Towards Continuous Gaze-Based Interaction in 3D Environments - Unobtrusive Calibration and Accuracy Monitoring

Renner P, Lüdike N, Wittrowski J, Pfeiffer T. Towards Continuous Gaze-Based Interaction in 3D Environments - Unobtrusive Calibration and Accuracy Monitoring. In: Bohn C-A, Mostafawy S, eds. Proceedings of the Workshop Virtuelle & Erweiterte Realität 2011. Aachen: Shaker Verlag; 2011: 13-24.The idea of using gaze as an interaction modality has been put forward by the famous work of Bolt in 1981. In virtual reality (VR), gaze has been used for several means since then: view-dependent optimization of rendering, intelligent information visualization, reference communication in distributed telecommunication settings and object selection. Our own research aims at improving gaze-based interaction methods in general. In this paper, gaze-based interaction is examined in a fast-paced selection task to identify current usability problems of gaze-based interaction and to develop best practices. To this end, an immersive Asteroids-like shooter called Eyesteroids was developed to support a study comparing manual and gaze-based interaction methods. Criteria for the evaluation were interaction performance and user immersion. The results indicate that while both modalities (hand and gaze) work well for the task, manual interaction is easier to use and often more accurate than the implemented gaze-based methods. The reasons are discussed and the best practices as well as options for further improvements of gaze-based interaction methods are presented

Molecular phylogeny and systematic in the genus Brachycaudus (Homoptera: Aphididae): insights from a combined analysis of nuclear and mitochondrial genes

Correspondance: [email protected] audiencePhylogenetic relationships among members of the Aphid genus Brachycaudus (Homoptera: Aphididae) were inferred from partial sequences of mitochondrial cytochrome B oxidase (CytB), two partial fragments of mitochondrial cytochrome C oxidase subunit I (COI) and the internal transcribed spacer II (ITS2) of ribosomal DNA. Twenty-nine species, with several specimens per species, were included, representing all the historically recognized species-groups and subgenera used in the genus except the monospecific subgenus Mordvilkomemor. Results indicate that the genus Brachycaudus is a well-supported monophyletic group. While our results validate the monophyly of subgenera Thuleaphis, Appelia and Brachycaudus s. str., they reveal two discrepancies in the classical taxonomy. First, the monotypic subgenus Nevskyaphis does not appear valid. Second, the traditionally defined Acaudus subgenus is not monophyletic. On the other hand, our phylogenetic trees corroborate Andreev's recent definition of Acaudus and Brachycaudina. However, they clearly show that the subgenera Prunaphis, Nevskyaphis and Scrophulaphis as defined by this author do not form monophyletic groups. Our results also highlight a highly supported clade that has not been discussed by previous authors; this clade could form a new subgenus, the subgenus Nevskyaphis. Finally, our study shows that molecular data and morphology meet the same limits in delimiting species groups and species themselves. Species groups in which taxonomic treatment is difficult are polytomous. Furthermore, except for one node clustering Brachycaudus s. str. and Appelia, intersubgeneric relationships remain poorly resolved even when several genes are added to the phylogenetic analysis. These results, together with previous studies in other aphid groups suggest that diversification might have been a rapid process in aphid