1. Integrating carbon tax and subsidies : an evolutionary game theory-based shore power promotional strategy analysisTingwei Zhang, Cheng Hong, Tomaž Kramberger, Yuhong Wang, 2025, original scientific article Abstract: Shore power represents one of the principal solutions for the green transformation within the port industry. It significantly aids in the reduction in carbon emissions from vessels while they are berthed in port, yet often necessitates an effective promotional strategy to foster its installation and utilization. Stakeholders including port authorities, ship operators, and local governments all play a crucial role in achieving this objective. This paper employs a tripartite evolutionary game model in conjunction with a system dynamics model to investigate the evolutionary responses of stakeholders when policy tools are applied, and consequently, to elucidate the dynamics of strategy effectiveness. In this context, six business scenarios are developed to ascertain the potential impacts of implementing subsidies and carbon taxes. The findings demonstrate that any singular strategy, whether a subsidy or a carbon tax, is inadequate for the successful advancement of shore power; on the contrary, a government-led, integrated, and dynamic reward–punishment strategy aids in stabilizing the inherent fluctuations within this game process. Moreover, the initial willingness of ship operators exerts a considerably greater influence than that of the other two stakeholders. Keywords: shore power, promotional strategies, reward–punishment, evolutionary game, system dynamics Published in DKUM: 18.06.2025; Views: 0; Downloads: 0
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2. Optimizing berth allocation for maritime autonomous surface ships (MASSs) in the context of mixed operation scenariosLixin Shen, Xueting Shu, Chengcheng Li, Tomaž Kramberger, Xiaoguang Li, Lixing Jiang, 2025, original scientific article Abstract: This study deals with berth allocation for Maritime Autonomous Surface Ships (MASSs) in the context of the mixed operation of MASSs and manned vessels from the perspective of port-shipping companies’ collaboration. Two berth allocation strategies, namely the separated-type and the mixed-type, are proposed in this article. Two mixed integer nonlinear programming models aimed at minimizing the total docking cost of the vessels in the port and the waiting time for berths are developed and solved using Gurobi, respectively. A large-scale simulation of the mixed-type berth allocation model is carried out using an improved simulated annealing algorithm. Several experiments are conducted to test the effectiveness of the model and to draw insights for commercializing autonomous vessels. The presented results show that multi-objective modeling and optimization should be conducted from the collaboration of port-shipping companies, which is more efficient from the perspective of shipping companies or ports, respectively. When berth resources are limited or there is a high requirement for operational safety, the separated-type berth allocation strategy is more efficient. When the number of MASS-dedicated berths reaches a certain proportion, the total docking cost of the vessel no longer changes, indicating that more dedicated berths are not better. Keywords: maritime autonomous surface ship (MASS), mixed operation scenarios, berth allocation, mixed integer programming, simulated annealing algorithm, port-shipping companies’ collaboration Published in DKUM: 18.06.2025; Views: 0; Downloads: 0
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3. Hybrid model for motorway EV fast-charging demand analysis based on traffic volumeBojan Rupnik, Yuhong Wang, Tomaž Kramberger, 2025, original scientific article Abstract: The expected growth of electric vehicle (EV) usage will not only increase the energy demand but also bring the requirement to provide the necessary electrical infrastructure to handle the load. While charging infrastructure is becoming increasingly present in urban areas, special attention is required for transit traffic, not just for passengers but also for freight transport. Differences in the nature of battery charging compared to that of classical refueling require careful planning in order to provide a resilient electrical infrastructure that will supply enough energy at critical locations during peak hours. This paper presents a hybrid simulation model for analyzing fast-charging demand based on traffic flow, projected EV adoption, battery characteristics, and environmental conditions. The model integrates a probabilistic model for evaluating the charging requirements based on traffic flows with a discrete-event simulation (DES) framework to analyze charger utilization, waiting queues, and energy demand. The presented case of traffic flow on Slovenian motorways explored the expected power demands at various seasonal traffic intensities. The findings provide valuable insight for planning the charging infrastructure, the electrical grid, and also the layout by anticipating the number of vehicles seeking charging services. The modular design of the model allowed replacing key parameters with different traffic projections, supporting a robust scenario analysis and adaptive infrastructure planning. Replacing the parameters with real-time data opens the path for integration into a digital twin framework of individual EV charging hubs, providing the basis for development of an EV charging hub network digital twin. Keywords: electric vehicles, EV charging, traffic flow, EV charging hub Published in DKUM: 11.04.2025; Views: 0; Downloads: 2
