Reinforcement learning utilizes proxemics: an avatar learns to manipulate the position of people in immersive virtual reality

A reinforcement learning (RL) method was used to train a virtual character to move participants to a specified location. The virtual environment depicted an alleyway displayed through a wide field-of-view head-tracked stereo head-mounted display. Based on proxemics theory, we predicted that when the character approached within a personal or intimate distance to the participants, they would be inclined to move backwards out of the way. We carried out a between-groups experiment with 30 female participants, with 10 assigned arbitrarily to each of the following three groups: In the Intimate condition the character could approach within 0.38m and in the Social condition no nearer than 1.2m. In the Random condition the actions of the virtual character were chosen randomly from among the same set as in the RL method, and the virtual character could approach within 0.38m. The experiment continued in each case until the participant either reached the target or 7 minutes had elapsed. The distributions of the times taken to reach the target showed significant differences between the three groups, with 9 out of 10 in the Intimate condition reaching the target significantly faster than the 6 out of 10 who reached the target in the Social condition. Only 1 out of 10 in the Random condition reached the target. The experiment is an example of applied presence theory: we rely on the many findings that people tend to respond realistically in immersive virtual environments, and use this to get people to achieve a task of which they had been unaware. This method opens up the door for many such applications where the virtual environment adapts to the responses of the human participants with the aim of achieving particular goals.

An Analysis of Eye Scanpath Entropy in a Progressively Forming Virtual Environment

A sign of presence in virtual environments is that people respond to situations and events as if they were real, where response may be considered at many different levels, ranging from unconscious physiological responses through to overt behavior,emotions, and thoughts. In this paper we consider two responses that gave different indications of the onset of presence in a gradually forming environment. Two aspects of the response of people to an immersive virtual environment were recorded: their eye scanpath, and their skin conductance response (SCR). The scenario was formed over a period of 2 min, by introducing an increasing number of its polygons in random order in a head-tracked head-mounted display. For one group of experimental participants (n 8) the environment formed into one in which they found themselves standing on top of a 3 m high column. For a second group of participants (n 6) the environment was otherwise the same except that the column was only 1 cm high, so that they would be standing at normal ground level. For a third group of participants (n 14) the polygons never formed into a meaningful environment. The participants who stood on top of the tall column exhibited a significant decrease in entropy of the eye scanpath and an increase in the number of SCR by 99 s into the scenario, at a time when only 65% of the polygons had been displayed. The ground level participants exhibited a similar decrease in scanpath entropy, but not the increase in SCR. The random scenario grouping did not exhibit this decrease in eye scanpath entropy. A drop in scanpath entropy indicates that the environment had cohered into a meaningful perception. An increase in the rate of SCR indicates the perception of an aversive stimulus. These results suggest that on these two dimensions (scanpath entropy and rate of SCR) participants were responding realistically to the scenario shown in the virtual environment. In addition, the response occurred well before the entire scenario had been displayed, suggesting that once a set of minimal cues exists within a scenario,it is enough to form a meaningful perception. Moreover, at the level of the sympathetic nervous system, the participants who were standing on top of the column exhibited arousal as if their experience might be real. This is an important practical aspect of the concept of presence.

The Impact of a Character Posture Model on the Communication of Affect in an Immersive Virtual Environment

This paper presents the quantitative and qualitative findings from an experiment designed to evaluate a developing model of affective postures for full-body virtual characters in immersive virtual environments (IVEs). Forty-nine participants were each requested to explore a virtual environment by asking two virtual characters for instructions. The participants used a CAVE-like system to explore the environment. Participant responses and their impression of the virtual characters were evaluated through a wide variety of both quantitative and qualitative methods. Combining a controlled experimental approach with various data-collection methods provided a number of advantages such as providing a reason to the quantitative results. The quantitative results indicate that posture plays an important role in the communication of affect by virtual characters. The qualitative findings indicated that participants attribute a variety of psychological states to the behavioral cues displayed by virtual characters. In addition, participants tended to interpret the social context portrayed by the virtual characters in a holistic manner. This suggests that one aspect of the virtual scene colors the perception of the whole social context portrayed by the virtual characters. We conclude by discussing the importance of designing holistically congruent virtual characters especially in immersive settings.

