scholarly journals BioMove: Biometric User Identification from Human Kinesiological Movements for Virtual Reality Systems

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2944
Author(s):  
Ilesanmi Olade ◽  
Charles Fleming ◽  
Hai-Ning Liang
Keyword(s):  
Virtual Reality ◽  
User Study ◽  
Eye Gaze ◽  
Initial Study ◽  
Physical World ◽  
Penetration Testing ◽  
Machine Learning Classification ◽  
Model Classification ◽  
Movement Characteristics ◽  
Identification Confidence

Virtual reality (VR) has advanced rapidly and is used for many entertainment and business purposes. The need for secure, transparent and non-intrusive identification mechanisms is important to facilitate users’ safe participation and secure experience. People are kinesiologically unique, having individual behavioral and movement characteristics, which can be leveraged and used in security sensitive VR applications to compensate for users’ inability to detect potential observational attackers in the physical world. Additionally, such method of identification using a user’s kinesiological data is valuable in common scenarios where multiple users simultaneously participate in a VR environment. In this paper, we present a user study (n = 15) where our participants performed a series of controlled tasks that require physical movements (such as grabbing, rotating and dropping) that could be decomposed into unique kinesiological patterns while we monitored and captured their hand, head and eye gaze data within the VR environment. We present an analysis of the data and show that these data can be used as a biometric discriminant of high confidence using machine learning classification methods such as kNN or SVM, thereby adding a layer of security in terms of identification or dynamically adapting the VR environment to the users’ preferences. We also performed a whitebox penetration testing with 12 attackers, some of whom were physically similar to the participants. We could obtain an average identification confidence value of 0.98 from the actual participants’ test data after the initial study and also a trained model classification accuracy of 98.6%. Penetration testing indicated all attackers resulted in confidence values of less than 50% (<50%), although physically similar attackers had higher confidence values. These findings can help the design and development of secure VR systems.

scholarly journals Back to reality: transition techniques from short HMD-based virtual experiences to the physical world

2021 ◽  
Author(s):  
Robin Horst ◽  
Ramtin Naraghi-Taghi-Off ◽  
Linda Rau ◽  
Ralf Dörner
Keyword(s):  
Virtual Reality ◽  
Virtual World ◽  
Visual Cues ◽  
User Study ◽  
Physical World ◽  
Direct Communication ◽  
Common Presentation ◽  
Presentation Media ◽  
Virtual Experiences ◽  
Short Times

AbstractEvery Virtual Reality (VR) experience has to end at some point. While there already exist concepts to design transitions for users to enter a virtual world, their return from the physical world should be considered, as well, as it is a part of the overall VR experience. We call the latter outro-transitions. In contrast to offboarding of VR experiences, that takes place after taking off VR hardware (e.g., HMDs), outro-transitions are still part of the immersive experience. Such transitions occur more frequently when VR is experienced periodically and for only short times. One example where transition techniques are necessary is in an auditorium where the audience has individual VR headsets available, for example, in a presentation using PowerPoint slides together with brief VR experiences sprinkled between the slides. The audience must put on and take off HMDs frequently every time they switch from common presentation media to VR and back. In a such a one-to-many VR scenario, it is challenging for presenters to explore the process of multiple people coming back from the virtual to the physical world at once. Direct communication may be constrained while VR users are wearing an HMD. Presenters need a tool to indicate them to stop the VR session and switch back to the slide presentation. Virtual visual cues can help presenters or other external entities (e.g., automated/scripted events) to request VR users to end a VR session. Such transitions become part of the overall experience of the audience and thus must be considered. This paper explores visual cues as outro-transitions from a virtual world back to the physical world and their utility to enable presenters to request VR users to end a VR session. We propose and investigate eight transition techniques. We focus on their usage in short consecutive VR experiences and include both established and novel techniques. The transition techniques are evaluated within a user study to draw conclusions on the effects of outro-transitions on the overall experience and presence of participants. We also take into account how long an outro-transition may take and how comfortable our participants perceived the proposed techniques. The study points out that they preferred non-interactive outro-transitions over interactive ones, except for a transition that allowed VR users to communicate with presenters. Furthermore, we explore the presenter-VR user relation within a presentation scenario that uses short VR experiences. The study indicates involving presenters that can stop a VR session was not only negligible but preferred by our participants.