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4. Designing efficient algorithms for logistics management : optimizing timeconstrained vehicle routingKarlo Bala, Martin Fale, Nebojša Gvozdenović, Tomaž Kramberger, Dejan Brcanov, 2025, original scientific article Abstract: Background: City logistics is a critical component of urban economic development, as it optimizes supply chains, enhances customer satisfaction through reliable deliveries, and minimizes environmental impacts in densely populated areas. This field addresses various challenges, including traffic congestion, environmental concerns, noise pollution, and the crucial need for timely deliveries. Routing and scheduling are central to logistics operations, with modern software integrating time windows to meet precise scheduling demands driven by detailed customer requirements and operational efficiencies. Furthermore, advanced vehicle routing models now effectively simulate real-world factors such as traffic congestion, stochastic travel times, and dynamic product demands. Purpose: This paper aims to develop an algorithm that addresses the routing decisions. Our approach extends to the time dimension, considering travel times and customer service times within predefined time windows. Study design/methodology/approach: The proposed algorithm is structured to execute in iterative phases, aiming to optimize key logistical objectives. In order to generate competitive solutions, we seek to minimize the number of vehicles utilized and overall travel costs. The evaluation of solution space was conducted via Simulated Annealing. Findings/conclusions: The performance of the proposed algorithm, evaluated using the Gehring and Homberger benchmark instances for 200 customers, demonstrates its effectiveness. The algorithm successfully meets the target number of vehicles required, and the associated travel costs are on average within 1% of the best solutions reported in the relevant literature. Limitations/future research: Given the ongoing need for timely solutions from decision-makers, future research endeavors will focus on enhancing the computational efficiency of the algorithm. Additionally, incorporating more time-related features, such as stochastic travel times, could further improve the algorithm's real-time applicability. Keywords: city logistics, vehicle routing, simulated annealing, time windows, scheduling Published in DKUM: 27.03.2025; Views: 0; Downloads: 2
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5. Analiza skladiščenja kemikalij v podjetju F.A MAIK d. o. o. : diplomsko deloMiha Bezjak, 2024, undergraduate thesis Abstract: Skladiščenje kemikalij predstavlja izziv za izvajalce skladiščnih storitev. Zaradi nevarnosti, ki jo predstavljajo manipulacije s kemikalijami, so skladiščni procesi teh snovi podvrženi strogi zakonodaji, sprejeti z namenom minimizirati tveganje za nastanek izrednih dogodkov. V primeru nesreč namreč lahko pride do hudih negativnih posledic v neposredni okolici nesreče. Zato je pri skladiščenju kemikalij ključnega pomena zagotavljanje ustreznih varovalnih sistemov in upoštevanje predpisane zakonodaje ter navodil proizvajalca kemikalij. Skladiščenje le-teh mora biti zasnovano na način, ki omogoča dober pregled in nadzor nad shranjenimi kemikalijami. Poleg podatkov o shranjenih kemikalijah je potrebno te skladiščne enote opremiti s podatki o skladiščenju, kar omogoča določitev skladiščnega mesta znotraj skladišča. Pri tem se lahko opremo na sisteme upravljanja skladišč. Sistem SQAS omogoča ocenjevanje kakovosti, varnosti, zanesljivosti in okoljske učinkovitosti logističnih procesov kemikalij ter primerjavo stanja podjetja z evropskimi standardi, ABC analiza pa nam poda oceno o učinkovitosti skladiščenja izdelkov v skladišču. V diplomskem delu smo pregledali skladiščenje kemikalij v podjetju F.A. MAIK d. o. o., določili kritične točke v procesu skladiščenja kemikalij in podali predloge za odpravo kritičnih točk. Keywords: skladiščenje, kemikalije, zakonodaja, ABC analiza, analiza SQAS Published in DKUM: 13.03.2025; Views: 0; Downloads: 33
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6. Distributed energy resource operation analysis using discrete event-simulationBojan Rupnik, Dušan Kragelj, Simona Šinko, Tomaž Kramberger, 2020, original scientific article Abstract: This paper presents a discrete-event simulation (DES) approach for simulation of distributed energy resources (DER). The DES approach provides means to adapt the energy workloads of the system according to any variations of demands that can occur due to temperature regulation requirements or operational demands. Along with a basic model based on a concrete DER configuration, additional models are presented and analysed in order to demonstrate the adaptability of the DES approach to analyse alternative configurations. The models were tested on historical energy consumption data in order to provide the expected workloads and costs. Models are capable to predict the amount of three different energies and cost for the company based on the inside and outside temperatures. Keywords: cost, discrete-event simulation, distributed energy resources, energy efficiency, hospitals, logistics Published in DKUM: 10.03.2025; Views: 0; Downloads: 8
