J. Sodnik

• Ph.D.
• Professor (Associate) at University of Ljubljana

Introduction Distress detection in virtual reality systems offers a wealth of opportunities to improve user experiences and enhance therapeutic practices by catering to individual physiological and emotional states. Methods This study evaluates the performance of two wearable devices, the Empatica E4 wristband and the Faros 360, in detecting distr...

Introduction/purpose: The application of virtual reality (VR) and simulation technologies in military training offers cost-effective and versatile approach to training enhancement. However, prevalence of cybersickness (CS), characterized by symptoms such as nausea, limits their widespread use. Methods: This study introduces objective parameters for...

This paper describes a rule-based Driver Scoring System model, derived from behavioral data collected using a driving simulator. It introduces a novel approach to establish driver profiles through feature engineering of acquired dataset, with features evaluating various aspects of driver behavior. The research aims to provide employers and drivers...

To address an emerging need for large number of diverse datasets for rigor evaluation of signal processing techniques, we developed and evaluated a new method for generating synthetic electrogastrogram time series. We used electrogastrography (EGG) data from an open database to set model parameters and statistical tests to evaluate synthesized data...

This paper describes the user-evaluation process of a head-up display (HUD) display for conditionally automated vehicle. The main goal of the presented HUD is to help drivers with the monitoring of the environment when operating a conditionally automated vehicle, and the transiting between different levels of automation. This paper presents the per...

This paper introduces an improved velocity-based method with optimal velocity threshold parameter for saccade detection to calculate saccade number per second, saccade duration, and velocity peak from the eye tracker data during driving simulation. The algorithm is tested on data recorded with low-sampling frequency of 50 Hz and on the interpolated...

Objective: To address an emerging need for large number of diverse datasets for rigor evaluation of signal processing techniques, we developed and evaluated a new method for generating synthetic electrogastrogram (EGG) time series. Methods: We used EGG data from an open database to set model parameters and statistical tests to evaluate synthesized...

We present a method to automatically calculate time to fixate (TTF) from the eye-tracker data in subjects with neurological impairment using a driving simulator. TTF presents the time interval for a person to notice the stimulus from its first occurrence. Precisely, we measured the time since the children started to cross the street until the drive...

Visual information complexity of automotive head-up displays (HUDs) may increase cognitive load and reduce driver performance in critical situations. This study examined whether physiological indicators of cognitive load could predict the type of HUD while driving. Physiological signals of heart rate variability (HRV), electrodermal activity (EDA),...

This paper discusses the concept of take-over (TO) in conditionally automated vehicles. Most of the current studies consider TO as a discrete event that is completed when the driver takes full control of the vehicle. Two problems with this approach are that the driver 1) needs time to gain sufficient situational awareness and 2) sometimes takes ove...

Most driver monitoring systems (DMS) rely on cameras facing the driver while detecting their gaze or head position. Both future automated driving (AD) in-vehicle interactions and AD vehicle interior designs (e.g., seating arrangement) might drastically reduce the effectiveness of such camera-based DMS solutions, however. Thus, alternative solutions...

In this paper we present a study aimed at distinguishing elderly (over 65 years) and young (under 25) participants in driving environment by observing solely their eye movements. Selected groups of elderly and young drivers were asked to drive 30 km on suburban, urban and regional roads in a high-fidelity motion-based driving simulator. During the...

The rapid development of driving simulators for the evaluation of automated driving experience is constrained by the simulator sickness-related nausea. The electrogastrogram (EGG)-based approach may be promising for immediate, objective, and quantitative nausea assessment. Given the relatively high EGG sensitivity to noises associated with the rela...

General introduction of unconditionally and conditionally automated vehicles is expected to have a highly positive impact on the society, from increased accessibility to mobility and road traffic safety, to decreased environmental and economic negative impacts. However, there are several obstacles and risks slowing down the adoption of this technol...

We present a method to automatically calculate sensing time (ST) from the eye tracker data in subjects with neurological impairment using a driving simulator. ST presents the time interval for a person to notice the stimulus from its first occurrence. Precisely, we measured the time since the children started to cross the street until the drivers d...

