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Abstract A “virtual mirror” is a promising interface for virtual or augmented reality applications in which users benefit from seeing themselves within the environment, such as serious games for rehabilitation exercise or biological education. While there is extensive work analyzing pointing and providing assistance for first-person perspectives, mirrored third-person perspectives have been minimally considered, limiting the quality of user interactions in current virtual mirror applications. We address this gap with two user studies aimed at understanding pointing motions with a mirror view and assessing visual cues that assist pointing. An initial two-phase preliminary study had users tune and test nine different visual aids. This was followed by in-depth testing of the best four of those visual aids compared with unaided pointing. Results give insight into both aided and unaided pointing with this mirrored third-person view, and compare visual cues. We note a pattern of consistently pointing far in front of targets when first introduced to the pointing task, but that initial unaided motion improves after practice with visual aids. We found that the presence of stereoscopy is not sufficient for enhancing accuracy, supporting the use of other visual cues that we developed. We show that users perform pointing differently when pointing behind and in front of themselves. We finally suggest which visual aids are most promising for 3D pointing in virtual mirror interfaces.
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Deformations of acid-mediated invasive tumors in a model with Allee effect
Abstract We consider a Gatenby–Gawlinski-type model of invasive tumors in the presence of an Allee effect. We describe the construction of bistable one-dimensional traveling fronts using singular perturbation techniques in different parameter regimes corresponding to tumor interfaces with, or without, an acellular gap. By extending the front as a planar interface, we perform a stability analysis to long wavelength perturbations transverse to the direction of front propagation and derive a simple stability criterion for the front in two spatial dimensions. In particular we find that in general the presence of the acellular gap indicates transversal instability of the associated planar front, which can lead to complex interfacial dynamics such as the development of finger-like protrusions and/or different invasion speeds.
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- Award ID(s):
- 2105816
- PAR ID:
- 10587985
- Publisher / Repository:
- Springer Science + Business Media
- Date Published:
- Journal Name:
- Journal of Mathematical Biology
- Volume:
- 90
- Issue:
- 6
- ISSN:
- 0303-6812
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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