Papers by Dejan Dragan, Prof., PhD.
Forecasting is important in many branches of logistics, including the logistics related to Touris... more Forecasting is important in many branches of logistics, including the logistics related to Tourism supply chains. With an increasing inflow of American tourists, planning and forecasting the US tourists' inflow to Slovenia have gained far more importance attention amongst scholars and practitioners. This study, therefore, was conducted to forecast the American tourists' inflow to Slovenia using one of the predictive models based on the exponential smoothing approach, namely Holt-Winters damped additive (HWDA) exponential smoothing method. The model was modified by several improvements, while the obtained results were generalized to other supply chain components. The results show that the forecasting system can predict well the observed inflow, while the methodology used to derive the model might have enriched the plethora of existing practical forecasting approaches in the tourism domain. Benchmarking demonstrates that the proposed model outperforms a competitive ARIMA model and official forecasts. The practical implications are also discussed in this paper.
Transport, Feb 29, 2016
The paper deals with studying the relationships between the motorcyclists' thinking about proper ... more The paper deals with studying the relationships between the motorcyclists' thinking about proper behaviour and their actual behaviour in the traffic. The impact of some control variables, such as riders' age, experience, driving history, and engine cubature, on actual behaviour, is also addressed here. For the purpose of research, two additional questionnaires were applied besides the well-known Motorcycle Rider Behaviour Questionnaire (MRBQ). To examine the causal relations between all-important latent factors present in this study, the structural equation model was designed. Exploratory and confirmatory factor analyses were also engaged in the analysis and the statistical modelling process. The results show that the higher awareness about alcohol danger and benefits of protective equipment and helmet can noticeably contribute to the bigger traffic safety. Besides, from the results is evident that the control variables are in most cases also significantly interrelated with the actual behaviour factors. The findings of this research could be important for the planning of better traffic safety strategies for the motorcyclists to decrease the fatalities and related costs and traumas.
Sharecopy and redistribute the material in any medium or format. Adaptremix, transform, and build... more Sharecopy and redistribute the material in any medium or format. Adaptremix, transform, and build upon the material for any purpose, even commercially. The licensor cannot revoke these freedoms as long as you follow the license terms. Under the following terms: Attribution-You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use. No additional restrictions You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.
The paper addresses the problem of the reconstruction and allocation of delivery positions in the... more The paper addresses the problem of the reconstruction and allocation of delivery positions in the urban area. The aim is to achieve the optimal reorganization of urban freight transport in old town core in the municipality of Celje. Optimal allocation relies on optimization based on the Monte Carlo simulation and represents a first stage of a two-stage optimization approach to redesign the existing urban freight transport. The number of optimal delivery positions is required to be as minimal as possible, which can still assure a maximal service area within the prescribed radius, while keeping the minimal walking distances of delivery personnel between the nearest delivery position and the customer's physical location. The main issues of the used heuristic allocation algorithm and the presentation of calculated results are provided. In the near future, the calculated delivery positions are going to be used for the purpose of physical implementation in order to improve the existing delivery transport. WIEDERAUFBAU VON DEM LIEFERPOSITIONEN IN STADT CELJE, SLOWENIEN Zusammenfassung. Der Artikel behandelt das Problem der Wiederaufbau und Allokation von den Lieferung Positionen in einem städtischen Gebiet. Der Zweck ist die optimale Reorganisation des städtischen Güterverkehrs im alten Stadtkern in der Gemeinde Celje zu Erreichen. Die optimale Allokation basiert auf der Optimierung auf Basis der Monte-Carlo-Simulationen und stellt die erste Stufe einer zweistufigen Optimierung Verfahren zur ReDesigns der bestehenden städtischen Güterverkehrs. Die Anzahl der optimalen Lieferpositionen sollte so wenig wie möglich sein, aber trotzdem einen maximalen Service-Bereich innerhalb des vorgeschriebenen Radius gewährleisten. Gleichzeitig sollte die Entfernung zwischen den nächstgelegenen Lieferpositionen und Kunden Positionen kleinstmöglich sein. Die wichtigsten Themen des verwendeten Heuristic Zuordnungsalgorithmus und die Darstellung der berechneten Ergebnisse sind gegeben. Die Standorte der berechneten Lieferung Positionen werden zum Zwecke der physikalischen Implementierung genutzt, um den bestehenden Güterverkehr zu verbessern.
Model-based condition monitoring of a gas-gas heat exchanger
The paper applies a two-stage modelling concept to a gas-gas heat exchanger located in a tyre pro... more The paper applies a two-stage modelling concept to a gas-gas heat exchanger located in a tyre production plant. Modelling relies on combination of prior knowledge and recorded data. During the identification procedure the estimates of continuous model parameters are calculated by the least squares method with state variable filters (SVF). The main issues of the modelling procedure are stressed. Based on the process model a simple detector is derived. An excerpt of the results obtained on operating records is given.
