmentation than with classic CNN-based object detectors. Specifically, Mask R-CNN is implemented and evaluated based on its performance with different parameters in order to achieve the best segmentation results. The implementation and methodologies used are thoroughly detailed in this work. The findings reveal that Mask R-CNN models can be utilized in the production process of potato sorting and can improve the process.
Ključne besede: image segmentation, potato sorting, neural network, mask RCNN, object detection, production process, machine learning, AI
Objavljeno v DKUM: 27.03.2025; Ogledov: 0; Prenosov: 10
Celotno besedilo (5,97 MB)
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3. Multicriteria assessment of the quality of waste sorting centers - ǂaǂ case studyKarmen Pažek, Jernej Prišenk, Simon Bukovski, Boris Prevolšek, Črtomir Rozman, 2020, izvirni znanstveni članek Opis: In this paper, the quality of the municipal waste sorting process in seven waste management centers in Slovenia was assessed using the qualitative multicriteria analysis (MCA) method DEX (Decision EXpert) implemented in DEXi software, which is based on multicriteria decomposition of the problem and utility functions in the form of ʺif-thenʺ decision rules. The study was based on eight types of secondary raw materials. The quality of the secondary raw materials, the regularity of the delivery of secondary raw materials to recycling units based on the sorting efficiency, and the loading weight of the individual baled fractions in the transport of secondary raw materials for recycling were the main parameters used in the model. The final assessment shows good waste management service in centers A and D. Centers B, C, and F were rated ʺaverageʺ. The ʺbadʺ rating was assigned to centers E and G.
Ključne besede: waste sorting, quality management, multicriteria decision analysis, expert system DEXi
Objavljeno v DKUM: 03.02.2025; Ogledov: 0; Prenosov: 4
Celotno besedilo (2,88 MB)
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4. A holistic approach to cooling system selection and injection molding process optimization based on non-dominated sortingJanez Gotlih, Miran Brezočnik, Snehashis Pal, Igor Drstvenšek, Timi Karner, Tomaž Brajlih, 2022, izvirni znanstveni članek Opis: This study applied a holistic approach to the problem of controlling the temperature of critical areas of tools using conformal cooling. The entire injection molding process is evaluated at the tool design stage using four criteria, one from each stage of the process cycle, to produce a tool with effective cooling that enables short cycle times and ensures good product quality. Tool manufacturing time and cost, as well as tool life, are considered in the optimization by introducing a novel tool-efficiency index. The multi-objective optimization is based on numerical simulations. The simulation results show that conformal cooling effectively cools the critical area of the tool and provides the shortest cycle times and the lowest warpage, but this comes with a trade-off in the tool-efficiency index. By using the tool-efficiency index with non-dominated sorting, the number of relevant simulation cases could be reduced to six, which greatly simplifies the decision regarding the choice of cooling system and process parameters. Based on the study, a tool with conformal cooling channels was made, and a coolant inlet temperature of 20 °C and a flow rate of 5 L/min for conformal and 7.5–9.5 L/min for conventional cooling channels were selected for production. The simulation results were validated by experimental measurements.
Ključne besede: conformal cooling, injection molding, tooling, additive manufacturing, numerical simulation, non-dominated sorting
Objavljeno v DKUM: 05.12.2024; Ogledov: 0; Prenosov: 5
Celotno besedilo (6,87 MB)
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5. A waste separation system based on sensor technology and deep learning: a simple approach applied to a case study of plastic packaging wasteRok Pučnik, Monika Dokl, Yee Van Fan, Annamaria Vujanović, Zorka Novak-Pintarič, Kathleen B. Aviso, Raymond R. Tan, Bojan Pahor, Zdravko Kravanja, Lidija Čuček, 2024, izvirni znanstveni članek Ključne besede: waste management, smart waste bin system, central post-sorting, sensor technology, deep learning, convolutional neural networks
Objavljeno v DKUM: 23.08.2024; Ogledov: 51; Prenosov: 9
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6. Rationalisation of costs in the collection, segregation and transport of municipal wastePaweł Zając, Ivona Bajor, Matevž Obrecht, Stanisław Ejdys, 2023, izvirni znanstveni članek Opis: The article contains answers to three "why" questions: - why the waste management system still does not bring the expected results, and the Polish state is one of the lowest-ranking in the European score regarding the amount of segregated waste; - why the sale of selected secondary raw materials and their material reuse in production processes do not cover the costs related to waste management; - why it does not bring additional profits. The article is based on research conducted in Wroclaw from 1998 to 2018. There is a cost model that can be adapted to similar cases. The article deals with removing organisational and/or technical reasons causing the stagnation of selective waste collection.