scholarly journals Towards estimating affective states in Virtual Reality based on behavioral data

2021 ◽  
Author(s):  
Valentin Holzwarth ◽  
Johannes Schneider ◽  
Joshua Handali ◽  
Joy Gisler ◽  
Christian Hirt ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Adaptive Systems ◽  
User Study ◽  
Affective State ◽  
Head Movements ◽  
Affective States ◽  
Physical Demand ◽  
Perceived Performance ◽  
Sequential Administration ◽  
Better Than

AbstractInferring users’ perceptions of Virtual Environments (VEs) is essential for Virtual Reality (VR) research. Traditionally, this is achieved through assessing users’ affective states before and after being exposed to a VE, based on standardized, self-assessment questionnaires. The main disadvantage of questionnaires is their sequential administration, i.e., a user’s affective state is measured asynchronously to its generation within the VE. A synchronous measurement of users’ affective states would be highly favorable, e.g., in the context of adaptive systems. Drawing from nonverbal behavior research, we argue that behavioral measures could be a powerful approach to assess users’ affective states in VR. In this paper, we contribute by providing methods and measures evaluated in a user study involving 42 participants to assess a users’ affective states by measuring head movements during VR exposure. We show that head yaw significantly correlates with presence, mental and physical demand, perceived performance, and system usability. We also exploit the identified relationships for two practical tasks that are based on head yaw: (1) predicting a user’s affective state, and (2) detecting manipulated questionnaire answers, i.e., answers that are possibly non-truthful. We found that affective states can be predicted significantly better than a naive estimate for mental demand, physical demand, perceived performance, and usability. Further, manipulated or non-truthful answers can also be estimated significantly better than by a naive approach. These findings mark an initial step in the development of novel methods to assess user perception of VEs.

scholarly journals Low-Asymmetry Interface for Multiuser VR Experiences with Both HMD and Non-HMD Users

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 397
Author(s):  
Qimeng Zhang ◽  
Ji-Su Ban ◽  
Mingyu Kim ◽  
Hae Won Byun ◽  
Chang-Hun Kim
Keyword(s):  
Virtual Reality ◽  
Virtual Environment ◽  
Mobile Device ◽  
User Satisfaction ◽  
Virtual World ◽  
User Study ◽  
Visual Display ◽  
Point Of View ◽  
Head Mounted Display ◽  
And Behavior

We propose a low-asymmetry interface to improve the presence of non-head-mounted-display (non-HMD) users in shared virtual reality (VR) experiences with HMD users. The low-asymmetry interface ensures that the HMD and non-HMD users’ perception of the VR environment is almost similar. That is, the point-of-view asymmetry and behavior asymmetry between HMD and non-HMD users are reduced. Our system comprises a portable mobile device as a visual display to provide a changing PoV for the non-HMD user and a walking simulator as an in-place walking detection sensor to enable the same level of realistic and unrestricted physical-walking-based locomotion for all users. Because this allows non-HMD users to experience the same level of visualization and free movement as HMD users, both of them can engage as the main actors in movement scenarios. Our user study revealed that the low-asymmetry interface enables non-HMD users to feel a presence similar to that of the HMD users when performing equivalent locomotion tasks in a virtual environment. Furthermore, our system can enable one HMD user and multiple non-HMD users to participate together in a virtual world; moreover, our experiments show that the non-HMD user satisfaction increases with the number of non-HMD participants owing to increased presence and enjoyment.

scholarly journals Presence Effects in Virtual Reality Based on User Characteristics: Attention, Enjoyment, and Memory

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1051
Author(s):  
Si Jung Kim ◽  
Teemu H. Laine ◽  
Hae Jung Suk
Keyword(s):  
Virtual Reality ◽  
Emotional State ◽  
Eye Gaze ◽  
Emotional Valence ◽  
Media Content ◽  
Eye Tracker ◽  
User Characteristics ◽  
Head Mounted Display ◽  
Age Range ◽  
Different Levels

