Dejan Zagar

Dr. Dejan Zagar

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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Journal Article
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DZDejan Zagar
Dejan Zagar
MSMatija Svetina
Matija Svetina
Andrej KoširAndrej Košir
Andrej Košir
FDFranc Dimc
Franc Dimc
This paper is intended to give an overview of the experiments to evaluate the cognitive load of the officer on watch (OOW) during a collision avoidance maneuver in a full-mission simulator. The main goal is to investigate the possibilities of recording the biometric parameters of an OOW during a simulated collision avoidance maneuver. Potentially dangerous navigation errors known as human erroneous action (HEA) are induced by excessive cognitive load. Despite modern navigational aids on the ship’s bridge, investigators of maritime incidents typically link the reason for incidents at sea with human factors, including high cognitive load. During the experimental tasks on the bridge, the biometric parameters of the OOW are recorded. Statistical tools are used to visualize the data and evaluate the cognitive load of the OOW. Biometric peaks of the OOW typically occur either during the collision avoidance maneuver or when the OOW has been exposed to disturbing factors that increase reaction time and cause potentially dangerous navigation. Assessing the cognitive load of OOWs in the simulator is challenging for several reasons: e.g., the environmental conditions of the simulator, the type of task to be simulated, and even the type of sensor used. After careful study of the available literature, an original experimental design using non-invasive biometric sensors is proposed.

31 March 2022 in Sensors
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DZDejan Zagar
Dejan Zagar
MSMatija Svetina
Matija Svetina
Tanja BrckoTanja Brcko
Tanja Brcko
Marko PerkovičMarko Perkovič
Marko Perkovič
FDFranc Dimc
Franc Dimc
Andrej KoširAndrej Košir
Andrej Košir
The purpose of this study is to analyse data from the marine pilots’ bio-sensor readings to determine how experience affects their biometrical response during the port approach. The experiences play a significant role in the participant’s decision-making process and correlate with the repetitions. Through the repetitions of the experimental task, the participants gain experience, which correlates with the biometrical response, e.g., heart rate, electrodermal activity, etc. After exposing the two experience-distinct groups of participants to the same simulated port-approaching task, their collected biometric data is analysed and discussed. The results show that biometrical readings of the less experienced participants typically vary compared to that of the experienced participants, who take the simulated task more seriously. The study also yields insight into the workload process, involving disturbing factors during the task.

3 September 2024 in Frontiers in Psychology
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AKAndrej Košir
Andrej Košir
MSMatija Svetina
Matija Svetina
MPMarko Perkovič
Marko Perkovič
FDFranc Dimc
Franc Dimc
TBTanja Brcko
Tanja Brcko
DADejan Agar
Dejan Agar
Maritime studies, encompassing a range of disciplines, increasingly rely on advanced data analytics, particularly in the context of navigation. As technology advances, the statistical averaging of large datasets has become a critical component of these analyses. However, recent studies have highlighted discrepancies between statistical predictions and observable realities, especially in high-stress environments like port approach procedures conducted by marine pilots. This study analyzed physiological responses recorded during simulation exercises involving experienced marine pilots. The focus was not on the specific outcomes of the simulations but on the potential faults arising from conventional statistical signal processing, particularly mean-centered approaches. A large dataset of signals was generated, including one signal with a dominant characteristic intentionally designed to introduce imbalance, mimicking the uneven distribution of real-world data. Initial analysis suggested that the average physiological response of the pilots followed an S-shaped curve, indicative of a psycho-physiological reaction to stress. However, further post hoc analysis revealed that this pattern was primarily influenced by a single participant’s data. This finding raises concerns about the generalizability of the S-curve as a typical stress response in maritime pilots. The results underscore the limitations of relying solely on conventional statistical methods, such as mean-centered approaches, in interpreting complex datasets. The study calls into question the validity of standardizing data interpretations based on dominant characteristic curves, particularly in environments as intricate as maritime navigation. The research highlights the need for a re-evaluation of these methods to ensure more reliable and nuanced conclusions in maritime studies. This study contributes to the ongoing discourse on data interpretation in maritime research, emphasizing the critical need to re-assess conventional statistical signal processing techniques. By recognizing the potential pitfalls in data generalization, the study advocates for more robust analytical approaches to better capture the complexities of real-world maritime challenges.

21 February 2025 in Electronics
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DZDejan Zagar
Dejan Zagar
GGGregor Geršak
Gregor Geršak
On large ships, Officers on Watch (OOW) work in a demanding environment where they are confronted with stress and dynamic conditions and frequently move from one wing of the vessel to another. Therefore, a physiological monitoring system to assess the activity of their autonomic nervous system, i.e., to detect their physiological responses, stress, and fatigue, should be lightweight and portable. This paper presents a comparison of wired and portable wearable psychophysiological systems. Although the wired system offers greater precision, its complexity, poor ergonomics, and the need for a controlled setup make it less suitable for the natural working conditions of OOWs. A wireless portable system, although weaker in precision, is more suitable due to its portability, ease of use, real-time data capabilities, ability to measure anxiety, and immediate insights into physiological states during real-world use in real time. Such an application provides a wearable physiological data collection solution that, in conjunction with a mobile app and cloud platform, enables seamless data collection and processing of participants’ autonomic nervous system arousal.

14 August 2026 in Frontiers in Future Transportation
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Journal Article
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DZDejan Zagar
Dejan Zagar
MSMatija Svetina
Matija Svetina
TSTanja Brcko Satler
Tanja Brcko Satler
The increasing reliance on ECDIS in maritime operations underscores the need to understand how navigational alarm affect human performance, yet evidence on their physiological impact during training remains limited. The study aimed to explore the effects of a stressful event on general autonomic arousal during navigational operations and how this relationship changes over the course of ECDIS training. A longitudinal design was employed with nine novice participants (N = 9), who completed repeated simulator sessions while physiological signals (EDA, ECG, PPG) were recorded and combined into a composite arousal index. The results showed that alarms significantly increased physiological arousal, with an initial rise followed by gradual attenuation across sessions. The findings indicate adaptation to repeated exposure and demonstrate that objective physiological measures capture dynamic training responses, supporting the need for their integration into simulator-based training to improve situational awareness, workload regulation, and maritime safety.

4 September 2025 in Sensors
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Journal Article
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DZDejan Zagar
Dejan Zagar
The purpose of the study is to research emotional labor and cognitive effort in radar-based collision avoidance tasks within a nautical simulator. By assessing participants’ emotional responses and mental strain, the research aimed to identify negative emotional states associated with a lack of experience, which, in the worst-case scenario, could contribute to navigational incidents. Fifteen participants engaged in multiple sessions simulating typical maritime conditions and navigation challenges. Emotional and cognitive effort were evaluated using three primary methods: heart rate monitoring, a Likert-scale questionnaire, and real-time facial expression recognition software. Heart rate data provided physiological indicators of stress, while the questionnaire and facial expressions captured subjective perceptions of difficulty and emotional strain. By correlating the measurements, the study aimed to uncover emotional patterns linked to task difficulty with insight into engagement, attention, and blink rate levels during the simulation, revealing how a lack of experience contributes to negative emotions and human factor errors. The understanding of the emotional labor and effort in maritime navigation training contributes to strategies for reducing incident risk through improved simulation training practices.