Ključne besede: waste, mixed, sorting, fee, management
Objavljeno v DKUM: 16.02.2024; Ogledov: 204; Prenosov: 20
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7. On the role of anisotropy of membrane constituents on the elastic properties of highly curved lipid membranesŠarka Perutkova, 2017, doktorska disertacija Opis: The primary objective of the thesis covers in the theoretical study the role of
anisotropic membrane components in the elasticity of highly curved biological
membranes. To show the importance of anisotropy, we focused on one
type of non-lamellar membrane self-assembly - the inverted hexagonal phase
and the membrane tubular protrusions with attached proteins. These two
structures represent excellent examples of highly curved structures in which
the anisotropy of molecules or small domains plays an important role. In
the first part of the thesis, we developed a theoretical model describing the
stability of the inverted hexagonal phase, which considers lipid anisotropy
and deviations from the circularity of the pivotal plane cross-section. We applied
a wedge-like model of phospholipid molecules, in which the phospholipid
molecule is described as a wedge, with the angle of the wedge increasing with
temperature. However, we also took into account the average orientation of
lipids by including the deviatoric bending energy contribution derived from
statistical physics. Theoretical predictions of our model showed that a crosssection
of the inverted hexagonal phase is an intermediate between a circle
and a hexagon, and that it has lower energy than the circular cross-section.
The results were in agreement with observations gathered by the small angle
X-ray scattering. By comparing our results with the experiments, we
predicted some values of the mean intrinsic curvature and the phospholipid
chain stiffness. In the second part of the thesis, we developed a theoretical
model, which describes the stabilisation of membrane nanotubes containing
attached anisotropic flexible rod-like proteins. We derived the free energy
of a vesicle with nanotube taking into account the rotational averaging of
the anisotropic attached proteins. We also added the entropy contribution
due to the non-homogeneous lateral distribution of proteins. Our theoretical
results showed that rod-like attached proteins and membrane domains
can stabilise the membrane tubular protrusions if we consider the protein/
domain anisotropy. Our results were also in agreement with experimental results
in which isotropic membrane constituents were found on the tips of the
nanotube or on the mother vesicle; however, the anisotropic membrane constituents
were detected along the nanotubes. Our results showed that rod-like
attached proteins and membrane domains can stabilise the membrane tubular
protrusions if we consider the protein/domain anisotropy. The anisotropy of membrane constituents can lower the membrane free energy in regions of high
curvature. The main aim of the thesis was to show that the anisotropy of
membrane constituents can lower the membrane free energy in regions of high
curvature and that the rotational averaging of anisotropic membrane components
should be considered in the evaluation of the membrane free energy at
highly curved membrane structures.
Ključne besede: Biomembranes, Lipid anisotropy, Inverted hexagonal phase, Rotational averaging, Rod-like proteins, Membrane nanotubes, Membrane
protein sorting
Objavljeno v DKUM: 25.05.2017; Ogledov: 2372; Prenosov: 110
Celotno besedilo (12,09 MB) |
8. An alternative sorting procedure for interactive group decision support based on the pseudo-criterion conceptAndrej Bregar, József Györkös, Ivan Rozman, 2003, izvirni znanstveni članek Opis: An original interactive procedure is proposed, which aims at overcoming some of the major weaknesses of existent pseudocriterion based methods for group decision analysis. It refers to absolute judgements of feasible alternatives and is focused on complementary activities of opinion elicitation and robustness analysis. As a foundation, four interdependent principles are introduced - problem localization, interactivity on the basis of aggregation/disaggregation approach, automatic derivation of criteria weights according to selective effects of veto tresholds, and group consensus seeking. The principles are grounded and realized by appropriate methodological solutions.
Ključne besede: decision analysis, pseudo-criterion concept, decision models, group consensus, alternative sorting, group work, fuzzy relation
Objavljeno v DKUM: 01.06.2012; Ogledov: 1852; Prenosov: 107
Celotno besedilo (216,38 KB)
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