With increasing levels of automation on modern vehicles, drivers need more knowledge about their vehicle than ever before. Thereby, the display of vehicle status and alerts are important means for safe and effective use. Nevertheless, there are currently no common and consistent ways of providing such status in‐formation to drivers. This is differe...

Monitoring the environment is an essential part of driving, as it increases the driver's situational awareness and enables them to make appropriate decisions for safe and comfortable driving. This paper presents a study to investigate how much and in which way should information be displayed to the driver in a semi-automatic vehicle with a head-up...

The article presents a cross-cultural study of take-over performance in highly automated driving. As take-over performance is an important measure of safe driving, potential cultural differences could have important implications for the future development of automated vehicles. The study was conducted in two culturally different locations, Seattle,...

The supplements file contains the following additions to the linked TIP paper (which were moved to the appendix because of size restrictions for the main article): - Glossary - The concept of Driving Style SCORES based on INDEXES * Related work on quantitative safety measures - On the impact of supervised driving and driving style feedback - Ch...

To investigate the full potential of non-speech sounds, this study explored the effects of different multimodal takeover request displays in semi-automated vehicles. It used a mixed design - the visual and auditory notification lead time was within-subjects, whereas the auditory notification spatiality was between-subjects. The study was conducted...

The introduction of shared autonomous vehicles into the transport system is suggested to bring significant impacts on traffic conditions, road safety and emissions, as well as overall reshaping travel behaviour. Compared with a private autonomous vehicle, a shared automated vehicle (SAV) is associated with different willingness-to-adopt and willing...

--- Objective: Road traffic laws explicitly refer to a safe and cautious driving style as a means of ensuring safety. For automated vehicles to adhere to these laws, objective measurements of safe and cautious behavior in normal driving conditions are required. This paper describes the conception, implementation and initial testing of an objective...

With increasing focus on privacy protection, alternative methods to identify vehicle operator without the use of biometric identifiers have gained traction for automotive data analysis. The wide variety of sensors installed on modern vehicles enable autonomous driving, reduce accidents and improve vehicle handling. On the other hand, the data these...

Autonomous vehicles are expected to take complete control of the driving process, enabling the former drivers to act as passengers only. This could lead to increased sickness as they can be engaged in tasks other than driving. Adopting different sickness mitigation techniques gives us unique types of motion sickness in autonomous vehicles to be stu...

Automated vehicle technology can be beneficial for many aspects of transport, especially, improving traffic flow stability and efficiency. However, the influence of different automated driving styles on traffic efficiency is still not fully understood. Transport systems are very complex and non-linear, i.e. many participants with different characte...

The technology that allows fully automated driving already exists and it may gradually enter the market over the forthcoming decades. Technology assimilation and automated vehicle acceptance in different countries is of high interest to many scholars, manufacturers, and policymakers worldwide. We model the mode choice between automated vehicles and...

Autonomous vehicles are anticipated to play an important role on future mobility offering encouraging solutions to today’s transport problems. However, concerns of the public, which can affect the AVs’ uptake, are yet to be addressed. This study presents relevant findings of an online survey in eight European countries. First, 1639 responses were c...

The final version of this preprint has been peer-reveiwed and published in "Traffic Injury Prevention" Volume 22, 2021 - Issue 5 - by Taylor&Francis and is available under DOI 10.1080/15389588.2021.1904508 . Note that the annexes (included in the preprint), especially a critical literature review, must be downloaded separately under 'Supplemental m...

A worldwide pandemic has brought many challenges in numerous areas of everyone's life. The AutomotiveUI 2020 has also been moved to a virtual conference. Although the situation seems to be improving in some parts of the world, the impacts that the pandemic has brought to the research and academia may last long even after the pandemic is over. In th...

Deficits in attentional and executive functioning may interfere with driving ability and result in a lower level of fitness to drive. Studies show mixed results in relation to the consistency of neuropsychological and driving simulator assessment. The objective of this study was to investigate the consistency of both types of assessment. Ninety-nin...