Advances in logistics, operations, and management science book series, 2016
The chapter deals with the road transport optimization and estimation of reduced CO 2 emissions. ... more The chapter deals with the road transport optimization and estimation of reduced CO 2 emissions. To reduce the latter, several approaches were adopted, like alternative technologies, sustainable community changes, and changes in driving behavior. Another possible approach is to reduce the vehicle miles of traveled (VMT) by the means of transport optimization. In this chapter, the heuristic optimization approach for VMT reduction is firstly presented and tested for the case of School Bus Routing Problem. Afterwards, main focus is dedicated to the models for estimation of reduced CO 2 emissions. Herein, MEET emission model is integrated into the Monte Carlo based scenario playing algorithm, which calculates the total CO 2 emissions in the dependence of the randomly independently changing average speeds of the vehicles of the driving fleet. This algorithm is applied to the optimized situation, and the calculated results are compared with the unoptimized case. Results show that the applied optimization concept can significantly reduce the CO 2 emissions compared to unoptimized conditions.
Quantitative Methods in Logistics
Dragan - General Research Information and CV 26.9.18
Sustainability
Managing empty-container movements is one of the most challenging logistics problems in the shipp... more Managing empty-container movements is one of the most challenging logistics problems in the shipping field. With the growth of global trade imbalance, the repositioning process has become necessary, immediately after emptying a container. The main contribution of this research paper is to enrich the most frequently used methods, models, and applications in the literature, for relaxing the empty-container-repositioning problem. The article presents practices that vary between organizational policies, technical solutions, and modelling applications. A review of optimization models has been used for comparisons, based on specified criteria, such as the time frame, inputs, outputs, scale of the project, and value. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was applied through the online database Web of Science (WOS). It gives a comprehensive description of all the relevant published documents. On the basis of conducting a brief systematic review, future ...
Model-based condition monitoring of a gas-gas heat exchanger
2001 European Control Conference (ECC), 2001
The paper applies a two-stage modelling concept to a gas-gas heat exchanger located in a tyre pro... more The paper applies a two-stage modelling concept to a gas-gas heat exchanger located in a tyre production plant. Modelling relies on combination of prior knowledge and recorded data. During the identification procedure the estimates of continuous model parameters are calculated by the least squares method with state variable filters (SVF). The main issues of the modelling procedure are stressed. Based on the process model a simple detector is derived. An excerpt of the results obtained on operating records is given.
Journal of Engineering Thermophysics, 2020
One of the key challenges to model condition monitoring is; how to suitable match the level of de... more One of the key challenges to model condition monitoring is; how to suitable match the level of detail of the model description of the diagnostic requirements. To do so, a counter-current heat exchanger of the tire factory was investigated. Moreover, a two-stage grey-box modelling was deployed. The modelling is deployed in a discrete state space, relying on a combination of prior knowledge, along with the recorded data. The nonlinear model structure of heat exchanger is derived considering the use of the prior knowledge; thereby, it is converted into linearized form. The discretization of the linearized model is applied. The optimization procedure based on recorded data is adopted to estimate the unknown physical parameters in state space system matrices. The well-known N4SID subspace identification method is used to compare the obtained results.
Throughput Forecasting in Seaports with Dynamic Factors and ARIMAX model Presentation for Wienna
MANAGEMENT AND CONTROL OF LOGISTIC SYSTEMS, PhD COURSE
Tehnicki vjesnik - Technical Gazette, 2022
As important as the classical approaches such as Akaikeꞌs AIC information and Bayesian BIC criter... more As important as the classical approaches such as Akaikeꞌs AIC information and Bayesian BIC criterion in model-selection mechanism are, they have limitations.
As an alternative, a novel modeling design encompasses a two-stage approach that integrates Fuzzy logic and Monte Carlo simulations (MCSs). In the first stage, an entire
family of ARIMA model candidates with the corresponding information-based, residual-based, and statistical criteria is identified. In the second stage, the Mamdani fuzzy
model (MFM) is used to uncover interrelationships hidden among previously obtained models criteria. To access the best forecasting model, the MCSs are also used for
different settings of weights loaded on the fuzzy rules. The obtained model is developed to predict the road freight transport in Slovenia in the context of choosing the most
appropriate electronic toll system. Results show that the mechanism works well when searching for the best model that provides a well-fit to the real data.
Quantitative Methods in Logistics, 2020
In the past decades, our capability to solve hard and large optimization problems has improved in... more In the past decades, our capability to solve hard and large optimization problems has improved intensely. The paper addresses a review of optimization methods, heuristics, and metaheuristics. Their role in supply chain management, logistics, and transportation is also discussed. The main goal is to update interested readers about an enormous class of prevailing optimization methods and heuristics that have been designed for solving of numerous types of optimization problems. It is assumed that comprehensiveness of the overview of these methods is one of the main contributions of this paper. In the perspective of actual practice, it is also briefly stressed how and where optimization methods can be effectively applied in the field of supply chains and logistics.