Presence refers to the emotional state of users where their motivation for thinking and acting arises based on the perception of the entities in a virtual world. The immersion level of users can vary when they interact with different media content, which may result in different levels of presence especially in a virtual reality (VR) environment. This study investigates how user characteristics, such as gender, immersion level, and emotional valence on VR, are related to the three elements of presence effects (attention, enjoyment, and memory). A VR story was created and used as an immersive stimulus in an experiment, which was presented through a head-mounted display (HMD) equipped with an eye tracker that collected the participants’ eye gaze data during the experiment. A total of 53 university students (26 females, 27 males), with an age range from 20 to 29 years old (mean 23.8), participated in the experiment. A set of pre- and post-questionnaires were used as a subjective measure to support the evidence of relationships among the presence effects and user characteristics. The results showed that user characteristics, such as gender, immersion level, and emotional valence, affected their level of presence, however, there is no evidence that attention is associated with enjoyment or memory.

Who is in the Room? Notification for Intrusions While in Virtual Reality

2020 ◽  
Vol 64 (1) ◽  
pp. 521-525
Author(s):  
Aaron Crowson ◽  
Zachary H. Pugh ◽  
Michael Wilkinson ◽  
Christopher B. Mayhorn
Keyword(s):  
Virtual Reality ◽  
Visual Field ◽  
Physical World ◽  
Visual Modality ◽  
Auditory Modality ◽  
Oculus Rift ◽  
Head Mounted Display ◽  
Sensory Modalities ◽  
Orientation Type

The development of head-mounted display virtual reality systems (e.g., Oculus Rift, HTC Vive) has resulted in an increasing need to represent the physical world while immersed in the virtual. Current research has focused on representing static objects in the physical room, but there has been little research into notifying VR users of changes in the environment. This study investigates how different sensory modalities affect noticeability and comprehension of notifications designed to alert head-mounted display users when a person enters his/her area of use. In addition, this study investigates how the use of an orientation type notification aids in perception of alerts that manifest outside a virtual reality users’ visual field. Results of a survey indicated that participants perceived the auditory modality as more effective regardless of notification type. An experiment corroborated these findings for the person notifications; however, the visual modality was in practice more effective for orientation notifications.

scholarly journals UNDERSTANDING UNDERWATER PHOTOGRAMMETRY FOR MARITIME ARCHAEOLOGY THROUGH IMMERSIVE VIRTUAL REALITY

2019 ◽  
Vol XLII-2/W10 ◽  
pp. 85-91 ◽  
Author(s):  
M. Doležal ◽  
M. Vlachos ◽  
M. Secci ◽  
S. Demesticha ◽  
D. Skarlatos ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Educational Software ◽  
User Study ◽  
Data Gathering ◽  
Maritime Archaeology ◽  
Archaeological Sites ◽  
Immersive Virtual Reality ◽  
Digital Form ◽  
3D Mesh ◽  
Initial Results

<p><strong>Abstract.</strong> Underwater archaeological discoveries bring new challenges to the field, but such sites are more difficult to reach and, due to natural influences, they tend to deteriorate fast. Photogrammetry is one of the most powerful tools used for archaeological fieldwork. Photogrammetric techniques are used to document the state of the site in digital form for later analysis, without the risk of damaging any of the artefacts or the site itself. To achieve best possible results with the gathered data, divers should come prepared with the knowledge of measurements and photo capture methods. Archaeologists use this technology to record discovered arteacts or even the whole archaeological sites. Data gathering underwater brings several problems and limitations, so specific steps should be taken to get the best possible results, and divers should well be prepared before starting work at an underwater site. Using immersive virtual reality, we have developed an educational software to introduce maritime archaeology students to photogrammetry techniques. To test the feasibility of the software, a user study was performed and evaluated by experts. In the software, the user is tasked to put markers on the site, measure distances between them, and then take photos of the site, from which the 3D mesh is generated offline. Initial results show that the system is useful for understanding the basics of underwater photogrammetry.</p>

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