In this paper we report on a user study in which we compared three different interaction designs in an in-vehicle infotainment system. Touchpad, free-hand and ordinary button interface designs were compared for usability, user experience and how they affect driving safety in different driving conditions. The study was performed in a high-fidelity d...

Objective: To identify driving characteristics of fit-, unfit-, and conditionally fit-to-drive neurological patient populations using a driving simulator with three high-risk scenarios comprising rural, highway, and urban environments. Methods: The study included 91 neurological patients undergoing a multidisciplinary assessment for driver’s licens...

The aim of the present study was to investigate the role of driving demands, neuroticism, and their interaction when predicting driving behavior. More precisely, we strived to examine how driving behaviors (i.e., speeding, winding, tailgating and jerky driving) unfold across low and high driving demands and whether they are contingent on a personal...

The ability to measure drivers’ physiological responses is important for understanding their state and behavior under different driving conditions. Such measurements can be used in the development of novel user interfaces, driver profiling, advanced driver assistance systems, etc. In this paper, we present a user study in which we performed an eval...

AutoUI conference is the premier forum for user interface research in the automotive domain, annually bringing together over 200 researchers and practitioners interested in both the technical and the human aspects of in-vehicle user interfaces and applications. However, over 80% of its published papers come from only five countries from western Eur...

A driving simulator study was conducted in Slovenia and the USA to examine cultural differences in driver response to take-over requests (TOR) in highly automated driving. There was a total of 38 participants (19 in each study location). Drivers engaged in secondary tasks while also monitoring the driving task. A TOR occurred at the end of the driv...

With autonomous driving on the horizon, new research challenges appeared and subsequently, new methods and research instruments became necessary. To adapt to these emerging research questions, driving simulators, the cornerstone of automotive human factors research, have been tweaked, modified or developed from scratch. This one-day workshop invite...

In the era of technological advances and innovations in transportation technologies, application of driving simulators for the investigation and assessment of the driving process provides a safe and suitable testing environment. Although driving simulators are crucial for further improvements in transportation, it is important to resolve one of the...

Various studies show that drowsiness reduces driver alertness and can significantly affect driver performance. In this paper, we investigate the effect of drowsiness on the interaction with the in-vehicle infotainment system (IVIS) while driving. The motivation was to investigate whether a specific type of user interface can provide better performa...

The Detection Response Task (DRT) is a method for measuring the attentional effects of secondary tasks on driver’s cognitive load and was standardized by ISO in 2016 [1]. It observes response times and stimuli detection performance (hit rates) to different stimuli types – visual, tactile and auditory –as indirect indicators of changes in cognitive...

This paper presents a driving simulator study in which we investigated whether the Eye Tribe eye tracker (ET) is capable of assessing changes in the cognitive load of drivers through oculography and pupillometry. In the study, participants were asked to drive a simulated vehicle and simultaneously perform a set of secondary tasks with different cog...

Objectives: There are three standardized versions of the Detection-response task (DRT), two using visual stimuli (remote DRT and head-mounted DRT) and one using tactile stimuli. In this paper, we present a study, which proposes and validates a type of auditory signal to be used as DRT stimulus and evaluate the proposed auditory version of this meth...

The Detection-Response Task is a method for assessing the attentional effects of cognitive load in a driving environment. Drivers are presented with a sensory stimulus every 3–5 s, and are asked to respond to it by pressing a button attached to their finger. Response times and hit rates are interpreted as indicators of the attentional effect of cog...

The correct determination of driver's level of fatigue has been of vital importance for the safety of driving. There are various methods, such as analyzing facial expression, eyelid activity, and head movements to assess the fatigue level of drivers. This paper describes the design and prototype implementation of a driver fatigue level determinatio...

Numerous studies have established that using various forms of augmented feedback improves human motor learning. In this paper, we present a system that enables real-time analysis of motion patterns and provides users with objective information on their performance of an executed set of motions. This information can be used to identify individual se...