The effect on lower spine muscle activation of walking on a narrow beam in virtual reality

To what extent do people behave in immersive virtual environments as they would in similar situations in a physical environment? There are many ways to address this question, ranging from questionnaires, behavioral studies, and the use of physiological measures. Here, we compare the onsets of muscle activity using surface electromyography (EMG) while participants were walking under three different conditions: on a normal floor surface, on a narrow ribbon along the floor, and on a narrow platform raised off the floor. The same situation was rendered in an immersive virtual environment (IVE) Cave-like system, and 12 participants did the three types of walking in a counter-balanced within-groups design. The mean number of EMG activity onsets per unit time followed the same pattern in the virtual environment as in the physical environment-significantly higher for walking on the platform compared to walking on the floor. Even though participants knew that they were in fact really walking at floor level in the virtual environment condition, the visual illusion of walking on a raised platform was sufficient to influence their behavior in a measurable way. This opens up the door for this technique to be used in gait and posture related scenarios including rehabilitation.

University teacher competences in a virtual teaching/learning environment : analysis of a teacher training experience

This paper attempts to shed light on the competencies a teacher must have inorder to teach in online university environments. We will relate a teacher trainingexperience, which was designed taking into account the methodological criteriaestablished in line with previous theoretical principles. The main objective of ouranalysis is to identify the achievements and difficulties of a specific formativeexperience, with the ultimate goal of assessing the suitability of this conceptualmethodologicalframework for the design of formative proposals aiming to contribute tothe development of teacher competencies for virtual environments.

User Centered Desing in E-Learning Environments : from Usability to Learner Experience

The advent of the Internet had a great impact on distance education and rapidly e-learning has become a killer application. Education institutions worldwide are taking advantage of the available technology in order to facilitate education to a growing audience. Everyday, more and more people use e-learning systems, environments and contents for both training and learning. E-learning promotes educationamong people that due to different reasons could not have access to education: people who could nottravel, people with very little free time, or withdisabilities, etc. As e-learning systems grow and more people are accessing them, it is necessary to consider when designing virtual environments the diverse needs and characteristics that different users have. This allows building systems that people can use easily, efficiently and effectively, where the learning process leads to a good user experience and becomes a good learning experience.

Predictors of smoking craving during virtual reality exposure

Cue exposure treatment (CET) consists of controlled and repeated exposure to drugrelated stimuli in order to reduce cue-reactivity. Virtual reality (VR) has proved to be a promising tool for exposition. However, identifying the variables that can modulate the efficacy of this technique is essential for selecting the most appropriate exposure modality. The aim of this study was to determine the relation between several individual variables and self-reported craving in smokers exposed to VR environments. Fortysix smokers were exposed to seven complex virtual environments that reproduce typical situations in which people smoke. Self-reported craving was selected as the criterion variable and three types of variables were selected as the predictor variables: related to nicotine dependence, related to anxiety and impulsivity, and related to the sense of presence in the virtual environments. Sense of presence was the only predictor of self-reported craving in all the experimental virtual environments. Nicotine dependence variables added predictive power to the model only in the virtual breakfast at home. No relation was found between anxiety or impulsivity and self-reported craving. Virtual reality technology can be very helpful for improving CET for substance use disorders. However, the use of virtual environments would make sense only insofar as the sense of presence was high. Otherwise, the effectiveness of exposure might be affected. © 2012 by the Massachusetts Institute of Technology.