Maritime Policy & Management, 2020
An accurate forecasting system has manifested its role as an enabler in supply chains (SC), which... more An accurate forecasting system has manifested its role as an enabler in supply chains (SC), which makes the operation possible in a maximally synchronized manner. Its applications have gained the attention of scholars across various disciplines such as forecasting in market behavior analysis and tourism industry; material requirement planning in production; transport and logistics foresight in networks and facilities. Seaports, as specific SC members, are not an exception. Accurate forecasting is needed in almost all aspects of the ports’ operation to avoid financial losses related to inappropriate investments and planning. The paper addresses the forecasting of joint demand-supply cargo throughputs in the Adriatic Seaport Koper. The research presents a new forecasting approach, namely, DFA-ARIMAX (Dynamic Factor Analysis-ARIMAX modeling). External economic indicators were screened to obtain useful information using the DFA prior to directing the dynamic factors into the ARIMAX fore...
Optimization and Modeling in Logistics and Transportation Forecasting Future Trends in Freight Transport in Slovenia Until the Year 2030
The Intergovernmental Panel on Climate Change (IPCC) has stated that climate change is a major on... more The Intergovernmental Panel on Climate Change (IPCC) has stated that climate change is a major ongoing process requiring strict restrictive actions on a global level. Also, other environmental challenges like “plasticification” of the world sea water is a huge and global thread, which should be mitigated. In every fields of human activities actions like recycling, zero CO2 production and responsible operations are expected. However, systems and functions in industries and public sectors have become extremely complicated, which are difficult to make emissions free. Also there are huge differences between countries how responsible production should be understood and organized. Logistics, transportation and supply chain processes in many industries are producing large amounts of emissions. Even if maritime logistics respond only fraction of total global CO2 emissions (round 2,6 %), locally, like in port areas, ships are producing heavily various polluting substances. In large process i...
Electric Vehicles as an Electricity Storage in Electricity Supply Chain
Electricity supply and demand must match all the time. It is not easy to achieve, because of a hi... more Electricity supply and demand must match all the time. It is not easy to achieve, because of a highly variable nature of electricity demand and a lack of electricity storing capacities. By introducing electricity from renewable energy sources, a variability occurs on the supply side as well. As electricity demand keeps rising and renewable energy sources become more and more in use, achieving an electricity supply-demand balance becomes more difficult. As one of the results, new resources are needed for dealing with that raised variability on both sides. In this paper, we consider the idea of using batteries of electric vehicles (EVs) as a resource for balancing electricity supply and demand. The idea implies charging and discharging of EVs batteries for keeping electricity supply and demand balanced. We observe batteries of EVs engaged in that process, as an electricity storage in electricity supply chain (ESC). In light of this, we explain the proposed idea, concepts of its realiz...
The paper addresses the problem of the reconstruction and allocation of delivery positions in the... more The paper addresses the problem of the reconstruction and allocation of delivery positions in the urban area. The aim is to achieve the optimal reorganization of urban freight transport in old town core in the municipality of Celje. Optimal allocation relies on optimization based on the Monte Carlo simulation and represents a first stage of a two-stage optimization approach to re-design the existing urban freight transport. The number of optimal delivery positions is required to be as minimal as possible, which can still assure a maximal service area within the prescribed radius, while keeping the minimal walking distances of delivery personnel between the nearest delivery position and the customerʼs physical location. The main issues of the used heuristic allocation algorithm and the presentation of calculated results are provided. In the near future, the calculated delivery positions are going to be used for the purpose of physical implementation in order to improve the existing d...
Summary. The paper addresses the problem of the reconstruction and allocation of delivery positio... more Summary. The paper addresses the problem of the reconstruction and allocation of delivery positions in the urban area. The aim is to achieve the optimal reorganization of urban freight transport in old town core in the municipality of Celje. Optimal allocation relies on optimization based on the Monte Carlo simulation and represents a first stage of a two-stage optimization approach to re-design the existing urban freight transport. The number of optimal delivery positions is required to be as minimal as possible, which can still assure a maximal service area within the prescribed radius, while keeping the minimal walking distances of delivery personnel between the nearest delivery position and the customer’s physical location. The main issues of the used heuristic allocation algorithm and the presentation of calculated results are provided. In the near future, the calculated delivery positions are going to be used for the purpose of physical implementation in order to improve the e...
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Papers by Dejan Dragan, Prof., PhD.
As an alternative, a novel modeling design encompasses a two-stage approach that integrates Fuzzy logic and Monte Carlo simulations (MCSs). In the first stage, an entire
family of ARIMA model candidates with the corresponding information-based, residual-based, and statistical criteria is identified. In the second stage, the Mamdani fuzzy
model (MFM) is used to uncover interrelationships hidden among previously obtained models criteria. To access the best forecasting model, the MCSs are also used for
different settings of weights loaded on the fuzzy rules. The obtained model is developed to predict the road freight transport in Slovenia in the context of choosing the most
appropriate electronic toll system. Results show that the mechanism works well when searching for the best model that provides a well-fit to the real data.