The goal of this tutorial is to demonstrate the use of a compact motion-based driving simulator intended for driver evaluation and assessment of psychophysiological signals of drivers. It will cover all steps of a typical simulator-based user study, from experiment design, development of simulation environment and scenarios, integration of external...

NERVteh is a Slovenian high-tech R&D company, specialized in vehicle simulation and driver evaluation technologies. Its main product is a compact driving simulator based on a 4DOF motion platform and powerful simulation software. It is modular and customizable software, providing a variety of virtual environments, road and weather conditions, AI-ba...

Human driving models aim at producing human-like driving strategies by mimicking the behavior of drivers. Drivers optimize several objectives when traveling along a route, such as the traveling time and the fuel consumption. However, these objectives are not taken into account when building human driving models. To overcome this shortcoming, we des...

V sklopu razpisa »Po kreativni poti do znanja 2016/2017« je v sodelovanju s tremi članicami Univerze v Ljubljani, Fakulteto za gradbeništvo in geodezijo, Fakulteto za elektrotehniko in Fakulteto za ekonomijo, ter dvema iz gospodarstva, podjetjem Petrolom d.d., in negospodarstva, Občino Jezersko, nastal projekt »Uvedba informacijskega sistema za gos...

Objectives: The Detection Response Task (DRT) is a method for measuring attentional effects of secondary tasks on a driver's cognitive load by measuring response times and hit rates to different types of stimuli as indirect indicators of increased cognitive load. ISO 17488 (2016) standard only provides guidelines for the technical implementation an...

In-vehicle voice interactions appear to be less distracting than those systems with visual-manual interfaces only. However, speaking with an auditory interface can still divert drivers' attention away from the primary driving task. A driving simulator study was conducted to compare the workloads of speaking and listening. Thirty-two participants we...

Objectives: In this paper, we evaluate the sensitivity to cognitive load of three versions of the Detection Response Task method (DRT), proposed in ISO Draft Standard DIS - 17488. Methods: We present a user study with 30 participants in which we compared the sensitivity to cognitive load of visual, audio and tactile DRT in a simulated driving en...

We present the results of the user studies of the CareMe prototype telecare service for supporting older adults with remote telecare services. The CareMe solution targets older adults who are capable of living independently and outside of a dedicated medical institution or a nursing home, but require occasional medical attention, and formal or info...

Although today's vehicles are technically more sophisticated and safer than ever, driving as a task is becoming ever more complex. The increasing level of complexity is a result of the general increase in number of vehicles on the road as well as the increased amount of information presented through the invehicle information-communication (IC) syst...

The paper reports on a user study of freehand gesture interaction with a prototype of autostereoscopic 3D light field display. The interaction was based on a direct touch selection of simple objects rendered at different positions in space. The main goal of our experiment was to evaluate the overall user experience and perceived cognitive workload...

This paper reports on the design and evaluation of direct 3D gesture interaction with a full horizontal parallax light field display. A light field display defines a visual scene using directional light beams emitted from multiple light sources as if they are emitted from scene points. Each scene point is rendered individually resulting in more rea...

This book focuses on a special group of auditory interfaces using spatial sound for the representation of information. The addition of information on the location of a selected sound source or a group of sources shows many advantages over a mere single-channel audio. This survey explains the most important limitations of the human hearing system an...

Spatial auditory interfaces use three-dimensional sound as an additional display dimension and consist of audio items at different spatial locations. They have evolved significantly in the last couple of years and can be found in a variety of environments where visual communication is obstructed or completely blocked by other activities, such as wa...

Sound is a vibration which propagates as a mechanical wave through various types of compressible media (air, gas, liquids, or even solids). In most cases it is a longitudinal mechanical wave of pressure and displacement, although it can also have the form of a transverse wave in solids. The most important properties of sound are its amplitude, freq...

People are very social beings and interact with their environment in many ways (O’Shaughnessy 2003). Information can be received through seeing, hearing, smelling, tasting or feeling, while, conversely, it can be sent back into the environment visually, vocally, and through body gestures. Interaction between a user and a machine is performed throug...