Brain Computer Interface for Virtual Reality Control

A brain-computer interface (BCI) is a new communication channel between the human brain and a computer. Applications of BCI systems comprise the restoration of movements, communication and environmental control. In this study experiments were made that used the BCI system to control or to navigate in virtual environments (VE) just by thoughts. BCI experiments for navigation in VR were conducted so far with synchronous BCI and asynchronous BCI systems. The synchronous BCI analyzes the EEG patterns in a predefined time window and has 2 to 3 degrees of freedom.

Cue-elicited anxiety and craving for food using virtual reality scenarios

Cue exposure therapy has been reported to be an effective intervention for reducing binge eating behavior in patients with eating disorders and obesity. However, in vivo food exposure conducted in the therapist's office presents logistical problems and lacks ecological validity. This study proposes the use of virtual reality technology as an alternative to in vivo exposure, and assesses the ability of different virtual environments to elicit anxiety and craving for food in a non-clinical sample. The results show that exposure to virtual environments provokes changes in reported craving for food. High-calorie food cues are the ones that elicit the highest increases in craving.

Multi-level SLA-driven resource management on Cloud Providers

Nowadays, service providers in the Cloud offer complex services ready to be used as it was a commodity like water or electricity to their customers with any other extra effort for them. However, providing these services implies a high management effort which requires a lot of human interaction. Furthermore, an efficient resource management mechanism considering only provider's resources is, though necessary, not enough, because the provider's profit is limited by the amount of resources it owns. Dynamically outsourcing resources to other providers in response to demand variation avoids this problem and makes the provider to get more profit. A key technology for achieving these goals is virtualization which facilitates provider's management and provides on-demand virtual environments, which are isolated and consolidated in order to achieve a better utilization of the provider's resources. Nevertheless, dealing with some virtualization capabilities implies an effort for the user in order to take benefit from them. In order to avoid this problem, we are contributing the research community with a virtualized environment manager which aims to provide virtual machines that fulfils with the user requirements. Another challenge is sharing resources among different federated Cloud providers while exploiting the features of virtualization in a new approach for facilitating providers' management. This project aims for reducing provider's costs and at the same time fulfilling the quality of service agreed with the customers while maximizing the provider's revenue. It considers resource management at several layers, namely locally to each node in the provider, among different nodes in the provider, and among different federated providers. This latter layer supports the novel capabilities of outsourcing when the local resources are not enough to fulfil the users demand, and offering resources to other providers when the local resources are underused.

Aplicació web per a la recollida i classificació d'informació en entorns virtuals d'interacció síncrona-xat

Desenvolupament d'una aplicació web per a la recollida i classificació d'informació en entorns virtuals d'interacció síncrona: xat + classificació automàtica de les converses generades + les seves pròpies interaccions en funció d'unes categories existents + fitxers log.

Aplicación web para la gestión de incidencias en entornos virtuales

Proyecto final de carrera sobre aplicaciones web para trabajo colaborativo, enfocado en una aplicación web para la gestión de incidencias en entornos virtuales como la UOC.

BSCDW : Implementació d'un entorn de treball col·laboratiu i distribuït

Aquest projecte ha representat la implementació d'un entorn de treball en col·laboració inspirat en el BSCW però amb una nova arquitectura, basada en miniaplicacions de servidor (

Una extensió de LaCOLLA : abstracció de processament

En aquest PFC s'estudia la possibilitat d'estendre LaCOLLA dotant-la d'abstracció de processament: es tracta d?oferir a les aplicacions la possibilitat d'utilitzar els recursos del grup per a executar processos de la manera més eficient i segura possible, sense que les aplicacions s'hagin de preocupar d'on i quan s'executen aquests processos.

Projecte AWITGV : aplicació web per a informes del treball en grups virtuals

Aquest projecte vol dissenyar i implementar una aplicació web que permeti omplir els informes d'autoavaluació als estudiants de les assignatures amb pràctiques amb grup de la UOC. Una de les solucions és treballar mitjançant un entorn virtual, com és el Basic Support for Collaborative Work (BSCW), en el qual cada grup té el seu lloc privat on només poden accedir ells i els seus consultors.