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To compare and evaluate locomotion interfaces for users who are (virtually) moving on foot in VEs, we performed a study to characterize task behavior and task performance with different visual and locomotion interfaces. In both a computer-generated environment and a corresponding real environment, study participants walked to targets on walls and stopped as(More)
Previous research has shown that even low end-to-end latency can have adverse effects on performance in virtual environments (VE). This paper reports on an experiment investigating the effect of latency on other metrics of VE effectiveness: physiological response, simulator sickness, and self-reported sense of presence. The VE used in the study includes two(More)
Figure 1. A participant who believes he is aiming at the virtual game board directly in front of him. ABSTRACT Without force feedback, a head-mounted display user's avatar may penetrate virtual objects. Some virtual environment designers prevent visual interpenetration, making the assumption that prevention improves user experience. However, preventing(More)
A common measure of effectiveness of a virtual environment (VE) is the amount of presence it evokes in users. Presence is commonly defined as the sense of being there in a VE. There has been much debate about the best way to measure presence, and presence researchers need and have sought a measure that is reliable, valid, sensitive, and objective. We(More)
—When a virtual environment system prevents a user's avatar hand from penetrating virtual objects, the seen and felt positions of the hand separate. We propose a new method for reducing this position discrepancy as quickly as possible without introducing perceptible discrepancy between the seen and felt motion of the user's hand. We performed one user study(More)
This paper presents an experiment investigating the impact of behavior and responsiveness on social responses to virtual humans in an immersive virtual environment (IVE). A number of responses are investigated, including presence, copresence, and two physiological responses— heart rate and electrodermal activity (EDA). Our findings suggest that increasing(More)
Effects of pulse separation on detection of electrical stimulation of the cochlea were studied in 12 profoundly deaf human subjects with Nucleus 22 cochlear implants. Biphasic symmetric pulses were used. Pulse separation is the time from offset of one biphasic pulse to the onset of the next biphasic pulse in the train. Effects of pulse separation were(More)
BACKGROUND Accurate antenna placement is essential for effective microwave ablation (MWA) of lesions. Laparoscopic targeting is made particularly challenging in liver tumours by the needle's trajectory as it passes through the abdominal wall into the liver. Previous optical three-dimensional guidance systems employing infrared technology have been limited(More)