This paper describes the basic structure and functionalities of a novel car driving simulator for a realistic simulation of various road and traffic conditions, and realistic car behavior on different terrains. Its main and most innovative component is a powerful and fast responsive 4DOF motion platform consisting of four electro motors. The propos...

This paper describes a user study on the interaction with an in-vehicle information system (IVIS). The motivation for conducting this research was to investigate the subjectively and objectively measured impact of using a single- or multi-modal IVIS while driving. A hierarchical, list-based menu was presented using a windshield projection (head-up...

Auditory interfaces present information with different types of sounds. They can complement visual interfaces or in some cases represent an independent input or output interface to a selected device. This paper focuses on a special group of auditory interfaces using spatial sound for the representation of information. The addition of information on...

The paper presents an evaluation of the performance of a Leap Motion Controller. A professional optical tracking system was used as a reference system. 37 stationary points were tracked in 3D space in order to evaluate the consistency and accuracy of the Controller’s measurements. The standard deviation of these measurements varied from 8.1 μm to 4...

We present the results of an evaluation of the performance of the Leap Motion Controller with the aid of a professional, high-precision, fast motion tracking system. A set of static and dynamic measurements was performed with different numbers of tracking objects and configurations. For the static measurements, a plastic arm model simulating a huma...

The aim of the user study presented in this paper was to investigate the efficiency of single and multimodal user interfaces for in-vehicle control and information systems and their impact on driving safety. A windshield projection (HUD) of a hierarchical list-based visual menu was compared to an auditory representation of the same menu and to a co...

The present paper describes the design of E-speranto, a formal computer language for recording multilingual texts on the Web. The vocabulary and grammar of E-speranto are based on the international auxiliary language Esperanto, while its syntax is based on XML (eXtensible Markup Language). The latter is one of the key features of E-speranto, as it...

Introduction This article reports on a study that explored the benefits and drawbacks of using spatially positioned synthesized speech in auditory interfaces for computer users who are visually impaired (that is, are blind or have low vision). The study was a practical application of such systems—an enhanced word processing application compared to...

In this paper, we propose a low cost, laboratory based testing framework for in-vehicle interfaces. Exemplified by a comparison between an auditory interface, a Head-up display, and a combination of both we show how task completion times, driving penalty points, mental workload, and subjective user evaluations of the interfaces can be collected thr...

The number of mobile web clients is increasing constantly and has already exceeded the number of their desktop predecessors. The following paper offers a survey of the current trends in the field of smart mobile devices, particularly with regard to the wide spectrum of the available hardware and software equipment and the corresponding operating sy...

This article presents a new Fast Hash-based File Existence Checking (FHFEC) method for archiving systems. During the archiving process, there are many submissions which are actually unchanged files that do not need to be re-archived. In this system, instead of comparing the entire files, only digests of the files are compared. Strong cryptographic...

This paper describes a user study on the benefits and drawbacks of simultaneous spatial sounds in auditory interfaces for visually impaired and blind computer users. Two different auditory interfaces in spatial and non-spatial condition were proposed to represent the hierarchical menu structure of a simple word processing application. In the horizo...

E-speranto is a formal language for generating multilingual texts on the World Wide Web. It is currently still under development. The vocabulary and grammar rules of E-speranto are based on Esperanto; the syntax of E-speranto, however, is based on XML (eXtensible Markup Language). The latter enables the integration of documents generated in E-spera...

Abstract This paper presents a new Fast Hash-based File Existence Checking (FHFEC) method,for archiving systems. During the archiving process there are many,submissions,which are actually unchanged,files which do not need to be re-archived. Instead of comparing the entire files, only digests of the files are compared. Strong cryptographic hash func...

In this paper, we propose a “Spatial speaker”, an enhancement of a Java FreeTTS speech synthesizer with the additional function of spatial positioning of both the speaker and the listener. Our module enables the reading of an arbitrary text from a file or webpage to the user from a fixed or changing position in space through normal stereo headphone...

