No / Virtual Reality Environments, which present a safer learning and training environment, are increasingly being adopted to simulate complex systems. In parallel, distribution services have become essential following advances in telecommunications and the subsequent demand on the mobility of users. Hence, middleware enables technologies to provide such services to existing and newly-developed applications. However, distributing VRE with existing APIs still requires lots of specific development and customization.Data Distribution Service (DDS) is one of the standardized middleware for real-time applications based on a peer-to-peer architecture. It requires awareness about the types of data distributed and which is achieved by defining an information-model using an Interface Definition Language (IDL) file. Consequently, distributing VRE using DDS introduces an additional step for modelling a specific IDL file to meet each application requirements. Considering the fact that domains addressed by VRE are populated by complex data types (procedural, behavioral, etc.) then engineering a specific IDL file for each application is a complex task that requires an intervention from the computer-scientist and the domain-expert each time an application has to be distributed. The first contribution of my thesis is to provide a generic information-model which is reusable upon distributing different VRE.The novelty of our approach is based on the coupling between conceptual models (in our case we use MASCARET meta-model) and the awareness need of DDS about data to distribute, so we create generic structures within the IDL file. By this, we eliminate one step of the workflow and consequently we simplify the process of using DDS. From another side, DDS remains a low level middleware for distribution that is based on peer-to-peer architecture with no control layer in the middle. Like other classical algorithms, lots of messages should be sent over the network to synchronize the distributed environment. Moreover, we should specify by code how to detect changes in the virtual environment to send updates. Thus, the second contribution we propose is to use a generic control layer that can dynamically detect when changes occur. This layer is based onthe explicit knowledge about executed behaviors.

This thesis explores the use of heart rate as a biofeedback game mechanic control in combination with physical movement in a Virtual reality (VR) environment using either teleportation, or a VR treadmill. A literature review, surveys, expert interviews, semi-structured interviews and a VR prototype were created. The prototype was iterated three times, and tested using the A-B method with 57 participants. The Polar H10 was used for the heart rate monitoring of the participants. The readings of the heart rate values were received via a script in Python in order to extract raw heart rate data from the participant in real time and sent to the prototype in Unity. It includes different interaction functionalities, a teleportation system, and a grabbing system from the SteamVR asset pack, a walk function using the Omnideck from Omnifinity, and includes assets from Unity for the graphics and sound. From the results and analysis of the data from the prototype, it can be interpreted that using some sort of movement in VR enhances the participants engagement and immersiveness in the environment. While heart rate biofeedback control enhances the VR experience, adding physical walking using treadmills improves it even more.

Children with autism spectrum disorder (ASD) think and understand social contexts primarily from a visual stand point. Feelings of being present in their social environment are a key component to their development (Strickland, Marcus, Mesibov, & Hogan, 1996). A virtual reality environment (VRE) can provide a therapeutic setting for children with ASD to learn social skills (Ehrlich & Munger, 2012). In the present research, a pilot study was used to assess the validity of a Second Life VRE developed by the researcher (Markopoulos, 2016b) by comparing the VRE to a real life film by The National Autistic Society (2016) in the United Kingdom. Feedback from the pilot study was used to make revisions to the VRE. The validated virtual reality therapy environment (VRTE) was used in the main research study. Twenty-eight Louisiana mental health practitioners’ perceptions of the VRTE were assessed using two random order conditions. Condition A required participation in the VRTE twice, first using a laptop computer only and then using the laptop with the new 2016 Oculus Rift head-mounted display (HMD, Oculus VR, LLC, 2016). Condition B required participation in the VRTE twice, first using a laptop with the new 2016 Oculus Rift HMD and then using a Laptop alone. Four out of eight subscales from the Temple Presence Inventory (TPI) (Lombard, Weinstein, & Ditton, 2011) were used to assess practitioners’ perceptions of presence in the VRTE. Results of a repeated-measures MANOVA showed that the order of the conditions were not significantly different. Additionally, participants’ TPI total and subscales scores were significantly higher when using the HMD than when using the Laptop, as well as their likelihood of using the HMD with children diagnosed with ASD than using the Laptop. All of the correlations for participants’ age and experience with technology were insignificant except for the subscale III, engagement was significant for participants’ age. Keywords: Autism spectrum disorder, therapy, virtual reality environment, head-mounted display, temple presence inventory, presence