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7. Spatial modelling of the transport mode choice : application on the Vienna transport networkSimona Šinko, Bojan Rupnik, Klemen Prah, Tomaž Kramberger, 2021, original scientific article Abstract: A new approach for spatial modelling of transport mode choice is presented in the paper. The approach tackles the problem by considering the trade-off between subjective and objective factors. To obtain mode Preference Rates (PRs) based on subjective factors, the Analytic Hierarchy Process (AHP) method is applied. The objective factors are expressed with the journey time from any point in the map to destination according to the available transport mode choice on the specific connection. The results are presented as PRs of individual transport modes. The model is validated on the con-ducted the survey, with students of Vienna University of Economics and Business (WU) as a target audience. Members of different target groups (age, national, employment) decide differently regarding the transport choice, so it is better to analyse them separately. The presented model can be used for the city transport planning in any urban area. It can help promote the sustainable modes of transport in the areas that are less adjusted in sustainable manner. Keywords: transport mode choice, passenger transport, spatial modelling, city transport planning, city mobility, urban logistics, ergonomics, AHP, decision-making policy, GIS, students, objective and subjective factors, transport management Published in DKUM: 10.12.2024; Views: 0; Downloads: 7
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8. Optimizacija skladiščenja v podjetju ZETA GmbH : magistrsko deloMatej Ivanek, 2024, master's thesis Abstract: V raziskavi smo si pogledali in raziskali problematiko skladiščenja in skladiščnih procesov v podjetju ZETA Holding na avstrijskem Štajerskem, natančneje v Liebochu, kjer proizvodni proces temelji na projektnih delih, kar pomeni potrebo po veliki prilagodljivosti skladiščenja. Ker se podjetje v zadnjih letih srečuje z rastjo in povečano proizvodnjo, je prišlo do težav in pomanjkanja skladiščnih prostorov ter ustrezne manipulacije. Pomanjkljivosti se odražajo tudi v samih skladiščnih sistemih in načinih skladiščenja. V ta namen smo raziskali različne pristope k reševanju omenjenega problema in trg sodobnih skladiščnih sistemov ter možnosti za njihovo uporabo. Hkrati potrebujemo za sodobne skladiščne sisteme različne vrste manipulativnih sredstev, ki smo jih s pomočjo izkušenj in znanj poiskali pri različnih dobaviteljih ter s tem poiskali najprimernejše izvedbe le-teh. Na koncu smo raziskave združili in poiskali optimizirano rešitev skladiščenja z najprimernejšimi manipulativnimi sredstvi tako, da smo maksimalno izkoristili velikost razpoložljivih skladiščnih prostorov. Keywords: skladiščni proces, skladiščenje, MRP, manipulacijska sredstva Published in DKUM: 27.11.2024; Views: 0; Downloads: 20
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9. Statistika in uvod v regresijske modele v Matlabu pri optimizaciji logističnih procesov : učbenikDejan Dragan, 2014, reviewed university, higher education or higher vocational education textbook Keywords: statistika, univariantna statistika, regresijski modeli, linearni regresijski modeli, Matlab, optimizacija, logistični procesi, stohastični procesi, logistika, učbeniki Published in DKUM: 20.11.2024; Views: 0; Downloads: 6
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10. Spatial modelling of modal shift due to COVID-19Simona Šinko, Klemen Prah, Tomaž Kramberger, 2021, original scientific article Abstract: The outbreak of COVID-19 caused many changes in people's life. One of the most significant is the travel behaviour and transport mode choice. This study focus on the changes that the inhabitants of Vienna made in their travel choices because of the virus. The same research about spatial modelling the transport mode choice of commuters in Vienna was completed in 2019 and is a topic addressed in our previous work. Based on our developed methodology, this article indicates that public transport is not a dominant transport mode choice as it was before the virus outbreak.The main result of this paper is geographically defined areas of application of individual alternatives shown on the final map of modal shift in Vienna, which could provide theoretical support for policy-makers and transportation planners. For the city of Vienna, we found that the area of the city where cars are now used has increased, which certainly has a negative impact on air quality and life in the city. The advantage of the methodology is that it can also be applied to other cities in the world. Keywords: coronavirus, city traffic, urban mobility, transport mode choice, passenger transport, geographical methods, spatial modelling, city logistics, Vienna Published in DKUM: 14.10.2024; Views: 0; Downloads: 21
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