In this paper we propose a prototype of a spatialized text reader for visually impaired users. The basic functions of the system are reading arbitrary files, converting text into speech using different synthesized voices and spatializing synthesized speech. Visually impaired users can thus listen to the content of a file read by various synthesized...

The paper gives an overview of the new features of web technologies. The general idea of the new version of HTML (Hyper Text Markup Language), i.e. HTML5, and other tools presented in this paper is the formal specification and the establishment of uniform solutions for technologies and functionalities which have already been in use through various...

In this paper we evaluate two different auditory interfaces for word processing application. The interfaces are in the form of hierarchical menu structures and use spatial sounds in two different spatial configurations. The first menu - AH - has a ring shaped horizontal configuration of the sound sources, whereas the second - AV - has a vertical co...

This paper describes a user study on interaction with a mobile device installed in a driving simulator. Two new auditory interfaces were proposed and their effectiveness and efficiency were compared to a standard visual interface. Both auditory interfaces consisted of spatialized auditory cues representing individual items in the hierarchical struc...

In this paper we evaluate the safety of the driver when using an embedded communication device while driving. As a part of our research, four different tasks were preformed with the device in order to evaluate the efficiency and safety of the drivers under three different conditions: one visual and two different auditory conditions. In the visual c...

This paper describes an alternative approach to elevation coding in an auditory display delivered through headphones. Objects in auditory display are presented as sound sources. Direction dependent cues for auditory display construction are most effectively presented by individualised head-related transfer functions (HRTFs), while generalised HRTFs...

Storage and exchange of simulation data are common processes in various simulation procedures. Although it is a rather simple task done by simulation practitioners, it is quite often a challenge because of huge quantities of data and different data formats. CostGlue application was developed to simplify that process. It was designed to handle diffe...

G of mobile communications describes the main research and development directives and technologies beyond the 3G of mobile communications. The name is interpreted slightly differently in various publications but signifies similar ideas.

This paper reports on a user study of simulated cell phone use in a driving simulator. The main questions we were seeking to answer were concerning the effectiveness and efficiency of the auditory interfaces in com- parison to a standard visual interface. In our experiment we tested two audio interfaces; one with many spa- tial audio sources and on...

This paper demonstrates that Principal Component Analysis (PCA) can be used as a very effective tool for identifying the components of Head Related Transfer Function (HRTF) magnitude that are significant for azimuth perception. The research focuses on the azimuth localization accuracy of non-individual HRTFs combined with individualized Interaural...

Augmented Reality (AR), the overlay of virtual images onto the real world, is an increasingly popular technique for developing new human-computer interfaces. As human navigation and orientation in different environments depend on both visual and auditory information, sound plays a very important role in AR applications. In this paper we explore use...

The mobile telephony has been one of the most perspective areas in telecommunications for some time already and it is still developing and growing. At present, we are witnessing the development of the third generation which is slowly establishing itself in the majority of the European countries. Based on current trends, the number of mobile devices...

The paper evaluates the human directional resolution of virtual sound sources synthesised with the aid of a generalised head related impulse response (HRIR) library, i.e., an HRIR library measured using a dummy head and torso. The original HRIR set is first expanded using linear interpolation, and then directional resolution measurements are perfor...

Spectral features of sound are believed to be the primary cues for the human perception of spatial sound elevation. It has also been observed that people connect higher frequencies of sound with a higher elevation of the sound source and lower frequencies with lower elevations. The most common approach to creating an acoustic image delivered by hea...

Head Related Transfer Function (HRTF) libraries enable the generation of virtual acoustic sources in arbitrary spatial positions. In experiments with a large number of test subjects, general or non-personified HRTF libraries are used, measured with human-shaped dolls. The resolution of azimuth in the frontal area is much better than in lateral area...

The synthesis of spatial sound, which is played through the headphones, can be done by the use of head related transfer functions (HRTF). The latter describe the changes in the sound wave as it propagates from a spatial sound source to the human eardrum. The functions include many different factors, which influence the accuracy of spatial sound sou...